Flow Control(RAN14.0 02)

Flow Control RAN14.0

Feature Parameter Description

Issue 02

Date 2012-07-20

HUAWEI TECHNOLOGIES CO., LTD.

Copyright © Huawei Technologies Co., Ltd. 2012. All rights reserved.

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WCDMA RAN

Flow Control Contents

Issue 02 (2012-07-20) Huawei Proprietary and Confidential

Copyright © Huawei Technologies Co., Ltd

i

Contents

1 Introduction ................................................................................................................................ 1-1

1.1 Scope ............................................................................................................................................ 1-1

1.2 Intended Audience......................................................................................................................... 1-1

1.3 Change History .............................................................................................................................. 1-1

2 Overview...................................................................................................................................... 2-1

2.1 Definition ....................................................................................................................................... 2-1

2.2 Overall Picture of Flow Control ..................................................................................................... 2-1

3 Flow Control for Overloaded RNC Units............................................................................. 3-1

3.1 Principle ......................................................................................................................................... 3-1

3.1.1 Overview ............................................................................................................................... 3-1

3.1.2 CPU Usage Monitoring ......................................................................................................... 3-2

3.1.3 Message Block Occupancy Rate Monitoring ........................................................................ 3-2

3.2 Whole Picture of Flow Control for Overloaded RNC Units............................................................ 3-3

3.3 Flow Control Triggered by CPUS Overload .................................................................................. 3-6

3.3.1 Overview ............................................................................................................................... 3-6

3.3.2 CPUS Basic Flow Control..................................................................................................... 3-6

3.3.3 Access Control ...................................................................................................................... 3-7

3.3.4 Paging Control ...................................................................................................................... 3-7

3.3.5 RRC Flow Control ................................................................................................................. 3-8

3.3.6 Flow Control on Signaling Messages over the Iur Interface ............................................... 3-10

3.3.7 CBS Flow Control ............................................................................................................... 3-11

3.3.8 Cell Update Flow Control.................................................................................................... 3-12

3.3.9 Flow Control over the Iur-g Interface .................................................................................. 3-14

3.3.10 DCCC Flow Control .......................................................................................................... 3-15

3.3.11 Measurement Report Flow Control ................................................................................... 3-16

3.3.12 Queue-based Shaping...................................................................................................... 3-17

3.3.13 CPUS-level Dynamic CAPS Control ................................................................................ 3-19

3.4 Flow Control Triggered by MPU Overload .................................................................................. 3-21

3.4.1 Basic Flow Control for the MPU ......................................................................................... 3-21

3.4.2 MPU Overload Backpressure ............................................................................................. 3-21

3.5 Flow Control Triggered by INT Overload ..................................................................................... 3-23

3.5.1 Basic Flow Control for the INT ........................................................................................... 3-23

3.5.2 Flow Control Triggered by INT Overload on the Control Plane .......................................... 3-24

3.5.3 Flow Control Triggered by Iub Interface Board Overload on the User Plane ..................... 3-25

3.6 Flow Control Triggered by DPU Overload ................................................................................... 3-25

3.6.1 DPU Basic Flow Control ..................................................................................................... 3-25

3.6.2 Flow Control Triggered by DSP CPU Overload .................................................................. 3-26

3.7 Flow Control Triggered by SCU Overload ................................................................................... 3-26

3.7.1 Principle .............................................................................................................................. 3-26

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3.7.2 Overload Indication ............................................................................................................. 3-27

3.8 Flow Control Triggered by GCU Overload .................................................................................. 3-27

3.8.1 Principle .............................................................................................................................. 3-27

3.8.2 Overload Indication ............................................................................................................. 3-27

4 Flow Control Triggered by NodeB/Cell Overload ............................................................. 4-1

4.1 CAPS Control ................................................................................................................................ 4-1

4.1.1 Overview ............................................................................................................................... 4-1

4.1.2 Static CAPS Control ............................................................................................................. 4-2

4.1.3 Dynamic CAPS Control ........................................................................................................ 4-3

4.1.4 Cell-level Dynamic CAPS Control Due to Congestion Reverse Pressure ........................... 4-4

4.2 PCH Congestion Control ............................................................................................................... 4-6

4.2.1 Principle ................................................................................................................................ 4-6

4.2.2 Overload Indication ............................................................................................................... 4-6

4.3 FACH Congestion Control ............................................................................................................. 4-6

4.3.1 Overview ............................................................................................................................... 4-6

4.3.2 Flow Control Based on Limited Number of UEs in the CELL_FACH State .......................... 4-8

4.3.3 CCCH Flow Control ............................................................................................................ 4-10

4.3.4 DCCH Flow Control ............................................................................................................ 4-12

4.3.5 DTCH Flow Control ............................................................................................................ 4-13

5 Flow Control over the Iu Interface ........................................................................................ 5-1

5.1 SCCP Flow Control ....................................................................................................................... 5-1

5.1.1 Overview ............................................................................................................................... 5-1

5.1.2 Flow Control Based on Iu Signaling Load ............................................................................ 5-2

5.1.3 Flow Control Based on SCCP Setup Success Rate ............................................................ 5-3

5.1.4 CN SCCP Congestion Control.............................................................................................. 5-3

5.2 Flow Control Triggered by CN RANAP Overload .......................................................................... 5-4

6 Service Flow Control................................................................................................................ 6-1

7 Load Sharing .............................................................................................................................. 7-1

7.1 Overview ....................................................................................................................................... 7-1

7.2 Load Sharing on the Control Plane ............................................................................................... 7-2

7.2.1 Procedure for Load Sharing on the Control Plane ............................................................... 7-2

7.2.2 Service Request Processing by a CPUS ............................................................................. 7-4

7.3 Load Sharing on the User Plane ................................................................................................... 7-6

7.3.1 Overview ............................................................................................................................... 7-6

7.3.2 Procedure for Load Sharing on the User Plane ................................................................... 7-6

7.4 Load Sharing in Transmission Resource Management ................................................................ 7-9

7.4.1 Background .......................................................................................................................... 7-9

7.4.2 Key Concepts ..................................................................................................................... 7-10

7.4.3 ATM Transmission Resource Management over the Iub, Iu, and Iur Interfaces ................ 7-11

7.4.4 IP Transmission Resource Management over the Iub, Iu, or Iur Interface ......................... 7-12

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8 Engineering Guidelines ........................................................................................................... 7-1

8.1 Queue-based RRC Shaping ......................................................................................................... 7-1

8.1.1 When to Use Queue-based RRC Shaping ........................................................................... 7-1

8.1.2 Configuration Principles and Suggestions............................................................................ 7-1

8.2 Queue-based Cell Update Request Shaping ................................................................................ 7-1

8.2.1 When to Use Queue-based Cell Update Request Shaping ................................................. 7-1


8.3 DCCC Flow Control ....................................................................................................................... 7-2

8.3.1 When to Use DCCC Flow Control ........................................................................................ 7-2


8.4 CAPS Control ................................................................................................................................ 7-2

8.4.1 Factors That Affect CAPS Control ........................................................................................ 7-2


8.4.3 Performance Optimization .................................................................................................... 7-2

9 Parameters.................................................................................................................................. 7-1

10 Counters.................................................................................................................................... 7-1

11 Glossary .................................................................................................................................... 7-1

12 References................................................................................................................................ 7-1

13 Appendix - Flow Control Algorithms ................................................................................. 7-1

13.1 Switch Algorithm .......................................................................................................................... 7-1

13.2 Linear Algorithm .......................................................................................................................... 7-1

13.3 Hierarchical Algorithm ................................................................................................................. 7-2

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Flow Control 1 Introduction



1-1

1 Introduction

1.1 Scope

This document concerns the feature WRFD-040100 Flow Control. It describes the functions and principles of RNC flow control and the overload indications.

Load control includes admission control and overload control. The goal is to ensure service quality and maximize system capacity. Flow control is part of overload control. Overload control works for the air interface, equipment, and the Iub/Iu interface. In addition, end-to-end (E2E) flow control can be implemented for the radio access network (RAN).

This document describes flow control for overloaded RNC units, flow control triggered by NodeB/cell overload, flow control over the Iu interface, and flow control on user services. For details about E2E flow control for the RAN, see the E2E Flow Control Feature Parameter Description. For details about other types of overload control, see the Load Control Feature Parameter Description.

This document describes the principles of flow control. If you need specific overload control measures for mass gathering events, contact Huawei's professional service teams, who can provide tailored solutions.

To learn more about admission control, see the Call Admission Control Feature Parameter Description.

1.2 Intended Audience

This document is intended for:

Personnel who have a good understanding of WCDMA principles

Personnel who need to learn about flow control

Personnel who work on Huawei products

1.3 Change History

This section describes the change history of this document. There are two types of changes:

Feature change: refers to a change in the flow control feature of a specific product version.

Editorial change: refers to a change in wording or the addition of the information that was not described in the earlier version.

Document Issues

The document issues are as follows:

02 (2012-07-20)

01 (2012-04-30)

Draft A (2012-02-15)

02 (2012-07-20)

This is the second commercial release of the document for RAN14.0.

Compared with 01 (2012-04-30) of RAN14.0, this issue incorporates the changes described in the following table.

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Change Type

Change Description Parameter Change

Feature change

Modified the principles of CAPS control. For details, see section 4.1 "CAPS Control."

None

Modified the principles of DTCH flow control. For details, see section 4.3.5 "DTCH Flow Control."

None

Editorial change

Added the configuration principles. For details, see chapter 8 "Engineering Guidelines."

None

01 (2012-04-30)

This is the first commercial release of the document for RAN14.0.

Compared with draft A (2012-01-10) of RAN14.0, this issue incorporates the changes described in the following table.

Change Type


Feature change

None None

Editorial change

The switch for changing the maximum number of UEs in the FACH state from 30 to 60 is now FACH_60_USER_SWITCH under CacSwitch, instead of PERFENH_FACH_USER_NUM_SWITCH under PerfEnhanceSwitch. PERFENH_FACH_USER_NUM_SWITCH is no longer used. For details, see section 4.3.2 "Flow Control Based on Limited Number of UEs in the CELL_FACH State."

None

Corrected the function of the DSPRestrainCpuThd parameter in user-plane load sharing. For details, see section 7.3.2 "Procedure for Load Sharing on the User Plane."

None

Draft A (2012-02-15)

This is the first draft of the document for RAN14.0.

Compared with issue 02 (2011-10-30) of RAN13.0, this issue incorporates the changes described in the following table.

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Change Type


Feature change

Added the following flow control functions to flow control triggered by CPUS overload:

DCCC Flow Control Queue-based Cell Update Request Shaping CPUS-level Dynamic CAPS Control Added the following function to FACH efficiency boost:

F2P Transition by Means of Physical Channel Reconfiguration. For details, see the FACH Efficiency Boost section.

Added the following function to load sharing:

Load Sharing in Transmission Resource Management

See relevant sections.

Optimized the following functions:

Cell update flow control: Priority-based flow control is performed for cell update requests. For details, see section 3.3.8 "Cell Update Flow Control."

Data transmission suspension: added data transmission suspension. For details, see the Data Transmission Suspension part in the FACH Efficiency Boost section.

Flow control triggered by DSP CPU overload: users in the CELL_FACH state cannot access in the case of DSP CPU overload. For details, see section 3.6.2 "Flow Control Triggered by DSP CPU Overload."

Flow control based on limited number of UEs in the CELL_FACH state. For details, see section 4.3.2 "Flow Control Based on Limited Number of UEs in the CELL_FACH State."

The wait time in RRC connection setup is service-specific. For details, see section 4.1 "CAPS Control."

Added the following parameters for cell update flow control:

CELLURAUPDATETHDFORMID CELLURAUPDATERSTTHDFORMID CELLURAUPDATETHDFORLOW CELLURAUPDATERSTTHDFORLOW

Added the DRA_UL_RACH_TX_INTERRUPT_AFT_TRIG_SWITCH sub-parameter to the DraSwitch parameter for data transmission suspension.

Added the FACH_USER_NUM_NOT_CTRL sub-parameter to the NBMCacAlgoSwitch parameter for flow control based on limited number of UEs in the CELL_FACH state.

Added the LowRrcConnRejWaitTmr parameter, which is used to configure the wait time in RRC connection setup.

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Change Type


Added overload indication for the following flow control functions:

RRC Flow Control

Flow Control on Signaling Messages over the Iur Interface

Queue-based Shaping

MPU Overload Backpressure

Flow Control Triggered by INT Overload on the Control Plane

CCCH Flow Control

None

Deleted the following flow control functions:

NodeB-level CAPS control. For details, see section 4.1 "CAPS Control."

URA update flow control

Editorial change

Optimized wording for the following functions:

Access control. For details, see section 3.3.3 "Access Control."

Flow control triggered by CN RANAP overload. For details, see section 5.2 "Flow Control Triggered by CN RANAP Overload."

Deleted the following flow control functions:

NodeB-level CAPS control

URA update flow control

None

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Flow Control 2 Overview



2-1

2 Overview

2.1 Definition

Flow control is a protective measure for communications between the RNC and its peer equipment. Flow control provides protection in the following ways:

It restricts incoming traffic to:

− Protect equipment from overload, thereby maintaining system stability.

− Ensure that equipment can properly process services even during heavy traffic.

It restricts outgoing traffic to reduce the load on the peer equipment.

2.2 Overall Picture of Flow Control

During mass gathering events, the amount of services surges, generating a significantly increased traffic volume that exceeds the processing capabilities of the system. As a result, the system becomes overloaded, which may lead to messages being randomly discarded and NE resetting, as well as response failures, call drops, service access failures, and other unexpected events.

Resources in a WCDMA system are limited, so how they are used affects system performance. The resources concerned here are:

Equipment system resources, including CPU resources and memory

Air interface resources, including channels, codes, and power

Transmission resources

Core network processing capabilities

To keep system stability and capabilities at the maximum possible level, Huawei RNCs perform flow control at five points in the system, which are numbered in Figure 2-1.

Figure 2-1 Five points in flow control

Flow control involves discarding originating messages (such as RRC connection requests) that overload the system when system resources are insufficient, refusing to process low-priority services, and rejecting access requests for low-priority services.

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Flow Control 2 Overview



2-2

To address problems caused by limited RNC resources (labeled in Figure 2-1), the RNC performs flow control for RNC units. The software of each RNC board monitors the system resource usage. When necessary, the RNC starts basic flow control functions that suspend non-critical functions, such as recording logs and printing to reduce the system load. Then, based on the system load and the switch status of flow control functions, the RNC may perform other flow control functions to ensure system stability. For details, see chapter 3 "Flow Control for Overloaded RNC Units."

To address problems caused by limited air interface resources (labeled in Figure 2-1), the RNC performs CAPS (Call Attempts Per Second) control, PCH congestion control and FACH congestion control.

− When the cell is overloaded with services, RNC limits the number of RRC connection requests admitted to a cell each second. For details, see section 4.1 "CAPS Control."

− When the paging channel is congested, the RNC allows CS-domain paging messages to preempt PS-domain paging messages in order to raise the paging success rate in the CS domain. For details, see section 4.2 "PCH Congestion Control."

− When the FACH (Forward Access Channel) is congested, the RNC restricts message retransmissions on the logical channels, rejects certain PS service requests, and triggers state transitions such as CELL_PCH to CELL_DCH (P2D) and CELL_DCH to idle (D2Idle). This gives priority to access requests for high-priority services such as CS services, keeps the cell update success rate high, and reduces call drops. For details, see section 4.3 "FACH Congestion Control."

The RNC performs admission control, load reshuffling, and overload control on code and power resources. For details about admission control, see the Call Admission Control Feature Parameter Description. For details about load reshuffling and overload control, see the Load Control Feature Parameter Description.

To address problems caused by limited signaling bandwidth over the Iu interface (labeled in Figure 2-1), the RNC works with the core network to perform flow control over the Iu interface. Based on link congestion conditions detected at the local end and congestion indications reported from the peer end, the RNC performs flow control on initial UE messages to reduce the signaling traffic over the Iu interface. This prevents severe congestion on the signaling link between the RNC and the core network and reduces the load on the core network when it is overloaded. For details, see chapter 5 "Flow Control over the Iu Interface."

The RNC supports user-plane congestion control over the Iub interface to restrict transmission rates when there is transmission congestion over the Iub interface. This prevents packet loss and makes more efficient use of the bandwidth. For details, see chapter 6 "Service Flow Control."

For access requests, the RNC supports load sharing within one subrack or between subracks on the user plane and control plane. This achieves dynamic sharing of resources, balancing the load among subracks and boards and improving service processing efficiency. For details, see chapter 7 "Load Sharing."



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Flow Control 3 Flow Control for Overloaded RNC Units



3-1

3 Flow Control for Overloaded RNC Units

3.1 Principle

3.1.1 Overview

Each RNC board monitors the following in real time to keep track of resource consumption:

CPU usage: The CPU resources of a board determine the processing capabilities of the board. All functions running on the board use CPU resources.

Message block occupancy rate: Message blocks are resources used to send and receive messages within the RNC.

When the CPU usage or message block occupancy rate of a board is high, the board processing capabilities may become insufficient. When this occurs, the board triggers flow control to ensure that basic functions can continue to run properly. Flow control based on message block occupancy rate is independent of flow control based on CPU usage. Related flow control functions will be triggered when either the message block occupancy rate or the CPU usage is excessively high. Generally, it is rare to run out of message blocks.

Figure 3-1 shows the flow control model that each board follows based on CPU usage and message block occupancy rate.

Figure 3-1 Flow control model

The XPUs, interface boards (collectively known as INTs), DPUs, SCUs and GCUs mentioned in this document are board types displayed on the LMT (Local Maintenance Terminal). An XPU comprises MPUs and CPUSs (CPU for Service), which have the following functions:

An MPU (Main Processing Unit) manages resources on the user plane, control plane, and transport plane, informs MPUs in other subracks about the load on the current subrack, and makes decisions regarding load sharing.

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A CPUS processes services on the control plane.

The XPU, INT, DPU, SCU, and GCU boards correspond to the following physical boards:

XPU: SPUa or SPUb

INT: AEUa, AOUa, AOUc, FG2a, FG2c, GOUa, or GOUc

DPU: DPUb or DPUe

SCU: SCUa or SCUb

GCU: GCUa or GCGa

For the detailed functions of each board, see the BSC6900 UMTS Hardware Description.

3.1.2 CPU Usage Monitoring

The system checks CPU usage in real time. If the CPU usage has reached the threshold for starting a flow control function that is based on the CPU usage and currently enabled, this function is started.

For details about flow control switches and CPU usage thresholds, see sections 3.3 "Flow Control Triggered by CPUS Overload," 3.4 "Flow Control Triggered by MPU Overload," 3.5 "Flow Control Triggered by INT Overload," 3.6 "Flow Control Triggered by DPU Overload," 3.7 "Flow Control Triggered by SCU Overload," and 3.8 "Flow Control Triggered by GCU Overload."

To prevent frequent flow control triggered by CPU usage fluctuations, the system also calculates the average CPU usage during a period of time that has just elapsed, and determines whether to perform flow control based on this CPU usage. The CPU usage values used to calculate the average CPU constitute a filter window, as shown in Figure 3-2.

Figure 3-2 Filter window for calculating the average CPU usage

The filter window of a flow control function is configurable only if this function is controlled by using the SET FCSW command. For details, see section 3.2 "Whole Picture of Flow Control for Overloaded RNC Units."

3.1.3 Message Block Occupancy Rate Monitoring

Once it has allocated message blocks ten times, the system checks the message block occupancy rate. If the message block occupancy rate has reached the threshold for starting a flow control function that is based on the message block occupancy rate and currently enabled, this function is started.

For details about flow control switches and CPU usage thresholds, see sections 3.3 "Flow Control Triggered by CPUS Overload," 3.4 "Flow Control Triggered by MPU Overload," 3.5 "Flow Control Triggered by INT Overload," 3.6 "Flow Control Triggered by DPU Overload," 3.7 "Flow Control Triggered by SCU Overload," and 3.8 "Flow Control Triggered by GCU Overload."

To prevent frequent flow control triggered by message block occupancy rate fluctuations, the system also calculates the average message block occupancy rate. The message block occupancy rate values

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3-3

used to calculate the average message block occupancy rate constitutes a filter window, as shown in Figure 3-3.

Figure 3-3 Filter window for calculate the average message block occupancy rate

The filter window of a flow control function is configurable only if this function is controlled by using the SET FCSW command. For details, see section 3.2 "Whole Picture of Flow Control for Overloaded RNC Units."

3.2 Whole Picture of Flow Control for Overloaded RNC Units

Table 3-1 provides a whole picture of flow control for overloaded RNC units.

Table 3-1 Whole picture of flow control for overloaded RNC units

Overload Source Flow Control Function

Flow Control Object Impact on Services

Controlling Command

CPUS High CPU usage or message block occupancy rate

Printing flow control

Printing No SET FCSW

Debugging flow control

Debugging

Performance monitoring flow control

Performance monitoring

Logging flow control

Logging

Resource audit flow control

Resource audit

MR flow control MR function Yes

Paging control Paging messages SET FCSW

Access control based on the CPU usage or message block occupancy rate

Users in AC0 to AC9 SET FCSW

RRC flow control RRC connection requests

None

Flow control on Some signaling SET FCSW

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3-4



Controlling Command

signaling messages over the Iur interface

messages over the Iur interface

Flow control over the Iur-g interface

All messages over the Iur-g interface

CBS flow control All broadcast messages delivered by the CBC

Cell update flow control

Some cell/URA update messages

DCCC flow control

DCCC procedure of the UE

MPU High CPU usage or message block occupancy rate


Printing None SET FCSW


Debugging


Logging

High CPU usage

MPU overload backpressure

RRC connection requests

Yes SET URRCTRLSWITCH

INT High CPU usage or message block occupancy rate




Debugging


Logging

High CPU usage

Flow control triggered by INT overload on the control plane

RRC connection requests

Yes SET TNSOFTPARA

Congestion in queues at the ports

Flow control triggered by Iub interface board overload on the user plane

BE service rates See related descriptions in 3.5.3 "Flow Control Triggered by Iub Interface Board Overload on the User Plane."

DPU High CPU usage or



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3-5



Controlling Command

message block occupancy rate


Debugging


Logging

High DSP CPU usage

Flow control triggered by DSP CPU overload

BE service rates Yes None

SCU High CPU usage or message block occupancy rate




Debugging


Performance monitoring


Logging

GCU High CPU usage or message block occupancy rate




Debugging


Logging

The filter windows for flow control functions configured by the SET FCSW command are configurable. The details are as follows:

For flow control decisions based on CPU usage, the SMWINDOW parameter of the SET FCCPUTHD command is used to configure the filter window.

For flow control decisions based on message block occupancy rate, the SMWINDOW parameter of the SET FCMSGQTHD command is used to configure the filter window.

For flow control functions configured by the SET FCSW command, the system also uses a fast judgment window to prevent the CPU usage and message block occupancy rate from rapidly rising to a high level. The details are as follows:

If all CPU usage values during this fast judgment window are greater than or equal to a critical threshold, all currently enabled flow control functions based on CPU usage are started. The FDWINDOW and CTHD parameters of the SET FCCPUTHD command are used to configure the fast judgment window and critical threshold, respectively. The value of SMWINDOW should be at least twice the value of FDWINDOW.

If the current message block occupancy rate value is greater than or equal to a critical threshold, all currently enabled flow control functions based on message block occupancy rate are started. The size of the fast judgment window for flow control based on the message block occupancy rate is 1. That is,

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the critical threshold decision does not use the filter mechanism. The CTHD parameter of the SET FCMSGQTHD command is used to configure the critical threshold.

When the FCSW parameter is set to OFF for a board, all flow control functions configured by the SET FCSW command are disabled for this board.

3.3 Flow Control Triggered by CPUS Overload

3.3.1 Overview

The CPUS software monitors the CPU usage and message block occupancy rate of the CPUS in real time. Upon detecting a high CPU usage or message block occupancy rate, the CPUS software starts basic flow control, which is performed on non-critical functions, such as printing and logging. When the CPU usage or message block occupancy rate reaches or exceeds their respective thresholds, the CPUS software starts the following flow control functions if they are enabled:

Access control

RRC flow control

Flow control over the Iur interface

CBS flow control



DCCC flow control

MR flow control

In addition, the CPUS software queue-based RRC shaping and queue-based cell update request shaping, which help stabilize the CPU usage.

3.3.2 CPUS Basic Flow Control

Principle

Basic flow control for a CPUS is performed on printing, debugging, performance monitoring, logging, and resource audit. The CPUS software monitors the CPU usage and message block occupancy rate of the CPUS in real time. Based on the monitored data, the CPUS software starts or stops all or some of the basic flow control functions.

When the CPU usage or message block occupancy rate reaches the threshold, the CPUS software starts flow control.

When the CPU usage and message block occupancy rate fall below their respective thresholds, the CPUS software stops flow control.

The SET FCSW command is used to enable the basic flow control functions. By default, all basic flow control functions are enabled.

The SET FCCPUTHD command is used to configure the thresholds for flow control based on CPU usage, and the SET FCMSGQTHD command is used to configure the thresholds for flow control based on message block occupancy rate.

Basic flow control for the CPUS has no impact on services.

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3-7

Overload Indication

When the CPU usage reaches a preset threshold (configured by the SET CPUTHD command), the ALM-20256 CPU Overload is reported. To find out whether the alarm was reported for an XPU, check the subrack number and slot number in the alarm.

EVT-22835 Flow Control is reported when a basic flow control function is started. To find out which basic flow control function was started, check the flow control type in the event.

The following counters indicate the CPU usage and message block occupancy rate.

Counter Description

VS.XPU.CPULOAD.MEAN Average CPU usage of the XPU

VS.XPU.MSGLOAD.MEAN Average message block occupancy rate of the XPU

3.3.3 Access Control

When the network is congested or overloaded, access control (AC) is performed to prevent users in some classes from access class 0 (AC0) to access class 9 (AC9) from accessing the network. This reduces the traffic impact on the network. The RNC has the following three access control methods:

AC restrictions

When the CPU usage or message block occupancy rate is too high, the RNC starts AC restrictions and prevents users in some classes from AC0 to AC9 from accessing the cell.

Domain-specific access control (DSAC)

When the core network (CN) node is congested or overloaded, AC can distinguish between the CS domain and the PS domain. This is achieved by means of domain-specific access control (DSAC). When one domain is overloaded or unavailable, DSAC keeps the other domain unaffected. This makes the network more tolerant of disasters.

For details about AC restrictions and DSAC, see the DSAC Feature Parameter Description.

Intelligent AC control

Based on the cell resource congestion status, the RNC dynamically adjusts the number of ACs prevented from accessing the cell. This is known as intelligent AC control. Intelligent AC control alleviates cell congestion and keeps the RNC running stably under heavy traffic. For details about intelligent AC control, see the Intelligent Access Class Control Feature Parameter Description.

3.3.4 Paging Control

Principle

Upon detecting that the CPU usage or message block occupancy rate of a CPUS is higher than a preset threshold, the RNC starts paging control to reduce paging traffic and ensure high paging success rates for high-priority services. The PAGESW parameter in the SET FCSW command is used to enable paging control. By default, it is enabled.

When the CPU usage or message block occupancy rate exceeds the threshold, the RNC starts paging control and discards paging messages.

When the CPU usage and message block occupancy rate fall below their respective thresholds, the RNC stops paging control.

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Paging control based on CPU usage varies by service. The SET FCCPUTHD command is used to configure paging control thresholds for different services, as described in Table 3-2. The higher the threshold for starting a flow control function, the more difficult it is for the flow control function to start.

Table 3-2 Thresholds for paging control based on CPU usage

Service Types Threshold for Starting Paging Control

Threshold for Stopping Paging Control

Real-time services CPAGECTHD CPAGERTHD

BE services, supplementary services, and location services

SLPAGECTHD SLPAGERTHD

SMS SMPAGECTHD SMPAGERTHD

To ensure a high paging success rate for high-priority services, such as CS services, the thresholds for starting paging control should be ranked as follows:

CPAGECTHD > SLPAGECTHD > SMPAGECTHD

This way, when paging control is in progress, SMS paging messages are the first to be discarded.

Paging control applies to terminating UEs, and load sharing is not used for paging messages. As a result, paging control for one CPUS affects all paging processes within the same RNC. The thresholds for starting paging control should be higher than the thresholds for starting other flow control functions triggered by CPUS overload.

Paging control based on message block occupancy rate does not vary by service. The threshold for starting this flow control function is configured by using the PAGECTHD parameter, and the threshold for stopping this flow control function is configured by using the PAGERTHD parameter.

Overload Indication


The following counters are related to paging control.

Counter Description

VS.Paging.FC.Disc.Num.CPUS Number of paging messages discarded because of paging control

VS.Paging.FC.Disc.Time.CPUS Duration of paging control in a measurement period

3.3.5 RRC Flow Control

Principle

Upon detecting that the CPU usage or message block occupancy rate of a CPUS is higher than a preset threshold, the RNC starts rejecting or discarding RRC connection requests to avoid raising the CPU load further. RRC Flow Control is disabled by default. It is started after load sharing fails for RRC connection

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requests. For more details on load sharing for RRC connection requests, see 7.2 "Load Sharing on the Control Plane."

When the CPU usage or message block occupancy rate of the CPUS exceeds the threshold, the RNC starts RRC flow control and rejects RRC connection requests. When the number of rejected RRC connection requests per second exceeds the value of SysRrcRejNum configured with the SET UCALLSHOCKCTRL command, the CPUS starts discarding subsequent RRC connection requests messages, without responding with RRC CONNECTION REJECT messages. When the CPU usage and message block occupancy rate fall below their respective thresholds, the RNC stops RRC flow control.

RRC flow control varies by service. The SET SHARETHD command is used to configure the necessary thresholds for the different services, as shown in Table 3-3.

Table 3-3 Thresholds for RRC flow control

Service Type Threshold for Starting RRC Flow Control Based on CPU Usage

Threshold for Stopping RRC Flow Control Based on CPU Usage

Threshold for Starting RRC Flow Control Based on Message Block Occupancy Rate

Threshold for Stopping RRC Flow Control Based on Message Block Occupancy Rate

Inter-RAT cell reselection, IMSI detach procedure, registration, and incoming voice calls

CRRCCONNCCPUTHD

CRRCCONNRCPUTHD

CRRCCONNCMSGTHD

CRRCCONNRMSGTHD

BE services and UE-originated voice calls

LRRCCONNCCPUTHD

LRRCCONNRCPUTHD

LRRCCONNCMSGTHD

LRRCCONNRMSGTHD

SMS SMRRCCONNCCPUTHD

SMRRCCONNRCPUTHD

SMRRCCONNCMSGTHD

SMRRCCONNRMSGTHD

To ensure high-priority services such as CS services are processed first, the thresholds for starting RRC flow control should be ranked as follows:

CRRCCONNCCPUTHD > LRRCCONNCCPUTHD > SMRRCCONNCCPUTHD

This way, when RRC flow control is in progress, RRC connection requests for SMS are the first to be discarded.

When the CPU usage of the CPUS exceeds 90%, the RNC starts discarding all RRC connection requests except those for emergency calls.

Overload Indication


The following counters indicate the number of RRC connection requests rejected and discarded because of RRC flow control.

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Counter Description

VS.LowPriRRC.FC.Disc.Num.CPUS Number of discarded RRC connection requests for SMS because of RRC flow control based on CPU usage

VS.NormPriRRC.FC.Disc.Num.CPUS Number of discarded RRC connection requests for BE services and outgoing voice services because of RRC flow control based on CPU usage

VS.HighPriRRC.FC.Disc.Num.CPUS Number of discarded RRC connection requests for registration and incoming voice services because of RRC flow control based on CPU usage

VS.RRC.CONV.FC.Num.CPU.CPUS Number of rejected and discarded RRC connection requests for real-time services (including conversational services and data services) in the CPUS because of RRC flow control based on CPUS CPU usage

VS.RRC.FC.Num.CPU.CPUS Number of rejected and discarded RRC connection requests in the CPUS because of RRC flow control based on CPUS CPU usage

VS.RRC.CONV.FC.Num.CPU.OverLoad

Number of rejected and discarded RRC connection requests for real-time services in the cell because of RRC flow control based on CPUS CPU usage

VS.RRC.FC.Num.CPU.OverLoad Number of rejected and discarded RRC connection requests in the cell because of RRC flow control based on CPUS CPU usage

3.3.6 Flow Control on Signaling Messages over the Iur Interface

Principle

Upon detecting that the CPU usage or message block occupancy rate of a CPUS is higher than a preset threshold, the RNC starts flow control to reduce signaling traffic over the Iur interface so that the CPU load does not rise further.

When the CPU usage or message block occupancy rate exceeds the threshold, the RNC starts flow control over the Iur interface and discards signaling messages over the Iur interface.

When the CPU usage and message block occupancy rate fall below their respective thresholds, the RNC stops flow control over the Iur interface.

Flow control on signaling messages over the Iur interface consists of uplink transmission flow control over the Iur interface and downlink transmission flow control over the Iur interface, as described in Table 3-4.

Table 3-4 Flow control over the Iur interface

Flow Control Function Flow Control Object Switch

Uplink transmission flow control over the Iur interface

UPLINK SIGNALLING TRANSFER INDICATION messages

IURULSW

Downlink transmission flow control over the Iur interface

RADIO LINK SETUP REQUEST messages

PAGING REQUEST messages

IURDLSW

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Flow Control Function Flow Control Object Switch

COMMON TRANSPORT CHANNEL RESOURCES REQUEST messages


Flow control over the Iur interface affects cell updates, handovers, and paging over the Iur interface. In addition, It affects ongoing service procedures because signaling messages are discarded. This may increase call drop rates.

Overload Indication


To learn about the number of Iur interface messages discarded because of Iur interface flow control, check the following counters:

Counter Description

VS.IurUpLinkSig.Disc.Num.CPU.CPUS Number of uplink messages discarded over the Iur interface on the uplink because of Iur interface flow control triggered by CPUS CPU overload in the CPUS

VS.IurDownLinkSig.Disc.Num.CPU.CPUS Number of downlink messages discarded over the Iur interface on the uplink because of Iur interface flow control triggered by CPUS CPU overload in the CPUS

3.3.7 CBS Flow Control

Principle

In cases where the UTRAN uses an external cell broadcast center (CBC) to provide the cell broadcast service (CBS), the RNC starts CBS flow control upon detecting that the CPU usage or message block occupancy rate of a CPUS is higher than a preset threshold. This reduces signaling traffic over the Iu-BC interface and thereby prevents the CPU load from rising further. The CBSSW parameter in the SET FCSW command is used to enable CBS flow control. By default, it is enabled.

When the CPU usage or message block occupancy rate exceeds the threshold, the RNC starts CBS flow control and discards all CBC broadcast messages.

When the CPU usage and message block occupancy rate fall below their respective thresholds, the RNC stops CBS flow control.


CBS flow control affects cell broadcast services.

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Overload Indication


The following counters are related to CBS flow control.

Counter Description

VS.CBS.FC.Disc.Num.CPUS Number of broadcast messages discarded because of CBS flow control

VS.CBS.FC.Disc.Time.CPUS Duration of CBS flow control in a measurement period

3.3.8 Cell Update Flow Control

Principle

Upon detecting that the CPU usage or message block occupancy rate of a CPUS is higher than a preset threshold, the RNC starts cell update flow control to reduce the number of cell update messages so that the CPU load does not rise further. The CELLURASW parameter in the SET FCSW command is used to enable cell update flow control. By default, it is enabled.

When the CPU usage or message block occupancy rate exceeds the threshold, the RNC starts cell update flow control. During cell update flow control, when a UE in the Cell_PCH or URA_PCH state originates a cell update request that involves a CELL_PCH to CELL_PCH (P2P), CELL_PCH to CELL_FACH (P2F), CELL_PCH to CELL_DCH (P2D) transition, the RNC discards the request.

When the CPU usage and message block occupancy rate fall below the threshold, the RNC stops cell update flow control.

The RNC assign three priorities to cell update requests for different services. When the CPU usage or message block occupancy rate of the CPUS is too high, the RNC first performs flow control on services with the low flow control priority. The RNC determines the flow control priority of a service based on the following information in the cell update request:

Whether the cell update request contains the extended information element (IE) UU_CELL_UPT_V590EXT_STRU.

Cell update cause value

UE version

Value of the IE enEstabCause

Table 3-5 describes the details about how the RNC determines the flow control priority of a service.

Table 3-5 Determining the flow control priority of a service

UU_CELL_UPT_V590EXT_STRU

Cell Update Cause Value

UE Version Value of enEstabCause Flow Control Priority

Not contained Cell reselection, periodic cell updates, serving cell reentry

Not applicable Not applicable High

Others Earlier than R5 Not applicable High

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UU_CELL_UPT_V590EXT_STRU

Cell Update Cause Value

UE Version Value of enEstabCause Flow Control Priority

R5 and later Not applicable Medium

Contained Not applicable Not applicable Emergency calls No flow control

Reselection between cells from different RATs, IMSI detach procedure, registration, and incoming voice calls

High

BE services and outgoing voice calls

Medium

Short message services Low

Different flow control priorities correspond to different flow control thresholds, as described in Table 3-6.

Table 3-6 Flow control thresholds

Flow Control Priority

Threshold for Starting Flow Control Based on the CPU Usage

Threshold for Stopping Flow Control Based on the CPU Usage

Threshold for Starting Flow Control Based on the Message Block Occupancy Rate

Threshold for Stopping Flow Control Based on the Message Block Occupancy Rate

High CELLURACTHD CELLURARTHD

CELLURACTHD CELLURARTHD Medium CELLURAUPDATETH

DFORMID CELLURAUPDATERSTTHDFORMID

Low CELLURAUPDATETHDFORLOW

CELLURAUPDATERSTTHDFORLOW

The SET FCCPUTHD command is used to configure the thresholds for flow control based on CPU usage, and the SET FCMSGQTHD command is used to configure the thresholds for flow control based on message block occupancy rate. To ensure success cell updates for high-priority services such as voice services, it is recommended that the relationships between the thresholds for starting flow control be as follows:

CELLURACTHD > CELLURAUPDATETHDFORMID > CELLURAUPDATETHDFORLOW

This way, when flow control is in progress, cell update requests for low-priority services such as short message services are the first to be discarded.

When the CPU usage of the CPUS exceeds 90%, the RNC discards all cell update requests except those for emergency calls.

Cell update flow control lowers the cell update success rate and affects uplink data transmission. In addition, UE locations recorded by the RNC may not be accurate because cell update messages are discarded. This may affect paging.

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For details about state transitions, see the State Transition Feature Parameter Description.

Overload Indication


The following counters are related to cell/URA update flow control.

Counter Description

VS.CU.FC.Disc.Num.CPUS Number of cell update requests discarded because of cell/URA update flow control

VS.CU.FC.Disc.Time.CPUS Duration of cell/URA update flow control in a measurement period

3.3.9 Flow Control over the Iur-g Interface

Principle

Upon detecting that the CPU usage or message block occupancy rate of a CPUS is higher than a preset threshold, the RNC starts Iur-g flow control to reduce signaling traffic over the Iur-g interface so that the CPU load does not rise further. The IURGSW parameter in the SET FCSW command is used to enable flow control over the Iur-g interface. By default, it is disabled.

When the CPU usage or message block occupancy rate exceeds the threshold, the RNC starts flow control and discards all messages sent over the Iur-g interface.

When the CPU usage and message block occupancy rate fall below their respective thresholds, the RNC stops flow control over the Iur-g interface.


When flow control over the Iur-g interface is started, the RNC is not informed of real-time information about the GSM network load. This may cause the following problems:

When the GSM network load is heavy, inter-RAT handovers initiated by the RNC fail.

When the GSM network load is light, the RNC does not initiate inter-RAT handovers, service distribution cannot be performed for UMTS services, and load sharing cannot be achieved between the UMTS and GSM networks.

For more details about load-based handovers, service distribution, and load balancing over the Iur-g interface, see the Common Radio Resource Management Feature Parameter Description.

Overload Indication


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3.3.10 DCCC Flow Control

Principle

When detecting that the CPU usage or message block occupancy rate of a CPUS is too high, the RNC starts Dynamic Channel Reconfiguration Control (DCCC) flow control for the DCCC procedure of PS BE services. This lowers the CPU load. DCCC flow control is disabled by default. To enable it, run the SET FCSW command with the DCCCSW parameter set to ON.

When the CPU usage or message block occupancy rate exceeds the threshold for starting DCCC flow control, the RNC starts DCCC flow control. Details are as follows:

− For PS BE services of UEs in the CELL_FACH state, the RNC does not trigger CELL_FACH to CELL_DCH (F2D) transitions upon receipt of a 4A measurement report based on traffic.

− For PS BE services of UEs in the CELL_DCH state, the RNC does not trigger the DCCC procedure upon receipt of a 4A report based on traffic.

− For PS BE services of UEs in the CELL_DCH state, the RNC does not trigger the HSUPA DCCC procedure upon receipt of a 4A report based on throughput.

− The RNC no longer makes periodic attempts to trigger CELL_DCH to CELL_E-DCH (D2E) or CELL_DCH to CELL_H-DSCH (D2H) transitions.

When the CPU usage or message block occupancy rate of the CPUS falls below the threshold for stopping DCCC flow control, the RNC stops DCCC flow control.

The SET FCCPUTHD command configures thresholds for flow control functions based on the CPU usage, and the SET FCMSGQTHD command configures thresholds for flow control functions based on the message block occupancy rate.

When DCCC flow control is in progress, UEs cannot promptly transit from the CELL_FACH state to the CELL_DCH state. This causes or aggravates FACH congestion. In addition, upon receipt of a 4A measurement report, the RNC does not trigger the DCCC procedure. As a result, the UE rate cannot be increased, and user experience is affected.

For details about state transitions, see the State Transition Feature Parameter Description. For details about the DCCC procedure, see the DCCC Feature Parameter Description.

Overload Indication


After DCCC flow control is started, the counters listed in the following table are reported:

Counter Description

VS.Traffic.Report4A.CellDch.Disc.Num.UpLink.FC

Number of A4 reports that are triggered by uplink traffic in PS BE services of UEs in the CELL_DCH state and are discarded because of flow control for the CPUS

VS.Traffic.Report4A.CellDch.Disc.Num.DownLink.FC

Number of A4 reports that are triggered by downlink traffic in PS BE services of UEs in the CELL_DCH state and are discarded because of flow control for the CPUS

VS.Throughput.Report4A.Disc.Num.UpLink.FC

Number of A4 reports that are triggered by the uplink throughput in the CELL_DCH state and are discarded because of flow control for the CPUS

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Counter Description

VS.Traffic.Report4A.CellFach.Disc.Num.UpLink.FC

Number of A4 reports that are triggered by uplink traffic in PS BE services of UEs in the CELL_FACH state and are discarded because of flow control for the CPUS

VS.Traffic.Report4A.CellFach.Disc.Num.DownLink.FC

Number of A4 reports that are triggered by downlink traffic in PS BE services of UEs in the CELL_FACH state and are discarded because of flow control for the CPUS

3.3.11 Measurement Report Flow Control

Principle

Upon detecting that the CPU usage or message block occupancy rate of a CPUS is higher than a preset threshold, the RNC starts measurement report (MR) flow control to reduce the number of MR messages so that the CPU load does not rise further. The MRFCSW parameter in the SET FCSW command is used to enable MR flow control. By default, it is enabled.

When the CPU usage or message block occupancy rate exceeds the threshold, the RNC starts MR flow control. After MR flow control is started, the RNC stops sending MR measurement control messages to newly admitted UEs. Consequently, NodeBs and these UEs stop submitting MR measurement reports. MR flow control does not apply to UEs admitted before MR flow control is started.

When the CPU usage and message block occupancy rate fall below their respective thresholds, the RNC stops MR flow control.


The MR function collects the following measurement reports:

Intra-frequency cell measurement reports

Inter-frequency cell measurement reports

Inter-RAT cell measurement reports

DL BLER (downlink block error ratio) measurement reports

Iub SIR (signal-to-interference ratio) measurement reports

UE transmit power measurement reports

LCS (location services) measurement reports, including UE location reports, Iub RTT (round trip time) measurement reports, and UE RX/TX (reception-transmission) measurement reports

RACH (random access channel) measurements reports

Overload Indication


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3.3.12 Queue-based Shaping

Overview

When new service attempts generate a traffic volume that exceeds the maximum processing capability of the CPU in a CPUS, the CPU usage rises to a high level. When a large number of service setup attempts are made in a short period of time, the CPU usage fluctuates sharply.

To address these problems, the RNC adopts a token- and queue-based shaping solution, which includes queue-based RRC shaping and queue-based cell update request shaping. Details are as follows:

Queue-based RRC shaping is performed on RRC connection requests to stabilize the CUP usage and increase RRC and RAB setup success rates under heavy traffic.

Queue-based cell update request shaping is performed on cell update requests to stabilize the CUP usage and increase the cell update success rate.

Tokens are permits to use the CPU resources of the CPUS. When an RRC connection request or cell update request arrives, it applies for a token. RRC connection processing or cell update processing can proceed only after being granted a token. If the RRC connection request or cell update request fails to obtain a token, it attempts to enter a specific queue and remains there until a token is available. If the queue is full, the RRC connection request or cell update request is discarded. Figure 3-4 shows how queue-based RRC shaping works.

Figure 3-4 Queue-based RRC shaping

Queue-based RRC Shaping

By default, queue-based RRC shaping is disabled. To enable it, run the SET UCACALGOSWITCH command with the RsvdPara1 parameter set to RSVDBIT14-1.

When an RRC connection request arrives, the CPUS checks its own CPU usage. If the CPU usage is higher than 90%, the CPUS discards the RRC connection request if it is not from an emergency call. If the CPU usage is not higher than 90%, the CPUS checks whether the CPU load meets the conditions for

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load sharing. If so, the CPUS forwards the RRC connection request to the MPU for load sharing. If not, RNC performs queue-based RRC shaping. For details about load sharing, see chapter 7.2 "Load Sharing on the Control Plane." Queue-based RRC shaping is as follows:

1. The RRC connection request applies for a token.

− If the request manages to obtain a token, the CPUS processes the request and this procedure ends.

− If the request fails to obtain a token and the queue is not full, the request enters the queue. Step 2 starts.

− If the request fails to obtain a token and the queue is full, the request is rejected and this procedure ends.

When the number of RRC connection requests rejected per second exceeds the value of the SysRrcRejNum parameter, the CPUS discards subsequent RRC connection requests.

2. The RRC connection request enters the queue.

3. The RRC connection request leaves the queue.

− The CPUS periodically scans the queues. If the RRC connection request has remained in a queue for longer than half of the value of T300, the CPUS discards the message.

− If a token is available for the request, the request leaves the queue and the CPUS processes the request.

The CPUS first processes RRC connection requests from emergency calls and terminated voice calls.

The RNC does not perform flow control on emergency calls, and emergency calls do not enter queues.

Queue-based Cell Update Request Shaping

Queue-based cell update request shaping is disabled by default. To enable it, run the SET UCACALGOSWITCH command with the FlowCtrlSwitch parameter set to CELL_UPDATE_QUEUE_FLOW_CTRL_SWITCH-1.

When a new cell update request arrives, the CPUS checks its own CPU usage. If the CPU usage is higher than 90%, the CPUS discards the cell update request if it is not from an emergency call. If the CPU usage is not higher than 90%, the RNC performs queue-based shaping. As shown in Figure 3-4, the procedure for queue-based shaping is as follows:

1. The cell update request applies for a token.

− If the request manages to obtain a token, the CPUS processes the request and this procedure ends.

− If the request fails to obtain a token and the queue is not full, the request enters the queue. Step 2 starts.

− If the request fails to obtain a token and the queue is full, the request is rejected and this procedure ends.

2. The cell update request enters the queue.

The RNC does not perform flow control on emergency calls. As a result, cell update requests for emergency calls do not enter the queue.

3. The cell update request leaves the queue.

− The CPUS periodically scans the queue. If the cell update request has remained in the queue for a period of time longer than half the value of T302, the CPUS discards the request.

− If a token is available to the request, the request leaves the queue and is then processed.

The CPUS preferentially processes cell update requests for emergency calls and conversational services.

4. The CPUS processes the cell update request.


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Overload Indication


After queue-based RRC shaping is started, the counters listed in the following table are reported:

Counter Description

VS.RRC.CONV.FC.Num.RRCQueue.CPUS Number of rejected and discarded RRC connection requests in the CPUS for real-time services because of queue-based RRC shaping

VS.RRC.FC.Num.RRCQueue.CPUS Number of rejected and discarded RRC connection requests in the CPUS because of queue-based RRC shaping

VS.RRC.CONV.FC.Num.RRCQueue Number of rejected and discarded RRC connection requests in the cell for real-time services because of queue-based RRC shaping

VS.RRC.FC.Num.RRCQueue Number of rejected and discarded RRC connection requests in the cell because of queue-based RRC shaping

VS.RRC.FC.Disc.Num.RRCQueue.CPUS Number of discarded RRC connection requests in the CPUS because of queue-based RRC shaping

After queue-based cell update request shaping is started, the counters listed in the following table are reported:

Counter Description

VS.CU.FC.Num.RRCQueue Number of discarded cell update requests in the cell because of queue-based cell update request shaping

VS.CU.CONV.FC.Num.RRCQueue Number of discarded cell update requests for conversational services in the cell because of queue-based cell update request shaping

3.3.13 CPUS-level Dynamic CAPS Control

Principle

The CPU of a CPUS only has a limited capacity to process services per second. If a large number of service setup attempts are made within a short period of time, CAPS overload occurs on the CPUS, leading to CPU overload. To address this problem, dynamic CAPS control based on the CPU usage has been introduced to the CPUS in order to control RRC connection requests. The goal is to stabilize the CPU usage and increase the RNC's effective capacity under heavy traffic. When the CallShockCtrlSwitch parameter in the SET UCALLSHOCKCTRL command is set to SYS_LEVEL_DYNAMIC-1, CPUS-level dynamic CAPS control is enabled. By default, CPUS-level dynamic CAPS control is enabled.

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With CPUS-level dynamic CAPS control, the CPU usage is compared with a preset target CPU usage threshold. Based on the comparison result, the target CAPS of the CPUS is dynamically adjusted per second. This controls the CPU usage. Details are as follows:

If the CPU usage is higher than the target CPU usage threshold, the target CAPS of the CPUS for the next second is lowered. This way, fewer RRC connection requests will be allowed the next second and the CPUS load is lowered.

If the CPU usage is lower than the target CPU usage threshold, the target CAPS of the CPUS for the next second is raised. This way, more RRC connection requests will be allowed the next second and the effective capacity of the system under heavy traffic is increased.

The target CPU usage threshold is configured by the DynaCapsFcTarCpu parameter, and the upper limit to the target CAPS is configured by the DynaCapsFcMaxRrc parameter.

When a new RRC connection request arrives, the CPUS compares the number of admitted RRC connection requests with the target CAPS for the current second.

If the number of admitted RRC connection requests is less than the target CAPS for the current second, the CPUS admits the request.

If the number of admitted RRC connection requests is greater than or equal to the target CAPS for the current second, the CPUS decides whether to use the target CAPS for the next second based on the service type in the request. If the target CAPS for the next second is still insufficient to admit the request, the CPUS rejects the request.

The target CAPS for the next second can be used if the service type in the request is one of the following:

− Emergency call

− Conversational service

− Streaming service

− Registration service

− Inter-RAT cell reselection

− IMSI detach

− Original subscribed traffic call

If the number of RRC connection requests rejected by the CPUS per second exceeds the value of the SysRrcRejNum parameter, the CPUS discards the RRC connection request.

CPUS-level dynamic CAPS control cannot work with RRC flow control, which is described in section 3.3.5 "RRC Flow Control." If they are both enabled, only CPUS-level dynamic CAPS control takes effect.

Overload Indication


After CPUS-level dynamic CAPS control starts, the counters listed in the following table are reported:

Counter Description

VS.RRC.FC.Num.CallShock.CPUS Number of rejected and discarded RRC connection requests because of dynamic CAPS control

VS.RRC.CONV.FC.Num.CallShock.CPUS Number of rejected and discarded RRC connection requests for real-time services because of dynamic

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Counter Description

CAPS control

3.4 Flow Control Triggered by MPU Overload

Flow control triggered by MPU overload is twofold: basic flow control for the MPU and MPU overload backpressure.

3.4.1 Basic Flow Control for the MPU

Principle

Basic flow control for an MPU is performed on printing, debugging, and logging. The MPU software monitors the CPU usage and message block occupancy rate of the MPU in real time. Based on the monitored data, the MPU software starts or stops all or some of the basic flow control functions.

When the CPU usage or message block occupancy rate reaches the threshold, the MPU software starts flow control.

When the CPU usage and message block occupancy rate fall below the threshold, the MPU software stops flow control.


The SET FCSW command is used to enable the basic flow control functions. By default, all basic flow control functions are enabled. Basic flow control for the MPU has no impact on services.

Overload Indication



The following counters indicate the CPU usage and message block occupancy rate.

Counter Description

VS.XPU.CPULOAD.MEAN Average CPU usage of the XPU

VS.XPU.MSGLOAD.MEAN Average message block occupancy rate of the XPU

3.4.2 MPU Overload Backpressure

Principle

Under heavy traffic, the CPU of the MPU may be overloaded and fail to process services properly as a result. The RNC adopts an overload backpressure function. With this function, CPUSs work with MPUs

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to perform flow control on RRC CONNECTION REQUEST messages to alleviate the impact of heavy traffic on MPUs.

Congestion detection is performed based on the instantaneous CPU usage of the MPU. When the CPU usage of the MPU reaches 80% (this percentage is unconfigurable) or higher, the MPU sends a congestion message to the CPUS bound to it, as shown in Figure 3-5.

Figure 3-5 Flow control based on MPU overload

Upon receipt of the congestion message from the MPU, the CPUS adjusts the flow control level. The RNC adjusts the number of RRC connection requests that can be admitted on the CPUS each second according to the flow control level change. Flow control for the CPUS is performed on a scale of 30 levels. A higher flow control level means fewer RRC connection requests admitted each second.

The CPUS adjusts the flow control level by using two timers, one with a value of 2.2 seconds, the other with a value of 0.8 seconds.

Upon receiving a congestion message from the MPU, the CPUS increases the flow control level by one and starts the two timers.

If MPU congestion messages are received before the 0.8-second timer expires, the CPUS does not take any actions.

If MPU congestion messages are received after the 0.8-second timer expires but before the 2.2-second timer expires, the CPUS increases the flow control level by one and restarts the two timers. After the 2.2-second timer expires, the CPUS decreases the flow control level by one.

When the RsvdPara1 parameter in the SET URRCTRLSWITCH command is set to RSVDBIT1_BIT19-1, MPU overload backpressure is enabled. By default, it is enabled.

Overload Indication

When the CPU usage reaches a preset threshold (configured by the SET CPUTHD command), the ALM-20256 CPU Overload is reported. To find out whether the alarm was reported for an XPU, check

the subrack number and slot number in the alarm.

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After MPU overload backpressure is enabled, the counters listed in the following table are reported:

Counter Description

VS.RRC.CONV.FC.Num.MPU.CPUS Number of rejected and discarded RRC connection requests in the CPUS for real-time services because of MPU overload backpressure

VS.RRC.FC.Num.MPU.CPUS Number of rejected and discarded RRC connection requests in the CPUS because of MPU overload backpressure

VS.RRC.CONV.FC.Num.MPU.OverLoad Number of rejected and discarded RRC connection requests in the cell for real-time services because of MPU overload backpressure

VS.RRC.FC.Num.MPU.OverLoad Number of rejected and discarded RRC connection requests in the cell because of MPU overload backpressure

VS.RRC.FC.Disc.Num.MPU.CPUS Number of discarded RRC connection requests in the CPUS because of MPU overload backpressure

3.5 Flow Control Triggered by INT Overload

Flow control triggered by INT overload is threefold: basic flow control for the INT, flow control triggered by INT overload on the control plane, and flow control triggered by Iub interface board overload on the user plane.

3.5.1 Basic Flow Control for the INT

Principle

When an interface board (INT) is heavily loaded, it starts basic flow control. Basic flow control for an INT is performed on printing, debugging, and logging. The INT software monitors the CPU usage and message block occupancy rate of the INT in real time. Based on the monitored data, the INT software starts or stops all or some of the basic flow control functions.

When the CPU usage or message block occupancy rate reaches the threshold, the INT software starts flow control.

When the CPU usage and message block occupancy rate fall below the threshold, the INT software stops flow control.

The SET FCCPUTHD command is used to configure the thresholds for flow control based on CPU usage, and the SET FCMSGQTHD command is used to configure the thresholds for flow control based on message block occupancy rate. Basic flow control for the INT has no impact on services.


Overload Indication

When the CPU usage reaches a preset threshold (configured by the SET CPUTHD command), the ALM-20256 CPU Overload is reported. To find out whether the alarm was reported for an INT, check the subrack number and slot number in the alarm.

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The counter VS.INT.CPULOAD.MEAN indicates the CPU usage.

3.5.2 Flow Control Triggered by INT Overload on the Control Plane

Principle

After a UE initiates an RRC connection request and obtains transmission resources on the MPU, the CPUS sends a session setup request to the interface board. When a large number of service setup requests are made in a short period of time, the interface board needs to process a large number of session setup requests and may be overloaded. The MPU adopts a flow control process based on service priorities and the instantaneous CPU usage of the interface board. This type of flow control improves the RAB setup success rate when the interface board is heavily loaded.

The interface board reports its CPU usage to the MPU each second, as shown in Figure 3-6. Based on the CPU usage of the interface board, the MPU adjusts the maximum number of session setup requests admitted by the interface board. If the number of RRC connection requests already admitted is larger than the maximum number allowed, the RNC only processes RRC connection requests from emergency calls and high-priority services. The FcOnItfBrd parameter in the SET TNSOFTPARA command is used to enable this type of flow control. It is enabled by default and applies to Iub, Iu, and Iur interface boards. The maximum number of session setup requests allowed determines the signaling processing capability of the interface board. High-priority services involved in this type of flow control refer to incoming and outgoing voice calls, inter-RAT cell reselection, and registration.

Figure 3-6 Flow control triggered by INT overload

When the CPU usage of the interface board exceeds 90%, the MPU starts discarding RRC connection requests from all UEs.

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Overload Indication

When the CPU usage reaches a preset threshold (configured by the SET CPUTHD command), the ALM-20256 CPU Overload is reported. To find out whether the alarm was reported for an INT, check the subrack number and slot number in the alarm.

After flow control triggered by INT overload on the control plane is started, the counters listed in the following table are reported:

Counter Description

VS.RRC.CONV.FC.Num.INT.CPUS Number of rejected and discarded RRC connection requests for real-time services in the CPUS because of flow control triggered by a high CPU usage of the INT

VS.RRC.FC.Num.INT.CPUS Number of rejected and discarded RRC connection requests for all services except emergency calls in the CPUS because of flow control triggered by a high CPU usage of the INT

VS.RRC.CONV.FC.Num.INT.OverLoad Number of rejected and discarded RRC connection requests for real-time services in the cell because of flow control triggered by a high CPU usage of the INT

VS.RRC.FC.Num.INT.OverLoad Number of rejected and discarded RRC connection requests for all services in the cell because of flow control triggered by a high CPU usage of the INT

3.5.3 Flow Control Triggered by Iub Interface Board Overload on the User Plane

When the amount of user-plane data sent from the DPU to the interface board exceeds the processing capability of the interface board, the interface board throughput decreases and the packet loss rate increases. To address this problem, the RNC adopts backpressure-based downlink congestion control. For more details, see the Transmission Resource Management Feature Parameter Description.

3.6 Flow Control Triggered by DPU Overload

3.6.1 DPU Basic Flow Control

When a DPU is heavily loaded, it starts basic flow control. Basic flow control for a DPU is performed on printing, debugging, and logging. The DPU software monitors the CPU usage and message block occupancy rate of the DPU in real time. Based on the monitored data, the DPU software starts or stops all or some of the basic flow control functions.

When the CPU usage or message block occupancy rate reaches the threshold, the DPU software starts flow control.

When the CPU usage and message block occupancy rate fall below the threshold, the DPU software stops flow control.

The SET FCCPUTHD command is used to configure the thresholds for flow control based on CPU usage, and the SET FCMSGQTHD command is used to configure the thresholds for flow control based on message block occupancy rate. Basic flow control for the DPU has no impact on services.


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Overload Indication

When the CPU usage reaches a preset threshold (configured by the SET CPUTHD command), the ALM-20256 CPU Overload is reported. To find out whether the alarm was reported for a DPU, check the subrack number and slot number in the alarm.


When all digital signal processors (DSPs) under the RNC have been heavily loaded for an extended period of time, the RNC reports the ALM-22305 Resource overload on the user plane.

3.6.2 Flow Control Triggered by DSP CPU Overload

Principle

To ensure admission of CS services and quality of ongoing CS services, the RNC lowers the rates of BE services when the CPU of a DSP is heavily loaded. By default, this type of flow control is enabled.

Each DSP of the DPU periodically monitors its own CPU usage.

When the CPU usage is between SSDSPAVEUSAGEALMTHD and SSDSPMAXUSAGEALMTHD, the RNC lowers the rates of BE services.

When the CPU usage is lower than the threshold SSDSPAVEUSAGEALMTHD, the RNC raises the rates of BE services.

To prevent the DSP from crashing, the RNC adopts a protection threshold, whose value is 90%. During a monitoring period, when the RNC detects that the CPU usage is above 90%, it further lowers service rates and starts to prevent users in the CELL_FACH state from accessing the network.

When the RNC raises or lowers service rates, the current monitoring period is ended. To prevent frequent changes in service rates, the RNC waits a period of time before starting the next monitoring period. During this period, the RNC does not increase or decrease rates of BE services.

Overload Indication

There are no indications when the CPU of a DSP is overloaded.

3.7 Flow Control Triggered by SCU Overload

3.7.1 Principle

When an SCU is heavily loaded, it starts basic flow control. Basic flow control for an SCU is performed on printing, debugging, performance monitoring, and logging. The SCU software monitors the CPU usage and message block occupancy rate of the SCU in real time. Based on the monitored data, the SCU software starts or stops all or some of the basic flow control functions.

When the CPU usage or message block occupancy rate reaches the threshold, the SCU software starts flow control.

When the CPU usage and message block occupancy rate fall below the threshold, the SCU software stops flow control.

The SET FCCPUTHD command is used to configure the thresholds for flow control based on CPU usage, and the SET FCMSGQTHD command is used to configure the thresholds for flow control based on message block occupancy rate. Basic flow control for the SCU has no impact on services.


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3.7.2 Overload Indication

When the CPU usage reaches a preset threshold (configured by the SET CPUTHD command), the ALM-20256 CPU Overload is reported. To find out whether the alarm was reported for an SCU, check the subrack number and slot number in the alarm.


The counter VS.SCU.CPULOAD.MEAN indicates the CPU usage.

3.8 Flow Control Triggered by GCU Overload

3.8.1 Principle

When a GCU is heavily loaded, it starts basic flow control. Basic flow control for a GCU is performed on printing, debugging, and logging. The GCU software monitors the CPU usage and message block occupancy rate of the GCU in real time. Based on the monitored data, the GCU software starts or stops all or some of the basic flow control functions.

When the CPU usage or message block occupancy rate reaches the threshold, the GCU software starts flow control.

When the CPU usage and message block occupancy rate fall below the threshold, the GCU software stops flow control.

The SET FCCPUTHD command is used to configure the thresholds for flow control based on CPU usage, and the SET FCMSGQTHD command is used to configure the thresholds for flow control based on message block occupancy rate. Basic flow control for the GCU has no impact on services.



When the CPU usage reaches a preset threshold (configured by the SET CPUTHD command), the ALM-20256 CPU Overload is reported. To find out whether the alarm was reported for a GCU, check the subrack number and slot number in the alarm.


The counter VS. GCU.CPULOAD.MEAN indicates the CPU usage.

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4-1

4 Flow Control Triggered by NodeB/Cell Overload

4.1 CAPS Control

4.1.1 Overview

When the number of calls in a cell sharply increases, most system resources (mainly radio resources) are consumed processing the enormous amount of RRC connection setup requests. Therefore, the remaining resources are insufficient for processing subsequent RAB assignment requests, resulting in call failures.

To solve this problem, the RNC implements cell-level CAPS control (also simply known as CAPS control). This function limits the number of RRC connection requests admitted to a cell each second. By preventing the traffic of a single cell from surging, CAPS control helps maintain a stable traffic volume on the network. Figure 4-1 shows the procedure for CAPS control.

Figure 4-1 Procedure for CAPS control

To prevent the UE from frequently retrying to set up an RRC connection and exacerbating network congestion, the RNC includes a wait time in the RRC CONNECTION REJECT message it sends to the UE. Upon an RRC connection setup failure, the UE waits this period of time before retrying. This function requires the support of the UE.

Different parameters configure the wait time for different types of services, as described in Table 4-1.

Table 4-1 Parameters for the wait time

Service Type Parameter

BE services and streaming services RrcConnRejWaitTmr

Other services LowRrcConnRejWaitTmr

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4.1.2 Static CAPS Control

Principle

Static CAPS control is disabled by default. With static CAPS control, the RNC periodically checks the total number of RRC connection requests received by a cell. When this number exceeds a preset threshold, the RNC triggers flow control.

To enable static CAPS control for the RNC, select CELL_LEVEL under CallShockCtrlSwitch by running the SET UCALLSHOCKCTRL command.

To enable static CAPS control for each cell, enable static CAPS control for the RNC first, and then select RSVDBIT4 under RsvdPara1 by running the ADD UCELLALGOSWITCH command. By default, RSVDBIT4 is set to 0. In addition, set the cell parameters CellTotalRrcNumThd, CellAmrRrcNum, and CellHighPriRrcNum.

The check period for static CAPS control is set by the CallShockJudgePeriod parameter.

This flow control function is triggered when the total number of RRC connection requests received in a cell within a measurement period exceeds the value of CellTotalRrcNumThd.

Table 4-2 describes the flow control policy for different services.

Table 4-2 Flow control policy

Service Flow Control Policy

PS BE services (interactive service and background service), streaming service, and short message service (SMS)

If the total number of RRC connection requests received in a cell within a measurement period reaches the value of the CellTotalRrcNumThd parameter, the RNC rejects the access requests of these services.

AMR services If the total number of RRC connection requests received in a cell within a measurement period reaches the value of the CellTotalRrcNumThd parameter, the RNC rejects the access requests of AMR services.

Registration and inter-RAT cell reselection

When the RegByFachSwitch parameter is set to ON, the RNC forcibly sets up the RRC connection of registrations on the FACH.

The number of RRC connection requests for registrations and inter-RAT cell reselections in a cell each second must not exceed the value of the CellHighPriRrcNum parameter. Once the limit is reached, the RNC rejects all subsequent requests.

Emergency call Flow control is not applied to emergency calls.

The SYS_LEVEL field of the CallShockCtrlSwitch parameter is used to enable CPUS-level static CAPS control, which no longer applies. The NODEB_LEVEL field of the CallShockCtrlSwitch parameter is used to enable NodeB-level static CAPS control, which no longer applies.

RESERVED_SWITCH_0_BIT10 of the ReservedSwitch0 parameter (set by running the SET UCORRMPARA command) specifies whether to enable CPU usage restriction to trigger cell-level static CAPS control. When RESERVED_SWITCH_0_BIT10 is selected, cell-level static CAPS control takes effect only if the CPU usage reaches a preset threshold. By default, RESERVED_SWITCH_0_BIT10 is not selected, indicating that CPU usage restriction does not take effect. The ReservedU8Para2 parameter indicates the threshold for starting static CAPS control due to CPU usage restriction. The


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parameter's default value is 80. The ReservedU8Para3 parameter indicates the threshold for stopping static CAPS control due to CPU usage restriction. The parameter's default value is 70.

Overload Indication

After static CAPS control is started, the counters listed in the following table are reported:

Counter Description

VS.RRC.FC.Disc.Num.CallShock.CPUS Number of RRC connection requests discarded on the CPUS because of CAPS control

VS.RRC.CONV.FC.Num.CallShock.CPUS

Number of rejected and discarded RRC connection requests in the CPUS for real-time services because of CAPS control

VS.RRC.FC.Num.CallShock.CPUS Number of rejected and discarded RRC connection requests in the CPUS because of CAPS control

VS.RRC.CONV.FC.Num.CallShock Number of rejected and discarded RRC connection requests in the cell for real-time services because of CAPS control

VS.RRC.FC.Num.CallShock Number of rejected and discarded RRC connection requests in the cell because of CAPS control

4.1.3 Dynamic CAPS Control

Principle

Offering an enhancement to static CAPS control, cell-level dynamic CAPS control adjusts the number of RRC connection requests allowed for a cell per second based on the real-time CPU usage. The algorithm for cell-level dynamic CAPS control is similar to that for CPUS-level dynamic CAPS control, which is described in section 3.3.13 "CPUS-level Dynamic CAPS Control."

Cell-level dynamic CAPS control is disabled by default. To enable this function, users can set CELLKPITOCAPS to ON by running the ADD UCELLFCALGOPARA command.

The cell compares the current RRC connection failure rate with RejectKPICTHD (threshold for triggering flow control) every 6s. If the threshold is reached, cell-level dynamic CAPS control starts. This function dynamically controls the number of admitted services in a cell. The specific policy is as follows:

If the RRC connection failure rate in the current period is greater than RejectKPIRTHD, the cell lowers the number of RRC connection requests allowed for the cell in the next period, reducing the impact of invalid service access on the CPU load of the cell.

If the RRC connection failure rate in the current period is less than RejectKPIRTHD, the cell raises the number of RRC connection requests allowed for the cell in the next period, enabling more services to access the cell.

If the RRC connection failure rate is less than RejectKPIRTHD for 10 consecutive periods, the cell stops cell-level dynamic CAPS control.

When a new RRC connection request arrives, the cell compares the number of admitted RRC connection requests with the target CAPS for the current second:


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If the number of admitted RRC connection requests is less than the target CAPS for the current second, the cell admits the request.

If the number of admitted RRC connection requests is greater than or equal to the target CAPS for the current second, the cell decides whether to use the target CAPS for the next second based on the service type in the request. If the target CAPS for the next second is still insufficient to admit the request, the cell rejects the request.


− Emergency call





− IMSI detach


Overload Indication

After cell-level dynamic CAPS control starts, the counters listed in the following table are reported:

Counter Description

VS.RRC.FC.Num.CAPS Number of RRC connection requests in a cell because of CAPS control

VS.RRC.CONV.FC.Num.CAPS Number of RRC connection requests for real-time services in a cell because of CAPS control

4.1.4 Cell-level Dynamic CAPS Control Due to Congestion Reverse Pressure

Principle

If the NodeB or NodeB control port (NCP) and the corresponding cell are configured on different CPUSs, cell-level flow control cannot be triggered. To resolve this issue, cell-level dynamic CAPS control due to congestion reverse pressure is used. This function is triggered by NCP link congestion or CPUS overload for the NodeB or NCP.

Specifically, cell-level dynamic CAPS control due to congestion reverse pressure is triggered when any of the following trigger conditions is met:

The RRC connection failure rate of the cell reaches RejectKPICTHD.

The CPUS serving the NodeB where the cell is established is overloaded.

The CPUS serving the NCP for the NodeB where the cell is established is overloaded.

The link on the NCP for the NodeB where the cell is established is congested.

Cell-level dynamic CAPS control due to congestion reverse pressure is stopped when none of the preceding four conditions is met. Cell-level dynamic CAPS control due to congestion reverse pressure is similar to cell-level dynamic CAPS control described in section 4.1.3 "Dynamic CAPS Control." The only difference lies in how flow control is triggered and stopped.


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The NRMFCSW parameter of the SET FCSW command specifies whether to enable flow control due to CPUS overload for the NodeB or NCP. The parameter's default value is ON, indicating that flow control is enabled. The NRMCPUCTHD parameter of the SET FCCPUTHD command sets the threshold for triggering flow control. The parameter's default value is 90. The NRMCPURTHD parameter sets the threshold for stopping flow control. The parameter's default value is 80.

Flow control due to NCP link congestion is controlled at the RNC and NodeB. To enable RNC-level flow control, set NcpCongFlowCtrSwitch to ON by running the SET ULDCALGOPARA command. To enable NodeB-level flow control, select RSVDBIT4 under RsvdPara1 by running the MOD UNODEBALGOPARA command. Users must enable RNC-level flow control before enabling NodeB-level flow control.

The RNC sends the information about CPUS load and NCP congestion (or congestion relief) to the cell every 3s. The cell decides whether to perform flow control based on the CPUS load and NCP congestion status:

If the CPUS is overloaded or the NCP is congested, the cell lowers the number of RRC connection requests allowed for the cell in the next period, reducing the impact of invalid service access on the CPU load of the cell.

If the CPUS is not overloaded and the NCP is not congested, the cell raises the number of RRC connection requests allowed for the cell in the next period, enabling more services to access the cell.

When a new RRC connection request arrives, the cell compares the number of admitted RRC connection requests with the target CAPS for the current second:

If the number of admitted RRC connection requests is less than the target CAPS for the current second, the cell admits the request.

If the number of admitted RRC connection requests is greater than or equal to the target CAPS for the current second, the cell decides whether to use the target CAPS for the next second based on the service type in the request. If the target CAPS for the next second is still insufficient to admit the request, the cell rejects the request.


− Emergency call





− IMSI detach


Overload Indication

After cell-level dynamic CAPS control due to congestion reverse pressure starts, the counters listed in the following table are reported:

Counter Description

VS.RRC.FC.Num.CAPS Number of RRC connection requests in a cell because of CAPS control

VS.RRC.CONV.FC.Num.CAPS Number of RRC connection requests for real-time services in a cell because of CAPS control

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4.2 PCH Congestion Control

4.2.1 Principle

Because PS services are growing so rapidly, the number of paging messages consuming a large amount of paging resources is also increasing rapidly. As a result, the paging success rate of CS services may be affected. To address this issue, the RNC implements PCH congestion control. With PCH congestion control, CS services are allowed to preempt the paging resources of PS services in the event of PCH congestion, increasing the paging success rate of CS services.

When the number of transmitted paging messages in a transmission time interval (TTI) reaches the maximum (known as PCH congestion), push to talk (PTT) services and conversational services can start preempting the paging resources of other services. If preemption fails, the paging message for a PTT or conversational service is discarded. The rules for PCH congestion control are as follows:

PTT services can preempt the paging resources of other services but its resources cannot be preempted by other services.

Conversational services can preempt the paging resources of non-conversational services.

The paging messages of other services (except PTT services and conversational services) are discarded.

By default, PCH congestion control is disabled. To enable PCH congestion control and allow the conversational services to preempt the paging resources of non-conversational services, run the SET UDPUCFGDATA command to set PAGINGSWITCH to ON.

If the value of the counter VS.RRC.Paging1.Loss.PCHCong.Cell is not 0, the PCH is congested. If this happens, enable PCH congestion control and do not disable it once it is enabled.


When the PCH is congested, the paging messages are discarded. The counter VS.RRC.Paging1.Loss.PCHCong.Cell indicates the number of discarded paging messages.

When the PCH congestion control function is enabled, CS services can preempt the paging resources of PS services. The counter VS.RRC.Paging1.PCHCong.CSPreemptAtt indicates the number of paging preemptions by CS services in a cell due to PCH congestion.

4.3 FACH Congestion Control

4.3.1 Overview

The Forward Access Channel (FACH) is a downlink common transport channel that carries control messages to a UE during initial access and state transition. The FACH may also carry a small quantity of user-plane data. FACH congestion may block information exchange between UEs and the network, affecting service provisioning. To address this issue, the RNC implements FACH congestion control. FACH congestion may be due to the fact that the number of UEs in the CELL_FACH state is limited, or the fact that the resources of the logical channels (CCCH/DCCH/DTCH) on the FACH are congested. Table 4-3 describes how flow control is implemented in different scenarios where FACH congestion is the problem.

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Table 4-3 FACH flow control

Cause of FACH Congestion

Flow Control Actions

Limited number of UEs in the CELL_FACH state

The P2D transitions are triggered.

The D2Idle transitions of PS BE services are triggered.

CCCH congestion Message retransmission is stopped.

New PS BE services are rejected and data transmission of admitted PS BE services is forbidden.

DCCH congestion The P2D transitions of CS services are triggered.

The D2Idle transitions of PS BE services are triggered.

The F2D transitions of PS BE services are forbidden.

The P2F transitions of PS BE services are forbidden.

DTCH congestion The traffic volume-based P2D transitions of PS services are triggered.

When there is CCCH/DCCH/DTCH congestion on the FACH, the RNC performs flow control based on the congestion level. The congestion level is determined by comparing the channel buffer size and preset thresholds, as described in Table 4-4.

Table 4-4 Determination on CCCH/DCCH/DTCH congestion level

Congestion Level

Determining Condition Parameter for CCCH Parameter for DCCH/DTCH

Non-congestion Channel buffer size less than the congestion clearance threshold

CCCHCongClearThd FachCongClearThd

Minor congestion

Channel buffer size greater than or equal to the congestion threshold

CCCHCongThd FachCongThd

Major congestion

Channel buffer size greater than or equal to the discard threshold

None N/A

The congestion and congestion clearance thresholds are set by using the SET UDPUCFGDATA command. Keep the default values (60 for the congestion threshold and 30 for the congestion clearance threshold). If you need to modify the parameter settings, consult Huawei technical support because the

modification affects flow control.

For details about WCDMA channels, see the Radio Bearers Feature Parameter Description. For details about state transitions, see the State Transition Feature Parameter Description.

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4.3.2 Flow Control Based on Limited Number of UEs in the CELL_FACH State

Principle

Generally, a state transition from CELL_DCH to CELL_FACH (referred to as a D2F transition) shall occur

if Event 4B is triggered, as indicated by procedure in Figure 4-2. Event 4B is triggered when the traffic volume of the UE is low for some time. If a UE in the CELL_PCH or URA_PCH state needs to transmit data or respond to a paging message, it initiates a cell update message to enter the CELL_FACH state, as shown in procedure in Figure 4-2.

The number of UEs on the FACH (UEs in the CELL_FACH state) is limited in a cell. The two types of state transition previously mentioned may fail if the number of UEs in the CELL_FACH state reaches the limit. As a result, UEs in the CELL_DCH state, having little or no data to transmit, may continuously occupy the dedicated channels and cell resource utilization may decrease as a result. UEs in the CELL_PCH or URA_PCH state may also fail to perform data transmission or respond to paging messages and finally enter the idle state, leading to PS service drops. Generally, the maximum number of UEs in the CELL_FACH state is 30. To raise this value to 60, run the SET UCACALGOSWITCH command to set the CacSwitch parameter to FACH_60_USER_SWITCH-1.

Figure 4-2 UE state transitions

The RNC allows D2Idle transitions (procedure in Figure 4-2) and P2D transitions (procedure in Figure 4-2), when the number of UEs in the CELL_FACH state has reached the upper limit. Table 4-5 describes the trigger conditions for these state transitions.

Table 4-5 Trigger conditions for a D2Idle transition and a P2D transition

UE State State Transition

Trigger Condition Switch

CELL_DCH D2Idle The IE "Volume" of all Event 4Bs is 0, triggering a D2F transition.

The D2F transition fails because the number of UEs in the CELL_FACH state has reached the upper limit.

The ReservedSwitch0 parameter is set to RESERVED_SWITCH_0_BIT16-1.


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UE State State Transition

Trigger Condition Switch

CELL_PCH/URA_PCH

P2D The cause of a cell update is "uplink data transmission" or "paging response", triggering a P2F transition.

The P2F transition fails because the number of UEs in the CELL_FACH state has reached the upper limit.

The RsvdPara1 parameter is set to RSVDBIT1_BIT20-1.

The D2Idle transition function is disabled by default, and can be enabled by running the SET UCORRMALGOSWITCH command. After a UE moves to the idle state, the RNC releases the dedicated channel for the UE in order to improve the cell resource utilization.

The P2D transition function is disabled by default, and can be enabled by running the SET URRCTRLSWITCH command. During a P2D transition, the RNC delivers the UE a cell update confirm message on the CCCH, which prevents call drops because the delivery does not use up resources designated for UEs in the CELL_FACH state. The initial access rate of a PS service is 8 kbit/s after the UE has entered the CELL_DCH state.

− The rate of PS BE services (non-PTT services) can be limited to 8 kbit/s to prevent excess usage of the DCH resources. This function can be enabled by running the SET UCORRMALGOSWITCH command with the ReservedSwitch1 parameter set to RESERVED_SWITCH_1_BIT6-1. This function is enabled by default.

− The PS BE service (non-PTT services) can be set up on the HS-DSCH or E-DCH when the call drop rate increases because of a large number of P2D transitions as well as H attempts or DCCC rate increase attempts of users on the DCH. An H attempt refers to a channel shift from DCH to HS-DSCH or E-DCH. This function is disabled by default. To enable it, run the SET UCORRMPARA command with the PerfEnhanceSwitch parameter set to PERFENH_PSTraffic_P2H_SWITCH-1.

If the number of UEs in the CELL_FACH state reaches the upper limit, cell updates may fail, including those triggered by radio link setup failures. As a result, call drops may occur. To prevent this, you can reserve some UEs in the CELL_FACH state for cell updates. To set the number of reserved users, run the SET UCORRMALGOSWITCH command and modify the ReservedU32Para1 parameter.

If the maximum number of UEs in the CELL_FACH state is 30 and the number of reserved UEs in the CELL_FACH state is 5, the D2F transition shown in Figure 4-2 will not be implemented when the number of UEs in the CELL_FACH state reaches 25. Instead, the D2Idle transition may be triggered. The resources for reserved UEs are for the users who send cell update messages.

If the value of the counter VS.CellFACHUEs, which indicates the number of UEs in the FACH state, is within the interval of [25,55), run the LST UCACALGOSWITCH command to check the value of the CacSwitch parameter. If the value of this parameter is FACH_60_USER_SWITCH-0, it is recommended that you run the SET UCACALGOSWITCH command to set CacSwitch to FACH_60_USER_SWITCH-1,

which means that the maximum number of UEs in the FACH state is 60.

If the value of the counter VS.CellFACHUEs is greater than or equal to 55, run the LST UCELLALGOSWITCH command to check the value of the NBMCacAlgoSwitch parameter, no matter what value the CacSwitch parameter has. If the value of the NBMCacAlgoSwitch parameter is FACH_USER_NUM_NOT_CTRL-0, it is recommended that you run the ADD UCELLALGOSWITCH command to set NBMCacAlgoSwitch to FACH_USER_NUM_NOT_CTRL-1, which lifts the restriction on the number of UEs in the FACH state.

After the restriction on the number of UEs in the FACH state is lifted, setting CacSwitch to FACH_60_USER_SWITCH-1

will not change the maximum number of UEs in the FACH state to 60.



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When there are no restrictions on the number of UEs in the CELL_FACH state, more UEs can always stay online. However, FACH congestion may occur if a large number of UEs are in the CELL_FACH state. Therefore, it is recommended that functions used to alleviate FACH congestion be enabled after restrictions on the number of UEs in the CELL_FACH state are lifted. These functions include P2D transitions, D2Idle transitions, D2F based on SDU delay, CCCH flow control, DCCH flow control, and DTCH flow control. Therefore, the CELL_FACH user number may be not very high due to the above actions according to FACH congestion.

For details about UE state transition in normal cases, see the State Transition Feature Parameter Description.

Overload Indication

The counter VS.CellFACHUEs indicates the number of UEs in the CELL_FACH state.

4.3.3 CCCH Flow Control

Principle

The common control channel (CCCH) is a logical channel that transmits control messages, such as RRC messages and cell update confirm messages, between the RNC and UEs. The CCCH processes the received messages in its buffer in sequence. The CCCH processes the following messages:

RRC CONNECTION SETUP

RRC CONNECTION REJECT

RRC CONNECTION RELEASE

CELL/URA UPDATE CONFIRM (used during a P2D transition for cell update)

The CCCH may be congested in either of the following situations:

UEs with PS services frequently send RRC connection requests.

A large number of UE registrations (including 2G/3G cell reselections) occur within a short period.

CCCH congestion may become severer in either of the following situations:

The RNC repeatedly sends a UE the RRC connection setup message or cell update confirm message within the time specified by T381, aiming to increase the success rate of the UE receiving the RRC connection setup message or cell update confirm message.

A UE repeatedly sends the RRC connection request or cell update message to the RNC if the UE does not receive the RRC connection setup message within T300 or the cell update confirm message within T302. This is because the RRC connection setup message and cell update confirm message sent by the RNC the first time may have been discarded if the CCCH is congested.

To guarantee the success rate of RRC connection setup and cell update in case of CCCH congestion, the RNC implements CCCH flow control.

The RNC performs CCCH flow control differentiating the RRC connection requests and the P2D transitions for cell update according to the CCCH congestion level. The CCCH congestion level is determined by comparing the CCCH buffer size and preset thresholds, as described in Table 4-4. Figure 4-3 shows CCCH flow control.






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Figure 4-3 CCCH flow control

In the event of minor CCCH congestion, the RNC performs flow control as follows:

− For CS service requests, the RNC handles the RRC connection requests and cell update messages as it normally does, but it does not retransmit these messages because T381 is stopped.

− For PS BE service requests, the RNC discards the retransmitted RRC connection requests after T300 expires and cell update messages after T302 expires. This means that the RNC only handles the service request transmitted for the first time. In addition, the RNC stops T381.

In the event of major CCCH congestion, the RNC performs flow control as follows:

The RNC discards RRC connection requests, rejects new PS BE services, discards the cell update messages, and forbids existing PS BE services from transmitting data. The RNC stops T381 for CS service requests.

CCCH flow control stops once the CCCH is no longer congested.

CCCH flow control is disabled by default. To enable it, run the MOD UCELLALGOSWITCH command and set the RsvdPara1 parameter to RSVDBIT5-1. Enable CCCH flow control in mass gathering events, in which case the traffic volume surges. Keep CCCH flow control enabled to increase the success rate of RRC connection setup and cell update when the CCCH is congested.

If CCCH congestion and Uu-interface resource (code/power/CE) congestion are detected, the RNC adds an IE "wait time" to the RRC connection reject message sent to the UE. The UE waits for the length of time specified by this IE and then retransmits an RRC connection request. When the FACH is congested, the RNC automatically sets the RrcConnRejWaitTmr parameter to 15.

Overload Indication

When CCCH congestion occurs, the counter VS.FACH.CCCH.CONG.TIME will be reported. This counter indicates the duration of CCCH congestion.

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4.3.4 DCCH Flow Control

Principle

The dedicated control channel (DCCH) is a logical channel that transmits dedicated control messages, such as reconfiguration messages and cell update confirm messages, between a UE and the RNC. The DCCH processes the received messages in its buffer in sequence. The DCCH processes the following messages:

RADIO BEARER RECONFIGURATION (F2D/F2P transitions)

CELL/URA UPDATE CONFIRM (P2F cell updates)

DOWNLINK DIRECT TRANSFER/SECURITY MODE COMMAND

The DCCH may be congested if:

UEs in the CELL_PCH state frequently initiate the PS service access requests, triggering the frequent transitions from P2F to F2D to D2F to F2P.

UEs in the CELL_PCH state frequently receive the paging messages from the CN, triggering the frequent transitions from P2F to F2D to D2F to F2P.

When a UE in unacknowledged mode (UM) initiates a F2D/F2P/P2F transition, the RNC periodically retransmits the radio bearer reconfiguration messages on the DCCH, resulting in severer DCCH congestion.

When there is minor or major congestion on the DCCH, the RNC enables P2D transitions for CS service to guarantee the CS service access. The function of P2D transition for CS service access is disabled by default. To enable it, run the SET URRCTRLSWITCH command with the RsvdPara1 parameter set to RSVDBIT1_BIT20-1.

As shown in Figure 4-4, the RNC enables P2D transitions for UEs to set up CS services when the DCCH is congested. The cell update confirm message in the P2D transition can be delivered on the CCCH without affecting CS service access or user experience. If the CCCH is congested, the RNC performs CCCH flow control to ensure CS service access. For details, see section 4.3.3 "CCCH Flow Control " DCCH flow control requires UEs of Release 5 or a later version.

The RNC performs flow control for PS BE services when there is congestion on the DCCH. Table 4-6 describes the trigger conditions and how DCCH flow control is implemented for PS BE services.

Table 4-6 Trigger conditions and actions of DCCH flow control for PS BE services

Trigger Conditions DCCH Flow Control Actions

The IE "Cell update cause" in the cell update message is "uplink data transmission" or "paging response", and the IE "Establishment cause" is not reported.

The P2F transitions are forbidden.

Event 4A The F2D transitions are forbidden.

Event 4B D2F transitions are replaced with D2Idle transitions.

D2F transitions can be replaced by D2Idle transitions only when the ReservedSwitch0 parameter is set to RESERVED_SWITCH_0_BIT16-1. By default, this parameter is set to RESERVED_SWITCH_0_BIT16-0. You can run the SET UCORRMALGOSWITCH command to modify this parameter value.



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P2F and F2D transitions of UEs with PS BE services are forbidden only when the PROCESSSWITCH3 parameter is set to FACH_DCCH_CONG_CTRL_SWITCH-1. By default, this parameter is set to FACH_DCCH_CONG_CTRL_SWITCH-0. You can run the SET URRCTRLSWITCH command to modify this parameter value.

DCCH flow control stops once the DCCH is no longer congested. The DCCH congestion level is determined by comparing the DCCH buffer size and preset thresholds, as described in Table 4-4.

If the value of the counter VS.FACH.DCCH.CONG.TIME is not 0, the DCCH is congested. If this happens, enable DCCH congestion control and do not disable it once it is enabled.

Figure 4-4 shows the UE state transition when DCCH flow control is enabled.

Figure 4-4 UE state transition when DCCH flow control is enabled


Overload Indication

The counter VS.FACH.DCCH.CONG.TIME indicates the duration of DCCH congestion.

4.3.5 DTCH Flow Control

Principle

The dedicated traffic channel (DTCH) is dedicated to one UE for the transfer of a small quantity of user-plane data.

The DTCH may be congested in either of the following situations:

The FACH carries a large number of signaling messages, resulting in insufficient DTCH bandwidth.

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A large number of UEs in the CELL_FACH state are transmitting data.

DTCH congestion results in an increased call drop rate and affects the experience of PS users transmitting data. To solve this problem, the RNC implements DTCH flow control for UEs with PS services. DTCH flow control consists of the following:

Optimized DTCH congestion decision

P2D procedure for UEs processing PS services in case of DTCH congestion

D2Idle procedure for UEs processing PS services in case of DTCH congestion

FACH efficiency boost

DTCH Congestion Decision

The RNC makes a DTCH congestion decision in the following way:

If FACHAdmCondSDUDelaySwitch is set to OFF, the RNC evaluates the DTCH congestion level by comparing the DTCH buffer size and preset thresholds, as described in Table 4-4.

The RNC considers the DTCH congested if the following conditions are met:

− FACHAdmCondSDUDelaySwitch is set to ON.

− There are 10 or more PDUs whose SDU delay is greater than FACHAdmSDUDelayThd in the DTCH buffer.

− The DTCH queue is congested.

P2D Procedure

When the DTCH is congested, RNC triggers P2D transition. The trigger conditions and how DTCH flow control is implemented are as follows: When a UE with PS services in the CELL_PCH state initiates a cell update, a P2D transition is triggered if the following conditions are met:

The PROCESSSWITCH2 parameter is set to FACH_DTCH_CONGEST_P2D-1.

The UE is of Release 5 or a later version.

The DTCH is congested but the CCCH and DCCH are not.

In the cell update message triggered by PS data transmission, the value of IE "Cell update cause" is "uplink data transmission" or "paging response", and the IE "Establishment cause" is not reported.

D2Idle Procedure

The following describes how a D2Idle procedure is triggered for UEs processing PS services when the DTCH is congested:

When PERFENH_DTCH_FACH_CONG_D2I_SWITCH is selected under PerfEnhanceSwitch, the RNC initiates a D2F transition request. If the DTCH is congested, the RNC evaluates the measurement quantities (indicating the traffic volume or throughput) contained in the uplink and downlink 4B measurement reports. If the measurement quantities are all 0, a D2Idle transition starts. If the measurement quantities are not all 0, the UE remains in the CELL_DCH state.

DTCH flow control stops once the DTCH is no longer congested.

FACH Efficiency Boost

FACH efficiency boost is achieved in the following manners:

Data Transmission Suspension

To make more efficient use of the FACH bandwidth and improve the experience of users whose UEs are in the CELL_FACH state and engaged in data transmission, the RNC suspends RLC data transmission when triggering an F2D state transition. The RNC keeps RLC data transmission suspended until the F2D

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state transition is complete or the UE returns to the CELL_FACH state. This ensures that user-plane data is transmitted over the DCH whenever possible. This function is disabled by default. Different switches are used on the uplink and downlink:

− To enable this function for the uplink, run the SET UCORRMALGOSWITCH command with the DraSwitch parameter set to DRA_UL_RACH_TX_INTERRUPT_AFT_TRIG_SWITCH-1.

After you do that, the RNC includes the IE Tx interruption after trigger when delivering the FACH traffic measurement control command. This IE indicates the duration for which data transmission is suspended after the UE reports a 4A measurement report. To set the value of this IE, run the SET UUESTATETRANS command with the TxInterruptAfterTrig parameter set to the desired value.

− To enable this function for the downlink, run the SET URRCTRLSWITC command with the PROCESSSWITCH3 parameter set to RNC_F2D_RLC_SUSPEND_SWITCH-1.

If the value of the counter VS.FACH.DTCH.CONG.TIME is not 0, DTCH congestion is in progress and you

are recommended to enable this function.

TVM-based P2D Transition

A UE with PS services in the CELL_PCH state initiates a P2D transition based on the Traffic Volume Measurement (TVM), when the following conditions are met:

− The PROCESSSWITCH3 parameter is set to RNC_TVM_BASED_P2D_SWITCH-0.

− The traffic volume from the CN is higher than the 4A threshold; or in the cell update message initiated by the UE, the value of the IE "traffic volume indicator" is TRUE and the value of the IE "Cell update cause" is "uplink data transmission."

TVM indicates 4A measurements in the uplink or measurements on traffic volume from the CN in the downlink.

This function enables UEs in the CELL_PCH state to enter the CELL_DCH state when the amount of data to be transmitted exceeds the 4A threshold. This eliminates the need for P2F transitions prior to F2D transitions and thereby improves the FACH resource utilization efficiency.

This function is disabled by default. To enable it, run the SET URRCTRLSWITCH command. If the value of the counter VS.FACH.DTCH.CONG.TIME is not 0, the DTCH is congested. In this case, enable TVM-based P2D transition.

F2P Transition by Means of Physical Channel Reconfiguration

F2P (CELL_FACH to CELL_PCH) transitions by means of physical channel reconfiguration reduce FACH bandwidth consumption, because physical channel reconfiguration messages generate 50% less air interface traffic than RB reconfiguration messages.

This function is disabled by default. To enable it, run the SET UCORRMALGOSWITCH command with the CmpSwitch parameter set to CMP_F2P_PROCESS_OPTIMIZATION_SWITCH-1. If the value of the counter VS.FACH.DTCH.CONG.TIME is not 0, the DTCH is congested, and you are recommended to enable this function.

Figure 4-5 shows the UE state transition when DTCH flow control is enabled.


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Figure 4-5 UE state transition when DTCH flow control is enabled


The P2D transition function is disabled by default, and can be enabled by running the SET URRCTRLSWITCH command. The initial access rate of a PS service is 8 kbit/s after the UE has entered the CELL_DCH state.

The rate of PS BE services (non-PTT services) can be limited to 8 kbit/s to prevent excess usage of the DCH resources. This function can be enabled by running the SET UCORRMALGOSWITCH command with the ReservedSwitch1 parameter set to RESERVED_SWITCH_1_BIT6-1. This function is enabled by default.

The PS BE service (non-PTT services) can be set up on the HS-DSCH or E-DCH when the call drop rate increases because of a large number of P2D transitions as well as H attempts or DCCC rate increase attempts of users on the DCH. An H attempt refers to a channel shift from DCH to HS-DSCH or E-DCH. This function is disabled by default. To enable it, run the SET UCORRMPARA command with the PerfEnhanceSwitch parameter set to PERFENH_PSTraffic_P2H_SWITCH-1.

If the value of the counter VS.FACH.DTCH.CONG.TIME is not 0, the DTCH is congested. If this happens, enable DTCH congestion control and do not disable it once it is enabled.

Overload Indication

The counter VS.FACH.DTCH.CONG.TIME indicates the duration of DTCH congestion.





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5 Flow Control over the Iu Interface

5.1 SCCP Flow Control

5.1.1 Overview

In cases where the bandwidth configured for signaling links over the Iu interface is insufficient or some signaling links over the Iu interface are faulty, signaling link congestion will occur when there are a large number of calls, location updates, or group short messages. Signaling link congestion must be quickly alleviated. Otherwise, it will lead to extended delays or even timeouts in signaling exchanges between UEs and the core network. Severe congestion may cause services to break down. To address these problems, the RNC supports Signaling Connection Control Part (SCCP) flow control, which prevents severe congestion on the signaling link between the RNC and the core network. By default, SCCP flow control is enabled.

The RNC uses a scale of 13 levels (0 to 12) to perform SCCP flow control based on service type. When the flow control level changes, the RNC adjusts the signaling traffic over the Iu interface. The higher the flow control level, the more initial UE messages will be discarded.

At Level 0, flow control is not performed. The RNC performs SCCP flow control on short message services, paging, location updates and registrations. Of these, short message service has the lowest priority, and location updates and registrations have the highest priority. At a particular flow control level, the RNC proportionally discards the initial UE messages of these services. The proportion is based on service priorities and is not configurable.

Of all the messages discarded during flow control, initial UE messages for lower-priority services account for the largest proportions. Assuming that 30 initial UE messages are to be discarded and the proportion of SMS messages discarded to paging messages discarded to location updates discarded is 3:2:1, the numbers of initial UE messages for different services to be discarded are calculated as follows:

SMS: 30 x 3/(3 + 2 + 1) = 15

Paging: 30 x 2/(3 + 2 + 1) = 10

Location registrations: 30 x 1/(3 + 2 + 1) = 5

SCCP flow control includes:

Flow control based on Iu signaling load

Flow control based on the SCCP setup success rate

CN SCCP congestion control

These three flow control functions have their own flow control levels, and the RNC performs SCCP flow control according to the highest among them. Table 5-1 provides details about SCCP flow control.

Table 5-1 SCCP flow control

Flow Control Method Switch Criteria for Adjusting Flow Control Levels

Flow control based on Iu signaling load

IUFCSW The SCCP receives an unsolicited SCCP-SSC message from the core network.

The SCTP link (in the case of IP transmission) or the SAAL/MTP3 link (in the case of ATM transmission) becomes congested.

Flow control based on the SCCP setup

FcSwicthByRatioBetweenCCAndCR

The ratio of the sum of CC and CREF to CR changes.

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Flow Control Method Switch Criteria for Adjusting Flow Control Levels

success rate

CN SCCP congestion control

CREFCongFc The RNC receives a CN CREF congestion indication after sending a CR.

5.1.2 Flow Control Based on Iu Signaling Load

Principle

When the CN SCCP is congested, the RNC receives an SCCP Subsystem-Congested (SCCP-SSC) message from the CN. This message carries the CN SCCP congestion level. The RNC maps the CN SCCP congestion level to an RNC SCCP flow control level.

In addition, the RNC monitors the load on the SCTP, SAAL, or MTP3 link in real time and adjusts the flow control level based on the congestion status.

Overload Indication

When a signaling link over the Iu interface is congested, the following alarms and counters are reported:

Transmission Mode over the Iu Interface

Alarms Counters

IP transmission ALM-21542 SCTP Link Congestion VS.SCTP.CONGESTION.INTERVAL

OS.M3UA.Lnk.Cong.Dur

ATM transmission ALM-21501 MTP3 Signaling Link Congestion

ALM-21502 MTP3 DSP Congestion

ALM-21532 SAAL Link Congestion

OS.MTP3.Lnk.Cong.Dur

OS.MTP3.Lnk.ConG

VS.SAAL.LnkErr.BufferLoss

The following counters indicate the number of initial UE messages discarded because of flow control over the Iu interface.

Counter Description

VS.IU.FlowCtrl.DiscInitDT.CS

Number of initial UE messages in the CS domain that are discarded because of flow control over the Iu interface

VS.IU.FlowCtrl.Disc.InitDT.PS

Number of initial UE messages in the PS domain that are discarded because of flow control over the Iu interface

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5.1.3 Flow Control Based on SCCP Setup Success Rate

Principle

In each flow control period, the RNC SCCP checks the number of connection requests (CRs) sent to the CN and the total number of Connection Confirm (CC) and Connection Refused (CREF) messages received from the CN. Each period is 5 seconds long.

Based on the changes in the ratio of the number of CCs plus the number of CREFs to the number of CRs, the RNC SCCP adjusts the flow control level to ensure that the number of messages received by the CN does not exceed its capabilities.

The flow control level is adjusted based on the following criteria:

When (CC+CREF)/CR shows an increasing trend in a flow control period:

− Flow control is lowered by one level if it is weaker than the previous period.

− Flow control is raised by one level if it is stronger than the previous period.

If (CC+CREF)/CR shows a decreasing trend in a flow control period:

− Flow control is raised by one level if it is weaker than the previous period.

− Flow control is lowered by one level if it is stronger than the previous period.

If the number of CRs sent to the CN from the RNC increases, flow control weakens. If the number of CRs sent from the RNC decreases, flow control strengthens.

Overload Indication

There are no indications when the CN is overloaded by CRs sent from the RNC.

5.1.4 CN SCCP Congestion Control

Principle

When the CN SCCP is congested, the RNC receives a CREF message carrying a congestion indication after sending a CR. The RNC SCCP periodically checks whether it has received CREF messages carrying congestion indications. When it does, it raises the flow control level by one. Otherwise, the RNC lowers the flow control level by one.

Overload Indication

The following counters indicate the number of initial UE messages discarded because of CN SCCP congestion control.

Counter Description

VS.IU.FlowCtrl.DiscInitDT.CS Number of initial UE messages in the CS domain that are discarded because of flow control over the Iu interface

VS.IU.FlowCtrl.Disc.InitDT.PS Number of initial UE messages in the PS domain that are discarded because of flow control over the Iu interface

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5-4

5.2 Flow Control Triggered by CN RANAP Overload

Principle

When the CN RANAP is overloaded (CPU overload, for example), it sends a RANAP OVERLOAD message to the RNC. Upon receipt of this message, the RNC adjusts the traffic level to the CN over the Iu interface in order to decrease the load on the CN. The IUCTHD parameter in the SET FCSW command is used to configure the percentage of the total traffic the RNC is restricted from sending to the CN. The default value of this parameter is 70, which means the RNC can only send 30% of the total traffic to the CN.

Flow control triggered by CN RANAP overload is performed on a scale of 21 levels (0 to 20). The lower the level, the more initial UE messages are discarded. The RNC uses two timers when adjusting the flow control level: IntrTmr and IgorTmr, as shown in Table 5-2, where T2 is IntrTmr and T1 is IgorTmr.

Table 5-2 Adjusting the flow control level

Current Status

Event Action Next Status

Idle The RNC receives an overload message from the CN.

Lower flow control by one level.

Start T1 and T2.

T1 and T2 are running.


The RNC receives an overload message from the CN.

None. T1 and T2 are running.

T1 expires. None. T2 is running.

T2 is running. The RNC receives an overload message from the CN.

Lower flow control by one level.

Start T1 and T2.


T2 expires. Raise flow control by one level.

Restarts T2 if the flow control level is not 20.

T2 is running.

Resets and stops T1 and T2 if the flow control level is 20.

Idle

Figure 5-1 shows how T1 and T2 work.

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Figure 5-1 T1 and T2

By default, this type of flow control is enabled.

Overload Indication

When the CN is overloaded, the ALM-22301 UMTS CN Overload is reported.

The following counters indicate the number of initial UE messages discarded because of flow control over the Iu interface.

Counter Description

VS.IU.FlowCtrl.DiscInitDT.CS Number of initial UE messages in the CS domain that are discarded because of flow control over the Iu interface

VS.IU.FlowCtrl.Disc.InitDT.PS Number of initial UE messages in the PS domain that are discarded because of flow control over the Iu interface

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Flow Control 6 Service Flow Control



6-1

6 Service Flow Control

The RNC and NodeB adopt congestion control algorithms on the user plane over the Iub interface to perform flow control on BE services. This restricts user transmission rates, prevents congestion and packet loss, and optimizes bandwidth utilization over the Iub interface. For more details, see the Transmission Resource Management Feature Parameter Description.


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Flow Control 7 Load Sharing



7-1

7 Load Sharing

7.1 Overview

Load sharing is performed on both the control plane and the user plane, and it is performed in transmission resource management. CPUSs, DSPs, and other boards can be bound to an MPU to form a logical subrack. The subracks mentioned in this chapter are all logical subracks.

Each CPUS controls some NodeBs and their cells. The CPUS performs signaling processing for service requests from the UEs under these cells, and the UEs are admitted to the CPUS.

The MPU in each subrack keeps a record of the user-plane load on the current subrack and shares this information with the MPUs in other subracks. When a service request arrives and the controlling CPUS is heavily loaded, the CPUS forwards the request to the MPU in the current subrack. The MPU selects the CPUS with the lightest load for signaling processing. The selected CPUS may be in the current subrack or another subrack. Figure 7-1 shows how load sharing works between two subracks.

Figure 7-1 Load sharing between two subracks

When a UE attempts to access the network and user-plane resources need to be allocated to the UE, the controlling CPUS sends a resource request to the MPU in the current subrack. The MPU attempts to allocate the user-plane resources of the current subrack to the UE. If this attempt fails, the MPU forwards the resource request to the MPU in the subrack with the lightest load. The user-plane resources in this chapter refer to DSP resources.

Figure 7-2 shows resource management on the user plane.

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7-2

Figure 7-2 Resource management on the user plane

When a UE attempts to access the network and transmission resources need to be allocated to the UE, the controlling CPUS sends a resource request to the MPU. The MPU attempts to allocate the transmission resources to the UE. MPUs are responsible for managing transmission resources for interface boards. Transmission resource management for interface boards is shared among MPUs. When the load is not evenly balanced among MPUs, the RNC automatically adjusts the proportion of transmission resource management of MPUs to achieve load balancing.

If the CPU usage of a CPUS is 90% or higher, the CPUS discards all service requests except those for emergency calls. Load sharing does not work for the CPUS.

When the CPU usage of an MPU is 95% or higher, the MPU discards the following requests to avoid resetting:

Resource requests from each UE, for example, requests for DSP resources and transmission resources

Load sharing requests

When this occurs, load sharing does not work.

7.2 Load Sharing on the Control Plane

7.2.1 Procedure for Load Sharing on the Control Plane

When a CPUS receives a service request, the controlling CPUS determines whether to perform load sharing. If so, the CPUS follows the procedure described in Figure 7-3.

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7-3

Figure 7-3 Load sharing on the control plane

Details are as follows:

Step 1 The CPUS receives a service request.

Step 2 Based on the current load, the CPUS determines whether to perform load sharing. For more details, see section 7.2.2 "Service Request Processing by a CPUS."

− If load sharing is to be performed, Step 3 starts.

− If load sharing is not to be performed, the CPUS processes the request, and the procedure ends.

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7-4

Step 3 The CPUS forwards the request to the MPU in the current subrack.

Step 4 Upon receipt of the load sharing request from the CPUS, the MPU checks the control-plane load on all subracks in the RNC.

If the control-plane load on the current subrack minus CtrlPlnSharingOutOffset is higher than the control-plane load on any other subrack, load sharing is performed between subracks.

The MPU forwards the request to the MPU in the subrack with the lightest load on the control plane, which is known as the target MPU. Following the criteria described in Table 7-1, the target MPU searches for all CPUSs that can take up the request.

− If the target MPU can find such CPUSs, it selects a CPUS with the lightest CPU load to process the request.

− If the target MPU cannot find such a CPUS, load sharing is performed within the current subrack.

If the control-plane load on the current subrack minus CtrlPlnSharingOutOffset is lower than or equal to the control-plane load on any other subrack, load sharing is performed within the current subrack. Following the criteria described in Table 7-1, the MPU in the current subrack attempts to find CPUSs that can take up the request from within the current subrack.

− If the target MPU can find such CPUSs, it selects a CPUS with the lightest CPU load to process the request.

− If the MPU cannot find such a CPUS, service access is rejected.

----End

The control-plane load on a subrack is the average CPU usage of the CPUSs managed by the MPU.

Load sharing is yielding noticeable effects if the load is balanced across the CPUs of the CPUSs. To check the CPU load of the CPUSs, run the DSP CPUUSAGE command. If the load is not balanced, consult Huawei engineers to adjust the thresholds for load sharing or adjust the configuration of XPUs in the subracks.

7.2.2 Service Request Processing by a CPUS

Generally, CPUSs are not heavily loaded. When a user initiates a service request, the controlling CPUS processes it. If the controlling CPUS is heavily loaded, load sharing is performed and the request is forwarded to a lightly loaded CPUS. Service requests cannot be forwarded to an overloaded CPUS. The CPUS load is indicated by the CPU load (CPU usage) and CAPS. The RNC considers a CPUS overloaded when any of the following conditions is met:

The CPU load is low and the CAPS is high.

The CPU load is high and the CAPS is low.

The CPU load is greater than or equal to the CPU overload threshold, which cannot be configured.

Based on the CPUS load, the RNC defines three CPUS states, as shown in Figure 7-4.

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7-5

Figure 7-4 CPUS load and states

The state of a CPUS determines how it processes service requests, as described in Table 7-1.

Table 7-1 Service request processing by CPUS state

CPUS State Definition Processing

State I The CPUS is lightly loaded. The CPUS load is considered light when both the following are true:

CPU load ≤ CtrlPlnSharingOutThd

CAPS ≤ MaxCAPSLowLoad

The CPUS directly processes new and forwarded requests.

State II The CPUS is heavily loaded. The CPUS load is considered heavy when both the following are true:

CtrlPlnSharingOutThd < CPU load < CPU overload threshold

CAPS ≤ MaxCAPSMidLoad

The CPUS forwards all new requests to the MPU for load sharing.

The MPUs can forward requests to the CPUS.

State III The CPUS is overloaded. The CPUS is considered overloaded when any of the following is true:

CPU overload threshold < CPU load

CPU load ≤ CtrlPlnSharingOutThd, and MaxCAPSLowLoad < CAPS

CtrlPlnSharingOutThd < CPU load < CPU overload threshold, and MaxCAPSMidLoad < CAPS

The CPUS forwards all new requests to the MPU for load sharing.

The MPUs cannot forward requests to the CPUS.

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7-6

7.3 Load Sharing on the User Plane

7.3.1 Overview

The RNC measures the following aspects of the DSP processing capability:

GBR capability of the DSP (DSP resources used for service access procedures are measured as GBRs)

Processing capability of the DSP CPU

Accordingly, the RNC measures the user-plane load of a subrack with the following:

Total GBRs consumed by admitted services on the DSPs (GBR consumption)

Average CPU usage of all DSP CPUs in a subrack (CPU load)

The remaining GBRs of a subrack refer to the total DSP GBR capabilities of the subrack minus GBR consumption in the subrack. The remaining CPU processing capability of a subrack is the average CPU processing capability of all DSPs in the subrack minus the CPU load.

7.3.2 Procedure for Load Sharing on the User Plane

When user-plane resources need to be allocated to a new user, the MPU in the current subrack determines whether to allocate resources in the current subrack or forward the resource request to another subrack based on the GBR consumption and CPU load. Figure 7-5 shows the procedure for load sharing on the user plane.

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7-7

Figure 7-5 Load sharing on the user plane

The procedure for load sharing on the user plane is as follows:

Step 1 The MPU receives a resource allocation request from the CPUS.

Step 2 The MPU uses the user-plane load on the current subrack to determine whether to perform load sharing.

− If GBR consumption in the current subrack is equal to or lower than UserPlnSharingOutThd and the CPU load on the current subrack is less than or equal to UserPlnCpuSharingOutThd, the MPU in

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7-8

the current subrack attempts to allocate user-plane resources to the user in the current subrack. Substep 1 starts.

− Otherwise, the MPU forwards the request to the MPU in the subrack with the lightest load, known as the target subrack. The MPU of this subrack will determine whether load sharing can be performed. Step 3 starts.

1. The MPU in the current subrack determines whether resources can be allocated.

If... Then...

The MPU finds in the current subrack the DSP with the lowest GBR consumption

The MPU selects this DSP as the target DSP, and substep 2 starts.

Note:

If this DSP has no GBR resources to consume and has a CPU load below DSPRestrainCpuThd, The MPU in the current subrack also selects this DSP as the target DSP.

The MPU cannot find such a DSP The RNC rejects the service access.

2. The target DSP allocates user-plane resources to the user.

Step 3 The target MPU determines whether load sharing can be performed.

1. If either of the following conditions is met, substep 2 starts:

− GBR consumption in the current subrack > UserPlnSharingOutThd, and remaining GBRs in the current subrack x (1 + UserPlnSharingOutOffset) < remaining GBRs in the target subrack

− CPU load in the current subrack > UserPlnCpuSharingOutThd, and the remaining CPU processing capability in the current subrack x (1 + UserPlnCpuSharingOutOffset) < remaining CPU processing capability in the target subrack.

If neither of these conditions is met, load sharing fails, and the MPU in the current subrack selects a DSP from the current subrack for resource allocation.

2. The MPU in the target subrack determines whether resources can be allocated.

If... Then...

The MPU in the target subrack finds in the target subrack a DSP whose GBR consumption is the lowest

This DSP is selected as the target DSP, and substep 3 starts.

Note:

If this DSP has no GBR resources to consume and has a CPU load below DSPRestrainCpuThd, The MPU in the target subrack also selects this DSP as the target DSP.

The MPU in the target subrack cannot find such a DSP The RNC rejects the service access.

3. The target DSP allocates user-plane resources to the user.

----End

The SET UUSERPLNSHAREPARA command configures thresholds for load sharing on the user plane.



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7-9

Load sharing is considered yielding noticeable effects if the load is balanced across the CPUs of the MPUs. To check the CPU load on an MPU, run the DSP CPUUSAGE command. If the load is not balanced, consult Huawei engineers to adjust the thresholds for load sharing or adjust the configuration of DPUs in the subracks.

When all DSPs under the RNC have been heavily loaded for an extended period of time, the RNC reports the ALM-22305 Resource overload on the user plane. This indicates DSP resources are insufficient and a capacity expansion is recommended.

7.4 Load Sharing in Transmission Resource Management

Load sharing in transmission resource management may also be called the MPU pool feature.

7.4.1 Background

MPUs are responsible for managing transmission resources over the Iub, Iu, and Iur interfaces. These transmission resources refer to all AAL2 or IP paths under the adjacent node of the Iub, Iu, and Iur interfaces.

Interface boards provide transmission resources. In versions earlier than RAN14.0, all AAL2 or IP paths carried on an interface board are managed by the MPU to which the interface board is bound. No matter which CPUS is assigned to process the signaling data for a call, the call always applies for transmission resources from the MPU to which the interface board is bound.

In the case of ATM transmission, the CARRYF and CARRYSN parameters of the ADD AAL2PATH command

determine which interface board carries AAL2 paths.

In the case of IP transmission, the IPADDR parameter of the ADD IPPATH command determines which interface board carries IP paths.

The ADD BRD command is used to bind interface boards to MPUs.

In Figure 7-6, the transmission resources over the Iub interface for NodeB1 and NodeB2 are managed by MPU1. A call coming into either NodeB applies for transmission resources over the Iub interface, no matter which CPUS is assigned to process the signaling data.

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7-10

Figure 7-6 MPUs managing transmission resources over the Iub interface in versions earlier than RAN14.0

This management mode has some drawbacks:

The load is not evenly balanced among the CPUs of MPUs. The load on an MPU depends on the load on the interface boards bound to the MPU.

To achieve load balancing among MPUs, NodeBs must be moved. Automatic load balancing is not possible.

The processing capabilities of individual MPUs restrict the Busy Hour Call Attempts (BHCA) specifications of interface boards. Because of such restrictions, additional interface boards and ports may be required even when some interface boards have abundant transmission resources.

To address these problems, a function called load sharing in transmission resource management has been introduced to RAN14.0. With this function, transmission resource management for interface boards is shared among MPUs, and therefore the load can be balanced among MPUs.

7.4.2 Key Concepts

A service request from a UE in a cell is processed by the CPUS serving the cell. This CPUS completes the signaling procedure and admits the UE.

Load balancing involves the following key concepts:

Controlling CPUS of a NodeB

Each NodeB and the cells under it are controlled by a CPUS, known as the controlling CPUS. The SRN, SN, and SSN parameters in the ADD UNODEB command used to add a NodeB specify a controlling CPUS for the NodeB.

Controlling MPU of a NodeB

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7-11

The MPU to which the controlling CPUS of a NodeB is bound is known as the controlling MPU of the NodeB.

7.4.3 ATM Transmission Resource Management over the Iub, Iu, and Iur Interfaces

ATM Transmission Resource Management over the Iub Interface

In RAN14.0, the transmission resources over the Iub interface for a NodeB are managed by only one MPU, namely the controlling MPU of the NodeB.

In Figure 7-7, the transmission resources over the Iub interface for NodeB1 are managed by MPU1, and those for NodeB2 are managed by MPU2.

A call coming into NodeB1 applies for transmission resources over the Iub interface from MPU1, no matter which CPUS is assigned to process the signaling data for the call. The similar is true of NodeB2 and MPU2.

Figure 7-7 MPUs managing ATM transmission resources over the Iub interface in RAN14.0

ATM Transmission Resource Management over the Iu-CS or Iur Interface

ATM transmission resources over the Iu-CS or Iur interface are managed based on the binding relationships between interface boards and MPUs. All AAL2 paths carried on an interface board are managed by the MPU to which the interface board is bound.

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7-12

The user-plane protocol stack over the Iu-PS interface is IP over ATM. Therefore, when ATM transmission is used over the Iu-PS interface, transmission resource management for the Iu-PS interface is performed the same way as when IP transmission is used over the Iu-PS interface.

7.4.4 IP Transmission Resource Management over the Iub, Iu, or Iur Interface

In RAN14.0, the transmission resources of an IP interface board can be managed by multiple MPUs, the transmission resources over one interface (Iub, Iu, or Iur) can also be managed by multiple MPUs. When the load is not evenly balanced among MPUs, the RNC automatically adjusts the proportion of transmission resource management of MPUs to achieve load balancing.

The load sharing algorithm for IP transmission resources over the Iub, Iu, or Iur interface works like this:

When the RNC has just started up:

− The transmission resources over the Iub interface for a NodeB are managed only by the controlling MPU of the NodeB. A call coming into this NodeB applies for transmission resources from the controlling MPU, no matter which CPUS is assigned to process the signaling data for the call.

− The RNC distributes IP transmission resource requests over the Iu or Iur interface equally among MPUs. Assuming that there are altogether five MPUs, each MPU processes 20% of all IP transmission resource requests over the Iu or Iur interface.

When the RNC has been running for some time

The RNC performs load balancing among MPUs when necessary. Assume that the load on the CPU of MPU1 is the heaviest at MaxCPULoadforMPU and that the load on the CPU of MPU2 is the lightest at MinCPULoadforMPU. When both the following are true, the RNC performs load balancing to shift some of the load on MPU1 to MPU2:

MaxCPULoadforMPU > MPULOADSHARETH

MaxCPULoadforMPU - MinCPULoadforMPU > MPULOADDIFFTH

The detailed action is as follows:

− For the Iub interface, the RNC picks some NodeBs whose transmission resources are managed by MPU1 and change their transmission resources managed by MPU2.

− For the Iu or Iur interface, the RNC lowers MPU1's share of the load and raises MPU2's.

The default values for MPULOADSHARETH and MPULOADDIFFTH are 40% and 10%, respectively.

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Flow Control 8 Engineering Guidelines



7-1

8 Engineering Guidelines

8.1 Queue-based RRC Shaping

8.1.1 When to Use Queue-based RRC Shaping

During mass gatherings, CPU usage soars and fluctuates with changes in traffic volume. When CPU usage exceeds the critical threshold (90%), the RRC and RAB setup success rates decrease. In this case, enable queue-based RRC shaping, which stabilizes the influx of RRC connection requests into the system. This stabilizes the CPU usage and increases RRC and RAB setup success rates.

Enable queue-based RRC shaping ahead of mass gatherings. At the same time, increase the values of the parameters for flow control functions that affect the CPU usage.

To enable it, run the command SET UCACALGOSWITCH (CME single configuration: UMTS Radio Global Configuration Express > CAC Algorithm Switch Configuration > CAC Algorithm Switch; CME batch modification center: Modifying RNC Parameters in Batches) with the RsvdPara1 parameter set to RSVDBIT14.

8.1.2 Configuration Principles and Suggestions

Once queue-based RRC shaping is enabled, the load-sharing threshold and the parameters for other flow control functions that affect the CPU usage (such as CAPS control) need to be adjusted. Contact Huawei technical support to determine a detailed plan.

8.2 Queue-based Cell Update Request Shaping

8.2.1 When to Use Queue-based Cell Update Request Shaping

It is recommended that queue-based cell update request shaping be enabled for large-scale gatherings such as parades and major sports events.

In the following situations, it is also recommended that queue-based cell update request shaping be enabled:

The switch for PS services to transit to the CELL_PCH state is set to ON.

To check whether the switch is set to ON, run the LST UUESTATETRANSTIMER to check the BeF2PStateTransTimer parameter or LST URRCTRLSWITCH command to check the RsvdPara1 parameter. If the value of the BeF2PStateTransTimer parameter is not 65535 or the value of the RsvdPara1 parameter is RSVDBIT1_BIT29-1, the switch is set to ON.

The value of the counter VS.AttCellUpdt, which indicates the number of cell update attempts, is greater than or equal to the value of the counter VS.RRC.AttConnEstab.Sum, which indicates the number of attempts to set up RRC connections.

The value of the counter VS.XPU.CPULOAD.MEAN, which indicates the CPU usage, has exceeded the fatal threshold 90%.

These situations result from a heavy presence of smartphones that impact the CPU. The RAB setup success rate drops when the CPU usage has exceeded the fatal threshold. In this situation, enable queue-based cell update request shaping to ensure that cell update requests slowly and steadily arrive at the RNC, stabilizing the CPU usage and increasing the RAB setup success rate.

To enable it, run the command SET UCACALGOSWITCH (CME single configuration: UMTS Radio Global Configuration Express > CAC Algorithm Switch Configuration > CAC Algorithm Switch; CME batch modification center: Modifying RNC Parameters in Batches) with the FlowCtrlSwitch parameter set to CELL_UPDATE_QUEUE_FLOW_CTRL_SWITCH-1.

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Flow Control 8 Engineering Guidelines



7-2


If queue-based cell update request shaping is enabled, the values of certain other flow control parameters related to the CPU usage need to be raised. Contact Huawei technical support for a detailed solution.

8.3 DCCC Flow Control

8.3.1 When to Use DCCC Flow Control

If the CPU usage of the CPUS is still above 90% when the flow control functions related to RRC and cell update requests are enabled, the UE reconfiguration procedure is triggered too frequently, consuming a large amount of CPU resources. In this case, it is recommended that DCCC flow control be enabled by running the command SET FCSW (CME single configuration: UMTS Radio Global Configuration Express > Flow Control Management > Flow Control Switch; CME batch modification center: Modifying RNC Parameters in Batches) with the DCCCSW parameter set to ON.

To learn about the CPU usage of the CPUS, check the value of the counter VS.XPU.CPULOAD.MEAN.


The default values are recommended for DCCC flow control thresholds.

8.4 CAPS Control

8.4.1 Factors That Affect CAPS Control

The effect of CAPS control depends on the accuracy of the estimation of the allowed number of RRC connection requests in the cell. If the allowed number of RRC connection requests is too large, CAPS control cannot yield noticeable effects. If the allowed number of RRC connection requests is too small, resources may not be fully utilized. The SET UCALLSHOCKCTRL command configures the allowed number of RRC connection requests per second in a cell. Contact Huawei technical support to adjust this number.


Check the value of VS.RRC.AttConnEstab.Sum. If the value is significantly higher than it was on the same day last week and the service setup success rate is low, it is recommended that CAPS control be enabled by running the command SET UCALLSHOCKCTRL (CME single configuration: UMTS Radio Global Configuration Express > Traffic Volume Control Parameter Configuration > Call Shock Control Parameters; CME batch modification center: Modifying RNC Parameters in Batches) with the CallShockCtrlSwitch parameter set to CELL_LEVEL.

CS service setup success rate = (VS.RAB.SuccEstabCS.Conv + VS.RAB.SuccEstabCS.Str)/(VS.RAB.AttEstabCS.Conv + VS.RAB.AttEstabCS.Str)

PS service setup success rate = (VS.RAB.SuccEstabPS.Conv + VS.RAB.SuccEstabPS.Str + VS.RAB.SuccEstabPS.Int + VS.RAB.SuccEstabPS.Bkg)/(VS.RAB.AttEstabPS.Conv + VS.RAB.AttEstabPS.Str + VS.RAB.AttEstabPS.Int + VS.RAB.AttEstabPS.Bkg)

8.4.3 Performance Optimization

Check the service-setup success rate of the cell. If the service-setup success rate is low, run the SET UCALLSHOCKCTRL command to reduce the allowed number of RRC connection requests per second in the cell. The minimum number is 2. If the service-setup success rate is high, run the SET UCALLSHOCKCTRL command.






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Flow Control 9 Parameters



7-1

9 Parameters

Table 9-1 Parameter description

Parameter ID NE MML Command Feature ID Feature Name Description

BeF2PStateTransTimer

BSC6900 SET UUESTATETRANSTIMER

WRFD-010202

UE State in Connected Mode (CELL-DCH, CELL-PCH, URA-PCH, CELL-FACH)

Meaning:Timer for state transition from FACH or E_FACH to PCH of BE services, used to check whether the UE in the CELL_FACH state is in the stable low activity state.

GUI Value Range:1~65535

Actual Value Range:1~65535

Unit:s

Default Value:65535

CacSwitch BSC6900 SET UCACALGOSWITCH

WRFD-020101

Admission Control

Meaning:1. NODEB_CREDIT_CAC_SWITCH: The system performs CAC based on the usage state of NodeB credit. When the NodeB's credit is not enough, the system rejects new access requests.

2. FACH_60_USER_SWITCH (Switch for Allowing a Maximum of 60 UEs Carried on the FACH): Whether a maximum of 60 or 30 UEs can be carried on the FACH. When this switch is turned on, a maximum of 60 UEs can be carried on the FACH. When this switch is turned off, a maximum of 30 UEs can be carried on the FACH.

GUI Value Range:NODEB_CREDIT_CAC_SWITCH(NodeB Credit CAC Switch), FACH_60_USER_SWITCH(FACH Allowed Max 60 Users Switch)

Actual Value Range:NODEB_CREDIT_CAC_SWITCH, FACH_60_USER_SWITCH



../RNCParaHtml/mbsc/m-mml/set-uuestatetranstimer.html




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Unit:None

Default Value:NODEB_CREDIT_CAC_SWITCH-1&FACH_60_USER_SWITCH-0

CallShockCtrlSwitch

BSC6900 SET UCALLSHOCKCTRL

WRFD-040100

Flow Control Meaning:The parameter specifies whether to perform Call Attempt Per Second (CAPS) control for the number of RRC connection establishments at SPU subsystem level, NodeB level, or cell level.

SYS_LEVEL indicates that the BSC6900 will perform flow control for the RRC connection requests at SPU subsystem level.

NODEB_LEVEL indicates that the BSC6900 will perform flow control for the RRC connection requests at NodeB level.

CELL_LEVEL indicates that the BSC6900 will perform flow control for the RRC connection requests at cell level.

SYS_LEVEL_DYNAMIC: the RNC compares the current CPU usage on an SPU subsystem with the target CPU usage and adjusts the CAPS on the SPU subsystem every second based on the comparison results.

GUI Value Range:SYS_LEVEL(SYS_LEVEL), NODEB_LEVEL(NODEB_LEVEL), CELL_LEVEL(CELL_LEVEL), SYS_LEVEL_DYNAMIC(SYS_LEVEL_DYNAMIC)

Actual Value Range:SYS_LEVEL, NODEB_LEVEL,



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CELL_LEVEL, SYS_LEVEL_DYNAMIC

Unit:None

Default Value:SYS_LEVEL-1&NODEB_LEVEL-1&CELL_LEVEL-1&SYS_LEVEL_DYNAMIC-1

CallShockJudgePeriod


WRFD-040100

Flow Control Meaning:The parameter specifies the period of entering flow control at SPU subsystem level, NodeB level, or cell level.

In the period, if the number of RRC connection requests that the SPU subsystem, NodeB, or cell receives exceed relative trigger threshold (the threshold can be set by "SysTotalRrcNumThd", "NBTotalRrcNumThd", or "CellTotalRrcNumThd"), BSC6900 will perform flow control for the RRC establishment request.

GUI Value Range:1~5


Unit:s

Default Value:3

CBSSW BSC6900 SET FCSW WRFD-040100

Flow Control Meaning:Whether to control CBS flow

GUI Value Range:ON, OFF

Actual Value Range:ON, OFF

Unit:None

Default Value:ON

CCCHCongClearThd

BSC6900 SET UDPUCFGDATA

None None Meaning:FACH CCCH congestion clearance threshold. If the duration to buffer data packets on the MACC CCCH is shorter than this threshold, the MACC reports a CCCH congestion clearance indication to L3.






../RNCParaHtml/mbsc/m-para/fcsw_cbssw.html

../RNCParaHtml/mbsc/m-mml/set-fcsw.html



../RNCParaHtml/mbsc/m-mml/set-udpucfgdata.html


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The parameter is in the unit of TTI.

This parameter is an advanced parameter. To modify this parameter, contact Huawei Customer Service Center for technical support.



Unit:None

Default Value:30

CCCHCongThd


None None Meaning:FACH CCCH congestion threshold. If the duration to buffer data packets on the MACC CCCH reaches this threshold, the MACC reports a CCCH congestion indication to L3. The parameter is in the unit of TTI.




Unit:None

Default Value:60

CellAmrRrcNum


WRFD-040100

Flow Control Meaning:The parameter specifies the number of RRC connection requests per second for originating conversational call at cell level.

This parameter is configurable in the current version. The RNC, however, does not use this parameter any longer. Later versions will not support this parameter. Therefore, users are not advised to use this parameter.










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7-5




Unit:None

Default Value:15

CellHighPriRrcNum


WRFD-040100

Flow Control Meaning:The parameter specifies the number of RRC connection requests per second for registration and inter-RAT cell reselection at cell level.

This parameter is configurable in the current version. The RNC, however, does not use this parameter any longer. Later versions will not support this parameter. Therefore, users are not advised to use this parameter.



Unit:None

Default Value:15

CELLKPITOCAPS

BSC6900 ADD UCELLFCALGOPARA

MOD UCELLFCALGOPARA

WRFD-020103

Inter Frequency Load Balance

Meaning:Whether to activate the cell-level dynamic CAPS flow control algorithm based on the ratio of RRC connection setup failures. When the switch is turned on, flow control is triggered if the ratio of RRC connection setup failures is higher than or equal to the value of "RejectKPICTHD"; flow control is stopped if the ratio of RRC connection setup failures is lower than or equal to the value of "RejectKPIRTHD". When flow control is triggered, the number of allowed RRC connection requests per second in the cell decreases based on the value of "KPIstepdownpercentage". When flow control is stopped,








../RNCParaHtml/mbsc/m-mml/add-ucellfcalgopara.html



../RNCParaHtml/mbsc/m-mml/mod-ucellfcalgopara.html



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the number of allowed RRC connection requests per second in the cell increases based on the value of "KPIstepuppercentage". The number of RRC connection requests does not change once the cell flow control status becomes stable.



Unit:None

Default Value:OFF

CellTotalRrcNumThd


WRFD-040100

Flow Control Meaning:The parameter specifies the threshold of entering flow control for RRC connection requests at cell level.

During the call shock judgment period (CallShockJudgePeriod), when the number of RRC connection requests exceed the value of the parameter, BSC6900 will perform flow control.

The flow control strategies for RRC connection requests are as follows:

If the originating interactive call, originating background call, or originating streaming call causes the RRC connection requests, BSC6900 will perform flow control directly.

If the number of admitted RRC connection requests for registration and inter-RAT cell reselection exceeds the value of "CellHighPriRrcNum", BSC6900 will perform flow control.

If the number of admitted RRC connection requests for AMR exceeds the value of






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7-7


"CellAmrRrcNum", BSC6900 will perform flow control.

If other services cause RRC connection requests, BSC6900 will not perform flow control.



Unit:None

Default Value:45

CELLURACTHD

BSC6900 SET FCMSGQTHD

WRFD-040100

Flow Control Meaning:Packet queue usage threshold for cell update flow control. When the average packet usage within several sliding windows reaches or exceeds "Cell URA update restore threshold", linear flow control is started on cell updates. When the average packet usage within several sliding windows reaches or exceeds "Cell URA update control threshold", 100% flow control is started on cell updates.



Unit:%

Default Value:95

CELLURACTHD

BSC6900 SET FCCPUTHD WRFD-040100

Flow Control Meaning:Threshold for triggering 100% flow control on high-priority CELL_UPDATE messages. When the average CPU usage in a sliding window reaches or exceeds the value of "Rst Thd for High-Pri Message Flow Ctrl", a linear flow control on the CELL_UPDATE messages is started. When the average CPU usage in a sliding window reaches or exceeds the value of "Ctrl Thd for High-Pri Message Flow Ctrl",



../RNCParaHtml/mbsc/m-mml/set-fcmsgqthd.html




../RNCParaHtml/mbsc/m-mml/set-fccputhd.html

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100% flow control is performed so that all CELL_UPDATE messages are discarded.When the CPU becomes overloaded, the recommended value for this parameter is 95.



Unit:%

Default Value:85

CELLURARTHD

BSC6900 SET FCMSGQTHD

WRFD-040100

Flow Control Meaning:Packet queue usage threshold for cell update control. When the average packet usage within several sliding windows reaches or exceeds "Cell URA update restore threshold", linear flow control is started on cell updates. When the average packet usage within several sliding windows is lower than "Cell URA update restore threshold", cell update control is stopped.



Unit:%

Default Value:80

CELLURARTHD


Flow Control Meaning:Threshold for canceling flow control on high-priority CELL_UPDATE messages. When the average CPU usage in a sliding window reaches or exceeds the value of "Rst Thd for High-Pri Message Flow Ctrl", a linear flow control on the CELL_UPDATE messages is started. When the average CPU usage in a sliding window falls below the value of "Rst Thd for High-Pri Message Flow Ctrl", flow control on the CELL_UPDATE








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messages is stopped.When the CPU becomes overloaded, the recommended value for this parameter is 85.



Unit:%

Default Value:75

CELLURASW BSC6900 SET FCSW WRFD-040100

Flow Control Meaning:Whether to control cell updates



Unit:None

Default Value:ON

CELLURAUPDATERSTTHDFORLOW


Flow Control Meaning:Threshold for canceling flow control on low-priority CELL_UPDATE messages. When the average CPU usage in a sliding window reaches or exceeds the value of "Rst Thd for Low-Pri Message Flow Ctrl", a linear flow control on the CELL_UPDATE messages is started. When the average CPU usage in a sliding window falls below the value of "Rst Thd for Low-Pri Message Flow Ctrl", flow control on the CELL_UPDATE messages is stopped.When the CPU becomes overloaded, the recommended value for this parameter is 75.



Unit:%

Default Value:65

CELLURAUP BSC6900 SET FCCPUTHD WRFD-040 Flow Control Meaning:Threshold for

../RNCParaHtml/mbsc/m-para/fcsw_cellurasw.html








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7-10


DATERSTTHDFORMID

100 canceling flow control on medium-priority CELL_UPDATE messages. When the average CPU usage in a sliding window reaches or exceeds the value of "Rst Thd for Mid-Pri Message Flow Ctrl", a linear flow control on the CELL_UPDATE messages is started. When the average CPU usage in a sliding window falls below the value of "Rst Thd for Mid-Pri Message Flow Ctrl", flow control on the CELL_UPDATE messages is stopped.When the CPU becomes overloaded, the recommended value for this parameter is 80.



Unit:%

Default Value:70

CELLURAUPDATETHDFORLOW


Flow Control Meaning:Threshold for triggering 100% flow control on low-priority CELL_UPDATE messages. When the average CPU usage in a sliding window reaches or exceeds the value of "Rst Thd for Low-Pri Message Flow Ctrl", a linear flow control on the CELL_UPDATE messages is started. When the average CPU usage in a sliding window reaches or exceeds the value of "Ctrl Thd for Low-Pri Message Flow Ctrl", 100% flow control is performed so that all CELL_UPDATE messages are discarded.When the CPU becomes overloaded, the recommended value for this parameter is 85.





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Unit:%

Default Value:75

CELLURAUPDATETHDFORMID


Flow Control Meaning:Threshold for triggering 100% flow control on medium-priority CELL_UPDATE messages. When the average CPU usage in a sliding window reaches or exceeds the value of "Rst Thd for Mid-Pri Message Flow Ctrl", a linear flow control on the CELL_UPDATE messages is started. When the average CPU usage in a sliding window reaches or exceeds the value of "Ctrl Thd for Mid-Pri Message Flow Ctrl", 100% flow control is performed so that all CELL_UPDATE messages are discarded.When the CPU becomes overloaded, the recommended value for this parameter is 90.



Unit:%

Default Value:80

CmpSwitch BSC6900 SET UCORRMALGOSWITCH

WRFD-01061006

WRFD-01061204

WRFD-020202

WRFD-020203

WRFD-021200

WRFD-010

HSDPA Mobility Management

HSUPA Mobility Management

Intra RNC Soft Handover

Inter RNC Soft Handover

HCS (Hierarchical Cell Structure)

Meaning:1. CMP_IU_IMS_PROC_AS_NORMAL_PS_SWITCH: When the switch is on, the IMS signaling assigned by the CN undergoes compatibility processing as an ordinary PS service. When the switch is not on, no special processing is performed.

2. CMP_IU_QOS_ASYMMETRY_IND_COMPAT_SWITCH: When the Iu QoS Negotiation





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7-12


696

WRFD-010202

DC-HSDPA


function is active and the switch is on, IE RAB Asymmetry Indicator is Symmetric bidirectional, The uplink and downlink "BSC6900" negotiation rate is asymmetric, "BSC6900" select the bigger rate as Iu QoS negotiation rate. When the switch is OFF, "BSC6900" select the less rate as Iu QoS negotiation rate.

3. CMP_IU_SYSHOIN_CMP_IUUP_FIXTO1_SWITCH: When the switch is on, the IUUP version can be rolled back to R99 when complete configurations are applied during inter-RAT handover.

4. CMP_IUR_H2D_FOR_LOWR5_NRNCCELL_SWITCH: When the switch is on, H2D is performed before a neighboring "BSC6900" cell whose version is earlier than R5 is added to the active set; E2D is performed before a neighboring "BSC6900" cell whose version is earlier than R6 is added to the active set. If the DRNC is of a version earlier than R5, DL services cannot be mapped on the HS-DSCH. If the DRNC is of a version earlier than R6, DL services cannot be mapped on the HS-EDCH.

5. CMP_IUR_SHO_DIVCTRL_SWITCH: When the switch is on, the diversity combination over the Iur interface is configured on the basis of that of the local "BSC6900". When the switch is not on, the diversity combination over the Iur interface is configured on the basis of services. The flag of diversity combination over

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7-13


the Iur interface can be set to MUST (for BE services) or MAY (for other services).

6. CMP_UU_ADJACENT_FREQ_CM_SWITCH: when the switch is on, the "BSC6900" initiates the inter-frequency measurement without activating the compressed mode if the following two conditions are met: the UE supports the non-compressed inter-frequency measurement, the inter-frequency neighboring cells work in a same frequency which is within 5 MHz higher or lower than the current frequency; when the switch is off, the "BSC6900" activates the compressed mode before initiating the inter-frequency measurement.

7. CMP_UU_AMR_DRD_HHO_COMPAT_SWITCH: This parameter specifies to enable AMR through DRD two-step procedure function. When SRB is set up on DCH, and "BSC6900" decides to setup the AMR through DRD procedure, When the switch is enabled, "BSC6900" will execute blind handover to the target cell, and then setup the AMR RBs on the target cell, When the switch is disabled, "BSC6900" will setup the AMR RBs on the target cell directly.

8. CMP_UU_AMR_SID_MUST_CFG_SWITCH: For narrowband AMR services, when the switch is on, the SID frame is always configured; when the switch is not on, the SID frame is configured on the basis of CN assignment.

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7-14


9. CMP_UU_FDPCH_COMPAT_SWITCH: When the switch is OFF, if the information element that indicates the F-DPCH capability of UE exists in the message "RRC_CONNECT_REQ" or "RRC_CONNECT_SETUP_CMP", the F-DPCH capability depends on that indicator. In other case, it means UE does not support F-DPCH. When the switch is ON, if the information element that indicates the F-DPCH capability of UE exists in the message "RRC_CONNECT_REQ" or "RRC_CONNECT_SETUP_CMP", the F-DPCH capability depends on that indicator. If that information element does not exist, UE supports F-DPCH when all the conditions meets: a) the version of UE is Release 6. b) UE supports HS-PDSCH.

10. CMP_UU_IGNORE_UE_RLC_CAP_SWITCH: When the switch is on, the RAB assignment request and the subsequent RB setup procedure proceed if the RLC AM capabilities of the UE fail to meet the minimum RLC TX/RX window buffer requirement of the RAB to be setup. When the switch is not on, the RAB assignment request is rejected.

11. CMP_UU_INTRA_FREQ_MC_BESTCELL_CIO_SWITCH: When this switch is on, the cell individual offset (CIO) of the best cell is always set to 0 in the INTRA-FREQUENCY MEASUREMENT CONTROL messages. Otherwise, the CIO information of the best

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7-15


cell is not carried in the INTRA-FREQUENCY MEASUREMENT CONTROL messages.

12. CMP_UU_IOS_CELL_SYNC_INFO_REPORT_SWITCH: When the switch is on, the cell synchronization information traced by the IOS need to be reported during the RRC measurement period.

13. CMP_UU_SERV_CELL_CHG_WITH_ASU_SWITCH: When the switch is on, the active set update is in the same procedure as the change of the serving cell. When the switch is not on, the serving cell is changed after the UE updates the active set and delivers reconfiguration of physical channels. This switch is applicable only to R6 or above UEs.

14. CMP_UU_SERV_CELL_CHG_WITH_RB_MOD_SWITCH: When the switch is on, channel transition is in the same procedure as the change of the serving cell. When the switch is not on, the serving cell is changed after the UE performs channel transition and delivers reconfiguration of physical channels.

15. CMP_UU_VOIP_UP_PROC_AS_NORMAL_PS_SWITCH: By default, the switch is on. In this case, the Alternative E-bit is not configured for L2.

16. CMP_F2F_RLC_ONESIDE_REBUILD_SWITCH: When the switch is set to ON, only uplink RLC or downlink RLC

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7-16


can be re-established during the state transition from CELL_FACH to CELL_FACH (F2F for short).

17. CMP_D2F_RLC_ONESIDE_REBUILD_SWITCH: When the switch is set to ON, only uplink RLC or downlink RLC can be re-established during the state transition from CELL_DCH to CELL_FACH (D2F for short).

18. CMP_RAB_5_CFG_ROHC_SWITCH: When the switch is set to ON, the service with RAB ID 5 can be configured with the Robust Header Compression (ROHC) function. When the switch is set to OFF, the service with RAB ID 5 cannot be configured with the ROHC function.

19. CMP_RAB_6_CFG_ROHC_SWITCH: When the switch is set to ON, the service with RAB ID 6 can be configured with the ROHC function. When the switch is set to OFF, the service with RAB ID 6 cannot be configured with the ROHC function.


21. CMP_RAB_8_CFG_ROHC_SWITCH: When the switch is set to ON, the service with RAB ID 8 can be configured

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7-17


with the ROHC function. When the switch is set to OFF, the service with RAB ID 8 cannot be configured with the ROHC function.


23. CMP_HSUPA_MACD_FLOW_MUL_SWITCH: When the switch is set to ON, MAC-d flow can be multiplexed without any restrictions. When the switch is set to OFF, only MAC-d flows whose scheduling priority is lower than that of the current MAC-d flow can be multiplexed.

24. CMP_SMLC_RSLT_MODE_TYPE_SWITCH: If the Client Type of a positioning request is Value Added Service or Lawful Intercept Client, the positioning result is reported by using the Ellipsoid Arc type. For other client types, the positioning result is reported by using the Ellipsoid point with uncertainty circle type.

25. CMP_F2P_PROCESS_OPTIMIZATION_SWITCH: Switch for optimizing the procedure for the CELL_FACH-to-CELL_PCH-or-URA_PCH state transition. When this switch is turned on, the algorithm for optimizing the procedure for the CELL_FACH-to-CELL_PCH-or-URA_PCH state transition is

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7-18


activated.

26. CMP_UU_SIB11_SIB12_WITH_1A1D_SWITCH: Whether to carry parameters related to events 1A and 1D in system information block type 11 (SIB 11) and SIB 12.

GUI Value Range:CMP_IU_IMS_PROC_AS_NORMAL_PS_SWITCH, CMP_IU_QOS_ASYMMETRY_IND_COMPAT_SWITCH, CMP_IU_SYSHOIN_CMP_IUUP_FIXTO1_SWITCH, CMP_IUR_H2D_FOR_LOWR5_NRNCCELL_SWITCH, CMP_IUR_SHO_DIVCTRL_SWITCH, CMP_UU_ADJACENT_FREQ_CM_SWITCH, CMP_UU_AMR_DRD_HHO_COMPAT_SWITCH, CMP_UU_AMR_SID_MUST_CFG_SWITCH, CMP_UU_FDPCH_COMPAT_SWITCH, CMP_UU_IGNORE_UE_RLC_CAP_SWITCH, CMP_UU_INTRA_FREQ_MC_BESTCELL_CIO_SWITCH, CMP_UU_IOS_CELL_SYNC_INFO_REPORT_SWITCH, CMP_UU_SERV_CELL_CHG_WITH_ASU_SWITCH, CMP_UU_SERV_CELL_CHG_WITH_RB_MOD_SWITCH, CMP_UU_VOIP_UP_PROC_AS_NORMAL_PS_SWITCH, CMP_F2P_PROCESS_OPTIMIZATION_SWITCH, CMP_UU_SIB11_SIB12_WITH_1A1D_SWITCH, CMP_F2F_RLC_ONESIDE_REBUILD_SWITCH, CMP_D2F_RLC_ONESIDE_REBUILD_SWITCH, CMP_RAB_5_CFG_ROHC_SWITCH, CMP_RAB_6_CFG_ROHC_SWITCH, CMP_RAB_7_CFG_ROHC_S

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WITCH, CMP_RAB_8_CFG_ROHC_SWITCH, CMP_RAB_9_CFG_ROHC_SWITCH, CMP_HSUPA_MACD_FLOW_MUL_SWITCH, CMP_SMLC_RSLT_MODE_TYPE_SWITCH

Actual Value Range:CMP_IU_IMS_PROC_AS_NORMAL_PS_SWITCH, CMP_IU_QOS_ASYMMETRY_IND_COMPAT_SWITCH, CMP_IU_SYSHOIN_CMP_IUUP_FIXTO1_SWITCH, CMP_IUR_H2D_FOR_LOWR5_NRNCCELL_SWITCH, CMP_IUR_SHO_DIVCTRL_SWITCH, CMP_UU_ADJACENT_FREQ_CM_SWITCH, CMP_UU_AMR_DRD_HHO_COMPAT_SWITCH, CMP_UU_AMR_SID_MUST_CFG_SWITCH, CMP_UU_FDPCH_COMPAT_SWITCH, CMP_UU_IGNORE_UE_RLC_CAP_SWITCH, CMP_UU_INTRA_FREQ_MC_BESTCELL_CIO_SWITCH, CMP_UU_IOS_CELL_SYNC_INFO_REPORT_SWITCH, CMP_UU_SERV_CELL_CHG_WITH_ASU_SWITCH, CMP_UU_SERV_CELL_CHG_WITH_RB_MOD_SWITCH, CMP_UU_VOIP_UP_PROC_AS_NORMAL_PS_SWITCH, CMP_F2F_RLC_ONESIDE_REBUILD_SWITCH, CMP_D2F_RLC_ONESIDE_REBUILD_SWITCH, CMP_RAB_5_CFG_ROHC_SWITCH, CMP_RAB_6_CFG_ROHC_SWITCH, CMP_RAB_7_CFG_ROHC_SWITCH, CMP_RAB_8_CFG_ROHC_SWITCH, CMP_RAB_9_CFG_ROHC_S

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7-20


WITCH, CMP_HSUPA_MACD_FLOW_MUL_SWITCH, CMP_SMLC_RSLT_MODE_TYPE_SWITCH, CMP_F2P_PROCESS_OPTIMIZATION_SWITCH, CMP_UU_SIB11_SIB12_WITH_1A1D_SWITCH

Unit:None

Default Value:CMP_IU_IMS_PROC_AS_NORMAL_PS_SWITCH-0&CMP_IU_QOS_ASYMMETRY_IND_COMPAT_SWITCH-0&CMP_IU_SYSHOIN_CMP_IUUP_FIXTO1_SWITCH-0&CMP_IUR_H2D_FOR_LOWR5_NRNCCELL_SWITCH-0&CMP_IUR_SHO_DIVCTRL_SWITCH-0&CMP_UU_ADJACENT_FREQ_CM_SWITCH-0&CMP_UU_AMR_DRD_HHO_COMPAT_SWITCH-1&CMP_UU_AMR_SID_MUST_CFG_SWITCH-0&CMP_UU_FDPCH_COMPAT_SWITCH-0&CMP_UU_IGNORE_UE_RLC_CAP_SWITCH-1&CMP_UU_INTRA_FREQ_MC_BESTCELL_CIO_SWITCH-0&CMP_UU_IOS_CELL_SYNC_INFO_REPORT_SWITCH-0&CMP_UU_SERV_CELL_CHG_WITH_ASU_SWITCH-0&CMP_UU_SERV_CELL_CHG_WITH_RB_MOD_SWITCH-1&CMP_UU_VOIP_UP_PROC_AS_NORMAL_PS_SWITCH-1&CMP_F2P_PROCESS_OPTIMIZATION_SWITCH-0&CMP_UU_SIB11_SIB12_WITH_1A1D_SWITCH-0&CMP_F2F_RLC_ONESIDE_REBUILD_SWITCH-0&CMP_D2F_RLC_ONESIDE_REBUILD_SWITCH-0&CMP_RAB_5_CFG_ROHC_SWITCH-0&CMP_RAB_6_CFG_ROHC_SWITCH-0&CMP_RAB_7_CFG_ROHC_SWITCH-0&CMP_RAB_8_CFG_ROHC_SWITCH-0&CMP_RAB_

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9_CFG_ROHC_SWITCH-0&CMP_HSUPA_MACD_FLOW_MUL_SWITCH-0&CMP_SMLC_RSLT_MODE_TYPE_SWITCH-0

CPAGECTHD BSC6900 SET FCCPUTHD WRFD-040100

Flow Control Meaning:CPU usage threshold for paging flow control over real-time services. BE services uses the same paging flow control thresholds as SS and LCS to ensure the paging success rate of real-time services. When the average CPU usage within several sliding windows reaches or exceeds "Call page restore threshold", the linear paging flow control on real-time services is started. When the average CPU usage within several sliding windows reaches or exceeds "Call page control threshold", the 100% paging flow control on real-time services is started.



Unit:%

Default Value:90

CPAGERTHD BSC6900 SET FCCPUTHD WRFD-040100

Flow Control Meaning:CPU usage threshold for paging control over real-time services. BE services uses the same paging flow control thresholds as SS and LCS to ensure the paging success rate of real-time services. When the average CPU usage within several sliding windows reaches or exceeds "Call page restore threshold", the linear paging flow control on real-time services is started. When the average CPU usage within several sliding windows is lower than "Call page restore threshold",

../RNCParaHtml/mbsc/m-para/fccputhd_cpagecthd.html


../RNCParaHtml/mbsc/m-para/fccputhd_cpagerthd.html


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paging control over real-time services is stopped.When the CPU becomes overloaded, the recommended value for this parameter is 85.



Unit:%

Default Value:75

CREFCongFc BSC6900 SET TNSOFTPARA

None None Meaning:Whether to enable Connection Refused (CREF) congestion flow control. If this switch is turned on, flow control is started automatically if the SCCP receives a CREF frame with a rejection cause of congestion.

GUI Value Range:OFF(OFF), ON(ON)

Actual Value Range:OFF, ON

Unit:None

Default Value:ON(ON)

CRRCCONNCCPUTHD

BSC6900 SET SHARETHD MRFD-210101

System Redundancy

Meaning:CPU usage threshold for stopping load sharing on call service RRC connection setup requests. When the CPU usage of an XPU subsystem reaches this threshold or CtrlPlnSharingOutThd, whichever is smaller, later call service RRC connection setup requests will be carried by other XPU subsystems. CtrlPlnSharingOutThd is set by using the command "SET UCTRLPLNSHAREPARA". If the CPU usage of all candidate XPU subsystems exceeds this threshold, flow control on call service RRC connection setup requests is triggered. The parameter value is invalid if the SYS_LEVEL_DYNAMIC

../RNCParaHtml/mbsc/m-para/tnsoftpara_crefcongfc.html

../RNCParaHtml/mbsc/m-mml/set-tnsoftpara.html




../RNCParaHtml/mbsc/m-mml/set-sharethd.html

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switch in the "CallShockCtrlSwitch" parameter of the "SET UCALLSHOCKCTRL" command is turned on.



Unit:%

Default Value:85

CRRCCONNCMSGTHD


System Redundancy

Meaning:Packet usage threshold for stopping load sharing on call service RRC connection setup requests. When the packet usage of an XPU subsystem reaches this threshold, later call service packets will be carried by other XPU subsystems. If the packet usage of all candidate XPU subsystems exceeds this threshold, flow control on call service RRC connection setup request packets is triggered.



Unit:%

Default Value:75

CRRCCONNRCPUTHD


System Redundancy

Meaning:CPU usage threshold for recoverying load sharing on call service RRC connection setup requests. If the CPU usage of an XPU subsystem is lower than this threshold, this XPU subsystem is the candidate subsystem for the load sharing on call service RRC connection setup requests. The parameter value is invalid if the SYS_LEVEL_DYNAMIC switch in the "CallShockCtrlSwitch" parameter of the "SET UCALLSHOCKCTRL" command is turned on.







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Unit:%

Default Value:75

CRRCCONNRMSGTHD


System Redundancy

Meaning:Packet usage threshold for recoverying load sharing on call service RRC connection setup requests. When the packet usage of an XPU subsystem is lower than this threshold, this XPU subsystem is a candidate subsystem for load sharing on call service RRC connection setup requests.



Unit:%

Default Value:65

CTHD BSC6900 SET FCCPUTHD GBFD-111705

WRFD-040100

GSM Flow Control

Flow Control

Meaning:Critical threshold for CPU usage. When all the CPU usages in "fast judgement window" reach or exceed this threshold, all active flow control mechanisms start to work immediately. Otherwise, the corresponding flow control mechanism is used.



Unit:%

Default Value:95

CTHD BSC6900 SET FCMSGQTHD

GBFD-111705

WRFD-040100

GSM Flow Control

Flow Control

Meaning:Critical threshold of packet queue usage. When the packet queue usage reaches or exceeds the threshold, all active flow control functions are implemented.





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Unit:%

Default Value:95

CtrlPlnSharingOutOffset

BSC6900 SET UCTRLPLNSHAREPARA

WRFD-020120

Service Steering and Load Sharing in RRC Connection Setup

Meaning:The sharing offset should be added to the target subrack. This parameter is used for preferable selection of the homing subrack during call forwarding.


Actual Value Range:0.01~0.1

Unit:%

Default Value:5

CtrlPlnSharingOutThd


WRFD-020120


Meaning:Forwarding threshold of control plane load sharing. When the CPU usage is between the sharing threshold and overload threshold, and call number in each second reaches "Sharing out capability middle load", new arrival call attempts will be shared out to other SPU subsystem.



Unit:%

Default Value:50

DCCCSW BSC6900 SET FCSW WRFD-040100

Flow Control Meaning:Whether to enable flow control on the Dynamic Channel Configuration Control (DCCC) procedure. When this parameter is set to ON, the flow control is enabled. When this parameter is set to OFF, the flow control is disabled.

GUI Value Range:OFF, ON


Unit:None



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Default Value:OFF

DraSwitch BSC6900 SET UCORRMALGOSWITCH

WRFD-01061111

WRFD-01061208

WRFD-01061404

WRFD-011502

WRFD-021101

WRFD-050405

WRFD-050408

WRFD-010690

WRFD-01061403

WRFD-010202

HSDPA State Transition

HSUPA DCCC

HSUPA 2ms/10ms TTI Handover

Active Queue Management (AQM)

Dynamic Channel Configuration Control (DCCC)

Overbooking on ATM Transmission

Overbooking on IP Transmission

TTI Switch for BE Services Based on Coverage

HSUPA 2ms TTI


Meaning:Dynamic resource allocation switch group.

1. DRA_AQM_SWITCH: When the switch is on, the active queue management algorithm is used for the BSC6900.

2. DRA_BASE_ADM_CE_BE_TTI_L2_OPT_SWITCH: When the switch is on, the TTI dynamic adjustment algorithm for admission CE-based BE services applies to the UE with the UL enhanced L2 feature. This parameter is valid when DRA_BASE_ADM_CE_BE_TTI_RECFG_SWITCH(DraSwitch) is set to ON.

3. DRA_BASE_ADM_CE_BE_TTI_RECFG_SWITCH: When the switch is on, the TTI dynamic adjustment algorithm is supported for admission CE-based BE services.

4. DRA_BASE_COVER_BE_TTI_L2_OPT_SWITCH: When the switch is on, the TTI dynamic adjustment algorithm for coverage-based BE services applies to the UE with the UL enhanced L2 feature. This parameter is valid when DRA_BASE_COVER_BE_TTI_RECFG_SWITCH(DraSwitch) is set to ON.

5. DRA_BASE_COVER_BE_TTI_RECFG_SWITCH: When the switch is on, the TTI dynamic adjustment algorithm is supported for coverage-based BE services.





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6. DRA_BASE_RES_BE_TTI_L2_OPT_SWITCH: When the switch is on, the TTI dynamic adjustment algorithm for differentiation-based BE services applies to the UE with the UL enhanced L2 feature. This parameter is valid when DRA_BASE_RES_BE_TTI_RECFG_SWITCH(DraSwitch) is set to ON.

7. DRA_BASE_RES_BE_TTI_RECFG_SWITCH: When the switch is on, the TTI dynamic adjustment algorithm is supported for differentiation-based BE services.

8. DRA_DCCC_SWITCH: When the switch is on, the dynamic channel reconfiguration control algorithm is used for the BSC6900.

9. DRA_HSDPA_DL_FLOW_CONTROL_SWITCH: When the switch is on, flow control is enabled for HSDPA services in AM mode.

10. DRA_HSDPA_STATE_TRANS_SWITCH: When the switch is on, the status of the UE RRC that carrying HSDPA services can be changed to CELL_FACH at the BSC6900. If a PS BE service is carried over the HS-DSCH, the switch PS_BE_STATE_TRANS_SWITCH should be on simultaneously. If a PS real-time service is carried over the HS-DSCH, the switch PS_NON_BE_STATE_TRANS_SWITCH should be on simultaneously.

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11. DRA_HSUPA_DCCC_SWITCH: When the switch is on, the DCCC algorithm is used for HSUPA. The DCCC switch must be also on before this switch takes effect.

12. DRA_HSUPA_STATE_TRANS_SWITCH: When the switch is on, the status of the UE RRC that carrying HSUPA services can be changed to CELL_FACH at the BSC6900. If a PS BE service is carried over the E-DCH, the switch PS_BE_STATE_TRANS_SWITCH should be on simultaneously. If a PS real-time service is carried over the E-DCH, the switch PS_NON_BE_STATE_TRANS_SWITCH should be on simultaneously.

13. DRA_IP_SERVICE_QOS_SWITCH: Switch of the algorithm for increasing the quality of subscribed services. When this parameter is set to ON, the service priority weight of the subscriber whose key parameters (IP Address, IP Port, and IP Protocol Type) match the specified ones can be adjusted. In this way, the QoS is improved.

14. DRA_PS_BE_STATE_TRANS_SWITCH: When the switch is on, UE RRC status transition (CELL_FACH/CELL_PCH/URA_PCH) is allowed at the BSC6900.

15. DRA_PS_NON_BE_STATE_TRANS_SWITCH: When the switch is on, the status of the UE RRC that carrying real-time services can be

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changed to CELL_FACH at the BSC6900.

16. DRA_R99_DL_FLOW_CONTROL_SWITCH: Under a poor radio environment, the QoS of high speed services drops considerably and the TX power is overly high. In this case, the BSC6900 can set restrictions on low data rate transmission formats based on the transmission quality, thus lowering traffic speed and TX power. When the switch is on, the R99 downlink flow control function is enabled.

17. DRA_THROUGHPUT_DCCC_SWITCH: When the switch is on, the DCCC based on traffic statistics is supported over the DCH.

18. DRA_VOICE_SAVE_CE_SWITCH: when the switch is on, the TTI selection based on the voice service type (including VoIP and CS over HSPA) is supported when the service is initially established.

19. DRA_VOICE_TTI_RECFG_SWITCH: when the switch is on, the TTI adjustment based on the voice service type (including VoIP and CS over HSPA) is supported.

20. DRA_CSPS_NO_PERIOD_RETRY_SWITCH: Whether to prohibit channel retries for CS and PS combined services. When this switch is turned on, channel retries are prohibited for CS and PS combined services. When this switch is turned off, channel retries are allowed for CS and PS

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combined services.

21. DRA_SMART_FAST_STATE_TRANS_SWITCH: Whether to activate the fast state transition algorithm. When this switch is turned on, the BSC6900 identifies UEs supporting fast state transition and then quickly transits the UEs from CELL_DCH to CELL_FACH.

22. DRA_PCH_UE_SMART_P2D_SWITCH: Whether to activate the algorithm for smart PCH-to-DCH state transition specific to UEs in the CELL_PCH or URA_PCH state. When this switch is turned on, the BSC6900 identifies UEs supporting smart PCH-to-DCH state transition and then transits the UEs from CELL_PCH or URA_PCH to CELL_DCH.

23. DRA_BASE_RES_BE_TTI_INIT_SEL_SWITCH: Whether initial TTI selection is allowed for differentiated BE services based on fairness

0: This switch is turned off. The TTI is selected according to the original algorithm.

1: This switch is turned on. In the dynamic TTI adjustment algorithm for differentiated BE services based on fairness, HSUPA UEs use 10-ms TTI if the RTWP, occupied Iub bandwidth, or consumed CE resources are congested.

24. DRA_BASE_COVER_BE_TTI_INIT_SEL_SWITCH: Whether to activate the coverage-based initial TTI selection algorithm specific to

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BE services. When this switch is turned on and conditions on 2 ms TTI specific to BE services has been met, the BSC6900 determines uplink coverage wideness of specific cells based on the Ec/N0 values reported by UEs during RRC connection. If the uplink coverage of the cells is weak, the BSC6900 allocates a 10 ms TTI to BE services as their initial TTI.

25. DRA_F2U_SWITCH: Whether to enable state transition from CELL_FACH to URA_PCH.When this switch is turned on, a UE can directly move from the CELL_FACH to URA_PCH state. When this switch is turned off, a UE must move from the CELL_FACH to CELL_PCH and then to URA_PCH state.

GUI Value Range:DRA_AQM_SWITCH, DRA_BASE_ADM_CE_BE_TTI_L2_OPT_SWITCH, DRA_BASE_ADM_CE_BE_TTI_RECFG_SWITCH, DRA_BASE_COVER_BE_TTI_L2_OPT_SWITCH, DRA_BASE_COVER_BE_TTI_RECFG_SWITCH, DRA_BASE_RES_BE_TTI_L2_OPT_SWITCH, DRA_BASE_RES_BE_TTI_RECFG_SWITCH, DRA_DCCC_SWITCH, DRA_HSDPA_DL_FLOW_CONTROL_SWITCH, DRA_HSDPA_STATE_TRANS_SWITCH, DRA_HSUPA_DCCC_SWITCH, DRA_HSUPA_STATE_TRANS_SWITCH, DRA_IP_SERVICE_QOS_SWITCH, DRA_PS_BE_STATE_TRANS_SWITCH, DRA_PS_NON_BE_STATE_

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TRANS_SWITCH, DRA_R99_DL_FLOW_CONTROL_SWITCH, DRA_THROUGHPUT_DCCC_SWITCH, DRA_VOICE_SAVE_CE_SWITCH, DRA_VOICE_TTI_RECFG_SWITCH, DRA_CSPS_NO_PERIOD_RETRY_SWITCH, DRA_SMART_FAST_STATE_TRANS_SWITCH, DRA_PCH_UE_SMART_P2D_SWITCH, DRA_BASE_RES_BE_TTI_INIT_SEL_SWITCH, DRA_BASE_COVER_BE_TTI_INIT_SEL_SWITCH, DRA_F2U_SWITCH

Actual Value Range:DRA_AQM_SWITCH, DRA_BASE_ADM_CE_BE_TTI_L2_OPT_SWITCH, DRA_BASE_ADM_CE_BE_TTI_RECFG_SWITCH, DRA_BASE_COVER_BE_TTI_L2_OPT_SWITCH, DRA_BASE_COVER_BE_TTI_RECFG_SWITCH, DRA_BASE_RES_BE_TTI_L2_OPT_SWITCH, DRA_BASE_RES_BE_TTI_RECFG_SWITCH, DRA_DCCC_SWITCH, DRA_HSDPA_DL_FLOW_CONTROL_SWITCH, DRA_HSDPA_STATE_TRANS_SWITCH, DRA_HSUPA_DCCC_SWITCH, DRA_HSUPA_STATE_TRANS_SWITCH, DRA_IP_SERVICE_QOS_SWITCH, DRA_PS_BE_STATE_TRANS_SWITCH, DRA_PS_NON_BE_STATE_TRANS_SWITCH, DRA_R99_DL_FLOW_CONTROL_SWITCH, DRA_THROUGHPUT_DCCC_SWITCH,

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DRA_VOICE_SAVE_CE_SWITCH, DRA_VOICE_TTI_RECFG_SWITCH, DRA_CSPS_NO_PERIOD_RETRY_SWITCH, DRA_SMART_FAST_STATE_TRANS_SWITCH, DRA_PCH_UE_SMART_P2D_SWITCH, DRA_BASE_RES_BE_TTI_INIT_SEL_SWITCH, DRA_BASE_COVER_BE_TTI_INIT_SEL_SWITCH, DRA_F2U_SWITCH

Unit:None

Default Value:DRA_AQM_SWITCH-0&DRA_BASE_ADM_CE_BE_TTI_L2_OPT_SWITCH-0&DRA_BASE_ADM_CE_BE_TTI_RECFG_SWITCH-1&DRA_BASE_COVER_BE_TTI_L2_OPT_SWITCH-0&DRA_BASE_COVER_BE_TTI_RECFG_SWITCH-0&DRA_BASE_RES_BE_TTI_L2_OPT_SWITCH-0&DRA_BASE_RES_BE_TTI_RECFG_SWITCH-1&DRA_DCCC_SWITCH-1&DRA_HSDPA_DL_FLOW_CONTROL_SWITCH-0&DRA_HSDPA_STATE_TRANS_SWITCH-0&DRA_HSUPA_DCCC_SWITCH-1&DRA_HSUPA_STATE_TRANS_SWITCH-0&DRA_IP_SERVICE_QOS_SWITCH-0&DRA_PS_BE_STATE_TRANS_SWITCH-1&DRA_PS_NON_BE_STATE_TRANS_SWITCH-0&DRA_R99_DL_FLOW_CONTROL_SWITCH-0&DRA_THROUGHPUT_DCCC_SWITCH-0&DRA_VOICE_SAVE_CE_SWITCH-0&DRA_VOICE_TTI_RECFG_SWITCH-0&DRA_CSPS_NO_PERIOD_RETRY_SWITCH-0&DRA_SMART_FAST_STATE_TRANS_SWITCH-0&DRA_PCH_UE_SMART_P2D_SWITCH-0&DRA_BASE_RES_BE_TTI_INIT

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_SEL_SWITCH-0&DRA_BASE_COVER_BE_TTI_INIT_SEL_SWITCH-0&DRA_F2U_SWITCH-0

DSPRestrainCpuThd

BSC6900 SET UUSERPLNSHAREPARA

WRFD-040100

Flow Control Meaning:The parameter is added to stop SPU from assigning users to a DSP whose CPU usage has exceeded this threshold.



Unit:%

Default Value:0

DynaCapsFcMaxRrc


WRFD-040100

Flow Control Meaning:Maximum number of RRC connection setup requests that can be processed by an SPU subsystem. After the CAPS dynamic adjustment function is enabled, the RNC adjusts the number of RRC connection setup requests to be processed by an SPU subsystem every second and this parameter value is the upper limit.




Unit:None

Default Value:1000

DynaCapsFcTarCpu


WRFD-040100

Flow Control Meaning:Threshold for the target CPU usage on an SPU subsystem. After the CAPS dynamic adjustment function is enabled, the RNC compares the current CPU usage on an SPU subsystem with this parameter value and



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adjusts the CAPS on the SPU subsystem every second based on the comparison results. The RNC will not set the CAPS to be larger than this parameter value.




Unit:%

Default Value:85

FACHAdmCondSDUDelaySwitch


None None Meaning:Whether SDU delay is considered in FACH admission. If this parameter is set to ON, FACH queues are congested, and the delay of 10 or more SDUs exceeds the threshold, the FACH enters the admission congestion state.



Unit:None

Default Value:OFF

FACHAdmSDUDelayThd


None None Meaning:SDU delay threshold. If the SDU Delay in FACH Admission Decision parameter is set to ON and the delay of 10 or more SDUs exceeds the threshold, the FACH enters admission congestion state.



Unit:100ms

Default Value:20










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FachCongClearThd


None None Meaning:FACH DTCH and DCCH congestion clearance threshold. If the duration to buffer data packets on the MACC is shorter than this threshold, the MACC reports a congestion clearance indication to L3. The parameter is in the unit of TTI.




Unit:None

Default Value:10

FachCongThd BSC6900 SET UDPUCFGDATA

None None Meaning:FACH DTCH and DCCH congestion report threshold. If the duration to buffer data packets on the MACC reaches this threshold, the MACC reports a CCCH congestion indication to MACD and L3. The parameter is in the unit of TTI.




Unit:None

Default Value:60

FcOnItfBrd BSC6900 SET TNSOFTPARA

None None Meaning:Whether to enable interface board flow control.

If this switch is turned on, the BSC6900 adjusts the traffic load on the interface board according to the CPU usage





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of the interface board.



Unit:None


FCSW BSC6900 SET FCSW GBFD-111705

WRFD-040100

GSM Flow Control

Flow Control

Meaning:Main switch for the flow control on a subsystem. Other flow control switches can take effect only when this switch is set to ON.



Unit:None

Default Value:ON

FcSwicthByRatioBetweenCCAndCR

BSC6900 SET TNSOFTPARA

None None Meaning:Whether to enable Connection Confirm/Connection Request (CC/CR) flow control. The SCCP periodically measures the number of connection setup requests that are sent and received by the BSC6900 for each signaling point.

If this switch is turned on, the BSC6900 starts flow control if the proportion of the connection setup responses to the connection setup requests is lower than the flow control threshold.



Unit:None


FDWINDOW BSC6900 SET FCCPUTHD GBFD-111705

WRFD-040

GSM Flow Control

Flow Control

Meaning:Number of CPU usage sampling times involved in fast judgment. The value of this parameter must be smaller than or equal to

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100 half of the value of "Filter window". "Fast judgment window" is applied to control the flow in the case that the CPU usage is too high in a short time. After "fast judgment window" is applied, the system compares the CPU usage in a short period of time before the current time with Critical threshold. If all CPU usages in the "fast judgment window" reach or exceed Critical threshold, all active flow control mechanisms start to work immediately.



Unit:None

Default Value:4

FlowCtrlSwitch BSC6900 SET UCACALGOSWITCH

WRFD-020101

Admission Control

Meaning:The parameter values are described as follows:

CELL_UPDATE_QUEUE_FLOW_CTRL_SWITCH(Switch for Queue-based Shaping):Whether to enable queue-based shaping for CELL_UPDATE messages. When this switch is turned on, queue-based shaping for CELL_UPDATE messages is enabled. If the CPU usage is high when a UE initiates a cell update, the RNC buffers the received CELL_UPDATE messages of the different priorities in different queues. When the CPU usage falls below a threshold, the RNC processes the buffered messages.

This parameter is an advanced parameter. To modify this parameter, contact Huawei Customer Service





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Center for technical support.

GUI Value Range:CELL_UPDATE_QUEUE_FLOW_CTRL_SWITCH(Switch for Queue-based Shaping)

Actual Value Range:CELL_UPDATE_QUEUE_FLOW_CTRL_SWITCH

Unit:None

Default Value:CELL_UPDATE_QUEUE_FLOW_CTRL_SWITCH-0

IgorTmr BSC6900 SET UIUTIMERANDNUM

WRFD-010101

3GPP R9 Specifications

Meaning:CN flow control timer (short). The OVERLOAD message received repeatedly in this period will be discarded.



Unit:ms

Default Value:20000

IntrTmr BSC6900 SET UIUTIMERANDNUM

WRFD-010101


Meaning:CN flow control timer (long). If the OVERLOAD message is not received in this period, the traffic volume will be increased by a degree.



Unit:ms

Default Value:60000

IUCTHD BSC6900 SET FCSW WRFD-040100

Flow Control Meaning:Maximum traffic rate for restriction in the case of congestion on the IU interface. This parameter is valid only when "Board Class" is "XPU".


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Unit:None

Default Value:70

IUFCSW BSC6900 SET FCSW WRFD-040100

Flow Control Meaning:Whether to control signaling traffic on the IU interface



Unit:None

Default Value:ON

IURDLSW BSC6900 SET FCSW WRFD-040100

Flow Control Meaning:Whether to control the traffic on the Iur downlink



Unit:None

Default Value:ON

IURGSW BSC6900 SET FCSW WRFD-040100

Flow Control Meaning:Whether to control traffic on the Iur-g interface



Unit:None

Default Value:ON

IURULSW BSC6900 SET FCSW WRFD-040100

Flow Control Meaning:Whether to control the traffic on the Iur uplink



Unit:None

Default Value:ON

LowRrcConnRejWaitTmr

BSC6900 SET USTATETIMER

WRFD-010510

3.4/6.8/13.6/27.2Kbps RRC Connection and Radio Access Bearer

Meaning:Wait time IE contained in the RRC CONNECTION REJECT message for a low-priority RRC connection setup

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Establishment and Release

request, that is, the minimum time for which a UE must wait before it sends another RRC connection setup request. An RRC connection setup request has a low priority only when neither of the following conditions is met:

1. The value of the IE CN domain identity contained in the RRC CONNECTION REQUEST message sent from the UE to the BSC6900 is CS domain.

2. The cause value contained in the RRC CONNECTION REQUEST message is Originating Conversational Cal, Terminating Conversational Call, or Emergency Call.



Unit:s

Default Value:4

LRRCCONNCCPUTHD


System Redundancy

Meaning:CPU usage threshold for stopping load sharing on location service RRC connection setup requests. When the CPU usage of an XPU subsystem reaches this threshold or CtrlPlnSharingOutThd, whichever is smaller, later location service RRC connection setup requests will be carried by other XPU subsystems. CtrlPlnSharingOutThd is set by using the command "SET UCTRLPLNSHAREPARA". If the CPU usage of all candidate XPU subsystems exceeds this threshold, flow control on location service RRC connection setup requests is triggered. The parameter value is invalid if




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the SYS_LEVEL_DYNAMIC switch in the "CallShockCtrlSwitch" parameter of the "SET UCALLSHOCKCTRL" command is turned on.



Unit:%

Default Value:90

LRRCCONNCMSGTHD


System Redundancy

Meaning:Packet usage threshold for stopping load sharing on location service RRC connection setup requests. When the packet usage of an XPU subsystem reaches this threshold, later call service packets will be carried by other XPU subsystems. If the packet usage of all candidate XPU subsystems exceeds this threshold, flow control on location service RRC connection setup request packets is triggered.



Unit:%

Default Value:75

LRRCCONNRCPUTHD


System Redundancy

Meaning:CPU usage threshold for recoverying load sharing on location service RRC connection setup requests. If the CPU usage of an XPU subsystem is lower than this threshold, this XPU subsystem is the candidate subsystem for load sharing on location service RRC connection setup requests. The parameter value is invalid if the SYS_LEVEL_DYNAMIC switch in the "CallShockCtrlSwitch"







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parameter of the "SET UCALLSHOCKCTRL" command is turned on.



Unit:%

Default Value:80

LRRCCONNRMSGTHD


System Redundancy

Meaning:Packet usage threshold for recoverying load sharing on location service RRC connection setup requests. When the packet usage of an XPU subsystem is lower than this threshold, this XPU subsystem is a candidate subsystem for load sharing on location service RRC connection setup requests.



Unit:%

Default Value:65

MaxCAPSLowLoad


WRFD-020120


Meaning:Maximum numbers of incoming calls in one second when the load is lower than the forwarding threshold. When the CPU usage is lower than the sharing out threshold and overload threshold, and call numbers in each second reach the threshold, new arrival call attempts will be shared out to other SPU subsystem and none will be shared in this SPU subsystem.



Unit:None

Default Value:150









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MaxCAPSMidLoad


WRFD-020120


Meaning:Maximum numbers of incoming calls in one second when the load exceeds the forwarding threshold. When the CPU usage is between the sharing out threshold and overload threshold, and call number in one second reaches the threshold, new arrival call attempts will be shared out to other SPU subsystem and none will be shared in this SPU subsystem.



Unit:None

Default Value:100

MPULOADDIFFTH

BSC6900 SET TNLOADBALANCEPARA

WRFD-140207

WRFD-140208

Iu/Iur Transmission Resource Pool in RNC

Iub Transmission Resource Pool in RNC

Meaning:Threshold of the CPU usage difference between the MPU with the highest load and the MPU with the lowest load. When the CPU usage difference between the MPU with the highest load and the MPU with the lowest load is larger than this threshold and the CPU usage of the MPU with the highest load is larger than the value of the "MPU Load Balance Threshold" parameter, the BSC6900 will allocate transmission resources to MPUs with low CPU usage to maintain CPU usage balance between MPU subsystems.



Unit:%

Default Value:10

MPULOADSHARETH

BSC6900 SET TNLOADBALAN

WRFD-140207

Iu/Iur Transmission Resource Pool

Meaning:The CPU usage threshold for the MPU with the highest load. When the CPU








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CEPARA WRFD-140208

in RNC

Iub Transmission Resource Pool in RNC

usage of the MPU board with the highest load exceeds the threshold and the CPU usage difference between the MPU with the highest load and that with the lowest load is larger than the value of the "MPU Load Difference Threshold" parameter, the BSC6900 will allocate transmission resources to MPUs with low CPU usage to maintain CPU usage balance between MPU subsystems.



Unit:%

Default Value:40

MRFCSW BSC6900 SET FCSW WRFD-040100

Flow Control Meaning:Whether to control MR flow



Unit:None

Default Value:ON

NBMCacAlgoSwitch

BSC6900 ADD UCELLALGOSWITCH

MOD UCELLALGOSWITCH

WRFD-020101

WRFD-020102

WRFD-010202

WRFD-021102

Admission Control

Load Measurement


Cell Barring

Meaning:Whether to enable the algorithms related to cell service admission. Selecting a switch enables the corresponding algorithm and clearing a switch disables the corresponding algorithm.

1. CRD_ADCTRL: Control Cell Credit admission control algorithm. Only when NODEB_CREDIT_CAC_SWITCH which is set by the SET UCACALGOSWITCH command and this switch are on,the Cell Credit admission control algorithm is valid.

2. HSDPA_UU_ADCTRL: Control HSDPA UU Load admission control algorithm.This swtich does not

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work when uplink is beared on HSUPA and downlink is beared on HSDPA.

3. HSUPA_UU_ADCTRL: Control HSUPA UU Load admission control algorithm. This switch does not work when uplink is beared on HSUPA and downlink is beared on HSDPA.

4. MBMS_UU_ADCTRL: Control MBMS UU Load admission control algorithm.

5. HSDPA_GBP_MEAS: Control HSDPA power requirement for GBR (GBP) measurement. The NodeB will report the GBP of HSDPA users to the RNC after the measurement is enabled.

6. HSDPA_PBR_MEAS: Control HSDPA provided bit rate (PBR) measurement. The NodeB will report the PBR of HSDPA users to the RNC after the measurement is enabled.

7. SYS_INFO_UPDATE_FOR_IU_RST: When this switch and the RNC-level SYS_INFO_UPDATE_FOR_IU_RST(SET URRCTRLSWITCH )are turned on, the Cell Barring function is available to the Iu interface.

8. HSUPA_PBR_MEAS: Control HSUPA PBR measurement. The NodeB will report the PBR of HSUPA users to the RNC after the measurement is enabled.

9. HSUPA_EDCH_RSEPS_MEAS: Control HSUPA Provided Received Scheduled EDCH Power Share measurement.

10. EMC_UU_ADCTRL:

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Control power admission for emergency user.

11. RTWP_RESIST_DISTURB: Control algorithm of resisting disturb when RTWP is abnormal.

12. SIGNALING_SHO_UL_AC_SWITCH: Whether to prohibit UEs that have established RRC connections but not start processing any services yet from performing soft handovers. When this switch is turned on, such UEs cannot access target cells by means of soft handover if the OLC procedure is progressing in target cells.

13. FACH_UU_ADCTRL: Admission control switch for the FACH on the Uu interface. This switch determines whether to admit a user in the RRC state on the CELL_FACH. 1) If this switch is enabled: if the current cell is congested due to overload, and the users are with RAB connection requests or RRC connection requests(except the cause of ""Detach"", ""Registration"", or ""Emergency Call""), the users will be rejected. Otherwise FACH user admission procedure is initiated. A user can access the cell after the procedure succeeds. 2) If this switch is disabled: FACH user admission procedure is initiated without the consideration of cell state.

14. MIMOCELL_LEGACYHSDPA_ADCTRL: Legacy HSDPA admission control algorithm in MIMO cell.

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15. FAST_DORMANCY_ADCTRL: Whether to enable or disable state transition of users in the CELL-DCH state, who are enabled with fast dormancy, to ease FACH congestion in a cell. If this switch is turned off in a cell, state transition of such users is disabled. Note that when this switch is turned off in multiple cells under an BSC6900, signaling storm may occur. As a result, the CPU usage of the BSC6900, NodeB, and SGSN increases greatly, leading to service setup failure.This switch has been removed from RAN13, so that this switch is now invalid.

16. FACH_USER_NUM_NOT_CTRL: Whether to allow for FACH UEs without restrictions.

GUI Value Range:CRD_ADCTRL(Credit Admission Control Algorithm), HSDPA_UU_ADCTRL(HSDPA UU Load Admission Control Algorithm), HSUPA_UU_ADCTRL(HSUPA UU Load Admission Control Algorithm), MBMS_UU_ADCTRL(MBMS UU Load Admission Control Algorithm), HSDPA_GBP_MEAS(HSDPA GBP Meas Algorithm), HSDPA_PBR_MEAS(HSDPA PBR Meas Algorithm), SYS_INFO_UPDATE_FOR_IU_RST(System Info Update Switch for Iu Reset), HSUPA_PBR_MEAS(HSUPA PBR Meas Algorithm), HSUPA_EDCH_RSEPS_MEAS(HSUPA EDCH RSEPS Meas Algorithm), EMC_UU_ADCTRL(emergen

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cy call power admission), RTWP_RESIST_DISTURB(RTWP Resist Disturb Switch), SIGNALING_SHO_UL_AC_SWITCH(Signaling Sho Ul power cac switch), FACH_UU_ADCTRL(FACH power cac switch), MIMOCELL_LEGACYHSDPA_ADCTRL(Legacy HSDPA Admission Control Algorithm in MIMO Cell ), FAST_DORMANCY_ADCTRL(Fast Dormancy User Admission Control Algorithm), FACH_USER_NUM_NOT_CTRL(FACH USER UNLIMITED)

Actual Value Range:CRD_ADCTRL, HSDPA_UU_ADCTRL, HSUPA_UU_ADCTRL, MBMS_UU_ADCTRL, HSDPA_GBP_MEAS, HSDPA_PBR_MEAS, SYS_INFO_UPDATE_FOR_IU_RST, HSUPA_PBR_MEAS, HSUPA_EDCH_RSEPS_MEAS, EMC_UU_ADCTRL, RTWP_RESIST_DISTURB, SIGNALING_SHO_UL_AC_SWITCH, FACH_UU_ADCTRL, MIMOCELL_LEGACYHSDPA_ADCTRL, FAST_DORMANCY_ADCTRL, FACH_USER_NUM_NOT_CTRL

Unit:None

Default Value:CRD_ADCTRL-1&HSDPA_UU_ADCTRL-0&HSUPA_UU_ADCTRL-0&MBMS_UU_ADCTRL-0&HSDPA_GBP_MEAS-0&HSDPA_PBR_MEAS-0&SYS_INFO_UPDATE_FOR_IU_RST-0&HSUPA_PBR_MEAS-0&HSUPA_EDCH_RSEPS_MEAS-0&EMC_UU_ADCTRL-1&RTWP_RESIST_DISTURB-0&SIGNALING_SHO_U

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L_AC_SWITCH-0&FACH_UU_ADCTRL-0&MIMOCELL_LEGACYHSDPA_ADCTRL-0&FAST_DORMANCY_ADCTRL-1&FACH_USER_NUM_NOT_CTRL-0

NcpCongFlowCtrSwitch

BSC6900 SET ULDCALGOPARA

WRFD-020106

Load Reshuffling

Meaning:Whether to activate the cell-level dynamic CAPS flow control algorithm based on the congestion status of the NCP link. This parameter must be used with "RSVDBIT4" of the "RsvdPara1" parameter in the "ADD UNODEBALGOPARA" command. When the switch is turned on, flow control is triggered if the NCP link is congested; flow control is stopped if the NCP link is not congested. When flow control is triggered, the number of allowed RRC connection requests per second in the cell decreases based on the value of "KPIstepdownpercentage". When flow control is stopped, the number of allowed RRC connection requests per second in the cell increases based on the value of "KPIstepuppercentage". The number of RRC connection requests does not change once the cell flow control status becomes stable.




Unit:None




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NRMCPUCTHD



Meaning:Threshold for triggering the cell-level CPU usage-based dynamic CAPS flow control algorithm. This algorithm considers the CPU usage of the SPU subsystem only. You are advised to set this parameter value to be 5% higher than the value of "DynaCapsFcTarCpu" in the "SET UCALLSHOCKCTRL" command.



Unit:%

Default Value:90

NRMCPURTHD



Meaning:Threshold for stopping the cell-level CPU usage-based dynamic CAPS flow control algorithm. This algorithm considers the CPU usage of the SPU subsystem only.



Unit:%

Default Value:80

NRMFCSW BSC6900 SET FCSW WRFD-020103


Meaning:Whether to activate the cell-level CPU usage-based dynamic CAPS flow control algorithm. This algorithm considers the CPU usage of the SPU subsystem only. When the switch is turned on, flow control is triggered if CPU usage of an SPU subsystem is higher than or equal to the value of "NRMCPUCTHD"; flow control is stopped if the CPU usage is lower than or equal to the value of "NRMCPURTHD". When flow control is triggered, the number of allowed RRC







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connection requests per second in the cell decreases based on the value of "KPIstepdownpercentage". When flow control is stopped, the number of allowed RRC connection requests per second in the cell increases based on the value of "KPIstepuppercentage". The number of RRC connection requests does not change once the cell flow control status becomes stable.



Unit:None

Default Value:ON

PAGECTHD BSC6900 SET FCMSGQTHD

WRFD-040100

Flow Control Meaning:Packet queue usage threshold for paging flow control. When the average packet usage within several sliding windows reaches or exceeds "Paging restore threshold", linear flow control is started on paging messages. When the average packet usage within several sliding windows reaches or exceeds "Paging control threshold", 100% flow control is started on paging messages.



Unit:%

Default Value:70

PAGERTHD BSC6900 SET FCMSGQTHD

WRFD-040100

Flow Control Meaning:Packet queue usage threshold for paging flow control. When the average packet usage within several sliding windows reaches or exceeds "Paging restore threshold", linear flow control is started on paging

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messages. When the average packet usage within several sliding windows is lower than "Paging restore threshold", paging flow control is stopped.



Unit:%

Default Value:60

PAGESW BSC6900 SET FCSW WRFD-040100

Flow Control Meaning:Whether to control paging flow.



Unit:None

Default Value:ON

PagingSwitch BSC6900 SET UDPUCFGDATA

None None Meaning:Paging preemption switch. When the switch is turned on, the paging preemption function is supported.



Unit:None


PerfEnhanceSwitch

BSC6900 SET UCORRMPARA

WRFD-01061111

WRFD-021104

WRFD-010202

WRFD-020400

WRFD-01061004

WRFD-02060501

HSDPA State Transition

Emergency Call


DRD Introduction Package

HSDPA Power

Meaning:1. PERFENH_AMR_SPEC_BR_SWITCH: When the switch is set to ON, the procedure specific to AMR service establishment takes effect.

2. PERFENH_AMR_TMPLT_SWITCH: When the switch is set to ON, the AMR template takes effect.

3. PERFENH_SRB_TMPLT_SWITCH: When the switch is set to ON, the SRB template

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WRFD-020402

WRFD-02040003

WRFD-01061404

Control

SRNS Relocation (UE Not Involved)

Measurement Based Direct Retry

Inter System Redirect

HSUPA 2ms/10ms TTI Handover

takes effect.

4. PERFENH_OLPC_TMPLT_SWITCH: When the switch is set to ON, the OLPC template takes effect.

5. PERFENH_AMR_SP_TMPLT_SWITCH: When the switch is set to ON, the AMR parameter template takes effect.

6. PERFENH_INTRAFREQ_MC_TMPLT_SWITCH: When the switch is set to ON, the intra-frequency measurement control template takes effect.

7. PERFENH_INTERRAT_PENALTY_50_SWITCH: After a UE fails to be handed over to a 2G cell during an inter-RAT handover, the BSC6900 forbids the UE to attempt a handover to the 2G cell in a certain period. When the switch is set to ON, the period is 50s. When the switch is set to OFF, the period is 30s.

8. PERFENH_SRB_OVER_HSUPA_TTI10_SWITCH: When the switch is set to ON, the uplink SRBs of HSUPA 10 ms non-conversational services are always carried on DCHs, and the original parameter Type of Channel Preferably Carrying Signaling RB is invalid. When the switch is set to OFF, SRBs for HSUPA 10 ms non-conversational services can be carried on HSUPA channels when the original parameter Type of Channel Preferably Carrying Signaling RB is set to HSUPA or HSPA. The switch is set to OFF by default.

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9. PERFENH_HSUPA_TTI2_ENHANCE_SWITCH: When the switch is set to ON, the single-user peak-rate improvement algorithm of HSUPA 2 ms TTI is enabled. When the switch is set to OFF, the algorithm is disabled. The switch is set to OFF by default.

10. PERFENH_UU_P2D_CUC_OPT_SWITCH: When this switch is turned on, the P2D cell update confirm message simplification algorithm takes effect. When this switch is turned off, the algorithm does not take effect. By default, this switch is turned off.

11. PERFENH_RL_RECFG_SIR_CONSIDER_SWITCH: This check box controls whether the BSC6900 considers the converged SIRTarget value that is used before radio link reconfiguration in outer loop power control performed after radio link reconfiguration. If the check box is not selected, the BSC6900 sends the initial SIRTarget value used after radio link reconfiguration to the NodeB.If the check box is selected, the BSC6900 selects a more appropriate value from the initial SIRTarget value used after radio link reconfiguration and the converged SIRTarget value used before radio link reconfiguration. Then the BSC6900 sends the selected value to the NodeB. Setting of this check box takes effect only when the PC_RL_RECFG_SIR_TARGET_CARRY_SWITCH check box is selected.

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12. PERFENH_RRC_REDIR_PROTECT_SWITCH: When the switch is set to ON, The mechanism to avoid endless back-and-forth RRC-redirections takes effect. The switch is set to OFF by default.

13. PERFENH_H2F_OPT_SWITCH: whether to enable the optimized algorithm for HSPA UE state transition from CELL_DCH to CELL_FACH (also referred to as H2F state transition). When the switch is turned on, the optimized H2F state transition algorithm is enabled, and event 4A measurement of traffic volume or throughput is added to the state transition procedure. The added event 4A measurement prevents an H2F state transition when data is being transmitted.

14. PERFENH_PSTRAFFIC_P2H_SWITCH: When the switch is turned on and a CELL_PCH/URA_PCH-to-CELL_DCH (P2D for short) state transition is triggered for a PS service, the PS service can be set up on HSPA channels after the state transition. When the switch is turned off, PS services can be set up only on DCHs after a P2D state transition. This switch is turned off by default.

15. PERFENH_VIP_USER_PCHR_MR_SWITCH: When the switch is set to ON, VIP UEs report their transmit power to the BSC6900 when required and periodically measure signal quality of intra-frequency cells. In

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addition, these UEs measure the downlink BLER, the NodeB measures the uplink SIR, and the BSC6900 records the measurement results.

16. PERFENH_TX_INTERRUPT_AFT_TRIG_SWITCH: Switch for including the Tx interruption after trigger IE in the uplink 4A traffic volume measurement control message. When this switch is turned on, the uplink 4A traffic volume measurement control message from BSC6900 includes the Tx interruption after trigger IE for UEs that are in the CELL_FACH or enhanced CELL_FACH state and processing PS BE services. The value of this IE can be changed by running the "SET UUESTATETRANS" command.

17. PERFENH_HSUPA_TTI_RECFG_PROC_OPT_SWITCH: Whether to use the optimized TTI switching algorithm for BE services

0: The optimized algorithm does not take effect. The original mechanism is implemented.

1: The optimized algorithm takes effect. After HSUPA services are configured or reconfigured with 10 ms TTI due to network resource (admission CEs, RTWP, consumed Iub bandwidth, or consumed CEs) congestion or insufficient coverage, these UEs cannot change to use 2 ms TTI if no data needs to be transmitted.

18. PERFENH_DOWNLOAD_EN

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HANCE_SWITCH: Whether to activate the algorithm for increasing the single-threaded download rate.

19. PERFENH_OLPC_BLER_COEF_ADJUST: Switch for adjusting the BLER coefficient specific to CS services based on the best cell's uplink load status. When this switch is turned on, the outer loop power control algorithm uses the target BLER set by the OMU board if the best cell's uplink load status is LDR or OLC. If the status is neither LDR nor OLC, this algorithm uses this target BLER after being divided by five.

20. PERFENH_EMG_AGPS_MC_DELAY_SWITCH: Whether to enable the function of delaying the sending of an RRC_MEAS_CTRL message containing AGPS information when an emergency call is made. When this switch is turned on, the BSC6900 delays the sending of this message until the emergency call is successfully set up. When this switch is turned off, the BSC6900 sends this message upon receiving a LOCATION_REPORTING_CONTROL message from the CN.

21. PERFENH_MULTI_RLS_CQI_PARA_OPT_SWITCH: Whether to enable a UE having multiple RLSs to use the value of "CQIReF" and the value of "CQIFbCk" that are for UEs having only one RLS. The two parameters can be set by running the "SET UHSDPCCH" and "ADD UCELLHSDPCCH"

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commands. When this switch is turned off, the UE does not use the values of the two parameters that are for UEs having only one RLS. When this switch is turned on, the UE uses the values of the two parameters that are for UEs having only one RLS.

22. PERFENH_RELOC_IE_CALCTIMEFORCIP_SWITCH: Whether to enable a RELOCATION REQUIRED message to contain the IE calculationTimeForCiphering.

When this switch is turned on, static relocation request messages contain the IE calculationTimeForCiphering.

23. PERFENH_IS_TIMEOUT_TRIG_DRD_SWITCH: Whether to trigger the DRD procedure and channel switchover from E-DCH or HS-DSCH to DCH when messages transmitted over the Uu and Iub interfaces do not arrive in time. When this switch is turned off, the DRD procedure and channel switchover from E-DCH or HS-DSCH to DCH are not triggered if messages transmitted over the Uu and Iub interfaces do not arrive in time. When this switch is turned on, the DRD procedure and channel switchover from E-DCH or HS-DSCH to DCH are triggered if messages transmitted over the Uu and Iub interfaces do not arrive in time.

24. PERFENH_CELL_CACLOAD_BROADCAST_AMEND: Whether to consider CE or code resource usage when determining the resource status of a cell whose serving

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boards or SPU sub-systems are different from those of its neighboring cells. When this switch is turned on, the RNC determines the resource status of such a cell based on power, CE, and code resource usage. If power, CE, or code resources in a cell become congested, the RNC determines that the cell experiences resource congestion. When this switch is turned off, the RNC determines the resource status of such a cell based on power resource usage only.

25. PERFENH_MBDR_TARCELLSEL_OPT_SWITCH: When this switch is turned on, candidate cells are ranked by "InterFreqMeasQuantity" (in the "ADD UCELLMBDRINTERFREQ" command) for MBDR, and the cell with the best signal quality is selected as the target cell. When this switch is turned off, candidate cells are not ranked by InterFreqMeasQuantity for MBDR.

26. PERFENH_RRC_DRD_PREADMISSION_SWITCH: Whether the BSC6900 makes a pre-admission decision on intra-RAT DRDs or redirections during an RRC connection setup. When this switch is turned on, the BSC6900 makes a pre-admission decision on intra-RAT DRDs or redirections during an RRC connection setup. When this switch is turned off, the BSC6900 does not make a pre-admission decision on intra-RAT DRDs or redirections during an RRC

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connection setup.

27. PERFENH_RRC_WEAK_REDIR_SWITCH: Whether to activate the RRC redirection in weak coverage algorithm. When this switch is turned on, UEs located in weak coverage are redirected to the neighboring GSM cell through RRC redirection. When this switch is turned off, this algorithm is disabled.

28. PERFENH_L2U_CSFB_COMMCALL_SWITCH: Whether to preferentially admit UEs processing PS services who are involved in CS fallbacks. When this switch is turned on, the non-real-time PS services of the UE involved in a CS fallback are switched to a DCH with a data rate of 8 kbit/s before the access to the UMTS network. For the real-time PS services, the UE follows the standard access procedure. If the access fails and the "PreemptAlgoSwitch" parameter under the "SET UQUEUEPREEMPT" command is turned on, the UE can preempt other UEs' resources. If this switch is turned off, the UE has to try to access the network as a common PS UE.

29. PERFENH_DLBLINDDETECT_WHEN_ONLYSRBONDCH: This parameter controls whether to enable blind detection for the HSDPA user-associated single-signaling R99 channel. When the switch specified this parameter is turned on, blind detection is enabled.

30. PERFENH_DLBLINDDETEC

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T_WHEN_SRBAMRONDCH: This parameter controls whether to enable blind detection for the HSDPA user-associated AMR R99 channel. When the switch specified by this parameter is turned on, blind detection is enabled if the HSDPA service has been set up and there are signaling and AMR traffic carried on the R99 channel.

31. PERFENH_R6_HSUPA_TTI_10MSTO2MS_LIMIT: Whether to allow R6 UEs to switch from HSUPA 10 ms to 2 ms TTI. When the switch is turned on, this switching is not allowed for R6 UEs. When the switch is turned off, this limit does not work.


GUI Value Range:PERFENH_AMR_SPEC_BR_SWITCH, PERFENH_AMR_TMPLT_SWITCH, PERFENH_SRB_TMPLT_SWITCH, PERFENH_OLPC_TMPLT_SWITCH, PERFENH_AMR_SP_TMPLT_SWITCH, PERFENH_INTRAFREQ_MC_TMPLT_SWITCH, PERFENH_INTERRAT_PENALTY_50_SWITCH, PERFENH_SRB_OVER_HSUPA_TTI10_SWITCH, PERFENH_HSUPA_TTI2_ENHANCE_SWITCH, PERFENH_UU_P2D_CUC_OPT_SWITCH, PERFENH_RL_RECFG_SIR_CONSIDER_SWITCH, PERFENH_RRC_REDIR_PR

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OTECT_SWITCH, PERFENH_H2F_OPT_SWITCH, PERFENH_PSTRAFFIC_P2H_SWITCH, PERFENH_VIP_USER_PCHR_MR_SWITCH, PERFENH_TX_INTERRUPT_AFT_TRIG_SWITCH, PERFENH_HSUPA_TTI_RECFG_PROC_OPT_SWITCH, PERFENH_DOWNLOAD_ENHANCE_SWITCH, PERFENH_OLPC_BLER_COEF_ADJUST, PERFENH_EMG_AGPS_MC_DELAY_SWITCH, PERFENH_MULTI_RLS_CQI_PARA_OPT_SWITCH, PERFENH_RELOC_IE_CALCTIMEFORCIP_SWITCH, PERFENH_IS_TIMEOUT_TRIG_DRD_SWITCH, PERFENH_CELL_CACLOAD_BROADCAST_AMEND, PERFENH_MBDR_TARCELLSEL_OPT_SWITCH, PERFENH_RRC_DRD_PREADMISSION_SWITCH, PERFENH_RRC_WEAK_REDIR_SWITCH, PERFENH_L2U_CSFB_COMMCALL_SWITCH, PERFENH_DLBLINDDETECT_WHEN_ONLYSRBONDCH, PERFENH_DLBLINDDETECT_WHEN_SRBAMRONDCH, PERFENH_R6_HSUPA_TTI_10MSTO2MS_LIMIT

Actual Value Range:PERFENH_AMR_SPEC_BR_SWITCH, PERFENH_AMR_TMPLT_SWITCH, PERFENH_SRB_TMPLT_SWITCH, PERFENH_OLPC_TMPLT_SWITCH, PERFENH_AMR_SP_TMPLT_SWITCH,

PERFENH_INTRAFREQ_MC

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_TMPLT_SWITCH, PERFENH_INTERRAT_PENALTY_50_SWITCH, PERFENH_SRB_OVER_HSUPA_TTI10_SWITCH, PERFENH_HSUPA_TTI2_ENHANCE_SWITCH,

PERFENH_UU_P2D_CUC_OPT_SWITCH, PERFENH_RL_RECFG_SIR_CONSIDER_SWITCH, PERFENH_RRC_REDIR_PROTECT_SWITCH, PERFENH_H2F_OPT_SWITCH, PERFENH_PSTRAFFIC_P2H_SWITCH, PERFENH_VIP_USER_PCHR_MR_SWITCH,

PERFENH_TX_INTERRUPT_AFT_TRIG_SWITCH,

PERFENH_HSUPA_TTI_RECFG_PROC_OPT_SWITCH, PERFENH_DOWNLOAD_ENHANCE_SWITCH, PERFENH_OLPC_BLER_COEF_ADJUST, PERFENH_EMG_AGPS_MC_DELAY_SWITCH, PERFENH_MULTI_RLS_CQI_PARA_OPT_SWITCH, PERFENH_RELOC_IE_CALCTIMEFORCIP_SWITCH, PERFENH_IS_TIMEOUT_TRIG_DRD_SWITCH, PERFENH_CELL_CACLOAD_BROADCAST_AMEND, PERFENH_MBDR_TARCELLSEL_OPT_SWITCH, PERFENH_RRC_DRD_PREADMISSION_SWITCH,

PERFENH_RRC_WEAK_REDIR_SWITCH,

PERFENH_L2U_CSFB_COMMCALL_SWITCH,

PERFENH_DLBLINDDETECT_WHEN_ONLYSRBONDCH,

PERFENH_DLBLINDDETEC

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T_WHEN_SRBAMRONDCH,

PERFENH_R6_HSUPA_TTI_10MSTO2MS_LIMIT

Unit:None

Default Value:PERFENH_AMR_SPEC_BR_SWITCH-1&PERFENH_AMR_TMPLT_SWITCH-1&PERFENH_SRB_TMPLT_SWITCH-1&PERFENH_OLPC_TMPLT_SWITCH-1&PERFENH_AMR_SP_TMPLT_SWITCH-1&PERFENH_INTRAFREQ_MC_TMPLT_SWITCH-1&PERFENH_INTERRAT_PENALTY_50_SWITCH-1&PERFENH_SRB_OVER_HSUPA_TTI10_SWITCH-0&PERFENH_HSUPA_TTI2_ENHANCE_SWITCH-0&PERFENH_UU_P2D_CUC_OPT_SWITCH-0&PERFENH_RL_RECFG_SIR_CONSIDER_SWITCH-0&PERFENH_RRC_REDIR_PROTECT_SWITCH-0&PERFENH_H2F_OPT_SWITCH-0&PERFENH_PSTRAFFIC_P2H_SWITCH-0&PERFENH_VIP_USER_PCHR_MR_SWITCH-0&PERFENH_TX_INTERRUPT_AFT_TRIG_SWITCH-0&PERFENH_HSUPA_TTI_RECFG_PROC_OPT_SWITCH-0&PERFENH_DOWNLOAD_ENHANCE_SWITCH-0&PERFENH_OLPC_BLER_COEF_ADJUST-1&PERFENH_EMG_AGPS_MC_DELAY_SWITCH-0&PERFENH_MULTI_RLS_CQI_PARA_OPT_SWITCH-0&PERFENH_RELOC_IE_CALCTIMEFORCIP_SWITCH-0&PERFENH_IS_TIMEOUT_TRIG_DRD_SWITCH-0&PERFENH_CELL_CACLOAD_BROADCAST_AMEND-1&PERFENH_MBDR_TARCELLSEL_OPT_SWITCH-0&PERFENH_RRC_DRD_PREADMISSION_SWITCH- 0&PERFENH_RRC_WEAK_

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REDIR_SWITCH- 0&PERFENH_L2U_CSFB_COMMCALL_SWITCH- 0&PERFENH_DLBLINDDETECT_WHEN_ONLYSRBONDCH- 0&PERFENH_DLBLINDDETECT_WHEN_SRBAMRONDCH- 0&PERFENH_R6_HSUPA_TTI_10MSTO2MS_LIMIT-0

PerfEnhanceSwitch

BSC6900 SET UNBMPARA WRFD-020101

WRFD-020402

WRFD-010612

Admission Control

Measurement Based Direct Retry

HSUPA Introduction Package

Meaning:1. PERFENH_R99_BRDCSTHSPA_SWITCH(R99CellBroadcastHspaCapSwitch): When this switch is turned on, R99 cells broadcast HSPA capability of neighboring cells in a system information message.

2. PERFENH_FACH_USER_NUM_SWITCH(Fach User Select Switch): This switch is configurable in the current version.The BSC6900, however,does not use this switch any longer.Later versions will not support this switch.Therefore,users are not advised to use this switch.

3. PERFENH_MBDR_LOADCOND_OPT_SWITCH(Optimized MBDR Load Calculation Algorithm Switch): When this switch is turned on, the DL transmit power in a cell is calculated using the following formula:Percentage of the DL transmit power in a cell = Percentage of the non-HSPA transmit power + Percentage of the HSDPA guaranteed bit power (GBP) + Reserved power coefficient for DL common channels + Reserved power factor for DL MBMS services + Reserved power factor for DL HSUPA users.If UL or DL load in a neighboring cell exceeds the



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value of InterFreqUlMbdrTrigThreshold or InterFreqDlMbdrTrigThreshold (in the ADD UCELLMBDRINTERFREQ command), handover to this neighboring cell cannot be performed. When this switch is turned off, the percentage of the HSDPA GBP is not considered during the calculation of the DL transmit power in a cell, and the original algorithm is used for selecting a neighboring cell using MBDR.

4. PERFENH_CALALGO_FOR_HSUPAENU_OPT_SWITCH: Whether to optimize the calculation results of equivalent HSUPA UEs. When this switch is turned on, the optimized calculation results can accurately reflect the uplink cell load.

5. PERFENH_HSUPA_CCH_PREEMPT_USER: Whether to allow resource preemption of common users for HSUPA common channels to ensure that the code resources are allocated to the left.

6. PERFENH_CE_RLS_ADM_OPT_SWITCH: Whether to activate the RLS CE-based admission optimization algorithm. When this switch is turned on, a local cell group consumes an RLS CE if multiple RLs occupy more than one local cell group, no matter whether the UE uses the DCH or EDCH under a NodeB. When this switch is turned off, all local cell groups consume an RLS CE if multiple RLs occupy more

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than one local cell group, no matter whether the UE uses the DCH or EDCH under a NodeB.

7. PERFENH_DTCH_FACH_CONG_D2I_SWITCH: When this switch is turned on and DTCHs are congested, the RNC transits UEs that are in the CELL_DCH state and do not process services to the idle mode.


GUI Value Range:PERFENH_R99_BRDCSTHSPA_SWITCH, PERFENH_FACH_USER_NUM_SWITCH, PERFENH_MBDR_LOADCOND_OPT_SWITCH, PERFENH_CALALGO_FOR_HSUPAENU_OPT_SWITCH, PERFENH_HSUPA_CCH_PREEMPT_USER, PERFENH_CE_RLS_ADM_OPT_SWITCH, PERFENH_DTCH_FACH_CONG_D2I_SWITCH

Actual Value Range:PERFENH_R99_BRDCSTHSPA_SWITCH, PERFENH_FACH_USER_NUM_SWITCH, PERFENH_MBDR_LOADCOND_OPT_SWITCH, PERFENH_CALALGO_FOR_HSUPAENU_OPT_SWITCH, PERFENH_HSUPA_CCH_PREEMPT_USER,

PERFENH_CE_RLS_ADM_OPT_SWITCH,

PERFENH_DTCH_FACH_CONG_D2I_SWITCH

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Unit:None

Default Value:PERFENH_R99_BRDCSTHSPA_SWITCH-0&PERFENH_FACH_USER_NUM_SWITCH-0&PERFENH_MBDR_LOADCOND_OPT_SWITCH-0&PERFENH_CALALGO_FOR_HSUPAENU_OPT_SWITCH-0&PERFENH_HSUPA_CCH_PREEMPT_USER- 1&PERFENH_CE_RLS_ADM_OPT_SWITCH- 0&PERFENH_DTCH_FACH_CONG_D2I_SWITCH-0

PROCESSSWITCH2

BSC6900 SET URRCTRLSWITCH

WRFD-010101

WRFD-140224


Fast CS Fallback Based on RIM

Meaning:1) LOAD_IRAT_HO_RNC_FILL_TL (Cell Load Information TL Input Switch)

During inter-RAT handovers from 3G cells to 2G cells, the BSC6900 can records information about load on 3G cells in the RELOCATION REQUIRED container in the Tag Length Value (TLV) format.

When the switch is turned on, the BSC6900 records the Tag Length in the container.

When the switch is turned off, the BSC6900 does not record the Tag Length.

2) SEND_IDT_JUDGE_IU_RESET (Switch for Transferring INITIAL UE Messages in the IU Reset State)

When the switch is turned on, the BSC6900 discards the INITIAL UE message from a CN node if the Iu interface is in the reset state.

When the switch is turned off, the BSC6900 handles the INITIAL UE message from a CN node if the Iu interface is



../RNCParaHtml/mbsc/m-mml/set-urrctrlswitch.html



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in the reset state.

3) RNC_RBRECFG_DRD_FAIL_ROLLBACK_SWITCH (RB Reconfiguration DRD Rollback Switch)

When the switch is turned on, the BSC6900 supports rollback caused by failed directed retry decisions (DRDs) of RB reconfiguration.

When the switch is turned off, the BSC6900 does not support rollback caused by failed DRDs of RB reconfiguration.

4) RNC_CS_QUERY_UE_IMEI_SWITCH (CS IMEI Request Switch)

When this switch is turned on, the BSC6900 rather than the CN sends an IDENTITY REQUEST message to obtain the international mobile equipment identity (IMEI) of a UE. Note: When the CN checks the serial number of direct transfer messages and the SEND_MSG_NULL_SWITCH switch is turned off, turning on this switch leads to inconsistency in the serial number of direct transfer messages between the CN and the UE. This causes CS service setup failures. Therefore, you are not advised to turn on this switch. Before turning on this switch, test the interworking between the BSC6900 and the CN. If the CN checks the serial number of direct transfer messages, turn on SEND_MSG_NULL_SWITCH under "PROCESSSWITCH4" in the "SET URRCTRLSWITCH"

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command.

When the switch is turned off, the BSC6900 does not send an IDENTITY REQUEST message to obtain the IMEI of a UE.

5) RNC_PS_QUERY_UE_IMEI_SWITCH (PS IMEI Request Switch)

When the switch is turned on, the BSC6900, rather than the CN, sends an IDENTITY REQUEST message to obtain the IMEI of a UE.

When the switch is turned off, the BSC6900 does not send an IDENTITY REQUEST message to obtain the IMEI of a UE.

6) FACH_DTCH_CONGEST_P2D (P2D Switch for Congested FACH or DTCH)

When the switch is turned on, UEs using PS services trigger the CELL_PCH-to-CELL_DCH procedure (P2D procedure for short) on a congested FACH or DTCH.

When the switch is turned off, UEs using PS services do not trigger the P2D procedure on a congested FACH or DTCH.

7) RNC_RBSETUP_DRD_FAIL_ROLLBACK_SWITCH (RB Establishment DRD Rollback Switch)

When the switch is turned on, the BSC6900 supports rollback caused by failed DRDs of RB establishment.

When the switch is turned off, the BSC6900 does not support rollback caused by

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failed DRDs of RB establishment.

8) PS_NOTIFYCN_NOTDOWNSIZE_SWITCH (Switch for Not Triggering Rate Reduction Negotiation Between the CN and the RNC After a PS Service Access Failure)

When the switch is turned on, the access rate is not negotiated between the BSC6900 and the CN if a PS service fails to be admitted.

When the switch is turned off, the access rate is negotiated between the BSC6900 and the CN if a PS service fails to be admitted.

9) ASU_RSP_TIMEOUT_HANDLE_SWITCH (Switch for Performing the Optimized Soft-Handover Timeout Procedure)

When the switch is turned on, the RNC considers that it has received an ACTIVE SET UPDATE COMPLETE message during soft handover procedure after the message has expired.

When the switch is turned off, RABs are directly released during soft handover procedure after the ACTIVE SET UPDATE COMPLETE message has expired.

10) RB_RECFG_USER_INACT_SWITCH (Switch for Performing the Optimized RRC Connection Release Procedure with No Data Transmitted on the UE upon UE State Transition Timeout)

When the switch is turned on, the RNC initiated the release

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process with the cause of user inactive when the UE have no data to transmit.

When the switch is turned off, the RNC initiated the release process with other causes when the UE have no data to transmit.

11) RRC_SCRI_NORM_REL_SWITCH (Switch for Performing the Optimized RRC Connection Release Procedure on Receipt of a SIGNALLING CONNECTION RELEASE INDICATION Message)

When the switch is turned on, the RNC initiated the normal release process after receive SIGNALLING CONNECTION RELEASE INDICATION message from UE.

When the switch is turned off, the RNC does not handle SIGNALLING CONNECTION RELEASE INDICATION message during the process.

12) CELLUPT_RLFAILURE_SRBREESTAB_SWITCH (Switch for SRB Reestablishment During a Cell Update with the Cause Value of RL Failure)

When the switch is turned on, SRBs are reestablished during cell update procedure with the "RL Failure" cause value.

When the switch is turned off, SRBs are not reestablished during cell update procedure with the "RL Failure" cause value.

13) CU_OVERLAP_DSCR_SWITCH (Switch for Performing the Optimized Procedure for

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Concurrent RB and Cell Update, Hard handover, or DRD)

When the switch is turned on, the DSCR procedure is performed if RNC can not handles different processes performed simultaneously.

When the switch is turned off,the DSCR procedure is not performed in this scenes.

14) TRB_RST_DSCR_SWITCH (Switch for Performing the Optimized TRB Reset Procedure for PS BE Services)

When the switch is turned on, the DSCR procedure is performed if a Layer 2 data transmission error occurs.

When the switch is turned off, the DSCR procedure is not performed if a Layer 2 data transmission error occurs.

15) RNC_FD_SCRI_FORCE_REL_SWITCH (Signaling Connection Release Switch for UEs Supporting Fast Dormancy)

When the switch is turned on, if the BSC6900 receives a SIGNALING CONNECTION RELEASE INDICATION from UE with the cause of "UE Requested PS Data session end", the BSC6900 triggers the state transition for the UE. Otherwise, the BSC6900 releases the signaling connection.

When the switch is turned off, if the BSC6900 receives a SIGNALING CONNECTION RELEASE INDICATION from UE, the BSC6900 triggers the

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state transition for the UE.

16) USRPLN_PRORATION_SHARED_ALO (Algorithm Switch for Inter-Subrack Load Sharing on the User Plane)

When the switch is turned on, load sharing can be performed based on the ratio of available user plane resources to total user plane resources in a subrack.

When the switch is turned off, load sharing cannot be performed based on the ratio of available user plane resources to total user plane resources in a subrack.

17) FP_IUUP_TRACE_SWITCH (Switch for Tracing UEs Failing in FP Synchronization)

When the switch is turned on, UEs using FP or Iu UP can be traced in terms of data streams.

When the switch is turned off, UEs using FP or Iu UP cannot be traced in terms of data streams.

18) RNC_PCHR_OUTPUT_CTRL_SWITCH (Switch for Reducing PCHR Log Information for Normal Procedure)

The switch RNC_PCHR_OUTPUT_CTRL_SWITCH controls whether the BSC6900 reduces information recorded in a PCHR log for a normal procedure.

When this switch is turned on, the BSC6900 reduces information in a performance call history record (PCHR) log

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recorded during a normal procedure and reports only the following information blocks:

-RRC_RELEASE

-CS_RAB_SETUP

-PS_RAB_SETUP

-CS_RAB_REL

-PS_RAB_REL

-SHO

-SYS_HO_OUT

-INTRA_FREQ_NET_OPT

-STAT

-CS_RAB_QUALITY_STAT

-PS_RAB_QUALITY_STAT

A procedure is abnormal only when either of the following conditions is met:

-The RRC connection setup fails.

-The RAB setup fails.

-The RAB is abnormally released.

-The value of the information element (IE) NAS-PDU contained in a DIRECT TRANSFER message is ATTACH REJECT, RAU REJECT, or LAU REJECT.

If this switch is turned off, the BSC6900 does not reduce information recorded in a PCHR log.

19) DTMF_SWITCH (DTMF Switch)

When the switch is turned on, the BSC6900 starts tracing after receiving a special RANAP_DIRECT_TRANSFER message from a UE.

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When the switch is turned off, the BSC6900 does not start tracing after receiving a special RANAP_DIRECT_TRANSFER message from a UE.

20) FAST_CS_FB_BASEDON_RIM_SWITCH (Switch for fast CSFB based on RIM)

When the switch is turned off, the BSC6900 supports fast CSFB(CS fallback) based on RIM.

When the switch is turned on, the BSC6900 does not support fast CSFB(CS fallback) based on RIM.

GUI Value Range:LOAD_IRAT_HO_RNC_FILL_TL, SEND_IDT_JUDGE_IU_RESET, RNC_RBRECFG_DRD_FAIL_ROLLBACK_SWITCH, RNC_CS_QUERY_UE_IMEI_SWITCH, RNC_PS_QUERY_UE_IMEI_SWITCH, FACH_DTCH_CONGEST_P2D, RNC_RBSETUP_DRD_FAIL_ROLLBACK_SWITCH, PS_NOTIFYCN_NOTDOWNSIZE_SWITCH, ASU_RSP_TIMEOUT_HANDLE_SWITCH, RB_RECFG_USER_INACT_SWITCH, RRC_SCRI_NORM_REL_SWITCH, CELLUPT_RLFAILURE_SRBREESTAB_SWITCH, CU_OVERLAP_DSCR_SWITCH, TRB_RST_DSCR_SWITCH, RNC_FD_SCRI_FORCE_REL_SWITCH, USRPLN_PRORATION_SHARED_ALO, FP_IUUP_TRACE_SWITCH,

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RNC_PCHR_OUTPUT_CTRL_SWITCH, DTMF_SWITCH, FAST_CS_FB_BASEDON_RIM_SWITCH

Actual Value Range:LOAD_IRAT_HO_RNC_FILL_TL, SEND_IDT_JUDGE_IU_RESET, RNC_RBRECFG_DRD_FAIL_ROLLBACK_SWITCH, RNC_CS_QUERY_UE_IMEI_SWITCH, RNC_PS_QUERY_UE_IMEI_SWITCH, FACH_DTCH_CONGEST_P2D, RNC_RBSETUP_DRD_FAIL_ROLLBACK_SWITCH, PS_NOTIFYCN_NOTDOWNSIZE_SWITCH, ASU_RSP_TIMEOUT_HANDLE_SWITCH, RB_RECFG_USER_INACT_SWITCH, RRC_SCRI_NORM_REL_SWITCH, CELLUPT_RLFAILURE_SRBREESTAB_SWITCH, CU_OVERLAP_DSCR_SWITCH, TRB_RST_DSCR_SWITCH, RNC_FD_SCRI_FORCE_REL_SWITCH, USRPLN_PRORATION_SHARED_ALO, FP_IUUP_TRACE_SWITCH, RNC_PCHR_OUTPUT_CTRL_SWITCH, DTMF_SWITCH, FAST_CS_FB_BASEDON_RIM_SWITCH

Unit:None

Default Value:LOAD_IRAT_HO_RNC_FILL_TL-0&SEND_IDT_JUDGE_IU_RESET-0&RNC_RBRECFG_DRD_FAIL_ROLLBACK_SWITCH-0&RNC_CS_QUERY_UE_IMEI_SWITCH-0&RNC_PS_QUERY_UE_IMEI_SWITCH-0&FACH_DTCH_CO

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NGEST_P2D-0&RNC_RBSETUP_DRD_FAIL_ROLLBACK_SWITCH-0&PS_NOTIFYCN_NOTDOWNSIZE_SWITCH-0&ASU_RSP_TIMEOUT_HANDLE_SWITCH-0&RB_RECFG_USER_INACT_SWITCH-0&RRC_SCRI_NORM_REL_SWITCH-0&CELLUPT_RLFAILURE_SRBREESTAB_SWITCH-0&CU_OVERLAP_DSCR_SWITCH-0&TRB_RST_DSCR_SWITCH-0&RNC_FD_SCRI_FORCE_REL_SWITCH-0&USRPLN_PRORATION_SHARED_ALO-0&FP_IUUP_TRACE_SWITCH-1&RNC_PCHR_OUTPUT_CTRL_SWITCH-1&DTMF_SWITCH-1&FAST_CS_FB_BASEDON_RIM_SWITCH-1

PROCESSSWITCH3

BSC6900 SET URRCTRLSWITCH

WRFD-010101

WRFD-010801

WRFD-010802

WRFD-02030802

WRFD-010202


Intra RNC Cell Update

Inter RNC Cell Update

PS Handover Between UMTS and GPRS


Meaning:1) FACH_DCCH_CONG_CTRL_SWITCH (Congestion Control Switch for FACH or DCCH)

When the switch is turned on, the BSC6900 restricts the P2F or CELL_FACH-to-CELL_DCH (F2D for short) procedure triggered by heavy PS traffic.

When the switch is turned off, the BSC6900 does not restrict the P2F or F2D procedure triggered by heavy PS traffic.

2) RNC_F2D_RLC_SUSPEND_SWITCH (RLC Suspension Switch for Event 4A)

When the switch is turned on, the BSC6900 triggers RLC suspension during the F2D procedure for a UE, and it resumes RLC transmission after the BSC6900 receives an RB RECONFIGURATION COMPLETE message or after the UE rolls back to the






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CELL_FACH state.

When the switch is turned off, the BSC6900 does not trigger RLC suspension during the F2D procedure for a UE, and it resumes RLC transmission after the BSC6900 receives an RB RECONFIGURATION COMPLETE message or after the UE rolls back to the CELL_FACH state.

3) UM_RRCRELCMP_RLDEL_DELAY_SWITCH (RL Deletion Delay Switch for RRC CONNECTION RELEASE COMPLETE Messages)

When the switch is turned on, the BSC6900 starts the timer for radio link deletion if it receives an RRC CONNECTION RELEASE COMPLETE message. After the timer has expired, the BSC6900 restarts to delete radio links.

When the switch is turned off, the BSC6900 immediately starts to delete radio links if it receives an RRC CONNECTION RELEASE COMPLETE message.

4) RNC_TVM_BASED_P2D_SWITCH (TVM-based P2D Switch)

When the switch is turned on, for UEs in the CELL_PCH state, the BSC6900 triggers the P2D procedure if the BSC6900 receives from a UE a cell update message in which the value of the IE "Traffic volume indicator" is TRUE, or if the dynamic traffic volume measured on the CN meets a specified threshold.

When the switch is turned off,

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the BSC6900 does not trigger the P2D procedure based on the value of the IE "Traffic volume indicator" or on the dynamic traffic volume measured on the CN.

5) CS_RLFAIL_RRCSETUP_STAT_SWITCH (Measurement Switch for Released CS Services of UEs Resending RRC Connection Requests Caused by RL Synchronization Loss)

When the switch is turned on, if radio links for a UE experience synchronization loss on the network side and the UE has released its RRC connection and resends an RRC connection request, the resulting CS services released are considered call drops.

When the switch is turned off, if radio links for a UE experience synchronization loss on the network side and the UE has released its RRC connection and resends an RRC connection request, the resulting CS services released are not considered call drops.

6) PS_INACT_NOTREL_FOR_CSPS_SWITCH (Switch for Not Releasing PS RABs After Timeout)

When this switch is turned on, the BSC6900 does not release PS RABs for inactive UEs that use combined CS and PS services (CS+xPS) after the PS user inactivity timer has expired. CS+xPS refers to one CS session and one or more PS sessions.

When this switch is turned off,

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the BSC6900 releases PS RABs for inactive UEs that use combined CS and PS services (CS+xPS) after the PS user inactivity timer has expired.

7) CS_CALL_DROP_DEFINITION (CS Call Drop Calculation Switch)

When this switch is turned on, the BSC6900 regards a circuit switched (CS) service release as a call drop while taking statistics under the following conditions:

The BSC6900 releases a CS service.

The BSC6900 receives an IU RELEASE COMMAND message with the cause value NORMAL from the CS core network (CN).

When this switch is turned off, the BSC6900 regards a CS service release as normal while taking statistics under the preceding conditions.

8) PS_CALL_DROP_DEFINITION (PS Call Drop Calculation Switch)

When this switch is turned on, the BSC6900 regards a packet switched (PS) service release as a call drop while taking statistics under the following conditions:

The BSC6900 releases a PS service.

The BSC6900 receives an IU RELEASE COMMAND message with the cause value NORMAL from the PS CN.

When this switch is turned off, the BSC6900 regards a PS service release as normal

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while taking statistics under the preceding conditions.

9) RNC_U2U_SWITCH (Switch for Resuming the URA_PCH State with the cause value of Re-entered Service Area)

When the switch is turned on, the BSC6900 instructs a UE to resume the URA_PCH state, upon receiving a CELL UPDATE message with the cause value of Re-entered Service Area.

When the switch is turned off, the BSC6900 instructs a UE to move from the URA_PCH to CELL_FACH state, upon receiving a CELL UPDATE message with the cause value of Re-entered Service Area.

10) INTERRAT2U_RESUME_PS_ASAP_SWITCH (Switch for Restoring PS Services ASAP During an Incoming Inter-RAT Handover)

When this switch is turned on, the BSC6900 resumes PS data transmission after receiving a Handover to UTRAN Complete message.

When this switch is turned off, the BSC6900 resumes PS data transmission after receiving a UTRAN Mobility Information Confirm message.

11) UE_TRB_RESET_IOT_SWITCH (Switch for Waiting for the UE's Response After a TRB Reset)

When this switch is turned on, after a UE in the CELL_FACH state sends a CELL UPDATE message with the cause value of TRB reset to the BSC6900, the BSC6900 performs the

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following procedure:The BSC6900 sends a CELL UPDATE CONFIRM message containing physical layer information to instruct the UE to respond.The BSC6900 waits for the UE to send a response message. If the BSC6900 does not receive the message before a timer expires, the BSC6900 sends an RRC RELEASE message to the UE.The UE will respond with one of the following messages:UTRAN MOBILITY INFORMATION CONFIRM,PHYSICAL CHANNEL RECONFIGURATION COMPLETE,TRANSPORT CHANNEL RECONFIGURATION COMPLETE,RADIO BEARER RECONFIGURATION COMPLETE,RADIO BEARER RELEASE COMPLETE.

When this switch is turned off, after a UE in the CELL_FACH state sends a CELL UPDATE message with the cause value of TRB reset to the BSC6900, the BSC6900 does not wait for the UE to send a response message. Instead, the BSC6900 performs the normal procedure.

12) CUC_CMP_NO_ACTIVE_CFN_SWITCH(No CFN in CELL UPDATE CONFIRM Response)

When this switch is turned on, the RNC does not release the connection for the UE performing CS services in the CELL_DCH state if the UE does not put the radio bearer activation time information element (IE) in the response to a CELL UPDATE CONFIRM message.

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When this switch is turned off, the RNC releases the connection for the UE performing CS services in the CELL_DCH state if the UE does not put the radio bearer activation time IE in the response to a CELL UPDATE CONFIRM message.

13) RAB_DL_BITRATE_MOD_SWITCH(Switch of DL RAB Bit Rate Changed by RNC)

When this switch is turned on, the RNC changes the PS downlink RAB bit rate to a value specified by "RabDLBitrate".

When this switch is turned off, the RNC does not change the PS downlink RAB bit rate assigned by the CN.

14) RAB_WAIT_IUUP_INIT_RESPONSE_SWITCH(Response After IUUP Initialization During RAB Setup Switch)

When this switch is turned on, the RNC sends an RAB assignment response message to the CN during the RAB setup procedure only after the IUUP initialization procedure has been completed.

When this switch is turned off, the RNC sends an RAB assignment response message to the CN regardless of whether the IUUP initialization procedure is complete.

15) RNC_RDY_FOR_INTERRAT_COMPATIBLE_SWITCH (Compatibility Switch for Relocations from LTE/GSM to UMTS When RNC Pool Is

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Enabled)

When this switch is turned on and a UE is handed over from an eNodeB to a NodeB without control rights in an RNC pool, the BSC6900 performs as follows:

(1)Upon receiving an LTE/GSM incoming relocation message, the BSC6900 sends a message containing the failure cause value IU_TIME_CRITI_RELOC.

(2)After the eNodeB initiates a RIM procedure for obtaining the system information about the cell where a UE camps on, the BSC6900 sends back a message containing the cell ID and the ID of the BSC6900 with the NodeB control rights.

When this switch is turned off and a UE is handed over from an eNodeB to a NodeB without control rights in an RNC pool, the BSC6900 performs as follows:

(1)Upon receiving an LTE/GSM incoming relocation message, the BSC6900 sends a message containing a failure cause value, which is the same as that used when a cell is unavailable.


GUI Value Range:FACH_DCCH_CONG_CTRL_SWITCH, RNC_F2D_RLC_SUSPEND_SWITCH, UM_RRCRELCMP_RLDEL_DELAY_SWITCH, RNC_TVM_BASED_P2D_SWITCH, CS_RLFAIL_RRCSETUP_ST

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AT_SWITCH, PS_INACT_NOTREL_FOR_CSPS_SWITCH, RAB_DL_BITRATE_MOD_SWITCH, RAB_WAIT_IUUP_INIT_RESPONSE_SWITCH, CS_CALL_DROP_DEFINITION, PS_CALL_DROP_DEFINITION, RNC_U2U_SWITCH, INTERRAT2U_RESUME_PS_ASAP_SWITCH, UE_TRB_RESET_IOT_SWITCH, CUC_CMP_NO_ACTIVE_CFN_SWITCH, RNC_RDY_FOR_INTERRAT_COMPATIBLE_SWITCH

Actual Value Range:FACH_DCCH_CONG_CTRL_SWITCH, RNC_F2D_RLC_SUSPEND_SWITCH, UM_RRCRELCMP_RLDEL_DELAY_SWITCH, RNC_TVM_BASED_P2D_SWITCH, CS_RLFAIL_RRCSETUP_STAT_SWITCH, PS_INACT_NOTREL_FOR_CSPS_SWITCH, RAB_DL_BITRATE_MOD_SWITCH, RAB_WAIT_IUUP_INIT_RESPONSE_SWITCH, CS_CALL_DROP_DEFINITION, PS_CALL_DROP_DEFINITION, RNC_U2U_SWITCH, INTERRAT2U_RESUME_PS_ASAP_SWITCH, UE_TRB_RESET_IOT_SWITCH, CUC_CMP_NO_ACTIVE_CFN_SWITCH, RNC_RDY_FOR_INTERRAT_COMPATIBLE_SWITCH

Unit:None

Default Value:FACH_DCCH_CONG_

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CTRL_SWITCH-0&RNC_F2D_RLC_SUSPEND_SWITCH-0&UM_RRCRELCMP_RLDEL_DELAY_SWITCH-0&RNC_TVM_BASED_P2D_SWITCH-0&CS_RLFAIL_RRCSETUP_STAT_SWITCH-0&PS_INACT_NOTREL_FOR_CSPS_SWITCH-0&RAB_DL_BITRATE_MOD_SWITCH-0&RAB_WAIT_IUUP_INIT_RESPONSE_SWITCH-0&CS_CALL_DROP_DEFINITION-0&PS_CALL_DROP_DEFINITION-0&RNC_U2U_SWITCH-0&INTERRAT2U_RESUME_PS_ASAP_SWITCH-0&UE_TRB_RESET_IOT_SWITCH-0&CUC_CMP_NO_ACTIVE_CFN_SWITCH-0&RNC_RDY_FOR_INTERRAT_COMPATIBLE_SWITCH-0

RegByFachSwitch


WRFD-040100

Flow Control Meaning:The parameter specifies whether to set up RRC connection for registration on the FACH instead of on the DCH in the call shock.

When ON is selected, BSC6900 will perform flow control at cell level or NodeB level, the RRC connection for registration is set up on the FACH instead of on the DCH.

When OFF is selected, the channel setup strategy of RRC connection request for registration can be set by running the SET URRCESTCAUSE command.



Unit:None

Default Value:ON

RejectKPICTHD


WRFD-020103


Meaning:Threshold for triggering the cell-level dynamic CAPS flow control algorithm based on the ratio of











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MOD UCELLFCALGOPARA

RRC connection setup failures.



Unit:%

Default Value:20

RejectKPIRTHD


MOD UCELLFCALGOPARA

WRFD-020103


Meaning:Threshold for stopping the cell-level dynamic CAPS flow control algorithm based on the ratio of RRC connection setup failures.



Unit:%

Default Value:10

ReservedSwitch0

BSC6900 SET UCORRMALGOSWITCH

WRFD-02040001

WRFD-021400

WRFD-020203

WRFD-021101

WRFD-010613

WRFD-020701

Intra System Direct Retry

Direct Signaling Connection Re-establishment (DSCR)

Inter RNC Soft Handover


AMR-WB (Adaptive Multi Rate Wide Band)

AMR/WB-AMR Speech Rates Control

Meaning:1. RESERVED_SWITCH_0_BIT2: When the switch is set to ON, only uplink RLC or downlink RLC can be re-established during the state transition from CELL_FACH to CELL_DCH (F2D for short) and from CELL_PCH to CELL_DCH (P2D for short).

2. RESERVED_SWITCH_0_BIT3: When the switch is set to ON, signaling radio bearers (SRBs) cannot be changed from DCHs to HSPA channels (including the channel change from DCH to E-DCH in the uplink and from DCH to HS-DSCH in the downlink) during directed retry.

3. RESERVED_SWITCH_0_BIT4: When the switch is turned on, the BSC6900 does not consider whether the cell is congested during AMR service establishment. That is,

















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parameters are set on the precondition that the cell is not congested. This prevents inconsistency in uplink and downlink AMR modes.

4. RESERVED_SWITCH_0_BIT5: When the switch is set to ON, the BSC6900 establishes the BE service of a UE on R99 channels instead of on HSUPA channels if the uplink coverage of the UE is limited. The BSC6900 determines whether the uplink coverage of a UE is limited on the basis of the Ec/N0 reported by the UE during RRC connection establishment.

5. RESERVED_SWITCH_0_BIT6: When the switch is set to ON, the directed retry algorithm based on downlink load balance is enabled. When the switch is set to OFF, this algorithm is disabled. This algorithm is an optimization of the original downlink load balance algorithm.

6. RESERVED_SWITCH_0_BIT7: When the switch is set to ON, BE services that are already established on E-DCHs can be re-established on DCHs due to insufficient coverage.

7. RESERVED_SWITCH_0_BIT8: When the switch is turned on, D2F state transition is allowed regardless of whether the CCCH exists on the Iur interface. If D2F state transition fails, DSCR is triggered. When the switch is turned off, the BSC6900 needs to determine whether the CCCH exists on the Iur interface before determining

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whether to trigger D2F state transition.

8. RESERVED_SWITCH_0_BIT9: When the switch is set to ON, the uplink 0 kbit/s transport format of subflow A of an AMR service (WB AMR service or NB AMR service) is 0*TbSize. When the switch is set to OFF, the uplink 0 kbit/s transport format of subflow A of an AMR service is 1*0.

9. RESERVED_SWITCH_0_BIT10: When the switch is turned on, multiple cross-Iur radio links (RLs) belonging to the same BSC6900 can be added simultaneously. If an RL fails to be added with the failure cause of RadioNetwork:unspecified (14), the BSC6900 attempts to reestablish the RL for only once.

10. RESERVED_SWITCH_0_BIT11: Whether to allow PS services in combined services to be carried over the DCH in the uplink. When this switch is turned on, PS services in combined services can be carried only over the DCH in the uplink. When this switch is turned off, an uplink channel can be selected by running the "SET UFRCCHLTYPEPARA" command.

11. RESERVED_SWITCH_0_BIT14: Whether a PS BE service is limited to 0 kbit/s on the DCH after a UE that has the PS BE service performs a CELL_PCH/URA_PCH-to-CELL_DCH (P2D for short) state transition triggered by a CS service. When this switch is

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turned on, the PS BE service is limited to 0 kbit/s on the DCH after the UE performs a P2D state transition. When this switch is turned off, the PS BE service is limited to 8 kbit/s on the DCH after the UE performs a P2D state transition. This switch is valid only when RESERVED_SWITCH_1_BIT6 is set to 1. It is recommended that RESERVED_SWITCH_0_BIT14 is set to 1 when RESERVED_SWITCH_0_BIT28 is set to 1.

12. RESERVED_SWITCH_0_BIT15: Whether to allow PS services in combined services to be carried over the DCH in the downlink. When this switch is turned on, PS services in combined services can be carried only over the DCH in the downlink. When this switch is turned off, a downlink channel can be selected by running the "SET UFRCCHLTYPEPARA" command.

13. RESERVED_SWITCH_0_BIT16: None.


15. RESERVED_SWITCH_0_BIT28: Whether a UE in the CELL_PCH or URA_PCH state is allowed to set up a CS service after performing a CELL_PCH/URA_PCH-to-CELL_DCH (P2D for short) state transition. When this switch is turned on, the UE is allowed to set up a CS service after performing a P2D state transition. When this switch is

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turned off, the UE is allowed to set up a CS service after performing a CELL_PCH/URA_PCH-to-CELL_FACH (P2F for short) state transition. It is recommended that RESERVED_SWITCH_1_BIT6 and RESERVED_SWITCH_0_BIT14 are set to 1 when RESERVED_SWITCH_0_BIT28 is set to 1.


17.RESERVED_SWITCH_0_BIT32: Whether to enable the function of H2F state transition optimization for PTT services. When this parameter is set to 1, the 4A measurement on traffic volume or throughput is added to the H2F state transition mechanism, which prevents UEs from state transition to the CELL_FACH when there is data to transfer.

Disuse statement: This parameter is used temporarily in patch versions and will be replaced with a new parameter in later versions. The new parameter ID reflects the parameter function. Therefore, this parameter is not recommended for the configuration interface.

GUI Value Range:RESERVED_SWITCH_0_BIT1, RESERVED_SWITCH_0_BIT2, RESERVED_SWITCH_0_BIT3, RESERVED_SWITCH_0_BIT4, RESERVED_SWITCH_0_BIT5, RESERVED_SWITCH_0_BIT

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6, RESERVED_SWITCH_0_BIT7, RESERVED_SWITCH_0_BIT8, RESERVED_SWITCH_0_BIT9, RESERVED_SWITCH_0_BIT10, RESERVED_SWITCH_0_BIT11, RESERVED_SWITCH_0_BIT12, RESERVED_SWITCH_0_BIT13, RESERVED_SWITCH_0_BIT14, RESERVED_SWITCH_0_BIT15, RESERVED_SWITCH_0_BIT16, RESERVED_SWITCH_0_BIT17, RESERVED_SWITCH_0_BIT18, RESERVED_SWITCH_0_BIT19, RESERVED_SWITCH_0_BIT20, RESERVED_SWITCH_0_BIT21, RESERVED_SWITCH_0_BIT22, RESERVED_SWITCH_0_BIT23, RESERVED_SWITCH_0_BIT24, RESERVED_SWITCH_0_BIT25, RESERVED_SWITCH_0_BIT26, RESERVED_SWITCH_0_BIT27, RESERVED_SWITCH_0_BIT28, RESERVED_SWITCH_0_BIT29, RESERVED_SWITCH_0_BIT30, RESERVED_SWITCH_0_BIT31, RESERVED_SWITCH_0_BIT32

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Actual Value Range:RESERVED_SWITCH_0_BIT1, RESERVED_SWITCH_0_BIT2, RESERVED_SWITCH_0_BIT3, RESERVED_SWITCH_0_BIT4, RESERVED_SWITCH_0_BIT5, RESERVED_SWITCH_0_BIT6, RESERVED_SWITCH_0_BIT7, RESERVED_SWITCH_0_BIT8, RESERVED_SWITCH_0_BIT9, RESERVED_SWITCH_0_BIT10, RESERVED_SWITCH_0_BIT11, RESERVED_SWITCH_0_BIT12, RESERVED_SWITCH_0_BIT13, RESERVED_SWITCH_0_BIT14, RESERVED_SWITCH_0_BIT15, RESERVED_SWITCH_0_BIT16, RESERVED_SWITCH_0_BIT17, RESERVED_SWITCH_0_BIT18, RESERVED_SWITCH_0_BIT19, RESERVED_SWITCH_0_BIT20, RESERVED_SWITCH_0_BIT21, RESERVED_SWITCH_0_BIT22, RESERVED_SWITCH_0_BIT23, RESERVED_SWITCH_0_BIT24, RESERVED_SWITCH_0_BIT25, RESERVED_SWITCH_0_BIT26,

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RESERVED_SWITCH_0_BIT27, RESERVED_SWITCH_0_BIT28, RESERVED_SWITCH_0_BIT29, RESERVED_SWITCH_0_BIT30, RESERVED_SWITCH_0_BIT31, RESERVED_SWITCH_0_BIT32

Unit:None

Default Value:RESERVED_SWITCH_0_BIT1-0&RESERVED_SWITCH_0_BIT2-0&RESERVED_SWITCH_0_BIT3-0&RESERVED_SWITCH_0_BIT4-0&RESERVED_SWITCH_0_BIT5-0&RESERVED_SWITCH_0_BIT6-0&RESERVED_SWITCH_0_BIT7-0&RESERVED_SWITCH_0_BIT8-0&RESERVED_SWITCH_0_BIT9-0&RESERVED_SWITCH_0_BIT10-0&RESERVED_SWITCH_0_BIT11-0&RESERVED_SWITCH_0_BIT12-0&RESERVED_SWITCH_0_BIT13-0&RESERVED_SWITCH_0_BIT14-0&RESERVED_SWITCH_0_BIT15-0&RESERVED_SWITCH_0_BIT16-0&RESERVED_SWITCH_0_BIT17-0&RESERVED_SWITCH_0_BIT18-0&RESERVED_SWITCH_0_BIT19-0&RESERVED_SWITCH_0_BIT20-0&RESERVED_SWITCH_0_BIT21-0&RESERVED_SWITCH_0_BIT22-0&RESERVED_SWITCH_0_BIT23-0&RESERVED_SWITCH_0_BIT24-0&RESERVED_SWITCH_0_BIT25-0&RESERVED_SWITCH_0_BIT26-0&RESERVED_SWITCH_0_BIT27-0&RESERVED_SWITCH_0_BIT28-0&RESERVED_SWITCH_0_BIT29-0&RESERVED_SWITCH_0_BIT30-0&RESERVED_SWITCH_0_BIT31-0&RESERVED_SWITCH_0

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_BIT32-0

ReservedSwitch0


None None Meaning:CORRM algorithm reserved switch 0. The switch is reserved for further change request use.


GUI Value Range:RESERVED_SWITCH_0_BIT1, RESERVED_SWITCH_0_BIT2, RESERVED_SWITCH_0_BIT3, RESERVED_SWITCH_0_BIT4, RESERVED_SWITCH_0_BIT5, RESERVED_SWITCH_0_BIT6, RESERVED_SWITCH_0_BIT7, RESERVED_SWITCH_0_BIT8, RESERVED_SWITCH_0_BIT9, RESERVED_SWITCH_0_BIT10, RESERVED_SWITCH_0_BIT11, RESERVED_SWITCH_0_BIT12, RESERVED_SWITCH_0_BIT13, RESERVED_SWITCH_0_BIT14, RESERVED_SWITCH_0_BIT15, RESERVED_SWITCH_0_BIT16, RESERVED_SWITCH_0_BIT17, RESERVED_SWITCH_0_BIT





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18, RESERVED_SWITCH_0_BIT19, RESERVED_SWITCH_0_BIT20, RESERVED_SWITCH_0_BIT21, RESERVED_SWITCH_0_BIT22, RESERVED_SWITCH_0_BIT23, RESERVED_SWITCH_0_BIT24, RESERVED_SWITCH_0_BIT25, RESERVED_SWITCH_0_BIT26, RESERVED_SWITCH_0_BIT27, RESERVED_SWITCH_0_BIT28, RESERVED_SWITCH_0_BIT29, RESERVED_SWITCH_0_BIT30, RESERVED_SWITCH_0_BIT31, RESERVED_SWITCH_0_BIT32

Actual Value Range:RESERVED_SWITCH_0_BIT1, RESERVED_SWITCH_0_BIT2, RESERVED_SWITCH_0_BIT3, RESERVED_SWITCH_0_BIT4, RESERVED_SWITCH_0_BIT5, RESERVED_SWITCH_0_BIT6, RESERVED_SWITCH_0_BIT7, RESERVED_SWITCH_0_BIT8, RESERVED_SWITCH_0_BIT9, RESERVED_SWITCH_0_BIT10, RESERVED_SWITCH_0_BIT11, RESERVED_SWITCH_0_BIT

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12, RESERVED_SWITCH_0_BIT13, RESERVED_SWITCH_0_BIT14, RESERVED_SWITCH_0_BIT15, RESERVED_SWITCH_0_BIT16, RESERVED_SWITCH_0_BIT17, RESERVED_SWITCH_0_BIT18, RESERVED_SWITCH_0_BIT19, RESERVED_SWITCH_0_BIT20, RESERVED_SWITCH_0_BIT21, RESERVED_SWITCH_0_BIT22, RESERVED_SWITCH_0_BIT23, RESERVED_SWITCH_0_BIT24, RESERVED_SWITCH_0_BIT25, RESERVED_SWITCH_0_BIT26, RESERVED_SWITCH_0_BIT27, RESERVED_SWITCH_0_BIT28, RESERVED_SWITCH_0_BIT29, RESERVED_SWITCH_0_BIT30, RESERVED_SWITCH_0_BIT31, RESERVED_SWITCH_0_BIT32

Unit:None

Default Value:RESERVED_SWITCH_0_BIT1-0&RESERVED_SWITCH_0_BIT2-0&RESERVED_SWITCH_0_BIT3-0&RESERVED_SWITCH_0_BIT4-0&RESERVED_SWITCH_0_BIT5-0&RESERVED_SWITCH_0_BIT6-0&RESERVED_SWITCH_0_BIT7-0&RESERVED_SWIT

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CH_0_BIT8-0&RESERVED_SWITCH_0_BIT9-0&RESERVED_SWITCH_0_BIT10-0&RESERVED_SWITCH_0_BIT11-0&RESERVED_SWITCH_0_BIT12-0&RESERVED_SWITCH_0_BIT13-0&RESERVED_SWITCH_0_BIT14-0&RESERVED_SWITCH_0_BIT15-0&RESERVED_SWITCH_0_BIT16-0&RESERVED_SWITCH_0_BIT17-0&RESERVED_SWITCH_0_BIT18-0&RESERVED_SWITCH_0_BIT19-0&RESERVED_SWITCH_0_BIT20-0&RESERVED_SWITCH_0_BIT21-0&RESERVED_SWITCH_0_BIT22-0&RESERVED_SWITCH_0_BIT23-0&RESERVED_SWITCH_0_BIT24-0&RESERVED_SWITCH_0_BIT25-0&RESERVED_SWITCH_0_BIT26-0&RESERVED_SWITCH_0_BIT27-0&RESERVED_SWITCH_0_BIT28-0&RESERVED_SWITCH_0_BIT29-0&RESERVED_SWITCH_0_BIT30-0&RESERVED_SWITCH_0_BIT31-0&RESERVED_SWITCH_0_BIT32-0

ReservedSwitch1


WRFD-021101


Meaning:1. CORRM algorithm reserved switch 1. The switch is reserved for further change request use.

2. RESERVED_SWITCH_1_BIT1: When the switch is set to ON, the "BSC6900" instructs the cells involved in the active set to report cell synchronization information by using an intra-frequency measurement control message. When the switch is set to OFF, the "BSC6900 instructs the cells involved in the active set not to report cell synchronization information by using an intra-frequency measurement control message. This avoids the






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transmission of too large measurement reports.

3. RESERVED_SWITCH_1_BIT2: When the switch is set to ON, the intra-frequency ReadSFNInd of a cell in system information SIB11/SIB12 is set to the fixed value READ.

4. RESERVED_SWITCH_1_BIT6: Whether the PS BE service rate is limited to a low level after the UE transits from CELL_PCH/URA_PCH to CELL_DCH (P2D for short). When the switch is turned on. The PS BE service rate is limited to a low level after performing a P2D state transition. When the switch is turned off. The PS BE service rate is not limited after performing a P2D state transition.


GUI Value Range:RESERVED_SWITCH_1_BIT1, RESERVED_SWITCH_1_BIT2, RESERVED_SWITCH_1_BIT3, RESERVED_SWITCH_1_BIT4, RESERVED_SWITCH_1_BIT5, RESERVED_SWITCH_1_BIT6, RESERVED_SWITCH_1_BIT7,

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RESERVED_SWITCH_1_BIT8, RESERVED_SWITCH_1_BIT9, RESERVED_SWITCH_1_BIT10, RESERVED_SWITCH_1_BIT11, RESERVED_SWITCH_1_BIT12, RESERVED_SWITCH_1_BIT13, RESERVED_SWITCH_1_BIT14, RESERVED_SWITCH_1_BIT15, RESERVED_SWITCH_1_BIT16, RESERVED_SWITCH_1_BIT17, RESERVED_SWITCH_1_BIT18, RESERVED_SWITCH_1_BIT19, RESERVED_SWITCH_1_BIT20, RESERVED_SWITCH_1_BIT21, RESERVED_SWITCH_1_BIT22, RESERVED_SWITCH_1_BIT23, RESERVED_SWITCH_1_BIT24, RESERVED_SWITCH_1_BIT25, RESERVED_SWITCH_1_BIT26, RESERVED_SWITCH_1_BIT27, RESERVED_SWITCH_1_BIT28, RESERVED_SWITCH_1_BIT29, RESERVED_SWITCH_1_BIT30, RESERVED_SWITCH_1_BIT31, RESERVED_SWITCH_1_BIT32

Actual Value Range:RESERVED_SWITCH_1_BIT1,

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RESERVED_SWITCH_1_BIT2, RESERVED_SWITCH_1_BIT3, RESERVED_SWITCH_1_BIT4, RESERVED_SWITCH_1_BIT5, RESERVED_SWITCH_1_BIT6, RESERVED_SWITCH_1_BIT7, RESERVED_SWITCH_1_BIT8, RESERVED_SWITCH_1_BIT9, RESERVED_SWITCH_1_BIT10, RESERVED_SWITCH_1_BIT11, RESERVED_SWITCH_1_BIT12, RESERVED_SWITCH_1_BIT13, RESERVED_SWITCH_1_BIT14, RESERVED_SWITCH_1_BIT15, RESERVED_SWITCH_1_BIT16, RESERVED_SWITCH_1_BIT17, RESERVED_SWITCH_1_BIT18, RESERVED_SWITCH_1_BIT19, RESERVED_SWITCH_1_BIT20, RESERVED_SWITCH_1_BIT21, RESERVED_SWITCH_1_BIT22, RESERVED_SWITCH_1_BIT23, RESERVED_SWITCH_1_BIT24, RESERVED_SWITCH_1_BIT25, RESERVED_SWITCH_1_BIT26, RESERVED_SWITCH_1_BIT27, RESERVED_SWITCH_1_BIT

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28, RESERVED_SWITCH_1_BIT29, RESERVED_SWITCH_1_BIT30, RESERVED_SWITCH_1_BIT31, RESERVED_SWITCH_1_BIT32

Unit:None

Default Value:RESERVED_SWITCH_1_BIT1-1&RESERVED_SWITCH_1_BIT2-1&RESERVED_SWITCH_1_BIT3-1&RESERVED_SWITCH_1_BIT4-1&RESERVED_SWITCH_1_BIT5-1&RESERVED_SWITCH_1_BIT6-1&RESERVED_SWITCH_1_BIT7-1&RESERVED_SWITCH_1_BIT8-1&RESERVED_SWITCH_1_BIT9-1&RESERVED_SWITCH_1_BIT10-1&RESERVED_SWITCH_1_BIT11-1&RESERVED_SWITCH_1_BIT12-1&RESERVED_SWITCH_1_BIT13-1&RESERVED_SWITCH_1_BIT14-1&RESERVED_SWITCH_1_BIT15-1&RESERVED_SWITCH_1_BIT16-1&RESERVED_SWITCH_1_BIT17-1&RESERVED_SWITCH_1_BIT18-1&RESERVED_SWITCH_1_BIT19-1&RESERVED_SWITCH_1_BIT20-1&RESERVED_SWITCH_1_BIT21-1&RESERVED_SWITCH_1_BIT22-1&RESERVED_SWITCH_1_BIT23-1&RESERVED_SWITCH_1_BIT24-1&RESERVED_SWITCH_1_BIT25-1&RESERVED_SWITCH_1_BIT26-1&RESERVED_SWITCH_1_BIT27-1&RESERVED_SWITCH_1_BIT28-1&RESERVED_SWITCH_1_BIT29-1&RESERVED_SWITCH_1_BIT30-1&RESERVED_SWITCH_1_BIT31-1&RESERVED_SWITCH_1_BIT32-1

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ReservedU32Para1


WRFD-021101


Meaning:CORRM algorithm reserved U32 para 1. The para of 32 bits is reserved for further change request use.




Unit:None

Default Value:4294967295

ReservedU8Para2


None None Meaning:CORRM algorithm reserved U8 para 2. The para of 8 bits is reserved for further change request use.




Unit:None

Default Value:0

ReservedU8Para3


None None Meaning:CORRM algorithm reserved U8 para 3. The para of 8 bits is reserved for further change request use.

Disuse statement: This














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parameter is used temporarily in patch versions and will be replaced with a new parameter in later versions. The new parameter ID reflects the parameter function. Therefore, this parameter is not recommended for the configuration interface.



Unit:None

Default Value:0

RrcConnRejWaitTmr

BSC6900 SET USTATETIMER

WRFD-010101


Meaning:Wait time IE contained in the RRC CONNECTION REJECT message for a high-priority RRC connection setup request, that is, the minimum time for which a UE must wait before it sends another RRC connection setup request. An RRC connection setup request has a high priority only when one of the following conditions is met:

1. The value of the IE CN domain identity contained in the RRC CONNECTION REQUEST message sent from the UE to the BSC6900 is CS domain.

2. The cause value contained in the RRC CONNECTION REQUEST message is Originating Conversational Call, Terminating Conversational Call, or Emergency Call.



Unit:s

Default Value:4





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RsvdPara1 BSC6900 SET UCACALGOSWITCH

WRFD-020101

Admission Control

Meaning:Reserved Parameter1.


GUI Value Range:RSVDBIT1(Reserved Switch 1), RSVDBIT2(Reserved Switch 2), RSVDBIT3(Reserved Switch 3), RSVDBIT4(Reserved Switch 4), RSVDBIT5(Reserved Switch 5), RSVDBIT6(Reserved Switch 6), RSVDBIT7(Reserved Switch 7), RSVDBIT8(Reserved Switch 8), RSVDBIT9(Reserved Switch 9), RSVDBIT10(Reserved Switch 10), RSVDBIT11(Reserved Switch 11), RSVDBIT12(Reserved Switch 12), RSVDBIT13(Reserved Switch 13), RSVDBIT14(Reserved Switch 14), RSVDBIT15(Reserved Switch 15), RSVDBIT16(Reserved Switch 16)

Actual Value Range:RSVDBIT1, RSVDBIT2, RSVDBIT3, RSVDBIT4, RSVDBIT5, RSVDBIT6, RSVDBIT7, RSVDBIT8, RSVDBIT9, RSVDBIT10, RSVDBIT11, RSVDBIT12, RSVDBIT13, RSVDBIT14, RSVDBIT15, RSVDBIT16

Unit:None





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Default Value:RSVDBIT1-0&RSVDBIT2-0&RSVDBIT3-0&RSVDBIT4-0&RSVDBIT5-0&RSVDBIT6-0&RSVDBIT7-1&RSVDBIT8-0&RSVDBIT9-0&RSVDBIT10-0&RSVDBIT11-0&RSVDBIT12-0&RSVDBIT13-0&RSVDBIT14-0&RSVDBIT15-0&RSVDBIT16-0

RsvdPara1 BSC6900 SET URRCTRLSWITCH

WRFD-010101


Meaning:2) NAS_QOS_MOD_SWITCH (QoS Change Switch for NAS)

When the switch is turned on, for UEs whose HS-DSCH category is smaller than 13, if the maximum downlink rate specified in the PDP activation requests from the UEs exceeds 16 Mbit/s, the requests are sent to the CN after the rate is changed to 16 Mbit/s.

When the switch is turned off, the PDP activation requests are sent to the CN without changing the maximum downlink rate.

15) RSVDBIT1_BIT15 (Reserved Parameter 1 Bit 15)

When the switch is turned on, the RNC enables the function of AMR mute detection.

When the switch is turned off, the RNC disables the function of AMR mute detection.


When the switch is turned on, the RNC can perform DRDs during the P2D procedure.

When the switch is turned off, the RNC cannot perform DRDs during the P2D





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procedure.

17) SYSHO_CSIN_PERMIT_SWITCH (2G-to-3G CS Handover Switch)

When the switch is turned on, inter-RAT CS handovers from 2G cells to 3G cells are allowed.

When the switch is turned off, inter-RAT CS handovers from 2G cells to 3G cells are not allowed.


When this switch is turned on, the RNC performs a state transition from CELL_PCH or URA_PCH to CELL_FACH (P2F) upon receiving a CELL UPDATE message with the cause value "uplink data transmission" or "paging response".

When this switch is turned off, if receiving a CELL UPDATE message with the cause value "uplink data transmission" or "paging response," the RNC performs a state transition from CELL_PCH or URA_PCH to CELL_DCH (P2D) in either of the following scenarios:

(1)Congestion occurs on the FACH.

(2)Congestion occurs on the DCCH, and the value of the Establishment cause information element (IE) in the message is Originating Conversational Call, Terminating Conversational Call, or Emergency Call.

21) RSVDBIT1_BIT21 (Reserved Parameter 1 Bit

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21)

When the switch is turned on, for UEs that are establishing AMR services and shifting from the CELL_FACH state to the CELL_DCH state, the RNC stops establishing AMR services to handle cell update if the RNC receives from the UEs a cell update message containing the cause value "cell reselection."

When the switch is turned off, for UEs that are establishing AMR services and shifting from the CELL_FACH state to the CELL_DCH state, if the RNC receives from the UEs a cell update message containing the cause value "cell reselection," the RNC stops establishing AMR services to handle cell update and resumes AMR services only after cell update is completed.


When the switch is turned on, the RNC does not trigger cell update with the cause value "RL Failure" if the RNC detects interrupted downlink transmission on SRB2.

When the switch is turned off, the RNC triggers cell update with the cause value "RL Failure" and reestablishes radio links if the RNC detects interrupted downlink transmission on SRB2.


When the switch is turned on, the RNC does not trigger cell update with the cause value "RL Failure" reported by a UE

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if the associated NodeB reports to the RNC that all radio links for the UE experience synchronization loss.

When the switch is turned off, the RNC triggers cell update with the cause value "RL Failure" reported by a UE and reestablishes radio links, if the associated NodeB reports to the RNC that all radio links for the UE experience synchronization loss.


When the switch is turned on, for UEs using CS services, the RNC does not trigger cell update with the cause value "RL Failure" reported by a UE, if the RNC detects interrupted downlink transmission on SRB2, or if the associated NodeB reports to the RNC that all radio links for the UE experience synchronization loss.

When the switch is turned off, for UEs using CS services, the RNC triggers cell update with the cause value "RL Failure" reported by a UE and reestablishes radio links, if the RNC detects interrupted downlink transmission on SRB2, or if the associated NodeB reports to the RNC that all radio links for the UE experience synchronization loss.


When the switch is turned on, for UEs using PS services only, the RNC does not reestablish radio links for a

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UE if the RNC detects interrupted downlink transmission on SRB2, or if the associated NodeB reports to the RNC that all radio links for the UE experience synchronization loss.

When the switch is turned off, for UEs using PS services only, the RNC triggers cell update with the cause value "RL Failure" reported by a UE and reestablishes radio link, if the RNC detects interrupted downlink transmission on SRB2, or if the associated NodeB reports to the RNC that all radio links for the UE experience synchronization loss.


When the switch is turned on, the RNC does not reestablish radio links for a UE if the UE reports to the RNC cell update caused by SRB reset.

When the switch is turned off, the RNC reestablishes radio links for a UE if the UE reports to the RNC cell update caused by SRB reset.


When the switch is turned on, for UEs using CS services, if a NodeB reports to the RNC that all radio links for a UE experience synchronization loss, the RNC starts the RL Restore timer whose duration is specified by the RlRstrTmr parameter in the SET USTATETIMER command. After the timer has expired, the RNC triggers cell update with the cause value "radio

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link failure" and reestablishes radio links for the UE.

When the switch is turned off, for UEs using CS services, if a NodeB reports to the RNC that all radio links for a UE experience synchronization loss, the RNC starts the RL Restore timer whose duration is specified by the T313 parameter in the SET UCONNMODETIMER command. After the timer has expired, the RNC triggers cell update with the cause value "radio link failure" and reestablishes radio links for the UE.


When the switch is turned off, the RNC performs the CELL_DCH-to-CELL_FACH (D2F for short) procedure on UEs that support fast dormancy.

When the switch is turned on, the RNC performs the CELL_DCH-to-CELL_PCH (D2P for short) procedure on UEs that support fast dormancy.


GUI Value Range:RSVDBIT1_BIT1, NAS_QOS_MOD_SWITCH, RSVDBIT1_BIT3, RSVDBIT1_BIT4, RSVDBIT1_BIT5,

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RSVDBIT1_BIT6, RSVDBIT1_BIT7, RSVDBIT1_BIT8, RSVDBIT1_BIT9, RSVDBIT1_BIT10, RSVDBIT1_BIT11, RSVDBIT1_BIT12, RSVDBIT1_BIT13, RSVDBIT1_BIT14, RSVDBIT1_BIT15, RSVDBIT1_BIT16, SYSHO_CSIN_PERMIT_SWITCH, RSVDBIT1_BIT18, RSVDBIT1_BIT19, RSVDBIT1_BIT20, RSVDBIT1_BIT21, RSVDBIT1_BIT22, RSVDBIT1_BIT23, RSVDBIT1_BIT24, RSVDBIT1_BIT25, RSVDBIT1_BIT26, RSVDBIT1_BIT27, RSVDBIT1_BIT28, RSVDBIT1_BIT29, RSVDBIT1_BIT30, RSVDBIT1_BIT31, RSVDBIT1_BIT32

Actual Value Range:This parameter is set to 0 or 1 according to the related domains.

Unit:None

Default Value:RSVDBIT1_BIT1-0&NAS_QOS_MOD_SWITCH-0&RSVDBIT1_BIT3-0&RSVDBIT1_BIT4-0&RSVDBIT1_BIT5-0&RSVDBIT1_BIT6-0&RSVDBIT1_BIT7-0&RSVDBIT1_BIT8-0&RSVDBIT1_BIT9-0&RSVDBIT1_BIT10-0&RSVDBIT1_BIT11-0&RSVDBIT1_BIT12-0&RSVDBIT1_BIT13-0&RSVDBIT1_BIT14-0&RSVDBIT1_BIT15-0&RSVDBIT1_BIT16-0&SYSHO_CSIN_PERMIT_SWITCH-1&RSVDBIT1_BIT18-1&RSVDBIT1_BIT19-1&RSVDBIT1_BIT20-1&RSVDBIT1_BIT21-1&RSVDBIT1_BIT22-1&RSVDBIT1_BIT23-1&RSVDBIT

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1_BIT24-1&RSVDBIT1_BIT25-1&RSVDBIT1_BIT26-1&RSVDBIT1_BIT27-1&RSVDBIT1_BIT28-1&RSVDBIT1_BIT29-1&RSVDBIT1_BIT30-1&RSVDBIT1_BIT31-0&RSVDBIT1_BIT32-1

RsvdPara1 BSC6900 ADD UNODEBALGOPARA

MOD UNODEBALGOPARA

WRFD-020101

Admission Control

Meaning:RSVDBIT4: This parameter must be used with the "NcpCongFlowCtrSwitch" parameter in the "SET ULDCALGOPARA" command to decide whether to activate the cell-level dynamic CAPS flow control algorithm based on the congestion status of the NCP link. When the flow control algorithm is activated, flow control is triggered if the NCP link is congested; flow control is stopped if the NCP link is not congested. When flow control is triggered, the number of allowed RRC connection requests per second in the cell decreases based on the value of "KPIstepdownpercentage". When flow control is stopped, the number of allowed RRC connection requests per second in the cell increases based on the value of "KPIstepuppercentage". The number of RRC connection requests does not change once the cell flow control status becomes stable.


GUI Value Range:RSVDBIT1(Reserved Switch 1),

../RNCParaHtml/mbsc/m-para/unodebalgopara_rsvdpara1.html

../RNCParaHtml/mbsc/m-mml/add-unodebalgopara.html



../RNCParaHtml/mbsc/m-mml/mod-unodebalgopara.html



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7-116


RSVDBIT2(Reserved Switch 2), RSVDBIT3(Reserved Switch 3), RSVDBIT4(Reserved Switch 4), RSVDBIT5(Reserved Switch 5), RSVDBIT6(Reserved Switch 6), RSVDBIT7(Reserved Switch 7), RSVDBIT8(Reserved Switch 8), RSVDBIT9(Reserved Switch 9), RSVDBIT10(Reserved Switch 10), RSVDBIT11(Reserved Switch 11), RSVDBIT12(Reserved Switch 12), RSVDBIT13(Reserved Switch 13), RSVDBIT14(Reserved Switch 14), RSVDBIT15(Reserved Switch 15), RSVDBIT16(Reserved Switch 16)


Unit:None

Default Value:RSVDBIT1-0&RSVDBIT2-0&RSVDBIT3-0&RSVDBIT4-0&RSVDBIT5-0&RSVDBIT6-0&RSVDBIT7-0&RSVDBIT8-0&RSVDBIT9-0&RSVDBIT10-0&RSVDBIT11-0&RSVDBIT12-0&RSVDBIT13-0&RSVDBIT14-0&RSVDBIT15-0&RSVDBIT16-0

RsvdPara1 BSC6900 ADD UCELLALGOSWITCH

MOD UCELLALGOSWI

WRFD-020101

Admission Control

Meaning:Reserved parameter 1.

Disuse statement: This parameter is used temporarily in patch versions and will be







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7-117


TCH replaced with a new parameter in later versions. The new parameter ID reflects the parameter function. Therefore, this parameter is not recommended for the configuration interface.

GUI Value Range:RSVDBIT1(Reserved Switch 1), RSVDBIT2(Reserved Switch 2), RSVDBIT3(Reserved Switch 3), RSVDBIT4(Reserved Switch 4), RSVDBIT5(Reserved Switch 5), RSVDBIT6(Reserved Switch 6), RSVDBIT7(Reserved Switch 7), RSVDBIT8(Reserved Switch 8), RSVDBIT9(Reserved Switch 9), RSVDBIT10(Reserved Switch 10), RSVDBIT11(Reserved Switch 11), RSVDBIT12(Reserved Switch 12), RSVDBIT13(Reserved Switch 13), RSVDBIT14(Reserved Switch 14), RSVDBIT15(Reserved Switch 15), RSVDBIT16(Reserved Switch 16)


Unit:None

Default Value:RSVDBIT1-0&RSVDBIT2-0&RSVDBIT3-0&RSVDBIT4-0&RSVDBIT5-0&RSVDBIT6-0&RSVDBIT7-0&RSVDBIT8-0&RSVDBIT9-0&RSVDBIT10-0&RSVDBIT11-0&RSVD

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7-118


BIT12-0&RSVDBIT13-0&RSVDBIT14-0&RSVDBIT15-0&RSVDBIT16-0

SLPAGECTHD BSC6900 SET FCCPUTHD WRFD-040100

Flow Control Meaning:CPU usage threshold for paging flow control over best effort (BE) services, supplementary services (SS), and the location service (LCS). BE services uses the same paging flow control thresholds as SS and LCS to ensure the paging success rate of real-time services. When the average CPU usage within several sliding windows reaches or exceeds "SS and LCS page restore threshold", the linear paging flow control on BE services, SS, and LCS is started. When the average CPU usage within several sliding windows reaches or exceeds "SS and LCS page control threshold", the 100% paging flow control on BE services, SS, and LCS is started.When the CPU becomes overloaded, the recommended value for this parameter is 85.



Unit:%

Default Value:80

SLPAGERTHD BSC6900 SET FCCPUTHD WRFD-040100

Flow Control Meaning:CPU usage threshold for paging flow control over best effort (BE) services, supplementary services (SS), and location service (LCS). BE services uses the same paging flow control thresholds as SS and LCS to ensure the paging success rate of real-time services. When the average CPU usage within several sliding windows reaches or

../RNCParaHtml/mbsc/m-para/fccputhd_slpagecthd.html


../RNCParaHtml/mbsc/m-para/fccputhd_slpagerthd.html


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exceeds "SS and LCS page restore threshold", the linear paging flow control on BE services, SS, and LCS is started. When the average CPU usage within several sliding windows is lower than the "SS and LCS page restore threshold", paging flow control over BE services, SS, and LCS is stopped.When the CPU becomes overloaded, the recommended value for this parameter is 75.



Unit:%

Default Value:70

SMPAGECTHD


Flow Control Meaning:CPU usage threshold for paging flow control over the short message service (SMS). When the average CPU usage within several sliding windows reaches or exceeds "SMS page restore threshold", the linear paging flow control on SMS is started. When the average CPU usage within several sliding windows reaches or exceeds the "SMS page control threshold", the 100% paging flow control on SMS is started.When the CPU becomes overloaded, the recommended value for this parameter is 80.



Unit:%

Default Value:70

SMPAGERTHD


Flow Control Meaning:CPU usage threshold for paging flow control over the short message service (SMS).







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When the average CPU usage within several sliding windows reaches or exceeds "SMS page restore threshold", the linear paging flow control on SMS is started. When the average CPU usage within several sliding windows is lower than "SMS page restore threshold", the flow control on SMS is stopped.When the CPU becomes overloaded, the recommended value for this parameter is 70.



Unit:%

Default Value:60

SMRRCCONNCCPUTHD


System Redundancy

Meaning:CPU usage threshold for stopping load sharing on SMS RRC connection setup requests. When the CPU usage of an XPU subsystem reaches this threshold or CtrlPlnSharingOutThd, whichever is smaller, later SMS RRC connection setup requests will be carried by other XPU subsystems. CtrlPlnSharingOutThd is set by using the command "SET UCTRLPLNSHAREPARA". If the CPU usage of all candidate XPU subsystems exceeds this threshold, flow control on SMS RRC connection setup requests is triggered. The parameter value is invalid if the SYS_LEVEL_DYNAMIC switch in the "CallShockCtrlSwitch" parameter of the "SET UCALLSHOCKCTRL" command is turned on.





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Unit:%

Default Value:70

SMRRCCONNCMSGTHD


System Redundancy

Meaning:Packet usage threshold for stopping load sharing on SMS RRC connection setup requests. When the packet usage of an XPU subsystem reaches this threshold, later SMS packets will be carried by other XPU subsystems. If the packet usage of all candidate XPU subsystems exceeds this threshold, flow control on SMS RRC connection setup request packets is triggered.



Unit:%

Default Value:75

SMRRCCONNRCPUTHD


System Redundancy

Meaning:CPU usage threshold for recoverying load sharing on SMS RRC connection setup requests. If the CPU usage of an XPU subsystem is lower than this threshold, this XPU subsystem is a candidate subsystem for the load sharing on SMS RRC connection setup requests. The parameter value is invalid if the SYS_LEVEL_DYNAMIC switch in the "CallShockCtrlSwitch" parameter of the "SET UCALLSHOCKCTRL" command is turned on.



Unit:%

Default Value:60







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SMRRCCONNRMSGTHD


System Redundancy

Meaning:Packet usage threshold for recoverying load sharing on SMS RRC connection setup requests. When the packet usage of an XPU subsystem is lower than this threshold, this XPU subsystem is a candidate subsystem for load sharing on SMS RRC connection setup requests.



Unit:%

Default Value:65

SMWINDOW BSC6900 SET FCMSGQTHD

GBFD-111705

WRFD-040100

GSM Flow Control

Flow Control

Meaning:Number of CPU usage sampling times involved in the calculation of the average CPU usage in the sliding window. "Filter window" is applied to avoid the change of the flow control status due to instantaneous overhigh CPU usage. After "filter window" is applied, the system compares the average CPU usage in a period before the current time with the corresponding threshold. In the case that the flow control switch is turned on, when the average CPU usage in "filter window" reaches or exceeds a flow control threshold, the corresponding flow control mechanism is triggered. When the average CPU usage is lower than a flow control threshold, the corresponding flow control mechanism is disabled.



Unit:None

Default Value:10




../RNCParaHtml/mbsc/m-para/fcmsgqthd_smwindow.html



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SMWINDOW BSC6900 SET FCCPUTHD GBFD-111705

WRFD-040100

GSM Flow Control

Flow Control

Meaning:Number of CPU usage sampling times involved in the calculation of the average CPU usage in the sliding window. "Filter window" is applied to avoid the change of the flow control status due to instantaneous overhigh CPU usage. After "filter window" is applied, the system compares the average CPU usage in a period before the current time with the corresponding threshold. In the case that the flow control switch is turned on, when the average CPU usage in "filter window" reaches or exceeds a flow control threshold, the corresponding flow control mechanism is triggered. When the average CPU usage is lower than a flow control threshold, the corresponding flow control mechanism is disabled.



Unit:None

Default Value:10

SN BSC6900 ADD UNODEB None None Meaning:UMTS XPU board slot Number.

GUI Value Range:0;2;4;8;10;12;14;16;18;20;22;24;26

Actual Value Range:0, 2, 4, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26

Unit:None

Default Value:None

SRN BSC6900 ADD UNODEB None None Meaning:Number of the EPS subrack managing the subsystem to which the NodeB belongs



../RNCParaHtml/mbsc/m-para/unodeb_sn.html

../RNCParaHtml/mbsc/m-mml/add-unodeb.html

../RNCParaHtml/mbsc/m-para/unodeb_srn.html


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Unit:None

Default Value:None

SSDSPAVEUSAGEALMTHD

BSC6900 SET CPUTHD MRFD-210304

Faulty Management

Meaning:DSP usage alarm clearance threshold. When the DSP usage is lower than the threshold, the DSP usage alarm is cleared. "DSP occupancy alarm clearance threshold" must be smaller than "DSP occupancy alarm threshold".



Unit:%

Default Value:80

SSDSPMAXUSAGEALMTHD

BSC6900 SET CPUTHD MRFD-210304

Faulty Management

Meaning:DSP usage alarm threshold. When the DSP usage exceeds the threshold, a DSP usage alarm is reported. "DSP occupancy alarm clearance threshold" must be smaller than "DSP occupancy alarm threshold".



Unit:%

Default Value:85

SSN BSC6900 ADD UNODEB None None Meaning:UMTS CPUS where the NodeB is located.

GUI Value Range:0~7


Unit:None

Default Value:None

SysRrcRejNum

BSC6900 SET UCALLSHOCKC

WRFD-040100

Flow Control Meaning:The parameter specifies the maximum number of RRC Connection



../RNCParaHtml/mbsc/m-mml/set-cputhd.html




../RNCParaHtml/mbsc/m-mml/set-cputhd.html

../RNCParaHtml/mbsc/m-para/unodeb_ssn.html






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TRL Reject messages per second from SPU subsystem to UE. When the SPU subsystem is in flow control state, the system will respond RRC Connection Reject message to UE. If the number of RRC Connection Reject messages exceeds the value of the parameter, RNC will discard the RRC connection request.



Unit:None

Default Value:100

T300 BSC6900 SET UIDLEMODETIMER

WRFD-010101


Meaning:T300 is started when UE sends the RRC CONNECTION REQUEST message. It is stopped when UE receives the RRC CONNECTION SETUP message. RRC CONNECTION REQUEST will be resent upon the expiry of the timer if V300 is lower than or equal to N300, else enter idle mode.

GUI Value Range:D100, D200, D400, D600, D800, D1000, D1200, D1400, D1600, D1800, D2000, D3000, D4000, D6000, D8000

Actual Value Range:100, 200, 400, 600, 800, 1000, 1200, 1400, 1600, 1800, 2000, 3000, 4000, 6000, 8000

Unit:ms

Default Value:D2000

T302 BSC6900 SET UCONNMODETIMER

WRFD-010101


Meaning:T302 is started after the UE transmits the CELL UPDATE/URA UPDATE message and stopped after the UE receives the CELL UPDATE CONFIRM/URA UPDATE CONFIRM


../RNCParaHtml/mbsc/m-mml/set-uidlemodetimer.html




../RNCParaHtml/mbsc/m-mml/set-uconnmodetimer.html



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message. CELL UPDATE/URA UPDATE will be resent upon the expiry of the timer if V302 less than or equal to N302; otherwise, the UE will enter idle mode. Protocol default value is 4000.

GUI Value Range:D100, D200, D400, D600, D800, D1000, D1200, D1400, D1600, D1800, D2000, D3000, D4000, D6000, D8000

Actual Value Range:100, 200, 400, 600, 800, 1000, 1200, 1400, 1600, 1800, 2000, 3000, 4000, 6000, 8000

Unit:ms

Default Value:D2000

T381 BSC6900 SET UCONNMODETIMER

WRFD-010101


Meaning:T381 is started after the RNC send message "RRC CONNECTION SETUP"(or "CELL UPDATE CONFIRM"). If T381 expire and RNC does not receive "RRC CONNECTION SETUP COMPLETE"(or the response of "CELL UPDATE CONFIRM") and V381 is smaller than N381, RNC resend "RRC CONNECTION SETUP"(or "CELL UPDATE CONFIRM") and restart timer T381 and increase V381. If RNC receive "RRC CONNECTION SETUP COMPLETE"(or the response of "CELL UPDATE CONFIRM"), T381 will be stopped. Default value is 600ms.

GUI Value Range:D0, D100, D200, D300, D400, D500, D600, D700, D800, D900, D1000, D1200, D1500, D2000

Actual Value Range:0, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1200, 1500,





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7-127


2000

Unit:ms

Default Value:D600

TxInterruptAfterTrig

BSC6900 SET UUESTATETRANS

WRFD-010202


Meaning:Duration during which UEs are prohibited from transmitting data over the RACH after reporting 4A measurement reports and triggering the procedure for the CELL_FACH-to-CELL_DCH state transition. For details about this parameter, see 3GPP TS 25.331.

GUI Value Range:D250, D500, D1000, D2000, D4000, D8000, D16000

Actual Value Range:250, 500, 1000, 2000, 4000, 8000, 16000

Unit:ms

Default Value:D2000

UserPlnCpuSharingOutOffset


WRFD-040100

Flow Control Meaning:The parameter is added to avoid ping-pong handovers during the load sharing triggered by DSP CPU usage.



Unit:%

Default Value:5

UserPlnCpuSharingOutThd


WRFD-040100

Flow Control Meaning:The parameter is added to trigger the load sharing when the DSP CPU usage exceeds this threshold, thus achieving load balance between subracks.



Unit:%



../RNCParaHtml/mbsc/m-mml/set-uuestatetrans.html













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Default Value:100

UserPlnSharingOutOffset


WRFD-040100

Flow Control Meaning:The available capacity of the user plane sharing subrack incoming load must be larger than the sum of the available capacity of the user plane sharing subrack outgoing load and this offset.



Unit:%

Default Value:5

UserPlnSharingOutThd


WRFD-040100

Flow Control Meaning:Percentage of User Plane Sharing Out Threshold.



Unit:%

Default Value:90











WCDMA RAN

Flow Control 10 Counters



7-1

10 Counters

Table 10-1 Counter description

Counter ID Counter Name Counter Description NE Feature ID Feature Name

67193095 VS.IU.FlowCtrl.DiscInitDT.CS

Number of Discarded CS Initial UE Messages when Signaling Flow Control is Triggered

BSC6900 WRFD-040100 Flow Control

67193096 VS.IU.FlowCtrl.Disc.InitDT.PS

Number of Discarded PS Initial UE Messages when Signaling Flow Control is Triggered


67194447 VS.GCU.CPULOAD.MAX

HR9750:Maximum CPU Usage of the GCU

BSC6900 GBFD-111705

GBFD-111203

WRFD-040100

GSM Flow Control

O&M of BSC

Flow Control

67194743 VS.DPU.CPULOAD.MAX

HR9760:Maximum CPU Usage of the DPU

BSC6900 GBFD-111705

GBFD-111203

WRFD-040100

GSM Flow Control

O&M of BSC

Flow Control

67194751 VS.SCU.CPULOAD.MAX

HR9730:Maximum CPU Usage of the SCU

BSC6900 GBFD-111705

GBFD-111203

WRFD-040100

GSM Flow Control

O&M of BSC

Flow Control

67203413 VS.CSLoad.Erlang.Equiv.CPUS

Equivalent CS Conversational Erlang for CPUS


67204336 VS.GCU.CPULOAD.MEAN

AR9750:Average CPU Usage of the GCU

BSC6900 GBFD-111705

GBFD-111203

WRFD-040100

GSM Flow Control

O&M of BSC

Flow Control

67204337 VS.GCU.CPULOAD.OVER

TR9750a:Rate of the Period in Which the CPU Usage of the GCU Exceeds the Alarm Threshold

BSC6900 GBFD-111705

GBFD-111203

WRFD-040100

GSM Flow Control

O&M of BSC

Flow Control

../RNCCounterHtml/mbsc/m-perf/Mt-3686.html








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67204338 VS.GCU.CPULOAD.LESS

TR9750b:Rate of the Period in Which the CPU Usage of the GCU is Lower than the Alarm Threshold

BSC6900 GBFD-111705

GBFD-111203

WRFD-040100

GSM Flow Control

O&M of BSC

Flow Control

67204463 VS.DPU.CPULOAD.MEAN

AR9760:Average CPU Usage of the DPU

BSC6900 GBFD-111705

GBFD-111203

WRFD-040100

GSM Flow Control

O&M of BSC

Flow Control

67204464 VS.DPU.CPULOAD.OVER

TR9760a:Rate of the Period in Which the CPU Usage of the DPU Exceeds the Alarm Threshold

BSC6900 GBFD-111705

GBFD-111203

WRFD-040100

GSM Flow Control

O&M of BSC

Flow Control

67204465 VS.DPU.CPULOAD.LESS

TR9760b:Rate of the Period in Which the CPU Usage of the DPU is Lower than the Alarm Threshold

BSC6900 GBFD-111705

GBFD-111203

WRFD-040100

GSM Flow Control

O&M of BSC

Flow Control

67204467 VS.SCU.CPULOAD.MEAN

AR9730:Average CPU Usage of the SCU

BSC6900 GBFD-111705

GBFD-111203

WRFD-040100

GSM Flow Control

O&M of BSC

Flow Control

67204468 VS.SCU.CPULOAD.OVER

TR9730a:Rate of the Period in Which the CPU Usage of the SCU Exceeds the Alarm Threshold

BSC6900 GBFD-111705

GBFD-111203

WRFD-040100

GSM Flow Control

O&M of BSC

Flow Control

67204469 VS.SCU.CPULOAD.LESS

TR9730b:Rate of the Period in Which the CPU Usage of the SCU is Lower than the Alarm Threshold

BSC6900 GBFD-111705

GBFD-111203

WRFD-040100

GSM Flow Control

O&M of BSC

Flow Control

67204521 VS.PSLoad.ULThruput.MPU

Throughput of PS Uplink Data for MPU


67204522 VS.PSLoad.DLThruput.MPU

Throughput of PS Downlink Data for MPU











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7-3


73390062 VS.XPU.CPULOAD.MAX

HR9780:Maximum CPU Usage of the XPU

BSC6900 GBFD-111705

GBFD-111203

WRFD-040100

GSM Flow Control

O&M of BSC

Flow Control

73390070 VS.XPU.MSGLOAD.MAX

HR9782:Maximum Packet Usage of the XPU

BSC6900 WRFD-040100

GBFD-111705

Flow Control

GSM Flow Control

73393776 VS.LowPriRRC.RanFC.Disc.Num

Number of Low-Priority RRC Connection Setup Requests Discarded During RAN Integrated Flow Control for Cell


73393777 VS.NormPriRRC.RanFC.Disc.Num

Number of Middle-Priority RRC Connection Setup Requests Discarded During RAN Integrated Flow Control for Cell


73393778 VS.HighPriRRC.RanFC.Disc.Num

Number of High-Priority RRC Connection Setup Requests Discarded During RAN Integrated Flow Control for Cell


73403674 VS.INT.CPULOAD.MAX

HR9700:Maximum CPU Usage of the INT

BSC6900 GBFD-111705

GBFD-111203

WRFD-040100

GSM Flow Control

O&M of BSC

Flow Control

73411191 VS.NodeB.CPU.Cong.Dur

Duration of CPU Resource Insufficiency Reported by NodeB for Cell


73415210 VS.XPU.CPULOAD.MEAN

AR9780:Average CPU Usage of the XPU

BSC6900 GBFD-111705

GBFD-111203

WRFD-040100

GSM Flow Control

O&M of BSC

Flow Control

73415211 VS.XPU.CPULOAD.OVER

TR9780a:Rate of the Period in Which the CPU Usage of the XPU Exceeds the Alarm

BSC6900 GBFD-111705

GBFD-111203

GSM Flow Control

O&M of BSC










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7-4


Threshold WRFD-040100 Flow Control

73415212 VS.XPU.CPULOAD.LESS

TR9780b:Rate of the Period in Which the CPU Usage of the XPU is Lower than the Alarm Threshold

BSC6900 GBFD-111705

GBFD-111203

WRFD-040100

GSM Flow Control

O&M of BSC

Flow Control

73415214 VS.XPU.MSGLOAD.MEAN

AR9782:Average Packet Usage of the XPU

BSC6900 WRFD-040100

GBFD-111705

Flow Control

GSM Flow Control

73415843 VS.INT.CPULOAD.MEAN

AR9700:Average CPU Usage of the INT

BSC6900 GBFD-111705

GBFD-111203

WRFD-040100

GSM Flow Control

O&M of BSC

Flow Control

73415844 VS.INT.CPULOAD.OVER

TR9700a:Rate of the Period in Which the CPU Usage of the INT Exceeds the Alarm Threshold

BSC6900 GBFD-111705

GBFD-111203

WRFD-040100

GSM Flow Control

O&M of BSC

Flow Control

73415845 VS.INT.CPULOAD.LESS

TR9700b:Rate of the Period in Which the CPU Usage of the INT is Lower than the Alarm Threshold

BSC6900 GBFD-111705

GBFD-111203

WRFD-040100

GSM Flow Control

O&M of BSC

Flow Control

73421890 VS.LowPriRRC.FC.Disc.Num.CPUS

Number of Low-Priority RRC Requests Discarded Due to Flow Control for CPUS Subsystem


73421891 VS.NormPriRRC.FC.Disc.Num.CPUS

Number of Normal-Priority RRC Requests Discarded Due to Flow Control for CPUS Subsystem


73421892 VS.HighPriRRC.FC.Disc.Num.CPUS

Number of High-Priority RRC Requests Discarded Due to Flow Control for CPUS Subsystem


73421893 VS.LowPriRRC.FC.Disc.Time.CPUS

Duration of Rejection of Low-Priority RRC Requests Due to Flow Control for











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7-5


CPUS Subsystem

73421894 VS.NormPriRRC.FC.Disc.Time.CPUS

Duration of Rejection of Normal-Priority RRC Requests Due to Flow Control for CPUS Subsystem


73421895 VS.HighPriRRC.FC.Disc.Time.CPUS

Duration of Rejection of High-Priority RRC Requests Due to Flow Control for CPUS Subsystem


73421896 VS.CBS.FC.Disc.Num.CPUS

Number of CBS Requests Discarded Due to Flow Control for CPUS Subsystem


73421897 VS.CBS.FC.Disc.Time.CPUS

Duration of CBS Flow Control for CPUS Subsystem


73421898 VS.Paging.FC.Disc.Num.CPUS

Number of Paging Messages Discarded Due to Flow Control for CPUS Subsystem


73421899 VS.Paging.FC.Disc.Time.CPUS

Duration of Paging Message Flow Control for CPUS Subsystem


73421900 VS.CU.FC.Disc.Num.CPUS

Number of Cell Update Requests Discarded Due to Flow Control for CPUS Subsystem


73421901 VS.CU.FC.Disc.Time.CPUS

Duration of Cell Update Flow Control for CPUS Subsystem


73423464 VS.RRC.FC.Disc.Num.CallShock.CPUS

Number of Discarded RRC Connection Requests Due to Burst Traffic for CPUS Subsystem


73423465 VS.RRC.FC.Disc.Num.MPU.CPUS

Number of Discarded RRC Connection Requests Due to MPU Overload for CPUS Subsystem












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7-6


73423466 VS.RRC.FC.Disc.Num.RRCQueue.CPUS

Number of Discarded RRC Connection Requests Due to RRC Queue Overflow for CPUS Subsystem


73423467 VS.RRC.FC.Disc.Num.CPU.CPUS

Number of Discarded RRC Connection Requests Due to High CPU Usage for CPUS Subsystem


73423468 VS.RRC.FC.Disc.Num

Number of Discarded RRC Connection Requests Due to Various Flow Control Functions for Cell


73423829 VS.INT.CFG.INTERWORKING.NUM

T6900:Number of Call Establishment Attempts on an Interface Board

BSC6900 GBFD-111705

WRFD-040100

GSM Flow Control

Flow Control

73423830 VS.INT.CFG.INTERWORKING.FAIL.NUM

T6920:Number of Call Establishment Failures on an Interface Board

BSC6900 WRFD-040100

GBFD-111705

Flow Control

GSM Flow Control

73423921 VS.LowPriCu.FC.Disc.Num.CPU

Number of Low-Priority CELL UPDATE Messages Discarded Because CPU Usage Exceeds the Threshold for CPUS Subsystem


73423923 VS.MidPriCu.FC.Disc.Num.CPU

Number of Medium-Priority CELL UPDATE Messages Discarded Because CPU Usage Exceeds the Threshold for CPUS Subsystem


73423924 VS.HighPriCu.FC.Disc.Num.CPU

Number of High-Priority CELL UPDATE Messages Discarded Because CPU Usage Exceeds the Threshold for CPUS Subsystem


73423925 VS.LowPriCu.FC.Disc.Num.Queue

Number of Low-Priority CELL UPDATE Messages Discarded Due to RRC Queue Overflow for CPUS











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7-7


Subsystem

73423926 VS.MidPriCu.FC.Disc.Num.Queue

Number of Medium-Priority CELL UPDATE Messages Discarded Due to RRC Queue Overflow for CPUS Subsystem


73423927 VS.HighPriCu.FC.Disc.Num.Queue

Number of High-Priority CELL UPDATE Messages Discarded Due to RRC Queue Overflow for CPUS Subsystem


73423928 VS.Traffic.Report4A.CellDch.Disc.Num.UpLink.FC

Number of Discarded UL Event 4A Measurement Reports on PS BE Traffic in the CELL_DCH State in a CPUS


73423929 VS.Traffic.Report4A.CellDch.Disc.Num.DownLink.FC

Number of Discarded DL Event 4A Measurement Reports on PS BE Traffic in the CELL_DCH State in a CPUS


73423930 VS.Throughput.Report4A.Disc.Num.UpLink.FC

Number of Discarded UL Event 4A Measurement Reports on Throughput for UEs in the CELL_DCH State in a CPUS


73423931 VS.Traffic.Report4A.CellFach.Disc.Num.UpLink.FC

Number of Discarded UL Event 4A Measurement Reports on PS BE Traffic in the CELL_FACH State in a CPUS


73423932 VS.Traffic.Report4A.CellFach.Disc.Num.DownLink.FC

Number of Discarded DL Event 4A Measurement Reports on PS BE Traffic in the CELL_FACH State in a CPUS


73424215 VS.RRC.FC.Num.CPU.CPUS

Number of RRC CONNECTION REQUESTS Under Flow Control Due to High CPU Usage for CPUS Subsystem










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7-8


73424216 VS.RRC.FC.Num.RRCQueue.CPUS

Number of RRC CONNECTION REQUESTS Under Flow Control Due to RRC Queue Overflow for CPUS Subsystem


73424217 VS.RRC.FC.Num.MPU.CPUS

Number of RRC CONNECTION REQUESTS Under Flow Control Due to MPU Overload for CPUS Subsystem


73424218 VS.RRC.FC.Num.CallShock.CPUS

Number of RRC CONNECTION REQUESTS Under Flow Control Due to Burst Traffic for CPUS Subsystem


73424219 VS.RRC.CONV.FC.Num.CPU.CPUS

Number of RRC CONNECTION REQUESTS for CS Services Under Flow Control Due to High CPU Usage for CPUS Subsystem


73424220 VS.RRC.CONV.FC.Num.RRCQueue.CPUS

Number of RRC CONNECTION REQUESTS for CS Services Under Flow Control Due to RRC Queue Overflow for CPUS Subsystem


73424221 VS.RRC.CONV.FC.Num.MPU.CPUS

Number of RRC CONNECTION REQUESTS for CS Services Under Flow Control Due to MPU Overload for CPUS Subsystem


73424222 VS.RRC.CONV.FC.Num.CallShock.CPUS

Number of RRC CONNECTION REQUESTS for CS Services Under Flow Control Due to Burst Traffic for CPUS Subsystem


73424223 VS.RRC.AttConnEstab.Msg.Conv

Number of Received RRC CONNECTION REQUESTS for CS Services in a Cell


73424224 VS.RRC.FC.Num.C Number of RRC CONNECTION REQUESTS











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7-9


PU.OverLoad Under Flow Control Triggered by High CPU Usage for Cell

73424225 VS.RRC.FC.Num.RRCQueue

Number of RRC CONNECTION REQUESTS Under Flow Control Triggered by RRC Queue Overflow for Cell


73424226 VS.RRC.FC.Num.MPU.OverLoad

Number of RRC CONNECTION REQUESTS Under Flow Control Triggered by MPU Overload for Cell


73424227 VS.RRC.FC.Num.CallShock

Number of RRC CONNECTION REQUESTS Under Flow Control Triggered by Burst Traffic for Cell


73424228 VS.RRC.CONV.FC.Num.CPU.OverLoad

Number of RRC CONNECTION REQUESTS for CS Voice Services Under Flow Control Triggered by High CPU Usage for Cell


73424229 VS.RRC.CONV.FC.Num.RRCQueue

Number of RRC CONNECTION REQUESTS for CS Voice Services Under Flow Control Triggered by RRC Queue Overflow for Cell


73424230 VS.RRC.CONV.FC.Num.MPU.OverLoad

Number of RRC CONNECTION REQUESTS for CS Voice Services Under Flow Control Triggered by MPU Overload for Cell


73424231 VS.RRC.CONV.FC.Num.CallShock

Number of RRC CONNECTION REQUESTS for CS Voice Services Under Flow Control Triggered by Burst Traffic for Cell


73424232 VS.CU.FC.Num.CPU.OverLoad

Number of Cell Updates Under Flow Control Triggered by High CPU










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7-10


Usage for Cell

73424233 VS.RRC.FC.Num.RanFC.Ph2

Number of RRC CONNECTION REQUESTS Under E2E Flow Control Phase 2 for Cell


73424234 VS.RRC.CONV.FC.Num.RanFC.Ph2

Number of RRC CONNECTION REQUESTS for CS Voice Services Under E2E Flow Control Phase 2 for Cell


73424482 VS.RRC.CONV.FC.Num.INT.CPUS

Number of RRC CONNECTION REQUESTS for CS Services in a CPUS Subsystem Under Flow Control Triggered by Interface-Board CPU Overload


73424483 VS.RRC.FC.Num.INT.CPUS

Number of RRC CONNECTION REQUESTS in a CPUS Subsystem Under Flow Control Triggered by Interface-Board CPU Overload


73424484 VS.IurUpLinkSig.Disc.Num.CPU.CPUS

Number of Discarded Iur-Interface Uplink Signalling Messages in a CPUS Subsystem Under Flow Control Triggered by CPU Overload


73424485 VS.IurDownLinkSig.Disc.Num.CPU.CPUS

Number of Discarded Iur-Interface Downlink Signalling Messages in a CPUS Subsystem Under Flow Control Triggered by CPU Overload


73424691 VS.RRC.CONV.FC.Num.INT.OverLoad

Number of RRC CONNECTION REQUESTS for CS Voice Services Under Flow Control Triggered by Interface-Board CPU Overload for Cell


73424692 VS.RRC.FC.Num.IN Number of RRC BSC6900 WRFD-040100 Flow Control









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7-11


T.OverLoad CONNECTION REQUESTS Under Flow Control Triggered by Interface-Board CPU Overload for Cell

73424693 VS.RRC.FC.Num.FACH.Cong

Number of RRC CONNECTION REQUESTS Under Flow Control Triggered by FACH Congestion for Cell


73424694 VS.RRC.CONV.FC.Num.RanFC.Ph1

Number of RRC CONNECTION REQUESTS for CS Voice Services Under E2E Flow Control Phase 1 for Cell


73424695 VS.RRC.FC.Num.RanFC.Ph1

Number of RRC CONNECTION REQUESTS Under E2E Flow Control Phase 1 for Cell


73424915 VS.AttCellUpdt.Msg Number of Cell Updates in a Cell


73424916 VS.AttCellUpdt.Msg.Conv

Number of Cell Updates Triggered by CS Service Establishments in a Cell


73424917 VS.CU.CONV.FC.Num.CPU.OverLoad

Number of Cell Updates that Are Under CPU Usage-Based Flow Control and Are Triggered by CS Service Establishments in a Cell


73424918 VS.CU.CONV.FC.Num.RRCQueue

Number of Cell Updates that Are Under RRC Queuing-Based Flow Control and Are Triggered by CS Service Establishments in a Cell


73424919 VS.CU.FC.Num.RRCQueue

Number of Cell Updates that Are Under RRC Queuing-Based Flow Control in a Cell


73424968 VS.RRC.FC.Num.C Number of RRC CONNECTION REQUESTS











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7-12


APS in a Cell Under Cell Dynamic CAPS Flow Control

73424969 VS.RRC.CONV.FC.Num.CAPS

Number of RRC CONNECTION REQUESTS for CS Services in a Cell Under Cell Dynamic CAPS Flow Control



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Flow Control 11 Glossary



7-1

11 Glossary

For terms that appear in this document, see Glossary.

Glossary.htm

WCDMA RAN

Flow Control 12 References



7-1

12 References

[1] Load Control Feature Parameter Description

[2] DSAC Feature Parameter Description

[3] Common Radio Resource Management Feature Parameter Description

[4] Transmission Resource Management Feature Parameter Description

[5] Radio Bearers Feature Parameter Description

[6] State Transition Feature Parameter Description

[7] E2E Flow Control Feature Parameter Description

[8] Intelligent Access Class Control Feature Parameter Description

[9] Call Admission Control Feature Parameter Description

[10] State Transition Feature Parameter Description

[11] DCCC Feature Parameter Description

[12] Intelligent Access Class Control Feature Parameter Description

Load%20Control.htm

DSAC.htm

Common%20Radio%20Resource%20Management.htm


Radio%20Bearers.htm


E2E%20Flow%20Control.htm




DCCC.htm


WCDMA RAN

Flow Control 13 Appendix - Flow Control Algorithms



7-1

13 Appendix - Flow Control Algorithms

The RNC uses three types of flow control algorithms for overloaded RNC units: switch algorithm, linear algorithm, and hierarchical algorithm. Different algorithms are used for different services. These algorithms, however, cannot be set on the LMT.

13.1 Switch Algorithm

The principles of the switch algorithm are as follows:

When resource usage, such as CPU usage or message block usage, exceeds the control threshold of a flow control item, flow control is performed.

When resource usage is lower than the restore threshold, flow control is not performed.

Figure 13-1 Switch algorithm

The following flow control functions use switch algorithms:





Resource audit flow control

AC

Paging control for BE services, supplementary services, location services, and short message services

Flow control over the Iur interface

CBS flow control


MR flow control

13.2 Linear Algorithm

The principles of the linear algorithm are as follows:

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7-2

When resource usage is higher than the control threshold of a flow control item, flow control is performed.

When resource usage is lower than the restore threshold of a flow control item, flow control is not performed.

When resource usage is between the restore threshold and the control threshold of a flow control item, the flow control level changes linearly with the resource usage.

Figure 13-2 Linear algorithm

The flow control level of the linear algorithm, that is, the probability (P) of performing flow control, is calculated as follows:

P = (resource usage - restore threshold) x 100%/ (control threshold - restore threshold)

The following flow control functions use linear algorithms:

Paging control for real-time services

RRC flow control based on the CPU usage or message block occupancy rate


DCCC flow control

13.3 Hierarchical Algorithm

The principles of the hierarchical algorithm are as follows:

When resource usage is higher than the control threshold of a flow control item, flow control is performed.

When resource usage is lower than the restore threshold of a flow control item, flow control is not performed.

When resource usage is between the restore threshold and the control threshold of a flow control item, the flow control level changes hierarchically with the resource usage.

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7-3

Figure 13-3 Hierarchical algorithm

The flow control level of the hierarchical algorithm is calculated as follows:

Flow control level = [(resource usage - restore threshold) x total number of flow control grades for the flow control item/(control threshold - restore threshold)]

The [ ] symbol indicates an integer value.

The total flow control grades for each flow control item are specified in the system software and cannot be set on the LMT. They vary according to the flow control items.

Documents

Flow Control(RAN14.0 02)