Uu Based Soft Synchronization(ERAN8.1_02)

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eRAN

Uu based Soft Synchronization

Feature Parameter Description

Issue 02

Date 2015-04-30

HUAWEI TECHNOLOGIES CO., LTD.


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Copyright Huawei Technologies Co., Ltd. 2015. All rights reserved.

No part of this document may be reproduced or transmitted in any form or by any means without prior written

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Notice

The purchased products, services and features are stipulated by the contract made between Huawei and the

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The information in this document is subject to change without notice. Every effort has been made in the

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Huawei Technologies Co., Ltd.

Address: Huawei Industrial Base

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Website: http://www.huawei.com

Email: [email protected]

Issue 02 (2015-04-30) Huawei Proprietary and Confidential

Copyright Huawei Technologies Co., Ltd.

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Contents

1 About This Document.................................................................................................................. 1

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

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

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

1.4 Differences Between eNodeB Types..............................................................................................................................2

2 Overview......................................................................................................................................... 3

2.1 Background.....................................................................................................................................................................3

2.2 Introduction.................................................................................................................................................................... 4

2.3 Benefits...........................................................................................................................................................................4

2.4 Architecture.................................................................................................................................................................... 4

3 Technical Description...................................................................................................................6

3.1 Overview........................................................................................................................................................................ 6

3.2 Initial Synchronization................................................................................................................................................... 73.2.1 Determining the Synchronization Zone and eNodeB Pairs.......................................................................................10

3.2.2 Collecting Time Differences Between Paired eNodeBs............................................................................................12

3.2.3 Adjusting the Time on Non-reference eNodeBs Based on the Time on the Reference eNodeB.............................. 14

3.3 Synchronization Tracing...............................................................................................................................................15

3.4 Synchronization Maintenance...................................................................................................................................... 15

3.5 Absolute Time Synchronization for eMBMS...............................................................................................................17

4 Related Features...........................................................................................................................19

5 NetworkImpact........................................................................................................................... 21

6 Engineering Guidelines............................................................................................................. 22

6.1 When to Use LOFD-080216 Uu based Soft Synchronization......................................................................................22

6.2 Required Information................................................................................................................................................... 22

6.3 Planning........................................................................................................................................................................23

6.3.1 RF Planning...............................................................................................................................................................23

6.3.2 NetworkPlanning......................................................................................................................................................23

6.3.3 Hardware Planning.................................................................................................................................................... 24

6.4 Feature Deployment..................................................................................................................................................... 24

6.4.1 Process.......................................................................................................................................................................24

6.4.2 Requirements.............................................................................................................................................................24

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6.4.3 Data Preparation........................................................................................................................................................ 25

6.4.4 Precautions.................................................................................................................................................................35

6.4.5 Activation.................................................................................................................................................................. 35

6.4.5.1 7.4.5.1 Using the CME to Perform Batch Configuration for Newly Deployed eNodeBs......................................36

6.4.5.2 Using the CME to Perform Batch Configuration for Existing eNodeBs............................................................... 36

6.4.5.3 Using the CME to Perform Single Configuration.................................................................................................. 37

6.4.5.4 Using MML Commands.........................................................................................................................................38

6.4.5.5 MML Command Examples.................................................................................................................................... 39

6.4.6 Activation Observation..............................................................................................................................................41

6.4.7 Deactivation...............................................................................................................................................................43

6.4.7.1 Using CME to Perform Batch Configuration.........................................................................................................43

6.4.7.2 Using the CME to Perform Single Configuration.................................................................................................. 44

6.4.7.3 Using MML Commands.........................................................................................................................................44

6.4.7.4 MML Command Examples.................................................................................................................................... 44

6.4.8 Reconfiguration......................................................................................................................................................... 44

6.5 Performance Monitoring...............................................................................................................................................44

6.5.1 Time Difference Measurements Between eNodeBs in eNodeB Pairs.......................................................................44

6.5.2 Absolute Values of Average Time Difference Changes Between eNodeBs..............................................................44

6.5.3 Absolute Values of Average Time Differences Between eNodeBs...........................................................................45

6.6 ParameterOptimization................................................................................................................................................46

6.7 Troubleshooting............................................................................................................................................................46

6.7.1 Related Alarms.......................................................................................................................................................... 46

6.7.2 Handling Exceptions on Message Reporting.............................................................................................................47

7 Parameter.......................................................................................................................................49

8 Counters........................................................................................................................................ 65

9 Glossary.........................................................................................................................................67

10 Reference Documents...............................................................................................................68

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1About This Document

1.1 Scope

This document describes LOFD-080216 Uu based Soft Synchronization, including its

technical principles, related features, network impact, and engineering guidelines.

This document applies to the following types of eNodeBs.

eNodeB Type Model

Macro 3900 series eNodeB

NOTE

Currently, LOFD-080216 Uu based Soft Synchronization does not apply to multimode base stations.

1.2 Intended Audience

This document is intended for personnel who:

l Need to understand the features described herein

lWork with Huawei products

1.3 Change History

This section provides information about the changes in different document versions. There are

two types of changes:

l Feature change

Changes in features and parameters of a specified version as well as the affected entities

l Editorial change

Changes in wording or addition of information and any related parameters affected byeditorial changes. Editorial change does not specify the affected entities.

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eRAN8.1 02 (2015-04-30)

This issue includes the following changes.

Change Type Change

Description

Parameter Change Affected Entity

Feature change None None -

Editorial change Revised descriptions

in 6.4.6 Activation

Observation.

None -

eRAN8.1 01 (2015-03-23)

This issue does not include any changes.

eRAN8.1 Draft A (2015-01-15)

This document is created for eRAN8.1.

1.4 Differences Between eNodeB Types

Feature Support by Macro, Micro, and LampSite Base Stations

Feature ID Description Supported byMacro eNodeBs Supportedby MicroeNodeBs

Supported byLampSiteeNodeBs

LOFD-080216 Uu based Soft

Synchronizatio

n

Yes No No

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2Overview

2.1 Background

Many LTE features pose high requirements on time synchronization.

l LOFD-070208 Coordinated Scheduling based Power Control (Cloud BB)

In most cases, neighboring evolved universal terrestrial radio access network (E-

UTRAN) cells on the same frequency interfere with one another. To reduce the

interference, the transmit power for downlink (DL) channels can be coordinated to

increase the signal to interference plus noise ratio (SINR) of cell edge user equipment

(UEs) and therefore improve network performance. LOFD-070208 Coordinated

Scheduling based Power Control (Cloud BB) is introduced to coordinate TTI-specific

transmit power configurations in individual cells. It reduces inter-cell interference based

on collaboration between scheduling and power control. (TTI is short for transmission

time interval.) This feature requires time synchronization between eNodeBs connecting

to the same universal switching unit (USU).

l LAOFD-002001 Static TDM eICIC

In an intra-frequency heterogeneous network (HetNet), micro eNodeBs supplement

network coverage and increase network capacity. Macro cells and micro cells cause

interference on each other. LAOFD-002001 Static TDM eICIC decreases interference

between macro cells and micro cells by coordinating available time-domain resources of

neighboring cells, thereby increasing downlink performance and throughput of CEUs in

an intra-frequency HetNet. TDM and eICIC are short for time division multiplexing and

enhanced inter-cell interference coordination, respectively TDM eICIC requires time

synchronization between macro cells and micro cells involved in interference

coordination.

l LOFD-070220 eMBMS Phase 1 based on Centralized MCE Architecture

This feature enables one data source to transmit data to multiple UEs based on network

resource sharing. eMBMS is short for evolved multimedia broadcast/multicast service.

eMBMS improves the resource utilization rate and enables multimedia services to be

broadcast in high data rates. eMBMS requires time synchronization between eNodeBs.

To support eMBMS in eNodeBs within 3 km from each other in the Multimedia

Broadcast multicast service Single Frequency Network (MBSFN) area, the time

difference between eNodeBs must be less than 3 microseconds (s).

l LAOFD-080201 Inter-eNodeB CA based on Relaxed backhaul

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According to 3GPP specifications, LTE-Advanced intends to provide the service data

rate as high as 1 Gbit/s in the downlink. Because frequency spectrums are in shortage

and bandwidths granted to operators are non-contiguous, a single frequency band can

hardly provide the bandwidths required by LTE Advanced. Therefore, 3GPP Release 10

TR36.913 introduced carrier aggregation (CA) to provide a maximum of 100 MHz

bandwidth by aggregating multiple contiguous or non-contiguous carriers. In addition,

CA improves the usage of scattered frequency spectrum, especially in refarming

scenarios. LAOFD-080201 Inter-eNodeB CA based on Relaxed backhaul requires that

time must be synchronized between eNodeBs with CA implemented. Specifically,

downlink CA requires the time accuracy of 1.5 s.

Currently, eNodeBs support features related to time synchronization such as LBFD-00300503

GPS Synchronization and LOFD-00301302 IEEE1588 V2 Clock Synchronization.

LBFD-00300503 GPS Synchronization requires GPS, which increases hardware deployment

cost. LOFD-00301302 IEEE1588 V2 Clock Synchronization requires transport devices to

support the IEEE1588 V2 protocol, which may require transport network reconstruction.

Compared with the preceding two features, LOFD-080216 Uu based Soft Synchronization

supports time synchronization at lower cost without the need for transmission networkreconstruction.

2.2 Introduction

Uu-based soft synchronization achieves time synchronization between eNodeBs by adjusting

time differences between the eNodeBs based on software measurement results. In Uu-based

soft synchronization, the time difference between two neighboring eNodeBs can be obtained

during inter-eNodeB handovers or physical random access channel (PRACH) measurements

initiated by CEUs or UEs in inter-eNodeB handovers. A centralized control node (for

example, the eCoordinator) collects all time differences reported by eNodeBs within the area

within which the coordination feature is applied (this area is called the Uu-based softsynchronization zone and also referred to as synchronization zone in this document),

calculates the time adjustment quantity of each eNodeB against the reference eNodeB, and

adjusts the time of all eNodeBs at the same time. In this way, all eNodeBs within the

synchronization zone achieve time synchronization with the reference eNodeB. The Uu based

Soft Synchronization feature is enabled only after eNodeBs achieve frequency

synchronization based on synchronous Ethernet. Frequency synchronization enables the

stability of time synchronization between eNodeBs.

2.3 Benefits

l The Uu based Soft Synchronization feature provides less than or equal to 3-s timesynchronization accuracy, which satisfies the demanding time synchronization

requirements of coordination features such as TDM eICIC and CSPC.

l In scenarios with synchronous Ethernet deployed, compared with LBFD-00300503 GPS

Synchronization and LOFD-00301302 IEEE1588 V2 Clock Synchronization, the Uu

based Soft Synchronization feature supports time synchronization at lower cost without

the need for transmission network reconstruction.

2.4 Architecture

Figure 2-1shows the network architecture for deploying LOFD-080216 Uu based SoftSynchronization. The architecture includes the following network elements (NEs): eNodeBs

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(one eNodeB functions as the reference eNodeB), a centralized control node (the

eCoordinator, which is abbreviated as eCo in the figure), and UEs in inter-eNodeB handovers

or CEUs under the neighboring eNodeBs.

Figure 2-1Network architecture for deploying the Uu based Soft Synchronization feature

l Reference eNodeB

The reference eNodeB works as the time synchronization source in a synchronization

zone. Other eNodeBs maintain time synchronization with the reference eNodeB.

Generally, an eNodeB located at the center of the synchronization zone and equippedwith the GPS is selected as the reference eNodeB.

l Centralized control node

A centralized control node is the control center for deploying this feature. A centralized

control node delivers configuration commands to eNodeBs, collects time differences

between eNodeBs, and calculates time adjustment quantity for each eNodeB. Currently,

the eCoordinator works as the centralized control node.

l UEs in inter-eNodeB handovers or CEUs under neighboring eNodeBs

A UE in inter-eNodeB handovers: The UE assists the serving eNodeB to collect the time

difference between the eNodeB and its neighboring eNodeB based on inter-eNodeB

handovers.

A CEU under neighboring eNodeBs: The UE assists the serving eNodeB to collect the

time difference between the eNodeB and its neighboring eNodeB based on random

access requests to the neighboring eNodeBs.

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3Technical Description

3.1 Overview

The overall procedure of Uu-based soft synchronization includes initial synchronization and

synchronization tracing. Initial synchronization includes the following three steps:

1. Determining the synchronization zone and neighboring eNodeB pairs

2. Collecting time differences between each pair of eNodeBs

3. Adjusting the time on non-reference eNodeBs based on the time on the reference

eNodeB

Synchronization tracing includes the following two steps:

1. Collecting time differences between each pair of eNodeBs

2. Adjusting the time on non-reference eNodeBs based on the time on the reference

eNodeB

After initial synchronization and synchronization tracing are complete, the eNodeBs enter the

synchronization maintenance state to maintain time accuracy.

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Figure 3-1Procedure for Uu-based soft synchronization

3.2 Initial Synchronization

After LOFD-080216 Uu based Soft Synchronization is enabled, a non-reference eNodeBperforms initial synchronization to generally adjust the time difference between the eNodeB

and the reference eNodeB. General adjustment is performed once only. The methods for

measuring time differences between eNodeBs in eNodeB pairs differ depending on whether a

UE is a UE in eNodeB boundaries or a UE involved in inter-eNodeB handovers.

l Figure 3-2shows the procedure that UEs involved in inter-eNodeB handovers measure

time differences between eNodeBs in eNodeB pairs.

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Figure 3-2Time difference measurement performed by UEs involved in inter-eNodeB

handovers

a. The source eNodeB sends a Handover Request message to the target eNodeB.

Then, the source eNodeB sends the Random Access Command to a UE. The UE

sends a random access preamble to the source eNodeB, based on which the source

eNodeB obtains the delay in transmitting the preamble from the UE to the source

eNodeB. The delay is recorded as Tpa1.

b. After receiving the Handover Request message, the target eNodeB sends the source

eNodeB a Handover Request Acknowledgement message. The source eNodeB

enables the preamble blind detection receive function and sends a handover

command to the UE.

c. The UE sends a random access preamble to the target eNodeB. The source eNodeB

blindly detects the preamble sent by the UE and obtains the delay in transmitting

the preamble from the UE to the target eNodeB. The delay is recorded as Tneigh.

d. The target eNodeB detects the preamble sent by the UE and obtains the delay in

transmitting the preamble from the UE to the target eNodeB. The delay is recordedas Taccess. The target eNodeB sends a Random Access Command message to the

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UE. The UE initiates a random access preamble to the target eNodeB. The target

eNodeB obtains the delay in transmitting the preamble from the UE to the target

eNodeB. The delay is recorded as Tpa2.

e. The target eNodeB sends the UE Context Release message to the source eNodeB.

After receiving the message, the source eNodeB stops preamble blind detection.f. The time difference between the target eNodeB and the source eNodeB is calculated

based on the following formula: Tdif = (TaccessTneigh) - (Tpa1 - Tpa2). In the

formula, "(Tpa1 - Tpa2)" indicates the difference between the delays in transmitting

UE's signals to the two eNodeBs.

l Figure 3-3shows the procedures that UEs in eNodeB boundaries measure time

differences between eNodeBs in eNodeB pairs.

Figure 3-3Time differences measured by UEs in eNodeB boundaries performing

random accesses

a. The source eNodeB sends a Blind Detect Request message to the neighboring

eNodeB. The neighboring eNodeB enables the preamble blind detection and receivefunction for preambles sent by a UE (this UE is in eNodeB boundaries) and sends a

Blind Detect Response message to the source eNodeB.

b. The serving eNodeB sends a Random Access Request message to the UE. The UE

sends random access signals to the serving eNodeB. The neighboring eNodeB

blindly detects the preambles sent by the UE and obtains Tneigh, and then stops

blind detection. The neighboring eNodeB sends the serving eNodeB the Blind

Detect Result message, including the obtained Tneigh.

c. The serving eNodeB detects the preamble and obtains the Taccess. The time

difference between the serving eNodeB and the neighboring eNodeB (Tdif) is the

difference between Taccess and Tneigh. The time difference is measured in the unit

of Ts.

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NOTE

l One eCoordinator supports a maximum of 256 synchronization zones and a maximum of 5000

eNodeBs for Uu-based soft synchronization.

l eNodeB pairs are automatically added and then can be manually changed.

The eCoordinator adds synchronization zones by running the ADD AISSZONEcommand.

Parameters AISSZONE.FrequencyBand, AISSZONE.DLFrequency, and

AISSZONE.DLBandWidthare used to verify whether an eNodeB to be added belongs to the

synchronization zone. If one of the parameters CELL.FreqBand, CELL.DlEarfcn, and

CELL.DlBandwidthof any cell under the eNodeB has the same value as any of parameters

AISSZONE.FrequencyBand, AISSZONE.DLFrequency, and AISSZONE.DLBandWidth,

the eNodeB can be added to the synchronization zone.

The eCoordinator adds eNodeBs to the synchronization zone by running the ADD ENBAISS

command. You can specify a primary reference eNodeB and a secondary reference eNodeB

by running the ADD ENBAISScommand twice with the ENBAISS.BaseStationType

parameter set to PRIBASEand BAKBASE, respectively. You can also specify commoneNodeBs by running the ADD ENBAISScommand with the ENBAISS.BaseStationType

parameter set to NORMALBASE. If the primary reference eNodeB experiences exceptions

(such as the synchronous Ethernet is faulty or the eNodeB is powered off), the secondary

reference eNodeB functions as the reference clock source.

The eCoordinator activates the automatic eNodeB pairing calculation function by running the

ACT AISSNENBCALCcommand. After the automatic calculation, you can manually

change some eNodeB pairs by running the RMV AISSNENBor ADD AISSNENB

command.

Collecting information about eNodeB pairs

The eCoordinator starts to collect information about eNodeB pairs after the synchronization

zone is activated and the automatic eNodeB pairing calculation function is enabled (or the

eNodeB pairs are manually added). As shown in Figure 3-5, the eCoordinator sends an

AISS_INFO_REQ message to an eNodeB. The eNodeB sends the eCoordinator an

AISS_INFO_RSP message. This message includes IEs AISS eNB Info and Neighber eNB

List, which carry the basic information about the eNodeB and intra-frequency neighboring

eNodeB list, respectively.

Figure 3-5Collecting information about eNodeB pairs

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3.2.2 Collecting Time Differences Between Paired eNodeBs

When a UE is handed over between two paired eNodeBs, both eNodeBs detect the random

access preamble sent by the UE simultaneously. Each eNodeB records the time when the

random access preamble is detected, and the eNodeBs then calculate their time difference

based on the delays in transmitting the UE's signals to the two eNodeBs.

The ADD AISSZONEcommand can be executed on the eCoordinator to specify parameters

related to Uu-based soft synchronization. The AISSZONE.MeasureTimeparameter specifies

the start time for measuring time differences between each two paired eNodeBs in a

synchronization zone. The AISSZONE.MeasureLastparameter specifies the duration during

which time differences between each two paired eNodeBs in a synchronization zone are

measured. The AISSZONE.DetectAvoidSwitchparameter specifies whether preamble blind

detection can be performed during data transmission over PRACH frequency resources. If this

parameter is set to OFF(Off), preamble blind detection cannot be performed during data

transmission over PRACH frequency resources. In this case, uplink throughput is not affected,

but the preamble blind detection success rate may decrease. If this parameter is set to

ON(On), preamble blind detection can be performed during data transmission over PRACH

frequency resources. In this case, uplink throughput decreases slightly, and the preamble blind

detection success rate increases. This parameter is set to OFF(Off)by default. You are

advised to set this parameter to ON(On)if the preamble blind detection success rate is low.

However, do not set this parameter to ON(On)if the system bandwidth is less than or equal to

5 MHz.

The time differences between paired eNodeBs are measured based on eNodeB pairs in

synchronization levels in ascending order. The message flow between the eCoordinator and

eNodeBs during time difference measurement is as follows:

1. Starting time difference measurements

When the time on the eCoordinator approaches the time specified by the

AISSZONE.MeasureTimeparameter, time difference measurement starts. As shown in

Figure 3-6, the eCoordinator delivers the AISS_MEAS_START_REQ messages to the

eNodeBs, instructing each eNodeB to measure the time difference with its neighboring

eNodeB in each eNodeB pair. The AISS_MEAS_START_REQ message includes IEs AISS

Measure Type, AISS Cell Para, and AISS Measure Para. The IE AISS Measure Type indicates

the UE types in intra-frequency neighboring eNodeBs involved in time difference

measurements, including CEUs in inter-eNodeB handovers, CEUs, and UEs in inter-eNodeB

handovers.

l If both a local eNodeB and its neighboring eNodeB transmit power at average strength,

the IE AISS Measure Type is automatically set to the value indicating CEUs in inter-

eNodeB handovers.

l If a local eNodeB transmits power at average strength and its neighboring eNodeB

transmits power in low strength, the IE AISS Measure Type is automatically set to the

value indicating CEUs.

l If a local eNodeB transmits power at low strength and its neighboring eNodeB transmits

power at average strength, the IE AISS Measure Type is automatically set to the value

indicating UEs in inter-eNodeB handovers.

The IE AISS Measure Para includes parameters Mea Last Timeand Rsrp Shreshold, which

indicate the time difference measurement duration and RSRP threshold, respectively. After

starting time difference measurements, the eNodeBs send the eCoordinator the

AISS_MEAS_START_RSP messages, indicating whether the time difference measurementsare successful.

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NOTE

Only CEUs that newly access cells trigger time difference measurements.

Figure 3-6Starting time difference measurements

2. Updating parameters related to time difference measurements

The eCoordinator sends eNodeBs the AISS_MEAS_PARA_UPT messages including the IE

AISS Measure Para UPT, instructing eNodeBs to update parameters related to time difference

measurements. The IE AISS Measure Para UPT is used to update parameters Neighber eNB

ID(indicating ID of a neighboring eNodeB), Ho Rsrp Shreshold(indicating RSRP threshold

for inter-eNodeB handovers), and Ce Rsrp Shreshold(indicating RSRP threshold received

by CEUs).

Figure 3-7Updating parameters related to time difference measurements

3. Sending time difference measurement reports

After time difference measurements, eNodeBs send the eCoordinator the AISS_

MEASURE_RPT messages including the IE AISS Measure Report. The IE AISS Measure

Report includes the time difference between a local eNodeB and its neighboring eNodeB.

TimeDif is calculated by (Taccess - Tneigh), and the transmission delay Tp Dif is calculatedby (Tpa1 - Tpa2).

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Figure 3-8Sending time difference measurement reports

4. Stopping time difference measurementsAfter the time on some eNodeBs approaches the time specified by the

AISSZONE.MeasureLastparameter, the eCoordinator delivers the

AISS_MEAS_STOP_REQ messages to these eNodeBs including the IE AISS Measure Stop

Type, instructing these eNodeBs to stop time difference measurements. The IE AISS Measure

Stop Type includes the Neighber eNB Listparameter indicating the list of neighboring

eNodeBs that are required to stop time difference measurements.

Figure 3-9Stopping time difference measurements

3.2.3 Adjusting the Time on Non-reference eNodeBs Based on theTime on the Reference eNodeB

After collecting time differences between paired eNodeBs in a synchronization zone, the

eCoordinator calculates the time differences between each eNodeB and the reference eNodeB,

and instructs all eNodeBs to adjust the time at the same time.

When the time on the eCoordinator approaches the time specified by the

AISSZONE.AdjustTimeparameter set in the ADD AISSZONE command, the eCoordinator

delivers eNodeBs the AISS_TIME_ADJUST_REQ messages including the IE AISS Time

Adjust, instructing each eNodeB to adjust the time and maintain time synchronization withthe reference eNodeB, as shown in Figure 3-10.

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NOTE

If the clock state is abnormal during time difference measurements, time difference measurements stop

even if the clock state restores to normal, and subsequent time difference adjustment cannot be

performed.

Figure 3-10Adjusting time differences

3.3 Synchronization Tracing

To maintain the time synchronization accuracy of Uu-based soft synchronization, eNodeBs

perform periodic fine-tuning on time differences between eNodeBs after initial

synchronization. Procedures for synchronization tracing include the collection of time

differences between each pair of eNodeBs and the adjustment of the time for non-referenceeNodeBs based on the time of the reference eNodeB.

3.4 Synchronization Maintenance

The synchronous Ethernet clock must be configured before Uu-based soft synchronization is

enabled so that frequency synchronization provided by the synchronous Ethernet clock serves

as the basis for time synchronization. Highly reliable and high-precision frequency

synchronization provided by synchronous Ethernet maintains time synchronization accuracy

during synchronization tracing.

The eNodeB-level parameter AISS.FLAGset in the SET AISS command specifies whetherto enable Uu-based soft synchronization on an eNodeB. The synchronous Ethernet clock can

be configured on an eNodeB by running the ADD SYNCETHcommand. The working mode

of the reference clock source and the clock synchronization mode of an eNodeB can be set by

running commands SET CLKMODEand SET CLKSYNCMODE, respectively.

eNodeBs report synchronization status to the eCoordinator, and the eCoordinator performs

different operations based on different synchronization status. Synchronization status

reporting involves three procedures: starting AISS synchronization status reports, sending

AISS synchronization status reports, and stopping AISS synchronization status reports.

1. During the starting of AISS synchronization status reports shown in Figure 3-11, the

eCoordinator sends eNodeBs the AISS_STATE_START_REQ messages, and then eacheNodeB sends the eCoordinator an AISS_STATE_START_RSP message.

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Figure 3-11Starting AISS synchronization status reports

2. During the sending of AISS synchronization status reports shown in Figure 3-12, each

eNodeB sends the eCoordinator an AISS_ STATE_RTP message including the IE Aiss

State that indicates the synchronization status. This message indicates whether the

frequency synchronization or time synchronization of the eNodeB is in the normal state.

Figure 3-12Sending AISS synchronization status reports

3. During the stopping of AISS synchronization status reports shown in Figure 3-13, the

eCoordinator sends an AISS_STATE_STOP_REQ message to the eNodeB that has sent

synchronization status reports, and then the eNodeB sends an AISS_STATE_STOP_RSP

message to the eCoordinator.

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Figure 3-13Stopping AISS synchronization status reports

3.5 Absolute Time Synchronization for eMBMS

eMBMS requires eNodeBs in a synchronization zone to achieve absolute time

synchronization with the Broadcast/Multicast Service Center (BM-SC), that is, the eNodeBs

must achieve time synchronization with the UTC time. UTC is short for Universal Time

Coordinated. However, Uu-based soft synchronization supports only the synchronization

between frame phases delivered by eNodeBs and frame numbers delivered by eNodeBs over

the Uu interfaces, and does not support time synchronization between eNodeBs and the UTC

time. The GPS (or IEEE1588 V2 clock) and Network Time Protocol (NTP) must be used to

achieve absolute time synchronization between eNodeBs within the synchronization zone and

the BM-SC.

NTP supports timing between eNodeBs and the U2000 in network operation and maintenance

(O&M). For details, see Time Management Feature Parameter Description. Both GPS (or

IEEE1588 V2 clock) and NTP support synchronization with the UTC time. However, the

NTP time is of lower precision and differs from the GPS time (or IEEE1588 V2 clock), which

requires time calibration.

The procedure for absolute time synchronization for eMBMS is as follows:

1. An eNodeB within the synchronization zone with the GPS (or IEEE1588 V2 clock)

installed is termed as the GPS eNodeB. The GPS eNodeB achieves time synchronization

with the UTC time obtained by the GPS (or IEEE1588 V2 clock).

2. eNodeBs within the synchronization zone with the NTP servers installed is termed as theNTP eNodeBs. The NTP eNodeBs achieve time synchronization with the NTP-obtained

UTC time. Compared with the GPS-obtained UTC time, the NTP-obtained UTC time

has the time difference T1.

3. Uu-based soft synchronization is enabled on eNodeBs within the synchronization zone.

Frame phases and frame numbers delivered by the GPS eNodeB and frame phases and

frame numbers delivered by the NTP eNodeBs are synchronized, respectively.

4. The GPS eNodeB calculates the time difference T1 and calibrates the time difference,

maintaining time synchronization between the NTP-obtained UTC time and the GPS-

obtained UTC time.

The methods for configuring the GPS, IEEE1588 V2 clock, and NTP are as follows:

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l GPS: Install the GPS on an eNodeB by running the ADD GPScommand. Set the

working mode of the reference clock source and the clock synchronization mode of the

eNodeB by running commands SET CLKMODEand SET CLKSYNCMODE,

respectively.

lIEEE1588 V2: Install the IEEE1588 V2 clock on an eNodeB by running the ADDIPCLKLINKcommand. Set the working mode of the reference clock source and the

clock synchronization mode of the eNodeB by running commands SET CLKMODE

and SET CLKSYNCMODE, respectively.

l NTP: Set the reference clock source to NTP by running theSET TIMESRCcommand.

Set the IP address, port number, timing period, and encryption mode of the NTP server

by running the ADD NTPCcommand. Set parameters related to the primary NTP server

by running the SET MASTERNTPScommand.

NOTE

l Set the SYNCCYCLEparameter in the ADD NTPCcommand to a value less than 60 minutes

to decrease the time differences between eNodeBs.

l The difference between the NTP time and the UTC time must be less than 4 seconds.

l The reference clock source of the synchronous Ethernet must be GPS.

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4Related FeaturesPrerequisite features

LOFD-00301301 Synchronization with Ethernet (ITU-T G.8261)

The Uu-based soft synchronization accuracy is dependent on synchronization reliability of the

synchronous Ethernet.

Mutually exclusive features

LOFD-080216 Uu based Soft Synchronization cannot be enabled if any of the following

features that are exclusive to LOFD-00301301 Synchronization with Ethernet (ITU-T G.

8261) is enabled:

l LBFD-00300504 Synchronization with BITSl LBFD-00300505 Synchronization with 1PPS

l LBFD-00300506 Synchronization with E1/T1

l LOFD-00301302 IEEE1588 V2 Clock Synchronization

l LOFD-00301303 Clock over IP (Huawei proprietary)

LOFD-080216 Uu based Soft Synchronization cannot be enabled if any of following features

that do not support the frame format on the PRACH is enabled:

l LOFD-001007 High Speed Mobility

l LOFD-001008 Ultra High Speed Mobility

l LOFD-001031 Extended CP

l LOFD-001009 Extended Cell Access Radius

The following features apply to multi-RRU cells and cannot work together with the Uu based

Soft Synchronization feature.

l LOFD-003029 SFN

l LOFD-070205 Adaptive SFN/SDMA

Impacted features

LOFD-080216 Uu based Soft Synchronization supports time synchronization for thefollowing features:

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LOFD-070220 eMBMS Phase 1 based on Centralized MCE Architecture

l LOFD-07022001 Multi-cell transmission in MBSFN area

l LOFD-07022002 Mixed transmission of unicast and broadcast

l LOFD-07022003 Data synchronization

l LOFD-07022004 Session admission control

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5Network ImpactSystem Capacity

No impact.

Network Performance

If the time differences between eNodeBs in eNodeB pairs are large during initial

synchronization, the time adjustment step is also large. As a result, services are interrupted for

several seconds during initial synchronization. Because initial synchronization is performed

once only after LOFD-080216 Uu based Soft Synchronization is enabled and performed when

traffic is light (for example, 02:00 in the morning), initial synchronization generally has little

impact on services. Synchronization tracing has no impact on services.

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6Engineering Guidelines

6.1 When to Use LOFD-080216 Uu based SoftSynchronization

Enable LOFD-080216 Uu based Soft Synchronization when all of the following conditions

are met:

l Related coordination features (listed in 4 Related Features) need to be deployed and

these features require eNodeBs to support time synchronization.

l Transmission devices support the synchronous Ethernet clock.

l Compared with LBFD-00300503 GPS Synchronization and LOFD-00301302 IEEE1588

V2 Clock Synchronization, operators want to deploy time synchronization at low cost

without the need for transmission network reconstruction.

6.2 Required Information

1. Determine the synchronization zone: Determine an area for deploying coordination

features (such as eMBMS and TDM eICIC) before enabling these features. This area is

called the synchronization zone.

2. Analyze traffic volume in the synchronization zone: Analyze the distribution of average

traffic volume in a week in different time spans within the synchronization zone.

Determine the time to collect time differences between eNodeBs in eNodeB pairs andthe time to adjust eNodeB time. Set the time to collect time difference to the time when

the traffic volume is neither too large nor too small. Because event A3 measurements are

required in time difference measurements and it takes 100 ms to perform preamble blind

detection in each event A3 measurement, the time to collect time differences cannot be

set to the peak traffic volume time to decrease impacts on services. In addition, time

difference measurements cannot be performed if the number of UEs in inter-eNodeB

handovers is too small. Therefore, the time to collect time differences cannot be set to

the time when the traffic volume is too small. You are advised to set the time to adjust

eNodeB time to the time when the traffic volume is light (for example, 02:00 in the

morning) in order to decrease impacts on services.

3. Analyze the stability of synchronization maintenance in synchronous Ethernet: Onlytime difference collection is activated in the synchronization zone, and time difference

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adjustment is not activated. Set the AISSZONE.MeasurePeriodparameter to 10in the

unit of day to check the stability of synchronization maintenance between eNodeB and

the fluctuation of time differences between eNodeBs in 10 days. The change of time

differences between more than 99% of eNodeBs must be less than 3 s.

4. Collect alarms reported by eNodeBs. First clear the following alarms if any is reported: ALM-25880 Ethernet Link Fault: This alarm indicates the frequency of

transmission link interruption in a single eNodeB and can be cleared by

troubleshooting transmission link faults.

ALM-26262 External Clock Reference Problem: This alarm indicates the frequency

that the reference clock source of a single eNodeB is unlocked and can be cleared

by troubleshooting clock link faults.

ALM-25621 Power Supply DC Output Out of Range, ALM-25622 Mains Input Out

of Range, and ALM-25626 Power Module Abnormal: These alarms indicate the

frequency that a single eNodeB is powered off and can be cleared by

troubleshooting power module faults.

(Optional) ALM-26266 Time Synchronization Failure: This alarm is reported only

when the NTP server is installed and indicates that a single eNodeB fails NTP

timing. This alarm can be cleared by troubleshooting NTP clock link faults.

6.3 Planning

6.3.1 RF Planning

This feature supports the deployment of Huawei eNodeBs providing consecutive intra-

frequency coverage and does not support mixed deployment of Huawei eNodeBs and non-Huawei eNodeBs.

6.3.2 Network Planning

l The eCoordinator is functioning normally. The Se interfaces between the eCoordinator

and eNodeBs are correctly configured and the Se links are in the normal state.

NOTE

For detailed descriptions of the Se interface, seeIP Transmission Feature Parameter Description.

For details about how to configure the Se interface, seeIP eRAN Engineering Guide Feature

Parameter Description.

l All eNodeBs within a synchronization zone must be configured with the same

synchronous Ethernet clock source and all transport devices within the synchronization

zone support synchronous Ethernet.

l Transmission devices must support the synchronization status message (SSM) protocol

defined by ITU-T G.8264.

l The synchronization accuracy of the clock in the upper level of the synchronous Ethernet

installed on eNodeBs must be less than or equal to 16 ppb.

l Distances between eNodeBs within a synchronization zone must be less than 15 km.

l The NTP server and GPS must be installed on eNodeBs when eMBMS is required. In

this case, the GPS must be selected as the synchronous Ethernet clock source.

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6.3.3 Hardware Planning

l ECO6910 is required.

l eNodeBs in any of the following types:

3900 series eNodeBs with the baseband processing unit being LBBPd or UBBP and themain control board being LMPT or UMPT.

NOTE

If a 3900 series eNodeB is equipped with the LBBPd and serves 4R and 8R cells, the PRACH

configurations of one cell cannot overlap with the PRACH configurations of another cell in the

time domain. This requires that the eNodeB level parameter PrachTimeStagSwitch be set to

ON(On)and cell-level parameter PrachConfigIndexCfgInd be set to NOT_CFG(Not

configure).

l The NTP server and GPS must be installed on eNodeBs when eMBMS is required. In

this case, the GPS must be selected as the synchronous Ethernet clock source.

6.4 Feature Deployment

6.4.1 Process

Step 1 Deploy the eCoordinator. The Se interfaces between the eCoordinator and eNodeBs arecorrectly configured and the Se links are in the normal state.

NOTE

For detailed descriptions of the Se interface, seeIP Transmission Feature Parameter Description. For

details about how to configure the Se interface, seeIP eRAN Engineering Guide Feature Parameter

Description.

Step 2 Enable Uu-based soft synchronization on eNodeBs, configure synchronous Ethernet clock forthe eNodeBs, and configure information about longitudes and latitudes of the eNodeBs.

Step 3 Configure X2 interfaces between eNodeBs.

Step 4 On the eCoordinator, configure a synchronization zone, add eNodeBs to the synchronizationzone, and configure a reference eNodeB.

Step 5 (Applied only to eMBMS) Install GPS (or IEEE1588 V2 clock) on one of the eNodeBs in thesynchronization zone, and then install NTP servers on all eNodeBs in the synchronization

zone. Synchronize the NTP time on all eNodeBs with the time on the eNodeB with GPS

installed.

Step 6 Activate the synchronization zone on the eCoordinator and activate the automatic eNodeBpairing calculation function.

----End

6.4.2 Requirements

Other Features

The prerequisite features of LOFD-080216 Uu based Soft Synchronization must be enabled

before this feature is enabled. For details, about the prerequisite features, see 4 RelatedFeatures.

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Hardware

For details, see 6.3.3 Hardware Planning.

LicenseFeature ID Feature

NameModel License

Control ItemNE Sales Unit

LOFD-080216 Uu based Soft

Synchronizati

on

LEC2AI

SS01

Uu based Soft

Synchronization(

LTE FDD) (per

eNodeB)

eCoordin

ator

per

eNodeBs

6.4.3 Data PreparationThe following table lists parameters related to eNodeB configurations.

The following table lists parameters related to synchronous Ethernet configuration.

Parameter Name Parameter ID Setting Notes Data Source

Link No. SYNCETH.LN Set this parameter to

0.

Network plan

(negotiation not

required)

Port No. SYNCETH.PN This parameter

specifies the numberof the port where the

synchronous-

Ethernet clock link

is configured. Set

this port and the

synchronous

Ethernet clock

source in the same

network.

Network plan

(negotiation notrequired)

SSM Selection SYNCETH.SSM Set this parameter to

the same value asthe setting on the

Ethernet clock

server.

Network plan


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Priority SYNCETH.PRI When two or more

clock sources are

used, a smaller value

of this parameter

specifies a higher

priority.

Set this parameter to

its default value

when the

synchronous

Ethernet is the only

clock source.

Network plan

(negotiation not

required)

Clock Working

Mode

CLKMODE.MOD

E

It is recommended

that this parameterbe set to

MANUAL(Manual

).

Network plan


Selected Clock

Source

CLKMODE.CLKS

RC


SYNCETH(SyncEt

h Clock).

Network plan

(negotiation not

required)

Clock Source No. CLKMODE.SRCN

O


the same value as

the established clock

link number.

Network plan

(negotiation not

required)

Clock

Synchronization

Mode

CLKSYNCMODE.

CLKSYNCMODE

The clock source

supports only

frequency

synchronization.

Therefore, set this

parameter to

FREQ(FREQ).

Network plan

(negotiation not

required)

The following table lists parameters related to the configuration of longitudes and latitudes of

eNodeBs.


Location Name LOCATION.LOCA

TIONNAME

This parameter

specifies the

location name of the

eNodeB.

Network plan

(negotiation not

required)

Geo-coordinate Data

Format

LOCATION.GCDF This parameter

specifies the format

of geographical

coordinates.

Network plan

(negotiation not

required)

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Altitude LOCATION.LATI

TUDEDEGFORM

AT

This parameter

specifies the altitude

of the eNodeB. A

negative value

indicates the south

latitude and a

positive value

indicates the north

latitude.

Network plan

(negotiation not

required)

Longitude LOCATION.LONG

ITUDEDEGFORM

AT

Indicates the

longitude of the base

station. A negative

value indicates the

west longitude and a

positive value

indicates the east

longitude.

Network plan

(negotiation not

required)

(Applied only to eMBMS) The following table lists parameters related to the configuration of

GPS and the NTP server.


GPS Clock No. GPS.GN This parameter

indicates the number

of the GPS clock

link.

Radio network plan

(internal planning)

GPS Work Mode GPS.MODE This parameter

specifies the

working mode of the

satellite card. Set

this parameter to

GPS(GPS). If the

eMBMS feature is

required, the

reference eNodeB

must have GPS

installed.

Radio network plan

(internal planning)

Time Source TIMESRC.TIMES

RC

This parameter

specifies the

external reference

time source of the

NE.

Radio network plan

(internal planning)

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IPv4 Address of

NTP Server

NTPCP.IP This parameter

specifies the IPv4

address of the NTP

server.

Radio network plan

(internal planning)

Port Number NTPCP.PORT This parameter

specifies the port

number of the NTP

server. An NTP

client performs time

calibration with the

NTP server through

the port specified by

this parameter.

Radio network plan

(internal planning)

AuthenticationMode

NTPCP.AUTHMODE

This parameterspecifies the

encryption mode. If

this parameter is set

to PLAIN, data is

transmitted in

plaintext.

Radio network plan(internal planning)

The following table lists parameters used to control whether to enable Uu-based soft

synchronization.


Uu Interface Soft

Synchronization

Switch

AISS.FLAG Set this parameter to

ON(On).

Radio network plan

(internal planning)

Soft-synchronized

Network Adaptive

Mode

AISS.NETMODE This parameter

specifies the

adaptive mode of the

soft synchronous

transport network. If

the network jitter islarge, set this

parameter to

ENH(Enhanced

Mode). Otherwise,

set this parameter to

GEN(General

Mode). This

parameter does not

apply to eGBTS.

Radio network plan

(internal planning)

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Uu Soft Syn Phase

Adjustment Period

AISS.FREQUENC

E

This parameter

specifies the

adjustment period of

the frame clock

phase when the Uu

interface soft

synchronization

Phase Lock function

is enabled on the

eNodeB.

This parameter is

negotiated with the

peer end.

The following tables list parameters that must be configured on the eCoordinator side related

to synchronization zone configuration, eNodeB addition, and eNodeB pair configuration.

The following table lists parameters related to synchronization zone configuration.


Synchronization

Zone ID

AISSZONE.AISSZ

oneId

This parameter

specifies the unique

ID of a Uu-based

soft synchronization

zone.

Network plan

(negotiation not

required)

Time Adjust Period AISSZONE.Adjust

Period

This parameter

specifies the cycle inwhich the eNodeB

time is adjusted.

Network plan


Time Measure

Period

AISSZONE.Measu

rePeriod

This parameter

specifies the cycle in

which the eNodeB

time is measured.

The time is

measured per cycle.

Network plan

(negotiation not

required)

Adjust Threshold AISSZONE.Adjust

Threshold

This parameter

specifies thethreshold for

adjusting the

eNodeB time. The

eNodeB time is not

adjusted when the

time difference is

less than this

threshold.

Network plan


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Start Time for

Measurement

AISSZONE.Measu

reTime

This parameter

specifies the start

time for measuring

time difference

between eNodeBs in

a Uu-based soft

synchronization

zone.

Network plan

(negotiation not

required)

Adjust Time AISSZONE.Adjust

Time

This parameter

specifies the

scheduled timing for

adjusting the time of

an eNodeB in the

Uu-based soft

synchronization

zone.

Network plan

(negotiation not

required)

Frequency Band AISSZONE.Freque

ncyBand

This parameter

specifies the

frequency band on

which a cell in the

Uu-based soft

synchronization

zone works. For

details about this

parameter, see 3GPP

TS 36.104. For cellsin the Uu-based soft

synchronization

zone, the frequency

band and downlink

EARFCN

configuration must

meet the relationship

specified in 3GPP

TS 36.104.

Network plan

(negotiation not

required)

Downlink EARFCN AISSZONE.DLFre

quency

This parameter

specifies thedownlink EARFCN

for a cell in the Uu-

based soft

synchronization

zone. For details

about this parameter,

see 3GPP TS

36.104.

Network plan


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Downlink

Bandwidth

AISSZONE.DLBan

dWidth

The parameter

specifies the

downlink bandwidth

of a cell. The

downlink bandwidth

is denoted by

number of RBs. If


to CELL_BW_N25,

25 RBs are allocated

in the downlink. If


to CELL_BW_N50,

50 RBs are allocated

in the downlink. Fordetails about this

parameter, see 3GPP

TS 36.104.

Network plan

(negotiation not

required)

RSRP Threshold AISSZONE.RSRPT

hreshold

This parameter

specifies the

minimum RSRP of a

cell that a UE can

select after

measurements. A

larger value of this

parameter results inbetter signal quality

of the area in the cell

in which the UE

locates and better

random access

performance.

Network plan

(negotiation not

required)

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A3 Offset for Soft

Synchronization

AISSZONE.A3Off This parameter

specifies the offset

used to trigger event

A3. The event A3

itself is reported by

UEs which measure

the time difference

on the edge of

neighboring cells.

For details about this

parameter, see 3GPP

TS 36.331. A larger

value of this

parameter results in

fewer UEs reportingevent A3 and a

lower probability of

CEUs being selected

for time difference

measurements. A

smaller value of this

parameter results in

a longer distance

between the UE and

the neighboring cell,

and a lower

probability thatpreambles sent by

the UE are being

blindly detected by

the neighboring cell.

Network plan

(negotiation not

required)

CEU Punish Time AISSZONE.Punish

Time

This parameter

specifies the interval

at which a CEU

cannot perform a

time difference

measurement after

the previousmeasurement ends.

A parameter either

too large or too

small in value has

negative impacts on

the time difference

measurements of

CEUs.

Network plan

(negotiation not

required)

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Blind Detection

Duration

AISSZONE.Detect

LastTime

This parameter

specifies the

duration for blind

preamble detection

on a neighboring

eNodeB. A larger

value of this

parameter requires

higher baseband

processing

capability. A

parameter of a

smaller value

decreases the

success rate of blinddetection.

Network plan

(negotiation not

required)

Leap Second

Adjustment Value

AISSZONE.LEAPS

ECOND

This parameter

specifies the leap

second value of the

Coordinated

Universal Time

(UTC). The NTP

time is derived from

UTC, which

deviates from the

GPS time in thelevel of leap

seconds. Therefore,

the eNodeB must

consider the leap

second deviation

when converting the

NTP time to the

GPS time. IfNTPis

configured, set this

parameter to a valid

value. Otherwise, set

this parameter to aninvalid value 0.

Radio network plan

(internal planning)

The following table lists parameters used to add eNodeBs into the synchronization zone.

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Base Station MCC ENBAISS.BaseStati

onMCC

This parameter

specifies the mobile

country code (MCC)

of a base station in a

Uu-based soft

synchronization

zone.

Network plan

(negotiation not

required)

Base Station MNC ENBAISS.BaseStati

onMNC

This parameter

specifies the mobile

network code

(MNC) of a base

station in a Uu-

based soft

synchronization

zone.

Network plan

(negotiation not

required)

Base Station ID ENBAISS.BaseStati

onId

This parameter

specifies the ID of a

base station in a Uu-

based soft

synchronization

zone.

Network plan

(negotiation not

required)

LPN Or Not ENBAISS.IsLPN This parameter

specifies whether an

eNodeB is a lower

power node (LPN).

Network plan

(negotiation not

required)

Base Station Type ENBAISS.BaseStati

onType

This parameter

specifies the

eNodeB type.

Network plan

(negotiation not

required)

The following table lists parameters related to the configuration of eNodeB pairs.


MCC of BaseStation 1

AISSNENB.BaseStation1MCC

This parameterspecifies the MCC

of base station 1.

Network plan(negotiation not

required)

MNC of Base

Station 1

AISSNENB.BaseSt

ation1MNC

This parameter

specifies the MNC

of base station 1.

Network plan

(negotiation not

required)

MCC of Base

Station 2

AISSNENB.BaseSt

ation2MCC

This parameter

specifies the MCC

of base station 2.

Network plan

(negotiation not

required)

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MNC of Base

Station 2

AISSNENB.BaseSt

ation2MNC

This parameter

specifies the MNC

of base station 2.

Network plan

(negotiation not

required)

6.4.4 Precautions

l During manual configuration of LOFD-080216 Uu based Soft Synchronization in

scenarios with LOFD-001037 RAN Sharing with Dedicated Carrier or LOFD-070206

Hybrid RAN Sharing deployed, one eNodeB has several IDs specified by the

ENBAISS.BaseStationIdparameter. Only the ID of the primary operator is added when

the eNodeB is added into the synchronization zone.

l The longitudes and latitudes of eNodeBs must be configured first before the

eCoordinator automatically calculates eNodeB pairs by running the ACT

AISSNENBCALCcommand. If the attributes of an eNodeB pair are changed, run this

command again to activate an automatic eNodeB pairing calculation. The attribute

changes include changes of longitude and latitude of eNodeBs in the pair, addition and

removal of eNodeBs, X2 interfaces between eNodeBs, or cells under eNodeBs, and

neighbor relationship changes.

l In Uu-based soft synchronization, the signal strength is determined based on the

reference signal received power (RSRP) contained in event A3 reports. However, if the

TriggerQuantityparameter is set to RSRQand the ReportQuantityparameter is set to

SAME_AS_TRIG_QUANduring the execution of the MOD CELLMCPARA

command, the eNodeB does not report RSRP. Therefore, do not set the TriggerQuantity

parameter to RSRQor set the ReportQuantityparameter to SAME_AS_TRIG_QUANwhen Uu-based soft synchronization is required.

l Preamble blind detection cannot distinguish which preamble is used in Uu-based soft

synchronization. Therefore, do not use the preambles on the same root sequence with the

preamble for blind detection. Otherwise, exceptions will occur during preamble blind

detection. The following conditions must be met before enabling Uu-based soft

synchronization:

The radius of all cells must be greater than 5 km to ensure normal preamble

allocation.

The RachAdjSwitch(RachAdjSwitch) option of the

CellAlgoSwitch.RachAlgoSwitchparameter must be deselected.

l The time difference adjustment time must be later than the time difference measurement

time. If Uu-based soft synchronization is deployed for the first time and the time

difference adjustment time is earlier than the time difference measurement time, the time

difference cannot be adjusted until the second time difference adjustment time is reached

after the first time difference measurement. You are advised to enable Uu-based soft

synchronization at least one day earlier than the time specified by parameter settings.

6.4.5 Activation

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6.4.5.1 7.4.5.1 Using the CME to Perform Batch Configuration for NewlyDeployed eNodeBs

Enter the values of the parameters listed in Table 6-1in a summary data file, which also

contains other data for the new eNodeBs to be deployed.

Then, import the summary data file into the Configuration Management Express (CME) for

batch configuration. For detailed instructions, see "Creating eNodeBs in Batches" in the initial

configuration guide for the eNodeB, which is available in the eNodeB product documentation.

The summary data file may be a scenario-specific file provided by the CME or a customized

file, depending on the following conditions:

l The managed objects (MOs) in Table 6-1are contained in a scenario-specific summary

data file. In this situation, set the parameters in the MOs, and then verify and save the

file.

l Some MOs in Table 6-1are not contained in a scenario-specific summary data file. In

this situation, customize a summary data file to include the MOs before you can set the

parameters.

Table 6-1MOs that must be configured in Uu-based soft synchronization

MO Sheet in theSummary DataFile

Parameter Group Remarks

Tasm Common Data Um Interface Soft Synchronization

Switch, ClkSource Type, Clock

Synchronization Mode, Working

Mode, ClkSource No

-

SyncEth Common Data SyncEth Type, SyncethNo, SSM

Selection, Priority, Cabinet No,

Subrack No, Slot No, Port No

-

GPS Common Data GpsNo, Cabinet No, Subrack No, Slot

No, Work Mode, Priority

-

TIMESRC Common Data Time Source -

NtpCp Common Data NTP IP, NTP IP Mask, Port,

SyncCycle, Authentication Mode,

Authentication Key, Authentication

Key Index, MasterFlag

-

Location Base Station

Transport Data

LocationName, LatitudeDegFormat,

LongitudeDegFormat

-

6.4.5.2 Using the CME to Perform Batch Configuration for Existing eNodeBs

Batch reconfiguration using the CME is the recommended method to activate a feature on

existing eNodeBs. This method reconfigures all data, except neighbor relationships, formultiple eNodeBs in a single procedure. The procedure is as follows:

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Step 1 After creating a planned data area, choose CME> Advanced> Customize Summary DataFile(U2000 client mode), or choose Advanced> Customize Summary Data File(CME

client mode), to customize a summary data file for batch reconfiguration.

NOTE

For context-sensitive help on a current task in the client, press F1.

Step 2 Choose CME> LTE Application> Export Data> Export Base Station BulkConfiguration Data(U2000 client mode), or choose LTE Application> Export Data>

Export Base Station Bulk Configuration Data(CME client mode), to export the eNodeB

data stored on the CME into the customized summary data file.

Step 3 In the summary data file, set the parameters in the MOs listed in Table 6-1and close the file.

Step 4 Choose CME> LTE Application> Import Data> Import Base Station BulkConfiguration Data(U2000 client mode), or choose LTE Application> Import Data>

Import Base Station Bulk Configuration Data(CME client mode), to import the summary

data file into the CME, and then start the data verification.

Step 5 After data verification is complete, choose CME> Planned Area> Export IncrementalScripts(U2000 client mode), or choose Area Management> Planned Area> Export

Incremental Scripts(CME client mode), to export and activate the incremental scripts.

----End

6.4.5.3 Using the CME to Perform Single Configuration

On the CME, set the parameters listed in the 6.4.3 Data Preparationsection for a single

eNodeB. The procedure is as follows:

Step 1 In the planned data area, click Base Stationin the upper left corner of the configurationwindow.

Step 2 In area 1 shown in Figure 6-1, select the eNodeB to which the MOs belong.

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Figure 6-1MO search and configuration window

NOTE

l To view descriptions of the parameters in the MO, click in area 4 and press F1.

lArea 5 displays the details of a selected area-4 entry in vertical format. Click the Detailsicon toshow or hide this area.

Step 3 On the Searchtab page in area 2, enter an MO name, for example, CELL.

Step 4 In area 3, double-click the MO in the Object Namecolumn. All parameters in this MO aredisplayed in area 4.

Step 5 Set the parameters in area 4 or 5.

Step 6 Choose CME> Planned Area> Export Incremental Scripts(U2000 client mode), orchoose Area Management> Planned Area> Export Incremental Scripts(CME client

mode), to export and activate the incremental scripts.

----End

6.4.5.4 Using MML Commands

Step 1 Enable Uu-based soft synchronization on eNodeBs.

Run the SET AISScommand to enable Uu-based soft synchronization on eNodeBs.

Step 2 Configure synchronous Ethernet on eNodeBs.

Run the ADD SYNCETHcommand to add synchronous Ethernet links.

Run the SET CLKMODEcommand to set the reference clock source to the synchronousEthernet clock.

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Run the SET CLKSYNCMODEcommand to set the clock synchronization mode to

frequency synchronization.

Step 3 Configure eNodeBs' longitudes and latitudes on eNodeBs.

Run the ADD LOCATIONcommand on eNodeBs to configure longitudes and latitudes ofeNodeBs.

Step 4 Bind the eNodeB's location to the sector equipment.

Run the MOD SECTORcommand to bind the eNodeB's location to the sector equipment.

Step 5 Configure a synchronization zone using the eCoordinator.

Run the ADD AISSZONEcommand to configure a synchronization zone.

Step 6 Add eNodeBs to the synchronization zone using the eCoordinator.

Run the ADD ENBAISScommand to add eNodeBs to the synchronization zone.

Step 7 (Optional) Configure GPS or IEEE1588 V2 clock on one eNodeB (This eNodeB does notrequire synchronous Ethernet.)

Run the ADD GPScommand to add GPS, or run the ADD IPCLKLINKcommand to add

the IP clock link.

Run the SET CLKMODEcommand to set the reference clock source to GPS.

Run the SET CLKSYNCMODEcommand on eNodeBs to set the clock synchronization

mode to time synchronization.

Step 8 (Applied only to eMBMS) Configure NTP on all eNodeBs in the synchronization zone.

Run the SET TIMESRCcommand to set the reference clock source to NTP.

Run the ADD NTPCcommand to configure the IP address, port number, timing period, and

encryption mode of the NTP server. Run the SET MASTERNTPScommand to configure

parameters related to the master NTP server.

Step 9 Add eNodeB pairs on the eCoordinator. eNodeB pairs can be added either automatically ormanually. eNodeB pairs are automatically added by default and can be manually adjusted.

l Adding eNodeB pairs automatically for Uu-based soft synchronization

Run the ACT AISSZONEcommand to activate the synchronization zone.

Run the ACT AISSNENBCALCcommand to activate automatic eNodeB pairing

calculation.

l Adding eNodeB pairs manually for Uu-based soft synchronization

Run the ADD AISSNENBcommand to add eNodeBs into eNodeB pairs for

synchronization.

Run the ACT AISSZONEcommand to activate the synchronization zone.

----End

6.4.5.5 MML Command Examples

//Enabling Uu-based soft synchronization on eNodeBs

SET AISS: FLAG=ON, NETMODE=ENH, FREQUENCE=480SEC;

//Configuring synchronous Ethernet on eNodeBs

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ADD ETHPORT: SN=7, SBT=BASE_BOARD, PA=COPPER, SPEED=AUTO, DUPLEX=AUTO;

ADD SYNCETH: LN=0, SN=7, PN=0;

SET CLKMODE: MODE=MANUAL, CLKSRC=SYNCETH;

SET CLKSYNCMODE: CLKSYNCMODE=FREQ;

//Configuring eNodeBs' longitudes and latitudes on eNodeBs

ADD LOCATION: LOCATIONNAME="hangzhou_NODE_ONE", GCDF=Degree, LATITUDEDEGFORMAT=0,

LONGITUDEDEGFORMAT=0;

//Binding the eNodeB's location to the sector equipment

MOD SECTOR:SECTORID=0,LOCATIONNAME="han