198686662 05 RAN HSDPA Principle and Configuration Updated to RAN11 (2)

HUAWEI TECHNOLOGIES CO., LTD. All rights reserved

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HSDPA Principles and

configuration

BSC6810V200R011

HUAWEI TECHNOLOGIES CO., LTD. All rights reserved Page 2

Main features

RAN5.0 HSDPA

Phase 1

RAN5.1 HSDPA

Phase 2

RAN6 HSDPA Phase 3 RAN10

Max rate

1.8Mbps/user

Max rate

3.6Mbps/user

Max rate 7.2Mbps/user Max rate

14.4Mbps/user

Max user no.

16/cell

Max user no. 64/cell

Basic admission

control

CAC/LDR/Schedule

based on GBR HSDPA over Iur

RNC controlled

dynamic code

allocation

NodeB-controlled

dynamic code

allocation

SRB over HSPA

Multi RAB（1CS +

2PS)

VOIP over HSPA


Upon completion of this course, you will be

able to:

Relevant principles of HSDPA

Features of HSDPA

Relevant data configuration of HSDPA


Chapter 1 HSDPA Principle

Chapter 2 HSDPA signaling procedure

Chapter 3 HSDPA radio resource

management

Chapter 4 HSDPA data configuratioin


Introduction

Higher downlink peak transmission rate: up to 14.4 Mbit/s

More efficient downlink codes and power utilization: for macro

cell coverage, the capacity is 50% higher; for micro cell

coverage, the capacity is 200%–300% or higher


Realization of the HSDPA

UTRAN side:

MAC-hs and HSDPA physical layer processing

HS-DSCH FP between the SRNC, CRNC, and NodeB for user plane

data transmission

CN side:

PS domain needs to support higher rate of service assignment and

user plane transmission and switching

PHY

MAC-hs

MAC-d

PHY TNL

MAC-hsHS-DSCH

FP

TNL

HS-DSCH FP

MAC-d

DTCH DCCH DTCH DCCH

UE NodeB CRNC/SRNCUu Iub


MAC_hs

MAC-hs

MAC – Control

HS-DSCH

TFRC selection

Priority Queuedistribution

Associated DownlinkSignalling

Associated UplinkSignalling

MAC-d flows

HARQ entity

Priority Queuedistribution

PriorityQueue

PriorityQueue

PriorityQueue

PriorityQueue

Scheduling/Priority handling


MAC_hs

Flow Control:

This function is intended to limit layer 2 signalling latency and reduce discarded

and retransmitted data as a result of HS-DSCH congestion. Flow control is

provided independently by MAC-d flow for a given MAC-hs entity.

Scheduling/Priority Handling:

This function manages HS-DSCH resources between HARQ entities and data

flows according to their priority. Based on status reports from associated uplink

signalling either new transmission or retransmission is determined. Further it

determines the Queue ID and TSN for each new MAC-hs PDU being serviced. A

new transmission can be initiated instead of a pending retransmission at any time

to support the priority handling.

HARQ:

One HARQ entity handles the hybrid ARQ functionality for one user. One HARQ

entity is capable of supporting multiple instances (HARQ process) of stop and

wait HARQ protocols. There shall be one HARQ process per HS-DSCH per TTI.

TFRC selection:

Selection of an appropriate transport format and resource for the data to be

transmitted on HS-DSCH


HSDPA Physical Channel

HS-PDSCH: High Speed Physical Downlink Shared Channel

The HS-PDSCH is used to carry downlink service data.

The spreading factor of the HS-PDSCH can be 16 only. Each cell can

provide at most 15 HS-PDSCHs whose codes must be continuous.

When a cell provides 15 HS-PDSCHs, the maximum rate reaches 14.4

Mbit/s.

The HS-PDSCH adopts the QPSK or 16QAM modulation mode

In RAN11 supporting HSPA+, 64QAM/MIMO is supported



HS-SCCH: High Speed Shared Control Channel

The HS-SCCH carries downlink control information. It is used to notify

the UE of the information about the HS-PDSCH, including modulation

mode, size of a transmission block, version redundant information, UE ID

and HS-PDSCH channel code.

HS-SCCH is aligned with the PCCPCH in timing and keeps fixed time

offset with the HS-PDSCH. Its spreading factor is fixed as 128 and

QPSK is the only modulation mode.

The number of HS-SCCHs (128 at most) and the channel codes in the

cell are decided by RNC, which notifies NodeB through the NBAP

signaling message. The UE can detect one to four HS-SCCHs specified

by the NodeB at one time



HS-DPCCH: High Speed Dedicated Physical Control Channel

The HS-DPCCH is used to carry the uplink feedback information related

to the downlink HS-PDSCH, including ACK/NACK and CQI. The

spreading factor of the HS-DPCCH is fixed as 256.

Subframe #0 Subframe # i Subframe #4

HARQ-ACK CQI

One radio frame T f = 10 ms

One HS-DPCCH subframe (2 ms)

2 T slot = 5120 chips T slot = 2560 chips


SRB over HSPA F-DPCH

(Tx OFF)

Slot #0 Slot #1 Slot #i Slot #14

Tslot = 2560 chips

1 radio frame: Tf = 10 ms

TPC

NTPC bits (Tx OFF)

512 chips

Figure 12B: Frame structure for F-DPCH

The F-DPCH carries control information generated at layer 1 (TPC

commands). It is a special case of the downlink DPCCH. The following

figure shows the frame structure of the F-DPCH.

Each frame of length 10 ms is split into 15 slots, each of length timeslot

= 2560 chips, corresponding to one power-control period.


SRB over HSPA F-DPCH

Through time division multiplexing of one SF256 F-DPCH channel

code by multiple UEs, the channel code resources and power resources

of a cell can be saved, and the system capacity can be improved.

Each UE occupies only one symbol in each slot to carry the TPC

command. The Pilot domain and TFCI are removed.

TPC

TPC

TPC

TPC

TPC

TPC

TPC

TPC

TPC

TPC

TPC

TPC

TPC

UE1

UE2

UE3

UE4

UE5

UE6

UE7

UE8

UE9

UE10

P-CCPCH frameoffset（256chip）

0

1

2

3

4

5

6

7

8

9


HSDPA Channel Mapping

HS-DSCH: High Speed Downlink Shared Channel

Traffic classes supported by the HS-DSCH

SET CORRMALGOSWITCH:

HspaSwitch=PS_STREAMING_ON_E_DCH_SWITCH-

1&PS_STREAMING_ON_HSDPA_SWITCH-1;

SET FRC: UlStrThsOnHsupa=D32, UlBeTraffThsOnHsupa=D64;

Traffic classes Description

Streaming

The switch [PS_STREAMING_ON_HSDPA_SWITCH] decides the

streaming service on the HS-DSCH.

When the switch is on, the streaming service is mapped to the HS-

DSCH.

When the switch is off, the streaming service is mapped to the DPCH.

Interactive The generic term for these two services is BE service.

The BE services are mapped to the HS-DSCH whenever possible. Background


HS-DSCH Mapping to HSDPA channel

F-DPCH


HSPDA Physical Channel Timing Relationship

HS-SCCH

HS-PDSCH

3 slots = 2 ms

DPCH

DPCH

Radio frame with (SFN modulo 2) = 0 P-CCPCH

2 slots

3 slots = 2 ms

Slot Slot Slot Slot Slot Slot Slot Slot Slot Slot Slot Slot Slot Slot Slot

15 slots = 10 ms

Subframe #0 Subframe #1 Subframe #2 Subframe #3 Subframe #4

Radio frame with (SFN modulo 2)=1

10 ms

Subframe #0 Subframe #1 Subframe #2 Subframe #3 Subframe #4


HSDPA Key Technology

2 ms TTI

Link adaptation through HARQ

AMC in the physical layer

Mac-hs scheduling

HSDPA flow control



2 ms TTI

Faster data scheduling

Faster data transmission

Shorter delay



HARQ Technology:

the HARQ is combination of the Forward Error Correction (FEC) and ARQ

Every HSDPA user has an HARQ entity on both the UE and NodeB sides, each

having up to six HARQ processes.

Coding combination Description Comparison

Chase Combining Retransmit the

same bit set

The second mode is better in that the

combination of the retransmitted bit

set and the former bit set raises the

redundant data and the possibility of

recovery from errors at the air

interface.

Increment Redundancy Retransmit

different bit sets

HARQ process 1

HARQ process 212ms or more

HS-SC

HS-PDS

HS-SC

HS-PDS

HS-SC

HS-PDS

HS-SC

HS-PDS

12ms or more



AMC Technology:

The UE reports the CQI to the NodeB through the HS-DPCCH and the

NodeB selects coding rate and modulation mode according to the radio

environment indicated by the CQI

The condition of the radio

environment Modulation and rate Result

Good

( The UE is near the NodeB)

High order modulation (for

example, 16QAM/64QAM)

High coding rate

High peak rate

Poor

(The UE is at the boarder of the cell

or there is a sever attenuation)

Low order modulation (for

example, QPSK)

Low coding rate

High

communication

quality



HSDPA Scheduling Algorithm :

Algorithm Description

Max C/I Allocates resources to the UE with the best channel conditions at each TTI,

maximizing the cell throughput.

Round Robin Allocates resources to the UE with the longest waiting time, Users’ time fairness is

guaranteed but the cell throughput is low.

Proportional

Fair (PF)

Allocates resources to the UE according to the radio condition and the achieved

data rate. The higher the CQI is, the more the opportunity of the user being

scheduled. The lower the achieved data rate is, the more the user can be

scheduled. The PF scheduling algorithm is a trade-off between the fairness and

the cell throughput.

EPF

Guarantees the GBR requirement of the streaming service and the BE service.

The GBR of BE service is configured by RNC LMT and NodeB LMT, which means

that if the BE service achieve the GBR, the BE user is satisfied.



HSDPA Scheduling Algorithm :

MML Commands:

NodeB Side

SET MACHSPARA: SM=EPF;;

SET MACHSSPIPARA:;

RNC side

SET USERPRIORITY

SET SCHEDULEPRIOMAP:;

SET USERGBR:;


HSDPA Flow Control

HS-DSCH Capacity Request

The HS-DSCH Capacity Request procedure provides means for the

CRNC to request HS-DSCH capacity by indicating the user buffer size

in the CRNC for a given priority level

Node B SRNC

CAPACITY REQUEST

1

User Buffer Size

User Buffer Size ( cont)

CmCH -PI Spare bits 7-4

Spare Extension

Payload

1

0-32

1

Number of Octets bit7 bit 0


HSDPA Flow Control

HS-DSCH Capacity Allocation procedure

It may be generated either in response to a HS-DSCH Capacity Request

or at any other time

Node B SRNC

CAPACITY ALLOCATION

HS-DSCH Interval

HS-DSCH Credits (cont)

Maximum MAC-d PDU Length

Maximum MAC-d PDU

Length (cont)HS-DSCH Credits

HS-DSCH Repetition Period

CmCH-PISpare bits 7-4

07

Spare Extension


HSDPA Flow Control in RAN10

Flow control is implemented in both RNC and NodeB

On the NodeB, use adaptive flow control and traffic shaping to avoid

congestion on the Iub interface.

On the RNC, use VP shaping and backpressure to avoid congestion

on the Iub interface.



Flow control in NodeB

Bandwidth allocation for UE queues

− A NodeB allocates the bandwidth on the Iub interface for each

MAC-hs queue according to the buffering status of the queue

and the rate on the Uu interface.

− If the queue lacks data, the bandwidth allocated by the NodeB is

higher than the rate on the Uu interface.

− If the queue contains sufficient data, the bandwidth allocated by

the NodeB is close to the rate on the Uu interface.

− If the queue contains excessive data, the bandwidth allocated by

the NodeB is lower than the rate on the Uu interface.




Traffic shaping on Iub interface

− During bandwidth allocation, guaranteed bit rate (GBR) UEs are

preferred. Then, the remaining bandwidth is allocated according

to the UE priority, that is, SPI weight proportionally

− When there is a severe lack of bandwidth, and the bandwidth

cannot meet requirements of all the GBR UEs, the GBR UEs

with high priority are preferred




Adaptive flow control on Iub interface

− If the frame loss rate in the HS-DSCH is beyond the threshold,

or the jitter of the HS-DSCH frames within a period of time

exceeds the delay threshold, the bandwidth for the HSDPA

service on the Iub interface is reduced.

− If the frame loss rate in the HS-DSCH is lower than the threshold,

or the jitter of the HS-DSCH frames within a period of time is

lower than the delay threshold, the bandwidth for the HSDPA

service on the Iub interface is increased




MML Commands:

− SET HSDPAFLOWCTRLPARA:

SWITCH=BW_SHAPING_ONOFF_TOGGLE



Flow control in RNC

VP shaping and backpressure

− Flow control and backpressure based on RLC retransmission

rate

− VP backpressure on virtual port in RNC of V210 and V110

− MML commands:

▪ SET PORTFLOWCTRLSWITCH

▪ ADD VP





management



HSDPA resource allocation CRNC Node B

PHYSICAL SHARED CHANNEL

RECONFIGURATION REQUEST

PHYSICAL SHARED CHANNEL

RECONFIGURATION RESPONSE

IE/Group Name Presence Range IE Type and Reference

Semantics Description

HS-PDSCH and HS-SCCH Total Power

O Maximum Transmission Power9.2.1.40

Maximum transmission power.to be allowed for HS-PDSCH and HS-SCCH codes

HS-PDSCH and HS-SCCH Scrambling Code

O DL Scrambling Code

9.2.2.13

Scrambling code on which HS-PDSCH and HS-SCCH is transmitted.

0= Primary scrambling code of the cell 1…15 = Secondary scrambling code

HS-PDSCH FDD Code Information

0..1 9.2.2.18F

HS-SCCH FDD Code Information

0..1 9.2.2.18G


User HSDPA channel setup

HSDPA channel setup procedure is the same as DCH setup，only the

signaling contains IE for HSDPA channel。

CRNC Node B

RADIO LINK RECONFIGURATION PREPARE

RADIO LINK RECONFIGURATION READY

UE UTRAN

RADIO BEARER SETUP

RADIO BEARER SETUP COMPLETE


HSDPA channel setup signaling examples (over Iur)

UE Node B Serving

RNC

Drift

RNC

RNSAP

RNSAP

RNSAP

NBAP

NBAP

RNSAP

NBAP

NBAP

RRC RRC

RRC RRC

4. RL Reconfig Ready

1. RL Reconfig Prepare

2. RL Reconfig Prepare

3. RL Reconfig Ready

ALCAP Iub Trans. Bearer Setup ALCAP Iur Trans. Bearer Setup

7. DCCH: Radio Bearer Reconfiguration

8. DCCH: Radio Bearer Reconfiguration Complete

HS-DSCH FP HS-DSCH-FP HS-DSCH-FP

HS-DSCH-FP HS-DSCH-FP HS-DSCH-FP

9. HS-DSCH Capacity Request 10. HS-DSCH Capacity Request

11. HS-DSCH Capacity Alloc 12. HS-DSCH Capacity Alloc.

13. Data transfer

NBAP NBAP

6. RL Reconfig Commit

MAC-hs MAC-hs

15. Shared control channel

16. Data transfer

RNSAP RNSAP

5. RL Reconfig Commit





management



HSDPA Power Allocation

In v1.8

The MML command is:ADD CELLHSDPA: HspaPower=430;

The power allocated for HSPA channels cannot exceed the value of

HspaPower, the downlink channel includes the HS-PDSCH, HS-SCCH,

E-AGCH, E-RGCH and E-HICHl.

In V2.10

The MML command is ADD CELLHSDPA: AllocCodeMode=Manual,

HspaPower=0, CodeAdjForHsdpaSwitch=ON;;


HSDPA Power Allocation

HSDPA Dynamic Power Resources Allocation

Except reserving for the common channels, the rest power resources of

the cell are allocated dynamically between the DPCH and HSPA DL

physical channels. After allocating power to DPCH and E-HICH , E-

AGCH, E-RGCH, the rest power is allocated to HS-SCCH and HS-

PDSCH. The power allocated for HSPA cannot exceed the value of the

HS-PDSCH, HS-SCCH, E-AGCH, E-RGCH and E-HICH Total Power.

MML Commands:

− ADD CELLHSDPA: AllocCodeMode=Manual, HspaPower=0;

− SET MACHSPARA: PWRMGN=10; (NodeB)


HSDPA Codes Allocation

V1.7

Static Allocation

RNC controlled dynamic alloction

V1.8 and V2.10

Static allocation

RNC-controlled dynamic allocation

NodeB-controlled dynamic allocation




Static Allocation

− In static allocation, the RNC reserves some codes for the HS-

PDSCH. The DPCH and other common channels use the rest

Code reserved

for common

channel

Codes

reserved for

HS-PDSCH

SF=16

Codes

available for

DPCH



Static Allocation example

suppose RNC is configured with:

2 HS-SCCH

2 HS-PDSCH

SF=256 SF=128 ┏━●C(256,0): PCPICH ┏ 0 ┫ SF=64 ┃ ┗━●C(256,1): PCCPCH ┏ 0 ┫ ┃ ┃ ┏━●C(256,2): AICH ┃ ┗ 1 ┫ SF=32 ┃ ┗━●C(256,3): PICH ┏ 0 ┫ SF=16 ┃ ┗ ●C(64,1):SCCPCH 1 ┏ 0 ┫ ┃ ┃ ┃ ┃ ┏ ●C(64,2):SCCPCH 2 ┃ ┃ ┃ ┃ ┗ 1 ┫ SF=8 ┃ ┃ ┏━●C(128,6): HS-SCCH 1

┏ 0 ┫ ┗ 3 ┫ SF=4 ┃ ┗━○1 ┃ ┏ 0 ┫ ┗━●C(128,7): HS-SCCH 2

┃ ┗ ○1 ┃ ┗━○1 ┏━○2 ┃ ┏ ○6 ● CCH

┃ ┃ SF=16 ● HSDPA

┃ ┃ ┏ ●



RNC-Controlled Dynamic Allocation

Extending the codes reserved for the HS-PDSCH

− If in cell's code tree there is at least one code can be reserved and this code's

SF is equal to or less than the Cell SF reserved threshold, NodeB will try to

increase HS-PDSCH code number.

Shared

codes

RNC extends the codes

reserved for HS-PDSCH

SF=16

Code reserved for

common channel

+HS-SCCH




Reducing the codes reserved for HS-PDSCH

− When allocating the code resources triggered by radio link setup, the RNC will

reallocate one of the shared codes reserved for HS-PDSCH to DPCH if the

minimum SF among free codes is larger than the Cell SF reserved threshold.

Shared

codes

RNC reduces the codes

reserved for HS-PDSCH

SF=16

Code reserved for

common channel

+HS-SCCH




In v1.7, the Cell SF reserved threshold is configure with command:

− ADD CELLHSDPA: AllocCodeMode=Automatic, RevSFThd=SF16;

In v1.8 and V2.10, the Cell SF reserved threshold is configure with command:

− ADD CELLLDR: CellSfResThd=SF16;



NodeB-Controlled Dynamic Allocation

NodeB-controlled dynamic allocation allows the NodeB to use the HS-

PDSCH codes that are statically allocated by the RNC. Besides, the

NodeB can dynamically allocate the idle codes of the current cell to the

HS-PDSCH channel

SET MACHSPARA: DYNCODESW=OPEN;

This codes allocation has better performance then RNC controlled

dynamic code allocation, so it is recommended to open this function and

disable the RNC controlled allocation in RAN10 and later version


HSDPA Cell Admission Control

HSDPA UE Admission control

The admission decision based on the power resources

The admission decision based on the Iub transmission resources

The admission decision based on the number of UEs

Only all the 3 aspects passed, then the user may be admitted.


HSDPA Cell Admission Control

HSDPA UE Admission control

ADD CELLALGOSWITCH: NBMCacAlgoSwitch=HSDPA_ADCTRL-

1&HSUPA_ADCTRL-1&HSDPA_GBP_MEAS-

1&HSDPA_PBR_MEAS-1;

ADD CELLCAC: CellId=65533, UlOtherThd=60, DlCellTotalThd=90,

HsdpaStrmPBRThd=70, HsdpaBePBRThd=30,

MaxHSDSCHUserNum=64;


HSDPA Channel Switch

Channel type transition after introducing the HSDPA

Channel Switching between HS-DSCH and FACH

UE will be switched from the HS-DSCH to the FACH to reduce occupation of the DPCH when the following conditions are met.

− The HS-DSCH carries the BE service or the PS streaming service for the UE.

− There is no data flow of any of the services for a certain length of time, which is

set to BE HS-DSCH to FACH transition timer for BE service or Realtime Traff

DCH to FACH transition timer for realtime service

When the data flow gets more active, the UE is switched from the FACH to the HS-

DSCH.

UE state transition Channel switching

CELL_DCH (with HS-DSCH) CELL_DCH HS-DSCH DCH

CELL_DCH (with HS-DSCH) CELL_FACH HS-DSCH FACH



Channel Switching between HS-DSCH and DCH

The switching from DCH to HS-DSCH can be triggered by mobility management, the

traffic volume or the timer. While the switching from HS-DSCH to DCH can only be

triggered by mobility management

− Triggered by mobility management

− Triggered by traffic volume

When the service is suitable to be carried on HSDPA and the UE supports

HSDPA but the service is actually mapped onto the DCH (for some reasons such

as the UE is rejected to access a HSDPA cell by CAC Algorithm). If the activity of

the H UE that performs data services increases and the RNC receives the report

of the 4a event, the H UE will try to switch from DCH to HS-DSCH



Channel Switching between HS-DSCH and DCH

− Triggered by timer

When the service is suitable to be carried on HSDPA and the UE supports

HSDPA but the service is actually mapped onto the DCH (for some reasons such

as the UE is rejected to access a HSDPA cell by CAC Algorithm), a timer is used

to periodical attempt to map the service onto the HS-DSCH. Firstly, attempt to

map onto HS-DSCH of the current cell, if failed, then attempt to map onto HS-

DSCH of the inter-frequency blind handover cell with the same coverage. This

timer length is set to H Retry timer length.

− SET COIFTIMER: HRetryTimerLen=10;


HSDPA Mobility Management

A UE may have two connections with the network after introducing the HSDPA

Connection Handover

HSDPA

connection

A UE can keep only one HSDPA connection with the network at a time. The

HSDPA handover includes:

Intra frequency handover

Inter frequency handover

Inter-rat handover

DPCH

connection

Similar to the R99 system handover, the DPCH handover includes soft handover,

hard handover and inter-RAT handover.


HSDPA Mobility Management

Intra frequency handover

For HSDPA connections, HS-DSCH does not support softhandover,

usually the handover is a process of serving HSDPA cell change which is

triggered by 1D event report.

Inter frequency handover

Generally, the hard handover and the serving HSDPA cell change take

place at the same time

Inter system handover

The procedure is very similar to R99 service inter-rat handover.

If the compressed mode is disabled by command: SET CMCF:

HsdpaCMPermissionInd=FALSE;, then the UE should fall back to DCH

and then make a 3G to 2G hard handover.





management



Setup HSDPA Cell

DSP LICENSE:; to check the HSDPA service is enabled.

Confirm that R99 cell has been configured by LST CELL:;

On the basis of R99 cell data, setup HSDPA cell:

Execute MML command: “ADD CELLHSDPA:

AllocCodeMode=Automatic, CodeAdjForHsdpaSwitch=ON;

ACT CELLHSDPA:; to activate the HSDPA function


Increase AAL2Path for HSDPA Service

In RAN10 and earlier version:

ADD AAL2PATH: PAT=HSPA_NRT;

ADD IPPATH: TFT=HSPA_NRT;

In RAN11

ADD IPPATH: ITFT=IUB, TRANST=IP, PATHT=AFxx/BE/EF

ADD AAL2PATH: AAL2PATHT=HSPA/R99/SHARE

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Documents

198686662 05 RAN HSDPA Principle and Configuration Updated to RAN11 (2)