02-HSDPA Principle V3.10

7/31/2019 02-HSDPA Principle V3.10

http://slidepdf.com/reader/full/02-hsdpa-principle-v310 1/45

© 2007 ZTE Corporation

HSDPA Principle

PPT Series for Technology Principle

Name :×××

E-mail :×××

WCDMA Product Planning Dept.

ZTE Marketing System



2

Modification records

Edition Date Writer/Modifier Approver Remark

V3.10 2007-8-30 Dong chuanghong Establish



Agenda

HSDPA Theory

HSDPA Physical Layer

HSDPA Key Technologies

HSDPA RRM

HSDPA Evolution



4

HSDPA H igh S peed D ownlink P acket Access

… …

3G

4G

HSDPA is a new technology introduced in R5

Goal: To provide a packet-oriented wireless

broadband access service with high performance

price ratio, high downlink bandwidth and short

delay for WCDMA

3GPP R5 standards are frozen in June, 2006

Small modification to R99/R4 structure

HSDPA insists on the concept of smooth evolution. HSDPA is the enhancement of R99

structure with the newly added MAC-hs layer to

achieve HARQ, scheduling and AMC. It also adds

three dedicated channels on the physical layer.

Improve the system capacity by applying new

technologies

Share channel transmission-Fast Scheduling

Shorter TTI - Fast retransmission and soft

combination

Link Adaptive - Permitting High order modulation

HSDPA High Performance Price Ratio

Downlink peak rate of single cell: 14.4MbpsMulti-user share of single cell, with 230

users in theory

Low cost：Small modification to R99

Good technical

evolution of WCDMA



5

HSDPA Protocol Stack

R99/R4

PHY

MAC

RLC

PHY L1

L2

DSCH

FP

L1

L2

DSCH

FP

MAC-c/sh

L1

L2

DSCHFP

L1

L2

DSCHFP

MAC-d

RLC

Uu Iub Iur

UE Node-B CRNC SRNC

MAC-hs

PHY(3 newCHs)

HS-DSCH

FP

HS-DSCH

FP

HS-DSCH

FP

HS-DSCH

FP

R5 HSDPA

MAC-hs

Uu: New additional 3 Physical layer

Channels, i.e.,HS-PDSCH

(Downlink Data), HS-SCCH

(Downlink Control Signalling), HS-

DPCCH (Uplink Control Signalling)

Additional MAC-hs layer

on Node-B (H-ARQ, AMC

and Scheduling etc)

Iub, Iur: HS-DSCH

FP (Downlink Data)



6

HSDPA Newly Added Physical Channels

R99 Channel

HSDPA Channel

HS-PDSCH：Bearing HS-DSCH，transmitting HSDPA user data (DL)

It is a 2ms subframe with 3 slots, SF=16 and multiple codes permitted. HS-PDSCH

can use two modulations of QPSK and 16QAM.

HS-SCCH Bearing the signaling information for demodulation of HS-PDSCH (DL)

It is a 2ms subframe with 3 slots and SF=128. HS-SCCH includes the information of modulation,

transport block size, UE identification, etc. It uses QPSK modulation.

HS-DPCCH Bearing feedback information transmitted by downlink HS-DSCH (UL)

Includes Hybrid-ARQ ACK/NACK and Channel-Quality Indication (CQI). It is a 2ms subframe with 3

slots and SF=256. First slot is ACK/NACK and the following two slots are CQI.

HS - DPCCH

HS - PDSCH

H S - S C C H UE

DPCH

DCCH (Signaling) + UL DTCH (PS Service)

DL DTCH ( P S Service)

CN UTRAN



HS-PDSCH Physical Channel Structure

HS-PDSCH can use QPSK or 16QAM modulation. M is the bit represented by each

modulation symbol. For example, M=2 stands for QPSK and M=4 stands for 16QAM.

All layer1 signaling are transmitted by affiliated HS-SCCH. HS- PDSCH doesn’t carry any

layer 1 signaling.

Slot #0 Slot#1 Slot #2

T slot = 2560 chips, M*10*2 k bits (k=4)

Data N data 1 bits

1 HS - PDSCH subframe: T f = 2 ms

HS-PDSCH Frame Format

Physical Channel Slot Format

Slot format #1Channel

BitRate

Channel

Symbol Rate SF

Bit/HS-DSCH Sub-

frame Bits/Slot N data

0(QPSK) 480kbps 240kbps 16 960 320 320

1(16QAM) 960kbps 240kbps 16 1920 640 640



HS-SCCH Physical Channel Structure

HS-SCCH adopts fixed code rate (60 kbps, SF=128), bearing the related downlink signaling for demodulation of HS-PDSCH

Slot #0 Slot#1 Slot #2

T slot = 2560 chips, 40 bits

Data

N data 1 bits

1 subframe: T f = 2 ms

HS-SCCH Frame Format

HS-SCCH

HS-PDSCH

3Tslot 7680 chips

HS-PDSCH (2Tslot 5120 chips)

3Tslot 7680 chips

HS-DSCH sub-frame

Timeslot relation of HS-SCCH and HS-PDSCH

HS-PDSCH begins after HS-SCCH starting 2 Tslot = 5120 chips



HS-DPCCH Physical Channel Structure

HS-DPCCH carries the feedback signaling transmitted by downlink HS-DSCH. The

feedback signaling includes HARQ-ACK and CQI.

Each 2ms subframe includes 3 slots with 2560 chips per slot, same as the normal

DPCCH. HARQ-ACK is at the first slot of HS-DPCCH subframe. CQI is at the second and

third slots.

HS-DPCCH: SF=256, each slot has 10bits.

Normally one wireless link has a HS-DPCCH and it must exist with one certain uplink DPCCH.

Subframe #0 Subframe #i Subframe #4

HARQ-ACK CQI

One radio frame Tf = 10 ms

One HS-DPCCH subframe (2 ms)

2 Tslot = 5120 chipsTslot = 2560 chips

HS-DPCCH Frame Format

Slot

format #1

Channel

Bit Rate

Channel

Symbol Rate SF

Bit/HS-DSCH

Sub-frame Bits/Slot

Transmitted slot per

sub-frame

0 15kbps 15kbps 256 30 10 3

HS-DPCCH Slot Format



HSDPA Newly Introduced Physical Channels’ Timing Relation

HS-

PDSCH

HS-SCCH

HS-DPCCH (ACK/NACK and/or CQI)

HS-SCCH

2 TS 7.5 TS +/- 128 Chip N TS

1 TS = 2560 Chip

The starting point of first HS-

SCCH subframe is the same asthe starting point of P-CCPCH



HSDPA Work Procedure

HS-DSCH deploys fixed spreading factor with SF 16. According to the CQI reported by

UE, Node B decides the size of data block, modulation, coding rate and the number of

code channels of HS-DSCH so that Node B can be quickly adaptive to the transmission

loss and channel fading when the data is transmitting.

Node B RNCUE

5) ACK/NACK on HS-DPCCH

6)Data packet+retransmit(if need) On HS-DSCH

Data Packet

2) Schedule and determine HS-DSCHparameter

3) Send HS-DSCH Parameter on HS-SCCH and Data on HS-DSCH

4) Check HS-DSCH parameter, If Ok, Receive,

Store data and demodulate

1) CQI on HS-DPCCH



Agenda

HSDPA Theory



HSDPA RRM

HSDPA Evolution



HS-DSCH Transport Channel

Only exists on the downlink channel

Number of transport block always equals to 1

One HS-DSCH handle one CCTrCH, decoding from one CCTrCH

One UE corresponds to the only one CCTrCH

CCTrCH can be mapping to one or several physical channels

One CCTrCH has only one HS-DSCH

Always accompanying DPCH and one or more share physical control

channels (HS-SCCHs)

Quality balance of different HS-DSCH channels

Static data match (Two rate matches in HARQ）

Transport block cascade

The number of transport block is 1 forever and as well as the number of transport

channel, and each CCTrCH only corresponds to one HS-DSCH, so the followingsdon’t exist:



HS- DSCH’s coding and multiplexing

CRC check: same as normal CRC, 24bit in L1

Bit scramble: The bit after CRC check is scrambled by bit

scrambler

Code block segment: same as R99, Turbo coding, Z=5114

Channel encode: same as R99, using 1/3 Turbo code

HARQ: Bits after adjusting channel encoding match with

the total bits mapping from HS-SDCH to HS-PDSCH

Physical channel segment: When using multiple HS-

PDSCH, the physical channels are segmented.

Interleave: progressed independently according to each

physical channel

16QAM constellation recomposition: This function is

transparent to QPSK

Physical channel mapping

CRC attachment a im1 ,a im2 ,a im3 ,...a imA

Code block segmentation

Channel Coding

Physical channel segmentation

PhCH#1 PhCH#P

Physical Layer Hybrid-ARQ functionality

d im1 ,d im2 ,d im3 ,...d imB

o ir1 ,o ir2 ,o ir3 ,...o irK

c i1 ,c

i2 ,c

i3 ,...c

i E

v p,1 ,v p,2 ,v p,3 ,...v p,U

u p,1 ,u p,2 ,u p,3 ,...u p,U

w 1 ,w 2 ,w 3 ,...w R

HS-DSCH Interleaving


Constellation re-arrangement

for 16 QAM r p,1 ,r p,2 ,r p,3 ,...r p,U

Bit Scrambling b

im1 ,b

im2 ,b

im3 ,...b

imB

Bit scramble is to guarantee the synchronization of receiving

data and transmitting data, without introducing the time

deviation. Bit Scramble is to encrypt the data bits and it does

not change the bit length of the data.



HARQ and Rate Matching

Systematic

bits

Parity 1

bits

Parity2

bits

RM_P1_1

RM_P2_1

RM_P1_2

RM_P2_2

RM_S

First Rate Matching Second Rate MatchingVirtual IR Buffer

Nsys

N

p1

Np2

Nt,sys

N

t,p1

Nt,p2

bitseparation

NTTI

bitcollection

N

data

C W

HARQ function block adjusts the bits after channel encoding and the total bits

mapping from HS-SDCH to HS-PDSCH to be matched. HARQ function block is controlled by the parameter of redundancy version (RV).

The output bits of HARQ function block is determined by input bits, output bits

and RV parameter.

HARQ function block is composed of two rate matcher and one virtual buffer



First Rate Matching and Second Rate Matching

The algorithm of first rate matching is almost the same with Rel99. Bits of encoder

output match with the bits of virtual IR buffer input. Virtual buffer capacity N IR is

given by the high layers. Encode bit N TTI is derived from the high layer signaling

and the signaling parameters of HS-SCCH of each TTI.

N IR ≥ N TTI then first rate matching is transparent.

N IR < N TTI then punch for N TTI bit.

First Rate Matching

Second rate matching lets the output bits after first rate matching match with the physical

channel bits provided by the HS-PDSCH set in one TTI. The parameters of second rate

matching is controlled by RV parameters.

Second rate matching execute the punch again according to the value of s and r of the RV

parameters. The punched data can be put into different data sets and different data sets

correspond to different RV parameters. Only one data set is transmitted in any fixed time

segment.

Second Rate Matching



HARQ Rate Matching and IR Method

During the second rate matching, the data set formed by punch are displayed by different

gray levels Deep, Medium, Low

Deploy different RV and punch method when retransmitting data

When 16QAM is deployed, different RV methods correspond to not only different punch

methods but also different constellation versions or reforming.

IR buffer size 10bit

Raw data 4bit，1/3 Turbo encoder



HS-SCCH Physical Procedure

Channel code set (7 bits): Code group indicator and

offset indicator

Modulation mode (1 bit): QPSK and16QAM

Size of transport block (6 bits): Index Mapping

Hybrid-ARQ progress (3 bits): Index Mapping

Redundancy and constellation version (3 bits):

Eight choices

New data indicator (1 bit)

UE Identification (16 bits) HS-DSCH radio network

identifier H-RNTI)

HS-SCCH carries following signaling info

16bit CRC＋UE Identification

Convolution code

Rate matching by punching at fixed place


ChannelCoding 1

HS-SCCH

Physicalchannelmapping

Ratematching 1

mux mux

Xccs Xms

Xue

X1X2

Xtbs Xhap

XrvXnd

Y

ChannelCoding 2

Ratematching 2

UEspecificmasking

Z1Z2

S1

R1 R2

Xue

RVcoding

r s b

UE specificCRC

attachment

CodeSet

Modulation

TransportFormat HARQ New Data

RV

UE Identification



HS-DPCCH Physical Procedure

HARQ-ACK/NACK encode 10bit full “1” and full“0”

CQI encode adopting (20, 5) code, 20bits CQI info bit encode

Create corresponding 0 30 total 31 CQI value HS-DPCCH and other uplink channels make frequency

spreading in parallel. If the max. number of DPDCH is even,

then HS-DPCCH is mapping to route I, otherwise it is mapping

to route Q.

HS of HS-DPCCH is derived from the power offset informed by

ACK, NACK and CQI


Channel Coding Channel coding

PhCH

b 0 ,b 1 ...b 19


HARQ-ACK CQI

a 0 ,a 1 ...a 4

PhCH

w 0 ,w 1 ,w ,...w 9

HARQ-ACK and CQI handle the encode in parallelDoing multiplexing at different times

I

j

cd,1 d

Sdpch,n

I+jQ

DPDCH1

Q

cd,3 d

DPDCH3

cd,5 d

DPDCH5

cd,2 d

DPDCH2

cd,4 d

cc c

DPCCH

S

CHSHS-DPCCH(If Nmax-dpdch

=odd)

DPDCH4

CHSHS-DPCCH(If Nmax-dpdch

=even)

HS

we e

HS

we e

cd,6 d

DPDCH6



Agenda

HSDPA Theory



HSDPA RRM

HSDPA Evolution



HSDPA Introduced Key Technologies

AMC Fast Scheduling

16QAMFixed SF16, 2ms short frame

Shared channelHARQ

1 2

3 4

5 6

① Adopt 2ms short frame, fixed SF, TDM

and CDM between the users at the

same time

② Introduce 16QAM high order

modulation, providing higher

modulation efficiency

③ AMC makes the data transport well

adaptive to the changes of radiochannels

④ Fast scheduling makes multi-user

share the radio resource.

⑤ HARQ quickly adjust the channel rate

according to the status of radio link

and achieve the error correction andretransmission of the data.

⑥ Shared channel makes the number of

access users not limited by the code

resources.



Key Technology 1 2ms radio frame

Share channel resources are dynamically assigned in every

2ms TTI

HARQ fast feedback retransmission based on 2ms TTI

2ms TTI makes scheduling response much faster and in time

10 ms

20 ms

40 ms

80 ms

Earlier releases

2 ms

Rel 5 (HS-PDSCH, HS-SCCH, HS-DPCCH)

“sub-frames” (2560 chips/slot, 3Slots)

Standard Frame length Channel feedback delay Remark

R99 10ms >100ms Scheduling feedback is in

RNC

HSDPA 2ms 5ms （ 7.5 Slots ）

Continuous feedback

supported, R5 still support

the 10ms frame of R99

Decrease the loop time effectively, improve the link adaptive ability highly



23

Key Technology 2 16QAM

HSDPA Modulation

QPSK

16QAM



24

Key Technology 3 AMC

Adaptive Modulation and Coding

（ AMC ）is a technique which changes

modulation, encode mode and size of

code block (TFRC) according to the

changes of channel situation. It makes

the data transmission changing

according to the channel situation. It is

a better link self-adaptive technique.

The feature of AMC is adaptive to the

changes of interference and fading

through changes of TFRC but not

through changes of transmission power.

Standar

d

AMC Remark

R99 - Deployed fast power control

HSDPA used Can satisfy the 15dB SIR

dynamic range



25

Key Technology 3 AMC

Modulation adaptiveGood channel condition: 16QAM

Bad channel condition: QPSK

Code efficiency adaptiveGood channel condition: ¾ code rate

Bad channel condition: 1/3 code rate

Code channel number adaptiveGood channel condition: more code channels

Bad channel condition: less code channels

Full use of channel conditions to transmit user data effectively

Good channel condition: High user data rate transmission

Bad channel condition: Low user data rate transmission

The combination of different parameters such as modulation mode, coding

mode, number of code channels, size of transport block, RV matching has

thousands of configuration choice. This makes AMC technique higher

efficiently and more flexible.



26

Key Technology 4 Fast Packet Scheduling

Scheduling based on time and code channel

Scheduling principle

Fair scheduling algorithm: Round

Robin (RR)

Max. C/I scheduling algorithm (Max

C/I)

Part fair scheduling algorithm (PF)

5

c o d e s

TTI 1

TDM

TTI 2 TTI 3 TTI 4

C D M

UE CNode B

UE A

UE B

HS-PDSCH

TTI1 TTI2 TTI3

TTI1

TTI2

TTI2

TTI3

TTI3



27

Key Technology 5 HARQ

Wrong Packet A

Packet A

Packet A

Wrong Packet A1

Packet A1

Packet A2

Packet A1

Packet A

Drop Reserved

FullRetransmission

Only retransmit

redundant info

Soft

Combination

Packet BPacket B

Node B UE Node B UE

Packet A2

Traditional ARQ, retransmission

mechanism inRNC

Low efficency, long delay

HARQ, retransmission mechanism in Node B

High efficency, short delay



28

Key Technology 6 Shared Channel

User1 User2 User3

DCH1

DCH2

DCH3

Shared

HS-DSCH

UMTSR99

HSDPA

Saved for Other Users

“Shared fat-pipe”

10ms

TTI = 2ms TimeMultiplexing

Code Multiplexing

Dedicated

TTI: Transmission Time Interval



29

Comparison of HSDPA and R99/R4

Item R99 HSDPA

Capacity Mbps 2.688 14.4

Frequency spectrum

efficiency (kbit/(MHz*Cell)) 537.6 2795.2

Handover Hard handover / Soft handover /

Softer handover / Intersystem handover (to GSM) Hard handover in HS-PDSCH

Power Control Open loop / Close loop / external loop

Fast speed/ Low speed

Low speed power control or no power

control in HS-PDSCH

Modulation QPSK QPSK 16QAM

Link Adaptive Fast power control/ soft handover AMC HARQ short frame and fast

channel feedback

Bit Scramble and Descramble N/A Only used in HS-PDSCH

MAC-hs N/A Used for fast scheduling

HSDPA

HSDPA is to adjust data rate

according to channel condition when

ensuring the power

Constant power Changing

data rate

R99/R4

R99/R4 is to adjust power according

to channel condition when ensuring

service rate

Constant data rate, changing

power



Agenda

HSDPA Theory



HSDPA RRM

HSDPA Evolution



31

RNC Radio Resource Management Summary

Code resource management

HSDPAchannelization

code

HSDPAscrambling code

Power resource management

HSDPA total powerresource management

Service amount measurement/ Dedicated measurement

Dynamic radio carrier control

ChannelAssignment

ChannelHandover

Access control

DPCH

channelization code

Channel

Handover

Mobile management

Congestion control

Load control

Handovermeasurement

Power control

Physical channel power control

Load balance

Dedicatedmeasurement

R4

Common

Measurement

HSDPA

Common

Measurement

Assignment of HSDPAresource for each cell

User resource assignmentand management



32

Code Resource Management

Assignment method of HS-PDSCH channelization code：

Continuous assignment from right to left of the code tree

Assignment method of HS-SCCH channelization code：

Not need continuous assignment, adopting the assignment method of DPCH

channelization code

Assignment method of DPCH channelization code：

Try to keep the highest use rate of code list

Assignment method of HS-PDSCH+HS-SCCH scrambling code：

Can assign primary scrambling code and secondary scrambling code. Use primary

scrambling code in the first stage, secondary scrambling code in the later stage

Channelization codesallocated for HS-DSCH

SF=16

SF=8

SF=4

SF=2

SF=1

Channelization codesallocated for DPCH Channelization codes

allocated for CCH



33

Power Control

HSDPA Physical control includes: HS-PDSCH, HS-SCCH and HS-DPCCH：

HS-PDSCHPower control

HS-SCCHPower control

HS-DPCCHPower control

Support open loop power control, configurationMeasurement Power Offset

Support open loop and internal loop power controlHS-SCCH Power Offset can be dynamically adjusted

Support open loop and internal loop power control, configuration

ACK ,NACK and CQI，and can be dynamically adjusted accordingto link status

HS-PDSCH and HS-SCCH dynamically adjust HS-PDSCH and HS-SCCH total power according

to the resource occupancy of system excluding HS-PDSCH and HS-SCCH.

For HS-DPCCH, its transmission power is determined by DPCCH. UE determine the

transmission power of HS-DPCCH according to gain factor HS.



34

Access Control

Because HS-PDSCH physical channel is shared resource, access control of HSDPA is different than the access control

of dedicated channel.

During the access control, the characteristics of streaming, interactive, background services and the working feature of

HS-DSCH must be fully considered. The high speed feature of HS-DSCH shared channel must be fully developed during

the access control.

H S

D P A

A c c e s s c on t r ol

UE support HSDPA

Number of HSDPA user

Power resource

Data throughput carried by HSDPA

DPCH channelizationcode resource

A c c e s s D e c i s i on

Node B support HSDPA



35

Dynamic Radio Carrier

C h ann el

A

s s i gnm en t

CS real time service

PS non-real time service

PS real time service

Choose DCH

Prefer FACH and HS-DSCH

Choose FACH and DCH

Choose DCH and HS-DSCH

Cell support HSDPA

Cell does not support HSDPA



36

HSDPA Channel Handover

HSDPA handover includes service cell change and channelhandover of HS-DSCH

Same frequency service cell change between Node B

First release the HS-DSCH resource of the old cell of source Node B, then

establish the same HS-DSCH resource as old cell in the new cell of Target

Node B.

Correspond to perform hard handover for HS-DSCH. The HS-DSCH transportchannel and radio carrier parameter do not change during the handover

procedure.

UE execute reassignment of physical channels. When the reassignment of

physical channel is valid, MAC-hs entity of UE needs to be reset and UE doesn’t

receive HSDPA service channel.

The valid time of physical channel reassignment of UE corresponds to the valid

time of radio link reassignment of Node B. At the valid time, the MAC-hs entity

of Source Node B releases and the MAC-hs entity of Target Node B establish.

The two Node Bs are not transmitting at this time. So the service is interrupted

instantaneously during the reassignment time.

Same frequency service cell

change inside Node B

Similar with the change of same

frequency service cell inside

Node B

The difference is that only one

Node B are controlling. Thus

MAC-hs entity of Node B does

not change and MAC-hs entity of

UE does not need to be reset. But

the service is interrupted at the

valid time of physical channel

reassignment.



37

Channel Handover Transfer Figure

1. Traffic Trigger

2. Transmission Power Trigger

3. Congestion Trigger

DCH

FACH

HS-DSCH

PCH

1. Traffic Trigger

2. Movement Trigger

1. Traffic Trigger

2. Movement Trigger

1 .T r af f i c T r i g g e

r

1 .T r af f i c T r i g g e

r

2 . C on g e s t i onT r i g

g er

1 .T r af f i c T r i g g er

2 .L o a d T r i g g er

1 .T r af f i c T r i g g er

3 . C on g e s t i onT r i g

g er

1. Traffic Trigger

1. Traffic Trigger

HS-DSCH DCH

HS-DSCH FACH

HS-DSCH PCH

DCH DCH

DCH FACH

FACH PCH



38

HSDPA Congestion Control

HSDPA congestion control means how to mitigate resource congestion under the condition of HSDPA

system resource congestion.

The resource of HSDPA is shared and utilized in the maximum. Thus the method of congestion control is slightly different from R99 cell. HS-DSCH resource congestion includes:

Power resource congestion

Limited HS-DSCH traffic

Data through congestion

Code resource congestion of accompanying DPCH

channelization code

Congestion control methodof HSDPA

Occupy in advance：When resource is congested, the high-priority user can occupy the resource in advance from the

low-priority user. It guarantees high-priority user can be always assigned resources.

Queue：The users who has no ability to occupy in advance but has the queue ability can be put into the queue and try

to access the resource again.

Decrease load：The policy of decreasing load is decreasing the speed. That is to decrease the rate of users who has

high background or interactive services for spare resources

HSDPA resource adjustment：Adjust the code resource or power resource of HSDPA to meet the requirements of users

R e s o ur c e c on g e s t i on

Occupyin advance

Queue

Decreaseload

HSDPAresourceadjustment

I m pr ov e c al l s u c c e s s r a t e ,

I n c r e a s e s y s t em c a p a c i t y



39

HSDPA Load Control

Decrease usable power of HSDPA Its ultimate goal is decreasing the PS data

throughput.

Decrease PS data throughput Decrease the PS data rate on DCH. Delete macro diversity link Decrease the radio link of overload cell to decrease the load.

Forced handover to another carrier or GSM system Inter-frequency handover and

intersystem handover can be used as the method for load transfer to decrease the load

of overload cell.

Force some low-priority users to drop their calls.

The goal of load control is to guarantee the system stability.

If the system is appropriately planned, then the access control

and packet scheduling can avoid the overload of the resources

but can not avoid the situation that the system is overload

induced by suddenly user power increasing when the wireless

environment is deteriorated. Thus radio resource management

needs to adopt load control to let the system to be stable.

For the load control, the difference between HSDPA and R99 is only

at the downlink. Thus only the downlink load control method is

described here. The policy of decreasing load includes：

O v e r l o a d

Decrease overall power of

HSDPA

Decrease PS data throughput

Delete macro diversity link

Forced handover

E n s ur e t h e s y s t e m

s t a b i l i t y



40

Influence of HSDPA to R99 RRM Algorithm

By introducing HSDPA, the related HSDPA physical channels are

added. Thus R99 RMM algorithm is needed to be upgrade： Add special handling of HS-PDSCH and HS-SCCH code resource

management

Add access control method of HS-DSCH

Add power control method of HSDPA

Add dynamic radio carrier control policy after introducing HS-DSCH

The introducing of HSDPA cell and handover characteristics of HSDPA

physical channel affect the mobile handover decision policy and handling.

Add load balancing characteristics for cells. Affect the selection of load

balanced destination cell and later handling, eg., accompanying the transfer

between HS-DSCH and DCH

Update in congestion control

Update in load control



Agenda

HSDPA Theory



HSDPA RRM

HSDPA Evolution



42

Mobile Communication Development

Mobile communication is developed from 2G→3G→3.9G. It is

developed from mobile voice service to high speed data service. Currently it is developed to 3.5G. For WCDMA, commercial R5

version and trial R6 version can be provided now.

3GPP is working on the standards of R7/HSPA+ and R8/LTE. It is

estimated that R7 will be finalized on 2007 and R8 will be finalized

on 2008.

The development of radio technology pays more attention to the

requirement of operator — NGMN organization proposed the system

development goal.

http://cgi.ebay.com.cn/ws/eBayISAPI.dll?ViewItem&category=94951&item=6752555293&rd=1



43

Mobile Communication Technology Evolution

2 G 2 . 5 G 3 G 3 . 5 G 3 . 75 G 3 . 9 G 2 . 75 G

GSMWCDMA

R99GPRS

EDGE

HSDPA HSUPA

HSPA+

LTE

IS-95CDMA20001X EV-DO

CDMA2000 1X

EV-DORev. A

EV-DORev. B

AIE

CDMA20001X EV-DV



44

WCDMA Roadmap

GSM

GPRS/EDGE

3GR99

3G+HSDPADownlink

Enhanced

3GHSDPA/HSUP

A

Downlink/UplinkEnhanced

GSM(GPRS/EDGE)

3G

Enhanced UMTS

Optimized UMTS

NGMN

NGMN（LTE,…） Broadband radio

IP based wideband

Peer to Peer

2002-3 2003-4 2005-6 2007-9 After 2009Year

DL

throughput

64-144kbps 64-384kbps 384kbps-4Mbps 384kbps-7Mbps 20-50Mbps



© 2007 ZTE Corporation

Documents

02-HSDPA Principle V3.10