UK VDF HSDPA Throughput Optimization Pptx

8/18/2019 UK VDF HSDPA Throughput Optimization Pptx

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HUAWEI TECHNOLOGIES CO., LTD.

www.huawei.com

Huawei Confidential

UK VDF HSDPA ThroughputOptimization

Liuaizhong 13 878



HUAWEI TECHNOLOGIES CO., LTD. Huawei Confidential Page 2

Basic of HSDPA Throughput

Users to transmit data

Power

Channel code

Data attributes

Data transfer

User n

Data transferUser 2

Available resources

Required resources

Middle statistics

HSDPA Scheduling

CQI

Data transfer

of User 1

Training: UMTS HSPA Data Transmission Performance Improvement Training

TG: 《URFSTG00325-Troubleshooting Guide to UMTS PS Data Transmission Problems-A-V2R1.doc》

Link： http://support.huawei.com/support/pages/kbcenter/view/product.do?actionFlag=detailProductSimple&web_doc_id=SE0000500963&doc_type=123-

2&doc_type=123-2/support/pages/kbcenter/view/product.do?actionFlag=detailProductSimple&web_doc_id=SE0000500963&doc_type=123-2



HUAWEI TECHNOLOGIES CO., LTD. Huawei ConfidentialPage 3

SGSN

RNC

NodeB

Water tankWater is discharged from the water tan

pool

Water is poured to the belt conveyer thr

valve-controlled water pipe

The valve size is determined by the be

conveyer.

The belt conveyer fills water to the b

certain rate.

Basic of HSDPA Data Transmission Model




ISSUE 1: HSDPA throughput can not get the target after swap in Glasgow 1B cluster;

ISSUE 2: DT throughput can not get the target;

ISSUE 3: Customer complain the PS data rate very low.

ISSUE: HSDPA Throughput vs. Target in Glasgow 1B




HSDPA Throughput issue analysis

Analysis flow Action Needs

Action of Parameter opt

Resource check

Parameter audit

TOP Cell analysis

TG: 《URFSTG00325-Troubleshooting Guide to UMTS PS Data Transmission Problems-A-V2R1.doc》




Out of RAN

Low HS

Throug

Some Server unstable

UE

Resource Uu Interface

Server

Power

Limitation

CQI

No Adjust by

Dynamic BLER

Schedule Algorithm

Code

Iub

Transmission

not enough data in Buffer

E1 num not

enough Coverage

Schedule

Resource

Allocate Method

Limitation

L2L swap

MPO not

proper

Transmission

Transmission limitation

Operator

tariff policy

adjust

tariff

policy

More high-cat UE

CAT

A lot small-packet

service in HSDPA

Service

Type

Large packet service

even

TP of

Access

More UE access in

the border of Cell

UE access

even in cell

center






Cause ction nalysis Optimization

Resource Allocate

Method

Parameter check

Top cell check

It is difficulty to divide the cell to ‘power limit’ or ‘code limit’,the ‘power and code balance’ method is better.

1, parameter tuning whole net

2, raise a RM to R&D to set thdefault value in R14

No Adjust by

Dynamic BLERParameter check

BE (non-conversation) can get better throughput based on

the real channel quality.

1, parameter tuning whole net

2, raise a RM to R&D to set th

default value in R14

A lot small-packet

service in HSDPA

Top cell check

Customer complain

1, Optimize the status transfer timer to put the small-packet

user to FACH

2, tuning parameter to make sure the user can transfer

status in HSDPA quickly.

1, parameter tuning in top cells

2, expansion 2nd SCCPCH

MPO not proper Parameter check

The UE measures the Ec/No of the Common Pilot Channel(CPICH) and adds a Measurement Power Offset (MPO) as

the Ec/No estimation value of the HS-PDSCH, to modify

the SNR of channel evaluation.

parameter tuning in top cells

E1 num not enoughResource check

Top cell checkThe Iub limit the throughput in some hotspots.

E1 expansion or change to IP(

not control)

not enough data in

Buffer

Top cell check

Customer complainThis is the limitation of server. None

More UE access in

the border of Cell

Top cell check

Customer complain The coverage have extension after the 3rd

carrier activation.

Need U900 activation to optim

the coverage of top cell.




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OPT 2. Configuring CQI Adjustment Based on Dynamic BLER Target

SET MACHSPARA: LOCELL=0, CQIADJALGOFNONCON=CQI_ADJ_BY_DYN_BLER ;With this feature, the NodeB can dynamically select the optimum BLER target value based on the channel quality fluctu

of HSDPA users. The NodeB then adjusts the Channel Quality Indicator (CQI) accordingly, improving user throughput a

throughput.

NO_CQI_ADJ : The UE measures the Ec/No of the Common Pilot Channel (CPICH) and adds a Measurement Power O

(MPO) as the Ec/No estimation value of the HS-PDSCH. That is, the UE assumes that the NodeB transmits the HS-PD

according to CPICH Power + MPO. Then, add the SF gain 10 * log16 to obtain the SNR of the HS-PDSCH. Obtain the

according to the relationship between the SNR and CQI of the simulated HS-PDSCH.

CQI_ADJ_BY_IBLER : 1st SBLER indicates the BLER of initial data transmission, also called IBLER. With this feature ,

can adjust CQI to a proper value according IBLER . But in some scenario ,If the SBLER is always around 10% no matt

you move the position, it may results from enabling the function of channel adjustment.

HSDPA Throughput Optimization



OPT 3. status transfer parameter optimization


MML Parameter Default value Opt value

SET UUESTATETRANS

BeF2DTvmTimeToTrig D0 D640

BeF2HTvmTimeToTrig D0 D640

BeF2ETvmTimeToTrigD0

D640

BeH2FTvmTimeToTrig D5000 D2560

D2FTvmTimeToTrig D5000 D2560

SET

UUESTATETRANSTIMER

BeD2FStateTransTimer 5 2

BeH2FStateTransTimer 5 2



The HSDPA throughput has a steady improvement after swap in the last 30 days.

The average HSDPA throughput reach the target 1776 bps.

HSDPA Throughput Optimization- OPT1&2&3



OPT 4. Modify Cell HSDPA Parameters (Recommended value of Power Compensate is set to 1~1.5)

MOD UCELLHSDPA : CellId=0, HsPdschMPOConstEnum = 0;This parameter named Measure Power Offset Constant is used to compute measurement power offset. Measurement

offset is used by UE to obtain total received HS-PDSCH power. The calculation for Measure Power Offset is as shown

CQI = CPICH Ec/No + MPO + 10 * log16 + 4.5

= SNRcpich + MPO + 4.5

= SNRhs-pdsch (based on assumed power) + 4.5 (with a round process, depending on the UE implementa

MPO = min(13, Pcell-Pcpich - MPO constant) dB , The MPO constant is 2.5 by default(For details of the IE "Measure Power Offset", refer to 3GPP TS 25.214)

.




HSDPA Throughput Optimization- OPT 4






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