Wcdma ps service_optimization_guide

WCDMA PS Service Optimization Guide For Internal Use Only
Product name Confidentiality level
WCDMA RNP For internal use only
Product version
Total 166 pages
3.2
WCDMA PS Service Optimization Guide
(For internal use only)
Prepared by Yu Yongxian Date 2006-03-22
Reviewed by Xie Zhibin, Chen Qi, Xu Zili, Xu
Dengyu, Jiao Anqiang, Hu Wensu,
Ji Yinyu, Qin Yan, Wan Liang,
and Ai Hua
Date
2006-03-22
Reviewed by Qin Yan and Wang Chungui Date 2006-03-30
Approved by Date

Huawei Technologies Co., Ltd.
All Rights Reserved

Revision Records
Date Version Description Reviewer Author
2004-11-
26
1.00
Initial transmittal. Yu Yongxian
2006-03-
09
1.01 Removing ABCD network for
optimization target; putting analysis of
traffic statistics in a single chapter;
completing the operations and
instructions at core network side by CN
engineers; removing CDR part.
Yu Yongxian
2006-03-
16
1.02 Moving the comparison of APP and
RLC throughput to DT/CQT data
analysis part; supplementing flow
charts.
Yu Yongxian
2006-03-
22
3.00 Changing the cover; removing BLER
target and changing power control
parameters; supplementing flow chats;
adding an HSDPA case.
Yu Yongxian
2006-05-
23
3.10 Supplementing HSDPA KPIs; adding
flow for analyzing the poor
performance for HSDPA to bear RAN
side data in data transfer; adding
analysis of interruption of data transfer
for HSDPA service; supplementing
HSDPA cases; revising minor errors in
V3.0 guide.
Wang Dekai
2006-10-
24
3.11 1 Adding analysis of throughput about
lub Overbooking to R99 and HSDPA
2 adding recommendation of EPE and
GBR import analysis of UE throughput.
3 Adding the third power assign
method’s description of HSDPA HS-
SCCH and the second power assign
method of baseline parameter’s change.
4 Adding the infection of V17
admittance arithmetic.
5 adding analysis of PLC Status Prohit
Timer to RLC layer throughput.
6 Adding analysis and description of
Wang Dekai

Date Version Description Reviewer Author
APP layer throughput.
7 Adding the recommendation of V17
SET HSDPATRF command’s change.
8 Modify the wrong description about
TCP/IP’s content.
2007-10-
30
3.2
Adding some content about HSUPA
Gao Bo
2008-04-
17
3.21 Adding checklist of HSPA throughput’s
problem on back-check and orientation.
Hua Yunlong
2008-10-
24
3.22 Adding UMAT tools analyze HSDPA’s
throughput problem. Modifying some
content
Hu Wensu, Ji
Shuqi , and
Fang Ming
Zheng Kaisi
2008-12-
18
3.23 Change the format and covert to KPI
Monitoring and Improvemnet Guilde
series.
He fengming

Contents
3.1 Traffic Statistics 19
3.2 DT/CQT 20
3.3 Others 22
4.1 Traffic Statistics Indexes Related to Throughput 25
4.2 Generic Analysis Flow 29
4.2.1 Flow for Analyzing RNC-level Traffic Statistics Data 29
4.2.2 Flow for Analyzing Cell-level Traffic Statistics Data 32
5.1 Access Failure 39
5.1.1 Originating PS Service by UE Directly 39
5.1.2 UE as the Modem of PC 40
5.2 Disconnection of Service Plane 46
5.2.1 Analyze Problems at RAN Side 46
5.2.2 Analyzing Problems at CN Side 51
5.3 Poor Performance of Data Transfer 54
5.3.1 Checking Alarms 55
5.3.2 Comparing Operations and Analyzing Problem 56
5.3.3 Analyzing Poor Performance of Data Transfer by DCH 57
5.3.4 Analyzing Poor Performance of Data Transfer by HSDPA at RAN Side 62
5.3.5 Analysis of the Problem about Poor Data Transmission Performance of the HSUPA on the RAN Side 81
5.3.6 Analyzing Poor Performance of Data Transfer at CN Side 115
5.4 Interruption of Data Transfer 119
5.4.1 Analzying DCH Interruption of Data Transfer 119
5.4.2 Analyzing HSDPA Interruption of Data Transfer 121
6.1 Cases at RAN Side 124
6.1.1 Call Drop due to Subscriber Congestion (Iub Resource Restriction) 124
6.1.2 Uplink PS64k Service Rate Failing to Meet Acceptance Requirements in a Test (Air Interface Problem)
124
6.1.3 Statistics and Analysis of Ping Time Delay in Different Service Types 125
6.1.4 Low Rate of HSDPA Data Transfer due to Over Low Pilot Power 126
6.1.5 Unstable HSDPA Rate due to Overhigh Receiving Power of Data Card 127

6.1.6 Decline of Total Throughput in Cell due to AAL2PATH Bandwidth larger than ActualPhysical
Bandwidth 128
6.1.7 Causes for an Exceptional UE Throughput and Location Method in a Field Test 130
6.2 Cases at CN Side 133
6.2.1 Low FTP Downloading Rate due to Over Small TCP Window on Server TCP 133
6.2.2 Simultaneous Uploading and Downloading 134
6.2.3 Decline of Downloading Rate of Multiple UEs 135
6.2.4 Unstable PS Rate (Loss of IP Packets) 136
6.2.5 Unstable PS Rate of Single Thread in Commercial Deployment (Loss of IP Packets) 138
6.2.6 Unavailable Streaming Service for a Subscriber 139
6.2.7 Unavailable PS Services due to Firewall of Laptop 139
6.2.8 Low PS Service Rate in Presentation Occasion 139
6.2.9 Abnormal Ending after Long-time Data Transfer by FTP 140
6.2.10 Analysis of Failure in PS Hanodver Between 3G Network and 2G Network 144
8.1 Transport Channel of PS Data 151
8.2 Theoretical Rates at Each Layer 152
8.2.1 TCP/IP Layer 152
8.2.2 RLC Layer 152
8.2.3 Retransmission Overhead 153
8.2.4 MAC-HS Layer 153
8.3 Bearer Methods ofPS Services 154
8.3.1 DCH 154
8.3.2 HSDPA 154
8.3.3 CCH 155
8.4 Method for Modifying TCP Receive Window 156
8.4.1 Tool Modification 156
8.4.2 Regedit Modification 156
8.5 Method for Modifying MTU 157
8.5.1 Tool Modification 157
8.5.2 Regedit Modification 158
8.6 Confirming APN and Rate in Activate PDP Context Request Message 159
8.6.1 Traffic Classes: 159
8.6.2 Maximum Bit Rates and Guaranteed Bit Rates 160
8.6.3 APN 160
8.7 APN Effect 162
8.7.1 Major Effect 162
8.7.2 Method for Naming APN 162
8.7.3 APN Configuration 162
8.8 PS Tools 163

8.8.1 TCP Receive Window and MTU Modification Tools 163
8.8.2 Sniffer 163
8.8.3 Common Tool to Capture Packet: Ethereal 164
8.8.4 HSDPA Test UE 164
8.9 Analysis of PDP Activation 165

Figures
Flow for analyzing RNC-level traffic statistics data 30
Flow for analyzing cell-level traffic statistics data 32
Flow for analyzing DT/CQT data 38
Flow for analyzing access failure problems when originating PS services by UE
directly 39
Flow for analyzing access problem when the UE serves as the modem of PC 40
Flow for processing problem of failure in opening port 41
Flow for analyzing access failure problems 42
Signaling flow of successful setup of a PS service in Probe 43
Flow for analyzing disconnection of service plane 46
Flow for analyzing RAN side problem about disconnection of service plane for DCH
bearer 47
Connection Performance Measurement-Downlink Throughput and Bandwidth
window 48
HSDPA parameters in Probe 50
Flow for analyzing problems at CN side about disconnection of service plane 52
Flow for analyzing poor performance of data transfer 55
Flow for analyzing RAN side problem about poor performance of data transfer on
DCH 58
Flow for analyzing data transfer affected by Uu interface 59
Flow for analyzing data transfer affected by Iub interface 61
Flow for analyzing poor performance of data transfer on HSDPA at RAN side 64
Confirming in the RNC message that PS service is set up on HSDPA channel 65
Confirming in Probe that service is set up on HSDPA channel 65

High code error of ACK->NACK/DTX in Probe 76
Uplink and downlink RL imbalance in handover areas 77
Residual BLER at MAC layer in WCDMA HSDPA Decoding Statistics window 80
Working process of an HSUPA UE 82
Optimization flow of a low throughput of the HSUPA UE 85
Confirming the service is set up on the HSUPA according to a signaling message of
the RNC 86
How to confirm the service is set up on the HSUPA through the drive test tool Probe
87
RRC CONNECTION REQUEST message 90
RRC CONNECT SETUP CMP message 91
RL RECFG PREPARE message 92
Display of the Assistant HSUPA related information (limited transmit power of the
UE) 93
Display of the Assistant HSUPA related information (limited traffic) 94
PHYSICAL SHARED CHANNEL RECONFIGURATION REQUEST message
(containing the target RTWP and the background) 96
ATM transmission efficiency 97
P bandwidth utilization 98
RAB assignment request message (containing an MBR) 99
RL RECFG PREPARE message (containing NodeB MBR) 100
RB SETUP message (containing the maximum number of available channel codes)
101
RLC PDU retransmission rate on the Probe 109
Receiver's CPU performance observation window 113
Flow for analyzing poor performance of data transfer at CN side 116
Flow for analyzing interruption of data transfer 120
Interruption delay of TCP displayed in Ethereal 122
Variation of total throughput of one IMA link of HSDPA codes 128
Variation of total throughput of two IMA links of HSDPA codes 129
Unstable PS rate (1) 137

Unstable PS rate (2) 137
Analyzing packets captured by Ethereal upon unstable PS rate 138
Interactive interface in CuteFTP 141
Signaling of normal downloading by FTP 142
Signaling of abnormal downloading by FTP 143
Signaling of normal handover between 3G network and 2G network 145
Normal signaling flow between UE and 2G SGSN. 146
Signaling flow traced on 2G SGSN 147
Transport channel of PS data 151
Packet Service Data Flow 152
Running interface of DRTCP 157
Detailed resolution of Activate PDP Context Request message 159
Converting ASCII codes into a character string by using the UltraEdit 161
PDP context activation process originated by MS 165

Tables
Requirements by DT/CQT on PS throughput 15
Major parameters to be collected in DT/CQT 20
Tools for collecting data 22
Measured items related to PS throughput in overall performance measurement of
RNC 25
Measured items related to PS throughput in cell performance measurement 26
Measured items related to HSDPA throughput (cell measurement) 27
related to HSUPA throughput (cell measurement) 27
Other measured items related to throughput 28
Indexes to judge whether a cell has PS service request 33
Cell measurement/cell algorithm measurement analysis 33
Analysis of cell performance/Iub interface measurement 34
Cell Measurement/Cell RLC Measurement Analysis 35
Comparing operations and analyzing problem 56
Relationship between CQI and TB size when the UE is in category 11–12 67
Relationship between CQI and TB size when the UE is at the level 1–6 68
HS-SCCH power offset 71
Categories of UE HSUPA capability levels 89
PO for the E-AGCH when the Ec/Io at the edge of cells is –12 dB 103
PO for the E-RGCH when the Ec/Io at the edge of cells is –12 dB 104
PO for the E-HICH when the Ec/Io at the edge of cells is –12 dB 107
Delay test result of ping packet 126
WCDMA PS Service Optimization Guide

Key words
WCDMA, PS service, and throughput
Abstract
The document serves the optimization of PS service problems in large networks. It describes problem
evaluation, data collection, and methods for analyzing problems.
Acronyms and abbreviations:
Acronyms and
abbreviations
Full spelling
RNO Radio Network Optimization
RNP Radio Network Planning
APN Access Point Name
CHR Call History Record
CQI Channel Quality Indicator
CQT Call Quality Test
DT Driver Test
HSDPA High Speed Data Packet Access
HS-PDSCH High Speed Physical Downlink Shared Channel
HS-SCCH Shared Control Channel for HS-DSCH
QoS Quality of Service
SF Spreading Factor
UE User Equipment

SBLER Scheduled Block Error Rate
IBLER Initial Block Error Rate
HHO Hard Handover
SHO Soft Handover
NE Network Element

1. Introduction
About This Guide
The following table lists the contents ofthis document.
Title Description
Chapter 1 Introduction
Chapter 2 Evaluation of PS Throughput Problems
Chapter 3 Data Collection
Chapter 4 Analysis of Traffic Statistics Data
Chapter 5 Analysis of DT/CQT Data
Chapter 6 Cases
Chapter 7 Summary
Chapter 8 Appendix

In WCDMA networks, besides traditional conversationalservice, data service is growing with
features. It has a significant perspective.
The indexes to indicate the performance of WCDMA data service includes:
 Access performance
It is reflected by the following indexes of data service:
 Success rate of RRC setup
 Success rate of RAB setup
 Success rate of PDP activation
 Call drop rate of PS service
 Throughput
 Delay
There are access delay and the service interruption delay caused by HHO.
This document addresses on problems in PS service optimization, such as access problems, data
transfer failure, low throughput ofdata transfer, unstable rate of data transfer, and interruption of data
transfer. It describes the method to analyze and solve DT/CQT problems. In addition, it describes the
flow for processing access failure and data transfer failure problems in optimization of PS throughput.
For access problems, call drop and handoverproblems, see W-KPI Monitoring and Improvement
Guide, which provides analysis in terms of signaling flow and performance statistics.This guide
supplements the possible causes and solutions to PS service access problems in terms of operations.
This guide is for RNO in commercial network, not in benchmark trial network.
The HSDPA problem analysis and description of MML command and product function are based on
the following product versions:
 BSC6800V100R006C01B064
 BTS3812E V100R006C02B040
When refer RRC arithmetic and product realization default is RNC V16, refer V17 it will be labeled.
The HSUPA problem analyses,description of MML command and product function are based on the
following product versions:
 BSC6800V100R008C01B082
 DBS3800-BBU3806V100R008C01B062

2.Evaluation of PS Throughput
Problems
About This Chapter
This chapter describes the evaluation of PS throughput problems.

Optimize PS throughput in terms of DT/CQT. In actual network optimization, the optimization objects
and test methods are according to contract.
2 lists the requirements by DT/CQT on PS throughput.
1. Requirements by
DT/CQT on PS
throughput
Ind
ex
Servi
ce
Referen
ce
Reference test method
Average
downlink
throughput of
R99
PS UL64k/DL
64k
48–56 kbps  Test in the areas
where Ec/Io is
large than –11
dB and RSCP is
larger than –90
dBm.
 Test when traffic
is low without
call drop
problems due to
congestion.
 Put FTP servers
in CN.
 Download with
5 threads.
 Exclude non-
RAN problems
or decline of
throughput
caused by UE.
PS UL64k/DL
128k
96–106 kbps
PS UL64k/DL
384k
300–350 kbps
Average uplink
throughput of
R99
PS UL64k/DL
64k
48–56 kbps  Test in the areas
where Ec/Io is
large than –11
dB and RSCP is
larger than –90
dBm.
 Test when traffic
is low (the
uplink and
downlink load is
not larger than

Ind
ex
Servi
ce
Referen
ce
planned load)
without call drop
problems due to
congestion.
 Put FTP servers
in CN.
 Download with
5 threads.
 Exclude non-
RAN problems
or decline of
throughput
caused by UE.
Downlink
average
throughput for
HSDPA single
subscriber
CAT12 1.52Mbps
(SBLER = 10%)
 The carrier
power, number
of HS-PDSCH
codes and Iub
bandwidth
resource are not
restricted. The
throughput is
determined by
capability of
UE.
 The average
CQI of tested
area is 18.
 Single
subscriber in
unloaded
conditions and
in the center of
cell.
760 kbps  Other resources
except power are
not restricted.
 The average

Ind
ex
Servi
ce
Referen
ce
CQI of tested
area is 10.
 Single
subscriber in
unloaded
conditions and
in the edge of
cell.
Throughput of
HSDPA cell
CAT12 3.25 Mbps  4 CAT12 UEs,
and 14 HS-
PDSCH codes
 It is restricted by
HS-PDSCH
code. The carrier
power and Iub
bandwidth are
not restricted.
 The average
CQI of tested
area is 18.
800 kbps  4 CAT12 UEs,
and 14 HS-
PDSCH codes
 It is restricted by
carrier power.
The HS-PDSCH
code and Iub
bandwidth are
not restricted.
 The average
CQI of tested
area is 18.
HSUPA Single
subscriber
throughput
CAT3
800kbps~1.1Mbps
(cell center)
 Uplink RTWP,
IUB bandwidth
resource and UE
TX power are

Ind
ex
Servi
ce
Referen
ce
not restricted.
 Pilot power
33dBm，RSCP
>=-70dBm;
 Single
subscriber in
unloaded
conditions
 Set MTU
size＝ 1500
bytes , set PDU
size= 336 bits.
 In UE QoS
profile in HLR,
MBR=2Mbps,
service type is
Background/Inte
ractive
 The data
resource of FTP
must make sure
that upload can
get the faster
rate in the wire
connection
conditions.
 Obtain the faster
rate, combine
UE capability,
get APP rate in
the conditions of
uplink
RTWP,IUB
bandwidth are
not restricted.
200kbps~400kbps
(cell edge)
 Uplink
RTWP,IUB
bandwidth

Ind
ex
Servi
ce
Referen
ce
resource and UE
TX power are
not restricted.
 Pilot power
33dBm，RSCP
>=-100dBm;
 Single
subscriber in
unloaded
conditions
 set
MTU ＝ 1500
bytes , set PDU
= 336 bits
 In UE QoS
profile in HLR,
MBR=2Mbps,
service type is
Background/Inte
ractive
 The data
resource of FTP
must make sure
that upload can
get the fast rate
in the wire
connection
conditions.
 Get the fast rate ,
combine UE
capability , get
APP rate in the
conditions of
uplink
RTWP,IUB
bandwidth are
not restricted.

3.Data Collection
About This Chapter
The following table lists the contents ofthis chapter.
Title Description
3.1 Traffic Statistics
3.2 DT/CQT
3.3 Others
There are two major methods for evaluating PS throughput:traffic statistics and DT/CQT.

1. Traffic Statistics
For collecting traffic statistics data,see W-Equipment Room Operations Guide.

2. DT/CQT
To obtain DT/CQT data, use the software Probe, UE, scanner, and GPS are involved. Obtain the
information output by UE, such as:
 Coverage
 Pilot pollution
 Signaling flow
 Downlink BLER
 TX power of UE
Based on the measurement tracing on RNC LMT, obtain the following information:
 Uplink BLER
 Downlink code transmission power
 Downlink carrier transmission power
 Signaling flow at RNC side
By the DT processing software Assistant,analyze comprehensively the data collected by Probe in
foreground DT and tracing record on RNC LMT.
3.2 lists the major parameters to be collected in DT/CQT.
1. Major
parameters to be
collected in
DT/CQT
Parameter Tool Effect
Longitude and latitude Probe + GPS Record trace
Scramble, RSCP, Ec/Io
of active set
Probe + UE Analyze problems
UE TX Power Probe + UE Analyze problems and
output reports
Downlink BLER Probe + UE Analyze problems and
output reports
Uplink/Downlink Probe + UE Analyze problems and

Parameter Tool Effect
application layer, RLC
layer throughput
output reports
RRC and NAS
signaling at UE side
Probe + UE Analyze problems
HSDPA CQI, HS-
SCCH scheduling
success rate,
throughput of APP,
RLC, and MAC
Probe + UE Analyze problems and
output reports
Uplink BLER RNC LMT Analyze problems and
output reports
Downlink transmission
code power
RNC LMT Analyze problems and
output reports
Single subscriber
signaling tracing by
RNC
RNC LMT Analyze problems
Iub bandwidth RNC/NodeB LMT Analyze problems
Downlink carrier
transmission power
and non-HSDPA
carrier transmission
power
output reports
Downlink throughput
and bandwidth
output reports
Dowlink traffic RNC LMT Analyze problems

In PS service test,to reduce the impact from TCP receiver window of application layer, using multi-
thread downloading tools like FlashGet is recommended. Set the number of threads to 5. For uplink
data transfer, start several FTP processes.
For the detailed test and operation methods of DT and CQT, see W-Test Guide. For detailed
operations on LMT, see W-Equipment Room Operations Guide.

3. Others
After finding problems by traffic statistics,DT/CQT, and subscribers'complaints, analyze and locate
problems with DT/CQT and the following aspects:
 RNC CHR
 Connection performance measurement
 Cell performance measurement
 Alarms on NEs
 States of NEs
 FlashGet
 DU Meter
3.3 lists the tools for collecting data.
1. Tools for
collecting data
Da
ta
Tools
for
collecti
ng data
Tools
for
viewin
g/
analyzi
ng data
Effe
ct
Rema
rk
Traffic
statistics data
M2000 Nastar Check the
network
operation
conditions
macroscopicall
y, analyze
whether there
are abnormal
NEs.
For detailed
operations on
LMT, see W-
Equipment Room
Operations
Guide. For usage
of Nastar, see the
online help and
operation manual
of Nastar.
DT/CQT data Probe + UE Assistant Analyze calls
in terms of
flow and
coverage based
on DT/CQT
data and traced
See W-Test
Guide.
Connection
performance
measurement,
RNC LMT Assistant or RNC
LMT
See the online
help of RNC
LMT

Da
ta
Tools
for
collecti
ng data
Tools
for
viewin
g/
analyzi
ng data
Effe
ct
Rema
rk
cell
performance
measurement,
signaling
tracing by
RNC
data on RNC
Alarm M2000 or RNC
LMT
M2000 or RNC
LMT
Check alarms
whether there
are abnormal
NEs
CHR RNC LMT Nastar or RNC
Insight Plus
Record historic
record of
abnormal calls
for all
subscribers,
help to locate
problems. For
subscribers'
complaints,
analyzing CHR
helps to find
the problem
happening to
subscribers.
None FlashGet None Downlink with
multiple
threads to
obtain more
stable
throughput
Assistant tool for
PS service test
None DU Meter None Observe
throughput of
Assistant tool for
PS service test

Da
ta
Tools
for
collecti
ng data
Tools
for
viewin
g/
analyzi
ng data
Effe
ct
Rema
rk
application
layer real-time,
take statistics
of total
throughput,
average
throughput, and
peak
throughput in a
period (the
result is
recorded by
PrintScreen
shot).
PS data packet Sniffer Sniffer Construct
stable uplink
and downlink
data
transmission
requirement.
Used by CN
engineers. For
usage, see
appendix.
PS data packet Ethereal Ethereal Sniff data
packet at
interfaces and
parse data
packet
Used by CN
engineers. For
usage, see
appendix.
Note: CHR is called CDL in those versions prior to RNC V1.6. CHR is used in these versions after V1.6.
When analyzing data with previous tools, engineers need to combine several data for analysis. For
example, in network maintenance stage,if some indexes are faulty, analyze some relative data such as
performance statistic,alarm data, and CHR. According to the level of problems, perform DT/CQT in
cell coverage scope; trace the signaling of single subscriberand conduct connection performance
measurement on RNC LMT.

If there are problems in DT/CQT, analyze them based on traffic statistics and alarms.

4. Analysis of Traffic Statistics Data
About This Chapter
This chapter analyzes traffic statistics data.
Title Description
4.1
Traffic Statistics Indexes Related to
Throughput
4.2 Generic Analysis Flow
The access,call drop, SHO, HHO, inter-RAT handoverproblems may affect throughput of PS
services. Therefore, before analyzing and optimizing throughput of PS services,analyze access,call
drop, SHO, HHO, inter-RAT handoverproblems.
To analyze access problems and traffic statistics indexes, see W-Access Problem OptimizationGuide.
To analyze handoverand call drop problems, and traffic statistics indexes, see W-Handover and Call
Drop Problem OptimizationGuide.

1. Traffic Statistics Indexes Related to
Throughput
The following four tables are based on RNC V1.6.
4.1 lists the measured items related to PS throughput in overall performance measurement of RNC.
1. Measured items
related to PS
throughput in
overall
performance
measurement of
RNC
Measured
item
Major indexes Effect
Overall performance
measurement of
RNC/RLC statistics
measurement
 RLC buffer
size
 Average
utilization of
buffer
 Number of
data packets
sent and
received by
RLC in
TM/AM/UM
mode
 Number of
data packets
dropped by
RLC
 Number of
retransmitted
data packets
 Check
whether the
RLC buffer
is
inadequate
 Check the
probability
of dropping
data
packets by
RLC
 Or whether
the
downlink
retransmissi
on rate is
over high
Overall performance
measurement of
RNC/UE state
Number of UEs in CELL_DCH,
CELL_FACH, CELL_PCH, and
URA_PCH state
Serve as reference for
understanding traffic model of
subscribers

Measured
item
measurement
Overall performance
measurement of
RNC/RB
measurement
 Number of
conversation
al service,
streaming
service,
interactive
service, and
background
service in
various
uplink and
downlink
rates in PS
domain
under RNC
 Times of
abnormal call
drops for
previous
services in
various rate
in PS domain
 Analyze the
number of
subscribers
using
different
services at
different
rate;
 Analyze the
call drop
problems of
various rate
Overall performance
measurement of
RNC/RNC traffic
measurement
Uplink and downlink traffic
(RLC layer excludes traffic of
RLC header) of all services in
PS domain under RNC
Overall performance
measurement of
RNC/PS inter-RAT
handover
measurement
 Times of
successful/fai
lure PS inter-
RAT
handovers
 The failure
causes
Frequent inter-RAT and the
call drop due to it will directly
affects PS service subscribers'
experiences. Guarantee high
handover success rate by
analyzing and optimizing the
measured item while avoid
ping-pong handover. Reduce
the impact from inter-RAT
handover on PS throughput.

4.1 lists the measured items related to PS throughput in cell performance measurement.
2. Measured items
related to PS
throughput in cell
performance
measurement
Measured
item
Cell
measurement/traffic
measurement
Uplink and downlink traffic
volume (number of MAC-d
PDU bytes) at Iub interface,
traffic of RACH, FACH, and
PCH; Iub CCH bandwidth
Analyze whether the CCH is
to be congested; take
statistics of Iub TCH traffic
Cell
measurement/cell
algorithm
measurement
DCCCC and congestion control Analyze cell congestion
problems and rationality of
DCCC parameters
Cell
measurement/cell
RLC measurement
Collect cell level data ,such as:
 Valid RLC
data rate
Downlink
service
 Number of
signaling
PDUs
 Number of
retransmitte
d PDUs
 Number of
discarded
PDUs
 Take
statistics
of valid
data rate
at RLC
layer
 The
transmissi
on rate of
service
and
signaling
 The
dropping
rate
Cell
measurement/cell
throughput of
Average throughput and
volume of various service
 Obtain the
average
throughpu

various services,
throughput t
measurement
t of
various
services
in the cell.
 Judge
whether
the
average
throughpu
t meets
the
optimizati
on
objectives
Cell
measurement/BLER
measurement of
various services in
cell
 Uplink
average
BLER of
various
services in
cell
 The ratio of
time of
maximum
value of
BLER
Cell
measurement/Iub
interface
measurement
 Number of
requested
RLs at Iub
interface
 Number of
successful
RLs
 Number of
failed RLs,
 Different
causes of
failures
Check the resource allocation
condition at Iub interface
whether Iub is congested.

In cell performance measurement, HSDPA part is added,and other indexes are the same as that of
R99. Some traffic statistics indexes corresponding to HSDPA services are not added to RNC traffic
statistics.
Table 4-3 lists the measured items related to HSDPA throughput (cell measurement).
3. Measured items
related to
HSDPA
throughput (cell
measurement)
Measured
item
Cell
measurement/HSDPA
service measurement
 Statistics of
HSDPA
service
setup and
deletion
 Number of
HSDPA
subscribers
in cell
 D-H, F-H
transition
 Serving cell
update
 Intra-
frequency
HHO
 Inter-
frequency
HHO
 MAC-D
flow
throughput
Know the
HSDPA
throughput and
number of
subscribers in
cell
Table 4-4 lists the measured items related to HSDPA throughput (cell measurement).Measured items
4. related to
HSUPA

throughput (cell
measurement)
Measured
item
Major indexes
Effect
Cell
measurement/HSDPA
service measurement
Measured item
”HSUPA.CELL” include
the PI of service setup ,
release and the number of
EDCH handover
Know the HSUPA
throughput and
number of subscribers
in cell
Table 4-5 shows othermeasured items related to throughput.
5. Other measured
items related to
throughput
Measured
item
Major
indexes
Effect
Performance
measurement at Iu
interface
Iu-PS reset times,
setup and release
times, and
overload control
times.
Analyze whether lu-PS interface
is normal
GTP-U measurement
Number of bytes
sent and received
by GTP-U
 Determine the
scope of
problems by
comparing
RLC layer
traffic and
GTP-U traffic
 Distinguish
RAN side
problems from
CN side
problems
UNI LINK Average receiving
and sending rate of

measurement UNI LINK
IMA LINK
measurement
Average receiving
and sending rate of
IMA LINK
IMA GROUP link
measurement
Average receiving
and sending rate of
IMA GROUP

2. Generic Analysis Flow
According to 4.1, the indexes related to PS throughput include:
 Overall performance measurement of RNC
 Cell measurement
 Performance measurement at Iu interface
 GTP-U measurement
 UNIUNI LINK measurement
 IMA LINK measurement
 IMA GROUP link measurement
Analyzing traffic statistics data is mainly based on overall performance measurement of RNC and cell
measurement. Analyzing RNC-level data addresses on evaluating and analyzing performance of entire
network. Analyzing cell-level data addresses on locating cell problems. Other measured items like Iu
interface and transmission help engineers to analyze problems in the whole process of performance
data analysis.
In actual traffic statistics analysis,evaluate the indexes of entire network and then locate cell-level
problems.
1. Flow for Analyzing RNC-level Traffic
Statistics Data
Figure 4-1 shows the flow for analyzing RNC-level traffic statistics data.

1. Flow for analyzing
RNC-level traffic
statistics data
The RNC traffic statistics indexes of current version do not include statistics of throughput ofvarious
services, but include RNC traffic volume measurement. The traffic volume measurement is relevant to
subscribers'behaviors and traffic model.

The traffic volume is not the same every day, but is fluctuating periodically from Monday to Saturday
and Sunday.Therefore, upon analysis of RNC traffic volume, observe the fluctuation of weekly traffic
volume. For example, compare the curve chart of traffic volume for a weak with that of last weak. If
they are similar, the network is running normally according to RNC-level analysis.If they are greatly
different from each other, analyze the problem in details.
When analyzing problems, check whether the RNC-level traffic statistics indexes are normal in
synchronization, such as RB, RLC, Iu interface. Then follow the flow for analyzing cell-level traffic
statistics data.
If the PS throughput ofone or two cells is abnormal, this cannot be reflected by RNC-level traffic
statistics.Therefore, analyzing cell-level traffic statistics data is necessary even if RNC-level traffic
statistics is normal.
2. Flow for Analyzing Cell-level Traffic
Statistics Data

1. Flow for analyzing cell-
level traffic statistics data

The cell-level traffic statistics data is obtainable from cell measurement/cell throughput of various
services, and volume measurement, including the average throughput and totalvolume of various
services.
Select a representative service in the network, or a continuous coverage service. Analyze the average
throughput ofeach cell for the selected service by Nastar and sort the cells by cell throughput.Select
the top N worst cells for analysis.
The cells with 0 PS RAB setup request is excluded from sorting alignment, namely, the total number
of the four indexes listed in 4.2.2 is 0. Such cells are considered as having no PS service request,so
they are excluded from sorting alignment the worst cells for PS throughput.
1. Indexes to judge
whether a cell has
PS service
request
Measured
item
Type Index
Cell measurement Number of
successful
RABs with
RAB
assignment
setup in PS
domain in cell
VS.RAB.AttEstabPS.Conv
VS.RAB.AttEstabPS.Str
VS.RAB.AttEstabPS.Inter
VS.RAB.AttEstabPS.Bkg
Cell
measurement/HSDPA
service measurement
Times of
HSDPA service
setup requests in
cell
VS.HSDPA.RAB.AttEstab
For the worst cell, check that they are not with access,call drop, and handoverproblems. Then
analyze the cell performance from cell measurement/traffic measurement, cell measurement/cell
algorithm measurement, and cell measurement/cell RLC measurement.
1）4.2.2 describes the cell measurement/cell algorithm measurement analysis.

2. Cell
measurement/cell
algorithm
measurement
analysis
Index Meani
ng
Analys
is
Soluti
on
VS.LCC.BasicCongNumUL
VS.LCC.BasicCongNumDL
Times of uplink
and downlink
basic congestion
in cell
If one of them is
large than 0, the
cell is with basic
congestion
problem
If the load of
inter-frequency
cells with
overlapped
coverage is low,
optimize load
balance
parameters.
Otherwise
consider adding
carriers.
VS.LCC.OverCongNumUL
VS.LCC.OverCongNumDL
Times of cell
congestion due to
uplink and
downlink overload
If one of them is
large than 0, the
cell must be badly
congested
If the load of
inter-frequency
cells with same
coverage is low,
optimize load
balance
parameters.
Otherwise
consider adding
carriers.
VS.DCCC.D2D.SuccRateDown.
UE
VS.DCCC.D2D.SuccRateUp.UE
Times of
successful
configuration of
DCH dynamic
channel with
decreasing
downlink rate in
cell
If the average
service throughput
is much lower
than the
bandwidth, the
DCCC algorithm
parameter may be
irrational.
Confirm the
DCCC algorithm
parameter
VS.Cell.UnavailTime.OM Length of
unavailable time
If it is large than
0, the cell must
have been
Check alarms and
CHR for causes of
system

of cell unavailable. abnormalities
2）4.2.2 describes the analysis of cell performance/Iub interface measurement.
3. Analysis of cell
performance/Iub
interface
measurement
Index Meani
ng
Analysis Soluti
on
VS.IUB.AttRLSetup
VS.IUB.SuccRLSetup
Number of
requested RLs set
up at lub interface
in cell.
Number of
successful RLs
set up at lub
interface in cell.
If SuccRLSetup <
AttRLSetup, the RL
setup must have failed
at lub interface. Analyze
the problem for detailed
causes.
VS.IUB.FailRLSetup.CfgUn
sup
VS.IUB.FailRLSetup.Cong
VS.IUB.FailRLSetup.HW
VS.IUB.FailRLSetup.OM
Number of RLs
failed at lub
interface due to
different causes
in cell
Analyze the setup
failure due to different
causes.
If the
VS.IUB.FailRLSetup.C
ong is large than 0, the
lub interface is probably
congested.
VS.DL.RL.Timing.Adjust.S
ucc
VS.DL.RL.Timing.Adjust.F
ail
Number of
downlink RLs of
successful and
failed RLs of
timing adjustment
in cell
If they are larger than 0,
timing adjustment is
present in cell. If timing
adjustment fails, the
normal sending and
receiving may be
affected.
3) Cell Measurement/Traffic Measurement Analysis

In cell measurement/traffic measurement analysis, take statistics of traffic at MAC layer.
Take statistics of traffic flow, signaling flow, FACH/RACH/PCH transport channel flow, and Iub
CCH bandwidth.
If the total service throughput approaches available Iub bandwidth of TCH, the throughput may
declines due to inadequate Iub bandwidth. Solve this problem by adding transmission bandwidth.
4) 4.2.2 describes Cell Measurement/Cell RLC Measurement Analysis
4. Cell
Measurement/Cel
l RLC
Measurement
Analysis
Index Meani
ng
Analys
is
Soluti
on
VS.RLC.AM.TrfPDU.Trans Number of PDUs
sent by RLC in
AM mode
Check the power
control parameters
like target value
of service BLER,
transmission error
rate, and clock
abnormality.
Check coverage.
VS.RLC.AM.TrfPDU.Retrans Number of service
PDUs
retransmitted by
RLC in downlink
in AM mode
Service
retransmission
rate = number of
PDUs for
retransmission
service/number of
sent service
PDUs. If the
retransmission
rate is high, there
may be some
problems.
VS.AM.RLC.DISCARD.TRF.P
DU
Number of service
PDUs dropped by
RLC in downlink
in AM mode of
cell
Dropping rate =
number of
dropped service
PDUs/number of
sent service
PDUs. If the PDU
drop rate is high,
there may be some
problems.

VS.RLC.AM.SigPDU.Trans Number of
signaling PDUs
sent by RLC in
AM mode
Check the power
control parameters
like target value
of service BLER,
transmission error
rate, and clock
abnormality.
Check coverage.
VS.RLC.AM.SigPDU.Retrans Number of
signaling PDUs
retransmitted by
RLC in downlink
in AM mode
Signaling
retransmission
rate = number of
retransmitted
signaling
PDUs/number of
sent signaling
PDUs
VS.AM.RLC.DISCARD.SIG.P
DU
Number of
signaling PDUs
dropped by RLC
in downlink in
AM mode of cell
Signaling
dropping rate =
number of
dropped signaling
PDUs/number of
sent signaling
PDUs
The causes of high RLC retransmission rate and PDU packet dropping rate are:
 Bad BLER of radio link (including weak coverage)
 High transmission error rate
 Clock abnormality
To confirm weak coverage problem, perform DT/CQT and analyze CHR as below:
 Perform DT/CQT to know the overall coverage conditions
 Analyze CHR to know the RSCP and Ec/Io of subscribers in the environment
 Sort the subscribers by RSCP in CHR analysis
 Record the worst N subscribers and visit the location
 Perform DT/CQT accordingly in these locations

5. Analysis of DT/CQT Data
About This Chapter
The following table lists the contents ofthis chapter.
Title Description
5.1 Access Failure
5.2 Disconnection of Service Plane
5.3 Poor Performance of Data Transfer
5.4 Interruption of Data Transfer

WCDMA PS service data transfer problems include the following three types in terms of phenomena:
 Access failure (or dial-up connection failure)
 Successful access but unavailable data transfer
 Available data transfer but low speed or great fluctuation
For the problem with different phenomena, follow different flows for processing them.
1. Flow for
analyzing DT/CQT data
For access,call drop, signaling plane, and handoverproblems, see W-Access Problem Optimization
Guide and W-Handover and Call Drop Problem Analysis Guide. This guide supplements some
operations in PS service test.

1. Access Failure
There are two ways to use PS services:
 Originating PS services directly on UE, browsing web pages, and watching
video streaming directly on UE
 Combining personal computer (PC) and UE. Namely, UE serves as the
modem of PC, and the service is originated through PC
In optimization test,the combination of PC and UE is most widely used.In DT/CQT, the PC is
usually a laptop with the DT software Probe installed on it. This is called Probe + UE. When the UE
fails to directly originate PS services, it can obtain more information by using Probe + UE. Therefore,
the following analysis is mainly based on Probe + UE.
1. Originating PS Service by UE Directly
5.1.1 shows the flow for analyzing access failure problems when originating PS services by UE
directly.

access failure problems
when originating PS
services by UE directly
The signaling of originating PS services by UE directly is the same as that of PC + UE. The difference
lies in the access point name (APN), and the way to set the address for service visiting.
If the UE fails to originate PS services directly, following the step below for analyzing causes:
 Verify the problem by PC + UE
If the PS services through PC + UE are normal, the system must work
normally. Then check and modify the APN, address for serving visiting,
Proxy, and password set on UE.
 Follow 5.1.2 if originating PS services by PC + UE fails.
2. UE as the Modem of PC
5.1.2 shows the flow for analyzing access problem when the UE serves as the modem of PC.
access problem when the

UE serves as the modem
of PC
Failure in Opening Port
5.1.2 shows the flow for processing problem of failure in opening port.

2. Flow for processing
problem of failure in
opening port
The major causes to failure in opening port include:
 Port in Hard Config of Probe is incorrectly configured
Check the configuration in Hardware Config. The port must be consistent
with the Com port and Modem port in Device Manager in Windows
operating system.
 The port state is abnormal
The driver is improperly installed. Or during DT, the DT tool may abort
abnormally, so the port mapped in Windows Device Manager is marked
by a yellow exclamatory mark.
To solve this problem, reinstall the driver, pull and plug data line or data
card of UE.

 After the software aborts abnormally, the port is not deactivated
The DT software like Probe may abort abnormally, so the corresponding
port is improperly closed.
To solve the problem, quit the Probe and restart it. If the problem is still
present, restart PC.
 The software of UE is faulty
Restart UE to solve the problem.
 The driver of UE is incompletely installed
Reinstall the driver. This problem usually occurs upon the first connection
of PC and UE.
Successful Activation of Port but Access Failure
Opening port succeeds,but access fails. This is probably due to signaling flow problem.
5.1.2 shows the flow for analyzing access failure problems

access failure problems
Trace the NAS and RRC signaling in Probe or trace the signaling of single subscriberon RNC LMT.
Analyze the problem by comparing it to the signaling flow for standard data service. For the signaling
flow for standard data service, see the senior training slides of RNP: W-RNP Senior Training-
Signaling Flow.
5.1.2 shows the signaling flow of successfulsetup ofa PS service in Probe.

4. Signaling flow of
successful setup of a PS
service in Probe
In 5.1.2, Probe contains two windows: RRC Message, and NAS Messages. The signaling point
in NAS Messages window corresponds to the point of direct transfer messages in RRC Message.
The following problem may occur due to the comparison of signaling flow:
 RRC connection setup failure
Description: in 5.1.2 , it is abnormal from the RRC Connection Request
message to the RRC Connection Setup Complete message.
Analysis: the UE fails to send the RRC Connection Request message
according to the RRC Messages window in Probe, probably due to:
 Modem port is not selected in the Hardware Config widow in Probe.
 Test Plan is not configured in Probe or improperly configured.
 The port of UE is abnormal. See the Failure in Opening Port in 5.1.2for
solution.
After the UE sends the RRC Connection Request message, it receives no
response or receives RRC Connection Reject message due to the

admission rejection caused by weak coverage and uplink and downlink
overload. For details, see the section Analyzing RRC Connection Setup
Problems in W-KPI Monitoring and Improvement Guide.
 UE's failure in sending Service Request
Description: There in no Service Request message in NAS Messages.
Analysis: The UE may have disabled PS functions or may have not
registered in PS domain.
 The UE may have disabled PS functions. Some UE supports CS or PS, or CS
+ PS. If the UE is set to support CS, PS services will be unavailable on it.
Check the UE configuration and Set it to support PS or CS + PS.
 The UE may have not registered in PS domain. According to signaling flow,
after the UE sends the Attach Request message, the network side responds the
Attach Reject message. The engineers at CN side need to check whether the
USIM supports PS services.
 The flow for authentication and encryption is abnormal
Description: it is abnormal from the Authentication AND Ciphering REQ
in NAS messages to the Security Mode Complete in RRC messages.
Analysis: the engineers at CN side need to check whether the
authentication switch in PS domain of CN is on, whether the CN CS
domain, PS domain, encryption algorithm of RNC, and the integrity
protection algorithm is consistent.
On RNC LMT, query the encryption algorithm by executing the
command LST UEA. Query the integrity protection algorithm by
executing the command LST UIA.
For details, see the section Analyzing Authentication Problems and the
section Analyzing Security Mode Problems in W-KPI Monitoring and
Improvement Guide.
 PDP activation is rejected
Description: after the UE sends the Activate PDP Context Request
message, it receives the Activate PDP Context Reject message.
Analysis: there are two types of problems, the improper configuration of
APN and rate at UE side, or CN problems.
 Improper APN at UE side
If the cause value of Activate PDP Context Reject is Missing or
unknown APN, the APN configuration is probably inconsistent with
CN side. Check the Probe and APN at UE side, and compare them with
HLR APN. For the method to set APN of UE and Probe, see the section
Connecting Test Device in Genex Probe Online Help. Ask the CN
engineers to check the APN in HLR.
 Improper rate at UE side

If the cause value of Activate PDP Context Reject is Service option not
supported, the requested rate of UE is probably higher than subscribed
rate in HLR. Check the requested rate at Probe and UE side, and
compare them with the subscribed rate in HLR. Ask the CN engineers
to check the subscriber rate in HLR.
Check the APN and requested rate in the Activate PDP Context Request
message. See the appendix 8.6.
 CN problem
If the APN at UE side and restricted rate are properly configured, the
problem is probably due to CN problem. If some interfaces of CN are
unavailable, locate the problem with engineers on PS domain of CN.
If the PS service is the initial commissioning, the APN for defining a
subscriber by HLR is inconsistent with that of gateway GPRS support
node (GGSN). Confirm this with engineers on PS domain of CN.
For the analysis of causes of PDP activation rejection, see 8.9.
 RB setup failure
Description: after Activate PDP Context Request, the system fails to
receive Radio Bearer Setup message, but receives the release message.
Analysis: for details, see the section Analyzing RAB or RB Setup
Problems in W-KPI Monitoring and Improvement Guide.
 Others
See 5.3.2. Shrink the scope of the problem by changing each device.

2. Disconnection of Service Plane
5.2 shows the flow for analyzing disconnection of service plane, though the PS service setup succeeds.
disconnection of service
plane
1. Analyze Problems at RAN Side
The connection setup succeeds,so the signaling plane is connected but the service plane is
disconnected.This is probably due to TRB reset at RAN side. For HSDPA, the service is carried by
HS-PDSCH and the signaling is carried by DCH. When the power of HS-PDSCH is inadequate,

probably the signaling plane is connected and service plane is disconnected.The following sections
distinguish PS services carried on DCH from PS services carried on HSDPA.
DCH bearer
5.2.1 shows the flow for analyzing RAN side problem about disconnection of service plane for DCH
bearer.
2. Flow for analyzing RAN
side problem about
disconnection of service
plane for DCH bearer
Check coverage conditions

Trace the pilot RSCP and Ec/Io of serving cell by Probe + UE. Judge
whether a point is in weak coverage area. For weak coverage area, such as
RSCP < –100 dBm or Ec/Io < –18 dB, the data transfer for PS services is
probably unavailable.
Solution: If the RSCP is bad, optimize it by improving coverage quality. If
the RSCP is qualified, but Ec/Io is bad, check:
 Pilot pollution. Then optimize the serious pilot pollution.
 Power configuration of pilot channel (LST PCPICH), usually 33 dBm.
 There is no external interference
Check call drop problem due to TRB reset
Obtain the CHR files corresponding to the occurrence point of problem.
On RNC LMT or in Nastar, check whether there is abnormal information
near the point of problem occurrence. This provides the evidence for
judgment.
For the analysis tool, see W-KPI Monitoring and Improvement Guide.
Trace uplink and downlink throughput and bandwidth
On RNC LMT, select Connection Performance Measurement > Uplink
Throughput and Bandwidth, Downlink Throughput and Bandwidth.
For details, see the online help for RNC LMT. Check the uplink and
downlink throughput and bandwidth.
5.2.1 shows the Connection Performance Measurement-Downlink
Throughput and Bandwidth window.
3. Connection Performance
Measurement-Downlink
Throughput and
Bandwidth window

In 5.2.1,
 The bandwidth shown is the bandwidth assigned for UE by system.
 The DLThroughput is the actual throughput of downlink data transfer.
Monitor the variation of access layer rate and non-access layer rate of
uplink and downlink data transfer for the current connection. This helps
analyze the functions of dynamic channel configuration and variation
features of service source rate.
 If the uplink throughput is 0, the uplink may be disconnected.
 If the downlink throughput is 0, the downlink may be disconnected.
When the RNC DCCC function is valid, distinguish the variation of
bandwidth caused by DCCC.
If the problem is still not located after previous operations, collect the data
packets received and sent at RNC L2 and by GTPU by using the tracing
tool RNC CDT. This helps judge whether the disconnection of subscriber
plane is in uplink or downlink, at CN side or RAN side.
Further
Check problems at the CN side according to analysis of problems at CN
side in 5.2.2.
Refer to Comparing Operations and Analyzing Problem. Change each part
and compare the operations. This helps reduce the scope of the problem.
Feed back the problem.
HSDPA Bearer
The HSDPA feature of cell is activated, The UE supports HSDPA. The rate requested by UE or the
subscribed rate is higher than HSDPA threshold for downlink BE service (for BE service) or HSDPA
threshold for downlink streaming service (for streaming service). When the PS services are carried by
HSDPA, follow the steps below:
Alarms in RNCs and CHR
Check the alarms and CHR for the point of problem occurrence whether
there are abnormalities. Provide diagnosis.
Deactivate HSDPA features so that PS services are set up on DCH
Deactivate HSDPA features by executing the command DEA
CELLHSDPA. Connect UE to the network by dial-up so that PS services
are set up on DCH.
If the data transfer is unavailable on DCH, see the troubleshooting in
previous block DCH Bearer.
If the data transfer is available on DCH, the problem must be about
HSDPA. Follow the steps below.
Check the CQI, HS-SCCH success rate, and SBLER

Check the CQI, HS-SCCH success rate, and SBLER by Probe + UE as
below:
 CQI
The UE estimates and reports CQI based on PCPICH Ec/Nt.
If the CQI reported by UE is 0, the NodeB will not send UE any data.
In the current version, if the CQI calculated by NodeB based on current
available power is smaller than 2, the NodeB will not schedule the UE and
send it any data.
If the common parameters like pilot Ec/Io, CellMaxPower, PcpichPower,
and MPO are normal, but the CQI is bad, change a PC. The PCs of
different types have different thermal noises, so they have different impact
on reported CQI.
 HS-SCCH success rate
The HS-SCCH success rate is obtainable in the WCDMA HSDPA
Decoding Statistics window and WCDMA HSDPA Link
Statistics window, as shown in 5.2.1.
4. HSDPA parameters in
Probe

Wherein, the HS-SCCH Success Rate (%) is the HS-SCCH scheduling
success rate of the UE. It is relevant to the following parameters:
 Number of HS-SCCHs
 Number of HSDPA subscribers
 Scheduling algorithm parameter
If an HS-SCCH is configured to the HSDPA cell, the scheduling algorithm
is the RR algorithm, and all the connected subscribers keeps data transfer,
the HS-SCCH success rate is the reciprocal of number of subscribers.
Namely, all the subscribers share the HS-SCCH resource.
If the HS-SCCH success rate of a subscriber approaches 0, the data
transfer rate of the subscriber approaches 0, and the service plane may be
disconnected.
The HS-SCCH success rate approaches 0 due to:
 The scheduling algorithm is much similar to MAX C/I algorithm, more than
one HSDPA subscribers connects to the cell, and the CQI of the subscriber is
low.
 The transmit power of HS-SCCH is over low. Now in the indoor scenario, the
transmit power of HS-SCCH is fixed to 2% of total transmit power of cell. In
outdoor scenarios, the proportion is 5%. If the transmit power of HS-SCCH is
lower than the fixed power, the UE may fail to demodulate HS-SCCH data.
 No data is transmitted at the application layer. Confirm this by the actual
transmitted data volume in the Connection Performance Measurement-
Uplink Throughput and Bandwidth, Downlink Throughput and
Bandwidth on RNC LMT.
 The CQI reported by UE is over low, so the NodeB will not schedule the
subscriber.
 SBLER being 100%
The SLBER is the slot block error rate of HS-DSCH. In 5.2.1, the right
pane of the WCDMA HSDPA Decoding Statistics window shows the
SBLER and retransmission conditions of transport blocks of different
sizes. The WCDMA HSDPA Link Statistics window shows the
following parameters:
 HS-DSCH SBLER-Deta
 HS-DSCH SBLER-Average
Wherein, the Delta is the instantaneous value. The Average is the average
value.
When the HS-PDSCH Ec/Nt is over low, the SBLER will be 100%. This is
actually caused by inadequate HSDPA power. Check the HSDPA power
configuration by executing the command LST CELLHSDPA. Wherein,
the HS-PDSCH and HS-SCCH power are the HSDPA power
configuration.

There are two methods for HSDPA power configuration: static power
configuration and dynamic power configuration.
 If the power of the parameter configuration is higher than or equal to the
maximum transmit power of cell, use dynamic power configuration.
 If the power of the parameter configuration is lower than the maximum
transmit power of cell, use static power configuration.
The available power of HS-PDSCH in static power configuration =
maximum transmit power of cell – power margin – R99 downlink load
(including CCH load) – HS-SCCH power.
The available power of HS-PDSCH in dynamic power configuration =
power of HS-PDSCH and HS-SCCH – HS-SCCH power.
Note the static power configuration. Due to power control, the R99
services can use HS-PDSCH power.
According to previous two formulas, in dynamic power configuration of
HSDPA power, if the power margin is over large, R99 downlink load is
over high, or HS-SCCH power is over high, the available power of HS-
PDSCH is over low. In static power configuration of HSDPA power, if the
HS-PDSCH and HS-SCCH power are over low, or HS-SCCH power is
over high, the available power of HS-PDSCH is over low.
SBLER is 100% seldom due to inadequate power, unless the CQI reported
by UE is over small. When the power of NodeB is inadequate, the CQI
calculated by NodeB is smaller, the scheduled TB blocks becomes smaller,
so the rate obtained by UE declines.
Solution: adjust parameter configuration. If the R99 load is over high, add
carriers.
Check the available bandwidth, occupied bandwidth, and assigned
bandwidth at Iub interface
Query Iub bandwidth by executing the command DSP AAL2PATH on
RNC LMT. Or start the task Periodic Reporting of Iub Bandwidth
Assignment Conditions of HSDPA on NodeB console.
If errors occur in data transmission, the IMA group number of
AAL2PATH (For HSDPA) on NodeB fails to match that on RNC. When
the available bandwidth of HSDPA is inadequate due to product software
problems, the data transfer is unavailable.
2. Analyzing Problems at CN Side
The problems at CN side include abnormal work state of service servers and incorrect username and
password.
5.2.2 shows the flow for analyzing problems at CN side about disconnection of service plane.

problems at CN side
about disconnection of
service plane
Confirm by other access network or LAN that the service software servers and service software run
normally.
 LAN

Use FTP or HTTP service on a PC connected to LAN, and check whether
the service is available. In addition, verify the user name and password of
the connected user.
 Other radio access network under the same CN
If different 3G access networks under the same CN sets up PS service or
sets up PS service from the GRPS network, check whether the service is
normal.
After previous checks, if the service servers work normally, focus on the problems at RAN side for
analysis. If the service servers are abnormal according to previous checks, ask the on-site engineers of
CN PS domain to solve the problem.
The IP address for visiting FTP and HTTP service servers by LAN is different from that for visiting
service servers after the UE sets up wireless connection. For details, turn to on-site engineers of CN
PS domain.

3. Poor Performance of Data Transfer
The poor performance of data transfer, in terms of throughput measurement, lies in the following
problems:
 Unstable rate like great fluctuation
 Low rate
The poor performance of data transfer, in terms of QoS, lies in the following problems:
 Unclear streaming image
 Buffering
 Low rate in browsing web pages
The appendix 8.1contains the transport path of PS data. The PS data passes Internet service servers,
GGSN, SGSN, RNC, NodeB, and finally UE. Meanwhile the PS data passes Gi, Gn, IuPS, Iub, and
Uu interfaces. During the process,the PS data passes Internet servers to GGSN using IP protocol.
Between them, there may be one or more devices like router and firewall.
The PS services use the AM mode of RLC and support retransmission function. The FTP and HTTP
services use TCP protocol which supports retransmission.The parameters of these two protocols
(RLC/TCP) have great impact on rate.
If the parameter configuration is improper, or missing and dropping data packet may cause the data
rate to decline. When checking the quality of service (QoS), engineers make UE as the modem of a
computer running applications, so the performance of computer and servers will influence the QoS.
By and large, several factors affect the performance of data transfer of PS services, and they include:
 RAN side
 CN equipment
 Applications and service software
The applications and service software problems are contained in the CN side problems. 5.3 shows the
flow for analyzing poor performance of data transfer.

1. Flow for analyzing poor
performance of data
transfer
1. Checking Alarms
If there is a problem, check whether there are alarms. Query the NodeB and RNC alarms at RAN side.
Query the SGSN, GGSN, LAN switch, router, and firewall at CN side. The alarms like abnormal
clock alarms, high transmission error rate, and abnormal equipment affect data transfer.
If problems cannot be located according NE alarms, refer to 5.3.2. By comparing operations and
analyzing problem, reduce the scope of problem.
 If the problem is at RAN side, refer to 5.3.3.

 If the problem is at CN side, refer to 5.3.6.
 If the problem concerns both the RAN and CN side, analyze it from both
sides.
2. Comparing Operations and Analyzing
Problem
Compare operations and analyze problem to focus on the possible faulty NE and to determine the
scope of problem: at CN side and service software, or at RAN.
1. Comparing
operations and
analyzing
problem
Order Operation Result Analysis
1 Change USIM card Data transfer
problem has been
solved
Problem maybe
related to user
information
configured in the
USIM card.
Data transfer
problem is still
unsettled
The problem cannot
be located, so
continue checks.
2 Change UE/data card Data transfer
problem has been
solved
Related to UE, such
as incompatibility
and poor
performance of UE
Data transfer
problem is still
unsettled
The problem cannot
be located, so
continue checks.
3 Change PC Data transfer
problem has been
solved
Related to drivers,
APN, restricted
rate, and firewall.
Data transfer
problem is still
The problem cannot
be located, so

unsettled continue checks.
4 Change PC under the
same server (ensure
than the service is
running normally,
and try to PING the
server and use
streaming services.
Data transfer
problem has been
solved
The problem at CN
side, related to
service software
Data transfer
problem is still
unsettled
The problem cannot
be located, so
continue checks.
5 Change a new
website for visiting
(from other
websites)
Data transfer
problem has been
solved
The problem at CN
side, related to
performance of
server, TCP/IP
parameters, or
service software
Data transfer
problem is still
unsettled
The problem cannot
be located, so
continue checks.
6 Change other access
network under the
same server, such as
GPRS network
Data transfer
problem has been
solved
The problem at
RAN side.
Data transfer
problem is still
unsettled
The problem cannot
be located.
7 Test on other
NodeBs
Data transfer
problem has been
solved
The NodeB
problem, or
improper
configuration of
parameters related
to the NodeB and
configured by RNC
Data transfer The problem cannot

problem is still
unsettled
be located.
After the approximate scope of problem cannot be located after previous checks, analyze it as a
problem of data transfer at RAN side and CN side.
3. Analyzing Poor Performance of Data
Transfer by DCH
The mechanism at the air interface of HSDPA is different from that of DCH, so different factors affect
data transfer on DCH and HSDPA.
5.3.3 shows the flow for analyzing RAN side problem about poor performance of data transfer on
DCH.

1. Flow for analyzing RAN
side problem about poor
performance of data
transfer on DCH
NE Alarms
Alarm check

If the performance of data transfer for PS services is poor, analyze NodeB
and RNC alarms. The clock alarms, alarms on transmission error rate, and
transmission interruption may cause fluctuation of PS data. For querying
NodeB and RNC alarms, see W-Equipment Room Operations Guide.
Data transfer affected by Uu interface
When PS services are carried by DCH, the factors affecting data transfer at
Uu interface includes:
 DCH bandwidth
 State transition
 Block error rate (BLER) at Uu interface
5.3.3 shows the flow for analyzing data transfer affected by Uu interface.
2. Flow for analyzing data
transfer affected by Uu
interface
 DCH bandwidth
When PS services are carried by DCH, the RNC assigns bandwidth for
each connected UE. The bandwidth depends on spreading factor and
coding method.

On RNC LMT, in the Connection Performance Measurement-Uplink
Throughput and Bandwidth, Downlink Throughput and Bandwidth
window, check the uplink and downlink assigned bandwidth and
throughput.
The bandwidth is the channel bandwidth assigned to UE by RAN. The
DlThroughput is the actual downlink rate of data transfer. Assigning
bandwidth (namely, code resource, power resource, and Iub resource are
normal) is normal if one of the following conditions is met:
 The bandwidth is the same as the request rate or subscribed rate.
 Maximum assignable rate (such as 384 kbps) is met upon DCH bearer.
If the bandwidth assigned to UE is smaller than the expectation, there are
two causes:
 Congestion or other causes. The RAN cannot assign UE with channels of
higher rate, which is abnormal.
 DCCC algorithm of RNC. If the DCCC algorithm parameter is rational, the
decline of rate is normal.
Enable the DCCC algorithm in the existing network so that the system can
save resource by reducing assigned bandwidth upon decline or pause of
data transfer. However, the DCCC algorithm configuration may be
irrational. DCCC algorithm involves rate adjustment based on traffic and
coverage, and rate adjustment in soft handover (SHO) SHO areas.
According to the parameters configured on site and based on algorithm,
judge whether the assignment and adjustment of DCH bandwidth are
rational, whether there are abnormalities, and whether the problem is solve
by adjusting parameters.
If the assigned DCH bandwidth is small due to congestion and other
abnormalities, solve the problem by the following methods:
 Trace signaling of single subscriber
 Query cell downlink load, assignment of code resource, and available
bandwidth at Iub interface
 Obtain CHR from BAM and check the abnormalities on RNC INSIGHT
PLUS or Nastar.
 BLER at Uu interface
The BLER at uplink and downlink Uu interface directly affect data
transfer of PS services. If the average of UL BLER or DL BLER measured
in a period is equal to or better than BLER Target, the code errors at Uu
interface are normal. Otherwise, analyze this problem.
DL BLER measurement: collect DT data by Probe and UE, and then
import the DT data to Assistant for analysis.
UL BLER measurement: In Connection Performance Measurement-
Uplink Transport Channel BLER window, import the measurement file
to Assistant, and analyze together with the Probe DT data files.

The power control and coverage affects the uplink and downlink BLER in
the following aspects:
 Outer loop power control switch. Check that the outer loop power control
switch of RNC is on.
 Coverage. Check whether the uplink and downlink are restricted in the areas
with bad UL BLER and DL BLER. For details, see W-RF Optimization
Guide.
 Performance of UE. Change a UE of other types and compare their
performance.
 In Sequence Delivery
 Set the sequence submission to TURE or FALSE. This affects the rate and
fluctuation of downlink. If you set the sequence submission to TURE, the
RLC keeps the transfer sequence of upper-layer PDUs. If set the sequence
submission to FALSE, the receiver RLC entity allows sending SDUs to
upper-layer in a sequence different from the sender. If you set the sequence
submission to FALSE, the uplink rate for data transfer will be low and data
transfer fluctuates much.
 Setting sequence submission to TURE by executing the command MOD
GPRS on Huawei HLR is recommended.
Data Transfer Affected by Iub Interface
The transport code error at Iub interface, delay jitter, and Iub bandwidth
affect the performance of data transfer.
5.3.3 shows the flow for analyzing data transfer affected by Iub interface.

3. Flow for analyzing data
transfer affected by Iub
interface
 Transport code error and delay jitter
According to transport alarms and clock alarms, check whether there are
problems.
Bandwidth at Iub interface
 Check whether the Iub interface is congested by the following methods:
 Querying the bandwidth at Iub interface on RNC LMT and NodeB LMT.
 Referring to the section Flow for Analyzing Cell-level Traffic Statistics Data.
 Checking abnormal record in CHR

Querying bandwidth at Iub interface at RNC side proceeds as below:
 Query adjacent node corresponding to each cell by executing the command LST AAL2ADJNODE
 Query the path of the NodeB by executing thecommand LST AAL2PATH.
 Query the bandwidth by executing the command LST ATMTRF.
 Query the residual bandwidth by executing the commands DSP AAL2ADJNODEand DSP
AAL2PATH at RNC side.
Querying the bandwidth at Iub interface at NodeB side proceeds as below:
AAL2PATH is necessary at NodeB. The relevant commands include LST AAL2PATH and DSP
AAL2PATH.
Comparison of Throughput at APP and RLC Layer
The throughput at APP and RLC layer is obtainable by DT/CQT. For
the theoretical relationship of rate at each layer, see the appendix 8.2.
If the rate of APP throughput and RLC throughout is lower than the
normal range according to theoretical analysis, the retransmission cost
of TCP/IP is over large. Check and modify the TCP receiver window
and MTU configuration. For the method, see the appendix 8.4 and 8.5.
4. Analyzing Poor Performance of Data
Transfer by HSDPA at RAN Side
The HSDPA network schedules power and code resources by code division or time division between
multiple subscribers.When there is only one HSDPA subscriberin a cell, the following factors affect
the rate for data transfer:
 HSDPA available power
 Number of HS-PDSCH codes in cell (when there is only one subscriber, a
HS-SCCH is necessary)
 Category of UE (maximum number of codes supported by UE and whether to
support 16QAM)
 Radio signals near UE
In addition, the following factors affect the reachable maximum rate:
 Subscribed rate
 Bandwidth at Iub interface
 Maximum rate supported by RNC, NodeB, GGSN, and SGSN.
When there are multiple subscribers,besides previous factors,the scheduling algorithm used by
NodeB and number of HS-SCCH configured to cell affects the rate of data transfer.
An HSDPA subscriberworks as below:
 The UE reports CQI on HS-DPCCH. The NodeB obtains the CQI of UE's
location.

 The scheduling module inside NodeB evaluates different subscribers by
channel conditions, the amount of data in cache for each subscriber, the last
serving time. It then determines the HS-DSCH parameters.
 The NodeB sends HS-DSCH parameters on HS-SCCH, and after two slots it
sends data on HS-DSCH.
 The UE monitors HS-SCCH for information sent to it. If there is any
schedule information, it starts receiving HS-DSCH data and buffers them.
 According to HS-SCCH data, the UE judges whether to combine the received
HS-DSCH data and data in soft buffer.
 The UE demodulates the received HS-DSCH data, and send the ACK/NACK
message on uplink HS-DPCCH according to CRC result.
 If the NodeB receives the NACK message, it resends the data until it receives
the ACK message or reaches the maximum retransmission times.
In the DT tool Probe, out of consideration for multiple subscriberscheduling and retransmission at
MAC-HS layer, there are three rates at MAC-HS layer:Scheduled Rate，Served Rate，MAC Layer
Rate.
Served Rate = Scheduled Rate * HS-SCCH Success Rate
MAC Layer Rate = Served Rate * (1- SBLER)
 Scheduled rate
Schedule rate = total bits of all TBs received in statistics period/total time
with TB scheduled in statistics period
The total bits of all TBs received in statistics period include all the bits
of received correct and wrong TBs.
The total time with TB scheduled in statistics period includes the time
with data received and excludes the time without data received.
 Served rate
Served rate = total bits of all TBs received in statistics period/statistics
period
The total bits of all TBs received in statistics period include the bits of
received correct and wrong TBs.
The statistics period includes the time with and without data received.
 MAC layer rate
MAC Layer Rate = total bits of correct TBs received in statistics
period/statistics period
The total bits of correct TBs received in statistics period include the bits
of correct TBs and exclude bits of wrong TBs.
The statistics period includes the time with and without data received.
 HS-SCCH success rate is the success rate for receiving HS-SCCH data by UE

 SLBER = wrong TBs received at MAC-HS layer/(received correct and wrong
TBs)
 ACK->NACK/DTX is the ratio that NodeB judges the ACK message as
NACK/DTX message.
5.3.4 shows the flow for analyzing poor performance of data transfer on HSDPA at RAN side.
1. Flow for analyzing poor
performance of data
transfer on HSDPA at
RAN side
NE Alarms
When the performance of data transfer for PS services is poor, analyze the NodeB and RNC alarms.
The clock alarms, alarms on transport code error, and transmission interruption may lead to
fluctuation of PS data. For querying NodeB and RNC alarms, see W-Equipment Room Operations
Guide.
Whether the Service Is Set Up on HSDPA Channel
Check the IE serving HSDSCH RL indicator of the message RB SETUP on RNC. If the IE is True,
and the SF of downlink channelcode is 256, the service must be carried by HSDPA channel, as shown
in 5.3.4.

2. Confirming in the RNC
message that PS service
is set up on HSDPA
channel
You can also check the information like reported CQI in the WCDMA HSDPA Link
Statistics window in the DT software Probe. If no information is in the window, the service must be
carried on DCH, as shown in 5.3.4.

3. Confirming in Probe
that service is set up on
HSDPA channel
If the service is not set up on HSDPA channel, it will automatically be set up on DCH. Now the
service rate is the rate of R99 service, usually equal to or smaller than 384 kbps.
If it is confirmed that the service is not set up on HSDPA channel, analyze it from the following
aspects.
 HSDPA cell is not set up
Check at RNC side whether the HSDPA cell is activated by executing the
command LST CELLHSDPA.
Check at NodeB side whether the local cell supports HSDPA. Check by
executing the command LST LOCELL whether the value of the local cell
is TRUE or FALSE.
If the HSDPA cell at RNC side is not activated, activate it by executing the
command MOD LOCELL: LOCELL=0, HSDPA=TRUE.
In addition, during modifying the HSDPA cell configuration on RNC, if
HSDPA codes are statically assigned, and if there are excessive R99
subscribers connected to the cell so the code assigned to HSDPA is
inadequate, the RNC still displays that the modifying HSDPA cell
configuration succeeds. However, actually the HSDPA cell is not
successfully set up. Check whether the codes assigned to HSDPA cell are
successful by selecting Realtime Performance Monitoring > Cell
Performance Monitoring > Code Tree Tracing on RNC.

 Incorrect type of HSDPA AAL2PATH or No Configuration
Set the type of HSPDA AAL2PATH to HSDPA_RT or HSDPA_NRT.
Otherwise the cell can support R99 services only, but not HSDPA
services. It is recommended that one HSDPA AAL2PATH is configured to
one NodeB. If multiple HSDPA AAL2PATHs are configured, the data
packets are easily dropped in the current version. Query it at RNC or
NodeB side by executing the command
LST AAL2PATH.
If the HSDPA AAL2PATH is set to RT or NRT, the downlink
subscription rate of UE is 2 Mbps. When the UE accesses the network,
setting subscriber plane for HSDPA service fails, and the RNC will
automatically set up the subscriber plane of PS 384kbps service.
According to signaling of the RB Setup message, the service is set up on
R99, and SF is 8.
 HSDPA subscriber's admission failure
The HSDPA subscriber's admission failure leads to that the RNC
reconfigures HSDPA service to be carried by PS384K channel of R99
service. If the service cannot be set up, the UE continues to access the
network after lowering the rate of R99 service. If the rate of connected
HSDPA subscriber is as low as 384 kbps, 128 kbps, or 64 kbps of R99
services according to test, confirm whether the service is set up on HSDPA
channel and whether the admission fails.
Check whether the following aspects are rational:
 Uplink and downlink load of R99 services
 Downlink code resource
 Iub transmission resource
 Number of HSDPA subscribers
 Threshold of HSDPA cell rate
 Guaranteed rate threshold of streaming service
 Guaranteed power threshold
 Over high HSDPA threshold for downlink BE service
The HSDPA threshold for downlink BE service defines the rate judgment
threshold for background or interactive services carried on HS-DSCH in
PS domain. If the request rate is great than or equal to the threshold, the PS
service is carried on HS-DSCH; otherwise, the PS service is carried on
DCH.
Set HSDPA threshold for downlink BE service by executing the command
SET FRC: DlBeTraffThsOnHsdpa=D384 on RNC.

Low Scheduled Rate
The TB size of NodeB scheduling depends on CQI, HSDPA codes,available power for HSDPA, and
so on. TB size/2ms is scheduled rate.
Normally, there is mapping relationship (depending on mapping table of NodeB CQI in actual use)
between the schedule rate and CQI reported by UE. The NodeB will filter and adjust the CQI reported
by UE, so the scheduled rate and CQI scheduled by NodeB have mapping relationship, not completely
having mapping relationship with the CQI reported by UE.
5.3.4 lists the relationship between CQI and TB size according to the protocol 3GPP 25.306. It is only
for reference, the product realization does not completely consist with protocol.
1. Relationship
between CQI and
TB size when the
UE is in category
11–12
C
Q
I
va
lu
e
Trans
port
Block
Size
Nu
mbe
r of
HS-
PDS
CH
Modul
ation
Referen
ce
power
adjustm
ent
0 N/A Out of range
1 137 1 QPSK 0
2 173 1 QPSK 0
3 233 1 QPSK 0
4 317 1 QPSK 0
5 377 1 QPSK 0
6 461 1 QPSK 0
7 650 2 QPSK 0
8 792 2 QPSK 0

C
Q
I
va
lu
e
Trans
port
Block
Size
Nu
mbe
r of
HS-
PDS
CH
Modul
ation
Referen
ce
power
adjustm
ent
9 931 2 QPSK 0
10 1262 3 QPSK 0
11 1483 3 QPSK 0
12 1742 3 QPSK 0
13 2279 4 QPSK 0
14 2583 4 QPSK 0
15 3319 5 QPSK 0
16 3319 5 QPSK –1
17 3319 5 QPSK –2
18 3319 5 QPSK –3
19 3319 5 QPSK –4
20 3319 5 QPSK –5
21 3319 5 QPSK –6
22 3319 5 QPSK –7
23 3319 5 QPSK –8

C
Q
I
va
lu
e
Trans
port
Block
Size
Nu
mbe
r of
HS-
PDS
CH
Modul
ation
Referen
ce
power
adjustm
ent
24 3319 5 QPSK –9
25 3319 5 QPSK –10
26 3319 5 QPSK –11
27 3319 5 QPSK –12
28 3319 5 QPSK –13
29 3319 5 QPSK –14
30 3319 5 QPSK –15
2. Relationship
between CQI and
TB size when the
UE is at the level
1–6
C
Q
I
va
lu
e
Trans
port
Block
Size
Nu
mbe
r of
HS-
PDS
CH
Modula
tion
Refere
nce
power
adjust
ment
0 N/A Out of range
1 137 1 QPSK 0

C
Q
I
va
lu
e
Trans
port
Block
Size
Nu
mbe
r of
HS-
PDS
CH
Modula
tion
Refere
nce
power
adjust
ment
2 173 1 QPSK 0
3 233 1 QPSK 0
4 317 1 QPSK 0
5 377 1 QPSK 0
6 461 1 QPSK 0
7 650 2 QPSK 0
8 792 2 QPSK 0
9 931 2 QPSK 0
10 1262 3 QPSK 0
11 1483 3 QPSK 0
12 1742 3 QPSK 0
13 2279 4 QPSK 0
14 2583 4 QPSK 0
15 3319 5 QPSK 0
16 3565 5 16-QAM 0

C
Q
I
va
lu
e
Trans
port
Block
Size
Nu
mbe
r of
HS-
PDS
CH
Modula
tion
Refere
nce
power
adjust
ment
17 4189 5 16-QAM 0
18 4664 5 16-QAM 0
19 5287 5 16-QAM 0
20 5887 5 16-QAM 0
21 6554 5 16-QAM 0
22 7168 5 16-QAM 0
23 7168 5 16-QAM –1
24 7168 5 16-QAM –2
25 7168 5 16-QAM –3
26 7168 5 16-QAM –4
27 7168 5 16-QAM –5
28 7168 5 16-QAM –6
29 7168 5 16-QAM –7
30 7168 5 16-QAM –8
The following factors affect scheduled rate:

 CQI
If the downlink rate of UE is low, check whether the CQI reported by UE
is over low, and check the PCPICH RSCP and Ec/Io of the serving cell
from the following aspects:
 The coverage is weak, and the CQI reported by UE is low.
 The interference is strong, and there is pilot pollution, and the CQI reported
by UE is low.
 When the HSDPA serving cell is frequently updated, the HSDPA subscribers
cannot change accordingly due to punishment, so the CQI reported by UE is
low.
If the coverage is weak, improve the CQI reported by UE by RF optimization and
constructing sites.
If the interference is strong,adjust the azimuth and down tilt in RF optimization. This
forms a primary cell.
If the HSDPA serving cell is frequently updated,avoid frequent handoverby adjusting
antenna azimuth and down tilt or constructing sites in RF optimization.
 Available power of HSDPA cell
If the available power of HSDPA cell is over low, the TB size of NodeB
scheduling will be affected.
HSDPA power configuration includes dynamic and static configuration.
The RNC MML is MOD CELLHSDPA: HSDPAPOWER=430. The unit
of HSDPA power is 0.1 dB. The total power of all HS-PDSCHs and HS-
SCCHs must not exceed the HSDPAPOWER.
When HSDPAPOWER in previous formula is higher than or equal to total
power of cell, the HSDPA power configuration is dynamic configuration.
The available power of HSDPA cell = total power of cell * (1 – power
margin) – power used by R99 TCH and CCH.
When HSDPAPOWER in previous formula is lower than total power of
cell, the HSDPA power configuration is static configuration. Namely, the
available power of HSDPA cell is the HSDPAPOWER. However, the
maximum available power = total power of cell * (1 – power margin) –
CCH power.
In staticpower distribution, theR99 services may occupy thepower of HSDPA cell, so the actual
power used by HSDPA cell is not the configured power.
Analyze the factors affecting available power of HSDPA cell from the
following aspects:
 Query power margin by executing the command LST MACHSPARA on
NodeB. The default power margin is 10%, namely, the total downlink load of
cell can use 90% of total power of cell.

 On RNC LMT, select Realtime Performance Monitoring > Cell
Performance Monitoring > Tx Carrier Power. Observe the transmit carrier
power and power used by non-HSDPA subscribers. The available power of
HSDPA = transmit carrier power - power used by non-HSDPA subscribers. If
the power used by non-HSDPA subscribers is over high, the available power
of HSDPA cell becomes low, so the scheduled rate is affected.
 Available codes of HSDPA cell
If inadequate codes are assigned to HSDPA subscribers, the TB size of
NodeB scheduling will be affected..
 HSDPA UE CATEGORY
The 3GPP protocol 25.306 defines 12 types of UE category. In a TTI, the
UE of a type obtains different maximum TB size, so the maximum
scheduled rate obtained by UE is different.
The UE reports its capability in the IE hsdsch physical layer category of
the RRC Connection Setup Complete message..
 Amount of data to be transmitted being smaller than the maximum TB size
The TB size scheduled by NodeB depends on the available power and
codes of the subscriber, as well as the amount of data transferred by the
subscriber. If the amount of data sent is smaller than the maximum
scheduled TB size, the rate at physical layer is lower than the expectation.
This problem occurs when there is data in NodeB buffer but the amount of
data is inadequate for a scheduled maximum TB size.
Low Served Rate
According to the previous formula Served Rate = Scheduled Rate * HS-SCCH Success Rate, if the
scheduled rate is normal, over low HS-SCCH success rate leads to over low served rate. If there is
only one subscriberin normal conditions,and the HS-SCCH power and traffic are not restricted, the
success rate of HS-SCCH is shall be highly approach to 100%.
The success rate of HS-SCCH is relevant to HS-SCCH power, number of HS-SCCHs, number of
subscribers,scheduling algorithm, and transported traffic. The following paragraphs describe them
respectively.
 HS-SCCH power distribution
The HS-SCCH is a downlink CCH, shared by all subscribers. The UE
keeps monitoring UE ID on HS-SCCH, and judge whether the UE ID is
for itself. If the UE ID is for itself, it demodulates HS-PDSCH data.
Therefore, correct demodulation of HS-SCCH goes before data transfer.
There are three types of HS-SCCH power, transit 【SET
MACHSPARA】 in NodeB , 0 shows that HS-SCCH power control is
based on CQI . 1 shows HS-SCCH power changeless; 2 shows use a power
control mode which go with DCH and keep a fixed power deflection
value. Default is 0. (Attention: the edition before
NodeB3812EV100R007C03B040 can’t be set to type 0, need use type 1 .)

The HS-SCCH power is in static configuration or dynamic configuration.
The default configuration is static configuration. Set the HS-SCCH power
to a fixed ratio of maximum transmit power of cell as below:
 Set the ratio to 3% in indoor environment.
 Set the ratio to 5% in outdoor environment.
Set the HS-SCCH power on NodeB LMT by executing the command
below:
SET MACHSPARA: PWRFLG=FIXED, PWR=5;
HS-SCCH power can be configured as dynamic power control, which is
achieved by setting a power offset to the pilot bit of DL-ADPCH. The
power offset is relevant to spreading factor of downlink DPCH and
whether the UE is in SHO state. When this method is used, the HS-SCCH
power offset is listed as in 5.3.4.
The MML command is as below:
SET MACHSPARA: PWRFLG=DYNAMIC;
1. HS-SCCH power
offset
Spreading
factor of
downlink
DPCH
HS-
SCCH
power
offset
in non-
SHO
period
HS-
SCCH
power
offset in
SHO
period
4 –10.75 –6.75
8 –7.75 –3.75
16 –4.75 –0.75
32 –1.75 +2.25
64 +1.25 +5.25
128 +4.25 +8.25
256 +7.25 +11.25

0 shows that HS-SCCH power control is based on CQI , which works like
this:
First set HS-SCCH initialization TX power
Then according to CQI change , adjust HS-SCCH power, like DCH inner-
loop power control.
At last , according to the ACK/NACK/DTX information from HS-
DPCCH’s feedback ,adjust HS-SCCH power , like DCH outer-loop power
control.
The parameter of the power control which base on CQI’s HS-SCCH : HS-
SCCH’s initial power , Default is 28(-3 dBm), relative to pilot power ; HS-
SCCH power control’s aim FER , Default is 10%(1%)
 Number of HSDPA subscribers and number of HS-SCCHs
The success rate of HS-SCCH is relevant to number of subscribers.
 If there is only one HSDPA subscriber in a cell, the traffic is not restricted
and HS-SCCH power is adequate, the success rate of HS-SCCH for the
subscriber approaches 100%.
 If there are multiple HSDPA subscribers in the cell, the success rate of HS-
SCCH for each subscriber is relevant to scheduling algorithm and number of
HS-SCCHs.
Usually set the HS-SCCH according to available power of HS-PDSCH,
code resource, and traffic of service source. For example, if UEs used in
the cell are all category 12 UE, set number of HS-PDSCH codes and
number of HS-SCCHs as below:
 If you set 5 codes to HS-PDSCH, it is recommended to set 2 HS-SCCHs.
 Scheduling algorithm
Using different scheduling algorithm for multiple subscribers enables each
subscriber to be scheduled at different probability. For example, after Max
C/I scheduling algorithm is used, the subscribers far from the cell center
will hardly or even never be scheduled due to low CQI.
The scheduling algorithm is one function of new function entity of
HSDPA, the MAC-hs function entity. Four factors are involved as below:
 CQI
CQI is the quality of signals received by UE at the location.
 Wait_Inter_TTI
It indicates the length of time that the UE must wait for service.
 Queue priority
 Queue length
The following scheduling algorithms are typical:

 Max C/I (only considering CQI value)
 RR (only considering wait_Inter_TTI)
 Classic PF (proportional fair, considering previous factors)
 EPF（Enhanced Proportional Fair），V17 edition
Parameters are not configured for current scheduling algorithm. Select one
of previous three algorithms by executing the command below:
SET MACHSPARA: LOCELL=10131, SM=PF;//The previous algorithm
corresponds to the PF scheduling algorithm.
 Traffic
After previous configuration and checks, there is no problem and CQI
reported by UE is high, but the rate of subscribers fluctuates. Check
downlink traffic in Connection Performance Monitoring window on
RNC LMT, and see whether there is enough traffic for scheduling. Or
check downlink traffic in HSDPA User Flow Control Performance
Periodic Report window on NodeB LMT.
The cause of this problem is unstable source rate, single thread used upon
downloading, and small TCP window.
In the HSDPA User Flow Control Performance Periodic Report window,
there are following selections:
 Queue Priority
 Queue Buffer Used Ratio
 RLC User Buffer Size
 Input Data Size
 Output Data Size
Select Queue Buffer Used Ratio to draw picture on LMT, and check the
occupation of NodeB queue.
Select RLC User Buffer Size to check RLC buffer.
Select Input Data Size and Output Data Size to check the sending and
receiving queue data. The data involved in Output Data Size is the data
with ACK indicator received.
 Restricted Rate at UE side
The request service type, uplink and downlink maximum rate are sent to
UE by AT commands. The UE sends the information to CN in the
following Active PDP context request message. When the subscribed rate
is higher than or equal to the requested maximum rate, the CN sends the
RAN Assignment request message at the requested maximum rate. If the
resource is not restricted at RNC side, the final output rate is the request
maximum rate. If the downlink maximum rate in the RAB Assignment
request message is much lower than scheduled rate, and the traffic in

buffer is inadequate upon NodeB's scheduling, the success rate of HS-
SCCH must be low.
Execute AT commands as below:
 Right click My Computer
 Select Property > Hardware > Device Manager > Modem > Property > Senior
 Type AT command into the Initialization Command text box. Set APN by AT
command. If you want to set APN to cmnet, the rate is restricted to 64 kbps in
uplink and 384 kbps in downlink, execute the following command:
AT+cgdcont=1,"ip","cmnet"; +cgeqreq=1,3,64,384
When you remove the restriction on rate, execute AT command to set the rate
to 0. The value 0 means that no specified rate is requested, so the system
assigns the subscribed rate as possible. Execute the following command:
AT+cgdcont=1,"ip","cmnet"; +cgeqreq=1,3,0,0
 Restriction of bandwidth at Iub interface
If the physical bandwidth at Iub interface is restricted, the HSDPA service
obtains inadequate AAL2PATH bandwidth. As a result, the traffic in
NodeB buffer is inadequate, so the success rate of HS-SCCH is low.
In addition, the R99 AAL2PATH and HSDPA AAL2PATH are
respectively configured, but they share the physical bandwidth. If multiple
R99 subscribers are using the bandwidth at Iub interface in the cell, the
HSDPA service obtains inadequate AAL2PATH bandwidth. As a result,
the success rate of HS-SCCH is low.
 ACK/NACK repeat factor
The following parameters at physical layer are sent to UE and NodeB in
the messages at higher layer:
 ACK/NACK repeat factor: N_acknack_transmit
 CQI repeat factor: N_cqi_transmit
 CQI feedback cycle: CQI Feedback Cycle k
After the UE demodulates HS-PDSCH data, the UE sends an HARQ ACK
or NACK message based on cyclic redundancy check (CRC) of MAC-hs,
and it repeats sending the ACK/NACK message in the continuous
N_acknack_transmit HS-DPCCH subframes. If the N_acknack_transmit is
larger than 1, the UE will not try to receive or demodulate transport blocks
between the HS-DSCH n+1 and n + N_acknack_transmit – 1 subframes.
The n is the sub frame number of last HS-DSCH in the received transport
blocks. Now the rate obtained by UE is as below:
Rate of UE when the ACK/NACK is not repeatedly sent * (1/
N_acknack_transmit)

Low MAC Layer Rate
According to a previous formula MAC Layer Rate = Served Rate * (1- SBLER), low MAC layer rate
is a result of high SBLER. Normally, when the IBLER is 10%, the SLBER will be lower than 15%.
The following factors affect SBLER.
 IBLER
IBLER affects MAC-HS retransmission, so it consequently affects the
actual rate of subscribers. The IBLER here is number of incorrect
TBs/number of total new data blocks when the NodeB transmits new data.
The SBLER here is number of incorrect blocks/(number of incorrect and
correct blocks) when the NodeB transmits new data or retransmits data.
IBLER directly affects SBLER. Now the default IBELR is 10%. IBLER
directly affects the power for scheduling each subscriber. This is similar
with outer loop power control of R99.
Execute the command SET MACHSPARA to set the following items:
 Scheduling algorithm
 MAC-HS retransmission times
 Power margin
 HS-SCCH power
 Initial BLER
The MML command is as below:
SET MACHSPARA: LOCELL=1, SM=PF, MXRETRAN=4,
PWRMGN=10, PWRFLG=FIXED, PWR=5, IBLER=10;
 Low CQI and inadequate HSDPA power
If the CQI reported by UE is low, and the available power of HSDPA is
inadequate, SBLER will be high. The size of an MAC-d PDU is 336 bits.
The MAC PDU requires the TB size larger than 336 bits in transmission.
As a result, the CQI upon NodeB's scheduling must be larger than a value
to meet that IBLER is within 10%.
 CQI reported by UE being higher than actual one
The CQI reported by UE is inaccurate, higher than the actual one. The
NodeB adjusts the CQI according to target IBLER, but it takes some time
for adjustment. During this period, the NodeB transfers data with low
power according to the CQI reported by UE. As a result, the SLBER is
high, so the performance of data transfer is affected.
Solution: by Windows HyperTerminal, connect UE to the data card.
Adjust the CQI reported by UE by executing AT commands (This solution
caters for Huawei data card only. The current version does not support
this).
Assume: before the following operations, the CQI reported by connected
UE is 25.

 Enable the function of adjusting CQI, set the offset to –200, and lower CQI.
Type the following command:
AT^CQI=1,-200
The UE responds OK. The CQI is 2–3 lower than before, and is 22–23.
 Enable the function of adjusting CQI, set the offset to 0, and the CQI restores
to be the actual value. Type the following command:
AT^CQI=1,0
The UE responds OK. The CQI is 25.
 Enable the function of adjusting CQI, set the offset to 200, and raise CQI.
Type the following command:
AT^CQI=1,200
The UE responds OK. The CQI is 2–3 lower than before, and is 27–28.
 Disable the function of adjusting CQI. Type the following command:
AT^CQI=0,200
The UE responds OK. The CQI remains 27–28.
 If you type wrong parameters as below:
AT^CQI=1,100,1
The UE responds TOO MANY PARAMETERS.
 If you query the state of CQI adjustment function, type the following
command:
AT^CQI?
When the UE responds +CME ERROR, the current NV time 4448
NV_CQI_ADJUST_I is not activated, and the adjustment function is
disabled.
When the UE responds ^CQI:0,200, the function of adjusting CQI is disabled.
When the UE responds ^CQI:1,200, the function of adjusting CQI is enabled.
 Over low pilot power
On prior version of NodeBs, according to RTT test,
 If the power of other channel is 10 dB higher than pilot channel, this leads to
a 10% code error for HSDPA.
 If the power of other channel is 13 dB higher than pilot channel, this leads to
a 100% code error for HSDPA.
Now the NodeB can adjust power in a certain scope according to HSDPA
SBLER. If the power of other channels is 13 dB higher than the pilot
power, the impact on throughput is little. Setting PICH over low is
forbidden; otherwise, the power is inadequate after adjustment by NodeB.
This leads to over high SBLER, and consequently the throughput is
affected.
Low RLC Layer Rate
RLC AM use the mode of “positive/ negative affirm decision” to carry through dependable data
transmission. Use “slip window agreement” carry through flux control.

Before RLC don’t receive affirm package , the most number PDU which can be send is “RLC send
window ” . the more betimes send point receive affirm information , the faster the window slip. The
faster RLC can send.Whereas , the slower RLC can send . even appear RLC replacement result in
drop call.
If Scheduled Rate、Served Rate and MAC Layer Rate is normal , it need more adjust whether RLC
Throughput is normal.
The relationship between RLC Throughput andMAC Layer Rate:
RLC Throughput=MAC Layer Rate * (1-MAC-HS PDU’s caput spending rate)
Because PDU’s caput spending rate is small , watch RLC Throughput and MAC Layer Rate from
Probe, the curve superposition
If RLC Throughput obvious less than MAC Layer Rate, it is abnormal.
 High ACK->NACK/DTX ratio
ACK->NACK/DTX is the ratio that the NodeB judges ACK as
NACK/DTX. Simulation requires the average probability of ACK-
>NACK/DTX to be lower than 1%. If the NodeB judges ACK as
NACK/DTX, the NodeB will retransmit the data correctly received by UE.
This wastes resource and lowers subscribers' rate.
The following parameters describe an example on Probe, as shown in .
4. High code error of
ACK->NACK/DTX in
Probe
In the WCDMA HSDPA Decoding Statistics window, you can see ACK-
>NACK/DTX. In , ACK->NACK/DTX is 76.01%. The right pane displays

detailed number of blocks that are correct received and retransmitted. As a
result, ACK->NACK/DTX=7808/(7808+2465)=76.01%.
In the WCDMA HSDPA Link Statistics window, the MAC Layer Rate-
Average is 67.33 kbps. In the left pane, the RLC DL Throughput is 16.19
kbps. The ratio of RLC rate and MAC rate is 16.19/67.33, equal to
24.05%. If the correct blocks that are repeated received is excluded from
calculating MAC layer rate, the MAC layer rate is 67.33 * (1- 76.01) =
16.15 kbps. The MAC layer rate is approximately equal to RLC rate.
 Over low configuration of HS-DPCCH power parameters
HS-DPCCH is an uplink dedicated physical channel, transporting the
ACK/NACK, and CQI messages at physical layer. HS-DPCCH is not
under respective power control, but has a power offset with downlink
DPCCH. When HS-DPCCH carries different information, it uses
different offset values.
If the ACK/NACK power offset on HS-DPCCH is over low, the ACK-
>NACK/DTX demodulated by NodeB in uplink will be overhigh, and
consequently the subscribers' rate is affected.
For the description of HS-DPCCH power parameters, see the appendix
HS-DPCCH Power Control Parameter Configuration.
 Uplink and downlink RL imbalance in handover areas
The uplink and downlink RL imbalance in handover areas are defined
as below, and shown in:
RL2_dl > RL1_dl
RL2_ul < RL1_ul
5. Uplink and downlink RL
imbalance in handover
areas
Because RL2_dl > RL1_dl, the serving cell is updated, and the HSDPA
service is set up in the cell 2. The RNC adjusts SIRtarget according to
combination result of two UL RLs due to SHO. The two cells perform

inner loop power control according to SIRtarget. The UE combines the
downlink TCP of the two cells. According to combination principles, if the
TCP of one cell is –1, lower power accordingly. When the TCP of two
cells is +1, raise power.
Because RL2_ul < RL1_ul, the RL1_ul SIR is converged to target value,
and RL2_ul SIR is lower than the target value. The power control over
HS-DPCCH is based on the associated channel of RL_ul, so the
demodulation performance of HS-DPCCH ACK/NACK/CQI cannot meet
requirement. As a result, the performance of data transfer for HSDPA
subscribers is poor.
Analysis proceeds as below:
 Obtain HSDPA-HSDPA handover test data, including the data at UE side and
RNC side.
 According to single subscribing signaling tracing, analyze to see whether
there is a serving cell updated due to UL RL failure. If yes, find the UE APP
throughput at the corresponding point.
 With the data at RNC side, draw a chart involving uplink SIR, SIRtarget, UL
BLER, downlink throughput, PCPICH RSCP and Ec/No. Obtain the SIR
information on HSDPA uplink associated channel.
 Based on the results from Step 2 and 3 above, obtain the information about
RL imbalance.
 Analyze RL imbalance and provide solutions.
 Impact from power control of uplink associated DCH
The impact from power control of uplink associated DCH includes the
following two aspects:
 HS-DPCCH is not under individual power control, but has a power offset
with uplink DPCCH. If the uplink DCH power control is not converged, and
BLER is overhigh, the uplink HS-DPCCH power will be over low, and the
NodeB will judge ACK as NACK/DTX in a great probability. As a result, the
rate of RLC layer for HSDPA subscribers is over low.
 TCP and RLC uses AM mode, so sending the ACK message is necessary on
uplink DCH.
TCP provides reliable transport layer, the receiver responds the ACK
message. Any the data and the ACK message may be lost during
transmission, so TCP sets a timer upon sending for solving this
problem. If the sender does not receive the ACK message till expiration
of the timer, it resends the data. As a result, the rate for data transfer is
affected. If the uplink DCH power control is not converged, and BLER
is over high, the sender TCP will fail to receive the ACK message and
resend the data. As a result, the rate of data transfer is affected.

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