W(Level3) WCDMA RNO PS Optimization 20041217 a 1[1].0

Wireless Curriculum Development SectionWireless Curriculum Development SectionWireless Curriculum Development SectionWireless Curriculum Development Section

ISSUEISSUE

WCDMA RNO PS OptimizationWCDMA RNO PS OptimizationWCDMA RNO PS OptimizationWCDMA RNO PS Optimization

1.01.0

Confidential Information of Huawei. No Spreading without Permission.

Security Level: Internal

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ObjectivesObjectives

Upon completion of this course, you will be able to:

know about the basic concepts of

WCDMA data service;

know how to optimize packet

switches performance.



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Course ContentsCourse Contents

Chapter 1 Characteristic of Data Service

Chapter 2 Performance Indicators of Data Service

Chapter 3 Radio Performance Optimization

Chapter 4 Test Methods



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Characteristic of Data ServicesCharacteristic of Data Services

1.1 QoS1.1 QoS

1.2 Protocol Architecture

1.3 User Behavior



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Category of Quality of ServiceCategory of Quality of Service

Traffic class Conversational class

conversational RT

Streaming classstreaming RT

Interactive classInteractive best

effort

BackgroundBackground

best effort

Fundamental characteristics

- Preserve time relation (variation) between information entities of the stream

Conversational pattern (stringent and low delay )

- Preserve time relation (variation) between information entities of the stream

- Request response pattern

- Preserve payload content

- Destination is not expecting the data within a certain time

- Preserve payload content

Example of the application

- voice - streaming video - Web browsing - background download of emails



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Packet data (PD) traffic is a non-real-time packet services

(PS) including interactive and background traffic classes.

Their properties are:

PD - Sometimes a large amount of data is transferred. At the

other times no data is sent. Thus, the required bit rate can

change rapidly.

PD tolerates longer delay than real-time services. It is

controllable traffic from the RNC; thus, RNC decides when and

how to send the data.

PD is transmitted by the radio link control layer to provide

retransmission and error correction services. It allows high

frame error rate with low transmission power.

Quality of ServiceQuality of Service



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1.1 QoS1.1 QoS


1.3 User Behavior



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PS Protocol ArchitecturePS Protocol Architecture



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PS Data FlowPS Data Flow



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1.1 QoS1.1 QoS


1.3 User Behavior



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User BehaviorUser Behavior



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User BehaviorUser Behavior

The figure depicts a Web-browsing session supported by a

UMTS wireless network.

At first, the session is in a dormant state where the user has been

disconnected from the network due to inactivity.

The user initiates a request for data (e.g., a new Web page) via a mouse

click and is reconnected to the network after a short access delay.

The requested data is downloaded in a series of data bursts with rates that

vary as user conditions vary.

After download, the user reads the page for a period that exceeds the

dormancy time, triggering channel disconnect in order to conserve

resources.

After some period, the user requests another download via a mouse click,

and the cycle repeats.



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Designated Objectives of PSDesignated Objectives of PS

Designated objectives of PS:

High Call Setup Success Rate (CSSR)/Low Call Drop Rate

(CDR)

High throughput (system and users)

Low delay (interaction between TCP and RLC)

Simplicity and effectiveness of radio RRM (including QoS

management)

Efficient usage of channelization codes on the DL

Efficient usage of BTS Tx power and hardware resources

(especially in the Node B)

Low terminal power consumption



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Performance Indicators - ThroughputPerformance Indicators - Throughput

About “throughput” peak data throughput (PDT)

the highest channel rate that can be achieved at the physical layer by a user

average user data throughput (UDT)

the ratios of total user data downloaded to total user session time perceived UDT

the ratio of the download size to the elapsed time forward link average aggregate throughput

it captures the average total rate of payload delivery across the cell coverage area to the hosted data users

min user throughput

the average user throughput for a user under the worst RF condition for a given unit of time



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Which throughput is the most important? PDT

Use to market a given technology, without regard to frequency of

occurrence, area of availability, or associated channel error rate.

Therefore, it alone is a poor indicator of user experience or of relative

performance across technologies.

average PDT

Be highly dependent on the data traffic characteristics since the total

session time usually includes large intervals of reading or thinking

time. To minimize the effects of the think time on this measure, it is

calculated using the “full-buffer” traffic model, with which the think

time is set to zero.



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Which throughput is the most important?

perceived UDT

The perceived throughput is distinct from the average UDT that it

excludes the data rate in the think time. This is desirable since

most users are insensitive to the download speed during the think

time.

DL average aggregate throughput

evaluate the network performance.

min user throughput

provide indications as to how wide the spread is between rates of

different users.



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Performance Indicators - Resource UtilizationPerformance Indicators - Resource Utilization

Resource utilization is defined as the ratio of

source data volume and resource allocated. It

reflects the efficiency of resource usage:

m

i

mtmbandwidthchannel

isizecallpacketnutilizatiosource

)()(_

)(___Re



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Radio Performance OptimizationRadio Performance Optimization

1.1 Improve CSSR and CDR1.1 Improve CSSR and CDR

1.2 Make Full Use of Resource

1.3 Perceived User Throughput



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Improve CSSR - Initial Access RateImprove CSSR - Initial Access Rate

CSSR - Call Setup Success Rate

Improve CSSR

Select appropriate channel

Configure lower initial access rate



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Improve CDRImprove CDR

CDR - Call Drop Rate

Improve CDR:

Adjust bandwidth (BW) based on DL Tx power



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1.1 Improve CSSR and CDR





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Make Full Use of Resource - DCCCMake Full Use of Resource - DCCC

－ Configured BW is fixed when no DCCC

－ Configured BW is changing when DCCC

－ Traffic rate

Rate

DCCC – dynamic channel configuration control



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DCCC – Gain and CostDCCC – Gain and Cost

Gain

OVSF code resource

NodeB hardware resource

Iub transport resource

Cost

Extra delay caused by channel reconfigurations



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1.1 Improve CSSR and CDR





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Satisfy Perceived User ThroughputSatisfy Perceived User Throughput

Because of DCCC and link adaptation, BW is not fixed and

sometime not equal to the required max bit rates. In order to

increase perceived UDT, network selects an appropriate

transport channel and allocates appropriate BW according to

traffic volume test report.

Threshold

Transport Channel Traffic Volume

Reporting event 4A

Time

Reporting event 4A



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Test MethodsTest Methods

1.1 Test Tools1.1 Test Tools

1.2 Test Overview

1.3 Traffic Model

1.4 Test

1.5 Data Analysis



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Test ToolsTest Tools

Data collecting tool

Agilent E6455C

Agilent E6474A with WAMS (RNP and RNO Software)

Motorola A835

Post-processing tool

Actix Analyzer RVS



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WAMS ArchitectureWAMS Architecture



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WAMS SequencerWAMS Sequencer



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1.2 Test Overview

1.3 Traffic Model

1.4 Test

1.5 Data Analysis



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Test OverviewTest Overview



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1.2 Test Overview

1.3 Traffic Model

1.4 Test

1.5 Data Analysis



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Traffic ModelTraffic Model

WAMS test capabilities include such as E-mail, SMS, WAP, HTTP,

PING and FTP, e.g. HTTP example below.



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Traffic Model – HTTP ExampleTraffic Model – HTTP Example



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1.2 Test Overview

1.3 Traffic Model

1.4 Test

1.5 Data Analysis



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TestTest



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1.2 Test Overview

1.3 Traffic Model

1.4 Test

1.5 Data Analysis



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Data AnalysisData Analysis



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W(Level3) WCDMA RNO PS Optimization 20041217 a 1[1].0

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