UMTS Radio Network Optimization Proposal(for New Network)_R1.0

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UMTS Radio Network

Optimization ProposalR1.0

(For xxx new network)


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UMTS Radio Network Optimization Proposal

ZTE Confidential Proprietary 2014 ZTE CORPORATION. All rights reserved. I

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ZTE Confidential Proprietary 2014 ZTE CORPORATION. All rights reserved. II

Revision History

Product Version Document Version Serial Number Reason for Revision

1.0 First published

Author

DateDocument

VersionPrepared by Reviewed by Approved by

2011-11-30 1.0 Mawei


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ZTE Confidential Proprietary 2014 ZTE CORPORATION. All rights reserved. IV

About This Document

Summary

Chapter Description

1 Introduction Introduction

2 Scope Scope

3 RF Design RNC/LAC/RAC/SAC and scrambling code/neighbor cellplanning

4 Optimization Process Optimization Process

5 Optimization definition fordifferent network implementationphases

Optimization definition for different network implementationphases

6 Organization Structure Organization Structure

7 Optimization Analysis Method Optimization Analysis Method

8 Optimization and diagnostics

tools

Optimization and diagnostics tools


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ZTE Confidential Proprietary 2014 ZTE CORPORATION. All rights reserved. V

TABLE OF CONTENTS

1

Introduction..................................................................................................... 1

2

Scope............................................................................................................... 1

3

RF Design ........................................................................................................ 2

3.1

RNC Planning ................................................................................................... 2

3.2

LAC/RAC planning............................................................................................ 3

3.3 SAC Planning ................................................................................................... 33.4

Scrambling code planning................................................................................. 4

3.5

Neighbor Cell Planning ..................................................................................... 6

4

Optimization Process ..................................................................................... 8

5

Optimization definition for different network implementation phases........ 9

5.1

Pre-launch Optimization ................................................................................... 9

5.1.1

Single Site Verification (SSV) ........................................................................... 9

5.1.2

Cluster Optimization ....................................................................................... 10

5.1.3

Whole Network Optimization ........................................................................... 13

5.2

Soft Launch (Trial-Running Period) Optimization ............................................ 14

5.3

Post Launch Optimization ............................................................................... 15

6

Organization Structure ................................................................................. 15

7 Optimization Analysis Method ..................................................................... 16

7.1

Optimization Target and Description ............................................................... 167.2

Optimization Based On Driver Test/Walk Test Data ........................................ 18

7.2.1

RF coverage optimization ............................................................................... 18

7.2.2

Call Failure Analysis ....................................................................................... 19

7.2.3

Call Drop Analysis .......................................................................................... 23

7.2.4

Handover Failure Analysis .............................................................................. 25

7.2.5

High Access Latency ...................................................................................... 25

7.2.6

Low Data Throughput ..................................................................................... 26

7.3

Optimization Based On OMC Performance Data ............................................ 27

7.3.1

Overall optimization process ........................................................................... 27

7.3.2

Call Setup Success Rate Optimization............................................................ 30

7.3.3 Call Drop Rate Optimization ........................................................................... 31

7.4

Optimization in Network Operational Phase .................................................... 32

7.4.1

Traffic and RTWP (Received Total Wideband Power) monitoring ................... 32

7.4.2

Code resource utilization monitoring ............................................................... 32

7.4.3

Transmission utilization rate and RLC retransmission rate monitoring ............ 33

7.4.4

Neighbour Cell Optimizaiton ........................................................................... 33

7.5

Optimization Based On Capacity .................................................................... 33

7.6

Optimization for VIP needs ............................................................................. 35

8

Optimization and diagnostics tools ............................................................. 35

8.1

Drive test and Analyzing tool .......................................................................... 35

8.2

ZXPOS-CNO .................................................................................................. 44

8.3

Detected set neighbor report analysis ............................................................. 47


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ZTE Confidential Proprietary 2014 ZTE CORPORATION. All rights reserved. VI

8.4

Signaling trace ................................................................................................ 49


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ZTE Confidential Proprietary 2014 ZTE CORPORATION. All rights reserved. VII

FIGURES

Figure 3-1 Illustration of Neighbor Cell Planning .................................................................. 7

Figure 4-1 Optimization Milestone ........................................................................................ 8

Figure 5-1 Cluster Optimization Work Process ................................................................... 11

Figure 5-2 Cluster definition ............................................................................................... 12

Figure 6-1 Optimization Organization Structure .................................................................. 16

Figure 7-1 RF optimization based on coverage .................................................................. 18

Figure 7-2 Call Failure Analysis Process ............................................................................ 20

Figure 7-3 Paging Problem Troubleshooting Process ........................................................ 21

Figure 7-4 RRC Connection Setup Problem Troubleshooting Process ............................... 22

Figure 7-5 Overall optimization process ............................................................................. 30

Figure 7-6 Call Setup Success Rate Analysis .................................................................... 31

Figure 7-7 Optimization Based On Capacity ....................................................................... 34

TABLES

Table 3-1 RNC division results ............................................................................................. 2

Table 5-1 Single Site Verification ......................................................................................... 9


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ZTE Confidential Proprietary 2014 ZTE CORPORATION. All rights reserved. 1

1 Introduction

The purpose of this document is to present the solution of UMTS radio network

optimization of ZTE for the Operator in 20xx, and make certain guidelines for the

activities involved in UMTS radio network optimization.

Network optimization is to verify whether the network design, installation, integration and

the corresponding network configuration have been implemented correctly, and whether

the implemented design is consistent with the planning. Through optimization, the

network performance will meet the operators requirement.

The core problems involved in optimization are input and output definition, resource

planning and working schedule as well as work process definition, the tools andmethodologies used in the optimization tasks.

During each stage of radio network optimization, related project staffs should check this

document for information like working scopes, plans, principles, procedures, tools,

resources and suggested troubleshooting methods, so that coordinated working results

can be expected.

Notes: Currently, because this document is still under developing, the following is only for

reference. In the project, the engineers should make some content adjustments according to the

actual project conditions.

2 Scope

From view point of project management and technical problems solving, this document

describes how important UMTS RF parameters are designed and how radio network

optimization tasks should be performed in different stages of targeted project. Topics are

merely concentrated on some important RF parameters planning and optimization

activities, coverage and capacity planning related work and acceptance test related

details are not included. Also, optimization works not related to RAN part of network are

not covered.

RNC/LAC/RAC/SAC planning

Scrambling code/Neighbor cell planning

Optimization process

Optimization analysis method

Resource for optimization

Optimization and diagnostics tools


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3 RF Design

RNC/LAC/RAC/SAC planning, scrambling code planning and neighbor cell planning will

be introduced in this section, but coverage and capacity planning related work are notincluded.

Notes: In the project, the detailed RNC/LAC/RAC/SAC design and scrambling code/

neighbor cell planning should be carried out based on actual network information.

3.1 RNC Planning

The principles of RNC planning are as follows:

The NodeBs managed by one RNC are geographically centralized to avoidgeographically overlapping with NodeBs managed by other RNCs, thus reducing the

number of unnecessary cross-RNC handovers.

Avoid planning the border area between RNCs in densely populated areas or along

highways.

When performing RNC border planning, avoid deploying RNC border along traffic

arteries including highways and railways so as to prevent ping-pong handover

between RNCs due to the movement of UEs. Furthermore, inter-RNC handovers are

hard handovers or cross-lur soft handovers with success rate lower than that of

intra-RNC soft handovers. Therefore, avoid deploying RNC border in denselypopulated areas so as to decrease inter-RNC handovers and reduce the signaling

load arising thereof.

It is recommended that RNC and the switching office are co-located so as to simplify

lu interface connection.

As for the RNC coverage planning, the factors that need to be taken into account

include the number of NodeBs and cells supported by RNC as well as the CS traffic,

PS traffic and signaling handling capability.

According to above principles and RNC dimensioning analysis, RNC division results ofthe operator network are as follows:

Table 3-1 RNC division results

RNC ID LocationNumber of

NodeBsNumber of Cells


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3.2 LAC/RAC planning

The Location Area Code (LAC) and Router Area Code (RAC) are two parameters used to

indicate UE paging location. The LAC is a part of the LAI (LAI = MCC + MNC + LAC). The

paging request of the CS domain is sent through the LAI. The RAC is a part of the RAI

(RAI = PLMN-ID + LAC + RAC). The paging request of the PS domain is sent through the

RAI. The numbering rules of RAI show that the RACs are numbered within the LAC.

Therefore, an LAC may contain several RACs and an RA cannot span more than one LA.

The principles of LAC/RAC planning are as follows:

The LAC/RAC cannot be too large.

When a UE is paged, CN will send a paging request to all UEs in the area in relation

to the LAC/RAC through RNC. One LAC/RAC may contain scores and even

hundreds of cells, thus resulting in incredibly high paging traffic to RNC. NodeB has

to send the paging request to UEs on a limited number of PCHs. Therefore, large

LAC/RAC may result in NodeB paging overload and eventually the signaling

congestion and loss of paging information.

The LAC/RAC cannot be too small.

If on the other hand, the LAC/RAC is too small, there will be a large number of

LAC/RAC borders and UEs on these borders are very prone to frequent LA/RA

update between LAs/RAs. When there is a paging message incoming to a UE which

happens to quickly move to another LA/RA and initiates the LA/RA update

procedure, the UE will not receive the paging message sent to the original LA/RA,

thus resulting in call connection failure.

It is recommended to plan the LAC/RAC border in areas with low user mobility and

small traffic.

When performing LAC/RAC border planning, avoid deploying LAC/RAC border

along traffic arteries including highways and railways so as to prevent ping-pong

LAC/RAC update due to the movement of UEs. On the other hand, avoid planning

the LAC/RAC border in densely populated areas due to the huge number of location

updates on the LAC/RAC border so as to reduce the signaling load arising thereof

3.3 SAC Planning

1. SAC definition for the 3G network


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SAC is Service Area Code, the only identification used to one cell or more than one cell

belonging to the same LAC. SACs main purpose is to designate UE to CN.

Generally one cell can have one or two SACs. One, called SACPC, is belonging to SAC

for both PS and CS domain. The other SAC, called SACBC, is belonging to BC domain.

Each cell must have one SACPC for PS and CS domain.

2. SAC planning principle for the network

Related SAC parameters have SACPC, SACB and SACCPre, Each parameter planning

principle is shown below:

SACPC:

SAC is Serving Area Code, uniquely identifies one cell or several cells in one location

area. It is used to locate UE for CN.

One cell has one or two SAC, one belongs to CS +PS domain, and another belongs to

BC domain. One cell has to own one SAC belongs to CS +PS domain, which is SACPC.

The value of cells serving area code belongs to CS+PS domain is corresponding to

RAC.

SACB

SACB is Serving Area Code belong to BC domain; its default value is 0.

SACBPre: (Service Area Code for BC Domain, current configuration is 0)

SACB Configuration Tag represents whether SACB is configured; its present default

value is 0.

3.4 Scrambling code planning

Downlink scrambling code planning is a process of distributing 512 groups of primary

scrambling codes to various cells. Several rules need to be followed during scrambling

code planning:

1 Reserve sufficient distances for geographical isolation of PSC reuse sites during thereuse of the same scrambling code.

The isolation distance required for scrambling code reuse is relevant to the radio

environment, and it is used to ensure that the identical scrambling code signal will

not be received at the same place and thus to prevent scrambling code confusion.

The longer the scrambling code reuse distance, the smaller the scrambling code

confusion probability, but the scrambling codes may be insufficient for distribution.

On the contrary, the shorter the scrambling code reuse distance, the greater the

scrambling code confusion probability, but the scrambling codes are sufficient for


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distribution. The scrambling code reuse distance can be determined based on your

experience or onsite test result.

2 The same scrambling code shall not be distributed to the primary cell and the

neighbor cell of one of the primary cells neighbor cells.

For instance, assume that A is a primary cell, B is a neighbor cell of A, and C is a

neighbor cell of B (C is known as the L2 neighbor cell), then A and C must not be

distributed with the same scrambling code; otherwise, two cells with the same

scrambling code will appear in the neighbor cell list of B, and the scrambling code

will be mixed up during the handover from B to A or C, which will affect the handover

success rate and service quality.

For another instance, assume that A and B are neighbor cells and they both stay in

an active set, C is another neighbor cell of A, and D is another neighbor of B, then C

and D must not be distributed with the same scrambling code. When both A and Bstay in the same active set, the neighbor cell of A and that of B will be merged to

form a new neighbor cell list to be distributed to UEs. In this case, C and D will

probably be merged into the same neighbor cell list. If C and D have the same

scrambling code, their scrambling code will be mixed up during the handover from A

or B to C or D, which will affect the handover success rate and service quality. Here,

C is known as the L3 neighbor cell of B, and D is known as the L3 neighbor cell of A.

Considering the two cases above, try to void using the same scrambling code in L2

and L3 neighbor cells, especially not in those cells within a certain range (e.g. the L2

and L3 neighbor cells within a radius of 20km from the primary cell) during

scrambling code planning; otherwise, the scrambling code may easily get mixed up

during handover decision.

Note: The detection of scrambling codes of neighbor cells is implemented through

the CNO developed by ZTE. At present, ZTE follows the scrambling code planning

procedure below:

i Perform scrambling code planning by using CNO. Take into account the reusedistance instead of neighbor cell relationship during planning.

ii Check planning results by using CNO based on the neighbor cell relationship orthe reuse distance. For details, see the description of scrambling optimizationfunction of CNO in Section 8.2.

3 The cells with different carriers in the same sector can be configured with identicalscrambling code in order to simplify the scrambling code planning and optimization.

The UMTS scrambling code planning of the operator is carried out by using CNO

practically, a scrambling code planning tool developed by ZTE. For details, see the

description of scrambling optimization function of CNO in Section 8.2.


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3.5 Neighbor Cell Planning

1. Intra-system neighbor cell planning

Principle of neighbor cell planning mainly includes neighbor cell number, geographic

topological structure, coverage interference, etc.

Because the maximum number of neighbor cell list within a system is regulated as 31 in

protocol, neighbor cell lists will be combined in soft handover status; we need to control

neighbor cell number in configuration and try to minimize it as much as possible in the

precondition of insuring the successful handover.

Whether neighbor cell configuration is reasonable impacts handover between sites; the

initial neighbor cell list formed in system design phase is set according to the following

mode, then neighbor cell list will be adjusted according to handover times after the

system is commissioned.

Cells of one same site have to be set as each others neighbor cell; the first layer and the

second layer cells can be chosen as the present cell s neighbor cell according to present

cells coverage (shown in the following figure). The second layer cells on the same

direction of the present sector are set as its neighbor cells, the first layer cells on the

opposite direction of the present sector are also set as its neighbor cells.

The following is an example of neighbor cell setting shown in the following figure.

The red one is the present cell whose scrambling codes are set as 4, 8 and 12; those

cells formed in boldfaced broken lines are present sectors neighbor cells. Pink ones are

the first layer cells; blue ones are the second layer cells.


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neighbor cell configuration method in UMTS system, but the situation of neighbor cell

traffic congestion shall also be considered at the same time.

For the interoperation between 2G and 3G system, besides configuring GSM cell

information in UMTS system, UMTS cell information and neighbor cell information should

also be configured in GSM system that requires cooperation with GSM equipment vendor.

Provided parameters vary with vendors

3. Inter-RNC Neighbor Cell Planning

Inter-RNC handover is hard handover; besides neighbor cell needs to be configured,

corresponding cell information should also be configured.

The UMTS neighbor cell planning of the operator is carried out by using CNO practically,

a neighbor cell planning tool developed by ZTE. For details, see the description of

scrambling optimization function of CNO in Section 8.2.

4 Optimization Process

Radio network optimization consists of three major stages generally: Pre-Launch

Optimization, Soft Launch Optimization (optional) and Post Launch Optimization.

Figure 4-1 Optimization Milestone

Network Construction

Network Design

Soft Launch Optimization

Pre-Launch Optimization

Site Survey & Planning

Whole Network Optimization

Single Site Verification

Cluster Optimization

Installation & Commissioning & Test

Network Soft Launch

Start End

Post Launch

Optimization

Network Commercial

Network Design Commissioning PAC FAC

1. Pre-Launch: The main objective of Pre-Launch Optimization is to control RF network

air interference, assure network hardware functionality work normally, and ensure the

KPI target of Preliminary Acceptance Test is achieved. Pre-Launch Optimization

inludes following three steps:

Single Site Verification

Cluster Optimization

Whole Network Optimization

2. Soft Launch (optional): There could be a several months trial period from the date of

issuing PAC. The optimization in this period is named as Soft Launch Optimization.


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The objective of Soft Launch Optimization is to assure that no Punch List items exists

in the System. The Punch List is the list that consists of all defects identified during

the respective Preliminary Acceptance Test, during the period prior to Final

Acceptance. When all items on the respective Punch List have been resolved in the

System, a Final Acceptance Certificate will be issued.

3. Post Launch: The optimizaiton after issuing FAC is named as Post Lauch

Optimization. The network can be put into commercial servies after FAC. The

objective of Post Lauch Optimization is to assure the network performance

stabilization when subscribes are increasing. Post Lauch Optimization focus on

customer experiences, system load, capcity balance, resource utilization, etc.

5 Optimization definition for different

network implementation phases

5.1 Pre-launch Optimization

5.1.1 Single Site Verification (SSV)

The goal of SSV is to eliminate potential errors introduced during the site construction

and configuration, so as to lay a reasonable basis for the following RF optimization, for it

will be time-consuming to find out causes of unexpected results during optimization.

Normally, functional requirements are the main concerns during the SSV; service

performance of the single site is not strictly required.

The check items involved in the SSV can be classified into several categories, such as

equipment-related problems, engineering-related problems, and configuration-related

problems. Typical problems are presented in the following table. These problems should

be solved before the service-related SSV test, which involves the coverage test, voice

call, video call, PS R99 download, HSDPA download specifically.

Table 5-1 Single Site Verification

Equipment-related Engineering-related Configuration-related


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Abnormal power alarm

PA alarm

Transmission broken

Board-related alarmsInternal/external linkalarms

Antenna VSWR alarm

Abnormal RTWP alarm

Clock source/GPS alarm

Cell/Node B down alarm

SW version alarm

Swap feeder

Loose connection of

connectorsUnreasonable antennaposition

Signal obstacle bybuildings

Wrong antenna tilt andazimuth

Frequency

Scrambling code

LAC/RACCPICH power

Cell capability

Cell status

Transmission bandwidth

CE configuration

Above mentioned problems are to be solved by corresponding technical staffs. Most

equipment-related problems are to be solved by RNS engineers; engineering- related

problems by RF optimization engineers and installation engineers together;

configuration-related problems by RF optimization engineers and OMC engineers. After

site verification, obvious problems that can make the site incapable of being put on air

should be eliminated.

The SSV process is mainly based on the stationary check and drive test (DT). The former

means performing desktop check on items according to configuration data, or walking

around the site using test terminals. Following items are needed for the stationary check:

Technical Site Survey (TSS) report

Planned Engineering Parameters

Planned Radio Parameters

Site Configuration Parameters.

These materials are also used in the DT verification of the site.

The SSV report is the main output of this step. Besides, SSV engineers will propose

suggestions for adjusting the site.

5.1.2 Cluster Optimization

Cluster optimization mainly involves the coverage optimization, neighbor cell optimization,

scrambling code optimization and solutions to service access failure, call drop, and

handover failure, etc. Data collected from the DT and stationary test will be analyzed to

locate problems, optimize the network and verify the adjusted schema. It is an iterative

process to achieve cluster acceptance standards.

The cluster optimization work flow is as follows:


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Figure 5-2 Cluster definition

2. Cluster Optimization Test Schedule

Generally if the ratio of on-air NodeB of one cluster is over 80%, the cluster can be

optimized. The clusters can be optimized according to priorities. After the optimization

suggestion is adopted, a new test schedule will be made to justify if it is effective.

3. Testing Route Planning

Before cluster optimization, it is necessary to define the testing route. Continuous

coverage is required along the testing route if not all of sites are on air.

4. Network Parameters Checking

Before the cluster optimization, system parameters, such as NodeB ID, Cell ID, LAC,

RAC, Scrambling codes, and Neighbor cell list, should be imported into the OMC.

5. Optimization Method Definition

There are two optimization methods. One is RF parameters adjustment, such as antennaazimuth, down tilt, and height. The other is radio parameters adjustment, such as channel

power allocation and handover parameters etc.

6. Document Preparation

Following documents need to be prepared before the cluster optimization:

Technical Site Survey report (TSS)

Single Site Verification report (SSV)


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Site Engineering Parameters Table

OMC Configuration Parameters

7. Optimization Equipments Preparation

Optimization equipment includes data collection software, post-processing and analysis

software, test mobile phone, HSPA data card, Scanner, Test laptop, digital map, GPS,

and Test vehicles.

5.1.3 Whole Network Optimization

The whole network optimization, based on the cluster optimization, follows the same

work flow as the cluster optimization. At this phase, optimization is first carried out in the

area including several clusters, then in a RNC area, and at last in the whole network. The

goal of whole network optimization is to verify the functionality of the future commercial

network operation, such as the cell camping, cell reselection, and handover between

different network layers.

Main tasks of the whole network optimization include:

Locating network problems which are not solved at the cluster optimization stage

Solving new problems

Making sure that the network offers continuous service by optimizing the boundary

of clusters

Optimizing the hard handover

Ensuring KPI acceptance level

The whole network optimization is related to the system commercial strategy. After

optimization, the network should be ready for commercial launch in terms of both function

and performance. Every new commissioning site should be integrated into the cluster

after optimization without degrading the overall performance.

The input required for the whole network optimization is listed below:

System commercial strategy description

Neighbor list configuration

Radio parameters configuration

TSS report and SSV report

Cluster optimization report


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Test equipment used for the whole network optimization is the same as that for the

cluster optimization.

5.2 Soft Launch (Trial-Running Period) Optimization

When network construction and Pre-Launch optimization work are finished, the network

can be put into a Soft Launch phase, which means friendly users with special access

right can begin to use services provided by network and generate useful feedback for the

enhancement of network performance. The goal of Soft Launch optimization is to further

optimize the whole network in order to provide a continuous service experience in the

majority of desired coverage area and assure that no Punch List items exists in the

System. If any problems are detected in the Soft Launch optimization phase, they should

be solved and checked thoroughly in the whole network. These problems might cover

diverse areas such as the CN, RNC, NodeB, transmission, UE, etc. Improving the relatedKPIs to be commercial launch ready is the main purpose.

The main target in Soft Launch Optimization stage is focused on coverage, neighbors,

RRM parameters, and border area of clusters. Neighbours optimization mainly includes

missing neighbour, unidirectional neighbour, inter-frequency neighbour, and inter-RAT

neighbour. Handover related parameters should be optimized as well. Other RRM

parameters such as access control, power configuration, load control, etc., should also

be tuned selectively to meet the traffic requirements.

The Soft Launch optimization is normally based on both drive test and friendly user

feedback. As a supplementary data source, the signaling tracing is needed to helptroubleshooting some inner system problems. Passive signaling monitoring equipments

like Iu signaling tracing system can be used too, which might also be helpful when drilling

down the identified problems.

Although there is not much traffic statistics from trial users at this stage, the KPI report

generated from the Soft Launched network is still helpful for problem analysis. At the

same time, some optimization assistant tools, helpful at the early phase of the

commercial network, based on OMC statistics, can also be used. For example, the

systems missing neighbor detecting function can be used to help optimize the wide

intra-frequency neighbor list.

The output of Soft Launch optimization is the performance optimization report for the

whole network, and the complete set of tuned parameters for the forthcoming commercial

launch. These parameters, which are to be further optimized in a dynamic process, serve

as a good baseline for future improvement of the system performance.

Note:


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Based on the different launch strategy from different custmer in the future, if immediately,

cluster or whole network is launched after PAC, Pre-Launch optimization and Soft Launch

optimization should be combined to finish together during Pre-Launch optimization.

5.3 Post Launch Optimization

Post Launch Optimization belongs to operation and maintenance optimization.The target

in this phase is both the coverage and system performance from OMC statistics.

Normally, after large subscribers register, the optimization goal is straight forward, that is,

to keep stable and satisfactory end to end system performance, and enhance the system

KPI. The daily KPIs from OMC statistics should be monitored and optimized to designed

level.

As the main input for this optimization stage, OMC statistics and customer complaints aregiven higher priority than the drive test and walk test data, for after the commercial launch,

the traffic data of the network is enough for providing detailed statistics on each KPI. The

end to end performance monitoring result also matters at this stage. For example, it is

conducive to problem drilling down, troubleshooting, KPI comparison, and cell traffic load.

The optimization process at this stage is mainly driven by KPI analysis result. For

selected KPIs, daily analysis is made to keep up-to-date view on the dynamically

changing network performance. If any problems are identified and classified into specific

domains, corresponding teams from different domains are responsible for the

troubleshooting work, and make possible testing, adjustments and verifications until the

problematic KPIs fall into the acceptable level again.

The output at this optimization stage includes daily and weekly KPI reports, as well as

monthly performance test reports based on the drive test data. Typical or critical

troubleshooting reports generated at this stage are documented, too.

6 Organization Structure

The network optimization team will be divided into 3 functional roles:

1. SSV engineers The key role of these engineers are to conduct SSV field test

according to predefined test schdeles, and analyzing of test files.

2. Cluster&network optimization test engineersThe key role of these engineers are to

conduct cluster&network DT test and perform post processed data analysis of drive

test data, identify network optimization solutions such as parameter neighbor list

changes, document such changes, monitor cluster improve throughout the

optimization process and generate reports.

3. Experts support engineers These engineers are mainly ZTE RNC, NodeB R&D

staffs. The key responsibility is to assists post processing and analysis engineers to

troubleshoot hardware/software related issues, core network and transmission


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issues. There are also key resources to identify network wide parameter changes

required during the optimization process.

Figure 6-1 Optimization Organization Structure

Optimization

PM

P&O Experts

Cluster & Network

Optimization TeamSSV Team

ExPerts Team

Analysis Engineer

Analysis Engineer

Analysis Engineer

Field Test Engineer

Field Test Engineer

Field Test Engineer

Analysis Engineer

Analysis Engineer

Analysis Engineer

Drive Test Engineer

Drive Test Engineer

Drive Test Engineer

RNS Experts

R&D Experts

Tools ExpertsSSV Team 1 SSV Team 2 SSV Team 3 Cluster & Network

Optimization Team 1

Cluster & Network

Optimization Team 2

Cluster & Network

Optimization Team 3

Notes: In the project, the detailed optimization resource and organization structure should

be decided based on actual project conditions.

7 Optimization Analysis Method

7.1 Optimization Target and Description

During different phases of network optimization, the emphasized optimization targets

might be a little different. Some target items need iterative tuning to become stable, while

some are not so frequently tuned. Some adjustments come with costs on time and

money, while others are easy to be implemented. Main optimization targets and their

descriptions are listed as follows.

1) Network hardware / software / configuration faults

When there are some major releases of network hardware or software, and the new

version can bring more features or more stable network performance, and then upgrade

of network is needed, this is some special kind of network optimization choice. Normally,

more common optimization activities related to the software and hardware are

configuration faults checking. When there are critical configuration errors, the network

performance would be unacceptable, even network down can be seen. Sometimes

configuration faults might cause a hidden problem only when the network develops to a

certain stage, for example, the configuration of transmission and CE wont be bottleneck

until the traffic increase to certain degree. This kind of configuration problem needs to be

analyzed proactively. This can be achieved by correlating monitoring performance KPIs


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such as Traffic (Erlang number of Call setup per RAB, Total Data throughput, Total

TxPower per cell, and CE usage) with NodeB CE and transmission configurations.

2) Radio parameters

Radio parameters cover nearly every aspect of the whole system, and they are

commonly used to fine tune the network performance, especially for those RRM related

radio parameters. Typical parameters include the channel power allocation parameters,

the handover parameters, the access control parameters, the load control/congestion

control/load sharing parameters, and so on. Please refer to RAN Feature Description for

details on parameters.

3) Default parameter values

From a statistical point of view, although there are many parameters can be changed,

practically only a small part of them are frequently modified others are regarded as

baseline parameters that have been optimized before the release of system hardware or

software. But for special purposes and scenarios, they can be modified anyway. These

half-fixed parameters are default ones, and their modification needs extensive

experiments to prove the validity of the change. Once the change proposal is accepted, it

is implemented in the baseline parameter set.

4) Site / Case specific parameter settings such as neighbor cell relationships, HO

parameters and power settings

These parameters are emphasized during the cluster optimization stage and they are

often performed together with RF adjustments. Traditionally these optimization targets

are most time-consuming part of the whole process, because its hard to have unified

parameter settings for all the sites, especially for the neighbor relationship optimization.

With the help of CNO/CNA, some analysis process will be automated, e.g., the detected

set neighbor reporting can help to find missing neighbors for each cell.

5) Antenna orientation ( in case of shared antennas, should take into account the effect

on other networks sharing the same antenna )

RF related adjustments play important role in the whole optimization work, because they

are proved to be the most effective way to complement the deficiency of network

planning and implement a good coverage basis for the network. All optimization work

related with radio parameters should base on a good coverage, or else the tuning can

hardly get a satisfactory result. Here good coverage means not only the signal strength

and Ec/Io, but network interference level in terms of pilot pollution, overshooting, etc.

Antenna related tuning are key parts of RF optimization, including antenna type, azimuth,

down tilt, even antenna height when possible. When the antenna system is shared by

multiple operators or radio systems, the influence of tuning to other system should be

carefully considered. With antenna types that down tilt can be tuned standalone, the

influence is negligible, but for antenna azimuth, the tuning can influent all combined


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system, so this work should be perform carefully. Normally, several round of drive test is

required to confirm the suitability of such changes.

6) Sectorization

sectorization may be one of the solutions when system traffic become a limiting factor of

network performance, and its related problems include neighbor list re-optimization, RF

retuning, power adjustments, radio parameters modification, etc. This should be a

progressive process to guarantee the stability of network.

7.2 Optimization Based On Driver Test/Walk TestData

7.2.1 RF coverage optimization

The optimization based on coverage process is shown in the following figure.

Figure 7-1 RF optimization based on coverage

RF Optimization

Finish

Meet Coverage

Requirement

Add Sites and RF

Optimization

Meet Coverage

Requirement

N

Poor Coverage

Y

N

Y

Scanner measurement data are mainly used for RF coverage optimization. The purpose

of RF coverage optimization is to provide a good coverage and build a solid basis for

various services. CPICH RSCP and Ec/Io are the key index for coverage analysis. RF

coverage optimization focuses on poor coverage area, pilot pollution, overshooting,

interference, etc.

Typical solutions for RF adjustments are given below:


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Tune the antenna azimuth, down tilt, or CPICH power, which are the most frequently

used methods to eliminate pilot pollution, overshooting and related intra-frequency

interference. When possible, the antenna type and antenna height can be changed

too.

Check the radio environment to avoid signal shadowing, canyon effect, water land

effect, etc. When no change can be made on site selection, adopt RF adjustments or

parameter modifications to eliminate the influence of unideal site selection.

Find the weak coverage area and try to optimize by RF adjustments. If the weak

coverage area exists in shopping malls, tunnels, underground parking lands, subway

entrance, or high buildings, etc., the coverage can be enhance by adding indoor

coverage system.

Check the hardware problems, especially the power output of NodeB, make sure

that there is no cell shrink caused by PA problems.

7.2.2 Call Failure Analysis

The troubleshooting process for call failure is shown as below.


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Figure 7-2 Call Failure Analysis Process

Call Fail

Paging problem

RRC connection

setup problem

Authentication and

ciphering problem

RAB setup problem

Handover problem

Coverage OK?

Caller? Paging received?

RRC connection

setup failed

Authentication and

ciphering failed

RAB setup failed

End

Handover causedfailure

Yes

Yes

Yes

Yes

Yes

Yes

No

No

No

No

No

No

Abnormal problem

Yes

No

Enhance coverage

For paging related problem, check the following flow chart.


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Figure 7-3 Paging Problem Troubleshooting Process

Paging problem

RNC sent paging?

UE received

Paging

Power allocation

insufficient

Cell reselection

problem

Abnormal

equipment problem

Chang power

allocation for

AICH/PICH/PCH

Optimize reselection

problem

Abnormal problem

End

Yes

No

No

No

No

Yes

Yes

Yes

For RRC connection setup related problem, check the following figure.


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Figure 7-4 RRC Connection Setup Problem Troubleshooting Process

RRC setup problem

UE sent RRC

request?

RNC received RRCrequest?

RNC sent setup

message?

UE received setupmessage?

UE abnormal

problem

Congestion or other

problem

Adjust FACHparameters

End

Yes

No

No

No

No

Yes

Yes

Yes

UE sent setup

complete message?

RNC received setupcomplete message?

Adjust PRACHparameters

Cell reselection

Optimize cell

reselection

UE abnormal

problem

Adjust UL openloop power control

param eters

Yes

Yes

Yes

No

No

No

Typical reasons that will cause the call failure are:

Originate call in weak coverage area that the signaling process cannot complete;

Callee is originating location update that results in the failure of paging;

Cell reselection not quick enough such that the call cannot be originated in the best

cell;

Cell radius is not properly configured, and the UE cannot access network.

Corresponding solutions can be given below:

Make RF optimization to eliminate coverage hole, pilot pollution, overshooting, etc;

Optimize the location area border, so that location update happens less frequently

and at the areas with low traffic if possible;


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Change cell reselection parameters for only problematic cells, so that the UE can

select to the best cell quickly;

Change power allocation parameters for PICH/AICH/PCH/PRACH/FACH if needed,

and also the random access parameters can be modified;

Modify the cell radius so that it can match the desired coverage radius of the cell.

7.2.3 Call Drop Analysis

The call drop rate reflects the system sustainability for different services; its the most

important performance indicator that users can directly experience. Wider range call drop

rate definition should include both the CN and UTRAN call drop, in this section; radio

related call drops are emphasized. From high level point of view, most call drops are

caused by the following three types of radio problems, that is, coverage, handover, andinterference. They are described below, respectively.

7.2.3.1 Caused by coverage problems

According to optimization experience, the following coverage problems may lead to call

drops:

Serving cell has the overshooting problem due to either good propagation

environment, or high power settings, or high site. When UE moves to the area

covered by both overshooting cells and normal expected cells, UE might handover tothe overshooting cells, but after that cannot make any outgoing handover from the

overshooting cells due to absence of neighbor cells, which result in the call drop;

Overshooting caused invalid scrambling code reuse;

Canyon effect or water reflection effect leads to the overshooting of serving cell,

handover decision maybe affected and result in the call drop;

Due to the isolated island effect, the UE in the isolated cell can not make outgoing

handover;

Pilot pollution arise due to no significant dominant pilot can be found, the ping pong

handover might be observed during the call and result in the call drop;

Coverage holes exist at the intersected area of two adjacent cells, UE lost coverage

during the call;

Shadowing effect caused by high buildings, this leads to weak coverage area or

areas with rapid signal fluctuation.

Possible solutions are given below:


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Eliminate the drifting or overshooting signals. Check the down tilt or azimuth of

antenna, or reduce the pilot power to optimize the coverage area. Pay attention to

special coverage scenarios such as street coverage or water area coverage.

Find the weak coverage area and try to optimize by RF adjustments. If the weak

coverage area exists in shopping malls, tunnels, underground parking lands, subway

entrance, or high buildings, etc., the coverage can be enhance by adding indoor

coverage system.

Check the hardware problems, especially the power output of serving cell and

neighbor cells, make sure that there is no cell shrink caused by PA problems.

7.2.3.2 Caused by handover problems

According to optimization experience, the following handover problems may lead to call

drops:

Missing neighbor cells;

Hardware problems result in abnormal handover;

Illegal scrambling code reuse result in handover failure;

Isolated island problem result in handover failure

Handover target cell is overloaded and result in handover failure;

Source cell in seriously interfered in downlink or uplink and result in handover failure;

Handover parameters are not properly set, such as 1a/1b/1c/1f/2d/2b/2c/3c/3a

related parameters, which result in handover latency or call drop;

Ping Pong handover failure result in call drop;

Signal sudden drop in corner or shadowed area, which result in handover failure and

call drop.


Check neighbor list definition;

Check hardware faults, make sure theres no hardware alarm;

Check scrambling code planning;

Make RF adjustments to control interference in network;

Control cell load at stable level;


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Modify handover related radio parameters according to radio environments;

Control and eliminate the internal and external interference in network,

7.2.3.3 Caused by interference problem

According to optimization experience, the following interference problems may lead to

call drops:

Intra-frequency multiple access interference;

Interference casued by missing neighbor;

Interference caused by illegal scrambling code reuse;

Pilot pollution;

Other system interference;

Interference caused by microwave, satellite receiver, radar, TV receiver, etc.


Control cell load;

Check neighbor list definition to avoid missing neighbors;

Check scrambling code planning;

Make RF adjustments to control the overshooting;

Add space isolation or Tx/Rx filter to reduce interference from other systems.

7.2.4 Handover Failure Analysis

For handover failure problem analysis, please refer to the call drop analysis methods

described above.

7.2.5 High Access Latency

If the service access delay time is abnormal, it is commonly a system level problem, that

is to say, not only part of cells suffers from the latency problem, but most cells should be

affected. The delay time is related with both RAN and CN. In order to find out the limiting

factor, tests can be made to check the time consumed in each major signaling stage, and

figure out which contributes most to the access time. The test should be made in fixed

spot where the signal Ec and Ec/Io is good and only one cell is dominant cell, in order to


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avoid the influence of weak coverage or signal fluctuation on the access time

measurement.

Since the measurement needs end to end signaling timing, the signaling tracing system

should cover the whole process of service call.

Main configurations that will affect the access delay time are listed as follows:

Early assignment or later assignment in CN;

Authentication switch in CN;

Maximum FACH power allocation;

PICH/AICH/PCH power allocation;

RRC setup on FACH or DCH 13.6k or DCH 3.4k;

Random access power settings;

RRC retransmission timer and counter T300 and N300;

Using later assignment and turn off authentication from CN can reduce the access time.

Increase the values of power related parameters can reduce the access time too, but

they need to be fine tuned to avoid interference and influence on capacity. A normally

used policy is to adopt DCH 13.6k high speed SRB to reduce the signaling time, and then

reconfigure it to 3.4k after service is established.

7.2.6 Low Data Throughput

Data throughput for PS services is related with many factors, so its optimization needs to

check many possible problematic configurations and find out the major reasons for low

data throughput. The troubleshooting process involves nearly all network elements

including USIM, UE, NodeB, RNC, HLR, SGSN, GGSN, Transmission, even

inter-connected routers and switches or cables. Data collected from other interfaces in

addition to Uu interface is often needed, for example, the signaling tracing from RNC, the

data log from Node B, the transmission test, etc. According to optimization experience,

the following problems may lead to low data throughput, and corresponding suggestions

are presented for reference.

Equipment Alarm. Alarm checking is the first action to be taken when facing with

performance problems. For throughput problem, alarms should be checked for Node

B, RNC, SGSN, GGSN, LAN switch, router, clock abnormal, transmission error, and

other equipment alarms.

Radio environment. Data services have strict requirements on the signal strength,

purity and stability. Signal strength is easy to be checked, signal purity is reflected by

pilot pollution situation in network. If no dominant pilot can be found, there might be


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interference or ping pong handover, which in turn will make throughput drops. The

stability of signal will also directly map to stability of throughput, without continuous

good coverage, there throughput might drop due to dynamic rate control to adapt to

the changing of radio conditions. The solution is to make RF optimization to provide

good basis for PS services.

Configuration faults for hardware or software. The following miscellaneous factors

might be concerned during the troubleshooting process. 1) USIM rate allocation; 2)

Compatibility of UE or data card; 3) Capability of UE or data card; 4) Device drivers

for test notebooks and servers; 5) Firewall settings for test notebooks and servers; 6)

APN settings for test notebooks; 7) Server performance, TCP/IP settings, or service

platform software configurations for PDN or other servers; 8) SGSN/GGSN problems.

The correctness of related configurations should be confirmed.

The power allocation and code allocation strategy, along with scheduling strategy in

network. Normally for different application scenarios, there are default strategies

recommended, but due to concrete optimization requirements, they can be tuned

case by case.

The Uu interface block error rate, including both UL BLER, DL BLER and CQI, the

solution is to check the coverage of interference, and make RF adjustments.

The Iub interface transmission error, delay jitter, or bandwidth insufficiently

configured. These factors should be checked so that Iub is not the bottleneck.

Check the rate of application layer throughput over RLC layer throughput, if the

value is considerably lower, there might be heavy overhead result from unnecessary

TCP/IP retransmission. The solution is to modify the TCP receive window or MTU

packet size, or try adopting advanced TCP features such as TCP SACK, to improve

the performance for single TCP connection. Another alternative way is to use

multi-threaded download or upload test tools so that TCP window and other

parameters are not the limiting factors during throughput evaluating process.

7.3 Optimization Based On OMC Performance Data

7.3.1 Overall optimization process

When the network is commercial launched, the traffic is expected to increase gradually,

and statistics from OMC can provide more and more rich support for performance

monitoring and optimization.

From the KPI report some KPI degradations can be observed and analyzed. The basic

idea for analyze the problems is judging from RNC level to cell level, try to exclude

unrelated factors. Correlated analysis between different KPIs is important for the

troubleshooting. The RNC level KPIs are firstly examined to understand the overall

performance. If RNC level KPIs are abnormal, more detailed cell level checks should be


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made to see whether the problem is common in the whole network or specific to some

certain cells. TopN Cell level abnormal KPIs will also be checked. For common problems,

analysis shall be made on coverage, capacity, interference, transmission, software,

hardware, radio parameters; for specific cells, cell level statistics should be checked in

detail. What needs to be noticed is that, when analyzing KPIs that are presented in form

of percentage, the absolute counts should be checked at the same time, because the

percentage value sometimes may cover some potential problems. One case is that the

percentage value is not good, but the denominator and numerator are small, which

means the statistics is not based on large number of samples and are not reliable

temporarily. The other case is that the failure counter as numerator is large, but the total

samples as denominator is much larger, so the percentage value is good and problems

are easy to be ignored, this case should be avoided.

During the troubleshooting, pure OMC data is not sufficient, other needed data sources

include alarm data, drive test data, signaling tracing data, etc. For complicatedperformance problems, only through combined analysis can the trouble been solved. The

following figure shows the troubleshooting process base on OMC statistics.

First, the sudden and self recoverable problems due to holiday, weather, and so on are

identified by the engineers, and corresponding actions are taken to prevent similar

problems happen again in the future. For other problems, equipment alarms are checked

in the first step, to make sure that problems are not caused by major alarms. Next, the

low KPI are filtered out and presented on the map, at the same time, collect some

background information such as transmission configuration table, software and hardware

version, radio parameters configuration, etc., check whether those filtered cells have

some characteristics in common, if any, focus on the common points to make furtheranalysis. Typical check points are listed below:

1) Whether software or hardware version upgrading is made recently

2) CPU load and link utilization rate;

3) Transmission broken or transmission bit error rate too high

4) Whether uplink interference exists

5) Check radio parameters with stand default configurations

6) Whether problems happens in certain time only

7) Whether problems happen in certain area only

8) Whether problematic cells belongs to certain logic group

9) Which reason contributes most to the failure

10) Neighbor list checking

11) Whether there is site work conducted recently


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If no common points can be found for abnormal cells, or after the optimization there are

still unqualified cells, then analysis focused on single cell is made. Main KPIs to be

analyzed are typically call setup success rate, call drop rate, various handover success

rate, etc.

The whole analysis process can benefit from CNO, which make the statistics and query

of huge volume of performance data easier for engineers


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Figure 7-5 Overall optimization process

StartRetrieval of

performance

data Abnormal RNC

performance

index

Equipment

alarms exist?

Handling alarms

RNC performance

index recovered?

Common

features exist in

abnormal cells?

Transmission, SW/HW

configuration, radio parameters

settings.

CN/RNCTransmis

sionHW

SW

version

Interfer

ence

Radio

parameters

Time

span

Sudden, self-

recoverable

abnormal?

Causation

analysis and

record

Improvement

suggestion

Analysis of common

characteristics

Problem

solved?

Call

seup

Call

drop

Soft

handover

2/3G

interoperationPS rate

Related problems

solving

Performance

index OK?

End

Weatherfluctuation,

holiday,

congregation,

sudden

broken of

transmission,

power supply

fault, etc.

Y

N

Y

Y

N

Y

N

Abnormal performance index

analysis for single cell

Y

N

N

N

Y

N

Y

Abnormal cells TopN analysis

and visualization on map

7.3.2 Call Setup Success Rate Optimization

The main process for optimization of call setup success rate based on OMC performance

data is similar to the process based on drive test data, and the process is given below.


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Figure 7-6 Call Setup Success Rate Analysis

Traffic analysis

Alarm existHandle equipment

problems

End

Yes

No

Yes

Yes

Yes

No

Low paging success

rate?

Handle paging

problems

No

Low RRC setup

success rate?

Low RAB setup

success rate?

Low RB setup

success rate?

Handle RAB setup

problems

No

No

No

Yes Handle RRC

problems

Handle RB setup

problems

Using CNO the TopN cells with deteriorated certain KPI can be filtered out quickly. At the

same time, some other counters and information should be used such as the access

attempt counter, the CS traffic or PS throughput to help making a combined judgment.

Analysis can focus on each signaling phase one by one, including the RRC setup

process, the paging process, the RL setup process, the RB setup process, the

transmission setup process, the synchronization process, the admission control process,

etc. Importantly, the OMC can generate statistics on each failure reason counts, which

provides a very helpful hint for tracing the problem in a correct way.

When reasons for problematic cells are found, then actions can be taken for optimization.

Analysis methods are the same as optimization based on drive test data.

7.3.3 Call Drop Rate Optimization

For call drop rate optimization, firstly TopN cells are identified, and then most serious call

drop reasons are figured out for analysis. Except the commonly used check points, other

typical check points for optimization of call drop rate include:

If the failure signaling is UciuError or RL failure, and the failure reason is RLC

unrecoverable, then the call drop might due to poor coverage;


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Analyze the incoming and outgoing handover success rate for the cell, to check

whether the handover failure caused the call drop;

Analyze the uplink RTWP during the time span with high call drop rate, if the RTWP

level is not accord with cell traffic, there might be uplink interference which caused

the call drop.

Check code utilization rate, if the percentage is above threshold, the call drops in the

cell might be caused by code resources congestion.

When call drop reasons are roughly identified, drive test in the problematic cell is needed

to collect more data for combined analysis. Finally, suggested optimization solutions are

implemented to verify the validity of solutions.

7.4 Optimization in Network Operational Phase

In the operational phase of network, daily KPI monitoring is needed to keep system

performance at a stable level. This is actually a active optimization action intended to find

potential performance problems before they affect the user experience. Typical active

performance optimization is described below.

7.4.1 Traffic and RTWP (Received Total Wideband Power) monitoring

With the correlated analysis function offered by CNO, the relationship curve of call drop

rate versus traffic and RTWP versus traffic can be drawn and monitored. If any abnormal

relationship or trend is observed, the engineer can use the hint to drill down the problems.

For example, if traffic and call drop rate both grows, and they embody proportional

relationship, also the traffic grows beyond certain threshold, then capacity expansion

might be needed.

Another example, if RTWP and traffic both grows, but the RTWP rise is not proportional

to the traffic grow, there might be outer interference from other radio systems. When cell

is unloaded, the RTWP is among the value of -106dBm and -104dBm. Considering

maximum 75% uplink load, which corresponds to 6dB noise rise, the RTWP around

-100dBm to -98dBm is regarded as normal. If the maximum or average cell RTWP is notstably increasing, the cell should be checked.

7.4.2 Code resource utilization monitoring

The utilization rate of code resources is expected to be at a desired level, too high or too

low utilization rate is not good situation. Practically, sites at network borders have low

utilization rate, while sites in dense urban or hot spots have a higher rate, which should

be monitored with special emphasis, to avoid the network congestion due to spreading

code.


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Normally the code resources are allocated dynamically, if the code resource congestion

lasts for too long time, the traffic might be too much for the cell, and capacity expansion

should be considered.

7.4.3 Transmission utilization rate and RLC retransmission ratemonitoring

For PS services, the throughput is main goal of optimization. From OMC point of view,

the transmission utilization rate and RLC retransmission rate can both hint the problems

related with transmission part of network.

If the Iub interface bandwidth is not configured sufficiently, then with the increasing of

data traffic, the bandwidth might be used up quickly. By filtering out those cells with high

transmission utilization rate, engineer can easily identify which cells should be equipped

with more transmission resources.

Another problem related with transmission is the bit error rate which can affect the PS

performance. From RLC retransmission rate monitoring, the potential transmission

problem can be noticed by engineer, and active troubleshooting can be made.

7.4.4 Neighbour Cell Optimizaiton

CNO can make neighbor cell optimization in terms of adding, deleting and reordering, all

of these decisions are made based on the statistics on handovers and detected set

report.

After the sorting the existing neighbor cells according to happened handovers within

several days, the more frequently used handover target cells are assigned with higher

priority, and those neighbor cells with handover occurrence count less than a threshold

can be ranked as low priority neighbor cells, when possible, they can be even be deleted.

Those defined neighbor cells with zero handover occurrences can be safely deleted too.

In this way, the work effort needed in neighbor list optimization is cut down, and some

potential performance problems can be solved.

7.5 Optimization Based On Capacity

The optimization based on capacity process is shown in the following figure.


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Figure 7-7 Optimization Based On Capacity

Monitor CE or

Power

CE or Power

Constrain

Meet Capacity

Requirement

Finish

Add BPC Boards and

RF Optimization

RF

Optimization

Add Freqency and

RF Optimization

CE ConstrainPower Constrain

Meet Capacity

Requirement

NCell Split and RF

Optimization

Meet Capacity

Requirement

Add EBBUB and RF

Optimization

Meet Capacity

Requirement

Y

Y

N

Y

Meet CapacityRequirement

Y

Add Sites

Meet Capacity

Requirement

Y

N

N

N

N

Y


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7.6 Optimization for VIP needs

1. Define a VIP list

We define both VIP sites and VIP customers in order to handle their problem with high

priority.

2. Optimization for VIP SSV

For the SSV of VIP sites, we arrange special engineers take charge for it, and use stricter

criterion compared to normal sites when SSV. Unless all the test items have been passed,

then the VIP SSV is finished. Meanwhile, we do RF adjustment and other measures to

first ensure the coverage for VIP sites, so as to give better service for them.

3. Optimization for VIP customer complain

Higher priority will be given when a VIP customers complain happens and we will deal

with it in sooner time.

According to the specific complain content, if it is need to implement a work order to

change some parameters of sites, the parameter track record for VIP will be checked

firstly, Only if the changes are new for the record or current changes will not have

adverse effect on recorded changes, the work order can be performed and the parameter

track record for VIP should be updated again. Otherwise a compromise or alternative

solution needs to be sorted out first.

8 Optimization and diagnostics tools

In the following sections, tools to be used to collect, analyze and improve the

performance during the various stages of the project are described. These tools are

introduced based on the stages they are applied in. For each tool, its features, its

applicable problem domains, as well as its usage are described. And, it s necessary to

check calibration of equipment before use.

Notes: In the project, the detailed optimization tools should be decided based on actual

project conditions.

8.1 Drive test and Analyzing tool

The CNT/CNA will be used to collect process and analyze the drive-test measurements

and reports generation.

In this document, CNT/CNA will be explicitly described as these are ZTE developed

products and hence are deeply understood by ZTE engineers.


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CNT is professional test software of UMTS radio network. It collects data accurately,

including GPS locating data, UE diagnostic test data, as well as data in every layer (RLC,

MAC) in the data service, and displays these data in the format of Map, Table, Text, or

Graph etc.

CNA is professional analysis software of UMTS radio network optimization. It is based on

the drive-test data and other auxiliary data. It provides versatile intelligent analysis for

radio network, and accordingly performing network optimization quickly and highly

efficiently. It provides abundant and useful analysis parameters. For example: Rx Power,

Tx Power, Total Aggregate Ec/Io, Best Ec or Ec/Io distribution, Best PSC distribution,

specific PSCs Ec or Ec/Io distribution, pilot pollution, coverage rate, overshooting

diagnose, and so on. It provides powerful message analysis functions, supports the

thorough decoding of RRC and NAS message, and can assemble system information

blocks of segment transmission. Moreover, it supports browse, play, query and filter of

messages, the statistics function for basic and user-defined event, as well as versatiledelay analysis and KPI analysis function.

The CNT software has the following features:

It provides quick and accurate acquisition and record of data, including GPS location

data, UE diagnostic test data, as well as data in each layer (RLC, MAC) in the data

service.

It can support both indoor and outdoor test.

It provides real time display of all sorts of test data in the format of Map, Table, Text,

or Graph etc.

It supports automatic detection of GPS and scanners in all available ports, and

manual configuration of these parameters.

It provides document processing function, including processing of NodeB

information, electronic map, dial test route, test data, test plan, and project

workspace.

It provides display of scanner related parameters, including scanner related

scrambling code, synchronization channel, frequency spectrum analysis, peak value

power and channel power.

It provides display of GPS information, including GPS locating information and

satellite signal.

It provides elaborate real time acquisition and display of parameters, including view

of physical channel parameters of layer 1, transport channel of layer 2, and RLC

related parameters.

It provides powerful browse, real time decoding, filtering and sort display of layer 3

messages.


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It provides powerful geographic display function and binding of data layer and GIS

graphic layer, which realizes coverage display and statistics and acquires space

distribution property of parameters. Additionally, it has operational functions,

including zoom, move, comment, select, information display, and automatic or

manual offset, which can avoid overlapping of data graphic layers.

It provides powerful service test function, and supports automatic test plan of voice

service and data service, as well as customizing automatic test plan document.

It provides data playback function, including getting the recorded file while testing,

and redisplaying test procedure.

It provides powerful function of event alarm analysis, and customized alarm setting

of test parameter items.

The CNA software has the following features:

It provides abundant and useful analysis parameters. For example: Rx Power, Tx

Power, Total Aggregate Ec/Io, Best Ec or Ec/Io distribution, Best PSC distribution,

specific PSCs Ec or Ec/Io distribution, pilot pollution, coverage rate, overshooting

diagnose, and so on.

Its data analysis is based on dial test data, and is a comprehensive analysis

combining station information and GIS information.

It adopts various analysis methods based on geography, graphs and tables,

statically and dynamically.

It supports outdoor test data as well as indoor test data. The indoor geography

analysis can be performed with indoor maps.

It provides powerful geography analysis functions, and binding of data layer with GIS

graphic layer, which realizes coverage display and statistics, and acquires space

distribution property of parameters. Additionally, it has operational functions,

including zoom, move, comment, select, information display, and automatic or

manual offset, which can avoid overlapping of data graphic layers.

It provides powerful message analysis functions, supports the thorough decoding ofRRC and NAS message, and can assemble system information blocks of segment

transmission. Moreover, it supports browse, play, query and filter of messages, the

statistics function for basic and user-defined event, as well as versatile delay

analysis and KPI analysis function.

It provides powerful and professional pilot analytic and diagnostic functions, such as

coverage render of specific or all PSCs, pilot pollution analysis, neighbor list

analysis, and coverage rate analysis etc.

It provides flexible and customizable statistics and report functions.


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It provides convenient and flexible station information management, and supports

establishment, modification and exchange of station information.

It provides powerful query function based on analysis.

It provides versatile customized playback functions, and supports integral data play

and single point track

UMTS Radio Network Optimization Proposal(for New Network)_R1.0

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