Upload
marferbor
View
231
Download
3
Embed Size (px)
Citation preview
8/3/2019 BSS Radio Network Optimization Guidelines
1/58
HUAWEI BSC6000 Base Station Subsystem
V900R008
BSS Radio Network Opimization Guidelines
Issue 01
Date 2008-06-10
INTERNAL
Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
8/3/2019 BSS Radio Network Optimization Guidelines
2/58
Huawei Technologies Co., Ltd. provides customers with comprehensive technical support and service. For any
assistance, please contact our local office or company headquarters.
Huawei Technologies Co., Ltd.
Address: Huawei Industrial Base
Bantian, Longgang
Shenzhen 518129
People's Republic of China
Website: http://www.huawei.com
Email: [email protected]
Copyright Huawei Technologies Co., Ltd. 2008. All rights reserved.
No part of this document may be reproduced or transmitted in any form or by any means without prior written
consent of Huawei Technologies Co., Ltd.
Trademarks and Permissions
and other Huawei trademarks are the property of Huawei Technologies Co., Ltd.
All other trademarks and trade names mentioned in this document are the property of their respective holders.
Notice
The information in this document is subject to change without notice. Every effort has been made in the
preparation of this document to ensure accuracy of the contents, but the statements, information, and
recommendations in this document do not constitute a warranty of any kind, express or implied.
Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
http://www.huawei.com/mailto:[email protected]:[email protected]://www.huawei.com/8/3/2019 BSS Radio Network Optimization Guidelines
3/58
Contents
About This Document.....................................................................................................................1
1 Introduction to Radio Network Optimization.....................................................................1-1
1.1 Triggering Conditions of Radio Network Optimization.................................................................................1-2
1.2 Procedure of Radio Network Optimization.....................................................................................................1-2
2 Network Optimization Startup...............................................................................................2-1
2.1 Organization of Radio Network Optimization Team......................................................................................2-2
2.2 Determination of Optimization Acceptance Counters....................................................................................2-3
2.3 Preparations of Network Optimization Tools.................................................................................................2-3
3 Single Site Verification.............................................................................................................3-1
3.1 Preparations for Single Site Test.....................................................................................................................3-3
3.2 Single Site Test and Troubleshooting.............................................................................................................3-3
4 RF Optimization.........................................................................................................................4-1
4.1 Preparations for RF Optimization Test...........................................................................................................4-4
4.2 Collection of RF Optimization Data...............................................................................................................4-4
4.3 Analysis of RF Optimization Data..................................................................................................................4-4
4.3.1 Analysis of Coverage Problems.............................................................................................................4-5
4.3.2 Analysis of Interference Problems.........................................................................................................4-7
4.3.3 Analysis of Hardware Faults..................................................................................................................4-8
4.3.4 Analysis of End-To-End Network Elements Interoperation..................................................................4-8
4.4 Implementation of RF Optimization...............................................................................................................4-8
5 KPI Optimization.......................................................................................................................5-1
5.1 Collection of KPI Optimization Data..............................................................................................................5-3
5.2 Analysis of KPI Optimization Data................................................................................................................5-3
5.2.1 Analysis of Access Counter Optimization.............................................................................................5-4
5.2.2 Analysis of Congestion Counter Optimization......................................................................................5-4
5.2.3 Analysis of Handover Counter Optimization.........................................................................................5-6
5.2.4 Analysis of Call Drop Counter Optimization.........................................................................................5-7
5.3 Implementation of KPI Optimization..............................................................................................................5-8
6 Network Acceptance..................................................................................................................6-1
6.1 Main Counters of Network Acceptance..........................................................................................................6-2
6.1.1 Drive Test Counters...............................................................................................................................6-2
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines Contents
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
i
8/3/2019 BSS Radio Network Optimization Guidelines
4/58
6.1.2 Performance Measurement Counters.....................................................................................................6-3
6.2 Contents of the Network Acceptance Report..................................................................................................6-4
7 Network Optimization Tools...................................................................................................7-1
7.1 Probe................................................................................................................................................................7-27.2 TEMS..............................................................................................................................................................7-2
7.3 ANT Pilot for GSM.........................................................................................................................................7-3
7.4 Assistant..........................................................................................................................................................7-3
7.5 ANT for GSM.................................................................................................................................................7-5
7.6 Nastar..............................................................................................................................................................7-6
Contents
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines
ii Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
Issue 01 (2008-06-10)
8/3/2019 BSS Radio Network Optimization Guidelines
5/58
Figures
Figure 1-1 Procedure of network optimization....................................................................................................1-2
Figure 2-1 Organization of the radio network optimization team........................................................................2-2
Figure 3-1 Verification procedure of a single site................................................................................................3-2
Figure 4-1 Procedure of RF optimization.............................................................................................................4-2
Figure 5-1 Procedure of KPI optimization...........................................................................................................5-2
Figure 5-2 Call dropped due to oversized coverage.............................................................................................5-7
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines Figures
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
iii
8/3/2019 BSS Radio Network Optimization Guidelines
6/58
8/3/2019 BSS Radio Network Optimization Guidelines
7/58
Tables
Table 2-1 Network optimization tools............................................................................. .....................................2-3
Table 6-1 Drive test counters of the GSM network..............................................................................................6-2
Table 6-2 Performance counters of the GSM network.........................................................................................6-3
Table 7-1 Main functions of the Assistant............................................................................................................7-3
Table 7-2 Main functions of the Nastar................................................................................................................7-6
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines Tables
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
v
8/3/2019 BSS Radio Network Optimization Guidelines
8/58
8/3/2019 BSS Radio Network Optimization Guidelines
9/58
About This Document
Purpose
BSS radio network optimization refers to appropriately adjusting the planning results of the
mobile communications network so that the network can operate more economically andreliably. Through radio network optimization, the service quality and resource usage of the
network are greatly improved. This document consists six major topics, which are overview of
GBSS radio network optimization, network optimization startup, single site verification, RF
optimization, KPI optimization, and network acceptance.
Product Version
The following table lists the product version related to this document.
Product Name Product Model Product Version
BSC BSC6000 V900R008
Intended Audience
This document is intended for network optimization engineers.
Change History
For changes in the document, refer to Changes in BSS Radio Network Optimization
Guidelines.
Organization
1 Introduction to Radio Network Optimization
Radio network optimization refers to appropriately adjusting the planning results of the mobile
communications network so that the network can operate more economically and reliably.
Through radio network optimization, the service quality and resource usage of the network are
greatly improved, and the balance among coverage, capacity, and quality is achieved.
2 Network Optimization Startup
Network optimization startup consists of organizing the network optimization team, determiningthe acceptance counters, and arranging the network optimization tools.
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines About This Document
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
1
http://-/?-http://-/?-http://-/?-http://-/?-8/3/2019 BSS Radio Network Optimization Guidelines
10/58
3 Single Site Verification
Single site verification is a self-test associated with the equipment in each site and each cell. The
purpose of single site verification is to verify that the basic functions, such as access, call, and
handover for each site and each cell in the area to be optimized are normal before RF
optimization. Single site verification is optional for the existing networks.
4 RF Optimization
RF optimization aims to optimize the signal coverage, mitigate the interference, and ensure the
even distribution and normal coverage of the radio signals after the service parameters are
optimized.
5 KPI Optimization
KPI optimization involves optimizing the service performance of the network to meet the
acceptance requirements. During KPI optimization, the engineers for the network optimization
find and solve the problems that do not meet the acceptance requirements through the analysis
of the drive test data and the traffic measurement data.
6 Network Acceptance
Network acceptance aims to make sure that the network performance meets the optimization
specifications. It involves the collection of traffic measurement data and drive test data, as well
as the evaluation of network quality and the presentation of network optimization.
7 Network Optimization Tools
Network optimization tools are used for data collection, data analysis, and simulation analysis.
They help to simplify network optimization and improve efficiency in work. The network
optimization tools are Probe, TEMS, ANT pilot for GSM, Assistant, ANT for GSM, and Nastar.
Conventions
1. Symbol Conventions
The following symbols may be found in this document. They are defined as follows
Symbol Description
DANGER
Indicates a hazard with a high level of risk that, if not avoided,
will result in death or serious injury.
WARNING
Indicates a hazard with a medium or low level of risk which, if
not avoided, could result in minor or moderate injury.
CAUTION
Indicates a potentially hazardous situation that, if not avoided,
could cause equipment damage, data loss, and performance
degradation, or unexpected results.
TIP Indicates a tip that may help you solve a problem or save your
time.
NOTE Provides additional information to emphasize or supplement
important points of the main text.
About This Document
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines
2 Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
Issue 01 (2008-06-10)
8/3/2019 BSS Radio Network Optimization Guidelines
11/58
2. General Conventions
Convention Description
Times New Roman Normal paragraphs are in Times New Roman.
Boldface Names of files,directories,folders,and users are in boldface. For
example,log in as userroot .
Italic Book titles are in italics.
Courier New Terminal display is in Courier New.
3. Command Conventions
Convention Description
Boldface The keywords of a command line are in boldface.
Italic Command arguments are in italic.
[ ] Items (keywords or arguments) in square brackets [ ] are optional.
{x | y | ...} Alternative items are grouped in braces and separated by vertical
bars.One is selected.
[ x | y | ... ] Optional alternative items are grouped in square brackets and
separated by vertical bars.One or none is selected.
{ x | y | ... } * Alternative items are grouped in braces and separated by verticalbars.A minimum of one or a maximum of all can be selected.
[ x | y | ... ] * Alternative items are grouped in braces and separated by vertical
bars.A minimum of zero or a maximum of all can be selected.
4. GUI Conventions
Convention Description
Boldface Buttons,menus,parameters,tabs,window,and dialog titles are in
boldface. For example,clickOK.
> Multi-level menus are in boldfaceand separated by the ">" signs.
For example,choose File > Create > Folder .
5. Keyboard Operation
Convention Description
Key Press the key.For example,press Enter and press Tab.
Key1+Key2 Press the keys concurrently.For example,pressing Ctrl+Alt+A
means the three keys should be pressed concurrently.
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines About This Document
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
3
8/3/2019 BSS Radio Network Optimization Guidelines
12/58
Convention Description
Key1,Key2 Press the keys in turn.For example,pressing Alt,A means the two
keys should be pressed in turn.
6. Mouse Operation
Action Description
Click Select and release the primary mouse button without moving the
pointer.
Double-click Press the primary mouse button twice continuously and quickly
without moving the pointer.
Drag Press and hold the primary mouse button and move the pointer
to a certain position.
About This Document
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines
4 Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
Issue 01 (2008-06-10)
8/3/2019 BSS Radio Network Optimization Guidelines
13/58
1 Introduction to Radio NetworkOptimization
About This Chapter
Radio network optimization refers to appropriately adjusting the planning results of the mobile
communications network so that the network can operate more economically and reliably.
Through radio network optimization, the service quality and resource usage of the network are
greatly improved, and the balance among coverage, capacity, and quality is achieved.
1.1 Triggering Conditions of Radio Network Optimization
Network optimization can be performed during the lifetime of the network. It helps to optimizethe network performance according to the telecom operator's requirements, and thus brings about
more benefits.
1.2 Procedure of Radio Network Optimization
Radio network optimization involves the following phases: project startup, single site
verification, RF optimization, KPI optimization, and network acceptance.
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines 1 Introduction to Radio Network Optimization
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
1-1
8/3/2019 BSS Radio Network Optimization Guidelines
14/58
1.1 Triggering Conditions of Radio Network Optimization
Network optimization can be performed during the lifetime of the network. It helps to optimizethe network performance according to the telecom operator's requirements, and thus brings about
more benefits.
The radio network optimization is mainly performed in the following two phases:
l Network construction period
Radio network optimization complements and rectifies the operational network planning
to raise the quality and efficiency of the network.
l Network maintenance period
When the network quality deteriorates due to changes in the propagation environment and
traffic volume, you can perform network optimization to adjust network parameters so that
the network can operate stably and efficiently.
1.2 Procedure of Radio Network Optimization
Radio network optimization involves the following phases: project startup, single site
verification, RF optimization, KPI optimization, and network acceptance.
Figure 1-1 shows the procedure of network optimization.
Figure 1-1 Procedure of network optimization
KPIoptimization outputs
Cell Parameter Table
Radio Network Planning Report
Engineering Parameter Table
Network
optimization
preparation
and startup
Start
Single site
verification
RF
optimization
KPI optimization
Network
acceptance
End
Network optimizationpreparation and startup inputs
Existing network inputs:
Performance measurement data
Alarm data
Complaints
Network optimization records
RF optimization outputs
Updated Cell Parameter Table/Cell
Parameter Optimization Record
Updated Engineering Parameter
Table/Engineering Parameter
Optimization Record
Updated Cell Parameter Table/Cell
Parameter Optimization Record
Updated Engineering Parameter
Table/Engineering Parameter
Optimization Record
Daily Performance Measurement
Report (Optional)Radio Network
Acceptance Report
Radio Network
Optimization Report
Radio network optimization reports
1 Introduction to Radio Network Optimization
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines
1-2 Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
Issue 01 (2008-06-10)
8/3/2019 BSS Radio Network Optimization Guidelines
15/58
Phase Description
2 Network
Optimization
Startup
According to the telecom operator's requirements for the GSM radio
network, discuss and determine the optimization counters. The
optimization counters are one of the criteria for network acceptance.
3 Single Site
Verification
The radio network optimization team begins to function when the site
is ready for service. Verify that the site runs properly and that the data
configuration is consistent with that determined during radio network
planning. Collect the information on the site and the ambient
environment for future optimization.
4 RF
Optimization
RF optimization ensures the radio signal coverage and solves the RF-
related service problems. RF optimization is performed based on
clusters. Several BTSs are from one cluster. RF optimization is
performed based on the drive test data. The overlapped areas must be
optimized.
5 KPI
Optimization
KPI optimization, consisting of the analysis of the drive test data and
that of the traffic measurement data, supplements the RF optimization
in radio network problems. Through KPI optimization, services-related
problems, such as access failures, call drops, and handover failures are
solved.
6 Network
Acceptance
The entire radio network is checked, if required. The acceptance is
passed when the final network KPIs meet the customers' requirements.
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines 1 Introduction to Radio Network Optimization
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
1-3
8/3/2019 BSS Radio Network Optimization Guidelines
16/58
8/3/2019 BSS Radio Network Optimization Guidelines
17/58
2Network Optimization StartupAbout This Chapter
Network optimization startup consists of organizing the network optimization team, determining
the acceptance counters, and arranging the network optimization tools.
2.1 Organization of Radio Network Optimization Team
During network optimization startup, you need to determine the members of the radio network
optimization team.
2.2 Determination of Optimization Acceptance Counters
The acceptance counters are the targets of network optimization. The definition, test
requirements, and test methods of the counters must be determined together with the telecom
operator before network optimization. Some counters that are already determined during the
planning period can be obtained from the contract.
2.3 Preparations of Network Optimization Tools
Each network optimization team must have at least one set of network optimization tools.
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines 2 Network Optimization Startup
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
2-1
8/3/2019 BSS Radio Network Optimization Guidelines
18/58
2.1 Organization of Radio Network Optimization Team
During network optimization startup, you need to determine the members of the radio network
optimization team.
Figure 2-1 shows the organization of the network optimization team.
Figure 2-1 Organization of the radio network optimization team
Project manager
......Area network 1 Area network N
......
......TS/TL TS/TLDT/signaling/
performance
measurement counter
selection engineer
Performancemeasurement counter
analysis engineer
Troubleshooting
engineer
Complaints
analysis engineer
Parameter
modification engineer
DT/signaling/
performance
measurement counter
selection engineer
Performancemeasurement counter
analysis engineer
Troubleshooting
engineer
Complaints
analysis engineer
Parameter
modification engineer
2 Network Optimization Startup
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines
2-2 Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
Issue 01 (2008-06-10)
8/3/2019 BSS Radio Network Optimization Guidelines
19/58
NOTE
l Technical Supporters (TSs)
l Team Leader (TL)
2.2 Determination of Optimization Acceptance Counters
The acceptance counters are the targets of network optimization. The definition, test
requirements, and test methods of the counters must be determined together with the telecom
operator before network optimization. Some counters that are already determined during the
planning period can be obtained from the contract.
The key counters that indicate the network quality include the coverage rate, call drop rate, call
setup success rate, and congestion rate.
The acceptance counters are classified into drive test counters and traffic measurement counters.
The type of the counters to be focused on varies with the type of the network.
l For new networks with comparatively few subscribers, the acceptance counters mainly
refer to drive test counters.
l For the existing network with a certain amount of subscribers, the acceptance counters
should refer to both drive test counters and performance counters.
2.3 Preparations of Network Optimization Tools
Each network optimization team must have at least one set of network optimization tools.
Table 2-1 lists the network optimization tools.
Table 2-1 Network optimization tools
SN Category Name Description
1 Drive test tools Genex Probe/
Assistant, TEMS,
ANT
Collects data on the Um
interface
2 Signaling
instruments
K1205, MA10,
Signaling Analyzer
Analyzes the signaling traced on
the A and Abis interfaces
3 Performanceanalysis tool
Genex Nastar Analyzes the trafficmeasurements
4 Spectrum
analyzer
YBT250 Sweeps frequencies
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines 2 Network Optimization Startup
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
2-3
8/3/2019 BSS Radio Network Optimization Guidelines
20/58
8/3/2019 BSS Radio Network Optimization Guidelines
21/58
3 Single Site VerificationAbout This Chapter
Single site verification is a self-test associated with the equipment in each site and each cell. The
purpose of single site verification is to verify that the basic functions, such as access, call, and
handover for each site and each cell in the area to be optimized are normal before RF
optimization. Single site verification is optional for the existing networks.
The functions of single site verification are as follows:
l Distinguishing the problems during network optimization from the equipment faults, for
example, distinguishing call drops and access failures caused by network coverage from
that caused by equipment faults. The differentiation facilitates locating and solvingproblems and also enhances the network optimization efficiency.
l Familiarizing the engineers for network optimization with the information, such as the site
location, site configuration, and surrounding environment in the area to be optimized as
well as laying foundation for the succeeding network optimization.
Single site verification involves the test preparations, single site test, and troubleshooting.Figure
3-1 shows the verification procedure of a single site.
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines 3 Single Site Verification
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
3-1
8/3/2019 BSS Radio Network Optimization Guidelines
22/58
Figure 3-1 Verification procedure of a single site
Radio Parameter
Planning Data Sheet
Test preparations
Site state check
Configuration data check
Other preparations
Single site test
Frequency checkLAC/CID check
Ambient site C/I check
Call functions check (voice/SMS)
Coverage DT check
Antenna system check
...
Troubleshooting
Radio Parameter
Configuration Data Sheet
Single Site Verification
Checklist
When all the cells in the area to be optimized pass the verification and no equipment fault occurs,
the single site verification ends and the RF optimization starts.
3.1 Preparations for Single Site Test
During preparations for single site test, you need to check the site status, check configuration
data, select test places or routes, and debugs test instruments.
3.2 Single Site Test and Troubleshooting
Single site test aims to locate the problems associated with the installation and functionality of
the equipment. After the signal site test is complete, the test results of each site should beproduced.
3 Single Site Verification
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines
3-2 Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
Issue 01 (2008-06-10)
8/3/2019 BSS Radio Network Optimization Guidelines
23/58
3.1 Preparations for Single Site Test
During preparations for single site test, you need to check the site status, check configuration
data, select test places or routes, and debugs test instruments.
You need to perform the following operations before single site test:
l Checking site status
Prepare the list of test cells and ensure that the cells are normal.
l Checking the configuration data
Check whether the configuration data in the Radio Parameter Configuration Data Sheet is
the same as that in the BSC database.
l Selecting test places or routes
To ensure that the test services are provided by the test cell, select a place within thecoverage of the test cell where the signal strength is strong.
l Other preparations
Consult the engineers for network optimization from the telecom operator to verify that
the power of each site is ready for transmission.
Obtain the test mobile phone number.
Select the position where signals are strong in the target cell.
Obtain the test SIM card and ensure that the relevant services are available.
Debug the instruments for the test to ensure that they are operational.
Ensure that the test MS is in engineering mode and that the battery is fully charged.
Print test forms.
Familiarize yourself with the test site information, including the site location, cell ID,
frequencies, omnidirectional or directional antenna, and antenna azimuth.
3.2 Single Site Test and Troubleshooting
Single site test aims to locate the problems associated with the installation and functionality of
the equipment. After the signal site test is complete, the test results of each site should be
produced.
Single site test involves the following aspects:
l Site configuration and troubleshooting
Checking frequencies
Check whether the ARFCNs are the same as those planned.
Checking LAI
Check whether the LAI is the same as that planned.
Checking handover
Check whether the configuration of the neighbor cell is complete and whether thehandover parameters are normal.
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines 3 Single Site Verification
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
3-3
8/3/2019 BSS Radio Network Optimization Guidelines
24/58
For the abnormal site configuration, you need to adjust related parameters to solve the
problem.
l Site coverage and troubleshooting
Check whether the field strength is normal and whether there are problems such as abnormal
power amplification, improper antenna system connection, blockage due to environmentalchange, and inconsistent antenna tilt and azimuth.
Solve the problems in site coverage by adjusting the antenna system.
l Site service test and troubleshooting
Perform Call Quality Test (CQT) to check whether the access and conversation of the
speech services are normal through dialing test.
Solve the service problems by adjusting related parameters or by rectifying hardware faults.
3 Single Site Verification
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines
3-4 Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
Issue 01 (2008-06-10)
8/3/2019 BSS Radio Network Optimization Guidelines
25/58
4 RF OptimizationAbout This Chapter
RF optimization aims to optimize the signal coverage, mitigate the interference, and ensure the
even distribution and normal coverage of the radio signals after the service parameters are
optimized.
RF optimization involves the following aspects:
l Signal coverage optimization
Problems in radio coverage are caused by the following factors:
Incomplete network planning and imperfect radio network structure Equipment faults
Low construction quality
New coverage requirements from the customers
The handling methods vary with the causes of the coverage problem.
l Interference optimization
For the downlink, the field strength is great and the speech quality is poor.
For the uplink, the interference level is high.
For the interference occurred during RF optimization, you need to locate the interference
sources. The interference sources that affect the GSM system are as follows:
Intra-network interference
Intra-network interference involves the co-channel interference and adjacent channel
interference. When C/I < 12 dB or C/A < -6 dB, interference occurs. Interference appears
more frequently when aggressive frequency reuse is used. The probability of
interference increases when tight frequency reuse patterns are used.
Interference from repeaters
Repeaters are used in the early phase of network construction to extend the BTS
coverage distance. If not appropriately used, the repeaters will cause interference to
BTSs.
Interference from other high-power communications equipment
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines 4 RF Optimization
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
4-1
8/3/2019 BSS Radio Network Optimization Guidelines
26/58
Radar sites, analog sites, and the communications equipment of the same frequency
band cause interference.
Hardware faults
Hardware faults consist of TRX fault, Combining and Distribution Unit (CDU) fault or
divider fault, spurious emission, and intermodulation.
Figure 4-1 shows the procedure of RF optimization.
Figure 4-1 Procedure of RF optimization
Yes
No
Start
Test preparations:Determining the optimization target
Categorizing the clusters
Determining the test route
Keeping ready the documentsand tools
Data collection:Drive test
Indoor test
BSC configuration data collection
Adjustment:Engineering parameter
adjustment
Neighbor cell parameter
adjustment
Problem analysis:
Coverage analysis
Interference analysisHardware faults analysis
End-to-end network elements
interoperation analysis
End
Are the
optimization resultsfactory?
4.1 Preparations for RF Optimization Test
The preparations for RF optimization test ensure the smooth operation of RF optimization. It
involves determining the optimization target, categorizing the clusters, determining the test
route, and arranging for the documents and tools.
4.2 Collection of RF Optimization Data
The RF optimization data can be collected through drive tests, indoor tests, and signaling tracing.
The collected data together with the BSC call tracing data and configuration data provide
reference for problem location. The data helps to check whether the network operates in
accordance with the specifications.
4.3 Analysis of RF Optimization Data
The DT and CQT are efficient means to locate radio network problems. After the tests are
complete, you need to analyze the collected data, and then to locate and solve the problems
according to the analysis result. Through the analysis of RF optimization data, you can locate
network problems related to coverage, interference, hardware failure, and interoperability of
network elements, and then make appropriate adjustments.
4.4 Implementation of RF Optimization
4 RF Optimization
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines
4-2 Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
Issue 01 (2008-06-10)
8/3/2019 BSS Radio Network Optimization Guidelines
27/58
The implementation of RF optimization involves the adjustment of the cell engineering
parameters and cell parameters based on the data analysis so that they meet the KPI requirements.
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines 4 RF Optimization
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
4-3
8/3/2019 BSS Radio Network Optimization Guidelines
28/58
4.1 Preparations for RF Optimization Test
The preparations for RF optimization test ensure the smooth operation of RF optimization. It
involves determining the optimization target, categorizing the clusters, determining the test
route, and arranging for the documents and tools.
The test preparation phase involves the following aspects:
l Determining the optimization target
Determine the optimization target so that the network can operate as planned and that the
KPIs meet the acceptance requirements.
l Categorizing the clusters
The coverage, capacity, and quality of the GSM network are related to each other.
Therefore, RF optimization must be performed in clusters instead of single BTSs.
l Determining the test route
Before the drive test, determine with the customer the KPI drive test route. The drive test
route must include the customer-specified route, if there is any.
l Getting ready the documents and tools
For details, refer to 2.3 Preparations of Network Optimization Tools. The required
documents include user guides, reports, and templates.
4.2 Collection of RF Optimization Data
The RF optimization data can be collected through drive tests, indoor tests, and signaling tracing.
The collected data together with the BSC call tracing data and configuration data providereference for problem location. The data helps to check whether the network operates in
accordance with the specifications.
The RF optimization data can be collected through the following methods:
l Drive test
In the coverage area of the network, use the mobile phone in standard conversation mode
to collect counters associated with the specified services.
l Call quality test
The call quality test (CQT) covers the continuous coverage services that are listed in the
commercial contract or in the planning report of the trial office. The test method is the same
as the drive test.
The CQT areas consist of the indoor areas (buildings, malls, subways, indoor stadiums,
and government agencies) and operator-required test areas (VIC and VIP).
The RF optimization data is collected through the DT and CQT. The DT is performed more
often, and the CQT is performed according to the contract or planning requirements.
4.3 Analysis of RF Optimization Data
The DT and CQT are efficient means to locate radio network problems. After the tests are
complete, you need to analyze the collected data, and then to locate and solve the problemsaccording to the analysis result. Through the analysis of RF optimization data, you can locate
4 RF Optimization
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines
4-4 Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
Issue 01 (2008-06-10)
8/3/2019 BSS Radio Network Optimization Guidelines
29/58
network problems related to coverage, interference, hardware failure, and interoperability of
network elements, and then make appropriate adjustments.
4.3.1 Analysis of Coverage Problems
The analysis of coverage problem, the key of RF optimization, focuses on signal distribution.
4.3.2 Analysis of Interference Problems
Interference is a key factor that influences network operation. It greatly affects the speech quality
and handover. Call drops or congestion may be caused. The interference analysis involves uplink
interference analysis and downlink interference analysis.
4.3.3 Analysis of Hardware Faults
Hardware faults affect the normal operation of the network or disrupt the network. Also, the
network performance deteriorates. Hardware faults consist of the network element faults and
transmission link faults. You can determine the type of the faults by checking the hardware
alarms and analyzing the traffic measurement results.
4.3.4 Analysis of End-To-End Network Elements InteroperationThe end-to-end network elements refer to the nodes on the mobile communications network.
The proper operation of the network elements, including the BTS, BSC, and MSC, is the
prerequisite for the normal operation of the network.
4.3.1 Analysis of Coverage Problems
The analysis of coverage problem, the key of RF optimization, focuses on signal distribution.
The common coverage problems and corresponding checking items are as follows:
l If the coverage area becomes smaller after the BTS starts services, check the following
items:
Check the ambient environment of the BTS antennas.
Check the changes in the propagation environment.
Check whether there are VSWR alarms and main and diversity receive alarms on the
Site Maintenance Terminal System.
Check whether the VSWR is less than 1.5.
Check whether the TMA is operational.
Check the engineering parameters such as the antenna tilt and azimuth.
Check the BTS transmit power.
Check whether the BTS receiver sensitivity is normal. Check whether the parameters associated with coverage are set properly.
Check whether the noise floor is high due to interference and poor electromagnetic
environment.
l If the coverage problems are caused by the expansion of the BTS capacity, check the
following items:
Check whether the configuration of combiners changes after capacity expansion.
Check whether appropriate antennas are selected.
Check whether the new antennas are installed in accordance with the requirements.
Check the location of the BCCH transmit antenna of the omnidirectional double transmitantennas.
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines 4 RF Optimization
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
4-5
8/3/2019 BSS Radio Network Optimization Guidelines
30/58
For the directional double transmit antennas, check whether the pitch and the azimuth
of the antennas are consistent.
Check the output power on top of the cabinet for different TRXs when the maximum-
coverage configuration is used.
l If the coverage problems are caused by BTS swapping or new construction, check thefollowing items:
Check whether the azimuth and height of the antennas is the same as those before
swapping.
Check whether the tilt of the directional antennas is the same as that before swapping.
Check whether the power on top of the cabinet for the BTS before and after swapping
are consistent.
Check whether the BTS receiver sensitivity is normal.
Check whether the noise floor is high due to interference and poor electromagnetic
environment.
Check whether there are VSWR alarms and main and diversity receive alarms on the
Site Maintenance Terminal System.
Check whether the parameters associated with coverage are set properly.
Check whether the antennas are installed in accordance with the requirements after the
BTS is put into operation or after new construction.
Check whether appropriate antennas are selected.
Check the location of the BCCH transmit antenna of the omnidirectional double transmit
antennas.
For the directional double transmit antennas, check whether the pitch and the azimuth
of the antennas are consistent. Check that there are inverse connections in the antenna system.
Check whether the TMA is operational.
Check the power on top of the cabinet for different TRXs when the maximum-coverage
configuration is used.
The common problems that affect coverage are as follows:
l Water running into the antennas
l Passive intermodulation antennas
l Inappropriate antenna type
Select the antennas that meet the network performance requirements and ensure there are
signals under the antenna tower.
l Tower influences on the omnidirectional antennas
The tower has great influences on the signal strength and the coverage area of the antennas.
The influences depend on the distance between the MS and the tower.
l Inappropriate installation of the directional antennas
The antennas may be connected inversely or wrongly. The azimuth and pitch of the transmit
antennas and the receive antennas are not consistent. The diversity spacing, the isolation
from the tower, and the shadows of the directional cells in the neighbor coverage areas are
not set appropriately.
l Inappropriate installation of the omnidirectional antennas
4 RF Optimization
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines
4-6 Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
Issue 01 (2008-06-10)
8/3/2019 BSS Radio Network Optimization Guidelines
31/58
The radiator of the omnidirectional antenna is blocked by the post. The diversity spacing
and the isolation from the tower are not set appropriately. The installation is not
perpendicular to the horizontal plane.
l Problems associated with the connection of the antenna system, combiner and divider, and
CDUWater leaks into the connectors and the feeders in the antenna system. The connectors are
not tightened. The connection of the jumpers is not consistent with data configuration,
which causes inverse connection of the transmit antennas and the receive antennas. The
jumpers and the feeders are not properly connected, which causes signal loss, excessive
VSWR, passive cross-modulation, and interference.
l TMA problems
Water leaks into the TMA. The lower noise amplifier (LNA) is damaged. The TMA is
connected inversely.
l BTS front-end module fault
The isolator, duplexer, or other filters break down. The false VSWR alarm, faulty LNA,and small output power of the TRX or the amplifier affect the coverage.
The parameters that affect coverage areas are as follows:
TRX power level, TMA power attenuation factor, MS maximum transmit power control level,
MS minimum receive signal level, and RACH minimum access level
4.3.2 Analysis of Interference Problems
Interference is a key factor that influences network operation. It greatly affects the speech quality
and handover. Call drops or congestion may be caused. The interference analysis involves uplink
interference analysis and downlink interference analysis.
l Analysis of uplink interference problems
If the traffic volume is low compared with the interference band, then the uplink
interference exists.
l Analysis of downlink interference problems
If the Received Signal Quality (RXQUAL) is lower than the predefined threshold and the
Received Signal Level (RXLEV) is higher than the predefined threshold, then the downlink
interference exists. If Both RXQUAL and RXLEV are lower than the predefined thresholds,
then the coverage problem exists.
The interference sources of the GSM network are as follows:
l Intra-network interference
l Interference from repeaters
l Interference from other high-power communications equipment
l Hardware faults
The location and troubleshooting are as follows:
1. Determine the cells that have interference on the basis of KPIs.
2. Check the OMC alarms.
3. Check the frequency planning.
4. Check the cell parameter setting.
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines 4 RF Optimization
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
4-7
8/3/2019 BSS Radio Network Optimization Guidelines
32/58
5. Perform the drive test.
6. Eliminate the interference based on the check results.
4.3.3 Analysis of Hardware Faults
Hardware faults affect the normal operation of the network or disrupt the network. Also, the
network performance deteriorates. Hardware faults consist of the network element faults and
transmission link faults. You can determine the type of the faults by checking the hardware
alarms and analyzing the traffic measurement results.
If the network performance deteriorates due to poor transmission quality and unstable operation
of boards and transmission links on the Abis and A interfaces, analyze as follows:
1. Check the transmission alarms and board alarms to see whether there is intermittent
transmission or faulty boards.
2. Check whether the transmission paths, bit error rate, and 2M connectors are normal. Also,
check whether the equipment is properly grounded.
4.3.4 Analysis of End-To-End Network Elements Interoperation
The end-to-end network elements refer to the nodes on the mobile communications network.
The proper operation of the network elements, including the BTS, BSC, and MSC, is the
prerequisite for the normal operation of the network.
The interoperation problems of the network elements refer to the problems in interface protocols,
version matching, A and Abis interface data configuration, and interface signaling compatibility.
All the problems affect the network performance.
4.4 Implementation of RF Optimization
The implementation of RF optimization involves the adjustment of the cell engineering
parameters and cell parameters based on the data analysis so that they meet the KPI requirements.
Antenna adjustment is a part of the RF optimization. You should consider the optimization cost
when replacing the antennas, adding TMAs, and adding BTSs.
You can solve most RF problems by adjusting the following engineering parameters:
l Antenna tilt
l Antenna azimuth
l Antenna height
l Antenna location
l Antenna type
l Adding TMAs
l Replacing site type, for example, replacing a site that supports 20 W power amplification
with a site that supports 40 W power amplification
l Adjusting the site location
l Adding sites
4 RF Optimization
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines
4-8 Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
Issue 01 (2008-06-10)
8/3/2019 BSS Radio Network Optimization Guidelines
33/58
CAUTION
The previous engineering parameter with higher adjustment priority is listed firstly.
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines 4 RF Optimization
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
4-9
8/3/2019 BSS Radio Network Optimization Guidelines
34/58
8/3/2019 BSS Radio Network Optimization Guidelines
35/58
5 KPI OptimizationAbout This Chapter
KPI optimization involves optimizing the service performance of the network to meet the
acceptance requirements. During KPI optimization, the engineers for the network optimization
find and solve the problems that do not meet the acceptance requirements through the analysis
of the drive test data and the traffic measurement data.
KPI optimization involves the counters such as the call-completion rate, call drop rate, handover
success rate, and congestion rate.
Figure 5-1 shows the procedure of KPI optimization.
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines 5 KPI Optimization
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
5-1
8/3/2019 BSS Radio Network Optimization Guidelines
36/58
Figure 5-1 Procedure of KPI optimization
No
Yes
Start
RF optimization
Data collection:
Configuration dataDrive test data
Performance
measurement data
Call trace data
End
Are the
optimization results
satisfactory?
Data analysis
Are the
optimization results
satisfactory?
Yes
Data analysis
and processing
No
Discuss solutions
Make solutions
5.1 Collection of KPI Optimization Data
The KPI optimization data consists of the drive test data, call tracing data, traffic measurement
data, and configuration data. The data helps to check whether the network operates in accordance
with the specifications. Also, the data provides reference for locating problems.
5.2 Analysis of KPI Optimization Data
The single site test focuses on the functional problems associated with the equipment, the RF
optimization focuses on the problems associated with signal coverage, and the KPI optimization
focuses on the KPI problems. The analysis of KPI optimization data helps solve the remaining
equipment and coverage problems. The common KPI problems are associated with call access,
congestion, handover, and call drops.
5.3 Implementation of KPI Optimization
During the implementation of KPI optimization, you can adjust the radio configuration
parameters to enhance the service performance.
5 KPI Optimization
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines
5-2 Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
Issue 01 (2008-06-10)
8/3/2019 BSS Radio Network Optimization Guidelines
37/58
5.1 Collection of KPI Optimization Data
The KPI optimization data consists of the drive test data, call tracing data, traffic measurement
data, and configuration data. The data helps to check whether the network operates in accordance
with the specifications. Also, the data provides reference for locating problems.
Collection of Drive Test Data
The data collected during drive test is associated with the MS. The drive test in KPI optimization
should be more detailed and comprehensive than that in RF optimization. The drive test in KPI
optimization involves the following aspects:
l Test services: speech and data
l Test methods: continuous conversation, dialing test, and automatic test
Collection of Call Tracing Data
The call tracing data is collected on the network equipment side. It consists of the following:
l User signaling messages
l Cell signaling messages
l Standard interface signaling messages
l LAC data
l Real-time performance monitoring data
Collection of Traffic Measurement Data
The performance measurement data indicates the radio performance on the network level and
the cell level. GBSS performance data consists of the following:
l Access data
l Call drop data
l Handover data
l Traffic volume
l Congestion data
Collection of Configuration Data
The configuration script files collected in the BSC are used for problem analysis and location.
5.2 Analysis of KPI Optimization Data
The single site test focuses on the functional problems associated with the equipment, the RF
optimization focuses on the problems associated with signal coverage, and the KPI optimization
focuses on the KPI problems. The analysis of KPI optimization data helps solve the remaining
equipment and coverage problems. The common KPI problems are associated with call access,
congestion, handover, and call drops.
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines 5 KPI Optimization
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
5-3
8/3/2019 BSS Radio Network Optimization Guidelines
38/58
5.2.1 Analysis of Access Counter Optimization
The analysis of access problems aims to make sure that the drive test data and traffic
measurement data meet the specifications.
5.2.2 Analysis of Congestion Counter Optimization
The congestion in the GSM network refers to the SDCCH congestion and TCH congestion. IfSDCCH congestion occurs, it means there are no idle SDCCH available. If TCH congestion
occurs, either the channel request fails because no idle TCHs are available or the TCH assignment
fails after the assignment command is issued. In the later case, there are various reasons that
cause the assignment failure.
5.2.3 Analysis of Handover Counter Optimization
The analysis of handover problems involve the analysis of the drive test data and the analysis
of the traffic measurement data. It aims to make sure whether the drive test data and traffic
measurement data meet the specifications. Before performing handover optimization, check
whether the handover problem is associated with radio handover failures or other causes.
5.2.4 Analysis of Call Drop Counter OptimizationCall drops are associated with coverage, handover, interference, antenna system, transmission,
and parameter setting.
5.2.1 Analysis of Access Counter Optimization
The analysis of access problems aims to make sure that the drive test data and traffic
measurement data meet the specifications.
l Access specifications (drive test)
The access specifications consist of the calling party completion ratio, called party
completion ratio, and access delay of the CS and PS services.
l Access specifications (traffic measurements)
The access specifications consist of the paging success rate and call setup success rate.
If access problems exist, the call drop counters obtained from drive test and traffic measurement
might fail to meet the acceptance requirements. The common access problems are as follows:
l Paging problems
l Assignment problems
l Authentication and encryption problems
l Equipment problems
To solve the access problems, you need to adjust the following antenna configuration parameters:
l Cell reselection parameters
The cell reselection parameters consist of the reselection start threshold, reselection delay,
reselection hysteresis, and cell offset.
l Radom access parameters
The random access parameters consist of the RACH minimum access threshold, BS-PA-
MFRAMS, MS minimum access level, and RACH error threshold.
5.2.2 Analysis of Congestion Counter Optimization
The congestion in the GSM network refers to the SDCCH congestion and TCH congestion. IfSDCCH congestion occurs, it means there are no idle SDCCH available. If TCH congestion
5 KPI Optimization
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines
5-4 Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
Issue 01 (2008-06-10)
8/3/2019 BSS Radio Network Optimization Guidelines
39/58
occurs, either the channel request fails because no idle TCHs are available or the TCH assignment
fails after the assignment command is issued. In the later case, there are various reasons that
cause the assignment failure.
The common congestion and troubleshooting are as follows:
l Congestion caused by high traffic volume
Check the performance measurement results to see whether the traffic volume of the
SDCCH and the TCH exceeds the specifications. For congestion caused by high traffic
volume, capacity expansion is the fundamental solution. Also, traffic sharing can be applied
to mitigate the congestion.
l SDCCH congestion caused by burst traffic
If the SDCCH congestion rate and the traffic volume are high while the TCH traffic volume
is normal, the SDCCH congestion may be caused by a traffic burst. To mitigate the SDCCH
congestion, you can configure more SDCCHs or enable the SDCCH-TCH dynamic
conversion function.
l Congestion caused by TRX failure
In a cell configured with multiple TRXs, if a faulty TRX is out of service, congestion may
occur. You can replace the faulty TRX. If you are not sure whether the fault lies in the TRX
or not, check whether the cables in the antenna system are properly connected and whether
the VSWR is normal. If the cables in the antenna system are properly connected and the
VSWR is normal, replace the TRX and then check whether the services recover.
l Congestion caused by interference
Interference on the Um interface also causes congestion. Mitigate the congestion by solving
the interference problems.
l
Congestion caused by channel assignment failure due to inconsistent coverageThe causes are as follows:
The transmit power of the TRXs in a cell are not the same. Check whether the combiner
and divider, CDU, and SCU are properly connected.
The coverage areas of the transmit antennas in a cell are not the same. You can solve
the problem through engineering adjustment.
The transmit and receive antennas are not on the same horizontal plane or their tilts are
not the same. You can solve the problem by adjusting the antennas.
l Congestion caused by inappropriate data configuration
The data configuration involved in such congestion is as follows:
Planning of location areas
Plan the location areas reasonably to decrease SDCCH congestion.
Dynamic allocation of SDCCHs
Enable the SDCCH dynamic allocation function to decrease SDCCH congestion.
Dual-band network
Set the dual-band network parameters (for example, CRO, CBA, CBQ, and Cell
Reselection Hysteresis) appropriately to decrease SDCCH congestion.
Timer setting
Check whether the timers, such as T3101, T3103, T3107, T3122, T3212, and T3111,are set appropriately.
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines 5 KPI Optimization
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
5-5
8/3/2019 BSS Radio Network Optimization Guidelines
40/58
5.2.3 Analysis of Handover Counter Optimization
The analysis of handover problems involve the analysis of the drive test data and the analysis
of the traffic measurement data. It aims to make sure whether the drive test data and traffic
measurement data meet the specifications. Before performing handover optimization, checkwhether the handover problem is associated with radio handover failures or other causes.
The common handover problems and troubleshooting are as follows:
l Unsuccessful handover
The MS fails to initiate a handover when the signals in the cell are weak or signal quality
is poor. Take the following aspects into consideration:
Whether the handover conditions are met
Whether there is a candidate cell that meets the handover conditions
Adjust relevant parameters based on the following causes:
The handover thresholds are set too low.
No neighboring cell relation is set.
The handover hysteresis is set inappropriately.
The best cell measurement time N and P are set inappropriately.
NOTE
P/N criterion: If the triggering conditions of an event are met for at least P seconds within N
seconds, then the event meets the P/N criterion.
The BTS clock expires.
l Handover problems caused by hardware failure
If a handover problem occurs while the configuration data of the faulty cell and its neighborcells is not changed recently, then check whether the problem is caused by hardware failure.
If so, replace the faulty hardware.
l Handover problems caused by inappropriate data configuration
In independent MSC networking mode, if the incoming or outgoing MSC handover is
abnormal, check whether the signaling settings are inconsistent in the local and peer
MSCs and whether the data of the local and peer MSCs is changed.
In co-MSC networking mode, if the handover between the BSCs from different
manufacturers is abnormal, check whether signaling settings are consistent in the two
BSCs, and then check whether the data of the two BSCs is changed.
If the handover failure applies to only one cell, then analyze the problem based on theactual situations.
Check the timers related to handover, such as the T3105, Ny1, T3103, and T3124.
To locate the handover problems, do as follows:
1. Check whether the fault lies in one cell or in all the cells. Check also the characteristics of
the faulty cells. For example, the faulty cells are neighboring cells of a cell or the faulty
cells share a BSC or an MSC.
2. Check whether the configuration data is adjusted before the problem occurs.
3. Check whether the problem is caused by hardware faults.
4. Register the related performance measurement counters such as handover performancemeasurement counters and TCH performance measurement counters.
5 KPI Optimization
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines
5-6 Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
Issue 01 (2008-06-10)
8/3/2019 BSS Radio Network Optimization Guidelines
41/58
5. Perform a drive test in the faulty cell and analyze the signaling.
5.2.4 Analysis of Call Drop Counter Optimization
Call drops are associated with coverage, handover, interference, antenna system, transmission,and parameter setting.
The causes and troubleshooting of common call drops are as follows:
l Coverage-related call drops are caused by the following:
Discontinuous coverage with blind areas
The signals on the edge of an isolated BTS are weak and of poor quality; thus, calls are
dropped as they cannot be handed over to other cells.
In complex landforms, for example, mountainsides, the transmission of the signals is
blocked and discontinuous, which causes call drops.
Bad indoor coverage
Densely distributed buildings and thick walls cause great attenuation and low indoor
level, which lead to call drops.
Cross-area coverage (isolated island)
In Figure 5-2, cell B is the neighbor cell of cell A, but cell C is not. If the MS roams
from cell A to cell C and still seizes the signals of cell A, when a handover is initiated
from cell A to cell B, the MS will not find a suitable target cell and the call is dropped.
Figure 5-2 Call dropped due to oversized coverage
Cell A
Cell B
Cell C
Can't find next cell
cause call drop
Expected Coverage
Actual Coverage
Undersized coverage
If the hardware of a cell is faulty, for example, the radiator of the antenna is blocked or
the BCCH TRX is faulty, calls might be dropped.
For calls dropped due to coverage, locate the areas with insufficient coverage through drive
test, and then remove inappropriate neighbor cell relations and rectify hardware faults,
provided that the indoor communications is acceptable. For details, refer to 4 RF
Optimization.
l Handover-related call drop
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines 5 KPI Optimization
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
5-7
8/3/2019 BSS Radio Network Optimization Guidelines
42/58
For details on the analysis of handover-related call drop and its troubleshooting, refer to
5.2.3 Analysis of Handover Counter Optimization.
l Interference-related call drop
For details on the analysis of interference-related call drop and its troubleshooting, refer to
4.3.2 Analysis of Interference Problems.
l Antenna system-related call drop
For details on the analysis of antenna system-related call drop and its troubleshooting, refer
to 4 RF Optimization.
l Transmission-related call drop
For details on the analysis of transmission-related call drop and its troubleshooting, refer
to 4.3.3 Analysis of Hardware Faults.
In addition, you can perform the analysis together with the following traffic measurement
results:
A interface failures during TCH seizure
TCH availability
Call drops due to terrestrial link interruption
l Parameter-related call drop
Check whether the parameters related to call drop are set appropriately. The parameters are
as follows:
Radio link timeout
SACCH multi-frames
Access control parameters
Timer T3101 and timer T3107
T200 and N200 parameters
5.3 Implementation of KPI Optimization
During the implementation of KPI optimization, you can adjust the radio configuration
parameters to enhance the service performance.
Before adjusting the radio configuration parameters, you need to perform the following
preparations:
l Make a detailed parameter adjustment plan with the following aspects included:
Adjustment objectives
Version of the network equipment and instructions
Adjustment procedures
Adjustment details (the parameter values before and after the adjustment should be
recorded)
Operation time
NOTE
Determine the operation time on the basis of the network security and the operation impacts on
the services. Generally, perform the adjustment at midnight (after 24:00) when the traffic volumeis low. Do not perform dynamic adjustment during peak hours.
5 KPI Optimization
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines
5-8 Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
Issue 01 (2008-06-10)
8/3/2019 BSS Radio Network Optimization Guidelines
43/58
Troubleshooting
l Review the adjustment plan.
Review the adjustment plan of the parameters in large size and that are of a high security
level.
l Submit theApplication for Network Operation to the customer. The application should
include at least the following items:
Operation content
Operation purpose
Operation time
Whether the resources such as personnel, vehicles, and SIM cards should be prepared
by the customer
Abnormal results that might occur and their troubleshooting measures
Operation impacts on the services (impacts on traffic counters)
CAUTION
Back up the original data and record the date before every operation.
After the adjustment of the radio configuration parameters, perform the following checks:
l Back up the latest data file on the GBAM server and record the date.
l Verify that the BTSs and cells are operational after the adjustment. Conduct a dialing test
and ensure that the services are normal.
l Check the traffic measurement results such as the access success rate, congestion rate, call
drop rate, and handover rate. Troubleshoot in time to ensure normal operation of the
equipment.
l Record the adjustment and its effects for future check.
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines 5 KPI Optimization
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
5-9
8/3/2019 BSS Radio Network Optimization Guidelines
44/58
8/3/2019 BSS Radio Network Optimization Guidelines
45/58
6 Network AcceptanceAbout This Chapter
Network acceptance aims to make sure that the network performance meets the optimization
specifications. It involves the collection of traffic measurement data and drive test data, as well
as the evaluation of network quality and the presentation of network optimization.
If the optimized network performance meets the requirements, you can perform network
optimization acceptance.
l Acceptance of counters through drive test
You are advised to perform the drive test after all the drive test counters meet the
specifications within specific areas.
l Acceptance of performance counters
You are advised to perform the performance counter acceptance after all the performance
counters meet the specifications with reliable state.
6.1 Main Counters of Network Acceptance
The main counters of network acceptance consist of the drive test counters and the performance
measurement counters.
6.2 Contents of the Network Acceptance Report
The to-be-submitted reports consist of the acceptance report and optimization report. The
acceptance report is optional for existing networks.
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines 6 Network Acceptance
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
6-1
8/3/2019 BSS Radio Network Optimization Guidelines
46/58
6.1 Main Counters of Network Acceptance
The main counters of network acceptance consist of the drive test counters and the performance
measurement counters.
6.1.1 Drive Test Counters
Drive test counters are obtained during drive tests along the predefined test route.
6.1.2 Performance Measurement Counters
The performance counters are obtained through traffic measurement.
6.1.1 Drive Test Counters
Drive test counters are obtained during drive tests along the predefined test route.
Table 6-1 Drive test counters of the GSM network
Counter Calculation Method
Call setup success rate (CS
services)
Call setup success rate (CS services) = number of put-
throughs/call requests x 100%
Call drop rate (CS services) Call drop rate (CS services) = call drops/number of
conversations x 100%
Coverage rate Coverage rate = samples with satisfactory signal level/total
samples x 100%
Speech quality l Method 1: speech quality level
l Method 2: Mean Opinion Score (MOS)
PDP activation success rate PDP activation success rate = PDP activation successes/total
activation attempts x 100%
GPRS attachment success
rate
GPRS attachment success rate = successful GPRS
attachments/total GPRS attachment attempts x 100%
Average attachment time Average attachment time = total successful attachment time/
successful attachments
PDP average activation time PDP average activation time = total successful PDP activation
time/successful PDP activations
WAP first page display
success rate
WAP first page display success rate = successful WAP first
page displays/WAP login attempts x 100%
WAP average first display
time
WAP average first display time = total successful WAP first
page display time/successful WAP first page displays
WAP download success rate WAP download success rate = successful WAP
downloadings/WAP download attempts x 100%
WAP downloading rate WAP downloading rate = successful downloading data input
(bytes)/successful downloading time (seconds)
6 Network Acceptance
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines
6-2 Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
Issue 01 (2008-06-10)
8/3/2019 BSS Radio Network Optimization Guidelines
47/58
8/3/2019 BSS Radio Network Optimization Guidelines
48/58
Counter Calculation Method
Call Establishment Success Rate Call Establishment Success Rate = Successful
Assignments/(SDCCH Seizures for Speech Service
+ Call Setup Indications (MOC Non SMS)
(TCHF) + Call Setup Indications (MTC) (TCHF) +
Call Setup Indications (Emergency Call) (TCHF) +
Call Setup Indications (Call Re-establishment)
(TCHF) + Call Setup Indications (MOC Non SMS)
(TCHH) + Call Setup Indications (MTC) (TCHH)
+ Call Setup Indications (Call Re-establishment)
(TCHH)) x 100%
Handover Success Rate Handover Success Rate = (Successful Internal Intra-
Cell Handovers + Successful Outgoing Internal
Inter-Cell Handover + Successful External
Outgoing Cell Handovers)/(Internal Intra-Cell
Handover Commands + Outgoing Internal Inter-
Cell Handover Commands + Outgoing External
Inter-Cell Handover Commands) x 100%
TCH Call Drop Rate (Including
Handover)
TCH Call Drop Rate (Including Handover) = Call
Drops on TCH/(Successful TCH Seizures (Signaling
Channel) + Successful TCH Seizures (Traffic
Channel) + Successful TCH Seizures in TCH
handovers (Traffic Channel)) x 100%
TCH Call Drop Rate (Excluding
Handover)
TCH Call Drop Rate (Excluding Handover) = (Call
Drops on TCH - Call Drops on TCH in Stable State
(Release Indication))/Successful TCH Seizures(Traffic Channel)
Traffic Call Drop Rate Traffic Call Drop Rate = 60 x Traffic Volume on
TCH/Call Drops on TCH
6.2 Contents of the Network Acceptance Report
The to-be-submitted reports consist of the acceptance report and optimization report. The
acceptance report is optional for existing networks.
Acceptance Report
TheXXX Radio Network Acceptance Reporthas the following contents:
l Project background
l Networking modes
l Acceptance area division and KPI test route
l Acceptance counters (drive test counters and performance counters)
l Acceptance method
l Conclusion and suggestions
6 Network Acceptance
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines
6-4 Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
Issue 01 (2008-06-10)
http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-http://-/?-8/3/2019 BSS Radio Network Optimization Guidelines
49/58
8/3/2019 BSS Radio Network Optimization Guidelines
50/58
8/3/2019 BSS Radio Network Optimization Guidelines
51/58
7Network Optimization ToolsAbout This Chapter
Network optimization tools are used for data collection, data analysis, and simulation analysis.
They help to simplify network optimization and improve efficiency in work. The network
optimization tools are Probe, TEMS, ANT pilot for GSM, Assistant, ANT for GSM, and Nastar.
7.1 Probe
Probe is a high-performance test tool used on the air interface in WCDMA, HSDPA, GSM, and
GPRS. It is used for data collection and verification of radio network planning and optimization.
7.2 TEMS
TEMS is a test tool used for real-time diagnosis on the air interface.
7.3 ANT Pilot for GSM
ANT pilot for GSM is a generic term for the GSM900/DCS1800 radio parameter collector and
system software.
7.4 Assistant
Assistant is a professional background analysis tool. It supports the WCDMA, HSDPA, GSM,
and GPRS modes and is compatible with multiple formats of drive test data provided by the
leading manufacturers. The Assistant performs the functions such as uplink and downlink data
combination analysis, intelligent expert system, event simulation, displaying, statistics, filtering,
and reporting.
7.5 ANT for GSM
ANT for GSM analyzes the data collected by the ANT Pilot, automatically locates the problems
found during drive tests, and provides troubleshooting suggestions.
7.6 Nastar
Nastar performs comprehensive analysis on the performance data, configuration parameters,
and engineering parameters of the GSM BSS network. It provides multiple display modes used
for network planning, performance analysis, and geographical display.
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines 7 Network Optimization Tools
Issue 01 (2008-06-10) Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
7-1
8/3/2019 BSS Radio Network Optimization Guidelines
52/58
7.1 Probe
Probe is a high-performance test tool used on the air interface in WCDMA, HSDPA, GSM, and
GPRS. It is used for data collection and verification of radio network planning and optimization.
The applications of the Probe are as follows:
l Test the network quality and radio parameters.
l Decode the messages on the air interface and display in real time the data, cells, and
geographical locations.
l Monitor, trace, and test the system status in real time
The Probe provides the following functions:
l Supports multi-mode tests in WCDMA, HSDPA, GSM, and GPRS
l Supports multiple CS and PS service tests
l Supports multi-MS tests
l Supports Scanner tests
l Supports indoor tests
l Supports the presetting of test plans
l Supports the judgment of predefined events
l Supports hardware alarms
l Supports filtering of the received data
l Supports automatic saving, exporting, and retrieving of the log
l Displays co-activated information
l Displays radio measurement parameters geographically in real time
l Adjusts the GPS location information dynamically and statically
l Displays and interprets the air interface messages
l Displays the RLC and APP throughput
l Displays customized parameters
l Supports GPS timing synchronization
7.2 TEMS
TEMS is a test tool used for real-time diagnosis on the air interface.
The TEMS monitors the speech channels as well as the data transfer of CSD/HSCSD and GPRS/
EDGE. It also measures the KPI of the PS network and evaluates operation performance of the
network.
The TEMS provides convenient and powerful drive test functions. It has the following features:
l The drive test supports four mobile phones at the same time. The test data and messages
are recorded in one file and you can have the information of one or all mobile phonesdisplayed.
7 Network Optimization Tools
HUAWEI BSC6000 Base Station Subsystem
BSS Radio Network Opimization Guidelines
7-2 Huawei Proprietary and Confidential
Copyright Huawei Technologies Co., Ltd
Issue