Radio Network Drive Test Guide

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RADIO NETWORK DRIVE TEST GUIDE

Prepared by Kathleen Muange Date 06 Jun, 2011

Approved by Date

Version 1.0 Date 06 Jun, 2011

Radio Network Test Guide | June 2011

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CONTENTS

1.0 INTRODUCTION1.1 About this document1.2 Intended users

2.0 PROCESS FLOWCHART3.0 TYPES OF TESTS3.1 Optimization & Troubleshooting3.2 Network Benchmarking3.3 Service Quality Monitoring(Voice Quality)

4.0 PREPARATION4.1 Introduction4.2 Tools checklist4.3 Network information and maps4.4 Drive test route4.5 Drive test schedule4.6 Vehicle arrangements4.7 Test methods4.8 Configurations

5.0 IMPLEMENTATION5.1 Positioning of test equipment5.2 Connections5.3 Vehicle speed during drive test5.4 Recording of test file information5.5 Monitored information and signaling

6.0 HAND-OVER PROCESS7.0 OPTIMIZATION7.1 Flow chart7.2 Implementation.

8.0 APPENDIX9.0 REFERENCES


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1.0 INTRODUCTION

1.1 ABOUT THIS DOCUMENT The purpose of a drive/walk test is to analyze the network system as observed by the user so as optimize the network in problematic areas. It may be done after new installations, optimization, before and after swaps.

This guide is designed to specify radio network drive test procedures to ensure smooth processes, accuracy and consistency of the tested data.

For instrument usage of specific products and drive test technologies, please refer to corresponding instrument usage guide and drive test guide.

1.2 INTENDED USERS This guide is drafted for radio network planning optimization engineers and drive test engineers to carry out drive tests.


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2.0 PROCESS FLOWCHART


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3.0 TYPE OF TESTSTesting can be broadly categorized into three types:

Optimization & Troubleshooting Network Benchmarking Service Quality Monitoring

3.1 SERVICE QUALITY MONITORING (VOICE QUALITY) This kind of test is an end to end, subjective, end user indicator used to evaluate the quality of the entire speech path including all network elements. It involves making test calls across the network to a fixed test unit to assess the relative quality of various services using Mean Opinion Score (MOS).

3.2 NETWORK BENCHMARKINGThis kind of test is done to evaluate the performance of different technologies, networks or operators and service types within a given area simultaneously. Drive testing to gather networking benchmarking data is the only way mobile network operators can collect accurate competitive data on the true level of their own and their competitor’s technical performance and quality levels.

3.3 OPTIMIZATION & TROUBLESHOOTINGOptimization and troubleshooting information is more typically used to aid in finding specific problems during the rollout phases of new networks or to observe specific problems reported by consumers during the operational phase of the network lifecycle.

In this mode drive testing data is used to diagnose the root cause of specific, typically localized, network issues such as dropped calls or missing neighbor cell assignments.


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4.0 PREPARATION4.1 INTRODUCTION

Based on test objectives and requirements, determine the following:

Drive test methods

Engineers to carry out the test.

Test area

Instruments and devices.

For comparison tests on the same network, should adopt the same test devices and methods to ensure the results consistent.

4.2 TOOLS CHECKLIST

The list below shows a list of tools required for a drive test but it is not limited to these. Additional tools/software may be required depending on the objective or purpose of the test.

Item no.

Tool Available(Y/N) Comment/ Status

1 Laptop 2 Laptop power adapter3 Handset(s) 4 Handset charger(s)5 Data Cable for handset6 GPS7 GPS Charger (if necessary)8 SIM Card(s) 9 DC/AC Inverter10 DT Software installed 11 DT License (if external)12 External antenna (optional)13 Scanner (if necessary)14 Data Card(s) (if necessary)15 Soundcard(s) (if necessary)


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4.3 NETWORK INFORMATION AND MAPS

Network information should be collected from the client before the test is started. This data should include cell information (e.g. Site Code, Site name, BCCH, LAC, BSIC, TCH, longitude, latitude, Hopping frequencies etc.) and engineering parameters. Maps containing vectors such as main roads, streets, airports, lakes, rivers etc. should also be obtained (not from the client).

This data should then be imported into the drive test devices before starting the test.

4.4 DRIVE TEST ROUTE

Select drive test routes based on test scope, objectives and the client’s requirements. Cluster drive tests should include the coverage areas of each cell and all the major roads and streets as well as any other important locations. Example of a drive test route in a town:

Drive test routes for single sites should include a network of roads close to the site as well as roads far from the site (up to extent of planned coverage distance of that sector/site). This will ensure that there is extensive data for coverage analysis.

4.5 DRIVE TEST SCHEDULE The schedule will be dependent on the scope of work, number of teams, test methods, targets and other conditions and requirements from the client/operator.


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4.6 VEHICLE & TIME ARRANGEMENTS

Arranging appropriate vehicles and test time based on drive test requirements and objectives. Specific time requirements from operator should be satisfied.

For coverage comparison tests, should use the same test vehicles and select consistent test time period.

Ensure that ports for plugging in test equipment in the car are functional before commencing the test.

4.7 TEST METHODSTesting methods vary and should be determined according to operator’s specifications.Testing methods include but are not limited to:

Long call Short call Dual mode ( e.g. If testing a GSM Network with GSM 900 & DCS 1800) Locked on a certain technology or band (WCDMA/GSM etc.)

Long calls are dedicated mobile originating calls (MOC) that are usually 120sec long (varies according to operators specifications). It is used to test retainability of a voice call in a network. Short calls are dedicated mobile originating calls (MOC) that are usually 15-30 sec long (varies according to operators specifications). It is used to test accessibility of a voice call in a network.

4.8 CONFIGURATION OF DT DEVICES/SOFTWAREThe following configurations should be carried out before commencing the test:

Install DT software and necessary drivers and ensure it is operating properly. Connect the GPS to the USB COM port and configure it using device manager Connect the test phone through the USB COM port and configure it as well. Open the drive test tool (already installed); import the maps (vector form). Create cellfiles (site info) using network information and import into the DT devices. Ensure all necessary configurations i.e. Frequency bands, technology, time

measurements, number of call repetitions or sequences to be used etc. are done. Configure the parameters that you have to be notified about during the drive test e.g.

handover failure, call drop, blocked calls, GPS failure, Attach, Detach etc. Set legends for the particular measurements required e.g. Rx Level, Rx Qual, C/I etc. Save workspace to avoid resetting again.


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5.0 IMPLEMENTATION

5.1 POSITIONING OF TEST EQUIPMENTHandset is placed in front of the drive tester for clear visibility. GPS is placed at the front of the car or on the roof of the car if the base is magnetic.If handset external antenna is used, it is placed on the roof of the car. Care should be taken that the antenna does not break when passing through bushy areas.

5.2 VEHICLE SPEED DT should be carried out at speeds of 40km/h to 55km/h. In towns a speed of 40km/h is used.

5.3 CONNECTIONS

Connect the inverter to the car DC port. The car should be on during this time. Connect the laptop to the power source to facilitate reliability when taking data. Connect the GPS to the USB COM. Configuration already done. Connect the test phone through the USB COM port. Open the drive test tool (already installed).Imported maps and sites should already be

there. Ensure all configurations are done. Start recording.

5.4 RECORDING TEST FILE INFORMATIONSave log files in predefined or selected folder. Every software has its own format of naming the file and the file name may be changed to include the site name/code_sector_date if desired.


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5.5 MONITORING INFORMATION AND SIGNALLING

Various information elements and events are monitored during the test depending on the technology being tested and the type of drive test being carried out. Signaling messages obtained from analyzing layer 2 and/or 3 messages.

Analysis is done using tools such as MapInfo Professional, TEMS Route Analysis, TEMS Discovery, Nemo Analyzer, Actix among others.

The common information elements and events monitored are shown below:5.5.1 Voice call

Rx Level Rx Quality Interference Dropped calls Blocked calls Anomalous events Call statistics Service level statistics QoS information Handover information Neighboring cell information Mean Opinion Score (MOS-if Voice quality test is done) GPS location co-ordinates


Sample of Rx level results Sample of C/I Results

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5.5.2 GPRS test

The success rate, failure rate and time taken to complete the following events:

GPRS Attach GPRS Attach Failure GPRS Detach GPRS PDP Context Activation GPRS PDP Context Activation Failure GPRS PDP Context Deactivation Ping response Ping success Ping timeout Average Throughput DL & UL Coding Scheme

Example of graphs and reports for GPRS test:


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5.5.3 WCDMA Test

The following are some of the information elements and events analyzed:

UL/DL Coverage Pilot strength (Ec/Io) Received Signal Code Power (RSCP) Call drop Handover rate UL/DL interference Pilot pollution

Example of information that can be analyzed from WCDMA tests:

After post processing and analyzing the log files, generate a report containing necessary maps, graphs and tables of the information elements and events observed and analyzed.

Recommendations to optimize the network should be made.

6.0 HAND-OVER PROCESS


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Necessary drive/walk test log files, complete drive/walk reports with recommendations should be handed over to the client.

1. OPTIMIZATION


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7.1 FLOW CHART

7.2 IMPLEMENTATION


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Recommendations made are dependent on the events /failures observed during the test.Common recommendations include (but are not limited to):

Antenna mechanical & electrical tilt changes. Antenna azimuth changes. Antenna Downtilt/Uptilt Addition or removal of neighbors. Power Control Frequency changes i.e. BCCH, SC BSIC changes Increase/decrease HO Margins. Antenna height changes. Checking of antenna feeders/ jumpers VSWR Sweeps Checking on and replacing faulty site equipment. Changing BSS parameters.

Before making any changes to the network, they should be verified with the client/operator.Once changes are made a new drive/walk test should be carried out.New results should be post processed and analyzed. If improvements in the network are observed then reports and log files should be generated and handed-over to the client.If no improvements are observed then the optimization process should be restarted.

8.0 APPENDIX


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BCCH Broadcast Control ChannelLAC Location Area CodeCI Cell IdentityBSIC Base Station Identity CodeGSM Global System for Mobile CommunicationGPRS General Packet Radio ServiceEDGE Enhanced Data Rates for GSM EvolutionWCDMA Wideband Code Division Multiple AccessCPICH Common Pilot ChannelRSCP Received Signal Code PowerSC Scrambling Code

9.0 REFERENCES


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1. http://en.wikipedia.org/wiki/Drive_testing 2. http://en.wikipedia.org/wiki/GSM_Radio_Frequency_optimization

-End of Document-


http://en.wikipedia.org/wiki/GSM_Radio_Frequency_optimization

http://en.wikipedia.org/wiki/Drive_testing

Documents

Radio Network Drive Test Guide