Rev A LMF/R/G/A/D Juha Sirkka3.6.2003 1

Diploma thesis presentation3 June 2003

Juha SirkkaOy L M Ericsson Ab

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Configuration, verification and optimisation of handover functionality in UMTS/GSM network

• SupervisorProfessor Sven-Gustav HäggmanS-72, Communications laboratory

• InstructorAnssi Kulju M.Sc.Oy L M Ericsson Ab

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Agenda

• Introduction (background, motivation, scope, objectives)• Literature review• Configuration• Verification and troubleshooting• Conclusions• Further study

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Background

Research carried out atGlobal Services Delivery Center (GSDC) Helsinki

• Support organisation for market units in Europe

• Provides technical competence services such as network integration, software supply, support etc.

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Motivation

• Commercial 3G launches in Europe – 2003• Operators have significant investments in 2G

(not many ”greenfielders”)• Coverage extension achieved with GSM

Seamless UMTS – GSM interwork placed high on operators’ priority list

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Scope

Inter radio access technology handover (IRATHO) of one circuit switched (CS) conversational radio access bearer (RAB) from UMTS to GSM

• No inter RNC mobility• No packet switched traffic• No idle mode behaviour

• Basic functionality, activating the UMTS – GSM interwork

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Objectives

Find an efficient way to:

• perform the feature activation of IRATHO in a combined UMTS/GSM network,

• verify the succesful feature activation,• perform troubleshooting to ensure the succesful feature

activation.

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Literature review

• Network overview (UTRAN, GSM RAN, core network)• Signalling interfaces and protocols (RANAP & RRC !)• Handover, basic concepts• IRATHO theory and a detailed example

• Mostly interpreting 3GPP technical specifications and comparing it with Ericsson documentation

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Configuration, core network & GSM RAN

• Establishing the connection between 3G and 2G• Ensuring that GSM can work as a target system

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Configuration, UTRAN

• Basic configuration:Measurement & handover triggersRetry parameters

• Cell relations:External GSM cellsCell relations

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Verification and troubleshooting

• Presenting the test arrangement

• Step-by-step verification, showing that necessary conditions are met

• Preferred workflow presented for troubleshooting- Measurement phase- Relocation preparation and execution phase

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Test arrangement

• Uu/Um interface via cables or over the air

• In both cases separate attenuators for 3G and 2G

• Monitors for UE and RNC

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Conclusions

• Configuration process:

• Troubleshooting flowcharts:

• Literature review gathers up the background information on subject

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Further study

Optimisation of IRATHO

• Tuning:Handover preparation and execution

• Follow up:Counters, measurements and subscriber feedback

• Creation of technical feedback for tuningfrom follow up information

Tuning Follow up

Feedback

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Questions?