Voice over LTE

(VoLTE) Miikka Poikselkä, Harri Holma, Jukka Hongisto, Juha Kallio, Antti Toskala-Voice over LTE-Wiley (2012)This edition first published 2012o 2012 John Wiley Sons LtdRegistered offieJohn wiley sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, Po19 8SQ, United KingdomFor details of our global editorial offices, for customer services and for information about how to apply for permission toreusethecopyrightmaterialinthisbookpleaseseeourwebsiteatwww.wiley.comThe right of the author to be identified as the author of this work has been asserted in accordance with the Copyright,Designs and Patents Act 1988All rights reserved. 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If professional advice or other expert assistance isequired, the services of a competent professional should be soughtLibrary of Congress Cataloging-in-Publication DataPoikselka. miikkaVoice over LTE (VoLTE)/ Miikka Poikselka, Harri Holma, Jukka Hongisto, Juha Kallio and Antti Toskalapages cmIncludes bibliographical references and indexISBN978-1-11995168-11. Long-Term Evolution(Telecommunications)2. Internet telephony. I. Holma, Harri, 1970-IL Hongisto, Jukka IIIKallio. Juha. IV. Toskala. Antti. V. TitleTK510348325P652012621.3845′6-dc232011047199A catalogue record for this book is available from the British LibraryPrint isbn:9781119951681Set in 10/12 Times by Laserwords Private Limited, Chennai, IndiaContentsPrefaceAcknowledgementsList of abbreviationsiBackgroundVOLTE Deployment StrategiesCommon Networks Everywhere2.2 GSMWCDMA View62. 3 CDMA View6VOLTE SYStem Architecture3.1 Overview93.2 LTE Radio103.2.1LTE Radio background103.2.2 TE Radio architecture3.3 Evolved Packet Core143.3.1 What is the Evolved packet Core?143.3.2 EPC Entities and functionalities143.3.3EPS Mobility Management173.3.4 EPS Session Management and Qos03.4 Control223.4.1 What is an IP Multimedia subsystem?3.4.2 MS Development History233.4.3 MS Fundamentals263.4.4MMS Entities323.4.5 Home subscriber server423.4.6 Policy and Charging rule Function433.5 SummaryContent:VOLTE Functionality474.1 Overview474.2 Radio functionalities474.2.1 Bearers and scheduling474.2.2 Mobility494.2.3 Circuit switched fallback handover514.2.4 Mobility from 2G/3G Back to LTE544.2.5 Power Saving Features554.2.6 Positioning Solutions564.2.7 UE Radio Access Capabilities for VOLTE574.3 EPC Functionalities584.3.1 LTE subscriber identification594.3.2 PDN Connectivity Establishment for the VOLTE User4.3.3 EPS Dedicated Bearer Setup4.4 MS Identification654.4.1 IP Multimedia services Identity module664.4.2 Public User Identity674.4.3 Private User Identity674.4.4 Relationship between Private and public User Identities4.4.5 Identification of User's Device684.4.6 Identification of Network entities704.4.7 Identification of services(Public service Identities)704.4.8 Identification Without ISIM704.5 IMS Service Provisioning714.5.1 Enforcement of allowed services724.5.2 Service-Triggering Information734.5.3 Selection ofas754.5.4 As Behaviour4.5.5 Service Provisioning in Action764.6 IMS Multimedia Telephony794.6.1Introduction794.6.2 Multimedia communication804.6.3 Supplementary Services81VoLTE End to End and signalling995.1 Overview5.2 VOLTE Subscription and Device Configuration1005.3 EPS Attach for CSFB/IMS VoIP and Default bearer Activation1025.4 IMS Registration1074. Constructing the REGIsTER Request1095.4.2 From the Ue to the p-CSCF1105.4.3From the p-cscf to the -CscF1105.4.4 From the -Cscf to the s-CSCF5.4.5 S-CSCF Challenges the uel11Contents5.4.6 UE's Response to the Challengel125.4.7 Registration at the s-CsCF1135.4.8 The 200(OK) Response1135.4.9 Third-Party Registration to Application Servers1145.4.10 Subscription to Registration Event Package1155.4.11 Re-Registration and Re-Authentication1155.4.12 De-Registration1165.4.13 Related standards1175.5 IMS VOIP Session5.5.1 Constructing the INVITE Request1205.5.2Routing1225.5.3 Media negotiation1275.5.4 Media resource reservation and Policy control1295.5.5 Charging1355.5.6Session release1415.5.7 Related standards1435.6 Voice Continuity1445.6.1 PS-PS Intersystem Handover1445.6.2 Single radio voice call Continuity14556.3Summary1575.7 IMS Emergency Session5.7.lPDN Connection Setup for Emergency Session5.7.2 Emergency Registration16l5.7.3 Emergency Session1635.8 CS Fallback for Evolved Packet System Call Case(s5.8.1 Architecture of Cs Fallback for EPS1665.8.2 Description of sGs Interface1685.8.3 dle Mode signalling reduction and Use of csFallback for EPs1695.8.4 dle mode versus active mode ue with csFallback for EPs1725.8.5 CS Fallback attachment1735.8.6 Mobile Originating Call Using CSFB1745.8.7 Mobile Terminating Call Using CSFB1805.8.8 Call Unrelated CsfB procedures1875.8.9 Mobile Terminating roaming retry and Forwarding1895.8.10 Summary1935.9 VOLTE Messaging1945.9.1 Native IMS Messaging19459.2SMS Interworking19659.3Multimedia Messaging service2145.9.4 Unstructured Supplementary Services Data Simulation in IMS21459.5Summary215vIllContent:IMS Centralized services217VolTE Radio performance2237. 1 Coverage2237.2 Capacity2247.3Latency2267.4 Summary2288HSPAⅴ oice over ip90References233Index237PrefaceVoice communication has become mobile in a massive way and the mobile is the preferredway for voice communication for more than six billion subscribers. The introduction ofgh speed packet access (HSPA) also allows a large set of data services from smartphones,tablets and laptops to go mobile. The data volumes in mobile networks greatly exceedthe voice volumes- from the traffic point of view networks have already turned fromvoice dominated to data dominated. The next generation mobile radio system, called longterm evolution (LTE), started commercially in 2009 and is designed to boost further thedata rates and capacities. LTE radio is primarily optimised for high capacity data but canalso support voice efficiently During 2012, smartphones with the capability to provide avoice service using the ltE network are becoming available. This book describes how thevoice service is supported with lte capable terminals. The voice support in LtE is not astrivial as in second generation(2G) GSM and third generation(3G)WCDMA Solutionswhere circuit switched(Cs) voice was used, since LtE is designed only for packetswitched(PS)connections. The voice service in LTE uses the voice over Internet protocol(VoIP)-called VoLtE (voice over LTE)-together with the IP multimedia system (IMs)There are also alternative solutions for supporting voice in the initial phase where thevoice service runs on legacy 2G/3G networks while only data is carried on LTE. Thevoice solutions, architectures and required functionalities are described in this bookThe book is structured as follows. Chapter I gives the background and Chapter 2describes the operator volte deployment strategies. The system architecture is presentedin Chapter 3 and VoLtE functionalities in Chapter 4. End to end signalling is illustratedin Chapter 5 and IMs centralized services in Chapter 6. The VoltE radio performanceis presented in Chapter 7 and the VolP over HSPA networks in Chapter 8LTE Will access a very large global market-not only GSM/WCDMA operators, butalso CDMa and WimAX operators and potentially also fixed network service providersThe large potential market can attract a large number of companies to the market placepushing the economics of scale, which enables wide scale lte adoption with lower costThe voice solution is a key part of the system design -every single LtE capable smartphone needs to have a good quality voice solution. This book is particularly designed forchip set and mobile vendors, network vendors, network operators, technology managersand regulators who would like to get a deeper understanding of voice over LtEAcknowledgementsWe would like to thank the following colleagues for their valuable comments: JariValimaki, Peter Leis, Curt Wong and martin OttlThe authors appreciate the fast and smooth editing process provided by John WileySons Ltd and especially Susan Barclay, Sandra Grayson, Sarah Tilley, Sophia Travis andMark hammondWe are grateful to our families for their patience during the late night and weekendediting sessionsThe authors welcome any comments and suggestions for improvements or changesthat could be used to improve future editions of this book. The feedback is welcomedtotheauthors'emailaddresses-miikka.poikselka@nsn.com,harriholma@nsn.com,ukka.hongisto@nsn.com,juhakallio@nsn.comandanttitoskala@nsn.comList of abbreviations1×RTTSingle carrier radio transmission technology3GPPThird generation partnership project3GPP2Third generation partnership project 2AAAAuthentication, authorization and accountingAALatM adaptation layerAARAA requestACAAccounting answerACKAcknowledgementACRAccounting requesAGCFAccess gateway control functionA-GNSSAssisted global navigation satellite systemAGWAccess gatewayAKAAuthentication and key agreementALgApplication level gatewayAMRAdaptive multi-rateAMR-WBAdaptive multi-rate widebandAOCAdvice of chargeAPAuthentication proxyAPNAccess point nameAPN-AMBr Access point name-aggregate maximum bit rateARPAllocation and retention priorityASApplication serverASAabort session answerASRAbort session requestATCHAccess transfer control functionATGWAccess transfer gatewayATMAsynchronous transfer modeAUCAuthentication centreAUIDApplication usage identificationAUTNAuthentication token