Andrew Rebeiro-Hargrave PhD, Nokia Networks, Finland. As Nokia Networks Multimedia Interoperability Manager, he is responsible for Interoperability testing of Nokia Push to talk, XDM and Presence enablers at OMA TestFests. He has been working with Nokia Push to talk (PoC R&D) as Product Competence Transfer Manager since 2001. In addition to technical work, he has published journal articles in the field of geographical modelling and teaches Geocomputation as a guest lecturer at the Helsinki University.

David Viamonte, Vodafone, will enhance the contents and contribute the operator perspective. In addition, to his telecommunication background, David has experience at Vodafone Global, Düsseldorf in selecting Push to talk technologies.

Foreword. Preface. Acknowledgements. Abbreviations. 1 Group Communication Concepts. 1.1 Introduction. 1.2 Group Communication Roles. 1.3 Mobile Group Communication Use Cases. 1.4 Multimedia Group Communication Implementation. 1.5 Summary and Conclusions. 1.6 References. 2 OMA Push to Talk Architecture. 2.1 Introduction. 2.2 Architectural Considerations. 2.3 OMA PoC Functional Architecture. 2.4 PoC Client. 2.5 XML Document Management Client. 2.6 PoC Server. 2.7 PoC XML Document Management Server. 2.8 External Entities Providing Services to PoC System. 2.9 Description of OMA PoC Reference Points. 2.10 Summary and Conclusions. 2.11 References. 3 The OMA XML Document Management (XDM) Enabler. 3.1 Introduction. 3.2 The OMA XDM Architecture. 3.3 XDM Reference Points.

3.4 The XML Capability Access Protocol (XCAP). 3.5 User Authentication and Authorization. 3.6 XCAP Applications and Documents Used in OMA XDM. 3.7 Summary and Conclusions. 3.8 References. 4 The OMA Presence Service. 4.1 Introduction. 4.2 General Presence Concepts. 4.3 The OMA Presence Service. 4.4 The Resource List Server. 4.5 XDM Presence Applications: Presence Policies and Resource Lists. 4.6 Enhancing PoC User Experience with Presence Capabilities. 4.7 Summary, Conclusions and Some Final Comments about the Presence Service. 4.8 References. 5 Deploying Group Communication with IMS. 5.1 Introduction. 5.2 3G IP Multimedia Subsystem (IMS) Concepts. 5.3 OMA PoC over IMS. 5.4 IMS User Identity Management.

5.5 IMS Connectivity.

5.6 Charging PoC Services with IMS.

5.7 Device Management.

5.8 Radio Access Network Parameters. 5.9 Summary and Conclusions.

5.10 References. 6 Examples of Group Communication Sessions. 6.1 Introduction. 6.2 PoC Service Registration.

6.3 Ad-hoc Group Session. 6.4 Pre-arranged Group Session. 6.5 Chat Group Session.

6.6 Restricted Chat session example.
6.7 Talk Burst Control Procedures without Queuing. 6.8 Talk Burst Control Procedures with Queuing.

6.9 Summary and Conclusions. 6.10 References. 7 Value Added PoC Services. 7.1 Introduction. 7.2 Value Added PoC Service Roles. 7.3 Integrating PoC Service with Existing Value Added Services.

7.4 Push-to-Infotainment.

7.5 Location Based Services with PoC and Presence. 7.6 PoC PC Client Example. 7.7 PoC for Vertical Segments. 7.8 Summary and Conclusions.

8 OMA PoC2 Group Communication Concepts. 8.1 Group Communication Roles. 8.2 Multimedia Group Communication Use Cases.

8.3 Multimedia Group Communication Implementation.

8.4 Summary and Conclusions.

8.5 References. 9 Multimedia Group Communication Evolution: PoC2, XDM2, Presence 2 and Simple IM. 9.1 Introduction. 9.2 Architectural Elements of OMA PoC2. 9.3 OMA XDMv2.

9.4 OMA Presence Version 2. 9.5 OMA SIMPLE Messaging. 9.6 Summary and Conclusions. 9.7 References. Index.