The Design And Implementation Of Group List Management Server In The PoC System

PoC (Push-to-talk over Cellular) is one kind of IMS (IP Multimedia Subsystem) service, which supports both 1-1 communication and group communication based on half-duplex VoIP.As an independent enabler, Group List Management Server (GLMS) provides support to manage group list written in XML (extensible Mark-up Language) documents, which are needed by various OMA (Open Mobile Alliance) enablers such as PoC, IM (Instant Messaging) and Presence.As a functional subsystem of PoC, GLMS has group service capabilities including contacts list management, group list management and PoC access policy management. OMA has defined specifications for PoC and GLMS, while IETF (Internet Engineering Task Force) published protocols like XCAP (XML Configuration Access Protocol) and SIP (Session Initiation Protocol) adopted as signaling protocols between GLMS and clients.This thesis focuses on the design and implementation of GLMS in PoC system. On the basis of deeply understanding of related standards published by OMA and IETF, we analyse the service requirements and provide a practicable solution of GLMS in PoC system.The thesis comprises five parts.In the first chapter, we firstly introduce the concepts of PoC and GLMS; then propose a brief presentation of the researches on stardards and specifications of GLMS in PoC system. The objective of our research is described at the end of this chapter.In chapter two, we analyse and classify the functions of GLMS in PoC system and demonstrate several key requirements. The detailed procedure to analyze the signaling messages is also provided.In the third chapter, the architecture of GLMS is suggested, which consists of Aggregation Proxy (AP), Shared XDMS (XML Document Management Server) and PoC XDMS. Each XDMS can be divided into XCAP Server and SIP Server. We also analyze each module in the architecture and propose the details of design and implementation. Lastly we present a list of the data table structures.Chapter four specifies several key issues in GLMS designing, including mechanism of joining a group, modeling on how to parse the list contents in the format of XML, techniques of data persistance, and detailed scheme of list change notifications.The fifth chapter includes the conclusions of the study and our future work.