The Application Of RTSP Extension In The MMS Sytem

In recent years, with the rapid development of mobile telecommunications network in china, SMS(Short Messaging Service), which provides short text exchange service, has got great success. The next generation messaging service following the SMS is EMS (Enhanced Messaging Service). EMS, which provides image service, becomes very popular too. But with the deployment of more bandwidth and more service requirement, EMS cannot satisfy customers' demand. In 2.5G and 3G network, the MMS (Multimedia Streaming Service), which provides video and audio function, develops very fast.The MMS system is composed of many network elements. The MMS system provides basic http download mode and small data trunk download mode which is based on RTP (Real-Time Transport Protocol) to transport video and audio information. However the interface between the MMSC (Multimedia Messaging Service Center) and streaming server is not standardized in the current MMS architecture. Nowadays most of the streaming servers support RTSP (Real-Time Streaming Protocol), but RTSP can only support part of the functions of the interface between MMSC and the streaming server. Now RTSP cannot provide all interfaces between MMSC and the streaming server. It also cannot provide the synchronization of different databases. So it is necessary to use RTSP extension to support all the functions.This thesis uses Darwin streaming server (DSS), which supports SDP (Session Description Protocol), RTP and RTSP, as streaming server to illustrate the extension of RTSP to support the communication between MMSC and DSS. Lots of work has been done on RTSP module and its encrypted module. An MMSC simulator is adopted to test the RTSP extension implement on the basic modules of DSS RTSP. The functions using the RTSP extension as interfaces between MMSC and DSS are implemented and studied in this thesis.