【作者】 赵建伟；

【导师】 李蔚；

【作者基本信息】 北京邮电大学 ， 电磁场与微波技术， 2008， 硕士

【摘要】 近年来,伴随着移动通信网络在我国的快速发展,基于提供交互文本消息的SMS(Short Messaging Service)在我国取得了巨大的成功。接着作为SMS的下一代服务,提供图片服务的EMS(Enhanced Messaging Service)也取得了不错的效益。随着网络带宽以及业务需求的需要,在2.5G以及3G网络中,提供视频音频服务的下一代信息服务MMS(Multimedia Messaging Service)逐渐发展起来。新一代信息系统MMS由很多个网络元素组成。它除了提供传统的HTTP下载模式,MMS系统还会提供流化的不完全下载模式。不完全下载模式利用RTP(Real-timeTransport Protocol)作为传输手段来对视频和音频信息进行传输。然而在MMS现有的体系架构当中,作为MMS系统核心控制器的MMSC(Multimedia Messaging Service Center)与流媒体服务器的接口并没有实现标准化。现有的流媒体服务器使用的接口信令RTSP(Real-Time Streaming Protocol)只能实现接口的部分功能,但却无法实现数据库间的同步。因此RTSP协议必须扩展其现有功能才能实现对MMS系统现有功能的支持。本文以支持RTSP,RTP,SDP(Session Description Protocol)等协议的Darwin流媒体服务器(下文称之为DSS)为例子,对现有RTSP的方法进行了补充和改进,同时进行了对其RTSP协议以及加密模块的开发,并开发了模拟MMS的中心服务器功能的代码作为测试,实现了支持RTSP扩展协议功能的DSS以及MMSC。提出了从MMSC到流媒体服务器的一套标准的规范。更多还原

【Abstract】 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.更多还原