SIP虽然被选定为IMS的核心呼叫/会话控制协议，但消息过长也成为了SIP在IMS无线环境下应用时的瓶颈。在SigComp框架下，通过对各种压缩算法的比较，结合SIP协议消息特点选择LZSS算法作为SIP信令压缩的基本算法。为了进一步提高SIP协议消息的压缩比，提出了基于LZSS＋Huffman的SigComp压缩算法，并对该算法的压缩效果进行了仿真分析。

Session initiation protocol(SIP) has been chosen as the call/session control protocol in IP multimedia subsystem(IMS). However, large SIP messages create a bottleneck for SIP application in IP multimedia subsystem(IMS) in wireless applications. Based on the SigComp, and by comparing various compression algorithms, lempel ziv storer szymanski(LZSS) is selected as the basic algorithm to compress SIP in accordance with the characteristics of messages in SIP protocol. To further improve the compression ratio, a new algorithm is proposed based on LZSS and Huffman. The performance of the compression algorithm is analyzed via simulation.

重庆市信息产业发展资金资助项目（2007ZB12003b）