一种新的基于IMS的SIP重传机制

A new sip retransmission mechanism based on IMS

目前,IP多媒体子系统(IMS)中基于会话初始化协议(SIP)的会话建立时间受到无线信道约束带宽、帧错误率(FER)值的影响,交换的消息数量、消息长度以及重传机制对于会话建立的时延有很大的影响,延长了会话建立的时间。将基于SIP的会话建立与无线信道的性能结合,提出一种新的SIP自适应重传机制。实验结果表明,该重传机制缩短了会话建立的时间,对IMS端到端的服务质量(QoS)性能有明显的改善。

At present, the session setup time based on the Session Initial Protocol （SIP） in IP Multimedia Subsystem （IMS） is affected by the constrained bandwidth of the wireless link, Frame Error Rate （FER）. The number and size of the message exchanged affect the average session setup delay, which can result in retransmission of packets lost and can lengthen the session setup time. In this paper, both the session setup and wireless link were taken into account and a new adaptive retransmission mechanism that was adjustable to the size of signaling packets involved in the session establishment was proposed. The numerical results indicate that the proposed new mechanism can make the session setup shorter and is efficient for optimizing the time of session setup.