A new sip retransmission mechanism based on IMS
一种新的基于IMS的SIP重传机制

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.