A Fast SA Update Mechanism for Secure SIP/IMS Mobility in Integrated UMTS-WLAN Networks

摘要

The 3rd Generation Partnership Project (3GPP) has adopted Session Initiation Protocol (SIP) as the signaling protocol to manage multimedia sessions in the IP Multimedia Subsystem (IMS). When the User Equipment (UE) moves between the heterogeneous networks such as Universal Mobile Telecommunications System (UMTS) and Wireless Local Area Network (WLAN), SIP is used to perform the handoff for SIP-based multimedia services. This paper proposes a Fast Security Association (SA) Update mechanism to improve the handoff performance for secure SIP/IMS access in the integrated UMTS-WLAN environments. Specifically, the Fast SA Update mechanism reduces the SIP messages transmitted between the UE and the IMS. Thus, this mechanism not only reduces the radio bandwidth consumption due to handoff but also saves the battery power of the UE.