SIP as an enabler for convergence in future wireless communication networks

The session initiation protocol (SIP) is the IETF signaling protocol for VoIP (voice over Internet protocol) and other text and multimedia sessions. 3GPP has begun the evolution to "all IP access" with the introduction of MSC Server-SGSN split in Release 4 and subsequent introduction of the IP multimedia sub-system (IMS) in Release 5 and 6. The long term evolution of 3GPP strives to achieve seamless mobility with the evolved-RAN (E-UTRAN) and inter-working with multiple access technologies over the common core network based on IP-all IP access network (AIPN). The arrival of mobility in the broadband systems such as 802.16e and 802.20 has propelled the industry trend towards ubiquity and seamless mobility irrespective of the access technology. SIP works as an application layer signaling protocol over the IMS infrastructure to facilitate convergence between the broadband providers and wireless carriers. This paper delivers the convergence model for inter-working and handovers using SIP over the IMS infrastructure. We propose the enhancement of SIP towards real-time conversational multimedia session transfer to realize the full potential of all IP access networks