SIP-based handoff in 4G mobile networks

It is commonly held that 4G mobile systems will be founded on the Internet joined with diverse access technologies. Future network architecture is regarded as various overlapping wireless access segments. To efficiently support seamless mobility is the most critical challenge to integrate various wireless networks in future heterogeneous networking environment. The characteristics of the lower layer protocols are understandably invisible to SIP which provides mobility in the application layer. Hence, SIP is a promising nominee for managing mobility in heterogeneous networks. However, the performance of SIP-based mobility management is downgraded resulting from adopting TCP/UDP for signaling. In this paper, a soft handoff method, namely Bi-CoA, is proposed to shorten the service interruption time when the mobile node frequently handovers between WLAN and UNITS. The simulation results show that the solution proposed in this paper can efficiently support vertical handoff in future heterogeneous wireless networks.