Fast End-to-End Mobility Support Using SIP for Vertical Handoffs in 4G Wireless Communication Networks

The mobility management is a significant issue in 4G heterogeneous networks. However, the mobility needs to be managed by upper layer in the networks because of the limitation of mobility management at link layer. Session Initiation Protocol (SIP) supports personal mobility so that a user can be found independent of location and network device. But it cannot support IP mobility and cannot maintain TCP connection when mobile node (MN) moves between different subnets during a session. In this paper, we propose a new mobility management scheme based on SIP to overcome mobility support problems of SIP. In the proposed scheme, an MN early gets an IP address that will be used in a new subnet and informs its correspondent node (CN) of the address. To minimize packet losses, the MN freezes data transmission during a handoff. The proposed scheme is compared with the previous mobility management scheme through computer simulations.