Incorporating MIP and SIP for Cross-Layer Fast Handoff in IPv6 Networks

Mobile IP and SIP are well-known approaches to support mobility. However, the triangular routing involved in Mobile IP makes it unsuitable for real-time RTP/UDP multimedia traffic, and SIP may cause the disconnect of ongoing TCP communications. To provide a cross-layer fast handoff in an IPv6 network, we propose incorporating both approaches to address different transport protocols. Because movement detection and IP address acquisition are the most time-consuming tasks during handoff, the proposed scheme utilizes a link-layer trigger and IP address pre-allocation to achieve fast handoff. It also takes into account the projected path of the mobile node. The experimental results show that for SIP mobility, handoff latency of the proposed scheme is 353.7 ms, less than one-fourth the 1596.7 ms of the original scheme. For Mobile IPv6, handoff latency of the proposed scheme is 1014.2 ms, just over one-half the 2011.2 ms of the original scheme. The average handoff frequency improvement in the scenarios of moving randomly and moving straight are 3% and 27%, respectively. This indicates that the proposed scheme can effectively reduce not only handoff latency but handoff frequency.