Fast Handoff for Hierarchical Mobile SIP Networks

Although it was originally developed as an application layer signalling protocol, SIP offers mobility management capability. However SIP Terminal Mobility suffers from considerable handoff latency which is unsuitable for real time applications and frequent local movements (infra domain handoffs). Hierarchical Mobile SIP (HMSIP) was then proposed as a solution to reduce the SIP handoff delay and to provide a complete micro-mobility solution for SIP environments. Unfortunately HMSIP handoff delays remain too high for real time multimedia applications which require handof delay between 50ms and 200ms to guarantee the Quality of Service. In this paper we propose to reinforce the HMSIP by integrating the Predictive Address Reservation (PAR) mechanism to get better handoff performance. A simple integration of PAR-SIP with HMSIP allows not only reducing handoff delay but also signaling overhead.