An Improved Inter-Domain Handover Scheme Based on a Bidirectional Cooperative Relay

In the process of inter-domain handover, according to the partner-based hierarchical mobile IPv6 protocol (PHMIPv6), the longer configuration time for a new care-of-address may cause an interrupt in the current wireless connections and cause higher handover latency and packet loss rate. This paper proposes an improved handover mechanism based on PHMIPv6, named B-CDHO. A fPN and bPN are defined respectively in B-CDHO as cooperative relay nodes during the handover process. fPN can get the new care-of-address instead of a mobile terminal before the handover triggers and bPN can avoid connection interrupt if the prehandover time is longer. The analysis and simulation results both show that B-CDHO can reduce the handover latency and packet loss in comparison to HMIPv6 and PHMIPv6 in case the pre-handover delay is longer.