Hybrid Handover Optimization for Multiple Mobile Routers-based Multihomed NEMO Networks

Network mobility (NEMO) provides continuous connectivity to the Internet to a mobile network when moving from one access router to another. Because of link switching delay and IP protocol operation, packets destined to a mobile network can be delayed or lost during handover period. This paper proposes a solution to improve NEMO handover performance for one kind of multihomed NEMO configuration (multiple mobile routers are located in a mobile network). To manage the traffic between access routers and mobile routers, a new control entity is introduced in order to provide low latency and no packet loss. This entity is also responsible to select the next access point for mobile router when the latter detects its movement. Using this hybrid approach, mobile router can predict a handover and has the best knowledge regarding its current location and state to initiate the handover. In addition, thanks to this entity, mobile router can, based on its current state, perform handover with different strategies, so as to improve handover performance. Despite this new mechanism, no additional function is required to mobile router in our proposition. We have carried out a comparison study of handover performance with NEMO basic protocol, and showed that our proposed scheme provides near-optimal performance in both intradomain and interdomain handover. Furthermore, certain parameters, the distance between two related MRs, the distance of overlapping area and the mobile network speed, which affect the performance of our proposition have also been studied. The results show that seamless handover can be achieved if these parameters are rightly configured.