A Robust Handover under Analysis of Unexpected Vehicle Behaviors in Vehicular Ad-Hoc Network

With the rapidly increasing demand of traffic applications, the need to support seamless multimedia services in the Vehicular Wireless Networks and Vehicular Intelligent Transportation Systems (V-WINET/V-ITS) is growing. Several mobility support protocols such as the Mobile IPv6 (MIPv6) and the fast handover for the MIPv6 (FMIPv6) have been developed to support seamless handover. However, MIPv6 depreciates Quality-of-Service (QoS) especially for multimedia service applications due to the long handover latency and the packet loss problem. FMIPv6 tries to solve these problems of MIPv6 through handover prediction but the high speed and sudden direction change of vehicles make predictions inaccurate. In this paper, we propose a seamless and robust handover scheme that supports multimedia services in V-WINET/V-ITS. Unlike MIPv6 or FMIPv6 where a new Care-of-Address (nCoA) has to be configured every time when a vehicle meets a new AR (nAR), the proposed scheme continuously maintains the original CoA (oCoA) configured at original Access Router (oAR) and reduces the handover delay caused by the Duplicate Address Detection (DAD). While a vehicle maintains its oCoA, the data packet destined to the vehicle is forwarded from the oAR to the nAR, and finally to the vehicle. At the intersection, the vehicle creates a nCoA to limit the packet forwarding hops between the oAR and the nAR. However, our background DAD scheme reduces the DAD delay at the intersection and also reduces the number of Home Agent (HA) binding updates. Through extensive simulations, we show that the proposed scheme significantly reduces the average handover latency by up to 40%.