Enhanced fast handover for proxy mobile IPv6 in vehicular networks

To reduce the handover latency in PMIPv6, Fast Handover for PMIPv6 (PFMIPv6) is being standardized in the IETF. On the other hand, vehicle-roadside data access has been envisioned to be useful in many commercial Internet services; however, integrating the current Internet into Vehicular Networks (VNs) presents a new set of challenges. In particular, to provide rapid IP handover in the VNs, simply applying PFMIPv6 to VNs may not improve handover performance since PFMIPv6 handover restricts the previous Mobile Access Gateway (MAG) from forwarding the packets until it receives an HAck/HI from the next MAG, even though the vehicle may have already arrived at the next MAG. We also note that PFMIPv6 does not consider the impact of geographic restriction on vehicular mobility. Therefore, in this paper, we propose an enhanced PFMIPv6 (ePFMIPv6) for VNs in which the serving MAG pre-establishes a tunnel with candidate next MAGs for next MAG so that the packets can be immediately forwarded to the next MAG once the serving MAG is indicated the vehicle's handover by the serving road side unit. To evaluate the performance of the proposed protocol, we derive analytical expressions for packet loss, latency and signaling overhead caused by ePFMIPv6 and PFMIPv6 handovers. Our analytical study is verified by simulation results.