A seamless handover scheme for IEEE WAVE networks based on multi-way proactive caching

This paper presents a seamless handover scheme for the IEEE WAVE (Wireless Access for Vehicular Environment) networks based on proactive caching of data packets. In the proposed scheme an On-broad Unit (OBU) uses the IEEE 802.11 disassociation message to inform the old Road-Side Unit (RSU) about its departure from the coverage area such that the old RSU can forward the buffered packets to candidate RSUs for caching. A multicast-based forwarding scheme is used to forward the buffered packets when there are multiple candidate new RSUs around crossroads or diverging roadways. One of the candidate RSUs becomes the new RSU which transmits the cached packets to the OBU upon its entry into the radio coverage. The IEEE 802.11f Move-notify message is used by the new RSU to request the rest of candidate RSUs to purge the cached packets in order to prevent the waste of radio resource. Simulation results show the proposed scheme outperforms a simple multicast-based scheme.