A new recovery method for greedy routing protocols in high mobile vehicular communications

Greedy perimeter stateless routing (GPSR) protocol is an appropriate and the most well-known routing protocol for high mobile vehicular ad-hoc networks. The protocol includes two routing modes, the greedy mode and the recovery mode, and utilizes a neighbor list to make a route decision. However, not only does the neighbor list in the protocol involve stale neighbor information, but also the stale nodes inherit a higher selection priority in the greedy mode according to the routing policy; besides, the useful redundant route information can be eliminated during planarization in the recovery mode. To overcome those problems, we propose a new recovery mode, named as greedy border superiority routing (GBSR), along with an adaptive neighbor list management (ANM) scheme. A node generates a border superior graph instead of generating a planar graph when the node faces the local maximum. Packets in the recovery mode can escape from the recovery mode as fast as possible using the graph. Here, GBSR protocol has the same assumption as that of GPSR, and does not require any additional information. With a network simulator, GBSR and ANM are evaluated using two vehicle mobility scenarios. GBSR shows higher network performance in comparison with GPSR protocol. In addition, we accomplish a nearly stale-free neighbor list using the ANM scheme.