GPCR-D: a Topology and Position based Routing Protocol in VANET

Compared with traditional GPCR, there are three differences in the new GPCR-D: 1) GPCR-D is a topology and position based routing protocol. 2) It can detect dynamically the network density and establish the local areas with high node density, where vehicles' speed is limited and topology changes slowly. Therefore, we adopt shortest path algorithm aimed at delivering packets speedily. While outside the local areas, topology changes rapidly, so greedy forwarding is used to avoid restoring and maintaining links frequently. Thus GPCR-D makes full use of their respective advantages. 3) The repair strategy of GPCR-D selects the neighbor whose direction is closest to destination in the neighbor table as the next forwarding hop. The simulation shows that GPCR-D works more effectively than GPCR in terms of average delivery success rate and end-to-end time delay.