A congestion-aware GPCR routing protocol for vehicular ad-hoc network in urban scenarios

Flooding broadcast is the main way of vehicular node forwarding packets in Vehicular ad-hoc network (VANET). However this way may cause network congestion especially when multiple broadcast nodes send packets to the same receiving node at the same time. In this paper, a Congestion-Aware GPCR Routing Protocol (CA-GPCR) has been proposed to improve the performance of GPCR routing protocol in urban scenarios. To choose the best next hop node in the restricted greedy forwarding procedure of GPCR routing protocol, we take two factors into consideration: free buffer queue size and the distance between the next node and destination node. We use VanetMobisim and NS-3 simulator to evaluate the performance against traditional protocols in urban scenarios. Simulation results show that CA-GPCR protocol outperforms the traditional protocols in terms of packet delivery ratio and time delay.