DSRC-based channel allocation algorithm for emergency message dissemination in VANETs

Abstract

VANET (Vehicular Ad-hoc Network) is divided into V2V (Vehicle-to-Vehicle) communication and V2I (Vehicle to Infrastructure) communication. V2V requires no infrastructure or roadside devices and vehicles communicate with each other using wireless inter-vehicle communication. V2I requires some infrastructure such as RSUs (Road Side Units). OBUs (On Board Units) installed in vehicles can access to backbone networks by using RSUs. Unlike MANET (Mobile Ad-hoc Network), VANET requires a mechanism to accommodate the environment that the moving speed of vehicles is very fast and the network topology changes frequently. VANET can use IEEE 1609.4 that supports multi-channel operation. The multi-channel approach of IEEE 1609.4 uses orthogonal channels to communicate between RSU and OBU. However, if emergency messages should be processed in high priority, the delay time will be increased because the multi-channel approach makes a fair share of available channels. Therefore, this paper proposes DMAE (DSRC-based Multi-Channel Allocation for Emergency Message Dissemination) algorithm to resolve this problem. DMAE allocates the highest bandwidth channel to the urgent message firstly, and guarantees QoS between RSU and OBU through periodic channel switching. Simulation results using ns-2 show performance improvement in terms of end-to-end delay and emergency message delivery rate. © 2011 Springer-Verlag.