On the Selection of Efficient Back-off with QoS Aware Routing in VANET

Abstract

Vehicular Ad-Hoc Network (VANET) is a new communication paradigm creating a network on wheels. QOS becomes critical in VANET because of its unique characteristics, such as high mobility, frequent disconnections, rapidly changing topology, bandwidth constraints. It necessitates the need to assess the suitability of different routing protocols in various vehicular environments. In this paper, we enhanced the default back-off method of MAC 802.11p by embedding other methods, called Binary Exponential Backoff (BEB) and Modified Back-off method (MBA).The three methods are compared and the best among these in terms of QoS parameters is selected for further analysis. Further, the resulting best back-off procedure is considered to evaluate the performance of various routing protocols AODV, OLSR and ZRP. The simulations are carried out using NS2.Nakagami propagation model with different modulation schemes, packet size variations and vehicle densities also used. The performance is investigated in terms of throughput, packet delivery ratio, routing load and end to end delay. The objective is to determine the suitable routing protocol in realistic urban scenarios with an efficient back-off mechanism.