A simulation based study of on-demand routing protocols for ad hoc wireless networks

Ad hoc networks are wireless, mobile networks that can be set up anywhere and anytime without the aid of any established infrastructure or centralized administration. Because of the limited range of each host´s wireless transmission, to communicate with hosts outside its transmission range, a host needs to enlist the aid of its nearby hosts in forwarding packets to the destination. However, since there is no stationary infrastructure such as base stations, each host has to act as a router for itself. A routing protocol for ad hoc networks is executed on every host and is therefore subject to the limit of the resources at each mobile host. A good routing protocol should minimize the computing load on the host as well as the traffic overhead on the network. Therefore, a number of routing protocols have been proposed for ad hoc wireless networks. We focus upon on-demand schemes. We study and compare the performance of the following three routing protocols AODV, CBRP and DSR. A variety of workload and scenarios, as characterized by mobility, load and size of the ad hoc network were simulated. Our results indicate that despite its improvement in reducing route request packets, CBRP has a higher overhead than DSR because of its periodic hello messages while AODV´s end-to-end packet delay is the shortest when compared to DSR and CBRP