International Journal of Computer Networks and Applications

May Sayed A. Nouh ¹, Salwa H. El-Ramly ¹, M. Zaki ², Husein A. A. Elsayed ¹

Affiliations
1 Electronics & Communications Department, Ain Shams University, Cairo, EG
2 Computers and Systems Department, Al Azhar University, Cairo, EG

Abstract

The Ad-hoc On Demand Distance Vector (AODV) is one of the most famed reactive routing protocols, which is used in Mobile Ad Hoc Networks (MANETs) for routing purposes, where the routes are built only when it is required. The AODV is related to the problem of route constructing and maintaining among any two-node in the presence of the dynamic topology of a network. High routing control packets, during route construction, is a limiting factor of AODV. Also, the route created during route discovery process may not be optimum (in terms of the number of hop counts between the originating and target node). The construction of non-optimal route arises from many reasons such as temporary congestion of one or more links in the short path to the target node, or nodes in those paths may contend the channel late, or the nodes may be busy for that moment to entertain other engagement. Moreover, during the route discovery phase, a large amount of unnecessary control packets may be generated which result in the debasement of the performance and the efficiency of the protocol by congesting the network and increasing the overhead. In this article the cases at which non-ideal routes are created and unimportant control packets generated during route discovery process will be identified. The modified AODV (AODV_MOD) with enhanced route discovery mechanism is proposed that will be used to avoid these cases by suppressing unimportant control packets and avoiding non-ideal routes formation. Simulation results, conducted in network simulator (NS2), prove the skillfulness of the proposed enhanced route discovery scheme from point of view of packet delivery ratio, end-to-end delay, and normalized overhead.

Keywords

Overhear, AODV, DSR, DSDV, RREQ, RREP, Broadcast, Collision and Overhear.

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