Enhanced Flooding Scheme for AODV Routing Protocol in Mobile Ad Hoc Networks

Abstract

Mobile Ad Hoc Networks (MANETs) are composed of wireless mobile devices (nodes) equipped with portable radios but without the aid of any centralized management or existing infrastructure such as base-station. Broadcasting is an inevitable operation of route discovery Mobile Ad hoc Network (MANET). Though the broadcast by flooding is simple but inefficient and results in redundant message relays. This in turn over use of limited network resources like channel node energy and bandwidth. The normal flooding scheme is cause high retransmissions which lead to packet collisions and media congestion that can significantly degrade the network performance and throughput. Knowing the geographical position of the mobile nodes can help the protocol to reduce the number of retransmissions, thus enhancing the protocol performance. In this paper, an improved Flooding Algorithm has been proposed that makes use of the nodes' position to rebroadcast the packets and efficiently spread the control traffic in the mobile ad hoc network. The proposed algorithm is applied on the route discovery process of Ad-hoc On Demand Distance Vector (AODV) routing protocol to reduce the number of propagating Route Request (RREQ) messages. The RREQ has been customized by assigning a list to the RREQ contain fourth Nominated Neighbours to Rebroadcast the RREQ (NNRR) and used concept of requested zone and expected Zone to limit area of route discovery. The results produced by simulator shows that our scheme reduces the routing overhead and improves network throughput.