INVESTIGATING MULTIPLE QoS METRICS FOR THE IMPROVEMENT OF AODV PROTOCOL IN MANET

Abstract

Mobile ad hoc network is a type of wireless network known by their characteristics such as infrastructure less, node mobility, frequent topology change, lack of central coordination and hence along. They are an aggregation of nodes capable of wireless communication. During the communication, node acts as sender, receiver or as a relay between the source and destination. Hence the node acts as both end devices and routers. These characteristics make it hard routing in MANET. Providing routing based Quality of Services needed by applications is more challenging due to instability of links between those nodes. In this paper, we have proposed QoS enabled AODV protocol, which selects a path based on residual bandwidth, delay and jitter on the path. To calculate the residual bandwidth we used hello bandwidth estimation. Delay and jitter on the path also calculated from hello message and putted on RREQ messages during the route discovery process. Finally, route reply part of AODV will make the decision of route selection based on the value of path cost; which in turn calculated from the value of bandwidth, delay and jitter. In case two paths have equal path cost, the selection will be based on hop count. We simulate our proposed approach on NS2 simulator. We have evaluated the efficiency of our protocol based on the packet loss ratio, throughput, end to end delay, and overhead. We have also compared original AODV and our QoS enabled AODV using the above mentioned parameters (packet loss ratio, throughput and end to end delay) and achieved competitive result; yet our approach showed little bit overhead.