IMPACT ON WIRELESS NETWORKS – COMPARISION OF UNIPATH AND MULTIPATH ROUTING RIGHT ANGLED BAISED GEOGRAPHICAL ROUTING TECHNIQUE (RABGR)

Abstract

In this paper, we analyze the benefits of optimal multipath routing, to improve fairness and increase throughput in wireless networks with location information, in a bandwidth limited ad hoc network. In such environments the actions of each node can potentially impact the overall network connections. This is done by making multipath routing method, named as Right Angled Biased Geographical Routing (RABGR), using AOMDV protocol and two congestion control algorithms, Biased Node Packet Scatter (BNPS) and Node-to-Node Packet Scatter (NNPS), which enhances the RABGR to avoid the congested areas of the network. In RABGR, the term “bias” i.e angle is inserted in each packet which determines the way of the path followed by the packet towards the destination. The bias is treated at each hop as an angle (90°). To avoid spiral trajectories, the modulus of the bias at each hop with a value inversely proportional to the square of the distance to the destination from the current node. The idea from physics as a parallel to natural forces like gravity is taken and the bias is reduced by the formula “bias” = 360° - 270° = 90° (bias). BNPS reduces congestion by splitting traffic immediately before the congested areas. BNPS split flows close to the congestion point. Each node monitors The congested status of all its neighbour and splits the flows that are going towards a congested neighbour. In contrast, NNPS alleviates long term congestion by splitting the flow at the source, and performing rate control. If BNPS cannot successfully support the aggregate traffic NNPS is used. NNPS selects the paths dynamically, and use free resources available in the network in order to avoid congestion .It starts sending packets on two additional side paths obtained with RABGR, searching for free resources and use a less aggressive congestion control mechanism to improve energy efficiency. If the source finds, there is any no other node at 90°, its uses the ant search method, and move to the nearest node and then find the node at 90° and sends the packets. The comparision was made between AODV and AOMDV protocols. After Simulation, the experimental results shows that the solution achieve its objectives. Extensive ns-2 simulations show that the solution improves both fairness and throughput as compared to greedy routing using only single path.