A Weighted Load Aware Routing Protocol in Mobile Ad Hoc Networks
Weighted Load Routing Protocol Mobile Ad;
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A future mobile computing environment will include both advanced infrastructure wireless networks and novel infrastructure-less mobile ad hoc networks(MANETs). A mobile ad hoc network is a self-organizing system of mobile nodes connected by multi-hop wireless links. Major challenge in such networks is to design an efficient routing protocol to establish and maintain multi-hop routes among the nodes, characterized by the frequent mobility, bandwidth imitation and power constraint. In this dissertation, we study the load distribution in an ad hoc network for reducing the possibility of power depletion and queuing delay in the node with heavy load. We examine the efficiency of dominant ad hoc routing protocols from a point of load balancing with ns2. Based on the simulation results, we design a new Weighted Load-Aware Routing(WLAR) protocol that considers the traffic load, through and around neighboring node, as the primary route selection metric. WLAR protocol includes two new metrics for determining the optimal route and novel route discovery algorithm. The traffic load in WLAR is defined as the product of the average queue size at the node and the number of sharing nodes. The average queue size is an exponentially weighted moving average(EWMA) for the number of packets in an interface queue. A sharing node is a neighboring node, which affects the traffic load of all nodes within its local transmission range. The correlation of these two metric is used to determine the optimal route. For improving the performance of route discovery, we propose the combination of the RREQ-delay and RREP-fast-forwarding. While the RREQ-delay reduces the redundant propagation of RREQ with node disjoint paths, RREP-fast-forwarding reduces the end-to-end delay of RREP with priority queuing discipline at intermediate nodes: differentiated forwarding for routing control packets. The proposed approaches are validated through simulation and real implementation. Simulation studies show that WLAR is better suited for the heavy load networks with low mobility because they reduce the congested areas by distributing traffic among ad hoc nodes. We decide to implement WLAR for validating the proposed algorithms in real environments since it shows potential for achieving load balancing in various simulation scenarios. We implement WLAR on PDA and laptop computer with Linux. The experimental results in real world with simple traffic patterns show that WLAR improves the performance for Internet traffic at heavy traffic load in static scenario (no mobility) and is applicable to real ad hoc networks.