An Efficient On-Demand Multipath Routing in Wireless Ad Hoc Network

Abstract

An ad hoc network consists of a collection of wireless nodes that are capable to communicate with each other without any fixed based-station infrastructure and centralized management. All nodes can be mobile and the topology changes frequently. Each mobile node can operate as a host and as a router, indicating that all of them take equal roles. In ad hoc networks, the responsibility of routing protocol includes exchanging the route information; finding a feasible path to a destination based on criteria such as hop length, minimum power required, and lifetime of the wireless link; gathering information about the path breaks; repairing the broken paths expending minimum processing power and bandwidth. Minimal control overhead, minimal processing overhead, quick route reconfiguration, and loop prevention are the major requirements of a routing protocol in ad hoc wireless networks. This thesis proposes an on-demand Directional Node-Disjoint Multipath Routing (DNDMR) protocol for the wireless ad hoc network. Multipath routing inherently allows the establishment of multipath or multiple routes between a single source and single destination. The important components of the protocol, such as path accumulation with a novel directional method, reducing routing overhead by controlled propagation, and ensuring the node-disjoint paths automatically, are explained. DNDMR improves the reliability of data communication (i.e., fault tolerance) over the wireless ad hoc network. Because DNDMR significantly reduces the total number of Route Request (RREQ) Packets, this results in lower control traffic overhead, smaller end-to-end delays, and better throughput. We evaluate the performance of the proposed scheme with ns-2 simulator and compare its performance with existing unipath routing protocols (DSDV, DSR, and AODV), and multipath routing protocol (AOMDV). Control traffic overhead, end-to-end delay, and throughput metrics are considered for the evaluation. In case of control traffic overhead, the cumulative packets for all mentioned protocols at the end of simulation time are: DSDV (6000 packets), DSR (5000 packets), AODV (2600 packets), AOMDV (2700), and DNDMR (2300 packets), whereas DNDMR is comparatively less than the other protocols. In case of end-to-end delay, DNDMR is faster than DSDV (3.25 times), DSR (3 times), AODV (3.5 times), and AOMDV (2 times). Also, analysis shows that DNDMR throughput is better than the other mentioned protocols. The experimental results reveal that DNDMR has better performance and more reliable than the contemporary unipath and multipath routing protocols.