Enhanced Multipath Routing Protocol Using Congestion Metric in Wireless Ad Hoc Networks

Abstract

Transmission over wireless ad hoc networks is a challenging problem, because the wireless channel is characterized by limited bandwidth, multi-hop connectivity, mobility of nodes, and dynamically varying network topology. Current unipath routing protocols result in performance degradation in mobile networks due to unreliability of the wireless infrastructure and mobility of nodes. Multipath routing is an attractive alternative for scalable and multiple sub-streamable multimedia traffic under highly error-prone and resourcedepleted network environments. However, existing multipath-capable routing protocols cannot split a single data flow into several sub-flows over a multipath, because these routing protocols use, mostly, an alternate path scheme that provides a secondary path in the event of link failure of the primary path. The Split Multipath Routing (SMR) protocol, which is a major multipath routing protocol based on Dynamic Source Routing (DSR) and uses decentralized transmission over multipath. In enhanced performance, Split Equal-cost Multipath Routing (SEMR) based on SMR is proposed, by introducing ‘congestion path metric’ as a novel metric, which can identify whether the path contains a bottleneck node and guide the selection of other non-congested paths in the path-selecting process. In using proposed concept, superior performance in comparison with SMR and DSR, can be achieved.