Improving QoS for real-time multimedia traffic in Ad-hoc Networks with delay aware multi-path routing

A mobile ad-hoc network (MANET) is a wireless network in which nodes, in the absence of fixed access points, communicate via single or multi-hop paths. Each node in a MANET should thus be able to perform necessary routing functions, and a MANET routing protocol should be able to adapt fast and effectively to sudden changes in network layout. Providing trustworthy quality of service guarantees in a MANET is very challenging due to the dynamic and uncertain nature of these networks. We extend the AODV routing protocol for MANETs to a multi-path protocol which uses end-to- end delay, instead of hop count, as metric for route selection. Multiple paths, together with the end-to-end delay provided by each path, are stored in routing tables. Upon route failure, the route table is first searched for an alternative route to the destination before a new route discovery process is initiated. This reduces both routing overhead and end-to-end packet delay. The proposed protocol is implemented and tested in OPNET Modeler and shows significant improvements in delay, delay variation, packet delivery fraction and routing overhead compared to AODV, DSR, OLSR and DYMO.