A rate adaptive and multipath routing protocol to support video streaming in MANETs

In this paper, we propose a solution consisting of two methods to provide reliable and efficient transmission of video streams over mobile ad-hoc networks. Our first method is a cross-layer rate adaptation scheme implemented at network layer. It works on the basis of video coding information provided by application layer. Proposed rate adaptation method adjusts the transmission rate during bursty traffic periods of data sessions according to the transmission rate of underlying wireless communication channel. Due to this, congestion on active routes and number of data packets waiting in nodes' out-going queues are reduced. Secondly, we propose an on-demand node-disjoint multipath routing protocol (NDMP-AODV) based on ad-hoc distance vector routing protocol. In NDMP-AODV, multiple routes between source-destination pairs allow the source to select a backup route in case current route is broken, without initiating a route discovery process. This reduces the routing overhead. We use network layer and physical layer metrics to evaluate the performance and effectiveness of proposed methods. Simulation results verify that proposed schemes not only increase the number of concurrent video sessions, but also decrease the distortion rate of transmitted video streams, thereby increasing the user perceived video quality.