Congestion-aware Multipath Routing in Ad hoc Networks

In an ad hoc network with flooding-based on-demand routing, many routing messages are propagated unnecessarily. Besides, the widely used minimum hop-count routing metric could not guarantee to find a network high-throughput path. For the above questions, we present a Congestion-aware Multipath Routing (CMR) algorithm in ad hoc networks. In the route discovery, by introducing parameter E which is related with the node density of the network, we propose the distance-based flooding constraint broadcasting. It restricts flooding in a certain area according to the node density, but guarantees almost all nodes to receive the packet. Route selection and traffic distribution among multipath of CMR algorithm are based on the link quality and node queue length. The proposed algorithm can find high throughput routes and decrease end-to-end delay. Simulation results show that the CMR algorithm achieves better performance than MSR [1] in terms of packet delivery fraction, end-to-end delay and routing overhead.