A hybrid meshed multipath forwarding scheme in wireless ad hoc networks

Flexibility and robustness are the two key features of multipath routing in multihop wireless networks. While robustness to node failures and link errors is important to achieve high end-to-end throughput, it is also important to judiciously use the routing flexibility to achieve a better traffic load distribution among the network nodes, so that the network lifetime can be extended.In this paper, we study point-to-point multipath forwarding strategies in relatively static but highly error-prone wireless sensor networks. We investigate a multipath forwarding scheme, called selective random forwarding (SRF), and compare its end-to-end throughput and traffic load distribution with respect to selective preferential forwarding (SPF) (or forwarding along primary/secondary routes). We first show that in node disjoint multipath routes SRF has a better overall performance. When considering meshed multipath routes [14], SRF offers a much better load balancing performance but a poorer throughput. Aiming at achieving a good performance trade-off in meshed multipath routes, we introduce a new hybrid packet forwarding scheme that takes the advantages of higher end-to-end throughput in SPF and more uniform load distribution in SRF. Our network performance studies show that while the hybrid approach always offers the throughput performance nearly as good as SPF, its improved load distribution performance becomes more significant with more inhomogeneous network activity. Our approach is guided by analytic intuition and verified by simulations.