Performance analysis of cross layer AODV for heterogeneously powered ad-hoc networks

Heterogeneously powered ad-hoc networks are characterized by asymmetry links. The low power nodes are able to receive from high power nodes but not vice versa. This poses challenges to routing discovery processes of routing protocols, those dependent on symmetry links. In this paper, we propose a cross layer design that effectively improves route discovery and hence the overall performance of heterogeneously powered ad-hoc networks. Our approach identifies and rejects the unidirectional links and seamlessly supports the usage of bi-directional links at the routing layer. This approach is based on calculating the path loss experienced by RREQ packet and judging the ability of the receiving node in delivering the RREP packet to the sending node of the link. That is, it integrates the routing decision of network layer, with signal strength of physical layer. Simulations are performed to study the performance of cross layer AODV (CLAODV) protocol using GloMoSim, the global mobile simulator. This cross layer protocol reduces delay in route discovery and improves packet delivery ratio around 25-35% in the heterogeneously powered ad-hoc network. It also reduces routing overhead around 75-85% and thereby reduces MAC collisions around 70-80%. In summary our design offers a simple, but efficient cross layer routing protocol to support routing in heterogeneously powered ad-hoc networks