DELAR: Device/energy/load aware relaying in heterogenous wireless ad hoc networks

Energy conservation is of great importance for mobile ad hoc networks in which most nodes are equipped with limited energy sources. In this paper, we propose a novel device/energy/load aware relaying scheme (DELAR) for heterogeneous mobile ad hoc networks, where some nodes, called P-nodes, are powered by powerful external or renewable energy sources. In DELAR the heterogeneity of nodal energy capabilities or device types, nodal residue energy information, and nodal load status are nicely incorporated into established routing protocols with the aim of prolonging the network lifetime as much as possible. In addition, we also resolve the rather challenging issue of how to support the MAC-layer acknowledgements in the presence of unidirectional links caused by asymmetrical power capabilities. Unlike other schemes that resort to outband channels or higher layer solutions when facing this problem, we propose an Asymmetric MAC (A-MAC) as an elegant solution. Taking full advantage of P-nodes, DELAR can significantly prolong the network lifetime; meanwhile, it strikes a good balance between power efficiency and the overall system performance. Moreover, our scheme operates in a distributed manner and is easy to implement. Detailed simulation study is carried out to justify and validate the effectiveness and efficiency of our scheme.