An energy-aware relay selection scheme for ALLIANCES

ALLIANCES is a newly proposed wireless MAC protocol that exploits the cooperation of source nodes and relay nodes to resolve collisions and further improve throughput. A relay selection scheme is a significant piece of ALLIANCES, directly affecting the throughput and the energy distribution. Previously researchers have proposed a location relay selection scheme (LRS); this scheme selects the best relay nodes based on the location of each node. LRS greatly improves the network's throughput compared to the random relay selection scheme (RRS); however, LRS does not take into account energy, which is the most precious commodity of mobile communication. In this paper, we propose an energy-aware relay selection scheme (ERS); ERS maintains the performance benefits of LRS, but more evenly distributes the amount to energy remaining throughout the network. Simulation results show that ERS provides 24.3% longer lifetime of the network than LRS, without a noticeable throughput degradation.