Adaptive relay selection in cooperative wireless networks

The concept of cooperative relaying promises gains in robustness and energy-efficiency in wireless networks. Although protocols for cooperative relay selection were proposed recently, their analysis was made without consideration of the energy required for receiving. Such an analysis is unfair, as relaying requires more receptions than direct source-destination transmission. We consider this lack of analysis and propose two refinements of cooperative relaying. Using ldquorelay selection on demand,rdquo relays are only selected if required by the destination. Using ldquoearly retreat,rdquo each potential relay assesses the channel state and decides whether to participate in the relay selection process or not. Simulation results show that these enhancements reduce the overall energy consumption significantly.