A Cross-layer Relay Selection Algorithm for Infrastructure-Based Two-hop Relay Networks

Relay selection is a key issue in multihop relay networks. This paper proposes a cross-layer design relay selection algorithm for the infrastructure-based two-hop relay networks by introducing a novel utility function as the relay selection criterion. The proposed algorithm considers both channel state information(CSI) at physical layer and queue state informance (QSI) at data link layer, the goal is to guarantee the diverse QoS requirements for different services. Simulation results show that the proposed algorithm can decrease packet transmission time delay and packet dropping probability significantly while make a slight penalty on system spectrum efficiency. Moreover, it can exploit multiuser diversity gain.