Relay Aided Lifetime Prolongation for User Equipments in Hotspots

In this paper, lifetime of user equipments in hotspots is prolonged by combining relay technology and power control policy. As to both cable relay and wireless relay scenarios, effective power control policies are adopted to maximize energy efficiency under the premise of guaranteeing QoS. In addition, the closed-form results for both power control and lifetime gain are obtained, which match well with numerical results. This work extends our understanding about the effect of relay technology on UE´s lifetime prolongation.