LTE-Advanced has exploited many state of the art technics to identify itself as the main 4G mobile communication system. Among others, Relay station (RS) serves as an important role of LTE-Advanced, which costs much less, consumes less energy, and has the basic function of base station (BS). RS is able to cooperate with BS in system functioning and allows the system to increase system capacity, enhance spectrum utilization, extend BS coverage, and reduce the power consumption of BS. This paper proposes an Adaptive BS / Relay Switch GREEN System (ASGS), which aims at reducing power consumption through the cooperation of BSs and RSs.

We propose to deploy many RSs instead of BS concerning cost reduction and energy saving. These RSs cooperate in a similar way to the LTE-Advanced CoMP joint processing in order to provide service to uncovered zones. We propose a decision function based on the current traffic load to determine whether to switch on / off the power of each individual BS and RS in order to optimize energy usage with guaranteed QoS. Simulation results show that ASGS is able to achieve significant energy saving at the cost of a bit less throughput.