||Traffic volume in cellular networks has increased considerably during recent years and is expected to continue at an exponential rate. As a result, the Third Generation Partnership Project (3GPP) has proposed Heterogeneous Networks, which add low power nodes such as pico cells and femto cells to the existing Homogeneous Networks, to improve system capacity. With the wide deployment of the base station, it increases the capacity of the networks, whereas the energy consumption also increases.|
In Release 12, 3GPP sets a standard of “D2D” communication technology, so that the two devices can communication directly without through the base station. In addition, D2D has the advantage of enhancing the system capacity and reducing the transmission time and device power consumption and so on. In Release 13, 3GPP proposes the concept of relaying to combine it with D2D communication, so that it can extend the network coverage further.
Of switching off base station, the scenario previous studies most consist of traditional cellular users. Therefore, in this paper we joint the D2D communication technology and D2D Relay technology. In this scenario, we consider how to select the base station into sleep mode and how to manage the users to handover to the neighbor’s base stations, so that we can achieve the better energy saving effect. We propose a BTS on/off algorithm and user association algorithm in order to have the better energy saving effect. Finally, simulation results show that the proposed methods have better energy consumption and throughput, compared with the existing methods.