Small cell switch policy: A consideration of start-up energy cost

In this paper, we focus on the energy consumption problem in heterogeneous networks with on-off switch operation for small cell base stations (SBS). In our scenario, the users in the small cell can either choose SBS when it is awaken or macro cell base station (MBS) to transmit data. The start-up cost is considered when SBS switches on. We suppose both the transmission power and the users´ number are time-varying. According to the knowledge on these two variables, we classify the energy consumption problem into two cases. In complete information case, to minimize the energy consumption, an offline solution is proposed according to critical segments. A heuristic algorithm for incomplete information case (HAIIC) is proposed by tracking the cumulative energy consumption difference. Further more, we derive the upper bound of the energy consumption ratio (ECR) to guarantee the performance of the proposed algorithm. To evaluate the impact of future information, a look-ahead window with size ω is supposed. The corresponding upper bound of ECR is derived as well. Simulation results show that the proposed HAIIC algorithm is able to save energy efficiency.