A Decentralized Sleep Mechanism in Heterogeneous Cellular Networks With QoS Constraints

We introduce a sleep mechanism for energy efficiency in heterogeneous cellular networks, where macro base stations and small base stations coexist in the same frequency band. The strategy is to put high-power macro base stations into sleep mode and off-load the users to low-power small base stations or neighboring macro base stations. To do so, we first formulate a joint optimization problem to minimize the total energy consumption while maintaining the QoS of users. Then we decouple it into two subproblems: user association and resource allocation, and macro base station sleep mechanism. We propose a modified many-to-one matching algorithm to solve the first one and a voting-based dynamic sleep mechanism for the second one. Simulation results show that our scheme has both lower energy consumption and lower user blocking ratio compared with existing sleep mechanisms.