Energy Cost Minimization in Green Heterogeneous Cellular Networks with Wireless Backhauls

In this paper, we study the problem of energy cost minimization in heterogenous cellular networks with hybrid energy supplies, where the network architecture consisting of radio access part and wireless backhaul links. Owing to the diversities of mobile traffic and renewable energy, the energy cost minimization problem involves both temporal and spatial dimensional optimization. Our proposed solution consists of four parts: At first, we obtain estimated average energy consumption profiles for all base stations based on the temporal traffic statistics, Second, we formulate the green energy allocation optimization in the temporal domain to minimize energy cost for each BS. Third, given the allocated green energy and practical user distribution in each slot, we propose a user association algorithm to minimize total energy cost in the spatial dimension. Fourth, based on the actual user association scheme, we readjust the green energy allocation for each BS. Simulation results show that our proposed solution can significantly reduce the total energy cost, compared with the recent peer algorithms.