An energy-saving cooperative small-cell switch on/off optimization for HetNets

The small-cell enhancement has emerged as a promising way to cope with both the explosive growth of need in mobile data traffic and green communications. However, overlaying macro base stations will still take a greater proportion of the network power. Under such an occasion, the design of techniques with an efficient utilization of infrastructure is one of the key challenges in HetNets. In this paper, we improve the network energy efficiency from two aspects. Firstly, we put forward an innovative cell association criterion, where the User Equipment is connected to small cells with top energy-efficiency priority instead of the maximal RSRP, which has a strong impact on the performance of the HetNets in terms of energy saving gains and load balancing. Secondly, a cooperative small-cell on/off optimization scheme is proposed in order to not only minimize the total energy consumption of the network, but also maintain pre-determined data-rate requirements of all users and ensure coverage. In our system-level simulations, the proposed scheme exhibits considerable increase in system energy-efficiency and decrease in outage probability.