Cell Zooming for Power Efficient Base Station Operation

With enormous growth in the telecommunication industry, energy efficiency has become a critical issue. Base stations and the core network account for a large amount of energy consumption today. Traditional energy saving techniques switch some base stations off completely during light loads to save energy. This creates problems for the backhaul network and also for quickly returning to full capacity when demand increases. In this paper, we propose novel cell zooming techniques to reduce energy consumption at base stations. With cell zooming, base stations dynamically adjust their coverage radius and hence their transmit powers based on user locations. The transmit power is set to the minimum required level depending on user locations, signal to interference and noise ratio (SINR) and quality of service (QoS) requirements of the users. Base stations are never completely switched off. Our simulations show that the proposed cell zooming algorithm reduces the energy consumption of base stations by up to 40% compared to traditional static-coverage-area base stations without compromising on the QoS requirements of any user in the cell.