Low-Carb: Reducing energy consumption in operational cellular networks

Electricity costs are a significant fraction of a cellular network's operations costs. We present Low-Carb, a practical scheme to decrease electrical energy consumption in operational cellular networks by coupling Base Transceiver Station (BTS) power savings with call hand-off—two features commonly used by cellular operators. Motivated by the practical observation that most callers are in the vicinity of multiple BTSs, Low-Carb presents and solves an optimization problem, allowing calls to hand-off from one BTS to another so that BTS power savings can be applied to a maximal number of BTSs throughout the cellular network. We use BTS locations and traffic volume data from a large live GSM network to evaluate the power savings possible using our proposed approach in Low-Carb. Our results indicate that for a GSM 1800 network operator with 7000 sites in an urban setting, a total of up to 35.36 MWh may be saved annually. This is at least 9.8% better than the energy savings obtained by just using BTS power savings alone. Other cellular operators can use the Low-Carb formulation with their own network data to estimate the electricity savings they may achieve on their networks.