Minimizing power consumption in HetNets with packet delay constraints

Heterogenous cellular networks can improve network capacity by co-deployment of macro and femto base stations (BSs). The capacity improvement comes with a higher power consumption. This paper proposes a method to minimize the power consumption without compromising the quality-of-service demand which is measured in terms of packet delay. First, we derive a closed-form expression for the packet delay as a function of macro and femto BS densities. Then, we determine the BS densities that minimize the network power consumption under a packet delay constraint. Evaluation results show that heterogeneous networks always outperforms a homogeneous network in terms of power-delay characteristics. With the optimal BS densities for a given packet delay requirement, the minimum power consumption of a heterogeneous network is always lower than that of a homogeneous network.