Joint Power-Delay Minimization in Green Wireless Access Networks

The growing energy demands, the increasing depletion of traditional energy resources, together coupled with the recent explosion of mobile internet traffic call for green solutions to address the challenges in energy efficient wireless access networks. In this paper, we consider possible power saving through reducing the number of active BSs and adjusting the transmit power of those that remain active while maintaining a satisfying service for all users in the network. Thus, we introduce an optimization problem that jointly minimizes the power consumption of the network and the sum of the transmission delays of the users in the network. Our formulation allows investigating the tradeoff between power and delay by tuning the weighting factors associated to each one. Moreover, to reduce the computational complexity of the optimal solution of our non-linear optimization problem, we convert it into a Mixed Integer Linear Programming (MILP). We provide extensive simulations for various decision preferences such as power minimization, delay minimization and joint minimization of power and delay. Presented results show that we obtain power savings up to 20\% compared to legacy network models.