Energy Efficiency Optimization for Dense Networks

The two major challenges for future wireless networks are the ever‐growing data traffic and the increasing energy consumption. This chapter discusses the fractional programs and the methods that can be used to solve these, including Dinkelbach's methods, parameter‐free equivalent transformation, and successive convex approximation. The alternating direction method of multipliers (ADMM) is introduced as a powerful approach for parallel optimization algorithms. The chapter illustrates the applications of these tools in two specific scenarios of dense networks. It presents a case study in which optimization tools are applied to optimize the energy efficiency of a dense network where multiple radio access technologies (RATs) coexist. In an ultra‐dense network, it is reasonable to assume that there are many geographic areas covered by multiple radio access networks (RANs). The chapter investigates resource allocation in a multi‐RAT scenario where users can simultaneously receive data from multiple RANs using multiple air interface.