Energy Efficiency Analysis for LTE Macro-Femto HetNets

This paper presents a simulation based energy consumption analysis of a heterogeneous network (HetNet) consisting of Long Term Evolution (LTE) macro-cells and LTE femto-cells. Two potential areas of energy savings are evaluated, namely, sleep modes and spectrum assignment. Sleep modes are demonstrated with practical component level power models, resulting considerable energy savings. Three spectrum allocation scenarios are considered: A) macro and femto nodes with frequency reuse 1 (no coordination), B) macro and femto nodes with frequency reuse 2, and dedicated femto channel with reuse 1, C) reduced bandwidth macro and femto nodes with frequency reuse 2, and dedicated femto channel with reuse 1. The three mentioned scenarios are also compared against an ideal case, i.e. when nodes experience no interference. Our analysis indicate that static partitioning of spectrum is highly energy inefficient and calls for a need to develop dynamic frequency domain intercell interference coordination techniques for HetNets.