Green Communication Concepts, Energy Metrics and Throughput Efficiency for Wireless Systems

The chapter provides an accessible analytical framework that can be used to compare the energy consumption and throughput characteristics of different RAN configurations based on the Long Term Evolution (LTE) family of standards. The technical approach is useful for exploring how an LTE RAN may be upgraded in an energy efficient manner to meet the expected growth in mobile data traffic. The approach also allows particular energy saving techniques to be evaluated, such as deployment techniques (e.g., cell size and RAN topology) and power state techniques (e.g., sleepmodes). The analysis uses accurate energy consumption models of base station and access point equipment which account for the load independent as well as load dependent energy consumption effects. The Energy Consumption Gain (ERG) and Throughput Gain (TPG) figures of merit are used together with a new figure of merit called the Energy Throughput Gain (ETG) which reliably accounts for the difference in energy consumption and throughput between two distinct RAN configurations. The energy consumption and throughput performance of a greenfield RAN deployment scenario that uses different cell sizes and base station types is evaluated. The chapter then explores energy savings obtained from sleepmodes and HetNet deployments.