Energy efficiency of heterogeneous cellular network

.The growing energy consumption driven by dramatic increases in the number of users and data usage becomes the key issue for the operators in meeting demands on cost reduction and environmental impact targets. Deployment of low power base stations or relay stations in conventional Macro cells is expected to reduce the total energy consumption of cellular radio networks. This paper investigates the cell's energy efficiency and area energy efficiency measured by "throughput per Joule" and "energy efficiency per unit area". The simulation results suggest that introducing Micro stations or Relay stations into Macro cell to form small cells can achieve improved energy efficiency and increased throughput as well.