This Recommendation specifies principles and concepts of energy efficiency metrics used to evaluate the energy efficiency of a base station site considering the energy consumption for: ? the telecom equipment inside the base station site e.g.@ backhaul and base station equipment; ? the entire infrastructure@ including cooling systems@ monitoring systems (for power consumption@ equipment running status@ environment parameters@ etc.)@ fire protection and lighting systems for all the sites; ? energy losses due to AC/DC rectifiers@ generators and cable losses. This Recommendation shall not be used to evaluate the energy efficiency of equipment that are covered by other Recommendations such as [ITU-T L.1310] and [ITU-T L.1320].