The main objective is reduction of the energy consumption. This can be obtained by **matching the offered capacity with the needed traffic demand** at any given time while the network is operative. The Support to the Energy Saving use case, on the 3GPP, specification defines **a switching-off solution based on cell load information**. To effectuate the switch-off, the eNB has to have a general oversight of the situation of all neighbouring cells. ### Motivations - Reduce Environmental Impact - Reduce Costs As mobile traffic grows, more complex networks are needed, which implies adding more base stations to the network. Greater complexity brings more operational costs. ## Environmental Impact > ITU says that ICT contributes 2-2.5% to GHG emissions. Proportion of worldwide electricity consumed by a telecommunications network: - Today - 10% - 2030 - 51% #### Base Stations make up ca. 55% of a mobile operators energy consumption ![[Pasted image 20230218151236.png]] #### Base station Energy Consumption Breakdown Ref: [[Base Stations]] ![[Pasted image 20230218151815.png]] #### Base Station Energy Saving Equation Required amount of energy for a base station to transmit N channels to N users randomly spread on an area: ![[Pasted image 20230218151959.png]] - First term - Fixed factor, energy needed for the base station to be operative - Po is the power needed to switch on the BS - Tf is the time duration - Edata is the energy required for data transmission - Esign is the energy required for signalling transmission Edata and Esign are variable and have a direct dependence on traffic load. Base station dependence with the load can be expressed as ![[Pasted image 20230218153509.png]] - Po is the fixed power for BS to be operative - Pout is the load power, variable and adjusted by Delta P - Ntrx is the no. of transceiver chains - Pmax is the max Rf output power at maximum load ### Energy Saving Approaches - Reduction of used power in radio transmission - Optimization of handset battery duration - **Optimization of no. of operative base station / no. of modules within a base station** ### Requirements - Avoid interference - Avoid instabilities - Minimize interventions - Avoid coverage holes - Guarantee QoS