A novel time-domain sleep mode design for energy-efficient LTE

This paper describes a time-domain approach for base station transmission sleep modes, taking the Long Term Evolution (LTE) system as a specific example. The idea of this design is to enable the base station to reduce RF energy consumption in low traffic conditions, while still properly supporting active user connections. By switching off traffic during a certain time period and delivering all user information with fewer transmissions under the same rate targets, the energy consumption can be reduced since the control signalling during non-active time is gated off. Taking the example of single user system for simplification, the optimum on-off time with associated power allocation are derived, which enables the energy consumption of the base station to scale with traffic loading. Compared with the corresponding non-sleep mode, this can achieve an up to 90% energy reduction in low traffic conditions.