zation Signal Block (SSB) transmission. It shows that the power consumption could theoretically be more than 90% lower for an idle base station compared to full power transmission. Figure 10.64 shows the estimated gains of the power savings technology. The simple assumption is that the base station power consumption is the same for LTE and for 5G during 100% loading. When the loading becomes lower, the power consumption also decreases both in LTE and in 5G radios, but the impact of loading is clearly higher in 5G with more efficient power saving solutions. The estimation shows that 5G macro base station power consumption can be even below 50 W in the very best case. For more details, see [12]. Off-time share 1 SSB 2 SSB 4 SSB 1 SSB 4 SSB 8 SSB 15 kHz 30 kHz Figure 10.63 Share of off-time in base station transmission when there is no data transmission. 10.10 Network Energy Efficiency 3-sector (2x2) BTS power consumption Watts 400 Loading Figure 10.64 Example three-sector base station power consumption. Radio power consumption in terms of kWh per GB of transmitted data is presented below. Three cases are assumed: 3G: Three-sector macro base station with 10 MHz of spectrum 4G: Three-sector macro base station with three carriers with a total of 50 MHz of spectrum 5G: Three-sector massive MIMO base station with 100 MHz of spectrum 5G: Small cell with mmWave and a total of 800 MHz of spectrum The electricity price is assumed to be 20 cent/kWh. The detailed assumptions are shown in Table 10.21, and the results in Figure 10.65. The 3G macro base station delivers mobile data at 5 cent/GB and LTE 2 cent/GB from the electricity bill point of view. 5G massive MIMO and 100 MHz brings SO much more capacity that the energy efficiency improves considerably by a factor of 10 compared to LTE. The 5G base station delivers Table 10.21 Assumption for the energy efficiency calculations. System parameter macro macro macro small Efficiency (bps/Hz/cell) Spectrum (MHz) Sectors Busy hour loading Busy hour share Sectors for 50% traffic BTS