or switching off the transmitter as well as the Timing Advance Offset (TAO), which reduces the practical safety range. These are included in the following picture showing the safety zone ranges for all LTE and 5G GP configurations (Figures 8.14-8.16). Having a greater GP allows for greater safety zones and helps to better cope with small timing alignment errors, but comes at the cost of capacity and peak throughput. Safety Zone Range, LTE 200 - (stan) 150 - SSF configuration number Figure 8.14 Safety zone ranges with different special subframe configurations for LTE. 8.7 Network Synchronization and Coordination Requirements Safety Zone Range, 5G NR 15 kHz 30 kHz # GP symbols Figure 8.15 Safety zone ranges with different GP configurations for 5G with 15 and 30 kHz subcarrier spacings. Safety Zone Range, 5G NR 60 kHz 120 kHz # GP symbols Figure 8.16 Safety zone ranges with different GP configurations for 5G with 60 and 120 kHz subcarrier spacings. For example, a GP of five symbols with 30 kHz allows a 50 km safety zone, but it takes 7% of the system capacity since there are a total of 70 symbols in the 2.5 ms frame. 8.7.5 Intra-Frequency Operation As there is often LoS between BTS antennas located on rooftops, the RF path between BTS sites provides very little isolation. Hence, BTS-to-BTS interference can be consid- ered the worst kind of interference that can occur in a TDD network. Figure 8.17 show the increase in dB to the noise floor assuming the worst-case scenario where transmit- ting and receiving antenna are pointing toward each other and there is no obstruction in between. The distance calculation assumes the worst-case scenario where both anten- nas are on rooftops and visible to each other, and hence free space path loss calculation is used. With these modest power and antenna gain assumptions, the potential interfer- ence over the thermal noise in the victim cell receiver would be a massive 40 dB as far as 50 km away. This is clearly an unwanted scenario, and it is obvious that BTSs on the same frequenc