re more likely to experience such conditions than others. 8.7 Network Synchronization and Coordination Requirements Figure 8.19 BTS-to-BTS interference due Leakage to timing misalignment between <-90 dBm >50 dBm adjacent operator bands. Operator 1 Operator 2 Frequency 1 Frequency 2 Adjacent channel interference, ACLR = 45 dB, TX.P = 80 W, f = 3500 MHz, BW = 100 MHz f(coupling loss) f(distance), FSPL, tx.g = 27 dB, rx.g = 9dB Coupling Loss (dB) BTS to BTS distance (km) Figure 8.20 Adjacent channel BTS-to-BTS interference. 8.7.6 Inter-Operator Synchronization The synchronization and coordination requirements also need to be considered between different operators in the same area. The inter-operator interference case is illustrated in Figure 8.19. Operators 1 and 2 have dedicated frequencies that are adjacent. The frequency domain filtering is not ideal, and there is some leakage between the frequen- cies. Figure 8.19 illustrates a case where two operators have their base stations co-sited and use adjacent frequencies. The base station transmission power can be more than 50 dBm, while the thermal noise level with 100 MHz bandwidth is less than -90 dBm. If we wish to have uncoordinated timing between the operators, the required isolation should be more than 140 dB. The adjacent channel leakage and selectivity can provide approximately 40 dB attenuation between frequencies, and we would need about 100 dB additional coupling loss between the two operator antennas. If the antennas are co-sited or located close to each other, it is not possible to guarantee such a high coupling loss. Therefore, the assumption is that adjacent operators need to synchronize their networks and apply the same asymmetry in macrocell deployments below 6 GHz bands. We will next consider more detailed calculations about inter-frequency interference cases. The adjacent channel leakage ratio (ACLR) and adjacent channel selectivity (ACS) performance are specified separately both for BTS and UE transmitters and receivers by 3GPP. For LTE, it is defi