Analysis of Isolation Distance Relaxation for TN/NTN Coexistence in the Adjacent 2 GHz Band

This study quantitatively evaluates the throughput loss of a non-terrestrial network (NTN) user equipment (UE) as a function of its isolation distance from a terrestrial network (TN) cluster when the TN and NTN operate in adjacent frequency bands. A 5 % throughput loss was defined as the interference threshold, and the minimum isolation distance required to satisfy this criterion was derived based on both the average and the 5th-percentile throughput loss values. The results indicate that the minimum isolation distance is approximately 0.197 km for the average case and 1.036 km for the 5th-percentile case, corresponding to a relaxation of about 1.3 km and 0.5 km, respectively, compared with the 1.5 km isolation distance recommended by 3GPP.