Evaluating the Influence of Satellite Systems on Terrestrial Networks: Analyzing S-Band Interference

The co-existence of terrestrial and non-terrestrial networks (NTNs) is essential for achieving comprehensive global coverage in sixth-generation cellular networks. Given the increasing demand for spectrum, there is an ongoing global discourse on the feasibility of sharing certain frequencies currently utilized by terrestrial networks (TNs) with NTNs. However, this sharing leads to co-channel interference and subsequent performance degradation. This paper specifically investigates the interference caused by NTNs on TNs in the S-band and its relationship with the relative position between satellite and TN user equipment. We analyzed the transmission mechanisms of satellite signals and employed the ITU two-state model for our interference analysis. Through simulations, we evaluated the interference intensity at different slant ranges. Our findings reveal that the angle between the user equipment direction and the sub-satellite point direction from the beam center significantly influences the interference level. Furthermore, satellites positioned in some relative directions will cause significant interference, even at considerable separation distances.