Impact of Terrestrial Blockage on the Coverage of Integrated Satellite-Terrestrial Networks

The integration of non-terrestrial networks (NTNs) with terrestrial networks (TNs) is an important step toward ubiquitous connectivity in sixth-generation (6G). Despite growing interest, the geometric impact of urban blockages on an integrated satellite-terrestrial network (ISTN) has not been rigorously quantified. In this paper, we develop a stochastic geometry-based analytical framework that incorporates a Boolean blockage model to characterize the downlink coverage probability of the ISTN and to provide insights for blockage-aware system design. Our analysis reveals that blockages affect satellite links in two competing ways: while they attenuate desired signals, they can also act as spatial shields that suppress aggregate interference. Leveraging this observation, we analytically show that satellite-terrestrial integration can enhance coverage probability across diverse environments ranging from open areas to dense urban deployments, offering a resilient and mathematically tractable approach to maintaining connectivity under heterogeneous blockage conditions.