Performance analysis of satellite-terrestrial integrated radio access networks based on stochastic geometry

TL;DR

This work introduces a stochastic-geometry-based framework to analyze the downlink coverage of satellite-terrestrial integrated radio access networks (STIRANs). By modeling satellites on a 1D PPP along a LEO orbit and terrestrial base stations as a PPP with a central hole, the authors derive satellite visible probabilities and conditional distance distributions; they then obtain analytic downlink coverage expressions for both distinct and shared frequency settings, validated by simulations. The study highlights how orbit geometry (inclination), node densities, and hole radius R0 influence performance, demonstrating that STIRANs can significantly improve coverage in terrestrial holes under appropriate conditions. The results provide design insights for joint satellite-terrestrial deployments in 6G, guiding parameter choices to maximize coverage and continuity.

Abstract

To enhance coverage and improve service continuity, satellite-terrestrial integrated radio access network (STIRAN) has been seen as an essential trend in the development of 6G. However, there is still a lack of theoretical analysis on its coverage performance. To fill this gap, we first establish a system model to characterize a typical scenario where low-earth-orbit (LEO) satellites and terrestrial base stations are both deployed. Then, stochastic geometry is utilized to analyze the downlink coverage probability under the setting of shared frequency and distinct frequencies. Specifically, we derive mathematical expressions for the distances distribution from the serving station to the typical user and the associated probability based on the maximum bias power selection strategy (Max-BPR). Taking into account real-world satellite antenna beamforming patterns in two system scenarios, we derive the downlink coverage probabilities in terms of parameters such as base station density and orbital inclination. Finally, the correctness of the theoretical derivations is verified through experimental simulations, and the influence of network design parameters on the downlink coverage probability is analyzed.

Figures (12)

• Figure 1: LEO network model
• Figure 2: Ground network model
• Figure 3: The downlink coverage probability of STIRANs with distinct frequencies, STIRANs with same frequency and terrestrial networks
• Figure 4: Effects of satellite density $\lambda_{\mathrm{sat}}$ on the downlink coverage probability under STIRANs with different frequencies
• Figure 5: Effects of satellite density $\lambda_{\mathrm{bs}}$ on the downlink coverage probability under STIRANs with different frequencies