Cross-link Interference Modeling in 6G Millimeter Wave and Terahertz LEO Satellite Communications

TL;DR

This work addresses cross-link interference in mmWave and THz LEO satellite inter-satellite links (ISLs) within 6G contexts. It develops a mathematical framework to characterize interference among directional cross-links across three deployment configurations—single orbit, co-planar, and shifted—and provides closed-form or semi-analytical expressions for the average interference $E[I]$ and the SIR $S$. The authors validate the framework with extensive system-level simulations, revealing time-varying and time-averaged interference patterns and identifying thresholds (e.g., orbit separation and beamwidth) that mitigate interference. The results show that even highly directional cross-links can experience non-negligible interference, underscoring the need to account for cross-link interference in constellation design and coexistence strategies for future 6G satellite networks.

Abstract

One of the important questions when discussing next-generation near-Earth mmWave and terahertz (THz) band satellite communications as an integral part of the 5G-Advanced and 6G landscape is the potential interference-related issues when deploying such systems. While the space-to-ground and ground-to-space interference has been explored in multiple works already, the interference at mmWave and THz cross-links, the links between the satellites themselves, have not been extensively studied yet. However, severe cross-link interference may both challenge the reliability of the data exchange within the constellation, as well as compromise the efficient co-existence of multiple satellite constellations (i.e., by different providers) covering the same or neighboring areas. In this paper, both relevant mathematical models and extensive simulation studies are presented for cross-link mmWave and THz satellite communications. Our results indicate that the cross-link interference in the considered setups is a non-negligible factor that must be further explored and accounted for in the design and deployment of next-general mmWave and THz satellite communication systems.

Figures (7)

• Figure 1: Interference modeling for LEO satellite THz directional cross-link communications.
• Figure 2: Modeling interference from same or co-planar orbit.
• Figure 3: Interference from a co-planar orbit (zoomed).
• Figure 4: Modeling interference from a shifted orbit.
• Figure 5: Average SIR with interference from the same orbit.