Enhancing Orbital Edge Computing Through ISL-Aided Federation of Satellite Constellations

Future sixth-generation (6G) systems will undoubtedly be based on a three-dimensional (3D) network architecture encompassing jointly optimized terrestrial and non-terrestrial components. Non-Terrestrial Networks (NTNs) traditionally represent a key communication technology for complementing or replacing the insufficient or unavailable terrestrial infrastructure coverage in remote or disaster-affected areas. In such missioncritical scenarios, where data provided by massive Internet of Things (IoT) deployments needs to be analyzed quickly to make intelligent and rapid disaster rescue decisions, providing ubiquitous sensing, computing, and communication capabilities is essential to remotely monitor the area, control critical conditions, and take appropriate actions. Edge computing from the sky has recently become possible, enabling satellites at Low Earth Orbits (LEO) to provide on-orbit computing and storage capabilities in addition to large-scale connectivity. In this paper, a cooperative strategy is proposed that allows federations of LEO satellites, which are reachable via Inter-Satellite Links (ISLs), to share their computing, sensing, and storage resources. Specifically, satellites from constellations owned by different tenants are grouped into federations, where CubeSats equipped with regenerative payloads establish ISLs with nearby satellites and collaboratively perform sensing, computing, and storage tasks directly in orbit. The simulation results demonstrate the effectiveness of the proposed ISL-aided federation strategy in terms of the percentage of completed tasks, mean federation size, and mean waiting time under various satellite constellation settings (e.g., orbital altitude and number of satellites).