Inter-Plane Inter-Satellite Connectivity in Dense LEO Constellations

Abstract

Low Earth orbit (LEO) satellite constellations rely on inter-satellite links (ISLs) to provide global connectivity. However, one significant challenge is to establish and maintain inter-plane ISLs, which support communication between different orbital planes. This is due to the fast movement of the infrastructure and to the limited computation and communication capabilities on the satellites. In this paper, we make use of antenna arrays with either Butler matrix beam switching networks or digital beam steering to establish the inter-plane ISLs in a LEO satellite constellation. Furthermore, we present a greedy matching algorithm to establish inter-plane ISLs with the objective of maximizing the sum of rates. This is achieved by sequentially selecting the pairs, switching or pointing the beams and, finally, setting the data rates. Our results show that, by selecting an update period of 30 seconds for the matching, reliable communication can be achieved throughout the constellation, where the impact of interference in the rates is less than 0.7 % when compared to orthogonal links, even for relatively small antenna arrays. Furthermore, doubling the number of antenna elements increases the rates by around one order of magnitude.

Fairness-Aware Link Optimization for Space-Terrestrial Integrated Networks: A Reinforcement Learning Framework

“…Let G and M E denote the gravitational constant and the mass of Earth in kilograms, respectively. Thus, the orbital speed of the satellites in the orbital plane can be determined as follows [35]:…”

“…where R E is the radius of Earth in meters. Therefore, the orbital period of the LEO satellites can be calculated as follows [35]:…”

Strategy of Multi-Beam Spot Allocation for GEO Data Relay Satellite Based on Modified K-Means Algorithm

“…B ij is the ranking results after sorting the Euclidean distance matrix M by column according to Equation (2). In other words, the sorting is executed toward the centroid from each object in the pool of samples; the final ranking, also known as the numerical order or sequence number, is normalized to generate the determination matrix D according to Equation (3). In this case, a certain object i can obtain a relatively high ranking in the sparse area with fewer objects, but a relatively poor ranking in the dense area with lots of objects, even with the similar Euclidean distance toward the certain centroid j.…”

“…The last decade has witnessed the booming revolution of satellite communication from fixed communication and mobile communication to high-throughput communication [2]. Several large constellations of low Earth orbit (LEO) satellites with altitudes of 1500 km or less were proposed to provide global wideband with cutting-edge technologies, shorter propagation delay and rapid global deployment [3,4]. Meanwhile, the control and operation of LEO constellations offers challenges to the ground stations.…”

A State-Space Approach for Tracking Doppler Shifts in Radio Inter-Satellite Links

“…This integration means that not only terrestrial cellular networks can count on satellites to support truly ubiquitous coverage, but also that the satellite industry has here an opportunity to expand its business. In fact, the deployment of mega-constellations counting several thousands satellites is currently underway (see [7] and references within), where low-earth orbits (LEO)s are preferred to the higher altitude medium-earth orbits (MEO)s or even the geostationary-earth orbits (GEO)s due to their reduced delay, path loss, and satellite production and launching costs [8]- [11]. Moreover, since propagation loss is small in LEOs, it is possible to realize practical communication systems with small satellites and earth stations.…”