Distributed On-Demand Routing for LEO Mega-Constellations: A Starlink Case Study

More on mega-constellations

1. On the Use of Mega Constellation Services in Space: Integrating LEO Platforms Into 6G Non-Terrestrial Networks Gabriel Maiolini Capez, Mauricio A. Cáceres, Roberto Armellin, Christopher P. Bridges, Juan A. Fraire, Stefan Frey, and Roberto Garello IEEE Journal on Selected Areas in Communications, 2024
   Abstract

   This paper presents a framework for integrating Low-Earth Orbit (LEO) platforms with Non-Terrestrial Networks (NTNs) in the emerging 6G communication landscape. Our work applies the Mega-Constellation Services in Space (MCSS) paradigm, leveraging LEO mega-constellations’ expansive coverage and capacity, designed initially for terrestrial devices, to serve platforms in lower LEO orbits. Results show that this approach overcomes the limitation of sporadic and time-bound satellite communication links, a challenge not fully resolved by available Ground Station Networks and Data Relay Systems. We contribute three key elements: (i) a detailed MCSS evaluation framework employing Monte Carlo simulations to assess space user links and distributions; (ii) a novel Space User Terminal (SUT) design optimized for MCSS, using different configurations and 5G New Radio Adaptive Coding and Modulation; (iii) extensive results demonstrating MCSS’s substantial improvement over existing Ground Station Networks and Data Relay Systems, motivating its role in the upcoming 6G NTNs. The space terminal, incorporating a multi-system, multi-orbit, and software-defined architecture, can handle Terabit-scale daily data volumes and minute-scale latencies. It offers a compact, power-efficient solution for properly integrating LEO platforms as space internet nodes.

   HALPublisher

2. RF-Assisted Uncertainty Cone Reduction in Free-Space Optical Inter-Satellite Links Elena Fernández-Niño, Juan A. Fraire, Adriano Camps, and Joan Adrià Ruiz-de-Azua IEEE Open Journal of the Communications Society, 2024
   Abstract

   One of the space communications industry’s current focuses is developing high-throughput communication terminals for satellite-to-satellite communication links. Optical inter-satellite links provide high data rates, long-range, and robustness against interferences, and they do not require frequency licensing as radiofrequency communication systems. Nevertheless, as the uncertain location of the receiver is comprised in an area larger than that illuminated by the transmitting laser, the pointing accuracy is a critical element in the success of the optical link establishment and maintenance, requiring a pointing, acquisition, and tracking mechanism. The acquisition process is the most time-consuming of the pointing processes, limiting the time available to send data, especially in highly dynamic networks. This paper focuses on reducing the acquisition time by reducing the initial satellite position uncertainty. To this end, a hybrid system that combines RF and optical technologies in a single communication module is proposed. Whereas the control plane is managed via the RF link to exchange more precise global navigation data, the optical link corresponds to the data plane in which payload data is exchanged. The pointing between two satellites is simulated to analyze its behavior, considering the error of cumulative orbital propagation data and global navigation satellite system data. This work also analyzes the cumulative error produced by the propagation of the TLEs over time. Finally, the results show how a system that relies on the exchange of global navigation satellite system positioning data achieves up to 99.45% better-pointing accuracy than a system that bases positioning data on TLE propagation.

   HALPublisher

3. Managing Fleets of LEO Satellites: Nonlinear, Optimal, Efficient, Scalable, Usable, and Robust Gregory Stock, Juan A. Fraire, Tobias Mömke, Holger Hermanns, Fakhri Babayev, and Eduardo Cruz IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, 2020
   Abstract

   Size and weight limitations of low-earth orbit (LEO) small satellites make their operation rest on a fine balance between solar power infeed and power demands of communication technologies on board, buffered by on-board battery storage. As a result, the problem of planning battery-powered payload utilization together with intersatellite communication is extremely intricate. Nevertheless, there is a growing trend toward constellations and megaconstellations that are to be managed using sophisticated software support. Earlier work has leveraged cost-optimal reachability in priced timed automata for deriving near-optimal finite-horizon schedules to operate a single LEO satellite in orbit. This article harvests that work and improves it in several dimensions, all needed for true in-orbit applicability: 1) the battery representation is no longer bound to be linear, but can be kinetic, which means that the optimization problem includes nonlinearities; 2) the management is perpetuated by a receding horizon scheduling strategy; 3) the model is continuously improved with the latest telemetry received from orbit; 4) a tandem of satellites equipped with state-of-the-art intersatellite link transponders is considered; 5) the core optimization problem is now solved using dynamic programming with antichain-based pruning, which is proven to be optimal and despite all the additional features outperforms the earlier approach by orders of magnitude; 6) the entire approach is grounded in the concrete requirements of the GOM X–4 LEO mission; 7) care is taken to make the approach usable by the space engineers, and robust against failures of parts of the toolchain; and 8) an extensive test campaign validates accuracy, efficiency, scalability, and robustness with respect to the operational requirements and constraints of LEO constellations.

   Publisher

Mega-constellations: the topic page All 33 papers on this topic