Telesat Lightspeed: enabling mesh network solutions for managed data service flexibility across the globe

Low Earth Orbit (LEO) satellite communication systems have evolved into a critical component of global broadband networks, enabling wide‐area connectivity, IoT services, and intelligent multilayer satellite–terrestrial integration. Despite rapid advancements in constellation deployment, routing mechanisms, resource management, and LEO–5G/6G convergence, the long‐term evolution of research themes and network architectures remains insufficiently mapped. This study analyzes 2420 Web of Science articles published between 1995 and 2025 and applies bibliometric techniques, main path analysis, and edge‐betweenness clustering to identify the core technological trajectories shaping the LEO communication domain. The results reveal five major phases of development: foundational constellation design, multilayer architecture integration, performance and QoS optimization, 6G‐driven intelligent connectivity, and secure collaborative networking. Four dominant research clusters emerge: communication and IoT applications, routing and topology management, satellite edge computing and task offloading, and LEO‐enhanced GNSS positioning, highlighting the field's structural diversification. Main path and key‐route analyses further show a gradual shift from traditional connectivity‐oriented engineering toward distributed, AI‐enabled, and security‐aware satellite communication frameworks. This study provides the first longitudinal mapping of LEO communication research, offering an integrated understanding of how architectural evolution, protocol innovation, and emerging intelligent services intersect. The findings support future advances in satellite networking, resource optimization, and the design of resilient and interoperable LEO systems.

With the emergence of cellular radio technology, there has been a renewal of interest in low-Earth orbit (LEO) satellite communication networks. Interest in these type of systems is fuelled by reduced propagation delays compared to those experienced by geostationary satellites as well as the benefits associated with mobile and tetherless communications. LEO systems are presently being proposed to provide global communications for both voice and data applications. These systems are being designed to provide communications to areas of the world where either public telephone systems do not exist or cannot be provided due to terrain constraints. This paper examines the effects of packet-switched low-Earth orbit satellite systems as a medium for wireless communications. An overview of LEO systems is provided, as well as critical issues associated with the implementation of such a system. The benefits as well as the detriments to the implementation of LEO systems over other types of communication networks are addressed. To illustrate the nature of LEO communications, six representative constellations, varying in size from 36 to 77 satellites and residing at orbital altitudes ranging from 765 to 1549 kilometers, are examined.

Low earth orbit (LEO) satellite communications are expected to be incorporated in future wireless networks to provide global wireless access with enhanced data rates. Massive multiple-input multiple-output (MIMO) techniques, though widely used in terrestrial communication systems, have not been applied to LEO satellite communication systems. In this paper, we propose a massive MIMO downlink (DL) transmission scheme with full frequency reuse (FFR) for LEO satellite communication systems by exploiting statistical channel state information (sCSI) at the transmitter. We first establish a massive MIMO channel model for LEO satellite communications and propose Doppler and time delay compensation techniques at user terminals (UTs). Then, we develop a closed-form low-complexity sCSI based DL precoder by maximizing the average signal-to-leakage-plus-noise ratio (ASLNR). Motivated by the DL ASLNR upper bound, we further propose a space angle based user grouping algorithm to schedule the served UTs into different groups, where each group of UTs use the same time and frequency resource. Numerical results demonstrate that the proposed massive MIMO transmission scheme with FFR significantly enhances the data rate of LEO satellite communication systems.

This work develops an analytical framework for downlink low Earth orbit (LEO) or medium Earth orbit (MEO) satellite communications, leveraging tools from stochastic geometry. We propose a tractable approach to the analysis of such satellite communication systems, accounting for the fact that satellites are located on circular orbits. We accurately incorporate this geometric property of LEO or MEO satellite constellations by developing a Cox point process model that jointly produces orbits and satellites on these orbits. Our work contrasts with previous modeling studies that presumed satellite locations to be entirely random, thereby overlooking the fundamental fact that satellites are jointly positioned on orbits. Employing this Cox model, we analyze the network performance experienced by users located on Earth. Specifically, we evaluate the no-satellite probability of the proposed network and the Laplace transform of the interference created by such a network. Using it, we compute its SIR (signalto-interference) distribution, namely its coverage probability. By presenting fundamental network performance as functions of key parameters, this model allows one to assess the statistical properties of downlink LEO or MEO satellite communications and can thus be used as a system-level design tool to operate and optimize forthcoming complex LEO or MEO satellite networks.

A hybrid multibeamforming receiver for low Earth orbit (LEO) satellite communication in the Ku-band is designed and tested. The proposed receiver is implemented with eight channels to enable multibeam control. The proposed receiver, including both analog and digital beamforming structures, is capable of multibeam reception using both analog and digital beamforming techniques simultaneously or selectively. Analog beamforming is implemented by employing a local oscillator phase shifter using direct digital synthesis and phase-locked loop (PLL) structures. In digital beamforming, a software-defined radio can control the phase of the signal in the digital baseband. The multibeam received using the proposed hybrid multibeamforming receiver was measured at 11.7 GHz and 12.7 GHz in an anechoic chamber. The phase-control resolutions of analog and digital beamforming were 0.022° and 0.72°, respectively. Analog beam-switching speed is slower than digital beamforming because it depends on the settling time of the PLL circuit, but it has a high phase-control resolution. Therefore, by using analog and digital beamforming when precise beam tilting and fast beam switching are required, respectively, the proposed hybrid multibeamforming is shown to be suitable in accordance with the communication situation.

Cognitive radio (CR) is an efficient way to increase spectrum efficiency for the small low earth orbit (LEO) satellite communication system. Due to the implementation difficulties, we focus on the CR in the uplink transmission. In CR, the cognitive medium access (CMA) is designed to enable the coexistence with the interferences from other systems. However, the CMA schemes designed for the terrestrial system cannot deal well with the global history of interferences in our system. Here, we design the memorized centroid bucket (MCB) scheme that can efficiently utilize the global history of interferences onboard without storing the complete interference samples. With MCB, we can achieve the effective long-term interference prediction to meet the special requirements of the LEO satellite. The key component in MCB is the matching algorithm that can help retrieve the useful historical information. In this paper, we propose three different matching algorithms and the corresponding MCB schemes. The schemes are also compared with the widely used Markovian method and the pair counting-based method. Among all the schemes, the Bayesian scheme MCB-FSNMI-Bayes is the best. The conclusion is validated experimentally with the real data that were collected by an LEO satellite.

Robust Connectivity in Time-Frequency Dual Fading Channels for the 6G Satellite IoT: Chirp and FRFT

Beam hopping (BH) has become one key technology for satellite communications due to its superior flexibility and efficient resource utilization. In order to balance the service latency of different users when BH is employed in low earth orbit (LEO) satellite communication systems, the objective of this paper is to minimize the maximum queuing delay among users by dynamically scheduling beams and allocating power among beams. The considered problem is a mixed-integer programming problem, and therefore is first transformed into two sub-problems, i.e., user selection and power allocation. Then, a two-stage low-delay algorithm is proposed in consideration of both the total transmit power constraint and traffic requirements. Simulation results indicate that the proposed algorithm can significantly reduce the maximum delay among users in each BH period compared to the existing algorithms.

Low Earth Orbit (LEO) satellite communication systems have emerged as a critical solution to address the growing demand for global, seamless, and low-latency connectivity. Compared with Geosynchronous Earth Orbit (GEO) satellites, LEO satellites enable reduced signal delays and broad coverage. Therefore, they are particularly suitable for remote and underserved regions. This paper provides a comprehensive review of LEO satellite communication systems, focusing on three major aspects: frequency band division, system architecture, and case analysis. The study explores the utilization of various frequency bands, including L, S, C, X, Ku, Ka, Q, and V bands, highlighting their characteristics and applications. The system architecture, including the space, user, and ground segments, is analyzed in detail. Additionally, the paper examines the Starlink constellation as a typical example and discusses its architecture, performance, and coverage capabilities. However, LEO satellite communication systems face significant challenges, such as limited resources, high costs, and problems due to the high speed of satellites. Therefore, advancements in artificial intelligence, ultra-narrow beamforming, and 5G and 6G networks present promising opportunities for future development.

Recently many companies and consortia have considered launching LEO satellites for such projects as remote sensing, transportation and mining operations. When the multiple low Earth orbit (LEO) satellites are transmitting they can interfere with existing terrestrial microwave and satellite earth‐stations in the fixed and mobile service. The interference problem is related to the number of proposed LEOs and the altitude and consequently the time to orbit the earth. These systems usually consist of many small satellites, and each satellite stays in the beam of a terrestrial station for up to 72 seconds in each 222 minute orbit. Earth coverage could be obtained by 48 (LEO) satellites 1500 km above the earth in polar orbit, and hence at least one LEO would always be interfering with terrestrial networks. A technical evaluation would then be required to determine the resultant BER (bit error rate) effecting existing terrestrial services. A determination can then be made to support such a LEO system or object via official channels such as the ITU.

As low Earth orbit (LEO) satellite communication systems are gaining increasing popularity, new theoretical methodologies are required to investigate such networks' performance at large. This is because deterministic and location-based models that have previously been applied to analyze satellite systems are typically restricted to support simulations only. In this paper, we derive analytical expressions for the downlink coverage probability and average data rate of generic LEO networks, regardless of the actual satellites' locality and their service area geometry. Our solution stems from stochastic geometry, which abstracts the generic networks into uniform binomial point processes. Applying the proposed model, we then study the performance of the networks as a function of key constellation design parameters. Finally, to fit the theoretical modeling more precisely to real deterministic constellations, we introduce the effective number of satellites as a parameter to compensate for the practical uneven distribution of satellites on different latitudes. In addition to deriving exact network performance metrics, the study reveals several guidelines for selecting the design parameters for future massive LEO constellations, e.g., the number of frequency channels and altitude.

The frequency diverse array (FDA) antenna can generate very directional beams with high gain that can be steered directly and continuously to track the low earth orbit (LEO) satellite, and produce nulls in directions of interfering signals. This is required to minimize complexity and cost of ground station that rely on reflectors or phased array antennas, while keeping an acceptable link budget. Although the FDA antenna has been growing in use for radar communication systems with the advantage of it is electronically beam steering, it is still not widely used in conjunction with LEO systems and might be a more promising solution. The mathematical model of frequency diverse array antenna for tracking LEO satellite is discussed. Furthermore, the simulation of beamforming based on the presented frequency diverse array mathematical model is achieved to obtain steerable beams for tracking the LEO satellite.

International organizations such as the 3rd Generation Partnership Project (3GPP) and the International Telecommunication Union (ITU) regard non-terrestrial networks (NTNs) as an essential component of the sixth-generation (6G) mobile communication technology and have advanced relevant standardization efforts. Low Earth orbit (LEO) satellite communication (SatCom) constitutes a key part of NTNs, and efficient uplink random access (RA) is crucial for establishing initial connections in LEO SatCom systems. However, the long propagation delay and wide coverage of LEO satellites substantially increase access latency and collision probability due to the limited number of beams and their constrained coverage areas. In addition, the highly non-uniform spatial distribution of user equipment (UE) further aggravates access inefficiency. To this end, this paper investigates joint beam position grouping and RA channel (RACH) occasions (ROs) allocation (JBPGRA) for LEO SatCom systems. Specifically, we develop a system model for RA under beam hopping and identify the key factors that influence RA performance. Furthermore, we derive expressions for both the instantaneous signal-to-interference-plus-noise ratio (SINR) and the average SINR under a given non-uniform UE spatial distribution. Building on this analysis, the JBPGRA problem is formulated as an integer linear programming problem that seeks to maximize RA success while conserving RO resources under non-uniform UE distribution. To achieve a practical solution, we propose an efficient JBPGRA algorithm composed of beam position classification, sparse beam position grouping, and RO allocation modules. Simulation results demonstrate that, under the same UE density, the proposed JBPGRA scheme achieves over 29% higher access success rate in dense beam positions compared with the uniform baseline adopted in existing SatCom systems, while reducing RO consumption by more than 49% and decreasing the number of beam position groups by over 57%.

Low Earth Orbit (LEO) satellite communication systems are known to have complicated spatial resource management. The problem occurs because of the impossibility to realize fully digital beamforming since its hardware implementation consumes too much power of the on-board battery. On another hand, analog beamforming can not provide enough system coverage in realistic user distribution scenarios. In this paper, we justify the choice of the hybrid multi-beamforming structure for some realistic user distributions. Such a structure guarantees enough coverage with minimal power consumption. For this structure, we propose a new spatial resource allocation intended to minimize handovers and to simplify the calculation of the time user spends inside each satellite beam spot. Numerical results with real system parameters are provided to confirm feasibility.

The spectrum sharing between the low earth orbit (LEO) and geostationary earth orbit (GEO) satellite communication systems provides a feasible solution to relieve the spectrum shortage and support the rapid expansion of LEO satellite systems. In order to improve the spectrum efficiency and avoid serious inter-system interference (ISI), we investigate the resource allocation for beam-hopping (BH) based LEO satellite systems which share the spectrum resources with a BH-based GEO satellite. The BH technology enhances the resource scheduling flexibility of the satellite systems, but it also makes the ISI more complicated and intractable. Considering the limited computing capability of the LEO satellite, the resource allocation problem is decomposed into the time slot allocation (TA) sub-problem and the transmit power optimization (TPO) sub-problem. A greedy algorithm is proposed for the TA sub-problem, and the TPO sub-problem is solved by using the convex optimization theory. Simulation results show that the proposed resource allocation scheme not only achieves higher system throughput, but also suppresses the ISI at a low level, which ensures the harmonious coexistence of the two satellite systems.