LEO Satellite Constellations for 5G and Beyond: How Will They Reshape Vertical Domains?

The rapid development of communication technologies in the past decades has provided immense vertical opportunities for individuals and enterprises. However, conventional terrestrial cellular networks have unfortunately neglected the huge geographical digital divide, since high bandwidth wireless coverage is concentrated to urban areas. To meet the goal of ``connecting the unconnected'', integrating low Earth orbit (LEO) satellites with the terrestrial cellular networks has been widely considered as a promising solution. In this article, we first introduce the development roadmap of LEO satellite constellations (SatCons), including early attempts in LEO satellites with the emerging LEO constellations. Further, we discuss the unique opportunities of employing LEO SatCons for the delivery of integrating 5G networks. Specifically, we present their key performance indicators, which offer important guidelines for the design of associated enabling techniques, and then discuss the potential impact of integrating LEO SatCons with typical 5G use cases, where we engrave our vision of various vertical domains reshaped by LEO SatCons. Technical challenges are finally provided to specify future research directions.Comment: 4 figures, 1 table, accepted by Communications Magazin

Proceedings of the Fifth International Mobile Satellite Conference 1997

Satellite-based mobile communications systems provide voice and data communications to users over a vast geographic area. The users may communicate via mobile or hand-held terminals, which may also provide access to terrestrial communications services. While previous International Mobile Satellite Conferences have concentrated on technical advances and the increasing worldwide commercial activities, this conference focuses on the next generation of mobile satellite services. The approximately 80 papers included here cover sessions in the following areas: networking and protocols; code division multiple access technologies; demand, economics and technology issues; current and planned systems; propagation; terminal technology; modulation and coding advances; spacecraft technology; advanced systems; and applications and experiments

QoS Provisioning for Multi-Class Traffic in Wireless Networks

Physical constraints, bandwidth constraints and host mobility all contribute to the difficulty of providing Quality of Service (QoS) guarantees in wireless networks. There is a growing demand for wireless networks to support all the services that are available on wired networks. These diverse services, such as email, instant messaging, web browsing, video conferencing, telephony and paging all place different demands on the network, making QoS provisioning for wireless networks that carry multiple classes of traffic a complex problem. We have developed a set of admission control and resource reservation schemes for QoS provisioning in multi-class wireless networks. We present three variations of a novel resource borrowing scheme for cellular networks that exploits the ability of some multimedia applications to adapt to transient fluctuations in the supplied resources. The first of the schemes is shown to be proportionally fair: the second scheme is max-min fair. The third scheme for cellular networks uses knowledge about the relationship between streams that together comprise a multimedia session in order to further improve performance. We also present a predictive resource reservation scheme for LEO satellite networks that exploits the regularity of the movement patterns of mobile hosts in LEO satellite networks. We have developed the cellular network simulator (CNS) for evaluating call-level QoS provisioning schemes. QoS at the call-level is concerned with call blocking probability (CBP), call dropping probability (CDP), and supplied bandwidth. We introduce two novel QoS parameters that relate to supplied bandwidth—the average percent of desired bandwidth supplied (DBS), and the percent of time spent operating at the desired bandwidth level (DBT)

Foundations of LEO Satellite Edge Computing: An Empirical Study Based on the Hypatia Simulator

Low Earth Orbit (LEO) satellite networks have gained significant attention in recent years due to their potential to revolutionize global connectivity. SpaceX, Amazon, and Telesat are the most prominent players aiming to provide global internet coverage and high-speed broadband connectivity. Despite significant advancements and ongoing research in the field, there have only been a few studies that managed to construct a comprehensive, scaled simulator for LEO satellite networks. Project Hypatia developed by Amazon stands out as one of the few publications that has effectively accomplished such a task. This thesis builds upon the foundation of Hypatia to explore and provide an insight into the key aspects of LEO Satellite networks. Our research consists of two main components: firstly, addressing fundamental issues such as network topology, routing delay, handover, and service provisioning in LEO Satellite networks, and secondly, deploying code on top of Hypatia to analyze and explore these issues in depth. All in all, this thesis aims to deepen the understanding of LEO satellite networks through the examination of the Hypatia simulator and its implications

Handover Management In Mobile Satellite Communications

Mobile satellite communication offers vast coverage area with moderate bandwidth demands. However, in mobile satellite communication using Low Earth Orbits (LEO) satellite service, handover frequently occurs due to high velocity and large number of mobile satellites. With increase demand of multimedia traffic, an optimum utilization of network resources has been investigated. To accommodate and maintain Quality of Service (QoS) of handover calls in mobile satellite communication, priority for handover calls are applied. Traffic parameters of traffic arrival rate, traffic duration and priority among traffic applications are introduced. Traffic applications of type voice, video and data are observed and analysis of traffic behavior on handover has been done. An optimum set of channels to serve the different traffic types is proposed after considering the handover initiation and handover execution criteria. The algorithm proposes a more accurate measurement of handover initiation angle, introduced as look-up angle, which further reduces handover rate and successfully conserve the network resources

A Handover Strategy in the LEO Satellite-Based Constellation Networks with ISLs

Abstract A new handover strategy named minimal-hops handover (MHH) Received 2003-06-05 Due to various economic and technical constraints, terrestrial mobile networks can only provide communication services with a limited coverage. Recently, in response to increasing demand of real-time multimedia services and the truly global coverage required by personal communication services (PCS), there is a vast research on non-geostationary orbit (NGSO) satellites systems, especially on low earth orbit (LEO) satellite constellations with an altitude between 700 km and 1 500 km. LEO satellite constellations equipped with inter-satellite links (ISLs), such as Iridium, Teledesic, Courier and so on, usually have onboard switching (OBS) and onboard routing (OBR) facilities and form an independent network in space. Direct connectivity between any pair of satellite mobile users can be achieved through the satellites and ISLs without any essential usage of the terrestrial core network. For the wide application prospect, they have already been the focus of the research on the satellite communication systems Key words low earth orbit(LEO) satellite-based constellation networks; time propagation delay; quality of services (QoS); inter-satellite link (ISL); inter-satellite handover In the LEO constellations, although handover procedure is closely correlated with rerouting, almost all the existing strategies pay more attention to the handovers themselves and ignore the rerouting. In this way, this paper proposes a new strategy name

The mobile satellite service (MSS) systems for global personal communications

A worldwide interest has arisen on personal communications via satellite systems. The recently proposed mobile satellite service(MSS) systems are categorized four areas: geostationary earth orbit(GEO) systems, medium earth orbit(MEO) systems, low earth orbit(LEO) systems, and highly elliptical orbit(HEO) systems. Most of the systems in each category are introduced and explained including some technical details. The communication links and orbital constellations of some systems are analyzed and compared with different categories, and with different systems. Some economical aspects of the systems are mentioned. The regulatory issues about frequency spectrum allocation, and the current technical trends in these systems are summarized

Adaptation of the IEEE 802.11 protocol for inter-satellite links in LEO satellite networks

Knowledge of the coefficient of thermal expansion (CTE) of a ceramic material is important in many application areas. Whilst the CTE can be measured, it would be useful to be able to predict the expansion behaviour of multiphase materials.. There are several models for the CTE, however, most require a knowledge of the elastic properties of the constituent phases and do not take account ofthe microstructural features of the material. If the CTE could be predicted on the basis of microstructural information, this would then lead to the ability to engineer the microstructure of multiphase ceramic materials to produce acceptable thermal expansion behaviour. To investigate this possibility, magnesia-magnesium aluminate sp~el (MMAS) composites, consisting of a magnesia matrix and magnesium aluminate s~ne'l (MAS) particles, were studied. Having determined a procedure to produce MAS fr alumina and magnesia, via solid state sintering, magnesia-rich compositions wit ~ various magnesia contents were prepared to make the MMAS composites. Further, the l\.1MAS composites prepared from different powders (i.e. from an alumina-magnesia mixture ahd from a magnesia-spinel powder) were compared. Com starch was added into the powder mixtures before sintering to make porous microstructures. Microstructural development and thermal expansion behaviour ofthe MMAS composites were investigated. Microstructures of the MAS and the MMAS composites as well as their porous bodies were quaritified from backscattered electron micrographs in terms of the connectivity of solids i.e. solid contiguity by means of linear intercept counting. Solid contiguity decreased with increasing pore content and varied with pore size, pore shape and pore distribution whereas the phase contiguity depended strongly on the chemical composition and was less influenced by porosity. ' The thermal expansion behaviour of the MAS and the MMAS composites between 100 and 1000 °C was determined experimentally. Variation in the CTE ofthe MAS relates to the degree of spinel formation while the thermal expansion of the MMAS composites depends strongly on phase content. However, the MMAS composites with similar phase compositions but made from different manufacturing processes showed differences in microstructural features and thermal expansion behaviour. Predictions of the CTE values for composites based on a simple rule-of-mixtures (ROM) using volume fraction were compared with the measured data. A conventional ROM accurately predicted the effective CTE of a range of dense alumina-silicon carbide particulate composites but was not very accurate for porous multiphase structures. It provided an upper bound prediction as all experimental values were lower. Hence, the conventional ROM was modified to take account of quantitative microstructural parameters obtained from solid contiguity. The modified ROM predicted lower values and gave a good agreement with the experimental data. Thus, it has been shown that quantitative microstructural information can be used to predict the CTE of multiphase ceramic materials with complex microstructures.EThOS - Electronic Theses Online ServiceGBUnited Kingdo