A communications satellite is an artificial satellite that relays and amplifies radio telecommunications signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. Satellite communications networks consist of user terminals, satellites and a ground network that provides control and interface functions.
Satellites play a crucial role to improve lives in today’s digital economy. Nearly every industry relies upon satellite technology in some way — from agriculture to banking to transportation. Satellites help save lives in emergencies and provide critical knowledge about how to better protect the environment. As the world national economies become more global and as all parts of the globe, the oceans, and the atmosphere are exploited by human enterprise, the need for effective wireless interconnection via terrestrial wireless and satellite communications will expand.
The basic structure of a satellite communication system consists of a space segment that includes the satellite constellation, a ground segment including GW stations and large ground facilities for control, network operations and backhauling, and a user segment with the user terminals deployed on fixed and mobile platforms (e.g. airplanes and ships).
The communication topology depends primarily on the target application of the communication system. The two typical topologies are star and mesh. In both cases, the satellite acts as a relay between each node and the hub (backhaul) or between multiple peer nodes, respectively. The point-to-multipoint connectivity as in traditional broadcast services, internet connections via satellite and data collection from the sensors deployed on the earth surface, the star topology is used, where each terminal is connected to the hub via satellite on a single-hop basis. The data collection from the sensors deployed on board of the satellite (e.g. in earth observation applications), can be viewed as a special case of star topology, since the satellite acts both as a relay and as a signal source.
For point-to-point connectivity as in video conferencing, the star topology would imply two-hop transmissions, which might be crucial with respect to the end-to-end latency of packet transmission. Hence, mesh topology is usually preferred, where each peer node can communicate with another peer node via satellite relay. However, this topology may require intelligent routing of data packets by the satellite. In addition, mesh topology has been recently proposed for various LEO and GEO satellite constellations based on optical ISLs in order to ensure a
sufficient connectivity and cooperation between satellites.
Upon being employed as a relay, the satellite can be either transparent or regenerative. Transparent satellites do not perform any signal processing besides amplification, spatial filtering and frequency conversion. Hence, the functionality of the satellite resembles an amplify-and-forward relay structure from traditional wireless communications. In contrast, regenerative satellites perform additional signal processing, e.g. decoding, interference cancellation, signal regeneration, etc., similar to decode-and-forward relaying. The payload of the satellite is designed accordingly.
Satellite communication technology trends
The increase in small satellites, the use of high-throughput satellites and low-Earth orbiting (LEO) satellites, launches on reusable rocket launch vehicles, satellites with all-electric propulsion and new use cases for 5G and the Internet of Things (IoT) are some of the are among the game-changing innovations enabling a range of solutions from digital financial services to better health care to smarter cities.
Traditionally, Geostationary (GEO) satellites have been mainly used for SatComs since they avoid fast movement between the terminals and the satellite transceiver and they allow for wide coverage using a single satellite. Today, a single 28 GHz band satellite can serve 1/3 of the Earth. The wide coverage provides all communities within a satellite’s footprint access to service. Coupled with easy to deploy user terminals, this means that consumers and businesses have near-instant access to fast, affordable broadband, anywhere. People can stream their favorite videos at home, walking around town, and even on an airplane. 28 GHz satellite-powered Wi-Fi now connects millions living in urban and rural centers and villages — many for the first time.
Recent years have also seen several advances in satellite systems and networks, allowing better efficiency, reliability, increased data rates, and new applications. However, new more ambitious constellation types are currently being developed, motivated by advanced communication technologies and cheaper launch costs.
By 2020-2025 there will be more than 100 High Throughput Satellite (HTS) systems using Geostationary (GEO) orbits but also mega-constellations of Low Earth Orbit (LEO) satellites, delivering Terabit per second (Tbps) of capacity across the world.
Multibeam satellite systems have been specifically developed to allow efficient frequency reuse and high-throughput broadband rates across the coverage area, not unlike their terrestrial cellular counterparts. Satellite broadcasting via geostationary satellites will remain in widespread use. It will be a main source of revenue for satellite operators for the foreseeable future. But technology evolution in the coming years will also offer the possibility of new services via “very high throughput satellites (VHTS)” and “multispot” geostationary satellites, says ITU.
Explosion of Smallsats
The satellite industry has seen a major shift from the manufacturing of massive traditional, multi-hundred-million-dollar satellites (>5000 kg) to the generation of several-million dollar smallsats (<500 kg). SmallSats can be constructed and launched less expensively and more quickly than traditional, large, geosynchronous orbit satellites. The incredibly shrinking satellite has given rise to less expensive rockets designed specifically to launch batches of small satellites. With traditional satellites taking a decade and hundreds of millions of dollars to develop and deliver into service, next-generation small satellites are delivered at 1/10th the time, and 1/100th the cost.
In addition constellation of smallsats address one of the most significant limitations of geosynchronous systems: high latency. Multiple companies, such as SpaceX, Amazon, OneWeb, TeleSAT, have already announced large LEO plans including thousands of satellites that will enable them to provide low-latency broadband with pervasive connectivity. OneWeb plans to launch at least 900 satellites, with broadband access while SpaceX, with its Starlink constellation comprised of nearly 12,000 satellites.
Launch vehicle innovations, such as SpaceX’s reusable rocket system Falcon 9, have reignited interest in LEO. Iridium is now in the process of rolling out its broadband Iridium Next constellation, using SpaceX as a launch provider. The potential for reusable rocket launch vehicles is a key driving factor in SmallSat growth; the small payload means that a launch vehicle can deliver them in large quantities. Moreover, satellites from more than one company can hitch a ride on a single launch.
In addition, there will be new non-geostationary satellites, low earth orbit (LEO) and medium Earth orbit (MEO), of different sizes and capabilities. In Medium Earth Orbit (MEO) where a constellation of 20 satellites (O3B) has been placed in a circular orbit along the equator at an altitude of 8063 km. Each satellite is equipped with twelve mechanically steerable antennas to allow tracking and handover of terminals. The next generation of O3B satellites is planned to use an active antenna which can generate thousands of beams along with an on-board digital transparent processor. This constellation type is unique since it manages to hit a trade-off between constellation size and latency.
Finally, the proliferation of new constellation types has given rise to hybrid constellations which combine assets in different orbits. One such example is the combination of MEO and GEO connectivity, where the terminals can seamlessly handover between the two orbits. Another example is the backhauling of LEO satellite data through higher orbit satellites.
Overall, there is likely to be major competition for services. Market forces will bring service costs down. Furthermore, future user terminals will achieve a larger degree of flexibility and lower costs. Finally, cheap launching costs and conveyor-belt manufacturing allow for deploying more risky/innovative approaches while keeping up with the latest evolutions in communication technology.
The small satellite industry has also caught the attention of the Pentagon and intelligence agencies that want to deploy swarms of small satellites, able to launch quickly and easily replaced carrying out surveillance of adversary activities such s missile launches.
Recent advances in the efficiency of power generation as well as the energy efficiency of radio frequency and digital processing components have allowed for enhanced on-board processing which can enable innovative communication technologies, such as flexible routing/channelization, beamforming, free-space optics and even signal regeneration.
Furthermore, space-hardened software-defined radios can enable on-board waveform-specific processing which can be upgraded during the satellite lifetime.
In order to enhance the performance of satellite constellations, ISLs can be created, such that multiple satellites can cooperatively accomplish complicated missions. Correspondingly, the complexity of each satellite is reduced. Furthermore, ISLs can be employed for data offloading.
The link can be established between multiple satellites of the same orbit (e.g. LEO-LEO) as well as between satellites of different orbits (e.g. GEO-LEO). A typical example for the latter is the use of GEO satellites as relays for the links between LEO satellites and GWs. This technique is employed by specifically designed GEO satellite constellations, such as European Data Relay System (EDRS) or Tracking and Data Relay Satellite System (TDRSS) in order to improve the connectivity and coverage. Both systems are intended to provide the requested on-demand services in nearly realtime, especially for emergency applications.
In the future, 5G networks will represent the global telecommunication infrastructure of the digital economy, which should cover the whole world including inaccessible areas not covered by 5G terrestrial networks. However, there are several use cases where standard terrestrial coverage is either not present or possible, making satellite systems uniquely positioned to provide a solution to bridge this gap.
Satellite communication will play a significant role in 5G and beyond as a complementary solution for ubiquitous coverage, broadcast/multicast provision, aeronautical & maritime communications, emergency/disaster recovery, and remote rural area coverage. Furthermore from a deployment point-of-view, the cost can be largely decreased by using 5G chipsets/systems and tapping into economies of a larger scale.
Non-Terrestrial Networks (NTN) is a term coined under 5G standardization to designate communication systems that include satellites, Unmanned Aerial Systems (UAVs) or High Altitude Platforms (HAPs). The main objective of this initiative is to seamlessly integrate these assets into the 5G systems by studying their peculiarities in terms of architecture and air interface.
Three major groups of use cases for NTN 5G systems have been defined by the 3GPP. Firstly, NTN can significantly enhance the 5G network reliability by ensuring service continuity, in cases where it cannot be offered by a single or a combination of terrestrial networks. This is especially true in case of moving platforms (e.g. car, train, airplane etc.) and mission-critical communications. Secondly, NTN can guarantee the 5G service ubiquity in un-served (e.g. desert, oceans, forest etc.) or underserved areas (e.g. urban areas), where a terrestrial network does not exist or it is too impractical/cost-ineffective to reach.
With the availability of high-throughput, high-capacity broadband geostationary satellite orbit (GSO) networks, such as the Hughes JUPITER System, and pending deployment of mega-constellations of non-geostationary satellite orbit (NGSO) systems, it is clear that the benefits of 5G can reach parts of the globe where terrestrial 5G networks may never be available. The demand for more bandwidth will only increase with Multiple Radio Access Technology (Multi-RAT) planning for 5G that will rely on various heterogeneous networks for over 99% availability such as WiGig, 4G, 100G Ethernet, and satellite networks.
Last but not least, NTN can enable the 5G service scalability due to the efficiency of the satellites in multicasting or broadcasting over a very wide area. This can be extremely useful to offload the terrestrial network, by broadcasting popular content to the edge of the network or directly to the users.
High-throughput (HTS) Satellites
The global demand for broadband communications continues unabated, and is not location specific. Such demand includes requirements of connectivity for users on aircraft, ships and vehicles (including first responders) that operate at both fixed locations and while in motion. These three different platforms need continuous connectivity along their travel routes, which often take them through unserved parts of major metropolitan areas, as well as less-densely populated areas.
The Broadband Global Area Network (BGAN) constellation of satellites (in L-band) offer seamless global mobile coverage, connecting people and machines in remote locations on land, at sea and in the air — enabling the Internet of Things (IoT), voice calls and Internet access.
Today’s 30/20 GHz geostationary orbit (GSO) fixed-satellite service (FSS) networks provide affordable and reliable connectivity that meet the broadband connectivity requirements of passengers and crew on aircraft, vehicles, and ships, including high-throughput (HTS) applications.
High-throughput satellite (HTS) systems represent a new generation of satellite communications systems, capable of delivering vast throughput compared to conventional fixed, broadcast and mobile satellite services (FSS, BSS, and MSS), as well as utilizing frequency reuse and multiple spot beams to reduce costs. HTS provides at least twice, though usually by a factor of 20 or more, the total throughput of a classic FSS satellite for the same amount of allocated orbital spectrum thus significantly reducing cost-per-bit. This further precipitates the need for highly efficient transmitters with solid-state power amplifiers (SSPA), highly sensitive receivers, and reconfigurable phased array antennas for flexibility.
Very High throughput satellites (V/HTS), with spot beams, can provide more than 100 Gbits/ sec
VHTS (Very High Throughput Satellite) systems utilizing spot beams in order to provide broadband services to end-users with bit rates in excess of Terabit/s. They are ideally suited to support 5G as they provide more flexibility than HTS and are capable of being able to better match traffic distributions, accommodate more demand per beam and support dynamic service delivery. Very High throughput satellites (V/HTS), with their multiple spot-beams, are key for delivering the future rate demands.
Expanding Satellite IoT Market
The Internet of Things (IoT) is a system of interrelated computing devices, mechanical and digital machines, objects, animals or people that are provided with unique identifiers (UIDs) and the ability to transfer data over a network without requiring human-to-human or human-to-computer interaction.
Satellite technology has the potential to be a strong player in Internet of Things (IoT) connectivity, along with “connecting the unconnected” in parts of the world where alternative communication paths, at present, simply do not exist. Satellites will cover large geographic areas, and so can be accessed from both rural and urban locations. Satellites are essential part of building the framework for a global IoT infrastructure.
New Space has inspired new opportunities in terms of collecting data from ground sensors directly via satellites, i.e. Satellite Internet of Things. In this direction, a wealth of data collection constellations have made it into orbit, spanning a wide range of services e.g. earth observation, radio frequency (RF) monitoring, asset tracking, sensor data collection etc.
Currently, tens of private companies are building demonstrators and competing to launch a viable commercial service. Almost all such ventures rely on low earth orbits and this raises additional communication challenges in efficiently downlinking the collected data back to
the ground for processing. Conventionally, each such venture would require an extensive network of earth stations for high availability. However, cloud-based services (e.g. Amazon Web Services) have rolled out ground station networks that can be shared among the various constellations, while providing easy access to high performance computing for the data processing.
Even though small in nature, the traffic generated by these IoT devices, will have a significant impact on the network load. Therefore, the satellites can help to offload the terrestrial IoT network through backhauling, or provide service continuity in cases where a terrestrial network cannot reach. This group of uses cases can be categorized into two smaller subgroups depending on the type of application that the satellite can support and on how the IoT sensors are distributed on Earth.
Wide area IoT services: This use case has to do with applications based on a group of IoT devices distributed over a wide area and reporting information to or controlled by a central server. Typical applications where the satellite can play a role include:
– Energy: Critical surveillance of oil/gas infrastructures (e.g. pipeline status)
– Transport: Fleet management, asset tracking, digital signage, remote road alerts
– Agriculture: Livestock management, farming
Local area IoT services: The IoT devices in this kind of applications are used to collect local data and report to the central server. Some typical applications can be a smart grid sub-system (advanced metering) or services to on-board moving platforms (e.g. container on board a
vessel, a truck or a train).
Very Low Earth Orbit
VLEO platforms operate closer to the Earth than LEO satellites. This allows them to be simpler, smaller, and thus, cheaper. However, such low altitudes contain a denser part of the atmosphere, and therefore, larger aerodynamic forces. This can be seen as a challenge, but they can also represent an opportunity for orbit and attitude control. Moreover, the increased drag represents a shortening of the orbital lifetime, but this also means a more frequent fleet replacement of smaller and cheaper spacecrafts, thus, becoming more responsive to technology
and market changes . Several private companies such as SpaceX, OneWeb or Telesat are planning to launch their Mobile Satellite Services (MSS) at VLEO.
Flexible payloads and Software-defined satellites
Current communications satellites generally have over a 15 year mission lifetime, in that time several scenarios can occur that require an adjustment in the operational requirements of the payload including changing business and political landscapes, new technologies and applications. Flexible payloads that can reconfigure its frequencies, coverage, and power allocation pose a solution to the rapidly evolving business, political, and technological environment.
The launch of the Highly Adaptable Satellite (HYLAS-1) in 2010 helped to establish the viability of flexible payload technology shifting the payload design challenge from compliance with multiple access, connectivity, and speed requirements to ‘transparent’ payload technologies. Three capabilities are necessary for a reduced cost-per-bit: Flexible coverage; Flexible power allocation to beams; Flexible spectrum allocation to beams.
Where conventional satellites were earlier tailored to comply with single mission requirements, satellite developers are gradually adapting the vision of software-defined satellite which can be reprogrammed and reconfigured, to allow a satellite to take up new applications and expand its performance. Instead of viewing a satellite as monolithic piece of hardware and software, designed to perform a specific mission, one can see the same satellite as a platform capable of running multiple different missions (defined as software applications) on the same hardware platform. This definition follows the same approach as other “software-defined” entities, such as “software-defined radio” transceivers that can be reconfigured for a variety of RF tasks or “software-defined networking” appliances that can support a wide range of telecommunications applications.
There are remarkable new technologies still to be developed in terms of space-based satellite communications systems, more powerful processors, new encoding capabilities, and new user terminal capabilities that can make user systems more mobile, more versatile, more personally responsive, more powerful in terms of performance, and yet lower in cost (Pelton 2005; Iida et al. 2003). In many ways today’s satellites are digital processors in the sky and specialized software defines how they perform and defines their communications capabilities.
Advances in satellite manufacturing and directional earth-station technology, particularly the development of multi-axis stabilized earth-station antennas capable of maintaining a high degree of pointing accuracy, while stationary or on rapidly moving platforms, have made earth stations with very stable pointing characteristics both available and practical.
These earth stations can operate in the same interference environment, and comply with the same regulatory and technical constraints as typical GSO FSS earth stations, says ITU. Satellite network operators are designing, coordinating, and bringing into use GSO FSS networks that can offer broadband services to both stationary and moving earth stations using a single stabilized directional antenna within existing GSO FSS technical parameters.
The issue of cybersecurity has been highlighted as a critical feature of business communications.
LeoSat was established to deliver a viable satellite solution for enterprise data. Backed by SKY Perfect JSAT and Hispasat, our mission is to provide fast, reliable and ubiquitous data connectivity which will enable business growth worldwide. To support the developing digital ecosystem, we plan to launch a constellation of up to 108 lowEarth-orbit, laser-connected satellites to provide the fastest, most secure, and the widest coverage international and intercontinental carrier-class, data network in the world, says Diederik Kelder Chief Strategy Officer, LeoSat.
The LeoSat constellation is designed with absolute security and resiliency in mind. Data will travel end-to-end across a single network. This physically separated network ensures security on the lowest networking level, additionally, the multi-satellite constellation provides inherent redundancy, should issues arise with a single satellite. At any one time, there are always 2–7 satellites in view, depending on the latitude of operation.
Regardless of technical or weather issues there are alternatives to route traffic. This underlines the myriad of safety options and high availability capabilities that the LeoSat constellation has inherently built in to ensure network resilience.
WARC Radio frequecy allocation
Satellite technologies are more and more diverse and pervasive but they all rely on the same core element: the availability of radio frequencies that can be operated free from harmful interference. In order to ensure this availability, the Radio Regulations, the international treaty governing the use of the radio-frequency spectrum and the associated satellite orbits (both geostationary and non-geostationary), on the one hand allocate specific frequencies for various space applications, and on the other hand, contain detailed technical provisions and regulatory procedures to ensure the rational, equitable, efficient and economic use of spectrum/orbit resources.
But, with rapidly evolving technologies, innovative applications and new business models recently blossoming in the satellite industry, this treaty needs to adapt and be regularly updated: this is the role of World Radiocommunication Conferences. Such Conferences take place every four years and consider an agenda elaborated and agreed by the previous one. The various agenda items trigger three years of technical and regulatory studies performed within the ITU–R Study Groups to support the work of the Conference by providing possible alternative options to satisfy the needs expressed by the agenda item.
However, the essential satellite frequencies needed to realize this goal are under threat. It should be understood that these millimeter wave bands were made available a decade or more ago to ensure that future high-speed data satellite networks had ample spectrum — and in fact are the basis of products and services designed and built to operate today, to support hundreds of millions of users globally. The efforts of the international mobile telecommunication (IMT) community to identify these bands under WRC-19 Agenda item 1.13 exclusively for IMT-2020 (terrestrial 5G), put this promise and investment at risk.
Many of these bands, including 37.5–42.5 GHz and 47.2–50.2 GHz are co-primary for fixed-satellite services, and satellite networks are being planned and constructed for operation in these bands globally. As a case in point, Hughes is actively expanding its broadband-satellite services across the Americas in these bands, developing a new ultra-high-throughput (HTS) satellite (JUPITER 3), to be launched in 2021, joining two existing HTS satellites.
The agenda for the year 2019 contains several items related to satellite communications are : Providing additional spectrum for satellite broadband Internet access on moving platforms like ships, planes or trains; looking for a harmonized band for telemetry and telecommand of small satellites; setting the operational conditions of nongeostationary satellite systems in the 50/40 GHz range; providing additional spectrum in the same range for geostationary satellite systems; regulating the deployment of megaconstellations of non-geostationary satellite systems to prevent radio-frequency warehousing.
According to Verified Market Research, the Global Satellite Communication Market size was valued at USD 65.68 Billion in 2020 and is projected to reach USD 131.68 Billion by 2028, growing at a CAGR of 9.10% from 2021 to 2028.
The use of Satellite Communication is extensively in television, telephone, radio, internet, and military applications. A large range of radio and microwave frequencies are used for Satellite Communication. The purpose of communications satellites is to relay the signal across the curve of the Earth allowing communication among broadly separated geographical points. It covers a wide area of the earth subsequently whole country or location may be covered with simply one satellite.
Growing applications and adoption of Artificial Intelligence (AI) and the Internet of Things (IoT) have paved the way for Intelligent Transport Systems (ITS). These systems permit customers to track cars or motors and permit freight operators to share and receive information promptly. Using satellite communication for transportation will permit seamless and non-stop transmission of data among the vehicle and the transport hub, filling the gaps of the terrestrial networks. Therefore, the usage of satellites for communication in transport networks, which includes logistics, will provide adequate growth opportunities for the market.
Key Developments in Satellite Communication Market
- In March 2021, SKY Perfect JSAT signs contract with Airbus to build Superbird-9 telecommunications satellite.
- In August 2020, Intelsat successfully launched of Galaxy 30, a satellite that will provide Intelsat Media customers in North America with high-performance broadcast distribution capabilities.
The major players in the market are EchoStar Corporation, SKY Perfect JSAT Group, L3 Technologies, Inc., SES S.A, Telesat, Intelsat, Viasat, Inc., Gilat Satellite Networks, and Thuraya Telecommunications Company.
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