Distributed Internet-Optimized Services via Satellite Constellations

Abstract

One of the most significant recent developments in satellite communications has been the sudden resurgence of large-scale constellation satellite programs to provide broadband services. This has occurred some 20 years after the several unsuccessful attempts to deploy such huge constellations like Teledesic in the USA and Skybridge in Europe. These were never deployed for several reasons that included financing and the bursting of the Internet bubble at the end of last millennium.

Of course, other telecommunication constellation programs have been deployed since that time (Globalstar 1st and 2nd generation and the Iridium and soon Iridium Next for instance). These systems, however, were designed to address narrower band services in low band frequencies (L and S-band) for mobile telephony and low-medium rate data.

These new types of constellations that are currently either recently operational or under design and development are intended to mainly provide broadband Internet-optimized services with the ability to offer low latency performances compared to geostationary satellite alternatives. These new systems, and in particular the O3b and OneWeb networks, both headquartered in the tax haven Jersey Island, UK, as well as the Leosat initiative, from a Delaware registered company, have been described as “disruptive,” “game-changing,” and “innovative” in their architecture (P. de Selding, “Never Mind the Unconnected Masses: Leosats Broadband Constellation is Strictly Business”, Space News, Nov. 20, http://spacenews.com/nevermind-the-unconnected-masses-leosats-broadband-constellation-is-strictly-business/, 2015).

One remarkable aspect is that each one represents very different and specific approaches to addressing broadband applications by satellite. Some are in Low Earth Orbits (LEO) at about 1000–1500 km altitude while O3b is flying much higher in Medium Earth Orbits (MEO) at about 8000 km altitude. O3b is an equatorial MEO system of 12 full-sized satellites. Others are intended to represent a network of some 100 satellites of 700–1300 kg mass while yet others are requiring several hundred spacecraft of 175–200 kg mass. Some are envisioned to provide “local” services connecting a gateway with users in visibility of a sole spacecraft scale (Proposed Leo Sat Constellation, Space News, March, 2015 http://spacenews.com/proposed-leosat-constellation-aimed-at-top-3000/Last. Accessed 9 Dec 2015).

Other systems are designed with a more interconnected architecture for connecting users to a gateway or another user that can be located far away in an another continent thanks to inter-satellite links.

However, each concept in its own way is raising a number of regulatory and technical challenges.

This trend to deploy new broadband constellations for fixed and mobile satellite services started with the deployment of the medium earth orbit O3b constellation in 2013 and 2014, and now OneWeb has selected in mid-2015 Airbus Defence and Space as a joint venture partner to invest and manufacture some 900 small satellites (i.e., operational plus spares) to be deployed starting in 2018. There may be other companies that follow suit to deploy similar so-called mega-constellation systems, but currently OneWeb is the only such LEO constellation system under a development contract to manufacture and launch such a large-scale network. Another possible system has started design and engineering phases such as Arlington, Virginia-based LeoSat (although officially headquartered in Delaware). This system is exploring an 80 satellite that might be expanded to about a 110 satellite constellation. This project involves Thales Alenia Space. Then there is the announced effort whereby Singapore Space Intelligent IoTS Pte. Ltd. (SSII) is partnering with German satellite maker OHB System to develop the world’s first Asia-based low Earth orbit Internet constellation (Singapore Space Intelligent IoTS Pte. Ltd. http://www.ssii.sg/Last. Accessed 8 Mar 2016).

Finally, there have been reports of a Space-X backed system that might deploy as many as 4000 satellites in a massive mega-LEO system.

These systems are, however, not yet contracted to manufacturing and thus are not addressed here in details. The Space X system would presumably like OneWeb involve quite a huge number of small satellites and be aimed at underserved developing countries’ markets among other more mature markets. The LeoSat system in contrast would involve much larger and capable satellites with more than 2 kW of power and would be aimed at meeting the special needs of the largest corporations in the world (Propose LeoSat).

The implications of such large-scale constellations of small satellite are manifold. These new type satellite networks would seem to revolutionizing the cost of manufacturing and launching spacecraft, concerns about radio frequency allotments and protection from interference, orbital debris build-up and removal, collision avoidance, management of liability concerns, and more. What is clear is that the deployment of those satellite constellations in low earth orbits will provide a satellite network that is quite different in many ways when compared to GEO satellites. The LEO satellites would typically be some 30 times closer to the Earth’s surface than GEO satellites with about 60 times less transmission delay for a round trip. Clearly such a network can accommodate latency-sensitive applications in Internet data transmissions (i.e., TCP/IP protocols) with greater efficiency and support voice conversation services with greater facility. On the other hand, their closer vicinity with the earth’s surface restricts their coverage reach, and this requires many more satellites for a continuous earth coverage.

This new trend to deploy satellite constellations for broadband satellite services is occurring in close parallel with the development and deployment of very high throughput satellites (VHTS) in geostationary orbit that provide much greater capacities at lower costs. Clearly these parallel and potential “disruptive” trends to deploy even more capacitive HTS and low earth orbit constellations could serve to drive down costs and make available new digital services to consumers around the world at much lesser costs. We can even expect in a midterm the integration of both complementary solutions, the very high capacitive geostationary HTS systems providing a much higher data rate per user together with mega-constellation services offering low latency data flow and a world coverage including the poles. The involvement of well-known international satellite operators of geostationary fleet such as Intelsat that is involved in the OneWeb project or SES in the O3B is probably a revealing clue.

This chapter describes the various systems that have been implemented or now in production to be deployed in the coming years – especially O3b and OneWeb. This chapter provides some of the basic technical and operational characteristics of these new systems. It also addresses the various types of new services that are being offered or planned by these types of networks.

It was thought in the 1990s, a mega-LEO satellite system for broadband fixed satellite services similar to OneWeb might deployed. This network, which was named Teledesic and financially backed by Bill Gates, Greg McCaw, and venture capitalist Ed Tuck, was proposed along with about 15 other Ka-band satellite networks. The Teledesic system and the other proposed Ka-band systems were never deployed – except for the Wild Blue Geo satellite network (renamed the Ka-band satellite system) and which was delayed over a decade in its actual launch and deployment. Today, some 20 years later, the viability of such large-scale lower earth orbit satellite systems now seem to be economically feasible again.

Thus, the first generation of O3b has been designed, manufactured, and successfully deployed, and rapid progress is being made to design, manufacture, and launch OneWeb in a not so distant future. The advent of 3D printing, advanced manufacturing techniques taking benefits of more automated processes for large-scale production and testing, more extensive use of commercial off-the-shelf (COTS) components, and new commercial systems to launch small satellites at low cost have combined in a positive fashion to greatly reduce the cost of building and launching such satellites.

New satellite networks, born out of Silicon Valley, such as the Skybox constellation for remote sensing, now acquired by Google, have served to unveil a whole new pattern of commercial satellite business. “Disruptive” technologies and new satellite system architectures are thus the hot trend of the day driven by so-called New Space commercial ventures.