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What Are the New Mobile Satellite Systems?

The WRC-97 will spend a considerable amount of time focusing on radio frequency allocations for new kinds of satellite systems, known in ITU-ese as GMPCS systems or NGSO MSS (short for non-geostationary satellites in the mobile satellite service), but more commonly, though not always accurately, called Big and Little LEOs. What are these systems, and why are they set to take centre stage at WRC-97, just at they did at WRC-95?

At the last World Radiocommunication Conference, held from 23 October to 17 November 1995, delegates witnessed an unprecedented phenomenon – the overt and very public presence of a number of satellite consortia, who came to the conference for the express purpose of lobbying for a rather obscure item – a piece of the radio frequency spectrum. This formerly sedate, ‘techies-only’ event had suddenly been transformed, if not into a political rally, then into something akin to it. Certainly, there was a good deal of ideology in the air, with some operators touting their systems as saviours of the world’s communications problems and great unifiers of all humanity. And as is often the case when the stakes are high, a lingering bitterness could be detected in the camps of some would-be operators when the event closed on a grey Saturday morning in November.

Why all the fuss over a few radio waves – and what are they needed for anyway? Radio waves form part of the frequency spectrum , along with infrared, ‘ultrasound’ rays, x-rays and visible light. The part of this spectrum which can support radiocommunications (from around 9kHz to 400GHz, well below the frequency of visible light) has come to support a huge and growing number of services. Mobile telephones, pagers, wireless computer networks, walkie-talkies, aircraft and maritime navigation equipment, meteorological and environmental monitoring systems, deep space research and of course television and radio broadcasting all use the radiocommunications spectrum to send and receive information.

The problem faced by the International Telecommunication Union, the UN-specialized agency which deals with telecommunications, is that the radio frequency spectrum, although ‘recyclable’, is a finite natural resource – and there is simply not enough of it to go round.

The development of new and useful technologies such as mobile telephony and mobile computing, satellite-based meteorological forecasting and improved positioning and safety systems for aircraft and shipping, as well as the growing market for direct-to-home subscriber broadcasting and other consumer services is stretching the capacity of the radio frequency spectrum to accommodate all the services already in place and planned for the near future. The job of each World Radiocommunication Conference is to examine the need for frequency allocation, and attempt to apportion the spectrum in an equitable and forward-looking way, while protecting the services already in place, which could be subject to harmful interference if arrangements to incorporate new services are not done in the proper way.

The intense interest from would be satellite system operators at WRC-95 was centered around this problem of frequency allocation and shortage of spectrum. Whilst we all know that satellites have been in use for many years for telecommunications, recent technological developments have enabled the development of a new breed of system which is small, relatively cheap to manufacture and launch, and capable of orbiting much closer to the earth. The operators vying for frequency allocations at the last WRC represent a new breed who bear little resemblance to the existing international satellite consortia. These new players are aggressive young companies, some with a background in the cellular telephony or information technology industries, who are keen to use these satellites to exploit a new market niche – truly global, seamless voice, fax, data and even Internet connections, anywhere in the world, at any time.

These new kinds of systems are generally known as Global Mobile Personal Communications by Satellite (GMPCS), a rather unwieldy acronym which in fact encompasses a range of systems, some of them based on existing geostationary satellite technologies. They do have enormous potential to change the way the world communicates, but for the moment, most are still in the planning stage. The World Radiocommunication Conference represents a key component in the establishment of these new systems, which cannot become operational without the right amount of spectrum under an appropriate regulatory regime.

The globalization of the world economy is the driving force behind the development of GMPCS. Increased personal mobility and the evolution of many businesses into large regional or even global operations is profoundly changing the way we communicate. The popularization of the fax machine, and later the widespread growth of worldwide data networks has greatly increased the traffic over international routes, and accelerated the pace of business operations.

Thanks to cellular telephony, staff have become more mobile and working practices more efficient. Two problems still remain, however. The first is that the user of a mobile phone is only contactable while within a mobile phone ‘cell’. Many countries’ cellular networks do not provide ‘blanket coverage’, that is, there are places where the phone will not work. This is especially true in remote areas or areas of low population density, where it may not be economically feasible to install the equipment necessary to support the network.

Additionally, while it may be possible to contact colleagues who are out of town on business, contacting them when they are out of the country is much harder. The first mobile telephone systems were designed for use within a single country. Later, it was recognized that the ability to use a mobile phone internationally was also desirable, particularly in regions such as Europe where business travellers frequently cross national borders. This thinking led to the development of the GSM system for mobile telephony, which offered users a feature known as ‘international roaming’. This allows a user to telephone from, and be telephoned in, any other country with a GSM network which has a ‘roaming agreement’ in place with the home country. The problem with this system is that it now seems unlikely to meet the original need for seamless international communication. Several countries in the world have implemented a GSM network, but some may have such a system but not allow users from certain countries to call or be called because a roaming agreement is not in place. Other countries have chosen a different path, and have implemented cellular and mobile technologies which are not compatible with GSM networks.

It was in an effort to overcome these problems that engineers began to examine the possibility of implementing a new type of system, which would use a number of small satellites to pick up and relay telephone calls, between towns, countries, and geographical regions. These systems would overcome the tyranny of distance, incompatible cellular standards, and poor local line quality, making people reachable by telephone virtually anywhere on the planet. They would bring state-of-the-art telecommunications to people in all countries of the world, regardless of the local terrain, the remoteness of the village, or even the presence of a local telephone network. It was this egalitarian dream that led to the development of GMPCS. And it is the emergence of a new, potentially highly lucrative untapped market that is causing the feeding frenzy we are currently witnessing in the satellite industry, as would be operators scramble for a piece of the action.

So how will the new GMPCS systems take shape? And when? Firstly, there is an important distinction to make between the two main types of system currently in the pipeline. The first, known generically as ‘Little LEO’ satellites, will offer a range of low-speed text and data services. The second type of satellite, known as Big LEOs, will offer users seamless global voice, fax and possibly even broadband services.

The ‘Low’ of LEO’s Low Earth Orbit refers to the altitude of 700 - 1,500 km at which the satellites are orbiting above the Earth’s surface – they are only ‘low’ in relation to traditional geostationary communications satellites, which orbit the Earth at a distance of 36,000 km. In fact, these Low Earth Orbit satellites are still nearly twice as high as Space Station Mir, which orbits at around 400 km from Earth. Both types of system are non-geostationary, meaning that the position of the satellites changes in relation to the surface of the planet. In operation, they will form a moving constellation, circling the globe and relaying messages back and forth between each other and users, and/or earth stations.

The Little LEOs could be the first systems in full operation, with some already partially on-line and promising commercial services in 1997 and 1998. Little LEO proponents hope to gain customers quickly by offering fast and inexpensive services, and by getting a foothold in the market well ahead of their bigger cousins.

Little LEOs are generally smallish satellites around 1m³ in size and weighing about 100kg. Most ventures currently in the pipeline propose to use the satellites as either ‘bent pipe’ systems, or store-and-forward systems. The so-called bent pipe system relays messages directly between users, while the store-and-forward approach means that a satellite receives information from a ground station, stores it in on-board memory, continues on its orbit, and releases the information to the next appropriate ground station, or user. Users will access the new Little LEO systems using small hand-held messaging units weighing less than 0.5 kg, and incorporating a low-power omni-directional antenna.

Little LEO services will tap into a range of markets. Messaging is expected to be a high-demand service, and will include e-mail, limited Internet access, two-way paging and fax. Remote data communications will also be an important area, especially for Emergency Services.

Other important niche markets will be digital tracking (for the transportation management market), environmental monitoring, and SCADA (Supervisory Control and Date Acquisition –a system which provides remote monitoring of isolated facilities such as mines, oil refineries etc).

But while these systems may well be first to market, it will be the Big LEOs that will attract the lion’s share of media attention. Most of these systems won’t be up and running until 1998 or later, but they do promise users a greater range of services. The most well-known of these is global mobile telephony – the ability to make and receive calls on a mobile telephone anywhere in the world. Other services, though, will include data and fax, and even (in the case of one proposed system in any case) broadband video. In this highly competitive market, the main contenders will offer small hand-held mobile terminals only a little larger than today’s diminutive cellular phones, and which incorporate a largish aerial. (The appearance of the units is, in fact, not unlike the analogue mobile telephones of the mid-1980s).

The Big LEO systems will comprise a constellation of several satellites, moving around the globe and picking up and relaying users’ telephone calls from one region, country, or continent, to another. Some of the proposed systems support satellite to satellite communications, making them, in reality, an enormous wide area network. Most, though, rely on uplinks and downlinks to earth stations to complete the call circuit, and will use existing terrestrial infrastructure whenever possible.

The advantages of the Big LEO systems seem obvious – until you factor in the cost. Compared with the Little LEOs, the cost of a call, at least initially, will probably be prohibitive for most users, with the exception of large corporations with a genuine need for instant global voice communications to remote areas at any time. Those users simply needing a global voice network, or a global high-speed computer network, can in many instances already meet their needs with existing fibre optic networks or via the kinds of value added networking services now being offered by most of the leading telecommunications carriers. Furthermore, some systems already operating in geostationary orbit, such as the system operated by Inmarsat, can already provide similar voice and data services from traditional types of telecommunications satellites.

The cost of calls over the new LEO systems are still a little hazy, but it would probably be safe to say that most systems plan to offer voice service at US$1-3.00 per minute. However, since most operators will market their services via resellers, this may not reflect the cost to the user, which could be substantially higher. Furthermore, the cost of buying a handset is expected to come in at a further US$700-3,000.

But before writing off the system as just too expensive to be feasible, it pays to bear in mind that the first analogue mobile phones sold for similar kinds of prices, and that the cost of calls on cellular networks around the world has dropped significantly as the volume of users has grown and markets have matured. There is every reason to expect that the same kind of thing will happen with the new global satellite services, although the time frame for a meaningful reduction in pricing will depend on how many people sign up for the service in its early stages.

The would-be GMPCS system operators still have a great deal of work cut out for them before these systems become a commonplace part of the global telecommunications environment. For a start, there are a number of technical problems to overcome in setting up, launching and operating such complex satellite constellations.

In addition, competition for a niche in this new market is very high, and many industry analysts have remarked that it is unlikely that the market can support the number of players currently lined up to provide services. It seems certain that there will be some casualties along the way as market forces work to weed out those operators who are unable to raise the necessary capital, who are less-competitive, or who fail to make the grade in terms of service provision.

International licensing, too, may prove a sticking point. The incompatibility problems which plague current cellular networks when roaming from country to country could be just as bad for the new GMPCS networks, unless most operators can secure operating licences in at least the majority of the world’s nations.

Finally, operators will have a tough job persuading customers to fork out what is, after all, a sizeable amount of cash for the ability to use a system many people may not actually need.

All that said, for operators, the first step is to secure the operating spectrum they need. Without this, they might just as well consign their system plans to the dustbin. In 1992 at the World Administrative Radiocommunications Conference in Torremolinos, Spain a sizeable amount of spectrum was won for GMPCS systems. Non-geostationary satellites in the mobile satellite service operating at below 1GHz – generally, the Little LEOs – were granted worldwide allocations on a primary basis in the bands 137-137.05MHz; 137.175-137.825MHz, 148-149.9MHz and 400.15-401MHz (primarily allocations being those which are reserved exclusively for that service), as well as on a secondary basis around 137MHz and in the bands 312-315MHz and 387-390MHz. A primary allocation was also made for the land-mobile satellite service in the band 149.9-150.05MHz.

For systems operating at above 1GHz, including Big LEO systems, allocations were made in the bands near 1.5, 1.6 and 2GHz.

WARC-92 also directed the ITU to undertake, as a matter of priority, technical, legal and operational studies which would lead to the establishment of standards governing the operation of these new types of satellite system, to ensure equitable and standard conditions of access for all ITU Members while guaranteeing proper protection for existing services and systems.

New allocations for GMPCS were made at WRC-95, with more spectrum made available for both systems below 1GHz and 400MHz of spectrum set aside for mobile satellite service ‘feeder links’. Feeder links are the communications channels by which satellites pick and download their information, and generally operate between satellites and earth stations, although some new GMPCS systems can also support direct satellite-to-satellite links.

WRC-95 also made an allocation of 400MHz to the non-geostationary fixed satellite service in the 20/30GHz bands, which was very warmly received by the then-leading contender for this kind of service offering, Teledesic Corporation, a joint venture between Microsoft’s Bill Gates and Craig McCaw (formerly of McCaw Cellular, a US cellular network operator now owned by AT&T). The win for Teledesic has been a win for other operators too. Many of them are now planning to offer services similar to Teledesic’s ‘Internet in the Sky’ plan, to take advantage of the rapid growth of the World Wide Web and other on-line services.

Nevertheless, all these allocations have still not been sufficient to satisfy operators, particularly in the Little LEO camp, who claim the amount of spectrum they have will not be enough to operate the number of systems already in the pipeline on a competitive basis. WRC-97 will be reconsidering this and other matters, and by the end of the intensive four weeks of debates, deliberations and late-night bargaining sessions, there are almost certain to be some who leave Geneva happy, and others who are disappointed.

The ITU’s role throughout the event will be to ensure that the ultimate winner will be the user. The Union must ensure that spectrum is allocated fairly to all systems, in a way that encourages growth in the market. But, at the same time, it will be careful to protect existing users of radio-based services, many of them in the developing world, who may rely heavily on such systems for basic communications and who may not have the economic means to simply replace old systems with new GMPCS equipment.

Achieving such a balance will be no mean feat. Nevertheless, since the decisions of World Radiocommunication Conferences become binding international treaties, getting the right mix between stimulating growth and protecting the interests of all in as fair a way as possible is absolutely essential. At the close, on 21 November, the world will be able to judge just how good a performance this global balancing act has been.