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by Mary Kay Williams
Director, Corporate Relations
Final Analysis Inc. (Lanham, MD, United States)
This past summer, people everywhere were astonished at those marvellous pictures from Mars made possible by the National Aeronautics and Space Administration (NASA) (United States) Pathfinder Mission. At Final Analysis, we felt a special kinship to the Pathfinder. Our FAISAT-2v satellite, a Little LEO spacecraft, carries the same on-board computer processor as the Pathfinder.
The same computer unit that guided Pathfinder's rendez-vous with Mars will provide a rendez-vous between Final Analysis and those countries participating in our awareness programme to gain "hands-on" experience with this new digital data technology. Among the countries testing with us are Brazil, Colombia, Germany, Indonesia, Mongolia, Poland, Senegal, the United States and Uruguay.
Commercial adaptations of this technology will benefit developing countries, as well as developed countries, around the world. In particular, the 48 least developed countries (LDC) stand to gain many socio-economic benefits from Little LEO technology. One of the top priorities in the Special Programme of the Buenos Aires Action Plan (BAAP) for LDCs is "rural communications". Little LEO systems can optimally address this priority for rural communications with solutions that are affordable, sustainable — and that complement (not threaten) existing terrestrial infrastructures.
For example, two-way personal messaging (paging and e-mail) and voice mail via Final Analysis FAISAT Infosats provide a low-cost, instantly-available rural communications system. This digital data system can also deliver rural communications to health and education centres, police units, and agricultural stations in small villages and mission outposts that may lack electric power and telephone service.
Consider how FAISAT Infosats can create a rural communications system which would make possible virtually instantaneous data transmission for collection, analysis and dissemination of lifesaving information on infectious diseases — facilitate medical diagnoses of complex cases remote from medical centres — provide virtual real-time safety and alarm monitoring in areas not otherwise served by telecommunications — provide early warning of hurricanes, earthquakes, volcano eruptions and other environmental and climatic disasters — and deliver educational information to school children in remote locations.
Little LEO systems are not basic telephony but digital data services which enhance, not replace, existing services thereby avoiding by-pass issues. Using the above example of rural communications, Little LEO services can extend the reach of public services for mere cents per minute and beyond areas served by terrestrial infrastructures. Regional or national service providers will keep a substantial amount of the revenues.
What is needed to speed these Little LEO services to the LDCs is additional spectrum which will help to close the telecommunications gap between the "haves and have-nots" nations. Delegates to the 1997 World Radiocommunication Conference (WRC-97) from the 48 LDCs and other countries have an opportunity to make their voices heard in Geneva. One loud and clear message should be that Little LEO services can stimulate economic development, and that LDCs and other countries should not be held back because of vested interests in terrestrial infrastructures, particularly in Western Europe which largely is unsupportive of additional Little LEO spectrum allocations.
Worldwide market demand
Little LEO systems are focused on digital data services which provide affordable messaging services targeted to the world’s underserved markets and on low-cost asset tracking and data monitoring applications. If sufficient spectrum is allocated, these new services could be available in the near term to governments and businesses worldwide. Indeed, a unique point favouring Little LEO services is the ability to cost-effectively serve less developed and remote regions at a margin profitable to participating regional or national service providers.
Indeed, the Little LEO market is a broad global growth market. Studies over the years have consistently increased the size of the market as new applications evolve. One such study commissioned by Final Analysis and conducted by a well-known market research firm concluded that the Little LEO addressable market would be USD 5.5 billion in the year 2002 in just five market segments. A few of these segments are discussed as follows:
Personal messaging and voice mail — FAISAT Infosats, for example, will provide two-way paging and variable messaging services (alphanumeric keypad and display) with message sizes exceeding current paging systems. Our voice mail service (microphone, speaker, and voice digitizer) is an ideal solution for people unable to read or write as the service relays the recorded speech after it has been digitized into a data transmission.
Tracking and asset management — FAISAT ground terminals (equipped with GPS receivers) will provide quick, accurate, low-cost positioning information for all sorts of cargo, shipping containers, rail cars, barges, and trucks. Control information can be easily provided through the same equipment. Anti-theft devices can report on the location of a stolen vehicle anywhere in a country or region and disable the vehicle via a satellite command. Commercial trucks can have customs control handled through remote sensors which can verify that the container was not opened. Anything that moves can be tracked, thus protected.
Data monitoring and control — FAISAT ground terminals (equipped with microprocessors) will provide the memory and operational systems to monitor crop conditions and feed supplies on large farms, climate conditions at weather stations, water quality conditions, consumable supplies in vending and copying machines, utility usage at homes and businesses, point-of-sale reports from retail stores and a wide variety of inventory management data. These Little LEO satellites can "read" many tens of thousands of sites in only a ten-minute pass, providing far greater efficiency than existing data collection methods, and at lower cost.
Little LEO systems
The term, "Little LEO", was originally conceived to distinguish those systems which operate below 1 GHz from "Big LEO" systems which operate above 1 GHz. The term "Little" implies the small size of the satellites, and the relatively low cost of system implementation. Both Little and Big LEO systems will launch their satellite constellations into low-earth orbit, hence the same word "LEO".
Little LEO systems, like FAISAT Infosats (see Figure 1), aim to operate in the UHF/VHF bands below 1 GHz, sharing these frequencies with existing users. The advantage of this plan is that the radiocommunication technology has been developed, tested, and successfully used in these frequency bands since the 1970s. Thus the technology is proven and is also low cost. Little LEO systems can also provide some commercial services with only one satellite in orbit, thereby delivering benefits of this new technology as soon as possible.
The downside of operating below 1 GHz, as we are all aware, is that these frequency bands are congested with existing user groups especially in Western Europe. These existing user groups do not want to share spectrum with Little LEO systems — even though spectrum sharing is the operating principle under which Little LEOs are designed. A number of studies in the Radiocommunication Sector (ITU–R) Study Groups explain how Little LEO systems, equipped with multiple interference avoidance techniques, can effectively share spectrum, thereby protecting existing users while increasing the efficiency of spectrum utilization.
There are three ways to help resolve what has been, up to this point, an allocation dilemma:
- Examine the interference avoidance techniques in Little LEO systems. Published studies and actual system demonstrations can provide the background for such examination.
- Review the process of spectrum allocation and frequency coordination which offers national regulators the steps and flexibility to deal with Little LEO frequency needs.
- Consider wider allocations on the international level to further maximize flexibility for national regulators on the domestic level.
Frequency sharing techniques
Numerous studies since WRC-95 show frequency sharing feasibility with existing radiocommunication users below 1 GHz. Little LEO systems are equipped with multiple interference avoidance techniques assuring the greatest protection to existing radio services:
- dynamic channel avoidance technique;
- GMSK modulation technique;
- adjustable power of transmission (pfd);
- adjustable transmission duration time;
- frequency agile "software" flight radios
- on-board computing capacity.
Spectrum allocation process
Allocations for Little LEO non-voice mobile satellite systems at the 1992 World Administrative Radio Conference (WARC-92) and WRC-95 are inadequate. In the 137–960 MHz frequency range, the WARC-92 and WRC-95 allocated to Little LEO commercial systems a total of only 0.7% of the available spectrum (see Figure 2). To make matters even worse, the 0.7% spectrum contains 2 MHz allocated only for the Western hemisphere.
These small allocations for Little LEO commercial mobile satellite systems must be shared with existing radiocommunication users who account for 100% available spectrum in the same frequency range. These allocations essentially require Little LEO systems to protect terrestrial users. Some system operators are beginning to look above 1 GHz at the potential of locating feeder links in limited portions of spectrum bands around 1.4 GHz.
Figure 1 — FAISAT Infosats
However, the remarkable thing about the current spectrum allocation process is that it can enable the expansion of new technologies while it protects existing users. Because Little LEO mobile satellite systems are inherently global systems, a frequency allocation decision at a WRC is only the first step in a lengthy country-by-country process. Thus, this process affords national regulators, at every step of the way, ultimate flexibility and control of domestic allocations and assignments to users.
Once the Table of Frequency Allocations of the International Telecommunication Union (ITU) is changed to reflect an international allocation decision made at a WRC, national regulators still have flexibility to adopt or not adopt that decision in their country. If the national regulators choose to adopt a particular allocation from the ITU Table, then these regulators first need to change their domestic table of allocations.
In the next step of this process, national regulators may decide to make an assignment of a specific frequency within their domestic table of allocations to a system operator or user. But here again, the national regulators have the option not to assign a frequency to an operator even if that frequency allocation already exists in the domestic table. In other words, the assignment may never be given, thus the frequency allocation may never be used.
If, however, the national regulators choose to make a frequency assignment to a user, then the technical and operating parameters of the system are notified to the ITU — giving other countries an opportunity to assess interference potential. Intergovernmental/industry bilateral or multilateral coordination results. This coordination could, in fact, modify or restrict the satellite operating over a particular country's terrain as occurred in a United States-France bilateral on Little LEO frequencies.
Wider international allocations
Because of differences in allocations and spectrum usage in bands below 1 GHz throughout the world, it has been impossible to identify the same allocations in every country sufficient for these systems to use. Although this situation is unlikely to change, there is a solution. With wider frequency allocations on the international level, Little LEO mobile satellite systems could be assigned different portions from the wider frequencies for use in different regions of the world. Thus, when used jointly, the different portions could provide a worldwide capability for Little LEO systems.
This concept of wider international allocations is supported by the frequency agile technology aboard Little LEO systems which allows for shifting or "hopping" from one frequency to another as the satellites fly over a particular geographical area or region.
Wider frequency allocations on the international level offers a solution for Little LEO systems which also gives greater flexibility to national regulators from developed or developing countries to make allocations and assignments on the national level, if they so choose.
At WRC-97, there are solutions to satisfactorily resolve the issue of allocating additional frequency bands to Little LEO systems. National regulators can look to the established spectrum allocation process, the concept of wider international allocations, frequency sharing techniques of the Little LEO systems, and related sharing studies.
These solutions would help achieve goals of the Special Programme for the 48 least developed countries (LDCs). At the same time, these solutions would assure the developed countries, of say Western Europe, that their existing radiocommunication users are fully protected. Among other benefits, these solutions would speed up the introduction of a new system of rural communications. That alone would be as marvellous an achievement as those pictures from Mars!
This text is an extract from ITU News 8/97