Before going into India’s efforts in satellite communications field, it would be worthwhile to review the international scene growth and status of technology and applications. In 1945,
Arthur Clarks predicted that the geosynchronous orbit at an altitude of about 36,000 kms will be the most suitable orbit for communications. A satellite in this Orbit “views” about one third of the surface of earth, and hence three such satellites could provide global communications.
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Thus, while SPUTNIK heralded the space age in 1957, SYNCOM-I, a geo-synchronous satellite; later renamed Early-Bird ushered in the era of operational satellite communication in 1964.
The extensive use of satellites for global communications started with the formation of INTELSAT in April, 1965. Since then the membership of INTELSAT has undergone considerable changes, the basic objective of the international organisation namely providing international communications to the member states on a commercial basis at economical rates has remained.
Image Source: spacesafetymagazine.com
As of now, INTELSAT has launched five generations of satellites and more are under development. INTELSAT has also played a leading role in the development of requisite technology.
With the vast expanse of the Soviet Union, spanning eleven time zones, it was natural for erstwhile USSR to go in for satellite for domestic communication. Use of 12-hour orbit proved to be ideal for covering the higher latitudes (70 degree North) of USSR.
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Thus, MOLNIYA Satellite in conjunction with the ORBITA ground system provided domestic satellite communications for quite some time till the emphasis gradually shifted to geosynchronous satellite, which could cover most of the populated regions and regions of population growth.
At present, USSR operates many geostationary satellite systems (such as Stationar, Raduge, Gorizont, etc.) to provide a variety of communication services including communications to remote and isolated communities, medical guidance and education through such links, etc. With its Anik-C and Anik- D series, Canada has also started Direct Broadcasting of TV programmes from satellites as an interim measure.
The real explosion of satellite communication system in the developed world can really be attributed to the far-reaching decisions taken in the USA regarding reregulation of communications environment in the late seventies. This led to commercialisation and diversification of the market and also demands for new services that could best be provided with satellites.
The increased competition also led the new entrants to the choice of satellite medium for conventional telecommunication where it proved to be economical.
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Further, the regulations on receive-only terminals were done away with. This almost “open sky” approach led to the establishment of several satellite systems, some of them exclusively for special applications such as business and data communications. However, most of the capacity built-up is being used primarily for TV programme distribution.
The Western Europe, which has had a fairly good terrestrial communication system, was also late in going for a satellite-based communication system, though certain experimental programmes had been underway for quite a while.
However, the establishment of European Space Agency and EUTELSAT hastened the process and presently, several systems, some covering Western Europe as a whole and some meant only for particular countries (e.g., France and Italy) are being established.
Japan has also established domestic satellite communication systems and has indeed been the first country to experiment with a 20-30 GHz satellite. Australia is also establishing a satellite system for domestic communications and broadcasting.
Indonesia was the first amongst the developing countries to establish an operational communications satellite system called PALAPA in 1976. Satellite system is ideally suited to provide the vital communications infrastructure in a fairly large country consisting of more than 13,000 islands spread over a large ocean areas (extending from E-950-140E longitude).
The capacity of PALAPA system (consisting of at present two satellites) is also leased to neighbouring countries like Malaysia and Thailand. Several other developing countries like Brazil, Argentina, etc. also have initiated the process for setting UP satellite systems. Twenty-two Arab countries have joined together to establish a regional satellite system called ARABSAT.
The first ARABSAT satellite is expected to be launched in 2015. China which has a strong and fairly advanced space programme launched its own experimental geostationary communications satellite in 1984 with a Chinese launch vehicle.
China has also leased INTELSAT capacity for domestic communications and has announced plans for establishing a TV broadcast satellite system. In fact, it is expected that by the end of this decade more than 50 countries will lease about 90 transponders from INTELSAT for domestic use.
The rapid growth of communication satellites can be judged by the fact that there is a large number of satellites that occupy the geostationary orbit in the Indian Ocean region. This has also led to the crowding of orbit and the frequency spectrum both of which are reusable natural resources.
Though the resources of orbit-spectrum are not depletable, when one country is using a particular portion, no one else could use the same.
This constraint has given rise to the apprehension on the part of many countries that have no need to establish a geostationary satellite communication system immediately (but may want to do so at a later time), that the early starters may prompt the resources.
A World Radio Administrative Conference under the aegis of the International Telecommunication Union took place in two sessions in 1985 and 1988 to come to the grips of the issue of equitable use of the orbit-spectrum.
India has taken a path of planned self-reliance in the field of satellite communication in the spirit of international cooperation. India has done reasonably well in this field, thanks to the vision and efforts of the founders of space programme.
It is, thus, that while the first training centre was established with the assistance of United Nations Development Programme, the Satellite Instructional Television Experiment (SITE) was conducted with the active collaboration of the USA.
The ATS-6 satellite, with a design life of two years and costing about Rs. 200 crores, was made available to India for conducting one-year experiment.
SITE is still the largest experiment in human communication for national development. It was conducted in 2,330 villages dispersed over 20 districts in six economically backward states for a period of one year. SITE was a leap forward in the use of satellite technology of direct broadcasting for educational and developmental purposes.
SITE was an innovative venture as for the first time; both technical (hardware) and social (software) aspects of the experiment were carefully studied for evolving a future satellite-based television broadcasting system in India. Both in production and engineering, several innovations have been made to meet the challenge.
In case of social evaluation, more or less field experimental design has been followed to measure the effect on the rural TV viewers largely unexposed to any mass media prior to commencement of the experiment.
TV viewing directly triggered the process of change in which illiterate women and men gained knowledge of health innovations and family planning at least as much as literate men and women.
It also led to adoption of some of the agricultural practices which were not dependent upon external and specialised information and least dependent upon agricultural developmental agencies and their infrastructure.
Significant gain in empathy, educational and occupational aspiration for male children was found. In the area of political socialisation, the illiterate rather than literate male viewers showed greater gain. In overall modernity, both attitudinal as well as in behavioural information, significant gain was observed.
SITE has been hailed as the largest communication experiment conducted anywhere, and the success-achieved is due to the end approach adopted. SITE was preceded by study of national developmental needs, the possible approaches and the technical and economic aspects.
While SITE concentrated on satellite TV broadcasting to community receivers, it was followed by experiments in telecommunications (telephony, data communications, etc.) using the Franco-German satellite SYMPHONE and APPLE.
Through a series of experiments has been gained very valuable experience in hardware, software and management of satellite based system which is relevant for operational systems.
INSAT System will introduce three special series on a semi-operational basis. There are Disaster Warning System, News Dissemination Service and Time Dissemination Service. In all these cases, simple and inexpensive receivers will be located in the user premises and these will receive the information broadcast from one or more central locations.
The Disaster Warning System will have an added feature in that the Cyclone Warning Centre could selectively address through the Satellite, a group of receivers located in a zone that is likely to be hit by a cyclone.
The News Dissemination Service will offer a combination of facsimile transmission and several channels of teleprinter messages so that the user can select the type of news or information that is of his/her interest. All the stations of All India Radio (over 100) will be networked for National Programmes of news through four channels using INSAT.
A simple scheme has been evolved for this purpose. One channel is also available for regional programme distribution and for programme exchange between regional centres on a time-shared basis.
INSAT also carries a Data Relay Transponder which is used to collect meteorological data from about 110 remote and unattended Data Collection Platforms. Similarly, the VHRR imageries transmitted by INSAT are being disseminated to twenty meteorological offices through a combination of satellite and terrestrial media.
The TV broadcasting relies on INSAT to a great extent. Except for 9 locations which are connected through a terrestrial microwave link, all other stations of Doordarshan are networked though the satellite using TV Receive Only terminals (TVRO).
The massive expansion of TV coverage in the country by deployment of about 200 Low Power Transmitters (LPT) in conjunction with TVROs is a major step in meeting a long felt need.
However, the most important feature of INSAT communication applications and technology and plans is that it is the first satellite with S-band Community TV broadcast capability.
INSAT-I has two high-powered transponders for TV broadcasting and Direct Community TV Receivers with 3.6 metre mesh antenna are being batch -produced in the country.
The global scenario in Satellite Communications is changing fast. Though, for Fixed Satellite Service (primarily telecommunication, TV distribution, data communications, etc. between fixed locations) the 4 and 6 GHz band is still widely in use, there is an increasing trend to utilise the higher frequency bands.
The Eighties was the decade of information revolution in India. The satellite broadcasting, telecommunications and remote sensing which were mere buzz words in foreign journals and magazines became a reality.
The age of satellite technology dawned with the launch of first of the INS AT-I series-INSAT-IA in 1982. The plan was for launching two satellites in the air, recalls U.R. Rao, Chairman of the Space Commission, “one providing the benefits, the other, an on-orbit spare.”
But the bird in the sky was a disaster. In the spring of 1982, the much publicized multipurpose satellite, expected to revolutionise broadcasting, telecommunications and meteorology jammed its solar sail. An INTELSAT satellite had to be leased to fulfill the needs of the country.
As India waited for INSAT-IB’s launch the following year, “television was born,” says O.R Khushu, Doordarshan’s Chief Engineer. The year 1982 saw the launch of the national network linking seven programme producing centers, switching from black and white to colour, and hosting the Asian Games. It was in this year that Doordarshan earned more money than ever before Rs. 1000 crores.
It took another year for the sister satellite INSAT-IB to be launched. And the benefits were immediately visible. The government decided to expand coverage to 70 per cent of the Population. It was not possible if India continued with high power transmitters.
So, Doordarshan switched to low power transmitters, and the isogstics changed. Khushu recalls how it happened. “Normally”, he says, “the low power transmitters need civil and infrastructural support. The three or four rooms in a vantage location. The power constraint was eliminated as well.
The LPT consumes one kilowatt of power what one consumed in a household, as against the HPT consumption of 100 KW. The LPT can be produced like a consumer product with indigenous know-how.” But hardware was not all. The blueprint that emerged from the Asian Games came in handy in handling the NAM and CHOGM conferences, several festivals abroad and the Cricket World Series.
With giant strides in Doordarshan’s hardware and a boost to its software capabilities, India began to feel the real impact of broadcasting. The morning and afternoon shows also entered the Doordarshan arena. Doordarshan also started sponsoring its own programmes documentaries, telefilms, serials, and feature films.
Latest development in the satellite technology has been useful in other areas as well. R.P Sirkar, the director of the meteorological department says: “In November 1977, in Orissa cyclone, about 10,000 people perished. During a similar cyclone in 2003, the death toll was less than one thousand, because of timely warning by the satellites”.
In another sphere, IRS-IA which was launched from Baikanaur cohesmodrome in Russia helped India join the pantheon of SPOT and Land sat remote-sensing from Europe and the US. This satellite has a number of successes to its credit. It has monitored recent floods in Brahmaputra.
It has also helped in delineating agro- climatic zones for significant inputs in agriculture planning, mapping forestry and wasteland, locating ground water, geological mapping and in integrated drought management.
The satellite technology has really made revolutionary changes in the field of long distance communications. It has made the world one by linking cities of the world with each other. Almost 65 per cent telecommunications in India is through INSAT.
Rao says that within a period of three years the entire cost of the satellite Rs. 675 million was recovered, the bulk from leasing telecom services. The satellites have also helped India truly reach out to the masses. “The specialised field of the expert has become the province man in the street.”