Technology, economic constraints and possible solutions for providing wide-coverage educational systems by means of satellites

After a brief history of Intelsat global system development for telephony, data and television relaying, some economic and commercial aspects, including comparison with other transmission media are considered. The particular advantages of satellites for television relaying are mentioned and present growth and future prospects for various forms of television programme distribution between and within countries or subcontinents reviewed. Problems of extended coverage to provide multi-point satellite reception via small aerials over a specified region must be resolved and technological features and economic trade-offs for one-way and both-way satellite distribution systems considered. There may be a possible need to employ terrestrial means for distribution over local areas surrounding a satellite earth station. Comparison is made of satellite systems with terrestrial means of providing an educational television network for selected situations. Suggestions for potential forms of satellite system development for carrying television to (and possibly from) schools are made and power, frequency spectrum, orbit and economic constraints reviewed. The possible impact on the technical form of television signals to be used are considered. The economic advantages of using a low-capacity communication channel to present a succession of pictures, diagrams, or alphanumeric displays are examined.