'I EDUCATIONAL OPPORTUNITIES WITH COMMUNICATIONS AND BREADG‘AST SATELLITES AND WIRED BROADBAND COMMUNICATION NETWORKS Thesis for the Degree of M. A MICHIGAN STATE UNIVERSITY JAI PRAKASH SINGII 19 72 .. .- 4w .; Ii! . \ EDUCATIONAL OPPORTUNITIES WITH COMMUNICATIONS AND BROADCAST SATELLITES AND WIRED BROADBAND COMMUNICATION NETWORKS By Jai Prakash Singh A THESIS Submitted to . Michigan State Univer51ty. in partial fquiIIment of the requ1rements for the degree MASTER OF ARTS Department of TeIevision and Radio T972 Accepted by the facuIty of the Department of TeIevision and Radio, CoITege of Communication Arts, Michigan State University, in partiaI fquiTIment of the requirements for the Master of Arts Degree. >W£wa Director of Thesis ii ACKNOWLEDGMENTS I would like to express my sincere appreciation to the following people for the parts they played in the various stages of this thesis. Professor J. David Lewis for supervising this thesis, many stimulating discussions, and his patience. Professor Robert P. Morgan, of Washington University, Saint Louis, Missouri, for many stimulating discussions on the various topics covered in this thesis and for providing an opportunity to work in this area. Professors Barry D. Anderson and Harold J. Barnett, of Washington University, Saint Louis, Missouri, for many ideas that are discussed in this thesis. Mrs. Emily S. Pearce, for an excellent typing of the final draft of this thesis. TABLE OF CONTENTS l. THE U.S. EDUCATIONAL SYSTEM, TECHNOLOGY AND TELECOMMUNICATIONS .................... l 2. OPPORTUNITIES WITH FIXED AND BROADCAST SATELLITES . . . . 16 Introduction .................... l6 Satellite-Based Educational Communication Services ...................... 2l Options for Educational Satellite Systems ...... 30 Operational Frequencies for Satellite Services . . . 30 Domestic Satellite Proceedings and Educational Communications ................... 39 A Dedicated Educational Satellite System ...... 55 3. WIRED BROADBAND COMMUNICATIONS NETWORKS AND EDUCATIONAL TELECOMMUNICATIONS IN URBAN AREAS ............ 70 Introduction .................... 70 Cable Communication Systems--Their Economics and Future Developments ................. 75 Education and Cable Communications ......... 94 4. SUMMARY AND RECOMMENDATIONS ............... l06 BIBLIOGRAPHY ......................... ll8 iv TABLE 10. ll. LIST OF TABLES . Primary Roles for Satellites Towards the Delivery of Certain Educational Communications Media and Services . . . . Public Radio Service Interconnection Requirements . . . . . Public Television Service Interconnection Requirements. . . . Fixed- and Broadcasting-Satellite Frequency Bands of Near-Term Importance ................. . Comparison of Microwave Channel Utilization by Terrestrial Facilities ............... . Summary of Domestic Satellite Filings ........ . Earth Segment Cost for 4/6 GHz Operation for the Proposed Fairchild-Hiller System ............. . Receiver Cost Based on Model Beginning Production Year, l97l ........................ . Summary of Representative Costs Results of General Electric Investigation .................. Potential CATV/Wired City/Broadband Communication System Services ..................... Distribution Costs per Subscriber for Selected Video Systems ...................... Page 25 28 29 33 34 43 54 57 68 79 88 FIGURE 1. 2. IO. ll. 12. 13. LIST OF FIGURES Systems within Systems of Communication Technology . . . . Possible Communications Satellite Systems for Education. . . Earth-Terminal Figure of Merit [G/T, dB/°K] Performances Calculated for a 99.95 Percent Link Reliability, 52 dB SNR Performance, 20 MHz RF Bandwidth and BRF/BV = 4.77 . . . . . Graphical Representation of Performance/Cost Trade-offs. . . Comparison of Operating Channel Capacities (TV Channels) of Domestic Satellite Proposals .............. . Total System Investment. . . . .............. . Cost Advantage of Direct Distribution Satellite ...... . Total System Costs as a Function of Operating Frequencies and Number of Channels .................. . Networking Terminal Costs as a Function of Operating Frequency and Number of Received Channels ......... Total Annual Costs for School Terminals as a Function of Operating Frequencies and Antenna Size ....... CATV Systems with Two-Way Capability ........... Rediffusion Dial-A-Program Local Distribution Network. . . Distribution System Cost Per Subscriber--Cable and Electronics ..................... vi Page 31 38 4O 45 45 62 64 66 67 78 85 87 CHAPTER I THE U.S. EDUCATIONAL SYSTEM, TECHNOLOGY, AND TELECOMMUNICATIONS The education industry is among the largest in the American economy. A recent article on the magnitude of the American educational establishment indicates that in the United States in the l970—7l academic year, there were more than 62 million students, teachers or administrators in the U.S. educational enterprise. In the last ten years, student enrollments in all categories increased by l3 million to a level of 59 million students.1 During the same period, while enrollments were increasing by 29 percent, the costs of education have risen by 60 percent to 70 billion dollars and one million new teachers have increased the teacher population by 5l percent to over three million. The primary approach for coping with increasing enrollments to date have been the multiplication of the number of conventional classrooms and teachers to the point where the growth in the educational expenditure has far exceeded the growth in Gross National Product (GNP). In l949, the United States, at all levels, spent about 9 billion dollars for all of education. This represented 3.5 percent of GNP. In l96l, 1"The Magnitude of the American Educational Establishment: l960—70,“ Saturday Review, November l9, l970, p. 67. educational expenditures accounted for some 5.6 percent of the national GNP and have currently grown to some 8 percent.2 There are indications that education may be nearing saturation in its relative share of the national economy. Current attempts to increase taxes for education have been meeting stiff opposition throughout the country. This is particularly evident in public ele- mentary and secondary education, whose major source of revenue for operating expenses has traditionally come from local property taxes and where a "tax-payer's revolt" has forced educational planners and administrators to study ways and means of making the system more efficient or productive to maintain the quality of education or to provide a diminished service. Here one can not fail to take notice of the fact that education is the most labor intensive of all major U.S. economic sectors, with over 74 percent of current outlays in elementary and secondary segment going to the salaries for the instruc- tors and administrators. Thus the productivity of the system is very heavily dependent upon the productivity of the instructors. Increasing the productivity of the teachers, increased allotments of monetary resources for more cost-effective instructional media and technology, and new instructional strategies involving optimal teacher-technology mixtures seem to be the key requirements for coping with the rising costs, enrollments and deficiencies. A recent study has tried to relate public elementary and secondary school expenditures to income per capita and enrollments 2A. T. Denzau, Public Education Finances: l949-l985, Memorandum 71-4 (Saint Louis, Missouri: Washington University, l97l), p. l. and has derived the following equation:3 _ 0.99845 1.5533 Dt - 0.337 Yt (0.7 Et + St) where, Dt = current expenditures (billions of l958 dollars), Yt = real personal income per capita (thousands of l958 dollars), I""| I t - K-8 enrollment (millions), (I) II t 9-12 enrollment (millions). It shows that for every lOO percent increase in the elementary and secondary school enrollments, the public school expenditures have had a tendency of increasing by 200 percent. The increase in expenditure obviously has been quite improportionate and unless new strategies for Controlling costs of education are defined and adopted without sacrificing the quality of education, the whole public education sector is in grave peril. One cannot expect tax-payers to keep on paying these improportionate increases indefinitely and if the number of property-tax increases that did not get through lately is any indication of the mood of the nation, the time to act has already come. The cost of education is only one of the areas of major dis- satisfaction of the educational establishment. There are two other key issues; the style and orientation of education and the equality of educational opportunity, that in combination with the soaring costs of education have led to a situation that is being described by many as an "educational crisis" and "crisis of confidence" with increasing regularity.‘+ The present dissatisfaction with the schools can be 3Ibid., p. 9. L'J. Cass, "The Crisis in Confidence--and Beyond,” Saturday Review, September l9, l970, pp. 61-62. traced to the criticisms that education still acts as a sorting device, benefitting the gifted more than the slow learners, and the children of the rich more than the children of the poor; that what the schools teach most of all is the importance of schooling; that schools serve to stratify society by wealth; that schools teach people to depend upon institutions rather than themselves for their well-being; and that failure is structured into the American system of public education where losers are essential to the success of the winners.5:6 Silberman,Z after an extensive study financed by the Carnegie Corpor- ation of New York, sees an enormous failure of the schools which is so pervasive that it extends into Scarsdale as well as Harlem, into Palo Alto as well as rural Mississippi; and indeed no level of education appears to be immune from its contagion. Silberman found the American schools to possess a systematic infection that is not recognized by the average citizen: Because adults take the schools so much for granted, they' fail to appreciate what grim, joyless places most American schools are, how oppressive and petty are the rules by which they are governed, how intellectually sterile and esthetically barren the atmosphere, what an appalling lack of civility obtains on the part of teachers and principals, what contempt they unconsciously display for children as children.8 5Barry D. Anderson and Edward Greenberg, "A Search for Educational Production Functions: The Problems and Possibilities" (unpublished research paper, Center for Development Technology, Washington University, l97l), pp. l6-ZO. 6P. Schrag, "End of the Impossible Dream," Saturday Review, September l9, l970, pp. 68-70. 7Charles E. Silberman, Crisis in the Classroom--The Making of American Education (New York: Random House, l970). 8Ibid., p. 10. Moreover, he concluded that the schools of this nation continue to deny, in the most systematic fashion, equality of educational opportunity for substantial number of youngsters. Both expenditures and educational outcomes are distributed disproportionately in favor of the rich, white, and suburban child.9 The inequalities in the U.S. educational system have also been documented in the Coleman report,10 which was prepared in response to the Civil Rights Act of l964. Comparative data from a very large sample of schools and students suggested that the differences among American public schools in class size, buildings, equipment, teacher skills, library services, and other inputs that can be easily changed by spending more or less money seemed to have less effect on the success in schools than social class, as indicated by family income. As Howe,11 former U.S. Commissioner of Education, puts it, the Coleman Report conclusions were disturbing to American educators who had long assumed that the way to get most out of education was to put more into it. In a nutshell, education is being asked to equalize opportunity, update itself, become more responsive to the individual learner and the real world, and control costs at the same time. In addition, there is also a rising demand for education, training, and retraining that if .7 91bid., p. 62. 1°J. 5. Coleman, et. al., Equality of Educational Opportunity, Report prepared for the U.S. Office of Education, Washington, D. C., 1966 (Washington, D. C.: Office of Education, l966). 11Harold Howe II, "Anatomy of A Revolution," Saturday Review, November 20, l97l, pp. 84-88. cannot be accommodated within the formal system. According to the Perkins report,12 there are 30 million Americans who have no more than a grammar school education and 50 million over the age of 25 who do not have a high school diploma. There are ten million unemployed and many million more who are underemployed. These millions of citizens have available to them only the bits and pieces of a non-formal educa- tion system. The opportunity and the demand for a more flexible educational system--complete with instructional training, examinations, and appropriate certification or degrees-—are rapidly coming into focus. Knowledge has been growing so fast that yesterday's solution to a problem may not be valid today. In modern times we cannot expect the education given once during youth will be sufficient for the next thirty to forty years, which is the active service period of a man. It seems that the time has come where technology is to become educa- tion's saviour. The Commission on Instructional Technology13 has clearly expressed its well founded conviction that technology can make education more productive, individual, and powerful, making learning more immediate, give instruction a more scientific base, and make access to education more equal. The Commission has concluded that the nation should increase its investment in instructional technology, thereby upgrading the quality of education, and, ultimately, the quality of individual's lives and of society generally. 12d. A. Perkins, et. al., Instructional Broadcasting: A Design For Future, Report to the Corporation for Public Broadcasting, WaShington, D. C., l97l (Washington, D. C.: Corporation for Public Broadcasting, l97l), p. 3. 13S. G. Tickton, ed., To Improve Learning:-An Evaluation of Instructional Technology (New York: R. R. BOWker Company, l970)i' Before proceeding further, it would be beneficial to clarify what one means by the phrase "instructional technology". Often it is used to denote media born out of the communications revolution that can be used for instructional purposes alongside the teacher, textbook, and blackboard. A less familiar but more accurate definition of instructional technology goes beyond any particular medium or device. "It is a systematic way of designing, carrying out, and evaluating the total process of learning and teaching in terms of specific objectives, based on research in human learning and communication, and employing a combination of human and nonhuman resources to bring about more effective instruction."ll+ One should take note that neither definition equates instructional technology with "machines"—-an easy mistake to make. By either definition, instructional technology includes a wide array of instruments, devices, techniques, and messages, each with its particular problems and potentials. In this study, as its title suggests, we are only concerned with the exploration of the two major options for the transmission of "information" related to the instruction. We will be dealing with the two options for transmission system segments of all telecommunica- tion media. Figure l, taken from a report authored by Bretz,15 shows .1”Ibid., p. 21. 15Rudy Bretz, Communication Media: Properties and Uses, A Report by The Rand Corporation, Santa Mbnica, California, September, 1969 (Santa Monica, California: The Rand Corporation, 1969), p. 13. (a) Transmission System MODULATOR DEMODLLATOR Input —> (Encoder) v TRANSMISSION v (Decoder) —r Output \ / \ / \ / . \ / (b) Racordrng System\ / Input —" RECORDER 7‘ RECORD F. Par/$25K —* Output \ \\ // / '\ ./ \ \ / / \,\ \ / ./ \ \ l / / (c) Communication System \ fi V PROGRAM TRANSMISSION ‘ PROGRAM "‘9‘" —' ORIGINATION 0R RECORDING DISPLAY '" °"""" SYSTEM \ ' ' 1’ \ ’ z’ \ / / (d) Instructional System ./ \ -l’ r INSTRUCTIONAL ‘ ‘ ‘7‘ DESIGN "" \ INSTRUCTIONAL wPCEMENrArION EVALUATION *' COMMUNICATION 1 SYSTEM Learner application: _ DriII and practice, Interaction, etc. FIGURE 1 Systems within Systems of Comunication Technology the relationship among transmission, communication and instructional systems.16 As suggested by the title itself,.this study is devoted to the examination of policy questions inherent in the complete realization of the educational opportunities offered by fixed- and broadcast satellites and wired broadband communication networks (BCN) through their particular configurations, possible reduction in the communica- tion costs, and, in the case of BCNs, an abundance of information carrying capacity due to the non-radiating nature of the system. It is assumed that economic, social, and political pressures would bring about increased utilization of telecommunication media in education and there would be an increasing need for long distance, area coverage, and local distribution capabilities offered by the satellites and BCNs. Competitive alternatives offered by recording-media and localized 16Communication media can be identified by the fact that they are capable of communicating messages that are complete within them- selves and do not require face-to-face verbal narration at the point of reception; and that they are capable of reproducing a program either by simultaneous reproducibility (point-to-point, or point-to-many- oint) or sequential reproducibility (recording or recording and printing). Com- munication media can be distinguished from each other if they utilize different or additional we 5 of representing information and if they are based on devices (hardware that are of a different kind. Thus, in a typical instructional system, not all the instructional devices fall in the communications medium category; some are merely teaching aids. Also, it is plausible to have a multi—media situation (for details, see Chapters III and IV of Bretz [1969]). Not all communication media use telecommunications or ”electronic transmission of information". Several communication media are based on a recording medium such as the CBS Electronic Video Recorder (EVR). However, many telecommunication media have recording-media counterparts, which could be used to record messages as they arrive via telecommunication media, or to record messages in ad- vance for later transmission via these media. It is only in telecom- munication media that message production or the reproduction source is at some distance from the receiver and electronic transfer of informa- tion over a "communication" channel (wire, waveguide, or radio-waves) is involved. 10 systems have been noted with the underlying assumption that telecom- munication media would still be needed in various situations where local control of the information transmitted or received is not a critical requirement, where an instantaneous transmission of informa- tion is desired, where a point-to-multipoint dissemination is needed, and where possible cost reductions due to the economies of scale and specialization are important. Discussions on comparative advantages and disadvantages of centralized and localized communication media are beyond the scope of this thesis. However, interested readers are referred to reports by Singh and Morgan,17.18 DuMolin,19 and Ohlman.20 While exploring the educational communication opportunities offered by satellites and BCNs or cable television systems, a broad view has been taken. Services have been extended to include not only radio and television broadcasting and distribution of television and radio signals for rebroadcasting but also facsimile and data trans- mission, information retrieval systems, and provision of remote computer services for instruction and instructional administration. Such an approach, though somewhat different than those often encountered in 4:4 l7Jai P. Singh and Robert P. Morgan, Computer-Based Instruction: A Background Paper on Its Status, Cost/Effectiieness and TeTecommunica- tions Requirements, Memorandum 71-1 iSaint Louis, Missouri: Washington Uhiversity, 1971). . 18Jai P. Singh and Robert P. Morgan, Educational Computer Utilization and Computer Communications, Memorandum 71—77(Saint Louis, Missouri: Washington University, 1971). 19James R. DuMolin and Robert P. Morgan, An Instructional Satel- lite System for the United States: Preliminary Considerations, Memoran- dum 71-2 (Saint Louis, Missouri: Washington University, 1971)} 2°Herbert Ohlman, "Communication Media and Educational Tech- nology: An Overview and Assessment with Reference to Communication Satellites" (unpublished M.S. dissertation, Washington University, l97l). 11 usual radio and television oriented approaches, is entirely consistent with the National Association of Educational Broadcasters Board Committee on Long Range Planning recommendations.21 Today, there is a great deal of emphasis on individualization of instruction, inter- active learning, and flexible-format access, sometimes to the point of on-demand access. These new pressures have caused several new trans- formations in the conventional passive media of television and radio. A number of demand-access audio systems have been implemented in the various parts of U.S.; Bell-Canada is experimenting with Information Retrieval Television (IRTV)22 and MITRE Corporation has already demonstrated the feasibility of a time-shared, interactive, computer- controlled, information television (TICCIT).23 Development of these new systems have also much to do with the development of wired broad- band communication systems, popularly known as cable TV systems, because it is they which have opened up the avenues for any large scale implementation of the individualized media. Earlier it was said that while exploring the opportunities offered by satellites and BCNs it would be assumed that future years would see increased and extensive use of technology in instruction, both in and out of the school house. At this point it onld be 21NAEB Board Committee on Long Range Planning, "Report of the NAEB Board Committee on Long Range Planning," Educational Broadcasting Review, IV (February, 1970), 23-29. 22C. A. Billows, "Information Retrieval by Television," Electronics and Communication, December, 1968, 35-37. 23J. Volks, The Reston, Virginia, Test of the MITRE Corpora- tion's Interactive Television System, Report MTP-362 (McLean, Virginia: The MITRE Corporation, l97l)1 12 desirable to make it clear that such an extensive utilization will not automatically come about itself. Realization of extensive technology utilization for instruction would require extensive institutional and curriculum engineering. So far the impact of technology has been small compared with the magnitude of the educational system in the United States as a whole. Its introduction into the U.S. schools has been uncoordinated, ineffective, and piecemeal. As Schramm states: Rather than filling a functional role in a comprehensive approach to the design of instruction, most (instructional technology) innovators have chosen or been forced to confine themselves to their own special medium or technique. Rather than moving into the center of the planning process in education, most technologically oriented educators are on its periphery.2“ To become more effective, instructional technology must be established on an integrated, total-system basis, with broad support from teachers, administrators, and the public, as well as long-term commitment from school boards. Today, the future of instructional technology does not lie so much in the development of hardware as in the organizational and curricular innovations and re—education of teachers and educators in the value of technology as an aid to instruction. Teachers have to be taught to look at technology as a resource for developing new alternatives and individualizing instruc- tion, rather than as a dangerous, mechanistic intruder threatening their jobs. Also, institutional reforms are necessary for the realization of the full potentials of certain technologies or instructional systems. For example, the flexibilities and speed inherent in Computer-Assisted-Instruction (CAI) systems become 2"Tickton, To Improve Learning, p. 23. 13 meaningless if it is to be implemented within a rigid lock-step educational environment. Planning for the technology utilization involves design of least-cost instructional strategy involving a proper mix of teachers, communication media and teaching aids. It becomes a straightfonward economic problem of allocating limited resources in an optimal way. Requirements are properly defined in terms of the end product and the least-cost alternative or strategy is selected from the several available alternatives. This kind of analysis requires information concerning cost and effectiveness of the various combinations of media, aids, and teacher—time for achieving certain learning goals in specific subject areas at certain educational levels. This kind of information is simply not available today. For example, as far as TV is concerned we know that it performs as well as face-to-face instruction but we do not know how the achievement varies when it is used in conjunction with other inputs. There is a need for a series of studies where a variety of instruction inputs are used towards achieving certain pre- specified instructional objectives and where relative trade-offs between various media, aids and teacher-time are obtained. With certain generalization and oversimplifications, if we assume that T and M represent the teacher and media inputs to the educational system whose output can be defined as Y = f(T,M), with the current experimental information we find that in most cases Y(=f(T,M)) §_f(T) + f(M) because in most situations media inputs have been used rather unimaginatively. There is no reason why, with a properly conceived strategy involving diverse instructional inputs and limited teacher-time substitution by media in subject areas where media l4 instruction is more cost-effective than teacher-instruction, one cannot achieve a situation where f(T,M) > f(T) + f(M). It seems that educational planners have realized this gap, and certain forth- coming educational telecommunications and technology experiments would attempt to take a first cut at it. The United States Office of Education has also realized the need for a comprehensive and coherent approach to educational planning and one should look forward to new initiatives and directions in this area through the newly established National Center for the Improvement of Educational Systems (NCIES) and National Center for Educational Technology (NCET).25 When one is planning a communication system, be it commercial or educatibnal, one of the first things one wants to know is the kinds of information the proposed system would be required to carry, the performance requirements, volume of the information that is to be transferred, and the points that are to be interconnected. Some of these things would not be known until the communication media and 25This new thrust is clearly evident in a document (Plan For A Satellite-Related Educational Systems Experiment) circulated by the Office of Telecommunications Policy of the U.S. Department of Health, Education, and Welfare in October l97l. In addition to raising the question of the cost-effectiveness of alternative combinations of media and teaching aids, it also raises the questions related to technology utilization -- how it could be made an integral and essen- tial part of a learning system, what kinds of informing and training of people are necessary to get them to modify their behavior and adopt roles as needed to operationalize a defined instructional system, and what changes in the structure and function of responsible institutions are necessary and how these can be accomplished. Communication with responsible people in the policy making divisions of the Office of Education suggests that the next few years will see some 200-500 experiments dealing with educational renewal and exploring various strategies for increased technology utilization. 15 and other educational input tradeoffs are known and understood and one has also discovered the acceptable balance between the localized flexibility and the economies of scale obtainable from certain centralization of the delivery system that would be acceptable to the users, teachers, and school administrators. It is in this respect that one hopes that the steps would be taken to answer questions related to the place of technology in the least-cost operation of the educational enterprise and the social engineering steps required to achieve greater technology utilization. Today, it seems self- evident that various communication media and systems hold the promise for greater cost-effectiveness and thus for increasing the efficiency of the educational system. But we have yet to find out the means and ways of exploiting the hidden potentials of these media and technology oriented instructional systems within the framework of the educational establishment. CHAPTER 2 OPPORTUNITIES WITH FIXED AND BROADCAST SATELLITES Introduction In this chapter, we will briefly examine the opportunities offered by the technology and the options open to educational interests for their realization. The opportunities discussed in the following section extend far beyond the much talked about program distribution for Public Broadcasting Service and National Public Radio on a national as well as sub-national scale; they cover broadcasting to remote areas and for thinly spread ethnic as well as professional groups, delivery of computer assisted instruction to remote and small schools, delivery of a great variety and volume of instructional TV programming to school CCTV, CATV and ITFS headends, and delivery of raw computing power for instructional as well as administrative uses. The discussion on system alternatives comprises the educational possi- bilities of the future domestic satellite systems as well as the .synthesis of a dedicated educational satellite system for serving a large number of small earth-stations with high-power satellites. It also describes the thinking to date starting from the famous Ford Foundation Broadcaster's Non-Profit Satellite Proposal in l966, and the educational satellite communication experiments that will be con- ducted through experimental high-power transponders onboard NASA's 16 17 Advanced Technology Satellites (ATS) -F and -G and joint United States-Canada Communications Technology Satellite (CTS). The communication satellite family may be defined as including three basic types: (1) Point~to~point relay satellites (2) Distribution satellites, and (3) Broadcasting satellites. Relay satellites serve to provide communication between one point on the earth and another, for example, for relaying telephone and tele- graph messages. This type of service is normally provided by Inter- national Telecommunications Satellite Consortium (INTELSAT) for international traffic. Distribution satellites, as they relate to sound broadcasting and television, distribute program material from one point origin to conventional terrestrial broadcasting stations, which transmit it to the end user. It corresponds closely to network operation. The distribution function may either be combined with a relay function, or be provided by a separate satellite system. The broadcasting satellite transmits signals for direct reception by the gen- eral public. The 1971 World Administrative Radio Conference (WARC) has defined only two types of communication satellite services: (1) Fixed- Satellite Service, and (2) Broadcasting-Satellite Service. Fixed- Satellite Service (FSS) is defined as a space service for point-to- point communication between fixed earth stations via active/passive satellites. By the virtue of the altitude of the satellite, this service is also capable of distributing program material over a wide area for rebroadcast purposes. Broadcasting-Satellite Service (855) is defined as a space service in Which signals transmitted or 18 retransmitted by satellites are intended for direct reception by the general public either individually or through a community installation. Community systems use moderately sized, medium power satellites to distribute a few television and/or radio channels to many augmented receivers which are either viewed directly by groups of people or connected to a local redistribution system. ETV/ITV systems, CATV systems, and CCTV installations are primary applications. The dif- ference between the program distribution services through F85 and 885 is that FSS generally uses low-power satellites and rather large, sophisticated earth terminals to meet the highest signal quality recommended by the International Radio Consultative Committee (CCIR), whereas program distribution involved in a community type 835 uses relatively high-power satellites and low-priced earth stations. In a community type 885 service, performance requirements for TV or radio signal distribution may be relaxed below CCIR recommendations. Direct broadcast systems intended for individual reception use large, high-power satellites to broadcast limited numbers of TV channels directly to augmented home receivers. Direct broadcast to unaugmented home receivers is no longer feasible as l97l WARC regulations do not allow use of conventional Amplitude Modulation - Vestigial Sideband (AM-VSB) transmission from space in the 620-790 MHz frequency band. WARC regulations specifically prescribe use of Frequency Modulation (FM) for space broadcasting in this band.1 Such a restriction requires addition of a sub-system to convert FM modulation to AM-VSB if 1Jai P. Singh, Operating_Frquencies for Educational Satellite Services, Memorandum 7l—lO (Saint Louis, Missouri: Washington Univers1ty, l97l). 19 if conventional home receivers are to be used. For transmissions in other space broadcasting frequency bands (2.5 GHz, 12 GHz, etc.), augmentation is required even with AM-VSB transmission because ordinary home receivers are not designed to receive transmissions in these frequency bands.2 The beginning of the communications satellites is traced to the successful launching of the Store and Forward Repeater (SCORE) satellite by the Signal Corps on December 18, 1958. SCORE was a low- altitude satellite with a delayed repeater without any power- generation facility onboard. Since this event, which took place almost thirteen years ago, communication satellite technology has travelled a long way and has acquired a high degree of SOphistication through a series of steps from SCORE, Courier IB, Echo I and II, to Telestar I and II and relay satellites and thereon to Syncom-II, Early Bird, Intelsat II, III and IV.3 Communications satellites prior to Syncom used controlled orbits of low to medium altitude and had antennae of negligible gain. Such satellites could be used only while mutually visible by two full-tracking earth stations. The successful launch of Syncom—II in July 1963 ushered in an era of uninterrupted fa...“ 4 2Direct broadcasting to unaugmented receivers was intentionally avoided because many nations feared exploitation of these services by developed nations (specifically U.S.A. and U.S.S.R.) for propaganda purposes. Even if Amplitude Modulation - Vestigial Sideband trans- missions were allowed in 620-790 MHz frequency band making possible direct broadcasting to standard home receivers, in all likelihood U.S.A. would hever have used it domestically because these frequencies are begng gsed rather extensively for terrestrial communications (including UH — V . 3J. R. Pierce, The Beginnings of Satellite Communication (San Francisco: San Francisco Press, T9687; 20 communications through stationary satellites and less complex non- tracking earth stations. Early Bird or Intelsat-I, launched in April 1965, was the first commercial communications satellite in the geo- stationary orbit linking Europe and America, and was patterned after Syncom. Since the launching of Intelsat-I, INTELSAT consortium has launched some 10 operational satellites in three different series (Intelsat-II, -III, and -IV), but the only significant changes have come about in the communications capacity of the satellites belonging to the various series. Intelsat—II had a 240 voice circuit capacity, Intelsat-III 1,200 circuits or 4 TV channels, and Intelsat-IV is capable of accommodating 3,000 circuits with transponders in the earth mode and 9000 circuits with transponders in spot beam coverage mode, or 12 TV channels.“ There has not been much increase in power radiated over an unit bandwidth. Communications satellites for defense have advanced from the lOO—pound Initial Defense Communication Satellite (IDCS) to 500—, 1000-, and lSOO—pound spacecraft (United Kingdom Skynet-I, U.S. Defense Phase II, and Tactical Communications Satellite Program, respectively). However, all of these satellite programs continue to use low-powered transmitters--under 10 watt of output except for the 20 watt transponder onboard TACSAT. As Feldman states: .‘a . . .this work with low-power satellites will not gain them (satellites) an ascendant role in the "communications revolution". To play a leading role, communications satellites must either provide significantly new services or drastically reduce the cost of existing ones.5 “Communications Satellite Corporation. Pocket Guide to the Global Satellite System (Washington: Communications Satellite Corporation, 1970). 5Nathaniel E. Feldman and Charles M. Kelly, "The Communication Satellite--A Perspective for the 1970's," Astronautics and Aeronautics, September, 1971, 25. 21 Intercontinental TV service provided by Intelsat, even through low-power satellites and complex earth-stations, is a new service, but the duplication of a similar system for domestic communications is bound to inhibit its extensive exploitation. The cost of communication has a direct bearing over the new opportunities and services, and duplication of an Intelsat type system with few isolated earth stations is certainly not going to reduce the communication cost significantly below what Intelsat charges ($3,000 per hour for TV relay). One should also realize that in an Intelsat type system, some 85 percent of this cost is directly attributable to complex earth stations located in isolated areas6 and the terrestrial microwave/cable facilities con- necting earth station with the TV operating center.7 However, high- power satellites, whether they be fixed- or broadcast type, operating in frequency bands that allow colocation of low-cost earth stations in the close proximity of the redistributing/originating centers and user clusters open up the avenues for significant cost reductions as well as introduction of many new services that can not be implemented with a low-power satellite operating in standard 4 and 6 GHz frequency bands. Satellite-Based Educational Communication Services -‘ A great deal has been written on satellite applications for education. However, most of it pertains to the distribution of public 6Intelsat satellites use 4 and 6 GHz frequency bands that are shared with terrestrial common carrier facilities on a coequal basis. Due to concentration of 4 and 6 GHz common carrier facilities in most urban areas, it becomes necessary to site the satellite earth station in isolated areas far away from the areas of common carrier concentration to avoid undue interference to and from terrestrial common carriers. 7Feldman and Kelly, Communication Satellite, p. 28. 22 television and radio network signal to affiliate stations, CATV headends and community installations in remote areas that lack either broadcast stations or CATV facilities. Anyone who has followed the literature in this area would readily concur with the statement that most authors have somehow treated TV and radio program distribution and broadcasting as the sole possibilities for satellite-based educational telecommunica- tions. The absence of any discussion on the delivery of educational interactive communication media by satellites is astonishing and even more so when there seems to be increasing emphasis on the individuali- zation of learning and learner-system interaction. What must be realized is that a satellite system is nothing but a delivery system with certain unique characteristics and could be made a part of any instructional system employing any combination of media as long as the information flow does not exceed the communication capacity of the satellite channel. Satellite channels could be used to distribute TV programs, carry voice or data. Their use will be primarily dictated in the situations where they seem to offer a distinct edge over competitive transmission alternatives in terms of cost or provide new services that are not possible without it. The high cost of present long-distance communications have resulted in their scant use in U.S. schools and colleges. Very few institutions use such services-~and then only in limited experimental operations. A Stanford Research Institute study has projected only a small decrease in the communication costs for the 1970's. This 8H. M. Zeidler, et. al., Patterns of Technology in Data Erocessinggand Data Communications, Report 7379B-4iiMenlo Park, California: Stanford Research Institute, 1969). 23 combined with the fact that cost of a telephone line has been very much constant over the last decade are quite surprising when one considers the advances in terrestrial microwave, coaxial line, millimeters waveguides, and satellite communication that have taken place. The fact is that such long-haul systems have indeed dropped the long—haul portion of the telephone circuit cost and further reductions are expected. But the problem is the local telephone plant that has become increasingly labor intensive and the cost increases therin have offset the reductions in the long-haul portion to the point where it accounts for over 80 percent of the cost of long-distance connections. In certain applications, those relating to data transmission, it is the nature of the existing telecommunica- tions plant that impedes its increased utilization. Because of the economic factors, the Bell plant has been built so that each improve- ment, in general, has been compatible with the existing facilities. The basic nature of the network has remained suited for analog communi- cation, particularly voice, and discriminates against digital trans- mission such as those encountered in remote computer time—sharing, inter-computer communication, etc. A detailed discussion on the . inadequacies of the existing telecommunications plant for data trans- mission are beyond the scope of this thesis and interested readers are referred to the SRI study on the matter.3.9 In a nutshell, there is a lot to be gained by developing a service that bypasses the local 9Donald A. Dunn, Policy Issues Presented_by the Interdependence of Computer and Communications Services, Report 73798-1 (Mehlo Park, California: Stanford Research Institute, 1969). 24 telephone plant facilities and provides direct interconnection between the user and the resource center, among resource centers, and between program origination centers and redistribution facilities. It has been suggested that satellites may have an important role in:10 (1) Interconnecting educational institutions, particularly those related to higher education, among themselves and with certain service and resource centers, for sharing of instructional, research and administrative resources; for providing institutions poor in certain resources with access to services which otherwise might not be available. (2) Interconnecting remote and isolated institutions with certain service and resource centers to provide students and teachers therein equitable access to services such as computing, computer-managed/based instruction (CAI/ CMI), etc. that are currently more readily available to their counterparts in urban and suburban areas, and to provide in-service teacher development programs; and (3) Delivery of both public as well as instructional television and radio programs to cable and ITFS headends and broadcast stations for either real-time or delayed redistribution for in—school as well as in-home utilization. Table 1 shows the possible roles for communications satellites in the delivery of certain media and services such as ITV, CAI, 10Robert P. Morgan and Jai P. Singh, Progress Report-~Program on Application of Communications Satellites to Educationfii Development (Sa1nt Louis, Missouri: Washington University, 1971)] pp. 43—52. 25 .mumwpmvuoam o» mmmuum mcwcwmm com vcm mucoaru_ugaa as» mo “cosm>os pmuwmxnn “occur: oucmcuxu coaumELoucv so» mcowpaurumcv pmcowumuzvo mo covuuaccougoucm .meuucmu «museum =o*uaecomcp gonna guy: mvcmnau; >pwumgu -mwcwEum can mcwuaaeou chowuuagum:_ so» mcopusppumcp muoEoc .FFmEm cu Luzon mcwuaasou 3mg mo >um>wpoo .mwm chommmg mo cowuuucos Im—asw uco m:_>—om Empaoeq mo mmmoagsa ecu Lou mcomu Izuwumcw muoemc ou mcwuzaeou m>wuuogmucw mo zgo>v~oo .mmcm couppoaocpms comes a Eocc xuzm ages so mopws chrom omega xFLmF=UVuLun .mcowuauwumc_ macaw» .——msm ou Huo>vpoo .c0wu=n_gumwvmc convene com mucmumm; mpnmu new map“ .mcowumum ummuvmoga oo .mcmucmo mascammF new upoosom o» xgm>wpmn pumgro mcpucucomcoua—oh pm>owguoz covumELomcu moose: wouusou=< cowuauvczseou aumcnrpeoucn unweucm mugaomoz copuoeuomcu cowuuoccougoucu gonzosou m:*mmoooga guumm auoEom aeronanu o>vuumcmucu mmooum—mh pmcowuuaeumcu mmhaggmkqm mom mmgom >mmmm mmu_>cmm vcm meow: m:o_umowcaeeou —mco_umu:vm cwmugmu mo xcm>w~mo on» mucmzoh meow—Pmuom so» mmfiom xumspgm — u4mou bzm>u 4<~uwmm az< >4mzmmm< zo¢m I ozzom unzozaommmhm mam m4mzzoma I Nzx mp mo zhonquwzz<4ma I oqzomhozm I monhoum I omm xuom .<¥m<4< II wuou 4ou mhh~zszzou o» onhsmHmhmHo hummao Amy zouhamuthuo zm .mu~>mum mm >z< ck mmmuu< m>mo mmoz: >4hzmmm=uV \zouhzmHmkao whmggwh~mumm Joozum oz< >h~znzzou azmmZV xmozkmz o~a<¢ 4hcmm cream umpnzm N gm»; 29 mt mm mo mzm < .u.w .mzo~k¢m>m maze: oceuIcooo 4o¢a as me m.m¢ so «2m < 12H: gZHS muszwmm< zoo qu>u o<_umam «on ozsom quozaozoz mos szzo¢a - mozmxmmz oz< mquzm>w «ca mamzzo¢a - sqzosomm m< 44m: ma 4oma - mmzo~quHP oma onhamHmpmHo o¥Uom .ou mpeHzazxou as zosesmememao CummHo ”my zo_eam_m»mfio zm Azpuv aozmgmoz onmH>m4mp manage—:u .muH>mum Ahsz onmH>mump opm >z< co mmuuu< m><= +02 on IUHI: ¥ooa cuumoo meager» mmw>Hmumm sooxum oz< >esz=zzou Acmzv onmH>mowh Spm4mh m4mu4mh 4 onmzuanmm mom monhPH\>Hm mom Ammmv muH>mmm wz-mcmm commw>mpwh u__nza m mgm~uuw¢ e xma\:0a axe m~_ a cmmsws o» mczsoaneIszsoa moooxum 2" mm: . h ~18 omo.~ FzHoansImhzmoa oh :u_; eaten” ~zz can I ape 33533... . 223—sz 20:3 3mm: 5 3:33.. 5:589. 223238 was» .3 ma»... 23.—FE” 32 1963 Extraordinary Administrative Radio Conference (EARC) and 1971 World Administrative Radio Conference (WARC) of the International Telecommunications Union (ITU). The communication—satellite service (now known as fixed—satellite service) was established by the 1963 EARC which allocated five frequency bands to it totalling 2,600 MHz of spectrum space. The United States was able to use only 2,000 MHz for communications satellites because of noncompatible use of 600 MHz for terrestrial purposes. Of 2,000 MHz spectrum space for communication—satellite service that is allocated within the U.S., only 50 percent of it is available for nongovernment purposes (3700-4200 MHz band for downlink and 5925—6425 MHz band for uplink). The 1971 World Administrative Radio Conference established a new space service--the broadcasting-satellite service—-and effected frequency allocation provisions for the same. In addition, WARC also effected new frequency allocation below 10 GHz as well as above it on shared as well as exclusive basis. The most important allocations from the near—term utilization viewpoint are summarized in Table 4 along with the two nongovernment allocations from 1963 EARC. It should be recognized that these allocations are shared with terrestrial services—~Instructional Television Fixed Service (ITFS) in the case of 2500—2690 MHz band and commercial common carriers in the case of 3700-4200, 5925-6425, and 11,700-12,200 MHz frequency bands. Downlink frequency allocation in the band 6625-7125 MHz for television program distribution is shared with terrestrial TV auxiliary broadcast (studio- to-transmitter links, etc.). Table 5 shows the current terrestrial utilization of these frequency bands. The greater is the terrestrial utilization, the more difficult is the use of frequency bands for 33 z I cmmssou coesou m I Lm_ccmu coesou u I cwwcsmu coesou “Nxz m~_~ImNmov omeuuaocn steepsxaa >p aazz mama Immmmv vwxwu —mcowumcmuo Lm_ccmu :oEEou meccmu coeeou muha muhH Ammhuv muw>me umxpm cowmw>o~mp ~mcowuuacumcm omN am am an omN um am an omN um om um omN um am pm Nzx NIx ~xx NIx Nzx NIx NI; Nzx Nzx ~zx ¢\~E\2mu Nap- op mcwumpoumo ¢\~e\3mu mmpI e\Ne\3me Ne_- cu mcwuapmumm ¢\~E\zmn NmPI ¢\~e\3mu NepI o» mcwumpuomo e\me\3mn NmPI e\N£\3mn Nv—I op scrum—mama ¢\~E\3mc Nm—I «\NE\3mv Nm~I ¢\~E\3mo empI x=*_czoo ausppauam m=.umaueaoem xcmpczoo any—poumm vmxpm x=_sczoo auw__aoam aux_a a xcs_czoo au2_sauem waxes xcepczoo au___auamIeax.e ace_a= aawr_auamIeax_a x=__=zoo outppauamInaxma ¥=_Pa= ao___auaquaxsa a... .2 2:8 mae_.auam acepmmaeaoam xcp—czon muw—quomIvoxwm NI: oow.~pIoo~._p NE 85.2-81: ~:z oom.—~I0mm.o_ ~12 mN—sImNmm sz muvoImNmm ~12 oomeIOONM NI: omoNImmmN NIX ommNIoomN NI: mmmNIoomw mmum>gmm powcummccoh vmcmzm cocoap_swo sawmcaonapa muw>som ucmm aucazaogm mucousoaem eLmPImez mo mnemm xucwacmcm «HVFPmpmmImcwummuuoogm wen Iuoxwu w mgm» one .zupog xuauguucv >k .ohm >h .aaIxuao >p mov:_u:~u .onmp .s umam=< vmumv awry zucoaaugm uuu scam umumsyumm a .mcwqaupgm>o:o: .zpv_3c=nn ezswxozm map omc mu o~ waxes P~=o_uaeaao oo~.~_Ioo~.~_ up mmuumogm e_ opm R RF >u~s__x=< >H om~.m.IooR.~_ oummuumogm mom omo.~ o_ mm sua,_ex=< >p mmp.~ Imam.» A—mwaumaucu ucm xumwmm uwpnaav ¢e~ o.n.~ on o_ taxed _meoepeaaao mum.m Imsm.m mam cum.~p as on Lasagna eoeeou m~e.m Immm.m use omo.mp RP on La.LLau season oo~.e Iooutn oop>gmm tox_m sawmw> ... mm_ _m w Ia_ak .acoppuaeamcm cam.~ Ioom.~ Razxv eea>_aaa causzucam pmccmzu Lug nmcoquNOLozus< m_mccmnu poccmzu wazv meowumuvgogu=< mo consaz mo sagas: o—nmzopp< mom>gom vcmm ucoaaogm mmwumpwumu Fumcumocgmh x5 cowum~wpwua Pmccmcu m>mzoguwz mo comwsmasou m medm(g. 35 satellite communications from the viewpoint of earth-station locations and interference avoidance. As is evident from Table 5, 3700-4200 and 5925—6425 MHz bands are the most heavily used of all the allocations. This necessitates use of highly directive antennae for the earth- station and, in most cases, siting the earth-station away from the urban areas saturated with common carrier microwave links operating in 4 and 6 GHz frequency bands. Earth-station siting is not that diffi- cult and expensive in the 2.5 GHz and 12 GHz frequency bands which are relatively little used. From the viewpoint of educational applications, 2.5 GHz frequency band20 offers most economical operation——manageable antenna size, relatively tested hardware and low hardware cost, low rain attenuation, etc. However, this band is only 190 MHz wide and it has been speculated that all 190 MHz bandwidth may never be used in the Northern America due to certain astronomical instruments that operate above 2670 MHz. In addition, 35 MHz-wide chunks of this band, on both ends, are also allocated to the fixed—satellite service for small earth-terminal communications. In these situations, the educators would be able to exploit only 120—155 MHz spectrum space in this band, 202500—2690 MHz frequency band was pushed by the United States in the WARC for educational applications. Though the WARC recommenda- tions mark this entire band (except the two 35-MHz wide pieces on the two extremes of it) for broadcasting-satellite downlink, it is specu- lated that the forthcoming domestic rule-making in the matter of the national table of frequency allocations would eliminate this restric- tion and allow the use of this band within the United States for all sorts of educational telecommunications. If this restriction is not removed, it would not be possible to use this band for interactive communications except for the two 35-MHz pieces. 36 i.e., distribution of some 4—6 TV channels or equivalent in a particular geographic area. It is very conceivable that the demands for educa- tional communications might exceed the capacity of this band. In this case, it has been suggested21 that educators should look to the 11,700-12,200 MHz frequency band for accommodating additional services. It is also recommended that interactive communication services be given preference over TV and radio program distribution in the 2500 MHz band and that program distributing services or broadcasting to community installations be accommodated in the 11,700-12,200 MHz band. Use of any other frequency band below 12,200 MHz with 2,500 MHz band would only further complicate the colocation problem. From a system economics viewpoint, under ideal conditions, lower frequency bands hold most promise. For area coverage satellite relays to small terminals where the available downlink power is the most limiting constraint on system performance, it has been shown that system capacity performance degrades rapidly with increasing frequency, e.g., 10 dB between 1 and 12 GHz, as determined by the potential satellite relay downlink capacity.22 Higher frequencies suffer from increased atmospheric attenuation, particularly during rainfall periods, and electronic equipment operating at higher frequencies cost more as well as have comparatively poorer raw electrical power to radio frequency power conversion efficiencies. However, it should be 21Singh, Operating Frequencies, pp. 50-51. 22John L. Hult, Spectrum for Area Coverage From Satellite Relays to Small Terminals, Paper P-430l (Santa Monica, California: The Rand Corporation, 1970). 37 realized that satellite systems seldom Operate under ideal conditions. As discussed earlier, satellite services share frequencies of near- term interest with terrestrial facilities. Since terrestrial systems have been in existence long before the inception of space services and lower frequency bands (1—10 GHz) are attractive for their purposes too, lower frequency bands were extensively exploited by the terrestrial systems. Interference protection considerations inherent in the fre- quency sharing framework limit the maximum power that satellites could radiate and dictate--a certain minimum separation between the stations of the two systems using same frequency bands. Figure 3 illustrates the performance of the various downlink bands listed in Table 4 for a high quality TV relay link (52 dB Signal-to—Noise Ratio) with 99.95 percent reliability.23 It shows the possible tradeoffs between the satellite power and ground station complexity and hence cost; it also shows the limit to which these tradeoffs could be carrier out—-1imits imposed by power flux density restrictions listed in Table 4. Satellite Effective Radiated Power (ERP) is directly related with the satellite cost whereas Earth Station Figure of Merit is a measure of the earth station sensitivity. The larger is the figure of merit, the greater is the sensitivity and the cost. It is clear from the tradeoffs shown in Figure 3 that 2.5 GHz and 12 GHz downlink have the potential of delivering high quality TV signal to very small terminals (costing few hundred of dollars). However, it should also be noted that operation with small terminals requires rather high—power transmissions from . 23Link reliability represents the availability of certain s1gnal strength for certain percent of the times. 38 nn.e u >m\mmm use cuvmzucwm mm ~22 om .mucmegomgmm mzm mu mm .xumpwnmmpmm xcwg ucmugma mm.mm a com woumpzupmu moucwELomgom on\mv .hxwu uwsoz mo oszm_m Fm:PELmhI;usem m museum 7.}. {IE tau: no manor. #5257154». 0. n O o O. 0. ON on On an 0* he . A q _ q . q q a . . 0. ON on 0' on (MON «"13 3LI1131VS 0» Oh O. 00 39 the satellite, and it presents the least-cost design only when the system is going to employ a large number of earth stations. Figure 4 shows the tradeoffs involved in synthesizing the least-cost system. As the space segment cost decreases, implying less flux density on ground or smaller power output from the satellite, the ground terminal (segment) cost must increase to provide a specified level of performance. The total system cost is the sum of space and ground segment costs and a minimum cost synthesis leads towards a more expensive satellite and a less expensive ground terminal as the number of ground terminals or stations increases. Figure 4 shows two trade- offs-—one with 10,000 ground terminals and the other with 1 million, and as shown the least—cost solution for 1 million direct delivery points would involve a satellite with higher radiated power and lower- cost earth terminal units than those for the system involving only 10,000 direct delivery points. Domestic Satellite Proceedings and Educational Communications On January 23, 1970, Peter Flanigan, Assistant to President Nixon, wrote a memorandum to Dean Burch, Chairman of the Federal Com- munications Commission recommending a competitive, unregulated approach for the establishment of domestic communication satellite facilities.2“ This memorandum constituted a clear and much needed Presidential-level direction for policy, the absence of which had been the real stumbling block in the domestic satellite proceedings to that date. Communication 2“United States, The White House, Press Release, Memorandum to Honourable Dean Burch from Peter Flanigan (Washington, D. C.: The White House Press Office, January 23, 1970). 4O mmmoImumeh umoo\mucmsgowsma mo cowpmucmmwcamm Paupcnasu e mmawmm .58 ...—23 1mm 4552.3... 0230mm 3(2:2¢m.—. #6— 500 #222me 0230mm ”23:2me map .500 Swhm>m 4- (U (U (U +-’ r— U '33 ‘8 8 03) '8 'E < ..1 (I) Z O L) Earth Station 6.09 8.84 6.19 8.27 8.95 8.16 Connecting Links 1.75 5.83 2.47 0.72 6.40 1.1 Source: Fairchild Hiller Corporation, Application for a Domestic Communication Satellite System, March, l97l—(Germantown, Maryland: Fairchild Hiller Corporation, 1971). television relays cost in the neighborhood of 60,000-lO0,000 dollars but still involve considerable cost in terrestrial interconnections. It is for this reason caution is required in evaluating the free offerings made by the domestic satellite system applicants. For example, today MCI—Lockheed Satellite Corporation plans to provide free use of five transponders for five years for educational applica- tions. But, the educational community would have to procure their own earth-stations to make use of this offer--receive—only earth-stations that are expected to cost in the neighborhood of $60,000. Even if the space segment cost is zero, the large earth station cost only allows use of the MCI-Lockheed offer in the situation where only a few delivery or interconnection points are involved. For a system 55 involving a large number of delivery points (from few hundred to couple of thousand), the earth segment cost dominates the total system cost and MCI-Lockheed offer does not lead to the most economic solution any more. A Dedicated Educational Satellite System In the previous section it was noted that the current domestic satellite proposals do not include any provision for satellite- broadcasting services except for a sole transponder operating in the 2.5 GHz band on the Fairchild Hiller satellite and are built around relatively low-power satellites precluding the many new service and cost reduction opportunities inherent in low—cost small earth—terminal operation. It is not that the technology is not available. What is lacking is a public and potential user awareness of the technology potential, public support for a meaningful exploitation of the available technology, appropriate government regulations and initi- atives, and special interests. In this section an attempt would be made to show what new communications technology can offer if exploited to its fullest extent and the limitations inherent in it. The key to new services or significant cost reductions lies 'in the use of low-cost receivers, high efficiency and high-power trans- mitters onboard satellites, narrow- and shaped-beam high-gain satellite—borne antennae, and increased satellite life-time and reduced placement cost per unit weight. Though the implications of these new developments have been examined in great detail 56 elsewhere,36-38 it would not be inappropriate to examine them again briefly. As opposed to the receive-only earth-stations costing in the neighborhood of $60,000-100,000 that are contemplated for use in the domestic satellite filings for TV program distribution, NASA has supported the development of single TV-channel receivers capable of providing high-quality TV signal on ground in conjunction with high- power satellites (50-57 dBW ERP for 800 MHz and 2.5 GHz bands: 65-68 dBW ERP for 12 GHz band) that are expected to cost in the neighborhood of $500-2000 per unit complete with a small antenna (5-7 feet diameter) and installation. Table 8 presents manufacturing costs of the various receivers when manufactured in the quantitites of 1000 and 1 million. These costs are based on 1971 manufacturing costs. These costs show marked decrease as the time progresses, and by 1975, the receiver costs for a production volume of 1 million are expected to be one-half to three-fourths of the costs quoted in Table 8. Some of these terminals, those operating in 800 MHz and 2.5 GHz frequency bands, are expected to go into use in 1974-75 when NASA's Advanced Technology Satellite-F (ATS-F) would be used in India and the Rocky Mountains for educational broadcasting from 36John L. Hult, Satellites and Future Communications Including Broadcast, Paper P-3477 (Santa Monica, California: The Rand— Corporation, 1967). 37Perry W. Kuhns, Directions and Implications of Communication Technology, Technical Memorandum NASA TM X-52911 (Cleveland, Ohio: Lewis Research Center, 1970). 38A. M. Greg Andrus, "Television Broadcasting Satellite Possibilities,“ Proceedings of Mexico International Conference on Systems, Networks, and Computers (Oaxtepec, Mexico, l97l), pp. 119-124. 57 .mczuuza humpozc cm>wm o musuoca op cmzoa Focmwm empowcoc muPFFmpom mo message commmF cow: mmwpw>_uwmcmm canoe; zpwz mcm>wmumc mmzoumn cmzoo mpw__mpmm asp saw: weowvocp o mmuw>oca mesh .umpmwz mew was“ mcmwmwFQEomca mo mu:_x msowcm> we“ smooccp me>wmmmcmoca mmom mco mo mmw>vamcmm comomcucw saw: mcm>zwomc mpocmn mwwcucm weapomm —o_umom .ncon xucmzcmcm comm cHo o m m oo.moz oo.mo_z eoece_oez ooeooEoeoo zoez oo.zmz oo._ozz eozcezoEooeo ooozo zooooe zoez oo.ozz oo.o_zz eoecz_oEooeo oz nzo N.N_-w.z_ oo.ooz oo.zm_z eozczzoez ozeooEoeoo zoo: oo.Nmz oo.oozz cozcezoEooeo ooo_o Fooooe zoez oo.Nmz oo.oozz eozcezoEooeo eoomooooee zo_z oo.ooz oo.om z eoocezoEooeo oz nzo oo.~-om.m oo._mz oo.oo z eooco_oez o_coo5oeoo zoez oo.ozz oo.mm z coecz_o2ooeo ooozo _ooooz zoez oo.zzz oo.~w z coocezoEooco eoomemooee zo_z oo.zoz oo.oz z eooee_o5ooeo oz nzz ooz-omo OF mumpcosc oz zuwgcozo mwczpomz meumam zUCmscmcm mep .me> :OquDUOLQ DCwCCwmmm PmUOZ CO Ummmm umou Lm>wwumm w m4mm zo_m_>m._m= 2.52m o... 1.. 55:5. “5 228;. T 33mm mzo:m~mh xcozpmz mo comuowzumw>cH c< ..pm .um .mecwmxa .: .6 "mucaomo zz m.m z NP» x mm” z 4.0 w 3 cum 2 mp” 2 mp» x 00m .muuoz n 3 use "muumzopzx u 22 uncamzosu u x "co—ppws a z z: m.e pp» pm“ ¢.o » 22!: 3x m.om z up» a up» 2 N a =zz§ PGQ'Q F 99me 2x23 WON” F “”0940 a . _No_ .ooz>eom ooeoooooooem o__ooo “.u .o ewpmouvoocm uzpnaa an» cu pconam .msuumxw A—o:=czuuom umou poacc< couocmao umou zoncc< Louocoqo m2mkm>m ~:o Np cmzom our—puuom ~mu0h umou mcm>moumm uwou poacc<.coumcmao «moo Foaec< coumcuao $55 ea 2 Luzon mapp—uumm Fouoh umou ucz>wauum umou poaec< couscono umou.poncc< couucmao mzwhm>m Nzw m.~ zooop_Pooom ov «zoooozo on a Aooo_zzooom my mpmccmcu we a zoo_zpooom .v ompmccanu o cowuomwumm>cm uzcuumpm pocmcmo mo mppammm mumou m>wumucmmocamm mo xumesam m Em: 69 dollars a year-~at least an order of magnitude less than the comparable cost for a similar service from the American Telephone and Telegraph Company (AT&T). Basie... . Bi 4...... iofifiwe. III-III. CHAPTER 3 WIRED BROADBAND COMMUNICATIONS NETWORKS AND EDUCATIONAL TELECOMMUNICATIONS IN URBAN AREAS Introduction Cable television, often called Community Antenna Television (CATV), began as a minor adjunct to the present system of over-the-air broadcasting in the late 1940's to bring distant TV signals to areas which did not have any coverage. Now it is on the verge of becoming a major communication medium in its own right. A system that was developed to provide TV Coverage to small towns in wide and sparsely populated areas seems to have set the stage for a great "communications revolution" in major metropolitan and urban areaS--a revolution that some experts call the coming of the Broadband Communication Networks or the beginning of a "wired nation".1-3 In 1950, the number of CATV installations in the country was only five. Today, nearly 22 years after the first CATV system was born in Clatsop County in the state of Oregon, the number of CATV installations has grown to over 2500 serving more than 5 million TV households out of a total of nearly 1Harold J. Barnett and Edward Greenberg, A Proposal for Wired City Television, Paper P-3668 (Santa Monica, California: The Rand ‘Corporation,71967). 2Electronic Industries Association. The Future of Broadband (knnmunications (Washington, D. C.: Electronic IndUstries Association, '1969). 3R. L. Smith, "The Wired Nation,“ Nation, May 18, 1970, pp. 583-606. 70 11!).1111' | 71 62 million. The number of homes having CATV available is expected to increase from under 9 million in early 1970 to almost 50 million by the end of 1980. During the same period, the number of CATV subscribers is expected to increase from 5 million to over 26 million.“ Thus by the end of 1980, two out of every three households will have CATV available and the saturation with CATV systems is expected to be in the neighborhood of 40 to 45 percent.5 The prediction of an ultimate penetration of 40 to 45 percent is based on the logistic growth curve and a measure of "attractiveness" defined in terms of missing network signals; it does not include additional increase in consumer demand resulting from extensive two-way services discussed later in this chapter. Wired communication systems have developed on different lines in the United States from those in the United Kingdom and elsewhere. In North America, cable systems have developed as a means whereby programs not clearly receivable from the air could be brought within economical reach of local subscribers, or as an alternative to local programming. Only since the middle 1960's CATV has been recognized as a means of overcoming limitations of the present TV broadcast frequency allocations for bringing a television of abundance to over- come common—denominator programming that had become the basic method of allocating broadcast time and content in the absence of other “R. W. Peters, et. al., Business Opportunities in Cable Tele- vision (Menlo Park, California: Stanford ResearCh Institute, 1970):7 pp. A3-4. 5Roland E. Park, Potential Impact of Cable Growth on Television Broadcasting, Report R-587-FF (Santa Monica, California: The Rand Corporation, 1970). quizimiwh . NHi‘JJw-Qfi‘ 72 workable methods short of dictatorship. With a common-denominator approach, as one often finds on the networks, content tends to be superficial and entertainment with mass appeal a major ingredient.6 However, with a non-radiating system with a large channel capacity (theoretically speaking 50-100 TV channels on a single coaxial cable), one could afford the luxury of speciality-oriented programming to serve a variety of interests in depth and escape the common-denominator prison. In the United Kingdom, where there were and still are generally speaking only two programs (BBC and ITV) and in every part of the country these signals are easily available from air, the early impetus for the development of wired systems came from the cheaper and better reception promised by the baseband transmission of TV signal and use of non-standard and cheaper receivers that do not have any VHF/UHF signal processing Circuits.7 However, today the impetus for the development of wired systems within the United States is provided by not only better reception and the diversity in programming that would be possible but also from the realization of the wired network as a minimum 300-megahertz (MHz) bandwidth "pipe" to provide many 6The television broadcast structure of today stems almost entirely from certain basic policy determinations made twenty years ago (Federal Communications Commission, Sixth Report and Order [17 Fed. Reg. 3905—1952]). Some seventeen percent of the American population has access to ten or more TV channels, nine percent to nine channels, eleven percent to eight Channels, twenty percent to seven channels, nine percent to six channels, thirteen percent to five channels, eleven per— cent to four channels, seven percent to one to three channels, and three percent to none. 7R. P. Gabriel, "Wired Television Systems: Their Economics and Details of Systems for Pay TV and Audience Measurement," _Igternational Broadcast Engineer, October, 1966, pp. 413-420. ......zuq e. EEK. .... 3i...J¢d..Qi_-H .3 1. “A. .11 “at; rm...” \ ...? TIL-E - 1,... :9. a . . - ...-....1.....my 73 information services for home, business and government. Since the cable or wired systems would reach Schools as well as homes and provide large channel capacity for standard TV programming as well as promise for many new telecommunications services, they provide an unparalleled opportunity to the educational interests for creating new learning situations that bypass the conventional schools with walls as well as for increased technology utilization within schools through resource sharing among the schools interconnected by the wired network. Whereas communications satellites have great promise for introducing new long—distance telecommunications services as well as wide-area coverage, the cable systems offer significant new opportunities for local interconnection and delivery. In October 1969, the Electronic Industries Association submitted a document8 to the Federal Communications Commission. This well-conceived report took the stand that the services to be provided by broadband communications networks (BCN) in the late 1970's and early 1980's were of "landmark importance", of "national resource dimensions", and that development of these resources should be a national goal. It said that broadband communication is the tool not only to provide a means for new styles in human settlements, but also to rebuild, in a sociological sense, the crowded inner core of major cities. Broadband communication systems using cable can be structured to promote small, self-determining communities within the massive megalopolis. Through these, city dwellers can find order, identificable territory, community pride, and opportunity to 8Electronic Industries Association, Broadband Communications. a “$11.5”.on synonnhz. affine}; 74 participate and vote on matters that can be of local option-- education, cultural pursuits, recreational interests, etc. Such wide—band systems in the 1980's appear to IED/EIA to be of absolute necessity if the nation is going to find solutions to national pollution, urban traffic, and inner-city trans- portation problems.9 In June of 1971, Electronic Industries Association suggestions received an endorsement from the Committee on Telecommuni- cations of the National Academy of Engineering. In a report submitted to the U.S. Department of Housing and Urban Development, the Committee on Telecommunications said that it believes that modern communications technology, thoughtfully applied, can help in relieving many problems besetting the cities and can upgrade the level of city life by pro- viding channels for citizen-government interaction, educational tele- communications, pollution control, health-care delivery, traffic control, and crime prevention and emergency services.10 With regard to education, it commented, The goals of any program for improved urban education should include increasing the attractiveness, relevance, and availability of service to the educationally deprived, and making education more available to all people. Vast Oppor- tunities for communications technology lie with the computer, two-way cable television, and, perhaps more importantlyi the willingness andicapacity of teachers to make them work. 1 With this kind of a scenario, in this chapter, we will examine the implications of present and probable CATV/broadband communications 9Ibid., p. 4. 10United States, National Academy of Engineering, Committee on Telecommunications, Communications Technology for Urban Improvement, Report to the Department of Housing and Uiban Development under Contract No. H-1221, June, 1971 (Springfield, Virginia: National Technical Information Center, 1971). 11Ibid., p. 8. 75 technology for educational telecommunications, CATV regulation as it relates to educational utilization of the system, the present status of educational utilization and the prospects for tomorrow. Cable Communication Systems-- Their Economics and Future Developments An inspection of the nature of human communication shows that in any communication Situation there is a Single originator of the message (defined by a particular set of space and time) but the recipient may be an individual, a small chosen group, or a large inchoate audience. Hence, any distinction among the various services rests in the differences in the nature of the signal (aural, visual, data; speed; etc.) and differences in the recipients or "addressees". Based on the differences in the "addressees" only, the services may be categorized as: (l) Discrete-address point-to-point service such as a phone service; (2) Multiple-address point-to—points service such as a professor addressing only his distant class or a particular set of distantly located classes; and (3) Broadcast service such as the President addressing the whole nation without any intent of excluding any particular set of recipients. Looking at the services from a more familiar viewpoint of "switched" versus "non-switched" services, one could see that discrete-address type services correspond to "switched" services whereas broadcast type services require un-switched trans- mission facilities. Multiple-address type services could be accom- modated on an un-switched facility using certain privacy arrangements such as "scramblers“ or could be implemented on a switched system as in the case of tele—conferencing. After an assessment of the tele- communications requirement of the various services, Electronic 76 Industries Association suggested to the Federal Communications Commission that it provide a regulatory environment allowing the development of two types of broadband communications networks (BCN) in the United States.12 (1) (2) A video telephone service similar to the "picture- phone" system of AT&T with the ability to act as a video output terminal with limited key-board access to computers and transmission and reception of high- speed facsimile information. A broadband communications network that would be a minimum BOO-MHz bandwidth "pipe" to provide many infor- mation services for home, business and government, including broadcast video, first-class mail, and edu- cational material, with limited return bandwidth for receiving and tabulating specific requests and responses by individual users of the cables. The first type of BCN is obviously a totally switched system whereas the second one is primarily unswitched with very limited return bandwidth for asymmetrical interaction—-asymmetrical interaction in the sense that outgoing information rate from the user will be two-to- three orders the source. what we know developments of magnitude smaller than what he will be receiving from It is the second BCN that in concept is compatible with today as CATV and has become the objective of the future in the urban cable communications for providing 12Electronic Industries Association, Broadband Communications, p. 2. 322.. :5... 93.3.33: :1... gages}; 77 multiple-address, multi-channel, aural, visual, and low-speed data signals of good quality at an attractive price to the general public and special interest groups. Evolution of tomorrow's broadband communication networks during the mid— to late-1970's would mark the third phase of CATV development in which dozens of services would be offered by means of a two-way service (Figure 11). Table 10 presents a glimpse of the wide array of potentical BCN services for households, business, schools, and government. We are currently in phase two of the CATV development that is witnessing the expansion of CATV into the larger communities and urban areas as well as a growth in the addition of automated and local live programming and greater use of underground distribution systems. Phase one of CATV development ended in the mid-1960's when CATV operators started to look beyond their then current role of providing TV service primarily to those communities that were geo- graphically isolated from the major TV transmission Sites and/or electronically blocked by the topography of the area. In the early days of CATV, single—channel systems were not uncommon. A received television signal was piped in the coaxial cables from the remote head-end site to individual subscribers. As more channels became available to the system operator, additional channels were placed on the existing facilities (up to 20) with the addition of wideband amplifiers covering the entire 54-252 MHz band or with the use of set-top converters while using amplifiers with a smaller bandwidth (54-108 MHz), since the coaxial cable had wideband characteristics. This practice has increased the capability of CATV systems from a 78 "in Signals from Caa-nicatiana Satellites "40. Signals III/fr. . "m“ hill-Channel mcmava Adjacent CATV System \ ‘1— cha to msyumnm . lat-taco Remote Head-[M in Regional flavor-k Subscriber cm. to and Distribution Point V ”W9 Locama head-End Mata-thorn \\ ‘ Mam local \ Signals Mf—tha-Mr “:ablabetolfm ‘ scri r. Schoo S . .. «a mum ' Mme..." _ or Inumt lien-ma lint TO/FIOH 70"”)! Silt-CRIB!!! 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