DOCSLIB.ORG

?R~Ctical Aspects Op Home Teletext Gary W. Stanton

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
?R~Ctical Aspects Op Home Teletext Gary W. Stanton ?R~CTICAL ASPECTS OP HOME TELETEXT GARY W. STANTON SOUTHERN SATELLITE SYSTEMS, INC. TULSA, OKLAHOMA 74136 ABSTRACT transmitted on the vertical blanking interval on a satellite signal. Since There have been many learned papers that date, knowledge has been obtained describing the detailed technical on the various parameters that affect aspects of teletext transmission; most successfull vertical blanking interval in language only understood by others transmission to and through the cable with an intimate knowledge of the environment. subject. This paper defines the During the last four years requirements for the practical knowledge has been gained, various implement~tion of home teletext standards have evolved, equipment has reception in the cable television been designed and services implemented environment. using vertical blanking interval Since data integrity is the measure technology. Numerous degradation factors of technical success, the items which peculiar to satellite television effect data integrity are deliniated. transmission and to the cable Included are the satellite path, receive environment have been identified. To earth station, satellite receiver, cable offset these factors, error correcting modulators, AML link, and the cable techniques have been developed which plant itself. Results of various give several orders of magnitude measurements and observations describing improvement in data integrity. With the effect of each subsystem have been these improvements, home teletext is made and the results will be described. suitable not only for video display, but Practical suggestions for achieving also for electronic mail and downloading desired results in the most critical of computer software and games. areas are presented. HISTORY INTRODUCTION It is generally acknowledged that The first vertical interval the first commercial use of vertical transmission to the cable television blanking interval technology was by the industry was conducted at the NCTA British Broadcasting Company in Great Convention in Las Vegas in 1979. This Britain. The BBC Ceefax system which was demonstration, although only partially designed specifically for the 625 line successfull, showed that data could be PAL television system in use in Great 173 Britain was not usable in the United broadcast standard. ~t the same time, States without significant change. the video screen format was impr~ved to Two of the most significant allow the display of 24 r~ws of text differences are data rate and screen instead of 20 rows. format. The 625 line system utilizes a data rate of 6.9375 Mbits/sec. which is CUSTOMER SERVICES faster than can be used in the NTSC system. The second difference is screen The initial services provided were format. In the Ceefax system there is a the delivery of two news services to fixed relation between the data byte's cable television headends. The equipment position in the transmit line and its utilized was a video-in/video-out position on the video display. In Great commercial quality teletext receiver. It Britain, forty usable data bytes are was packaged in a rack mount chassis and transmitted on each vertical blanking specifically designed for direct interval line which correspond to a interface to a satellite receiver. ~t video screen format of forty character this point in time, only problems width. Depending on data rate, only 36 inherent in satellite transmission and or 37 usable bytes can be transmitted in satellite receivers had been addressed. the NTSC system. In order to use a Shortly thereafter a teletext version of the Ceefax system in the transmission format was developed and a United States these two parameters receiver designed featuring a data needed to be modified to fit the NTSC output rather than the video output. The system. The basic incentive for using initial purpose was to provide an the Ceefax system is the availibility of interface between the vertical blanking LSI chips from several sources which interval and a character generator at a make teletext decoders reliable and cable television headend. This provided economically practical. the operator the opportunity to use his ~t the NCT~ Convention in 1979, sophisticated character generator for Southern Satellite Systems displayed a both a national alphanumeric news primitive implementation with a data channel and for local generated text or rate of approximately 3.2 Mbits/sec weather information. ~s is the case with using two vertical blanking interval the video output unit, the data output lines for one display line. By late 1980 unit was packaged in a rack mount a data rate of 5.554 Mbits/sec was in chassis with an interface specifically use and the screen was formated with a designed to interface with a satellite 40 character by twenty row display. The receiver. As may be noted, both of these mapping technique used was formulated by units were designed for installation at Mullard Labs.l In early 1983, the data a cable television headend or other rate was increased to 5.7272 Mbits/sec commercial location where a baseband to be compatible with the proposed video signal was available. 174 l:iOME TELP.TEXT ~s a companion to the above teletext decoder which has a typical Recently Southern Satellite Systems Channel 3 or 4 output, a similar unit is has introduced Keyfax, a home teletext being designed which has a standard service. This service utilizes the RS232C data interface. This will be United States proposed version of the ideal for downloading information to BBC Ceefax standard which was proposed printers and home computers. Its to the Federal Communications addressable funtion will allow specific Commission.2 The service features over users to get only the data to which they one hundred video pages of text from subscribe. which the viewer can select. This The data interface unit, combined service is presently being transmitted with vertical blanking interval on the vertical blanking interval of technology offers the ability to deliver HTBS \vhich is on Sl\TCOM IIIR Transponder one way data from a central point to 6. thousands of locations simultaneously. To implement this service, a This feature is particularly useful to set-top teletext decoder was necessary. the news services, commodity services, The unit designed features a full cable and financial information industries. It television converter with infrared is presently being used by customers in remote control and a built in teletext these industries to deliver information decoder. This unit can be used to to cable television headends and to home replace existing converters in subscribers. non-scrambled systems or as an add on unit where scrambling is used. l\ block diagram is shown in Figure l. CABLE TV VERTICAL TELE . EXT DROP INTERVAL TIMING PROCESSOR CHAIN f VARACTOR TUI'<ER VIDEO SWITCH () TELE EXT 0 z RECOVERY RAM -t CHIP - :D 0 __..!: CD )> I FRARED 8748 MICROPROCESSOR t (/) DETECTOR WITH RAM & ROM m I CD )> z I 0 0 ' R < TELETEXT ___G__ RGBTO a I m CHARACTER B BASEBAND 0 I GENERATOR y RECONSTRUCT INFRARED REMOTE DJK CONTROL 1!1-112 TO ANTENNA INPUT OF T.V. R F MODULATOR - CHANNEL 3/4 175 of the receiver. Tests indicate that a THE C~BLE TELEVISION SYSTEM bandwidth of 30 mHz or greater is required for successful teletext There are numerous factors in the 0peration. Some of the home quality cable environment that effect teletext receivers have an IF bandwidth of 25 mHz performance. ~t the headend, the earth or lower: usually to improve apparant station, satellite recei~er, and the video threshold. The lower bandwidth cable modulator all affect performance. will distort the data by limiting the In the cable plant, the ~ML microwave, frequency response of the system. This the amplifiers, and the drops can also limiting will severely round the data affect performance. Each item will be pulses and cause both positive and discussed separately. negative overshoots in the data area. In one extreme case, the negative data 1. Receive Earth Station overshoot exceeded 20 IRE units with the The quality of data received is directly result being the television receiver's proportional to the signal to noise sync circuitry became erratic. performance of the receive earth The test instrument required to station. ~typical 3.6 meter with a 100 ueasure and observe this effect is a degree LN~ in the central United States full function waveform monitor, such as produced an error performance of 1 error a Te"ktronics 1480. Alternately, a 50 mHz in 106 bits transmitted. For some data oscilloscope can be use if it features a applications this error rate may not be television sync horizontal trigger. adequate. ~ larger receive dish would be For most purposes, most commercial necessary to lessen the number of bit quality satellite receivers that have errors. ~ 4.5 meter dish appears been used in the cable industry over the suitable for most applications. last five years meet the 30 mHz requirement. HQwever, due to cost 2. Satellite Receivers pressure, several major manufacturers The quality of the satellite receiver have been considering lower bandwidth can have a major effect on the products to be competitive with the home performance of the teletext system. Of satellite offerings. These lower extreme importance is the IF bandwidth bandwidth units will not function properly on a teletext system. ~ second effect inherent in the satellite receiver is video filtering. It is common practice today to incorporate bandpass filter on the video output which limits the band to 4.2 mHz. The portion of the band above 4.2 mHz contains the aural carrier at 6.8 mHz 176 and most often numerous other with too deep a notch will cause as much subcarriers and/or noise. All receivers degredation as no filter at all. are equipped with either a 6.8 mHz notch filter or the low pass filter. However, 4.
Load more

Recommended publications
  • Specific Assumptions Milestone 1
    Specific Assumptions Milestone 1 - Advisory Committee Final Report A. Assumptions 1. Advisory Committee completes final report on current schedule 2. Advisory Committee report recommends system choice 3. No litigation that impedes process Task 2 - NPRM Generation & Channel Allotment A. Assumptions 1. FCC issues NPRM on announced schedule 2. Channels are allotted to cities at release of NPRM 3. FCC accepts Advisory Committee recommendation on system choice 4. No litigation that impedes process Task 3 - Comment & Decision Period A. Assumptions 1. Allows time for comments & reply comments 2. Provides time for preparation of Final Report & Order 3. No litigation that impedes process Milestone 4 - FCC Report & Order A. Assumptions 1. Final Report & Order confirms choice of single system Task 5 - Station Assignment Process A. Assumptions 1. Station channel assignment conducted after Final Report & Order 2. Stations cannot begin designs until after channel assignment 3. No litigation that impedes process Task 6 - Litigation A. Assumptions 1. Stations will experience some delay from litigation 2. All litigation, wherever in process, aggregated at this point 3. Litigation is not extended, is resolved on expedited basis 4. Litigation affects certainty of channel assignment for stations -2- Task 7 - Transmitter Site Acquisition A. Assumptions 1. Station determines non-usability of existing tower well in advance 2. Station begins search for land in advance of FCC decision 3. Station waits for end of litigation before completing acquisition 4. Little suitable space available in major metropolitan areas 5. Sufficient space can ultimately be found on the market Task 8 - AntennalTower Design A. Assumptions 1. Station will not begin final design until channel & location are certain 2.
    [Show full text]
  • ANSI/SCTE 232 2016 Key Performance Metrics
    ENGINEERING COMMITTEE Energy Management Subcommittee AMERICAN NATIONAL STANDARD ANSI/SCTE 232 2016 Key Performance Metrics: Energy Efficiency & Functional Density of CMTS, CCAP, and Time Server Equipment ANSI/SCTE 232 2016 NOTICE The Society of Cable Telecommunications Engineers (SCTE) Standards and Operational Practices (hereafter called “documents”) are intended to serve the public interest by providing specifications, test methods and procedures that promote uniformity of product, interchangeability, best practices and ultimately the long term reliability of broadband communications facilities. These documents shall not in any way preclude any member or non-member of SCTE from manufacturing or selling products not conforming to such documents, nor shall the existence of such standards preclude their voluntary use by those other than SCTE members. SCTE assumes no obligations or liability whatsoever to any party who may adopt the documents. Such adopting party assumes all risks associated with adoption of these documents, and accepts full responsibility for any damage and/or claims arising from the adoption of such documents. Attention is called to the possibility that implementation of this document may require the use of subject matter covered by patent rights. By publication of this document, no position is taken with respect to the existence or validity of any patent rights in connection therewith. SCTE shall not be responsible for identifying patents for which a license may be required or for conducting inquiries into the legal validity or scope of those patents that are brought to its attention. Patent holders who believe that they hold patents which are essential to the implementation of this document have been requested to provide information about those patents and any related licensing terms and conditions.
    [Show full text]
  • Cable Network Handbook
    CEL-TR-HFC-HANDBOOK-V4_3-091001 Technical Report Cable Network Handbook; Overview of Architecture, Technical Features and Services of Integrated Broadband and Cable TV Networks CEL-TR-HFC-HANDBOOK-V4_3-091001 2 Cable Network Handbook Keywords Cable Network, HFC Network, Television, Broadband Services Cable Europe Labs Cable House Avenue des Arts 41 B – 1040 Brussels BELGIUM Tel.: +32 2 521 17 63 Fax: +32 2 521 79 76 Important notice This technical report is the result of a cooperative effort undertaken at the direction of Cable Europe Labs for the benefit of the cable industry and its customers. This document may contain references to other documents not owned or controlled by Cable Europe Labs. Use and understanding of this document may require access to such other documents. Designing, manufacturing, distributing, using, selling, or servicing products, or providing services, based on this document may require intellectual property licenses from third parties for technology referenced in this document. Neither Cable Europe Labs nor any member company is responsible to any party for any liability of any nature whatsoever resulting from or arising out of use or reliance upon this document, or any document referenced herein. This document is furnished on an "AS IS" basis and neither Cable Europe Labs nor its members provides any representation or warranty, express or implied, regarding the accuracy, completeness, noninfringement, or fitness for a particular purpose of this document, or any document referenced herein. Individual copies of the present document can be downloaded from: http://www.cable-europe.eu/labs The present document may be made available in more than one electronic version or in print.
    [Show full text]
  • Distributed PON Architectures for North American MSO's Next
    FEATURED TOPIC Distributed PON Architectures for North American MSO’s Next-Generation Access Keiichi TSUJIMOTO*, Yohei HAMADA, Howard ABRAMSON, and Kazuya MATSUMOTO ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- A traditional PON (passive optical network) consists of an OLT (optical line terminal) installed in a cable television headend and ONUs (optical network units) at subscriber premises (Fiber-to-the-Premise, FTTP) or a distribution point serving multiple subscribers (Fiber-to-the-Distribution-Point, FTTdp). This paper describes a new class of products Sumitomo Electric Industries, Ltd. is introducing to assist North American MSOs (multiple system operators) to address fundamental requirements for their access networks such as distance, subscribers served per port, trunk fiber conservation, uniform operations support systems, and the cost of space, power, and cooling of equipment. ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Keywords: 10G-EPON, FTTH, DPoE 1. Introduction PON (passive optical network) is an efficient, economical, large capacity method for providing network access to subscribers. A conventional PON architecture, which
    [Show full text]
  • (12) United States Patent (10) Patent No.: US 6,510,152 B1 (*) Notice R
    USOO651O152B1 (12) United States Patent (10) Patent No.: US 6,510,152 B1 Gerszberg et al. (45) Date of Patent: Jan. 21, 2003 (54) COAXIAL CABLE/TWISTED PAIR FED, 5,880,446 A 3/1999 Mori .......................... 235/380 INTEGRATED RESIDENCE GATEWAY 5,940,387 A * 8/1999 Humpleman ................ 370/352 CONTROLLED, SET TOP BOX 5,978,780 A 11/1999 Watson ........................ 705/40 5.991,800 A * 11/1999 Burke et al. ................ 709/218 5.999.207 A 12/1999 Rodriguez et al. ............ 348/14 (75) Inventors: SES inton.sty 6,026,158. A 2/2000 Bayless et al. ............. 379/355 Martin, Y. plinger, 6,034,689 A * 3/2000 White et al. ................ 345/357 Morristown, Philip Andrew Treventi, 6,049,831. A 4/2000 Gardell et al. .............. 709/236 Murray Hill; Hopeton S. Walker, 6,137,839 A * 10/2000 Mannering et al. ......... 375/260 Haledon, all of NJ (US) OTHER PUBLICATIONS (73) Assignee: AT&T Corp., Middletown, NJ (US) David Iler, “Telephony Over Cable, Communications Engi (*)* ) Notice:Notice RSubject t Neildisclai TGI. the E."t f thi neeringLee Goldbers, and Design”, MCNA/DOCSIS 12/98, http://www.cednagazine.com. MAC Clear a Path For the Cable-Modem Invasion, Electronic Design”, Dec. 7, 1997, U.S.C. 154(b) by 0 days. http://www.penton.com/ed/PageS/magpages/dec0197/ comtech/1201ct1.htm. (21) Appl. No.: 09/224,281 Ralph W. Brown, “Pegasus Set-top Terminal', 3/97, http:// (22) Filed: Dec. 31, 1998 www.pathfinder.com/corp/tech/brown?pegasuS/pegasuSSet topnctapaper.html, Time Warner Cable. Related U.S.
    [Show full text]
  • Broadband Today
    BROADBAND TODAY BROADBAND TODAY A STAFF REPORT TO WILLIAM E. KENNARD, CHAIRMAN FEDERAL COMMUNICATIONS COMMISSION ON INDUSTRY MONITORING SESSIONS CONVENED BY CABLE SERVICES BUREAU DEBORAH A. LATHEN BUREAU CHIEF CABLE SERVICES BUREAU OCTOBER 1999 BROADBAND TODAY TABLE OF CONTENTS FOREWORD . 6 EXECUTIVE SUMMARY . 8 I. BROADBAND: THE DEBATE OVER ACCESS . 9 A. The Debate Defined . 9 The Issue . 10 The Parties . 10 Arguments For Mandated Open Access . 11 Arguments Against Mandated Open Access . 11 B. Roots of the Debate . 12 The First 706 Report . 12 The AT&T/TCI Merger. 12 AT&T/TCI v. City of Portland . 13 C. Recent Developments . 14 Broward County. 14 San Francisco. 14 City of Fairfax . 14 Other Localities. 15 Congressional Action. 15 Federal Policy . .15 II. TECHNICAL BACKGROUND . .16 A. What is Broadband? . 16 As Defined in the Section 706 Report . .17 The Definition of Broadband is Elastic and Does Not Include Content. .17 B. Cable Broadband. 18 Changing Architecture. 18 Hybrid Fiber-Optic Coaxial Cable (HFC) . .18 Increased Bandwidth, Cleaner Transmission . 18 Not Without Problems. 19 C. Telephone Company Broadband- Digital Subscriber Lines (xDSL). 20 D. Wireless Technologies: Fixed Wireless and Satellite . .21 BROADBAND TODAY 3 III. THE BROADBAND INDUSTRY . 23 A. Generally. 23 Narrowband Still Dominant. 23 B. Internet Over Cable. 23 Cable Modem Deployment: Over 1 Million Subscribers . .25 Industry Projections for Cable Modem Deployment and Plant Upgrades. 26 C. DSL Deployment. 27 Industry Projections and Announcements for DSL. 28 D. Wireless Technologies: Fixed Wireless and Satellite . 29 IV. PRELIMINARY FINDINGS . 31 A. The Cable Bureau’s Monitoring Sessions. 31 B.
    [Show full text]
  • TR 102 881 V1.1.1 (2010-06) Technical Report
    ETSI TR 102 881 V1.1.1 (2010-06) Technical Report Access, Terminals, Transmission and Multiplexing (ATTM); Cable Network Handbook 2 ETSI TR 102 881 V1.1.1 (2010-06) Reference DTR/ATTM-003009 Keywords broadband, cable, IPCable ETSI 650 Route des Lucioles F-06921 Sophia Antipolis Cedex - FRANCE Tel.: +33 4 92 94 42 00 Fax: +33 4 93 65 47 16 Siret N° 348 623 562 00017 - NAF 742 C Association à but non lucratif enregistrée à la Sous-Préfecture de Grasse (06) N° 7803/88 Important notice Individual copies of the present document can be downloaded from: http://www.etsi.org The present document may be made available in more than one electronic version or in print. In any case of existing or perceived difference in contents between such versions, the reference version is the Portable Document Format (PDF). In case of dispute, the reference shall be the printing on ETSI printers of the PDF version kept on a specific network drive within ETSI Secretariat. Users of the present document should be aware that the document may be subject to revision or change of status. Information on the current status of this and other ETSI documents is available at http://portal.etsi.org/tb/status/status.asp If you find errors in the present document, please send your comment to one of the following services: http://portal.etsi.org/chaircor/ETSI_support.asp Copyright Notification No part may be reproduced except as authorized by written permission. The copyright and the foregoing restriction extend to reproduction in all media.
    [Show full text]
  • The Effects of Single Ended, Push-Pull, and Feedforward Distribution Systems on High Speed Data and Video Signals
    THE EFFECTS OF SINGLE ENDED, PUSH-PULL, AND FEEDFORWARD DISTRIBUTION SYSTEMS ON HIGH SPEED DATA AND VIDEO SIGNALS RONALD J. HRANAC Western Division Engineer JONES INTERCABLE, INC. Englewood, Colorado ABSTRACT Do different types of cable television distribution electronics-- single ended, push-pull, Field testing was conducted to investigate the and feedforward -- have any effect on video or high effects of cable television system electronics on speed data signals in the downstream path? Are video downstream video and high speed data transmission. signals and high speed data signals affected Three system configurations were used for the similarly by cable system characteristics such as testing: a 15 year old single ended 12 channel plant; a frequency response, noise, channel loading, and 3 year old 35 channel push-pull plant; and a 1 year old signal levels? 54 channel feed forward plant. Various RF, video, and digital tests and measurements were performed to To address these questions, several tests and determine if a relationship exists between typical measurements were performed in cable systems cable television system operating characteristics operating with single ended, push-pull, and and the performance of video and high speed data feedforward distribution electronics. Measurements signals on these systems. were made to determine the extent of video delay and phase distortions, data errors, and data waveform INTRODUCTION envelope distortions in the three types of distribution systems. Analog RF tests and Cable television systems have provided operators measurements determined the effects of frequency with an excellent means of delivering entertainment response, carrier to noise, channel loading, signal services to subscribers for over 30 years.
    [Show full text]
  • February 1999 Newsletter
    Chapter 24, Inc. Madison, Wisconsin Next Meeting: Tuesday, February 23, 1999 Society of Broadcast Engineers February 1999 Year 2000 Station BROADBAND NETWORKS Preparations PART 28 - HEADENDS II By Neal McLain Dutch Treat Dinner This is Part 28 in a series of articles about broadband networks. In this article, we’ll continue with our discussion of headends. and Meeting INTRODUCTION J.T. Whitney's Last month, we began a discussion of the equipment located in a typical 674 S. Whitney Way cable television headend. We noted that a typical headend is a “star” network at 5:30pm in which a number of NTSC signals are combined into a single wire: Program at WNWC-AM/FM BROADBAND OUTPUT TO 5606 Medical Circle DISTRIBUTION SYSTEM at 7:00pm COMBINER In This Issue: We further noted that three types of devices are commonly used to generate these NTSC signals: strip amplifiers, processors, and modulators. Minutes .............................. page 2 This month, we’ll take a look at how these devices are used in a hypothetical Amateur Radio News ..... page 3 headend, and the kinds of equipment located upstream from these devices. Local Legals ..................... page 7 The design of any headend begins with the channel lineup: a list of the signals to be carried. For the purpose of this discussion, we will adopt the Telecom News ................... page 8 hypothetical 12-channel lineup shown in Figure 1. This lineup doesn’t actually exist at any real headend; it was chosen for this article because it’s a relatively FCC Rulemakings ........page 10 (continued on page 4) Digital Television Demonstration This April At UW Engineering EXPO By Steve Paugh convention being held in Las Vegas.
    [Show full text]
  • Before the FEDERAL COMMUNICATIONS COMMISSION Washington, D
    Before the FEDERAL COMMUNICATIONS COMMISSION Washington, D. C. 20554 In the Matter of ) ) File No. EB-02-TS-069 Waiver of the Rules ofthe Federal ) FO Docket No. 91 -301 Communications Commission Relating ) FO Docket No 91-171 to Implementation ofthe Emergency ) Broadcast System ) Branch Cable, Inc. To: Chief, Office of Homeland Security, Enforcement Bureau PETITION FOR FURTHER WAIVER OF EMERGENCY ALERT SYSTEM REOUIREMENTS Branch Cable, Inc. (hereinafter "Petitioner"), by its attorneys, respectfully requests a further waiver of Section 11.11 of FCC Rules, 47 U.S.CO § 11.11. Specifically, Petitioner seeks further additional time to comply with the requirement to implement Emergency Alert System ("EAS") equipment and procedures at Petitioner's cable television headend systems at Crosby, New Augusta, New Hebron and Roxie, Mississippi. Section 11.II(a) requires cabletelevision systems serving fewer than 5,000 subscribers eitherto providethe national level EAS message on all programmed channels- including the required testing - or to install EAS equipment and provide a video interrupt and audio alert on all prognumned channels and EAS audio and visual messages on at least one progrmmned channeL Petitionerrequests a furtherwaiverperrnitting additional time for the cable television headend systems at the nmned communities to comply with these requirements., Petitioner relies herein upon the mechanism for waiver established in the SecondReport andOrderin FO DocketNos. 91-30I and 91-171, FCC 97-338, found at 12 FCC Rcd 1550.3, see ~19 et seq. (1997). 2 Background On February 12, 2002 Petitioner filed a Petition For Waiver Of Emergency Alert System Requirements, which were then scheduled to take effect on October 1, 2002 The Enforcement Bureau ("the Bureau") granted Petitioner a temporary waiver of the requirements for EAS implementation, including the requirements for testing and monitoring.
    [Show full text]
  • Planning Alternative Organizational Frameworks for a Large Scale
    r. DOCUMENT RESUME ED 078 663 EM 011 206 AUTHOR Walkmeyer, John TITLE Planning Alternative Organizational.Frameworks For a Large Scale Educational Telecommunications System Served by Fixed/Broadcast Satellites. Memorandum Number 73/3. INSTITUTION Washington Univ., St. Louis, 4o. F.,:ogram on Application of Communication Satellites to Educational Development. SPONS AGENCY National Aeronautics and Space Administration, Washington, D.C. REPORT NO M-73-3 PUB DATE Jun 73 NOTE 120p. EDRS PRICE MF-$0.65 HC-$6.58 DESCRIPTORS Broadcast Television; Cable Television; *Communication Satellites; *Computers; Educational Equipment; Educational Technology; Fixed Service Television; Information Dissemination;-Information Storage; *Networks; *Organization; Programing; State of the Art Reviews; *Telecommunication ABSTRACT Considerations relating to the design of organizational structures for development and control of large scale educational telecommunications systems using satellites are explored. The first part of the document deals with four issues of system-wide concern. The first is user accessibility to the system, including proximity to entry points, ability to pay, permission to use facilities, and control over use. Next, integration and control of the system's components by private or public agencies are considered. Third, the matter of equipment control is covered.- Fourth, the question of what developmental initiatives are needed in order to move from concept to action is dealt with. Four issues relating to specific system components are included in the second part of the report. These are the sources of software programing, software storage, the means of its transmission, and the matter of local and regional distribution.' Also treated are the social cons.quences of educational networking. (Author/PB) PLANNING:ALTERNATIVEOR6ANIZATIONAL FRAMEWORKS FOR VLARGE-SCALEIDUCATIONALTELECOMMUNICATIONS-SYSTEM SERVED BY FIXED/BROADCASTSATELLITES JOHN WALKMEYER SHINGTON UNIVERSITY/ ST.
    [Show full text]
  • 011 Cablelabs Request of Proposal, 1991.Pdf
    „Th I CL:L i_obs eccle Teievisicr, Lctoratories, inc. Attached is a copy n1 the letter that was sent with the RFP ro the vendors. August 30, 1991 Mr. John Doe President Cable Corporation i234 Main Street Any City, IA 50000 Dear Mr. Doe: Attached is a copy of a Request of Proposak(RFP) offered by Cable Television Laboratories, Inc.(CableLabs), Tele-Communications, Inc.(TCI) and Viacom Networks (Viacom). It specifies a Digital Compression Program Delivery System (the System) which will allow program suppliers to provide multiple programs per satellite transponder channel to cable television system headends. As specified in the RFP, of paramount importance is the compatibility of the System with the future digital compression distribution requirements of cable television systems. Given the rapid developments occurring in the realm of digital compression transmission systems, it is critical that the System be robust enough to accommodate the to-be- developed requirements and needs of digital compression use by cable television system operators in their provision of service to cable customers. Any entity that intends to be a respondent to the attached RFP shall submit a letter evidencing its intention to bid on this RFP by the close of business on September 16, 1991 to the following address: CableLabs 1050 Walnut Street. Suite 500 Boulder, CO 80302 Attn: Craig K. Tanner Intent to Bid Digital Compression Program Delivery System RFP It is contemplated that we will conduct a bidder's conference on September 19, 1991s.—Your—m--- -- intent to bid letter will serve also as your stated intention to attend that bidder's conference.
    [Show full text]