Freeze-frame television can be a cost-effective choice for images that don't require motion to be understood.
Freeze-frame television has been selected as the medium of choice by many US corporations. The technology holds its own as a means of economically and efficiently communicating "hard' information to a remote audience. When compared with fullmotion and even the most advanced of digital data-compression technologies, freeze-frame television is very cost-effective in delivering detailed images that don't require motion.
What freeze-frame television is not is an inexpensive substitute for full or partial-motion video teleconferencing, and as such is not designed to convey face-to-face conversations. When others' emotional reactions need to be experienced, it's best to use either audio or motion-teleconferencing technology, or to communicate in person.
In essence, freeze-frame television involves the use of standard television cameras, monitors and peripheral devices such as image storage systems. Freeze-frame TV transmits only stationary images over narrowband communications channels that have much smaller capacity than normally needed for the reproduction of moving images. This form of an "electronic slide show' may be regarded as a form of television facsimile that's highly versatile in terms of visual inputs, display methods and picture storage.
Low-cost transmission is a key element in the use of freeze-frame television. The availability of communications circuits is another important, but not too commonly recognized, consideration. The conventional voice-grade telephone network is widely used for freeze-frame picture transmission because of its convenience and because the ubiquity of the telephone throughout the world can provide visual communications even in the most remote of locations.
Voice-Grade Channels Can Be Used
Freeze-frame television may, of course, be transmitted via satellite on voice-grade communications channels. These may be too limiting it bandwidth to provide images rapidly enough when there is a fast-moving presentation. With wider bandwidths, however, the situation changes.
The use of satellite communications channels for freeze-frame picture transmission is highly desirable from several standpoints. First, intermediate data rates, both digital and analog, seem to be more generally available than in the case of terrestrial services. Second, relatively small and inexpensive receiving and transmitting equipment can be located at sites where conventional communications services aren't available. Third, when a "broadcast' mode is desired, satellite distribution of signals continues to remain as the most-economical method of reaching multiple locations over a very wide geographic area.
TV News Pioneered Freeze-Frame
In 1978, United Press International pioneered the use of freeze-frame in broadcasting by creating a 24-hour television news program. (At that time, the technology was called "slow-scan' because the picture images built up across the screen in a left-to-right sweep.) Broadcast under the name of UPI Newstime, this service reached more than one million US households subscribing to cable television services. Audience acceptance of this kind of "still-picture' programming was considered to be very good, as reflected in the results of an A. C. Nielsen survey conducted in 1979 for UPI.
Newstime transmission was accomplished through the use of subcarrier channels on Transponder Six of Satcom I. The main channel of Transponder Six was used to distribute programming from WTBS to cable systems throughout the country. An 8-kHz channel was used for the slow-scan video component, and an adjacent 5-kHz channel for simultaneous voice and music accompaniment. The subcarrier multiplexing equipment was designed and manufactured by Wegener Communications, the slow-scan video transmitting and receiving equipment by Colorado Video, and the actual satellite uplinking of the transmission was made through the Georgia ground station of Southern Satellite Systems (SSS).
Full Color Added to the Image
The original UPI Newstime programming was in black and white, but a year later SSS started a second 24-hour slow-scan television service in full color. The new Women's Channel transmission time was also eight seconds per picture, but used a slightly wider subcarrier bandwidth of 10 kHz.
In both services, a scan converter using solid-state computer memory components was located at a cable system headend, to reconvert pictures into standard television format. When tuning into either slow-scan channel, the audience would hear normal audio and see new pictures dynamically appear on the screen, with a new image replacing the old in a horizontal wipe.
Program production for both UPI Newstime and The Women's Channel was relatively simple and involved small staffs. UPI relied upon its older existing services for daily material. It blended a combination of newswire, audio commentary and interviews, facsimile pictures and a stock inventory of 10,000 slides to provide a fast-moving 15-minute basic news program that was frequently updated throughout the day. Considered by some to be a radio newscast illustrated with pictures, the format was an effective one. It contained some highly emotional still images from the skilled photographers who were employed in UPI's worldwide organization.
Magazine Programming Format Used
The Women's Channel, although technically similar, used a magazine programming format, deriving much of its material from well-known print publications such as Family Circle. The production crew, located in Tulsa, prepared programs on three-quarter-inch tape cassettes. These were flown to the SSS uplink station in Douglasville, Georgia, for subsequent conversion to slow-scan television format and transmission. Tape playback allowed for program repetition, with a basic two-hour segment being repeated during a 24-hour period and a 10-hour block of material broadcast on weekends.
Special Tone Initiated Slow-Scan
UPI Newstime programs were also produced on three-quarter-inch video tape at studios located at the Georgia uplink site. Six tape machines were used for a combination of continuous playback, program production and editing purposes. In both the UPI and SSS programs, the first audio channel of the tape machine was used conventionally, for audio conversation. The second audio channel was used to record a special tone that initiated the slow-scan conversion and transmission process. Conventional CCTV cameras were used as video sources. Each stationary image was recorded for about 10 seconds on tape.
Cable system operators subscribed to Newstime at a fee of approximately five cents per subscriber per month. National advertising was accepted as an additional revenue source. The Women's Channel was based on a different set of economics. It was provided without charge to cable systems on the assumption that national advertising income would make it a profitable venture. It is estimated that Women's Channel reached approximately 500,000 homes by direct slow-scan broadcast, and another three million homes indirectly by transmission of a two-hour reconverted segment over the SPN satellite channel.
In 1980, both services began to feel the pressures of an extremely competitive cable-program supplier marketplace. (The success of UPI Newstime helped influence Ted Turner to launch a full-motion 24-hour news service, Cable News Network. This in turn spawned the launch of the Satellite News Channel in 1983, a cable-TV program service that survived for only a few months.)
Slow-Scan Format Was Profitable
In 1981, Newstime and Women's Channel were sold to Eastern Broadcast Services, which merged the two services into a new format initially called North American Newstime and subsequently redesignated North American Travel. A combination of news, travel information and advertising produced an increase in subscriber count from a low of 600,000 to more than 800,000 homes. The slow-scan program format was one of the few profitable cable services at that time.
In the ambitious programming era of cable from 1980 through 1983, many other kinds of program services were considered adaptable to the still-frame television format, including video shopping catalogs, auctions, real estate sales, and specialty programming such as channels on stamp and coin collecting.
Even today, freeze-frame TV narrowcasting to selected audiences seems an excellent opportunity for the entrepreneur. Advances in technology have made it much more attractive. Origination equipment is of improved quality and is now available with computer-based image storage-and-retrieval capabilities for convenient program preparation. Both analog and digital formats are available. Scan "wipe' has been replaced by a "slide show' format. Furthermore, the cost/ performance ratio of freeze-frame receiving equipment has improved markedly.
On-Premise Uplinks May Be Used
Due to the relatively small bandwidth required for freeze-frame television, relatively small, inexpensive on-premise uplinks may be used. A five-meter dish with a 20-watt transmitter can cost as little as $80,000 and will handle a 10-kHz freeze-frame video channel and a simultaneous 5-kHz audio channel. Using single-channel-per-carrier modulation, a small earth station of this kind may be used for direct broadcast to low-cost earth stations, or to relay programming to a major uplink location for subsequent insertion on a subcarrier channel of a transponder.
Along with broadcast applications of freeze-frame television, two-way visual communications on a point-to-point or multipoint basis are equally significant. Their importance rests in economical, rapid, visual information dissemination. A number of federal agencies, including the National Aeronautics and Space Administration, use freeze-frame technology for digital transmission at rates ranging from 56 kilobits per second to 1.5 megabits per second. Digital has been the preferred mode, both for the convenience of interfacing to satellite communications circuits and because digital signals can be encrypted when confidential information is involved.
Corporate use of freeze-frame television has been largely confined to voice-grade terrestrial circuits; however, a major expansion to satellites seems likely. The use of 56-kb/s data communications circuits for freeze-frame teleconferencing is becoming an attractive option to some corporations as these communications channels become more-readily available for satellite transmission.
Some Other Uses of Freeze-Frame
Although corporate teleconferencing is most often thought of in terms of executive meetings, new-product introductions or press conferences, a major corporation can have other uses for visual communications. As one example, freeze-frame TV is used on offshore oil platforms in Canada to obtain medical assistance via satellite from the Memorial University of Newfoundland in St. John's. In another example, on an offshore rig off the coast of Southern California, freeze-frame equipment has been used to "diagnose' broken equipment and to expedite the shipment of replacement parts. Satellite communications may be the only feasible way of contacting remote locations, and freeze-frame television does it economically.
Freeze-frame video also works well with transportable equipment for all types of industrial or commercial problem solving. The old adage, "A picture is worth a thousand words,' "can never be taken too lightly. In corporations where time is of the essence and decision makers are geographically separated, rapid visual communication is of crucial importance. A well-designed freeze-frame system using anything from voice-grade to 56-kb/s channels can shave hours of delay off decisions requiring visual information, particularly when transoceanic communication is involved. And while multinationals may well have elaborate teleconferencing facilities in a multi-site network configuration, these may not be able to communicate with isolated locations that don't cost-justify expensive facilities.
Freeze-frame television is ideal for the transmission of photographs, slides, drawings, blueprints, products (for quality control), models, broken parts, advertising storyboards, new product designs, samples and the like. The use of quality cameras and monitors with a high-resolution freeze-frame system can show a tremendous amount of detail. As long as time-zone restrictions are adhered to, visually oriented decision making can take place whenever the need arises. Such an application has been utilized by engineers in New York and Paris to discuss the Statue of Liberty restoration.
Further Examples of Uses
Intercompany communications can be just as important. An equipment or service provider can enhance its communications with a key client. An ideal use of this is in the preparation of material by an advertising agency. Trips from the agency to the client can be minimized, and agencies can become more competitive by offering lower overhead costs for a given account.
Communication with subcontractors can also be enhanced. One real example that took place via voice-grade satellite communications channels involved a well-known New York fashion designer and a Hong Kong manufacturer. It was necessary to inspect the first production-line garments of the fall season. Ordinarily, these items would be sent from Hong Kong to New York by courier. With a freeze-frame system, it was possible to inspect the items immediately. It was noticed that a pattern had been reversed in one garment. With freeze-frame, this mistake was rectified immediately, with no delays.
In the cited examples, motion was not necessary for decision making. Freeze-frame met the needs of immediacy, and with tremendous cost efficiency.
The instructional use of satellite-delivered freeze-frame television offers much potential. Our society is used to instructional television and freeze-frame may at first glance seem like a step down. However, not all corporations have the resources to provide "real-time' satellite-delivered course to their widely scattered employees.
When analyzing standard instructional television, programming usually consists of a moving upper torso of a human being supplemented by blackboard drawings, overheads and slides. Eliminating the moving torso, a well-delivered lecture with interactive audio, using the same visual aids (blackboard, overheads and slides), can achieve the same effect. This can be a very economical way to train employees. With freeze-frame, a corporation can use one transponder for literally hundreds of courses or share a transponder with other companies that are doing the same thing.
Academic Institutions Can Benefit
Similarly, academic institutions can reach an international audience with specialized instruction, either through degree programs or with targeted continuing-education programs. While universities have been the pioneers in teaching via teleconference, such possibilities as providing university-level instruction for gifted, motivated high school students are within the realm of affordability using freeze-frame television.
Another potential use of satellite-delivered freeze-frame video includes a variety of medical applications, particularly diagnostic assistance and treatment to isolated communities. A two-way satellite-delivered service from a university medical center in Canada to a hospital in a less-developed African nation is about to be launched. This type of enterpreneurial medical service provides a level of immediate expertise that otherwise would be unavailable.
Although there are estimated to be some 50 suppliers of freeze-frame television worldwide, fewer companies are manufacturing equipment for satellite transmission. Employing its own equipment, NEC participated with Satellite Business Systems in a project using digital transmission of color freeze-frame images for teleconferencing demonstrations. Like video equipment has been promoted for use in the nationwide distribution of weather information to local television stations. Both NEC and Colorado Video have customers who use voice-grade, 56-kb/s and TI satellite channels for freeze-frame images.
Capital Equipment Costs Listed
A user's capital equipment costs are as follows:
A color transceiver with serial digital output may cost in the $10,000 to $20,000 range. Cameras, monitors and other peripheral equipment may be an additional $3,000 to $30,000, depending on the quality and quantity of equipment. A 56-kb /s circuit will allow a picture update every 10 to 20 seconds for a single-field NTSC-like format. Higher or lower bit rates may be used, depending on system requirements, and picture access times will change accordingly.
In broadcast applications, a color freeze-frame transmitter with a 10-kHz analog output signal costs approximately $12,000. Companion receiving equipment is about $4,000 per location. A transmitter with serial digital output sells for about $10,000 and may be operated at any rate from 2400 b/s to 200 kb/s. Its receiving unit costs approximately $6,000.
Various means of satellite delivery may be employed. Subcarrier channels may be leased if access is available to a major uplink location. A recently developed technique also allows the insertion of color freeze-frame TV signals into an unused line in the vertical blanking interval of a conventional television program, thus providing a new and convenient method of information delivery.
Present technology allows the production of high-quality, reasonably priced freeze-frame equipment for use with satellite communications, either on a point-to-point or broadcast mode. Future developments will include high-resolution (1,000-line) monochrome and color equipment, as well as personal computer-based systems and low-cost receiving equipment for school, office and even home use.
Photo: Distance teaching can be done by freeze-frame via satellite.
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|Date:||Apr 1, 1986|
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