et al.: A Cable is a Very Big Wire "For all the promise that has intrigued some of the best minds in industry and government, CATV is a grubby infant. " - Business Week, Nov. 6, 1971 Introduction A cable is a cavernous communications highway three hundred million radio-frequencies wide, as much larger than a telephone wire ;:; ..we are than an ant. The immense frequency capacity of the cable is indefinitely Foundation 70 repeatable and infinitely flexible. In its atomic form of a A Cable is a Very Big Wire single closed system, the concept and technology of cable is comparatively simple. But to envision it in its evolved aggregated form, the architectural complexity of cable communications presents an almost metaphysical challenge. The importance of cable? A mixture of fact and fancy, dreams and nightmares. The availability of tens to hundreds of video channels and thousands to millions of data channels on a mass basis can serve every imaginable communications purpose. Access by cable to computers, libraries, social services, commercial services, and education; community forums, soapbox studios, and cradle-to-grave records; Sears and Roebuck, The Whole Earth Catalogue, and pornography; wall screens, three-dimensional holography, burglar alarms, and surveillance; electronic mail, instantaneous credit verification, and the Internal Revenue Service on the home terminal. As cable communications matures, it will profoundly reorganize the pattern of our collective and individual lives. Where. will cable be in 1984? Who will control it? Will it accelerate and lock in trends to centralization, or will it create complementary mechanisms of decentraliza­ tion? Will cable expand the economic base and sources of social power, or will cable aggravate present distortions in the body politic? Will the system serve 199 Foundation '70 is a cable consulting group located in West Newton, Mass. It has recently developed an economic planning tool for cable which is adaptable to unique local or regional characteristics and choices. Published by Yale Law School Legal Scholarship Repository, 1972 1 Yale Review of Law and Social Action, Vol. 2 [1972], Iss. 3, Art. 2 people, or will people serve the system'! be carried before its quality becomes too poor for use. The germinal structure of our communications future Actually, signals can travel only a short distance before is now emerging from federal and state agencies and weakening, at which point an amplifier is inserted into legisratures, from the White House and the Courts, from the cable to strengthen the signals, there being generally private industry and public foundations. But the nuclear about four or five amplifiers for each mile of cable. core of the future cable network is being established by Repeated amplification, however, gradually degrades the the individual cities and towns granting construction signal; this, and the small amount of signal energy lost rights to build CATV systems. In particular, the pattern with each subscriber tap, limits how large an area can be of cable is being formed at the centers of population by served from one headend. In rural areas, this limit is the major market municipalities. often about twenty miles, but in the city the limit may The major municipalities are future-makers. So are all be only five or six miles. those individuals, groups, agencies, and institutions Good as the tree image is, it is essentially rural in which are formulating advice, policies, and laws intended origin and application. A more illustrative image for to help shape the municipal CATV franchise. The urban cable might be found directly in the system of quality of thought and information invested in the cable city streets. Major thoroughfares would represent trunk process at this embryonic stage will determine whether lines, arterial streets the branching feeder lines, and the cable becomes a tool of growth or stagnation, of short residential or apartment drive the drop. Since the liberation or oppression. design of a cable system often roughly coincides with the street plan, such an image is immediately descriptive of the distribution system itself. But a proper image for From Rural to Urban the urban headend is, however, more difficult. The classical rural system does little more than relay The most direct way to explain the function of broadcast signals in one direction from the headend to community antenna television is to start with the home the home. The urban system of the near future will carry set and point out the short wire leading to the "rabbit a great variety of video. audio and data signals to, from, ears". If the house has an outdoor antenna, a longer wire and among individuals, institutions, businesses, and connects the rooftop antenna to the set. In an apartment governments. That is, the communications highway will building, a roof antenna may be connected by many carry many kinds of traffic for many kinds of purposes. wires to many apartments in the building. This is the To achieve a flexible communications network a city classical cable distribution system in miniature. may have not one but many headends, not one but The earmark of the classical system in a rural setting is many channel capacities, and not one but many a tall master antenna which supports an elaborate array directional capabilities to serve different areas and of special directional antennae designed to receive the purposes. In short, the design of urban cable systems has clearest possible broadcast signals. These signals are just begun and there will be many and complex processed and prepared for distribution at the system's variations on the basic tree theme. headend. The headend is the point of entrance for all signals to be carried on the sysrem. As such, it is the point of origin for one or more trunk lines (large-size cable) which extend to the limits of the service area. Branching off the main trunk cables are secondary feeder lines (medium-size cable) and the final connection to a home is made with a short drop (small-size cable). These are the basic components of the so-called "three-type" distribution system, the most common (though not necessarily the best) type of system in use in the United States. The image of a tree is a good one for the classical 200 one-way cable system. The roots and base of the tree represent the headend where the (cable) trunk originates and stretches the height (length) of the tree; branches extend from the trunk lo support a network of twig-like drops; and together, the trunk, feeders, and drops connect the leaf-life subscribers to the signals/nutriment introduced through the headend/roots. The tree image is also good because it illustrates the closed and limited nature of the cable system. Just as the size of the tree is limited by the height to which the necessary and sufficient chemicals can be carried from roots to topmost branch, so the length of a trunk line from the headend is limited by the distance a signal can https://digitalcommons.law.yale.edu/yrlsa/vol2/iss3/2 2 et al.: A Cable is a Very Big Wire Cable is a Medium The cable system will carry twelve broadcast signals, three of which will be imported from outside the The dramatic transformations in cable systems as they. market. These outside signals have been the crux of the move from the country to the city will appear primarily CATV debate since the FCC imposed its freeze on at the headends and in the subscriber homes. Satellite, distant signal importation in 1968. The argument of the microwave, and laser links will connect the local cable industry has been that unless distant signals (e.g., headend to regional and national programming and NYC signals into Boston) are permitted, people will have information sources. Central and remote origination no reason to subscribe to cable television. It has been a facilities, on-line computers, and libraries of video widely held belief that unless the freeze is relaxed, cable cassettes and data will characterize the capabilities of the cannot be viable in the cities. The FCC has announced urban headend. In the home, the TV set will be joined its intention to permit some distant signals by March I, by new electronic "appliances" such as record/playback 1972. units, digital keyboards, and hard-copy printers. Yet the basic function of the cable system will remain unchanged. The wire which connects a subscriber to the Local Factors headend is simply a practical and controllable medium for the transmission of electromagnetic signals. Cable's A cable plant is built to reach some given number of virtue lies in its capacity for expansion to meet. • potential subscribers, in this model about 20,000 homes. accelerating communications needs. It is the technology To pass 20,000 homes, 162 miles of cable are required in which releases, increases, and distributes this potential our example, which means that the average number of for communication which can be uniquely called "cable potential subscribers per mile of installed plant is 120, a technology". factor called density. Clearly, the higher the density, the By concentrating attention on the cable distribution smaller the plant cost for reaching a given number of technology one al~o defines CA TV's field of economic subscribers. This relation of plant size to homes varies considerations. To illustrate the interrelation of significantly in different markets and within each technology and economics we shall outline and discuss a market. Boston, for instance, has a density of almost "real-world" basic CATV distribution system. The 340; within the core area of Boston, Brookline has a parameters and cost totals in the illustration are taken density of 234, Chelsea 210, and Somerville 328.