San Francisco — Like calculators, wrist watches, stereos, and TVs, the telephone is going digital. This is transforming millions of miles of copper wire, thousands of switches, dozens of satellites into the highway system of the information age. After the process is complete, the system will carry all types of information -- voice, computer text, graphics, and ultimately full video -- with equal facility. ``We don't look at ourselves as a phone company anymore, but as an information management kind of animal,'' explains Robert Degenhardt, spokesman for AT&T's Bell Laboratories. Unfamiliar choices
This transformation is not likely to be smooth. The marriage of phone and computer technologies has confronted many consumers with unfamiliar and often unwanted choices. Over the long haul this fusion will play a major role in office productivity and the transition from the industrial to information age.
Despite the Bell System breakup, the telephone industry remains highly regulated. As a result, the pace of change depends to a large degree on political and regulatory decisions.
Jack Nilles, a futurist at the University of Southern California, sketches two different scenarios of what the future could hold. In the first, the phone companies remain tightly regulated, with the emphasis on providing low-cost, universal service. In this case, innovation will occur at a snail's pace. ``This is probably the safest prediction to make because the regulators tend to listen to all the public interest groups,'' Professor Nilles says.
His second scenario makes the opposite assumption. At least for heavy communications users like businesses, regulations will be loosened enough to create free-market conditions. In this case, the futurist forecasts significant changes in the next decade or two which will profoundly effect the way Americans ``reach out and touch'' one another.
Telecommunications consultant Carroll G. Bowen of Cambridge, Mass., leans toward Professor Nilles's second scenario. Already, the ``pace and acceleration of technological innovation is just galloping along,'' says Dr. Bowen.
As a result, the telephone customer can expect a plethora of services. The first of these AT&T calls ``local area signaling services'' (LASS), which are currently under test in Harrisburg, Pa., and Tampa, Fla. Essentially, these new services promise phone users more control over calls they receive. They are made possible by the replacement of older relays with modern, digital switches, a conversion the phone companies are committed to make, at least in major cities. Participants in these trials are provided a small box with a liquid crystal display which plugs into the phoneline. When the phone rings, the number of the incoming call is displayed. Call blocking, tracing
Another LASS service is ``call blocking.'' A customer specifies which number he or she does not want to receive calls from. A caller from that number gets a recorded message stating that ``the party you are attempting to reach has activated their call-block service indicating they do not wish to receive this call.''
The final feature being tested gives individuals the ability to trace calls. By pushing a few buttons after a nuisance call, a person can report the number to a special phone company office.
Changes the office worker can expect are considerably more profound.
With sales of personal computers to businesses growing by about 30 percent per year, providing communications between machines is a high priority. Companies are working on ``local area networks'' to link personal computers together in an office. The first of these networks, however, requires special cabling, is expensive to install and alter.
An alternative is integrating voice and data over existing phone lines. This is the approach of DAVID Systems of Sunnyvale, Calif. Its phones plug into phone jacks and a computer can be plugged into the telephone, giving the office worker simultaneous voice and high-speed data communications. It's all controlled by a file cabinet sized box of microelectronics.
For several years before the breakup, AT&T was pushing its electronic telephone switchboards (called a private branch exchange, or PBX) for the business market. But regional phone companies are reviving Centrex, which duplicates many PBX features by using the phone company's own switches.
``We're trying to put as much intelligence into the network as possible,'' explains Michael A. Gibbons, executive director of new systems development for Pacific Bell. His company is bent on modernizing its Centrex system, giving business customers all the features offered by PBX equipment for a monthly fee.
One of the latest office phone features -- which people seem to either love or hate -- is voice mail. This uses voice digitization to record, store, and forward voice messages over the telephone. Voice mail systems allow busy managers to exchange information without talking directly. Purveyors of voice mail are betting on the growing frustration of ``telephone tag'' to make their equipment attractive. Improving the computer link
While steady growth in voice traffic over the nation's phone lines is predicted, analysts foresee greater growth rates in the transmission of computer data. Eighty percent of this communication is likely to be within office walls and so will be handled by local networks. However, 20 percent or so will enter the public phone system.
Today, linking computers over the phone is generally a Rube Goldberg affair. Each computer must be plugged into a special device called a modem. This translates between the digital language of the computer and an analog code which the phone line can handle -- and it severely limits transmission speeds. Computer networks have sprung up which allow users to exchange messages and information by dialing into local access numbers, but they remain relatively expensive. This situation is likely to change radically in the next few years.
Many large companies will probably follow the lead of Xerox, which recently signed an agreement with GTE Spacenet. Installation of four-foot dishes on its far-flung buildings will offer instant data communications via GTE's communication satellites.
The FCC recently amended its rules to allow the regional phone companies to engage in ``protocol conversion.'' This means that they will be able to translate between different computer communication codes. With this judgment, the phone companies are expected to move aggressively into the computer networking area.
Professor Nilles anticipates that capabilities of this sort will give a major impetus to telecommuting -- working at home via computer. But major investments in programming are necessary to make these systems accessible to the general public.
As technology moves closer to conveniently handling computer information at high speed and over long distances, the volume of computer traffic is expected to swell. This will create new problems. Anticipating the growth of data traffic, phone companies are rapidly deploying optical fiber transmission lines. These send information by light wave and have a tremendous capacity, or bandwidth. The newest fibers transmit 169,000 conversations at a time.
Besides swelling the volume of communications traffic, computer usage will have other effects. Today, the average phone call lasts about four minutes. System analysts use this to determine the ratio of switches to phone lines they must put in. Because computer users tend to tie up lines for longer periods, growing numbers of switches will be required as well. There have been phone systems tie-ups in West Los Angeles attributable to heavy terminal use.
With the growing capabilities of microcomputers, users will demand high speeds (for data transmission) for short periods of time, something the phone company cannot currently provide. Bell Labs was recently awarded a patent for complex communication scheme which could provide this capability. This system, a potential successor to the digital switching system now being developed, is a refinement of an approach called ``packet switching.'' As a voice or data transmission is digitized every millisecond or so, it is divided into ``packets'' of data. The computer attaches an identification and destination code to each. These packets may travel by a number of different pathways. When they reach their destination, they are reassembled. Video via optical fiber
Optical fiber may revive an old idea, the picture phone. If so, bandwidth-hungry video will represent a significant new source of traffic.
Earlier this year AT&T abandoned its televised conferencing service because it wasn't attracting enough business. But other developments are making full video on the office desk look more promising.
Techniques -- such as not repeatedly transmitting an entire picture, but only the elements which change -- have been decreasing the data transmission rate required, while other techniques have been increasing the rates which can be achieved over ordinary telephone lines. DAVID Systems, for instance, could broadcast full video over its network today. The major cost, compressing and decompressing the signal, is likely to decline.
Bringing the picture phone into the home is further in the future. Wiring the local telephone exchange with fiber or coaxial cable will increase the potential bandwidth of the average residential line by a factor of 10. This is nearly enough for slow-scan video, the transmission of a series of still pictures. For full video, the ``local loop'' would probably have to be wired with fiber. The current cost of the fiber-end electronics is prohibitive.
Still, the merger of computer technology and telecommunications is creating a spectrum of potential new services. The big question at this point is, what will people accept as useful and pay for?