SAN JOSE, Calif. -- For making possible the global phone network -- and with it 976 numbers, home-delivered Chinese food and "Larry King Live" -- the world owes copper wire a debt of gratitude.
Copper wire, though inexpensive and ubiquitous, has had a klutzy reputation as a relatively crude transmission medium. It was expected to give way to snazzy, speedy and expensive fiber optics for the next communications revolution -- that of high-speed data exchanges between computers.
But in recent years, spurred by research aimed at getting the most out of the world's millions of miles of existing telephone wire, copper has won new technological respect. In the process, it has made possible several breakthroughs for desktop computer users.
Thanks partly to improvements in wire-manufacturing techniques, but mostly to remarkable advances made by several Silicon Valley companies, copper telephone wire is now capable of transmission speeds of more than 100 million bits a second, more than 100 times faster than some scientists believed was possible on copper only a few years ago.
It's as if engineers at Sony had found a way for ordinary audio tape cassettes to record compact-disk-quality sound.
"Copper has found new life," said Mike Barnick, a product manager for American Telephone & Telegraph Co., which has done extensive work in copper and fiber optics.
"It's not nasty old phone wire anymore," said Jayshree Ullal, vice president of marketing at Crescendo Communications Inc., a Sunnyvale, Calif., company that is doing much of the work in expanding copper's potential.
This copper renaissance means that sophisticated computer networks can now be run over existing office phone lines. More significantly, there is a new generation of better-grade copper wire being installed in most offices -- wire that will be able to handle high-speed networks. These networks will make possible elaborate multimedia workstations that combine numerous video images on a single screen.
Previously, most people thought that these fast new networks would require fiber optics, meaning that their widespread acceptance would have to wait until the total costs of fiber declined, something happening more slowly than many had hoped.
So there's now a scramble in the networking industry, as companies rush to bring new copper-based products to market.
Copper phone wire, known in the industry as "twisted pair," is cheaper than fiber optics, not only because the raw cable is cheaper and easier to work with, but also because the electronic components needed to connect copper to computers are cheaper than their fiber-oriented counterparts.
Copper's new life, industry observers said, does not preclude a large role for fiber optics, which is still technically superior and will continue to be used everywhere except in the "final link" to each desk top.
But that final link is the heart of commercial networking. Forrester Research Inc. of Cambridge, Mass., predicts that copper-based desktop connections in the United States will increase 67 percent by 1996, to 7.3 million. During the same time, it predicted, fiber connections will grow only from 120,000 to 146,000.
Faster networks are needed because computer terminals are being asked to do more work.
For example, transmitting a medium-sized, modest-quality live video signal over a network to a terminal requires speeds of 8 million bits a second.
The multimedia work stations that most people presume will sit on desk tops in a few years could have many such images on their screens and would quickly choke on slower networks.
It's not only in the world of local area networks that copper wire is shedding its old no-can-do reputation. Modems, which transmit computer data over the regular telephone system, are also speeding up.
This expansion of copper is happening now because, in one sense, networking got off on the wrong foot. Its pioneers, like the technicians at Xerox's Palo Alto (Calif.) Research Center, assumed that they were designing for small groups of engineers, where issues of cost were not so important.
So rather than working with existing phone wires in developing the 10 million bits per second Ethernet, one of the first networking systems, Xerox engineers chose bulky, expensive coaxial cable, because it had many technical advantages. The conventional wisdom of the time also assumed that copper was a technical dead-end.
The subsequent effort to run Ethernet and other networks over regular phone wire was led by people who realized that with millions of office desk tops "copper ready," a fortune awaited the company able to sell networking connectors for them. (The cable that runs to most desk tops usually contains two or more pairs of wires. Since only one pair is needed for the phone, the other can be used for computer networking.)
Synoptics Communications Inc. of Santa Clara, Calif., has become a fast-growing $250-million-a-year company by pioneering the installation of Ethernet on office twisted pair copper. The company also sells copper-based connection devices for another popular networking system known as token ring. Its success in both markets has attracted an entourage of competitors.
The same marketplace dynamics are expected to occur now that copper-based networking is speeding up from the 10 million bits per second of Ethernet to a new networking standard that is 10 times faster. This new system is named FDDI, or "Fiber Distributed Data Interface," because it had previously been assumed to require fiber optics to work properly.