Fiber`s bandwidth outpaces users` needs
George Kotelly
Executive Editor
Network designers and planners dealing with voice, video, and data communications insist that more and more bandwidth is continuously needed to satisfy the seemingly insatiable appetite of user-information applications. For example, according to Business Communications Co. (BCC), a Norwalk, CT-based market research firm, sales in 1995 conducted over the World Wide Web totaled $400 million and are projected to zoom to $75 billion in the year 2000, at an average annual growth rate of more than 100%. The number of Web users, claims BBC, is expected to surge from 15 million in 1995 to 40 million in 2000, at an annual rate of 21%.
Indeed, to meet the burgeoning user demand for information during the past several years, transmission rates over fiber-optic networks have had to be steadily increased from kilobits per second, to megabits, and on to gigabits. Moreover, at OFC `96, three post-deadline papers described terabit-per-second optical networks (see Lightwave, April 1996, page 6). The reason: Market studies show that the maximum available transmission rate is doubling every 18 to 24 months to meet increasing user bandwidth needs.
According to renowned technologist Robert W. Lucky, corporate vice president for applied research at Bell Communications Research, in a recent article he wrote for Convergence magazine, there is no end to the need for bandwidth. He claims that users will always need more bandwidth, and given more, will find new uses for it.
Of course, fiber-optic cables provide virtually unlimited bandwidth. But most fiber-cable installations have been installed in trunk and backbone networks. For example, long-distance carrier MCI Corp. is currently deploying 40-Gbit/sec technology on a 275-mile route between Chicago and St. Louis over existing singlemode fiber for such advanced services as interactive multimedia, teleconferencing, and medical imaging.
Says Fred Briggs, MCI`s chief engineering officer, "From the growth of the Internet to developing multimedia applications, MCI is seeing tremendous demand for bandwidth. Working closely with our vendors [Hitachi Telecom and Pirelli], we are using state-of-the-art technologies to expand the capacity of our network to meet the needs of customers today and in the future, in a cost-effective manner."
In the local-access link to users, however, because of alleged high installation costs and because copper wire and coaxial cable are already embedded, fiber has not been routinely connected to homes, businesses, and desktops, despite its inherent high-bandwidth--and other numerous performance--advantages.
To appear as a viable bandwidth-competing medium, the copper infrastructure has been tweaked by diligent designers via an array of communications technologies to boost bandwidth, such as Integrated Services Digital Network, asymmetric digital subscriber line, and cable modem. Some of these technologies have been able to nudge the copper bandwidth to several tens of megabits per second.
However, this upward bump has been plagued with cost, noise, implementation, and delivery problems. And all these efforts have not reached the hundred-megabit level. Even this supposedly high rate would still prove slow, inadequate, and costly in short order. An onslaught of futuristic, bandwidth-hungry multimedia services stand poised on the horizon, waiting for the proper transport and bandwidth opportunities.
The obvious solution to the bandwidth problem is fiber-to-the-user technology directly to the desktop. This technology possesses the capability to both transmit and receive all the advanced communications services available now or expected in the foreseeable future.
Many telephone companies and cable-TV operators assert that fiber-to-the-user is too expensive. On the other hand, numerous industry studies demonstrate that the cost of installing fiber versus copper is virtually equivalent (see Lightwave, December 1996, page 6). Another obstacle, say telephone companies and operators, is that user demand for high bandwidth has not been substantiated by field trials and experiments. However, these trials have proved impractical because of specialized goals.
In the real world, network users are clamoring for yet more bandwidth, as video-based applications are spurring exponential demands for teleconferencing, interactive television, three-dimensional special effects, virtual reality, faster Internet access, and advanced data services.
The solution to skyrocketing bandwidth, says Lucky in his article, is fiber-optic networking technology, with its capability to expand indefinitely. He declares that optical fiber in telecommunications and cable networks serves as an untapped reservoir of capacity.
With this capacity, service providers will unleash a flood of content, and users will quickly absorb all available services. q