LIGHTning Strikes cause Bandwidth Glut
by Wayne Caswell, IBM Microelectronics, December 10, 1998
Comdex is the computer industry's premier trade show and love-fest, but this year the computers themselves seemed absent. Compaq, Dell, IBM and other industry leaders decided not to exhibit. In their place was an industry buzz around information appliances, home networks, and their connections to information services. A major driver behind this shifting emphasis, although not evident at the show, was the availability of communications bandwidth.
In 1996, Qwest Communications exploited its access rights to railroad lines and starting installing optical fibers alongside the tracks, with cars designed to ride the rails, dig trenches, and lay fiber inside of coduits at the rate of a mile per day. One conduit was filled with 96 strands of optical cable while a second conduit remains empty for additional cables if needed. Chasing Quest and installing similar fiber networks are IXC Communications, Level 3 Communications, and Williams Communications. Collectively, these four will have deployed over 60,000 miles of fiber (AT&T has another 41,000 miles). And many more companies are also installing fiber in short- and long-haul networks. Alcatel and Fujitsu, for example, are starting construction of an 18,000 mile under-sea fiber cable loop with over 400 fibers from Australia and New Zealand to the U.S. and then back via Hawaii and Fiji. In short, the world is getting "wired" rapidly -- at a LIGHTning rate.
Optical engineers are developing fancy prisms that split infrared light into more and more distinguishable colors using a technology called wavelength division multiplexing (WDM). WDM made its debut in 1995 with just eight colors but is already available with more than 40. And Lucent demonstrated 100 colors on a single fiber last spring. At the same time, they jacked up the data rate of laser transceivers four times to 10 Gbps. Throughput from a single strand of glass was an amazing 1 Tbps, more than enough to satisfy all of North America's current needs. Bell Labs expects this technology will be on the market by 2000 with the ability to deliver theater quality movies (better than HDTV) in the blink of an eye. And one terabit per fiber is just the beginning. With IBM's SiGe technology, future laser transceivers will pulse at 40 Gbps, and WDM enhancements will add even more color spectrum. Soon, Bell Labs engineers expect to push 200 terabits per second down a single fiber. That's enough to send the entire Library of Congress every second. It's mind-boggling.
Bandwidth becomes Essentially Unlimited and Practically Free
Multiply the implications of faster laser transceivers times that of more colors and more fiber -- if your calculator can handle that many significant digits. So much additional capacity is coming on-line between now and 2002 that analysts wonder how the world will use it all. So do I. Most businesses haven't begun to think about the impact this will have on their operations.
Where Does Fiber End?
It's getting closer to the building and information access appliances -- fiber to the curb, to the home and (eventually) inside. As the last mile gets shorter, the capacity of the legacy wire increases. That's the vision of telecom suppliers Nortel and Alcatel, and I share that vision. So what happens when fiber reaches the home? Its termination requires power... and a gateway. (If you know me, you must have seen this punch line coming.) And it helps enable e-Commerce. This prospect will drive even more technology investments in home networks.
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