June 2001

The Telecom System

How that e-mail gets to your desk.

By Technology Review

If Samuel Morse were alive today, he'd be proud. the first U.S. telegraph line, completed in 1844, helped pave the way for America's modern telecommunications network. In the 1850s, telegraph wires crisscrossed the country, connecting hundreds of railroad stations, and by the turn of the century they had made their way to Europe via transatlantic cables. The invention of the telephone, and, later, satellites and computers, expanded telecommunications into virtually every geographical nook and cranny and transformed communicating via Morse's dots and dashes into the exchange of ideas using words and images.

The network today is a mesh of wired and wireless connections, with mobile phones, telephones, television, cable, fax machines, e-mail and the Web sharing much of the same infrastructure. Large transmission lines, known as backbones, link local and regional networks the way interstate highways connect towns and cities. An assortment of sophisticated computer hardware, including hubs, bridges, gateways, repeaters and routers, shuttles information to its destination-around the building or across the world-along the most efficient path. The pathways can be any combination of wired or wireless technology, including copper lines, glass fiber, radio and satellite.

Like any kind of infrastructure that' inundated with traffic, the telecom system has its inadequacies. Decades-old copper wire chokes on floods of information, especially in the areas closest to home-the so-called last mile. At the same time, people want the networks to give them access to more sophisticated forms of communication, including video on demand, videoconferencing and online game playing.

The immediate fix appears to be more or better fiber-optic cable to accommodate broader bandwidths at faster speeds. Better use of wireless technology, including radio, fixed wireless and even laser beams is also attracting attention. For the longer term, advances in a hot branch of physics known as photonics could dramatically expand a fiber's transmission capabilities (see "The Next Generation of Optical Fibers," TR May 2001). But of course, those solutions will last only so long before people crave more data, faster.