Wireless Communications

Wi-Fi may eventually give way to another radio technology known as ultrawideband (UWB), according to some experts. Unlike Wi-Fi, UWB does not use a single radio frequency but sends its radio signals in short pulses across the entire radio spectrum. This technology reduces interference and enables UWB to send larger amounts of data than Wi-Fi. UWB is expected to be used to connect all types of electronic equipment within a home without the use of wires. For example, stereo speakers could be connected to a high-definition television set, and the television could receive signals from a DVD player, and the DVD player could be connected to a personal computer, and all these connections could be done wirelessly.

A single standard for UWB technology was approved in March 2005 by the Federal Communications Commission (FCC). The single standard was expected to end a standoff between various industry groups and lead to faster implementation of UWB technology. Devices using UWB technology could reach the marketplace by 2006, according to some predictions.

The idea of wireless radio communications arose in the mid-1800s from the theories of two English physicists, Michael Faraday and James Clerk Maxwell. In 1888 German physicist Heinrich Hertz applied these theories to construct a spark-gap transmitter, a device that generated radio waves from an electric spark. In 1895 Italian electrical engineer Guglielmo Marconi extended the range of such transmissions and adapted the technology to send and receive wireless telegraph signals. In 1901 Marconi built the first transoceanic telegraph transmitter, which had a 3,400 km (2,100 mi) link from Poldhu, Cornwall, England, to St. John’s, Newfoundland.

Developments in vacuum tube technology in the early 1900s by English physicist and engineer Sir John Ambrose Fleming and American inventor Lee De Forest made it possible to modulate and amplify wireless signals to send voice transmissions. The range and clarity of voice transmissions increased as advancements in technology were made, and in 1915 the American Telephone & Telegraph Company transmitted a voice message by radio between the United States and France. By the 1930s small two-way radio transmitters were in common use among law enforcement and civil emergency authorities. Improvements in technology have made two-way communications systems smaller and lighter, with extended range and capabilities. See also Radio: History; Telecommunications: History; Telegraph.