Most enterprises that deploy wireless LANS (WLAN) estimate their coverage area in terms of hundreds of feet.

Hans Werner-Braun, a researcher at the San Diego Supercomputer Center and principal investigator for the San Diego County High Performance Wireless Research and Education Network (HPWREN) plans and develops wireless circuits that routinely span miles, including HPWREN's current distance-record holder, a 72-mile-hop installed last month from San Diego to San Clemente Island.

Although standard 802.11b WLAN gear operating in the unlicensed 2.4-GHz frequency serves as the baseline hardware for the new network, Werner-Braun said that HPWREN, backed by grants from the National Science Foundation, uses far-from-routine hardware configurations to serve rural San Diego County.

The link to San Clemente Island -- used to carry data from a seismograph, data logger and Global Positioning System receiver -- runs with the maximum 1-watt power output allowed by the Federal Communications Commission for 2.4-GHz equipment, Werner-Braun said. At both ends of the link, HPWREN technicians installed high-gain, 2-foot parabolic antennas to provide an additional boost to the signal.