The antenna itself does not move, but the antenna elements create a coverage pattern that changes as each packet of information is delivered to the antenna, Belanger said. This allows the switch to send and receive data across 100-degree swath up to 250 or 300 meters depending on line-of-sight restrictions, he said.
The range of WLAN devices built using the 802.11 standards vary from about 15 meters for 802.11a devices to about 30 meters feet for 802.11b or 802.11g devices. These range numbers can vary quite a bit, however, based on the types of building materials used in a home, and the amount of interference from other devices.
Each switch can support about 100 clients, Belanger said. Florida State University in Tallahassee purchased an outdoor switch, which normally costs US$13,000, and installed it in Doak Campbell Stadium to cover the entire stadium, including coach Bobby Bowden's offices underneath the grandstand, he said.
American University in Washington, D.C., recently purchased two outdoor switches from Vivato in order to cover some external spots that couldn't be reached by the university's extensive indoor WLAN setup, said Carl Whitman, executive director of e-operations for the university.
American is trying to get students to move to cell phones and VOIP (voice over Internet Protocol) technology so the university can stop maintaining a traditional phone network, Whitman said. It has wired about 40 buildings on campus for both 802.11b and GSM/GPRS (Global System for Mobile Communications/General Packet Radio Services) networks. The original plan had been to cover outside areas with spillover from the inside networks, but coverage was added for those outside areas to ensure students and faculty could have a seamless connection, he said.
Bandspeed Inc. of Austin, Texas, also sells WLAN access points with smart antenna technology. The company's Gypsy line of switches divides the coverage areas into six unique segments in which up to two radiating elements can be placed, said Blaine Kohl, Bandspeed vice president of marketing.
Because the radiating elements have to focus on only a 60-degree area, the switches can send signals across a long distance, as much as 500 meters, Kohl said. The switch can also host different 802.11 networks, depending on bandwidth needs, she said.
While the antenna is pretty smart, the real intelligence lies in the software Bandspeed has developed to run the switch, Kohl said. Over time, the company wants to move that intelligence into silicon, which would allow it to reduce the cost and complexity of both the antenna and the software, she said.
A semiconductor company in Stamford is working on those chips. Motia is developing a chip that combines signals from different antenna elements and optimizes the signal, said Jack Winters, chief scientist at Motia.