Here, There, WiFi Anywhere

Wireless Web's Spread Is Crossing Our Signals

Peter Kastner moved from the suburbs to an apartment in Boston last summer while his new home was under construction. As soon as he got set up in the temporary digs, Kastner -- chief technology analyst at the research firm Aberdeen Group -- set up his WiFi home network to enjoy some wireless Web surfing.

Everything worked fine, but in a few weeks he found that the airwaves started getting crowded.

"Around about Labor Day, when all the college students moved back to Boston, all of these [wireless] access points showed up around me," he said. Soon, his laptop started getting dizzy from all the conflicting networks and began dropping connections.

Kastner did a little research into the matter and now worries that WiFi technology will be undercut by its own success.

"The end of the WiFi world as we know it is imminent," he later wrote in a report, arguing that the boom of WiFi hardware sales compared with the available airspace in urban areas will lead this year to a wireless Internet traffic jam that in some places could be worse than the Beltway on the Friday of Memorial Day weekend.

Now that WiFi access points can cost under $100, the technology has jumped quickly from esoteric to everyday. And as more consumers learn the convenience of untethered Internet access, they're also learning what things can stop WiFi from working.

Traffic jams are at the top of that list: When multiple WiFi access points, the hubs of individual wireless networks, sit near each other, WiFi receivers can see senseless noise instead of a clear data stream. This is what happened at the CeBIT computer trade show in Germany last year, where a maze of overlapping WiFi networks stopped many laptops from getting online.

MobileAccess Networks, a Vienna-based firm that installs cellular and WiFi networks inside office areas, regularly runs into this issue. The company uses software originally developed by WiFi enthusiasts to sniff out open wireless connections -- not to find free Internet access, but to know what WiFi channels to avoid when setting up wireless networks in clients' offices.

The treatment for WiFi interference should be familiar to anybody who has wrestled with an old analog cordless phone: Change the channel. The WiFi standard most people use, called 802.11b in technical jargon, allows for 11 different frequencies, clustered around the 2.4 GHz band.

WiFi experts, however, generally recommend choosing from only three of these channels -- 1, 6 and 11 -- to ensure there's enough room between to avoid interference.