FCC, U.S. military in discussions over WLAN spectrum
By Elizabeth Biddlecombe for Total Telecom

19 December 2002

The U.S. Department of Defense (DoD) is pitted against the Wireless LAN industry, reports claim.

The U.S. Department of Defense is pressing for spectrum allocation for wireless LAN services to be constrained on security grounds, the New York Times reported Tuesday.

What wasn't made clear, however, was that the spectrum in question is the 5Ghz band rather than the 2.4Ghz band currently used for Wi-Fi services.

The DoD and the Federal Communications Commission have been developing a formal U.S. position as part of an ongoing effort by the World Radiocommunication Conference to clear the 5Ghz spectrum worldwide for WLAN services.

The DoD is concerned about interference with ten different radar systems such as those that track storms, monitor aircraft or guide missiles and other weapons.

The FCC's Fred Thomas, spectrum coordination branch chief at the Office of Engineering and Technology, told Total Telecom a U.S. position on the 5Ghz band will be developed in time for the WRC meeting in June next year. The FCC is also looking at using the same spectrum for WLAN systems and television broadcasts.

Thomas said the FCC is looking at technologies such as Dynamic Frequency Selection (which avoids interference issues and is already in use in Europe as part of the HyperLAN 2 standard), "as a way to allow both systems to share the band." Press reports suggest that the DoD is not in favor of this
approach though Brian Grimm, communications director for industry trade body, the Wi-Fi Alliance, questioned whether the U.S. military will be happy with any commercial usage in the 5Ghz band whatever mitigating technologies are introduced.

Grimm denied that there are interference issues amongst the burgeoning number of Wi-Fi networks themselves. This is despite the fact that since it is an unlicensed service, an unlimited number of operators could theoretically set up shop in the same area, and that the 2.4Ghz band is also used for microwaves, cordless phones and Bluetooth.

"Even at [Wi-Fi] trade shows, which could be the worst scenario, you don't see a problem," he said. Rather, said Grimm, the Wi Fi industry will be tackling other challenges in the New Year such as keeping up with growth as well as surmounting the technical challenges associated with implementing Wi-Fi in consumer electronics devices.

Senators Barbara Boxer (D-CA) and George Allen (R-VA) announced at the end of November that they plan to introduce a bill in the next Congress to further the aim of universal broadband access by requiring the FCC to allocate a minimum of 255Mhz of contiguous spectrum for unlicensed wireless broadband services as well as make more broadcast spectrum available though without compromising DoD systems.

Although he applauds this proposed legislation, Nigel Ballard, a wireless solutions provider based in Oregon, and board member of Personal Telco, said that the easiest thing to do would be to allow U.S. operators to use all 14 channels available on Wi-Fi gear like their European counterparts, rather than the 11 allowed at present. This would avoid the need to scrap existing hardware, he said, while going "some way to help ease the expected channel congestion issues folk seem to think are on the road ahead."

It is through his involvement with Personal Telco, a Portland, Oregon community Wi-Fi network, that Ballard has encountered the nearest thing to interference between Wi-Fi operators.

Despite having been operational in a central Portland Square for six months, the group's network began experiencing degradation this past August when T-Mobile set up shop on the same frequency channel (channel number 1) in a Starbucks coffee shop on the square. This impacted the performance of both their networks, he recalled.

"It is not a good neighborly policy nor is it good from a technical standpoint," he said. "But they did it for a very good reason. They want to be the first and only person on channel 1," he said, explaining that this way they would be the first Wi-Fi provider to be picked up by a new user in the area when sniffing for available networks.

However once media attention highlighted the story, the weight of public disapprobation meant that the commercial operator soon changed channels.

Copyright Total Telecom 2002