Computerworld December 31, 2002
Wi-Fi spectrum battle pits antiterrorism efforts against commercial growth
By Bob Brewin
The U.S. Defense Department has played the antiterrorist and rogue state card in its attempts to restrict the use of wireless LANs, including those already operating in the lower portion of the 5-GHz band, according to engineers and analysts.
The Pentagon is concerned about the ability of military radar to detect terrorist vehicles as well as stealth aircraft or missiles operated by foreign powers in the face of WLAN interference, the analysts added.
Portions of the 5-GHz band have already been assigned for unlicensed WLAN use in the U.S., Europe and Japan with more than 50 OEMs making products that operate in these bands.
At a meeting Nov. 11 in Geneva of the the International Telecommunications Union (ITU), the United Nations body that oversees spectrum allocations worldwide, the U.S. said it wants the 5-GHz band protected for the use of radars that can "pick out smaller and less reflective targets out of background clutter," and therefore cannot afford any interference from WLANs, according to the official U.S. draft position paper submitted to the ITU and obtained by Computerworld.
John Pike, a defense analyst at GlobalSecurity.org in Washington, said the references to "small targets and background clutter" pertain to small boats or planes that terrorists could use to attack U.S. forces. He added that the Defense Department is also concerned about the ability of its radars to pick up "stealth" aircraft. Pike said China is capable of developing stealth technology of the kind used in the U.S. B2 bomber, which allows the aircraft to hide its presence from most conventional radars.
Will Strauss, a former radar engineer and analyst at Forward Concepts Co. in Tempe, Ariz., agreed with Pike, saying that it would be a "small task" for a country such as China to develop its own stealth aircraft.
The U.S. wants to protect these radars by sharply restricting the use of Wi-Fi gear in portions of the 5-GHz band (5.150-5.350) already opened up for use in the U.S., Japan and Europe.
The U.S. position paper, submitted to the ITU at its November meeting in preparation for the ITU's World Radio Conference (WRC) in June, which will make the spectrum decisions, endorses a global allocation for WLANs in the 5.150-5.350 band as long as radars are protected by a technique know as Dynamic Frequency Selection (DFS), which shuts down WLAN transmissions when a radar signal is detected.
Bill Calder, a spokesman for Intel Corp., which has bold plans to incorporate WLAN chips into its next-generation mobile computing technology, said that the industry views the Pentagon's DFS restrictions, which he did not specify, as too conservative. He added the company is working to reach a compromise with the Pentagon before the June WRC meeting.
"We do not want to see that low band [5.150-5.350] unduly restricted. This is a big issue for Intel as we move toward a wireless world," where spectrum is an essential raw material, Calder said.
Rich Redelfs, president and CEO of Atheros Communications Inc., a Sunnyvale, Calif., developer of WLAN 5-GHz chip sets, views the Pentagon's position on restricting WLANs as akin "to trying to put the genie back in the bottle." Atheros already has more than 50 OEM customers for its 5-GHz chip sets, Redelfs said, making it difficult to change the rules.
Craig Mathias, an analyst at Farpoint Group in Ashland, Mass., agreed, saying that while national security is a key concern today, it "would take an extraordinary set of circumstances" for the Defense Department position to prevail, considering the growth potential of WLANs.
Clyde Ensslin, a spokesman for the National Telecommunications and Information Administration, a division of the Commerce Department, which administers all federal spectrum, said the document represents the positions of all federal agencies including the Pentagon and the Federal Communications Commission, but it is still a draft until the final U.S. position is prepared for the June WRC meeting.
Ensslin added the radar section pertains to both military and commercial radars, such as advanced systems that could be used by commercial pilots to detect small planes. Pentagon spokesmen did not return calls for comment by deadline.
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