WASHINGTON-The Federal Communications Commission is investigating reports that Wi-Fi devices were responsible for disrupting radar at Eglin Air Force Base in Florida, a probe that comes amid the Bush administration’s failure to date to craft a solution that would enable wireless Internet operations in the 5 GHz band without causing interference to military radar.
“We’re not there yet. We’re getting there,” said Clyde Ensslin, a spokesman for the National Telecommunications and Information Administration, a unit of the Commerce Department.
Ensslin made no mention of a possible breakthrough that NTIA and other governmental agencies are now pushing on the 5 GHz front. Most commercial Wi-Fi services operate at bands other than 5 GHz, but getting commercial services at 5 GHz is important as Wi-Fi growth continues and those existing bands get more populated.
At a meeting two weeks ago, Wi-Fi industry representatives offered a new approach to resolve the 5 GHz dilemma. However, government officials, according to sources, were not altogether satisfied. NTIA and others made changes to industry’s proposal and offered a modified solution.
Industry engineers with security clearance plan to conduct testing during the next month to determine whether government’s latest plan solves the problem.
Why security clearance? Because DoD cannot disclose characteristics of military radar systems. It’s a tricky situation, both for testing and for equipment design. Wi-Fi devices with dynamic frequency selection supposedly will be able to detect-and thus avoid-military radar through complex mathematical calculations.
NTIA, defense and industry officials have been working on 5 GHz interference issues for more than two years. They thought they had the problem licked in early 2003, after agreeing that a dynamic frequency selection, or DFS, capability would be built into Wi-Fi gear. The United States sent a major delegation to an international telecom conference in Geneva that year believing the 5 GHz interference issue was under control.
The DFS feature, as U.S. officials believed and told others, would monitor the airwaves to avoid military radar signals. However, during the past 24 months or so, government and high-tech officials came to discover a huge imperfection. DFS could identify and dodge military radar, but it could not distinguish radar from other sources of radio frequency energy-including Wi-Fi. That meant Wi-Fi units with DFS programming would unnecessarily forgo otherwise usable radio channels, making for inefficient use of the spectrum.
Back to the drawing board.
“We are struggling with it,” said Edmond Thomas, chief engineer at the Federal Communications Commission. Still, Thomas said he believes a solution is within reach.
Thomas downplayed the possibility that a single Wi-Fi user caused interference to radar at Eglin Air Force Base, where sophisticated radio-based munitions are tested.
Thomas said the potential for Wi-Fi interference to military radar comes from the cumulative operation of high-speed wireless Internet operations. Indeed, the FCC-with the Pentagon’s blessing-last month said Wi-Fi gadgets without DFS could be sold and imported until January 2006. The rule clarification reflects the FCC’s and DoD’s acknowledgment that introducing a year’s worth of new Wi-Fi devices (without DFS) into the market does not pose a threat to military radar.
The future is trickier though, particularly for Wi-Fi vendors. Until DFS is refined to the satisfaction of government and industry, would-be 5 GHz Wi-Fi suppliers appear left in relative limbo.
Thomas said it is possible radar interference at Eglin Air Force Base was caused by an individual who increased Wi-Fi power beyond legal limits.
Lois Walsh, a spokeswoman at Eglin Air Force Base, said the military’s investigation appeared to show normal Wi-Fi use as the culprit. “The issue seems to be the 5 GHz band,” said Walsh.
Others, like Thomas, said they too are optimistic about finding a fix for the 5 GHz conundrum. Still, they do not deny a tangible solution remains elusive. And stakeholders have ceased predicting a timetable for success.
“Nobody said this was going to be easy,” said Badri Younes, director of spectrum management at DoD.
Younes said there is good cooperation among the stakeholders. “We have not lost hope. We remain encouraged,” he said.
At the same time, Younes said no solution should come at the cost of diminishing military radar.
Scott Harris, a lawyer for the Wi-Fi Alliance, said the government’s latest approach to the 5 GHz quandary may well do the trick. “It’s a potential breakthrough … I came away [from the most recent meeting] feeling confident about finding a solution,” he said.
The stakes are high all the way around.
For the growing Wi-Fi sector, a cloud will hang over an additional 255 megahertz at 5 GHz-made available by the FCC in 2003-until the military radar interference matter is put to bed. It is serious business for Intel Corp., Cisco Systems Inc. and other firms that have big stakes in the future of wireless Internet.
Commercial deployment of Wi-Fi systems-including those at 5 GHz-is an important component of President Bush’s goal to make affordable broadband available to all Americans by 2007.
Getting the sticky 5 GHz problem resolved soon is also important for NTIA chief Michael Gallagher, a key player in several wireless policy achievements and possibly a candidate to succeed outgoing FCC Chairman Michael Powell.
