Why WiFi?

Somewhere over the rainbow, Wi-Fi may lead to a pot of gold. At the moment, though, it leads to debate over the future of the wireless communications industry.

Wi-Fi illustrates the need to set national priorities for wireless communications, and how compromises may actually mean no resolution.

This is why we have something of a series about Wi-Fi running in MRT. In January, we took a look at the security problems of Wi-Fi as a technical and practical matter.

This month, we have a look at the legal complications by Jason Kerben of the law firm of Shulman, Rogers, Gandal, Pordy & Ecker. As the International Telecommunications Union’s World Radio Conference — where standards are decided — approaches in June, Wi-Fi will be literally as well as figuratively on our radar screens.

Tech companies and the Department of Defense said January 31 that they addressed military concerns about radar interference from Wi-Fi. The resolution establishes a new radio frequency threshold for products using unlicensed radio spectrum — mostly Wi-Fi products. Not only is Wi-Fi hyped as the technology to revive the communications industry, it is supposed to be a component in all types of consumer devices, including PCs, DVD players and every hand-held device imagined. The technology is supposed to have applications in the household and in the public safety sector.

Government agencies other than the military have been working to promote the use of wireless networking. The Federal Communications Commission even floated the idea of opening up unlicensed parts of the broadcast television spectrum for use by Wi-Fi devices. The move would help the FCC push TV broadcasters toward digital television to free analog TV spectrum for uses such as wireless home networking and freeing spectrum for first-responders.

But Wi-Fi gear in 5.15-5.35-GHz portions of the 5-GHz band might impede the ability of military radar to detect stealth aircraft or missiles. Perhaps the more frightening problem, though, is the Defense Department fear that interference in the 5-GHz band would impair its ability to “pick out smaller and less reflective targets out of background clutter” in its radar transmissions. Flooding an area with Wi-Fi signals might offer enough cover, for example, to move a small boat with a dirty bomb through Chesapeake Bay into the nation’s capitol without any radar detection.

Since the band is already open for use in the United States, Japan and Europe and more than 50 manufacturers make products that operate in these bands, it might be a bit late to address these concerns in any meaningful way, however. And given all the hype of a Wi-Fi led communications revival, few politicians will make the stand that Homeland Security overrides the concerns of their biggest telco donors.

Additional spectrum in the 5GHz band is requested by Sens. Barbara Boxer, D-Calif., and George Allen, R-Va., under the proposed Jumpstart Broadband Act, which they say will bring powerful, inexpensive, long-range wireless broadband access to the masses, especially in rural areas where service providers will not find enough subscribers to cover costs. Boxer immediately said the compromise removes an obstacle to the acceptance of the bill and encourages the use of the 5GHz band in the United States and internationally.

Yet this agreement needs to be tested in the real world, and no one can predict what that means. The compromise between the Pentagon and industry reps means radar will be protected through dynamic frequency selection that closes other transmissions when a radar signal is detected. By mimicking the signal of the military radar, though, it might be possible to launch denial of services attacks against industries using Wi-Fi.

On the other hand, dynamic frequency selection offers no guarantees that terrorists are unable to exploit it.

So trading national security against the security of the users’ systems might mean no security at all for either. Only after technologies such as Wi-Fi are ubiquitously deployed do we know for sure what the implications are. So the debate goes round and round.