Interference issues extend ultrawideband debate

Interference issues extend ultrawideband debate
WASHINGTON — The Federal Communications Commission is readying guidelines for ultrawideband transmission systems, but officials are downplaying the chances for a final decision to be made at a commission meeting next Wednesday (Dec. 12).

Several government agencies have called for a delay on final regulations to review concerns about interference. The Department of Defense and other agencies are concerned particularly about possible interference with the Global Positioning System (GPS) and other systems.

The FCC's agenda for its Dec. 12 meeting includes consideration of pending rule changes to accommodate ultrawideband devices. But agency officials stressed that the issue may only be discussed and that a final decision could be months away. "It's up on the agenda for discussion [and] there could or could not be a vote," an FCC spokesman said.

The Pentagon is reportedly seeking a delay of at least 60 days on FCC action until interference issues can be resolved. The Defense Department, the Federal Aviation Administration and several other agencies, all of which are represented in the policy debate by the Commerce Department's National Telecommunications and Information Administration (NTIA), want closer scrutiny of the ultrawideband transmission scheme to determine whether it will interfere with existing services.

The interference concerns stem from the transmission of millions of pulses per second over an extremely wide 3-GHz bandwidth. The technique is designed to dilute signal energy across existing FCC frequency assignments so that they are well below detection thresholds for narrowband receivers.

Government agencies reportedly want assurances that ultrawideband transmissions will be forbidden below 3 GHz

Companies anxiously awaiting an FCC decision on ultrawideband rules argue that new wireless networking devices based on the technology could coexist with current narrowband services. Intel Corp., which is evaluating ultrawideband technology for use in future wireless networks, argued in recent comments to the FCC that ultrawideband "should share the useable spectrum without causing 'harmful' interference to these narrowband systems."

Intel further argued that "interference potential is reduced when based upon more realistic channel propagation environments, operational scenarios and coexistence criteria."

The FCC has granted waivers to a handful of companies to operate ultrawideband equipment as it continues to investigate interference claims. Representative's of the FCC's Office of Engineering and Technology are expected to discuss their findings at the Wednesday meeting, but the head of the FCC's task force has said the agency would still have to coordinate with NTIA.