ARRL, IARU Contribute to ITU UWB Interference Studies
December 9, 2005
Many users of the radio spectrum, including broadcasters, have expressed concern that emissions from Ultra Wide Band (UWB) devices could interfere with their communications. UWB devices, by definition, transmit over a wide range of frequencies that are shared with other users. The FCC, in a Report and Order released in 2002, recognized that the benefits of UWB could be diminished if it caused interference to other communications.
In the article ARRL, IARU Contribute to ITU Ultra-Wide Band Studies, the American Radio Relay League, representing Amateur Radio operators in the United States covered the work of ITU-R Task Group 1/8, which worked to characterize UWB emissions by looking at frequency range, pulse characteristics and power levels. Amateur radio operators participating in the study included ARRL chief technology officer Paul Rinaldo (W4RI) and ARRL technical relations specialist Walt Ireland (WB7CSL). Peter Chadwick (G3RZP) represented IARU (International Amateur Radio Union).
Ireland explained, "Having described the characteristics of UWB devices, then the problem was to determine how UWB emissions propagate from the device to a radio system that might be interfered with." The wide frequency range over which UWB operates made that task difficult.
The article notes that the United States was not able to convince the rest of the world to adopt the FCC Report and Order without question. Rinaldo said, "The Europeans in particular came up with their own ideas on UWB systems and potential interference to systems they want to protect. As a radio service, amateurs didn't get everything they desired either, but got the characteristics of our radio systems on record." Walt Ireland added, "The bottom line? UWB is capable of interfering with radio services. If the UWB device and the radio system, including antenna, are in the same room, interference is likely." He noted that interference could be reduced by adding walls or increasing the distance between the UWB device and the receiver.
Task Group 1/8 has now been disbanded after producing four Draft New Recommendations (DNRs) on UWB characteristics, compatibility, framework and measurement. The ARRL article said these reports received approval at the ITU Task Group and Study Group levels and will soon be circulated to individual administrations for their approval.
Any additional work required on the DNRs will be handled by ITU Study Group 1 and Working Groups 1A and 1C.