Prepared for the agency by market research group Mason Communications, the report suggests UWB could interfere with emerging third-generation UMTS networks across Europe.

Acknowledging that UWB's impact on UMTS would be limited to short-range effects, and that any likley effects will be minor over wide areas, the report nevertheless maintained that UWB transceivers could swamp a 3G handset with noise, which could lead to dropped calls.

"There are discernible effects, with UWB degrading UMTS when the UWB devices are within a few meters of the UMTS handset," the report concluded.

The researchers said the potential for dropped calls will depend on several factors, including handset distance from a basestation and, crucially, on the nature of the applications being run on the 3G handset and the UWB device.

The report is based on modeling exercises, and Mason Communications acknowledged limitations "compared to the power of results from real world tests."

The study recommends establishing a series of such tests "whereby the effects of UWB devices are measured in UMTS handsets as a function of UWB power, pulse repetition frequency and separation distance." Such trials should be conducted both in the laboratory and in "realistic settings such as living rooms of houses, offices and outdoors."

The researchers said additional testing is necessary because "the effects of UWB multipath are not well understood with only a limited range of measurements and modeling being done to date."

While the U.S. Federal Communications Commission has authorized limited UWB deployment, the technology is currently illegal in Europe, even though several European based companies such as ST Microelectronics are developing the technology.