Sirius, XM claim UWB Report and Order flawed

Sirius and XM Satellite Radio filed a joint petition with the FCC for partial reconsideration (6/17), claiming its Ultrawideband (UWB) First Report and Order rulemaking (released 4/22/02), adopted rules which will "cause harmful interference to satellite radio receivers from UWB communications and surveillance devices." This is not the first time the satellite broadcasters have asked for the Commission's help. They've also claimed new generations of high-efficiency public lighting systems cause massive interference.

UWB is a quickly evolving transmission technology that can replace communications wiring in everything from planes to homes; and deliver hundreds of megabits per second data rates over LANs and WANs. UWB is currently used mostly in communications and radar applications for the military (see-though-walls and ground penetrating capabilities) and auto industry (collision avoidance systems). Ultrawideband, from its name, uses very short and fast data "pulses" over a spread spectrum of frequencies. UWB systems are particularly well suited for high-speed, mobile wireless applications.

Sirius and XM went on to say in adopting the UWB rules, the Commission has "failed to meet the standards of the Administrative Procedure Act because it relied on assumptions contradicted by or unsupported by the record, failed to provide reasoned explanation for its decisions, and adopted rules contrary to existing Part 15 rules by shifting the burden of interference mitigation to users of licensed services and by not adhering to its definition of harmful interference."

The satellite broadcasters are asking that the R&O be reconsidered in lieu of improperly adopted emission limits into the SDARS band. They ask that the Commission adopts for interference into the SDARS frequency band a previously submitted emission limit of 8.6 microvolts per meter @ three meters.

A leading UWB developer, Multispectral Solutions of Germantown, MD (RBR 5/15/00, p.7), actually filed with XM and Sirius in total agreement. "The issue with the S-DARS service is the same issue that the GPS folks have-they're dealing with very, very weak signals and as a consequence, any amount of interference that falls into the band can cause a problem," Explains Dr. Robert Fontana (pictured), Multispectral's President. "Particularly when you're dealing with the types of systems that people want to put in cars for UWB, sending high-speed data form the front to the back for DVDs, audio transmission etc. The problem is that when you start operating in these bands that have been assigned to these other players [2.3 GHz], the potential for interference occurs."

He adds, "We had signed a submission along with XM Radio and Sirius Satellite backing up their claims that they need 8.6 microvolts/meter sensitivity or lower for the interference, in order to not have problems with their systems. And we agree with that assessment. They have very valid points. I think they've been poo-pooed by the FCC a bit and that's what, I think, led to this filing. Unfortunately, the FCC has gotten to the point where they really are not technically capable of addressing some of the more sophisticated problems that are erupting over interference. They just don't have the staff. There are 957 submissions at the FCC on UWB and some of them are half an inch thick. Having worked in this field for over 18 years now, I know that you can easily build something that can jam [signals]. And the way to prevent that from happening, particularly on the commercial side, is to move up in frequency-stay above 3.1 GHz [right now the FCC allows some UWB applications to operate down as low as 1.99 GHz]. This is where everyone wants us to operate-the NTIA, the Department of Defense-and all these problems disappear. You no longer have problems with SDARS, GPS, PCS cellular."

Fontana says, in fact, that many of the products he's tested and built with UWB applications on can operate successfully even above 6 GHz: "There's a coalition of companies that had asked the FCC to keep UWB emissions above 6 GHz. And so we looked at the opportunity of doing it up there and sure enough, things worked just fine. You can build see through the walls sensors, radar systems, communications systems."