Ultra-wideband sensor arguably does not use enough bandwidth to qualify as ultra-wideband.
Ultra-wideband (UWB) radio works by spreading a very low power signal across a very wide range of frequencies. The FCC approved ultra-wideband in 2002, following what it understatedly called “an unusually controversial proceeding.” Almost every category of spectrum user, including parts of the federal government, told the FCC that authorizing UWB devices would cause intolerable interference. In okaying UWB despite those objections, the FCC cautiously limited the technology to eight specific applications and imposed the strictest emissions limits anywhere in its rulebook. One of those limits – at 3 picowatts, or 3 trillionths of a watt – is so low that, at the time of its adoption, only a few labs in world could measure it reliably.
Perhaps foreseeing that the rules would soon go out of date, the 2002 order promised a further rulemaking “within the next six to twelve months” to explore more flexible standards and perhaps allow additional types of UWB operations and technology.
That never happened. Despite subsequent reconsideration orders in 2003, 2004, and 2010, the basic rules remain unchanged to this day. But the engineers have stayed busy, creating new UWB products that, in some cases, don’t fit within the old 2002 rules. The natural result has been a series of requests to waive those rules.
The latest such is for a heart-rate monitor made by Sensifree, Inc. The device uses UWB as a kind of nano-powered radar to look inside the body for changing artery diameters, which in turn signal heartbeats. It fails to comply with a rule that requires a UWB transmitter to occupy a certain minimum amount of spectrum at every instant. Sensifree argues persuasively that the rule is too restrictive and should be more flexibly interpreted. In the meantime, it asks for a waiver so as to get its product on the market.
Waivers are sometimes necessary, but regulating an entire class of product by successive waivers can lead to industry-wide confusion and uncertainty. We think the FCC should promptly grant Sensifree’s waiver, and should also fulfill its promise from 13 years ago to fix the rules so as to make such waivers unnecessary.
(FHH represents several participants in the UWB industry, but not Sensifree.)