Facebook is raising some red flags over Google’s request to operate its Project Soli radars at higher power levels in the 60 GHz band, asking the FCC to further study the matter.
Google in March filed a waiver request for its Project Soli motion-sensing technology, saying it needs higher signal powers to allow the sensors to recognize gestures when a user’s hand is farther from a device. Google said the FCC’s current power levels are too restrictive and it wants to operate at power levels consistent with draft European Telecommunications Standards Institute standards. The FCC asked for public comment on Google’s request.
Facebook said Google’s waiver request and supporting simulation study don’t address the potential impact of Soli radars operating at the requested power levels on point-to-point communications between short-range devices (SRDs) in the 60 GHz band. Facebook has been working on technology to operate at 60 GHz and already has built a sizable 60 GHz network in San Jose, California.
Facebook said one scenario the commission should examine involves how a Soli radar, embedded in a watch or smartphone, would act in close proximity—possibly within centimeters—of an SRD transmitter or receiver embedded in a laptop or other handheld device. Such close proximity could lead to harmful interference, resulting in degraded performance and latency, and given the high likelihood that Soli radars and SRD devices would be located very close together, statistical modeling of interference is unlikely to reveal the true impact of Soli radars on SRD communications, according to Facebook.
In addition, “due to the proprietary aspects of Project Soli, the behavior of its coexistence mechanisms is not as well known and merits further empirical testing to substantiate the analytical model,” wrote Facebook's Alan Norman in an ex parte filing (PDF). Norman reiterated that Facebook is open to working collaboratively with all stakeholders to study these concerns.
Google has explained that Project Soli devices capture motion in a three-dimensional space using a radar beam. Data collected by the Soli sensors can then be used to enable touchless control of device functions or features.
For instance, sensor data allows devices to be more "aware" of their surroundings to allow them to enter sleep mode due to inactivity, or to allow users to trigger simple actions without having to touch the device. Plus, at higher signal powers, the radar signal could penetrate fabrics, enabling controls that could work in a pocket or a backpack.