Google says it has been working with Facebook to resolve concerns related to its waiver request for Project Soli.
Google requested a waiver in March to enable equipment certification, marketing and operation of the Project Soli motion-control technology, noting ETSI standards allow for operation of generic short-range devices (SRDs) within the 60 GHz band at power levels higher than those permitted under the FCC’s rules.
Facebook registered its concerns (PDF), saying further study of potential interference caused by Soli devices was necessary before moving forward on the waiver request. Facebook is working on delivering high-speed internet connectivity through its Terragraph technology that uses the 60 GHz band.
Facebook asserted that it’s probable a Soli radar, embedded in a watch or smartphone, could be in close proximity—possibly within centimeters—of an SRD transmitter or receiver embedded in a laptop or other similar handheld device in the 60 GHz band. Such a small radius between Soli's radar and another co-channel SRD device could lead to harmful interference resulting in degraded performance and latency, according to Facebook.
Google last week (PDF) visited the FCC and reiterated how granting its petition to allow Project Soli to operate at higher power levels would serve the commission’s efforts to harmonize its regulations and keep pace with global standards. Google also explained what minimum levels are necessary to allow current Soli technology to function in generally the same way for users in the U.S. and Europe: peak EIRP of +13 dBm/MHz and maximum transmit duty cycle of 18% in any 11 ms interval.
Google told the commission how it continues to collaborate with interested parties about its waiver request. In particular, Google has been working with Facebook “to learn more about the assumptions and measurement parameters underlying its analysis” that it filed on July 20 (PDF).
Facebook proposed a set of conditions for Google to meet before its waiver request gets approved, including a demonstration that Soli radars can coexist and share spectrum fairly with 802.11ad/ay SRDs.
Google explained in its waiver request (PDF) that Project Soli emerged from the work of its Advanced Technology and Projects group. Using a sensor that operates between 57 and 64 GHz, Soli devices capture motion in a three-dimensional space using a radar beam. Data collected by the Soli sensor can then be used to enable touchless control of device functions or features. For instance, sensor data allow devices to be more "aware" of their surroundings to permit them to enter sleep mode due to inactivity, or to allow users to trigger simple actions without having to touch the device.
With higher signal powers, the radar signal could also penetrate fabrics, enabling controls that could work in a pocket or a backpack, and there would be more flexibility to integrate the Project Soli sensors in devices that partially occlude the antennas due to mechanical constraints, according to Google.