5/4 FCC TV White Space Comments On Behalf of Public Interest Spectrum Coalition

New America's Open Technology Institute wrote and filed comments with the Federal Communications Commission (Commission) in tandem with the Public Interest Spectrum Coalition urging the Commission to adopt changes to its rules governing the operation of TV White Spaces to facilitate broader use of TVWS spectrum for high-speed broadband in rural, tribal, and other hard-to-serve areas. Public Knowledge, Consumer Reports, Access Humboldt, Next Century Cities, Common Cause, Tribal Digital Village Network, Benton Institute for Broadband and Society, and X-Lab all signed onto the comments as well. A summary of the comments is available below:

The lack of broadband internet access in many rural and tribal communities underscore the urgency of boosting TV White Space technology and deployments to help bridge this gap. These less-densely-populated areas tend to have lower rates of broadband adoption due to the high costs for both backhaul and last mile buildout. TV White Space technology has proven itself as a powerful tool for expanding broadband access in hard-to-serve areas. Because of its superior propagation characteristics, unlicensed TVWS spectrum can serve as the infrastructure to support broadband internet connectivity for unserved and underserved consumers at a relatively low cost to providers.

First, PISC urges the Commission to authorize or require White Space Databases (“WSDBs”) to utilize propagation models that take accurate account of real-world terrain and clutter in the local area where operators request use of TVWS channels. WSDBs currently overprotect TV viewers within standardized and static contours based on an outdated free space propagation model that takes no specific account of basic geographic features (e.g., mountains, dense forests), nor of buildings or other “clutter” that more sophisticated GIS models use. The Commission should authorize use of the Longley-Rice Irregular Terrain Model (ITM) methodology, which the Commission has authorized for automated frequency coordination by geolocation databases in other shared bands (e.g., 6 GHz).

Second, PISC supports the Commission’s proposal to permit fixed WSDs to operate at higher power limits in locations where operators have 6 megahertz of separation from TV stations, at least in areas of the country with lower population densities.

Third, PISC likewise supports the Commission’s proposal to increase the maximum height above average terrain (“HAAT”) to 500 meters for fixed WSDs operating with at least 6 megahertz separation from TV stations.

Fourth, and relatedly, PISC urges the Commission not to limit the higher transmit power and HAAT limits proposed in the NPRM for fixed WSDs to “less congested areas” defined as a percentage of TV channels that are vacant. This definition is unnecessarily restrictive, since it’s tied to the number of TV stations in operation rather than the specific interference environment. If the Commission allows or requires WSDBs to make interference calculations using a terrainbased propagation model, such as the ITM model noted above, this would focus the calculation on power, elevation and the actual terrain in that local area rather than arbitrarily restricting the locations where higher-power WSDs can provide service.

Fifth, PISC urge the Commission to authorize higher-power TV White Space devices (“WSDs”) on moveable platforms that can operate within a geofence. To facilitate the public interest benefits for education, agriculture, and many other purposes, PISC urges the Commission to adopt rules that would allow a geofence of available white space channels to be calculated across a pre-defined area, or a pre-planned route. The Commission should also make it clear that the list of available channels can differ across the geofence.

Sixth, the Commission should allow for higher power operations on channels immediately adjacent to television operations provided the WSD is separated by 3 megahertz from the adjacent TV channel. Three megahertz of spacing between a TVWS signal and a TV broadcast channel appears sufficient to avoid harmful interference to TV viewers at power levels even significantly greater than 100 milliwatts.

Seventh, PISC urges the Commission to authorize White Space Databases to take account of directional antenna characteristics rather than assume, unrealistically, that all antennas are omnidirectional. Doing so is critical to enable rural broadband deployments on a point-to-multipoint basis in many areas where ISPs cannot access TVWS, or all the actually vacant TVWS, today.

Finally, PISC supports the Commission’s proposal to create a new class of narrowband WSDs with technical rules that facilitate applications relevant to the emerging Internet of Things (IoT), as well as remote monitoring, SCADA and other innovation.