3/29 FCC PISC TV White Space FNPRM Comments on Use of Terrain Modeling

New America's Open Technology Institute wrote and filed comments for the Public Interest Spectrum Coalition (PISC) along with Tribal Digital Village, Access Humboldt, Public Knowledge, Common Cause, the Schools, Health, Libraries Broadband (SHLB) Coalition, the Institute for Local Self Reliance, and the Benton Institute for Broadband & Society urging the Federal Communications Commission (Commission) to adopt reforms to the rules governing the use of TV White Space (TVWS) spectrum to better empower extending broadband service into Tribal, rural, and other hard-to-serve areas. These comments were filed in response to a Further Notice of Proposed of Rulemaking the Commission issued seeking feedback on a proposal made by PISC in comments and reply comments last year urging the Commission to allow TVWS Databases to use real-world propagation modeling, specifically terrain-based models such as Longley-Rice Irregular Terrain Model (“ITM”), to more accurately identify vacant broadcast frequencies in a certain area.

The introduction and summary is copy and pasted below:

The Public Interest Spectrum Coalition (“PISC”) filed both comments and reply comments last year urging the Commission to update the decade-old TV White Space operating rules and thereby adopt common-sense reforms to enable more extensive wireless broadband deployment in rural and remote areas. Among the modernization improvements that PISC proposed in those comments was to allow or require TVWS Databases to use real-world propagation modeling, and in particular terrain-based models such as Longley-Rice Irregular Terrain Model (“ITM”), to more accurately identify vacant broadcast frequencies in a local area. PISC applauds the Commission for adopting this FNPRM to seek further comment on the feasibility of updating the TV White Space rules to allow this well-established technique.

PISC believes that authorizing the Longley-Rice ITM, or other terrain-based propagation models, will promote fixed wireless broadband in rural, Tribal, and other hard-to-serve areas. In far too many communities, TV band spectrum lays idle because the outdated rules for opportunistic TVWS use assume a flat earth with no mountains, valleys, or other topographical features that often render a distant TV signal both unavailable and irrelevant to the local residents who are being denied wireless broadband connections under the current rules.

Longley-Rice ITM should be an optional method for TV White Space operators and database providers to determine channel availability. Since 2015 the Commission has authorized terrain-based modeling in the two other shared bands coordinated by automated frequency control databases. A terrain-based modeling system similar to the one the Commission approved years ago to enhance opportunistic sharing in the Citizens Broadband Radio Service (“CBRS”) band would also work well in this band, that is: in point-to-point mode, with the points located along and within the protection curve, rather than merely the nearest point.