FCC Invites Comments on Request for Greater Flexibility for TV DTS Transmitters

The Federal Communications Commission ("FCC") has invited comments on a petition filed jointly by America's Public Television Stations ("APTS") and the National Association of Broadcasters ("NAB"), requesting a relaxation of restrictions on where digital television stations may locate Distributed Transmission System ("DTS") antennas.

Digital television technology allows a station to broadcast from multiple transmitters on the same channel without each transmitter causing interference with the others. It is the same concept as cellular telephone systems. To keep the signal strength strong and even throughout the service area, phone systems have lots of transmitter sites, or "cells." If you have only one central transmitter site, the way most TV stations now operate, the signal will become weaker the further away you get, and terrain obstacles will also result in pockets of poor service. Multiple transmitter sites can alleviate this poor service problem.

DTS has not taken off under the Advanced Television Systems Committee's ("ATSC") 1.0 digital TV standard, because of concerns about its actual effectiveness and whether any benefits exceed the costs. But DTS is easier to implement with ATSC 3.0 than with ATSC 1.0, and DTS improves the ability to reach mobile receivers; so TV broadcasters are now taking a greater interest in the technology.

The FCC's existing rule requires that the signal from a DTS transmitter be completely confined within the noise-limited service area of the primary transmitter. The idea is to prevent stations from using DTS to extend their service areas and become regional rather than local service providers. The downside, however, is that if you want to put up a DTS transmitter to fill in a weak pocket near the edge of your service area, its effectiveness may be impaired if you have to point a directional signal back into the center of the primary transmitter's service area to avoid any leakage outside the permitted area. In other words, the more you push DTS transmitters back inside the main station service area, the less good they will do.

Another problem with the FCC's "keep it local" theory is that TV stations can establish regional service through translators. Some are already regional powerhouses, particularly in geographically expansive Designated Market Areas ("DMAs") in the Mountain states. But the translators occupy additional channels, so they are less frequency efficient than DTS. Moreover, the day could come when TV stations become all "cellular"; i.e., they no longer have a primary centralized high-powered transmitter. How will the FCC define the permissible DTS service area then? Based on a hypothetical high-powered transmitter that does not exist?

The basic idea behind the APTS-NAB petition is to redefine the permitted coverage area to allow more flexibility in locating DTS transmitters. The noise-limited-service contour (41 dBu for UHF stations), is supposed to be the place where the signal drops out because of "noise," or interference, from other signals. The petition asks to redefine the DTS signal limit to be the primary transmitter's 36 dBu contour. That would allow DTS transmitter signals to extend out beyond the main transmitter's service area at least a little and thus do a better job of filling in gaps in the station's fringe signal both inside and outside the noise-limited contour. The value 36 dBu was chosen because it will supposedly not result in new interference to other full-power stations and will also not interfere within the protected contour of Low Power TV ("LPTV") stations (51 dBu on UHF channels).

We will let the engineers speak to the interference protection claims, although the FCC should take into account the fact that LPTV stations are freely permitted to accept incoming interference, so there may be some stations that will suffer an unexpected increase if the APTS-NAB proposal is adopted. On the other hand, there is merit in more flexibility, and some would say that the purpose of the FCC's rules should be focused on encouraging better overall service of the public, not preventing any slight expansion of a station's service area that might make it less "local."

The prospects for LPTV stations could also be improved if the FCC encouraged full power stations constructing DTS systems to relinquish digital replacement translators (DRTs and DTRT's) that were intended to fill in service area gaps that no longer exist after implementation of DTS. Relinquished translator channels could provide homes for LPTV stations that were displaced in the recent repacking of the TV band and were forced to move to channels with less signal coverage.

Comments on the APTS-NAB petition are due by November 12, 2019, with Replies due November 27. If you have any questions regarding the preparation and filing of Comments and Replies, please contact your counsel.