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FCC Modifies DTS Rules for ATSC 3.0 Flexibility

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(Image credit: John Lund via Getty Images)

WASHINGTON—The FCC released an update to its DTS (distributed transmission system) coverage rules to expand the permissible range of signal spillover and replace the subjective “minimal amount” language used to describe spillovers as a way to promote ATSC 3.0 reaching its full potential.

The change gives broadcasters more flexibility in placement of DTS transmitters. For UHF stations, the rule change mandates that the 41 dBu F(50,50) contour for each DTS transmitter in use does not exceed the reference station’s 41 dBu F(50,50) contour. The corresponding values for low VHF are now 28 dBu and for high VHF 36 dBu.

The Report and Order, adopted Jan. 13, explained that the agency’s actions are intended to afford “broadcasters greater flexibility in the placement of DTS transmitters …” that will “allow them to enhance signal capabilities and fill coverage gaps, improve indoor and mobile reception, and increase spectrum efficiency by reducing the need for television translator stations operating on separate channels.”

The change gives no protection to DTS transmissions beyond a station’s authorized service area. It also removes the requirement for Class A, LPTV and TV translator stations to apply for DTS facilities on an experimental basis. The new DTS contour-based limit for these broadcasters is similar to the change adopted for full-power broadcasters but is “modified slightly to account for technical differences …,” it said.

“[O]ur adopted approach will allow broadcasters to improve coverage in their service areas, without causing more spillover than necessary to promote DTS deployment,” the R&O said.

While the change increases the permitted area for DTS spillover, it does not change a station’s area of interference protection, the R&O said.  “Specifically, such spillover will be subject to a bright-line limitation …”

By relaxing and clarifying how much DTS spillover is allowed at the fringe of a full-power station’s coverage contour, stations will be permitted to deliver a stronger signal to viewers located at the edges of their service areas and where terrain hampers delivery, it said.

The R&O was prompted by a petition for rulemaking filed by America’s Public Television Stations (APTS) and NAB. The FCC issued a Notice of Proposed Rulemaking seeking comment.  

FCC Chairman Ajit Pai and Commissioner Brendan Carr supported the rule change. Commissioners Jessica Rosenworcel and Geoffrey Stark approved in part and dissented in part. 

More information is available on the FCC website

Phil Kurz

Phil Kurz is contributing editor to TV Technology