RAYMOND, Maine – March 15, 2017 – Dielectric, Raymond, Maine February 2017……Dielectric, a pioneer in purpose-engineered antennas and RF systems for TV and radio broadcasters, is encouraged by the FCC’s release of the Notice of Proposed Rulemaking (NPRM), which seeks comments on the voluntary adoption of ATSC 3.0 by broadcasters as long as their ATSC 1.0 signal is kept available.
http://www.dielectric.com/news/dielectric-welcomes-fcc-release-atsc-3-0-nprm/
The FCC had already decided to not mandate an adoption time frame or mandatory switchover to ATSC 3.0. Thus a call for comments is probably nothing more then smoke and mirrors.
Under those conditions no broadcaster that cares about OTA customers would abandon ATSC 1.0 until they absolutely had a business reason to.
The real question is that since ATSC 1.0 is much more inefficient then ATSC 3.0 and many broadcasters already have a primary and 3-4 sub-channels, what sub-channels may need to be dropped to fit ATSC 3.0 into their assigned frequency.