FCC Auction Rules Could Open Door for non-ATSC Broadcasts

In examining the FCC’s new 484-page Incentive Auction Report and Order, I’ve discovered a few details about the auction, the 600 MHz band plan and the repacking process that lead to some questions and don’t seem to have been covered in the commission’s earlier summary.

One of these discoveries is that it appears in some cases stations will be able to apply for a waiver to use transmission methods other than ATSC.

The Report and Order explains, "Section 6403(b)(4)(B) of the Spectrum Act provides that a television licensee may, instead of being reimbursed for relocation costs, receive a waiver of the Commission’s 'service rules' permitting it to make 'flexible use" of its spectrum in order 'to provide services other than broadcast television services.' The R&O states: "We conclude that broadcasters seeking to take advantage of section 6403(b)(4)(B) may submit a request for a waiver of any of our service rules, including a request to use a transmission technology other than the ATSC standard. We agree with Sinclair that we should interpret this provision broadly in terms of the kinds of service rules we will consider waiving."

The R&O delegates authority to the Media Bureau to evaluate and act on waiver requests on a case-by-case basis and directs the Bureau to ensure the applicant will protect against interference and provide at least one broadcast television program stream at no change to the public..."

As the FCC will accept requests for use of technology other than ATSC, does this imply that a station can met the "one broadcast television program stream" by provide an IP multicast channel that requires special equipment to receive, or would this service have to be provided using a standard, such as DVB-T2, where consumer receivers already exist?

Also, will stations that are not required to change channels be able to file for a waiver of service rules, or will waivers be available only to stations assigned a new channel in the repacking process?

There won't a single national date for moving to new channels. The FCC expects broadcasters and the FCC Media Bureau to come up with a plan that will allow some stations or regions to move to new channels before others. This should ease the burden on tower crews and contractors, but opens the possibility that one station could delay the transition in an entire region. It isn't clear how the Media Bureau will deal with this, other than requiring that station to shut down its old channel even if it can't complete its build-out on the new channel in time.

I did note that stations not changing channels, but incurring costs from repacking due to sharing of towers or facilities with other stations that are changing channels won't be able to file for reimbursement from the FCC. They’ll have to obtain reimbursement from the station or stations changing channels.

The FCC declined to permit re-assigned stations to file initially for facilities that would extend their coverage area up to five miles in any direction. The R&O will allow stations assigned new channels that can't exactly match their old facilities "to propose transmission facilities in their initial construction permit applications that will increase their coverage contour if such facilities: (1) are necessary to achieve the coverage contour specified in the Channel Reassignment PN or to address loss of coverage area resulting from their new channel assignment; (2) will not extend a full power station’s noise limited contour or a Class A station’s protected contour by more than one percent in any direction; and (3) will not cause new interference, other than a rounding tolerance of 0.5 percent, to any other station."

There will be a limited period of time following the repacking during which repacked stations can apply to expand facilities, limited to minor changes, or even seek an alternative channel. Applications for a channel other than that assigned in the repacking process will be considered a major change.

The FCC has recognized that VHF stations face special challenges and is allowing several DTV stations transmitting on VHF frequencies to significantly increase power. Stations moving from UHF to high-band or low-band VHF slots, or moving from high-band VHF to low-band VHF frequencies will not be subject to the one percent limit on coverage expansion. However, a station moving to a VHF channel may specify an antenna that would result in a larger coverage contour than that resulting from the parameters specified in the FCC's Channel Reassignment Public Notice, as long as the proposed facility doesn’t cause more than 0.5 percent new interference to any other station.

If many stations move from UHF to VHF, this is likely to greatly limit any opportunity for these new VHF stations to extend coverage and, more importantly, increase the signal strength available to the smaller antennas widely used today for both indoor and outdoor reception. A congested VHF band is not good news for viewers. High-VHF stations in the crowded northeast part of the country are already power-limited, with ERPs in many cases to ERPs of less than10 kW. (This is in contrast to some high-band west coast VHF stations which operate with ERPs greater than 100 kW.)

The Report and Order outlines the inputs and parameters that will be used in TVStudy and these are different from those used in the past for OET-69 interference and coverage studies. Key differences are use of the 2010 census for determining population; use of one-second, rather than three-second terrain data; calculation of depression angles based on true geometry; and use of the electrical beam tilt specified on the license. TVStudy software will not use mechanical beam tilt data. This makes sense, as stations that use mechanical beam tilt have antenna patterns stored in CDBS bearing no relation to their antenna's main beam azimuth pattern. Adding mechanical beam tilt to the already distorted elevation patterns would have moved the predicted coverage further from reality.

It isn't clear if the FCC will use the actual elevation and azimuth patterns, if they’re available in CDBS. Early indications were that they would, as some stations depend on accurate pattern calculations to prevent interference, but adding these special cases could slow interference and coverage studies. I'll explain how the treatment of antenna patterns impacts coverage in TVStudy in my next RF Technology column in TV Technology.

Most other TVStudy parameters match those used for current OET-69 studies (including two kilometer cell size) count Longley-Rice Error Code 3 cells as having service and no interference, and no clutter adjustment.

I encourage broadcasters to look the Report and Order: Expanding the Economic and Innovation Opportunities of Spectrum Through Incentive Auctions (FCC 14-50). In additional to providing more detail on the topics I've discussed here, the document outlines the time frame for the auction and repacking, as well as details on reimbursements.

A lot will be happening in the 36 months allowed for the channel changes.

Doug Lung

Doug Lung is one of America's foremost authorities on broadcast RF technology. As vice president of Broadcast Technology for NBCUniversal Local, H. Douglas Lung leads NBC and Telemundo-owned stations’ RF and transmission affairs, including microwave, radars, satellite uplinks, and FCC technical filings. Beginning his career in 1976 at KSCI in Los Angeles, Lung has nearly 50 years of experience in broadcast television engineering. Beginning in 1985, he led the engineering department for what was to become the Telemundo network and station group, assisting in the design, construction and installation of the company’s broadcast and cable facilities. Other projects include work on the launch of Hawaii’s first UHF TV station, the rollout and testing of the ATSC mobile-handheld standard, and software development related to the incentive auction TV spectrum repack. A longtime columnist for TV Technology, Doug is also a regular contributor to IEEE Broadcast Technology. He is the recipient of the 2023 NAB Television Engineering Award. He also received a Tech Leadership Award from TV Tech publisher Future plc in 2021 and is a member of the IEEE Broadcast Technology Society and the Society of Broadcast Engineers.