Cochannel operations in 7GHz, 13GHz bands bad idea, says SBE

The Society of Broadcast Engineers in comments filed Oct. 25 told the FCC that proposed rule changes allowing fixed-service (FS) operations to share the 7GHz and 13GHz bands would directly affect broadcasters and be “exceptionally difficult” to accomplish.

The SBE filed the comments in response to a Notice of Proposed Rulemaking and Notice of Inquiry (NPRM/NOI) regarding removal of barriers to the use of spectrum for wireless backhaul and other point-to-point and point-to-multipoint communications. The commission wants to update “regulatory classifications that may not have kept pace with the evolution of converged digital technologies.”

The SBE filing lays out its concerns about four specific areas of the NPRM, including:

  • to allow FS operations to have access to the bands 6875MHz-7125MHz and 12700MHz-13200MHz, currently allocated to the Broadcast Auxiliary Service (BAS) and the Cable TV Relay Service (CARS);
  • to eliminate the “final-link” rule, which currently prohibits broadcasters from using FS stations as the final RF link in the chain of distribution of program material to broadcast stations, thus allowing broadcasters to become licensed in FS bands;
  • to modify the Part 101 rules governing minimum payload capacity, so as to permit temporary operations below the minimum capacity under certain circumstances; and
  • to relax the standards for antenna performance in these bands.

The SBE told the commission that the bands in question are used for “fixed, mobile, temporary fixed and aeronautical mobile applications in virtually all TV markets, at all times of the day and night” for electronic newsgathering. Given the unpredictability of where and when newsgathering occurs, FS links cannot “have a substantial degree of reliability in this environment.” Because of the nature of newsgathering, coordination of BAS and FS operations on a cochannel basis “is impractical and incompatible,” the SBE filing said.

The Part 101 frequency coordination process also is flawed as pertains to Part 74 BAS facilities and impractical for use in the 7GHz and 13GHz bands, the filing said. According to the filing, “eight years of the PCN process” has made obvious its limitations, especially in bands with mixed fixed and mobile/temporary fixed operations. “SBE suggests that the PCN process is inapplicable to the proposed admission of FS facilities in the 7GHz and 13GHz band due to the presence of mobile/temporary fixed operations in that band,” the filing said.

In the filing, the SBE also told the commission that it does not oppose elimination of an FCC rule prohibiting the use of Part 101-licenses stations “as the last RF link in the chain of distribution of program material for broadcast stations.” However, the SBE said the utility of the proposal is “limited.”

The use of the 7GHZ and 13GHz bands by broadcasters and cablecasters is “not consistent with adding numerous additional FS links on a cochannel basis,” the filing said. “The impact of the commission’s proposal on mobile operations and temporary fixed links (portable microwave) in covering video production events, news and sporting events is extensive, and for the future, completely preclusive in any urban, suburban or even small-town markets.”

Phil Kurz

Phil Kurz is a contributing editor to TV Tech. He has written about TV and video technology for more than 30 years and served as editor of three leading industry magazines. He earned a Bachelor of Journalism and a Master’s Degree in Journalism from the University of Missouri-Columbia School of Journalism.