Panel Says Expect Interference from Reallocated Broadcast Spectrum


WASHINGTON: Broadcasters will have to expect some levels of interference from wireless transmissions as part of the reallocation of broadcast spectrum, says a report by a Department of Commerce (DoC) advisory committee on managing broadcast spectrum.

At a meeting of the DoC’s Commerce Spectrum Management Advisory Committee (CSMAC) held on Nov. 10, 2011, CSMAC accepted the report from its Search for 500 MHz Subcommittee, the recommendations of which says “commercial users” of reallocated spectrum “accept reasonable and defined levels of interference.”

The report will be forwarded to the National Telecommunications and Information Administration (NTIA), says CSMAC. NTIA is the DoC agency tasked with advising the president on telecommunications and information policy issues.

The recommendations were made public in August 2011, and few comments have been received on them, said Michael Calabrese, who is member of CSMAC and the subcommittee.

However, while few comments were filed on the report’s recommendations, comments by CSMAC member Jennifer Warren, which the committee considers to be “clarifications” and which were included with the recommendations as attachments.

The report’s recommendations are:

  • • NTIA should utilize “long-term evolution” (LTE)—which is the latest standard in the mobile network technology—characteristics for its initial interference and other analyses, and should work closely with industry to fully understand system impacts and refine analysis and sharing solutions.
  • • NTIA should implement an informal process, consistent with all applicable laws, to directly exchange data and have a dialogue between government and industry in order to facilitate and implement the spectrum recommendations in this report.
  • • NTIA should stage the availability of the 1755-1850 MHz band for commercial use, with a priority on the early availability of 1755-1780 MHz, and extending in contiguous stages as necessary to accommodate the relocation and returning of government users.
  • • NTIA should make spectrum available such that commercial users have exclusive use of spectrum; however, given existing government uses, industry supports making spectrum available subject to pre-defined sharing zones where the commercial users accepts reasonable and defined levels of interference.
  • • Warren’s comments say that both “the two-stage approach outlined for 1755-1850 MHz” and “any reallocation decisions must address upfront how relocation will be addressed for users across the entire band.” Since that band is of highest priority to industry, “auction revenue could be optimized for the full 95 MHz if relocation issues, such as replacement spectrum and timing for relocation of incumbents, were dealt with as early as possible to provide adequate planning and preparation time for both prospective bidders and current incumbents, according to Warren.


“Bifurcating the process by needlessly delaying challenging decisions associated with clearing the entire band would sacrifice a reasoned, longer-term decision cycle for the near-term expediency of holding the ‘first’ auction in this band,” she said.

In addition, the principle that “clearing spectrum should be the goal,” should include the caveat “when feasible,” according to Warren. For “auctioning cleared spectrum is the clearest path forward for optimizing auction revenue, and should be pursued whenever possible,” she wrote. However, it is difficult to support the recommendation for specific bands “without a full understanding of the costs and benefits of full clearance, particularly when key considerations such as replacement spectrum are not yet known. The latter is an especially important factor in light of the lack of ‘open’ bands to which incumbents may easily be moved, which is itself a factor that could add time and cost to a cost-benefit analysis of how and when a band may be auctioned,” she wrote.

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