The Society of Broadcast Engineers filed a petition for reconsideration with the FCC May 2 regarding a footnote in its Fourth Memorandum Opinion and Order allowing Department of Defense uplinks to relocate to the 2025MHz to 2110MHz TV Broadcast Auxiliary Services (BAS) band.
In its filing, the SBE said it “was shocked to read” a footnote that appears to abandon a requirement imposed upon 11 DoD tracking, telemetry and commanding (TT&C) uplinks to demonstrate that their operation will degrade the noise floor of an ENG receiver by no more than 0.5dB is alarming.
Specifically, the SBE filing cited Footnote 43 to Paragraph 17 of the Fourth MO&O, which stated:
“Finally, the commission noted that, during ongoing coordination, receiver threshold degradation, on which this worst case analysis was based, may be supplanted by less stringent criteria which fully consider actual ENG power, modulation, performance, or other requirements.”
According to the SBE filing, the 0.5dB noise floor degradation threshold was acceptable to the society and not challenged in an earlier petition to reconsider. The society’s May 2 filing said this level of noise floor degradation “permits frequency re-use, which the SBE has never opposed.” This condition contrasts sharply with “incompatible frequency sharing,” which the SBE has never endorsed.
The noise floor degradation threshold is critical because DoD-generated interference would be “one-way from DoD uplinks to BAS receivers,” creating a situation in which the defense department would have no incentive to coordinate frequency usage.
The SBE filing acknowledges that the footnote “perhaps was not meant to disavow” the interference criteria. If the MO&O’s intent was to state that in the future when a DoD uplink moves to the 2GHz TV BAS band all mitigation measures must end up in 2GHz TV BAS receiver noise threshold degradation of no more than 0.5dB, there would be no problem.
However, if the footnote means the DoD can “dispense” with the 0.5dB threshold, “this is an abandonment of a reasonable and necessary interference protection provision and constitutes an impermissible rule making ‘end run’,” the filing said. The SBE filing asked the FCC to clarify the meaning of the footnote, reconsider it or delete it in a subsequent order.
For more information visit www.sbe.org.
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