Pai, O'Rielly Raise Concerns on Interservice Interference Order, Despite 5-0 Vote

The FCC released its order on the methodology to be used during the TV incentive auction to predict interservice interference (ISIX) between broadcasters and wireless providers. The vote was 5-0, though Commissioners Ajit Pai and Mike O’Rielly both had quibbles with some decisions. The order largely follows the approach approved last year on ISIX methodology (see 1410170053). The agency affirmed its decision from last year not to adopt a cap on the aggregate amount of new interference a TV station may receive from other TV stations in the repacking process.

The order approves a 0 percent threshold for harmful interference from wireless operations to the reception of TV signals. “We find that a zero percent threshold, with no rounding tolerance, as supported by NAB, is warranted in the post-auction environment,” the agency said.

The FCC rejected CTIA arguments that some interference should be allowed. “Given the different interference environment that television stations will face in the 600 MHz Band, we find that it would be impractical, if not infeasible, to manage any interference percentage other than zero percent,” the order said. Wireless licensees will be able to configure their networks to avoid interference to broadcast operations “through the use of directional antennas, antenna downtilt and other mitigation techniques,” the FCC said.

The order adopts methodology spelled out in OET-74, based on the Longley-Rice propagation model “which has long been used by the Commission to predict interference to television receivers,” the FCC said. It said that the methodology is “supported by measurements showing that wireless LTE signals have similar interference characteristics to DTV signals.”

Pai objected to the decision to stand firm on its earlier call to use the F(50,50) statistical measure for interference broadcasters cause to wireless operators. That assumes that a DTV signal is strong enough to interfere with the wireless base station or wireless user equipment in 50 percent of the locations within the wireless license area 50 percent of the time. “We affirm our conclusion that F(50,50) is an appropriate statistical measure for this purpose, whereas the F(50,10) measure is unnecessarily conservative,” the order said.

Industry commenters made a strong case for using the F(50,10) measure, with broadcasters and carrier groups agreeing, Pai said. But Pai also said he was pleased the FCC agreed to provide sufficient information to allow carriers to do their own interference analyses using the F(50,10) standard before the auction. “Carriers should then be able to use this information in formulating their bidding strategies,” he said. “I hope that it will be easy for carriers to conduct these analyses and that the Commission will provide any necessary assistance, particularly with respect to small carriers.”

Pai also noted that the order does address viewer losses TV stations may face as a result of changing channels during the repacking. The order allows broadcasters that lose more 1 percent of populations served to seek expedited relief, including an alternate channel or expanded broadcast facilities, he said. “While much attention focused early in this proceeding on population loss caused by interference between television stations, the change in a station’s coverage area due to a channel change was more of a sleeper issue.”

O’Rielly said that despite lots of opposition, the FCC earlier opted to place stations in the 600 MHz uplink, downlink and duplex gap. The agency has adopted rules for what constitutes impairment -- allowing an impairment rate of as much as 14 percent, he said. “Such a ridiculously high percentage of impairment is unnecessary, especially in light of deals reached with Canada and Mexico to limit cross-border interference,” he said. “Instead of minimizing market variation and the number of impaired licenses, the Commission is inclined to place more broadcasters in the 600 MHz Band in order to increase the number of licenses that can be auctioned, even if these licenses are not ‘clean.’”

AT&T in particular has raised concerns about the levels of interference carriers could face in the spectrum they buy in the incentive auction (see 1509110026). Analysts said last week that interference concerns could mean some carriers are less likely to go big in the upcoming auction (see 1510230057).