Staff at the FCC, America's communications watchdog, have been accused of not doing enough to prevent TV broadcasts from interfering with mobile broadband signals.
This comes as television stations in the US prepare to auction off some of their radio frequencies, which can then be used by cellphone networks to extend their wireless broadband coverage.
The regulator published on Tuesday a plan for preventing interference between the TV stations that will sell their portions of the 600MHz band and the mobile networks that will end up using the frequencies.
The plan includes rules for separating and operating phone masts near television transmission stations so that the mobile networks do not prevent the transmission of television signals in a new limited 600MHz band.
The new rules will aim to ease the transition of television stations from their previous spectrum space to the smaller 600MHz band, a move that has caused groups including the National Association of Broadcasters to worry that the crunch between television stations and wireless networks will lead to interference problems in many parts of the country.
Freeing up portions of the 600MHz space is key to the FCC's upcoming 2016 spectrum auction. The sale will ask broadcasters to offer up their spectrum holdings in markets across the US for re-use as wireless broadband networks. The auction is expected to raise billions of dollars for the government.
The FCC's plan calls for a "zero per cent threshold" for interference, seeking to protect the stations and minimize any loss of coverage that stations would experience due to shifting into a smaller portion of the spectrum.
Some critics, including FCC commissioner Ajit Pai, argue that the latest plan does not do enough to prevent interference from a "spectrum crunch" of broadcasters and wireless networks trying to operate alongside one another.
"Much of this is an attempt to make the best of a bad situation," Pai wrote in a memo.
(Pai is one of four commissioners, plus the chairman, at the FCC.)
"In its post-auction 600MHz band plan, the Commission chose to place too many broadcast television stations in the wireless portion of the band," Pai added.
"That decision, in turn, was an attempt to mask other mistakes that the Commission had made designing the incentive auction and thus to salvage the Commission's chances of holding a successful incentive auction."
The incentive auction is slated to take place in the first quarter of 2016. ®