T-Mobile US stepped up its campaign for expanded competitive access to wireless low-band spectrum resources as it asked the FCC this week to deny AT&T’s request to acquire three lower 700 MHz C-block wireless licenses currently held by East Kentucky Network LLC (EKN) in the states of Kentucky, Ohio and West Virginia.

Low-band spectrum below 1 GHz is coveted by wireless broadband providers for its ability to penetrate buildings and to cover a wide geographic area with fewer transmitters than higher band channels. T-Mobile, which is pressing the FCC to increase the amount of low-band 600 MHz reserve spectrum in next year’s incentive auction, has taken issue with the amount of sub-1 GHz spectrum controlled by Verizon and AT&T. T-Mobile informed the FCC earlier this month that each of those carriers holds “roughly 50 MHz” of sub-1 GHz spectrum which represents “more than 73% of all low-band spectrum available for commercial use across the entire industry.” Although an FCC official said this week that the agency has no plan at this time to boost the incentive auction reserve beyond 30 MHz, the Justice Department voiced indirect support for T-Mobile’s position in a letter on Wednesday which asks the FCC to “ensure that the allocation of spectrum through the auction does not enable carriers with high market shares to foreclose smaller carriers.”

In its petition, T-Mobile declared that the EKN acquisition, if approved, would reduce the number of entities that hold low-band spectrum in the affected markets from six to five. While stressing that AT&T and Verizon already “hold more than 36 MHz of low-band spectrum” in two of the three cellular market areas involved in the transaction, T-Mobile proclaimed that no other competitor “holds more than 14 MHz” of low-band spectrum in these markets and that T-Mobile holds none. Moreover, T-Mobile told the FCC that, as a result of the transaction, AT&T would hold “more than one-third of the spectrum below 1 GHz” in the markets in question. As such, T-Mobile said AT&T had failed to show “that the proposed transaction is in the public interest when balanced with the serious anti-competitive risks posed by the increased concentration of below-1 GHz spectrum.”

In a blog post, however, AT&T Vice President Joan Marsh defended the proposed purchase as one that will give her company “the needed spectrum footprint to deploy a 10X10 MHz LTE network . . . which will enable AT&T to offer faster and higher quality services to its rural customers.” As she observed that T-Mobile “has only limited plans to invest in the rural markets covered by these licenses,” Marsh declared that the deal “will not reduce any actual competition” because “the spectrum at issue currently sits completely fallow and unused.”