Verizon Wireless came out swinging in an ex parte filing with the FCC over the agency’s proposed data roaming rules, arguing that the commission lacks the authority to impose a data roaming mandate.

The FCC is considering rules that would mandate automatic data roaming, a proposal that has been supported by regional carriers like MetroPCS but opposed by their Tier 1 competitors.

In its ex parte filing, Verizon claimed that two provisions of the Communications Act prohibit the FCC from extending an automatic roaming obligation to data services. The carrier argued that data services were a private radio service rather than a commercial mobile service and were not a telecommunications service, forbidding the FCC from imposing common carrier requirements.

“Imposition of a data roaming obligation would be flatly inconsistent with two independent provisions of the (Communications) Act,” Verizon wrote. “In sum, nothing in Title I or Title II supplies the Commission with statutory authority to impose a data roaming requirement.”

Last week, T-Mobile USA filed a document with the FCC claiming AT&T refused to cooperate on 3G data roaming. AT&T denied T-Mobile’s claim, saying “if T-Mobile wishes to roam on AT&T’s network, AT&T will amend the current bi-lateral voice and data roaming agreement between AT&T and T-Mobile to include 3G roaming.”