As AT&T’s acquisition of T-Mobile looms, the mobile giant was hit with a new regulation, along with other wireless leader Verizon. Today, the Federal Communications Commission ruled that AT&T and Verizon must make data roaming deals that allow smaller carriers to piggyback off their networks.

The network-sharing agreements are already mandatory for voice calls, but until today any agreements made in terms of data roaming were strictly voluntary. The vote to give smaller companies access the the larger companies’ networks was a partisan vote, with three Democrats defeating two Republicans.

Roaming for actual voice calls has been available for quite some time, but the need for data roaming is a newer phenomenon. With more and more mobile users using their smartphones for much more than phone calls, the need to address the issue was paramount.

“Roaming deals are simply not being widely offered, and the requirement will spur investment and promote competition,” said Julius Genachowski, FCC Chairman according to Bloomberg. Dissenting Republicans questioned the FCC’s legal authority to implement the mandate.

Obviously, AT&T and Verizon aren’t happy with the ruling. They said that data roaming agreements are already being offered in abundance, and a mandate isn’t necessary. In an e-mail to Bloomberg, AT&T chief privacy offer Robert Quinn said:

“A data-roaming mandate is unwarranted and will discourage investment. Proponents of a roaming mandate were seeking government intervention, not to obtain agreements — which are plentiful — but rather to regulate rates downward.”

Verizon also released a statement on the ruling to their website, saying:

“Today’s action represents a new level of unwarranted government intervention in the wireless marketplace. By forcing carriers that have invested in wireless infrastructure to make those networks available to competitors that avoid this investment, at a price ultimately determined by the FCC, today’s order discourages network investment in less profitable areas. That is directly contrary to the interests of rural America and the development of facilities-based competition and potential job creation. Therefore, it is a defeat for both consumers and the innovation fostered by true competition.

We are also concerned that the FCC is taking this action even though it does not have the statutory authority to do so. Consumers benefit from the deployment of wireless networks that have more capacity to offer new services, and Verizon is committed to working with policymakers to accomplish that goal.”

This ruling is sure to thrill smaller carriers from Sprint all the way down to rural providers. We know how Sprint feels about the current competitive climate, as they publicly bashed the upcoming AT&T / T-Mobile deal.

Is this FCC ruling good or bad for the wireless customer? Should the FCC be able to implement such a mandate? Tell us what you think.