Comcast confirmed some form of a cable wireless MVNO plan today on their quarterly earnings conference call. An imminent wireless move by Comcast, and maybe other cable MSOs, has been rumored for the past few weeks. Comcast and a few other cable MSOs have had a framework of an agreement with Verizon for a cable wireless MVNO option for a few years, dating back to the sale of the cable industry’s AWS spectrum to Verizon.

The Verizon deal should allow Comcast to leverage Verizon’s extensive wireless network for their own MVNO efforts, but there are many details to be worked out. While confirming some form of cable wireless MVNO, Comcast executives were a little tight lipped with details.

“It takes about six months to activate the MVNO,” commented Comcast Corporation CEO Brian Roberts on today’s call. “We’re going to trial some things and test some things after we activate.”

Roberts pointed to Comcast’s success with Wi-Fi, and it’s widely rumored that Comcast’s extensive Wi-Fi footprint will play a major role in any mobile play. And why wouldn’t it? Comcast now has 11.7 million Wi-Fi access points across its footprint, up from 4.9 million just a year ago.

“We’re pretty excited about the roadmap that we’re trying to develop,” said Roberts.

Wi-Fi calling has taken on major significance of late, with just about all of the four major carriers either already offering Wi-Fi calling or planning to do so. Apple opened up iPhone Wi-Fi calling with iOS 8.

“We’re in test and learn mode,” added Comcast Cable CEO Neil Smit. “I think it’s a natural part of the evolution of our entry or our participation in the mobile space beyond Wi-Fi.”

With such an extensive Wi-Fi footprint and the growing amount of calling that will take place over Wi-Fi, Comcast is well positioned to do something. Besides the obvious appeal of bundling wireless service with their broadband and video offers, Comcast may also be looking to augment declining traditional voice revenues.

They’ve had a great run with home phone service, using it to power triple play bundles and take millions of access lines from telephone incumbents. But that run can only go on for so long.

Comcast reported their total voice revenue declined 1.4% in 3Q 2015. They are still adding voice customers, netting 17K in the quarter. But their overall voice revenues are declining, which they report contributed to a modest decline in overall ARPU.

By adding some form of wireless, Comcast can also counter AT&T, who hopes to muscle in on Comcast’s turf by combining DirecTV, broadband and wireless for competitive bundles.