Some of the big fixed-line broadband providers in the United States are quiet on the network functions virtualization (NFV) front, at least in terms of public announcements. For example, Comcast Business had a presence at the GEN15 conference in Dallas this week. But while others were talking about virtualizing network functions and implementing software defined networking (SDN), Comcast didn’t offer any specifics about its work in those areas.

Steve Cassell, senior director of enterprise data and IP with Comcast Business, told SDxCentral the company has implemented various virtual capabilities in terms of service activation going back before the term SDN was even coined. But the company is so big, with 22 million business and enterprise customers, that “customers depend on us delivering services that are fully baked,” he said.

“We see SDN, NFV, and lifecycle services orchestration as an opportunity to improve the way we deliver services internally through driving cost out of the business as well as potentially enabling rapid service creation,” said Cassell. “We are exploring the opportunities.”

We’ll have to wait until Comcast is ready to tell us more about virtualization within its business services group, but in the meantime, Affirmed Networks hinted that some large fixed-line service providers may be looking at NFV within the WiFi realm.

Affirmed is a five-year-old company that provides NFV components for mobile networks, mostly. It has raised $160 million, and it got its name on the radar when AT&T announced it was a customer in 2013.

In October, Affirmed announced it was offering fully virtualized WiFi gateway functionality for mobile and fixed operators to offer virtualized WiFi access, which would allow WiFi calling as a new service.

“We’re seeing a lot of interest from fixed operators. They see WiFi calling as the big app,” says Angela Whiteford, VP of marketing for Affirmed. “Look at Comcast; they’ve blanketed the East Coast with WiFi. The cost point to get into the [WiFi calling] market is very low.”

Fixed-line operators could run the Affirmed application on whatever hardware they choose, and they would have to make sure that customers' handsets support the application. But Whiteford says iOS 8 natively supports WiFi calling. With the native support, a WiFi calling customer could call anyone, whether or not she has the app or the native device.

Why would fixed-line providers such as Comcast want to use an NFV application to do WiFi calling?

“It’s about the opportunity for new revenue,” says Ray Mota, principal analyst with ACG Research. “They don’t have an existing mobile subscriber base, but they do have a lot of wireless access from wholesaling backhaul.”

MSOs have tried to get into wireless calling in the past, buying spectrum and creating partnerships. But they mostly threw in the towel on those aspirations due to the extremely high costs of investing in new infrastructure and licenses. Now, with an NFV application and native WiFi calling embedded in iOS 8, they may still get in on some of that wireless revenue without having to spend money for spectrum.

Mota says Google is working on a WiFi calling project known as Project Fi, and the MSOs are looking at doing something similar.

One speed bump to the whole WiFi calling idea for companies such as Comcast is that mobile users are accustomed to pretty good coverage. Most people don’t want a phone service that only works when they have WiFi coverage.

“Depending on the region, they might have to partner with a licensed spectrum provider,” says Mota.

For Project Fi, Google has partnerships with Sprint and T-Mobile.

“One challenge is when you’re doing a voice call, you need to encrypt,” says Whiteford, adding that it can get really complicated, with millions of encryption tunnels. “We’ve partnered with Intel and leveraged some Intel software. It’s a fully NFV WiFi gateway.”