Lowell McAdam, Verizon CEO. AP / Paul Sakuma With the flip of a switch, normal WiFi routers owned by more than 50,000 customers in Houston joined a massive public WiFi hotspot network late Tuesday afternoon, thanks to a new initiative from Comcast.

On Wednesday, Comcast activated another 3 million residential hotspots nationwide, in cities like Indianapolis and Philadelphia.

Comcast’s goal, according to the company’s VP of Xfinity Internet Product Amalia O’Sullivan, is to make it easier for people to use each other’s home Wi-Fi networks.

“Instead of coming over to your house and saying, ‘Hey, what’s your Wi-Fi password?’ your friends can just connect to the Xfinity Wi-Fi hotspot,” O’Sullivan told the Houston Chronicle.

That’s Comcast’s official logic for the hotspot rollout, but the company’s real goal might have to do more with competition.

In its bid to buy Time Warner Cable for $32 billion, Comcast wrote in an SEC filing to federal regulators that a massive WiFi network enabled by residential hotspots — like the one that just launched in Houston — “could make a ‘WiFi first’ service, which combines commercial mobile radio service with Wi-Fi.”

Comcast is already battling other wireless carriers like AT&T, which currently own large networks of WiFi hotspots for businesses and major chains like Starbucks. Comcast also has some WiFi beachheads in some public places like Houston’s Minute Maid Park, but this is the first time the company is rolling out an initiative for residents.

This could mean Comcast and Time Warner Cable want to compete with Verizon and AT&T in the phone business. O’Sullivan said Comcast has no current plans to enter the wireless phone business, but it is possible “in the longer term.”

Spencer Kurn, a partner with New York-based New Street Research, said Comcast is indeed setting itself up for a phone network that would allow its users to switch seamlessly between traditional cellular connections and WiFi. Since Verizon purchased some of Comcast’s wireless spectrum last year, Comcast in return is able to access Verizon’s wireless network.

In other words, a Comcast-owned wireless phone service could leverage Verizon’s cellular network and its own Wi-Fi networks.

“We think it’s not a matter of if, but when,” Kurn said.

Comcast is hoping its Wi-Fi initiative will help the company gain favor with cellular customers. The public hotspot network is available to any Comcast subscribers for free, and after a customer signs into any Xfinity WiFi hotspot once, they will be connected to any available hotspot after that automatically. Non-Comcast customers will also be able to access the hotspots, but only for a limited time; they’ll need to pay a fee to Comcast after that.

Comcast’s free network will only be broadcast on Wi-Fi routers issued by the company. Customers with their own routers won’t be able to broadcast the hotspot.

By the end of the month, Comcast hopes to have 150,000 of these hotspots populating the greater Houston area. By the end of the year, Comcast hopes to have 8 million WiFi hotspots available for its customers.

O’Sullivan said Comcast’s public WiFi network is separate from private home networks so others can’t access each others’ devices. But for those still concerned about their privacy, the hotspot can be disabled — customers can call Comcast’s customer service or disable it themselves on Comcast’s website. So far, however, customers don’t seem to mind: Comcast spokesman Michael Bybee said “less than 1 percent of customers have opted to turn it off.”