U.S. Cellular to start selling a home phone service that still uses the mobile network

For $20 a month U.S. Cellular(s usm) will sell you a home phone line starting June 7. No, U.S. Cellular isn’t becoming a local phone company. It’s using its CDMA cellular network instead of copper wires to deliver calls to wired and cordless phones.

Simply called Home Phone, the service is the same as Verizon’s Home Phone Connect(s vz)(s vod) or Sprint’s Connect 2(s s) – a way of squeezing whatever life is left out of the home voice market. As more and more traffic migrates over to data networks, carriers are finding they have a lot of excess space on their voice networks. Why not put that capacity to use in the residential market?

The home device is basically a switch you plug your home phones into. The device then converts your conversation into a CDMA signal which traverses the airwaves to the nearest cell tower. U.S. Cellular will sell the device for a penny in its stores June 7 and online June 20, and for your $20 monthly fee, you get unlimited voice, voicemail, caller ID, call waiting and forwarding and three-way calling. You can’t use SMS, and U.S. Cellular’s data networks are off limits with the switch. You can also port your old home phone number to the device.

Of course, you might figure if you get a U.S. Cellular signal in your home, why even bother with a separate home line? That’s why the service is so much cheaper than a regular mobile phone service. Not everyone will bite, but unless U.S. Cellular suddenly starts experiencing a huge uptick in mobile voice traffic, it’s got nothing to lose.