Make your house a personal AT&T cell tower

AT&T is joining Sprint and Verizon in offering “femtocells,” small boxes that increase signal strength in indoor environments, for its wireless customers across the US.

So named for the scientific word “femto,” which denotes something extremely tiny, femotcells act as wireless routers that send out cellular signals. They can connect to a broadband modem in the house and relay mobile calls through that Internet connection.

It increases indoor service reliability and reduces strain on nearby cell towers. AT&T also offers a $20-a-month plan that allows unlimited calling for calls directed through a femtocell.

Sprint and Verizon have been offering the same kind of product for a couple years now, with stagnant consumer adoption. AT&T’s version is the only one that can relay both phone calls and broadband data.

AT&T’s femtocell, the 3G MicroCell will be available in select markets within the next month. AT&T will then roll out the product to the rest of the country by the end of the year, according to the Associated Press. The device will be priced at $150. New customers to AT&T’s home broadband service can get a $50 rebate on that price, and new subscribers to the free femtocell calling service get a $100 rebate, with the purchase of a MicroCell.