Sprint Corp. (NYSE: S) has revealed its first femtocell -- a $50 box intended to provide free calls and improved in-house coverage for users of its CDMA network.

The $49.99 Airave box from Samsung Corp. is being launched first in Denver and Indianapolis before rolling out to the rest of the country in 2008. The Reston, Va.-based operator says it will charge a flat fee of $15 a month for the service -- $30 for families -- but in-home calls will not use up subscriber's existing wireless minutes.

The appliance uses a tiny CDMA radio to connect to the subscriber's cellphone and then pumps the call over a local Internet connection. Several major operators around the world are testing or planning to use home base stations -- or femtocells -- to improve indoor coverage and decrease calling costs for subscribers. Sprint, however, is the first of the big U.S. operators to launch such a product.

Airave currently most directly competes with T-Mobile US Inc. 's [email protected] service. The differences being that the T-Mobile service requires a dedicated dual-mode handset with WiFi to work. AT&T Inc. (NYSE: T) is also rumored to be looking into femtocells. (See T-Mobile Launches UMA in USA and Is AT&T Putting Out Femto Feelers?)

Sprint is also expected to introduce similar devices as it rolls out its first nationwide WiMax network in 2008. (See Sprint Goes Femto With WiMax.)

— Dan Jones, Site Editor, Unstrung