Sprint has begun offering customers with poor indoor reception a free, updated version of its Airave femtocell that supports 3G service, a Sprint spokesman said.

The device, which is not yet available online or in stores, is given to customers with specific in-building coverage issues, according to Sprint spokesman Mark Elliot.

Sprint has been offering its 2G Airave free to reception-challenged customers since 2008 but the 3G version of the Airave has only shipped for a few weeks, Elliot said. 

According to Elliot, subscribers with qualifying reception issues can get the device for free, with voice, data and text messages coming out of the customer’s monthly plan. Customers must return the device when they deactivate service or will be charged a non-return fee.

“It’s part of our effort to help our customers have the best possible experience,” Elliot said. He could not provide any details as to how many Sprint customers have received 2G- or 3G-compatible Airave femtocells.