A few months ago I posted about femtocells and their potential use in the cell phone industry. Verizon has begun selling these units, which they label "Network Extenders". Verizon's Network Extender are connected to a broadband Internet line and act as a miniature cellular tower, listening for signals from a subscriber's cell phone up to 5,000 square feet.

Verizon Wireless, the country's largest carrier, is following in the footsteps of Sprint, which started selling a femtocell under the airave brand last year.

Sprint's Airave costs $100, but the company charges an extra $5 per month for use. Verizon Wireless is not charging a monthly fee. Both Verizon Wireless and Sprint femtocells are made by Samsung and relay voice and low-speed data connections.

AT&T is currently testing femtocells in employees' homes. Plans to conduct customer trials will begin in the second quarter. The AT&T unit will relay fast 3G data connections.
T-Mobile has chosen a different technological standard to expand indoor coverage. It offers Wi-Fi routers and handhelds that can make calls over Wi-Fi in addition to regular wireless calls.