A CDE Definition

An indoor cellular access point that routes cellphone calls over the Internet. Connecting to the home or office network, which must have a broadband Internet connection, the femtocell is a mini cell tower with a range of approximately 5,000 square feet. When users are within range, their phones pick up the stronger femtocell signal rather than a weaker signal from an external cell tower.

Help the User; Help the Carrier
Femtocells let people make and receive calls inside buildings where cellular reception may be poor. They also help the carrier, because calls that traverse the femtocell and Internet provide relief to their over-the-air networks in congested metropolitan areas. Contrast with mobile broadband router.

AIRAVE, MicroCell, Network Extender
In 2007, Sprint introduced AIRAVE, the first cellphone femtocell in the U.S. In 2009, AT&T and Verizon introduced the MicroCell and Network Extender, respectively. WiMAX carriers also encourage the use of femtocells for improved indoor coverage (see WiMAX).

(Worldwide Interoperability for Microwave Access) An earlier wireless 4G wide area network (WAN) technology that conformed to certain parts of the IEEE 802.16 standard (for more details, see 802.16).

Governed by the WiMAX Forum (www.wimaxforum.org), WiMAX allowed ISPs and carriers to offer last mile connectivity to homes and businesses over the air without the expense of routing wires. In addition, Mobile WiMAX (WiMAX 2) supported users on the go. Whereas Wi-Fi hotspot coverage is measured in feet, WiMAX cells were measured in miles similar to cellular systems. WiMAX competed with 4G LTE service (see LTE, 4G and IMT-Advanced).

Femto Access Points Inside a Building
A "WiMAX femto access point" (WFAP) was a small, indoor base station with a limited range. It connected to the organization's network and passed data to the WiMAX carrier's network via the Internet (see femtocell).

Google, Clearwire and WiMAX
In 2008, Sprint and Clearwire merged to develop Internet access to mobile devices using WiMAX, rather than the traditional CDMA and GSM cellular technologies. Google also invested in the venture. As Sprint transitioned to LTE, in November 2015, WiMAX was shut down. However, a court ordered Sprint to keep WiMAX running an additional 90 days for two large customers covering some 75 cities across the U.S. See Clearwire.