Femtocells, an emerging technology for improving cellular coverage in homes and enterprises, have attracted the interest of Google.

The search giant participated in a $25 million round of funding for Ubiquisys Ltd., a femtocells vendor based in Swindon, U.K. Technology venture funds Accel Partners, Atlas Venture and Advent Venture Partners LLP also invested, Ubiquisys announced Friday.

The Ubiquisys ZoneGate femtocell offers mobile users high-quality mobile coverage in the home using their usual 3G cell phones. The device plugs into an existing home broadband gateway or is built into a gateway product that includes WiFi, DSL, Ethernet, phone ports and USB.

"Our mission is to empower mobile carriers to bring compelling service packages into homes using our ZoneGate solution," said Chris Gilbert, CEO Ubiquisys. "We're delighted by the confidence our investors have shown in our technology and its ability to deliver innovative applications via ZoneGate's unique services platform."

Femtocells are cellular base stations for individual homes or offices. Mobile operators hope to sell them to customers who will install them and immediately enjoy better coverage for data and entertainment services. Weak cellular signals indoors, where most high-speed data services are used, have stunted the growth of those lucrative offerings, according to industry analysts.

Ubiquisys is a privately owned communications company formed in 2004 and earlier this year introduced the ZoneGate femtocell system. Many established carrier equipment vendors, including Nokia Siemens Networks BV, Motorola Inc. and Alcatel-Lucent SA, also are developing and testing femtocell technology. Commercial deployment of the devices is expected to start in earnest next year.