Google has invested in a British company that makes femtocell stations, technology for improving mobile phone coverage in homes and companies.

The search giant has participated in a $25-million round of funding for Ubiquisys, a femtocell vendor based in Swindon. Accel Partners, Atlas Venture and Advent Venture Partners also invested, according to Ubiquisys.

Femtocells, named after an order of size in physics smaller than "pico" or "nano," 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. Weak signals indoors, where most high-speed data services are used, have stunted the growth of those lucrative offerings, according to industry analysts.

Google invested in Ubiquisys to help people use the Internet wherever they are, with the best possible experience, spokesman David-John Collins said.

"It's about promoting different ways and platforms for people to access the Internet itself," Collins said. In related news, Google has also told the US Federal Communications Commission it would bid at least $4.6 billion in an upcoming auction of 700MHz wireless spectrum, if the FCC imposes certain conditions. They include letting consumers buy any phone, use it on any network, and download any applications, services or content they want. Google also wants the auction winner to have to sell access wholesale to other service providers.

Google's investments in unused optical fiber networks and a free Wi-Fi system for its hometown, plus its involvement in a planned San Francisco Wi-Fi network, have led to theories that it plans to compete with incumbent broadband providers.

The company has also invested in Wi-Fi sharing technology vendors Fon Technology and Meraki Networks, and power-line broadband provider Current Communications Services, Collins said.

Privately-held Ubiquisys was founded in 2004 and earlier this year introduced the ZoneGate femtocell system. Many established carrier equipment vendors, including Nokia Siemens Networks, Motorola and Alcatel-Lucent, also are developing femtocell technology. Commercial deployment of the devices is expected to start in earnest next year.