The company recently made the $20 wireless service available across the United States to any user of a Nexus device.
U.S. Cellular has become the third carrier to partner with Google on its Project Fi wireless service initiative.
The partnership will significantly expand the 4G LTE network coverage available to Project Fi customers, which currently comprises owners of the company's Nexus smartphones and tablets.
U.S. Cellular provides service to customers in 23 states. Ninety-nine percent of those customers currently have 4G LTE network coverage. U.S. Cellular's network will become automatically available to Project Fi subscribers in the coming weeks, Google Product Manager Evan Jacobs said in a post
on the company's official Android blog.
Google announced Project Fi last year as a relatively low-cost, high-speed alternative to available wireless services. The company has described the service as a network of networks that combines WiFi and 4G LTE network connectivity to give users high-speed services at a lower cost than other carriers.
The service is different from those offered by the large incumbents in the space in that it combines cellular networks from different providers. To deliver the service, Google has entered into so-called Mobile Virtual Network Operator (MVNO) agreements to buy excess wireless capacity from Sprint, T-Mobile and, starting this week, U.S. Cellular.
When subscribers make a call, the service checks to see if a free open WiFi network is available and then uses what Google describes as a network-quality database to determine if the connection is reliable and fast enough to support a call. If not, the call is routed through the network of one of its partners.
Google has previously said that Project Fi uses more than 1 million previously vetted WiFi hotspots to route calls. All Project Fi calls that are routed through a public WiFi hotspot are sent through a virtual private network (VPN) to protect privacy and call integrity.
In situations where multiple carrier networks are available, Google again routes the call through the network it determines to be the fastest at that specific location and time.
Project Fi service starts at $20 per month. The price includes unlimited domestic calls and text and unlimited international texts. The subscription also gives users the ability to use their phone as a mobile hotspot to access cellular service in more than 120 countries, according to Google.
The company charges a flat $10 per GB of data per month. Users get a refund for any data that remains unused at the end of the month at the rate of 1 cent per MB. So if a user paid for 2GB of data but only used 1.5GB, he or she would get a refund of $5. Subscribers are not required to sign an annual contract to get the service.
Currently, Project Fi is available only to users of Google Nexus 6P, Nexus 5X and Nexus 6 devices. Owners of these devices who sign up for the service get a Project Fi SIM card that allows them to connect to the multiple partner networks. Google also offers a data-only SIM that allows Project Fi subscribers to access online data from tablets and other devices at no additional charge. Users can transfer their existing numbers to Project Fi.
Until recently, the service was available to Nexus users on an invite-only basis. But after a 10-month trial period, the company dropped
its invitation requirement in March and now offers Project Fi across the United States to any Nexus user interested in signing up for the service.