Google Fi adds support for a second 5G network, won’t say which one

Google has announced a “super network” upgrade for its Fi cell service. For the past few years, Google Fi has operated exclusively on the T-Mobile network, but now it’s adding support for a second 5G network. Oddly, Google refuses to say which one. Google’s MVNO (mobile virtual network operator) launched in 2015 as Project Fi with support for both T-Mobile and Sprint service. The service initially only worked on Google’s Nexus phones, which would switch between networks based on signal strength. After T-Mobile absorbed Sprint, Fi switched to being a single-network service in the US while continuing to hop between networks for international travel. With the super network, Google Fi is again a dual-carrier service stateside. Phones connected to Fi will be able to hop between…