Wi-Fi calling is perfect for those times when you're outside of your carrier's coverage area, but you do have access to a zippy Wi-Fi connection. In many cases, a call made over Wi-Fi just sounds better. Some MVNOs, like Project Fi, try to keep the price they charge you for service low by first trying to connect your phone to a Wi-Fi hotspot. If there is no compatible Wi-Fi signal in the area, the MVNO will connect to a carrier's network; in the case of Project Fi that would be either T-Mobile or Sprint, whichever one has the strongest signal at the subscriber's current location.

VoIP is rolling out now to the Google Voice app
ncG1vNJzZmivp6x7sbTOp5yaqpWjrm%2BvzqZmp52nqHyIu86go55loqS5rb%2BMqKytZYaklpF5xaipZn%2BfpLStsYyPpqKblZS2pX2QbGhubQ%3D%3D