Re: Project Fi is already network agnostic with one phone number but multiple networks
Google Fi is just an MVNO, with roaming agreements to multiple networks and a list of preferred networks. Nothing magic there in a technical sense. You only need a single IMSI. Switching to a different IMSI on the same directory number and a different network is essentially porting the number and cannot be done instantaneously nor transparently to the user to protect against slamming. They use a USA country code (310) and MNC (260).