What? I mean your provider ships you a computer that's dedicated to authentication your device on the network (a sim card) - it shouldn't be infeasible to authenticate the nodes when you can bootstrap off an actual trusted device.
With roaming, your provider could cross sign other providers - and for long range/international roaming you could maybe allow forwarding of encrypted requests for authentication over an untrusted channel.
That would probably be enough for some level of (location) tracking - but there'd be no need to allow any regular traffic over such links. In theory. In practice, that'd probably be too expensive, and you'd get better service and security relying on wlan and something like signal....
With roaming, your provider could cross sign other providers - and for long range/international roaming you could maybe allow forwarding of encrypted requests for authentication over an untrusted channel.
That would probably be enough for some level of (location) tracking - but there'd be no need to allow any regular traffic over such links. In theory. In practice, that'd probably be too expensive, and you'd get better service and security relying on wlan and something like signal....