[JoshTriplett]

Current smartphones are already more careful about cell modems than they used to be. And in an ideal world, cell modems would have even less information than they do, and could be (and should be) powered off by the phone until needed.

Imagine an architecture in which you had a pervasive cellular data connection that was intentionally uncorrelated with any identifying information, the way wifi is.

Right now, the only legitimate reason cell networks have to identify specific devices to users is for billing, and for PSTN. The latter could be made utterly irrelevant with VoIP. The former could be solved in various ways, either by making it a public good, or by integrating anonymous payment mechanisms for a "session". Then, we could just have pervasive data connections.

[im3w1l]

To some extent I agree, but if the modem is off how long latency is acceptable for inbound messages? I suppose a low bandwidth broadcast "user 0x76abc937* has a new message" could work. Devices would filter out broadcasts that don't concern them.

* Ideally the user id should be used only once and derived from some pre-shared secret.

[JoshTriplett]

I'm talking about two different cases here.

First, in a case closer to the current world, I'm just suggesting that disabling the cell modem should power it off so it can't do any kind of location or tracking.

Second, in a more ideal world, the concept of "data connection" would be entirely separate from any identity attached to a phone or text message, and you could handle the latter via whatever connection you have, whether a cell data connection or wifi or something else.

[im3w1l]

That makes a lot of sense.