03-17-2022, 03:08 AM
It's not as simple as saying "LTE Just Works" - it won't for everyone, for a variety of reasons. One of these is the modem firmware's limited selection of profiles as discussed in this issue for the open version of the modem firmware:
https://github.com/Biktorgj/pinephone_mo...1046315286
That isn't the problem in the case above though - with the SIM from the iPhone the modem in the PinePhone works with VoLTE, and with the SIM from the PinePhone the iPhone can't do VoLTE. The other part of the problem is that, whether by misconfiguration or by policy, some carriers block VoLTE from some phones that are capable of using it. Some are openly operating explicit allow or block lists of phone models. It appears AT&T aren't doing this, but are inappropriately associating VoLTE capability with the SIM not the phone, with no clear explanation of how it gets set or how it can be corrected.
https://github.com/Biktorgj/pinephone_mo...1046315286
That isn't the problem in the case above though - with the SIM from the iPhone the modem in the PinePhone works with VoLTE, and with the SIM from the PinePhone the iPhone can't do VoLTE. The other part of the problem is that, whether by misconfiguration or by policy, some carriers block VoLTE from some phones that are capable of using it. Some are openly operating explicit allow or block lists of phone models. It appears AT&T aren't doing this, but are inappropriately associating VoLTE capability with the SIM not the phone, with no clear explanation of how it gets set or how it can be corrected.
