Failover roaming

My MNO has an arrangement whereby on designated towers, if my MNO is unavailable then the phone can roam to another specific MNO, at no cost to the customer. So if there is a hardware failure on a tower that is specific to my MNO, it can be designated by the MNO to allow roaming in this way, and the failure is essentially transparent to the customer. (This was originally designed simply to expand the coverage of my MNO i.e. in areas where they have no coverage at all, the customer can roam to the other MNO, at no cost to the customer.)

Here’s my problem:

This works on my gf’s iPhone.
This doesn’t work on the Librem 5.

I have no knowledge of really how this works internally. I have described it above as best I can.

On the one hand, this might seem like a niche situation that is not worth developer time on. On the other hand, the situation where widespread hardware failures have occurred might be exactly the situation where being unable to use a mobile is a major problem. (You can presumably still call the emergency number if the major problem becomes a life-threatening problem.)

Such as is occurring right now, hence why I am aware of this problem.

Any insights on what I should be trying? (I can’t guarantee how long my MNO will be out on the tower however.)

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One thing could be to try in other phones as well, if you can get your hands on some other phone(s) to test with. To see if it works on all phones except the Librem 5 or if some other phones have the problem as well.

In the F-Droid store on android there are apps that analyse, map, track or log nearby cellular transmitters, IIRC. Maybe that helps to see which transmitters are there and which you connect to. I am unaware of such software for Linux. There may be. I just don’t know.

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The pinephone has the option to allow roaming in the WWAN/mobile settings (using manjaro phosh). I guess you checked there already?

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The L5 has a Data Roaming toggle in the Mobile settings.
I’m not sure if that is specific to national, or international roaming.

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From what I read it’s “tower” roaming, so I think it’s applicable to this case.

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Yes. While I don’t know what that toggle actually does, I did already try to enable it, and have left it enabled, and have rebooted many times since. So I’m pretty confident that that setting is not doing the trick.

I would suppose that not too many people are able to test international roaming, myself included.

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Good suggestion. Was just in the process of charging up another phone to try that and … the MNO has fixed the fault. So I don’t think I can make any further progress on diagnosing this … until the next extreme weather event. :wink:

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