Non-persistent FPLMN

RE: Non-persistent FPLMN

Hakon — Tue, 20 Feb 2024 11:42:29 GMT

[quote user="Alex Rawstorne"]What is the preferred method or retaining a persistent PLMN list which is SIM agnostic?[/quote]

I'm not sure there is a good way for this. When the modem wakes up from PSM it should try to connect to the same network, so then you shouldn't need to worry about connecting to some other undesired network. But if you want to keep the FPLMN list in the modem at all times regardless of SIM then rewriting it to the modem seems like the best solution.

RE: Non-persistent FPLMN

JonathanG — Tue, 13 Feb 2024 13:26:19 GMT

Thanks Hakon. I agree and so that's my next plan.

I'll check the PLMN after connection with AT%XMONITOR against our list of forbidden PLMNs and if it matches, disconnect, update the FPLMN list on the SIM and connect again.

RE: Non-persistent FPLMN

Hakon — Tue, 13 Feb 2024 13:18:02 GMT

The modem will return to the same network after exiting PSM, if possible.

[quote user="JonathanG"]Do I need to be concerned about roaming after the FPLMN has disappeared?[/quote]

I would check the PLMN ID with %xmonitor after every +CEREG notification, if the concern is accidentally entering into a roaming network.

RE: Non-persistent FPLMN

Alex Rawstorne — Tue, 13 Feb 2024 12:44:17 GMT

Just some more info, customer says that when the modem is turned off (CFUN=0), and then turns on, the PLMN list is not persistent. This is not the case for the Onomondo SIM. They use 02, 1nce and Vodafone SIMS. After connection the SIM appears to power down and again the PLMN list is lost. What is the preferred method or retaining a persistent PLMN list which is SIM agnostic? Is there some unsolicited message they can use to reissue a refresh of the PLMN ?

RE: Non-persistent FPLMN

Achim Kraus — Mon, 12 Feb 2024 16:58:58 GMT

I'm just an other user. I did some tests about that list a couple of months ago and found that it depends on the SIM card. I don't have more details on it.

RE: Non-persistent FPLMN

JonathanG — Mon, 12 Feb 2024 14:58:17 GMT

Is there any more information available on this issue? We can't change SIM provider.

Do I need to be concerned about roaming after the FPLMN has disappeared? If so, should I eg trap the %XMODEMSLEEP notification to setup the FPLMN again?

RE: Non-persistent FPLMN

JonathanG — Mon, 12 Feb 2024 12:01:41 GMT

I am indeed doing this, but I also notice that the modem will power-down the SIM within a few minutes of connecting to save power, and then I worry that it might roam back onto a previously forbidden network...

RE: Non-persistent FPLMN

JonathanG — Mon, 12 Feb 2024 11:59:57 GMT

Unfortunately we don't have a contract with Flo.Live. Should I take this question up with our SIM providers?

RE: Non-persistent FPLMN

Achim Kraus — Mon, 12 Feb 2024 11:57:05 GMT

I guess, in order to use that function with these SIM cards, you will need to set the list on every on/off.

RE: Non-persistent FPLMN

Achim Kraus — Mon, 12 Feb 2024 11:55:44 GMT

Flo.Live keeps it ;-).

RE: Non-persistent FPLMN

JonathanG — Mon, 12 Feb 2024 11:53:40 GMT

I've tried three different SIM cards - Vodafone, O2 and 1nce. They all behaved the same, each one in turn forgetting the FPLMN list over a power-cycle.

RE: Non-persistent FPLMN

Achim Kraus — Mon, 12 Feb 2024 11:49:33 GMT

In my experience that depends on the used SIM-card.