Measured scanning procedure a few minutes after connection establishment

RE: Measured scanning procedure a few minutes after connection establishment

Christian22 — Tue, 29 Nov 2022 10:10:28 GMT

Hi all,

Sorry for the delay, I was in vacation and I'm also very busy this week so I will come back to the question next week.

RE: Measured scanning procedure a few minutes after connection establishment

Achim Kraus — Mon, 21 Nov 2022 15:35:02 GMT

I'm not really wondering, that the answer in this other ticket is slightly different. Maybe, an other expert has a different view on it. Using +COPS is exactly the opposite, the HPPLMN is good for. So I'm really not wondering, that the expert involved here doesn't recommend it.

> "The only true workaround would be to use only home network instead of roaming as in home network there are no HPPLMN searches."

At that point I' struggling. I use several SIM card providers in several countries. Exactly 0 of them are reporting to be in the "home network", all are reporting "roaming". If you read the other ticket, the question there was, how someone knows, that device spends energy in such HPPLMS searchs. I use the time from RRC idle to sleep and that indicates, that it doesn't depend on "home network" or "roaming", it's more the question, if your modem connects already to a "highest priority network".

With an explicit event for such HPPLMNS search (that's requested in the other ticket), Nordic would make this transparent to users and the users may be able to chose the proper SIM card for the region. That saves a lot of energy.

RE: Measured scanning procedure a few minutes after connection establishment

Michal — Mon, 21 Nov 2022 14:42:36 GMT

Hello again Christian,

Sorry for the long delay, I had an unexpected event I had to attend to.

I have consulted my colleagues about it and using the +COPS command is not recommended for that at all.

The issue is that when using a SIM card in roaming mode, the card has to do those searches as it is something required by the 3GPP specification.

The only true workaround would be to use only home network instead of roaming as in home network there are no HPPLMN searches.

Best regards,

Michal

RE: Measured scanning procedure a few minutes after connection establishment

Susheel Nuguru — Tue, 15 Nov 2022 12:16:48 GMT

Sorry for delays in the response, Michal is currently OoO and will return in few days. I need to seek some help from the colleagues on your last query as I am not an expert in this.

RE: Measured scanning procedure a few minutes after connection establishment

Michal — Fri, 04 Nov 2022 13:35:04 GMT

Hello Christian,

I will look more into it.

Best regards,

Michal

RE: Measured scanning procedure a few minutes after connection establishment

Christian22 — Thu, 03 Nov 2022 13:15:14 GMT

Thanks for your answers.

The +COPS command did the job in the first test. But how can I handle it if I sell the product almost world wide? How flexibile is the +COPS command if it is used in semi mobile devices?

Would it be possible to start the nrf9160 in automatic network search mode and change the network search to manual mode after the connection has been established for the first time in case the device is used in the same location for a longer time?

Would it also be possible switch back to automatic mode at any time in case the device is moved to another location?

RE: Measured scanning procedure a few minutes after connection establishment

Michal — Tue, 01 Nov 2022 12:49:41 GMT

Thank you for the link Achim.

Christian, please let me know if that answer satisfies you, or if we should look more into it.

Best regards,

Michal

RE: Measured scanning procedure a few minutes after connection establishment

Achim Kraus — Mon, 31 Oct 2022 07:15:37 GMT

Seems to be a topic, which irritates more people. Here is an link with some additional background information:

nRF9160-DK - sometimes busy for 1 minute before entering PSM

It's a little long to read all the comments, but after passing the questions the issue was answered by the modem team:

"The log shows that there is Higher Priority PLMN (HPPLMN) search initiated after one of the RRC connection releases and that caused the delay."

In the case, you operate the device more statically, you may try to use a PLMN lock, which suppresses such HPPLMN searches (see the comments after the answer).