Don't register while doing a network search with +COPS=?

RE: Don't register while doing a network search with +COPS=?

dejans — Tue, 15 Jul 2025 11:28:22 GMT

Hi,

What happens if you try to do manual selection of PLMN using AT+COPS=1,2,<PLMN>?

Best regards,
Dejan

RE: Don't register while doing a network search with +COPS=?

klaasg — Tue, 15 Jul 2025 07:43:08 GMT

Our command sequence is:

// lte_lc_system_mode_set(LTE_LC_SYSTEM_MODE_LTEM_NBIOT, LTE_LC_SYSTEM_MODE_PREFER_NBIOT);

// turning on notifications
TX: AT+CSCON=1
RX: OK
TX: AT+CEREG=5
RX: OK
TX: AT%MDMEV=2
RX: OK
TX: AT+CGEREP=1
RX: OK

// starting search
TX: AT+CFUN=1
> Exit sleep
RX: OK
TX: AT+CFUN?
RX: +CFUN: 1
RX: OK
TX: AT+COPS=?

// all kinds on notifications
> LTE searching
> LTE cell changed: Cell ID: -1, LAC: -1
> LTE cell changed: Cell ID: 102623837, LAC: 19110
> Mode NB-IoT
> ECL 0
> RRC mode: Connected
RX: +CGEV: ME PDN ACT 0,0
> Event: Search done
> LTE registered roaming
> PSM update: TAU: 93600, Active time: 0
> RRC mode: Idle
> LTE cell changed: Cell ID: 102623836, LAC: 19110
> Enter PSM

// results
RX: +COPS: (1,"","","20601",9),(2,"","","20610",9),(1,"","","20620",9)

As you can see, the modem connects to an NB-IoT network and then the results of +COPS=? only include NB-IoT networks.

RE: Don't register while doing a network search with +COPS=?

dejans — Tue, 15 Jul 2025 06:45:37 GMT

Hi,

Can you show your complete AT command sequence?

Best regards,
Dejan

RE: Don't register while doing a network search with +COPS=?

klaasg — Mon, 14 Jul 2025 10:13:45 GMT

Hi.

In summary:

We want to select a PLMN manually. We can do this with AT+COPS=1,2,"<PLMN>"
To know what PLMNs are available, so we use AT+COPS=?. We need this because our devices travel to many countries.
We see that the modem is registering on a network during the AT+COPS=? command. I think we don't want that because:
- We might want to prefer a different network.
- If it's connected on a NB-IoT network, it will not see LTE-M networks.

So our question is: can we search for available networks/PLMNs without registering on a network?

Thank you for your reply.

RE: Don't register while doing a network search with +COPS=?

dejans — Fri, 11 Jul 2025 12:23:54 GMT

Hi,

Can you provide details about your use case?

What would be desired modem behavior in your case?

Best regards,
Dejan