Modem not trying other PLMN's if nw_mode is not included in the dataplan?

RE: Modem not trying other PLMN's if nw_mode is not included in the dataplan?

JyriLehtinen — Wed, 02 Oct 2024 10:59:59 GMT

Great. I'll report back when I've tested with a fresh device whether I can replicate the original issue.
After that I'll change the CONFIG_LTE_UNLOCK_PLMN=y in the prj.conf and remove the AT+COPS=0-call.

RE: Modem not trying other PLMN's if nw_mode is not included in the dataplan?

Øyvind — Wed, 02 Oct 2024 10:56:51 GMT

Thanks for the info. Good to hear that AT+COPS=0 fixed the issue on your side. The CONFIG_LTE_UNLOCK_PLMN=y is equivalent to AT+COPS=0 in the LTE link controller.

[quote user="JyriLehtinen"]The application code now calls COPS=0 while starting, so it's been able to connect consistently.[/quote]

Just an FYI, as long as you do not often use PLMN lock there is no reason to call this on every startup of the application.

Kind regards,
Øyvind

RE: Modem not trying other PLMN's if nw_mode is not included in the dataplan?

JyriLehtinen — Tue, 01 Oct 2024 07:59:07 GMT

The application code now calls COPS=0 while starting, so it's been able to connect consistently. In normal operation, I have CONFIG_LTE_NETWORK_MODE_LTE_M_NBIOT=y and LTE-M as preference, but for this test I've disabled LTE-M.

CONFIG_LTE_CONNECT_RETRY_DELAY_S=120
CONFIG_LTE_LINK_CONTROL=y
# CONFIG_LTE_LOCK_BANDS is not set
# CONFIG_LTE_LOCK_PLMN is not set
# CONFIG_LTE_UNLOCK_PLMN is not set
CONFIG_LTE_PSM_REQ=y
CONFIG_LTE_PSM_REQ_FORMAT_STRING=y
# CONFIG_LTE_PSM_REQ_FORMAT_SECONDS is not set
CONFIG_LTE_PSM_REQ_RPTAU="11000001"
CONFIG_LTE_PSM_REQ_RAT="00000101"
CONFIG_LTE_PSM_REQ_RPTAU_SECONDS=1800
CONFIG_LTE_PSM_REQ_RAT_SECONDS=60
# CONFIG_LTE_PROPRIETARY_PSM_REQ is not set
# CONFIG_LTE_EDRX_REQ is not set
CONFIG_LTE_EDRX_REQ_VALUE_LTE_M="1001"
CONFIG_LTE_EDRX_REQ_VALUE_NBIOT="1001"
CONFIG_LTE_PTW_VALUE_LTE_M=""
CONFIG_LTE_PTW_VALUE_NBIOT=""
# CONFIG_LTE_NETWORK_MODE_DEFAULT is not set
# CONFIG_LTE_NETWORK_MODE_LTE_M is not set
# CONFIG_LTE_NETWORK_MODE_LTE_M_GPS is not set
CONFIG_LTE_NETWORK_MODE_NBIOT=y
# CONFIG_LTE_NETWORK_MODE_NBIOT_GPS is not set
# CONFIG_LTE_NETWORK_MODE_LTE_M_NBIOT is not set
# CONFIG_LTE_NETWORK_MODE_LTE_M_NBIOT_GPS is not set
CONFIG_LTE_MODE_PREFERENCE_AUTO=y
CONFIG_LTE_MODE_PREFERENCE_VALUE=0
# CONFIG_LTE_RAI_REQ is not set
CONFIG_LTE_RAI_REQ_VALUE="0"
# CONFIG_LTE_NETWORK_USE_FALLBACK is not set
CONFIG_LTE_NETWORK_TIMEOUT=300
# CONFIG_LTE_LC_TAU_PRE_WARNING_NOTIFICATIONS is not set
CONFIG_LTE_LC_TAU_PRE_WARNING_TIME_MS=5000
CONFIG_LTE_LC_TAU_PRE_WARNING_THRESHOLD_MS=1200000
CONFIG_LTE_NEIGHBOR_CELLS_MAX=10
# CONFIG_LTE_LC_MODEM_SLEEP_NOTIFICATIONS is not set
CONFIG_LTE_LC_MODEM_SLEEP_PRE_WARNING_TIME_MS=5000
CONFIG_LTE_LC_MODEM_SLEEP_NOTIFICATIONS_THRESHOLD_MS=1200000
# CONFIG_LTE_LC_TRACE is not set
# CONFIG_LTE_LINK_CONTROL_LOG_LEVEL_OFF is not set
# CONFIG_LTE_LINK_CONTROL_LOG_LEVEL_ERR is not set
# CONFIG_LTE_LINK_CONTROL_LOG_LEVEL_WRN is not set
# CONFIG_LTE_LINK_CONTROL_LOG_LEVEL_INF is not set
# CONFIG_LTE_LINK_CONTROL_LOG_LEVEL_DBG is not set
CONFIG_LTE_LINK_CONTROL_LOG_LEVEL_DEFAULT=y
CONFIG_LTE_LINK_CONTROL_LOG_LEVEL=3

If I re-enable LTE-M and set it as preference, the device will join DNA (24412) over LTE-M. Makes sense, as it was the PLMN it was previously connected to.

By manually connecting to Elisa (24405), then removing the "AT+COPS=1,2,24405", reflashing with NB-Iot only, it does manage to connect to DNA over NB-IoT, without explicit AT+COPS=0, just the lte_lc_connect_async()

As I'm unable to replicate the original issue with this device, I think it might have been because the device in question had never connected to DNA before, and for some reason didn't try. I think I need to get a fresh device at some point and try to replicate the issue.

RE: Modem not trying other PLMN's if nw_mode is not included in the dataplan?

Øyvind — Mon, 30 Sep 2024 18:29:58 GMT

[quote user="JyriLehtinen"]Is there a reason why lte_lc_connect_async() doesn't behave the same or is something misbehaving?[/quote]

The lte_lc_connect_async() is essentially just sending AT+CFUN=1.

[quote user="JyriLehtinen"]Calling AT+COPS=0 seemed to do the trick, device now connected to DNA network on NB-IoT[/quote]

After rebooting the device, do you still have a connection? In the .config file found in build/zephyr of you project folder, are you able to see if what CONFIG_LTE* that are set?

Here is an example from a project I have:

CONFIG_LTE_LINK_CONTROL=y
# CONFIG_LTE_LOCK_BANDS is not set
# CONFIG_LTE_LOCK_PLMN is not set
# CONFIG_LTE_UNLOCK_PLMN is not set
CONFIG_LTE_PSM_REQ=y
CONFIG_LTE_PSM_REQ_FORMAT_STRING=y
# CONFIG_LTE_PSM_REQ_FORMAT_SECONDS is not set
CONFIG_LTE_PSM_REQ_RPTAU="11000001"
CONFIG_LTE_PSM_REQ_RAT="00001010"
CONFIG_LTE_PSM_REQ_RPTAU_SECONDS=1800
CONFIG_LTE_PSM_REQ_RAT_SECONDS=60
# CONFIG_LTE_PROPRIETARY_PSM_REQ is not set
# CONFIG_LTE_EDRX_REQ is not set
CONFIG_LTE_EDRX_REQ_VALUE_LTE_M="1001"
CONFIG_LTE_EDRX_REQ_VALUE_NBIOT="1001"
CONFIG_LTE_PTW_VALUE_LTE_M=""
CONFIG_LTE_PTW_VALUE_NBIOT=""
# CONFIG_LTE_NETWORK_MODE_DEFAULT is not set
# CONFIG_LTE_NETWORK_MODE_LTE_M is not set
# CONFIG_LTE_NETWORK_MODE_LTE_M_GPS is not set
# CONFIG_LTE_NETWORK_MODE_NBIOT is not set
# CONFIG_LTE_NETWORK_MODE_NBIOT_GPS is not set
# CONFIG_LTE_NETWORK_MODE_LTE_M_NBIOT is not set
CONFIG_LTE_NETWORK_MODE_LTE_M_NBIOT_GPS=y
# CONFIG_LTE_MODE_PREFERENCE_AUTO is not set
# CONFIG_LTE_MODE_PREFERENCE_LTE_M is not set
# CONFIG_LTE_MODE_PREFERENCE_NBIOT is not set
CONFIG_LTE_MODE_PREFERENCE_LTE_M_PLMN_PRIO=y
# CONFIG_LTE_MODE_PREFERENCE_NBIOT_PLMN_PRIO is not set
CONFIG_LTE_MODE_PREFERENCE_VALUE=3
# CONFIG_LTE_RAI_REQ is not set
CONFIG_LTE_RAI_REQ_VALUE="0"
# CONFIG_LTE_NETWORK_USE_FALLBACK is not set
CONFIG_LTE_NETWORK_TIMEOUT=600
# CONFIG_LTE_LC_TAU_PRE_WARNING_NOTIFICATIONS is not set
CONFIG_LTE_LC_TAU_PRE_WARNING_TIME_MS=5000
CONFIG_LTE_LC_TAU_PRE_WARNING_THRESHOLD_MS=1200000
CONFIG_LTE_NEIGHBOR_CELLS_MAX=10
# CONFIG_LTE_LC_MODEM_SLEEP_NOTIFICATIONS is not set
CONFIG_LTE_LC_MODEM_SLEEP_PRE_WARNING_TIME_MS=5000
CONFIG_LTE_LC_MODEM_SLEEP_NOTIFICATIONS_THRESHOLD_MS=1200000
# CONFIG_LTE_LC_TRACE is not set

Thanks.

Kind regards,
Øyvind

RE: Modem not trying other PLMN's if nw_mode is not included in the dataplan?

Øyvind — Mon, 23 Sep 2024 15:15:26 GMT

Thanks for clarifying! Happy to hear that it is working as intended.

I have forwarded the question and hope to have an answer by tomorrow.

Kind regards.
Øyvind

RE: Modem not trying other PLMN's if nw_mode is not included in the dataplan?

JyriLehtinen — Fri, 20 Sep 2024 13:51:46 GMT

Calling AT+COPS=0 seemed to do the trick, device now connected to DNA network on NB-IoT. Without the AT command it was offline for days until I terminated the test.

Is there a reason why lte_lc_connect_async() doesn't behave the same or is something misbehaving?

RE: Modem not trying other PLMN's if nw_mode is not included in the dataplan?

JyriLehtinen — Fri, 20 Sep 2024 13:43:08 GMT

The application does not explicitly call AT+COPS=0, it uses lte_lc_connect_async().

I can try if adding the AT+COPS=0 works.

RE: Modem not trying other PLMN's if nw_mode is not included in the dataplan?

Øyvind — Fri, 20 Sep 2024 13:27:31 GMT

Have you issued AT+COPS=0

Note: The set command selects a mobile network automatically or manually. The command configuration is stored to NVM approximately every 48 hours and when the modem is set to minimum functionality mode with the +CFUN=0 command.

RE: Modem not trying other PLMN's if nw_mode is not included in the dataplan?

JyriLehtinen — Fri, 20 Sep 2024 13:20:37 GMT

But in my case, it does not automatically try to attach to other networks, even though it should

RE: Modem not trying other PLMN's if nw_mode is not included in the dataplan?

Øyvind — Fri, 20 Sep 2024 13:18:54 GMT

Reject cause is #15 “No suitable cells in tracking area” is sent by network when the subscription does not allow operation in the tracking area of this network. In automatic network selection mode (AT+COPS=0) modem can try to Attach also to other networks in the area. In manual network selection mode modem just tries to find another, allowed tracking area within the same, manually selected network.

RE: Modem not trying other PLMN's if nw_mode is not included in the dataplan?

JyriLehtinen — Wed, 18 Sep 2024 11:31:16 GMT

Right, makes sense. However, the modem does not connect to other allowed PLMN's in this case, but remains disconnected until LTE-M is enabled or PLMN is selected manually with AT+COPS.

RE: Modem not trying other PLMN's if nw_mode is not included in the dataplan?

Øyvind — Wed, 18 Sep 2024 10:54:00 GMT

From the modem trace it is clear that your device is rejected from the NB-IoT network

CEREG: 2,"BFE1","00120A67",9,0,15

Cause #15 – No suitable cells in tracking area
This EMM cause is sent to the UE if it requests service, or if the network initiates a detach request, in a tracking
area where the UE, by subscription, is not allowed to operate, but when it should find another allowed tracking
area or location area in the same PLMN or an equivalent PLMN.

Kind regards,
Øyvind

RE: Modem not trying other PLMN's if nw_mode is not included in the dataplan?

JyriLehtinen — Wed, 18 Sep 2024 08:19:43 GMT

The operator is 1oT

Plan is 1oT Global eUICC, "optimal coverage"

RE: Modem not trying other PLMN's if nw_mode is not included in the dataplan?

Øyvind — Wed, 18 Sep 2024 07:56:01 GMT

Hello,

Thank you for providing modem traces and information on modem fw version. I will have a look at the trace. What SIM card are you using?

Kind regards,
Øyvind