NB-IOT JIO SIM Not connecting asset tracker Work Up to RRC Connected and stuck there.

[Hardik.Harpal]

Using NB- IOT JIO SIM in india, not connecting asset tracker Work Up to RRC Connected and stuck there. This is custom code very similar to asset tracker example. We are using custom board, same setup works fine on Ibasis SIM in USA.

[00:00:00.215,576] [0m<inf> asset_tracker: Connecting to LTE network.[0m
[00:00:00.215,942] [0m<inf> asset_tracker: This may take several minutes.[0m
[00:00:00.223,205] [0m<dbg> lte_lc.lte_lc_system_mode_set: Sending AT command to set system mode: AT%XSYSTEMMODE=0,1,1,0[0m
[00:00:00.259,643] [0m<inf> lte_lc: PDP Context: AT+CGDCONT=0,"IPV6","JioIPIoT"[0m
[00:00:00.267,608] [0m<dbg> lte_lc.lte_lc_system_mode_set: Sending AT command to set system mode: AT%XSYSTEMMODE=0,1,1,0[0m
[00:00:27.635,711] [0m<dbg> lte_lc.at_handler: +CEREG notification: +CEREG: 2,"C061","00282218",9
[0m
[00:00:27.636,444] [0m<inf> asset_tracker: LTE cell changed: Cell ID: 2630168, Tracking area: 49249[0m

trace-2021-07-13T00-06-58.563Z.pcapng

trace-2021-07-13T00-06-58.563Z.bin

[Heidi]

Hi! Håkon has gone on vacation so I have taken over this case.

The conclusion from the modem trace you provided is that the Attach procedure is prevented due to the modem reset loop restriction feature which was introduced in MFW 1.3.0. We have just released a white paper on the feature which should explain the functionality in detail: nWP042 - nRF9160 Modem Reset Loop Restriction

In short, the feature restricts Attach attempts to the network for 30 minutes in the case where the modem detects that the UE is in a reset loop. This can also happen if the modem is manually reset too many times.

The AT+CFUN = 0 command should be used for shutting down the modem gracefully in order to avoid this restriction. 

Please let me know if this solves the issue you are seeing. 

Best regards,

Heidi

[Hardik.Harpal]

Hi,

But I am seeing similar results in Modem firmware version 1.2.3 and earlier version on Dev kit I have 1.2.3 let me send you modem log from it. I will use MQTT simple example and configure it for nbiot.

Can AT_Client example running with link monitor can provide modem trace by default or do I have to change prj config changes to enable it?

Can you analyze this  new log withing next 22 hours? I have meeting with  JIO support team. If anything from their side I can provide our observation from Log they're asking for more detailed modem log as I explained in previous replies, I shared same modem trace (wireshark playable) with them. There are higher chances it is from network, but we need to figure it out as it is a month long now.

Regards,

Hardik Harpal

[Hardik.Harpal]

Please find modem trace NCS 1.5.1. More info (LTE Physical, MAC, RRC, NAS signaling) is required by JIO. Info already there in PCAP is not sufficient for them to analyze issue. 

 trace-2021-08-12T09-23-55.246Z.bin

trace-2021-08-12T09-23-55.246Z.pcapng

[Heidi]

Hi,

Unfortunately, in the new log, the Attach is still blocked by the modem reset loop detection.

If the modem is reset during the wait period (i.e during the blocking), the wait period is restarted with the initial wait time of 30 minutes. 

There is a network cell available according to the log, but you must keep the device powered on and wait 30 minutes for the reset loop detection to go away. 

Please take a new modem trace of this. 

[Hardik.Harpal]

Hi,

Modem FW Version 1.2.3, NCS 1.6.0, AT Client App, Modem Trace Enabled. Using At command using link monitor to test NBIoT JIO SIMs.

trace-2021-08-17T05-55-25.899Z.bin

trace-2021-08-17T05-55-25.899Z.pcapng

[Heidi]

Hi, we need the modem trace with MFW 1.3.0, because that's the version with the reset loop functionality.

Please take a new trace using MFW 1.3.0 and wait 30 minutes for the reset loop detection to go away. 

. 

[Hardik.Harpal]

Heidi

I will provide that log in next 30 minutes, but I have confusions.

1)  My problem is not reset loop but Network registration issue which is also happening in modem firmware 1.2.3. Is it not possible to find out the reason from that log what is LTE level error? I think it is possible. Our development is stuck due to this issue can we at least make it work on modem firmware 1.2.3 where there is no reset loop then meanwhile we can also work on modem fw v1.3.0 in parallel. Our objective is to find out why NBIOT registration failing in any modem fw version we can use.

Please can we not find anything related issue in this log because my doubt is after submitting new log from 1.3.0 without reset loop we will see similar issue in log as current log, and then it will take one extra day to start from there  

2) I have nrf9160 SIP marked B0, but it is showing Model: NRF9160_xxAA_REV2.in nrf programmer but as per modem firmware download section it is showing  \different B0 = Rev1 and as per guideline it is recommended to use rev1.3.0 on B1 = Rev 2 So can you clarify I am hesitating to use modem fw version 1.3.0 on our custom board I had one board with modem FW1.3.0 due to some hardware issue that board is not working. I need to upgrade modem fw in another board but is it safe.