LTE-m Reconnect after LoS

RE: LTE-m Reconnect after LoS

helsing — Wed, 21 Dec 2022 12:48:00 GMT

Hi,

Great news! I have let the modem team know. Thank you for performing the tests and confirming this works!

Best regards,

Håkon

RE: LTE-m Reconnect after LoS

ibiglari — Mon, 19 Dec 2022 03:22:03 GMT

[quote userid="90815" url="~/f/nordic-q-a/93386/lte-m-reconnect-after-los/398083"]The MFW team had actually recently prepared a test firmware for you[/quote]

Hi,

I can confirm the combination of the test firmware and SDK 2.2.0 Asset Tracker over LwM2M has been stable, with no issue after LoS.

Kind Regards,
Iman

RE: LTE-m Reconnect after LoS

helsing — Mon, 12 Dec 2022 12:50:57 GMT

Thank you for the update. It will be interesting to hear how it goes 🙂

RE: LTE-m Reconnect after LoS

ibiglari — Mon, 12 Dec 2022 01:06:33 GMT

Hi,

A little bit of good news. I moved my changes to asset tracker v2 to the latest SDK (2.2.0) which uses Location library instead of gnss module, and could not make the tracker lose connection permanently while driving or flying. I am planning on performing more tests within the week, but fingers crossed the issue is now resolved 🙂

I will update the ticket by Friday (or sooner if I can reproduce the issue).

Kind Regards,
Iman

RE: LTE-m Reconnect after LoS

ibiglari — Thu, 08 Dec 2022 21:13:33 GMT

Hi,

The application is asset tracker v2 (slightly modified to include SUPL library for faster TTFF), running in ACTIVE mode.

Last data packet was received by the server at 06:48:52 (local time). The logs end at (around) 07:05:00 (again local time) when I turned the device off.The instances of `LWM2M_RD_CLIENT_EVENT_NETWORK_ERROR` in the log are about two minutes apart.

Regarding your questions about timing, I'm not sure. However asset tracker v2 is set up, that's the way it is working.

I will capture a longer log on Sunday when I am driving out of town. Glad the logs are readable :)

RE: LTE-m Reconnect after LoS

helsing — Thu, 08 Dec 2022 13:24:56 GMT

Hi, and thank you for the logs.

Our modem team has had a look and did not find anything wrong. They found a couple of cell losses where the modem is able to find the cell again. Unfortunately there are no time stamps in the application log indicating when the problem appears.

Could you please confirm that the problem in the latest log is that data is not successfully transferred? How often does the application send data? And how soon is it considered that the transmission is failed? We are asking because the simultaneous usage of GNSS and LTE may affect LTE functionality. There are also neighbor cell measurement requests which take some time, too.

RE: LTE-m Reconnect after LoS

ibiglari — Wed, 07 Dec 2022 20:47:25 GMT

Hi,

Perfect. Attached!

RE: LTE-m Reconnect after LoS

helsing — Wed, 07 Dec 2022 14:53:29 GMT

[quote user="ibiglari"]I was wondering if you could check to see whether this log is readable or not?[/quote]

Yes, this log seems readable. Please capture a log of the failure scenario and we will analyze it.

RE: LTE-m Reconnect after LoS

ibiglari — Wed, 07 Dec 2022 00:44:21 GMT

Hi,

Made a few changes to my serial port app and captured another log. This log is not a "failure" log as the device was just sitting on my table. I was wondering if you could check to see whether this log is readable or not? If it is, I will use the same piece of software to capture logs while traveling.

devzone.nordicsemi.com/.../2022_5F00_12_5F00_07_5F00_10_5F00_19_5F00_AM_2D00_trace.log.gz

RE: LTE-m Reconnect after LoS

ibiglari — Tue, 06 Dec 2022 09:56:42 GMT

Hi,

I'm afraid that's almost impossible as my laptop is in dire need of a new battery. I wish it were possible to compile your trace collector for ARM.

RE: LTE-m Reconnect after LoS

helsing — Tue, 06 Dec 2022 09:29:49 GMT

Hi Iman,

Thank you very much for generating logs. Unfortunately, these logs were not possible to read:

It turns out that the old logs also were more difficult to read than initially thought.

The modem team is checking out these logs now:

Is there any chance you could capture modem traces using a laptop so that you could capture the standard way?

RE: LTE-m Reconnect after LoS

ibiglari — Mon, 05 Dec 2022 20:44:55 GMT

Hi,

3rd set of logs attached. Again, happened while driving (and going through a tunnel).

I have increased the buffer in my logger from 256 bytes to 65535. Hopefully it also resolves the problem with buffers being truncated.

RE: LTE-m Reconnect after LoS

ibiglari — Sun, 04 Dec 2022 06:57:43 GMT

Hi,

Second set of logs attached. Happened while driving.

RE: LTE-m Reconnect after LoS

ibiglari — Sun, 04 Dec 2022 03:37:06 GMT

Hi,

First set of logs attached. Induced LoS using aluminum foil for about 10 minutes, and then unwrapping the unit and waiting for AoS for another 10 minutes.

RE: LTE-m Reconnect after LoS

helsing — Fri, 02 Dec 2022 14:27:21 GMT

It will probably be sufficient if you could provide new the soonest possible, the same way you did previously.

The feedback on the logs the first time was that "the logs appear to be very corrupted, mostly truncated trace buffers." There were some errors, however, they were still very useful.

RE: LTE-m Reconnect after LoS

ibiglari — Thu, 01 Dec 2022 19:57:24 GMT

Hi,

Thanks for your reply and will do. Could you please clarify what was wrong with previous logs? I might be able to modify the small piece of code I wrote to capture logs to fix it.

RE: LTE-m Reconnect after LoS

helsing — Thu, 01 Dec 2022 13:55:14 GMT

Thank you very much for the feedback. New logs would also be useful and appreciated.

RE: LTE-m Reconnect after LoS

ibiglari — Wed, 30 Nov 2022 20:39:28 GMT

Hi,

Seems like the problem still persists. If the logs I had captured previously (despite having a problem) are helpful, I can capture more logs using the same mechanism.

Kind Regards,
Iman

RE: LTE-m Reconnect after LoS

ibiglari — Tue, 29 Nov 2022 22:13:21 GMT

Hi,

Thanks for the update and your email. I will test the firmware over the next few days and weekend and will update this ticket.

RE: LTE-m Reconnect after LoS

helsing — Tue, 29 Nov 2022 11:48:13 GMT

Hi Iman,

Good thing you asked. The MFW team had actually recently prepared a test firmware for you that includes the fix for your issue. I have emailed the firmare to you, along with the license. This is a version that can be used only for R&D and test purposes.

Your feedback will be appreciated.

Best Regards,

Håkon

RE: LTE-m Reconnect after LoS

ibiglari — Tue, 29 Nov 2022 08:39:03 GMT

Hi,

Is there any projection on when MFW 1.3.4 might be available?

Also, if there is a need to test the firmware, I am more than happy to flash a pre-release and provide the logs. I am effectively stuck until I can move past this issue.

Kind Regards,
Iman

RE: LTE-m Reconnect after LoS

helsing — Mon, 07 Nov 2022 14:24:28 GMT

The solution the modem team point at is waiting for MFW 1.3.4.

They also replied that there is not need for new modem traces at the moment. The usual way is the official nRF Connect running on a PC.

RE: LTE-m Reconnect after LoS

ibiglari — Mon, 07 Nov 2022 10:46:02 GMT

Hi,

Thanks for the update.

As I mentioned earlier, I am forced to capture the trace logs on an ARM machine (Raspberry Pi) using basic Linux tools like cat. That might be the reason behind the logs being "incomplete" or somewhat corrupt. I understand nRF Connect is not available for ARM. I can try and write a custom application in C / C++ to open serial port and capture trace logs, but I thought I'd ask first if your team has ever captured these traces in a Linux shell without nRF SDK tools, and if yes, maybe you could advise how they have managed to achieve that.

Looking forward to your future updates.

Cheers,
Iman

RE: LTE-m Reconnect after LoS

helsing — Mon, 07 Nov 2022 10:30:37 GMT

For some reason, the modem traces are somewhat corrupted and new logs are probably needed. However, the traces are not unreadable and the modem team has been able to find a couple of things so far.

It appears that the fixes for the issue you are experiencing is not taken into MFW 1.3.3. I have asked for more details regarding future fixes and solutions.

Another issue was also found. I will keep you updated as the internal discussion is evolving.

RE: LTE-m Reconnect after LoS

ibiglari — Thu, 03 Nov 2022 11:10:59 GMT

Hi,

I'm using 2.1.0. I contemplated updating the SDK to 2.1.1, but since I have to reapply the modifications to Asset Tracker (implementing SUPL and replacing the LOG_XXX functions with my own), I'd need to find a little bit of free time. I'll give it a go on Saturday or Sunday anyway.

Cheers,
Iman