When, after a successful attachment to a standalone NB-IoT enode, the GM02S is detached and a new attachment is attempted, the GM02S sends an incorrect RRC message instead of an RRC Connection Setup Complete message.
10:38:48.114 [RRC] UL 0017 DCCH-NB: can’t decode message
0000: 10 44 20 00 40 58 85 d5 c7 37 e4 82 01 d0 44 82 .D .@X…7…D.
0010: fd 8c bd 01 60 00 40 5d 33 70 36 41 fc 3c 00 00 …`.@]3p6A.<..
0020: 00 21 02 00 0a c0 80 f4 04 74 5e c0 08 e0 20 08 .!..t^… .
0030: 44 00 40 00 04 20 41 80 00 00 00 20 c1 80 00 00 D.@.. A… …
0040: 00 00 02 80 00 03 40 00 03 80 00 05 80 00 06 40 …@…@
0050: 14 8c bd 01 40 00 84 cc bd 01 40 00 44 40 d1 c2 …@…@.D@..
0060: 00 3d 78 30 44 00 a6 e0 20 .=x0D…
+SVER: BootloaderOTP, “NA”, 0
+SVER: Bootloader0, “8.2.1.0 [61488]”, 1
+SVER: Bootloader1*, “8.2.1.0 [61488]”, 1
+SVER: Bootloader2, “NA”, 0
+SVER: Updater, “NA”, 0
+SVER: UE, “8.2.1.0 [61488] by robot-soft at 2024-07-22 16:27:48”, 1
+SVER: M1-L1P, “8.2.1.0 [61488] by robot-soft at 2024-07-22 16:27:48”, 1
+SVER: NB1-L1P, “8.2.1.0 [61488] by robot-soft at 2024-07-22 16:27:48”, 1
+SVER: ZSP0_CATM, “2.0.0-16859”, 1
+SVER: ZSP0_NB1, “1.0.98-693”, 1
+SVER: ZSP1_CATM, “1.0.99-16912”, 1
+SVER: ZSP1_NB1, “1.0.98-693”, 1
+SVER: PXL, “8.2.1.0-61488”, 1
+SVER: Ecopaging, “8.2.1.0 [61488] by robot-soft at 2024-07-22 16:27:48”, 1
Hi,
To understand this issue, we would need to compare and match each message from the UE NAS and RRC layers against the messages of the eNB, starting from the first successful attachment until the failure.
Would you be able to record the UE log with the DM Light Tool ? The tool is available at Sequans Communications with your customer account, or at Sequans Communications with your individual account.
To record with the DM Light tool:
- Plug the UART1 of the GM02S module to the PC
- Open the DM Light tool
- Click on “Connect”. It will take 5~10 seconds for the modem to be detected
- Once the DM Light tool is connected to the modem, click on the “Start record” button.
- Click on “Change path” to choose where to record the log. Leave the other recording configuration parameters by default, it will record NAS and RRC messages.
- Click “Start Record”.
- In parallel, also start recording logs on the eNB side
- From the MCU or UART0 terminal, do AT+CFUN=1 to start attach to network
- Wait until the problem happens
- On the DM Light tool, click on “Stop record” button.
The DM Light tool will produce the UE log in a “.evt” file.
Please attach the UE and eNB log files here.
For the UE “.evt” log, You may use the menu "File → Export from EVT to PCAP” to generate a Wireshark file. It allows you to see the RRC and NAS layer messages from Wireshark.
We will compare messages one by one between the UE and the eNB, to see at which point the UL RRC received message is invalid, and what the UE had actually sent to the eNB.
Best regards,
Benoit.
Thanks for your message
Attached requested files.
Do not hesitate if you need some information more.
Kind Regards
enb0.log (85.0 KB)
359197350570710_2026-03-02-18h24m08.evt (306.1 KB)
Hi,
Thank you for the logs.
On the DM Light Tool EVT log file, somehow, the RRC messages where not recorded and only 1 NAS message was recorded.
We can still match the timing of these messages, but we don’t have the RRC message on UE side:
UE:
18:25:20’574.64> UL NAS Attach request :
17 00 00 00 00 04 07 41 12 0b f6 32 f4 05 00 02 01 c2 00 48 ba 07 f0 f0 00 00 00 84 08 00 2b 02 03 d0 11 d1 7b 00 23 80 80 21 10 01 00 00 10 81 06 00 00 00 00 83 06 00 00 00 00 00 0a 00 00 0d 00 00 0e 00 00 16 00 00 19 00 52 32 f4 05 00 02 90 11 03 47 08 00 f5 e0 c1
eNB:
17:25:17.216 [RRC] UL 001b CCCH-NB: RRC Connection Request
17:25:17.216 [RRC] DL 001b CCCH-NB: RRC Connection Setup
17:25:17.327 [RRC] - 001b DCCH-NB: ASN1 decode error
17:25:17.327 [RRC] UL 001b DCCH-NB: can’t decode message
0000: 10 44 00 00 80 56 45 ea 19 9c d8 41 01 d0 44 82 .D…VE…A..D.
0010: fd 8c bd 01 40 00 80 70 80 12 2e 81 fc 3c 00 00 …@..p…<..
0020: 00 21 02 00 0a c0 80 f4 04 74 5e c0 08 e0 20 08 .!..t^… .
0030: 44 00 40 00 04 20 41 80 00 00 00 20 c1 80 00 00 D.@.. A… …
0040: 00 00 02 80 00 03 40 00 03 80 00 05 80 00 06 40 …@…@
0050: 14 8c bd 01 40 00 a4 04 40 d1 c2 00 3d 78 30 60 …@…@…=x0`
I notice that your Amarisoft eNB version is very old from 2017!
# lteenb version 2017-06-02, gcc 6.3.1
There is a very high chance that the reason of the issue is the eNB version. Do you have any possibility to upgrade to a more recent version ?
If not, we can try to get another DM Light log by changing the log mask. I attach to this comment a “.dmrec” log mask file. After you click on “Start Record” button from the main window, click on “Change Configuration” button, and select the attached “.dmrec” file. Then, click on “Start record” button.
During the recording, try several time attach and detach, so we can catch some successful and failed cases. Also extract the corresponding eNB log.
Best regards,
Benoit.
Cat-M_NB_default_mask.dmrec (1.1 KB)