BG770A module "LIMSRV" Issue with while Attempting CAT M1 LTE via SK Telecom

Hello,

We are in the process of testing CAT M1 communication using the BG770A-GL module. We have successfully registered the service number with SK Telecom and are on “SRV” status. However, the status changes to “LIMITED” within a few seconds.

Below are some of the logs for your reference:

[2023-10-10_17:27:43:357]AT+CGDCONT=1,"IPV4V6","lte.sktelecom.com"
[2023-10-10_17:27:43:357]OK
[2023-10-10_17:27:45:287]
[2023-10-10_17:27:45:287]+QCOTA: 0
[2023-10-10_17:27:46:704]AT+QCDS?
[2023-10-10_17:27:46:704]+QCDS: "SRV","CAT-M",45005,2500,154420F,R13,3,154,18470,-102,-109,-7,3,0,0,0,0
[2023-10-10_17:27:46:704]OK
[2023-10-10_17:28:19:547]AT+CNUM
[2023-10-10_17:28:19:547]+CNUM: ,"01232982269",129
[2023-10-10_17:28:19:547]OK
[2023-10-10_17:28:33:356]AT+QICSGP=1,3,"lte.sktelecom.com","","",0
[2023-10-10_17:28:33:764]OK
[2023-10-10_17:28:35:381]AT+QIACT=1
[2023-10-10_17:28:35:381]ERROR
[2023-10-10_17:28:41:031]AT+QCDS?
[2023-10-10_17:28:41:031]+QCDS: "LIMITED","CAT-M",45012,2500,154420F,R13,2,154,18470,-90,-107,-3,3,0,0,0,0
[2023-10-10_17:28:41:031]OK
[2023-10-10_17:28:41:031] AT+QCDS?
[2023-10-10_17:28:41:031] +QCDS: "LIMITED","CAT-M",45012,2500,154420F,R13,2,154,18470,-90,-107,-3,3,0,0,0,0
[2023-10-10_17:28:41:031] OK

When running at+qcnc?, the output is as follows:

[2023-10-10_17:47:13:698] at+qcnc?
[2023-10-10_17:47:13:698] +QCNC: 0,17,0,,0
[2023-10-10_17:47:13:698] OK

Upon investigation, this appears to be a PLMN failure, and I would like to know how to solve this problem.

Additionally, I have a question regarding the at+cgdcont command. During the LTE activation with SK Telecom, the document submitted had PDP CIL, APN Default Context Id, and APN Context ID set to 27, 10, and 35 respectively. Should I use these Context IDs when executing the at+cgdcont command?

Regards.

Hi

Please try to do AT+QCFG=“restored/cell”,1 and reboot module. PDP contextID should be 1 and for APN it should be set as which required by operator.

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We found out that it was a mistake of the mobile carrier that opened cat m1. Thank you.