Automatic COPS choice

4 thoughts on “Automatic COPS choice

  1. GE864-QUAD 07.03.000

    We have recently had returned several of our trackers which have suddenly stopped working after several years in the field.
    The trackers were no longer connecting via GPRS, indeed the modems were no longer registering.
    Replacing the SIMs fixed the problem.

    All the SIMs were Orange (EE nowadays).

    Investigating the SIMs in an EVK2.

    AT+CMEE=2
    [OK]
    AT+COPS=0,2
    [OK]
    AT+COPS?
    [+COPS: 0,2,”23415″]

    Operator 23415 seems to be vodafone UK

    I discovered that if I executed
    AT+COPS=4,2,”23430″
    The problem is resolved, however I am puzzled as to why the automatic operator selection has failed, and want toknow how to avoid more failures in future.

    1. Hi Steve,

      this product is quite old and in EoL since almost 4 years now, anyway I will try to help you.

      What is the AT+CREG? response?

      Assuming it is +CREG: 0,3 a possible explanation is that for some reason (network maintenance or other causes) the modules were rejected by EE operator. In that case EE is put in the forbidden PLMN list in the SIM, and any future access prevented.

      The only way to recover from this situation is to force a manual registration to the EE PLMN with AT+COPS=4 or 1, or deleted the forbidden PLMN list.

      On later modules there is the command AT#FPLMN to delete/read the list.

      On GE864QUAD 7.03.000 this operation can only be performed with AT+CRSM command, reading the Efplmn file into the SIM and deleting the content. The procedure is quite long but I can post it if you are interested.

      Anyway this is only an hypothesis since we don’t know the root cause.

      1. Andrea, your hypothesis is correct. Using a newer module I can read the forbidden list. I can also cause individual entries to be deleted using +COPS=1 or +COPS=4. Thank you!

        You say

        On GE864QUAD 7.03.000 this operation can only be performed with AT+CRSM command, reading the Efplmn file into the SIM and deleting the content. The procedure is quite long but I can post it if you are interested.

        Yes please! I am interested.

        1. Howto read and delete the FPLMN (Forbidden  PLMN list) file from a 2G SIMcard:

          Read:

          AT+CRSM=176,28539,0,0,12

          Typical answer is: +CRSM: 144,0,47F02062F61052F94047F440 that should be elaboratedas follow, to recognize MNOs codes:

           

          47F020|62F610|52F940|47F440 

          47F440-> 744 04

          52F940-> 259 04

          62F610-> 266 01

          47F020-> 740 02

          Note: F shall be ignored for MNC with 2 digits

          Delete all the records in the FPLMN file:

          AT+CRSM=214,28539,0,0,12,FFFFFFFFFFFFFFFFFFFFFFFF

          Howto read and delete the FPLMN (Forbidden  PLMN list) file from a 3G SIMcard:

          if the SIM is 3G, the FPLMN file can be longer than 12 (variable length).

          3GSIM can be discovered with this command:

          AT+CRSM=192,12258

          +CRSM:144,0,621F8202412183022FE2A506C00140DE01208A01058B032F06058002000A880110

          62-> 3G SIM

          Lengthof FPLMN file can be extracted with the command below:

          AT+CRSM=192,28539

          +CRSM:144,0,621C8202412183026F7BA5038001718A01058B036F06048002000C880168

          80-> TAG

          02-> number of bytes of next field (length_FPLMN_file)

          000C-> length_FPLMN_file (12)

          Read:

          AT+CRSM=176,28539,0,0,<length_FPLMN_file>

          Delete: 

          AT+CRSM=214,28539,0,0,<length_FPLMN_file>,FFFFFFFFF..FF (FF x length_PLMN_file)