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Modem troubleshooting guide

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tansiowk edited this page Jan 8, 2024 · 14 revisions

Issue 1: Modem is unable to detect eSIM

Symptoms

  1. Check whether the SIM is READY
    If the modem is unable to detect eSIM
    AT+CPIN?
        +CME ERROR: 10 SIM not inserted

    If the modem is able to detect eSIM
    AT+CPIN?
        +CPIN: READY
        OK

  2. Read the ICCID of the active profile
    If the modem is unable to detect eSIM
    AT+ICCID
        +CME ERROR: 13 SIM failure

    If the modem is able to detect eSIM
    AT+ICCID
        +ICCID: 8931070422315950187
        OK

Design-related causes

  1. Check the board schematics, in particular, the eSIM power supply and ISO7816 interface to the modem. Refer to the Design-in chapter in the eSIM Datasheet.

  2. Use the eSIM CAD files in the PCB layout.

  3. Verify that the modem SIM_VCC pin can deliver sufficient power to the eSIM and other components on the ISO7816 lines. Consider that:

    • An eSIM may require a higher current than a classic SIM card. Refer to the Electrical Characteristics chapter in the eSIM Datasheet.
    • Since an eSIM is non-detachable, components for ESD protection (resistors, diodes, eClamps) may be unnecessary. Their removal will reduce current consumption and save cost.

  4. Review the board schematics / PCB layout with the modem supplier and Infineon application engineer.

Board-related causes

  • If the eSIM is soldered to a SIM card slot as a prototype, verify that the eSIM pins are electrically-connected to the modem pins.

Configuration-related causes

  1. Read the modem documentation to see how to disable the SIM detection pin. If the modem supports SIM hot-swapping feature, consider disabling the feature. More info on Modem SIM detection pin.

  2. If the modem has support for more than 1 SIM, verify that the eSIM is the active SIM. To specify the active SIM, a proprietary AT command may need to be sent. Refer to the modem AT Command Guide.

  3. If the modem has an integrated SIM, verify that the eSIM is not assigned to the same 'slot' as the integrated SIM.

Issue 2: Modem is unable to attach to the network

Symptoms

  1. Read the IP address of PDP context 1
    If the modem is unable to get a valid IPv4 address
    AT+CGPADDR=1
        +CGPADDR: 1,"0.0.0.0"

    If the modem is able to get an IPv4 address
    AT+CGPADDR=1
        +CGPADDR: 1,"192.168.11.27"
        OK

  2. Read the network operator
    If the modem is unable to read the network operator
    AT+COPS?
        +COPS: 0

    If the modem is able to read the network operator (e.g. Singapore)
    AT+COPS?
        +COPS: 0,0,"Singtel Tata",7
        OK

  3. Consume some data e.g. ping Google
    If the modem (e.g. Quectel) is unable to ping
    AT+QPING=1,"google.com",5,3
        +QPING: 5xx Error code 5xx

    If the modem is able to ping
    AT+QPING=1,"google.com",5,3
        +QPING: 0,"142.250.194.238",32,104,255
        +QPING: 0,"142.250.194.238",32,109,255
        +QPING: 0,"142.250.194.238",32,110,255
        +QPING: 0,3,3,0,104,110,107
        OK

Account-related causes

  1. Verify that the eSIM EID has been registered with TATA. If you have an account on TATA MOVE, enter the EID in the search field of the Connections Inventory menu and see if it can be found.

  2. Verify that the eSIM subscription has not been terminated. TATA MOVE Connections Inventory menu can be used to show active and terminated eSIM EIDs.
    image

  3. Verify that the eSIM has data credit available.
    image

  4. If your application requires IPv6, contact your TATA representative to get the IPv6 package.

Configuration-related causes

  • Verify that the application has set the APN move.dataxs.mobi using AT+CGDCONT command. More info on Modem configuration steps.

Issue 3: Modem is unable to send and receive SMS

Symptoms

  1. Register to the cellular network (Voice & SMS)
    If the modem is unable to register to the cellular network (Voice & SMS)
    AT+CREG?
        +CREG: 0,3 3: registration denied

    If the modem is able to register to the cellular network (Voice & SMS)
    AT+CREG?
        +CREG: 0,5 5: registered, roaming
        OK

  2. Send an SMS to a mobile number
    AT+CMEE=2 2: enable result code and use verbose values
        OK

    AT+CMGF=1 1: set message format to text mode
        OK

    AT+CSMP? read SMS text mode parameters
        +CSMP: 17,255,0,0
        OK

    AT+CSMP=17,167,0,16 set SMS text mode parameters
        OK

    AT+CMGW="+6587654321" write short message to memory
        > hello world terminated by Ctrl+Z
        +CMGW: 1 1 : stored message index
        OK

    If the modem is unable to send SMS
    AT+CMSS=1 send message from storage, specify 1 as the message index
        +CMS ERROR: unknown error

    If the modem is able to send SMS
    AT+CMSS=1 send message from storage, specify 1 as the message index
        +CMSS: 10 10 : message reference number; SMS received by recipient
        OK

Account-related causes

  1. Contact your TATA representative for the SMS-add on package.

  2. Verify that the eSIM has SMS credit available.

Issue 4: Modem is unable to perform Remote SIM Provisioning (RSP)

Symptoms

  • Downloading a profile or switching profiles failed on TATA MOVE

Modem Firmware-related causes

  1. Check whether the modem is listed in the Modem Compatibility List.

  2. If the modem is not listed, contact Infineon Technical Support or an Infineon distributor.

  3. To learn more about modem requirements to support RSP, refer to the System Integration chapter in the eSIM Datasheet.

  4. Contact the modem supplier to see if a new firmware is available.

OPTIGA™ Connect IoT - Infineon eSIM IoT Solution

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