FiPy unable to connect to T-Mobile NL (LTE-M)



  • Hello,

    I'm trying to connect to the LTE-M network of T-Mobile NL. But the FiPy is unable to connect to the network.

    The simcard used in the FiPy is a special IoT Creators LTE-M simcard.

    When I use the command AT+CPIN? it returns Ready.

    To verify if the network is found the command AT+COPS=? is used, this returns 20416 what means that the network is found.

    To verify the freqency band the command AT+SQNINS=0 is used, this returns the T-Mobile celltower on frequencyband 8.

    To verify the operational capabilities the command AT+CFUN? is used, this returns 1.

    The code used:

    from network import LTE
    import time
    import socket
    
    lte = LTE()
    
    lte.attach(band=8, apn="iot.t-mobile.nl")
    print("attaching..",end='')
    while not lte.isattached():
        time.sleep(0.25)
    
        print('.',end='')
        print(lte.send_at_cmd('AT!="fsm"'))         
    print("attached!")
    
    lte.connect()
    print("connecting [##",end='')
    while not lte.isconnected():
        time.sleep(0.25)
        print('#',end='')
        #print(lte.send_at_cmd('AT!="showphy"'))
        print(lte.send_at_cmd('AT!="fsm"'))
    print("] connected!")
    
    

    It returns:

    DL SYNCHRO STATISTICS
    =====================
        Synchro state                         : OFF
        PPU SIB1 ACQ watchdog                 : 0
        Frequency Hypothesis RF  (Hz)         : 0
        RSRP (dBm)                            : 0.00
        RSRQ  (dB)                            : 0.00
        Channel estimation state (Cell-spec.) : LOW CINR
        Channel estimation state (UE-spec.)   : LOW CINR
        Channel estimation state (MBSFN)      : LOW CINR
        Channel estimation CINR               : 0.00
        Channel length                        : SHORT
      AGC
        AGC RX gain (dB)                      : 0.00
        RX PSD BO (dBFs)                      : 0.00
        RX PSD (dBm)                          : 0.00
        Noise level RS (dBm)                  : 0.00
        Digital gain (dB)                     : 0.00
        CINR RS (dB)                          : 0.00
      NARROWBANDS
        Last DL NB                            : 0
        Last UL NB                            : 0
      AFC
        Frequency offset RF  (Hz)             : 0
        Frequency offset BB  (Hz)             : 0
      PBCH
        MIB received quantity                 : 0
        MIB timeout quantity                  : 0
    
    OK
    
    attaching...
    SYSTEM FSM
    ==========
        +--------------------------+--------------------+
        |            FSM           |        STATE       |
        +--------------------------+--------------------+
        | RRC TOP FSM              |SCANNING            |
        | RRC SEARCH FSM           |WAIT_CELL_ID        |
        | RRC ACTIVE FSM           |NULL                |
        | PMM PLMN FSM             |ANY_WAITCELL        |
        | EMM MAIN FSM             |NULL                |
        | EMM AUTH FSM             |KASME_DEFINED       |
        | EMM CONN FSM             |NULL                |
        | EMM TAU FSM              |NULL                |
        | EMM TEST FSM             |NULL                |
        | ESM BEARER FSM           |BEARER_NULL         |
        | SMS MT FSM               |IDLE                |
        | SMS MO FSM               |IDLE                |
        | HP MAIN FSM              |IDLE                |
        | HP USIM FSM              |READY               |
        | HP SMS MO FSM            |IDLE                |
        | HP SMS MT FSM            |IDLE                |
        | HP CAT FSM               |IDLE                |
        +--------------------------+--------------------+
    
    OK
    
    .
    SYSTEM FSM
    ==========
        +--------------------------+--------------------+
        |            FSM           |        STATE       |
        +--------------------------+--------------------+
        | RRC TOP FSM              |SYNCING             |
        | RRC SEARCH FSM           |WAIT_SYNC           |
        | RRC ACTIVE FSM           |NULL                |
        | PMM PLMN FSM             |ANY_WAITCELL        |
        | EMM MAIN FSM             |NULL                |
        | EMM AUTH FSM             |KASME_DEFINED       |
        | EMM CONN FSM             |NULL                |
        | EMM TAU FSM              |NULL                |
        | EMM TEST FSM             |NULL                |
        | ESM BEARER FSM           |BEARER_NULL         |
        | SMS MT FSM               |IDLE                |
        | SMS MO FSM               |IDLE                |
        | HP MAIN FSM              |IDLE                |
        | HP USIM FSM              |READY               |
        | HP SMS MO FSM            |IDLE                |
        | HP SMS MT FSM            |IDLE                |
        | HP CAT FSM               |IDLE                |
        +--------------------------+--------------------+
    
    OK
    
    .
    SYSTEM FSM
    ==========
        +--------------------------+--------------------+
        |            FSM           |        STATE       |
        +--------------------------+--------------------+
        | RRC TOP FSM              |CAMPED              |
        | RRC SEARCH FSM           |CAMPED_ANY          |
        | RRC ACTIVE FSM           |IDLE                |
        | PMM PLMN FSM             |ANY_CAMPED          |
        | EMM MAIN FSM             |NULL                |
        | EMM AUTH FSM             |KASME_DEFINED       |
        | EMM CONN FSM             |NULL                |
        | EMM TAU FSM              |NULL                |
        | EMM TEST FSM             |NULL                |
        | ESM BEARER FSM           |BEARER_NULL         |
        | SMS MT FSM               |IDLE                |
        | SMS MO FSM               |IDLE                |
        | HP MAIN FSM              |IDLE                |
        | HP USIM FSM              |READY               |
        | HP SMS MO FSM            |IDLE                |
        | HP SMS MT FSM            |IDLE                |
        | HP CAT FSM               |IDLE                |
        +--------------------------+--------------------+
    
    OK
    

    Does anyone have any experience of connecting to the T-Mobile NL LTE-M network? I tried resetting multiple times and codes from the forum but i did not have any succes (so far).

    Thanks,

    Lars


  • Global Moderator

    Could you contact me at support@pycom.io linking this forum thread, we might be able to help you further there!
    Gijs



  • Hello,

    Thanks for the quick reaction!

    After the update the RCC TOP FSM switches from Scanning to Syncing to Camped and back. It seems that it is stuck somewhere.

    SYSTEM FSM
    ==========
        +--------------------------+--------------------+
        |            FSM           |        STATE       |
        +--------------------------+--------------------+
        | RRC TOP FSM              |SCANNING            |
        | RRC SEARCH FSM           |WAIT_CELL_ID        |
        | RRC ACTIVE FSM           |NULL                |
        | PMM PLMN FSM             |ANY_WAITCELL        |
        | EMM MAIN FSM             |NULL                |
        | EMM AUTH FSM             |KASME_DEFINED       |
        | EMM CONN FSM             |NULL                |
        | EMM TAU FSM              |NULL                |
        | EMM TEST FSM             |NULL                |
        | ESM BEARER FSM           |BEARER_NULL         |
        | SMS MT FSM               |IDLE                |
        | SMS MO FSM               |IDLE                |
        | LPP FSM                  |IDLE                |
        | HP MAIN FSM              |IDLE                |
        | HP USIM FSM              |READY               |
        | HP SMS MO FSM            |IDLE                |
        | HP SMS MT FSM            |IDLE                |
        | HP CAT FSM               |IDLE                |
        +--------------------------+--------------------+
    
    OK
    
    .
    SYSTEM FSM
    ==========
        +--------------------------+--------------------+
        |            FSM           |        STATE       |
        +--------------------------+--------------------+
        | RRC TOP FSM              |SYNCING             |
        | RRC SEARCH FSM           |WAIT_SYNC           |
        | RRC ACTIVE FSM           |NULL                |
        | PMM PLMN FSM             |ANY_WAITCELL        |
        | EMM MAIN FSM             |NULL                |
        | EMM AUTH FSM             |KASME_DEFINED       |
        | EMM CONN FSM             |NULL                |
        | EMM TAU FSM              |NULL                |
        | EMM TEST FSM             |NULL                |
        | ESM BEARER FSM           |BEARER_NULL         |
        | SMS MT FSM               |IDLE                |
        | SMS MO FSM               |IDLE                |
        | LPP FSM                  |IDLE                |
        | HP MAIN FSM              |IDLE                |
        | HP USIM FSM              |READY               |
        | HP SMS MO FSM            |IDLE                |
        | HP SMS MT FSM            |IDLE                |
        | HP CAT FSM               |IDLE                |
        +--------------------------+--------------------+
    
    OK
    
    .
    SYSTEM FSM
    ==========
        +--------------------------+--------------------+
        |            FSM           |        STATE       |
        +--------------------------+--------------------+
        | RRC TOP FSM              |CAMPED              |
        | RRC SEARCH FSM           |CAMPED_ANY          |
        | RRC ACTIVE FSM           |IDLE                |
        | PMM PLMN FSM             |ANY_CAMPED          |
        | EMM MAIN FSM             |NULL                |
        | EMM AUTH FSM             |KASME_DEFINED       |
        | EMM CONN FSM             |NULL                |
        | EMM TAU FSM              |NULL                |
        | EMM TEST FSM             |NULL                |
        | ESM BEARER FSM           |BEARER_NULL         |
        | SMS MT FSM               |IDLE                |
        | SMS MO FSM               |IDLE                |
        | LPP FSM                  |IDLE                |
        | HP MAIN FSM              |IDLE                |
        | HP USIM FSM              |READY               |
        | HP SMS MO FSM            |IDLE                |
        | HP SMS MT FSM            |IDLE                |
        | HP CAT FSM               |IDLE                |
        +--------------------------+--------------------+
    
    OK
    

    This has been going on for more than an hour. Most of the time the device is Scanning.

    Does anyone have any other suggestions?

    Thanks,

    Lars


  • Global Moderator

    Hi,

    Could you perhaps update the LTE modem firmware to the latest available version and try again? The update procedure is described here: https://docs.pycom.io/updatefirmware/ltemodem/. Shifting locations to get a better signal might help as well.

    Let me know!


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