Mbed OS 5.15.8: Add +UMNOPROF set option, set +URAT only if required and add third RAT to RAT list.

mbed_app.json

{
    "config": {
        ...
        "cellular-mno": {
            "help": "Ublox SARA R412M cellular MNO Profile (100: Standard Europe)",
            "value": 100
        },
        ...
    },
    "target_overrides": {
        "*": {
            ...
            "cellular.radio-access-technology": "CellularNetwork::RadioAccessTechnology::RAT_EGPRS",
            ...
        }
    }
}

UBLOX_AT_CellularNetwork.cpp

nsapi_error_t UBLOX_AT_CellularNetwork::set_access_technology_impl(RadioAccessTechnology opRat)
{
    nsapi_error_t ret = NSAPI_ERROR_OK;
    CellularNetwork::AttachStatus status;

    get_attach(status);
    if (status == Attached) {
        tr_debug("RAT should only be set in detached state");
        return NSAPI_ERROR_UNSUPPORTED;
    }

/* Add +UMNOPROF set option. */
#if defined (UBX_MDM_SARA_R412M)
    _at.lock();

    int mno;
    _at.at_cmd_int("+UMNOPROF", "?", mno);

    if (mno != (int)MBED_CONF_APP_CELLULAR_MNO) {
        _at.at_cmd_discard("+UMNOPROF", "=", "%d", (int)MBED_CONF_APP_CELLULAR_MNO);
        _at.unlock();
        ubx_reboot();
    } else {
        _at.unlock();
    }
#endif
/* End add +UMNOPROF set option. */

    _at.lock();

    /* Check radio access technology (RAT). If RAT change is required set new RAT. */
    int act;
    CellularNetwork::RadioAccessTechnology rat;

    _at.at_cmd_int("+URAT", "?", act);

    switch (act) {
        case 0:
            rat = CellularNetwork::RadioAccessTechnology::RAT_GSM;
            break;
        case 1:
            rat = CellularNetwork::RadioAccessTechnology::RAT_GSM;
            break;
        case 2:
            rat = CellularNetwork::RadioAccessTechnology::RAT_UTRAN;
            break;
        case 7:
            rat = CellularNetwork::RadioAccessTechnology::RAT_CATM1;
            break;
        case 8:
            rat = CellularNetwork::RadioAccessTechnology::RAT_NB1;
            break;
        case 9:
            rat = CellularNetwork::RadioAccessTechnology::RAT_EGPRS;
            break;
        default:
            rat = CellularNetwork::RadioAccessTechnology::RAT_UNKNOWN;
            break;
    }

    if (opRat == rat) {
        _at.unlock();
        return (ret);
    }
    /* End check radio access technology (RAT). If RAT change is required set new RAT. */

    switch (opRat) {
        case RAT_EGPRS:
#if defined (UBX_MDM_SARA_R412M)
            /* Replace RAT list with additional third RAT. */
            /* _at.at_cmd_discard("+URAT", "=", "%d%d", 9, 8); */
            _at.at_cmd_discard("+URAT", "=", "%d%d%d", 9, 8, 7);
            break;
#endif
#if defined(UBX_MDM_SARA_U201)
        case RAT_GSM:
            _at.at_cmd_discard("+URAT", "=", "%d%d", 0, 0);
            break;
        case RAT_UTRAN:RAT_EGPRS
        case RAT_HSDPA:
        case RAT_HSUPA:
        case RAT_HSDPA_HSUPA:
            _at.at_cmd_discard("+URAT", "=", "%d%d", 2, 2);
            break;
#elif defined(UBX_MDM_SARA_R41XM)
        case RAT_CATM1:
            /* Replace RAT list with additional third RAT. */
            /* _at.at_cmd_discard("+URAT", "=", "%d%d", 7, 8); */
            _at.at_cmd_discard("+URAT", "=", "%d%d%d", 7, 8, 9);
            break;
        case RAT_NB1:
            /* Replace RAT list with additional third RAT. */
            /* _at.at_cmd_discard("+URAT", "=", "%d%d", 8, 7); */
            _at.at_cmd_discard("+URAT", "=", "%d%d%d", 8, 7, 9);
            break;
#endif
        default:
            _op_act = RAT_UNKNOWN;
            ret = NSAPI_ERROR_UNSUPPORTED;
            break;
    }
    _at.unlock();
    ubx_reboot();

    return (ret);
}