Diff: UbloxCellularBase.cpp

Revision:

0:5cffef3371f6

Child:

1:5aaecf2572dc

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/UbloxCellularBase.cpp	Mon Jun 12 21:28:56 2017 +0000
@@ -0,0 +1,881 @@
+/* Copyright (c) 2017 ublox Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "UARTSerial.h"
+#include "APN_db.h"
+#include "UbloxCellularBase.h"
+#include "onboard_modem_api.h"
+#ifdef FEATURE_COMMON_PAL
+#include "mbed_trace.h"
+#define TRACE_GROUP "UCB"
+#else
+#define tr_debug(format, ...) debug(format, ## __VA_ARGS__)
+#define tr_info(format, ...)  debug(format, ## __VA_ARGS__)
+#define tr_warn(format, ...)  debug(format, ## __VA_ARGS__)
+#define tr_error(format, ...) debug(format, ## __VA_ARGS__)
+#endif
+
+/**********************************************************************
+ * PRIVATE METHODS
+ **********************************************************************/
+
+void UbloxCellularBase::set_nwk_reg_status_csd(int status)
+{
+    switch (status) {
+        case CSD_NOT_REGISTERED_NOT_SEARCHING:
+        case CSD_NOT_REGISTERED_SEARCHING:
+            tr_info("Not (yet) registered for circuit switched service");
+            break;
+        case CSD_REGISTERED:
+        case CSD_REGISTERED_ROAMING:
+            tr_info("Registered for circuit switched service");
+            break;
+        case CSD_REGISTRATION_DENIED:
+            tr_info("Circuit switched service denied");
+            break;
+        case CSD_UNKNOWN_COVERAGE:
+            tr_info("Out of circuit switched service coverage");
+            break;
+        case CSD_SMS_ONLY:
+            tr_info("SMS service only");
+            break;
+        case CSD_SMS_ONLY_ROAMING:
+            tr_info("SMS service only");
+            break;
+        case CSD_CSFB_NOT_PREFERRED:
+            tr_info("Registered for circuit switched service with CSFB not preferred");
+            break;
+        default:
+            tr_info("Unknown circuit switched service registration status. %d", status);
+            break;
+    }
+
+    _dev_info.reg_status_csd = static_cast<NetworkRegistrationStatusCsd>(status);
+}
+
+void UbloxCellularBase::set_nwk_reg_status_psd(int status)
+{
+    switch (status) {
+        case PSD_NOT_REGISTERED_NOT_SEARCHING:
+        case PSD_NOT_REGISTERED_SEARCHING:
+            tr_info("Not (yet) registered for packet switched service");
+            break;
+        case PSD_REGISTERED:
+        case PSD_REGISTERED_ROAMING:
+            tr_info("Registered for packet switched service");
+            break;
+        case PSD_REGISTRATION_DENIED:
+            tr_info("Packet switched service denied");
+            break;
+        case PSD_UNKNOWN_COVERAGE:
+            tr_info("Out of packet switched service coverage");
+            break;
+        case PSD_EMERGENCY_SERVICES_ONLY:
+            tr_info("Limited access for packet switched service. Emergency use only.");
+            break;
+        default:
+            tr_info("Unknown packet switched service registration status. %d", status);
+            break;
+    }
+
+    _dev_info.reg_status_psd = static_cast<NetworkRegistrationStatusPsd>(status);
+}
+
+void UbloxCellularBase::set_nwk_reg_status_eps(int status)
+{
+    switch (status) {
+        case EPS_NOT_REGISTERED_NOT_SEARCHING:
+        case EPS_NOT_REGISTERED_SEARCHING:
+            tr_info("Not (yet) registered for EPS service");
+            break;
+        case EPS_REGISTERED:
+        case EPS_REGISTERED_ROAMING:
+            tr_info("Registered for EPS service");
+            break;
+        case EPS_REGISTRATION_DENIED:
+            tr_info("EPS service denied");
+            break;
+        case EPS_UNKNOWN_COVERAGE:
+            tr_info("Out of EPS service coverage");
+            break;
+        case EPS_EMERGENCY_SERVICES_ONLY:
+            tr_info("Limited access for EPS service. Emergency use only.");
+            break;
+        default:
+            tr_info("Unknown EPS service registration status. %d", status);
+            break;
+    }
+
+    _dev_info.reg_status_eps = static_cast<NetworkRegistrationStatusEps>(status);
+}
+
+void UbloxCellularBase::set_rat(int AcTStatus)
+{
+    switch (AcTStatus) {
+        case GSM:
+        case COMPACT_GSM:
+            tr_info("Connected in GSM");
+            break;
+        case UTRAN:
+            tr_info("Connected to UTRAN");
+            break;
+        case EDGE:
+            tr_info("Connected to EDGE");
+            break;
+        case HSDPA:
+            tr_info("Connected to HSDPA");
+            break;
+        case HSUPA:
+            tr_info("Connected to HSPA");
+            break;
+        case HSDPA_HSUPA:
+            tr_info("Connected to HDPA/HSPA");
+            break;
+        case LTE:
+            tr_info("Connected to LTE");
+            break;
+        default:
+            tr_info("Unknown RAT %d", AcTStatus);
+            break;
+    }
+
+    _dev_info.rat = static_cast<RadioAccessNetworkType>(AcTStatus);
+}
+
+bool UbloxCellularBase::get_iccid()
+{
+    bool success;
+    LOCK();
+
+    MBED_ASSERT(_at != NULL);
+
+    // Returns the ICCID (Integrated Circuit Card ID) of the SIM-card.
+    // ICCID is a serial number identifying the SIM.
+    // AT Command Manual UBX-13002752, section 4.12
+    success = _at->send("AT+CCID") && _at->recv("+CCID: %20[^\n]\nOK\n", _dev_info.iccid);
+    tr_info("DevInfo: ICCID=%s", _dev_info.iccid);
+
+    UNLOCK();
+    return success;
+}
+
+bool UbloxCellularBase::get_imsi()
+{
+    bool success;
+    LOCK();
+
+    MBED_ASSERT(_at != NULL);
+
+    // International mobile subscriber identification
+    // AT Command Manual UBX-13002752, section 4.11
+    success = _at->send("AT+CIMI") && _at->recv("%15[^\n]\nOK\n", _dev_info.imsi);
+    tr_info("DevInfo: IMSI=%s", _dev_info.imsi);
+
+    UNLOCK();
+    return success;
+}
+
+bool UbloxCellularBase::get_imei()
+{
+    bool success;
+    LOCK();
+
+    MBED_ASSERT(_at != NULL);
+
+    // International mobile equipment identifier
+    // AT Command Manual UBX-13002752, section 4.7
+    success = _at->send("AT+CGSN") && _at->recv("%15[^\n]\nOK\n", _dev_info.imei);
+    tr_info("DevInfo: IMEI=%s", _dev_info.imei);
+
+    UNLOCK();
+    return success;
+}
+
+bool UbloxCellularBase::get_meid()
+{
+    bool success;
+    LOCK();
+
+    MBED_ASSERT(_at != NULL);
+
+    // Mobile equipment identifier
+    // AT Command Manual UBX-13002752, section 4.8
+    success = _at->send("AT+GSN") && _at->recv("%18[^\n]\nOK\n", _dev_info.meid);
+    tr_info("DevInfo: MEID=%s", _dev_info.meid);
+
+    UNLOCK();
+    return success;
+}
+
+bool UbloxCellularBase::set_sms()
+{
+    bool success = false;
+    char buf[32];
+    LOCK();
+
+    MBED_ASSERT(_at != NULL);
+
+    // Set up SMS format and enable URC
+    // AT Command Manual UBX-13002752, section 11
+    if (_at->send("AT+CMGF=1") && _at->recv("OK")) {
+        tr_debug("SMS in text mode");
+        if (_at->send("AT+CNMI=2,1") && _at->recv("OK")) {
+            tr_debug("SMS URC enabled");
+            // Set to CS preferred since PS preferred doesn't work
+            // on some networks
+            if (_at->send("AT+CGSMS=1") && _at->recv("OK")) {
+                tr_debug("SMS set to CS preferred");
+                success = true;
+                memset (buf, 0, sizeof (buf));
+                if (_at->send("AT+CSCA?") &&
+                    _at->recv("+CSCA: \"%31[^\"]\"", buf) &&
+                    _at->recv("OK")) {
+                    tr_info("SMS Service Centre address is \"%s\"", buf);
+                }
+            }
+        }
+    }
+
+    UNLOCK();
+    return success;
+}
+
+void UbloxCellularBase::parser_abort_cb()
+{
+    _at->abort();
+}
+
+// Callback for CME ERROR and CMS ERROR.
+void UbloxCellularBase::CMX_ERROR_URC()
+{
+    char buf[48];
+
+    if (read_at_to_char(buf, sizeof (buf), '\n') > 0) {
+        tr_debug("AT error %s", buf);
+    }
+    parser_abort_cb();
+}
+
+// Callback for circuit switched registration URC.
+void UbloxCellularBase::CREG_URC()
+{
+    char buf[10];
+    int status;
+
+    // If this is the URC it will be a single
+    // digit followed by \n.  If it is the
+    // answer to a CREG query, it will be
+    // a ": %d,%d\n" where the second digit
+    // indicates the status
+    // Note: not calling _at->recv() from here as we're
+    // already in an _at->recv()
+    if (read_at_to_char(buf, sizeof (buf), '\n') > 0) {
+        if (sscanf(buf, ": %*d,%d", &status) == 1) {
+            set_nwk_reg_status_csd(status);
+        } else if (sscanf(buf, ": %d", &status) == 1) {
+            set_nwk_reg_status_csd(status);
+        }
+    }
+}
+
+// Callback for packet switched registration URC.
+void UbloxCellularBase::CGREG_URC()
+{
+    char buf[10];
+    int status;
+
+    // If this is the URC it will be a single
+    // digit followed by \n.  If it is the
+    // answer to a CGREG query, it will be
+    // a ": %d,%d\n" where the second digit
+    // indicates the status
+    // Note: not calling _at->recv() from here as we're
+    // already in an _at->recv()
+    if (read_at_to_char(buf, sizeof (buf), '\n') > 0) {
+        if (sscanf(buf, ": %*d,%d", &status) == 1) {
+            set_nwk_reg_status_psd(status);
+        } else if (sscanf(buf, ": %d", &status) == 1) {
+            set_nwk_reg_status_psd(status);
+        }
+    }
+}
+
+// Callback for EPS registration URC.
+void UbloxCellularBase::CEREG_URC()
+{
+    char buf[10];
+    int status;
+
+    // If this is the URC it will be a single
+    // digit followed by \n.  If it is the
+    // answer to a CEREG query, it will be
+    // a ": %d,%d\n" where the second digit
+    // indicates the status
+    // Note: not calling _at->recv() from here as we're
+    // already in an _at->recv()
+    if (read_at_to_char(buf, sizeof (buf), '\n') > 0) {
+        if (sscanf(buf, ": %*d,%d", &status) == 1) {
+            set_nwk_reg_status_eps(status);
+        } else if (sscanf(buf, ": %d", &status) == 1) {
+            set_nwk_reg_status_eps(status);
+        }
+    }
+}
+
+// Callback UMWI, just filtering it out.
+void UbloxCellularBase::UMWI_URC()
+{
+    char buf[10];
+
+    // Note: not calling _at->recv() from here as we're
+    // already in an _at->recv()
+    read_at_to_char(buf, sizeof (buf), '\n');
+}
+
+/**********************************************************************
+ * PROTECTED METHODS
+ **********************************************************************/
+
+#if MODEM_ON_BOARD
+void UbloxCellularBase::modem_init()
+{
+    ::onboard_modem_init();
+}
+
+void UbloxCellularBase::modem_deinit()
+{
+    ::onboard_modem_deinit();
+}
+
+void UbloxCellularBase::modem_power_up()
+{
+    ::onboard_modem_power_up();
+}
+
+void UbloxCellularBase::modem_power_down()
+{
+    ::onboard_modem_power_down();
+}
+#else
+void UbloxCellularBase::modem_init()
+{
+    // Meant to be overridden
+}
+
+void UbloxCellularBase::modem_deinit()
+{
+    // Meant to be overridden
+}
+
+void UbloxCellularBase::modem_power_up()
+{
+    // Meant to be overridden
+}
+
+void UbloxCellularBase::modem_power_down()
+{
+    // Mmeant to be overridden
+}
+#endif
+
+// Constructor.
+// Note: to allow this base class to be inherited as a virtual base class
+// by everyone, it takes no parameters.  See also comment above classInit()
+// in the header file.
+UbloxCellularBase::UbloxCellularBase()
+{
+    _pin = NULL;
+    _at = NULL;
+    _at_timeout = AT_PARSER_TIMEOUT;
+    _fh = NULL;
+    _modem_initialised = false;
+    _sim_pin_check_enabled = false;
+    _debug_trace_on = false;
+
+    _dev_info.dev = DEV_TYPE_NONE;
+    _dev_info.reg_status_csd = CSD_NOT_REGISTERED_NOT_SEARCHING;
+    _dev_info.reg_status_psd = PSD_NOT_REGISTERED_NOT_SEARCHING;
+    _dev_info.reg_status_eps = EPS_NOT_REGISTERED_NOT_SEARCHING;
+}
+
+// Destructor.
+UbloxCellularBase::~UbloxCellularBase()
+{
+    deinit();
+    delete _at;
+    delete _fh;
+}
+
+// Initialise the portions of this class that are parameterised.
+void UbloxCellularBase::baseClassInit(PinName tx, PinName rx,
+                                      int baud, bool debug_on)
+{
+    // Only initialise ourselves if it's not already been done
+    if (_at == NULL) {
+        if (_debug_trace_on == false) {
+            _debug_trace_on = debug_on;
+        }
+
+        // Set up File Handle for buffered serial comms with cellular module
+        // (which will be used by the AT parser)
+        _fh = new UARTSerial(tx, rx, baud);
+
+        // Set up the AT parser
+        _at = new ATCmdParser(_fh, OUTPUT_ENTER_KEY, AT_PARSER_BUFFER_SIZE,
+                           _at_timeout, _debug_trace_on);
+
+        // Error cases, out of band handling
+        _at->oob("ERROR", callback(this, &UbloxCellularBase::parser_abort_cb));
+        _at->oob("+CME ERROR", callback(this, &UbloxCellularBase::CMX_ERROR_URC));
+        _at->oob("+CMS ERROR", callback(this, &UbloxCellularBase::CMX_ERROR_URC));
+
+        // Registration status, out of band handling
+        _at->oob("+CREG", callback(this, &UbloxCellularBase::CREG_URC));
+        _at->oob("+CGREG", callback(this, &UbloxCellularBase::CGREG_URC));
+        _at->oob("+CEREG", callback(this, &UbloxCellularBase::CEREG_URC));
+
+        // Capture the UMWI, just to stop it getting in the way
+        _at->oob("+UMWI", callback(this, &UbloxCellularBase::UMWI_URC));
+    }
+}
+
+// Set the AT parser timeout.
+// Note: the AT interface should be locked before this is called.
+void UbloxCellularBase::at_set_timeout(int timeout) {
+
+    MBED_ASSERT(_at != NULL);
+
+    _at_timeout = timeout;
+    _at->set_timeout(timeout);
+}
+
+// Read up to size bytes from the AT interface up to a "end".
+// Note: the AT interface should be locked before this is called.
+int UbloxCellularBase::read_at_to_char(char * buf, int size, char end)
+{
+    int count = 0;
+    int x = 0;
+
+    if (size > 0) {
+        for (count = 0; (count < size) && (x >= 0) && (x != end); count++) {
+            x = _at->getc();
+            *(buf + count) = (char) x;
+        }
+
+        count--;
+        *(buf + count) = 0;
+
+        // Convert line endings:
+        // If end was '\n' (0x0a) and the preceding character was 0x0d, then
+        // overwrite that with null as well.
+        if ((count > 0) && (end == '\n') && (*(buf + count - 1) == '\x0d')) {
+            count--;
+            *(buf + count) = 0;
+        }
+    }
+
+    return count;
+}
+
+// Power up the modem.
+// Enables the GPIO lines to the modem and then wriggles the power line in short pulses.
+bool UbloxCellularBase::power_up()
+{
+    bool success = false;
+    int at_timeout;
+    LOCK();
+
+    at_timeout = _at_timeout; // Has to be inside LOCK()s
+
+    MBED_ASSERT(_at != NULL);
+
+    /* Initialize GPIO lines */
+    tr_info("Powering up modem...");
+    onboard_modem_init();
+    /* Give modem a little time to settle down */
+    wait_ms(250);
+
+    for (int retry_count = 0; !success && (retry_count < 20); retry_count++) {
+        onboard_modem_power_up();
+        wait_ms(500);
+        // Modem tends to spit out noise during power up - don't confuse the parser
+        _at->flush();
+        at_set_timeout(1000);
+        if (_at->send("AT")) {
+            // C027 needs a delay here
+            wait_ms(100);
+            if (_at->recv("OK")) {
+                success = true;
+            }
+        }
+        at_set_timeout(at_timeout);
+    }
+
+
+    if (success) {
+        success = _at->send("ATE0;" // Turn off modem echoing
+                            "+CMEE=2;" // Turn on verbose responses
+                            "&K0" //turn off RTC/CTS handshaking
+                            "+IPR=%d;" // Set baud rate
+                            "&C1;"  // Set DCD circuit(109), changes in accordance with the carrier detect status
+                            "&D0", 115200) && // Set DTR circuit, we ignore the state change of DTR
+                  _at->recv("OK");
+    }
+
+    if (!success) {
+        tr_error("Preliminary modem setup failed.");
+    }
+
+    UNLOCK();
+    return success;
+}
+
+// Power down modem via AT interface.
+void UbloxCellularBase::power_down()
+{
+    LOCK();
+
+    MBED_ASSERT(_at != NULL);
+
+    // If we have been running, do a soft power-off first
+    if (_modem_initialised && (_at != NULL)) {
+        _at->send("AT+CPWROFF") && _at->recv("OK");
+    }
+
+    // Now do a hard power-off
+    onboard_modem_power_down();
+    onboard_modem_deinit();
+
+    _dev_info.reg_status_csd = CSD_NOT_REGISTERED_NOT_SEARCHING;
+    _dev_info.reg_status_psd = PSD_NOT_REGISTERED_NOT_SEARCHING;
+    _dev_info.reg_status_eps = EPS_NOT_REGISTERED_NOT_SEARCHING;
+
+   UNLOCK();
+}
+
+// Get the device ID.
+bool UbloxCellularBase::set_device_identity(DeviceType *dev)
+{
+    char buf[20];
+    bool success;
+    LOCK();
+
+    MBED_ASSERT(_at != NULL);
+
+    success = _at->send("ATI") && _at->recv("%19[^\n]\nOK\n", buf);
+
+    if (success) {
+        if (strstr(buf, "SARA-G35"))
+            *dev = DEV_SARA_G35;
+        else if (strstr(buf, "LISA-U200-03S"))
+            *dev = DEV_LISA_U2_03S;
+        else if (strstr(buf, "LISA-U2"))
+            *dev = DEV_LISA_U2;
+        else if (strstr(buf, "SARA-U2"))
+            *dev = DEV_SARA_U2;
+        else if (strstr(buf, "LEON-G2"))
+            *dev = DEV_LEON_G2;
+        else if (strstr(buf, "TOBY-L2"))
+            *dev = DEV_TOBY_L2;
+        else if (strstr(buf, "MPCI-L2"))
+            *dev = DEV_MPCI_L2;
+    }
+
+    UNLOCK();
+    return success;
+}
+
+// Send initialisation AT commands that are specific to the device.
+bool UbloxCellularBase::device_init(DeviceType dev)
+{
+    bool success = false;
+    LOCK();
+
+    MBED_ASSERT(_at != NULL);
+
+    if ((dev == DEV_LISA_U2) || (dev == DEV_LEON_G2) || (dev == DEV_TOBY_L2)) {
+        success = _at->send("AT+UGPIOC=20,2") && _at->recv("OK");
+    } else if ((dev == DEV_SARA_U2) || (dev == DEV_SARA_G35)) {
+        success = _at->send("AT+UGPIOC=16,2") && _at->recv("OK");
+    } else {
+        success = true;
+    }
+
+    UNLOCK();
+    return success;
+}
+
+// Get the SIM card going.
+bool UbloxCellularBase::initialise_sim_card()
+{
+    bool success = false;
+    int retry_count = 0;
+    bool done = false;
+    LOCK();
+
+    MBED_ASSERT(_at != NULL);
+
+    /* SIM initialisation may take a significant amount, so an error is
+     * kind of expected. We should retry 10 times until we succeed or timeout. */
+    for (retry_count = 0; !done && (retry_count < 10); retry_count++) {
+        char pinstr[16];
+
+        if (_at->send("AT+CPIN?") && _at->recv("+CPIN: %15[^\n]\n", pinstr) &&
+            _at->recv("OK")) {
+            done = true;
+            if (strcmp(pinstr, "SIM PIN") == 0) {
+                _sim_pin_check_enabled = true;
+                if (_at->send("AT+CPIN=\"%s\"", _pin)) {
+                    if (_at->recv("OK")) {
+                        tr_info("PIN correct");
+                        success = true;
+                    } else {
+                        tr_error("Incorrect PIN");
+                    }
+                }
+            } else if (strcmp(pinstr, "READY") == 0) {
+                _sim_pin_check_enabled = false;
+                tr_info("No PIN required");
+                success = true;
+            } else {
+                tr_debug("Unexpected response from SIM: \"%s\"", pinstr);
+            }
+        }
+
+        /* wait for a second before retry */
+        wait_ms(1000);
+    }
+
+    if (done) {
+        tr_info("SIM Ready.");
+    } else {
+        tr_error("SIM not ready.");
+    }
+
+    UNLOCK();
+    return success;
+}
+
+/**********************************************************************
+ * PUBLIC METHODS
+ **********************************************************************/
+
+// Initialise the modem.
+bool UbloxCellularBase::init(const char *pin)
+{
+    MBED_ASSERT(_at != NULL);
+
+    if (!_modem_initialised) {
+        if (power_up()) {
+            tr_info("Modem Ready.");
+            if (pin != NULL) {
+                _pin = pin;
+            }
+            if (initialise_sim_card()) {
+                if (set_device_identity(&_dev_info.dev) && // Set up device identity
+                    device_init(_dev_info.dev) && // Initialise this device
+                    get_iccid() && // Get integrated circuit ID of the SIM
+                    get_imsi() && // Get international mobile subscriber information
+                    get_imei() && // Get international mobile equipment identifier
+                    get_meid() && // Probably the same as the IMEI
+                    set_sms()) {
+
+                    // The modem is initialised.
+                    _modem_initialised = true;
+                }
+            }
+        }
+    }
+
+    return _modem_initialised;
+}
+
+// Perform registration.
+bool UbloxCellularBase::nwk_registration()
+{
+    bool atSuccess = false;
+    bool registered = false;
+    int status;
+    int at_timeout;
+    LOCK();
+
+    at_timeout = _at_timeout; // Has to be inside LOCK()s
+
+    MBED_ASSERT(_at != NULL);
+
+    if (!is_registered_psd() && !is_registered_csd() && !is_registered_eps()) {
+        tr_info("Searching Network...");
+        // Enable the packet switched and network registration unsolicited result codes
+        if (_at->send("AT+CREG=1") && _at->recv("OK") &&
+            _at->send("AT+CGREG=1") && _at->recv("OK")) {
+            atSuccess = true;
+            if (_at->send("AT+CEREG=1")) {
+                _at->recv("OK");
+                // Don't check return value as this works for LTE only
+            }
+
+            if (atSuccess) {
+                // See if we are already in automatic mode
+                if (_at->send("AT+COPS?") && _at->recv("+COPS: %d", &status) &&
+                    _at->recv("OK")) {
+                    // If not, set it
+                    if (status != 0) {
+                        // Don't check return code here as there's not much
+                        // we can do if this fails.
+                        _at->send("AT+COPS=0") && _at->recv("OK");
+                    }
+                }
+
+                // Query the registration status directly as well,
+                // just in case
+                if (_at->send("AT+CREG?") && _at->recv("OK")) {
+                    // Answer will be processed by URC
+                }
+                if (_at->send("AT+CGREG?") && _at->recv("OK")) {
+                    // Answer will be processed by URC
+                }
+                if (_at->send("AT+CEREG?")) {
+                    _at->recv("OK");
+                    // Don't check return value as this works for LTE only
+                }
+            }
+        }
+        // Wait for registration to succeed
+        at_set_timeout(1000);
+        for (int waitSeconds = 0; !registered && (waitSeconds < 180); waitSeconds++) {
+            registered = is_registered_psd() || is_registered_csd() || is_registered_eps();
+            _at->recv(UNNATURAL_STRING);
+        }
+        at_set_timeout(at_timeout);
+
+        if (registered) {
+            // This should return quickly but sometimes the status field is not returned
+            // so make the timeout short
+            at_set_timeout(1000);
+            if (_at->send("AT+COPS?") && _at->recv("+COPS: %*d,%*d,\"%*[^\"]\",%d\n", &status)) {
+                set_rat(status);
+            }
+            at_set_timeout(at_timeout);
+        }
+    } else {
+        registered = true;
+    }
+    
+    UNLOCK();
+    return registered;
+}
+
+bool UbloxCellularBase::is_registered_csd()
+{
+  return (_dev_info.reg_status_csd == CSD_REGISTERED) ||
+          (_dev_info.reg_status_csd == CSD_REGISTERED_ROAMING) ||
+          (_dev_info.reg_status_csd == CSD_CSFB_NOT_PREFERRED);
+}
+
+bool UbloxCellularBase::is_registered_psd()
+{
+    return (_dev_info.reg_status_psd == PSD_REGISTERED) ||
+            (_dev_info.reg_status_psd == PSD_REGISTERED_ROAMING);
+}
+
+bool UbloxCellularBase::is_registered_eps()
+{
+    return (_dev_info.reg_status_eps == EPS_REGISTERED) ||
+            (_dev_info.reg_status_eps == EPS_REGISTERED_ROAMING);
+}
+
+// Perform deregistration.
+bool UbloxCellularBase::nwk_deregistration()
+{
+    bool success = false;
+    LOCK();
+
+    MBED_ASSERT(_at != NULL);
+
+    if (_at->send("AT+COPS=2") && _at->recv("OK")) {
+        _dev_info.reg_status_csd = CSD_NOT_REGISTERED_NOT_SEARCHING;
+        _dev_info.reg_status_psd = PSD_NOT_REGISTERED_NOT_SEARCHING;
+        _dev_info.reg_status_eps = EPS_NOT_REGISTERED_NOT_SEARCHING;
+        success = true;
+    }
+
+    UNLOCK();
+    return success;
+}
+
+// Put the modem into its lowest power state.
+void UbloxCellularBase::deinit()
+{
+    power_down();
+    _modem_initialised = false;
+}
+
+// Set the PIN.
+void UbloxCellularBase::set_pin(const char *pin) {
+    _pin = pin;
+}
+
+// Enable or disable SIM pin checking.
+bool UbloxCellularBase:: sim_pin_check_enable(bool enableNotDisable)
+{
+    bool success = false;;
+    LOCK();
+
+    MBED_ASSERT(_at != NULL);
+
+    if (_pin != NULL) {
+        if (_sim_pin_check_enabled && !enableNotDisable) {
+            // Disable the SIM lock
+            if (_at->send("AT+CLCK=\"SC\",0,\"%s\"", _pin) && _at->recv("OK")) {
+                _sim_pin_check_enabled = false;
+                success = true;
+            }
+        } else if (!_sim_pin_check_enabled && enableNotDisable) {
+            // Enable the SIM lock
+            if (_at->send("AT+CLCK=\"SC\",1,\"%s\"", _pin) && _at->recv("OK")) {
+                _sim_pin_check_enabled = true;
+                success = true;
+            }
+        } else {
+            success = true;
+        }
+    }
+
+    UNLOCK();
+    return success;
+}
+
+// Change the pin code for the SIM card.
+bool UbloxCellularBase::change_sim_pin(const char *pin)
+{
+    bool success = false;;
+    LOCK();
+
+    MBED_ASSERT(_at != NULL);
+
+    // Change the SIM pin
+    if ((pin != NULL) && (_pin != NULL)) {
+        if (_at->send("AT+CPWD=\"SC\",\"%s\",\"%s\"", _pin, pin) && _at->recv("OK")) {
+            _pin = pin;
+            success = true;
+        }
+    }
+
+    UNLOCK();
+    return success;
+}
+
+// End of File
+