QMultiPortMultiplexer *mux = new QMultiPortMultiplexer( device );

    // Add the Primary channel.
    QSerialPort *pri = QSerialPort::create( "/dev/ttyS0" );
    mux->addChannel( "primary", pri );
    // Add the Secondary channel.
    QSerialPort *sec = QSerialPort::create( "/dev/ttyS0" );
    mux->addChannel( "secondary", sec );
    // Add the GPRS channel.
    QSerialPort *data = QSerialPort::create( "/dev/ttyS8" );
    mux->addChannel( "data", data );
    // Add the GPRS Setup channel channel.
    QSerialPort *datasetup = QSerialPort::create( "/dev/ttyS0" );
    mux->addChannel( "datasetup", datasetup );
    return mux;