the method and apparatus for detecting in a receiver a transmitter local time , comprising determining a reference time for the transmitter local time ; receiving from the transmitter a transmission time duration signal that elapsed on the transmitter since the reference time for the transmitter local time ; and determining the transmitter local time based on the reference time for the transmitter local time and the received transmitter time duration . a time stamp signal based on the transmitter local time signal is generated at the receiver and is superimposed on the sensor data stream transmitted to the receiver . consequently , the advantage is provided that a data stream can be transmitted without the incorporation of any time stamp .