Optical wireless communication transceiver and method for controlling the power mode of such a transceiver

An optical wireless communication (OWC) transceiver apparatus comprising:

• at least one light transmitter configured to transmit light of a first wavelength or first range of wavelengths and to produce a modulated optical signal representative of a data signal;
• at least one photodetector configured to receive light and to produce a detection signal in response to the received light;
• receiver circuitry configured to receive and process the detection signal to produce a receiver signal;
• a motion sensor configured to sense motion of at least one object in a region about the OWC transceiver apparatus and to produce motion sensor output based on said sensed motion;
• and
• a controller configured to move the OWC transceiver apparatus from a lower power configuration to an intermediate power configuration in response to the motion sensor sensing motion,
• wherein in the intermediate power configuration the controller is configured to monitor output from at least the at least one photodetector and/or the receiver circuitry and move the OWC transceiver apparatus from the intermediate power configuration to a higher power configuration in response to the monitored output being indicative that the at least one photodetector has received light representative of at least one of an optical wireless communication signal or activity on an optical channel.