An optical wireless communication transceiver apparatus comprising: at least one light transmitter configured to transmit light of a first wavelength or first range of wavelengths; driver circuitry configured to receive a data signal and to process the data signal to produce a driving signal to drive the at least one light transmitter such that the at least one light transmitter produces a modulated optical signal representative of said data signal; at least one photodetector configured to receive light of a second wavelength or second range of wavelengths 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; demodulation circuitry configured to perform a decoding and/or demodulation process in accordance with an OWC protocol thereby to extract data from the receiver signal; wherein the transceiver apparatus further comprises: a motion sensor configured to sense motion of at least one object in a region about the transceiver apparatus and to produce motion sensor output based on said sensed motion, and a controller configured to move the 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 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 an optical wireless communication signal. at least one light transmitter configured to transmit light of a first wavelength or first range of wavelengths; driver circuitry configured to receive a data signal and to process the data signal to produce a driving signal to drive the at least one light transmitter such that the at least one light transmitter produces a modulated optical signal representative of said data signal; at least one photodetector configured to receive light of a second wavelength or second range of wavelengths 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; demodulation circuitry configured to perform a decoding and/or demodulation process in accordance with an OWC protocol thereby to extract data from the receiver signal; a motion sensor configured to sense motion of at least one object in a region about the transceiver apparatus and to produce motion sensor output based on said sensed motion, and a controller configured to move the 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 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 an optical wireless communication signal.