An optical wireless communication (OWC) unit for transmitting and/or receiving data installable in a further device comprises at least one transmitter device for transmitting modulated light comprising an OWC signal of said data and/or at least one receiver device for receiving modulated light comprising an OWC signal representative of said data, wherein the at least one receiver device comprises at least one detector. The OWC unit further comprises analogue electronic circuitry for processing electronic signals and at least one power connection and/or at least one data connection for connection to a power source and/or processing resource of the further device. The OWC unit is operable to provide OWC communication under control of said further device and/or so as to transmit data from/provide data to said further device. The OWC unit is for use in an OWC system having an analogue bandwidth greater than or equal to 80 MHz.