Abstract: An optical wireless communication (OWC) interface apparatus comprises: at least one input and/or output configured to transfer data signals from and/or to a bus device; optical interface circuitry configured to transfer optical wireless communication (OWC) signals representative of the data signals between the OWC interface apparatus and a light transmitter and/or receiver apparatus, wherein the light transmitter and/or receiver apparatus is configured to transmit and/or receive the OWC signals as free-space light signals; and interface control circuitry that is configured to establish and/or maintain communication with the bus device in accordance with a bus protocol thereby to enable transfer of the data signals between the OWC interface apparatus and the bus device.