A photocoupler includes: a support substrate; a MOSFET; a light receiving element; a light emitting element; and a bonding layer. The user requests more information about the automobile through the computer, and the additional information is displayed to the user. To insure the system feasibility in variable channel conditions, an optimization scheme manages the assignment of UWB devices to respective channels subject to their suitability to the requested users’ transmission rates. This package structure can flexibly arrange the conductive traces and effectively shorten the bonding wires, thereby improve trace routability and quality of electrical connection for the semiconductor package.