A gateway for assigning an access authorization for a mobile operating device to a field device, including a first interface that wirelessly communicates with the mobile operating device, a second interface that communicates with an authorization assignment device, a memory device that stores an access authorization of the mobile operating device transmitted by the authorization assignment device, authorization assignment circuitry that reads the access authorization of the mobile operating device from the memory device and transmits the access authorization to the mobile operating device via the first interface.