The present invention provides an apparatus, in particular an optical network unit, which comprises a first part operably coupled to an arm of an optical fiber network, the first part comprises an optical module including an optical-electric interface and/or an electric-optical interface locked on a preset wavelength band, and an interface module, and at least one second part operably coupled to a network entity of a communication network, each comprising a control unit, a signal processing unit and an interface module. One of the control units of the at least one second part is set by a optical line terminal of the optical fiber network as a master control unit configured to tune and control the optical module of the first part. The first part and the at least one second part are wireless coupled with respect to each other via the interface modules.