A light-emitting device includes a plurality of light-emitting elements provided on a base material, each of the light-emitting elements including a pair of electrodes, and a light-emitting layer interposed between the electrodes. The nanostructured coatings can include Si or metallic, ceramic or polymeric nanowires that may have a re-entrant or mushroom-like tip geometry. Moreover, a dispersion adder for beforehand adding a predetermined positive dispersion amount to the WDM signal before transmission is included in the optical transmitter or at least one relay node. By these means, structures in the lower dermis are irradiated. The mapping of the modulation symbols in at least one resource region is independent of a certain control channel information that is carried in the time domain subframe, and the mapping of the modulation symbols in at least another resource region is dependent upon that certain control channel information. The first end of the second audio signal conduit is detachably coupled to the second end of the first audio signal conduit, and the second end of the second audio signal conduit is detachably coupled to the audio system.