Abstract: A method and apparatus for transferring to a second communication band and returning to an original communication band according to a channel state in a multiband communication system are provided. The method includes communicating with a peer device in a first band, determining a channel state of a second band, and transferring to the second band based on a result of the determination, thereby efficiently using a plurality of bands and thus improving a data transmission speed.

Abstract: A visible light communication system and method for transmitting and receiving an information symbol in a visible light communication system for a Color Code Modulation (CCM) scheme using a chromaticity diagram. The method includes determining a first coordinates value corresponding to an information symbol to be transmitted on the chromaticity diagram; determining a first color ratio corresponding to the first coordinates value; determining a second coordinates value corresponding to a compensation symbol for compensating for the first color ratio into a color white and determining a second color ratio corresponding to the second coordinates value; and emitting a visible ray corresponding to each of the first color ratio and second color ratio. The first and second coordinates values are located on a line on the chromaticity diagram.

Abstract: An optical communication apparatus includes an optical signal transmitting unit to output an optical signal; an optical signal receiving unit to receive an optical signal; a retro-reflector to retro-reflect the received optical signal in a direction opposite to an incident angle of the received optical signal; and a control unit to direct the retro-reflector to receive the optical signal and to retro-reflect a response signal, which includes the received optical signal and data to be transmitted, in response to the received optical signal.

Abstract: Disclosed are a remote control method in a remote control system including a display panel, and a terminal for remote-controlling the display panel, and the remote control system. The remote control system includes a terminal for transmitting a light signal to a point on the screen of a display panel according to user input, and a display panel for executing an operation corresponding to the light signal received point.

Abstract: Disclosed relates to a wavelength division multiplexing-passive optical network (WDM-PON) system that can lock wavelengths of upstream light signals output from a plurality of optical network units (ONUs) by using coherent multi-wavelength light sources and reduce mode partition noises caused when using the coherent multi-wavelength light sources.