Abstract: A reconnection method and device for a peripheral interface using VLC provide a protocol for when a communication link between a primary device and a secondary device is disconnected. The primary device generates an R-XID message including reconnection information and a warning indication signal indicating the disconnection. The secondary device aligns the communication link with the primary device using the warning indication signal, receives the R-XID message from the primary device by the secondary device, and transmits an R-XID response message for the R-XID message to the primary device.

Abstract: A system for performing indoor positioning using a Light Emitting Diode (LED) lighting unit is provided. The system includes the LED lighting unit for determining whether transmission packet data exists in a frame to be transmitted, modulating the transmission packet data in accordance with a predetermined method in order to maintain a uniform brightness of the LED lighting unit when the transmission packet data exists, and transmitting the frame including the modulated transmission packet data. The system also includes a mobile terminal for receiving the frame, demodulating the modulated transmission packet data to determine the transmission packet data, and performing indoor positioning by using the demodulated transmission packet data and information included in the frame.

Abstract: An apparatus and a method for providing synchronized data by using visible light communication includes, receiving a synchronization channel from a mobile communication base station using a specific mobile communication network, by a Light Emitting Diode (LED) lighting; analyzing the received synchronization channel, and extracting a synchronization signal for synchronizing the LED lighting with at least one LED lighting adjacent to the LED lighting; selecting a specific time slot of the synchronization signal based on IDentifications (IDs) of the LED lightings; and including a data frame of the LED lighting in the specific time slot, and transmitting the specific time slot, which includes the data frame of the LED lighting, to a mobile terminal.

Abstract: A method and apparatus for performing a navigation service in a mobile terminal is provided. Map information and an IDentification (ID) of an information spot, which is connected to a map server, are received from the information spot. A current position is determined. The map information and the current position are displayed A destination input by a user is received. An optimal path from the current position to the destination is calculated and displayed by using the map information. When the mobile terminal receives an ID of a general spot from the general spot, a current position of the mobile terminal is re-determined. When the re-determined current position is on the optimal path, the optimal path is updated and the updated optimal path from the re-determined current position to the destination is displayed.

Abstract: A retransmission apparatus using an IP multicasting method for a DMB service including a plurality (n) of radio frequency (RF) receivers, each for receiving a DMB RF signal of a corresponding channel, a plurality (n) of DMB decoders, each for outputting a transport stream (TS) by decoding the DMB RF signal received from a corresponding RF receiver, a plurality (n) of slicers, each for processing the TS input from a corresponding DMB decoder; a plurality (n) of network interfacers, each for IP packetizing the TS sliced by a corresponding slicer; a network switch for receiving the IP packets from the plurality (n) of network interfacers, transferring the received IP packets to a multicasting processing unit, and receiving multicasting data from the multicasting processing unit, and the multicasting processing unit for receiving the IP packets from the network switch, creating a single piece of multicasting data by assigning multicasting addresses to the received IP packets, and outputting the created multicasti

Abstract: An apparatus and method for transmitting and receiving data in one-to-one communication are provided. A first buffer for temporarily storing file data and a second buffer for temporarily storing message data are connected to a data transmitter for transmitting data and a data receiver for receiving data, respectively or vice versa, according to a request for data transmission or reception. The buffer for storing file data and the buffer for storing message data are differently constructed, thereby reducing the waste of memories of the buffers and achieving the miniaturization and high-speed data transmission of a portable terminal device.

Abstract: A display device for providing additional information using Visible Light Communication (VLC), including a decoder for dividing an input signal into a video signal and a data signal including additional information on at least one object included in an image output through the video signal; a display; a VLC controller for receiving the data signal from the decoder and encoding the data signal in accordance with a VLC protocol to output the data signal as a visible light signal through the VLC; light source blocks, which include light sources, back light the display, and output the data signal encoded in accordance with the VLC; and a control unit for controlling the encoded data signal including the additional information on the object, to be output as the visible light signal through a light source block at a position corresponding to the object from among the light source blocks.

Abstract: Provided is an apparatus and method for transmitting and receiving data in a visible light communication system, the apparatus including a visible light communication (VLC) transceiver for converting a visible light signal received from a counterpart into an electrical signal and outputting the electrical signal, by using a light receiving device during a reception operation, and converting an electrical signal containing information into a visible light signal and transmitting the visible light signal to the counterpart, by using a light emitting device during a transmission operation, a VLC controller comprising a visible frame engine (VFE) for generating a visible frame and outputting the visible frame to the VLC transceiver, in which the VFE generates the visible frame for transmission to a counterpart during non-transmission of respective frames for communication at a sender and a receiver in order to provide visibility to a communication link, and a host controller for controlling the VLC controller and

Abstract: A Visible Light Communication (VLC) method in a VLC terminal, in which the VLC terminal requests initial access to an Access Point (AP) on a selected mini-slot among a plurality of mini-slots constituting a control slot, based on control information in a frame, sends an association request to the AP on an allocated uplink time slot, if the uplink time slot allocated to correspond to the selected mini-slot exists in control information in a next frame, and transmits data at a data rate appointed to the VLC terminal included in control information in the current frame using an association Identifier (ID) included in a response received in reply to the association request and the allocated uplink time slot.

Abstract: Provided is a method of measuring the position of a portable terminal, comprising detecting indoor illuminating light, and outputting an electric signal corresponding to the detected indoor illuminating light, obtaining a plurality of data frames from the output electrical signal, and calculating a position of the portable terminal based on information regarding the position of a corresponding reference light source included in each data frame and an identifier corresponding to the reference light source included in said each frame and a reception time of said each data frame.

Abstract: A data communication apparatus based on digital image processing is provided, in which a display displays a color block array including color blocks corresponding to transmission data, a camera captures an image of a color block array displayed on a display of a transmitting side, a storage stores a code table including information about colors mapped to data values, and a Digital Signal Processor (DSP) creates a color block array by converting transmission data to color blocks according to the code table during data transmission, and identifies the color block array in the image captured by the camera, detects colors of color blocks in the color block array, and extracts data values corresponding to the detected colors during data reception.

Abstract: Disclosed is an apparatus and method for constructing and broadcasting a multi-screen broadcasting program by using a transport stream in a digital broadcasting, and for decoding the constructed transport stream to restore image and voice signals. The method includes the steps of analyzing a program access table (PAT) of broadcasting data to determine whether there are at least two image packets, performing signal decoding when the input broadcasting data is a single screen program having one image packet, performing a multi-decoding when the input broadcasting data is a multi-screen program having at least two image packets.

Abstract: Disclosed are an optical signal concentrator and an optical receiver for wireless optical communication. The concentrator includes a diffusion sheet and a light guide plate positioned below the diffusion sheet for guiding diffused optical signals perpendicularly to the incident direction the diffused optical signals, the light guide plate being formed with at least one concentric circle pattern facing the diffusion sheet. The receiver includes an optical signal concentrator including a diffusion sheet, a light guide plate positioned below the diffusion sheet for guiding the optical signals perpendicularly to the incident direction the diffused optical signals, one or more optical detectors for detecting light projected to the side of the light guide plate, and a reflection plate for reflecting light incident to the light guide plate.

Abstract: A retransmission apparatus is provided that uses a packet method for a DMB service and includes: a DMB receiver for receiving DMB data from a medium; a DMB transmission mode release unit that outputs an MPEG-2 TS by releasing a DMB transmission mode in the DMB data received from the DMB receiver; a channel information extractor that extracts channel information contained in a Fast Information Channel (FIC) of the DMB data in the DMB transmission mode release process of the DMB transmission mode release unit; a data information extractor that receives the MPEG-2 TS from the DMB transmission mode release unit and extracts data information indicating a location of an elementary stream from the received MPEG-2 TS; a channel information database (DB) that stores the channel information extracted by the channel information extractor and the data information extracted by the data information extractor as channel data; a first IP streamer that IP-streams the MPEG-2 TS output from the data information extractor; and a

Abstract: Provided is a method for broadcasting visible light information in visible light communication. The method includes determining a time interval for a simultaneous signal and a time interval for an individual signal of information to be displayed on a display device; simultaneously modulating output signals of three Red-Green-Blue (RGB) Light Emitting Diodes (LEDs) making up one pixel, and transferring the modulated information to the display device; individually modulating output signals of the three RGB LEDs and transferring the modulated information to the display device; and displaying the modulated information for any selected one of the time interval for the simultaneous signal and the time interval for the individual signal.

Abstract: A reconnection method and device for a peripheral interface using VLC provide a protocol for when a communication link between a primary device and a secondary device is disconnected. The primary device generates an R-XID message including reconnection information and a warning indication signal indicating the disconnection. The secondary device aligns the communication link with the primary device using the warning indication signal, receives the R-XID message from the primary device by the secondary device, and transmits an R-XID response message for the R-XID message to the primary device.

Abstract: A method for generating a visible signal for a data transmission frame in a visible-light communication system includes: receiving specific data constituted by a plurality of frames from a sender; checking and converting a received signal strength indication (RSSI) signal measured from the sender; whenever each frame of the specific data is consecutively received, checking the converted RSSI, determining a level of a visible signal for distinctively displaying a state of a corresponding communication channel, and transmitting the level of the visible signal to the sender; and when reception of the specific data has finished, transmitting a corresponding response message to the sender, according to whether the specific data has been successfully received.

Abstract: A wireless communication method between mobile terminals using visible light and a mobile terminal therefore are disclosed. The method includes: periodically transmitting device discovery signals for searching for a visible light communication device when there is a request for a visible light communication; transmitting only reference clock signals between the device discovery signals; and connecting a link to a receiving terminal to transmit data when a response signal for the device discovery signal is received from the receiving terminal.

Abstract: A method of providing a visible light communication in a data link layer of a visible light communication system adopting an infrared communication link connection protocol includes: broadcasting a discovery exchange station identification (D-XID) frame; generating a visible frame to provide a visibility to a link for a specified waiting time period for responding to the broadcast D-XID frame; exchanging a set normal response mode (SNRM) frame and an unnumbered acknowledgement (UA) frame for requesting a link setting between the transmitting and receiving terminals; generating visible frames for a waiting time for receiving the SNRM frame and the UA frame; exchanging an information transfer frame (I-frame) and a receive ready (RR) frame, which is a response to the I-frame, between the transmitting and receiving terminals; and generating visible frames for a specified waiting period for receiving the I-frame and the RR frame.

Abstract: A method and apparatus for arranging communication links in visible light communication increases the user visibility of the system. The method includes the steps of: (a) synchronizing, by a visible light communication (VLC) exchange identification (XID) frame, (b) transmission timing of a primary device and a secondary device in an allocated time slot, and securing time so as to allow the primary device and the secondary device to perform an operation required for transmitting data; (c) transmitting an XID command frame from the primary to the secondary device and (d) transmitting an XID response frame from the secondary receiving the XID command frame to the primary; and (e) filling remaining space of the allocated time slot with a visibility field so as to increase visibility of the remaining space of the allocated time slot after receiving the XID command frame or the XID response frame.