Patent application number | Description | Published |
20090010654 | Communication link apparatus and method for maintaining visibility in visible light communication - A system and method for continuing a communication link while maintaining visibility in visible light communication. A frame is transmitted by a sender for establishing a communication link before data transmission to a receiver by a sender. A receiver sends a response frame that reports on establishment of the communication link prior to data transmission by the sender. A data frame containing information is transmitted by the sender to the receiver. An acknowledgment frame is transmitted to the sender in response to the data frame. A disconnect frame is transmitted by the sender which is acknowledged by the receiver. A visible sequence is transmitted during a time period when the sender and the receiver do not transmit respective frames for communication to maintain visibility between two devices that may be communicating otherwise by, for example, infrared communication. | 01-08-2009 |
20090022112 | METHOD AND APPARATUS FOR NOTIFYING STATUS OF MOBILE NODE IN A WIRELESS LOCAL AREA NETWORK SYSTEM USING VISIBLE LIGHT COMMUNICATION - A method and apparatus for notifying status of an MN in a WLAN system using VLC are provided, in which an AP allocates a first predetermined number of time slots per frame as unallocated slots, for status notification of an initially accessing MN and allocates a second predetermined number of time slots per frame as reserved slots, for status notification of an initially accessing MN and uplink data transmission of an MN, and the MN transmits a visible light signal carrying status information about the MN in one of an unallocated slot and a reserved slot, if the MN initially accesses the AP. | 01-22-2009 |
20090022496 | Apparatus and method for arranging communication links in visible light communication - 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. | 01-22-2009 |
20090028558 | Method for providing visible light communication in a visible light communication system - 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. | 01-29-2009 |
20090073952 | METHOD AND APPARATUS FOR RETRANSMITTING DATA IN WIRELESS LAN SYSTEM USING VISIBLE LIGHT COMMUNICATION - A method for retransmitting data when data transmission/reception has failed in a wireless LAN system using visible light communication. A mobile node searches a received frame for a fast feedback slot allocated for retransmission information when momentary data transmission/reception failure has occurred. One mini-slot from among the plurality of mini-slots is selected from the fast feedback slot. The mobile node transmits a fast feedback message, including information for retransmission, to an access point by using the selected mini-slot. | 03-19-2009 |
20090110405 | METHOD OF COMMUNICATING BETWEEN TERMINALS USING OPTICAL WIRELESS LINE AND MOBILE TERMINAL FOR PERFORMING THE SAME - 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. | 04-30-2009 |
20090185802 | Method and apparatus for generating visible signal for data transmission frame in visible-light communication system - 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. | 07-23-2009 |
20090213099 | APPARATUS AND METHOD FOR BROADCASTING VISIBLE LIGHT INFORMATION IN VISIBLE LIGHT COMMUNICATION - 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. | 08-27-2009 |
20100098439 | OPTICAL SIGNAL CONCENTRATOR AND OPTICAL RECEIVER USING THE SAME - 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. | 04-22-2010 |
20100110088 | METHOD AND APPARATUS FOR DATA COMMUNICATION BASED ON DIGITAL IMAGE PROCESSING - 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. | 05-06-2010 |