Abstract: 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.

Abstract: A subscriber distribution network includes a backplane board that has a network switch and a plurality of subscriber line units, the network data, the plurality of subscriber line units being provided between the network switch and subscriber set-tops, providing data from the network switch to a corresponding subscriber set-top, and providing data transmitted from the subscriber set-tops to the network switch. In the subscriber distribution network apparatus, the network switch can be connected in simple fashion to the subscriber line units by connectors.

Abstract: A system and method for performing a handover of a mobile station (MS) by considering Quality of Service (QoS) in a broadband mobile communication system. The method can include the steps of: receiving information about one or more neighbor base stations and reception strengths for the neighbor base stations from a Serving Radio Access System (RAS) currently communicating with the MS; extracting a value of a specific field from the received information about the neighbor base stations; combining the extracted value of the specific field with the reception strengths to thereby obtain combined values, and selecting a maximum value among the combined values; and transmitting a handover (handoff) request message to a base station corresponding to the selected maximum value. The system includes an MS that analyzes information about neighbor stations received in a Mobile Neighbor Base-station Advertisement (MOB_NBR_ADV) message to select a target RAS.

Abstract: A photoelectric cross-connect system for an optical-communication system minimizes service recovery time when an error is generated. A plurality of nodes are connected by an optical-transmission line wherein each nodes automatically recognizes a data rate of an input signal and communicates over a redundant channel with an adjacent node when there is a certain type of error. An optical-receiving unit receives an optical signal performs O/E conversion. A main optical-transmitting unit recovers clock and data signals according to the converted signal and sets a data rate according to the converted signal for subsequent transmission; a redundant optical-transmitting unit recovers a clock and data according to the converted signal and sets a data rate according to the converted signal for subsequent transmission A switch provides selectively connection state between the optical-receiving unit and the main optical-transmitting unit and between the optical-receiving unit and the redundant optical-transmitting unit.

Abstract: A method, apparatus and system for providing a video service of a video service system including multimedia video in real time to a mobile terminal connected by a wireless network. A video frame coded by a coding scheme is transmitted to the mobile terminal for decoding and display. The coding scheme may include a first coding scheme and a second coding scheme used together at a predetermined ratio according to the mobile terminal demanding the video service. A server typically receives coding scheme change determining information from the mobile terminal in order to determining whether or not to change the coding scheme for the video frame during transmission of the video frame. The changed coding scheme can be used to transmit the video frame to the mobile terminal according to the result of analyzing the coding scheme change determining information.

Abstract: A method and apparatus for error concealment in decoding of a moving picture. The method includes the steps of determining an erroneous macro block in a present frame when the moving picture is decoded, finding a first macro block having a highest similarity to the erroneous macro block and a second macro block having a next highest similarity to the erroneous block in a previous frame by comparing adjacent pixels of respective blocks in the previous frame with adjacent pixels of the erroneous block in the present frame; and replacing the erroneous block by using an average between the found macro blocks having the highest similarity and the second highest similarity to thereby conceal the erroneous macro block. The apparatus includes a parser, an entropy decoder, an inverse quantizer, an inverse converter, and a concealment unit that uses motion compensation from a previous frame to correct a macro block in a current frame.

Abstract: An apparatus for reception of a mobile broadcast is disclosed. The apparatus includes a mobile broadcast reception unit for receiving a broadcast signal transmitted through a mobile broadcasting network, demodulating the broadcast signal into a baseband signal, and outputting the baseband signal; and a wireless Internet broadcast reception unit for receiving a broadcast signal transmitted through a wireless Internet network, demodulating the broadcast signal into a baseband signal, and outputting the baseband signal, and the apparatus also includes a post-processing unit for checking reception sensibilities of the mobile broadcast reception unit and the wireless Internet broadcast reception unit, selecting and decoding one signal of output signals of the mobile broadcast reception unit and the wireless Internet broadcast reception unit according to a result of the checking, and outputting the selected and decoded signal.

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: 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 is disclosed for seamlessly transmitting video content to a terminal in a communication system which supports a multimedia service. The apparatus generally comprises a transcoding information generation unit for generating transcoding information for performing a transcoding operation in consideration of the bandwidth of a network, a transcoding unit for adaptively transcoding video content to be transmitted according to the generated transcoding information; and a database server for storing the video content to be transmitted from the apparatus to the terminal.

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: A system having a transmitter and a receiver provides sign language video data in a broadcasting-communication convergence system. A transmitter extracts data, to which a sign language is to be applied, from the multimedia data, converts the extracted data into motion data, converts the motion data into an avatar motion schema indicative of avatar motion data, converts the avatar motion schema into metadata, multiplexes the multimedia data and the metadata, and transmits the multiplexed data. A receiver receives the multiplexed data, demultiplexes the received multiplexed data, extracts an avatar motion schema using the metadata, generates sign language video data by controlling a motion of an avatar through the avatar motion schema, multiplexes the sign language video data and the multimedia data, and transmits the multiplexed data to a display unit.

Abstract: Disclosed are a personal video recorder (PVR) using metadata and a recording control method thereof that facilitates the selective recording of user-preferred segments of a broadcast program in real time. The PVR includes a broadcast receiver for receiving the digital broadcast and dividing the digital broadcast program into video data, audio data, and metadata.

Abstract: A method for transmitting packetized multimedia content over a network is disclosed. The method comprises, receiving packetized multimedia content to be transmitted over the network; classifying respective frame of the packetized multimedia content according to an assigned priority by analyzing a frame header of each frame of the packet; separately storing the classified frames in accordance with said classification; and differentially marking the classified frames according to quality-of-service (QoS).

Abstract: A bit rate control apparatus having a delay unit for delaying an input signal received in an optical receiver in an optoelectrically-converted state; a DC level outputting unit for exclusively OR'ing the input signal with the delayed signal outputted from the delay unit; an A/D converting unit for A/D converting a DC level outputted from the DC level outputting unit; a clock/data reproducing unit for reproducing clocks and data based on a bit rate control signal; and a control unit for calculating a variation in the DC level at every interruption timing, which is previously set, based on the A/D converted signal, and for determining whether the DC level variation occurs under the influence of temperature or due to a variation in bit rate based on a difference between the calculated DC level variation from a predetermined variation limit.

Abstract: A subscriber distribution network includes a backplane board that has a network switch and a plurality of subscriber line units, the network data, the plurality of subscriber line units being provided between the network switch and subscriber set-tops, providing data from the network switch to a corresponding subscriber set-top, and providing data transmitted from the subscriber set-tops to the network switch. In the subscriber distribution network apparatus, the network switch can be connected in simple fashion to the subscriber line units by connectors.

Abstract: The present invention relates to an optical-communication system having a plurality of nodes connected by an optical-transmission line there-between, in which each of the nodes automatically recognizes the data rate of an input signal and includes a redundant channel to communicate with an adjacent node when there is a disconnection from one adjacent node.

Abstract: Disclosed is a bit rate discrimination device that accurately discriminates a bit rate regardless of variations in the operating temperature. A photoelectric converter converts an input optical signal into an electric signal, and a bit rate detector detects a bit rate of the optical signal from the electric signal and outputs a discrimination signal indicating the bit rate. A DC amplifier outputs a bit rate detection signal by amplifying the discrimination signal, and a temperature detector detects the operating temperature of the DC amplifier and outputs a temperature signal indicating the detected operating temperature. A variation amplifier outputs a temperature compensation signal by amplifying the voltage level difference between the temperature signal and a predetermined reference signal, so as to cancel variations in an output voltage of the DC amplifier according to the operating temperature.

Abstract: Disclosed is a bit rate discrimination device that accurately discriminates a bit rate regardless of variations in the operating temperature. A photoelectric converter converts an input optical signal into an electric signal, and a bit rate detector detects a bit rate of the optical signal from the electric signal and outputs a discrimination signal indicating the bit rate. A DC amplifier outputs a bit rate detection signal by amplifying the discrimination signal, and a temperature detector detects the operating temperature of the DC amplifier and outputs a temperature signal indicating the detected operating temperature. A variation amplifier outputs a temperature compensation signal by amplifying the voltage level difference between the temperature signal and a predetermined reference signal, so as to cancel variations in an output voltage of the DC amplifier according to the operating temperature.

Abstract: A bit rate control apparatus and method for an optical receiver capable of avoiding an erroneous determination of the bit rate occurring under the influence of temperature.