Abstract: Disclosed is a method, apparatus and computer product for ensuring QoS (Quality of Service) of isochronous data in a Residential Ethernet system including a legacy Ethernet device and a first Residential Ethernet switch, in which the first Residential Ethernet switch transmits data packets to the legacy Ethernet device, the method comprising the steps of inserting, by the first Residential Ethernet switch, virtual local area network (VLAN) tags into the data packets in order to allocate priorities to the data packets, and establishing priorities of the VLAN tags such that a highest priority is allocated to isochronous packets from among the data packets.

Abstract: Disclosed is a method for forming a synchronous frame to be transmitted in a Residential Ethernet System, which is capable of discretely transmitting synchronous data and asynchronous data, wherein the synchronous frame includes synchronous packets which are formed according to destinations of synchronous data. The method includes the steps of: receiving the synchronous data having different destinations, and classifying the received synchronous data according to the destinations of the synchronous data; adding a synchronous header to each of the synchronous data classified according to the destinations in order to insert synchronous information into each synchronous data; and adding an Ethernet header for Ethernet processing, thereby forming the synchronous packets.

Abstract: Transmitting data in a synchronous Ethernet passive optical network employs a synchronous Ethernet for ensuring QoS during transmission of multi-media data, thereby specifying transmission of synchronous data and asynchronous data, respectively. The Ethernet passive optical network has an optical line terminal, which is a central base station, and a plurality of optical network units. The method includes the steps of forming a synchronous frame using the OLT to transmit synchronous data for the ONUs, forming an asynchronous frame using the OLT to transmit asynchronous data for the ONUs, forming a super frame including the synchronous and asynchronous frames using the OLT, and transmitting the super frame using the OLT.

Abstract: Disclosed is a method for transmitting asynchronous data in a synchronous Ethernet having a sync frame section and an async frame section. The method includes the steps of: a) allocating a priority to motion picture data for transmission through the sync frame section; b) determining if a size of the data of all frames for transmission in one cycle exceeds the predetermined length; c) dropping motion picture data having a lower priority (e.g. which corresponds to the size of the data exceeding the predetermined length); and d) transmitting the data in one cycle unit when the size of the data to be transmitted does not exceed the predetermined length.

Abstract: A method and apparatus by which a reception device of a communication system can sense and compensate for an error of a program clock reference (PCR), and can sense and compensate for bit rate variation of transmission data in a transmitted MPEG-2 TS. The method and apparatus compensates for a PCR jitter, or a change in a data bit rate, which may occur in processing an MPEG-2 TS in a reception device of the MPEG-2 TS transmission system, thereby preventing the deterioration of image quality due to the jitter or loss of an input MPEG-2 TS data. The apparatus includes a PAT sensing unit for sensing a PAT from a received MPEG-2 TS, a PMT sensing unit for sensing a PMT based on information provided from the PAT sensing unit, a PCR PID unit for sensing a PCR PID based on information provided from the PMT sensing unit and a PCR data unit for outputting a PCR data based on information provided from the PMT sensing unit and PID information provided from the PCR PID unit.

Abstract: Disclosed are a method and an apparatus for quantitatively measuring a delay caused according to communication environments during a transmission of multimedia data, particularly, MPEG (Moving Picture Experts Group)-2 TS (Transport Stream), in a multimedia system. The apparatus includes a transmitter that generates and transmits a counter information packet (CIP), which is required to measure the delay in the transmission of the multimedia data, by inserting into the multimedia data the results of counting predetermined bits using a first counter; and a receiver that receives the CIP and computes the delay by comparing the counting results in the CIP with counting results received from a second counter.

Abstract: A method of configuring system layers for a synchronous Ethernet is provided. In the method, a physical layer takes charge of input and output of an Ethernet frame in direct relation to hardware, an xMII (x Media Independent Interface) layer connects the physical layer to a data link layer. The data link layer has a sync frame processor for processing a synchronous frame and an async frame processor for processing an asynchronous frame. A parser and multiplexer (MUX), included in the x MII layer, construct a super frame with a synchronous frame and an asynchronous frame, transmit the super frame through the physical layer, parse a received super frame into a synchronous frame and an asynchronous frame, and transmit the synchronous and asynchronous frames to the data link layer.

Abstract: A method of enabling transmission of a time-critical control signal event in a sync frame period, such as a pause signal that is generated when the receive buffer of an Ethernet switch is filled with packets beyond a threshold due to congestion of uplink asynchronous data, is disclosed. To transmit time-critical information in a synchronous Ethernet system, a current transmission period is checked upon detection of a time-critical event. If the current transmission period is a sync frame period, time-critical control information is generated, inserted into the first sub-sync frame after the time-critical event, and transmitted. If the current transmission period is an async frame period, a control frame including the time-critical control information is generated and transmitted.

Abstract: Disclosed is a method for establishing a synchronization in a synchronous Ethernet system. Devices are classified according to the type of the devices, and a device having a highest class in the synchronous Ethernet system is detected, then it is determined if the device having the highest class is able to serve as the timing master. If so, the device having the highest class is able to serve as the timing master if only one such device is detected; otherwise, the timing master between devices having the highest class is selected through a collision algorithm.

Abstract: A field programmable gate array (FPGA) for multiplexing data and enable signals input from a plurality of input ports and outputting the multiplexed signal to one output port is disclosed. The FPGA includes a plurality of memories, which are connected to the input ports, for storing the input data and enable signals, respectively, and outputting one-shot signals at trailing edges of the enable signals; and a finite state machine (FSM) for sequentially reading the data signals stored in the memories in an order of the one-shot signals input from the memories.

Abstract: A communication/broadcast multiplexer and demultiplexer for multiplexing and demultiplexing communication and broadcast signals using a specific transmission standard in an optical network system that integrates broadcast and communication services using a channel selection technique. The multiplexer comprises a broadcast data input unit, a communication data input unit, and a synchronous Ethernet framer. The broadcast data input unit receives broadcast data switched on a subscriber basis through a broadcast switch in an optical line terminal (OLT) in the system, and transfers it as a synchronous data frame to the synchronous Ethernet framer. The communication data input unit receives communication data on a subscriber basis through an Ethernet switch in the OLT and transfers it as an asynchronous data frame to the synchronous Ethernet framer.

Abstract: A broadcast/communication convergence system and a method for transmitting and receiving Ethernet data using the same is disclosed. The system is equipped with an optical network unit performing a time division multiplexing operation on the Ethernet data switched by a network switch and a plurality of broadcast data units, transmitting a resultant signal of the operation to a corresponding subscriber set-top box, and providing data from the subscriber set-top box to the network switch. In one aspect of the invention, the optical network unit produces a length of an Ethernet data frame provided from the network switch. An encapsulation operation is carried out by generating data length information and inserting the generated length information into an Ethernet data frame. Encapsulated Ethernet data is transmitted to the subscriber set-top box.

Abstract: A TDM (Time Division Multiplexing) frame applicable to digital broadcast data transmission in an FTTH (Fiber To The Home) system and a method for transmitting and receiving the TDM frame is disclosed. The TDM frame and methods are applicable to transmit a plurality of digital broadcast data units having different synchronous clocks using a simple format.

Abstract: An apparatus and a method for adjusting a transmission rate of data, in particular a moving picture experts group 2 (MPEG-2) data. The apparatus includes a receiving buffer for buffering multi program transport stream (MPTS) packets received at various transmission rates, and a packet storage for storing MPEG-2 null packets. A signal processing section reads data buffered in the receiving buffer at a predetermined output transmission rate, wherein the signal processing section stops an operation of reading data buffered in the receiving buffer, and reads and transmits the MPEG-2 null packets stored in the packet storage when a predetermined underflow occurrence forecast situation is caused in the receiving buffer.

Abstract: A broadcast/communication convergence system, and an FTTH (Fiber To The Home) system that can accommodate broadcast signals of various channels and variable band signals by converging broadcast and communication signals and transmitting the converged broadcast and communication signals using an IEEE 1394 transmission method serving as a standard interface in the FTTH system for broadcast/communication convergence. An OLT (Optical Line Terminal) transfers a plurality of broadcast signals and a communication signal received from external broadcast and communication providers through a single optical signal (A).

Abstract: Disclosed is a transport stream transmission apparatus, for example an MPEG Motion Picture Experts Group)—transport stream transmission apparatus.

Abstract: A fiber to the home FTTH network for convergence of broadcasting and communication is disclosed. The network includes: an OLT for receiving and converting a first predetermined number of broadcast signals and an Ethernet signal into a plurality of converted optical signals, combining the converted optical signals into converged optical signals for subsequent transmission by an optical wavelength division multiplexing method; and an optical network unit (ONU) for classifying the optical signal transmitted from the OLT into the first predetermined number of broadcast signals and the Ethernet signal, switching a second predetermined number of broadcasting signals of the first predetermined number of broadcasting signals according to each SIU by channel selection information contained in upstream Ethernet information, and switching the Ethernet signal to be transmitted to the SIU according to each SIU so as to transmit the switched signal.

Abstract: A heat exchanger includes a flow passage formed by stacking a plurality of laminated plates, cooling fins installed between the plates, and a tank part prepared on top of the plates and connected to a coolant inlet and a coolant outlet. The tank part has a bypass means for allowing the coolant in a gas state to move toward the coolant outlet without returning to the flow passage.