Abstract: A method of localizing a defect location and a method of identifying a cause of a defect in an optical transport network (OTN). The method of localizing a defect location in an OTN includes generating tandem connection monitoring (TCM) coordinates consisting of a TCM level and trail information of an optical data unit (ODU) based on a relationship between an OTN line card (LC) and the ODU in the OTN, localizing the defect location in the OTN by converting the TCM level to a segment on the TCM coordinates, and identifying a root cause using a defect identification algorithm that traces back the cause of the defect in an opposite direction to that in which the defect is propagated based on an OTN layer structure.

Abstract: Provided is a data processing system, including: a plurality of line matching blocks each including a data processor configured to store predefined preliminary transmission tables corresponding to the respective events requiring change of a data path, to determine whether to change a transmission table based on information received through an internal communication device, and to select and activate a preliminary transmission table corresponding to an event from among the preliminary transmission tables, wherein the preliminary transmission tables include destination information on all the physical or logical paths; and a shared bus configured to enable information on an event requiring change of the data path to be transmitted and received between the plurality of line matching blocks.

Abstract: A processor time synchronization apparatus and method in a data communication system which includes a plurality of processors and line interfaces. The processor time synchronization apparatus includes a first local processor configured to recognize a time difference between an external device and the system based on a time message exchanged with the external device, and synchronize time between the external device and the system, and a second local processor configured to receive time information from the first local processor that has been time-synchronized with the external device, the time information containing the time difference between the external device and the system, and synchronize the first local processor with a system's internal time using the received time information.

Abstract: Provided is a failure recovery method in a non-revertive mode of an Ethernet ring network. In an Ethernet ring network, link priorities between nodes or node priorities are determined based on media access control (MAC) addresses and the nodes having blocked ports are determined after failures are recovered from based on the priorities so that the blocked ports can be distributed.

Abstract: Provided is a data processing system, including: a plurality of line matching blocks each including a data processor configured to store predefined preliminary transmission tables corresponding to the respective events requiring change of a data path, to determine whether to change a transmission table based on information received through an internal communication device, and to select and activate a preliminary transmission table corresponding to an event from among the preliminary transmission tables, wherein the preliminary transmission tables include destination information on all the physical or logical paths; and a shared bus configured to enable information on an event requiring change of the data path to be transmitted and received between the plurality of line matching blocks.

Abstract: A method and apparatus for optical signal control using a filter in a multicasting ring network node and protection switching in an optical multiplex section is disclosed, in which a multicasting ring network node extracts or passes a wavelength from a node requiring optical signal wavelength extraction, transmits the passed optical signal to a neighboring node through control as necessary, and readily performs protection switching on an optical multiplex section signal.

Abstract: An optical communication apparatus and an optical communication method are disclosed. An optical communication apparatus mounted in a first node in a linear network coupled among a plurality nodes through an optical transmission line includes a multiplexer for receiving a plurality of optical signals having different wavelengths to output a first multi-wavelength optical signal obtained by coupling the plurality of optical signals, and a first optical coupler for dividing the first multi-wavelength optical signal into respective multi-wavelength optical signals to be transmitted to at least two different neighboring nodes.

Abstract: A processor time synchronization apparatus and method in a data communication system which includes a plurality of processors and line interfaces. The processor time synchronization apparatus includes a first local processor configured to recognize a time difference between an external device and the system based on a time message exchanged with the external device, and synchronize time between the external device and the system, and a second local processor configured to receive time information from the first local processor that has been time-synchronized with the external device, the time information containing the time difference between the external device and the system, and synchronize the first local processor with a system's internal time using the received time information.

Abstract: In a switching system using an N+1 switch redundancy method, a backplane connects a plurality of switch cards that are mounted in a half-slot of an upper end portion and a lower end portion of the center of a chassis and a plurality of line cards that are mounted in the half-slot of the upper end portion and the lower end portion of the chassis at both sides of the plurality of switch cards. In this case, in each line card and each switch card, a line card and a switch card of the same position are connected in the upper end portion or the lower end portion of the chassis using some connector groups, and a line card and a switch card that are disposed at the upper end portion or the lower end portion of the chassis are crossed and connected using the remaining connector groups.

Abstract: Provided is a failure recovery method in a non-revertive mode of an Ethernet ring network. In an Ethernet ring network, link priorities between nodes or node priorities are determined based on media access control (MAC) addresses and the nodes having blocked ports are determined after failures are recovered from based on the priorities so that the blocked ports can be distributed.

Abstract: Provided is a failure recovery method in a non-revertive mode of an Ethernet ring network. In an Ethernet ring network, link priorities between nodes or node priorities are determined based on media access control (MAC) addresses and the nodes having blocked ports are determined after failures are recovered from based on the priorities so that the blocked ports can be distributed.

Abstract: In a wireless optical communication system in which communication is performed based on a free space and a plurality of the communication apparatuses are arranged in a ring form around a central office terminal (COT), the communication apparatus monitors optical signals received in a first direction or in a second direction opposite to the first direction, and selects a first path through which the optical signals in the first direction are received and a second path through which the optical signals in the second direction are received. The communication apparatus converts an optical signal having a predetermined unique wavelength from among the optical signals received through the selected path into a signal of a frequency domain having a plurality of subcarriers, and obtains packet data mapped to each of the subcarriers.

Abstract: A packet transferring apparatus and method that may be applied to all packet systems operated on a packet transport network, to ensure the same level of reliability and availability as a circuit network. A path providing unit may acquire packet transfer path information regarding a packet transfer path from a transport network, and a subscriber interface unit may generate transport packet data by adding the packet transfer path information to packet data received from a subscriber network and may output the transport packet data. A packet switch may switch the transport packet data inputted from the subscriber interface unit, and a network interface unit may transmit the transport packet data switched by the packet switch, to the transport network along the packet transfer path.

Abstract: Provided are a method and apparatus for transmitting error information between an Ethernet network and a synchronous digital hierarchy (SDH) network. According to the present invention, when an error occurs in the Ethernet network or the SDH network, OAM information is transferred to the opposite network by using a conventional MAC control frame from a linked part of the Ethernet network and the SDH network and thus the EoS network may be efficiently operated and managed. Also, by using standardized MAC control frame, the present invention may be applied to an existing system without additionally changing hardware or defining a new OAM frame.

Abstract: An Ethernet protection switching method based on a change in link status in a link aggregation sublayer is disclosed. If an Ethernet link aggregation sublayer is present on an Ethernet connection path, a link aggregation sublayer Management Entity Group (MEG) end point is assigned to the Ethernet link aggregation sublayer to generate a link aggregation message for Ethernet connection management and protection switching. When a change in link status is detected in the Ethernet link aggregation sublayer, the link-aggregation-sublayer MEG end point generates and sends the link aggregation message to an MEG end point performing Ethernet connection management and protection switching. Adequate Ethernet protection switching may be performed even in the presence of the link aggregation sublayer.

Abstract: Provided is a failure recovery method in a non-revertive mode of an Ethernet ring network. In an Ethernet ring network, link priorities between nodes or node priorities are determined based on media access control (MAC) addresses and the nodes having blocked ports are determined after failures are recovered from based on the priorities so that the blocked ports can be distributed.

Abstract: A method for providing mobility of a mobile node in a packet transport network, and a packet transport network system are provided. The packet transport network system includes a plurality of gateway switches configured in a plurality of packet transport access networks to connect a packet transport core network and transmit/receive a packet to/from a certain terminal via a certain access switch. When the certain terminal moves, each gateway switch updates a tunnel mapping and management table according to the movement of the certain terminal, allocates a pre-set tunnel by using information included in the tunnel mapping and management table, and transmits/receives a packet to/from a counterpart terminal via the allocated tunnel. Thus, a packet loss and delay due to the influence of handover occurring when the mobile node moves between networks can be minimized and the handover procedure can be simplified.

Abstract: Provided is a protection switching method via forwarding table correction in an Ethernet ring network. Upon detecting a failure in a link, a node generates a protection switching frame including an address list of a forwarding table corresponding to a port connected to the link, and transmits the protection switching frame to a port at an opposite direction of the link. A node that receives the protection switching frame deletes its own address from the address list included in the protection switching frame, and changes a port number of an address in the address list of the protection switching frame from among addresses of the forwarding table corresponding to a port that received the protection switching frame to a port number in an opposite direction of the port that received the protection switching frame or deletes the port number of the address in the address list.

Abstract: Provided is a method of processing a packet for improving performance of an Ethernet switch. According to the present invention, a routine of searching a virtual local area network (VLAN) table by a decapsulation microblock and a bridge microblock may be performed by a core component when a core component generates tables and thus the number of memory accesses may be reduced. Also, VLAN port state information of an input port and VLAN port tagging information of an output port may be stored in metadata and may be transmitted to a next microblock. Accordingly, a duplicate memory access routine of the bridge microblock and an encapsulation microblock may be removed and thus an access time delay may be reduced, thereby improving performance of an Ethernet switch.

Abstract: Provided are a data receiving apparatus that can determine data by adjusting a reference level for determining a logic value of inputted data based on Inter-Symbol Interference in a data signal inputted through a transmission line, and receive the data without errors by compensating for timing margin decrease caused by the inter-symbol interference, and a method thereof. The apparatus includes: a reference generator for monitoring the level of an inputted data signal or generating reference levels according to an external control command; a comparator for comparing the inputted data with the reference levels and determining logic values of the inputted data; a selector for selecting the logic values of the inputted data as a valid logic value; and a selection controller for monitoring the valid logic value of the selector, transmitting a selection control signal to the selector, and controlling a process for selecting the valid logic value.