Abstract: A transmitting apparatus in a transport network performs forward error correcting encoding for each virtual lane set as a multiple of the transmission channels, to generate virtual frames including independent parity bytes for each virtual lane. The generated virtual frames are transmitted through at least one transmission channel. In addition, a receiving apparatus detects the virtual frames for each virtual lane from a signal received through a transmission channel by using a frame assignment sequence, and performs forward error correcting decoding by using the parity bytes included in the virtual frames detected for each virtual lane.

Abstract: Provided are an apparatus and a method for generating a CS-RZ optical signal. The apparatus includes: a classifier distributing an input signal into two NRZ (non-return-to-zero) signals with an identical transmission speed; a first signal transformer converting one of the two NRZ signals into a first RZ signal using a full-frequency clock; a second signal transformer converting the other one of the two NRZ input signals into a second RZ signal using a full-frequency clock; a phase adjuster adjusting the first and second RZ signals so that a delay time corresponding to half a period of the input signal exists between the first and second RZ signals; a bias unit adding different DC (direct current) bias voltages to the first and second RZ signals; and a dual electrode optical modulator transforming the two electrical RZ signals into an optical CS-RZ signal.

Abstract: Provided is an apparatus for matching Gigabit Ethernet (GbE) signals to an Optical Transport Hierarchy (OTH). The apparatus real-time records a source address and input port information of GbE Ethernet frames in a memory, compares a destination address of the Ethernet frame which is a payload of a GFP frame with memory table information, searches an output port location of the GbE, and interreceives GbE frames and Generic Frame Procedure (GFP) frames by multiplexing/demultiplexing.

Abstract: A method of transmitting data in an optical transport network is provided. The method comprises generating an optical transmission unit frame including an in-band area including a first area to which information data is allocated and a second area to which the information data is not allocated and an out-band area including parity information and transmitting the data through the optical transmission unit frame.

Abstract: A method and apparatus for processing a timestamp using signature information on a physical layer is provided. The timestamp processing terminal uses a pseudo-random binary sequence to assign signature information to a message which is to be sent to another terminal, and verifies the signature information on a physical layer. The signature information is used to identify the message as a sync message. Accordingly, it is possible to precisely process the timestamp.

Abstract: Disclosed area method and apparatus of transporting client signals and a method and apparatus of mapping or demapping tributary slots for transport of client signals. The client signal transporting apparatus defines a bit rate of an optical transport signal, and bit-transparently maps and multiplexes client signals that operate at the defined bit rate. Also, the client signal transporting apparatus adjusts a bandwidth by extending a mapping area to increase a data capacity to be allocated to tributary slots.

Abstract: Provided are an equalization apparatus and method of compensating a distorted received signal. The equalization apparatus includes: a filter unit removing inter-symbol interference (ISI) from a multi-channel signal that is received; and a zero-offset controller identifying a zero offset of the multi-channel signal and determining operating coefficients of the filter unit by reflecting the identified zero offset. A response filter, which reduces loss and noise, can be used, and the structure of the response filter can be simplified. In addition, channel characteristics are estimated in real time at an initial stage of data transmission and reception. Thus, an equalizer optimized for channel interference characteristics can be provided.

Abstract: An optical communication system is provided. In particular, multi-lane signal transmitting and receiving apparatuses capable of transmitting and receiving a multi-lane signal using the same inverse multiplexing scheme even when optic modules having several transport lane numbers are selected according to a purpose of use are provided. Each OTUk capable of containing a client signal in a transport hierarchy signal (OTUk-Xv) is defined as a virtual container, and Y virtual lanes are allocated to respective virtual containers X, in which identification information for the allocated virtual lanes is inserted into an overhead area and a transport hierarchy multi-lane signal is transmitted in the form of OTUk-XvYd.

Abstract: An Ethernet apparatus for performing lane fault recovery is provided. An Ethernet apparatus capable of lane fault recovery includes a data transmitter using a backup lane in the transport link to transmit data intended to be transmitted via the faulty lane when at least one faulty lane is detected from the data transfer lanes, and a data receiver recognizing the data received via the backup lane as data transferred via the faulty lane when the faulty lane is detected. In an Ethernet apparatus having a multi-lane structure, a lane fault and faulty lanes can be accurately recognized while maintaining compatibility with a standard Ethernet apparatus.

Abstract: A method for reducing power consumption in an Ethernet switch is provided. The method includes: checking a state of packet data input through each of connection ports; detecting a connection port which has a packet rate lower than a predetermined reference value based on a result of the checking; and generating a data transfer control frame with respect to the connection port having the low packet rate and transmitting the generated data transfer control frame to an Ethernet apparatus connected to the corresponding connection port. Accordingly, a transmission line between the Ethernet switch and an Ethernet apparatus having the low to transmission rate is maintained in a low-power state, thereby reducing energy consumption in both Ethernet apparatuses.

Abstract: A pseudo-inverse multiplexing/de-multiplexing apparatus and method are disclosed. The pseudo-inverse multiplexing apparatus maps a client signal to an OPUk-Xpv signal. The OPUk-Xpv signal has a payload area that can be segmented into a plurality of tributary slots and an overhead area into which frame configuration information related to the tributary slots is inserted. The pseudo-inverse multiplexing apparatus decides the number of tributary slots to be used to map client signals, according to a bit rate or bit tolerance of the client signals, and maps the client signals using the determined number of tributary slots. Accordingly, it is possible to map or frame a variety of client signals.

Abstract: Provided are a time-division data multiplexing/demultiplexing system and method capable of preventing errors in processing data signals which occur due to a phase difference between data signals and a multiplexing reference clock in a multiplexing process or a phase difference between a multiplexed data signal and a demultiplexing reference clock in a demultiplexing process. The time-division data multiplexing system includes: a phase adjusting unit which adjusts a phase of each of a plurality of data signals having different phases from one another for enabling the data signals to be time-division multiplexed when a plurality of values of the data signals indicate a stable state; and a multiplexer time-division multiplexing the phase adjusted data signals according to a multiplexing reference clock.

Abstract: Provided are a frequency extracting apparatus and a signal extracting system employing the same. The signal extracting system can reduce the effect of an input signal pattern by extracting two frequency components and beating them to extract a desired clock signal, and improve a signal-to-noise ratio of an extracted clock signal. The frequency extracting apparatus includes: a circulator for changing an output direction of an input signal; a reflective filter for extracting a desired frequency component among frequency components of the input signal; a wavelength and amplitude controlling unit; and the frequency amplitude controller.

Abstract: Provided are a method and an apparatus for converting an interface between high speed data having various capacities. The apparatus includes a data transmitting part and a data receiving part. The data transmitting part generates a deskew channel having respective timing data of a plurality of data transmitted from a first communicating device, and outputs the generated deskew channel together with the plurality of data to a second communicating device. The data receiving part compares the deskew channel transmitted from the second communicating device with the plurality of data to measure skew values of the data, aligns bits and bytes of the plurality of data using the skew values, and transmits the plurality of data to the first communicating device.

Abstract: The present invention relates to an apparatus and method for extracting an optical clock using filters and an amplifier. The object of the present invention is to provide an extraction of neighboring frequency components using wavelength fixed optical filters and an amplifier. In accordance with an aspect of the present invention, there is provided an apparatus for extracting an optical clock to extract a clock from the optical signal provided with plurality of peaks on a spectrum, including a first filter for extracting a central frequency component, a second filter for extracting a frequency component adjacent to the first frequency component, the amplifier for amplifying amplitude of the second frequency component until the amplitude of the second frequency component becomes the same as that of the first frequency component and the receiver for extracting a clock to do beating the first frequency component and the second frequency component.

Abstract: An apparatus and method for extracting an optical clock signal are provided. The method includes splitting a predetermined polarization component from an input optical signal, selecting frequency components for clock signal extraction from the predetermined polarization component and amplifying the selected frequency components, rotating the amplified frequency components by a predetermined angle and then reflecting them, amplifying the reflected frequency components and removing noise from the amplified frequency components using a Fabry-Perot filter, and obtaining a beat frequency component from the frequency components from which noise has been removed using the Fabry-Perot filter to extract a clock signal. Accordingly, influence of the pattern of the input optical signal is reduced and the apparatus and method are provided at low price.

Abstract: An apparatus and method for extracting an optical clock signal are provided. The apparatus includes a first reflection filter selecting and reflecting only a first frequency component in an input optical signal; a first Fabry-Perot laser diode matching the first frequency component reflected by the first reflection filter with a predetermined output mode and outputting the first frequency component in the predetermined output mode; a second Fabry-Perot laser diode selecting a second frequency component in an input optical signal that has not been reflected but has been transmitted by the first reflection filter, matching the second frequency component with a predetermined output mode, and outputting the second frequency component in the predetermined output mode; and a photodetector receiving the first frequency component from the first Fabry-Perot laser diode and the second frequency component from the second Fabry-Perot laser diode and beating them to extract a clock signal.

Abstract: Provided is an apparatus for matching Gigabit Ethernet (GbE) signals to an Optical Transport Hierarchy (OTH). The apparatus real-time records a source address and input port information of GbE Ethernet frames in a memory, compares a destination address of the Ethernet frame which is a payload of a GFP frame with memory table information, searches an output port location of the GbE, and interreceives GbE frames and Generic Frame Procedure (GFP) frames by multiplexing/demultiplexing.

Abstract: Provided is an apparatus and method for restoring clock signals by using a circulator in an optical transmission system. The apparatus includes a circulator, which allows one of N types of input data signals having different transmission speeds to circulate in a single direction, band pass filters, which extract N types of clock frequency components respectively corresponding to each transmission speed of the N types of input data signals, and clock amplifiers, which amplify each of the N types of clock frequency components.

Abstract: Provided are a method of and apparatus for processing a virtual local area network (VLAN) tag frame. The apparatus includes a filtering data base (FDB) for storing a VLAN tag frame which is created by a gigabit passive optical network (GPON) master; an uplink processing unit for removing by referring to the FDB a VLAN tag from the VLAN tag frame which is received from the GPON master, and transmitting a data frame to an Ethernet switch; and a downlink processing unit for inserting by looking up the FDB a VLAN tag into the data frame which is received from the Ethernet switch, and then transmitting the data frame to the GPON master. According to the present invention, port identification (ID) information that is lost in a GPON master may be provided to a switch above the GPON master by using a VLAN tag frame processing technology.