Abstract: Provided is an automatic optical power control method for an optical line terminal (OLT) of a passive optical network (PON). The automatic optical power control method includes at the OLT, measuring an allowable range of the optical power allowing a normal network operation on the PON, at the OLT, setting an optimum optical signal level within the measured allowable range of the optical power, and at the OLT, adjusting a power level of a transmitter to the set optimum optical signal level. Accordingly, an appropriate power level can be selected depending on an optical distribution network (ODN) structure to drive the transmitter. Also, when the entire optical network units are deactivated, a laser of the transmitter is turned off to thereby minimize unnecessary power consumption at the OLT.

Abstract: Provided are a laser diode which has low power consumption and can realize a high on/off extinction ratio by small variation of current and which can modulate optical signals at high speed, an optical transmitter, and an optical communication apparatus including the optical transmitter. The laser diode having an abrupt turn-on characteristic, comprises: an active region in which light is generated by application of current and gain is controlled; and an absorption region absorbing light generated in the laser diode at a current lower than an abrupt threshold current that is the same as or lower than an operation current, the operation current being a current level that allows the laser diode to generate a target optical power, wherein the output optical power rapidly increases at the abrupt threshold current.

Abstract: A passive optical network system includes: a plurality of optical signal splitter receiving optical signals from a plurality of optical network units (ONUs) to provide a plurality of upstream optical signals having different wavelengths; a hybrid optical filter multiplexing the plurality of upstream optical signals in a wavelength division multiplexing (WDM) scheme; and an optical line terminal (OLT) receiving the multiplexed upstream optical signals in a time division multiplexing (TDM) scheme. Therefore, the network system can be easily expanded when the number of subscribers increases, and the optical loss can be minimized.

Abstract: Provided are an optical output power control method that provides optical communication without harming the human body even when a transmission line is cut or no optical network unit (ONU) accesses a communication system, and a passive optical network (PON) system using the method. In the method, an optical signal having a predetermined period is transmitted when an optical communication system is in an abnormal state, wherein the predetermined period includes a laser-on time interval in which the optical signal has a normal power level and a laser-off time interval in which the optical signal is off or has a power level lower than the normal power level, so that the optical communication system performs optical communication without harming the human body even during the abnormal state.

Abstract: Provided are a sing-unit integrated transceiver having a pump source and a transceiver module using the transceiver.

Abstract: Provided is an optical filtering apparatus which is applied to a Time Division Multiplexing Passive Optical Network (TDM-PON) based on a wavelength division multiplexing (WDM) method. The optical filtering apparatus includes: an optical signal distributing unit dividing an optical signal received from an optical line terminal into at least one optical signal with uniform output intensity, and distributing the at least one optical signal into at least one optical network unit; and a multiplexing unit combining a plurality of optical signals having different wavelengths received from the at least one optical network unit using a wavelength division multiplexing (WDM) method, and outputting the combined optical signal to the optical line terminal. Therefore, by using the optical filtering apparatus, it is possible to connect a large number of subscribers to an Optical Line Terminal (OLT) on a network such as Fiber To The Home (FTTH), thereby increasing efficiency in costs.

Abstract: Provided is a time division multiplex (TDM)/wavelength division multiple access (WDMA) passive optical network (PON) device. The TDM/WDMA PON device comprises a base station terminal, a wavelength splitter, and a subscriber terminal optical transceiver. The base station terminal comprises a transmitter time-division-multiplexing and simultaneously modulating and outputting a plurality of different wavelength optical signals, an optical circulator transmitting the optical signals output from the transmitter to an optical distribution network and transmitting optical signals received from the optical distribution network to a receiver and the receiver demultiplexing wavelength division multiplexed upstream signals from the optical distribution network through the optical circulator, converting the demultiplexed upstream signals into a plurality of electrical signals, and delivering the electrical signals to an upper layer.

Abstract: A touch screen using infrared cameras hardly affected by external disturbance light includes an infrared radiation base having a plurality of infrared emitting elements and the infrared cameras, thereby preventing malfunction resulting from the external disturbance light. The touch screen includes a body having a screen part to which an image is output, an infrared radiation base having a plurality of infrared emitting elements and disposed around the screen part in transverse and longitudinal directions, and infrared cameras receiving the infrared light emitted from the infrared emitting elements of the infrared radiation base and detecting the position of an object touched on the screen part according to whether or not the infrared light emitted from each infrared emitting element is received.

Abstract: Provided are high power PLC optical Tx module and PLC optical Tx/Rx module. The PLC optical Tx/Rx module is located in an OLT of a PON system. The high power PLC optical Tx/Rx module includes a photodiode, a laser diode, an SOA, an optical coupler, and a PLC platform. The photodiode converts an input optical signal into an electrical signal, and the laser diode generates an optical signal of a predetermined wavelength. The SOA amplifies the optical signal generated by the laser diode, and the optical coupler couples optical signals, outputs the coupled signal to a splitter, divides an optical signal from the slitter, and outputs the divided signals to the photodiode. The PLC platform incorporates the photodiode, the laser diode, the SOA, and the optical coupler into one package to allow an optical signal to be output with high power.

Abstract: A pluggable optical transceiver module is provided. The pluggable optical transceiver module is fitted to and removed from a receptacle having a clamp at an end in an optical communication system body and includes a housing frame having an adaptor at which a light emitting diode (LED) display unit and an optical transceiver element are installed; a rotary lever comprising a handle at one side and a pressing portion at another side so that the rotary lever rotates by a predetermined angle with respect to one side of the housing frame; and an elastic arm which is pivoted on the housing frame to be rotated by the rotary lever and includes one end contacting the pressing portion according to rotation of the rotary lever and another end coupled with or separated from the clamp of the receptacle by the rotation.

Abstract: Provided are a hybrid optical transceiver module having an optical amplifier packaged thereto for outputting a high-power optical signal to remove problems regarding narrow emission angle and optical alignment, and a passive optical network (PON) system having an improved optical network terminal (ONT) accommodation capability using the hybrid optical transceiver module. The hybrid optical transceiver module includes a first package in which an LD (laser diode) is packaged, and a second package in which SOA (semiconductor optical amplifier) and a PD (photo diode) are packaged. The first and second packages are coupled to be one package so as to output a high-power optical signal.

Abstract: Disclosed are an optical module interfacing device for connecting an RJ interface and an SFP type optical module to an SFP type optical module connector without additional processing, and an Ethernet system using the optical module interfacing device, thus supporting data transmission and reception. The optical module interfacing device includes a board having the same dimensions as those of the optical module, a male connector, having the same dimensions as those of the optical module, formed at a side surface of one end of the board to be connected to the female connector for the optical module mounted on a host board, and an RJ female connector provided with a plurality of pins formed on an upper surface of the board, respectively corresponding to pins of the male connector, according to standards. Further, UTP data is provided to MDI supporting ports of a physical layer through an interfacing unit.

Abstract: A method for managing a content addressable memory (CAM) look-up table using the longest prefix matching (LPM) is provided. The method includes providing a pair of pointers per every band of data having the same prefix in length, wherein one of the pair of pointers stores the address of data having the lowest address in each band of data, and the other pointer of the pair of pointers stores the next higher address of data having the highest address in each band of data; and making a space in which data is to be added in the CAM look-up table by moving data having the addresses stored in the pair of pointers provided per each band of data that has a shorter prefix length than the prefix length of the data to be added, when data is added to the CAM look-up table. According to the method, it is possible to easily and efficiently add new data into the look-up table of the CAM.

Abstract: Provided is a method of scheduling an output in a crosspoint buffered switch by searching whether a cell exists in a crosspoint buffer at a start position for each output port, wherein the crosspoint buffer at the start position is a crosspoint buffer at a predetermined position among the crosspoint buffers respectively corresponding to output ports, outputting all cells stored in the crosspoint buffer at the start position and searching for a cell in a crosspoint buffer at a next position, outputting all cells stored in the crosspoint buffer at the next position and searching for a cell in the crosspoint buffer in a next position to the crosspoint buffer at the final position, and outputting all cells stored in the crosspoint buffer at the final position and searching for a cell in the crosspoint buffer at the start position.

Abstract: A substrate assembly is disclosed. The assembly includes a flat substrate having oppositely disposed planar surfaces and a conductor. The conductor is formed on at least one of the planar surfaces and defines a conductor plane. The structure further includes an oversized-in-diameter anti-pad formed through the substrate layer and the conductor layer. The anti-pad further includes a spacer formed substantially coplanar with the conductor plane.

Abstract: A VC merging apparatus and a method of establishing or terminating connection as well as a recording medium storing instructions for embodying the same method are disclosed. The method of establishing/terminating connection includes the steps of; a) determining a kind of connection with reference to connection parameters according to an order of connection establishment or termination from a central controller; b) establishing/terminating a multi point-to-point connection based on ingress/egress connection labels, if the kind of the connection is a VC merging connection; and c) establishing/terminating a point-to-point connection based on the ingress/egress connection labels, if the kind of the connection is a non-VC merging connection.

Abstract: The present invention relates to a memory allocation method using multi-level partition, which is capable of analyzing an allocation-requested fixed size to be used as a basic allocation unit, dividing the memory into a plurality of blocks, subdividing each of the blocks into the same number of subblocks and designating subblocks having the same orders in different blocks with the same pointer value. The memory allocation method according to the present invention comprises the steps of analyzing an allocation-requested fixed size to be used as a basic allocation unit and dividing the memory into a plurality of blocks, subdividing each of the divided blocks into one or more subblocks of the same size, the divided blocks being subdivided into the same number of subblocks, designating each of the subblocks having the same orders in different blocks with the same pointer value, and allocating the subblocks designated with the same pointer value as one memory space.

Abstract: Disclosed are an optical module interfacing device for connecting an RJ interface and an SFP type optical module to an SFP type optical module connector without additional processing, and an Ethernet system using the optical module interfacing device, thus supporting data transmission and reception. The optical module interfacing device includes a board having the same dimensions as those of the optical module, a male connector, having the same dimensions as those of the optical module, formed at a side surface of one end of the board to be connected to the female connector for the optical module mounted on a host board, and an RJ female connector provided with a plurality of pins formed on an upper surface of the board, respectively corresponding to pins of the male connector, according to standards. Further, UTP data is provided to MDI supporting ports of a physical layer through an interfacing unit.

Abstract: A massive packet transmitter in a WAN (wide area network) . The transmitter includes: an encoder for segmenting packets for transmission through the WAN into messages having a predetermined length, encoding the respective segmented messages, adding a parity bit to each encoded message to make it into a codeword, and transmitting the codeword/ A decoder is used for receiving the codeword from the encoder through the WAN, correcting an error of the corresponding codeword, and removing a parity bit included in the corresponding codeword to recover the codeword to an original message. Errors generated when transmitting massive packets through the WAN are removed using a FEC method, and massive packets such as a IPv6 jumbogram can be used without errors in the WAN.

Abstract: The present invention relates to a memory allocation method using multi-level partition, which is capable of analyzing an allocation-requested fixed size to be used as a basic allocation unit, dividing the memory into a plurality of blocks, subdividing each of the blocks into the same number of subblocks and designating subblocks having the same orders in different blocks with the same pointer value. The memory allocation method according to the present invention comprises the steps of analyzing an allocation-requested fixed size to be used as a basic allocation unit and dividing the memory into a plurality of blocks, subdividing each of the divided blocks into one or more subblocks of the same size, the divided blocks being subdivided into the same number of subblocks, designating each of the subblocks having the same orders in different blocks with the same pointer value, and allocating the subblocks designated with the same pointer value as one memory space.