Abstract:
Disclosed herein is a variable length packet switching system. The variable length packet switching system includes at least two switching means, a plurality of multiplexing units and a plurality of demultiplexing units. The switching means switch ATM cells or variable length packet data in parallel. The multiplexing means are arranged upstream of the switching means for multiplexing data inputted from a line card to the switching means in packet units and dividing a packet into packets of a number corresponding to the number of the switching means. The demultiplexing means are arranged downstream of the switching means for combining packets inputted after being switched in parallel by the at least two switching means and outputting the combined packet converted into a format adequate to the line card.
Abstract:
Provided are an apparatus and a method for interfacing a 10 Gbps small form factor pluggable (XFP) optical transceiver with a 300-pin multi-source agreement (MSA)_optical transceiver. The apparatus includes: a direct interface providing direct interfacing paths through which signals that can be directly interfaced with one another between the XFP optical transceiver and the 300-pin MSA optical transponder; and a processor converting clock signals and data between the XFP optical transceiver and the 300-pin MSA optical transponder so that formats of the clock signals and the data coincide with one another.
Abstract:
A PON slave controller for use in a PON ONU system capable of processing in unit of byte outputs an enable signal to external for a mini-slot payload and receives a byte input signal for enabling usage of an arbitrary MAC (Medium Access Control) technique loading arbitrary data in a mini-slot. An ATM-PON ONU controlling apparatus of the present invention includes a cell receiving unit for transferring an ATM cell through a receiving UTOPIA interfacing unit to external and transferring a message in a PLOAM cell, a cell transmitting unit for loading the ATM cell received through a transmitting UTOPIA interfacing unit in a granted slot and transferring in upstream and downstream by loading the message being on standby in payload of the PLOAM cell when the PLAOM cell is transmitted, and a message processing unit for setting internal signals by processing the received message or instructing operation of a plurality of functional blocks, and transferring the message requested by the plurality of functional blocks through the cell transmitting unit.
Abstract:
An analytic structure includes a plurality of analytic fields formed on a predetermined region of a semiconductor substrate; semiconductor transistors arranged in the analytic fields to compose an array structure, each transistor having a gate electrode and an impurity region; wordlines arranged crosswise on the analytic fields and connecting the semiconductor transistors; and bitline structures connecting the impurity regions of the semiconductor transistors lengthwise, each bitline structure having a bitline and a vertical interconnection structure connecting the bitline with the impurity region. The bitlines have different heights according to their positions on the analytic fields.
Abstract:
A method for operating a polymer electrolyte membrane fuel cell at temperatures below the freezing point of water and an apparatus thereof are provided to prevent damage and performance degradation of the membrane-electrode assemblies. Non-humidified gas flows for several seconds before temperature of the polymer electrolyte membrane fuel cell falls below the freezing temperature of water when operation of the polymer electrolyte membrane fuel cell stops. Simultaneously, anode of the polymer electrolyte membrane fuel cell is filled with a solution having a low freezing point to prevent the temperature of a polymer electrolyte membrane fuel cell falling below the freezing point of water due to the lower ambient temperature in the winter. When the polymer electrolyte membrane fuel cell is restarted, the cell performance is not degraded reflecting that the present invention stably preserves the fuel cell.
Abstract:
A multi-dimensional optical cross-connect switching system. The system is capable of multi-dimensionally using wavelength resources, such as in the forms of optical fibers, optical wavelength bands and optical wavelengths. The system can three-dimensionally use the wavelength resources by being matched with an optical transport network through the optical fiber layer, optical wavelength band layer and optical wavelength layer. In addition, the multi-dimentional optical cross-connect switching system is constructed in such a way that two cross-connect switches are symmetrically arranged and an insertion/extraction switch is added to switch addition/dropping links between the two switches.
Abstract:
Disclosed is a variable optical attenuator comprising: a transmitting fiber for transmitting light; a receiving fiber concentrically placed with said transmitting fiber for absorbing light; a shutter between said transmitting fiber and said receiving fiber for absorbing light to adjust optical transmittance; and an actuator for driving said shutter. The size and price of the optical attenuator is remarkably reduced compared to a conventional mechanical connector-type attenuator to provide an article excellent in competitive edge.
Abstract:
An optical packet header processing apparatus for processing a header of an optical packet expressing an address of a destination node to control a switching operation of an optical packet switch. The optical packet header processing apparatus comprises a beam splitter for splitting the optical packet header into a predetermined number of optical packet header elements, and a plurality of time interval detectors. Each of the time interval detectors receives a corresponding one of the optical packet header elements from the beam splitter and outputs a detect optical pulse if a pair of optical pulses having a predetermined time interval therebetween are present in the received optical packet header element. A plurality of optical pulse detectors are adapted to convert the detect optical pulses from the time interval detectors into electrical signals and transfer the converted electrical signals to the optical packet switch, respectively. Therefore, the optical packet switch determines the destination node in response to the electrical signals from the optical pulse detectors and outputs the optical packet to an output port corresponding to the determined destination node.
Abstract:
The present invention is to provide an automatic gain-controlled optical fiber amplifier, comprising: a first optical branch for branching a portion of an optical signal inputted into the optical fiber amplifier; a second optical branch for branching a portion of an optical signal outputted from the optical fiber amplifier; an optical distributor for receiving the optical signal of an input side branched partially by the first optical branch and for outputting it separately; a first wavelength selector for receiving the optical signal of a one side distributed by the optical distributor and for selecting a predetermined wavelength optical signal; a second wavelength selector for receiving the optical signal of an output side branched partially by the second optical branch and for selecting the predetermined wavelength optical signal; a signal processor for receiving the optical signal of a second side distributed by the optical distributor and the predetermined wavelength optical signal selected by the first and second optical wavelength selector and for measuring a total power of an input signal and a number of input channels; and a controller for generating a control signal according to the total power of the input signal and the number of input channels measured by the signal processor.
Abstract:
A multichannel light source wavelength and strength stabilizing apparatus and a method thereof are disclosed. The apparatus includes a first proportional/integrator for receiving an output signal from the error detector, detecting a value proportional thereto, integrating the detected proportional value, generating a signal corresponding to the optimum feedback circuit, and outputting to the temperature controller; a current controller for providing the current capable of controlling the light strength in accordance with the signal inputted to the light source and stabilizing the light strength; a second optical coupling unit for dividing the output signal from the first optical coupling unit; a photodetector for converting the strength of a light among the output signals from the second optical coupling unit into an electrical signal; and a second proportional/integration unit for detecting a proportional value of the output signal from the optical detector, integrating the detected proportional value, generating a signal corresponding to the optimum feedback circuit, and outputting to the current controller.