摘要:
A passive optical network includes a central office and a subscriber-side apparatus connected with the central office through an optical fiber link. The subscriber-side apparatus performs communication with the central office based on wavelength-division-multiplexed optical signals. The central office has a routing section, provided with first to fourth multiplexing ports, for demultiplexing multi-wavelength light inputted from the fourth multiplexing port into a plurality of channels. Each of the demultiplexed channels is amplified and multiplexed for output through the first multiplexing port. Optical signals inputted through the third multiplexing port are demultiplexed and outputted upstream. The routing section also multiplexes channels for downstream optical signals, outputting the multiplexed channels through the second port. A splitting section, provided with first to third splitting ports and arranged on a loop optical waveguide connects the first and fourth multiplexing port with each other. The splitting section causes some of multi-wavelength light inputted into the first splitting port to be outputted through the second splitting port and causes the remainder of multi-wavelength light to be outputted through the third splitting port connected with the fourth multiplexing port. A circulator causes the multi-wavelength light inputted through the second splitting port to be transmitted to the subscriber-side apparatus and causes upstream optical signals received from the subscriber-side apparatus to be outputted to the third multiplexing port.
摘要:
A wavelength-path-monitoring/correcting apparatus used in a transparent OXC is disclosed. The apparatus includes: a path-information-generating section for generating path-monitoring information; a plurality of optical couplers for coupling each output signal of the wavelength-division demultiplexers with the pertinent path-monitoring information; a plurality of optical switches for switching each optical signal inputted from the optical couplers; a plurality of wavelength-division multiplexers for multiplexing optical signals inputted through the optical switches; a path-information-detecting section for detecting the path-monitoring information from optical signals outputted from the wavelength-division multiplexers; and, a path-control section for comparing the path-monitoring information detected through the path-information-detecting section with predetermined optical-switching information and for correcting switched paths.
摘要:
Disclosed is a method for estimating an available bandwidth of a network. A plurality of periodic time-stamp packets are transmitted to a receiving-party communication apparatus, which is connected to the network, through the network at a currently-set test transmission rate, and then a changing tendency of transmission delay time differences between the time-stamp packets is checked on the basis of reception times at which the receiving-party communication apparatus have received the respective time-stamp packets. When the transmission delay time differences are located outside a stable range and show a tendency to increase, the test transmission rate is set to a decreased value and the time-stamp packets are repeatedly transmitted at the decreased rate and when the transmission delay time differences are located outside the stable range and show a tendency to decrease, the test transmission rate is set to be an increased value and the time-stamp packets are repeatedly transmitted at the increased rate. A test transmission rate is determined as the available bandwidth when the transmission delay time differences are within the stable range.
摘要:
A large-capacity optical router is disclosed that exchanges data traffic such as IP packets, Ethernet frames, etc., at high speed in units of optical frames. The large-capacity optical router uses an electric buffer including input ports, output ports, an add port for inputting data received from a lower IP router, a drop port for outputting data to the lower IP router, a wavelength division demultiplexing section for wavelength-division-demultiplexing wavelength signals input through the input ports and the add port, an input interface section for converting optical frames from the wavelength division demultiplexing section into electric signals, and an optical switch for performing a high-speed switching of the optical frames from the input interface section. The large-capacity optical router also includes an output interface section for processing the optical frames output from the optical switch, a wavelength division multiplexing section for wavelength-division-multiplexing outputs of the output interface section and transmitting the multiplexed outputs to another large-capacity optical router, a drop interface section for processing the optical frames from the wavelength division multiplexer to the lower IP router, a header processing section for recognizing header information, an optical switch control section for controlling a connection state of the optical switch, a header reinserting section for reinserting headers into outputs of the optical router, and an edge traffic aggregator including of an ingress part for converting IP packets input from the lower IP router into optical frames and an egress part for converting the optical frames into IP packets and transmitting the converted packets to the IP router.
摘要:
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.
摘要:
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.
摘要:
The present invention relates to a linear compressor, and more particularly, to a linear compressor which supplies a necessary cooling capacity through a natural cooling capacity modulation and a forcible cooling capacity modulation, and a cooling system using the same. The linear compressor according to the present invention includes a compression space into which refrigerant is sucked, a movable member which linearly reciprocates to compress the refrigerant sucked into the compression space, one or more springs which are installed to elastically support the movable member in a motion direction of the movable member, a motor unit which includes a motor and a capacitor connected in series to the motor so as to make the movable member linearly reciprocate, and a motor control unit which performs a natural cooling capacity modulation according to a load by reciprocation of the movable member.
摘要:
Disclosed is a method for estimating an available bandwidth of a network. A plurality of periodic time-stamp packets are transmitted to a receiving-party communication apparatus, which is connected to the network, through the network at a currently-set test transmission rate, and then a changing tendency of transmission delay time differences between the time-stamp packets is checked on the basis of reception times at which the receiving-party communication apparatus have received the respective time-stamp packets. When the transmission delay time differences are located outside a stable range and show a tendency to increase, the test transmission rate is set to a decreased value and the time-stamp packets are repeatedly transmitted at the decreased rate and when the transmission delay time differences are located outside the stable range and show a tendency to decrease, the test transmission rate is set to be an increased value and the time-stamp packets are repeatedly transmitted at the increased rate. A test transmission rate is determined as the available bandwidth when the transmission delay time differences are within the stable range.
摘要:
Disclosed is an optical cross-connect device for communication between first and second optical networks communicating with each other using forward and backward optical signals each including of a plurality of channels. The device includes a first circulating part having first through fourth ports configured to output an optical signal, which is input to a higher-order port thereof, from a lower-order port thereof arranged adjacent to the higher-order port. The first circulating part is connected at the first and third ports thereof to a first optical network. A second circulating part has first through fourth ports configured to output an optical signal, which is input to a higher-order port thereof, from a lower-order port thereof arranged adjacent to the higher-order port. A first reflecting part is connected to respective second ports of the first and second circulating parts, and adapted to selectively reflect each channel of a forward optical signal which is input thereto or allow the channel to pass therethrough, and a second reflecting part is connected to respective fourth ports of the first and second circulating parts, and adapted to selectively reflect each channel of a backward optical signal which is input thereto or allow the channel to pass therethrough.
摘要:
A refrigerating system for a refrigerator is disclosed. The refrigerator includes a compressor that compresses refrigerant, a condenser connected to the compressor that condenses compressed refrigerant, an expansion valve connected to the condenser that expands condensed refrigerant, freezing chamber and refrigerating chamber evaporators connected to the expansion valve that cool air in a freezing chamber and a refrigerating chamber by using refrigerant, respectively, and a regulating valve between the condenser and the refrigerating chamber evaporator that regulates refrigerant supply to the refrigerating chamber evaporator, thereby providing a refrigerating system for a refrigerator having high efficiency.