Abstract: A system and method for interface translation between a system packet interface level 3 (SPI-3) defines an interface between a physical device (PHY device) and a link layer device, and a gigabit media independence interface (GMII) which defines an interface between a media access control (MAC) portion of a gigabit Ethernet and a physical device. The system includes a translation circuit for translating a GMII reception signal, received from a GMII interface device, into an SPI-3 reception signal synchronized with an SPI3 reference clock, and for translating an SPI-3 transmission signal, received from an SPI-3 interface device, into a GMII transmission signal synchronized with a GMII reference clock.

Abstract: A centralized control apparatus and a method thereof manages an Multi Protocol Label Switching (MPLS) network, in which the centralized control apparatus performs Label Switched Path (LSP) setting of the MPLS network and management for set LSP, to reduce a load of the MPLS network generated upon setting LSP and to reduce a time for setting the LSP, and to improve management efficiency for the set LSP.

Abstract: In a network system using dynamic addresses, an address management server assigns dynamic addresses to hosts attempting to use the dynamic addresses in response to dynamic address requests from the hosts, and a router manages packet exchange between hosts connected to the network system based upon authenticated dynamic address information. In a method for assigning dynamic addresses in a network, dynamic addresses are assigned to hosts attempting to use the dynamic addresses in response to a request therefrom, the dynamic address information of assigned dynamic addresses is delivered to the host, and the dynamic address assignment information is registered in a dynamic address management table. In this way, invasion of the network by malicious hosts is prevented.

Abstract: In transferring a service context during hand-over of a mobile node located in a wireless mesh network, transfer boundaries are set according to positions spaced from an initial Access Point (AP) to which the mobile node is initially connected to, AP types being determined based upon the set transfer boundaries. Prior to hand-over of the mobile node in response to its movement, a service context is transferred to APs arranged in a moving direction of the mobile node based upon context transfer policies according to the determined AP types.

Abstract: An optical fiber amplifier features an optical amplifying section for amplifying an inputted optical signal. A sampling section is provided for shunting part of the optical signal amplified by the optical amplifying section and detecting a first test light belonging to a short wavelength band and a second test light belonging to a long wavelength band. An input power control circuit serves to compare respective powers of the first and second test lights and then outputs a control signal for controlling an input power of the optical signal inputted to the optical amplifying section according to the power differential of the first and second test lights. An output power control circuit derives an output power of the optical amplifying section from the power of the optical signal shunted at the sampling section and also controls the optical amplifying section so that the output power of the optical amplifying section attains a predetermined value.

Abstract: Disclosed is a temperature-compensating device for an APD optical-receiver system using an APD (Avalanche Photo Diode). The device includes a temperature-compensating circuit which employs a digital potentiometer capable of linear compensation through data look-up in compensating the decrease in gain caused by the temperature change of the APD.

Abstract: A wireless power supply and method of wirelessly supplying power use light to directly supply power wirelessly to an electrical apparatus without a power cable. The wireless power supply includes: a plurality of pressure switches adapted to switch ON/OFF in response to an applied pressure; and a plurality of light emitting devices respectively connected to the plurality of pressure switches, the plurality of light emitting devices adapted to emit light to supply the power to a load in response to at least one of the pressure switches being switched ON.

Abstract: A wideband amplifier is provided with at least one erbium-doped fiber, for use in a wavelength division multiplexing optical communication system that performs transmission/receipt of wavelength-division-multiplexed optical signals through at least one optical fiber.

Abstract: An optical fiber amplifier is disclosed for amplifying an input optical signal in the long wavelength band. The amplifier include first and second pumping light sources, a photo detector for detecting the intensity of the input optical signal, an erbium-doped optical fiber, and a controller. The optical fiber is brought to a first-pumped state by the first pumping light output from the first pumping light source. This generates an amplified spontaneous emission in the short wavelength band. The optical fiber is brought to a second-pumped state by the amplified spontaneous emission and outputs an induced emission light in the long wavelength band. The second pumping light source outputs a second pumping light in the same wavelength band as the amplified spontaneous emission, while controlling the intensity of the second pumping light by an output control signal, thereby controlling the intensity of the second-pumped state of the optical fiber.

Abstract: In allocating bandwidth using a Resilient Packet Ring (RPR) fairness mechanism in a node connected to an RPR network, when congestion occurs, an amount of traffic that the node has transmitted to a ring during one aging interval is recorded together with its own identifier in a fairness message as a fairness transmission rate to be advertised to its own upstream nodes and to be stored. The amount of traffic transmitted from the upstream node during the aging interval is measured and stored. When the congestion has been solved, an available bandwidth is calculated with reference to the fairness transmission rate which was recently advertised and the amount of traffic which has been transmitted from the upstream nodes, and the fairness transmission rate is calculated in order to fairly allocate the available bandwidth to the upstream nodes effectively so that the fairness transmission rate is transmitted to the upstream nodes.

Abstract: An apparatus for converting IPv4 to IPv6 using a dual stack and method thereof, where it is possible to support an IPv4-to-IPv6 conversion when a connection from an IPv4 node to an IPv6 node is initialized and even in case that there exists two or more DSTM TEPs in a DSTM domain.

Abstract: A WDM optical source, in adopting a spectrum-sliced method, advantageously needs neither an optical source with specific generation wavelength nor a wavelength-stabilizing circuit for stabilizing wavelength. Affording high power and a very narrow line width, the WDM optical source can provide a broadcasting service without signal distortion by a chromatic dispersion effect and also avoids the expense of an amplifier and/or external modulator, thereby relieving subscribers of the economical burden. The practical use of WDM-PON and of WDM-PON using an inventive WDM optical source can therefore be brought to fruition and broadcasting service can be provided economically.

Abstract: Disclosed is a temperature-compensating device for an APD optical-receiver system using an APD (Avalanche Photo Diode). The device includes a temperature-compensating circuit which employs a digital potentiometer capable of linear compensation through data look-up in compensating the decrease in gain caused by the temperature change of the APD.

Abstract: A passive optical network system is disclosed that simultaneously provides both broadcasting service and data service. The passive optical network (PON) amplifies the optical signals for the broadcasting service in an optical amplifier media of the local office by pumping optical signals generated from the central office and provides the optical signals for the broadcasting service to the subscriber terminals. Therefore, the present invention can simultaneously provide broadcasting service and data service for more subscribers without reducing the number of subscribers to the PON. Also, the present invention uses a plurality of optical sources for the data service and the broadcasting service and receives the optical signals generated from the optical sources by using a plurality of optical receivers in the subscriber terminals, and thus can provide a greater amount and variety of data services and broadcasting services.

Abstract: A wideband amplifier is provided with at least one erbium-doped fiber, for use in a wavelength division multiplexing optical communication system that performs transmission/receipt of wavelength-division-multiplexed optical signals through at least one optical fiber.

Abstract: An optical fiber amplifier features an optical amplifying section for amplifying an inputted optical signal. A sampling section is provided for shunting part of the optical signal amplified by the optical amplifying section and detecting a first test light belonging to a short wavelength band and a second test light belonging to a long wavelength band. An input power control circuit serves to compare respective powers of the first and second test lights and then outputs a control signal for controlling an input power of the optical signal inputted to the optical amplifying section according to the power differential of the first and second test lights. An output power control circuit derives an output power of the optical amplifying section from the power of the optical signal shunted at the sampling section and also controls the optical amplifying section so that the output power of the optical amplifying section attains a predetermined value.

Abstract: Disclosed is an optical transmission system that can improve transmission quality and perform high-speed transmission by using a conventional optical phase modulator. The optical transmission system employs a duobinary technique using a phase modulator, so as to overcome the dependency of transmission quality on the filtering characteristic and the bit pattern as in the conventional duobinary transmission system having a low pass filter, and to improve the non-linearity and dispersion characteristics of the NRZ transmission of more than 10 Gbps, and to further realize a transmitter capable of generating DCS-RZ.

Abstract: Disclosed is a duobinary optical transmission apparatus. The duobinary optical transmission apparatusenhances nonlinear and dispersion characteristics for an intermediate-long distance transmission at a high-speed transfer rate without the use an electric LPF. The duobinary optical transmission apparatus includes a light source for generating a carrier wave, a duobinary optical signal generator for receiving a Non Return to Zero (NRZ) signal and generating a modulated optical signal generated by modulating the carrier wave according to the NRZ signal, and a Return to Zero (RZ) signal generator for converting the NRZ signal into a RZ (Return to Zero) signal. Therefore, optical intensity and a phase are modulated using only a single interferometer-type optical modulator.

Abstract: An optical multi-ring network for burst data communication is disclosed. The multi-ring network includes a plurality of optical single-ring networks having a plurality of optical add/drop routers connected with each other through fiber links, and a core optical router for supporting communication between the optical single-ring networks. The core optical router includes a wavelength division demultiplexing section for demultiplexing optical signals received from the each single-ring network and outputting the demultiplexed optical signals as channels whose wavelengths are different from each other; a branching section for branching off and outputting a portion of each channel; and a switching section for switching each channel to a path directed to the destination of each channel according to a first control signal.

Abstract: Disclosed is a duobinary optical transmitter, which includes a laser source for outputting light with a predetermined wavelength; a Mach-Zehnder interferometer-type optical intensity modulator for modulating the intensity of the light according to a three-level data signal inputted through a modulation terminal; a low-pass filter for converting an inputted two-level binary data signal into a three-level data signal through an interference among codes; and, a modulator driver/amplifier for amplifying the three-level data signal and then outputting it to the modulation terminal, wherein the overall bandwidth of the low-pass filter, the modulator driver/amplifier, and the optical intensity modulator corresponds to approximately ¼ of the clock frequency of the two-level binary data signal.