Abstract: An arrayed waveguide grating device and a method for manufacturing the arrayed waveguide grating device. The arrayed waveguide grating device includes input channel waveguides formed on a substrate; output channel waveguides formed on the substrate that correspond to the input channel waveguides; and arrayed waveguides with different lengths interposed between the input channel waveguides and the output channel waveguides on the substrate while free propagation regions being formed at both ends of the arrayed waveguides, wherein the arrayed waveguides are designed so that a free spectral range (FSR) of a higher-order mode is twice or greater than a bandwidth of a region of interest (ROI).

Abstract: An apparatus for monitoring an optical signal includes a light absorbing layer formed on an optical waveguide consisting of a core layer and upper and lower cladding layers; and a photodiode comprising electrodes arranged on both the optical waveguide and the light absorbing layer.

Abstract: A tunable optical network unit (ONU) for a multi-wavelength passive optical network (MW PON) system and an operation method thereof are provided. The tunable ONU includes a cyclic tunable filter configured to have cyclic wavelength transmission properties that allow all wavelength channels of both a downstream signal and an upstream signal and to vary a wavelength to pass therethrough; a wavelength splitter configured to split an upstream signal wavelength band and a downstream signal wavelength band; a photodetector element configured to detect a downstream signal that is transmitted through the wavelength splitter, passing through the cyclic tunable filter which is aligned to a specific downstream signal wavelength channel; and a tunable transmitter configured to output to the wavelength transmitter an upstream signal of a wavelength channel that is determined based on an aligned downstream signal wavelength channel of the cyclic tunable filter.

Abstract: A tunable optical network unit (ONU) for a multi-wavelength passive optical network (MW PON) system and an operation method thereof are provided. The tunable ONU includes a cyclic tunable filter configured to have cyclic wavelength transmission properties that allow all wavelength channels of both a downstream signal and an upstream signal and to vary a wavelength to pass therethrough; a wavelength splitter configured to split an upstream signal wavelength band and a downstream signal wavelength band; a photodetector element configured to detect a downstream signal that is transmitted through the wavelength splitter, passing through the cyclic tunable filter which is aligned to a specific downstream signal wavelength channel; and a tunable transmitter configured to output to the wavelength transmitter an upstream signal of a wavelength channel that is determined based on an aligned downstream signal wavelength channel of the cyclic tunable filter.

Abstract: A software-defined networking (SDN) method. The SDN method according to an exemplary embodiment may be used in managing and operating SDN-based network resources in an optical communications network, a fixed mobile convergence subscriber network, a wired broadband subscriber network, a distributed mobile communications base station network, etc.

Abstract: Provided are an apparatus and method for controlling packet flow in a multi-stage switch. According to an aspect, there is provided an apparatus for controlling packet flow in a multi-stage switch, including: one or more source line cards configured to receive one or more packets, and to transfer the one or more packets to a switch fabric including a plurality of switch modules forming one or more switching stages such that the one or more packets are transferred along different switching paths in the switch fabric; and a destination line card configured to receive the one or more packets output from the switch fabric, and to transfer Acknowledge (ACK) messages for informing that the packets have been received, to the source line cards, in a predetermined time period.

Abstract: Provided are a method and apparatus for blocking forged multicast packets.

Abstract: An integrated access system for All-IP converged network is provided. According to an aspect, by integrating the common factors of existing complex wireless networks to load-reduce and simplify the wireless networks and convert them using Internet access technology to thereby simplify a network architecture, integratively operating radio accesses, ensuring end-to-end quality, and providing service adaptiveness, easiness in operation, CAPEX/OPEX, and excellent service adaptiveness can be achieved.

Abstract: Performance values between an access point (AP) and one or more networks to which the AP is connected are measured, and performance information is generated based on the measured performance values. When a request for the performance information is received from a terminal connected to the AP, the performance information is broadcast to the terminal at a pre-set time to allow the terminal to select an optimum AP based on the received performance information and attempt to access a wireless network.

Abstract: Provided are an apparatus and method for providing an advertisement service personalized for each user or for each group. The personalized advertisement providing method includes: a personalized advertisement providing method which is used in an Internet Protocol Television (IPTV) System, including: receiving at least one broadcasting program of a plurality of broadcasting programs classified according to a plurality of channels; and determining whether a present time is an advertisement broadcasting time, transmitting a received broadcasting program to a plurality of user terminals which selects a channel on which the broadcasting program is provided if the present time is not an advertisement broadcasting time, dividing the plurality of user terminals into a plurality of groups and transmitting an advertisement classified for each group to one or more user terminals belonging to the group if the present time is an advertisement broadcasting time.

Abstract: In order for a packet transporting system to transport packets for service in real time, the system estimates whether the first route for transporting the packet provides the quality of service (QoS) required by the service. If the first route is qualified to provide the QoS for transporting the packet, the system estimates whether the first route group including the first route satisfies the reliability required by the service. If the first route group is disqualified to provide the reliability required by the service, the system searches for the second route different from the first route, adds the second route to the first route group, and estimates whether the updated first route group satisfies the reliability, and if, as a result of the reliability estimation, the updated first route group is qualified to provide the reliability, transports the packet in real time by using the first route group which is comprised of the first route and the second route.

Abstract: Provided are an acousto-optic filter and an optical code division multiple access (CDMA) system using the acousto-optic filter. The acousto-optic filer includes: an acousto-optic mode converter (AOMC) converting an optical signal of a specific optical frequency corresponding to a frequency of an electric signal of an optical signal of a first mode having a predetermined optical frequency band; and a mode stripper (MS) stripping an optical signal of the optical signal of the first mode that has been converted to a second mode.

Abstract: There are provided a method and a system for providing a source specific multicast service on an Ethernet network. The system includes: a router managing a subscriber; a user terminal transmitting an IGMP packet to the router and transmitting channel reception information that uses an MAC address of the router as a destination MAC address; and an Ethernet switch receiving the channel reception information from the user terminal, determining whether there is a channel subscriber in a port to which the channel reception information has been input based on the contents of the channel reception information, and then outputting a frame that has a channel MAC address, which is the same as that of the channel reception information, as a destination address to the input port in a case where there is a channel subscriber in the input port.

Abstract: A system for and a method of providing IPTV service in a next generation network are provided. The system includes a service control unit, a transmission control unit, and an L2 switch unit. A service control unit authenticates a user terminal by receiving a request for providing a service from the user terminal which desires to receive the IPTV service and search for subscription information including the IPTV service for which the user has watching authority, when the user is an IPTV service subscriber. A transmission control unit extracts identification information of the user and a multicast address through which the IPTV service is provided from the subscription information found by the service control unit.

Abstract: Provided are a method and apparatus for blocking forged multicast packets.

Abstract: Provided are an acousto-optic filter and an optical code division multiple access (CDMA) system using the acousto-optic filter. The acousto-optic filer includes: an acousto-optic mode converter (AOMC) converting an optical signal of a specific optical frequency corresponding to a frequency of an electric signal of an optical signal of a first mode having a predetermined optical frequency band; and a mode stripper (MS) stripping an optical signal of the optical signal of the first mode that has been converted to a second mode.

Abstract: A method and apparatus for providing a video-on-demand (VOD) service are provided.

Abstract: Provided are an apparatus and method for providing an advertisement service personalized for each user or for each group. The personalized advertisement providing method includes: a personalized advertisement providing method which is used in an Internet Protocol Television (IPTV) System, including: receiving at least one broadcasting program of a plurality of broadcasting programs classified according to a plurality of channels; and determining whether a present time is an advertisement broadcasting time, transmitting a received broadcasting program to a plurality of user terminals which selects a channel on which the broadcasting program is provided if the present time is not an advertisement broadcasting time, dividing the plurality of user terminals into a plurality of groups and transmitting an advertisement classified for each group to one or more user terminals belonging to the group if the present time is an advertisement broadcasting time.

Abstract: An optical communication system and method using Manchester encoded signal remodulation are provided. The optical communication system includes a transmitter generating and transmitting a Manchester encoded optical signal including a first data stream, and a receiver receiving an optical signal obtained by dividing power of the Manchester encoded optical signal into two parts and modulating one of the two parts to include a second data stream, and recovering the second data stream. In two-way communication, the optical communication system and method allow one party to generate and transmit a Manchester encoded signal (i.e., a downstream signal) to the other party and allow the other party to generate an upstream signal by modulating the optical power of the downstream signal without using a light source.

Abstract: Provided are an apparatus and a method for reducing a signal noise of an OCDMA receiver and an OCDMA receiver and method. The includes: a clock recovery unit extracting sine wave clock from an output signal of an OCDMA decoder including an MAI (multiple access interference) noise; a time gating unit separating an auto-correlation peak signal and the MAI noise from the output signal of the OCDMA decoder using the sine wave clock; and an optical interferometer removing an SI (signal interference) noise remaining in the auto-correlation peak signal.