Abstract: It is necessary to completely remove overlapping of signals between plural PONs in order to make the PONs coexist. Accordingly, it is required to share or intensively manage bandwidth use conditions over an optical fiber that serves as a common band between plural systems. Therefore, transmission clocks should be synchronized with high accuracy between plural systems. A reference clock is provided from an external device or a representative OLT to the entire systems to perform clock synchronization between plural systems, so that the overall systems are synchronized by synchronizing each OLT with the reference clock. A hierarchical management method is selected that manages ONUs under the control of each OLT by managing band use information arranged for each OLT with respect to an external device or a representative OLT for sharing of bandwidth use conditions between plural systems.

Abstract: It is necessary to completely remove overlapping of signals between plural PONs in order to make the PONs coexist. Accordingly, it is required to share or intensively manage bandwidth use conditions over an optical fiber that serves as a common band between plural systems. Therefore, transmission clocks should be synchronized with high accuracy between plural systems. A reference clock is provided from an external device or a representative OLT to the entire systems to perform clock synchronization between plural systems, so that the overall systems are synchronized by synchronizing each OLT with the reference clock. A hierarchical management method is selected that manages ONUs under the control of each OLT by managing band use information arranged for each OLT with respect to an external device or a representative OLT for sharing of bandwidth use conditions between plural systems.

Abstract: When a signal of weak optical power is received immediately after a signal of intense optical power, input of the signal of intense optical power readily causes saturation, and the influence interferes in the signal of weak optical power to deteriorate receiver sensitivity. Moreover, when a reverse-bias voltage of APD is changed, if a difference between the voltages is large, a next optical signal is received until the receiver sensitivity of the APD becomes stable, so that receiver sensitivity deteriorates. A DBA order is determined so that a difference in reverse-bias voltage is small, and reverse-bias voltage is controlled in line with reception timing from ONU.

Abstract: It is necessary to completely remove overlapping of signals between plural PONs in order to make the PONs coexist. Accordingly, it is required to share or intensively manage bandwidth use conditions over an optical fiber that serves as a common band between plural systems. Therefore, transmission clocks should be synchronized with high accuracy between plural systems. A reference clock is provided from an external device or a representative OLT to the entire systems to perform clock synchronization between plural systems, so that the overall systems are synchronized by synchronizing each OLT with the reference clock. A hierarchical management method is selected that manages ONUs under the control of each OLT by managing band use information arranged for each OLT with respect to an external device or a representative OLT for sharing of bandwidth use conditions between plural systems.

Abstract: A method for manufacturing a liquid ejecting head includes performing a dry cleaning process of cleaning the surface of a wire side of a second substrate by dry etching of a plasma etching mode, and performing a liquid cleaning process of cleaning the surface of a pressure generation chamber side of a first substrate.

Abstract: A passive optical network (PON) system which enables plural types of ONUs having different signal transmission speeds to be connected to one OLT. An optical line terminating apparatus (OLT) connected to plural types of ONUs having different signal transmission speeds through an optical distribution network includes an optical transmitter-receiver connected to the optical distribution network, a transmission/reception line interface connected to a wide area network, a downstream frame processing section for converting a packet received by the transmission/reception line interface from the wide area network into a downstream frame containing identification information on a destination ONU in a header, and a downstream transmission controller for modulating the downstream frame at a speed corresponding to a signal transmission speed of the destination ONU and outputting the modulated frame to an electrical/optical converter connected to the optical transmitter-receiver.

Abstract: An optical access communication apparatus and an optical access communication system for the coexistence of two wideband PON systems without using an expensive optical device or module. A low-speed PON and a high-speed PON have a same upstream wavelength, and an OLT receives optical signals by a same optical receiver in the two systems, converts the optical signals into electric signals, amplifies the electric signals, branches the amplified electric signals, and processes the branched signals by clock and data recovery sections of bit rates corresponding to the two PON systems, thereby achieving an optical communication apparatus and an optical communication system for constructing a simple and low-cost triple-play service system of excellent transmission quality.

Abstract: When the number of DUTs carried on a loader buffer and scheduled to be held by contact arms at the next test is less than N, a DUT at a contact arm corresponding to a missing position at the loader buffer among the N number of DUTs being held for execution of a current test is held as it is without being ejected. While holding this DUT, the DUTs carried at the loader buffer for execution of the next test are picked up and the test is executed in that state.

Abstract: An IP broadcast terminal 30 is connected with a multicast address management device 10 for IP broadcast that holds multicast information via an IP multicast network 40 over which IP broadcast service is provided, and when a user issues a request to change an IP broadcast channel, generates a query message including an IP broadcast channel identifier requested from the IP broadcast terminal 30 to transmits it to the multicast address management device 10 for IP broadcast. The IP broadcast terminal 30 receives a response message showing the correspondence between IP broadcast channel identifiers and multicast addresses from the multicast address management device 10 for IP broadcast, and transmits a video reception request message to a multicast group decided for reception.

Abstract: In the bandwidth-allocating method of the present invention for PON (: Passive Optical Network), a bandwidth is allocated from an optical line terminal to each optical network unit. The optical line terminal stores a bandwidth contract table for indicating a correspondence relationship between communication flow IDs and service quality parameters, each communication flow ID identifying each communication flow between the optical line terminal and each optical network unit. The bandwidth-allocating method includes a step of transmitting a service-quality request message including the communication flow IDs and the service quality parameters from each optical network unit to the optical line terminal, and a step of the optical line terminal's updating the bandwidth contract table based on the service quality parameters, and performing the bandwidth allocation to a communication flow specified by the corresponding communication flow ID based on the bandwidth contract table.

Abstract: The present invention provides an IP broadcasting system that can receive IP broadcasting videos over an IP multicast network. In the IP broadcasting system, a multicast group management apparatus for IP broadcasting that holds multicast group identifiers is connected via an IP multicast network over which IP broadcasting services are provided. When a user issues a request to switch an IP broadcasting channel from an IP broadcasting terminal, a query message including the requested IP broadcasting channel identifier is transmitted to a management apparatus. The IP broadcasting terminal receives a response message indicating the correspondence between the IP broadcasting channel identifier and a multicast group identifier, and transmits a video reception request message to a multicast group by using the received multicast group identifier.

Abstract: There is provided a plasma display device including: a plasma display panel having a plurality of address electrodes selecting a display cell to emit light; a data generation circuit generating and outputting a plurality of address data for an application of a voltage to the plurality of address electrodes; a plurality of output ports outputting the plurality of address data; a selector switching over connections of outputs of the plurality of address data generated by the data generation circuit and the plurality of output ports.

Abstract: The maximum number of virtual local area networks (VLANs) is increased beyond the number provided solely with the VLAN ID, by a factor related to the number of wavelengths of a Wavelength Division Multiplexing (WDM) used by a network switching. An optical VLAN number (OVLAN ID) is a combination of the VLAN ID from the packet header and a path or wavelength ID (WL ID) that identifies a selected one of available wavelengths of a WDM transmission line. An Optical VLAN (OVLAN) conversion table stores data of the OVLAN ID, the VLAN ID and optical path ID, for an optical VLAN node.

Abstract: A method and system for controlling service of quality of an IP packet in a passive optical network system. An optical line terminal (OLT) in the passive optical network system having an optical distribution network (ODN) and at least one optical network unit (ONU), has a processing unit for determining QoS, i.e., a priority order, at a PON layer in accordance with IP layer information of received data, and assigning a LINK ID to the data. Accordingly, quality of service of data at a network layer can be mapped to quality of service of data at a physical layer and quality of service of an IP data stream in the PON system can be controlled to thereby ensure the quality of transfer of the IP data stream in the passive network system.

Abstract: A method and an apparatus for implementing a storage function in a passive optical network (PON) system. On the basis of a LINK ID held by the data, data requiring storage, e.g. data making exclusive use of a wide bandwidth such as audiovisual data and large-volume data packages, are determined among all the data sent to an optical network unit. These data requiring storage are stored in a storage device installed in the optical network unit. In case the user requests data stored in the storage device, the stored data are transferred directly to the user, without any need to request and send these data for the second time via an IPTV server and the core network. It is possible to avoid duplicate transfers of data, and in particular to avoid duplicate transfers of data making exclusive use of a comparatively wide bandwidth such as audiovisual data and large-volume data packages, to improve the utilization factor of the downlink bandwidth, and to reduce flow congestion and data delays.

Abstract: A passive optical network (PON) system includes at least one optical line terminal (OLT), a plurality of optical network units (ONUs) connected to each OLT, and an OLT management server used to manage the OLT. The OLT management server creates a VLAN access control table in response to a user's request to indicate a VID translation relation among different VLAN identifiers (VIDs) and sends a VID translation relation described in the VLAN access control table to the OLT, and the OLT creates a VLAN translation table indicating a correspondence relation between a source VID and a destination VID, which are waiting for translation, based on the received VID translation relation. If the OLT determines that a VID included in a received frame must be translated based on the VLAN translation table, the OLT references the VLAN translation table to translate the VID included in the received frame to a corresponding destination VID.

Abstract: Channel switching system and method of an IPTV service in a passive optical network (PON) are disclosed. To reduce a channel switching time of an IPTV system in the passive optical network, the system and the method use a channel switching control module and a channel list module in the passive optical network. In a case where a passive optical network system receives an IPTV channel switching request transmitted from a terminal user, the channel switching control module checks a recording of a channel list module and a recording of an authentication list module, and then updates a filter recording of an optical network unit to thereby directly transmit an image flow of a new channel in the passive optical network. When such system and method are applied to the passive optical network, high-speed switching of the IPTV service channel by the terminal user can be realized.

Abstract: A network is protected against interruption of service while one or more faulty switches or optical fiber transmission lines are repaired or replaced, by an interconnecting configuration of small N×N optical input/output switches, where N is 2 or greater than 2. The switches are configured among protection and working transmission lines. The small number of fibers for each switch improves repair and installation connection reliability and permits configurations that flexibly meet differing requirements. Also the fault is monitored with a fault check signal.

Abstract: A presence-base packet routing control apparatus having a presence policy management data base for indicating routing policies in association with user terminal's presence statuses analyzes presence information notified from a user terminal, translates the presence information into a presence status of the user terminal, searches the presence policy management data base for a routing policy corresponding to the presence status of the user terminal, and issues a command to install the routing policy in a particular router to which the user terminal is connected.

Abstract: This invention provides a method of implementing a multi-party conference service (MPCS) using broadcast/multicast service of a wireless communications system used for a conference focus, the context of a corresponding broadcast/multicast service session is generated based on the media flow information, multicast service session information and MPCS information. The generated context of the broadcast/multicast service session is then sent respectively to at least one content provider server, at least one mobile terminal and the broadcast/multicast service controller so that the one or more mobile terminals acquires the content media flow through the broadcast/multicast service session.