Abstract: A session relay apparatus for preventing the packet relay delay by detecting the start and end of the policy settable peer-to-peer communication is disclosed. The session relay apparatus for relay a session control message transmitted and received between communication terminals to control the peer-to-peer communication detects the start and end of the communication from the session control message, and acquires the information for identifying a session and the information on the peer-to-peer communication carried out on the session. Upon generation of a policy indicating the packet relay control process by a policy generating unit, edge nodes for passing the packet are searched for and the policy is distributed to the edge nodes. The policy is set in the edge nodes accommodating the communication terminals at the start of communication, and the policy setting is canceled at the end of communication.

Abstract: In an IP packet communication apparatus, an operation and maintenance function capable of monitoring a transmission path is provided to a layer used to process a packet, which corresponds to an upper layer of an optical network. As one method for applying the operation and maintenance function to the packet layer, in the case of IP over PPP over WDM, an operation/maintenance frame is defined to a PPP frame so as to realize the operation/maintenance function of a PPP connection. In the case that a plurality of connections are multiplexed on the same transmission path, a maintenance frame is conducted in order to operate/manage these connections by being grouped, so that a fault occurring in the optical network is monitored. As another method for applying the operation and maintenance function to the packet layer, an operation/maintenance frame is defined to an IP packet so as to realize an operation and maintenance function of an IP flow.

Abstract: Interlayer-coordinated communication-line switching in a network including two layers, each having a switching function. In the present invention, a communication apparatus which (1) is connected with a network including (i) lower layer apparatus which are connected with communication lines of a lower layer and communication lines of an upper layer and conducts line switching in the lower layer and (ii) upper layer apparatuses which are connected with the communication lines of the upper layer and have means for line switching in the upper layer and (2) detects line failure and coordinates line switching using failure information on the lower and upper layer communication lines.

Abstract: In an inkjet printer configured so that dry air in a drying unit is blown out to a conveyance unit, the conveyance unit conveys one or more pieces of paper laid thereon in a direction substantially orthogonal to a direction of paper output and a collecting unit downstream of the conveyance unit in the direction of paper conveyance collects the pieces of paper and conveys the collected pieces of paper in a direction substantially orthogonal to the direction of paper conveyance of the conveyance unit.

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: In a network system for communication between a first terminal with an encrypting function and a second terminal without the encrypting function, a control data transmission device includes a receiving unit receiving control data sent from the first terminal to the second terminal, a data processing unit for extracting cipher information of the first terminal from the control data, a memory storing the cipher information of the first terminal, and a sending unit for sending the control data without the cipher information toward the second terminal, or sending to the first terminal the control data with the cipher information, and further sending the cipher information to the user data transmission device; a user data transmission device includes an encryption processing unit for decrypting the data that was sent from the first terminal to the second terminal while encrypting the data as sent from the second terminal to the first terminal.

Abstract: In a GPON system conforming to ITU-T Recommendations G.984.3, an optical line terminal is provided which has an active bandwidth allocation function that preferentially puts small bandwidth signals in a particular segment of a frame, e.g., at a head of the frame, to prevent fragmentations that may occur particularly when allocating small bandwidths of about 100 kbits/s.

Abstract: A station-side apparatus adapted for use in a passive optical network (PON) system is disclosed, which remotely collects inside information of optical network terminals (ONTs) even before completion of start-up of an optical network unit (ONU), permits an obstruction-detected ONU to send out an emergency notification message to the station-side apparatus, e.g., optical line terminal (OLP), and permits the OLT that received this message to interrupt the transmission of an upload signal toward another ONU after the elapse of a fixed length of time while at the same time receiving information from the obstruction-suffering ONU to thereby facilitate cut-and-divide or “segmentation” of obstruction. A subscriber-side device for use in the PON system is also disclosed.

Abstract: A lens element has an annular flange portion which has a tapered lateral surface so as to form at least an annular clearance tapering from a rear edge thereof when it is received in a lens holder. An adhesive which is partly filled in the clearance curs in wedge-shape to secure the lens element to the lens holder, and besides forming wedges by which the lens element is forced and held in an axial direction so as thereby to prevent the lens element from falling out of the lens holder even if the adhesive exfoliates from either one or both of the lens element and the lens holder.

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: An optical access system capable of avoiding cutoffs or interruption in the periodically transmitted signals that occur during the ranging time is provided. A first method to avoid signal cutoffs is to stop periodic transmit signals at the transmitter during the ranging period, and transmit all the periodic transmit signals together when the ranging ends, and buffer the signals at the receiver to prepare for ranging. A second method is to fix definite periods ahead of time for performing ranging, then cluster the multiple periodic transmit signals together in sets at the transmitter and send them, and then disassemble those sets back into signals at the receiver. The transmitting and receiving is then controlled so that the transmit periods do not overlap with the ranging periods. In this way an optical access system is provided that can send and receive signals requiring periodic transmissions without interruption even during ranging operation.

Abstract: In a PON system with WDM, at the time of initial setting, each ONU negotiates with an OLT, and automatically acquires a wavelength which can be used by the ONU. One wavelength for negotiation of assigned wavelength is fixed as a default, and a newly connected ONU first uses the wavelength. The OLT 200 includes a plurality of light sources for downstream communication. The ONU 300 includes a wavelength variable filter selectively receiving one of wavelengths of downstream communication, and a wavelength variable light source selectively emitting light of one of plural wavelengths for upstream communication. The ONU 300 uses a transmission wavelength (for example, ?u32) for negotiation and transmits a wavelength assignment request 1000 to the OLT 200. The OLT 200 selects a wavelength ?u1 to be assigned from unused wavelengths, and transmits wavelength information to the ONU 300. The OLT 200 and the ONU 300 communicates using the notified wavelengths.

Abstract: Session Initiation Protocol (SIP), a protocol used in VoIP (Voice over IP) communications, enables a caller to send a SIP message to a callee with his/her UserID concealed from the callee, which in turn, prevents A SIP server from making an attempt to manage the caller. If the same IP Telephone address is used whenever the IP call is made, a third party may guess the IP address easily during conversation. The SIP message sent by the caller is converted and conversion tables are managed by the SIP server. The IP Telephone modifies its IP address for each IP call. Thus, the caller can make a call to the callee with his/her UserID concealed from the callee using the SIP server with a message conversion function and communications carriers having SIP servers installed to manage the callers using their conversion tables. It is difficult to any malicious third party to guess the IP Telephone address, because the IP Telephone address is modified for each call.

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: In a PON system by WDM, IP broadcast can be received without oppressing a band used by a user for Internet communication. An OLT provides a first wavelength received in common by respective ONUs and plural second wavelengths by which the OLT and the respective ONUs perform communication individually. With respect to signals in the downstream direction, each of the OLTs includes a transmitter to transmit the first wavelength and plural transmitters to transmit the second wavelengths used for the individual communication with the respective ONUs. Each of the ONUs includes a receiver to receive the first wavelength and a receiver to receive the second wavelength used in the ONU itself. The OLT transmits data of the IP broadcast by the first wavelength and transmits individual data of each of the ONUs by the second wavelength corresponding to the ONU.

Abstract: For continuing multicast data transfer according to path control information after being switched from an active status to a standby status, it is necessary that the standby status hold the same path control information as the active status. However, a synchronization of the path control information thereof is not guaranteed. To solve the above-mentioned problem, this invention provides a data transfer apparatus coupled to a network, including a plurality of interfaces for transmitting and receiving data, in which the data transfer apparatus is configured to: create transfer destination information for correlating a destination of the data with the interfaces for transmitting the data to be transmitted to the destination; and transmit, upon reception of multicast data via one of the interfaces before being judged that the transfer destination information has been created, the multicast data from at least one of the interfaces irrespective of the transfer destination information.

Abstract: A packet routing apparatus has a routing information table comprised of a plurality of sub-tables. Each sub-table includes an entry of a first format indicative of routing information, and at least one of the sub-tables includes, in addition to the entry of the first format, an entry of a second format for designating another sub-table to be referred to. A routing processor of the packet routing apparatus refers to a sub-table designated by an input line interface. As a result, when the entry of the second format is retrieved, the routing processor executes routing of an input packet and header conversion by referring to another sub-table designated by the entry.

Abstract: An optical access system capable of avoiding cutoffs or interruption in the periodically transmitted signals that occur during the ranging time is provided. A first method to avoid signal cutoffs is to stop periodic transmit signals at the transmitter during the ranging period, and transmit all the periodic transmit signals together when the ranging ends, and buffer the signals at the receiver to prepare for ranging. A second method is to fix definite periods ahead of time for performing ranging, then cluster the multiple periodic transmit signals together in sets at the transmitter and send them, and then disassemble those sets back into signals at the receiver. The transmitting and receiving is then controlled so that the transmit periods do not overlap with the ranging periods. In this way an optical access system is provided that can send and receive signals requiring periodic transmissions without interruption even during ranging operation.

Abstract: A plastic lens comprises a lens portion and a flange portion which are cast as an integral piece by injection molding using separate molds. A positioning reference surface is formed as an integral part of the lens portion between the lens portion and the flange portion by a casting mold for forming the lens portion. When the plastic lens is installed in a lens barrel and adjusted in position, a fixture holds the plastic lens at the positioning reference surface.

Abstract: A biaxial hinge having a rotating mechanism that realizes durability, a good tactile feedback, smaller size and more lightweight is provided for use in a notebook computer or a portable telephone that needs to be smaller and more lightweight. The biaxial hinge is constituted such that a rotating shaft support member is fixed to a rotational shaft support member, a rotation-side member is inserted and attached to the outer periphery of the rotating shaft member, and an opening/closing torque unit mechanism for opening and closing operations is disposed at the rotation-side member, wherein sliding friction torque and click torque are generated by the load produced by a coil spring between pressing members and the rotating shaft support member or a sliding member attached to the rotating shaft member. The rotating mechanism of the biaxial hinge of the present invention affords good durability, a good tactile feedback, and a reduction in size and weight.