OPTICAL ADD/DROP MODULE (OADM) AND ITS MANUFACTURE

    公开(公告)号:JP2001053723A

    公开(公告)日:2001-02-23

    申请号:JP2000177065

    申请日:2000-06-13

    Abstract: PROBLEM TO BE SOLVED: To obtain an optical add/drop module to improve isolation without increasing cost and a storage loss due to increase of components in a network. SOLUTION: This optical add/drop module(OADM) is constituted by including exactly two thin film filters (TFF) with respective path band wavelength of which approximately coincide with each other in a through path. Each TFF is provided with each across-the-band isolation level to indicate the minimum isolation to be achieved in either wavelength in the path bands. Reflection characteristic curves of each of the two TFFs are at least partially complementary so that an OADM isolation level exceeds logarithmic sum of the across-the- band isolation levels of each of the TFFs.

    WIDE BAND OPTICAL PACKET RING NETWORK SYSTEM

    公开(公告)号:JP2001036557A

    公开(公告)日:2001-02-09

    申请号:JP2000178068

    申请日:2000-06-14

    Abstract: PROBLEM TO BE SOLVED: To efficiently increase capacity of operation by connecting a series of nodes with hubs by a dual ring bi-directional optical fiber transmission system and constituting an optical additional drop module of a broad band filter like a dielectric thin film filter at each node. SOLUTION: Nodes are connected together to make a ring 101 to connect only one of optical transmission rings with three additional/drop nodes 110 to 112 and a hub 130 transmit a packet in the clockwise direction and to make a similar ring to transmit the packet in the counterclockwise direction. Each of the nodes 110 to 112 is provided with corresponding optical additional drop modules OADM 210 to 212. Namely, in a specified wavelength band corresponding to a specified widely spaced C-WAM channel, only a signal is extracted from a wavelength division multiplexed signal existing in the ring 101 and inserted into the same wavelength band and a C-WDM channel so as to be returned on the ring 101.

    NODE TO BE USED IN AN ASYNCHRONOUS TRANSFER MODE (ATM) TRANSMISSION SYSTEM

    公开(公告)号:JPH1084362A

    公开(公告)日:1998-03-31

    申请号:JP20667097

    申请日:1997-07-31

    Abstract: PROBLEM TO BE SOLVED: To attain high speed restoration within a processing limit at a cost of a node with protection switching for each virtual channel by utilizing a node that recognizes a defect specific to ATM and employing a virtual path group technology allowing'ltigh speed ATM virtual connection/restoration with a minimized processing. SOLUTION: Supposing that a physical layer defect takes place between a virtual path group(VPG) source node 101 and a VPG intermediate node 102, the VPG intermediate node 102 uses a transmission path/ATM adaptive function to detect the defect and generates a virtual path segment level alarm instruction signal (VP-AIS) cell for all virtual path identifiers(VPI) receiving the effect and inserts the signal to a cell stream. A VPG SYNC node 103 monitors continuously the reception of the VP-AIS and a VPG selector selects a protection VPG upon the receipt of it. Thus, high speed restoration is attained through protection switching or each virtual channel within a processing limit at a node cost.

    COMMUNICATION NETWORK
    5.
    发明专利

    公开(公告)号:JP2001044944A

    公开(公告)日:2001-02-16

    申请号:JP2000178072

    申请日:2000-06-14

    Abstract: PROBLEM TO BE SOLVED: To reduce patch panel loss applied to the traffic of another receiver by taking the optical multiplexing and demultiplexing module (OADM) of a double ring two-way optical fiber transmission system out of an electronic cabinet and arranging the optical multiplexing and demultiplexing module at a place where an access possibility is low. SOLUTION: A WDM ring has an OADM that multiplexes and demultiplexes the signal of each node in the node. The WDM ring also has a power terminal device adjusting input - output data and performing conversion between a light area and an electricity area in each node. The OADM 501 of a node is arranged at a place that is physically separated from the power terminal device and connected to the power terminal device through an optical medium. In each node, traffic that is not to the node is subjected to routing through only one housing in the in-house of a subscriber requesting connection. In the case such a housing exists, the housing includes the OADM.

    Wideband optical packet ring network

    公开(公告)号:AU3934900A

    公开(公告)日:2000-12-21

    申请号:AU3934900

    申请日:2000-06-07

    Abstract: A dual-ring, bi-directional optical fiber transmission system interconnects a series of add/drop nodes with a hub, such that multiple, widely spaced coarse wavelength division multiplexed (C-WDM) channels are established on each ring. At each node, an optical add/drop module (OADM) includes broadband filters (BBF's), such as dielectric thin film filters, arranged to (a) extract, for the purposes of a receiver, or (b) insert, for the purposes of a transmitter, information in one or more of the channels. The signals in the one or more channels are coupled to the OADM's by a standard optical transceiver, which performs modulation and demodulation. Each filter passband can be populated with multiple dense wavelength division multiplexed (D-WDM) channels, so that the capacity of traffic that can be handled at each node can be easily upgraded. The transceiver is, in turn, coupled to packet framer, such as an IP packet over SONET framer, which supplies received packets to, and receives outgoing packets from, a conventional Layer 3 routing engine. While in most instances, endpoints at each of the nodes communicate with other endpoints connected to the hub, if desired, endpoints at one or more nodes can communicate directly with endpoints on other nodes, using a direct or bypass connection through the hub. The bypass can be "permanent" or controlled via a switch, such as a micro-electro-mechanical switch (MEMS).

    8.
    发明专利
    未知

    公开(公告)号:DE60000119T2

    公开(公告)日:2002-10-31

    申请号:DE60000119

    申请日:2000-06-06

    Abstract: A fiber-optic WDM ring carries communication traffic among a plurality of nodes, each node associated with respective subscriber premises. The WDM ring includes an optical add-drop module (OADM) at each node for adding and dropping signals associated with that node. The WDM ring also includes active terminal equipment at each node for conditioning incoming and outgoing data and for converting between the optical and electrical domains. The OADM at each of at least some nodes, to be referred to as enhanced nodes, is situated at a site physically separated from the powered terminal equipment, and is coupled to the powered terminal equipment via an optical medium. At each enhanced node, traffic not destined for that node is routed through no more than one enclosure on subscriber premises that requires a connection. If there is such enclosure, it contains the OADM.

    9.
    发明专利
    未知

    公开(公告)号:DE60000119D1

    公开(公告)日:2002-05-16

    申请号:DE60000119

    申请日:2000-06-06

    Abstract: A fiber-optic WDM ring carries communication traffic among a plurality of nodes, each node associated with respective subscriber premises. The WDM ring includes an optical add-drop module (OADM) at each node for adding and dropping signals associated with that node. The WDM ring also includes active terminal equipment at each node for conditioning incoming and outgoing data and for converting between the optical and electrical domains. The OADM at each of at least some nodes, to be referred to as enhanced nodes, is situated at a site physically separated from the powered terminal equipment, and is coupled to the powered terminal equipment via an optical medium. At each enhanced node, traffic not destined for that node is routed through no more than one enclosure on subscriber premises that requires a connection. If there is such enclosure, it contains the OADM.

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