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OPTICAL CROSS-CONNECT DEVICE UPDATE

外国特許コード F180009344
整理番号 S2016-0448-C0
掲載日 2018年4月17日
出願国 世界知的所有権機関(WIPO)
国際出願番号 2017JP009333
国際公開番号 WO 2017155001
国際出願日 平成29年3月8日(2017.3.8)
国際公開日 平成29年9月14日(2017.9.14)
優先権データ
  • 特願2016-044823 (2016.3.8) JP
発明の名称 (英語) OPTICAL CROSS-CONNECT DEVICE UPDATE
発明の概要(英語) An OXC device of route-and-select architecture in the prior art requires 120 1×9 WSSs in the entire device when the number of ports is 20. An OXC device of route-and-select type exceeding 20 ports requires a large quantity of expensive WSSs and lacks feasibility in terms of cost. Expansion matched to the extent of increase in traffic of a node is impossible, there is a lack of flexible scalability, and reasonable network operation including economy is difficult. An OXC device of the present disclosure uses smaller-scale WSSs than in prior art and internally connects the WSSs from a different viewpoint than in prior art, irrespective of the number of input ports and the number of output ports of the device, thereby making it possible to greatly reduce the cost of the device. Furthermore, this OXC device can be expanded flexibly, economically, stepwise only as necessary, and without limits in accordance with the initial state of traffic and subsequent increases thereto.
従来技術、競合技術の概要(英語) BACKGROUND ART
And the optical fiber as a transmission medium is optical communication technology, uncompressed result in a signal transmission distance, a large-scale optical network has been constructed. In recent years, ADSL(Asymmetric Digital Subscriber Line: asymmetric digital subscriber line) via the communication line or Internet line FTTH(Fiber To The Home) is widely used, a portable wireless through the communication line and a wireless terminal reaches the situation of the commodity. As a result, in both wired and wireless networks, and communication traffic is explosively increasing, the capacity of the communication network, high-speed, high function and low power consumption are increasingly required. In recent years, the amount of the streaming music service or using a high definition movie distribution service is popular, the world's future IP traffic continues to increase at a rate of 1.3 times per year is predicted.
In optical communication, a plurality of different wavelengths of the optical fiber transmission path 1 optical signals transmitted at the same time by the introduction of wavelength division multiplexing communication techniques, it is possible to increase the transmission capacity between the point 2 becomes possible. Further collects a plurality of transmission paths in a communication network in the node, the optical signal into an electrical signal of the optical signal without converting the signal path remains set and the switching processing method is used, the so-called photonic network has been realized. By using a photonic network, and dramatically increase the throughput of the node, significantly reducing the power consumption of the node device can be expected.
Using the optical node system includes a photonic network, a plurality of nodes connected in a bus ring or a reconfigurable optical add drop multiplexing (ROADM: Reconfigurable Optical Add Drop Multiplexing) system, a plurality of nodes connected to a mesh optical cross-connect (OXC: Optical Cross-Connect) system is well known. OXC system, each node and a plurality of input side optical fiber transmission path, a plurality of output side is connected to the optical fiber transmission path, the optical fiber transmission line on the input side inputted from the wavelength division multiplexed optical signal (hereinafter, referred to as a wavelength multiplexed light) with respect to, the connection path for each wavelength (path) switching the optical switch is provided. With this configuration, the input side of the optical fiber transmission path from any input wavelength-multiplexed optical signal of any wavelength of light, any of the output side can be output to the optical fiber transmission path.
Fig. 1 is, in the OXC system diagram illustrating an outline of switching traffic path of the optical node to the invention. OXC system in the optical network, the mesh node 1 to a plurality of adjacent nodes are connected, the other adjacent node as a plurality of optical fibers 10 connected to an input node 1. A specific traffic node 1 after the path switching is performed, the traffic is again one of the plurality of optical fibers 11 through 1 is transferred to the other nodes. Specifically, in one of the 1 input optical fiber 10-1, in the plurality of adjacent nodes of the two nodes of 1, λ1 from λx a plurality of wavelength multiplexed optical signal of wavelength multiplexed light 12 propagates. In the node 1, any of the wavelength multiplexed light 12 1 the signal light of one wavelength, the wavelength of the optical signal λ k 14-1 is selected. The selected optical signal, a plurality of output optical fiber 11 the output of any of the one optical fiber 1, for example an output optical fiber 11-n wavelength multiplexed light 13 propagates in the light of the wavelength λ k as the 14-2 signal, is transmitted to the other adjacent node. Therefore, node 1 is, the number m of the m input optical fiber is connected to the input to the input ports of the optical signal of any wavelength, one of n output optical fiber is connected to any output port is switched to the operation. In this manner, m and n input ports has two output ports, each port of the wavelength-multiplexed light propagated through the optical fiber is connected and light, having a particular wavelength remains in the optical signal to any node which performs the path switching, the optical cross connect (OXC: Optical Cross-Connect) called. Incidentally, this node may be referred to as a ROADM is, in the description herein below, this node (Patent Document 1) is referred to as OXC device.
Fig. 2A and Fig. 2B is, one of the OXC 2 a diagram schematically showing an example of the configuration of the present invention. Fig. 2A is, the configuration of the OXC device of the broadcast and select type & and 20-1, m of the m input ports to the optical fiber is connected, to the n output ports n is connected to the optical fiber. M on an input side optical coupler 21 of the 1xn configuration and are arranged, each optical coupler of the input wavelength-multiplexed light branched into n pieces so as to operate. The optical coupler 21, a substantially constant level because the simple branching, the branch of the optical signal after a lower level. N mx1 is the output side of the configuration of the wavelength selective switch (WSS: Wavelength Selective Switch) 22 and arranged, each of the WSS is one from the optical coupler in the respective m included in the light of light in the wavelength-multiplexed optical signal of any wavelength can be selected in any combination.
WSS is, the same wavelength from different wavelength multiplexed light are simultaneously selected at the output side of the optical signal cannot be distinguished from each other, light from different wavelength multiplexed optical signals of different wavelengths is selected. WSS is, the optical signal having wavelength selectivity and can be selected, for example an arrayed waveguide grating (AWG) and an optical switch or a combination are available and, further, instead of the AWG of the other of the diffraction grating can be utilized for the bulky. Fig. 2A is a configuration of a 20-1 OXC apparatus, light wavelength-multiplexed by the optical coupler 21 (branching) and distributed, and then selects an optical signal of an arbitrary wavelength by WSS22 since, referred to as broadcast and select type &.
Fig. 2B is, the root OXC device of the combined configuration of the & 20-2 and, in the configuration of the broadcast and select type & reverse the direction of the optical signal and the configuration. That is, an input side of the configuration of m 1xn and WSS23 are arranged, the output side optical coupler 24 is configured of n mx1 are arranged. For selecting a wavelength and the order is different from the broadcast and select type &, any input port of the wavelength multiplexed optical signal of any wavelength of any output port from the viewpoint of operation, Fig. 2A and Fig. 2B there is a difference between each of the components. Incidentally, generally the number of input ports of the OXC device n and m the number of output ports may be different from each other, may be the same.
As described above, the optical coupler 21, in 24, the insertion loss increases in accordance with the number of branches. Specifically, when n number of branches (n) 10log (dB) is generated due to the loss, for example the number of branches is increased to 13dB to 20 and loss. On the other hand, the input 1 (1xL) configuration of the WSS output L, the same number of branches can be configured with a less loss than an optical coupler (output port number 7dB in the case of at most about 20). OXC device increases the number of the ports of the optical coupler 21, 24 increases the loss, Fig. 2A and Fig. 2B may be any configuration, a reduction in the level of the optical signal introduced into the optical amplifier such as is required. Loss caused by the optical coupler in order to avoid the problem, without the use of an optical coupler may be composed only of WSS OXC apparatus, as an optical switch for a large-scale node is promising.
Fig. 3 is, the root OXC & showing the configuration of a select type of the present invention. Fig. 2A and in the same manner as the configurations shown in Fig. 2B, m input ports of the optical fiber is connected to the m, n of n to output ports connected to the optical fiber. Route referred to as OXC & select type in the present configuration of the device, without the use of an optical coupler so as to switch the path by the WSS, described in Fig. 2A and Fig. 2B & & route and combine the broadcast and select type such as a combination type according to the embodiment. Fig. 2A and Fig. 2B each of the compared with the configuration, the number of input ports and output ports of the OXC device increase even if the increase in the insertion loss is suppressed, the number of the ports in the case of more than about 8, typically the root OXC & select type are used as a device.
Fig. 4A and Fig. 4B is, in the actual network which the device operates as the OXC in accordance with this embodiment. Fig. 4A is, shown as squares and a plurality of nodes which are connected to each other in a mesh network that indicates the physical locations of the. For example, four square 1 corresponds to the city, the city (node) between the plurality of optical fiber transmission path are connected by a link corresponds. A white square with regard to the node 40, node 40 as the center, directly connected to the 40 node 6 surrounded by two adjacent nodes are shown by dotted-line circles. In the nodes, transmission links are directly connected to the node number of the adjacent nodes (Node Degree) called order. Therefore, in the case of the node arrangement of Fig. 4A, and 6 is the node degree. To each node connected to the mesh, the neighbor node for processing traffic between the OXC apparatus is arranged.
Fig. 4B is, central node 40 of the OXC device arranged in the configuration shown in Fig. 41. OXC apparatus 41 in the root & select type, the input port side and the output port side of the WSS are both provided. Fig. 4A in the case of a network layout, when viewed from the center node 40 connected to the central node 40 since only one 6 is the number of neighbor nodes, each node 1 is connected between the optical fiber in the case of a pair (uplink and downlink), the input optical fiber and output optical fiber and the number of m 6 respectively. In the drawing, an optical fiber and the input of the OXC device 41 from the input port and #1-6, output optical fiber and output port number 1-6 and from the top. A first input 1 of the optical fiber 1 of the optical fiber and output port number, 6 in two adjacent node 1 and connected to the first node. Similarly, the same number of input optical fibers and output optical fiber is, the numbers corresponding to adjacent and connected to the node. In the OXC apparatus 41, the adjacent node connected to the same input optical fiber and the output optical fiber is generally between the note is not necessary to connect to. And the input-side WSS WSS connection between the output side, the same number of input ports and output ports 44 shown in dotted line connecting between the internal connection is generally not necessary. In the same node and to route optical signals no meaning, such a switching path for which are prepared in advance is wasteful in some cases. That is, in one of the adjacent node of the optical signal from 1, via the central node 40, except the neighbor node of the path switching to the adjacent node 5 suffices. Therefore, the input side and output side of each of the N number of ports of the WSSWSS may be a (m-1) =5.
As shown in Fig. 4B, a central node and the OXC apparatus is installed between the two neighbor nodes is 1, the input (upstream) optical fiber and the output 2 of the optical fiber of the fiber (the downlink) may be provided as a pair. Therefore, the amount of traffic through the node increases with time in order to perform the extension of the OXC as a result, a new additional optical fiber as the fiber optic link at the time of an additional, dedicated downlink and uplink optical fiber is usually a dedicated pair of optical fiber 2 is added as this. This is because, in the wide area network, typically 1 optical fibers for two-way communication is not used in some cases. In addition, Fig. 2A and Fig. 2B and Fig. 3 is a configuration example of, the number of input ports and m n is the number of output ports is described as being different, and the number of input ports of the OXC apparatus is usually the number of output ports will be the same. The uplink and downlink traffic amount is very different from, one transmission path in the optical fiber link 1 is the number of uplink and downlink may differ between, usually be regarded as m=n.
As the first-mentioned, the more traffic between optical nodes, OXC device also increases the amount of traffic handled by, one of the transmission path 1 on the link increases the number of the optical fiber. The number of the optical fiber when an attempt to, connecting optical fiber to the OXC device according to the present embodiment also increases the number of ports required.
  • 出願人(英語)
  • ※2012年7月以前掲載分については米国以外のすべての指定国
  • NAGOYA UNIVERSITY
  • 発明者(英語)
  • Kenichi Sato
  • HASEGAWA HIROSHI
  • Yojiro Mori
  • Kosuke Sato
国際特許分類(IPC)
指定国 National States: AE AG AL AM AO AT AU AZ BA BB BG BH BN BR BW BY BZ CA CH CL CN CO CR CU CZ DE DJ DK DM DO DZ EC EE EG ES FI GB GD GE GH GM GT HN HR HU ID IL IN IR IS JP KE KG KH KN KP KR KW KZ LA LC LK LR LS LU LY MA MD ME MG MK MN MW MX MY MZ NA NG NI NO NZ OM PA PE PG PH PL PT QA RO RS RU RW SA SC SD SE SG SK SL SM ST SV SY TH TJ TM TN TR TT TZ UA UG US UZ VC VN ZA ZM ZW
ARIPO: BW GH GM KE LR LS MW MZ NA RW SD SL SZ TZ UG ZM ZW
EAPO: AM AZ BY KG KZ RU TJ TM
EPO: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
OAPI: BF BJ CF CG CI CM GA GN GQ GW KM ML MR NE SN ST TD TG
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