JP3764342B2 - Optical monitoring switching device, optical transmission device, optical communication system, and optical communication path switching method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical monitoring switching device, an optical transmission device, an optical communication system, and an optical communication path switching method. For example, a plurality of communication terminals (nodes) are connected to each other using an optical fiber, and voice, image, data The present invention relates to an optical monitoring switching device, an optical transmission device and an optical communication system, and an optical communication path switching method in a wavelength division multiplexing optical network system for communicating.
[0002]
[Prior art]
FIG. 11 is a diagram showing a schematic configuration of a conventional wavelength division multiplexing optical network system. For example, when four nodes (switching hubs) 911, 912, 913, and 914 arranged in a star are duplicated and connected to each other, the wavelength multiplexing optical network system has two as shown in FIG. It is composed of two circular AWGs (arrayed waveguide gratings) 901 and 902 and eight multi-wavelength light source devices 903 to 910. In general, in a star-type network using a recurring AWG, N different wavelengths are required to realize a full mesh connection between N nodes by wavelength multiplexing technology. Further, when the connection is duplicated in order to improve the reliability of the system, N × 2 light sources are required.
[0003]
When a failure occurs in such a conventional configuration (light source deterioration or optical fiber breakage), signal detection cannot be performed on the receiving side, and an abnormality is detected at the ports of the switching hubs 911 to 914. Then, the switching hub that has detected the abnormality sequentially changes the port by the auto-negotiation function, communicates with the other switching hub, searches for a detour while confirming conduction, and avoids a failure.
[0004]
[Problems to be solved by the invention]
However, in such a conventional wavelength division multiplexing optical network system, when a failure occurs due to deterioration of the light source and the corresponding path is interrupted, switching to a new detour is performed in software, so the network configuration However, there is a problem that it usually takes 30 seconds to several minutes.
[0005]
In order to prepare a backup light source for avoiding failures, it is necessary to prepare light sources of N different wavelengths in order to cope with all occurrences of failures. Therefore, there has been a problem that twice as many light sources must be prepared.
[0006]
Furthermore, the conventional wavelength division multiplexing optical network system has a problem that a failure at one node may affect all the nodes.
[0007]
The present invention has been made to solve such a problem, and the object of the present invention is to respond instantaneously even when a failure occurs in a transmission line or a wavelength revolving optical multiplexer / demultiplexer. optical monitoring switching device capable of realizing a highly reliable network, is to provide an optical transmission apparatus and optical communication systems.
[0009]
[Means for Solving the Problems]
The present invention, in order to achieve the above object, the invention according to claim 1, and two-wavelength ring-type optical demultiplexer, a star shape from each of the two wavelengths ring-type optical demultiplexer said disposed on each node of the optical network system comprising a optical communication path for transmission and reception extending, and a plurality of nodes connected by the optical communication path and each of the two-wavelength ring-type optical demultiplexer an optical monitoring switching apparatus for managing communication among nodes Te, an optical switch that you switch the optical communication paths of the optical communication path between one wavelength ring-type optical demultiplexer and the other wavelength ring-type optical demultiplexer An optical coupler that extracts a WDM signal from the reception path of the optical communication path that has passed through the optical switch, an AWG-PD that converts the WDM signal extracted by the optical coupler into an electrical signal, and a conversion by the AWG-PD Based on the generated electrical signal Zui and to detect failures of the wavelength ring-type optical demultiplexer or the optical communication path that WDM signal is not detected, characterized by comprising an electrical circuit for controlling the pre Symbol of optical switch switching.
[0010]
The invention described in claim 2 is an optical transmission device, which demultiplexes the WDM signal received from the optical communication path via the optical monitoring switching device according to claim 1 and transmits the demultiplexed signal to the optical transmission device. A demultiplexer that converts the plurality of optical signals incident from the optical transmission device into WDM signals, and a multiplexer that multiplexes the converted WDM signals and transmits the multiplexed signals to the optical monitoring switching device. A WDM interface is connected.
[0014]
The invention described in Claim 3 is the optical communication system, characterized by comprising an optical monitoring switching device according to claim 1.
[0017]
In the present invention, a wavelength ring-type optical demultiplexer, connected by optical fiber to the star-wavelength ring-type optical demultiplexer, full-mesh wavelength of N nodes multi-wavelength light source disposed therein In an optical network management system for monitoring and managing a multiple optical network system or a network system in which the full mesh wavelength division multiplexing optical network system is multiplexed, an arrayed waveguide grating type multiplexer / demultiplexer as means for detecting when a failure occurs and a plurality of photodiodes, switching the optical path by the optical switch.
[0018]
Thereby, even when a failure occurs in the light source, it is possible to realize a highly reliable network that can respond instantaneously.
[0019]
In addition, even when a light source fails, a flexible and economical network can be realized by switching wavelengths without preparing backup for all light sources.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0021]
(First embodiment)
FIG. 1 is a diagram showing a schematic configuration of a full mesh wavelength division multiplexing network system to be managed by the optical network management system of the present invention, showing a configuration example when the number of nodes is N = 4 and the number of multiplexing is M = 2. . In the present embodiment, as shown in FIG. 1, the wavelength revolving optical multiplexer / demultiplexers 101 and 102 and the wavelength revolving optical multiplexer / demultiplexer mainly disposed at the center are connected to communication paths extending in a star shape. 4 nodes. Each wavelength revolving optical multiplexer / demultiplexer and one node are connected by two communication paths for transmission and reception. Each of the four nodes includes an optical monitoring switching device 111, 121, 131, or 141, a wavelength division multiplexing (WDM) interface 112, 122, 132, or 142, and a conventional optical transmission device 113, 123, 133, or 143. ing.
[0022]
FIG. 2 is a structural diagram of an arrayed waveguide grating type multiplexer / demultiplexer (AWG ) used as an example of the wavelength-circulating type optical multiplexer / demultiplexers 101 and 102. The wavelength multiplexed light incident from the N input waveguides 201 is branched into 100 or more lights by the slab waveguide 202 and enters the arrayed waveguide 203. At this time, since the optical path lengths of the arrayed waveguides are slightly different, the output waveguide 205 can be selected by entering the exit-side slab waveguide 204 and recombining it depending on the wavelength. . By using this arrayed waveguide grating type multiplexer / demultiplexer, an N wavelength signal can be multiplexed / demultiplexed for each of the N ports.
[0023]
Table 1 shows the multiplexing / demultiplexing characteristics in the case of 8 ports, and an 8 × 8 full mesh can be realized with 8 wavelengths different from λ1 to λ8.
[0024]
[Table 1]
[0025]
Furthermore, it is good also as a structure which combined the optical coupler for uniformization of a wavelength characteristic and an equivalent loss.
[0026]
FIG. 3 is a diagram illustrating an internal configuration of the optical monitoring switching device 111. The light monitoring switching devices 121, 131, and 141 also have the internal configuration shown in the example of FIG.
[0027]
The optical monitoring switching device 111 includes an array waveguide diffraction grating type multiplexer / demultiplexer (AWG-PD) 301 having a built-in photodiode array, optical switches 302 and 303, an optical coupler 304 for extracting a part of an optical signal, and an AWG. -An electric circuit 305 that detects a PD signal and discharges an Ethernet signal to the monitoring port 351. For example, an SNMP (Simple Network Management Protocol) agent is used as the electric circuit 305. Further, a personal computer (network manager) (not shown) operated by a supervisor is connected to the end of the monitoring port 351, and a history regarding switching of the optical switches 302 and 303 based on a signal from the monitoring port 351 is connected. Is accumulated.
[0028]
Reference numerals 331, 332, 341, and 342 represent connection relationships with the optical input / output ports. As for the optical input / output ports of the optical monitoring switching devices 111, 121, 131 and 141, 331 and 341 are connected to the wavelength revolving optical multiplexer / demultiplexer 101, and 332 and 342 are connected to the wavelength revolving optical multiplexer / demultiplexer 102. Reference numerals 311, 312, 321, and 322 represent local connection relationships, and these are connected to the WDM interface 112.
[0029]
FIG. 4 is a block diagram of the AWG-PD 301. Similar to the AWG in FIG. 2, the wavelength multiplexed light incident from one input waveguide 401 is branched into 100 or more lights by the slab waveguide 402 and arrayed waveguides. Incident at 403. At this time, since the optical path lengths of the arrayed waveguides are slightly different, the output waveguide 405 can be selected because the place to be strengthened differs depending on the wavelength when entering the slab waveguide 404 on the exit side and recombining. Thereafter, a photodiode array 406 is integrated, and an incident optical signal is converted into an electrical signal.
[0030]
FIG. 5 is a diagram showing an example of a schematic configuration of the WDM interface, and conceptually shows only a part related to the present invention. The WDM interface 112 includes a DEMUX (demultiplexer) 1101, a MUX (multiplexer) 1102, a laser diode (DFB-LD) 1103, a conversion unit 1104, and a PD (Photo Detector) 1105.
[0031]
The multiwave signal received from the optical monitoring switching device 111 through the connection 311 is demultiplexed by the DEMUX 1101 and transmitted to the optical transmission device 113. On the other hand, the optical signal transmitted from the optical transmission device 113 is received by the PD 1105 which is a light receiving element, and is converted into WDM light by the conversion unit 1104. The DFB-LD 1105 transmits the converted WDM light to the MUX 1102. The MUX 1102 multiplexes the received WDM light and transmits it to the optical monitoring switching device 111 through the connection 321.
[0032]
Next, the operation of the light management system of the present invention will be described with reference to FIG. The optical signals sent from the optical transmission devices 113, 123, 133 and 143 are sent to the WDM interfaces 112, 122, 132 and 142. In the WDM interfaces 112, 122, 132, and 142, an incident optical signal is converted into a WDM signal. The converted WDM signal is transmitted to the wavelength loop optical multiplexer / demultiplexer 101 via the optical monitoring switching devices 111, 121, 131, and 141, and is multiplexed / demultiplexed for each destination and transmitted to the target node.
[0033]
At this time, when a failure occurs in the transmission path or the wavelength revolving optical multiplexer / demultiplexer 101, the failure is detected by the optical monitoring switching devices 111, 121, 131, and 141, and instantaneously connected to the wavelength revolving optical multiplexer / demultiplexer 102 The failure is avoided by switching.
[0034]
(First Reference Example ) In the above-described embodiment, an example of failure avoidance when a failure has occurred in a transmission line or a wavelength revolving optical multiplexer / demultiplexer has been described. However, in this reference example , in order to cope with a failure of a light source. An example in which the light source is doubled will be described. FIG. 6 is a diagram showing the connection relationship of the optical network management system when the light source is duplicated, and conceptually shows only the portion related to this reference example .
[0035]
The optical monitoring switching device 500 includes an AWG-PD 501, an optical switch 502, and an optical coupler 503. A signal from the optical transmission device 504 is branched into two by an optical coupler 505 and input to two WDM interfaces 506 or 507. Normally, the WDM interface 506 is used and sent to the wavelength recursive multiplexer / demultiplexer 508. However, when a failure is detected by the AWG-PD 501, the failure is avoided by switching the optical switch 502 and using the WDM interface 507.
[0036]
( Second Reference Example ) In this reference example , an example will be described in which the route is switched by switching the wavelength incident on the WDM interface without using the backup light source. FIG. 7 is a diagram showing the connection relationship of the optical network management system at that time, and conceptually shows only the portion related to this reference example . The optical monitoring switching device 600 includes an AWG-PD 601, an optical switch 602, and an optical coupler 603. A signal from the optical transmission device 604 is input to the WDM interface 605 via the optical switch 602 and sent to the wavelength recursive multiplexer / demultiplexer 606 connected to the receiving side node 607, but the AWG-PD 601 detects a failure. In such a case, the failure is avoided by switching to a light source having a different wavelength by the optical switch 602.
[0037]
( Third Reference Example ) In this reference example , an example corresponding to duplex transmission lines without using a backup light source will be described. FIG. 8 is a diagram showing the connection relationship of the optical network management system at that time, and conceptually shows only the portion related to this reference example . The optical monitoring switching device 700 includes an AWG-PD 701, optical switches 702 and 706, and an optical coupler 703.
[0038]
A signal from the optical transmission apparatus 704 is input to the WDM interface 705 via the optical switch 702, and to the wavelength recursive multiplexer / demultiplexer 707 connected to the reception-side node 709 via the optical coupler 703 and the optical switch 706. Sent. When the AWG-PD 701 detects a failure, the optical switches 702 and 706 are switched in conjunction to use light sources of different wavelengths, and the transmission path is switched, and the wavelength recursive multiplexer / demultiplexer connected to the receiving side node 710 Use this to avoid obstacles.
[0039]
( Fourth Reference Example ) In the above embodiments and reference examples , only the detection of the optical failure by combining the detection of the failure in the AWG-PD and the switching of the optical switch has been described. As a result, it is possible to perform more effective failure avoidance.
[0040]
FIG. 9 is a diagram showing an example of a conventional optical transmission apparatus in consideration of address sync using an IP address, for example, and includes a network manager 801, network apparatuses 802, 803, 804, and another network 805. FIG. 9A shows an initial state, in which the network device 802 has an IP address A.A. A. A. Communication with another network 805 is performed through A. When a failure occurs between the network devices 802 and 803 shown in FIG. 9A, a failure notification (for example, SNMP TRAP) is sent from the network device 802 to the network manager 801 as shown in FIG. 9B. Is called.
[0041]
When the network manager 801 senses this, it forcibly rewrites the routing table of the network device 802, and as shown in FIG. 9C, all signals to other networks 805 are sent to the network device 804 (IP address B.1). B. B. B. B). Thereby, it is possible to forcibly avoid the failure. By applying the configuration of this reference example in combination with the first embodiment and the first to third reference examples described above, more effective failure avoidance can be realized.
[0042]
FIG. 10 is a diagram summarizing the flow of failure avoidance when a switching hub is used as the optical transmission apparatus. When a failure occurs in the light source or the optical fiber (S1), a photodiode such as the light monitoring switching device 111 instantaneously detects the failure (S2) and switches the optical switch (S3). In parallel with this processing, the switching hub may detect a port disconnection (S4). Both devices notify the manager 801 of the occurrence of a failure (S5). If the failure is avoided by switching the light monitoring switching device (Yes route of S6), the manager ends normally.
[0043]
On the other hand, if a failure remains (No route in S6), the manager notifies the switching hub of the switching (S7). In accordance with the notification, the switching hub switches the route by rewriting the routing table (S8). Then, the failure is avoided by notifying the manager of the result (S9, S10, and S11).
[0044]
【The invention's effect】
As described above, according to the present invention, so far can not be reached, the advantage that a large number of available in the optical network system using the node can be realized a practical optical network management system is there.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing a configuration of an optical network management system according to the present invention.
FIG. 2 is a block diagram of a wavelength recursive multiplexer / demultiplexer according to the present invention.
FIG. 3 is a configuration diagram of an optical monitoring switching device according to the present invention.
FIG. 4 is a configuration diagram of an arrayed waveguide grating type multiplexer / demultiplexer incorporating a photodiode array according to the present invention.
FIG. 5 is a diagram showing an example of a schematic configuration of a WDM interface according to the present invention.
FIG. 6 is a diagram showing a configuration of an optical network management system according to a first reference example of the present invention.
FIG. 7 is a diagram showing a configuration of an optical network management system according to a second reference example of the present invention.
FIG. 8 is a diagram showing a configuration of an optical network management system according to a third reference example of the present invention.
FIG. 9 is a diagram showing a configuration of an optical network management system according to a fourth reference example of the present invention.
FIG. 10 is a diagram summarizing a flow of trouble avoidance when a switching hub is used as an optical transmission apparatus.
FIG. 11 is a diagram illustrating a conventional optical network management system.

Claims (3)

And two-wavelength ring-type optical demultiplexer, optical communication path for transmission and reception extending in a star shape from each of the two wavelengths ring-type optical demultiplexer said, the two-wavelength ring-type optical combining and branching An optical monitoring and switching device arranged in each node of an optical network system having each of a wave filter and a plurality of nodes connected by the optical communication path to manage inter-node communication,
An optical switch that you switch one optical communication path between the wavelength ring-type optical demultiplexer in the optical communication path between the other wavelength ring-type optical demultiplexer,
An optical coupler that extracts a WDM signal from the reception path of the optical communication path that has passed through the optical switch ;
AWG-PD that converts the WDM signal extracted by the optical coupler into an electrical signal;
Based on the electric signal converted by the AWG-PD, an electric circuit for detecting a failure of the wavelength ring-type optical demultiplexer or the optical communication path that WDM signal is not detected, and controls the pre Symbol of optical switch switching An optical monitoring switching device comprising:   A demultiplexer that demultiplexes a WDM signal received from the optical communication path via the optical monitoring switching device according to claim 1 and transmits the demultiplexed signal to the optical transmission device, and a plurality of optical signals incident from the optical transmission device. 2. An optical transmission apparatus comprising: a WDM interface having a conversion unit that converts the signal into a signal and a multiplexer that multiplexes the converted WDM signals and transmits the multiplexed signal to the optical monitoring switching device. An optical communication system comprising the optical monitoring switching device according to claim 1 .