NETWORK DEVICE AND DATA EXCHANGE METHOD

Abstract

A communication network for transferring user data has network devices. The network device comprises an acquisition unit, an identification unit, and a transmission unit. The acquisition unit acquires inter-network device data, which is superimposed on the user data in an out-of-band manner and exchanged between the network devices, from data obtained by branching or copying data transmitted on the transmission line of a communication network. When the destination of the acquired data, which is the inter-network device data acquired by the acquisition unit, is its own device, the identification unit outputs the acquired data to a processing unit that performs a predetermined process, and when the destination is not its own device, the identification unit discards the acquired data. The transmission unit superimposes inter-network-device data from its own device to another network device on the user data transmitted on the transmission line in an out-of-band manner.

Description

[Technical field]

[0001] The present invention relates to a network device and a data exchange method. [Background technology]

[0002] A communication network uses systems that have control and communication functions. An example of such a system is an L3 (layer 3) router that has a routing table and a switch function. In some cases, the control function and the communication function are separated into different devices.

[0003] FIG. 25 is a diagram showing a configuration example of a conventional communication system. In the communication system, communication devices #1 and #2 constitute a communication network for transmitting and receiving user data. The communication device has an information measurement unit having a function of measuring information, and an information exchange unit for exchanging measured information with other devices. The communication device collects necessary information by transmitting and receiving an information measurement signal and an information response between other communication devices. For example, a routing protocol in an L3 router such as RIP (Routing Information Protocol) is used for transmitting and receiving these information (for example, see Non-Patent Document 1). As shown in FIG. 26, in the conventional technology, user data U and data V between network devices in which an information measurement signal or an information response is set are multiplexed and transmitted by time division multiplexing (in-band) on the same communication path.

[0004] Also, as shown in Fig. 25, there are cases where a communication network has a monitoring and control device that uses quality measurement results in communication devices. An information collection unit of the monitoring and control device collects quality measurement results measured by quality measurement units of the communication devices and transmitted from information reporting units. The function of the information collection unit is realized by a conventional remote quality measurement method such as Simple Network Management Protocol (SNMP) or Telemetry (see, for example, Non-Patent Document 2). In such a case, as shown in Fig. 26, in the conventional technology, user data U and data V between network devices in which quality measurement results are set are multiplexed and transmitted by time division multiplexing on the same communication path.

[0005] The network configuration shown in FIG. 25 is an example, and other configurations are possible. For example, the communication devices can be connected in a ring structure or a tree structure. In addition, the information measurement unit and the information exchange unit may be provided in separate devices. In addition, the monitoring and control device and the communication device may be integrated. [Prior art documents] [Non-patent literature]

[0006] [Non-Patent Document 1] RFC1058, "Routing Information Protocol", [online], 1988, Internet <URL: https: / / datatracker.ietf.org / doc / html / rfc1058> [Non-Patent Document 2] RFC1157,"A Simple Network Management Protocol (SNMP)",[online],1990,Internet〈URL:https: / / datatracker.ietf.org / doc / html / rfc1157〉 Summary of the Invention [Problem to be solved by the invention]

[0007] As described above, data between network devices and user data are multiplexed and transmitted by time division multiplexing, so in order to transmit a signal for information measurement and a response to the information measurement, or a quality measurement result, it is necessary to establish in-band communication in advance.

[0008] Furthermore, in order to identify and separate data between network devices and user data, it is necessary to unify network protocols to, for example, IP (Internet Protocol) or Ethernet (registered trademark), and to make a judgment using a destination or an identifier set in the data. Therefore, when the user data is a signal such as Radio over Fiber (RoF), it is not possible to multiplex the information measurement signal or the information response as it is. Furthermore, even if the user data can be multiplexed and separated by time division multiplexing, the network quality is affected by inserting the information measurement signal and the information response. For example, delays and jitters occur, and the bandwidth used for user data is reduced.

[0009] In view of the above circumstances, the present invention aims to provide a network device and a data exchange method that can transmit and receive information between devices that make up a network, regardless of the protocol of the user data, and while reducing the impact on the quality of the user data. [Means for solving the problem]

[0010] One aspect of the present invention is a network device owned by a communication network that transfers user data, comprising: an acquisition unit that acquires network-to-device data, which is superimposed out-of-band on user data from data obtained by branching or copying data transmitted over a transmission path of the communication network and is data exchanged between network devices owned by the communication network; an identification unit that outputs the acquired data, which is the network-to-device data acquired by the acquisition unit, to a processing unit that performs predetermined processing if the destination of the acquired data is the own device, and discards the acquired data if the destination is not the own device; and a transmission unit that superimposes out-of-band network-to-device data addressed from the own device to another network device on user data transmitted over the transmission path.

[0011] One aspect of the present invention is a data exchange method executed by a network device in a communication network that transfers user data, comprising: an acquisition step of acquiring network-device data, which is superimposed out-of-band on user data from data obtained by branching or copying data transmitted over a transmission path of the communication network, and which is data exchanged between network devices in the communication network; an identification step of outputting the acquired data, which is the network-device data acquired in the acquisition step, to a processing unit that performs predetermined processing if the destination of the acquired data is the own device, and discarding the acquired data if the destination is not the own device; and a transmission step of superimposing out-of-band network-device data addressed from the own device to another network device on user data transmitted over the transmission path. Effect of the Invention

[0012] According to the present invention, it becomes possible to transmit and receive information between devices constituting a network, regardless of the protocol of the user data, while reducing the impact on the quality of the user data. [Brief description of the drawings]

[0013] [Figure 1]FIG. 2 illustrates data transmission according to an embodiment of the present invention. [Diagram 2] FIG. 11 is a diagram showing data transmission according to the embodiment. [Diagram 3] FIG. 11 is a diagram showing data transmission according to the embodiment. [Figure 4] 1 is a configuration diagram of a communication system according to a first embodiment. [Diagram 5] FIG. 2 is a configuration diagram of a communication device according to the embodiment. [Figure 6] FIG. 11 is a flow diagram showing a network signal transmission process of the communication device according to the embodiment. [Figure 7] FIG. 11 is a flow diagram showing a network signal receiving process of the communication device according to the embodiment. [Figure 8] FIG. 2 is a configuration diagram of a communication system according to the embodiment. [Figure 9] FIG. 11 is a configuration diagram of a communication system according to a second embodiment. [Figure 10] FIG. 2 is a configuration diagram of a monitoring control device and a communication device according to the embodiment. [Figure 11] FIG. 2 is a configuration diagram of a communication device according to the embodiment. [Figure 12] 4 is a flow diagram showing a network signal transmission / reception process of the monitoring and control device according to the embodiment. FIG. [Figure 13] FIG. 11 is a flow diagram showing a network signal transmission process of the communication device according to the embodiment. [Figure 14] FIG. 11 is a flow diagram showing a network signal receiving process of the communication device according to the embodiment. [Figure 15] FIG. 2 is a configuration diagram of a communication system according to the embodiment. [Figure 16] FIG. 2 is a configuration diagram of a separation device according to the same embodiment. [Figure 17] 11 is a flowchart showing a network signal transmission and reception process of the separation device according to the embodiment. FIG. [Figure 18] FIG. 2 is a configuration diagram of a communication system according to the embodiment. [Figure 19] FIG. 2 is a configuration diagram of a monitoring control device and a distribution device according to the embodiment. [Figure 20] FIG. 2 is a flow diagram showing a network signal transmission and reception process of the communication system according to the embodiment. [Figure 21] FIG. 11 is a configuration diagram of a communication system according to a third embodiment. [Figure 22] FIG. 2 is a diagram showing a configuration related to an optical switch function of the communication device according to the embodiment. [Diagram 23] FIG. 11 is a diagram showing an example of quality information according to the embodiment. [Figure 24] FIG. 2 is a diagram illustrating a hardware configuration of a communication device according to the first embodiment. [Diagram 25] FIG. 1 is a diagram illustrating a configuration of a conventional communication system. [Figure 26] FIG. 1 illustrates conventional data transmission. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In this embodiment, data between network devices, which is data exchanged between network devices constituting a communication network that transmits user data, is superimposed on user data, which is a main signal transferred by the communication network, in an out-of-band manner. The out-of-band method is, for example, AMCC (Auxiliary Management and Control Channel) technology specified in NG-PON2. AMCC is a control method using a protocol-free control signal that can be superimposed on a main signal. The AMCC signal is transmitted by superimposing a low-speed carrier on the main signal and conveys information by intensity modulation. The AMCC signal superimposed in this manner can be separated from the main signal. AMCC is described, for example, in Reference 1 "G.989.3, "40-Gigabit-capable passive optical networks (NG-PON2): Transmission convergence layer specification", ITU-T, 2021".

[0015] Hereinafter, a signal for transmitting and receiving data between network devices between network devices is referred to as a network signal. The network devices include a communication device that transfers user data and a monitoring control device that monitors and controls a communication network. Examples of network signals include an information measurement signal and an information response transmitted and received between communication devices, a report instruction transmitted from a monitoring control device to a communication device, and a quality information report transmitted from a communication device to a monitoring control device. The information measurement signal is a signal for measuring information. The information response is a signal that notifies the measured information. The report instruction is a signal that instructs to report the measurement result of the network quality. The quality information report is a signal that notifies the measurement result of the network quality. Note that the network signal is not limited to these examples. In addition, in the following, a case where the communication network that transmits user data is a network that performs optical communication will be described as an example, but it may be a network that performs communication other than optical communication, such as wireless communication.

[0016] 1 to 3 are diagrams showing data transmission using an out-of-band method in the communication system of this embodiment. User data U is data of the U-Plane (transfer plane). Data V between network devices is data that sets a network signal. The information measurement signal and the information response are network signals of the C-Plane (control plane) transmitted and received between the communication devices. The report instruction and the quality information report are network signals of the M-Plane (management plane) transmitted and received between the communication device and the monitoring control device.

[0017] In Fig. 1, network device data V from one network device is superimposed on user data U by the out-of-band method. In Fig. 2, network device data V from each of a plurality of network devices is superimposed on user data U by the out-of-band method in time division. In Fig. 3, network device data V from a plurality of network devices is superimposed on user data U by channels with different wavelengths @f1, @f2, @f3. Note that Fig. 2 and Fig. 3 may be combined, and network device data V may be superimposed on user data U by the out-of-band method in time division on each channel. The time used in the case of superimposition using time division and the channel used in the case of superimposition using multiple channels may be designated by the monitoring control device, or each communication device may monitor the usage status and determine the available time or channel.

[0018] The AMCC signal of the prior art is used for control between transceivers. In this embodiment, the AMCC signal is used not for the purpose of control between transceivers, but for signals between communication devices and between a communication device and a monitoring control device. The communication system of this embodiment transmits a network signal by superimposing it out of band on a communication network that transmits user data. Therefore, it is possible to transmit and receive information measurement signals and information responses between communication devices, and to notify the network quality measurement results from the communication devices to the monitoring control device, protocol-free and without affecting the quality of the user data. In addition, by using out of band, it is possible to transmit and receive network signals between network signal devices even in a state where in-band communication for transmitting and receiving user data is not established. Furthermore, even when there are multiple communication devices, it is possible to transmit and receive information measurement signals and information responses between communication devices using out of band, and to notify the network quality measurement results from the communication devices to the monitoring control device. The present embodiment will be described in detail below.

[0019] (First embodiment) In this embodiment, an information measurement signal and an information response are transmitted and received between communication devices.

[0020] FIG. 4 is a diagram showing a configuration example of a communication system 101 according to the first embodiment. The communication system 101 has a communication network configured with N communication devices 120 connected in cascade. The N communication devices 120 are respectively described as communication devices 120-1 to 120-N. A user device 140 may be connected to the communication device 120. The communication device 120 is connected to another adjacent communication device 120 by an optical transmission path 160. The direction from the communication device 120-1 to the communication device 120-N is an upper direction, and the direction from the communication device 120-N to the communication device 120-1 is a lower direction. Although the communication devices 120 are connected in cascade in FIG. 4, a different topology may be used.

[0021] The communication device 120 relays user data. The communication device 120 transmits and receives network signals by an out-of-band method using a wavelength different from the wavelength of an optical signal that transmits and receives user data to and from other communication devices 120. The network signal includes destination information, source information, and data type information. The destination information indicates a network device to which the network signal is to be transmitted. The source information indicates a network signal device that is the source of the network signal. The data type information is an identifier that indicates the type of data transmitted as a network signal.

[0022] FIG. 5 is a block diagram showing a configuration example of the communication device 120. In FIG. 5, only functional blocks related to this embodiment are extracted and shown. The communication device 120 has an information storage unit 121, an information measurement unit 122, a measurement response unit 123, a transmission control unit 124, a transmission / reception unit 125-1, a transmission / reception unit 125-2, a coupler 126-1, a coupler 126-2, a destination identification unit 127, and a data identification unit 128. The coupler 126-1 and the coupler 126-2 are collectively referred to as a coupler 126, or when neither is specified. The transmission / reception unit 125-1 and the transmission / reception unit 125-2 are collectively referred to as a transmission / reception unit 125, or when neither is specified.

[0023] The information storage unit 121 stores information. The information stored in the information storage unit 121 is, for example, routing information between adjacent communication devices 120, network quality information such as network delay time, etc., but is not limited to these.

[0024] The information measurement unit 122 learns or updates information held by the own device by performing information measurement on the other communication device 120. The information measurement unit 122 generates an information measurement signal to be transmitted to the other communication device 120. The information measurement signal includes destination information indicating the other communication device 120 as the destination, source information indicating the own device, and data type information indicating information measurement. The destination information may be set to a unicast destination using the address of the communication device 120, or may be set to a multicast or broadcast destination including the destination communication device 120. The information measurement unit 122 outputs the generated information measurement signal to the transmission control unit 124. In addition, the information measurement unit 122 receives an information response returned from the other communication device 120 in response to the information measurement signal transmitted by the own device. The information measurement unit 122 learns or updates information stored in the information storage unit 121 based on information set in the received information response.

[0025] The measurement response unit 123 receives a signal for information measurement from another communication device 120. The measurement response unit 123 reads out information corresponding to the signal for information measurement from the information storage unit 121. The measurement response unit 123 generates an information response that sets the read out information, destination information indicating the communication device 120 to which the signal for information measurement is to be transmitted, source information indicating the own device, and data type information indicating the information response. The measurement response unit 123 outputs the generated information response to the transmission control unit 124. The information response is transmitted in the direction in which the signal for information measurement was received.

[0026] The transmission control unit 124 controls the transmission / reception unit 125 to transmit network signals, such as the information measurement signal output by the information measurement unit 122 and the information response output by the measurement response unit 123, in an out-of-band manner. That is, the transmission control unit 124 determines the transmission timing and frequency when transmitting the network signal in an out-of-band manner, and instructs the transmission / reception unit 125. The transmission control unit 124 can transmit the network signal in either the upper or lower direction based on the determination of the information measurement unit 122 and the measurement response unit 123. The transmission control unit 124 outputs a network signal addressed to a communication device 120 lower than the own device to the transmission / reception unit 125-1, and outputs a network signal addressed to a communication device 120 higher than the own device to the transmission / reception unit 125-2.

[0027] The transmitting / receiving unit 125 is, for example, an optical transceiver (TRx). The transmitting / receiving unit 125 receives a network signal and an instruction of the transmission timing and wavelength of the network signal from the transmission control unit 124. The transmitting / receiving unit 125 converts the network signal from an electrical signal to an out-of-band optical signal of the indicated wavelength. The transmitting / receiving unit 125-i (i=1, 2) outputs the network signal converted into an optical signal to the coupler 126-i at the indicated transmission timing. The transmitting / receiving unit 125-i also receives light branched by the coupler 126-i, separates the network signal transmitted in an out-of-band manner from the received optical signal, and converts it into an electrical signal. The transmitting / receiving unit 125-i outputs the network signal converted into an electrical signal to the destination identification unit 127.

[0028] The coupler 126-1 is provided on the optical transmission path 160 on the lower side, and the coupler 126-2 is provided on the optical transmission path 160 on the upper side. The coupler 126-1 branches the light transmitted on the optical transmission path 160 from the lower side to the upper side, and outputs the branched light to the transceiver 125-1. The coupler 126-1 also couples the optical signal output by the transceiver 125-1 to the lower side of the optical transmission path 160. The coupler 126-2 branches the light transmitted on the optical transmission path 160 from the upper side to the lower side, and outputs the branched optical signal to the transceiver 125-2. The coupler 126-2 also couples the optical signal output by the transceiver 125-2 to the upper side of the optical transmission path 160.

[0029] An optical filter may be provided between the coupler 126-i and the transceiver 125-i. The optical filter removes signals in unnecessary frequency bands. The communication device 120 may use an in-line modulator instead of the coupler 126-i and the transceiver 125-i.

[0030] Destination identification unit 127 reads out destination information set in the network signal. If the destination information indicates a unicast address of the own device, or a multicast or broadcast including the own device, destination identification unit 127 determines that the network signal is addressed to the own device. Destination identification unit 127 outputs the network signal addressed to the own device to data identification unit 128. If destination identification unit 127 determines based on the destination information that the network signal is not addressed to the own device, it discards the received network signal.

[0031] The data distinguishing unit 128 reads out data type information set in the network signal. When the data type information indicates information measurement, the data distinguishing unit 128 outputs an information measurement signal, which is the received network signal, to the measurement response unit 123. When the data type information indicates an information response, the data distinguishing unit 128 outputs an information response, which is the received network signal, to the information measurement unit 122.

[0032] The measurement signal and the response information may be transmitted and received between the communication device 120 and the user device 140, or between the user devices 140. In this case, the user device 140 performs the same process as the communication device 120 in Fig. 5. Furthermore, the transceiver 125 of the user device 140 transmits and receives an in-band optical signal in which user data is set.

[0033] 6 is a flow diagram showing a network signal transmission process in the communication device 120. The information measurement unit 122 generates an information measurement signal addressed to another communication device 120, and outputs the generated information measurement signal to the transmission control unit 124 (step S101). The transmission control unit 124 determines the transmission time of the information measurement signal, and the channel and the transmission / reception unit 125 used for transmission (step S102).

[0034] For example, the transmission control unit 124 determines the transmission time and channel when transmitting a network signal in an out-of-band manner based on the transmission control information. The transmission control information is information that can determine the transmission time and the channel to be used, for example, corresponding to a source device, a destination device, or a combination of both. Note that if all communication devices 120 use the same wavelength for transmitting network signals, it is not necessary to determine the channel. Also, the transmission control information may be notified in advance from a higher-level device, or may be set in advance specifically for each device.

[0035] Alternatively, the transmission control unit 124 may monitor the communication status of the out-of-band data and autonomously determine the transmission time and the channel to be used without using the transmission control information. The communication status of the out-of-band data is obtained based on the network signal separated by the transmission / reception unit 125.

[0036] Furthermore, when the destination information indicates a unicast address to another communication device 120, the transmission control unit 124 determines whether to output the network signal to the transmission / reception unit 125-1 or the transmission / reception unit 125-2. That is, when the destination other communication device 120 is lower than the own device, the transmission control unit 124 determines to output the network signal to the transmission / reception unit 125-1, and when the destination other communication device 120 is higher than the own device, the transmission control unit 124 determines to output the network signal to the transmission / reception unit 125-2. The transmission control unit 124 determines the routing destination, whether the destination other communication device 120 is lower or higher than the own device, based on, for example, routing information stored in the information storage unit 121 or set in the transmission control information. When the destination information indicates a multicast address, the transmission control unit 124 determines the output destination of the network signal to one or both of the transmission / reception units 125-1 and 125-2 based on the multicast address. Furthermore, when the destination information indicates a broadcast, the transmission control unit 124 determines both the transmitting / receiving units 125-1 and 125-2 as the output destination.

[0037] The transmission control unit 124 outputs the measurement signal to the transceiver 125-i determined as the output destination, and further indicates the determined transmission time and channel. The transceiver 125-i converts the measurement signal output by the transmission control unit 124 from an electrical signal to an optical signal having a wavelength used for the indicated channel. The transceiver 125-i outputs the measurement signal converted into an optical signal to the coupler 126-i at the indicated transmission time. The coupler 126-i couples the measurement signal output by the transceiver 125-i to the optical transmission path 160 (step S103).

[0038] 7 is a flow diagram showing a network signal reception process in the communication device 120. The coupler 126-1 and the coupler 126-2 branch an optical signal transmitted through the optical transmission path 160. The coupler 126-i outputs the branched optical signal to the transceiver 125-i. The transceiver 125-i separates a network signal transmitted in an out-of-band manner from the optical signal branched by the coupler 126-i and converts it into an electrical signal. The transceiver 125-i outputs the network signal converted into an electrical signal to the destination identification unit 127 (step S201).

[0039] The destination identification unit 127 reads out destination information set in the network signal. The destination identification unit 127 judges whether the destination information indicates its own device's address (step S202). If the destination information indicates its own device's unicast address, its own device's multicast address, or its own broadcast address, the destination identification unit 127 judges that the destination information is its own device's address (step S202: YES) and outputs the network signal to the data identification unit 128.

[0040] The data identification unit 128 identifies the data based on the data type information set in the network signal (step S203). When the data type information indicates information measurement, the data identification unit 128 outputs the information measurement signal, which is the received network signal, to the measurement response unit 123.

[0041] The measurement response unit 123 reads out information on the measurement target corresponding to the information measurement signal from the information storage unit 121 (step S204). The measurement response unit 123 generates an information response including the read out information, destination information indicating the communication device 120 that is the transmission source of the information measurement signal, transmission information indicating the device itself, and data type information indicating the information response (step S205). The measurement response unit 123 outputs the generated information response to the transmission control unit 124.

[0042] The transmission control unit 124 determines the transmission time of the information response, and the channel and the transceiver 125 used for transmission by the same process as in step S102 in FIG. 6 (step S206). The transmission control unit 124 may select the transceiver 125-i that received the information measurement signal. The transmission control unit 124 outputs the information response to the determined transceiver 125-i, and further indicates the determined transmission time and channel. The transceiver 125-i converts the information response from an electrical signal to an optical signal of a wavelength used for the indicated channel by the same process as in step S103 in FIG. 6, and outputs the information response to the coupler 126-i at the indicated transmission time. The coupler 126-i couples the information response to the optical transmission path 160 (step S207).

[0043] On the other hand, in step S203, if the data type information indicates an information response, the data identification unit 128 determines that the received network signal is an information response returned in response to the information measurement signal transmitted by the own device. The data identification unit 128 outputs the information response to the information measurement unit 122. The information measurement unit 122 learns or updates the information stored in the information storage unit 121 based on the information set in the received information response (step S208).

[0044] Furthermore, in step S202, if destination identification unit 127 determines that the signal is not addressed to its own device (step S202: NO), it discards the received network signal (step S209).

[0045] Some of the functions of the communication device 120 may be included in another device. FIG. 8 is a diagram showing an example of the configuration of a communication system 102. The communication system 102 has N communication devices 180 that are cascade-connected. In FIG. 8, the N communication devices 180 are respectively described as communication devices 180-1 to 180-N. Some of the communication devices 180 are connected to a control device 190. In FIG. 8, the control device 190 connected to the communication device 180-n is described as the control device 190-n. The communication device 180 that is not connected to the control device 190 has the same configuration as the communication device 120 shown in FIG. 5.

[0046] 5, and the control device 190 has the other functions of the communication device 120. Except for the fact that the communication device 180 has the coupler 126, it can be arbitrarily determined which functional units of the communication device 120 each of the communication device 180 and the control device 190 has. For example, the communication device 180 may have the information storage unit 121, the information measurement unit 122, the measurement response unit 123, the transmission / reception unit 125, and the coupler 126, and the control device 190 may have the transmission control unit 124, the destination identification unit 127, and the data identification unit 128. Furthermore, communication device 180 may have information storage unit 121, information measurement unit 122, measurement response unit 123, transmission / reception unit 125, coupler 126, and data identification unit 128, and control device 190 may have transmission control unit 124 and destination identification unit 127. Furthermore, communication device 180 and control device 190 may realize the same functional units of communication device 120.

[0047] According to this embodiment, since the information measurement signal and the information response are transmitted and received between communication devices using an out-of-band method, it is possible to transmit this information even when in-band communication is not established.

[0048] Second embodiment In this embodiment, a network signal between a communication device and a monitoring and control device is superimposed on user data and transmitted by an out-of-band method.

[0049] 9 is a diagram showing an example of the configuration of a communication system 201 according to the second embodiment. The communication system 201 has a communication network made up of a monitor control device 210 and N communication devices 220 that are cascade-connected.

[0050] The monitoring control device 210 manages and controls the communication network. The monitoring control device 210 is connected to the communication device 220 via an optical transmission path 161. In Fig. 9, the monitoring control device 210 is connected to one communication device 220 by way of example, but may be connected to a plurality of communication devices 220.

[0051] The communication device 220 is connected to other adjacent communication devices 220 by an optical transmission path 160. A user device 140 may be connected to the communication device 220. The communication device 220 relays user data. The N communication devices 220 are respectively described as communication devices 220-1 to 220-N. In FIG. 9, the communication devices 220 are cascade-connected, but may have a different topology.

[0052] The communication device 220 transmits and receives network signals between the communication device 220 and the monitoring control device 210 by an out-of-band method using a wavelength different from the wavelength of light used to transmit and receive user data between other communication devices 220. Furthermore, the communication device 220 may transmit and receive network signals between the communication devices 220 by an out-of-band method. As in the first embodiment, the network signal includes destination information, source information, and data type information.

[0053] In the following, the communication device 220 connected to the monitoring control device 210 is referred to as the communication device 220a, and the communication device 220 not connected to the monitoring control device 210 is referred to as the communication device 220b. In addition, the monitoring control device 210 connected to the communication device 220a is referred to as the adjacent monitoring control device 210 of the communication device 220a.

[0054] Fig. 10 is a block diagram showing a configuration example of the monitoring control device 210 and the communication device 220a. In Fig. 10, only the functional blocks related to this embodiment are extracted and shown.

[0055] The monitoring control device 210 includes an information collecting unit 211 and a transmitting / receiving unit 212. The information collecting unit 211 transmits a network signal addressed to the communication device 220. The network signal transmitted by the information collecting unit 211 is one or both of a report instruction and a transmission control information notification. The report instruction includes destination information indicating the destination communication device 220, source information indicating the device itself, and data type information indicating the report instruction. The transmission control information notification includes destination information indicating the destination communication device 220, source information indicating the device itself, data type information indicating the transmission control information, and transmission control information to be notified to the destination communication device 220. The transmission control information is information that can acquire a channel and transmission timing used for transmitting an out-of-band signal. The transmission control information may include routing information. A unicast destination using the address of the communication device 220 may be set in the destination information, or a multicast or broadcast destination including the destination communication device 220 may be set. Moreover, the information collecting unit 211 receives a quality information report returned in response to a report instruction.

[0056] The transmitting / receiving unit 212 is an optical transceiver (TRx). The transmitting / receiving unit 212 converts the signal output from the information collecting unit 211 from an electrical signal to an optical signal and outputs the signal to the optical transmission path 161. The transmitting / receiving unit 212 also converts the optical signal received from the communication device 220 via the optical transmission path 161 into an electrical signal and outputs the electrical signal to the transmitting / receiving unit 212.

[0057] In the communication device 220a shown in Fig. 10, the same parts as those in the communication device 120 of the first embodiment shown in Fig. 5 are denoted by the same reference numerals, and the description thereof will be omitted. The communication device 220a has a quality information storage unit 221, a quality measurement unit 222, an information report unit 223, a transmission control unit 224, a transmitting / receiving unit 125-1, a transmitting / receiving unit 125-2, a coupler 126-1, a coupler 126-2, a transmitting / receiving unit 225, a destination identification unit 226, and a data identification unit 227.

[0058] The quality information storage unit 221 stores network quality information. The network quality information indicates the measurement result of the network quality. The quality measurement unit 222 measures the network quality and writes the network quality information indicating the measurement result to the quality information storage unit 221. The quality measurement unit 222 measures the network quality by transmitting a quality measurement signal to the other communication device 220. The quality measurement signal includes destination information indicating the other communication device 220 as the destination, source information indicating the own device, and data type information indicating the quality measurement. In addition, the quality measurement unit 222 receives a quality measurement result notification returned from the other communication device 220 in response to the quality measurement signal. The quality measurement unit 222 writes the measurement result of the network quality set in the received quality measurement result notification to the quality information storage unit 221.

[0059] When the information reporting unit 223 receives a report instruction from the monitoring control device 210, it generates a quality information report. The quality information report includes destination information indicating the monitoring control device 210 that sent the report instruction, source information indicating the device itself, data type information indicating the quality information, and the measurement result of the network quality that the information reporting unit 223 reads out from the quality information storage unit 221. The information reporting unit 223 outputs the generated quality information report to the transmission control unit 224.

[0060] Furthermore, when the information reporting unit 223 receives a quality measurement signal from another communication device 220, it generates a quality measurement result notification. The quality measurement result notification includes destination information indicating the communication device 220 that is the source of the quality measurement signal, source information indicating the own device, data type information indicating the quality measurement result, and the measurement result of the network quality that the information reporting unit 223 reads out from the quality information storage unit 221. The information reporting unit 223 outputs the generated quality measurement result notification to the transmission control unit 224. The quality measurement result notification is transmitted in the direction in which the quality measurement signal was received.

[0061] The transmission control unit 224, like the transmission control unit 124 in the first embodiment, controls the transceiver unit 125 to transmit a network signal addressed to another communication device 220 in an out-of-band manner. Furthermore, the transmission control unit 224 outputs a network signal addressed to the adjacent monitoring control device 210 to the transceiver unit 225 and instructs the transmission.

[0062] The transmitting / receiving unit 225 is, for example, an optical transceiver (TRx). The transmitting / receiving unit 225 inputs a network signal transmitted by the adjacent monitoring control device 210 from the optical transmission path 161, converts the input network signal from an optical signal to an electrical signal, and outputs the converted signal to the destination identification unit 226. The transmitting / receiving unit 225 also converts a network signal addressed to the monitoring control device 210 from an electrical signal to an optical signal, and outputs the converted signal to the optical transmission path 161.

[0063] The destination identification unit 226 reads out destination information set in the network signal. When the destination identification unit 226 determines that the destination information is addressed to the own device or the adjacent monitoring control device 210, it outputs the network signal to the data identification unit 227. The destination identification unit 226 stores destination information of the adjacent monitoring control device 210 in advance. When the destination information of the network signal output from the transmission / reception unit 225 is not addressed to the own device, the destination identification unit 226 outputs the received network signal to the transmission control unit 224. When the destination information of the network signal output from the transmission / reception unit 125 is neither addressed to the own device nor to the adjacent monitoring control device 210, the destination identification unit 226 discards the received network signal.

[0064] The data distinguishing unit 227 reads out data type information set in the network signal. If the data type information indicates a report instruction or quality measurement, the data distinguishing unit 227 outputs the received network signal to the information reporting unit 223. If the data type information indicates a quality measurement result, the data distinguishing unit 227 outputs the network signal to the quality measuring unit 222. If the data type information indicates quality information, the data distinguishing unit 227 outputs the received network signal to the transmitting / receiving unit 225. If the data type information indicates transmission control information, the data distinguishing unit 227 outputs the network signal to the transmission control unit 224.

[0065] As in the first embodiment, an optical filter may be provided between the coupler 126-i and the transceiver 125-i. The optical filter removes signals in unnecessary frequency bands. The communication device 120 may use an in-line modulator instead of the coupler 126-i and the transceiver 125-i.

[0066] In addition, instructions and reports between the information collecting unit 211 of the monitoring control device 210 and the information reporting unit 223 of the communication device 220a may be of a poll / report type such as SNMP (Simple Network Management Protocol) or of a pub / sub type such as Telemetry. In addition, transmission and reception of network signals between the monitoring control device 210 and the communication device 220a may be either an in-band method or an out-of-band method since there is no transmission and reception of user data. In addition, the monitoring control device 210 and the communication device 220a may be integrated into a single communication device. In this case, the integrated communication device does not have the transmitting / receiving unit 212 and the transmitting / receiving unit 225, and the information collecting unit 211 may directly transmit and receive data to and from the transmission control unit 224 and the data identifying unit 227.

[0067] Fig. 11 is a block diagram showing a configuration example of a communication device 220b. In the communication device 220b shown in Fig. 11, the same parts as those of the communication device 220a of the first embodiment shown in Fig. 10 are given the same reference numerals, and the description thereof will be omitted. The communication device 220b differs from the communication device 220a in that it does not include a transmission / reception unit 225, that it includes a destination identification unit 228 instead of the destination identification unit 226, and that it includes a data identification unit 229 instead of the data identification unit 227.

[0068] The destination identification unit 228 reads out destination information set in a network signal received from the transmission / reception unit 125. If the destination identification unit 228 determines that the destination information indicates a destination for its own device, it outputs the network signal to the data identification unit 229. If the destination identification unit 228 determines that the destination information does not indicate a destination for its own device, it discards the received network signal.

[0069] When data type information set in a received network signal indicates a report instruction or quality measurement, the data distinguishing unit 229 outputs the network signal to the information reporting unit 223. When the data type information indicates a quality measurement result, the data distinguishing unit 229 outputs the network signal to the quality measuring unit 222. When the data type information indicates transmission control information, the data distinguishing unit 229 outputs the network signal to the transmission control unit 224.

[0070] 12 is a flow diagram showing a network signal transmission / reception process in the monitoring control device 210. The information collecting unit 211 of the monitoring control device 210 generates a network signal that is a report instruction or a transmission control information notification addressed to the communication device 220, and outputs the generated network signal to the transmitting / receiving unit 212. The transmitting / receiving unit 212 converts the network signal into an optical signal and transmits it to the communication device 220a connected to the own device via the optical transmission path 161 (step S301). When the transmitting / receiving unit 212 receives a network signal from the communication device 220a via the optical transmission path 161 (step S302), it converts the received network signal from an optical signal to an electrical signal and outputs it to the information collecting unit 211 (step S303). The received network signal is a quality information report returned from the communication device 220 in response to the report instruction.

[0071] 13 is a flow diagram showing a network signal transmission process in the communication device 220. The quality measurement unit 222 generates a quality measurement signal addressed to another communication device 220, and outputs the generated quality measurement signal to the transmission control unit 224 (step S401). The transmission control unit 224 determines the transmission time of the quality measurement signal, and the channel and the transmission / reception unit 125 used for transmission in the same manner as in step S102 in the first embodiment (step S402). The transmission control unit 224 outputs the quality measurement signal to the determined transmission / reception unit 125-i, and further indicates the determined transmission time and channel. The transmission / reception unit 125-i and the coupler 126-i output the quality measurement signal to the optical transmission path 160 by the same process as in step S103 in the first embodiment (step S403).

[0072] Fig. 14 is a flow diagram showing a network signal reception process in the communication device 220a. The transmission / reception unit 225 of the communication device 220a receives the network signal transmitted from the monitoring control device 210 in step S301 of Fig. 12 (step S501: YES). The transmission / reception unit 225 converts the network signal into an electrical signal and outputs it to the destination identification unit 226. The destination identification unit 226 judges whether the destination of the network signal is the own device (step S502). If the destination identification unit 226 judges that the destination is the own device (step S502: YES), it outputs the network signal to the data identification unit 227. If the destination identification unit 226 judges that the destination is not the own device (step S502: NO), it outputs the network signal to the transmission control unit 224.

[0073] On the other hand, when the transmitting / receiving unit 125 of the communication device 220a receives a network signal (step S501: NO), it converts the network signal into an electrical signal and outputs it to the destination identification unit 226. When the destination is addressed to the device itself or to the adjacent monitoring control device 210 (step S503: YES), the destination identification unit 226 outputs the received network signal to the data identification unit 227.

[0074] If the answer is YES in step S502 or YES in step S503, the data identification unit 227 determines the data type information set in the network signal (step S504). If the data type information indicates transmission control information, the data identification unit 227 determines that the received network signal is a transmission control information notification from the monitoring control device 210 addressed to the device itself. The data identification unit 227 outputs the transmission control information notification to the transmission control unit 224 (step S505). The transmission control unit 224 stores the transmission control information set in the received transmission control information notification.

[0075] When the data type information indicates a report instruction, the data identification unit 227 judges that the received network signal is a report instruction received from an adjacent monitoring control device 210 or a report instruction transmitted from a monitoring control device 210 not adjacent to the own device via another communication device 220. The data identification unit 227 outputs the report instruction to the information reporting unit 223. The information reporting unit 223 reads out the measurement result of the network quality requested by the quality measurement signal from the quality information storage unit 221. The information reporting unit 223 generates a quality information report in which destination information indicating the monitoring control device 210 that is the transmission source of the quality measurement signal, transmission source information indicating the own device, data type information indicating a quality information report, and quality information indicating the read measurement result are set (step S506). The information reporting unit 223 outputs the generated quality information report to the transmission control unit 224.

[0076] In step S504, when the data type information indicates quality measurement, the data identification unit 227 determines that the received network signal is a quality measurement signal transmitted from another communication device 220. The data identification unit 227 outputs the received quality measurement signal to the information reporting unit 223. The information reporting unit 223 reads out a measurement result of the network quality corresponding to the quality measurement signal from the quality information storage unit 221. The information reporting unit 223 generates a quality measurement result notification in which destination information indicating the communication device 220 that is the transmission source of the quality measurement signal, source information indicating the own device, data type information indicating the quality measurement result, and quality measurement result information indicating the read measurement result are set (step S507). The information reporting unit 223 outputs the generated quality measurement result notification to the transmission control unit 224.

[0077] After the process of step S506 or step S507, the transmission control unit 224 judges whether the destination of the network signal to be transmitted is the adjacent monitoring control device 210 (step S508). The network signal to be transmitted is the quality information report generated in step S506 or the quality measurement result notification generated in step S507. When the transmission control unit 224 judges that the destination is the adjacent monitoring control device 210 (step S508: YES), it outputs the network signal to the transmitting / receiving unit 225.

[0078] The transmitting / receiving unit 225 converts the network signal to be transmitted from an electrical signal to an optical signal, and transmits it to the monitoring control device 210 via the optical transmission path 161 (step S509). The transmitting / receiving unit 212 of the monitoring control device 210 performs the processes of steps S302 to S303 in FIG. 12, converts the network signal received from the communication device 220a from an optical signal to an electrical signal, and outputs it to the information collecting unit 211.

[0079] When the transmission control unit 224 determines that the destination of the network signal to be transmitted is not the neighbor monitoring control device 210 of the own device (step S508: NO), or when the determination is NO in step S502, the transmission control unit 224 performs the process of step S510. That is, the transmission control unit 224 determines the transmission time of the network signal, and the channel and the transmitting / receiving unit 125 to be used for transmission by the same process as step S102 in FIG. 6 (step S510). Note that, when the network signal to be transmitted is a quality measurement result notification, the transmission control unit 224 may select the transmitting / receiving unit 125-i that received the quality measurement signal. The transmission control unit 224 outputs the network signal to the determined transmitting / receiving unit 125-i, and further indicates the determined transmission time and channel. The transmitting / receiving unit 125-i converts the network signal from an electrical signal to an optical signal of a wavelength used for the indicated channel by the same process as step S103 in FIG. 6, and outputs the network signal to the coupler 126-i at the indicated transmission time. The coupler 126-i couples the network signal to the optical transmission line 160 (step S511).

[0080] If the data discrimination unit 227 determines in step S504 that the data type information indicates quality information, it determines that the received network signal is a quality information report from another communication device 220 addressed to the adjacent monitoring control device 210. The data discrimination unit 227 outputs the quality information report to the transmission / reception unit 225. The transmission / reception unit 225 converts the quality information report from an electrical signal to an optical signal, and transmits it to the adjacent monitoring control device 210 via the optical transmission path 161 (step S509). The transmission / reception unit 212 of the monitoring control device 210 performs the processes of steps S302 to S303 in FIG. 12, converts the received network signal from an optical signal to an electrical signal, and outputs it to the information collection unit 211.

[0081] In step S504, if the data identifying unit 227 determines that the type of data is a quality measurement result, it determines that the received network signal is a quality measurement result notification returned from another communication device 220 in response to the quality measurement signal transmitted by its own device. The data identifying unit 227 outputs the quality measurement result notification to the quality measuring unit 222 (step S512). The quality measuring unit 222 acquires the measurement result of the network quality in the other communication device 220 from the quality measurement result notification, and stores the acquired measurement result in the quality information storage unit 221.

[0082] In addition, in step S503, if the destination identification unit 226 determines that the destination information is not addressed to the own device or the adjacent monitoring control device 210, but to another communication device 220 (step S503: NO), it discards the received network signal (step S513).

[0083] In step S506, when the information reporting unit 223 receives a report instruction from the monitoring control device 210, the information reporting unit 223 may instruct the quality measuring unit 222 to measure quality. After the quality measuring unit 222 finishes the quality measurement, the information reporting unit 223 reads out the measurement result to be set in the quality information report from the quality information storage unit 221. Furthermore, when the quality measuring unit 222 is instructed to measure quality from the information reporting unit 223, the quality measuring unit 222 may transmit a quality measurement signal to another communication device 220. The information reporting unit 223 reads out the measurement result to be set in the quality information report after the quality measuring unit 222 writes the measurement result of the network quality in the quality information storage unit 221 based on the quality measurement result notification returned by the quality measuring unit 222.

[0084] The network signal reception process of the communication device 220b is similar to the network signal reception process of the communication device 220a shown in Fig. 14. However, in step S501, the transmitting / receiving unit 225 of the communication device 220b always judges NO, and in step S508, the transmission control unit 224 of the communication device 220b judges NO. In addition, the communication device 220b does not have an adjacent monitoring control device 210. Therefore, the communication device 220b may execute the process of step S503 without executing the processes of steps S501 to S502, and may execute the process from step S510 after the process of step S506 or step S507 without executing the processes of steps S508 to S509. In addition, in step S503, when the destination identification unit 228 judges that the destination information does not indicate the destination of the device itself, the destination identification unit 228 executes the process of step S513.

[0085] The monitor and control device 210 may be connected to a demultiplexer as shown in Fig. 15. The demultiplexer is a device that separates in-band user data from out-of-band network signals.

[0086] FIG. 15 is a diagram showing a configuration example of a communication system 202 according to the second embodiment. In the communication system 202 shown in FIG. 15, the same parts as those in the communication system 201 shown in FIG. 9 are denoted by the same reference numerals, and their description will be omitted. The communication system 202 includes a monitor control device 210, communication devices 220-1 to 220-N, and a demultiplexer 240. The communication devices 220-1 to 220-N in the communication system 202 are the communication device 220b shown in FIG. 11. The communication system 202 includes a communication network including the monitor control device 210 and the communication devices 220-1 to 220-N connected in cascade. The demultiplexer 240 is provided between two communication devices 220. The monitor control device 210 is connected to the demultiplexer 240 by an optical transmission path 161.

[0087] 16 is a block diagram showing a configuration example of the demultiplexer 240. In FIG. 16, only functional blocks related to this embodiment are extracted and shown. In the demultiplexer 240 shown in FIG. 16, the same parts as those in the communication device 220a shown in FIG. 10 are given the same reference numerals, and the description thereof will be omitted. The demultiplexer 240 has a transmission control unit 224, a transceiver unit 125-1, a transceiver unit 125-2, a coupler 126-1, a coupler 126-2, a transceiver unit 225, a destination identification unit 226, and a data identification unit 241.

[0088] The data distinguishing unit 241 reads out data type information set in the network signal. If the data type information indicates transmission control information, the data distinguishing unit 241 outputs the received network signal to the transmission control unit 224. If the data type information indicates quality information, the data distinguishing unit 241 outputs the received network signal to the transmission / reception unit 225.

[0089] Fig. 17 is a flow diagram showing network signal reception processing in the demultiplexer 240. In the flow diagram shown in Fig. 17, the same processes as those in Fig. 14 are given the same reference numerals, and detailed description thereof will be omitted.

[0090] The transmitter / receiver 225 of the demultiplexer 240 converts the network signal received from the monitor and control device 210 from an optical signal to an electrical signal and outputs the signal to the destination identification unit 226 (step S501: YES). If the destination identification unit 226 determines that the destination is its own device, it outputs the network signal to the data identification unit 241 (step S502: YES), and if it determines that the destination is not its own device, it outputs the network signal to the transmission control unit 224 (step S502: NO).

[0091] Furthermore, the transmitting / receiving unit 125 of the separation device 240 converts the received network signal into an electrical signal and outputs it to the destination identification unit 226 (step S501: NO). When the destination identification unit 226 determines that the destination is the own device or the adjacent monitoring control device 210 that is the monitoring control device 210 connected to the own device (step S503: YES), it outputs the network signal to the data identification unit 241.

[0092] If the determination in step S502 is YES, or if the determination in step S503 is YES, the data identification unit 241 determines the data type information set in the network signal (step S601). If the data type information indicates transmission control information, the data identification unit 241 determines that the received network signal is a transmission control information notification addressed to the device itself from a monitoring control device 210 connected to an adjacent monitoring control device 210 or another demultiplexer 240. The data identification unit 241 outputs the transmission control information notification to the transmission control unit 224 (step S602). The transmission control unit 224 stores the transmission control information set in the received transmission control information notification.

[0093] When the data discrimination unit 241 determines that the data type information indicates quality information, it determines that the received network signal is a quality information report from the communication device 220 to the adjacent monitoring control device 210. The data discrimination unit 241 outputs the quality information report to the transmission / reception unit 225. The transmission / reception unit 225 converts the quality information report from an electrical signal to an optical signal, and transmits it to the adjacent monitoring control device 210 via the optical transmission path 161 (step S603). The transmission / reception unit 212 of the monitoring control device 210 performs the processes of steps S302 to S303 in FIG. 12, converts the received quality information report from an optical signal to an electrical signal, and outputs it to the information collection unit 211.

[0094] If the result of the determination in step S502 is NO, the demultiplexer 240 performs the same processes as steps S103 and S104 in FIG. 6, and transmits the network signal received from the adjacent monitoring control device 210 to the optical transmission path 160 (steps S510 and S511).

[0095] Furthermore, in step S503, if the destination identification unit 226 determines that the destination information is neither addressed to the own device nor to the adjacent monitoring control device 210 (step S503: NO), it discards the received network signal (step S513).

[0096] The monitor and control device may be connected to a distribution device as shown in Figure 18. A distribution device is a device that copies signals transmitted through a network, both in-band and out-of-band.

[0097] 18 is a diagram showing a configuration example of a communication system 203. In the communication system 203 shown in FIG. 18, the same components as those in the communication system 202 shown in FIG. 15 are denoted by the same reference numerals, and their description will be omitted. The communication system 203 has a monitor control device 250, communication devices 220-1 to 220-N, and a distribution device 260. The communication devices 220-1 to 220-N in the communication system 203 are the communication device 220b shown in FIG. 11. The distribution device 260 is provided between two communication devices 220. The monitor control device 250 is connected to the distribution device 260 by an optical transmission path 161.

[0098] Fig. 19 is a block diagram showing a configuration example of the monitoring control device 250 and the distribution device 260. In Fig. 19, only functional blocks related to this embodiment are extracted and shown. In the monitoring control device 250 and the distribution device 260 shown in Fig. 19, the same parts as those of the monitoring control device 210 and the communication device 220a shown in Fig. 10 are given the same reference numerals, and the description thereof will be omitted.

[0099] The monitoring control device 250 includes an information collecting unit 211, a transmission control unit 251, a destination identifying unit 252, a transmitting / receiving unit 125-1, and a transmitting / receiving unit 125-2. The transmission control unit 251 controls the transmitting / receiving unit 125 to transmit a network signal such as a report instruction or a transmission control information notification output by the information collecting unit 211 to the destination communication device 220 in an out-of-band manner. The transmission control unit 251 determines a transmission timing and a frequency when transmitting a network signal in an out-of-band manner, similar to the transmission control unit 224 of the communication device 220, and instructs the transmitting / receiving unit 125. When the destination information set in the received network signal indicates that the network signal is addressed to the device itself, the destination identifying unit 252 outputs the network signal to the information collecting unit 211, and when the destination information is not addressed to the device itself, the destination identifying unit 252 discards the received network signal.

[0100] The distribution device 260 has a coupler 126-1 and a coupler 126-2. An optical filter for removing signals in unnecessary frequency bands may be provided between the coupler 126-i of the distribution device 260 and the transmitting / receiving unit 125-i of the monitor and control device 250. The distribution device 260 may multiplex in an out-of-band system using an in-line modulator instead of the coupler 126-i and the transmitting / receiving unit 125-i.

[0101] 20 is a flow diagram showing network signal transmission and reception processing in the monitoring control device 250. The information collection unit 211 of the monitoring control device 250 generates a network signal that is a report instruction or a transmission control information notification addressed to the communication device 220, and outputs the generated network signal to the transmission control unit 251 (step S701).

[0102] 6, and determines the transmission time of the network signal, and the channel and the transceiver 125 to be used for the transmission (step S702). The transmission control unit 251 outputs the network signal to the transceiver 125-i to be used for the transmission, and further indicates the determined transmission time and channel.

[0103] The transmitting / receiving unit 125-i converts the network signal from an electrical signal to an optical signal with a wavelength used for the specified channel. The transmitting / receiving unit 125-i outputs the information measurement signal converted into an optical signal to the coupler 126-i of the distribution device 260 at the specified transmission time. The coupler 126-i couples the information measurement signal output by the transmitting / receiving unit 125-i of the monitor and control device 250 to the optical transmission path 160 (step S703).

[0104] The coupler 126-1 and the coupler 126-2 of the distribution device 260 branch the optical signal transmitted through the optical transmission path 160. The coupler 126-i outputs the branched optical signal to the transmitting / receiving unit 125-i of the monitoring control device 250. The transmitting / receiving unit 125-i receives the optical signal branched by the coupler 126-i. The transmitting / receiving unit 125-i separates the network signal transmitted in an out-of-band manner from the optical signal and converts it into an electrical signal. If the transmitting / receiving unit 125-i does not obtain the network signal (step S704: NO), the monitoring control device 250 ends the process of FIG. 20. If the transmitting / receiving unit 125-i obtains the network signal (step S704: YES), it outputs the network signal converted into an electrical signal to the destination identification unit 252.

[0105] The destination identification unit 252 reads out destination information set in the network signal. The destination identification unit 252 judges whether the destination information indicates its own device (step S705). If the destination information indicates its own device, the network signal is a quality information report. If the destination identification unit 252 judges that the network signal is addressed to its own device (step S705: YES), it outputs the received network signal to the information collection unit 211 (step S706). If the destination identification unit 252 judges that the network signal is not addressed to its own device (step S705: NO), it discards the received network signal (step S707).

[0106] According to this embodiment, the communication system transmits and receives report instructions and quality measurements using an out-of-band method, making it possible to measure quality and report quality even when in-band communication is not established.

[0107] (Third embodiment) In the third embodiment, the monitoring and control device applies the second embodiment to collect quality information before establishing a main signal connection, and determines a communication path to be used for the main signal based on the collected quality information.

[0108] FIG. 21 is a diagram showing a configuration of a communication system 300. The communication system 300 includes a monitoring control device 310 and four communication devices 320 connected in a ring shape. The communication devices 320 are connected to adjacent communication devices 320 via optical transmission paths 360. The four communication devices 320 are referred to as communication devices 320-1 to 320-4. The monitoring control device 310 is connected to some of the communication devices 320-1 to 320-N via optical transmission paths. The monitoring control device 310 has the function of the monitoring control device 210 in the second embodiment. The communication device 320 connected to the monitoring control device 310 has the function of the communication device 220a in the second embodiment, and the communication device 320 not connected to the monitoring control device 310 has the function of the communication device 220b in the second embodiment.

[0109] Alternatively, the monitoring control device 310 is connected to a demultiplexer 240 or a distribution device 260 (not shown) provided on the optical transmission path 360. When the monitoring control device 310 is connected to the demultiplexer 240, the monitoring control device 310 has the function of the monitoring control device 210 in the second embodiment, and the communication device 320 has the function of the communication device 220b in the second embodiment. When the monitoring control device 310 is connected to the distribution device 260, the monitoring control device 310 has the function of the monitoring control device 250 in the second embodiment, and the communication device 320 has the function of the communication device 220b in the second embodiment.

[0110] The communication device 320-1 and the communication device 320-3 are each connected to the user device 140 by an optical transmission path 361. The user device 140 connected to the communication device 320-1 is referred to as user device A, and the user device 140 connected to the communication device 320-3 is referred to as user device B.

[0111] 22 is a diagram showing a configuration related to an optical switch function of the communication device 320. The communication device 320 has an optical branching unit 321, a wavelength multiplexing / demultiplexing unit 322, an access system management control unit 323, an amplifier 324, and an amplifier 325. The two wavelength multiplexing / demultiplexing units 322 included in the communication device 320 are respectively described as a wavelength multiplexing / demultiplexing unit 322-1 and a wavelength multiplexing / demultiplexing unit 322-2.

[0112] The optical branching unit 321 has a plurality of input / output ports (not shown). The optical branching unit 321 outputs an optical signal input from one input / output port from another input / output port. The connection relationship between the input / output ports can be changed by an instruction from the monitoring control device 310. Some of the input / output ports of the optical branching unit 321 are connected to the user device 140 via an optical transmission path 361. Other of the input / output ports of the optical branching unit 321 are connected to the wavelength multiplexing / demultiplexing unit 322-1 via an optical transmission path 363, and still other of the input / output ports are connected to the wavelength multiplexing / demultiplexing unit 322-2 via the optical transmission path 363. In addition, one of the input / output ports is connected to the access system management control unit 323 via the optical transmission path 363.

[0113] The wavelength multiplexing / demultiplexing unit 322 has a plurality of first ports (not shown) and one second port (not shown). The plurality of first ports correspond to different wavelengths. The first ports of the wavelength multiplexing / demultiplexing unit 322 respectively correspond to different wavelengths λ 1 ~λ p (p is an integer of 2 or more) via an optical transmission path 363. The second port of the wavelength multiplexing / demultiplexing unit 322 is connected to another communication device 320 via an optical transmission path 360. The wavelength multiplexing / demultiplexing unit 322 multiplexes light of different wavelengths input from the first port and outputs the light from the second port. The wavelength multiplexing / demultiplexing unit 322 also separates the wavelength-multiplexed light input from the second port by wavelength and outputs the separated light from the second port according to the wavelength. In the case of the communication device 320-1, the second port of the wavelength multiplexing / demultiplexing unit 322-1 is connected to the optical transmission path 360 between the communication device 320-2 and the communication device 320-3, and the second port of the wavelength multiplexing / demultiplexing unit 322-2 is connected to the optical transmission path 360 between the communication device 320-4 and the communication device 320-5.

[0114] The amplifier 324 is provided on the optical transmission line 361, and the amplifier 325 is provided on the optical transmission line 363. The amplifier 324 and the amplifier 325 are, for example, variable attenuators (ATTs). The amplifier 324 amplifies the light transmitted through the optical transmission line 361. Furthermore, the amplifier 325 amplifies the light transmitted through the optical transmission line 363.

[0115] FIG. 23 is a diagram showing an example of quality information. The quality information indicates the latency and reception level measured in each communication device 320. The communication device 320-1 measures the latency and reception level between the communication device 320-1 and user device A as quality qA1. The communication device 320-2 measures the latency and reception level between the communication device 320-2 and the communication device 320-1 as quality q12, and measures the latency and reception level between the communication device 320-2 and the communication device 320-3 as quality q23. The communication device 320-3 measures the latency and reception level between the communication device 320-3 and user device B as quality qB3. The communication device 320-4 measures the latency and reception level between the communication device 320-4 and the communication device 320-1 as quality q14, and measures the latency and reception level between the communication device 320-4 and the communication device 320-3 as quality q34. Note that the quality information measured by the communication device 320 may include bandwidth information such as a communication bandwidth, a switching bandwidth, and a computing processing bandwidth.

[0116] Next, the operation of the communication system 300 shown in FIG. 21 will be described. The communication system 300 performs an initial connection procedure as described in Reference 2 "Kaneko Shin, Hara Kazutaka, Kani Junichi, Seki Tsuyoshi, Kawahara Mitsutaka, Miyamura Takashi, Maeda Hideki", "New System Architecture for Realizing All-Photonics Networks", Journal of the Institute of Electronics, Information and Communication Engineers, Vol. 104, No. 4, FIG. 4, 2021, p. 474". In this initial setting procedure, the monitoring control device 310 of the communication system 300 collects quality information from each communication device 320 using AMCC, triggered by the device information report. The monitoring control device 310 determines a communication path between user device A and user device B using the collected quality information. Note that the communication system 300 may collect quality information before the device information report. For example, the communication system 300 may collect quality information by a trigger from the monitoring control device 310. The monitoring control device 310 sets the determined communication path as an optical path setting in the communication device 320. The features of this embodiment will be described below.

[0117] First, user device A transmits a new connection request. For example, the new connection request requests communication between user device A and user device B. The optical splitter 321 of the communication device 320-1 outputs the new connection request transmitted by user device A to the access system management control unit 323. The access system management control unit 323 outputs the received new connection request to the monitoring control device 310.

[0118] When the monitoring control device 310 receives a new connection request, it transmits a report instruction of an AMCC signal to each communication device 320 in order to select an appropriate communication path that satisfies the end-to-end service request. The communication device 320-1 transmits quality information Q1 in which quality qA1 is set to the monitoring control device 310 as a quality information report. The communication device 320-2 transmits quality information Q2 in which quality q12 and quality q23 are set to the monitoring control device 310 as a quality information report. The communication device 320-3 transmits quality information Q3 in which quality qB3 is set to the monitoring control device 310 as a quality information report. The communication device 320-4 transmits quality information Q4 in which quality q14 and quality q34 are set to the monitoring control device 310 as a quality information report.

[0119] The monitoring control device 310 calculates quality information between the communication devices 320, between the user device A and the communication device 320-1, and between the user device B and the communication device 320-3, based on the quality information Q1 to Q4 reported by the quality information report transmitted by each communication device 320. The monitoring control device 310 selects an appropriate end-to-end communication path based on the calculation result of the quality information. The monitoring control device 310 generates route information for transferring user data through the selected communication path. The monitoring control device 310 transmits a transmission control information notification in which the route information Pn in the communication device 320-n is set, to the communication device 320-n. Alternatively, the monitoring control device 310 may transmit a transmission control information notification in which the route information of all the communication devices 320 is set, by multicast or broadcast. The optical branching unit 321 of each communication device 320 routes an optical signal in which user data is set between the user device A and the user device B according to the route information Pn set in the transmission control information notification.

[0120] When selecting an appropriate communication path as described above, the monitoring control device 310 judges whether the end-to-end quality satisfies the service requirements, etc. for each possible combination of communication paths based on the latency indicated by the quality information Q1 to Q4 received from each communication device 320. In the case of FIG. 21, there are two types of communication paths: a first communication path that passes through user device A, communication device 320-1, communication device 320-2, communication device 320-3, and user device B in this order, and a second communication path that passes through user device A, communication device 320-1, communication device 320-4, communication device 320-3, and user device B in this order. The monitoring control device 310 judges whether the end-to-end quality satisfies the service requirements, etc. for each of the first communication path and the second communication path.

[0121] For example, the service requirement is a latency of 100 msec (milliseconds). If the latency of the first communication path is 80 msec and the latency of the second communication path is 150 msec, the monitoring control device 310 selects the first communication path as an appropriate communication path. Also, for example, there may be a case where the latency of the second communication path is 100 msec and both the first and second communication paths satisfy the service requirement. In this case, the monitoring control device 210 selects one of them according to a predefined policy, such as selecting the one with higher quality.

[0122] Furthermore, the monitoring control device 310 adjusts the amplifiers 324, 325 in each communication device 320 so as to satisfy the system requirements. For example, the monitoring control device 310 judges whether the receiving input level of the optical signal is within the range of the allowable receiving input level based on the receiving levels indicated by the received quality information Q1 to Q4. If it exceeds the upper limit of the allowable receiving input level, the monitoring control device 310 adjusts the amplifiers 324, 325 in the communication device 320 so that the receiving input level of the optical signal falls within the range of the allowable receiving input level. Conversely, if the receiving input level of the optical signal falls below the lower limit of the allowable receiving input level, the monitoring control device 310 adjusts the amplifiers 324, 325 in the communication device 320 so that it falls within the range of the allowable receiving input level.

[0123] Once a communication path is set, it may be fixed without being changed, but the monitoring and controlling device 310 may periodically measure and learn quality information using network signals during operation of the system. This allows the monitoring and controlling device 310 to dynamically change to a communication path of higher quality. For example, if multiple communication paths are accommodated in the same communication device 320, and if some tendency is observed in the change in quality information due to temporal fluctuations, it is possible to dynamically change to an appropriate communication path that takes into account the temporal fluctuations. However, the monitoring and controlling device 310 changes the communication path at a timing when communication of the main signal does not occur, etc.

[0124] 24 is a diagram showing an example of the hardware configuration of the communication device 120. The communication device 120 includes a processor 701, a storage unit 702, a communication interface 703, and a user interface 704.

[0125] The processor 701 is a central processing unit that performs calculations and control. The processor 701 is, for example, a CPU (central processing unit). The storage unit 702 is a storage device such as various memories and a hard disk. The processor 701 reads out and executes a program from the storage unit 702, thereby realizing the information measurement unit 122, the measurement response unit 123, the transmission control unit 124, the destination identification unit 127, and the data identification unit 128. Some of the functions of the information measurement unit 122, the measurement response unit 123, the transmission control unit 124, the destination identification unit 127, and the data identification unit 128 may be realized using hardware such as an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array). The storage unit 702 further has a work area when the processor 701 executes various programs. The communication interface 703 is connected to other devices so as to be able to communicate with them. The communication interface 703 corresponds to the transmission / reception unit 125 and the coupler 126. The user interface 704 is an input device such as a keyboard, a pointing device (mouse, tablet, etc.), a button, a touch panel, etc., and a display device such as a display. Human operations are input through the user interface 704.

[0126] The hardware configuration of the communication device 220a is also similar to that shown in Fig. 24. The processor 701 reads out and executes a program from the storage unit 702, thereby realizing the quality measurement unit 222, the information reporting unit 223, the transmission control unit 224, the destination identification unit 226, and the data identification unit 227. The communication interface 703 corresponds to the transmitting / receiving unit 125, the coupler 126, and the transmitting / receiving unit 225.

[0127] The hardware configuration of the communication device 220b is also similar to that shown in Fig. 24. The processor 701 reads out and executes a program from the storage unit 702 to realize the quality measurement unit 222, the information reporting unit 223, the transmission control unit 224, the destination identification unit 228, and the data identification unit 229. The communication interface 703 corresponds to the transmission / reception unit 125 and the coupler 126.

[0128] The hardware configuration of the monitoring and controlling device 210 is also the same as that shown in Fig. 24. The processor 701 reads out and executes a program from the storage unit 702, thereby implementing the information collecting unit 211. The communication interface 703 corresponds to the transmitting and receiving unit 212.

[0129] The hardware configuration of the monitoring control device 250 is also the same as that shown in Fig. 24. The processor 701 reads out and executes a program from the storage unit 702, thereby realizing the information collection unit 211, the transmission control unit 251, and the destination identification unit 252. The communication interface 703 corresponds to the transmission / reception unit 125.

[0130] The hardware configuration of the demultiplexer 240 is also the same as that shown in Fig. 24. The processor 701 reads out and executes a program from the storage unit 702, thereby realizing the transmission control unit 224, the destination identification unit 226, and the data identification unit 241. The communication interface 703 corresponds to the transmitting / receiving unit 125, the coupler 126, and the transmitting / receiving unit 225.

[0131] According to the above-described embodiment, the communication system is capable of transmitting and receiving information between network devices, regardless of the protocol of the user data, while reducing the impact on the quality of the user data.

[0132] According to the above-mentioned embodiment, the communication network that transfers user data has a plurality of network devices. The network devices have an acquisition unit, an identification unit, and a transmission unit. For example, the network devices correspond to the communication device 120 and the monitoring control device 250 of the embodiment, the acquisition unit and the transmission unit correspond to the transmission / reception unit 125 of the embodiment, and the identification unit corresponds to the destination identification units 127 and 252 of the embodiment. The acquisition unit acquires network device data, which is data that is superimposed on user data out-of-band and exchanged between network devices, from data obtained by branching or copying data transmitted through a transmission path of the communication network. The identification unit outputs the acquired data, which is the network device data acquired by the acquisition unit, to a processing unit that performs a predetermined process when the destination of the acquired data is the own device, and discards the acquired data when the destination is not the own device. The transmission unit superimposes network device data addressed to another network device from the own device out-of-band on user data transmitted through a transmission path.

[0133] The network device may further include a receiving unit for receiving network-to-device data transmitted by an adjacent network device that is connected to the network device itself and does not transfer user data. For example, the network device corresponds to the communication device 220a in the embodiment, the receiving unit corresponds to the transmitting / receiving unit 225 in the embodiment, and the adjacent network device corresponds to the monitoring control device 210. When the destination of the network-to-device data received by the receiving unit is the network device itself, the identifying unit outputs the network-to-device data received by the receiving unit to a processing unit that performs a predetermined process. When the destination of the network-to-device data received by the receiving unit is another network device, the transmitting unit superimposes the network-to-device data received by the receiving unit on user data transmitted through the transmission path out-of-band.

[0134] The identification unit determines whether the destination of the acquired data is an adjacent network device, and discards the acquired data when the destination of the acquired data is neither the adjacent network device nor the device itself. The transmission unit outputs the acquired data to the adjacent network device when the destination of the acquired data is the adjacent network device.

[0135] The transmitting unit may superimpose the data between the network devices on user data transmitted through the transmission path by out-of-band transmission using a transmission timing or frequency different from that of other data between the network devices. Also, the transmission path may transmit an optical signal.

[0136] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and designs that do not deviate from the gist of the present invention are also included. [Explanation of symbols]

[0137] 101, 102 Communication systems 120, 120-1~120-N, 180-1~180-N Communication equipment 121 Information Storage Department 122 Information Measurement Department 123 Measurement response unit 124 Transmission control section 125-1, 125-2 Transmitter / Receiver 126-1, 126-2 Coupler 127 Destination Identification Part 128 Data Identification Section 140 User device 160, 161 Optical transmission line 190-1, 190-2 Control device 201, 202, 203 Communication Systems 210 Monitoring and control equipment 211 Information Gathering Department 212 Transmitter / receiver 220-1~220-N, 220a, 220b Communication equipment 221 Quality Information Storage Department 222 Quality Measurement Department 223 Information Reporting Department 224 Transmission control section 225 Transmitter / Receiver 226, 228 Destination Identification Part 227, 229 Data Identification Section 240 Separation equipment 241 Data Identification Unit 250 Monitoring and control equipment 251 Transmission control section 252 Destination Identification Part 260 Distribution device 300 Communication Systems 310 Monitoring and control equipment 320-1~320-4 Communication equipment 321 Optical branching unit 322-1, 322-2 Wavelength multiplexing / demultiplexing section 323 Access System Management Control Unit 324, 325 Amplifier 360, 361, 363 Optical transmission line 701 Processor 702 Storage section 703 Communication Interface 704 User Interface

Claims

1. A network device included in a communication network that transfers user data, an acquisition unit that acquires data between network devices, which is superimposed on user data out-of-band and is exchanged between network devices included in the communication network, from data obtained by branching or copying data transmitted through a transmission path of the communication network; a receiving unit for receiving data between network devices transmitted from an adjacent network device which is another network device connected to the own device and does not transfer user data; an identification unit that performs a process of outputting the acquired data, which is the network device data acquired by the acquisition unit, to a processing unit that performs a predetermined processing when the destination of the acquired data is the own device, and discarding the acquired data when the destination is not the own device, and a process of outputting the network device data received by the receiving unit to a processing unit that performs a predetermined processing when the destination of the network device data received by the receiving unit is the own device; a transmitting unit which performs a process of superimposing, by out-of-band, inter-network device data addressed from the device itself to another network device on user data transmitted over the transmission path, a process of superimposing, by out-of-band, the inter-network device data received by the receiving unit on user data transmitted over the transmission path when the destination of the inter-network device data received by the receiving unit is the other network device, and a process of outputting, to the adjacent network device, the acquired data or the inter-network device data generated by the device itself, when the destination of the acquired data or the inter-network device data generated by the device itself is the adjacent network device; Equipped with the own device is a communication device that transfers user data transmitted through the transmission path, the adjacent network device is a monitoring and control device that monitors or controls the communication network, the acquired data or the data between network devices that is output to the adjacent network device includes information on communication quality of the communication network; the data between network devices transmitted by the adjacent network device includes information on a communication path in the communication network determined by the adjacent network device based on information on communication quality; Network device.

2. the identification unit determines whether the destination of the acquired data is the adjacent network device, and discards the acquired data when the destination of the acquired data is neither the adjacent network device nor the device itself. The network device according to claim 1 .

3. the transmitting unit superimposes the data between the network devices on user data transmitted through the transmission path by out-of-band transmission using a transmission timing or frequency different from that of other data between the network devices; 3. The network device according to claim 1 or 2.

4. the transmission path transmits an optical signal; The network device according to any one of claims 1 to 3.

5. A data exchange method executed by a network device in a communication network for transferring user data, comprising: an acquisition step of acquiring data between network devices, which is superimposed on user data out-of-band and is exchanged between network devices included in the communication network, from data obtained by branching or copying data transmitted through a transmission path of the communication network; a receiving step of receiving data between network devices transmitted from an adjacent network device which is another network device connected to the own device and does not transfer user data; an identification step of outputting the acquired data, which is the network device data acquired in the acquisition step, to a processing unit that performs a predetermined processing when the destination of the acquired data is the own device, and discarding the acquired data when the destination is not the own device, and outputting the network device data received in the reception step to a processing unit that performs a predetermined processing when the destination of the network device data received in the reception step is the own device; a transmitting step of performing a process of superimposing, by out-of-band, inter-network device data addressed from the own device to another network device on user data transmitted on the transmission path, a process of superimposing, by out-of-band, the inter-network device data received in the receiving step on user data transmitted on the transmission path when the destination of the inter-network device data received in the receiving step is the other network device, and a process of outputting, to the adjacent network device, the acquired data or the inter-network device data generated by the own device when the destination of the acquired data or the inter-network device data generated by the own device is the adjacent network device; having the network device is a communication device that transfers user data transmitted along the transmission path, the adjacent network device is a monitoring and control device that monitors or controls the communication network, the acquired data or the data between network devices that is output to the adjacent network device includes information on communication quality of the communication network; the data between network devices transmitted by the adjacent network device includes information on a communication path in the communication network determined by the adjacent network device based on information on communication quality; Data exchange methods.

Images