WO2024029033A1

WO2024029033A1 - Communication system and normality determination method

Info

Publication number: WO2024029033A1
Application number: PCT/JP2022/029937
Authority: WO
Inventors: 學吉野
Original assignee: 日本電信電話株式会社
Priority date: 2022-08-04
Filing date: 2022-08-04
Publication date: 2024-02-08

Abstract

This communication system comprises one or more control devices and one or more user devices, wherein a first user device or a first control device responds, with a second control signal, to a first control signal transmitted from a second user device or a second control device, and the second user device or the second control device determines, on the basis of the second control signal used in the response, whether or not a signal route including a path between the first user device or the first control device and the second user device or the second control device is normal. The first user device or the first control device may loop back the first control signal transmitted from the second user device or the second control device, and the second user device or the second control device may determine, on the basis of the looped-back first control signal, whether or not the signal route including a path between the first user device or the first control device and the second user device or the second control device is normal.

Description

Communication system and normality determination method

The present invention relates to a communication system and a normality determination method.

With the spread of IoT (Internet of Things) and the progress of digitalization of society and industry, the amount of data flowing on the Internet is increasing. Additionally, service use cases of a type different from the best-effort type are emerging. Toward the advancement of such services, demands for guaranteed bandwidth and low latency are increasing for communication networks. For example, in cyber-physical systems, it is necessary to upload a huge amount of sensing data obtained from the real world (physical space) to the information processing infrastructure (cyber space) in real time without loss, and to transfer control information to the real world with high reliability and low delay. Transport infrastructure is required to provide feedback and transmit high-definition images. A cyber-physical system is a system in which a huge amount of sensing data obtained from the real world is analyzed on a computer, and the analysis results are fed back to achieve optimal control of the real world. It is expected that such cyber-physical systems will create new values and solutions.

Based on these considerations, all photonics networks (APNs) based on photonics technology are being considered as a new architectural network to accommodate traffic that requires large capacity and low latency. (See Non-Patent Document 1). APN is one of the transparent networks that transmits arbitrary user signals. APN provides an end-to-end optical path, independent of specific communication protocols and optical modulation schemes.

However, a method for determining the normality (continuity check) of optical signal paths that transparently transmit main signals of various protocols in an APN has not yet been established. Hereinafter, determining the normality of the optical signal path will be referred to as "signal path normality determination." For example, when a communication abnormality occurs, in order to identify the location where the abnormality has occurred, the optical signal transmission path is divided, and signal path normality determination (normality monitoring) is performed for each divided section. In the signal path normality determination for each section, continuity of the optical signal is confirmed from one section to the other of the target section of the signal path normality determination. Here, the continuity check is made by performing optical-electrical conversion (hereinafter referred to as "OE conversion") of at least a part of the optical signal at the end point of the target section for determining the normality of the signal path, and terminating and determining Alternatively, determination is made using nonlinear optical effects or the like regarding the optical signal. Here, the use of nonlinear optical effects, etc. refers to changes in the gain in gain media and light absorption media, the current and voltage applied to those media, and the changes in pump light and gain clamp light input to those media. This means using changes in intensity after passing through a medium, changes in light generated by nonlinear optical effects such as idler light, etc. In signal path normality determination, a loopback method is mainly used in which a response is returned from the other target section in response to a request from one of the target sections. In optical signal loopback, an OE converter that transmits a requested optical signal to one end point or beyond the target section for optical signal path normality determination and receives a response responds to the request at the other end point or beyond. Optical-Electrical-Optical conversion (hereinafter referred to as "OEO conversion") is required at the turning point of the optical signal at which the received response is turned back. Unlike conventional networks, in transparent networks, there is not necessarily a device that performs photoelectric conversion and termination according to the protocol of the main signal depending on the user equipment for each section in which normality is determined. If each section is terminated with such a device, it will no longer be transparent.

FIG. 16 is a diagram showing an example of the frequency of the control signal and the frequency of the main signal (user signal). In FIG. 16, the control signal is an AMCC (Auxiliary Management and Control Channel) signal. In the APN, a photonic gateway (hereinafter referred to as "Ph-GW") in the station transmits an AMCC signal whose frequency is superimposed on the main signal to devices constituting the network such as user equipment and other Ph-GWs. A user device or another device constituting a network such as a Ph-GW may transmit an AMCC signal whose frequency is superimposed on a main signal to another user device or a device constituting a network such as Ph-GW. Devices constituting the network, such as user equipment and Ph-GW, may receive the AMCC signal.

In view of the above circumstances, an object of the present invention is to provide a communication system and a method for determining normality that are capable of determining the normality of a signal path in a transparent network.

One aspect of the present invention is a communication system including one or more control devices and one or more user devices, wherein a first user device or first control device is connected to an opposing second user device or second user device. the second control device or the second control device responds with a second control signal to the first control signal transmitted from the second control device; determining whether a signal path including between the control device and the second user device or the second control device is normal based on the second control signal used in the response; Alternatively, the first user device or the first control device returns the first control signal transmitted from the opposing second user device or second control device, and returns the first control signal to the second user device or the second control device. The device or the second control device determines whether the signal path including between the first user device or the first control device and the second user device or the second control device is normal. The communication system determines whether or not the received signal is received based on the returned first control signal.

One aspect of the present invention is a communication system including one or more control devices and one or more user devices, wherein a first user device or first control device is connected to an opposing second user device or second user device. generating and terminating a main signal in a signal format selected based on the signal format used by the second control device; returning the first main signal transmitted from the second user device or the second control device; The second user device or the second control device has a signal path including between the second user device or the second control device and the first user device or the first control device. The first user device or the first control device determines whether or not it is normal based on the returned first main signal, or the first user device or the first control device determines whether the second user device or the first control device is normal. A second main signal transmitted from the second user device or the second control device is returned in a signal format selected based on a signal format used by the second control device, and the second main signal is returned to the second user device. Alternatively, the second control device determines whether a signal path including between the second user device or the second control device and the first user device or the first control device is normal. is determined based on the returned second main signal, or the first user device or the first control device determines the second main signal of the opposing second user device or the second control device. a third main signal transmitted from the second user equipment or the second control device that generates and terminates the main signal in a signal form selected based on the signal form to be used; In response with a main signal, the second user device or the second control device connects the second user device or the second control device with the first user device or the first control device. The first user device or the first control device determines whether or not a signal path including a the second main signal transmitted from the second user device or the second control device in a signal format selected based on a signal format used by the second user device or the second control device; the second user device or the second control device responds with a fourth main signal to the second user device or the second control device, and The present invention is a communication system that determines whether a signal path including a signal path with a first control device is normal based on the fourth main signal used in a response.

One aspect of the present invention is a normality determination method executed by a communication system including one or more control devices and one or more user devices, wherein the first user device or the first control device responds with a second control signal to a first control signal transmitted from a user equipment or a second control device, and the second user equipment or the second control device Whether or not a signal path including between the device or the first control device and the second user device or the second control device is normal or not is determined by the second control signal used in the response. or the first user device or the first control device returns the first control signal transmitted from the second user device or the second control device and The second user device or the second control device is configured such that the signal path including between the first user device or the first control device and the second user device or the second control device is normal. This is a normality determination method for determining whether or not this is the case based on the returned first control signal.

One aspect of the present invention is a communication system including a first control device, a second control device, a first user device, and a second user device, wherein the first control device receives a first control signal instructing return. to the first user device, the second control device sends a second control signal instructing the return to the second user device, and the second user device transmits a second control signal to the first user device. and the first user device determines whether a signal path including between the first user device and the second user device is normal based on the returned main signal. It is a communication system that makes decisions based on

One aspect of the present invention is a communication system including a first user device and a second user device, wherein the second user device transmits an instruction signal representing a return instruction to the first user device, and Returning the control signal transmitted from one user device, the first user device transmits an instruction signal representing the return instruction to the second user device, and transmits a signal between the first user device and the second user device. The communication system determines whether a signal path included in the communication path is normal based on the returned control signal.

According to the present invention, it is possible to determine the normality of a signal path in a transparent network.

1 is a diagram showing a configuration example of a communication system in this embodiment. 1 is a diagram showing a first example of a configuration of a communication system in a first embodiment; FIG. FIG. 2 is a diagram showing a second example of the configuration of a communication system in the first embodiment. FIG. 3 is a diagram showing a third example of the configuration of a communication system in the first embodiment. It is a figure showing the 4th example of composition of a communication system in a 1st embodiment. FIG. 3 is a diagram showing a first example of the configuration of a communication system in a second embodiment. FIG. 3 is a diagram showing a second example of the configuration of a communication system in a second embodiment. It is a figure showing the 3rd example of composition of a communication system in a 2nd embodiment. It is a figure showing an example of composition of a communication system in a 3rd embodiment. It is a figure which shows the 1st example of the structure of a communication system in 4th Embodiment. It is a figure which shows the 2nd example of the structure of a communication system in 4th Embodiment. It is a figure which shows the example of a structure of the communication system in 5th Embodiment. It is a figure showing an example of composition of a communication system in a 6th embodiment. It is a figure which shows the modification of the example of a structure of a communication system in 6th Embodiment. 1 is a diagram showing an example of a hardware configuration of a communication system. FIG. 3 is a diagram showing an example of the frequency of a control signal and the frequency of a main signal (user signal).

(Basic configuration example of APN)
Since the APN employs a flat architecture, there is no need for the electrical termination of optical signals provided between layers in the communication network as a comparative example with the APN. APN has very low delay due to end-to-end optical path connections. Furthermore, APN has high flexibility and expandability in that it can easily provide a high-capacity, low-latency communication network for each function without depending on a specific communication protocol.

APN operates two types of optical nodes: photonic gateways (Ph-GW) and photonic exchanges (hereinafter referred to as "Ph-EX"), which minimize electrical processing such as exchange, multiplexing, and switching. (Ph-GW is connected to full mesh). The Ph-GW is an optical node located at the entrance of a full mesh network and accommodates various user equipment. Full mesh is a connection form in which all elements making up a communication network are directly connected to each other. Ph-EX is an optical node that provides a huge number of optical paths. These vast numbers of optical paths transparently traverse the optical backbone network. Ph-EX connects optical networks to which different optical multiplexing methods are applied by converting the optical multiplexing method.

With such a configuration, in the APN, it is possible to directly connect arbitrary points (installation points of user devices) with optical signals without performing electrical processing. By allocating dedicated wavelengths to user services, it becomes possible to realize high-capacity, low-latency communications. With APN, it is possible to provide a variety of services by flexibly combining necessary service function processing at necessary points. Further, the APN can provide a communication environment that does not make the user aware of service types, protocols, optical wavelengths, etc.

In order to achieve end-to-end optical direct connection and service function processing at required points, Ph-GW has the five basic functions illustrated below.

The first basic function is to determine which wavelength the user equipment uses and remotely set wavelength information to the user equipment. In order to open an end-to-end optical path, the wavelength must be assigned to each optical path so that the wavelengths of optical signals do not overlap between the optical paths that share the transmission medium (optical fiber, etc.) within the APN. The Ph-GW is required to have the function of allocating. Further, the Ph-GW is required to have a function of remotely setting wavelength information of an optical signal of a user equipment that is an end point of an optical path.

The second basic function is to communicate optical signals between ports on the access network side and ports on the full mesh network side when an optical path is opened. This function is to stop unnecessary signals. Here, the access network is a network between the Ph-GW and the user equipment, and the full mesh network is a network between the Ph-GWs or between the Ph-GWs and the Ph-EX. Depending on the destination, Ph-GW transmits optical signals input from the access network to the access network, optical signals input from the access network to the full mesh network, optical signals input from the full mesh network to the access network, and optical signals input from the full mesh network to the access network. Optical signals input from the mesh network are transferred (distributed) as optical signals to the full mesh network.

The third basic function is the function of concentrating and distributing optical paths that share a transmission medium within a full mesh network.

The fourth basic function is a loopback function for directly optically connecting user devices housed in the same Ph-GW. By enabling loopback at the Ph-GW located at the entrance of the full mesh network, rather than loopback at the upper optical node, direct optical connection is achieved through the shortest route.

The fifth basic function is the extraction and insertion function. The eject and insert functions enable electrical processing at the Ph-GW location in order to perform regenerative repeating of optical signals in terms of optical signal transmission and to perform service function processing.

FIG. 1 is a diagram showing a configuration example of a communication system 1 in each embodiment. The communication system 1 is a communication system that communicates using a transparent communication network such as an all-photonics network (APN). The communication system 1 transmits an optical signal from a device at one end of a section to be determined, photoelectrically converts the received signal at the device at the other end, and converts the received signal or a response according to the received signal into electrical light and transmits it. In other words, the path of the optical signal in the section to be determined can be determined by converting the optical signal or control signal back to OEO, converting the returned optical signal or control signal to OE on the transmitting side, and checking the content of the signal. Determine normality. The interval to be determined may include the areas between the user equipment 300 and the Ph-GW 100, between the Ph-GW 100 and the Ph-GW 100, and between the user equipment 300 and the user equipment 300. In FIG. 1, the user device 300 and the Ph-GW 100 are illustrated as devices at the ends of the section.

The communication system 1 includes a Ph-GW 100-1, a Ph-GW 100-2, an APN controller 200, a user device 300-1, and a user device 300-2. Note that in order to simplify the explanation, two Ph-GWs and two user devices are shown in FIG. 1. In an actual communication system, a large number of Ph-GWs and user equipments are arranged, and there are cases where Ph-EX is interposed between Ph-GWs and user equipments are interposed only through a single Ph-GW. etc. is assumed.

The Ph-GW 100 is a device (transmission/reception device) that transmits and receives optical signals. The Ph-GW 100 transmits and receives optical signals for monitoring and controlling the user device 300 and determining the normality of sections with the user device and other Ph-GWs 100. If the end point of the section does not reach the Ph-GW 100, the optical signal may pass through the Ph-GW 100.

Additionally, the Ph-GW 100 is a device (distribution device) that distributes optical signals to destinations. The Ph-GW 100-1 includes an optical distribution section 101-1, a wavelength demultiplexing section 102-1, and an access system management control section 103-1 (control device). The Ph-GW 100-2 includes an optical distribution section 101-2, a wavelength demultiplexing section 102-2, and an access system management control section 103-2 (control device). The light distribution unit 101 includes a plurality of input/output ports (not shown). Note that the wavelength multiplexing/demultiplexing section 102-2 is not necessarily placed in the path of the target optical signal.

The user device 300-1 includes an optical transceiver 301-1 (optical TRx) (not shown). User equipment 300-2 includes an optical transceiver 301-2 (optical TRx) (not shown).

The optical distribution unit 101-1 and the optical distribution unit 101-2 transfer (distribute) optical signals input from the access network and the full mesh network as optical signals according to the destination. Thereby, the optical distribution section 101-1 and the optical distribution section 101-2 realize a loopback function (the fourth basic function described above) for direct optical connection.

The optical distribution unit 101-1 and the optical distribution unit 101-2 realize a loopback function (the above-mentioned fourth basic function) for directly optically connecting the user devices 300 housed in the same Ph-GW 100. . Further, the optical distribution section 101-1 and the optical distribution section 101-2 realize optical add/drop (the above-mentioned fifth basic function) to an electrical processing section (not shown).

The wavelength multiplexing/demultiplexing section 102-1 wavelength-multiplexes the optical signals that share the same path among the optical signals output from the optical distribution section 101-1. The wavelength multiplexing/demultiplexing section 102-1 outputs the wavelength-multiplexed optical signal to the full mesh network. The wavelength multiplexing/demultiplexing section 102-1 separates the wavelength multiplexed signal input from the full mesh network in units of wavelengths.

The wavelength multiplexing/demultiplexing section 102-2 wavelength-multiplexes optical signals having the same destination among the optical signals output from the optical distribution section 101-2. The wavelength multiplexing/demultiplexing section 102-2 outputs the wavelength-multiplexed optical signal to the full mesh network. The wavelength multiplexing/demultiplexing section 102-2 separates the wavelength multiplexed signal input from the full mesh network in units of wavelengths (the above-mentioned third basic function).

In the Ph-GW 100, an access system management control unit 103-1, which is one of the devices (transmission/reception device) included in the Ph-GW 100 that transmits and receives optical signals, performs access system management at the time of initial connection of the user device 300-1. Control information is exchanged between the control unit 103-1 and the user device 300-1. Access system management control unit 103-1 transmits a wavelength setting instruction to user device 300-1.

The access system management control unit 103-2 exchanges control information between the access system management control unit 103-2 and the user device 300-2 at the time of initial connection of the user device 300-2. The access system management control unit 103-2 transmits a wavelength setting instruction to the user device 300-2 (the first basic function described above).

The optical signals transmitted and received by the access system management control unit 103 (hereinafter referred to as "access system optical signals") may be demultiplexed onto the path to the user device 300 at any point. For example, access optical signals may be demultiplexed in wavelength multiplexing/demultiplexing section 102, access optical signals may be demultiplexed between wavelength multiplexing/demultiplexing section 102 and optical distribution section 101, or optical The access optical signal may be demultiplexed in the distribution section 101, or the access optical signal may be demultiplexed between the optical distribution section 101 and the user equipment 300.

Instead of multiplexing the access system optical signal with the main signal optical signal by space division multiplexing, polarization division multiplexing, wavelength division multiplexing, etc., the access system management control unit 103 adds a control signal onto the main signal optical signal. It may be multiplexed in the form of frequency division multiplexing such as time division multiplexing, code division multiplexing, or AMCC, or the control signal may be multiplexed on the optical signal of the main signal in the form of intensity modulation, phase modulation, frequency modulation, or polarization modulation. Multiplexing may be performed by modulating. In this case, instead of multiplexing using a multiplexer/brancher, multiplexer/demultiplexer, etc., multiplexing may be performed using a modulator or an amplifier or attenuator that can modulate the amplification factor or attenuation factor. The explanation below will mainly be based on multiplexing the control signal onto the main optical signal, but it is clear that it can also be used to multiplex an access optical signal that is separate from the main optical signal. . Note that if the access optical signal is multiplexed on the loopback side and the access optical signal and main signal optical transmitter and optical receiver are separate, the main signal optical transmitter and optical receiver deviates from the normality determination, so in order to determine the normality of the section that is outside the normality determination, a loopback is performed between the optical transmitter and the optical receiver, or the normality is determined by means other than loopback. It is desirable to do so. In addition, by using these methods, if the loopback signal is looped back from the optical transmitter of the access system optical signal only when the normality of the optical transmitter and optical receiver of the main signal is determined, a single loopback signal can be generated. It is possible to notify the normality of the main signal optical transmitter and optical receiver. Of course, the normality of the main signal optical transmitter and optical receiver, the access system optical signal optical transmitter and optical receiver, etc. may be separately determined and notified.

APNs that support a variety of social infrastructure networks are required to be able to set up optical paths for a variety of user devices so that dedicated networks for functionally specific wavelengths can be easily provided. Therefore, a mechanism is required in which an optical path is immediately opened just by connecting the user equipment 300-1 and the user equipment 300-2 to the optical fiber.

First, the user device 300-1 or the user device 300-2 reports its own device information and opposing device information to the nearest Ph-GW 100, for example. The user device 300-1 or the user device 300-2 may report its own device information and opposing device information to the Ph-GW 100-1 or Ph-GW 100-2. Although it is assumed that the notification is made to the most recent Ph-GW 100, the notification may be made to a Ph-GW 100 other than the most recent one. For example, the user device 300-1 or the user device 300-2 may report its own device information and opposing device information to the Ph-GW 100-2 or Ph-GW 100-1. The latter is suitable when, for example, when restoring a connection, the information on the PhGW to which the opposite device is connected is known. Below, we will mainly explain the case where the most recent declaration is filed.

Second, the APN controller 200 performs wavelength resource management and optical path design within the APN. In response to the notification from the user device 300-1 or the user device 300-2, the Ph-GW 100-1 or Ph-GW 100-2, in cooperation with the APN controller 200, sends the notification to the user device 300-1 or the user device 300-2. Determine the allocated wavelength for. Ph-GW 100-1 or Ph-GW 100-2 notifies user equipment 300-1 or user equipment 300-2 of the wavelength.

Third, an internal route of Ph-GW 100-1, an internal route of Ph-GW 100-2, and an internal route of Ph-EX are each set. In FIG. 1, an internal route of Ph-GW 100-1, an internal route of Ph-GW 100-2, and a route connecting Ph-GW 100-1 and Ph-GW 100-2 are set. When Ph-GW100-1 and Ph-GW100-2 are connected via Ph-EX (not shown), the internal route of Ph-GW100-1 and the internal path of Ph-GW100-1 and Ph-EX ( A route inside the Ph-EX (not shown), a route inside the Ph-EX (not shown) and the Ph-GW100-2, and a route inside the Ph-GW100-2 are set. .

In the APN, optical signals according to signals of various communication protocols are transmitted from user equipment 300-1 and user equipment 300-2. Therefore, a management control method that does not depend on communication protocols is required. For example, AMCC is used for such access system management control. In the communication system 1, the user device 300-1 communicates via the Ph-GW 100 within the station.

(First embodiment)
<Main signal loopback>
In each of the figures from FIG. 2 to FIG. 5, the present embodiment is a communication system that includes a device that transmits and receives optical signals, and one opposing device uses a format (protocol and It selectively generates an optical signal of the modulation method, modulation rate, code format (form of main signal known in advance), and transmits the generated optical signal to the other opposing device. The other opposing device returns and transmits the received optical signal or its response, and the opposing device receives the returned optical signal or its response (in a format that the other opposing device can transmit and receive). A communication system that determines whether a signal path including a signal path between one opposing device and another opposing device is normal based on the received reflected optical signal or its response. .

Hereinafter, selecting an optical signal in a receivable format will be referred to as "format selection." Hereinafter, generating and transmitting a signal, receiving and terminating the returned signal will be referred to as "generation, transmission, reception, and termination."

In each figure from FIG. 2 to FIG. 5, one device (the device that selects and processes the signal format used by the opposite device) is Ph-GW, and the other device (the device that processes the signal format of its own device). An example is shown in which is the user equipment. That is, a system configuration pattern of "format selection + generation transmission/reception terminal side: Ph-GW" and "return side: user equipment" is shown.

FIG. 2 is a diagram showing a first example of the configuration of a communication system in the first embodiment. The access system management control unit 103 determines the optical signal in a format (protocol, modulation method, modulation speed, code format) (form of main signal known in advance) that can be transmitted and received by the other device facing the judgment control unit 401. It includes a plurality of corresponding signal termination sections 402 (for example, signal termination sections 402a to 402d), a SW 403, a combination/separation section 404, an optical interface section (optical IF section) 405, and an optical interface section (optical IF section) 406. The determination control unit 401 is a functional unit that determines the normality of the conduction section. The determination control unit 401 instructs the selected signal termination unit 402 to transmit the main signal to the target user device. The thick arrow represents the route of the main signal that is looped back. In FIG. 2, the combiner/demultiplexer 404 multiplexes and demultiplexes the control signal onto the main signal selected by the SW 403 using an electrical stage. The thick line arrow in FIG. 2 corresponds to "format selection + generation transmission/reception terminal side: Ph-GW" and "return side: user equipment." "Format selection + return side: Ph-GW" and "generation transmission reception termination side: User equipment route may be used. This is also the same in Figure 3-9, which will be described later, and Figure 12-14, which will be described later. .

FIG. 3 is a diagram showing a second example of the configuration of the communication system in the first embodiment. The access system management control unit 103 determines the optical signal in a format (protocol, modulation method, modulation speed, code format) (form of main signal known in advance) that can be transmitted and received by the other device facing the judgment control unit 401. It includes a plurality of corresponding signal termination units 402 (for example, signal termination units 402a to 402d), a SW 403, a plurality of (for example, two) combining/separating units 404, and a plurality of (for example, four) optical interface units (optical IF units). . The thick arrow represents the route of the main signal that is looped back. In FIG. 3, the combiner/demultiplexer 404 multiplexes and demultiplexes the control signal onto the main signal selected by the SW 403 using an optical stage.

FIG. 4 is a diagram showing a third example of the configuration of the communication system in the first embodiment. The access system management control unit 103 includes a determination control unit 401, a plurality of signal termination units 402 (for example, 402a to 402d), a SW 403, a plurality of (for example, four) combining/separating units, and a format that can be transmitted and received by the other opposing device ( A plurality of (for example, eight) optical interface units (optical IF units) are provided that correspond to optical signals of various protocols, modulation methods, modulation speeds, and code formats (forms of main signals known in advance). The thick arrow represents the route of the main signal that is looped back. In FIG. 4, the SW 403 selects the optical signal obtained by demultiplexing the control signal and the main signal using an electrical stage.

In FIGS. 2 and 4, control signals are demultiplexed at the electrical stage. In FIG. 2, the order from the signal termination section to the user equipment is the order of the SW403, the optical IF section, and the coupling/separation section, or the order of the signal termination section, instead of the order of the SW403, the combining/separating section, and the optical IF section. The order of the optical IF section, SW 403, and combination/separation section for each section 402 may be adopted. In FIG. 4, the order from the signal termination unit to the user equipment is the order of the optical IF unit, the combining/separating unit, and the SW, and the order of the optical IF unit, the combining/separating unit, and the SW, instead of the order of the combining/separating unit 404, the optical IF unit, and the SW. , SW, and the combining/separating section may be arranged in this order. The combining/separating section may be a modulating section and a receiving section that receives at least a part of the signal, as shown in FIG. 8, which will be described later. 2 and 4 show the configuration of a system in which a main signal and a control signal are multiplexed and separated in an electrical stage by frequency division multiplexing or time division multiplexing.

FIG. 5 is a diagram showing a fourth example of the configuration of the communication system in the first embodiment. The access system management control unit 103 includes a determination control unit 401, a plurality of signal termination units 402 (for example, 402a to 402d), a SW 403, a plurality of (for example, two) combination/separation units, and a format that can be transmitted and received by the other opposing device ( A plurality of (for example, 10) optical interface units (optical IF units) are provided that correspond to optical signals of different protocols, modulation methods, modulation speeds, and code formats (forms of main signals known in advance). The thick arrow represents the route of the main signal that is looped back. In FIG. 5, a control signal is multiplexed and demultiplexed on the main signal selected by the SW 403 in an optical stage by a demultiplexer. Figures 3 and 5 show, for example, wavelength division multiplexing with an optical signal for a control signal of a different wavelength so that beat noise with the main signal can be ignored, or polarization between the main signal and the main signal so that polarization fluctuations of the main signal can be ignored. This represents the configuration of a communication system in which a control signal is multiplexed and demultiplexed into a main signal at an optical stage, such as by polarization division multiplexing with optical signals for different control signals whose polarizations are orthogonal to each other.

2 to 5 are diagrams showing the communication system 1 of the first embodiment. 2 to 5, among the devices included in the communication system 1, only the devices related to one section that is the target of signal path normality determination are shown. In the first embodiment, the access system management control unit 103 performs signal path normality determination for the user device 300 connected to its own device (Ph-GW 100). For example, the access system management control unit 103-2 or 103-1 in FIG. 1 performs signal path normality determination for the section with the user device 300-2.

Depending on the determination interval and direction, the user device 300-2 performs signal path normality determination on the access system management control unit 103-2, the access system management control unit 103-1, and the user device 300-1. Further, the access system management control unit 103-2 or the access system management control unit 103-1 may perform signal path normality determination for the section with the user device 300-1, or the access system management control unit 103-1 may -2 may be performed for the section with the access system management control unit 103-1, or the access system management control unit 103-1 may perform the process for the section with the access system management control unit 103-2. . However, in the first embodiment, since the main signal generation/termination functional unit (signal form or format) is selected in accordance with the main signal format of the opposing device, even when the access system management control units perform the same, the corresponding path It is desirable to select a format that conforms to the format of the main signal used by the user equipment using the .

In the first embodiment, when communicating using the main signal (that is, excluding initial connection, monitoring, etc.), the main signal generation termination section (signal termination section) according to the protocol used by the user device 300 generates the main signal. The Ph-GW is a relay device that only performs optical distribution without terminating the light. If the end point of the section for normality determination in this embodiment is installed in a relay device such as Ph-EX, which does not terminate the main signal, in the same way as Ph-GW, A generation termination section (signal termination section) is also provided.

(A1) System configuration where the user equipment loops back and multiple main signal termination units on the Ph-GW side (“format selection + generation transmission/reception termination side: device on the Ph-GW side” and “return side: user equipment”) As shown in the pattern, the device on the Ph-GW side selects the main signal termination section according to the main signal used by the opposite device (in this case, the user device), and at the selected main signal termination section, the normality of the main signal is determined. Generates a request for determination, transmits a response regarding normality determination in response to the request in the opposite device (user device here), and transmits the received response to the selected main signal termination of the device on the Ph-GW side. or the device on the Ph-GW side selects the main signal termination section according to the main signal used by the opposite device (in this case, the user device), and the main signal is normally terminated at the selected main signal termination section. Generates a signal for gender determination, sends the normality determination signal back at the opposite device (in this case, the user device), and transmits the received return (loopback signal) to the selected device on the Ph-GW side. (terminated at the main signal termination section)

Set up the optical distribution unit etc. so that the access system management control unit and the user device can communicate. The access system management control section selects the termination section of the main signal of the protocol according to the user device. A detection unit (not shown) may be provided to detect the format of the main signal, and selection may be made based on the detection result, or selection may be made based on a response to a request to the user device or a value declared from the user device. , you may choose based on the value held at the time of service contract, service order, or database, or choose whether to obtain or declare the MAC (Media Access Control) address of the transceiver that is transmitting and receiving the main signal, etc. It may be obtained from the address and estimated from the manufacturer and product type according to the address.

The access system management control unit instructs the user device to loop back the main signal (return instruction). The instruction may be a control signal or a main signal. In the case of a control signal, the termination section (signal termination section) according to the user device may be selected after the instruction is given. In the case of using the main signal, the instruction is given after selection because the instruction is made using the main signal.

The access system management control unit generates and transmits a downlink main signal for normality determination using a protocol according to the user device. Note that when no instruction is given by the control signal, it is not necessary to modulate the main signal with the control signal or to superimpose the control signal on the main signal. The user equipment returns the downlink main signal or its response as the uplink main signal.

Note that when there is no response to the control signal, it is not necessary to modulate the main signal with the control signal or to superimpose the control signal on the main signal. The returned upstream main signal is received and terminated by the access system management control unit and judged. The loopback of the main signal of the user device is canceled with the passage of time or an instruction from the access system management control unit. The instruction at this time may be a control signal or a main signal.

Here, the protocol of the main signal transmitted and received by the user equipment is at least determined by obtaining instructions from the APN controller, information from the DB, or from the user equipment, or by receiving the main signal and determining whether it can be terminated as a normal signal. Choose one. This also applies to the description below.

(A2) System configuration pattern where the user equipment loops back and multiple main signal termination units on the user equipment side (“format selection + loopback side: user equipment” and “generation transmission/reception termination side: Ph-GW side device”) , the user equipment selects the main signal termination section according to the main signal used by the opposite device (here, the device on the Ph-GW side), and selects the main signal termination section of the opposite device (here, the device on the Ph-GW side). , generates a request for normality determination using the main signal, transmits a response regarding normality determination in response to the request at the main signal termination section selected by the user equipment, and transmits the received response to the Ph-GW side. or the user equipment selects the main signal termination part according to the main signal used by the opposite device (here, the Ph-GW side device), and The main signal termination section of the GW side device) generates a normality determination signal using the main signal, and the selected main signal termination section of the user device returns and transmits the normality determination signal. Terminate the loopback signal at the main signal termination part of the opposing device (Ph-GW side device here) (not shown)

A main signal termination section (signal termination section) corresponding to the signal format used by the opposing device may be arranged in the user device. The optical distribution unit and the like are set so that the access system management control unit and the user device can communicate. The access system management control unit selects a main signal termination unit (signal termination unit) located in the user device. The user equipment loops back the main signal at the selected signal termination. The Ph-GW receives and terminates the returned uplink main signal, and determines normality.

As another connection, if a transmitting unit (optical IF unit) that transmits an optical signal that is returned by the opposing device for normality determination is placed in the Ph-GW, it is connected via an optical distribution unit. In addition to the access system management control section, a transmitting section (optical IF section) may be arranged. For example, a transmitting section (optical IF section) is installed at a position where an optical signal can be outputted to a folding device via an optical multiplexer/brancher or an optical multiplexer/demultiplexer installed outside the input port or output port of the optical distribution section. ) may be placed. For example, a transmission unit (optical IF unit) is placed in a monitoring unit that monitors the optical intensity of an optical signal on at least one of the input side and output side of the Ph-GW and exchanges control signals with a user device. may be done. Instead of outputting combined or multiplexed light through an optical multiplexer/brancher or an optical multiplexer/demultiplexer, light generated by an optical nonlinear effect of the light to be folded back may be output.

When exchanging main signals, a monitor is inserted in the middle of the main signal path to monitor the optical intensity and wavelength of the main signal and determine whether there are any abnormalities. It is used to extract and monitor a part of the data, etc., or to control the user equipment by inserting a control signal. Instead of branching a part of the main signal, etc. using a multiplexer/brancher or multiplexer/demultiplexer, or multiplexing a control signal with the main signal, light is generated using nonlinear optical effects, etc., which will be described later. That is, changes in the gain in gain media and light absorption media, changes in current and voltage applied to those media, pump light input to those media, and changes in gain clamp light after it passes through the medium. A change in intensity or a change in light generated by a nonlinear optical effect such as idler light may also be used. Note that these are not shown in FIG. 1.

When a receiving unit (optical IF unit) that receives at least part of the optical signal returned by the opposing device is placed in the Ph-GW for normality determination, the access connected via the optical distribution unit A receiving section (optical IF section) may be arranged in addition to the system management control section. For example, a position where the optical signal returned from the return device or at least part of its components can be inputted via an optical multiplexer/brancher or optical multiplexer/demultiplexer installed outside the input port or output port to the optical distribution section. A receiving section (optical IF section) may be placed in the receiver. For example, a receiving unit (optical IF unit) is placed in a monitoring unit that monitors the optical intensity of an optical signal on at least one of the input side and output side of the Ph-GW and exchanges control signals with a user device. may be done. Instead of inputting branched or demultiplexed light through an optical multiplexer/brancher or an optical multiplexer/demultiplexer, light generated by an optical nonlinear effect of folded light may be input.

When looping back on the Ph-GW side, the signal received at the receiving section (optical IF section) is looped back at the selected signal termination section 402 and output from the transmitting section (optical IF section).

Regarding the access system management control unit 103, on the network side from the combining/separating unit 404, the main signal is either looped back at the signal termination section or generated and terminated. On the user side from the combining/separating unit 404, if the optical IF unit is common for the control signal and the main signal (FIGS. 2 and 4), since they are common, both are transmitted and received at the optical IF unit. If at least one of the transmission and reception of the optical IF section is different between the control signal and the main signal (if both transmission and reception are different, as shown in Figures 3 and 5), different transmissions or receptions, or both, are performed in the optical IF section corresponding to the control signal or the main signal, respectively. .

Regarding the user device 300, the user side from the combining/separating unit 322 returns or generates and terminates the main signal on the UNI side. On the network side from the combining/separating unit 322, if the optical IF unit is common for the control signal and the main signal, since they are common, both are transmitted and received at the optical IF unit. If at least one of the transmission and reception of the optical IF section of the user equipment is different between the control signal and the main signal (like the access system management control section in FIGS. 3 and 5), the control signal or the main signal may be different from each other. This is performed at the corresponding optical IF section.

In FIG. 2, the combining/demultiplexing unit 404 multiplexes and demultiplexes the control signal on the main signal selected by the SW 403 using an electrical stage. In FIG. 3, the combiner/demultiplexer 404 multiplexes and demultiplexes the control signal onto the main signal selected by the SW 403 using an optical stage. In FIG. 4, the SW 403 selects the optical signal obtained by demultiplexing the control signal and the main signal using an electrical stage. In FIG. 5, a control signal is multiplexed and demultiplexed on the main signal selected by the SW 403 in an optical stage by a demultiplexer.

The combining/separating section may be a modulating section and a receiving section that receives at least a part of the signal, as shown in FIG. 8, which will be described later.

The access system management control unit 103 transmits a main signal to the user device 300 (hereinafter referred to as "target user device") connected to the section targeted for signal path normality determination. In transmitting the main signal, the access system management control unit 103 transmits a main signal of a protocol that can be processed by the target user device. In order to realize such processing, the access system management control unit 103 uses the judgment control unit 401 to determine the format (protocol, modulation method, modulation speed, code format) (protocol, modulation method, modulation speed, code format) that can be transmitted and received by the other device that is facing the determination control unit 401. A plurality of signal termination sections 402 (for example, 402a to 402d), SW 403, combining/separating section 404, optical interface section (optical IF section) 405, and optical interface section (optical IF section) 406, which correspond to the optical signal (in the form of main signal) Equipped with

In FIGS. 2 and 3, after the light is terminated at the optical IF section and photoelectrically converted, the control signal and the main signal are branched at the electrical stage, the control signal is sent to the judgment control section, and the main signal is sent to the electrical SW at the signal termination section. The output from the signal termination section is selected by an electric switch, superimposed on a control signal at an electric stage, inputted to an optical IF section, photoelectrically converted, and outputted as light. As shown in FIG. 4, without optical termination, the SW403 (optical SW) selectively outputs to the signal termination sections each equipped with an optical IF section, and the optical output from the signal termination section equipped with the optical IF section is sent to the optical switch. You can select and output. The latter case is suitable when the requirements and configurations for the optical IF section differ for each signal termination section. The required conditions are, for example, conditions regarding line width, frequency stability, transmission band, etc. Specific examples of different configurations include, for example, direct detection and coherent detection using local light. Furthermore, the input and output to the determination control section may be a combination of those shown in FIGS. 2, 3, and 5, and may be a combination of electricity and light or light and electricity. Note that in FIGS. 2 and 4, multiplexing is performed in electrical stages.

When instructing with a control signal, the determination control unit 401 outputs a control signal indicating execution of loopback to the combination/separation unit 404. When the signal transmitted from the user device 300 is received by the signal termination unit 402, the determination control unit 401 determines the normality of the route to be determined based on the received signal. The signal from the Ph-GW may be determined by the user equipment, and the Ph-GW may receive the determination result. The user equipment may receive the looped back signal at the Ph-GW and make a determination. The user equipment transmits a loopback signal according to instructions from the Ph-GW, loops back at the Ph-GW, receives the looped back signal at the user equipment, makes a decision, and the user equipment uses the determination result to The information may be transmitted to the Ph-GW using a control signal or a main signal. Note that in the first embodiment, control information can also be exchanged using the main signal.

The signal termination unit 402 generates a main signal in a format (protocol, modulation method, modulation rate, code format) (form of main signal known in advance) that can be transmitted and received by the user equipment, and outputs it to the SW 403. There may be cases where the Ph-GW transmits a unidirectional transmitter or a loopback signal. In the former case, the user equipment receives and terminates the main signal for determining normality, determines normality, and notifies the Ph-GW of the result using a control signal or the like. In the latter case, the user equipment loops back the main signal for loopback from the Ph-GW to the Ph-GW, receives and terminates the looped-back signal at the Ph-GW, and determines normality.

The signal termination unit 402 outputs information regarding reception of the main signal to the determination control unit 401. When the Ph-GW receives a one-way reception side or a loop pack signal, in the former case, the user equipment generates and transmits a main signal for normality determination toward the Ph-GW according to instructions from the Ph-GW, etc. , the Ph-GW receives and terminates the main signal to determine normality. In the latter case, the user equipment loops back the main signal for loopback from the Ph-GW to the Ph-GW, receives and terminates the looped-back signal at the Ph-GW, and determines normality. (The latter is a part of the case where the signal termination section 402 described above generates and transmits a main signal according to a specific protocol that can be used by the user equipment, and outputs it to the SW 403.)

For example, if the signal termination unit 402 cannot receive the main signal that is supposed to be looped back even after a predetermined period of time has elapsed, it outputs information indicating this to the determination control unit 401. When the signal termination unit 402 receives the main signal that has been looped back, it outputs information regarding the received main signal (an example of information regarding reception of the main signal) to the determination control unit 401 . The information regarding the main signal is information used to determine the normality of the route. More specifically, the information regarding the main signal is, for example, information indicating whether or not loopback has been performed correctly and as requested.

In accordance with instructions from the Ph-GW, etc., the user equipment may generate and transmit a main signal according to a specific protocol that can be used by the user equipment, and the reception may be terminated at the Ph-GW to determine normality. In accordance with instructions from the Ph-GW, etc., the user equipment generates and transmits a main signal according to a protocol with characteristics that can be used by the user equipment, loops back at the Ph-GW, terminates reception at the user equipment, determines normality, The result may be notified to the Ph-GW etc. by a control signal or the like.

The SW 403 outputs the main signal output from the signal termination section 402 to the combining/separating section 404. The SW 403 outputs the main signal output from the combining/separating section 404 to the signal termination section 402 according to the main signal.

The combining/separating unit 404 superimposes the control signal output from the determination control unit 401 on the main signal output from the signal termination unit 402. For example, the combining/separating unit 404 may frequency-superimpose the control signal on the main signal. The combining/separating unit 404 separates a control signal from the signal received from the user device 300 and outputs the separated control signal to the determination control unit 401 . The combining/separating section 404 outputs a signal (main signal) in which the control signal is separated to the signal terminating section 402 via the SW 403 .

The optical interface section 405 converts the electrical signal output from the combining/separating section 404 into an optical signal. Optical interface unit 405 transmits the converted optical signal to user device 300 via an optical communication path.

The optical interface unit 406 receives the optical signal transmitted from the user device 300 via the optical communication path, and converts the received optical signal into an electrical signal. The optical interface section 406 outputs the electrical signal obtained by the conversion to the combining/separating section 404 .

The user device 300 includes an optical transceiver 301 and a control unit 330. The optical transceiver 301 includes an optical interface section 321 (optical IF section), a combining/separating section 322, a processing section 323, a UNI_PHY (Tx) 324, a UNI_PHY (Rx) 325, and an optical interface section 326 (optical IF section). ).

The optical interface unit 321 converts the optical signal received from the Ph-GW 100 into an electrical signal. The optical interface section 321 outputs the electrical signal obtained by the conversion to the combining/separating section 322 . In the following, the user equipment performs photoelectric conversion, and within the user equipment (UNI_PHY), during loopback, either all signals are looped back, some signals are looped back, and the rest is output to the user side, or loopback is performed. output to the user.

The combining/separating unit 322 separates the control signal from the signal received from the Ph-GW 100 and outputs the separated control signal to the control unit 330. The combining/separating section 322 outputs a signal (main signal) in which the control signal is separated to the processing section 323 . The combining/separating section 322 superimposes the control signal output from the control section 330 on the main signal output from the processing section 323 . For example, the combining/separating section 322 may frequency-superimpose the control signal on the main signal. Note that a user device configuration that includes a processing unit is only an example, and there is also a configuration that does not include a processing unit.

The processing unit 323 is, for example, a regenerative repeater, in which case it has an equalization (Reshaping) function, a retiming (Retiming) function, and an identification regeneration (Regenerating) function. For example, there is a multiplexing section and a separating section. For example, it is a conversion unit that converts a signal from an access network into a signal format transmitted by APN. For example, a framer that demultiplexes signals from an access network into transmission frames. The processing unit 323 is, for example, a MAC, in which case it performs media access control on the main signal output from the combining/separating unit 322. The processing unit 323 defines and allocates an address (MAC address) for identifying a device. The processing unit 323 may control the signal transmission timing. The MAC outputs the main signal to the UNI_PHY (Tx) 324. The MAC may perform media access control on the electrical signal output from the UNI_PHY (Rx) 325. The processing section 323 outputs the main signal to the combination/separation section 322.

Note that the configurations of the combining/separating section 322 and the processing section 323 do not need to be limited to those described above. For example, the combining/separating section 322 may be placed closer to the network than the optical interface section 321 and the optical interface section 326. In this case, the combining/separating unit 322 performs AMCC superimposition and separation on the optical signal. Furthermore, when control signals are exchanged using OTN frames, GCC, etc., the combining/separating section 322 and the processing section 323 may function as an OTN framer.

The normality of the route may be determined using "Ethernet (registered trademark) OAM (Operation Administration Maintenance)." The normality of the path may be determined using the control channel of the lower header whose payload is the main signal (user signal). For example, the general communication channel (GCC) of the optical transport network (OTN) may be used to determine the health of the path.

The UNI_PHY (Tx) 324 is a transmission function unit in the physical layer of the user network interface. The UNI_PHY (Tx) 324 performs predetermined reception processing on the electrical signal (main signal) output from the processing unit 323, and transmits the main signal to the user side. Note that the user side may be electrical or optical.

The UNI_PHY (Rx) 325 is a reception function unit in the physical layer of the user network interface. The UNI_PHY (Rx) 325 receives a main signal from the user side, performs a predetermined transmission process, and outputs an electrical signal according to the main signal to the processing unit 323. Note that the user side may be electrical or optical.

The optical interface section 326 converts the control signal into an optical signal. The optical interface section 326 transmits the optical signal obtained by the conversion to the Ph-GW 100.

The control signal receiving unit 331 receives from the combining/separating unit 322 the control signal separated by the combining/separating unit 322 . The control signal receiving unit 331 operates according to information indicated by the received control signal. If the control signal is information indicating an instruction to execute a loopback, the control signal receiving unit 331 instructs the optical transceiver 301 to execute a loopback in accordance with the instruction. For example, the control signal receiving unit 331 instructs the UNI_PHY (Tx) 324 to perform loopback of the main signal.

The flow of processing for determining signal path normality in the first embodiment will be explained. An example will be explained in which the Ph-GW generates and transmits a main signal for loopback, the user equipment loops back the main signal, and the Ph-GW receives and terminates the looped-back main signal.

At a predetermined timing, the determination control unit 401 instructs the signal termination unit 402 to output the main signal according to a protocol that can be processed by the target user device. The predetermined timing may be, for example, the timing at which a problem in communication with the user device 300 is detected. Note that this instruction may be an instruction from the APN controller 200 or an instruction from the access system management control unit 103.

Upon receiving the instruction, the signal termination unit 402 generates a main signal and outputs it to the SW 403. The output main signal may be, for example, a signal with a predetermined content in the signal path normality determination. The determination control unit 401 generates a control signal for instructing execution of loopback and outputs it to the combination/separation unit 404 . The combining/separating section 404 superimposes the control signal on the main signal and outputs it to the optical interface section 405 . The optical interface unit 405 converts the electrical signal input from the combining/separating unit 404 into an optical signal, and transmits the optical signal to the user device 300 via the transmission path. The procedure is to instruct the user device to loop back via a control signal or the like. After that, it is correct to have the signal termination section according to the protocol of the user equipment transmit the loopback signal. This is because if the loopback signal is transmitted before the user equipment responds, there is a risk that the user equipment will leak the loopback signal, which normally should not be transmitted, to the user side.

Upon receiving the optical signal from the access system management control unit 103 , the optical interface unit 321 of the user device 300 converts the received optical signal into an electrical signal and outputs it to the combining/separating unit 322 . The combining/separating unit 322 separates the received signal into a control signal and a main signal. The combining/separating section 322 outputs a control signal to the control section 330 and outputs a main signal to the processing section 323.

When the control signal receiving section 331 of the control section 330 receives the control signal from the combining/separating section 322, it operates according to the content of the control included in the control signal. The control signal includes a signal indicating an instruction to perform loopback. In response to this instruction, the control signal receiving unit 331 instructs the optical transceiver 301 to execute loopback of the main signal. The main signal received by the optical transceiver 301 is the main signal transmitted from the signal termination section 402 that performs a protocol operation that can be processed by the optical transceiver 301. Therefore, the optical transceiver 301 can loop back the main signal without any problem. Since the response is usually slow compared to the control response and the main signal, the control signal is transmitted, and the main signal for loopback is transmitted after the user equipment is ready for loopback in response.

For example, the processing unit 323 may serve as a loopback point to execute loopback processing, or the UNI_PHY (Tx) 324 or UNI_PHY (Rx) 325 may serve as a loopback point to execute loopback processing. . The loopback process may be implemented as a full channel loopback, a partial loopback, or a logical loopback, for example. Further, when loopback processing is executed in the optical interface unit 321, the combining/separating unit 322, or the processing unit 323, intra-device loopback, which will be described later, may be executed within the optical transceiver 301. In this case, for example, the control unit 330 may include an in-device return control unit 334, which will be described later.

The looped back main signal is converted into an optical signal at the optical interface unit 326 and transmitted to the access system management control unit 103. In the loop 1 equivalent, the main signal is looped back between the optical IFs or immediately after the optical IF as seen from the access network (in Figures 2 to 5, the combining/separating section, etc.), and in the loop 2 equivalent, the main signal is looped back between the optical IFs or immediately after the optical IF as seen from the access network, and in the loop 2 equivalent, the main signal is returned between the optical IFs or immediately after the optical IF when viewed from the access network. When viewed from the network, the process loops back just before Rx and Tx of UNI_PHY (processing section in FIGS. 2 to 5). When looping back at the optical IF section, there is a possibility that control signals such as AMCC are included, but even when looping back at the optical IF section, the control signal may be a different optical signal from the main signal, or the control signal may be removed. When the signal is returned by a processing unit or UNI_PHY, the control signal may not be included in the return signal. In this state, when the control signal is also looped back, the control signal to be looped back is superimposed or multiplexed on the main signal to be looped back, which does not include the control signal, and the control signal and the main signal are looped back. In this embodiment, the main signal is looped back using a protocol that can be used by the user equipment, so the control signal may also be looped back, but this is not essential. Conversely, in the control signal loopback embodiment described below, loopback of the control signal is essential, but loopback of the main signal is not essential.

The looped back main signal is converted into an electrical signal at the optical interface section 406, and is input to the signal termination section 402, which was the source of the main signal. The signal termination unit 402 performs a predetermined evaluation on the input main signal according to the continuity check. For example, an evaluation may be made as to whether the loopback was performed correctly. The signal termination unit 402 outputs information indicating the evaluation result to the determination control unit 401. The determination control unit 401 performs a signal path normality determination regarding the target user device based on the evaluation result received from the signal termination unit 402. The determination control unit 401 may output the determination result to another device or record it in a storage device as a log.

According to the communication system 1 of the first embodiment configured in this way, the main signal to be looped back is transmitted to the user device 300 using a signal of a protocol that can be processed by the user device 300. Therefore, loopback can be performed at a loopback point after the main signal passes through the path after optical-to-electrical conversion in the optical transceiver 301. Therefore, it is possible to determine the normality of the signal path including the inside of the user device 300 in a protocol-independent APN that does not depend on a specific communication protocol or modulation method.

The process of determining the normality of both up and down sections using loopback has been described above. Note that only one optical signal may be conducted from the access system management control unit 103 to the user device 300 and from the user device 300 to the access system management control unit 103, and only the normality in that direction may be determined. In that case, if it is downlink (from the access system management control unit 103 to the user device 300), the user device 300 declares the determination result using a control signal. If it is an uplink (from the user device 300 to the access system management control unit 103), the user device 300 sends a signal to the access system management control unit 103 according to the instruction in the control signal.

When a communication system includes an optical signal transmitting/receiving device, one opposing device (Ph-GW) selectively generates an optical signal in a format that can be transmitted and received by the other opposing device, and transmits the generated optical signal to the opposing device. Fold back to the device. The other opposing device (user device) receives the reflected optical signal or its response (in a format that can be transmitted and received), and uses the received reflected optical signal or its response to communicate with the opposing device. Determine whether the signal path including the signal path with the other device is normal.

(B1) System of loopback at Ph-GW and multiple main signal termination units on Ph-GW side (“format selection + loopback side: device on Ph-GW side” and “generation transmission/reception termination side: user equipment”) The configuration pattern is that the device on the Ph-GW side selects the main signal termination section according to the main signal used by the opposite device (here, the user device), and the main signal termination section of the opposite device (here, the user device) selects the main signal termination section. Generates a request for normality determination using the main signal, transmits a response regarding normality determination in response to the request at the main signal termination section selected by the Ph-GW side device, and transmits the received response to the user device. or the device on the Ph-GW side selects the main signal termination section according to the main signal used by the opposite device (user device here), and terminates at the main signal termination portion of the opposite device (user device here). The main signal termination unit generates a normality determination signal using the main signal, and the main signal termination unit selected by the Ph-GW side device returns the normality determination signal, and the received return ( (loopback signal) is terminated at the main signal termination section of the opposite device (user device here) (not shown)

Set up the optical distribution unit etc. so that the access system management control unit and the user device can communicate. The access system management control section selects the termination section of the main signal of the protocol according to the user device. The access system management control unit instructs the user equipment to generate and transmit an uplink main signal for normality determination. The instruction may be a control signal or a main signal. In the case of a control signal, the termination unit according to the user device may be selected after the instruction is given. Note that in the case of using the main signal, since the main signal is used for the instruction, the instruction is given after selection. The user equipment generates and transmits an uplink main signal for normality determination. Note that when there is no response to the control signal, it is not necessary to modulate the main signal with the control signal or to superimpose the control signal on the main signal. The access system management control unit returns the uplink main signal or its response as a downlink main signal. That is, the signal received by the optical IF section 406 is returned by the selected signal termination section 402, and the optical IF section 405 outputs the returned signal. Note that when no instruction is given by the control signal, it is not necessary to modulate the main signal with the control signal or to superimpose the control signal on the main signal. The returned downlink main signal is received, terminated, and determined by the user equipment. With the passage of time or an instruction from the access system management control unit, the generation and transmission of the main signal for determining the normality of the user device is canceled, and the determination result is acquired from the user device. The instruction at this time may be a control signal or a main signal. The acquisition at this time may be either a control signal or a main signal.

Here, when connecting the user device and the access system management control unit, the connection was changed at the optical distribution unit. Note that such a connection may be made in other ways.

(B2) System configuration of loopback at Ph-GW and multiple main signal termination units on user equipment side (“format selection + generation transmission/reception termination side: user equipment” and “return side: device on Ph-GW side”) Pattern, the user equipment side selects the main signal termination section according to the main signal used by the opposite device (here, the device on the Ph-GW side), and requests normality determination using the main signal at the selected main signal termination section. The opposite device (Ph-GW side device in this case) transmits a response regarding normality determination in response to the request, and the received response is terminated at the selected main signal termination section of the user device. Or, the user equipment selects the main signal termination section corresponding to the main signal used by the opposite device (here, the device on the Ph-GW side), and uses the selected main signal termination section to perform normality determination using the main signal. Generates a signal, sends back a signal for determining its normality at the opposite device (Ph-GW side device here), and transmits the received return (loopback signal) to the selected main signal terminal of the user device. terminating in (not shown))

A main signal termination section (signal termination section) corresponding to the signal format used by the opposing device may be arranged in the user device. The optical distribution unit and the like are set so that the access system management control unit and the user device can communicate. The access system management control unit selects a main signal termination unit (signal termination unit) located in the user device. The user equipment transmits the main signal at the selected signal termination. Ph-GW returns the main signal. The user equipment receives and terminates the returned downlink main signal, and determines normality.

As described above, for example, the first user device (user device 300-1) or the first control device (access system management control unit 103-1) is connected to the opposing second user device (user device 300-2). Or transmitted from a second user device or second control device that generates and terminates a main signal in a signal format selected based on the signal format used by the second control device (access system management control unit 103-2). The first main signal sent back is looped back. The second user device or second control device determines whether the signal path including between the second user device or second control device and the first user device or first control device is normal. is determined based on the folded first main signal.

For example, a first user device (user device 300-1) or a first control device (access system management control unit 103-1) is connected to an opposing second user device (user device 300-2) or a second control device. The second user device (user device 300-2) or the second control device (access system management control unit 103) uses a signal format selected based on the signal format used by the device (access system management control unit 103-2). -2) may be looped back. The first user device (user device 300-1) or the first control device (access system management control unit 103-1) is connected to the opposing second user device (user device 300-2) or second control device. The second main signal transmitted from the third user device or the third control device may be looped back in a signal format selected based on the signal format used by the access system management control unit 103-2. The second user device or second control device determines whether the signal path including between the second user device or second control device and the first user device or first control device is normal. may be determined based on the returned second main signal.

For example, a first user device (user device 300-1) or a first control device (access system management control unit 103-1) is connected to an opposing second user device (user device 300-2) or a second control device. The first signal transmitted from the second user device or the second control device that generates and terminates the main signal in the signal format selected based on the signal format used by the device (access system management control unit 103-2) The main signal may be responded to with a second main signal or a third main signal. The second user device or second control device determines whether the signal path including between the second user device or second control device and the first user device or first control device is normal. may be determined based on the second main signal or the third main signal used for the response.

For example, a first user device (user device 300-1) or a first control device (access system management control unit 103-1) is connected to an opposing second user device (user device 300-2) or a second control device. The second user device (user device 300-2) or the second control device (access system management control unit 103) uses a signal format selected based on the signal format used by the device (access system management control unit 103-2). -2) may respond with a fourth main signal to the second main signal transmitted from the terminal. The first user device (user device 300-1) or the first control device (access system management control unit 103-1) is connected to the opposing second user device (user device 300-2) or second control device. The fourth main signal is transmitted from the third user device or the third control device in the signal format selected based on the signal format used by the You may respond with the main signal. The second user device or second control device determines whether the signal path including between the second user device or second control device and the first user device or first control device is normal. may be determined based on the fourth main signal used for the response.

(Modified example of the first embodiment)
A description will be given of what to do when the Ph-GW does not receive the main signal that should be used as a downlink signal (when the main signal does not reach the Ph-GW from outside the normality determination target section).

In the main signal loopback that receives the normality determination result from the opposite device, the generation and/or termination of the main signal for normality determination is performed by the device on the opposite side of the normality determination target section, for example, another Ph - Instruct the GW or user device, and in the case of termination, the determination result may be obtained from that device. The signal termination unit may be configured to be used only when instructions cannot be given due to a break in the route, or when generation or termination is not performed according to the instructions even if instructions are given. Note that in a configuration other than the configuration shown in FIG. 7, which will be described later, in the case of an abnormality, the configuration example shown in FIG. 7, which will be described later, may be used.

Main signal loopback, which instructs the opposing device to return, instructs the device on the opposite side of the normality determination target section, for example, another Ph-GW or user device, to respond to or return the main signal for normality determination. Good too. The signal termination section may be configured to be used only when the instruction cannot be given due to a break in the route, or when the instruction is not responded to or returned in accordance with the instruction. Note that in a configuration other than the configuration shown in FIG. 7, which will be described later, in the case of an abnormality, the configuration example shown in FIG. 7, which will be described later, may be used.

(Second embodiment)
<Control signal loopback>
6 to 8 are diagrams showing the communication system 1 of the second embodiment. 6 to 8, among the devices included in the communication system 1, only the devices related to one section that is the target of the signal path normality determination are shown. In the second embodiment, an example will be described in which the access system management control unit 103 performs signal path normality determination on the user device 300 connected to its own device (Ph-GW 100). For example, the access system management control unit 103-2 in FIG. 1 performs a signal path normality determination on the user device 300-2. The normality determination may be performed in sections other than "between the Ph-GW and the user device" described in the first embodiment.

When looping back the control signal, when the control signal and the main signal are connected to different optical IF sections, the optical IF section connected to the combining/separating section 322 is the signal termination section of the main signal, and the loopback is performed. Regarding the control signal, the optical IF unit connected to the combining/separating unit 322 is on the control signal side, not on the signal termination side of the main signal.

The access system management control unit 103 transmits a control signal for instructing loopback to the user device 300 (target user device) connected to the section targeted for signal path normality determination. In the loopback in the second embodiment, the Ph-GW does not need to generate and terminate the main signal according to the protocol used by the user equipment 300.

Regarding the access system management control unit 103, on the network side from the combination/separation unit 404, the control signal is looped back by the determination control unit 401 and generated and terminated. In other words, the access system management control unit 103 determines whether the internal signal path (internal path) of the access system management control unit 103 is normal based on the control signal returned by the determination control unit 401. Good too.

Regarding the user device 300, on the user side from the combining/separating unit 322, the control signal is looped back or generated and terminated at the control unit 330, and the main signal is looped back or generated and terminated at the UNI side. In both cases, the combination/separation section 322 multiplexes the signals. On the network side from the combining/separating unit 322, if the optical IF unit is common for the control signal and the main signal, since they are common, both are transmitted and received at the optical IF unit. When at least one of the transmission and reception of the optical IF section of the user equipment is different between the control signal and the main signal, different transmissions or receptions, or both, are performed at the optical IF sections corresponding to the control signal or the main signal, respectively. Note that in a user device, control signal loopback usually involves main signal processing.

In the loopback itself in the second embodiment, the normality of the portion where the control signal is not conducted, for example, the path between the UNI_PHY and the processing unit 323 is not determined. The control signals used may be transmitted by a plurality of user devices 300 (all user devices 300 of the communication system 1) each corresponding to optical signals of different transmission/reception formats (protocols, modulation methods, modulation speeds, and code formats). ) is a control signal commonly used in In particular, it is a control signal that is commonly used by user equipments with different main signal protocols. A specific example of such a control signal is, for example, AMCC. For example, there is a control signal for at least one of the transmitting side and the receiving side that uses different optical IF sections, light sources, receivers, and main signals, and that does not depend on the format of the main signal. Other specific examples of such control signals include Ethernet (registered trademark) OAM and OTN frame GCC. Ethernet OAM can carry different protocols when encapsulated in Ethernet. The OTN frame can pack client signals of different protocols within the OTN frame. Note that when using Ethernet (registered trademark) OAM, OTN frame GCC, etc., the control signal is time-division multiplexed with the main signal. Therefore, the delay may vary in Ethernet (registered trademark) OAM. However, other than that, the communication quality of the main signal itself is not affected. On the other hand, AMCC loopback is modulated by being superimposed on the main signal. Therefore, the communication quality of the main signal itself may be affected. In order to realize such processing, the access system management control unit 103 includes a determination control unit 401, a combination/separation unit 404, an optical interface unit (optical IF unit) 405, and an optical interface unit (optical IF unit) 406.

The determination control unit 401 outputs a control signal indicating execution of loopback to the combination/separation unit 404. The control signal used is a signal that can be used in common by a plurality of user devices 300 that correspond to optical signals of different transmission/reception formats (protocols, modulation methods, modulation speeds, and code formats). Upon receiving the looped back control signal from the user device 300, the determination control unit 401 determines the normality of the route to be determined based on the received signal.

The combining/separating unit 404 superimposes the control signal output from the determination control unit 401 on the main signal output from another device (for example, a signal termination unit). For example, the combining/separating unit 404 superimposes a control signal (for example, AMCC) on the optical signal of the main signal to the user equipment 300 or the optical signal of another carrier. For example, the combining/separating unit 404 may frequency-superimpose the control signal on the main signal. The combining/separating unit 404 separates a control signal from the signal received from the user device 300 and outputs the separated control signal to the determination control unit 401 . The combining/separating unit 404 outputs a signal (main signal) from which the control signal is separated to another device (for example, a signal termination unit).

Note that the light source for the optical signal used as the loopback signal may be separate from the light source for the main signal, or there may be multiple light sources. The light source of the optical signal used as the loopback signal may be shared as the light source of the optical signal used as the main signal. If the light source for the main signal and the light source for the control signal are different light sources, the optical interface unit 406 may receive at least the signal from the light source for the control signal. If the main signal light source and the control signal light source are shared, the signal from that light source is received.

Note that when the light source of the main signal and the light source of the control signal are different light sources, the loopback receiving section 310 may receive at least the signal of the light source of the control signal. If the main signal light source and the control signal light source are shared, the signal from that light source is received.

The optical interface section 405 converts the electrical signal output from the combining/separating section 404 into an optical signal. The optical interface unit 405 transmits the optical signal obtained by the conversion to the user device 300 via an optical communication path.

The user device 300 includes an optical transceiver 301 and a control section 330. The optical transceiver 301 of the second embodiment has the same configuration as the optical transceiver 301 of the first embodiment, so a description thereof will be omitted.

Note that in the first embodiment, when instructions, generation termination, or loopback are performed using only the main signal, there is no need to transmit the control signal to the control unit of the user device. In the second embodiment, when the generation and termination of the main signal and the loopback are not essential, the transmission and reception of the control signal with the control unit in the user device is the main function. In this respect, the second embodiment is not similar to the first embodiment.

The control signal receiving section 331 receives from the combining/separating section 322 the control signals separated by the combining/separating section 322 . The control signal receiving section 331 operates according to information indicated by the received control signal. If the control signal is information indicating an instruction to execute loopback, control signal receiving section 331 instructs return section 333 to execute loopback in accordance with the instruction.

The control signal transmitter 332 outputs the control signal to be transmitted to the combiner/separator 322. When receiving an instruction to perform loopback from control signal receiving section 331, loopback section 333 executes loopback processing in accordance with the instruction. The target of loopback processing in the loopback unit 333 is, for example, a control signal. The loopback process may be implemented as a full channel loopback, a partial loopback, or a logical loopback, for example. The looped back control signal is converted into an optical signal by the optical interface unit 326 and transmitted to the access system management control unit 103.

In FIGS. 7 and 9, optical signals such as continuous light (CW light) that are not based on the protocol of the user equipment can receive control signals (for example, AMCC) without damaging the optical IF section, etc. , an optical IF unit, etc. may transmit and receive the data. In FIGS. 7 and 9, in the control signal loopback, as long as the control signal can be transmitted and received, the main signal according to the signal format of the user equipment is not transmitted and received as in the first embodiment. Therefore, as long as the control signal is used, the optical signal may be unmodulated continuous light.

7 and 9 are suitable when the main signal does not reach the access system management control unit from the opposite side of the section where normality is to be determined. In FIGS. 7 and 9, it is assumed that the connection of the optical distribution unit is switched from the user device-user device path to the path between the user device and the access system management control unit. In Figures 6 and 8, which are assumed to connect and branch in the middle of the route without switching the connection of the optical distribution unit, the route is not switched, and the main signal is used for access system management from the opposite side of the section where normality is determined. When the control unit is not reached, unlike in FIGS. 7 and 9, a combination/separation unit is built into the access system management control unit, but the result is substantially the same as in FIGS. 7 and 9.

Note that in FIGS. 6 and 8, the normal user device-to-user device connection is monitored, so there is no switching of the light distribution unit. In FIGS. 7 and 9, the normal user device-user device connection is switched to the user device-control unit for normality determination.

The optical distribution unit etc. are set so that the access system management control unit and the user device can communicate. The access system management control unit instructs the user device 300 to loop back the control signal. The instruction may be a control signal. The same applies below.

In FIGS. 6 and 8, the main signal from outside the section for determining normality is modulated and the control signal is multiplexed (FIG. 8), or the control signal is multiplexed onto another optical signal (FIG. 6). In Figure 8, the main signal for multiplexing the control signal is not input, but unmodulated continuous light is used instead of the main signal to carry the control signal when the main signal does not come from outside the section for determining normality. etc. may also be entered.

As mentioned above, in FIGS. 6 and 8, it is assumed that the monitor is originally built into the path during normal main signal conduction, so the path of the optical distribution section regarding the main signal is not changed. On the contrary, in the cases of FIGS. 7 and 9, all generation or all termination is performed without branching and multiplexing the main signal, and it is essential to switch to connect the optical distribution section to the access system control section.

The user equipment 300 modulates the uplink main signal using the downlink control signal or its response as an uplink control signal, or superimposes the downlink control signal or its response on the uplink main signal as an uplink control signal, and returns it in the uplink direction at the folding unit 333. . The access system management control unit receives and terminates the return uplink control signal, and makes a determination. The loopback of the control signal of the user device is canceled with the passage of time or an instruction from the access system management control unit. Note that the instruction may be a control signal. Note that if the control signal is multiplexed as another optical signal, the access system management control unit receives and terminates the control signal. When the control signal is multiplexed on the main signal, light is generated by branching a part of the upstream signal or by nonlinear optical effects, etc., and at least generates light that can read the control signal, and performs access system management and control. section terminates it. At least a portion of the uplink signal is output outside the section targeted for normality determination.

The optical distribution unit etc. are set so that the access system management control unit and the user device can communicate. The access system management control unit selects the termination part (signal termination part) of the main signal of the protocol according to the user device. The instruction may be a control signal. The user equipment modulates the uplink main signal with the uplink control signal for normality determination, or superimposes the uplink control signal for normality determination on the uplink main signal, and transmits it in the uplink direction. The access system management control unit modulates the downlink main signal using the uplink control signal or its response as a downlink control signal, or superimposes the uplink control signal or its response on the downlink main signal as a downlink control signal, and returns it in the downlink direction. ,Send. That is, the signal received by the optical IF section 406 is returned and the optical IF section 405 outputs it. The user equipment 300 receives and terminates the returned downlink control signal, and makes a determination. With the passage of time or an instruction from the access system management control unit, generation of a control signal for determining the normality of the user device 300, and cancellation of modulation of the uplink main signal or superposition of the uplink main signal with the generated control signal, The optical IF section acquires the determination result from the user device. The instruction may be a control signal.

In Figures 6 and 8, the access system uses an optical signal such as unmodulated continuous light instead of the main signal to carry the control signal when the main signal does not come from outside the section for determining normality. It is not generated by the management control unit. In FIGS. 6 and 8, the control signal is multiplexed by modulating the main signal from outside the section for determining normality (FIG. 8), or the control signal is multiplexed onto another optical signal (FIG. 6). As described above, in FIGS. 6 and 8, it is assumed that the monitor is originally built into the path during normal main signal conduction, so the path of the optical distribution section regarding the main signal is not changed. On the contrary, in the cases of FIGS. 7 and 9, all generation or all termination is performed without branching and multiplexing the main signal, and it is essential to change the connection so that the optical distribution section is connected to the access system control section.

In FIGS. 6 and 8, the main signal and control signal are demultiplexed inside the access system management control unit, so they are similar to the monitor.

In FIGS. 6 and 8, when the transmitting unit (optical IF unit) that transmits the optical signal that is returned by the opposing device is placed in the Ph-GW for normality determination, the connection is made via the optical distribution unit. In addition to the access system management control unit 103, a transmission unit (optical IF unit) may be arranged. For example, a transmitting section (optical IF section) is installed at a position where an optical signal can be outputted to a folding device via an optical multiplexer/brancher or an optical multiplexer/demultiplexer installed outside the input port or output port to the optical distribution section. ) may be placed. For example, a transmission unit (optical IF unit) is placed in a monitoring unit that monitors the optical intensity of an optical signal on at least one of the input side and output side of the Ph-GW and exchanges control signals with a user device. may be done. Instead of outputting combined or multiplexed light through an optical multiplexer/brancher or an optical multiplexer/demultiplexer, light generated by an optical nonlinear effect of the light to be folded back may be output.

When a receiving unit (optical IF unit) that receives at least part of the optical signal returned by the opposing device is placed in the Ph-GW for normality determination, the access connected via the optical distribution unit A receiving section (optical IF section) may be arranged in addition to the system management control section. For example, a position where the optical signal reflected from the folding device or at least a part of its components can be inputted via an optical multiplexer/brancher or optical multiplexer/demultiplexer installed outside the input port or output port to the optical distribution unit. A receiving section (optical IF section) may be placed in the receiver. For example, a receiving unit (optical IF unit) is placed in a monitoring unit that monitors the optical intensity of an optical signal on at least one of the input side and output side of the Ph-GW and exchanges control signals with a user device. may be done. Instead of inputting branched or demultiplexed light through an optical multiplexer/brancher or an optical multiplexer/demultiplexer, light generated by an optical nonlinear effect of folded light may be input.

Effectively, this corresponds to the case where light for modulation with a control signal is inserted in each of the figures from FIG. 6 to FIG. 8, which will be described later. When superimposing a control signal from a separate light source independent of the main signal, unless there is a reason such as aligning the gains of amplifiers in the path, the main signal that does not comply with the protocol of the user equipment or unmodulated light (CW light) should be superimposed. ) is not necessary.

The access system management control unit 103 may determine the normality of the route using the AMCC signal of the APN. The access system management control unit 103 may determine the normality of the route using "Ethernet (registered trademark) OAM (Operation Administration Maintenance)." The access system management control unit 103 may determine the normality of the route using a control channel of a lower header whose payload is a main signal (user signal). The normality of the route may be determined by using, for example, a general communication channel (GCC) of an optical transport network (OTN) as the control channel.

The flow of processing for determining signal path normality in the second embodiment will be described.
The following is a flow related to control signal loopback, and the same applies when receiving a response to a normality determination request (instead of returning predetermined loopback information according to the loopback instruction, a response is returned to the request. ).

At a predetermined timing, the determination control unit 401 generates a control signal for instructing execution of loopback and outputs it to the combination/separation unit 404. The predetermined timing may be, for example, the timing at which a problem in communication with the user device 300 is detected. The timing may be in accordance with instructions from the controller. The combining/separating section 404 outputs a control signal to the optical interface section 405. The optical interface unit 405 converts the electrical signal input from the combining/separating unit 404 into an optical signal, and transmits the optical signal to the user device 300 via the transmission path.

Upon receiving the optical signal from the access system management control unit 103 , the optical interface unit 321 of the user device 300 converts the received optical signal into an electrical signal and outputs it to the combining/separating unit 322 . The combiner/separator 322 separates the control signal from the received signal and outputs the control signal to the controller 330 .

When the control signal receiving section 331 of the control section 330 receives the control signal from the combining/separating section 322, it operates according to the content of the control included in the control signal. The control signal includes a signal indicating an instruction to perform loopback. In response to this instruction, the control signal receiving section 331 instructs the loopback section 333 to perform loopback of the control signal. The return unit 333 performs loopback processing on the received control signal and outputs the control signal to the combination/separation unit 322 .

The looped back control signal is converted into an electrical signal at the optical interface section 406, and is input to the determination control section 401, which was the source of the control signal. The determination control unit 401 performs a predetermined evaluation on the input control signal according to the continuity check. For example, an evaluation may be made as to whether the loopback was performed correctly. The determination control unit 401 performs a signal path normality determination regarding the target user device based on the evaluation result. The determination control unit 401 may output the determination result to another device or record it in a storage device as a log.

As described above, for example, the first user device (user device 300-1) or the first control device (access system management control unit 103-1) is connected to the opposing second user device (user device 300-2). Alternatively, it responds with a second control signal to the first control signal transmitted from the second control device (access system management control unit 103-2). The second user device or second control device determines whether the signal path including between the first user device or first control device and the second user device or second control device is normal. is determined based on the second control signal used in the response.

For example, a first user device (user device 300-1) or a first control device (access system management control unit 103-1) is connected to an opposing second user device (user device 300-2) or a second control device. The first control signal transmitted from the device (access system management control unit 103-2) may be returned. The second user device or second control device determines whether the signal path including between the first user device or first control device and the second user device or second control device is normal. may be determined based on the returned first control signal.

For example, if the optical signal for carrying the second control signal does not reach the first control device (user device 300-1), the first control device (user device 300-1) differs from the main signal. A second control signal is multiplexed onto another optical signal, and when the optical signal for carrying the second control signal reaches the control device, the second control signal is added to the optical signal for carrying the second control signal. The signals may be multiplexed and whether or not the signal path is normal may be determined based on another optical signal or a second control signal multiplexed on the optical signal.

According to the communication system 1 of the second embodiment configured in this way, a control signal that can be processed by the user device 300 is transmitted to the user device 300. Therefore, loopback can be performed at a loopback point (return unit 333) after the main signal passes through the path after optical-to-electrical conversion in the optical transceiver 301. Therefore, in a protocol-independent APN that does not depend on a specific communication protocol or modulation method, the normality of the signal path including the inside of the user device 300 (for example, the optical interface unit 321, the combining/separating unit 322, and the optical interface unit 326) is determined. It becomes possible to do so.

This type of processing is superior to other signal path normality determinations in the following points. In the conventional main signal loopback processing, whether or not the processing can be performed depends on the protocol that can be processed by the user device 300. Therefore, as in the first embodiment, it is necessary to additionally provide equipment compatible with various main signals depending on the signal format used by the user equipment 300 on the station side. In contrast, in the communication system 1 of the second embodiment, there is no protocol dependence, and there is no need to additionally provide equipment compatible with various main signals on the station side. Furthermore, in OTDR, it is necessary to additionally provide dedicated equipment on the station side. In contrast, in the communication system 1 of the second embodiment, there is no need to additionally provide dedicated equipment on the station side. Furthermore, in the method of installing a monitor, it is necessary to additionally provide a monitor device on the station side. In contrast, in the communication system 1 of the second embodiment, there is no need to additionally provide special monitoring equipment such as an OTDR on the station side.

Note that the control signal transmitting section 332 communicates with the Ph-GW via the combining/separating section 322. For example, the control signal transmitter 332 responds to a loopback instruction. For example, the control signal transmitter 332 responds to the Ph-GW with the result of the normality determination determined by the user device.

(First modification of the second embodiment)
<Main signal loopback + control signal loopback>

The access system management control unit 103 may loop back the control signal, loop back the main signal, or loop back both the control signal and the main signal. In this embodiment, a communication system includes devices that communicate with each other using optical signals, and one device transmits a control signal to another device using an optical signal. The other devices loop control signals or their responses back to one device. An example of a communication system in which one device receives a returned control signal or its response and determines whether a signal path including a signal path between one device and another device is normal. show. When looping back the control signal and looping back the main signal, both the control signal and the main signal are looped back.

More specifically, it is a communication system that includes a device that transmits and receives a control signal by superimposing it on its own optical signal or an optical signal from another device, or modulating its own optical signal or an optical signal from another device. One of the opposing devices generates and generates an optical signal in a format that can be transmitted and received by the other opposing device (an optical signal that can receive control signals such as AMCC without damaging the optical IF unit, etc.). A control signal obtained by superimposing the generated optical signal or modulating the generated optical signal is transmitted to the other opposing device. The other opposing device returns the received control signal or its response by superimposing it on its own optical signal or the optical signal from the other device, or modulating the own optical signal or the optical signal from the other device. and send. One of the opposing devices superimposes or modulates the optical signal and receives the returned control signal or its response. The opposing device determines whether the signal path including the signal path between the opposing device and the other opposing device is normal, based on the received returned control signal or its response. .

(C1) System configuration in which the user equipment loops back and multiple main signal termination units on the Ph-GW side (“format selection + generation transmission/reception termination side: device on the Ph-GW side” and “return side: user equipment”) As shown in the pattern, the device on the Ph-GW side selects the main signal termination section (signal termination section) according to the main signal used by the opposite device (in this case, the user device), and uses the selected main signal termination section to Generates a request for normality determination using the main signal, transmits a response regarding normality determination to the opposite device (user device here) in response to the request, and transmits the received response to the device on the Ph-GW side. Terminate at the selected main signal termination section, or the device on the Ph-GW side selects the main signal termination section (signal termination section) according to the main signal used by the opposite device (in this case, the user device), and The signal termination section generates a normality determination signal using the main signal, the opposite device (here, the user device) returns the normality determination signal, and receives the received return (loopback signal). It is terminated at the selected main signal termination part of the device on the Ph-GW side.In this embodiment, in addition to the main signal normality determination request and its response, or the main signal normality determination signal and its return, The device on the Ph-GW side generates a request for normality determination using a control signal, the opposite device (user device here) transmits a response regarding normality determination in response to the request, and the received response is sent to the Ph-GW. - Terminates at the device on the GW side, or the device on the Ph-GW side generates a signal for determining normality using a control signal, and transmits the signal for determining normality at the opposite device (here, the user device) in return, The received return (loopback signal) is terminated by the device on the Ph-GW side, or the user device generates a request for normality determination using a control signal, and the opposite device (here, the device on the Ph-GW side) In response to the request, a response regarding normality determination is transmitted, and the received response is terminated at the user device, or the user device generates a normality determination signal using a control signal and generates a normality determination signal from the opposite device (here, Ph- (GW side device) sends back a signal for determining the normality, and the received return (loopback signal) is terminated at the user device)

Set up the optical distribution unit, etc. so that the access system management control unit and the user device can communicate. The access system management control section selects the termination section of the main signal of the protocol according to the user device. The access system management control unit instructs the user device to loop back the control signal. The instruction may be a control signal or a main signal. However, control signals are more appropriate for obtaining instructions. The same applies below. In the case of a control signal, a termination unit corresponding to the user equipment may be selected after the instruction is given. The access system management control unit generates a downlink main signal not limited to normality determination using a protocol according to the user equipment, and modulates the main signal with a downlink control signal for normality determination, or modulates the main signal with a downlink control signal for normality determination. A downlink control signal for normality determination is superimposed and transmitted in the downlink direction. The user equipment modulates the uplink main signal with the downlink control signal or its response as an uplink control signal, or superimposes the downlink control signal or its response on the uplink main signal as an uplink control signal, and transmits the signal back in the uplink direction. The returned uplink control signal is received and terminated by the access system management control unit and judged. The loopback of the control signal of the user device is canceled with the passage of time or an instruction from the access system management control unit. Note that the instruction may be a control signal or a main signal. Furthermore, after the loopback is released, the connection form of the light distribution section is returned to its original state.

(C2) System configuration pattern where the user equipment loops back and multiple main signal termination units on the user equipment side (“format selection + loopback side: user equipment” and “generation transmission/reception termination side: Ph-GW side device”) , the user equipment selects the main signal termination section (signal termination section) according to the main signal used by the opposite device (here, the device on the Ph-GW side), and The main signal termination unit generates a request for normality determination using the main signal, and the main signal termination unit selected by the user equipment transmits a response regarding normality determination in response to the request, and transmits the received response. , terminate at the main signal termination section of the device on the Ph-GW side, or the user equipment terminates at the main signal termination section (signal termination section) according to the main signal used by the opposite device (here, the device on the Ph-GW side). The main signal terminal of the opposite device (here, the device on the Ph-GW side) generates a signal for determining normality using the main signal, and the selected main signal terminal of the user device determines its normality. The received return signal (loopback signal) is terminated at the main signal termination section of the opposing device (here, the device on the Ph-GW side).In this embodiment, the normality determination of the main signal is performed. In addition to the request and its response, or the main signal's normality judgment signal and its return, the Ph-GW side device generates a normality judgment request with a control signal, and the opposite device (here, the user device) generates a normality judgment request. In response to the request, a response regarding normality determination is transmitted, and the received response is terminated by a device on the Ph-GW side, or the device on the Ph-GW side generates a signal for determining normality using a control signal, The opposite device (user device in this case) sends back a signal for determining its normality, and the received return (loopback signal) is terminated by the Ph-GW side device, or the user device uses a control signal to indicate that the signal is normal. Generates a request for normality determination, transmits a response regarding normality determination in response to the request in the opposite device (here, the device on the Ph-GW side), and terminates the received response in the user device, or The device generates a normality determination signal using a control signal, the opposite device (here, the device on the Ph-GW side) returns the normality determination signal, and receives the received return (loopback signal). (terminated at user equipment (not shown))

A main signal termination section (signal termination section) corresponding to the signal format used by the opposing device may be arranged in the user device. The optical distribution unit and the like are set so that the access system management control unit and the user device can communicate. The access system management control unit selects a main signal termination unit (signal termination unit) located in the user device. The user equipment loops back the main signal and control signal at the selected signal termination. The Ph-GW receives and terminates the returned uplink main signal and control signal, and determines normality.

(D1) A system in which the Ph-GW loops back and multiple main signal termination units on the Ph-GW side ("format selection + loopback side: device on the Ph-GW side" and "generation transmission reception termination side: user equipment") The configuration pattern is that the device on the Ph-GW side selects the main signal termination section (signal termination section) according to the main signal used by the opposite device (user device here), and then selects the main signal termination section (signal termination section) according to the main signal used by the opposite device (user device here). The termination unit generates a request for normality determination using the main signal, and the main signal termination unit selected by the device on the Ph-GW side transmits a response regarding normality determination in response to the request, and The response is terminated at the main signal termination section of the user equipment, or the device on the Ph-GW side selects the main signal termination section (signal termination section) according to the main signal used by the opposite device (user equipment here). , the main signal terminal of the opposite device (user device in this case) generates a signal for determining normality using the main signal, and the selected main signal terminal of the device on the Ph-GW side generates a signal for determining normality. is sent back, and the received return (loopback signal) is terminated at the main signal termination section of the opposing device (here, the user device).In this embodiment, the main signal normality determination request and its response, or In addition to the main signal for normality determination and its return, the device on the Ph-GW side generates a request for normality determination using a control signal, and the opposite device (in this case, the user device) determines the normality in response to the request. A response related to the determination is sent and the received response is terminated by the Ph-GW side device, or the Ph-GW side device generates a normality determination signal using a control signal, device) returns a signal for determining the normality, and the received return (loopback signal) is terminated by the device on the Ph-GW side, or the user device generates a request for normality determination using a control signal. Then, in response to the request, the opposite device (Ph-GW side device in this case) transmits a response related to the normality determination, and the received response is terminated at the user device, or the user device uses a control signal to determine the normality. Generates a signal for determining the normality, returns the signal for determining the normality at the opposite device (here, the device on the Ph-GW side), and terminates the received return (loopback signal) at the user device ( (not shown))

Set up the optical distribution unit, etc. so that the access system management control unit and the user device can communicate. The access system management control section selects the termination section of the main signal of the protocol according to the user device. The access system management control unit instructs the user device to generate and transmit a control signal for normality determination. The instruction may be a control signal or a main signal. In the case of a control signal, a termination section (signal termination section) according to the user device may be selected after giving an instruction. The user equipment modulates the uplink main signal not only for normality determination with the normality determination uplink control signal, or superimposes the normality determination uplink control signal on the uplink main signal, and transmits the modulated uplink main signal in the uplink direction. The access system management control unit modulates the downlink main signal using the uplink control signal or its response as a downlink control signal, or superimposes the uplink control signal or its response as a downlink control signal on the downlink main signal, and transmits it back in the downlink direction. do. That is, the signal received by the optical IF section 406 is returned by the selected signal termination section 402 and output from the optical IF section 405.

The user equipment receives and terminates the returned downlink control signal, and makes a determination. With the passage of time or an instruction from the access system management control unit, the generation of a control signal for determining the normality of the user equipment, the modulation of the uplink main signal with the generated control signal, or the superimposition of the uplink main signal is canceled, and the judgment is made. Obtain the results from the user device. The instruction may be a control signal or a main signal. The acquisition may be a control signal or a main signal. Furthermore, after the loopback is released, the connection form of the light distribution section is returned to its original state.

(D2) Ph-GW returns and multiple main signal termination units on the user equipment side (system configuration of "format selection + generation transmission/reception termination side: user equipment" and "return side: device on Ph-GW side") pattern, the user equipment side selects a main signal termination section (signal termination section) according to the main signal used by the opposite device (here, the device on the Ph-GW side), and uses the selected main signal termination section to transmit the main signal. Generates a request for normality determination, transmits a response regarding normality determination in response to the request in the opposite device (here, Ph-GW side device), and transmits the received response to the selected master of the user device. Terminate at a signal termination section, or the user equipment selects a main signal termination section (signal termination section) according to the main signal used by the opposite device (here, the device on the Ph-GW side), and selects the selected main signal termination section. Then, the main signal is used to generate a normality determination signal, the opposite device (here, the device on the Ph-GW side) returns the normality determination signal, and the received return (loopback signal) is sent back. , is terminated at the selected main signal termination section of the user equipment.In this embodiment, in addition to the main signal normality determination request and its response, or the main signal normality determination signal and its return, the Ph-GW The side device generates a request for normality determination using a control signal, the opposite device (in this case, the user device) transmits a response regarding normality determination in response to the request, and the received response is sent to the Ph-GW side. or the device on the Ph-GW side generates a normality determination signal using a control signal, and the opposite device (in this case, the user device) returns the normality determination signal, and the received The return (loopback signal) is terminated at the device on the Ph-GW side, or the user device generates a request for normality determination using a control signal, and the opposite device (here, the device on the Ph-GW side) responds to the request. In response, a response regarding normality determination is transmitted, and the received response is terminated at the user equipment, or the user equipment generates a normality determination signal using a control signal and sends a response to the opposite equipment (here, the Ph-GW side). device) returns a signal for determining its normality, and the received return (loopback signal) is terminated at the user device (not shown).

A main signal termination section (signal termination section) corresponding to the signal format used by the opposing device may be arranged in the user device. The optical distribution unit and the like are set so that the access system management control unit and the user device can communicate. The access system management control unit selects a main signal termination unit (signal termination unit) located in the user device. The user equipment transmits the main signal and the control signal at the selected signal termination. The Ph-GW loops back the main signal and control signal. The user equipment receives and terminates the returned downlink main signal and control signal, and determines normality.

In (C1) and (D1) above, not only the control signal but also the main signal may be looped back, or only the control signal may be looped back and the main signal may be transmitted. In the latter case, the thick line arrow (loopback) shown in the figure indicates that the normality determination path does not reach the UNI of the user device 300 and loops back at the combining/separating unit 322, as shown in FIGS. 6 to 8. The signal is generated and terminated by the determination control unit 401 instead of the signal termination unit (in the case of (C1)). In the case of (D1), it is looped back from the control unit 330 of the user device through the optical transmission path to the determination control unit 401 of the access system management control unit, looped back to the control unit 330 of the user device, and reaches the UNI of the user device 300. The same goes for not doing so.

In addition, in Figures 7 and 9, the combination of "main signal loopback + control signal loopback" cannot be implemented (in addition, in Figure 2-5, the combination of "main signal loopback" and "main signal loopback + control signal loop" is not possible). (You can choose any combination of backs).

Regarding the access system management control unit 103, on the network side from the combination/separation unit 404, the control signal is looped back or generated and terminated at the determination control unit 401, and the main signal is looped back or generated and terminated at the signal termination unit. In both cases, the multiplexing unit 404 multiplexes the signals. On the user side from the combining/separating unit 404, if the optical IF unit is common for the control signal and the main signal, since they are common, both are transmitted and received at the optical IF unit. When at least one of the transmission and reception of the control signal and the main signal by the optical IF section is different, different transmissions or receptions, or both, are performed by the optical IF sections corresponding to the control signal or the main signal, respectively.

When looping back the main signal in addition to the control signal, the control signal receiving unit 331 also instructs the loopback unit 333 and UNI_PHY to execute the loopback according to the instruction.

When looping back on the Ph-GW side, the signal received by the receiving section (optical IF section) is looped back by the selected signal termination section 402, and the transmitting section (optical IF section) outputs it.

Also, the main signal may be generated and terminated by the access system management control unit or may not be looped back, and the main signal modulated by the control signal or superimposed with the control signal by the access system management control unit may be The main signal may be generated, terminated, or folded back only when the main signal cannot be obtained from the section opposite to the target section.

The determination control unit 401 selects a signal termination unit 402 according to a protocol that can be processed by the target user device. The selection may be made based on information from databases inside and outside the Ph-GW, instructions from a control system such as an APN controller, determined from signals that can be received at the signal termination section, or made by the user. This may be performed based on the result of an inquiry to the device. The determination control unit 401 instructs the selected signal termination unit 402 to transmit the main signal to the target user device (the Ph-GW receives the main signal for continuity check from the user device). , when determining normality). Receive the main signal (when the user equipment receives the main signal for continuity check from the Ph-GW and determine the normality), or transmit/receive the main signal (the main signal for continuity check from the Ph-GW is received by the user equipment) When looping back at the user equipment, receiving it at the Ph-GW, and determining normality using the loopback, the main signal for continuity check from the user equipment is looped back at the Ph-GW, received at the user equipment, and then the main signal for continuity confirmation is determined by the loopback. (when determining normality).

There are two types of AMCC loopback: the entire signal including the AMCC signal and the main signal, and the AMCC signal only. In the case of the entire signal, the user equipment 300 receives only the main signal that is not affected by AMCC and loops it back instead of outputting it to the user side. Therefore, AMCC is not included in the loopback of the main signal. Therefore, by receiving AMCC separately from the main signal and re-modulating the loopback of the main signal with AMCC, the entire signal is looped back. Therefore, when looping back the entire signal, there are cases where the timing of the downlink main signal and the downlink AMCC signal are synchronized so that they are the same as the uplink main signal and uplink AMCC signal that are looped back, and cases where they are not synchronized. There is.

In the case of synchronization, regardless of the modulation method of the main signal, it is necessary to align the time from separation to multiplexing through the respective turning points of the main signal and AMCC signal. By synchronizing in time and matching the AMCC modulation index with the transmitting side, it is possible to send back the reproduced signal while taking into account the influence of AMCC.

If not synchronized, it can be easily multiplexed. If there is only an AMCC signal, only the AMCC control signal is sent back. In this case, since the main signal is arbitrary, a loopback test can be performed without interfering with communication of the main signal.

Note that the above ISDN example is an analogy for explanation. The ISDN concept is applied to this embodiment. In the case of BRI (Basic Rate Interface), channels in ISDN include two B channels for data communication and one D (Data) channel for communication control. Depending on the definition of a channel in the APN, for example, if the main signal and AMCC are considered as channels, one or more designated channels, for example certain modifications to certain information in the AMCC signal, for example certain information in the AMCC signal, For example, it may be returned with corrections according to quality-related information such as error rate, an Ack or response to a Request, or RDI (Remote Defect Indication) such as a transmission failure notification in the upstream direction. The quality information, RDI, etc. may be returned not on the AMCC signal side but on the main signal side as a measurement result of the main signal or a failure notification. The AMCC signal and the main signal may each be sent back as multiple channels. An example of a configuration in which quality information is returned is the configuration of the fourth embodiment described later.

(Second modification of the second embodiment)
A case where the main signal on which the control signal is superimposed cannot be used will be described.

The main signal from the device on the opposite side of the normality determination target section (for example, another Ph-GW or user equipment) is It may be configured such that the signal termination unit of the first embodiment is used only when the signal is not available.

By being configured as shown in FIGS. 6, 8, and 14, a user device that uses main signals from other Ph-GWs or user devices and returns control signals and an opposing device (for example, another user device) When performing a normality determination, or by using the main signal from another Ph-GW or user equipment, continue to conduct the signal light between the user equipment that loops back the control signal and the opposing equipment (for example, another user equipment). Then, either extract only the superimposed control signal and terminate it (using a wavelength filter, etc. if the wavelengths are different), or terminate only part of the branched signal light, or at least remove the signal light from the influence of nonlinear optical effects, etc. of the control signal. If the light that can receive the control signal is terminated but the main signal is transmitted, there is an effect that communication using the main signal can be continued even during normality determination.

without generating or terminating the main signal that modulates with the return control signal or superimposing the return control signal, and without generating or terminating the main signal and/or from the device on the opposite side of the normality determination target section (for example, another Ph-GW or user equipment). The main signal may be used, and the signal termination section of the first embodiment may be used only when the main signal is not available.

By being configured as shown in FIGS. 6, 8, and 14, a user device that uses main signals from other Ph-GWs or user devices and returns control signals and an opposing device (for example, another user device) When performing a normality determination, or by using the main signal from another Ph-GW or user equipment, conduction of signal light between a user equipment that generates and terminates a control signal and a device facing the user equipment, such as another user equipment. If the control signal is continued and only the superimposed control signal is extracted, or if the signal light is terminated with at least the control signal transferred due to some branched signal light or a nonlinear optical effect, the main signal is continued even during normality determination. This has the effect of allowing continuous communication.

Note that in the case of control signal loopback, since the control signal is used for determination, determination is possible even if the main signal does not correspond to the protocol of the user device or is unmodulated light (CW light).

(Third embodiment)
FIG. 9 is a diagram showing a third embodiment of the communication system 1. The third embodiment differs from the second embodiment in that the control section 330 further functions as an internal return control section 334, and is the same as the second embodiment in most other respects. The third embodiment of the communication system 1 will be described below, focusing on the differences from the second embodiment of the communication system 1.

The access system management control unit 103 transmits a control signal for instructing loopback to the user device 300 (target user device) connected to the section targeted for signal path normality determination. The loopback in the third embodiment corresponds to loop 2, and the normality of the path between the UNI_PHY and the MAC is also determined.

The determination control unit 401 performs signal path normality determination processing. The determination control unit 401 outputs to the optical interface unit 405 a control signal indicating execution of loopback and execution of internal loopback using the main signal. Upon receiving the control signal transmitted from the user device 300, the determination control unit 401 determines the normality of the route to be determined based on the received signal. At this time, the determination control unit 401 performs a signal path normality determination for the path including the inside of the optical transceiver 301 based on the result of intra-device loopback.

The user device 300 includes an optical transceiver 301 and a control section 330. The optical transceiver 301 of the third embodiment has the same configuration as the optical transceiver 301 of the second embodiment, except that it performs internal loopback, so a description thereof will be omitted.

The control signal receiving section 331 receives from the combining/separating section 322 the control signals separated by the combining/separating section 322 . The control signal receiving section 331 operates according to information indicated by the received control signal. If the control signal is information indicating an instruction to execute loopback, control signal receiving section 331 instructs return section 333 to execute loopback in accordance with the instruction. If the control signal further includes information indicating an instruction to execute intra-apparatus loopback, the control signal receiving section 331 instructs the intra-apparatus loopback control section 334 to execute intra-apparatus loopback.

Upon receiving an instruction to perform loopback from the control signal receiving section 331, the loopback section 333 executes loopback processing in accordance with the instruction. The target of loopback processing in the loopback unit 333 is, for example, a control signal. The loopback process may be implemented as a full channel loopback, a partial loopback, or a logical loopback, for example.

The loopback unit 333 may perform loopback, for example, to show the execution result of intra-device loopback. For example, the loopback unit 333 may be configured to loop back the control signal only when normal conduction is determined as a result of performing internal loopback. In this case, the determination control unit 401 may determine that the signal path is normal in response to receiving the looped back control signal. The loopback unit 333 may be configured to include, for example, information indicating the execution result of intra-apparatus loopback in the looped back control signal. In this case, the determination control unit 401 may determine whether the signal path is normal based on information included in the looped back control signal. The looped back control signal is converted into an optical signal by the optical interface unit 326 and transmitted to the access system management control unit 103.

The intra-device loopback control unit 334 controls the optical transceiver 301 to perform intra-device loopback using the main signal of a protocol compatible with the optical transceiver 301 of the device itself. In determining the normality of the signal path of the optical transceiver 301 by internal loopback, the internal loopback control unit 334 determines whether the main signal and the control signal pass through different routes in the optical transceiver 301, or if the main signal and the control signal When different transmitters are used for the main signal and the control signal, or when different receivers are used for the main signal and the control signal, intra-device loopback is performed for each route, transmitter, or receiver.

FIG. 9 is a diagram showing a specific example of folding back within the device in the third embodiment. In the device internal loopback control unit 334 of this embodiment, when a plurality of transmitters with different specifications (for example, a main signal transmitter and a control signal transmitter) are included in the own device (optical transceiver 301), Intra-device loopback may be performed for each transmitter. The same applies to the receiver.

For example, in FIG. 9, the optical interface section 321 includes a main signal Rx 321_1 and a control signal Rx 321_2. The main signal Rx 321_1 processes the main signal and does not process the control signal. Similarly, the control signal Rx 321_2 processes the control signal and does not process the main signal. In FIG. 9, the optical interface unit 326 includes a main signal Tx 326_1 and a control signal Tx 326_2. The main signal Tx 326_1 processes the main signal and does not process the control signal. Similarly, the control signal Tx 326_2 processes the control signal and does not process the main signal. In such a configuration, intra-device loopback is performed for each of the main signal Rx 321_1 and the control signal Rx 321_2. Similarly, intra-device loopback is performed for each of the main signal Tx 326_1 and the control signal Tx 326_2.

For example, the loop for normality determination in device loopback is a loop of the combining/separating unit 322, the processing unit 323, the UNI_PHY(Tx) 324, the UNI_PHY(Rx) 325, the processing unit 323, and the combining/separating unit 322. It is. For example, the loop for normality determination during intra-device loopback may be a loop of the processing unit 323, UNI_PHY (Tx) 324, UNI_PHY (Rx) 325, and processing unit 323. For example, the loop for normality determination in the device internal loop may be a loop including the processing section 323, the combining/separating section 322, the optical interface section 326, the optical interface section 321, the combining/separating section 322, and the processing section 323. .

For example, in the loop of normality determination in the internal loop of the device, if at least one of the light source or the receiving section of the optical IF section differs between the main signal and the control signal, the main signal is It may be a loop between the side where the optical interface section 321 conducts, the side where the main signal conducts at the optical interface section 321, and the combining/separating section 322. For example, the loop for normality determination in the internal loop of the device includes the control section 330, the combining/separating section 322, the optical interface section 326 on which the main signal is conducted, the optical interface section 321 on the side where the main signal is conducted, A loop between the combining/separating section 322 and the control section 330 may be used.

Furthermore, when the main signal and the control signal pass through different routes, the configuration is such that internal loopback within the device is executed via the respective routes.

For example, internal loopback is performed by looping back the main signal so that it is input from the processing unit 323 to the processing unit 323 via the UNI_PHY (Tx) 324 and UNI_PHY (Rx) 325, and the signal path of the optical transceiver 301 is A normality determination may also be performed. Furthermore, loopback within the device is performed by looping back the main signal so that it is input from the processing section 323 to the processing section 323 via the combining/separating section 322, the optical interface section 326, the optical interface section 321, and the combining/separating section 322. Then, the signal path normality of the optical transceiver 301 may be determined. The intra-apparatus loopback control unit 334 outputs the determination result of the signal path normality determination by executing the intra-apparatus loopback to the loopback unit 333.

The flow of processing for determining signal path normality in the third embodiment will be explained. At a predetermined timing, the determination control unit 401 generates a control signal for instructing execution of loopback, and outputs it to the optical interface unit 405. The predetermined timing may be, for example, the timing at which a problem in communication with the user device 300 is detected. The optical interface unit 405 converts the electrical signal input from the determination control unit 401 into an optical signal, and transmits the optical signal to the user device 300 via the transmission path.

When the control signal receiving section 331 of the control section 330 receives the control signal from the combining/separating section 322, it operates according to the content of the control included in the control signal. The control signal includes a signal indicating an instruction to perform loopback. In response to this instruction, the control signal receiving section 331 instructs the loopback section 333 to perform loopback of the control signal. Further, the control signal receiving unit 331 instructs the intra-device loopback control unit 334 to execute intra-device loopback.

The intra-device return control unit 334 executes intra-device return according to the instruction, and determines the normality of the signal path of the optical transceiver 301 based on the execution result. The intra-device loopback control section 334 outputs the determination result to the loopback section 333. The loopback unit 333 performs loopback processing on the received control signal according to the determination result of the internal loopback control unit 334. By executing the loopback process, the return section 333 outputs a control signal to the combination/separation section 322.

The looped back control signal is converted into an electrical signal at the optical interface section 406, and is input to the determination control section 401, which was the source of the control signal. The determination control unit 401 performs a predetermined evaluation on the input control signal according to the continuity check. For example, an evaluation may be made regarding whether or not loopback has been performed correctly, or an evaluation may be made regarding the execution result of intra-device loopback. The determination control unit 401 performs a signal path normality determination regarding the target user device based on the evaluation result. The determination control unit 401 may output the determination result to another device or record it in a storage device as a log.

According to the communication system 1 of the third embodiment configured in this way, a control signal that can be processed by the user device 300 is transmitted to the user device 300. Therefore, loopback can be performed at a loopback point (return unit 333) after the main signal passes through the path after optical-to-electrical conversion in the optical transceiver 301. Therefore, it is possible to determine the normality of the signal path including the inside of the user device 300 in a protocol-independent APN that does not depend on a specific communication protocol or modulation method.

Furthermore, according to the communication system 1 of the third embodiment, intra-device loopback is performed in the optical transceiver 301 of the user device 300, and the normality of the signal path within the device is determined. For example, the normality of the signal paths in the processing unit 323, UNI_PHY (Tx) 324, UNI_PHY (Rx) 325, and processing unit 323 is determined. At this time, since the signal is returned within the device, processing is naturally performed using a signal of a protocol that can be processed by the optical transceiver 301. Therefore, in a protocol-independent APN that does not depend on a specific communication protocol or modulation method, it is possible to determine the normality of the signal path including the inside of the user device 300 (in particular, devices that depend on protocols such as MAC and UNI_PHY). becomes possible. Similar to the second embodiment described above, such processing is superior to other signal path normality determinations.

Normality may be determined by continuity confirmation or self-diagnosis function, which is not limited to loopback. In order to avoid the situation where it is only possible to determine whether or not the transmission path is normal until the test signal is turned back at the turning point, it is necessary to ) may be equipped with a self-diagnosis function.

For example, when receiving a test start request or a test start response to a test start request (if it is on the transmitter/receiver side), a means for creating a test signal and transmitting it via an optical transmission line, and a means for transmitting the test signal via an optical transmission line. , means for receiving the result of the self-diagnosis function, and means for transmitting a test termination request via the optical transmission line when the result of the self-diagnosis function is received.

When receiving a test start request or a test start response to a test start request (if it is on the return side), a means for receiving a test signal via an optical transmission line, a means for receiving a result of a self-diagnosis function, and a self-diagnosis function. When a function result is received, a response signal or return signal is created and transmitted via an optical transmission line. (The response or return signal may be sent separately from the self-diagnosis result. (In this case, if an abnormality is detected by the self-diagnosis function, it is preferable to send data that identifies the abnormality.)

The self-diagnosis function is also not limited to test signal return. If the self-diagnosis function is test signal loopback, for example, by providing a loopback switch in advance that directly connects the signal from the receiving section of the transmitting/receiving section directly to the transmitting section, and turning it on and off under control, the signal will be output only during the loopback test. Set to wrap. For example, when transmitting by ATM, the client signal is transmitted from the AAL5 terminal to the UNI, and when transmitting by OTN frame, the client signal is transmitted from the UNI to the OTN frame. This applies to the section up to the framer that is to be incorporated. The ATM payload used in the test and the pseudo-random pattern included in the OTN client signal may be generated within the device, or they may be generated by the opposing device and then cut out and used within the device. good.

If the test signal is not looped back, the determination may be made using the self-diagnosis function of each circuit through which the signal does not pass. For example, in the case of a frame buffer, only a small portion of the memory area is used for folded test signal data such as frame data only. In most areas, the test signal uses only a small portion of the memory area, so it is not possible to find abnormalities in most parts of the frame buffer only by looping tests. Therefore, a read/write test of the memory that makes up the buffer is performed as a self-diagnosis.

As described above, for example, the second user device (user device 300-2) uses a predetermined signal inside the second user device to determine whether the signal path is normal or not. It is further determined (self-diagnosis) whether or not the inside of the user device No. 2 is normal.

(Fourth embodiment)
FIG. 10 is a diagram showing a fourth embodiment of the communication system 1. The fourth embodiment differs from the second embodiment in that the access system management control unit 103 further includes an error rate measurement unit 411, and is the same as the second embodiment in most other respects. The fourth embodiment of the communication system 1 will be described below, focusing on the differences from the second embodiment of the communication system 1.

The access system management control unit 103 transmits a control signal for instructing loopback to the user device 300 (target user device) connected to the section targeted for signal path normality determination.

The error rate measurement unit 411 generates a signal for measuring the error rate and outputs it to the determination control unit 401. The signal for measuring the error rate may be generated using any method. For example, the signal for measuring the error rate may be generated as a PRBS (Pseudo-Random Binary Sequence) pattern. The error rate measurement unit 411 measures the error rate based on the control signal looped back in the user equipment 300. Error rate measurement section 411 outputs the measurement result to determination control section 401.

The determination control unit 401 performs signal path normality determination processing. The determination control unit 401 outputs a control signal indicating execution of loopback to the optical interface unit 405. Upon receiving the control signal transmitted from the user device 300, the determination control section 401 outputs the received signal to the error rate measurement section 411. The determination control unit 401 determines the normality of the route to be determined based on the received signal and the measurement result in the error rate measurement unit 411.

The user device 300 has a configuration similar to that of the second embodiment, so a description thereof will be omitted.
The flow of processing for determining signal path normality in the fourth embodiment will be described. At a predetermined timing, the error rate measurement section 411 generates a signal for measuring the error rate and outputs it to the determination control section 401. The determination control unit 401 generates a control signal for instructing execution of loopback, and outputs it to the optical interface unit 405. This control signal includes a signal for measuring the error rate. The predetermined timing may be, for example, the timing at which a problem in communication with the user device 300 is detected. The optical interface unit 405 converts the electrical signal input from the determination control unit 401 into an optical signal, and transmits the optical signal to the user device 300 via the transmission path.

The operation in the user device 300 is the same as that in the second embodiment, so the explanation will be omitted. The control signal looped back in the user device 300 is converted into an electrical signal in the optical interface section 406. The error rate measuring section 411 measures the error rate based on the received signal. Error rate measurement section 411 outputs the measurement result to determination control section 401. The determination control unit 401 performs a predetermined evaluation on the input control signal according to the continuity check. For example, an evaluation may be made as to whether the loopback was performed correctly. The determination control unit 401 performs a signal path normality determination regarding the target user device based on the evaluation result. Even if the loopback is performed correctly, the determination control unit 401 may determine that the signal path is abnormal if a predetermined condition indicating a poor error rate is satisfied. The determination control unit 401 may output the determination result to another device or record it in a storage device as a log.

According to the communication system 1 of the fourth embodiment configured in this way, a control signal that can be processed by the user device 300 is transmitted to the user device 300. Therefore, loopback can be performed at a loopback point (return unit 333) after the main signal passes through the path after optical-to-electrical conversion in the optical transceiver 301. Therefore, it is possible to determine the normality of the signal path including the inside of the user device 300 in a protocol-independent APN that does not depend on a specific communication protocol or modulation method.

Furthermore, according to the communication system 1 of the fourth embodiment, the error rate is measured based on the control signal. Therefore, it is possible to determine the normality of the signal path also from the viewpoint of error rate.

(Modified example)
The user device 300 of the fourth embodiment may be configured to further include the intra-device loopback control section 334 of the third embodiment. In this case, when looping back the control signal, the intra-device loopback control unit 334 instructs the optical transceiver 301 to perform intra-device loopback. The return unit 333 may perform loopback so as to indicate the execution result of intra-device return. The determination control unit 401 may determine the normality of the signal path based on the measurement result of the error rate and the execution result of intra-device loopback.

The user device 300 of the fourth embodiment may have a configuration similar to that of the error rate measurement unit 411. In this case, the user equipment 300 may measure the error in the downlink direction by measuring the downlink signal from the Ph-GW 100-2.

The user device 300 of the fourth embodiment may include a pseudo-random number generator. In this case, the user equipment 300 transmits an uplink signal containing random numbers generated by a pseudo-random number generator to the Ph-GW 100-2, and the error rate measuring unit 411 of the Ph-GW 100-2 measures errors. Misdirection may also be measured. The Ph-GW 100-2 may include both a pseudo-random number generator and an error rate measurement unit. In this case, downlink, return, and uplink errors may be measured. The user device 300 may include both a pseudo-random number generator and an error rate measurement unit to measure uplink, turnback, and downlink errors.

In the fourth embodiment, among the processes performed by the error rate measuring unit 411, the process of measuring the error rate may be executed in the user device 300.

FIG. 11 is a diagram showing a second example of the configuration of the communication system 1 in the fourth embodiment. In this case, the control unit 330 of the user device 300 includes an error rate measurement unit 335. The measurement result by the error rate measurement unit 335 is transmitted to the determination control unit 401 of the access system management control unit 103. The determination control section 401 makes a determination based on the measurement results of the error rate measurement section 335.

As described above, for example, the second control device (access system management control unit 103-2) transmits the control signal or main signal representing the signal for measuring the error rate to the second user device (user device 300-2). ) does not transmit the control signal or the main signal representing the signal for measuring the error rate to the second user equipment, and the control signal or the main signal that is returned by the second user equipment. It is further determined whether the signal path is normal based on the measurement result of the error rate based on the signal.

For example, the second control device (access system management control unit 103-2) transmits a control signal or main signal representing a signal for measuring an error rate to a second user device (user device 300-2). When transmitting to the control device, it may be determined whether the signal path is normal based further on the error rate measurement result based on the control signal or main signal transmitted from the second user device.

(Fifth embodiment)
FIG. 12 is a diagram showing a fifth embodiment of the communication system 1. In the fifth embodiment, the access system management control unit 103 includes an FEC determination control unit 412. The access system management control unit 103 may include an FEC judgment control unit 412 instead of the judgment control unit 401. This embodiment differs from the second embodiment in that the control unit 330 of the user device 300 further includes an FEC switching unit 336, and is the same as the second embodiment in most other respects. The fifth embodiment of the communication system 1 will be described below, focusing on the differences from the second embodiment of the communication system 1.

The FEC determination control unit 412 generates a control signal indicating execution of loopback, and adds an FEC (Forward Error Correction) error correction code to the control signal. The FEC determination control unit 412 performs signal path normality determination processing by transmitting a control signal to which an FEC error correction code is attached to the user equipment 300. The FEC determination control unit 412 outputs the control signal generated by the above-described processing to the optical interface unit 405.

Upon receiving the looped back control signal from the user device 300, the FEC determination control unit 412 determines the normality of the route to be determined based on the received signal. For example, the FEC determination control unit 412 may determine the normality of the route based on whether or not a predetermined process is performed on the control signal in the user device 300. As a specific example of the predetermined processing, a new error correction code is generated using a different encoding method from that used in the FEC determination control unit 412, and the new error is applied to the control signal. A possible process is to add a correction code. Further, as another specific example of the predetermined processing, a case where the FEC determination control unit 412 adds an error correction code to the control signal and intentionally adds an error value to a numerical value within a range that can be corrected with the error correction code. In this case, it is possible that the user device 300 assigns the same error value to the control signal.

When the FEC switching unit 336 of the control unit 330 of the user device 300 receives an instruction to perform loopback from the control signal receiving unit 331, it executes loopback processing in accordance with the instruction. The target of loopback processing in the FEC switching unit 336 is, for example, a control signal including an error correction code. The FEC switching unit 336 generates a control signal for loopback by performing the above-described predetermined processing. The FEC switching section 336 outputs the generated control signal to the combining/separating section 322. The looped back control signal is converted into an optical signal by the optical interface unit 326 and transmitted to the access system management control unit 103.

The flow of processing for determining signal path normality in the fifth embodiment will be explained. At a predetermined timing, the FEC determination control unit 412 generates a control signal for instructing loopback, and adds an error correction code to the control signal. The predetermined timing may be, for example, the timing at which a problem in communication with the user device 300 is detected. The optical interface unit 405 converts the electrical signal input from the FEC determination control unit 412 into an optical signal, and transmits the optical signal to the user device 300 via the transmission path.

Upon receiving the optical signal from the access system management control unit 103, the optical interface unit 321 of the user device 300 converts the received optical signal into an electrical signal and outputs it to the combining/separating unit 322. The combiner/separator 322 separates the control signal from the received signal and outputs the control signal to the controller 330 .

When the control signal receiving section 331 of the control section 330 receives the control signal from the combining/separating section 322, it operates according to the content of the control included in the control signal. The control signal includes a signal instructing execution of loopback. In response to this instruction, the control signal receiving section 331 instructs the FEC switching section 336 to perform loopback of the control signal. The FEC switching unit 336 generates a control signal that is looped back to the access system management control unit 103 by performing predetermined processing on the received control signal. The FEC switching section 336 outputs the generated control signal to the combining/separating section 322.

The control signal looped back at the user device 300 is converted into an electrical signal at the optical interface section 406. The FEC determination control unit 412 determines whether a predetermined process is performed on the control signal in the user device 300 based on the received signal. The FEC determination control unit 412 determines the normality of the route according to the determination result. The FEC determination control unit 412 may output the determination result to another device or record it in a storage device as a log.

According to the communication system 1 of the fifth embodiment configured in this way, a control signal that can be processed by the user device 300 is transmitted to the user device 300. Therefore, loopback can be performed at the loopback point (FEC switching unit 336) after the main signal passes through the path after optical-to-electrical conversion in the optical transceiver 301. Therefore, it is possible to determine the normality of the signal path including the inside of the user device 300 in a protocol-independent APN that does not depend on a specific communication protocol or modulation method.

The user device 300 of the fifth embodiment may be configured to further include the intra-device loopback control section 334 of the third embodiment. In this case, when looping back the control signal, the intra-device loopback control unit 334 instructs the optical transceiver 301 to perform intra-device loopback. The FEC switching unit 336 may perform loopback so as to indicate the execution result of intra-device loopback. In addition to determining whether predetermined processing is performed on the control signal in the user device 300, the FEC determination control unit 412 further determines the normality of the signal path based on the execution result of intra-device loopback. You may judge.

As described above, for example, the second control device (access system management control unit 103-2) transmits a control signal to which an error correction code is attached to the second user device (user device 300-2), and It is further determined whether the signal path is normal based on whether predetermined processing has been performed on the control signal returned from the second user device (user device 300-2).

(Sixth embodiment)
FIG. 13 is a diagram showing a sixth embodiment of the communication system 1. In the sixth embodiment, each access system management control unit 103 instructs the user device 300 connected to its own device (Ph-GW 100) regarding execution of loopback. This instruction is given using a control signal such as AMCC. In response to this control signal, loopback is performed in communication between the user devices 300, thereby determining the signal path normality of the path between the user devices 300.

The determination control unit 401-1 of the access system management control unit 103-1 sends a control signal for performing a loopback to the user device 300-1 connected to the section that is subject to signal path normality determination. Send. This control signal instructs to generate a main signal for loopback and transmit it to user equipment 300-2.

The determination control unit 401-2 of the access system management control unit 103-2 sends a control signal for performing a loopback to the user device 300-2 connected to the section that is subject to signal path normality determination. Send. This control signal instructs to receive the main signal for loopback and loop back.

The user device 300-1 includes an optical transceiver 301-1 and a control unit 330-1. The control section 330-1 includes an LB signal generation section 337 and an LB signal determination section 338.

Upon receiving the loopback instruction from the determination control unit 401-1, the LB signal generation unit 337 transmits a main signal of a protocol that can be processed by the user device 300-2.

Upon receiving the main signal looped back from the opposing user device 300-2, the LB signal determination unit 338 performs a predetermined evaluation on the received main signal according to the continuity check. For example, an evaluation may be made as to whether the loopback was performed correctly. The LB signal determination section 338 outputs information indicating the evaluation result to the determination control section 401.

The flow of processing for determining signal path normality in the sixth embodiment will be described. At a predetermined timing, the determination control unit 401-1 instructs the user device 300-1, which is one of the target user devices, to output a main signal for loopback using a control signal. At a predetermined timing, the determination control unit 401-2 instructs the user device 300-2, which is the other target user device, to execute loopback using a control signal. The predetermined timing may be, for example, the timing at which a problem in communication with the user device 300 is detected.

Upon receiving the instruction, the LB signal generation unit 337 of the user device 300-1 generates a main signal for loopback and outputs it to the optical transceiver 301-1. The optical transceiver 301-1 converts the main signal into an optical signal and transmits it to the user device 300-2 via the Ph-GW 100-1 and Ph-GW 100-2.

The control unit 330-2 of the user device 300-2 controls the optical transceiver 301-2 of the user device 300-2 in response to receiving a control signal indicating loopback execution from the access system management control unit 103-2. Instructs main signal loopback. Upon receiving an optical signal from the opposing user device 300-1, the optical transceiver 301-2 converts the received optical signal into an electrical signal. The optical transceiver 301-2 loops back the main signal within the optical transceiver 301-2. At this time, the processing unit 323 may serve as a loopback point and loopback processing may be executed, or the UNI_PHY (Tx) 324 or UNI_PHY (Rx) 325 may serve as a loopback point and loopback processing is executed. good. The optical transceiver 301-2 converts the looped back main signal into an optical signal and transmits it to the user equipment 300-1 via the Ph-GW 100-2 and Ph-GW 100-1.

The looped back main signal is converted into an electrical signal by the optical transceiver 301-1 and input to the LB signal determining section 338. The LB signal determination unit 338 performs a predetermined evaluation on the input main signal according to the continuity check. For example, an evaluation may be made as to whether the loopback was performed correctly. The LB signal determination unit 338 transmits information indicating the evaluation result to the access system management control unit 103-1. The determination control unit 401-1 of the access system management control unit 103-1 performs a signal path normality determination regarding the signal path between the user devices 300 based on the evaluation result received from the LB signal determination unit 338. The determination control unit 401-1 may output the determination result to another device or record it in a storage device as a log.

According to the communication system 1 of the sixth embodiment configured in this way, the access system management control unit 103 executes a loopback for each user device 300 connected to the path that is the target of signal path normality determination. Instructions are given using control signals. The control signal used here is a control signal that can be processed by each user device 300. Furthermore, a main signal to be looped back is transmitted from one user device 300 (300-1) to the other user device 300 (300-2) using a signal of a protocol that can be processed by the user device 300. Therefore, loopback can be performed at a loopback point after the main signal passes through the path after optical-to-electrical conversion in the optical transceiver 301. Therefore, it is possible to determine the normality of the signal path including the inside of the user device 300 in a protocol-independent APN that does not depend on a specific communication protocol or modulation method.

(Modified example of the sixth embodiment)
FIG. 14 is a diagram showing a modification of the sixth embodiment. In the example of FIG. 13 described above, in the user equipment 300-2, loopback is executed in the optical transceiver 301-2 without going through the control unit 330-2. On the other hand, as shown in FIG. 14, loopback may be executed in the user device 300-2 via the control unit 330-2. However, in this case, the signal to be looped back is the control signal.

The control signal transmitter 332 of the user device 300-1 transmits an instruction signal instructing loopback to the control signal receiver 331 of the user device 300-2. Control signal transmitter 332 of user device 300-2 transmits an instruction signal instructing loopback to control signal receiver 331 of user device 300-1.

The LB signal generation section 337 and the LB signal determination section 338 do not necessarily need to be provided in the user device 300-1. For example, the LB signal generation section 337 and the LB signal determination section 338 may be provided in the Ph-GW 100-1, a communication device (relay device), etc. (not shown), or the like. In this case, the device that receives the control signal for loopback execution from the access system management control section 103-1 is a communication device that includes the LB signal generation section 337 and the LB signal determination section 338.

In the sixth embodiment, one user device 300 (300-1) may include a pseudo-random number generator, and the other user device 300 (300-2) may include an error rate determination unit. In this case, one user device 300 transmits a signal containing random numbers generated by a pseudo-random number generator to the opposing user device 300 (the other user device), and the error rate measuring unit 411 of the other user device 300 makes an error. By measuring , the error in the direction from one user device 300 to the other user device 300 may be measured. One user device 300 (300-1) may include both a pseudo-random number generator and an error rate measuring section. In this case, downlink, return, and uplink errors for one user device 300 may be measured.

As explained above, from FIG. 2 to FIG. The normality of the optical signal (main signal) is determined by the control signal superimposed on the optical signal (main signal) or modulated in the optical signal (main signal) from Fig. 2 to Fig. 8. The normality is determined.

The communication system having the configuration (sub-configuration) illustrated in each figure from FIG. 2 to FIG. 5 is a transparent network that transmits main signals of various protocols. , the instruction from the APN controller, information from the DB, acquisition from the user equipment, or reception of the main signal and whether it can be terminated as a normal signal, and generates and terminates the optical signal of the selected protocol. , sends a signal to the user equipment and terminates the signal looped back by the user equipment, or loops back the signal transmitted from the user equipment to the user equipment and terminates the signal, and determines the normality (the user equipment In the case of loopback, the range of normality determination of the route inside the user device is wider).

Alternatively, the communication system having the configuration (main configuration) illustrated in each figure from FIG. 6 to FIG. 8 is a transparent network that transmits main signals of various protocols, and the main signal used in the transparent network is protocol-independent. The normality is determined by the loopback of the control signal.

Alternatively, a communication system that combines the configuration illustrated in each figure from FIG. 2 to FIG. 5 (secondary configuration) and the configuration illustrated in each figure from FIG. 6 to FIG. 8 (main configuration) is In a transparent network that transmits main signals of various protocols, the protocol of the main signals sent and received by the user equipment is determined by instructions from the APN controller, information from the DB, or obtained from the user equipment, or by receiving the main signal and determining whether the main signal is a normal signal. Generates and terminates the optical signal of the selected protocol, and in that state determines the normality by looping back the protocol-independent control signal of the main signal used in the transparent network. do.

The communication system illustrated in FIGS. 13 and 14 is a communication system that includes a first device and a second device that communicate with each other using optical signals, and the first device sends a control signal to the second device using the optical signal. the second device returns the control signal or its response to the first device, the first device receives the returned control signal or its response, and the second device returns the control signal or its response to the signal path between the first device and the second device. A communication system that determines whether a signal path including a signal path is normal or not.

In the communication system illustrated in FIG. 13, the first control device (access system management control unit 103-1) transmits a first control signal (instruction signal representing a callback instruction) instructing return to the first user device. do. The second control device (access system management control unit 103-2) transmits a second control signal (instruction signal representing a return instruction) instructing a return to the second user device. The second user device returns the main signal transmitted from the first user device. The first user device determines whether the signal path including between the first user device and the second user device is normal based on the returned main signal.

In the communication system illustrated in FIG. 14, the second user device transmits an instruction signal representing a return instruction to the first user device. The second user device returns the control signal transmitted from the first user device. The first user device transmits an instruction signal representing a return instruction to the second user device. The first user device determines whether the signal path including between the first user device and the second user device is normal based on the returned control signal.

The normality determination method executed by the communication system illustrated in FIGS. 13 and 14 is a communication method carried out by a communication system including a first device and a second device that communicate with each other using optical signals, in which the first device , transmitting the control signal to the second device as an optical signal; the second device returning the control signal or its response to the first device; and the first device receiving the returned control signal or its response. and a step of determining whether a signal path including a signal path between the first device and the second device is normal.

The communication system illustrated in each figure from FIG. 2 to FIG. 5 is a communication system comprising a first device and a second device facing each other and transmitting and receiving optical signals, and the first device is capable of transmitting and receiving optical signals to and from the second device. selectively generates an optical signal in a different format, transmits the generated optical signal to an opposing second device, the second device returns and transmits the received optical signal or its response, and the first device transmits the returned optical signal. A communication system that receives a signal or its response and determines whether a signal path including a signal path between a first device and a second device is normal from the received folded optical signal or its response. It is.

In the communication systems illustrated in the figures from FIGS. 2 to 5, the user device 300 loops back the main signal transmitted from the control device (access system management control unit) that generates and terminates the main signal. The control device determines whether the signal path including the one between the control device and the user device is normal based on the returned main signal.

In the communication systems illustrated in the figures from FIG. 2 to FIG. 5, the control device (access system management control section) may return the main signal transmitted from the user device. The user device may determine whether the signal path including the one between the user device and the control device that generates and terminates the main signal is normal, based on the returned main signal.

In the communication systems illustrated in the figures from FIG. 2 to FIG. It may be further determined based on the control signal whether or not. The control device may multiplex the control signal on an input optical signal different from the main signal, and determine whether the signal path is normal based on the control signal multiplexed on the input optical signal. The input optical signal is an input optical signal, for example, unmodulated continuous light. Note that the input optical signal is an optical signal regardless of the form of the main signal used by the user equipment. Further, the optical power of the input optical signal is adjusted, for example, so that the input optical signal does not destroy the receiving side equipment (user equipment, etc.).

The communication system illustrated in each figure from FIG. 2 to FIG. A communication system includes a first device and a second device that transmit an optical signal, the first device and the second device are devices facing each other, and the first device transmits an optical signal in a format that can be transmitted and received by the second device. The second device generates a control signal and superimposes it on the generated optical signal or modulates the generated optical signal to a second device, and the second device superimposes it on its own optical signal or an optical signal from another device or transmits it to the second device. The first device modulates the optical signal or the optical signal from another device and returns and transmits the received control signal or its response, and the first device superimposes it on the optical signal or modulates the optical signal and transmits the returned control signal or its response. The communication system receives the control signal and determines whether the signal path including the signal path between the first device and the second device is normal based on the received looped-back control signal or its response.

The communication system illustrated in each of the figures from FIG. 6 to FIG. A communication system comprising a first device and a second device that communicate with each other, the first device and the second device are devices facing each other, and the first device transmits an optical signal of its own device or an optical signal from another device. A control signal that is superimposed on the optical signal of the own device or an optical signal from another device is transmitted to the second device, and the second device superimposes the control signal on the optical signal of the own device or the optical signal from the other device or The first device modulates the optical signal or the optical signal from another device and returns and transmits the received control signal or its response, and the first device superimposes it on the optical signal or modulates the optical signal and transmits the returned control signal or its response. The communication system receives the control signal and determines whether the signal path including the signal path between the first device and the second device is normal based on the received looped-back control signal or its response.

In the communication systems illustrated in the figures from FIG. 6 to FIG. 8, the user device 300 loops back the control signal transmitted from the control device (access system management control unit). The control device determines whether the signal path including the one between the control device and the user device is normal based on the returned control signal.

In the communication system illustrated in FIG. 9, the user equipment 300 not only determines whether the signal path is normal, but also loops back a predetermined signal inside the user equipment, and determines whether the inside of the user equipment is normal. You may further determine whether or not there is.

(Hardware configuration example)
FIG. 15 is a diagram showing an example of the hardware configuration of the communication system 1 in the embodiment. Some or all of the functional units of the communication system 1 are configured such that a processor 201 such as a CPU executes a program stored in a storage device 203 having a non-volatile recording medium (non-temporary recording medium) and a memory 202. By executing it, it is realized as software. For example, the determination control unit 401 and the control unit 330 described above may be configured using the processor 201 such as a CPU and a nonvolatile recording medium. The program may be recorded on a computer-readable non-transitory recording medium. Computer-readable non-transitory recording media include, for example, portable media such as flexible disks, magneto-optical disks, ROM (Read Only Memory), and CD-ROM (Compact Disc Read Only Memory), and hard disks built into computer systems. It is a non-temporary recording medium such as a storage device such as. The communication unit 204 executes predetermined communication processing. The communication unit 204 may acquire data of an optical signal transmitted through an optical fiber (eg, main signal data, wavelength data) and a program.

A part or all of each functional unit of the communication system 1 uses, for example, an LSI (Large Scale Integrated Circuit), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array). It may be realized using hardware including an electronic circuit or circuitry.

Each embodiment may be combined.

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and includes designs within the scope of the gist of the present invention.

The present invention is applicable to a communication system that communicates using a communication network such as an all-photonics network (APN).

DESCRIPTION OF SYMBOLS 1... Communication system, 100... Ph-GW, 101... Optical distribution part, 102... Wavelength multiplexing/demultiplexing part, 103... Access system management control part, 200... APN controller, 201... Processor, 202... Memory, 203... Storage device , 204... Communication unit, 300... User device, 301... Optical transceiver, 321, 326... Optical interface unit, 322... Combining/separating unit, 323... Processing unit, 324... UNI_PHY (Tx), 325... UNI_PHY (Rx), 330... Control unit, 331... Control signal receiving unit, 332... Control signal transmitting unit, 333... Turning unit, 334... Device loopback control unit, 335... Error rate measuring unit, 336... FEC switching unit, 337... LB signal generation 338... LB signal judgment section, 401... Judgment control section, 402... Signal termination section, 403... SW, 404... Combination/separation section, 405, 406... Optical interface section, 411... Error rate measurement section, 412... FEC judgment control unit

Claims

A communication system comprising one or more control devices and one or more user devices,
The first user device or the first control device responds with a second control signal to the first control signal transmitted from the opposing second user device or second control device,
The second user device or the second control device has a signal path including between the first user device or the first control device and the second user device or the second control device. determining whether or not it is normal based on the second control signal used in the response;
Or
The first user device or the first control device returns the first control signal transmitted from the opposing second user device or the second control device,
The second user device or the second control device may be connected to the signal path including between the first user device or the first control device and the second user device or the second control device. determining whether or not is normal based on the returned first control signal;
Communications system.
The first control device transmits the second control signal to another optical signal different from the main signal when the optical signal for carrying the second control signal does not reach the first control device. When the optical signal for carrying the second control signal reaches the control device, the second control signal is multiplexed on the optical signal for carrying the second control signal, and the optical signal for carrying the second control signal is multiplexed. The communication system according to claim 1, wherein whether or not a route is normal is determined based on the other optical signal or the second control signal multiplexed on the optical signal.
A communication system comprising one or more control devices and one or more user devices,
The first user device or the first control device generates and terminates a main signal in a signal form selected based on the signal form used by the opposing second user device or second control device. returning the first main signal transmitted from the user device or the second control device;
The second user device or the second control device has a signal path including between the second user device or the second control device and the first user device or the first control device. determining whether or not it is normal based on the returned first main signal;
Or
The first user device or the first control device transmits a signal to the second user device in a signal format selected based on a signal format used by the opposing second user device or second control device. or returning the second main signal transmitted from the second control device,
The second user device or the second control device has a signal path including between the second user device or the second control device and the first user device or the first control device. determining whether or not it is normal based on the returned second main signal;
Or
The first user device or the first control device generates the main signal in a signal format selected based on the signal format used by the opposing second user device or the second control device. responding with a third main signal to the first main signal transmitted from the second user device or the second control device terminating;
The second user device or the second control device has a signal path including between the second user device or the second control device and the first user device or the first control device. determining whether or not it is normal based on the third main signal used in the response;
Or
The first user device or the first control device transmits a signal to the second user device in a signal format selected based on a signal format used by the opposing second user device or second control device. or responding with a fourth main signal to the second main signal transmitted from the second control device,
The second user device or the second control device has a signal path including between the second user device or the second control device and the first user device or the first control device. determining whether or not it is normal based on the fourth main signal used in the response;
Communications system.
In addition to determining whether the signal path is normal, the second user equipment determines whether the inside of the second user equipment is normal by using a predetermined signal inside the second user equipment. The communication system according to claim 1 or claim 3, further determining whether or not there is.
When the second user equipment does not transmit a control signal or a main signal representing a signal for measuring the error rate to the second control device, the second control device is configured to transmit a signal for measuring the error rate. further based on a measurement result of the error rate based on the control signal or the main signal that is returned by the second user equipment by transmitting the control signal or the main signal representing the signal to the second user equipment; , determining whether the signal path is normal;
Or
When the second user equipment transmits the control signal or the main signal representing a signal for measuring the error rate to the second control equipment, the second control equipment further determining whether the signal path is normal based on a measurement result of the error rate based on the control signal or the main signal transmitted from the device;
The communication system according to claim 1 or claim 3.
The second control device transmits a control signal provided with an error correction code to the second user device, and performs predetermined processing on the control signal returned from the second user device. 4. The communication system according to claim 1, further determining whether the signal path is normal based on whether the signal path is normal or not.
A normality determination method executed by a communication system including one or more control devices and one or more user devices, the method comprising:
The first user equipment or the first control device responds with a second control signal to the first control signal transmitted from the second user equipment or the second control device,
The second user device or the second control device has a signal path including between the first user device or the first control device and the second user device or the second control device. determining whether or not it is normal based on the second control signal used in the response;
Or
The first user device or the first control device returns the first control signal transmitted from the second user device or the second control device,
The second user device or the second control device may be connected to the signal path including between the first user device or the first control device and the second user device or the second control device. determining whether or not is normal based on the returned first control signal;
Normality determination method.
A communication system comprising a first control device, a second control device, a first user device, and a second user device,
The first control device transmits a first control signal instructing return to the first user device,
The second control device transmits a second control signal instructing the return to the second user device,
The second user device returns the main signal transmitted from the first user device,
The first user device determines whether a signal path including between the first user device and the second user device is normal based on the returned main signal.
Communications system.
A communication system comprising a first user device and a second user device,
The second user device transmits an instruction signal representing a return instruction to the first user device, returns the control signal transmitted from the first user device,
The first user device transmits an instruction signal representing the return instruction to the second user device, and determines whether a signal path including between the first user device and the second user device is normal. making a determination based on the returned control signal;
Communications system.