JP2003051765A - Optical access network, node device, optical access network control method and control program - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide an optical access network control method capable of restoring a line as quickly as possible while minimizing the influence on a user due to a failure or deterioration of a transmission line. SOLUTION: An active transmission path including an active relay fiber transmission path and a standby transmission path including a standby relay fiber transmission path are set as signal light transmission paths between an upper node apparatus and a lower node apparatus. In the upper node device, one of the upstream signal lights transmitted from the lower node device to the upper node device via the working or protection transmission path is selected.
The signal is branched and sent to the working and protection relay fiber transmission lines, and the lower node device selects one of the downstream signal lights transmitted from the upper node device to the lower node device via the working or protection transmission path. Further, the signal light for the upper node device is branched into two and transmitted to the working and protection relay fiber transmission lines.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical access network, a node device, an optical access network control method, and a control program, and more particularly, in a wide area access network, wavelength division multiplexing (WDM;
Even if a failure occurs in the part that multiplexes a large number of users using Wavelength Division Multiplex technology, it is a backup system route that avoids the effects on users such as signal interruptions and deterioration as much as possible and restores the line immediately. And a switching method.

[0002]

2. Description of the Related Art A wide-area access network system shown in FIG. 12 has been proposed as a network for realizing a high-speed access network that handles gigabit-class signals at low cost (see Japanese Patent Application No. 2000-334684). In the wide area access network system shown in FIG. 12, the access system optical branch circuit 5 is connected to the lower node device 2
And access subscriber equipment (OLT; Opti
cal Line Terminatiol, hereinafter simply referred to as OLT. )
4 in the upper node device 1, and in the OLT 4,
A subscriber side device (ONU; Op) via a relay fiber transmission line 6, an access system optical branch circuit 5 and a subscriber fiber 7.
tical network unit) 8 is connected in a star shape. In the OLT 4, an optical transmitter, an optical receiver,
Optical transmission / reception unit (OS
U: Optical Subscriber Unit, hereinafter simply referred to as OSU. ) 52 is arranged. FIG. 13 is a block diagram showing the basic configuration of the wide area access network system shown in FIG. In FIG. 13, 14 is an optical transmitter (OS), 15 is a wavelength multiplexer / demultiplexer, and 16 and 19 are WDM.
(Wavelength Division Multiplexing) coupler, 17 optical amplifier, 18 transponder, 20 optical coupler, 2
1 is a user group, 22 is a subscriber network interface, 23 is a terminal device, and 39 is an optical receiver (OR). Here, the user group 21 is defined as a set of users who are connected to the same optical coupler 20 and share the same wavelength of the downlink signal light.

A method of transmitting signal light in the prior invention will be described below. First, the downlink signal light will be described. Optical transmitters (OS1, ..., OS) based on electrical signals from the outside of the upper node device 1 (for example, a server)
n) 14 has wavelengths λ1, λ2, ..., λn, respectively.
Convert to optical signal. These optical signals are wavelength-multiplexed by the wavelength multiplexer / demultiplexer 15 and input to the relay fiber transmission line 6. In the lower node device 2, the wavelength-multiplexed optical signal input from the relay fiber transmission line 6 passes through the WDM coupler (for example, 1.55 / 1.58 coupler) 16 and then all the wavelengths are collectively collected by the optical amplifier 17. After being amplified, the wavelength multiplexer / demultiplexer 15 demultiplexes the output ports corresponding to the respective wavelengths. Then, each wavelength is divided into uniform optical power by the optical coupler 20 connected to each output port, and then the subscriber side device (O) is transmitted through the subscriber fiber transmission line 7.
NU11, ..., ONUNm) 8 and is converted into an electric signal and then transmitted to the terminal device 23.

Next, the upstream signal light will be described. From the terminal device 23 to each subscriber side device (ONU11,
,, ONUNm) 8 has an electric signal of wavelength λa
Of the optical coupler 2 based on the transmission instruction from the OLT 4 in the upper node device.
The signal is transmitted to the subscriber fiber 7 at a timing such that the signal does not collide with 0. In the lower node device 2, this optical signal passes through the optical coupler 20 and is input to the access-system optical branch circuit 5, and the optical signal of the wavelength λa is a WDM coupler (for example, 1.3 / 1.5 coupler) 19 By this, the downstream signal light is separated, and in the transponder 18, the wavelengths λ1 ′ and λ corresponding to the wavelength periodicity of the wavelength multiplexer / demultiplexer 15 are separated.
2 ′, ..., λn ′ are converted into optical signals. These optical signals are wavelength-multiplexed in the wavelength multiplexer / demultiplexer 15 and then input to the relay fiber transmission line 6 via the WDM coupler 16 and transmitted to the upper node device 1. In the upper node device 1, the wavelength division multiplexed optical signal input from the relay fiber transmission line 6 is demultiplexed into each wavelength by the wavelength multiplexer / demultiplexer 15 and converted into an electrical signal by the optical receiver (OR1, ..., ORn) 39. It is converted and output to the outside of the upper node device 1.

Here, the wavelengths λ1, λ2, ..., λn belong to, for example, the 1550 nm band and the 1580 nm band,
A plurality of wavelengths with high wavelength accuracy having an optical frequency interval of several tens GHz to several hundreds GHz are used. Specifically, as a wavelength-specified light source with high wavelength accuracy, a distributed feedback type (DF
B) It is conceivable to use a laser. On the other hand, the wavelength λa
As for, a wavelength accuracy of about ± 20 nm is allowed, and for example, the 1300 nm band and the 1550 nm band are used. As the light source, an inexpensive Fabry-Perot laser can be considered in order to reduce the financial burden on the subscriber. The wavelengths λ1 ′, λ2 ′, ...
2, ..., λn, for example, 1550 nm band or 15
A plurality of wavelengths with a high wavelength accuracy having a predetermined optical frequency interval in the 80 nm band are used. Here, as in the case of the downlink, it is possible to use a DFB laser as a light source with high wavelength accuracy.

[0006]

If the number of wavelengths of the wavelength multiplexer / demultiplexer 15 shown in FIG. 12 is m (m is a natural number) and the number of branches of the optical coupler 20 is n (n is a natural number), In the wide area access network system shown in FIG. 12, a relay fiber transmission line 6 arranged between the OLT 4 of the upper node device 1 and the access optical branch circuit 5 of the lower node device 2.
Uses WDM technology to multiplex and transmit m × n user signal lights (11, 12, 13) at maximum. However, in the wide area access network system shown in FIG. 12, the relay fiber transmission line 6 is composed of only one line, and the relay fiber transmission line 6 suffers a failure or the like, resulting in signal interruption or signal deterioration. In this case, there is a problem that the network cannot be restored unless the relay fiber transmission line 6 is restored. That is, as shown in FIG. 14, when a failure 9 or the like occurs in the relay fiber transmission line 6 multiplexed by using the WDM technique, the relay fiber transmission line 6 has no redundancy, and thus signal deterioration is caused. Or, all users will be affected by the signal interruption. That is,
Assuming that the number of wavelengths of the wavelength multiplexer / demultiplexer 15 is m and the number of branches of the optical coupler is n, one failure of the relay fiber transmission line 6 will affect up to m × n users. .

Similarly, a wide area access network has one
It is composed of one OLT 4 and one access system optical branch circuit 5. Even if these devices fail, signal deterioration or signal interruption occurs, and the network cannot be restored unless the faulty part is restored. That is, as shown in FIG. 15, even when the failure 9 occurs in the OSU 52 in the upper node device 1, the OLT 4 can transmit a signal to a user with a maximum of m × n or a signal from the user. Will also be impossible to receive. Further, even if the access system optical branch circuit 5 in the lower node device 2 fails, the maximum m × n users will be similarly affected. In SONET (SDH) technology, which is often used in relay systems, by multiplexing stations between multiple fiber transmission lines and superimposing supervisory control information on section overhead (SOH), high-speed recovery in the event of a fiber transmission line failure is possible. It is possible (“SDH transmission method” issued by Ohmsha (ISBN4-274-03430-5))
In the wide area access network, it is difficult to implement the same function as a SONET repeater in the access subscriber branch circuit in the wide area access network. Therefore, another technique for realizing low-cost recovery is required. Will be needed.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is a failure or deterioration of a transmission line in an optical access network and a method of controlling the optical access network. It is an object of the present invention to provide a technology capable of promptly restoring the line by avoiding the influence of the above on the user as much as possible. Another object of the present invention is to provide a node device applied to the above-mentioned optical access network. Another object of the present invention is to provide a control program that causes a computer to execute the above-described optical access network control method. The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[0009]

Among the inventions disclosed in the present application, a brief description will be given to the outline of typical ones.
It is as follows. That is, the present invention relates to the transmission of signal light between the upper node device and the lower node device in an optical access network in which the upper node device and the lower node device are connected via a relay fiber transmission line. The route is characterized by being configured with a working transmission route including a working relay fiber transmission line and a backup transmission route including a backup relay fiber transmission line. As a result, even if a failure occurs in the active transmission path, it is possible to quickly secure the transmission path, and it is possible to restore the signal at high speed.

Therefore, according to the present invention, in the above-mentioned upper node device, a working and a spare optical transmitting / receiving unit, and
A first working standby switching circuit is arranged, and a working optical multiplexing / demultiplexing unit connected to the working optical transmitting / receiving unit via the working relay fiber transmission line in the lower node device; A spare optical multiplexing / demultiplexing unit connected to the spare optical transmission / reception unit via a spare relay fiber transmission line, and a second working spare switching circuit are arranged. Here, the working transmission path comprises a working optical transmission / reception unit, a working relay fiber transmission path, and a working optical multiplexing / demultiplexing unit, and the backup transmission path is a backup optical transmission / reception unit, a backup relay. It is composed of a fiber transmission line and a spare optical multiplexing / demultiplexing unit.

In the first active protection switching circuit, the upstream signal light transmitted from the lower node device to the upper node device is the upstream signal light output from the active optical transceiver unit. Alternatively, one of the upstream signal lights output from the spare optical transmission / reception unit is selected, and the signal light for the access-system optical branch circuit is split into two to be used as the working and spare relay fiber transmission lines. Send out. In the second active protection switching circuit, the downstream signal light transmitted from the upper node device to the lower node device is the downstream signal light output from the active optical add / drop unit, or One of the downlink signal lights output from the spare optical multiplexing / distributing unit is selected, and the signal light for the access subscriber device is split into two and sent to the working and spare relay fiber transmission lines.

Further, according to the present invention, the working and protection optical transmission / reception units are respectively provided at connection points of the wavelength multiplexer / demultiplexer, the wavelength multiplexer / demultiplexer, and the working or protection relay fiber transmission line. And a signal light and a working / standby upper-side coupler for multiplexing / demultiplexing the supervisory control light in a wavelength band different from the signal light, and a working / standby upper-side coupler connected to the working / standby upper-side coupler. And a monitoring control device. The working and standby optical multiplexer / demultiplexer units are respectively provided at the connection points of the wavelength multiplexer / demultiplexer, the wavelength multiplexer / demultiplexer, and the working or standby relay fiber transmission line, and the signal light and It has working and protection lower side couplers for multiplexing and demultiplexing the supervisory control light, and working and protection lower side supervisory control devices connected to the working and protection lower side couplers. Then, between the working upper side supervisory controller and the working lower side supervisory controller, and between the spare upper side supervisory controller and the spare lower side supervisory controller, the working and The supervisory control light is transmitted and received via a spare relay fiber transmission line.

Further, according to the present invention, the working and protection upper side supervisory control devices are arranged in the upstream direction transmitted from the lower order node device to the higher order node device via the working or protection relay fiber transmission line. Based on the supervisory control light, a transmission state of the supervisory control light transmitted through the working and standby relay fiber transmission lines is determined. Further, the working and protection lower side supervisory control devices are based on the downlink monitoring control light transmitted from the higher order node device to the lower order node device via the working or protection relay fiber transmission line. , Determining the transmission state of the supervisory control light transmitted through the working and standby relay fiber transmission lines. In this case, the upper and lower supervisory control devices compare the bit error rate of the supervisory control light with a predetermined threshold to determine the transmission state of the supervisory control light.

Further, according to the present invention, the upper node device controls the power of the upstream signal light transmitted from the lower node device to the upper node device via the working and standby relay fiber transmission lines. Measure for each wavelength,
It has an upstream monitor that determines whether the upstream signal light for each wavelength is normal or abnormal. In addition, the lower node device is transmitted from the upper node device to the lower node device via the working and protection relay fiber transmission lines, and is output from the working and protection optical multiplexing / demultiplexing units in the downstream direction. There is a downlink monitor that measures the power of the signal light for each wavelength and determines whether the signal light in the downlink direction for each wavelength is normal or abnormal. In this case, the upstream monitor and the downstream monitor compare the measurement result of the power of each wavelength of the signal light to be measured with a predetermined threshold to determine whether the signal light is abnormal or normal. judge.

Further, in the present invention, the upper node apparatus has an in-apparatus monitoring control apparatus, and the in-apparatus monitoring control apparatus is provided with a determination result (or a determination result in the upstream monitor, Also, based on the determination results of the working and standby upper side supervisory control devices), as the transmission path of the signal light in the upstream direction, the working optical transmission / reception unit, the working optical multiplexing / demultiplexing unit, and the working The working transmission path composed of the relay fiber transmission path is continuously used, or the spare optical transmission / reception unit, the spare optical multiplexing / demultiplexing unit, and the spare relay fiber transmission path It is determined for each wavelength of the signal light whether to use the transmission path of. Also,
In the present invention, a system management device that is connected to the upper node device and manages the entire system is provided, and the in-device monitoring control device, when using the backup transmission path,
A switching command for switching to the spare optical transmission / reception unit side is transmitted to the upper side switch in the first working standby switching circuit, and the upper side switch,
When the switching is normally performed, the system management device is notified that the switching is normally performed.

Further, according to the present invention, the lower node device includes a lower node management device, and the lower node management device determines the determination result of the downlink monitor (or the determination result of the downlink monitor, and Based on the determination results of the working and standby lower side supervisory control devices), the working optical transmission / reception unit, the working optical multiplexing / demultiplexing unit, and the working relay fiber are used as the transmission path of the signal light in the downstream direction. The working transmission path formed by the transmission path is continuously used, or the spare transmission is formed by the spare optical transmission / reception unit, the spare optical multiplexing / demultiplexing unit, and the spare relay fiber transmission path. Whether to use the path is determined for each wavelength of the signal light. Also,
In the present invention, a system management device that is connected to the upper node device and manages the entire system is provided, and the lower node management device, when using the backup transmission path,
A switching command for switching to the spare optical multiplexing / demultiplexing unit side is transmitted to the lower side switch in the second working standby switching circuit, and the lower side switch,
When the switching is normally performed, the system management device is notified that the switching is normally performed.

Further, according to the present invention, a system management device that is connected to the upper node device and manages the entire system is provided, and the in-device monitoring and control device is based on an instruction from the system management device, and the standby optical device is operated. A switching command for switching to the transmission / reception unit side is transmitted to the upper-level switch in the first active backup switching circuit, and when the upper-level switch normally performs switching, the system management device is notified. On the other hand, the normal switching is notified that the lower node management device
Based on an instruction from the system management device, a switching command for switching to the spare optical multiplexing / demultiplexing unit side
To the lower-side switch in the working standby switching circuit, and when the lower-side switch normally performs the switching, the normal switching is performed to the system management device. Notice. The present invention is also a node device applied to the above-mentioned optical access network. Further, the present invention is a control program for causing a computer to execute the above-described optical access network control method.

According to the above-mentioned means, when an optical component, a relay fiber transmission line, or the like is broken in the upper node device and the lower node device, and the signal light of a certain wavelength is deteriorated or disconnected, it is promptly performed. It is possible to restore various transmission lines for each wavelength. In addition, since the access system subscriber device, the optical components of the access system optical branch circuit, the relay fiber transmission line, and the like are constantly monitored, it is possible to detect failures of the devices.
As a result, the probability that a signal cannot be transmitted due to all failures of the access subscriber device, the optical components of the access optical branch circuit, the relay fiber transmission path, etc. will be reduced, and the restoration of the path for each wavelength is possible Is. Therefore, in the wide area optical access network, even if a failure occurs in the optical components or the multiplexed parts of the upper node device and the lower node device, it is possible to quickly restore the transmission line for each wavelength, and to the user. It is possible to minimize the effects of signal deterioration and disconnection.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In all the drawings for explaining the embodiments, the same reference numerals are given to those having the same function, and the repeated description thereof will be omitted. [Embodiment 1] FIG. 1 is a block diagram showing the concept of an optical access network according to Embodiment 1 of the present invention. As shown in FIG. 1, the optical access network of the present embodiment has an OLT 4 arranged in an upper node device 1 and an access system optical branch circuit having a simple function such as multiplexing and demultiplexing in a lower node device 2. 5 is arranged, and the upper node device 1
In the wide area access network in which the relay fiber transmission line 6 connects between the lower node device 2 and the lower node device 2, the OLT 4
The OSU of the active system (52a) and the OSU of the standby system (5a)
2b) and the first active backup switching circuit 54 are arranged. Further, in the optical branching circuit 5 for access system, two optical multiplexing / demultiplexing units (53a) for the active system, a standby optical multiplexing / demultiplexing unit (53b), and a second active backup switching circuit 34 are arranged. And the active OSU (52a)
And the active-system optical multiplexing / demultiplexing unit (53a) are connected via the active-system relay fiber transmission line 6, and the standby system OSU (52b) and the active-system optical multiplexing / demultiplexing unit (5) are connected.
3b) is connected via the relay fiber transmission line 10 of the standby system. The optical multiplexer / demultiplexer unit (53a) of the current system
The wavelength multiplexer / demultiplexer 15 is arranged in each of the auxiliary optical multiplexer / demultiplexer unit (53b).

The first active spare switching circuit 54 splits the downstream signal light to the access optical branch circuit 5 into two, and selects one of the two upstream signal lights from the access optical branch circuit 5. To do. Further, the second working standby switching circuit 34 has a switch 40, branches the upstream signal light toward the OLT 4 into two, and selects either one of the signal light from the OLT 4. As described above, the optical access network of this embodiment has two OSUs.
(52a, 52b) Two optical multiplexing / demultiplexing units (53
a, 53b) two active spare switching circuits (34, 5)
4) and that two relay fiber transmission lines (6, 10) are arranged, which is different from the conventional optical access network. In this specification, the relay fiber transmission line 6
OSU (52a) connected to the active system relay fiber transmission line and the relay fiber transmission line 10 to the standby system relay fiber transmission line and the active system relay fiber transmission line 6.
And the optical multiplexing / demultiplexing unit (53a) are respectively connected to the OSU of the active system, the optical multiplexing / demultiplexing unit of the active system, and the OSU (52b) connected to the relay fiber transmission line 10 of the standby system.
And the optical multiplexing / demultiplexing unit (53b) are referred to as a standby OSU and a standby optical multiplexing / demultiplexing unit, respectively. In addition,
In FIG. 1, reference numerals 11, 12, 13 denote signal lights transmitted through the active repeater fiber 6, and reference numerals 41, 42, 43 denote
The signal light transmitted through the relay fiber 10 of the standby system is shown.

In the case where a failure or the like occurs, the first and second working standby switching circuits (34, 54) actuate the switches in the circuit when receiving a switching command, and activate the backup system from the working system transmission path. It is possible to change the route to the transmission route of. As a result, in the present embodiment, as shown in FIG.
As shown in, failure 9 occurs in the working repeater fiber transmission line 6.
If an abnormality such as the above occurs, the transmission path of the signal light of the upstream / downstream signal is switched from the transmission path of the working system to the transmission path of the standby system, and the transmission path of the signal light of the upstream / downstream signal is immediately restored. It becomes possible to do. Thereby, the influence of the failure is avoided, and as shown by 41, 42, 43 in FIG.
The signal from the LT 4 is transmitted through the backup system, that is, the standby OSU (52b) and the standby relay fiber transmission line 10.
And to the user via the standby optical multiplexing / demultiplexing unit (53b), and similarly, the standby optical multiplexing / demultiplexing unit (53b), the standby relay fiber transmission line 10 and the standby OSU (52b). A signal from the user can also be transferred to the OLT 4 via the. Furthermore, FIG.
As shown in, the active OSU (52a) in the OLT 4
Even if the failure 9 occurs, the signal light path can be promptly restored by switching to the backup transmission path. Thereby, the influence of the failure is avoided, and the signal from the OLT 4 is transferred to the user via the transmission path of the standby system as shown by 41, 42, 43 in FIG. A signal from the user can also be transferred to the OLT 4 via the transmission path. Further, even if the optical multiplexing / demultiplexing unit 5 of the active system fails, the signal can be transmitted via the transmission path of the backup system by switching to the transmission path in the same manner.

Next, the basic configuration of the optical access network of this embodiment, which is constructed by using optical components and the like, will be described. FIG. 4 is a block diagram showing the basic configuration of the optical access network of this embodiment. As shown in FIG. 4, in this embodiment, the OSU (52
The new OSU (52b) and the first active spare switching circuit 54 for connecting the OSUs (52a, 52b) are arranged in the vicinity of (a), and the optical multiplexing / demultiplexing unit (53a) in the access optical branching circuit 5 is arranged. ), A new optical multiplexing / demultiplexing unit (53b) is arranged, and the optical multiplexing / demultiplexing unit (53a, 53b) is connected to the subscriber fiber 7.
The active spare switching circuit 34 is arranged. The first and second working backup switching circuits (34, 54) actuate the switches (40, 45) in the circuit when the switching command is received in the case of failure 9 etc. Therefore, the transmission path can be changed to the backup transmission path. In FIG. 4, 14 is an optical transmitter (O
S), 15 is a wavelength multiplexer / demultiplexer, and 16 is 1.55 / 1.58
A coupler, 17 is an optical amplifier, 18 is a transponder, 19
Is a 1.3 / 1.5 coupler, 20 is an optical coupler, 21 is a user group, 22 is a subscriber network interface, 2
3 is a terminal device, 39 is an optical receiver (OR).

In the optical access network of the present embodiment, the signal light input to the OLT 4 is branched into two by the coupler (electrical coupler or optical coupler) 46 in the first active backup switching circuit 54. As a result, the downstream signal light is always transmitted to the active optical multiplexing unit (53a) and the standby optical multiplexing unit (53b) in the access optical branching circuit 5. Also, by switching the switch (electrical switch or optical switch) 45, the upstream signal light of the OSU (52a) of the active system and the upstream signal light of the OSU (52b) of the standby system are selected, and the upstream network is selected. Can be output. The receiving section in the transponder 18 in the second working standby switching circuit 34 branches the electric signal into two, and via the transmitting section of the transponder 18, the working optical multiplexing / demultiplexing unit (53a) and the standby optical multiplexing / demultiplexing unit. Output to the wave unit (53b). As a result, the upstream signal light is transmitted to the active OSU in the OLT 4.
(52a), and OSU (52b) OSU5 of the standby system
Up to 2 is always transmitted. Also, by switching the optical switch 40, the optical multiplexing / demultiplexing unit (53a) of the active system is used.
It is possible to select the downstream signal light of 1) and the downstream signal light of the standby system multiplexing / demultiplexing unit (53b) and transmit them to the ONU 8.

The first and second working spare switching circuits (34, 54) will be described. The first working backup switching circuit 54 is composed of a switch 45 and a coupler 46 that branches into two. The switch 45 is an operating system OS
The upstream signal light from the two OSUs of the U (52a) and the backup OSU (52b) is selected, and the upstream signal light is OL.
Output from T4. The coupler 46 splits the downstream signal light input to the OLT 4 into two, and the active OSU (52a),
And the two OSUs of the spare OSU (52b). The second active spare switching circuit 34 includes the switch 4
0, a transponder 18, a WDM coupler 19 for demultiplexing the upstream signal light and the downstream signal light, and an optical coupler 20 for branching a maximum of m. Switch 40
The optical multiplexing / demultiplexing unit (53a) of the active system and the optical multiplexing / demultiplexing unit (53b) of the standby system are respectively connected to the ports that output only one downlink wavelength of the optical multiplexing / demultiplexing unit of the active system. However, the downlink signal lights of those wavelengths are assigned to the same user group 21. Upon receiving the optical signal from the user group 21, the transponder 18 converts the optical signal into an electric signal. The electrical signal is branched into two and output to the transmission units of the two transponders 18. The wavelength-converted optical signals in the respective transmitting units are input to only one upstream wavelength in the two optical multiplexing / demultiplexing units of the working optical multiplexing / demultiplexing unit (53a) and the standby optical multiplexing / demultiplexing unit (53b). Input to each port.

[Embodiment 2] The above-mentioned Embodiment 1 is
It shows a basic configuration in which the transmission path through which the signal light is transmitted is duplicated. With this alone, it is not possible to detect deterioration and disconnection of the active transmission path or the standby transmission path,
Further, it is impossible to detect a failure or send or receive a command signal for switching the transmission path. The optical access network according to the present embodiment is configured to detect deterioration and disconnection of the working transmission path and switch to the protection transmission path. FIG. 5 is a block diagram showing the basic configuration of the optical access network according to the second embodiment of the present invention. As shown in FIG. 5, in the present embodiment, the power of each wavelength of the upstream signal light is monitored in the active OSU (52a) and the standby OSU (52b) in the upper node device 1. A monitor 35, a supervisory control transceiver 30,
A WDM coupler 32 that multiplexes and demultiplexes the signal light and the supervisory control light is newly arranged. In addition, the first active spare switching circuit 54
In-device monitoring control circuit (NEMF; Network Elemen)
t Management Function, hereinafter simply referred to as NEMF. ) Place 50. Further, the supervisory control transceiver 3 is provided in the optical multiplexing / demultiplexing unit (53a) of the active system and the optical multiplexing / demultiplexing unit (53b) of the standby system in the lower node device 2.
0, WDM coupler 32 for multiplexing / demultiplexing signal light and supervisory control light
And so on, and a downlink monitor 37 for monitoring the power of each wavelength of the downlink signal light and a lower node management circuit 51 are arranged in the second active backup switching circuit 34.

The optical switch 45 in the first active spare switching circuit 54 operates in accordance with a command signal from the NEMF 50 when the use of the active relay fiber transmission line becomes difficult due to a failure or the like. It has a function of switching from (52a) to the spare OSU (52b). Optical switch 4 in second working spare switching circuit 34
When 0 makes it difficult to use the relay fiber transmission line of the active system due to a failure or the like, the optical multiplexing / demultiplexing unit 53a of the active system is operated according to the command signal from the lower node management circuit 51.
From the standby optical multiplexer / demultiplexer unit 53b. Up monitor 35, down monitor 37, supervisory control transceiver 30, WDM coupler 32, NEMF5
0, the lower node management circuit 51, and the user group 21 will be described. The upstream monitor 35 is the active OSU (52a).
And the upstream side, which is arranged between the receiver 39 and the wavelength multiplexer / demultiplexer 15 in the OSU (52b) of the standby system, after transmitting the active-system relay fiber transmission line 6 and the standby-system relay fiber transmission line 10. The power of each wavelength of signal light is measured.

The downstream monitor 37 includes the optical switch 40 in the second working standby switching circuit 34, the working optical multiplexing / demultiplexing unit (53a) and the standby optical multiplexing / demultiplexing unit (5).
3b) is arranged near the connection point with the access system optical branch circuit 5 in the second working standby switching circuit 34 between the wavelength multiplexing and demultiplexing unit 15 in 3b), and the working relay fiber transmission line 6 and the backup The power of each wavelength of the downlink signal light after being transmitted through the relay fiber transmission line 10 of the system is measured. Upstream monitor 35,
A method of determining the power value of each wavelength of the signal light in the downlink monitor 37 will be described. When the power values of the up monitor 35 and the down monitor 37 are increased, an appropriate threshold value P1 shown in Table 1 is set, and when the monitored power value is P1 or less, it is normal, and when it exceeds P1. Judge as abnormal. On the other hand, when the power values of the ascending monitor 35 and the descending monitor 37 have decreased, as shown in Table 2, the threshold value P2 (P2 <P2 <
P1) is set, and it is determined that the monitored power value is abnormal if it is P2 or less, and normal if it exceeds P2. If the monitored power value is equal to P1 or P2, it is implementation-dependent whether to judge normal or abnormal.

[0028]

[Table 1]

[Table 2]

The supervisory control transmitter / receiver 30 is arranged in the upper node device 1 and the lower node device 2, and via the active and standby relay fiber transmission lines (6, 10),
The supervisory control light in a wavelength band different from that of the signal light is constantly transmitted and received. The supervisory control transmitter / receiver 30 includes an error rate measuring device (not shown) therein and measures the bit error rate of the supervisory control light. It is used to monitor the performance state of the relay fiber transmission line by measuring the bit error rate, and to transmit information such as the state of node devices. A method of making a determination according to the value of the measured error rate in the supervisory control transceiver 30 of each node device will be described. When the error rate decreases, as shown in Table 3, the thresholds BER1 and B
ER2 (BER1 <BER2) is set and the error rate is 0
From BER1 to BER1 is normal, between BER1 and BER2 is deteriorated, and when larger than BER2, it is judged to be abnormal. On the other hand, when the error rate increases, as shown in Table 4, thresholds BER3 and BER4 (BER1 <BE
R3 <BER2 <BER4) is set, and if the error rate is between 0 and BER3, it is determined to be normal, if it is between BER3 and BER4, it is deteriorated, and if it is greater than BER4, it is determined to be abnormal. The measured error rate values are BER1, BER3, BE
If it is equal to R2 or BER4, it is implementation-dependent whether to judge normal, deteriorated, or abnormal.

[0030]

[Table 3]

[Table 4]

The supervisory control transmitter / receiver 30 arranged in the upper node apparatus 1 is connected to the upper node apparatus 1, and is a system management apparatus (NE-OpS; Network Element) arranged to manage the entire optical access network. Operat
ion System, hereinafter, simply referred to as NE-Ops. ) 55
However, there is a function of notifying the lower node device of the transmitted command signal for switching the transmission path. Lower node management circuit 51
Is the determination content of the downlink signal light power of each wavelength determined by each downlink monitor 37 in the lower node device 2, the state of the relay fiber transmission lines (6, 10) of the active system and the standby system (relay fiber transmission line (6 , 10) for transmitting the supervisory control light) and the state of the node device or the like, the optical switch 40 is switched. In addition, NE-OpS5
It has a function of switching the transmission path in the downward direction in accordance with the instruction to switch the transmission path from 5. The WDM coupler 32 is an operating system and a standby system OS of the upper node device 1.
In the U (52a, 52b), in the vicinity of the connection point with the relay fiber transmission lines (6, 10) of the working system and the protection system, and the optical multiplexing and demultiplexing unit of the working system and the protection system in the lower node device 2 ( 53a and 53b), they are arranged in the vicinity of connection points with the relay fiber transmission lines (6, 10) of the working system and the standby system, and multiplex / demultiplex the wavelength bands of the above-mentioned signal light and supervisory control light.

The NEMF 50 constantly monitors the state of the upper node device 1 and continuously uses the active transmission path for each wavelength in the upstream direction or switches from the active transmission path to the standby transmission path. To determine. Further, when it is determined that the switching is performed, the switching instruction signals are transmitted to the switch 45. Also, OLT
4 and the access system optical branch circuit 5 constantly monitor the temperature and output power of optical components and the like, and determine the temperature and output power of optical components and the like as normal, deteriorated or abnormal. The result is the NEM in the own node device in the upper node device 1.
Notify F50. On the other hand, the lower node device 2 notifies the lower node management circuit 51 in the second active backup switching circuit 34 in its own node device.

Next, the procedure of the method of monitoring the power of the wavelength of each signal light and the method of monitoring the relay fiber transmission lines (6, 10) will be described. FIG. 6 shows, in the present embodiment,
It is a flowchart which shows the processing procedure of the power of the wavelength of upstream signal light, and the monitoring method of a relay fiber transmission line (6, 10). First, the upstream monitor 142 transmits the monitor value determination content to the NEMF 101 (step 144), and N
The EMF 101 receives the upstream monitor value (step 12)
3). The active supervisory control transmitter / receiver 102 in the upper node device transmits the determination result of the error rate of the supervisory control light received via the active relay fiber transmission line 6 to the NEMF 101 (step 106). Similarly, the standby supervisory control transmitter / receiver 104 in the upper node apparatus transmits the error rate determination result received via the standby relay fiber transmission line 10 to the NEMF 101 (step 124). N
The EMF 101 receives the determination results of the error rates of the active and standby relay fiber transmission lines (6, 10) from the supervisory control transceivers (102, 104) of the active system and the standby system (step 107). The NEMF 101 determines the notified monitor value and error rate (step 156),
If there is no abnormality notification (145 in FIG. 6), the above-mentioned processing is repeated. If there is an abnormality notification in step 156 (146 in FIG. 6), the processing in FIG. 7 is executed.

FIG. 7 shows a case where abnormality is notified to the upstream signal light monitoring information in the present embodiment (146 in FIG. 6).
3 is a flowchart showing a flow of processing in FIG. N
The EMF 101 determines whether to continue to use the active transmission path or switch to the standby transmission path according to Table 5 or Table 6 (step 112). Which table is used depends on whether the information of the supervisory control light is used or not. First, when using the information of the supervisory control light, the NEMF 101 selects the transmission path according to Table 5. Only when the combination of the upstream power monitor value of each wavelength of the active system and the standby system and the state of the relay fiber transmission lines (6, 10) of the active system and the standby system corresponds to the colored part in the table, the transmission path To switch to the standby system.

Here, the upstream signal light and the downstream signal light when switching the switches (40, 45) will be described. In the configuration of this embodiment, the downlink signal light is always transmitted to the optical multiplexing / demultiplexing unit 53b of the standby system. A failure etc. occurred in the transmission path of the active system, and the second
Only when the switch 40 in the active spare switching circuit 34 of the above is switched to the transmission path of the standby system, the downlink signal light transmitted through the transmission path of the standby system passes through the subscriber fiber 7,
It is transmitted to the ONU 8 on the user side. Similarly, the upstream signal light is always transmitted to the OSU 52b of the standby system. The upstream signal light is output from the upper node device 1 only when the switch 45 in the first active backup switching circuit 54 is switched to the standby transmission path for each wavelength due to a failure of the active transmission path or the like.

[0036]

[Table 5]

Below, the upstream monitor values of the respective wavelengths of the working system and the protection system, which correspond to the colored parts in Table 5, and the relay fiber transmission lines (6, 1) of the working system and the protection system are shown.
The combination of the determination contents of the bit error rate of 0) is shown. 1. The value of the power monitor of the working system is normal, and the error rate of the supervisory control light of the working system is notified that the power monitor value of the standby system is normal, and the error rate of the supervisory control light of the standby system is normal. When notified. 2. The value of the power monitor of the active system is normal, and the error rate of the supervisory control light of the active system is notified as abnormal. The value of the power monitor of the standby system is normal and the error rate of the supervisory control light of the standby system is normal. Is notified. 3. The value of the power monitor of the active system is normal, and the error rate of the supervisory control light of the active system is notified as abnormal, and the value of the power monitor of the standby system is normal and the error rate of the supervisory control light of the standby system is degraded. Is notified. 4. The value of the power monitor of the active system is abnormal, and the error rate of the supervisory control light of the active system is notified as normal. The value of the power monitor of the standby system is normal and the error rate of the supervisory control light of the standby system is normal. Is notified.

5. It is notified that the value of the power monitor of the active system is abnormal and that the error rate of the supervisory control light of the active system is degraded.
When the value of the power monitor of the standby system is normal and the error rate of the supervisory control light of the standby system is normal. 6. It is notified that the value of the power monitor of the working system is abnormal, and the error rate of the supervisory control light of the working system is degraded, the power monitor value of the standby system is normal, and the error rate of the supervisory control light of the standby system is degraded. Is notified. 7. The value of the power monitor of the active system is abnormal, and the error rate of the supervisory control light of the active system is notified as abnormal, the value of the power monitor of the standby system is normal, and the error rate of the supervisory control light of the standby system is normal. Is notified. 8. The value of the power monitor of the active system is abnormal, and the error rate of the supervisory control light of the active system is notified as abnormal, the value of the power monitor of the standby system is normal, and the error rate of the supervisory control light of the standby system is degraded. Is notified. 9. The value of the power monitor of the active system is abnormal, and the error rate of the supervisory control light of the active system is notified as abnormal, the value of the power monitor of the standby system is normal, and the error rate of the supervisory control light of the standby system is abnormal. Is notified. NEMF1 only when the above 9 cases are applicable
01 determines to switch the transmission path of the wavelength to the backup system (switch determination 134 in FIG. 7).

On the other hand, when not using the information of the supervisory control light but using only the judgment contents of the power monitor value, the NEMF 101 decides whether to switch the transmission path or continuously use it according to Table 6. .

[Table 6]

Specifically, it is determined to switch the transmission path only when the power monitor value of the active system is abnormal and the power monitor value of the standby system is normal (switching determination 134 in FIG. 7). The NEMF 101 notifies the NE-OpS 55 of the content determined to switch the transmission path whether the information of the supervisory control light is used or not (step 119). Then, the switching signal is transmitted to the switch 150 (45 shown in FIG. 5) in the upper node device 1 (step 113). The switch 150 receives the switching signal (step 147) and switches the transmission path from the active system to the standby system. When the switching is completed (step 148), the switching completion signal is transmitted to the NEMF 101 (step 149). When the NEMF 101 receives the switching completion signal (step 142), the NE-Op 101
It notifies S55 that the switching of the transmission path is completed (step 121). On the other hand, if the above switching determination is not applicable, it is determined that the transmission path will be continuously used without switching (step 135). Further, the content of the determination is notified to the NE-Ops (step 121), and the processing of FIG. 10 is performed again.

Next, in the present embodiment, the power of the wavelength of the downstream signal light and the repeater fiber transmission line (6, 10)
The monitoring method of will be described. FIG. 8 is a flowchart showing the processing procedure of the method for monitoring the power of the wavelength of the downstream signal light and the relay fiber transmission line (6, 10) in the present embodiment. The downlink monitor 141 transmits the determination content of the monitor value to the lower node management circuit 120 (step 143). The lower node management circuit 120 receives the downlink monitor value (step 152). Further, the active system supervisory control transceiver 103 and the standby system supervisory control transceiver 105 in the lower node device are the lower node management circuit 1
The determination content of the error rate measured via the active and standby relay fiber transmission lines (6, 10) is transmitted to 20 (steps 108, 124). The lower node management circuit 120 receives the information (step 130). The lower-level node management circuit 120 judges the received contents (step 156), repeats the above processing if there is no abnormality notification (no abnormality notification 145 in FIG. 8), and if there is an abnormality notification (in FIG. 8). When there is an abnormality notification 146), the processing shown in FIG. 9 is executed.

FIG. 9 shows a case in which an abnormality is notified to the downlink signal light monitoring information in the present embodiment (146 in FIG. 8).
3 is a flowchart showing a flow of processing in FIG. The lower-node management circuit 120, according to Table 5 or Table 6,
It is determined whether to continue to use the active transmission path or switch to the standby transmission path (step 112). Which table is used depends on whether the information of the supervisory control light is used or not. First, when using the information of the supervisory control light, the lower node management circuit 120 selects a transmission route according to Table 5. Lower node management circuit 120
Is the power monitor value of the downlink monitor 37 for each wavelength of the active system and the standby system transmitted from the lower node device 2, and the relay fiber transmission lines (6, 1) of the active system and the standby system.
Only when the combination of the states of 0) corresponds to the colored part in the table, it is determined to switch the transmission path. The details of the combinations in the table are the same as in the case of the upstream signal light described above, that is, like the upstream signal light, the lower node management circuit 120 determines that the lower node management circuit 120 has a transmission path of the wavelength only when there are nine cases. To switch to the standby system (Fig. 9
Switching determination 134).

In other cases, the lower node management circuit 120 determines that the transmission path will not be switched (see FIG. 9).
135), and notifies the NE-OpS 55 of the contents (step 121). Then, returning to the processing of FIG. 8, the above-described operation is repeated. When the information of the supervisory control light is not used, as in the case of the upstream signal light, according to Table 6,
The lower node management circuit 120 determines whether to switch the transmission path or continue to use it. Specifically, it is determined to switch the transmission path only when the power monitor value in the active downlink monitor 37 is abnormal and the power monitor value in the standby downlink monitor 37 is normal (switching in FIG. 9). Decision 134). In other cases, the lower node management circuit 120 determines that the transmission path should not be switched (135 in FIG. 9) and notifies the NE-OpS 55 of the content (step 121). Then, returning to the processing of FIG. 8, the above-described operation is repeated.

Returning to FIG. 9, when it is determined that the transmission path is switched, whether the information of the supervisory control light is used or not is used, the content is notified to the NE-OpS (step 119). The lower node management circuit 120
The switch 151 in the second active spare switching circuit 34
A switching command signal is transmitted to (the switch 40 shown in FIG. 5) (step 132). The switch 151 in the second active backup switching circuit 34 switches to the backup system after receiving the signal (step 147). Switch 1
When the switching is completed (step 148), the 51 transmits a switching completion signal to the lower node management circuit 120 (step 149). The lower node management circuit 120 receives the switching completion signal (step 141), and the NE-O
Notify pS (step 121). Then, returning to the processing of FIG. 8, the above-described operation is repeated. Here, the processing when the lower node management circuit 120 notifies the NE-OpS 55 will be described. The lower node management circuit 120
The above-described notification (for example, the notification that the transmission path is not switched) is transferred to at least one of the monitoring and controlling transceivers 30 of the active system and the standby system of the lower node device 2. At least one of the supervisory control transceivers 30 of the active system and the standby system of the lower node device 2 superimposes the notice on the supervisory control light after receiving the notice, and transmits / receives the supervisory control transceiver of the upper node device 1. Send to 30. The supervisory control transmitter / receiver 30 of the upper node apparatus 1 that has received the notification transfers the notification to the NEMF 101, and the NEMF 101
The NE-OpS55 is notified of the notification.

In the above description, the case has been described in which the state of the signal light transmitted through the repeater fibers (6, 10) of the working system and the standby system is monitored and which signal light is to be adopted is determined. However, in reality, it may be necessary to change the route in advance for fiber replacement or maintenance. At this time, the active transmission path is switched to the standby transmission path based on the notification from the NE-OpS 55. FIG. 10 shows that in the present embodiment, N
It is a flowchart which shows the process procedure at the time of switching the path | route of the upstream signal light from the working system to the protection system based on the notification from E-OpS55. First, NE-OpS154
Sends a transmission path switching signal to the NEMF 101 (step 155). After receiving the signal (step 136), the NEMF 101 transmits the switching signal to the switch 150 (45 shown in FIG. 5) in the first active backup switching circuit 54 in the upper node device 1 (step). 113). The switch 150 receives the switching signal (step 147), and when the switching of the route is completed (step 148), transmits the switching completion signal to the NEMF 101 (step 149). NEM
After receiving the switching completion signal (step 142), the F 101 notifies the NE-Ops 154 that the switch 150 has been switched (step 143). After the switching of the upstream signal light is completed, the states of the OLT 4, the access optical branch circuit 5, and the active and standby relay fiber transmission lines (6, 10) are monitored and controlled according to the procedure shown in FIG.

FIG. 11 shows the NE-
Based on the notification from OpS55,
It is a flow chart which shows a processing procedure at the time of switching from an active system to a standby system. NE-OpS154 is NEMF
A transmission path switching signal is transmitted to 101 (step 155). After receiving the signal (step 119), the NEMF 101 sends a command signal for switching the switch 151 in the second active backup switching circuit 34.
Transmitter / receiver 10 for supervisory control in the upper node device 1
4 (30 shown in FIG. 5) (step 153).
Transmitter / receiver 10 for supervisory control in the upper node device 1
After receiving the command signal, the data No. 4 transfers the command signal to the lower node device 2 (step 114). The supervisory control transmitter / receiver 105 (30 shown in FIG. 5) of the lower node device 2 is
After receiving the command signal, the lower node management circuit 12
0 (step 115). The lower node management circuit 120 transmits a switching command signal to the switch 151 in the second active backup switching circuit 34 (step 132).

After receiving the command signal (step 147), the switch 151 switches the transmission path from the active system to the standby system. Then, when the switching is completed (step 148), the switching completion signal is transmitted to the lower node management circuit 120 (step 149). When receiving the switching completion signal, the lower node management circuit 120 transfers it to the supervisory control transceiver 105 of the standby system of the lower node device 2 (step 140). After receiving the switching completion signal, the standby system supervisory control transmitter / receiver 105 of the lower node device 2 transmits the switching completion signal to the standby system supervisory control transmitter / receiver 104 of the upper node device 1 (step 144). The standby control transmitter / receiver 104 of 1 is
After receiving the switching completion signal, the NEMF 101
(Step 141). When the NEMF 101 receives the information signal whose transmission path has been switched (step 142), the NEMF 101 notifies the NE-OpS 154 (step 143). When the switching of the downstream signal light is completed, the states of the OLT 4, the optical branch circuit 5 of the access system, and the relay fiber transmission lines (6, 10) of the active system and the standby system are monitored and controlled according to the procedure shown in FIG.

In the above description, the NEMF 50 or the lower node management circuit 51 is configured by a dedicated device, but the NEMF 50 or the lower node management circuit 51 may be configured by a computer. It is possible. In this case, the computer executes the control program stored in the hard disk or the like in the computer, so that the computer shown in FIG.
The process 1 is performed. Here, this control program is
It is supplied by a flexible disk (FD), a CD-ROM, or downloaded via a network. Although the invention made by the present inventor has been specifically described based on the above-described embodiment, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. Of course,

[0049]

The effects obtained by the invention disclosed in the present application will be briefly described as follows. (1) According to the present invention, in a wide area access network, a working transmission path including a working relay fiber transmission path and a backup relay fiber are used as a signal light transmission path between an upper node device and a lower node device. A backup transmission path including a transmission path can be set, and the signal light transmission path can be duplicated. (2) According to the present invention, by constantly monitoring the active and standby relay fiber transmission lines, optical components, and the like,
When a failure of the station equipment or a failure of the relay fiber transmission line occurs, it is possible to detect it immediately and switch to the backup system transmission route, and the time for signal disconnection and deterioration to the user can be reduced. It can be shortened.

[Brief description of drawings]

FIG. 1 is a block diagram showing a concept of an optical access network according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a case where a failure occurs in a relay fiber transmission line in the optical access network according to the first embodiment of the present invention.

FIG. 3 is a diagram illustrating a case where a failure occurs in an optical transmission / reception unit in the optical access network according to the first embodiment of the present invention.

FIG. 4 is a block diagram showing a basic configuration of an optical access network according to the first embodiment of the present invention.

FIG. 5 is a block diagram showing a basic configuration of an optical access network according to a second embodiment of the present invention.

FIG. 6 is a flowchart showing a processing procedure of a wavelength power of upstream signal light and a method of monitoring a relay fiber transmission line in the optical access network according to the second embodiment of the present invention.

FIG. 7 is a flowchart showing a flow of processing in the optical access network according to the second embodiment of the present invention when an abnormality is notified to the upstream signal light monitoring information.

FIG. 8 is a flowchart showing a processing procedure of a method of monitoring the power of the wavelength of the downstream signal light and the relay fiber transmission line in the optical access network according to the second embodiment of the present invention.

FIG. 9 is a flowchart showing the flow of processing in the optical access network according to the second embodiment of the present invention when abnormality is notified to the downlink signal light monitoring information.

FIG. 10 is a flowchart showing a processing procedure in the optical access network according to the second embodiment of the present invention when switching the route of the upstream signal light from the working system to the protection system based on the notification from the NE-OpS.

FIG. 11 is a flowchart showing a processing procedure in the optical access network according to the second embodiment of the present invention when switching the path of the downlink signal light from the working system to the protection system based on the notification from the NE-OpS.

FIG. 12 is a block diagram showing the concept of a conventional optical access network.

FIG. 13 is a block diagram showing a basic configuration of a conventional optical access network.

FIG. 14 is a diagram illustrating a case where a failure occurs in a relay fiber transmission line in a conventional optical access network.

FIG. 15 is a diagram illustrating a case where a failure occurs in an optical transmission / reception unit in a conventional optical access network.

[Explanation of symbols]

1 ... Upper node device, 2 ... Lower node device, 4 ... Access system subscriber device (OLT), 5 ... Access system optical branch circuit, 6, 10 ... Relay fiber transmission line, 7 ... Subscriber fiber, 8 ... Subscriber Side device (ONU), 9 ... Failure, 11, 1
2, 13, 41, 42, 43 ... Signal light, 14 ... Optical transmitter (OS), 15 ... Wavelength multiplexer / demultiplexer, 16, 19, 20, 3
2, 46 ... Optical coupler, 17 ... Optical amplifier, 18 ... Transponder, 21 ... User group, 22 ... Subscriber network interface, 23 ... Terminal device, 30 ... Supervisory control transceiver, 32 ... WDM coupler, 34, 54 ... Working spare switching circuit, 35 ... Upstream signal monitor, 37 ... Downstream signal monitor, 39 ... Optical receiver (OR), 40, 45 ... Switch, 50 ... In-apparatus supervisory control circuit (NEMF), 51 ...
Lower node management circuit, 52a, 52b ... Optical transmission / reception unit (OSU), 53a, 53b ... Optical multiplexing / demultiplexing unit, 5
5 ... System monitoring device (NE-OpS).

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04J 14/02 F term (reference) 5K002 DA02 DA04 DA09 DA12 EA06 EA33 FA01 5K021 CC13 DD02 EE02 FF11

Claims (36)

[Claims] 1. A lower node apparatus having an access type optical branch circuit connected to a subscriber side apparatus via a subscriber fiber, an upper node apparatus having an access type subscriber apparatus, the lower node apparatus and the upper order. An optical access network comprising working and protection relay fiber transmission lines arranged between a node device and the node device, wherein the upper node device is a working and protection optical transmission / reception unit, and a first working protection switching circuit. Wherein the lower node device is a working optical multiplexing / demultiplexing unit connected to the working optical transmission / reception unit via the working relay fiber transmission line, and the spare relay fiber transmission line. A spare optical multiplexing / demultiplexing unit connected to the spare optical transmission / reception unit, and a second working spare switching circuit; The equipment switching circuit is an upstream signal light transmitted from the lower node device to the upper node device, and is an upstream signal light output from the active optical transceiver unit, or from the standby optical transceiver unit. It has an upper switch for selecting one of the output signal lights in the upstream direction, and means for branching the signal light for the access optical branch circuit into two and sending it to the working and standby relay fiber transmission lines. The second working standby switching circuit is a downstream signal light transmitted from the upper node device to the lower node device and is a downstream signal light output from the working optical add / drop unit, or A lower switch for selecting one of the downlink signal lights output from the spare optical combining / distributing unit and the access system subscriber device. The signal light and second branched, optical access network, characterized in that it comprises a means for delivering to the working and protection relay fiber transmission line. 2. The working optical transmission / reception unit is provided at a connection point of a wavelength multiplexer / demultiplexer, the wavelength multiplexer / demultiplexer, and the working relay fiber transmission line. And a working upper-side coupler that multiplexes and demultiplexes supervisory control light in a different wavelength band from, and a working upper-side supervisory controller connected to the working upper-side coupler, and the spare optical transceiver unit. A wavelength multiplexer / demultiplexer, the wavelength multiplexer / demultiplexer, and a spare upper coupler provided at the connection point of the spare relay fiber transmission line, for multiplexing / demultiplexing the signal light and the supervisory control light. , A spare upper supervisory controller connected to the spare upper coupler, the working optical multiplexer / demultiplexer unit is a wavelength multiplexer / demultiplexer, the wavelength multiplexer / demultiplexer, and the working optical multiplexer / demultiplexer. The signal light and the supervisory control are provided at the connection point with the repeater fiber transmission line. An active lower-side coupler for multiplexing and demultiplexing, and an active lower-side supervisory controller connected to the active lower-side coupler, wherein the spare optical multiplexing / demultiplexing unit is a wavelength multiplexer / demultiplexer, The wavelength multiplexer / demultiplexer and a spare lower-side coupler that is provided at a connection point between the spare relay fiber transmission line and multiplexes / demultiplexes the signal light and the supervisory control light; and the spare lower-side coupler. A backup lower side supervisory controller connected thereto, and the supervisory control between the active upper side supervisory controller and the active lower side supervisory controller via the active relay fiber transmission line. Transmitting and receiving light, and transmitting and receiving the supervisory control light between the spare upper side supervisory controller and the spare lower side supervisory controller via the spare relay fiber transmission line. Optical access network according to item 1 3. The upper monitoring control device in use, based on the upstream monitoring control light transmitted from the lower node device to the upper node device via the active relay fiber transmission line, The transmission state of the supervisory control light transmitted through the working relay fiber transmission line is determined, and the spare upper supervisory control device is transferred from the lower node device to the higher node device via the spare relay fiber transmission line. Based on the upstream supervisory control light transmitted to the backup relay fiber transmission line, the transmission state of the supervisory control light is determined, the active lower-side supervisory control device, the active relay fiber Based on the downstream supervisory control light transmitted from the upper node device to the lower node device through the transmission line, the working relay fiber transmission line is transmitted. Determine the transmission state of the supervisory control light, the backup lower side monitoring control device, through the backup relay fiber transmission line, in the downstream direction transmitted from the upper node device to the lower node device The optical access network according to claim 2, wherein the transmission state of the supervisory control light transmitted through the backup relay fiber transmission line is determined based on the supervisory control light. 4. The upper node device measures, for each wavelength, the power of upstream signal light transmitted from the lower node device to the upper node device via the working and standby relay fiber transmission lines. However, the upstream node device for determining whether the signal light in the upstream direction for each wavelength is normal or abnormal, the lower node device, the upper node device via the working and standby relay fiber transmission line From each of the working / standby optical multiplexing / demultiplexing units to measure the power of the downlink signal light for each wavelength, and normalize the downlink signal light for each wavelength. The optical access network according to any one of claims 1 to 3, further comprising a downlink monitor for determining abnormality. 5. The upper node device has an in-device monitoring control device, and the in-device monitoring control device, based on a determination result of the upstream monitor, as a transmission path of the upstream signal light,
The working optical transmission / reception unit, the working optical multiplexing / demultiplexing unit, and the working transmission path composed of the working relay fiber transmission line are continuously used, or
It is determined for each wavelength of the signal light whether to use a backup transmission path composed of the backup optical transmission / reception unit, the backup optical multiplexing / demultiplexing unit, and the backup relay fiber transmission path. The optical access network according to claim 4. 6. The upper node device has an in-device monitoring control device, wherein the in-device monitoring control device determines whether the determination result of the upstream monitor and the active and standby upper monitoring control devices are present. Based on the determination result, as the transmission path of the signal light in the upstream direction, the working transmission path composed of the working optical transmission / reception unit, the working optical multiplexing / demultiplexing unit, and the working relay fiber transmission path is continued. Or use
Alternatively, it is determined for each wavelength of the signal light whether to use a backup transmission path composed of the backup optical transmission / reception unit, the backup optical multiplexing / demultiplexing unit, and the backup relay fiber transmission line. The optical access network according to claim 4, wherein: 7. A system management device that is connected to the upper node device and that manages the entire system, wherein the in-device monitoring control device is provided on the side of the spare optical transceiver unit when the spare transmission path is used. A switching command to switch to the upper-side switch in the first working backup switching circuit, and in the upper-side switch, when the switching is normally performed, to the system management device, The optical access network according to claim 5 or 6, which notifies that normal switching has been performed. 8. A system management device that is connected to the upper node device and manages the entire system, wherein the in-device monitoring control device is operated from the active optical transmission / reception unit based on an instruction from the system management device. The system is transmitted when a switching command for switching to the spare optical transceiver unit side is transmitted to the upper switch in the first working standby switching circuit, and the switching is normally executed in the upper switch. The optical access network according to claim 5, wherein the management device is notified that normal switching has been performed. 9. The lower node apparatus has a lower node management apparatus, and the lower node management apparatus, as a transmission path of the signal light in the downlink direction, based on a determination result in the downlink monitor,
The working optical transmission / reception unit, the working optical multiplexing / demultiplexing unit, and the working transmission path composed of the working relay fiber transmission line are continuously used, or
It is determined for each wavelength of the signal light whether to use a backup transmission path composed of the backup optical transmission / reception unit, the backup optical multiplexing / demultiplexing unit, and the backup relay fiber transmission path. The optical access network according to claim 4. 10. The lower node device includes a lower node management device, and the lower node management device determines a determination result in the downlink monitor and a determination result in the active and standby lower monitoring control devices. Based on the above, as the transmission path of the signal light in the downstream direction, the current transmission path composed of the current optical transmission / reception unit, the current optical multiplexing / demultiplexing unit, and the current relay fiber transmission path is continuously used. Or,
Alternatively, it is determined for each wavelength of the signal light whether to use a backup transmission path composed of the backup optical transmission / reception unit, the backup optical multiplexing / demultiplexing unit, and the backup relay fiber transmission line. The optical access network according to claim 4, wherein: 11. A system management device that is connected to the upper node device and manages the entire system, wherein the lower node management device is provided on the side of the spare optical multiplexing / demultiplexing unit when the spare transmission path is used. A switching instruction to switch to the lower side switch in the second active backup switching circuit, and in the lower side switch, when the switching is normally executed, to the system management device, The optical access network according to claim 9 or 10, which notifies that normal switching has been performed. 12. A system management device that is connected to the upper node device and manages the entire system, wherein the lower node management device operates from the working optical multiplexer / demultiplexer unit based on an instruction from the system management device. A switching command for switching to the spare optical multiplexing / demultiplexing unit side is transmitted to the lower side switch in the second working standby switching circuit, and in the case where the lower side switch normally performs switching, The optical access network according to claim 9 or 10, wherein the system management device is notified that normal switching has been performed. 13. An access system optical branch circuit, which is connected to an access system subscriber device provided in an upper node device, via an active and a standby relay fiber transmission line in which a wavelength-multiplexed signal light is transmitted. A node device having: a working optical multiplexing / demultiplexing unit connected to the working relay fiber transmission line, a spare optical multiplexing / demultiplexing unit connected to the spare relay fiber transmission line, and a working spare switching circuit. The active standby switching circuit is a downstream signal light transmitted from the upper node device, a downstream signal light output from the active optical add / drop unit, or the backup optical add / drop unit. The switch for selecting one of the downlink signal lights output from the switch and the signal light for the access system subscriber device are split into two, and And spare node device; and a means for delivering to the relay fiber transmission line. 14. The working optical multiplexer / demultiplexer unit is provided at a connection point between a wavelength multiplexer / demultiplexer, the wavelength multiplexer / demultiplexer, and the working relay fiber transmission line, and the signal light and the signal An active coupler that multiplexes and demultiplexes supervisory control light in a wavelength band different from that of light, and an active supervisory control device that is connected to the active coupler. A multiplexer, the wavelength multiplexer / demultiplexer, and a spare coupler that is provided at a connection point between the spare relay fiber transmission line and that multiplexes and demultiplexes the signal light and the supervisory control light, and the spare coupler. A backup supervisory controller connected to the active supervisory controller, and the active supervisory controller is connected to the active supervisory controller in the upper node device via the active relay fiber transmission line. Control light is transmitted and received, and the backup monitoring control device is Between the pre-monitoring control unit in the device, via the relay fiber transmission path of the spare node device according to claim 13, characterized in that transmitting and receiving the monitoring control light. 15. The active supervisory control device, based on the downstream supervisory control light transmitted from the upper node device via the active relay fiber transmission line, the active relay fiber transmission line. To determine the transmission state of the monitor control light, the backup monitor control device, via the backup relay fiber transmission line, to the downlink monitor control light transmitted from the upper node device. 15. The node device according to claim 14, wherein the transmission state of the supervisory control light transmitted through the backup relay fiber transmission line is determined based on the above. 16. The power of the downlink signal light transmitted from the upper node device through the working and protection relay fiber transmission lines and output from the working and protection optical multiplexing / demultiplexing units for each wavelength. 16. The node device according to claim 13, further comprising a downlink monitor that determines whether the signal light in the downlink direction is normal or abnormal for each wavelength. 17. A node management device, wherein the node management device comprises a determination result of the downlink monitor,
Also, based on the determination results in the working and standby monitoring control devices, the working optical multiplexing / demultiplexing unit and the working relay fiber transmission path are configured as a transmission path for transmitting the downlink signal light. For each wavelength of the signal light, whether to continue to use the current transmission path or to use the backup optical transmission / reception unit and the backup transmission path including the backup relay fiber transmission path is used. 17. The node device according to claim 16, wherein the node device is determined. 18. The node management device, when using the backup transmission path, transmits a switching command for switching to the backup optical multiplexing / demultiplexing unit side to the switch in the working backup switching circuit. When the switching is normally performed in the switch, the system switching device that is connected to the upper node device and manages the entire system is notified that the normal switching is performed. The node device according to claim 17. 19. The node management device switches from the working optical multiplexing / demultiplexing unit side to the spare optical multiplexing / demultiplexing unit side based on an instruction from a system management device that is connected to an upper node device and manages the entire system. A switching command is transmitted to the switch in the active backup switching circuit, and when the switch normally executes the switching, the normal switching is executed to the system management device. A notification is given, characterized by the above-mentioned.
7. The node device according to 7. 20. An access system optical branch circuit provided in a lower node device, and an access system subscriber device connected via working and standby relay fiber transmission lines, through which wavelength-multiplexed signal light is transmitted. A node device having: a working optical transmission / reception unit connected to the working relay fiber transmission line; a spare optical transmission / reception unit connected to the backup relay fiber transmission line; and a working backup switching circuit. Having, the active standby switching circuit is an upstream signal light transmitted from the lower node device, an upstream signal light output from the active optical transceiver unit, or
A switch for selecting one of the upstream signal lights output from the spare optical transmission / reception unit and a signal light for the access system optical branch circuit are split into two and sent to the working and standby relay fiber transmission lines. And a node device. 21. The optical transmission / reception unit for use, wherein the signal light and the signal light are provided at a connection point between the wavelength multiplexer / demultiplexer, the wavelength multiplexer / demultiplexer, and the active relay fiber transmission line. An active coupler that multiplexes and demultiplexes supervisory control lights of different wavelength bands, and an active supervisory controller that is connected to the active coupler, and the spare optical transmission / reception unit is a wavelength multiplexer / demultiplexer, At the connection point between the wavelength multiplexer / demultiplexer and the spare relay fiber transmission line, a spare coupler that multiplexes and splits the signal light and the supervisory control light, and a spare monitor connected to the spare coupler. A control device, the active monitoring control device, between the active monitoring control device in the lower node device, via the active relay fiber transmission line, transmits and receives the monitoring control light, The backup supervisory controller is a backup node in the lower node device. Between the visual control device, via the relay fiber transmission path of the spare node device according to claim 20, characterized in that transmitting and receiving the monitoring control light. 22. The active supervisory control device, based on the upstream supervisory control light transmitted from the lower node device via the active relay fiber transmission line, uses the active relay fiber transmission line. To determine the transmission state of the monitor control light, the backup monitor control device, via the backup relay fiber transmission line, to the upstream monitor control light transmitted from the lower node device. 22. The node device according to claim 21, wherein a transmission state of the supervisory control light transmitted through the backup relay fiber transmission line is determined based on the transmission state. 23. The power of the upstream signal light transmitted from the lower node device via the working and protection relay fiber transmission lines is measured for each wavelength, and the upstream direction is measured for each wavelength. 21. An upstream monitor for determining whether the signal light of the device is normal or abnormal is provided.
23. The node device according to claim 22. 24. An in-apparatus monitoring control apparatus is provided, wherein the in-apparatus monitoring control apparatus is based on a determination result of the upstream monitor and a determination result of the monitoring control apparatus.
As the transmission path of the signal light in the upstream direction, the working transmission path composed of the working optical transmission / reception unit and the working relay fiber transmission path is continuously used, or
Alternatively, it is determined for each wavelength of the signal light whether to use a backup transmission path composed of the backup optical transmission / reception unit and the backup relay fiber transmission path. The node device described. 25. The in-device supervisory control device, when using the backup transmission path, transmits a switching command to switch to the backup optical transmission / reception unit side to the switch in the active backup switching circuit. When the switch is normally executed, the system management device that is connected to the node device and manages the entire system is notified that the normal switch is executed. Item 24. The node device according to Item 24. 26. The switching command for switching the working optical transceiver unit to the standby optical transceiver unit side, based on an instruction from a system management device that is connected to a node device and manages the entire system, Is transmitted to the switch in the active spare switching circuit, and when the switch normally executes the switching, the system management device is notified that the normal switching has been executed. 2. The method according to claim 2, wherein
4. The node device according to 4. 27. A lower node apparatus having an access type optical branch circuit, which is connected to a subscriber side apparatus via a subscriber fiber, an upper node apparatus having an access type subscriber apparatus, and the access type optical branch circuit. A control method for an optical access network, comprising: a working and a standby relay fiber transmission line for connecting the access subscriber device and transmitting wavelength-multiplexed signal light, the upper node device and the lower node device. As a signal light transmission path between and, set a working transmission path including the working relay fiber transmission path, and a backup transmission path including the backup relay fiber transmission path, in the upper node device, Upstream signal light transmitted from the lower node apparatus to the upper node apparatus via the working transmission path, or the backup transmission signal. One of the upstream signal lights transmitted from the lower node device to the upper node device via a route is selected, and the signal light for the lower node device is split into two to divide the working and standby relay fiber transmission lines. In the lower node device, the downlink signal light transmitted from the upper node device to the lower node device via the working transmission path, or the upper node via the backup transmission path. One of the downlink signal lights transmitted from the device to the lower node device is selected, and the signal light for the upper node device is branched into two and sent to the working and standby relay fiber transmission lines. Optical access network control method. 28. The supervisory control light of a wavelength band different from the signal light is transmitted and received between the upper node device and the lower node device via the working and standby relay fiber transmission lines, In the device, the working and protection relay fiber transmission lines are transmitted based on the upstream supervisory control light transmitted from the lower node device to the higher node device through the working and protection relay fiber transmission lines. Determining the transmission state of the supervisory control light, in the lower node device, the downstream supervisory control light transmitted from the upper node device to the lower node device via the working and standby relay fiber transmission lines 28. The transmission state of the supervisory control light transmitted through the working and standby relay fiber transmission lines is determined based on the above. The method of mounting an optical access network. 29. In the upper node apparatus, the power of the upstream signal light transmitted from the lower node apparatus to the upper node apparatus via the working and standby relay fiber transmission lines The measurement is performed for each wavelength, and the normality or abnormality of the signal light in the upstream direction is determined for each wavelength, and in the lower node device, the upper node device through the working and standby relay fiber transmission lines. From the signal power of the downlink signal transmitted from the lower node device from, to measure each wavelength of the signal light, to determine the normal or abnormal of the signal light in the downlink for each wavelength. 29. The optical access network control method according to claim 27 or 28. 30. In the upper node device, based on the determination result of the upstream monitor and the determination result of the transmission state of the supervisory control light, the working relay fiber is used as a transmission path of the upstream signal light. It is determined for each wavelength of the signal light whether to continuously use the current transmission path including the transmission path or to use the backup transmission path including the backup relay fiber transmission path. The optical access network control method according to claim 29. 31. The upper node device is connected to the upper node device to determine whether to continue to use the working transmission path or to use a backup transmission path, and manages the entire system. 31. The method of controlling an optical access network according to claim 30, wherein the system management device is notified. 32. In the subordinate node device, based on the determination result of the downlink monitor and the determination result of the transmission state of the supervisory control light, the working relay fiber is used as a transmission path of the signal light in the downlink direction. It is determined for each wavelength of the signal light whether to continuously use the current transmission path including the transmission path or to use the backup transmission path including the backup relay fiber transmission path. The optical access network control method according to claim 29. 33. The lower node device is connected to the upper node device to determine whether to continue to use the working transmission path or to use a backup transmission path, and manage the entire system. 33. The method of controlling an optical access network according to claim 32, wherein the system management device is notified. 34. The upper node device and the lower node device are connected to the upper node device, and an active transmission path including the active relay fiber transmission line based on an instruction from a system management device that manages the entire system. 30. The optical access network control method according to claim 29, further comprising: switching from a backup transmission path to a backup transmission path including the backup relay fiber transmission path. 35. A lower node device having an access type optical branch circuit, which is connected to a subscriber side device via a subscriber fiber, an upper node device having an access type subscriber device, and the access type optical branch circuit. A signal light transmission path between the upper node device and the lower node device, which is connected to the access subscriber device and includes working and standby relay fiber transmission lines for transmitting the signal light wavelength-multiplexed. In an optical access network having a working transmission path including the working relay fiber transmission path and a backup transmission path including the backup relay fiber transmission path, the computer provided in the upper node device Is a control program for switching the transmission path of the , The determination result of the upstream signal light of each wavelength transmitted from the lower node device to the upper node device via the working and protection transmission paths, and the transmission and reception via the working and protection relay fiber transmission paths. A procedure 1 for receiving the determination result of the transmission state of the supervisory control light in the wavelength band different from that of the signal light
And executing the procedure 2 for determining for each wavelength of the signal light whether to continuously use the working transmission line or to use the backup transmission path based on the received determination result. A control program characterized by the above. 36. A lower node device having an access system optical branch circuit, which is connected to a subscriber side device through a subscriber fiber, an upper node device having an access system subscriber device, and the access system optical branch circuit. A signal light transmission path between the upper node device and the lower node device, which is connected to the access subscriber device and is provided with working and standby relay fiber transmission lines for transmitting signal light multiplexed in wavelength. In the optical access network having a working transmission path including the working relay fiber transmission path and a backup transmission path including the backup relay fiber transmission path, the computer provided in the lower node device is Is a control program for switching the transmission path of the A determination result of downlink signal light for each wavelength transmitted from the upper node device to the lower node device through the working and protection transmission paths, and transmission / reception via the working and protection relay fiber transmission paths The procedure 1 for receiving the determination result of the transmission state of the supervisory control light in the wavelength band different from the signal light, and whether the working transmission line is continuously used based on the received determination result, A control program for executing a procedure 2 of determining whether to use the backup transmission path for each wavelength of signal light.