JP2009118064A - Optical communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To locate an ONU in an extinction inadequate state simply without costing such much labor that a system maintenance person designates the ONU manually to issue a command of controlling an extinction, etc., and also to reliably isolate the ONU in the extinction inadequate state from a system. <P>SOLUTION: This system includes an OLT 1 which locates an ONU 2 as an ONU in the extinction inadequate state when the ONU 2 to which a temporary extinction instruction command is sent pauses an emission of an optical signal temporarily and the number of linkups increases, and then sends an always extinct instruction command instructing extinction at all times to the ONU 2 concerned. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an optical communication system in which an optical signal is transmitted and received between a master station (OLT: Optical Line Terminal) which is a station side device and a slave station (ONU: Optical Network Unit) which is a plurality of subscriber devices, particularly GE-PON. (Gigabit Ethernet (registered trademark) Passive Optical Network) system.

A conventional GE-PON system is a system in which an OLT and a plurality of ONUs perform two-way communication of optical signals using an optical data communication network, and a single PON optical fiber is shared by a plurality of ONUs. System.
In the GE-PON system, when the OLT distributes a downstream packet (optical signal) to a plurality of ONUs, a method of distributing the downstream packet in a broadcast form is adopted.
On the other hand, when the ONU distributes the upstream packet (optical signal) to the OLT, there is a collision unless some sort of traffic control is performed, so the OLT controls the upstream packet distributed from the ONU and transmits it in a time division manner. ing.

However, when the optical link circuit of the ONU fails, it may fall into a quenching failure state and the OLT may not be able to transmit / receive optical signals. For example, Patent Document 1 below discloses a technique for determining ONU failure.
Specifically, the following discrimination techniques are disclosed.
First, the OLT designates a plurality of ONUs one by one, and transmits a signal including a command for controlling the light emission of the ONU to be downlinked.
When each ONU receives a signal including a command for controlling the extinction of light emission from the OLT, each ONU extinguishes the light emission of its own station.
The OLT extinguishes its own light emission when the ONU that is in a quenching failure state extinguishes, so that the optical signal that has been continuously received disappears, and accordingly, it is determined that the ONU has failed. .

Here, the following method is adopted as a method for isolating the ONU when an ONU in a quenching failure state is detected.
First, the OLT issues a command for controlling the quenching of the optical transmission unit of the ONU that is in a quenching failure state.
When the ONU receives a command for controlling the extinction of the optical transmission unit issued from the OLT, the ONU stops the output of the upstream optical signal by stopping the power supplied to the optical transmission unit.
As a result, the ONU that is in a quenching failure state is isolated from the system.

JP 2004-112746 A (paragraph number [0033], FIG. 9)

Since the conventional optical communication system is configured as described above, when detecting an ONU in a quenching failure state, the system maintainer manually designates ONUs under the OLT one by one and controls quenching. There is a problem that a lot of work is required.
Even if an ONU that is in a quenching failure state is isolated from the system, if the system maintainer turns on the power supply of the ONU before repairing or replacing the ONU, the quenching failure is reproduced. There was also a problem that ended up.

  The present invention has been made to solve the above-described problems, and the system maintenance person can easily specify the ONU and issue the extinction control easily without the need for issuing a command for extinction control. It is an object of the present invention to provide an optical communication system that can identify an ONU in a state and can reliably isolate an ONU in a quenching failure state from the system.

  In the optical communication system according to the present invention, when the station side device receives a specific command of a subscriber device in a poor extinction state from the supervisory control terminal, a temporary extinction instruction command for instructing temporary extinction is sent to the plurality of subscriber devices. If the temporary extinction instruction command transmission means for sequentially transmitting to the subscriber apparatus to which the temporary extinction instruction command is transmitted by the temporary extinction instruction command transmission means temporarily stops the emission of the optical signal, and the number of link-ups increases, A failure device specifying means for specifying that the subscriber device is a subscriber device in a quenching failure state, and a constant extinction instruction command for instructing normal quenching is always transmitted to the subscriber device specified by the failure device specifying means. And when a plurality of subscriber units receive a temporary extinction instruction command from the temporary extinction instruction command transmission unit of the station side apparatus, optical transmission is performed. Temporarily stops the emission of the optical signal at the station, and when the constant extinction instruction command is transmitted from the constant extinction instruction command transmission means of the station side device, the optical transmission unit stops emitting the optical signal and maintains the emission stop state. The optical transmission unit control means is provided.

  According to the present invention, when the station side device receives a specific command for a subscriber device in a quenching failure state from the supervisory control terminal, a temporary quenching instruction command for instructing temporary quenching is sequentially transmitted to a plurality of subscriber devices. The temporary extinction instruction command transmitting means, and the subscriber device to which the temporary extinction instruction command is transmitted by the temporary extinction instruction command transmitting means temporarily stops the emission of the optical signal, and the number of link-ups increases. Defective device specifying means for specifying that the device is a subscriber device in a poor extinction state, and a constant extinction instruction command for transmitting a constant extinction instruction command for instructing constant extinction to the subscriber device specified by the defective device specifying means And when a plurality of subscriber apparatuses receive a temporary extinction instruction command from the temporary extinction instruction command transmission means of the station side apparatus, Optical transmission that stops the light emission of the optical signal and stops the light emission of the optical signal in the optical transmission unit when receiving the constant extinction instruction command from the constant extinction instruction command transmission means of the station side device. Subscribers who are in a poorly extinguished state without needing to manually specify a subscriber device and issue a command for extinction control. In addition to being able to identify the device, there is an effect that it is possible to reliably isolate a subscriber device in a poor extinction state from the system.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing an optical communication system according to Embodiment 1 of the present invention. In FIG. 1, an OLT (Optical Line Terminal) 1 as a station side device is connected to a plurality of subscriber devices via an optical network 5. Is connected to ONU2 (Optical Network Unit).
Although FIG. 1 shows an example in which three ONUs 2 (ONU # n, ONU # n + 1, ONU # n + 2) are connected, it goes without saying that four or more ONUs 2 may be connected. 1 shows the internal configuration of the ONU 2 (ONU # n), but the internal configuration of the ONU 2 (ONU # n + 1, ONU # n + 2) is the same as the internal configuration of the ONU 2 (ONU # n).

The supervisory control terminal 3 is a terminal that issues a specific command (extinction defective ONU specific command) for the ONU 2 that is in a poor extinction state, for example, under the direction of a system maintenance person.
The passive optical branching device 4 is a network device that branches the optical network 5 in order to connect a plurality of ONUs 2 to the optical network 5.
Note that the distance from the passive optical branching device 4 to each ONU 2 is different for each ONU 2, and the downstream direction transmitted from the OLT 1 to each ONU 2 and the upstream direction transmitted from each ONU 2 to the OLT 1 are the optical transmission direction or wavelength. They are separated by differences.

The optical transmitter 11 converts an electrical signal (for example, a packet including a temporary extinction instruction command or a constant extinction instruction command) into an optical signal under the instruction of the PON interface termination unit 14 and transmits the optical signal to the ONU 2. Interface equipment.
The optical receiver 12 is a network interface device that converts an optical signal transmitted from the ONU 2 into an electrical signal and outputs the electrical signal to the PON interface termination unit 14.

The ONU linkup database 13 is a storage device that records the number of linkups of ONU2 (ONU # n, ONU # n + 1, ONU # n + 2) in real time.
When the PON interface termination unit 14 receives an ONU 2 specification command (quenching failure ONU specification command) from the supervisory control terminal 3, the optical transmission unit sends an instruction to sequentially transmit temporary extinction instruction commands for instructing temporary extinction to a plurality of ONUs 2. 11, if the ONU 2 to which the temporary extinction instruction command is transmitted temporarily stops the emission of the optical signal and the link-up number increases, the ONU 2 is identified as the ONU 2 in the extinction defective state. And a process for outputting to the optical transmitter 11 an instruction to transmit a constant extinction instruction command for instructing constant extinction to the ONU 2 identified as being in a quenching failure state.
The optical transmission unit 11 and the PON interface termination unit 14 constitute a temporary extinction instruction command transmission unit and a constant extinction instruction command transmission unit, and the ONU link-up database 13 and the PON interface termination unit 14 constitute a defective device identification unit. Has been.

The optical receiver 21 converts an optical signal (for example, a packet including a temporary extinction instruction command or a constant extinction instruction command) transmitted from the OLT 1 into an electrical signal, and outputs the electrical signal to the PON interface termination unit 23 Equipment.
The optical transmission unit 22 is a network interface device that converts the electrical signal output from the PON interface termination unit 23 into an optical signal and transmits the optical signal to the OLT 1.
The PON interface terminator 23 terminates the electrical signal output from the optical receiver 21 and performs a process of outputting the electrical signal to be transmitted to the optical transmitter 22.

The storage circuit 24 is a memory that stores the current extinction setting in the optical transmitter 22.
When the optical receiving unit 21 receives the temporary extinction instruction command transmitted from the OLT 1 and the PON interface termination unit 23 sets the current extinction setting in the optical transmitting unit 22 to “temporary extinction”. The optical transmission unit 25 temporarily stops the emission of the optical signal, and the optical reception unit 21 receives the constant extinction instruction command transmitted from the OLT 1, and the PON interface termination unit 23 performs the current transmission in the optical transmission unit 22. When the extinction setting is set to “always extinguishment”, the process of stopping the light emission of the optical signal in the optical transmission unit 25 and maintaining the light emission stop state is performed.
The optical receiving unit 21, the PON interface terminating unit 23, the storage circuit 24, and the optical transmitting unit extinction control unit 25 constitute an optical transmitting unit control means.

FIG. 2 is a flowchart showing the processing contents of the optical communication system according to Embodiment 1 of the present invention.
FIG. 3 is a packet configuration diagram showing a packet including a MAC frame transmitted / received between the OLT 1 and the ONU 2.
The MAC frame is divided into a header and data.
The header is composed of data such as a destination address DA (destination address), a self address SA (source address), and a time length LEN (length).
A preamble PA is added to the MAC frame.
Preamble PA is a part for data synchronization, a terminal ID for designating OLT1 (or ONU2) to communicate, a command from OLT1 to ONU2 (or a response from ONU2 to OLT1), various parameters, error check code FCS, start It consists of each byte of the packet demilita SFD.

Next, the operation will be described.
If a quenching failure occurs in any ONU 2 and the system maintenance person detects the occurrence of a quenching failure, the supervisory control terminal 3 is operated to instruct the identification of the ONU 2 in the quenching failure state.
Thereby, the supervisory control terminal 3 issues a specific command (quenching defective ONU specific command) for the ONU 2 in the poor extinction state, and transmits the extinction defective ONU specific command to the OLT 1 (step ST1).

The PON interface termination unit 14 of the OLT 1 receives the ONU 2 specification command (quenching failure ONU specification command) from the monitoring control terminal 3 and temporarily extinguishes instruction command (command to instruct extinction for a certain period of time). Are sequentially transmitted to the plurality of ONUs 2.
In the example of FIG. 1, since three ONUs 2 (ONU # n, ONU # n + 1, ONU # n + 2) are connected, an instruction to transmit a temporary extinction instruction command to the three ONUs 2 in order is transmitted. Output to the transmitter 11.
The optical transmission unit 11 of the OLT 1 converts a packet (see FIG. 3) including a temporary extinction instruction command, which is an electrical signal, into an optical signal under the instruction of the PON interface termination unit 14 and converts the optical signal into a plurality of ONUs 2. Sequentially.
Here, for convenience of explanation, first, it is assumed that an optical signal (packet including a temporary extinction instruction command) is transmitted to ONU # n (step ST2).

When receiving the optical signal (packet including the temporary extinction instruction command) transmitted from the OLT 1, the optical receiving unit 21 of the ONU 2 (ONU # n) converts the optical signal into an electrical signal, and the electrical signal is terminated at the PON interface termination. To the unit 23.
If the electrical signal output from the optical receiver 21 is a packet including a temporary extinction instruction command, the PON interface terminator 23 of the ONU 2 (ONU # n) is currently in the optical transmitter 22 recorded in the storage circuit 24. Set the extinction setting to “temporary extinction”.

When the PON interface termination unit 23 sets the current extinction setting in the optical transmission unit 22 to “temporary extinction”, the optical transmission unit extinction control unit 25 of the ONU 2 (ONU # n) emits an optical signal in the optical transmission unit 25. Stop temporarily. That is, the optical signal is not emitted from the optical transmission unit 25 for a certain time (when the certain time elapses, the light emission of the optical signal is resumed).
At this time, if ONU2 (ONU # n) is an ONU in a quenching failure state, OLT1 transmits from other ONU2 (ONU # n + 1, ONU # n + 2) by quenching the optical transmitter 25 of ONU # n. The received optical signal can be normally received, and the link-up number of the ONU 2 increases.

When the optical transmitter 11 transmits a temporary extinction instruction command to the ONU 2 (ONU # n), the ONU 2 (ONU # n) temporarily stops the emission of the optical signal. It is determined whether the number of link-ups has increased (step ST3).
That is, the PON interface termination unit 14 confirms the reception status of the optical signal in the optical receiving unit 12, and the optical transmission unit 11 of the link-up number (ONU2 (ONU # n)) after the temporary extinction instruction command is issued. ONU2 (ONU # n, ONU # n + 1, ONU) recorded in the ONU linkup database 13 is obtained after grasping the number of linkups when extinguishing) and issuing the temporary extinction instruction command. It is determined whether or not it is greater than the number of link ups (# n + 2) (the number of link ups before the temporary extinction instruction command is issued).

If the number of link-ups increases, the PON interface terminator 14 identifies that the ONU 2 (ONU # n) is an ONU in a quenching failure state, and always isolates the ONU2 (ONU # n) from the system. An instruction to transmit a constant extinction instruction command for instructing the extinction of light to the ONU 2 (ONU # n) is output to the optical transmitter 11.
Under the instruction of the PON interface terminator 14, the optical transmitter 11 of the OLT 1 converts a packet (see FIG. 3) including a constant extinction instruction command, which is an electrical signal, into an optical signal, and converts the optical signal to ONU 2 (ONU #N) (step ST4).

When the optical receiver 21 of the ONU 2 (ONU # n) receives the optical signal (packet including the constant extinction instruction command) transmitted from the OLT 1, it converts the optical signal into an electrical signal, and the electrical signal is terminated at the PON interface termination. To the unit 23.
The PON interface termination unit 23 of the ONU 2 (ONU # n), if the electrical signal output from the optical receiving unit 21 is a packet including a constant extinction instruction command, is currently in the optical transmitting unit 22 recorded in the storage circuit 24. Set the extinction setting to “always extinguish”.

When the PON interface termination unit 23 sets the current extinction setting in the optical transmission unit 22 to “always extinction”, the optical transmission unit extinction control unit 25 of the ONU 2 (ONU # n) emits an optical signal in the optical transmission unit 25. Stop.
As long as the extinction setting recorded in the storage circuit 24 is “always extinguish”, the optical transmission unit extinction control unit 25 is able to operate in the optical transmission unit 25 even if the ONU 2 (ONU # n) is turned on again. Maintain the emission stop state.

If the link-up number does not increase, the PON interface termination unit 14 of the OLT 1 determines that the ONU 2 (ONU # n) is not an ONU in a quenching failure state.
When the optical transmission unit 11 of the OLT 1 determines that the ONU 2 (ONU # n) is not in a quenching failure state by the PON interface termination unit 14, the optical transmission unit 11 transmits an optical signal (a packet including a temporary quenching instruction command) to the ONU # n + 1. (Steps ST5 and ST2).

When receiving the optical signal (packet including the temporary extinction instruction command) transmitted from the OLT 1, the optical receiving unit 21 of the ONU 2 (ONU # n + 1) converts the optical signal into an electrical signal, and the electrical signal is terminated at the PON interface termination. To the unit 23.
If the electrical signal output from the optical receiver 21 is a packet including a temporary extinction instruction command, the PON interface terminator 23 of the ONU 2 (ONU # n + 1) is currently in the optical transmitter 22 recorded in the storage circuit 24. Set the extinction setting to “temporary extinction”.

When the PON interface termination unit 23 sets the current extinction setting in the optical transmission unit 22 to “temporary extinction”, the optical transmission unit extinction control unit 25 of the ONU 2 (ONU # n + 1) emits an optical signal in the optical transmission unit 25. Stop temporarily. That is, the optical signal is not emitted from the optical transmission unit 25 for a certain time (when the certain time elapses, the light emission of the optical signal is resumed).
At this time, if the ONU 2 (ONU # n + 1) is an ONU in the extinction failure state, the optical transmission unit 25 of the ONU # n is extinguished so that the OLT 1 transmits an optical signal transmitted from another ONU 2 (ONU # n + 2). Can be received normally, and the link-up number of the ONU 2 increases.

When the optical transmitter 11 transmits a temporary extinction instruction command to the ONU 2 (ONU # n + 1), the ONU 2 (ONU # n + 1) temporarily stops the emission of the optical signal. It is determined whether the number of link-ups has increased (step ST3).
That is, the PON interface termination unit 14 confirms the reception status of the optical signal in the optical receiving unit 12, and the optical transmission unit 11 of the link-up number (ONU2 (ONU # n + 1) after the temporary extinction command is issued) The number of link-ups after the temporary extinction command is issued is the number of ONUs 2 (ONU # n + 1, ONU # n + 2) recorded in the ONU link-up database 13. It is determined whether or not the number of linkups has increased from the number of linkups (the number of linkups before the temporary extinction instruction command is issued).

If the number of link-ups increases, the PON interface terminator 14 identifies the ONU 2 (ONU # n + 1) as an ONU that is in a quenching failure state, and always isolates the ONU 2 (ONU # n + 1) from the system. An instruction to transmit a constant extinction instruction command for instructing extinction of light to the ONU 2 (ONU # n + 1) is output to the optical transmitter 11.
Under the instruction of the PON interface terminator 14, the optical transmitter 11 of the OLT 1 converts a packet (see FIG. 3) including a constant extinction instruction command, which is an electrical signal, into an optical signal, and converts the optical signal to ONU 2 (ONU # N + 1) (step ST4).

When the optical receiver 21 of the ONU 2 (ONU # n + 1) receives the optical signal (packet including the constant extinction instruction command) transmitted from the OLT 1, the optical receiver 21 converts the optical signal into an electrical signal, and the electrical signal is terminated at the PON interface. To the unit 23.
The PON interface termination unit 23 of the ONU 2 (ONU # n + 1), if the electrical signal output from the optical receiving unit 21 is a packet including a constant extinction instruction command, the current PON interface terminating unit 23 in the optical transmission unit 22 recorded in the storage circuit 24. Set the extinction setting to “always extinguish”.

When the PON interface termination unit 23 sets the current extinction setting in the optical transmission unit 22 to “always extinction”, the optical transmission unit extinction control unit 25 of the ONU 2 (ONU # n + 1) Stop.
As long as the extinction setting recorded in the storage circuit 24 is “always extinguish”, the optical transmission unit extinction control unit 25 is able to operate the optical transmission unit 25 even when the ONU 2 (ONU # n + 1) is turned on again. Maintain the emission stop state.

If the PON interface terminator 14 determines that the ONU 2 (ONU # n + 1) is not an ONU in the extinction failure state, if the ONU 2 whose extinction failure state has not been investigated is the last one (step ST5), the last ONU 2 is It is specified that the ONU is in a quenching failure state (step ST6).
In this example, the ONU 2 that has not been investigated for the quenching failure state is only the ONU # n + 2, and therefore, the ONU # n + 2 is identified as the ONU in the quenching failure state.

When the ONU 2 (ONU # n + 2) is identified as an ONU that is in a quenching failure state, the PON interface termination unit 14 instructs the constant quenching instruction to isolate the ONU 2 (ONU # n + 2) from the system. Is transmitted to the optical transmitter 11 to the ONU 2 (ONU # n + 2).
Under the instruction of the PON interface terminator 14, the optical transmitter 11 of the OLT 1 converts a packet (see FIG. 3) including a constant extinction instruction command, which is an electrical signal, into an optical signal, and converts the optical signal to ONU 2 (ONU # N + 2) (step ST4).

When the optical receiver 21 of the ONU 2 (ONU # n + 2) receives the optical signal transmitted from the OLT 1 (packet including the constant extinction instruction command), the optical receiver 21 converts the optical signal into an electrical signal, and the electrical signal is terminated at the PON interface. To the unit 23.
The PON interface termination unit 23 of the ONU 2 (ONU # n + 2), if the electrical signal output from the optical reception unit 21 is a packet including a constant extinction instruction command, the current PON interface termination unit 23 in the optical transmission unit 22 recorded in the storage circuit 24. Set the extinction setting to “always extinguish”.

When the PON interface termination unit 23 sets the current extinction setting in the optical transmission unit 22 to “always extinction”, the optical transmission unit extinction control unit 25 of the ONU 2 (ONU # n + 2) Stop.
As long as the extinction setting recorded in the storage circuit 24 is “always extinguish”, the optical transmission unit extinction control unit 25 does not stop the optical transmission unit 25 even if the ONU 2 (ONU # n + 2) is turned on again. Maintain the emission stop state.

  As is apparent from the above, according to the first embodiment, when a specific command for the OLT 2 in the quenching failure state is received from the supervisory control terminal 3, temporary quenching command commands for instructing temporary quenching are sent to a plurality of OLTs 2. If the ONU 2 that has been sequentially transmitted and the temporary extinction instruction command is transmitted temporarily stops emitting the optical signal and the number of link-ups increases, the ONU 2 is identified as an ONU that is in a quenching failure state, An OLT 1 for transmitting a constant extinction instruction command for instructing extinction to the ONU 2 is provided, and when a plurality of ONUs 2 receive the temporary extinction instruction command from the OLT 1, the optical transmission unit 22 temporarily stops emitting optical signals, and the OLT 1 When the constant extinction instruction command is received from the optical transmission unit 22, the light transmission of the optical signal in the optical transmission unit 22 is stopped and the light emission stop state is maintained. The system maintenance person can easily specify the ONU 2 in the extinction defective state without requiring the trouble of manually specifying the ONU 2 and issuing a command for extinction control, and the ONU 2 in the extinction defective state. It is possible to reliably isolate the system from the system.

Embodiment 2. FIG.
FIG. 4 is a block diagram showing an optical communication system according to Embodiment 2 of the present invention. In the figure, the same reference numerals as those in FIG.
When the PON interface termination unit 31 receives an ONU 2 specification command (extinction failure ONU specification command) from the supervisory control terminal 3, the optical transmission unit issues an instruction to simultaneously transmit a temporary extinction instruction command for instructing temporary extinction to a plurality of ONUs 2 In addition to the process of outputting to the optical transmitter 11 and the process of outputting to the optical transmitter 11 an instruction to sequentially transmit the light emission instruction command to the plurality of ONUs 2 after the temporary extinction instruction command is transmitted from the optical transmitter 11. If the ONU 2 to which the light emission instruction command has been transmitted starts to emit an optical signal and another ONU 2 is linked down, the ONU 2 is instructed to identify the ONU 2 in the extinction defective state, or to instruct constant quenching. For example, a process of outputting an instruction to transmit the constant extinction instruction command to the ONU 2 identified as being in a quenching failure state to the optical transmission unit 11 is performed.
The optical transmission unit 11 and the PON interface termination unit 31 constitute a temporary extinction instruction command transmission unit, a light emission instruction command transmission unit, and a constant extinction instruction command transmission unit. The ONU link-up database 13 and the PON interface termination unit 31 A defective device specifying means is configured.

When the optical receiving unit 21 receives the temporary extinction instruction command transmitted from the OLT 1 and the PON interface termination unit 23 sets the current extinction setting in the optical transmitting unit 22 to “temporary extinction”. The optical transmission unit 25 stops the emission of the optical signal, the optical reception unit 21 receives the emission instruction command transmitted from the OLT 1, and the PON interface termination unit 23 sets the current extinction setting in the optical transmission unit 22. When “light emission” is set, the optical transmitter 25 starts to emit an optical signal, and the optical receiver 21 receives the constant extinction instruction command transmitted from the OLT 1, and the PON interface termination unit 23 receives the optical transmitter. When the current extinction setting in 22 is set to “always extinguishment”, the optical transmission unit 25 stops light emission and maintains the light emission stop state. To implement the management.
The optical receiver 21, the PON interface terminator 23, the storage circuit 24, and the optical transmitter extinction controller 41 constitute an optical transmitter controller.
FIG. 5 is a flowchart showing the processing contents of the optical communication system according to the second embodiment of the present invention.

Next, the operation will be described.
If a quenching failure occurs in any ONU 2 and the system maintenance person detects the occurrence of a quenching failure, the supervisory control terminal 3 is operated to instruct the identification of the ONU 2 in the quenching failure state.
As a result, the supervisory control terminal 3 issues a specific command (extinction defective ONU specific command) for the ONU 2 in the extinction defective state, and transmits the extinction defective ONU specific command to the OLT 1 (step ST11).

When the PON interface termination unit 31 of the OLT 1 receives the ONU 2 specifying command (quenching failure ONU specifying command) from the monitoring control terminal 3, the temporary extinction command command (temporary extinction command command for instructing temporary extinction) is received. , A command for instructing extinction) is output to the optical transmitter 11 simultaneously.
In the example of FIG. 4, since three ONUs 2 (ONU # n, ONU # n + 1, ONU # n + 2) are connected, an instruction to transmit a temporary extinction instruction command to the three ONUs 2 at the same time is transmitted. Output to the transmitter 11.
The optical transmission unit 11 of the OLT 1 converts a packet (see FIG. 3) including a temporary extinction instruction command, which is an electrical signal, into an optical signal under the instruction of the PON interface termination unit 14 and converts the optical signal into a plurality of ONUs 2. Simultaneous transmission to (ONU # n, ONU # n + 1, ONU # n + 2) (step ST12).

When the optical receiver 21 of the ONU 2 (ONU # n, ONU # n + 1, ONU # n + 2) receives the optical signal (packet including the temporary extinction instruction command) transmitted from the OLT 1, it converts the optical signal into an electrical signal. The electrical signal is output to the PON interface terminator 23.
The PON interface terminator 23 of the ONU 2 (ONU # n, ONU # n + 1, ONU # n + 2) is recorded in the storage circuit 24 if the electrical signal output from the optical receiver 21 is a packet including a temporary extinction instruction command. The current extinction setting in the optical transmitter 22 is set to “temporary extinction”.

  The optical transmission unit extinction control unit 41 of the ONU 2 (ONU # n, ONU # n + 1, ONU # n + 2) transmits the optical signal when the PON interface termination unit 23 sets the current extinction setting in the optical transmission unit 22 to “temporary extinction”. The light emission of the optical signal in the unit 25 is temporarily stopped. That is, the optical signal is prevented from being emitted from the optical transmitter 25 until the optical receiver 21 receives the emission instruction command.

The PON interface termination unit 31 of the OLT 1 transmits a temporary extinction instruction command from the optical transmission unit 11 and the ONU 2 (ONU # n, ONU # n + 1, ONU # n + 2) extinguishes the optical signal. An instruction to sequentially transmit commands to the plurality of ONUs 2 is output to the optical transmitter 11.
In the example of FIG. 4, since three ONUs 2 (ONU # n, ONU # n + 1, ONU # n + 2) are connected, an instruction to sequentially transmit a light emission instruction command to the three ONUs 2 is optically transmitted. To the unit 11.
The optical transmitter 11 of the OLT 1 converts a packet (see FIG. 3) including a light emission instruction command, which is an electrical signal, into an optical signal under the instruction of the PON interface termination unit 31, and converts the optical signal to a plurality of ONUs 2. Send sequentially.
Here, for convenience of explanation, it is assumed that an optical signal (packet including a light emission instruction command) is first transmitted to ONU #n (step ST13).

When receiving the optical signal (packet including the light emission instruction command) transmitted from the OLT 1, the optical receiving unit 21 of the ONU 2 (ONU # n) converts the optical signal into an electrical signal, and the electrical signal is converted into a PON interface termination unit. To 23.
If the electrical signal output from the optical receiver 21 is a packet including a light emission instruction command, the PON interface terminator 23 of the ONU 2 (ONU # n) presents the current in the optical transmitter 22 recorded in the storage circuit 24. Set the extinction setting to “flash”.
The optical transmission unit extinction control unit 41 of ONU2 (ONU # n) starts light emission of the optical signal in the optical transmission unit 25 when the PON interface termination unit 23 sets the current extinction setting in the optical transmission unit 22 to “light emission”. To do.

  The PON interface terminator 31 of the OLT 1 transmits ONU2 (ONU # n) when the optical transmitter 11 transmits a light emission instruction command to the ONU2 (ONU # n), and the ONU2 (ONU # n) emits an optical signal. Is the ONU2 to which the light emission instruction command is first transmitted (step ST14). Here, the packet including the light emission instruction command, which is an electrical signal, without determining the quenching failure state of the ONU2 (ONU # n) (FIG. 3) is converted into an optical signal, and the optical signal is transmitted to ONU2 (ONU # n + 1) (step ST13).

When receiving the optical signal (packet including the light emission instruction command) transmitted from the OLT 1, the optical receiving unit 21 of the ONU 2 (ONU # n + 1) converts the optical signal into an electrical signal, and the electrical signal is converted into a PON interface termination unit. To 23.
The PON interface terminator 23 of the ONU 2 (ONU # n + 1), if the electrical signal output from the optical receiver 21 is a packet including a light emission instruction command, the current PON interface termination unit 23 recorded in the storage circuit 24 in the optical transmitter 22. Set the extinction setting to “flash”.

The optical transmission unit extinction control unit 41 of the ONU 2 (ONU # n + 1) starts light emission of an optical signal in the optical transmission unit 25 when the PON interface termination unit 23 sets the current extinction setting in the optical transmission unit 22 to “light emission”. To do.
At this time, if the ONU 2 (ONU # n + 1) is an ONU in the extinction failure state, the optical transmitter 25 of the ONU 2 (ONU # n + 1) starts emitting an optical signal, thereby causing another ONU 2 (ONU # n). Link down.
On the other hand, if ONU2 (ONU # n) is in an extinction failure state, ONU2 (ONU # n + 1) is linked up even if the optical transmitter 25 of ONU2 (ONU # n + 1) starts emitting an optical signal. do not do.

The PON interface terminator 31 of the OLT 1 transmits ONU2 (ONU # n + 1) when the optical transmitter 11 transmits a light emission instruction command to the ONU2 (ONU # n + 1), and the ONU2 (ONU # n + 1) emits an optical signal. Is not the ONU 2 to which the light emission instruction command is first transmitted (step ST14), it is determined whether or not the other ONU 2 (ONU #n) is linked down (step ST15).
That is, the PON interface termination unit 31 confirms the reception status of the optical signal in the optical receiving unit 12, and the optical transmission unit 11 of the link-up number (ONU2 (ONU # n + 1) after the emission instruction command is issued) emits light. The link-up number after the light emission instruction command is issued is the link-up number (light-emitting instruction) of ONU 2 (ONU # n) recorded in the ONU link-up database 13. It is determined whether or not it is less than the number of link ups before the command is issued.

If the other ONU 2 (ONU # n) is linked down, the PON interface termination unit 31 identifies the ONU 2 (ONU # n + 1) as an ONU that is in a quenching failure state, and sets the ONU 2 (ONU # n + 1) to the system. In order to isolate from the optical transmission unit 11, an instruction to transmit a constant extinction instruction command for instructing constant extinction to the ONU 2 (ONU # n + 1) is output to the optical transmission unit 11.
Under the instruction of the PON interface termination unit 31, the optical transmission unit 11 of the OLT 1 converts a packet (see FIG. 3) including a constant extinction instruction command, which is an electrical signal, into an optical signal, and converts the optical signal into the ONU 2 (ONU 2 # N + 1) (step ST16).

When the optical receiver 21 of the ONU 2 (ONU # n + 1) receives the optical signal (packet including the constant extinction instruction command) transmitted from the OLT 1, the optical receiver 21 converts the optical signal into an electrical signal, and the electrical signal is terminated at the PON interface. To the unit 23.
The PON interface termination unit 23 of the ONU 2 (ONU # n + 1), if the electrical signal output from the optical receiving unit 21 is a packet including a constant extinction instruction command, the current PON interface terminating unit 23 in the optical transmission unit 22 recorded in the storage circuit 24. Set the extinction setting to “always extinguish”.

When the PON interface termination unit 23 sets the current extinction setting in the optical transmission unit 22 to “always extinction”, the optical transmission unit extinction control unit 41 of the ONU 2 (ONU # n + 1) emits an optical signal in the optical transmission unit 25. Stop.
As long as the extinction setting recorded in the storage circuit 24 is “always extinguish”, the optical transmission unit extinction control unit 41 does not stop the optical transmission unit 25 even if the power of the ONU 2 (ONU # n + 1) is turned on again. Maintain the emission stop state.

If the PON interface terminator 31 of the OLT 1 determines that the ONU 2 (ONU # n + 1) is not an ONU that is in a quenching failure state, it determines whether the ONU 2 (ONU # n + 1) is linked up, and the ONU 2 (ONU # n + 1). ) Is not linked up, it is determined that ONU2 (ONU # n) is an ONU in a quenching failure state.
When the PON interface terminator 31 specifies that the ONU 2 (ONU # n) is an ONU in the extinction failure state, the normal extinction instruction command for instructing the normal extinction in order to isolate the ONU 2 (ONU # n) from the system. Is transmitted to the optical transmission unit 11 to the ONU 2 (ONU # n).
Under the instruction of the PON interface termination unit 31, the optical transmission unit 11 of the OLT 1 converts a packet (see FIG. 3) including a constant extinction instruction command, which is an electrical signal, into an optical signal, and converts the optical signal into the ONU 2 (ONU 2 #N) (step ST16).

When the optical receiver 21 of the ONU 2 (ONU # n) receives the optical signal (packet including the constant extinction instruction command) transmitted from the OLT 1, it converts the optical signal into an electrical signal, and the electrical signal is terminated at the PON interface termination. To the unit 23.
The PON interface termination unit 23 of the ONU 2 (ONU # n), if the electrical signal output from the optical receiving unit 21 is a packet including a constant extinction instruction command, is currently in the optical transmitting unit 22 recorded in the storage circuit 24. Set the extinction setting to “always extinguish”.

The optical transmission unit extinction control unit 41 of the ONU 2 (ONU # n) emits an optical signal in the optical transmission unit 25 when the PON interface termination unit 23 sets the current extinction setting in the optical transmission unit 22 to “always quenching”. Stop.
As long as the extinction setting recorded in the storage circuit 24 is “always extinguish”, the optical transmission unit extinction control unit 41 does not stop the optical transmission unit 25 even if the ONU 2 (ONU # n) is turned on again. Maintain the emission stop state.

  When the optical transmission unit 11 of the OLT 1 determines that the ONU 2 (ONU # 1, ONU # n + 1) is not an ONU in the extinction defective state by the PON interface termination unit 31, the packet including the light emission instruction command which is an electric signal (see FIG. 3) is converted into an optical signal, and the optical signal is transmitted to ONU2 (ONU # n + 2) (steps ST17 and ST13).

When receiving the optical signal (packet including the light emission instruction command) transmitted from the OLT 1, the optical receiving unit 21 of the ONU 2 (ONU # n + 2) converts the optical signal into an electrical signal and converts the electrical signal into a PON interface termination unit. To 23.
If the electrical signal output from the optical receiver 21 is a packet including a light emission instruction command, the PON interface terminator 23 of the ONU 2 (ONU # n + 2) is the current one in the optical transmitter 22 recorded in the storage circuit 24. Set the extinction setting to “flash”.

The optical transmission unit extinction control unit 41 of the ONU 2 (ONU # n + 2) starts the optical signal emission in the optical transmission unit 25 when the PON interface termination unit 23 sets the current extinction setting in the optical transmission unit 22 to “light emission”. To do.
At this time, if the ONU 2 (ONU # n + 2) is an ONU in a quenching failure state, the ONU # n + 2 optical transmission unit 25 starts emitting an optical signal, thereby causing another ONU2 (ONU # n, ONU # n + 1). ) Link down.

The PON interface terminator 31 of the OLT 1 transmits ONU2 (ONU # n + 2) when the optical transmitter 11 transmits a light emission instruction command to the ONU2 (ONU # n + 2). Is not the ONU 2 to which the light emission instruction command is first transmitted (step ST14), it is determined whether or not the other ONU 2 (ONU #n, ONU # n + 1) is linked down (step ST15).
That is, the PON interface termination unit 31 confirms the reception status of the optical signal in the optical receiving unit 12, and the optical transmission unit 11 of the link-up number (ONU2 (ONU # n + 2)) after the emission instruction command is issued emits light. The link-up number after the start of the light emission instruction command is determined, and the link-up number of ONU 2 (ONU # n, ONU # n + 1) recorded in the ONU link-up database 13 is determined. It is determined whether the number is less than the number (the number of link-ups before the light emission instruction command is issued).

If the other ONU 2 (ONU # n, ONU # n + 1) is linked down, the PON interface terminator 31 specifies that ONU2 (ONU # n + 2) is an ONU in a quenching failure state, and turns ONU2 (ONU #) In order to isolate n + 2) from the system, an instruction for transmitting a constant extinction instruction command for instructing constant extinction to ONU 2 (ONU # n + 2) is output to the optical transmitter 11.
Under the instruction of the PON interface termination unit 31, the optical transmission unit 11 of the OLT 1 converts a packet (see FIG. 3) including a constant extinction instruction command, which is an electrical signal, into an optical signal, and converts the optical signal into the ONU 2 (ONU 2 # N + 2) (step ST16).

When the optical receiver 21 of the ONU 2 (ONU # n + 2) receives the optical signal transmitted from the OLT 1 (packet including the constant extinction instruction command), the optical receiver 21 converts the optical signal into an electrical signal, and the electrical signal is terminated at the PON interface. To the unit 23.
The PON interface termination unit 23 of the ONU 2 (ONU # n + 2), if the electrical signal output from the optical reception unit 21 is a packet including a constant extinction instruction command, the current PON interface termination unit 23 in the optical transmission unit 22 recorded in the storage circuit 24. Set the extinction setting to “always extinguish”.

The optical transmission unit extinction control unit 41 of the ONU 2 (ONU # n + 2) emits an optical signal in the optical transmission unit 25 when the PON interface termination unit 23 sets the current extinction setting in the optical transmission unit 22 to “always quenching”. Stop.
As long as the extinction setting recorded in the storage circuit 24 is “always extinguish”, the optical transmission unit extinction control unit 41 does not stop the optical transmission unit 25 even if the ONU 2 (ONU # n + 2) is turned on again. Maintain the emission stop state.

  As is apparent from the above, according to the second embodiment, when a specific command for the ONU 2 in the quenching failure state is received from the supervisory control terminal 3, the temporary quenching instruction command for instructing temporary quenching is sent to a plurality of ONUs 2. Simultaneously transmit, and then sequentially transmit a light emission instruction command for instructing light emission to a plurality of ONUs 2. If the ONU 2 to which the light emission instruction command has been transmitted starts light emission and the other ONUs 2 are linked down, light emission occurs. The ONU 2 that has started the operation is identified as an ONU that is in a quenching failure state, and an OLT 1 that transmits a constant extinction instruction command that instructs constant extinction is provided to the ONU 2, and a plurality of ONUs 2 receive the extinction instruction command from the OLT 1 Then, the emission of the optical signal in the optical transmission unit 22 is stopped, and when the emission instruction command is received from the OLT 1, the optical signal in the optical transmission unit 22 is received. When the light emission is started and the constant extinction instruction command is received from the OLT 1, the optical transmission unit 22 stops the light emission of the optical signal and maintains the light emission stop state. It is possible to easily identify the ONU 2 that is in the quenching failure state without requiring the trouble of designating and issuing a command for controlling the quenching, and to reliably isolate the ONU 2 in the quenching failure state from the system. There is an effect that can.

Embodiment 3 FIG.
6 is a block diagram showing an optical communication system according to Embodiment 3 of the present invention. In the figure, the same reference numerals as those in FIG.
The uplink statistical information confirmation unit 51 performs a process of observing the uplink error rate from the reception status of the optical signal by the optical receiver 12 and recording statistical information indicating the statistics of the uplink error rate.
The PON interface terminator 52 performs the same processing as the PON interface terminator 14 in FIG. 1, and the ONU 2 to which the temporary extinction instruction command is transmitted temporarily stops the emission of the optical signal, and the error rate of the upstream error rate is increased. If the statistical information is improved, a process of specifying that the ONU 2 is an ONU 2 in a quenching failure state is performed.
The optical transmission unit 11 and the PON interface termination unit 51 constitute a temporary extinction instruction command transmission unit and a constant extinction instruction command transmission unit. The ONU link-up database 13, the uplink statistical information confirmation unit 51, and the PON interface termination unit 52 are configured. Thus, a defective device specifying means is configured.
FIG. 7 is a flowchart showing the processing contents of the optical communication system according to the third embodiment of the present invention.

Next, the operation will be described.
In the third embodiment, only the parts different from the first embodiment will be described.
The uplink statistical information confirmation unit 51 of the OLT 1 monitors the reception status of the optical signal by the optical reception unit 12, observes the uplink error rate from the reception status of the optical signal, and records statistical information indicating the statistics of the uplink error rate. .

When the optical transmitter 11 transmits a temporary extinction instruction command to, for example, ONU2 (ONU # n), the ONU2 (ONU # n) temporarily stops emission of the optical signal. Then, with reference to the statistical information of the uplink error rate recorded in the uplink statistical information confirmation unit 51, it is determined whether or not the statistical information of the uplink error rate is improved (step ST21).
The PON interface terminator 52 is in a poor extinction state even if the statistical information of the uplink error rate is improved or the statistical information of the uplink error rate is not degraded, even if the other ONU 2 does not fall into the link down state. Therefore, in order to isolate the ONU 2 (ONU # n) from the system, the optical transmitter 11 is instructed to transmit a constant extinction instruction command to the ONU 2 (ONU # n). Output.
Under the instruction of the PON interface termination unit 52, the optical transmitter 11 of the OLT 1 converts a packet (see FIG. 3) containing a constant extinction instruction command, which is an electrical signal, into an optical signal, and converts the optical signal to the ONU 2 (ONU 2 #N) (step ST4).

  As is apparent from the above, according to the third embodiment, when a specific command for the OLT 2 in the quenching failure state is received from the supervisory control terminal 3, temporary quenching instruction commands for instructing temporary quenching are sent to a plurality of OLTs 2. If the ONU 2 that has been sequentially transmitted and the temporary extinction instruction command has been transmitted temporarily stops the emission of the optical signal and the statistical information of the upstream error rate has not improved or deteriorated, the ONU 2 is in a poor extinction state. An OLT 1 that identifies a certain ONU and transmits a constant extinction instruction command that instructs constant extinction to the ONU 2 is provided, and when a plurality of ONUs 2 receive temporary extinction instruction commands from the OLT 1, an optical signal in the optical transmission unit 22 is provided. Is temporarily stopped, and when a constant extinction instruction command is received from the OLT 1, the optical transmission unit 22 stops emitting the optical signal and emits light. Since the system is configured to maintain the stop state, the system maintainer can easily specify the ONU 2 in the extinction defective state without requiring the manual operation of specifying the ONU 2 and issuing a command for extinction control. In addition, the ONU 2 in the extinction failure state can be reliably isolated from the system.

BRIEF DESCRIPTION OF THE DRAWINGS It is a block diagram which shows the optical communication system by Embodiment 1 of this invention. It is a flowchart which shows the processing content of the optical communication system by Embodiment 1 of this invention. It is a packet block diagram which shows the packet containing the MAC frame which OLT1 and ONU2 transmit / receive. It is a block diagram which shows the optical communication system by Embodiment 2 of this invention. It is a flowchart which shows the processing content of the optical communication system by Embodiment 2 of this invention. It is a block diagram which shows the optical communication system by Embodiment 3 of this invention. It is a flowchart which shows the processing content of the optical communication system by Embodiment 3 of this invention.

Explanation of symbols

  1 OLT (station side device), 2 ONU (subscriber device), 3 supervisory control terminal, 4 passive optical branching device, 5 optical network, 11 optical transmission unit (temporary extinction instruction command transmission means, emission instruction command transmission means, (Normally extinguishing instruction command transmitting means), 12 optical receiving units, 13 ONU link-up database (defective device specifying means), 14 PON interface terminator (temporary extinguishing instruction command transmitting means, constantly extinguishing instruction command transmitting means, defective device specifying means) , 21 Optical receiver (optical transmitter controller), 22 Optical transmitter, 23 PON interface terminator (optical transmitter controller), 24 Storage circuit (optical transmitter controller), 25 Optical transmitter extinction controller ( Optical transmission unit control means), 31 PON interface termination unit (temporary extinction instruction command transmission means, emission instruction command transmission means Constant extinction instruction command transmission means, defective device identification means), 41 Optical transmission section extinction control section (optical transmission section control means), 51 Up statistics information confirmation section (defective device identification means), 52 PON interface termination section (temporary extinction instruction) Command transmission means, constant extinction instruction command transmission means, defective device identification means).

Claims (3)

  In an optical communication system in which a station-side device and a plurality of subscriber devices are connected by an optical network, the station-side device temporarily receives a specific command for a subscriber device in a quenching failure state from a supervisory control terminal. Temporary extinction instruction command transmission means for sequentially transmitting a temporary extinction instruction command for instructing extinction to the plurality of subscriber apparatuses, and the subscriber apparatus to which the temporary extinction instruction command is transmitted by the temporary extinction instruction command transmission means If light emission is temporarily stopped and the number of link-ups increases, defective device specifying means for specifying that the subscriber device is a subscriber device in a quenching failure state, and a constant extinction instruction command for instructing constant quenching And a constant extinction instruction command transmitting means for transmitting to the subscriber device specified by the defective device specifying means, and the plurality of subscriber devices are the station side devices. When receiving the temporary extinction instruction command from the temporary extinction instruction command transmission means, temporarily stops the emission of the optical signal in the optical transmission unit, and when receiving the constant extinction instruction command from the constant extinction instruction command transmission means of the station side device, An optical communication system comprising: an optical transmission unit control means for stopping light emission of an optical signal in the optical transmission unit and maintaining a light emission stop state.   In an optical communication system in which a station-side device and a plurality of subscriber devices are connected by an optical network, the station-side device temporarily receives a specific command for a subscriber device in a quenching failure state from a supervisory control terminal. Temporary extinction instruction command transmission means for simultaneously transmitting a temporary extinction instruction command for instructing extinction to the plurality of subscriber devices, and light emission for instructing light emission after the temporary extinction instruction command is transmitted from the temporary extinction instruction command transmission means A light emission instruction command transmitting means for sequentially transmitting an instruction command to the plurality of subscriber devices, and a subscriber device to which the light emission instruction command is transmitted by the light emission instruction command transmitting means starts emitting an optical signal, If the subscriber device is linked down, a defective device specifying means for specifying that the subscriber device that has started to emit light is a subscriber device in a quenching failure state; A constant extinction instruction command transmitting means for transmitting a constant extinction instruction command for instructing extinction at the time to the subscriber apparatus specified by the defective apparatus specifying means, and the plurality of subscriber apparatuses are temporarily connected to the station side apparatus. When the extinction instruction command is received from the extinction instruction command transmission means, the emission of the optical signal in the optical transmission section is stopped. When the emission instruction command is received from the emission instruction command transmission means of the station side device, the optical signal in the optical transmission section The optical transmitter that stops the emission of the optical signal in the optical transmitter and maintains the emission stop state when receiving the constant extinction instruction command from the constant extinction instruction command transmission means of the station side device An optical communication system comprising control means.   In an optical communication system in which a station-side device and a plurality of subscriber devices are connected by an optical network, the station-side device temporarily receives a specific command for a subscriber device in a quenching failure state from a supervisory control terminal. Temporary extinction instruction command transmission means for sequentially transmitting a temporary extinction instruction command for instructing extinction to the plurality of subscriber apparatuses, and the subscriber apparatus to which the temporary extinction instruction command is transmitted by the temporary extinction instruction command transmission means If the statistical information of the uplink error rate is improved by temporarily stopping the light emission, a faulty device specifying means for specifying that the subscriber device is a subscriber device in a poor extinction state, and instructing a constant extinction A constant extinction instruction command transmission means for transmitting a constant extinction instruction command to the subscriber apparatus specified by the defective apparatus specifying means, and the plurality of subscriber apparatuses are Upon receiving a temporary extinction instruction command transmission means from the station side apparatus temporary extinction instruction command transmission means, the optical transmission unit temporarily stops emission of the optical signal, and the station extinguishment instruction command transmission means of the station side apparatus transmits a constant extinction instruction. An optical communication system comprising: an optical transmission unit control means for stopping emission of an optical signal in the optical transmission unit and maintaining a light emission stop state when receiving a command.

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