JP2009081662A - Point-to-multipoint optical communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To adopt the duplex structure of ONUs #1 (a, b) without reducing the maximum number of ONU installation stations connectable with station line terminating equipment OLTIF. <P>SOLUTION: The ONU installation station comprises a pair of the ONU #1a and the ONU #1b. An optical switch 1, a switching part (I)2 and a switching part (O)3 set one of the ONU #1a and the ONU #1b to an active system and the other to a standby system. A monitoring control part 12 monitors the operation state of the active system, and when detecting an abnormal state, switches the active system to the standby system, and the standby system to the active system, and notifies the OLTIF of the switched result. The OLTIF connects communication with the active system on the basis of an advised result by the monitoring control part 12. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a point-to-multipoint optical communication system in which a station line terminal device and a plurality of subscriber terminal devices are connected by a single optical network.

FIG. 5 is a system configuration diagram of a conventional point-to-multipoint optical communication system.
As shown in the figure, in a conventional point-to-multipoint optical communication system, an OLT (Optical Line Terminal) installation station is provided with a station line terminator OLTIF, and N subscribers centering on this station line terminator OLTIF. A person accommodation device ONU (Optical Network Unit) is provided. The N subscriber accommodation units ONU are combined by a one-to-two branch optical coupler with a pair of the active subscriber accommodation unit ONU and the standby subscriber accommodation unit ONU as one pair, and one ONU installation station is provided. Composed. This ONU installation station is connected to the station line termination device OLTIF via a 1 to N / 2 branch optical coupler. This is because the adoption of the duplex structure of the subscriber accommodation device ONU inside the ONU installation station is indispensable for achieving a reduction in the recovery time of a line accident during system operation.
JP 2005-328294 A

  In the prior art, the maximum number of ONU installation stations that can be connected to one station line termination unit OLTIF is 1 / of the maximum number of subscriber accommodation units ONU that is limited by the maximum optical output of the station line termination unit OLTIF. The problem to be solved remains that the transmission efficiency is reduced to 2.

  The present invention is a point-to-multipoint optical communication system in which one OLTIF (station line terminator) and N ONU installation stations are communicatively connected via a 1 to N branching optical coupler. Monitors the operating status of the working system and detects an abnormal condition by setting a pair of ONUs (subscriber accommodation units), a system setting unit for setting one of the pair of ONUs as a working system and the other as a standby system Then, the active system is switched to the standby system, the standby system is switched to the active system, and the switching control unit notifies the OLTIF of the switching result. The OLTIF is based on the notification result from the monitoring control unit. The main feature is that it includes transmission / reception means for communication connection with the active system of the ONU.

  According to the present invention, the ONU installation station monitors the operational state of the active system, the system setting unit that sets one of the pair of ONUs, one of the pair of ONUs as the active system, and the other as the standby system, and detects an abnormal state. If detected, the monitoring system is provided with a monitoring system that switches the working system to the working system and the working system to the working system, so that ONU # 1 (a, b ) To obtain a double structure.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a system configuration diagram of a point-to-multipoint optical communication system according to the present invention.
As shown in the figure, in the point-to-multipoint optical communication system 200 according to the present invention, the station line termination device OLTIF # 1 provided in the OLT installation station 100 is used as an aggregation port of the optical coupler 150 of 1 to N branch. The branch port of the optical coupler 150 and the ONU installation stations (# 1 to #N) are connected to each other via an optical fiber (# 1 to #N) and connected to a network (for example, Ethernet ( (Registered trademark)) and subscriber terminal devices (# 1 to #N) are optical communication systems in which data is transmitted and received in a time division multiplexing manner.

  The OLT installation station 100 is a relay station, and includes station line terminators OLTIF (# 1 to #M) and an OLT monitoring controller 110 therein. The station line terminator OLTIF (# 1 to #M) is connected to the network and the optical fiber # 0, receives an electrical signal from the network, converts it into an optical signal, and sends it to the optical coupler 150 via the optical fiber # 0. At the same time, it is a device that receives an optical signal from the optical coupler 150 via the optical fiber # 0, converts it into an electrical signal, and sends it to the network. The OLT monitoring control unit 110 is a part that monitors the operating states of a plurality of OLTIFs (# 1 to #M) arranged in the OLT installation station 100. In the following, description will be given by limiting to a system configured mainly by the station line termination device OLTIF # 1 as an example.

  The optical coupler 150 receives an optical signal from the station line termination device OLTIF # 1 via the optical fiber # 0, branches it into N optical fibers (# 1 to #N), and the optical fibers (# 1 to ##). N) are transmitted to the ONU installation stations (# 1 to #N) to which each is connected, and light is transmitted from the ONU installation stations (# 1 to #N) to which each of the optical fibers (# 1 to #N) is connected. It is an optical component that receives and multiplexes signals and sends them to the station line terminator OLTIF (# 1 in the figure) via the optical fiber # 0.

  Each of the ONU installation stations (# 1 to #N) is connected to the optical coupler 150 via one optical fiber (one of the optical fibers (# 1 to #N)), and further identifies itself. This is a device connected to one subscriber terminal device (# 1 to #N) corresponding to # 1 to #N.

  The ONU installation stations (# 1 to #N) perform predetermined transmission processing on the electrical signals received from the corresponding subscriber terminal devices (# 1 to #N), convert the electrical signals into optical signals, and It is sent to the optical coupler 150 through a fiber (one of the optical fibers (# 1 to #N)). Furthermore, the optical signal received from the optical coupler 150 via one optical fiber (one of the optical fibers (# 1 to #N)) is converted into an electric signal, and a predetermined reception process is executed. To the subscriber terminal devices (# 1 to #N).

  Unlike the conventional example shown in FIG. 5, the point-to-multipoint optical communication system of the present invention described above has one ONU installation station (# 1 to #N) in each branch port of the 1-to-N branch optical coupler 150. Any) is connected. Therefore, the maximum number of ONU installation stations that can be connected to one station line termination unit OLTIF is equal to the maximum number of ONUs (subscriber accommodation units) that are limited by the maximum optical output of the station line termination unit OLTIF. Specific examples thereof will be described in detail below.

FIG. 2 is a block diagram of an ONU installation station according to the first embodiment.
Since all the ONU installation stations (# 1 to #N) shown in FIG. 1 have the same configuration, the ONU installation station # 1 will be described as an example here, and the other ONU installation stations (# 2 to #N) will be described. Description is omitted.

  As shown in the figure, the ONU installation station of Example 1 includes an optical switch 1, a switching unit (I) 2, a switching unit (O) 3, an ONU # 1a, an ONU # 1b, and a SEL (1). And SEL (2).

  The optical switch 1 is an optical switch that connects the optical fiber # 1 connected to the optical coupler 150 (FIG. 1) and any one of the ONU # 1a and the ONU # 1b based on switching by the switching unit (I) 2. It is.

  The switching unit (I) 2 is a part that executes switching of the optical switch 1 based on the control of the monitoring control unit 12 described later. The switching unit (O) 3 performs switch switching between the SEL (1) and the SEL (2) based on the control of the monitoring control unit 12 described later, and the subscriber terminal device # 1 (FIG. 1) and the ONU # 1a Or it is a part which connects ONU # 1b.

  The SEL (1) is an electrical signal switch that sends a received signal from the ONU # 1a or ONU # 1b, which will be described later, to the subscriber terminal device # 1 (FIG. 1) based on switch switching of the switching unit (O) 3. is there. SEL (2) is an electrical signal switch that sends a transmission signal from subscriber terminal device # 1 (FIG. 1) to ONU # 1a or ONU # 1b, which will be described later, based on switch switching of switching unit (O) 3. is there.

  The ONU # 1a includes a WDM 4, an O / E 5, an E / O 6, a reception processing unit 7, a transmission processing unit 8, an information storage unit 10, an ONU setting holding unit 11, and a monitoring control unit 12. And performing predetermined transmission processing on the electrical signal received from the subscriber terminal device # 1 (FIG. 1) via the SEL (2), converting the electrical signal into an optical signal, and transmitting the optical signal to the optical switch 1. 1 is a subscriber accommodation device that converts an optical signal received from 1 into an electrical signal, performs a predetermined reception process, and sends the signal to subscriber terminal device # 1 (FIG. 1) via SEL (1).

  The WDM 4 is a wavelength multiplexing / demultiplexing filter that inputs / outputs an input optical signal received from the optical switch 1 and transmitted to the O / E 5 and an output optical signal received from the E / O 6 and transmitted to the optical switch 1 from the same port. . Usually, a dielectric multilayer filter is used. Here, the input optical signal and the output optical signal have different optical wavelengths.

  The O / E 5 is a photoelectric conversion element that receives an optical signal from the WDM 4, converts it into an electrical signal, and sends it to the reception processing unit 7. Usually a PIN diode is used. The E / O 6 is a photoelectric conversion element that receives an electrical signal from the transmission processing unit 8, converts it into an optical signal, and sends it to the WDM 4. Usually a laser diode or LED is used.

  The reception processing unit 7 accepts a frame in which an optical signal transmitted from the OLT installation station 100 (FIG. 1) is converted into an electrical signal by the O / E 5 and recognizes and acquires only a frame destined for the own station. In this part, a predetermined reception process is executed and sent to SEL (1). Recognition of a frame destined for the own station is executed by the reception processing unit 7 determining the LLID value included in the preamble of the frame. The LLID value is set in advance in the ONU setting holding unit 11 to be described later by an instruction of a transmission / reception control frame transmitted from the OLT at the time of ONU registration.

  The transmission processing unit 8 executes predetermined transmission processing on the electrical signal frame received from the subscriber terminal device # 1 (FIG. 1) via the SEL (2), recognizes the transmission timing assigned to the own station, This is the part sent to E / O6. This transmission timing is set in advance in the ONU setting holding unit 11 to be described later or appropriately changed based on an instruction of a transmission / reception control frame transmitted from the OLT at the time of ONU registration and at a predetermined time.

  The information storage unit 10 is a memory that stores state information inside the ONU installation station based on the control of the monitoring control unit 12 described later. That is, the memory stores the ONU number 10a and the current / spare type 10b based on the control of the monitoring control unit 12, and provides information as necessary. As the ONU number 10a, the N part (ONU number “1” in the figure) of ONU # N (a, b) is stored. In the active / standby type 10b, the monitoring control unit 12 stores “0” when operating as the active system and “1” when standing by as the standby system. Normally, a rotary switch, a DIP switch, etc. are used for setting the ONU number, working / spare type, and the like.

  The ONU setting holding unit 11 is a memory that holds various setting information set in the ONU # 1a. The various information is normally set via a transmission / reception control frame transmitted by the station line termination device OLTIF # 1. A part of examples of various setting information will be described below.

(1) Authentication information Information used for authentication as to whether or not the subscriber terminal device # 1 connected to the ONU installation station # 1 is a registered user is set. For example, a user ID or a password corresponds to this.
(2) Encryption information Encryption keys necessary for encryption are set.
(3) The size of the queue buffer for data processing in the ONU is set.
Depending on the type of service provided by the carrier, the processing capability of the ONU is set from the OLT. If the buffer size is large, large data processing can be performed in a batch, which improves performance.

  (4) The reception processing unit 7 uses an LLID value as an identifier for frame recognition destined for the own station, and the transmission processing unit 8 sets or changes the information for recognizing the transmission timing assigned to the own station. Is set.

  The monitoring control unit 12 monitors the operating state inside the apparatus, that is, the received light level drop and the optical transmission unit failure monitoring, loopback control, power supply failure, etc., and when the ONU # 1a is operating as the active system When the abnormal state is detected, the ONU # 1b waiting as the standby system is replaced with the ONU # 1a and is operated as the active system. The switch switching unit 12a, the synchronization unit 12b, and the serial number management unit 12c are provided therein.

  When the abnormal state of the ONU # 1a operating as the working system is detected, the switch switching means 12a sends a switch switching signal to the switching unit (I) 2 and the switching unit (O) 3, and the working system signal This is a means for switching the route from ONU # 1a to ONU # 1b.

  The synchronization unit 12 b is a unit that copies the stored contents of the ONU setting holding unit 11 to the ONU setting holding unit 31. When it is detected that ONU # 1b is set as the standby system for ONU # 1a operating as the active system, all of the setting information stored in the ONU setting holding unit 11 is transferred to the ONU setting holding unit 31. A means for copying.

Further, the synchronization unit 12b detects an abnormal state of the ONU # 1a operating as the active system, and sends a switch switching signal to the switching unit (I) 2 and the switching unit (O) 3, so that the active system signal This is means for copying all of the setting information stored in the ONU setting holding unit 11 to the ONU setting holding unit 31 when the path is switched.
The synchronization unit 12b may operate at a specified time as described above, or may automatically operate at regular time intervals.

  The serial number management means 12c is a means for managing the operating state of the ONU # 1a. When the ONU # 1a operating as the active system is changed to the standby system, it is means for changing the active / standby type 10b of the information storage unit 10 from “0” to “1”. Furthermore, when the storage content of the information storage unit 10 is changed, it is also means for generating a transmission / reception control frame and transmitting it to the station line terminal unit OLTIF # 1.

  The ONU # 1b includes a WDM 24, an O / E 25, an E / O 26, a reception processing unit 27, a transmission processing unit 28, an information storage unit 30, an ONU setting holding unit 31, and a monitoring control unit 32. And performing predetermined transmission processing on the electrical signal received from the subscriber terminal device # 1 (FIG. 1) via the SEL (2), converting the electrical signal into an optical signal, and transmitting the optical signal to the optical switch 1. 1 converts the optical signal received from 1 into an electrical signal, performs a predetermined reception process, and sends it to the subscriber terminal device # 1 (FIG. 1) via SEL (1). Represents a state.

  Here, WDM 24 is WDM 4, O / E 25 is O / E 5, E / O 26 is E / O 6, reception processing unit 27 is reception processing unit 7, transmission processing unit 28 is transmission processing unit 8, and information storage. The unit 30 has the same functions as the information storage unit 10, the ONU setting holding unit 31 has the same function as the ONU setting holding unit 11, and the monitoring control unit 32 has the same function. Only the mutual relationship between them will be described here.

  The same information is stored in the ONU number 10a of the information storage unit 10 and the ONU number 30a of the information storage unit 30. Here, 1 is stored in both (# 1a and # 1b).

  If the current / spare type 10b of the information storage unit 10 and the current / spare type 30b of the information storage unit 30 store 0 (active system) in one, 1 (standby system) is stored in the other. ing. If one is changed from 0 to 1, the other is changed from 1 to 0.

  The stored contents of the ONU setting holding unit 11 and the stored contents of the ONU setting holding unit 31 are the same as the ONU setting holding unit 11 (or the ONU setting holding unit 31) that was actually operating as the working system every time the working system is changed. ) Is copied to the ONU setting holding unit 31 (or the ONU setting holding unit 11) that is actually waiting as a standby system. However, the stored contents of the active system may be periodically copied to the standby system regardless of the change of the active system.

FIG. 3 is a block diagram of the OLTIF of the present invention.
Since all the station line termination devices OLTIF (# 1 to #M) shown in FIG. 1 have the same configuration, the station line termination device OLTIF # 1 will be described as an example, and other station line termination devices OLTIF (# 2) will be described. The description of ~ # M) is omitted.

  As shown in the figure, the station line termination device OLTIF # 1 includes a WDM 51, an O / E 52, an E / O 53, a reception processing unit 54, a transmission processing unit 55, an information storage unit 57, and a monitoring control unit 58. With.

  The WDM 51 is a wavelength multiplexing / demultiplexing filter for inputting / outputting an input optical signal received from the optical fiber # 0 and transmitted to the O / E 52 and an output optical signal received from the E / O 53 and transmitted to the optical fiber # 0 from the same port. It is. Usually, a dielectric multilayer filter is used. Here, the input optical signal and the output optical signal have different optical wavelengths.

  The O / E 52 is a photoelectric conversion element that receives an optical signal from the WDM 51, converts it into an electrical signal, and sends it to the reception processing unit 54. Usually a PIN diode is used. E / 053 is a photoelectric conversion element that receives an electrical signal from the transmission processing unit 8, converts it into an optical signal, and sends it to the WDM 4. Usually a laser diode or LED is used.

  The reception processing unit 54 receives frames in which the optical signal transmitted from the ONU installation station # 1 (FIG. 1) is converted into an electrical signal by the O / E 52, accumulates the frames in the reception order, and executes predetermined reception processing. And send it to the network. In addition, when a transmission / reception control frame is received from the ONU installation station # 1 (FIG. 1), it is a part that is sent to the monitoring control unit 58.

  The transmission processing unit 55 assigns a predetermined identifier serving as a frame destination to the electrical signal frame received from the network, executes a predetermined transmission process, and transmits to the optical fiber # 0 via the E / O 53 and the WDM 51. It is. Here, the identifier is given by the transmission processing unit 55 acquiring the LLID value stored in the LLID management table 57c of the information storage unit 57 and including it in the preamble of the frame.

  The monitoring control unit 58 has an ONU management unit 58a in the inside thereof, and monitors the operating state inside the apparatus, that is, monitoring of the reception light level drop and optical transmission unit failure monitoring, loopback control, power supply failure, etc., and notifies the user. At the same time, it is a part for monitoring the state change of the ONU installation stations (# 1 to #N) (FIG. 1) via the transmission / reception control frame.

  The ONU management means 58a is a pair of the active system and the standby system included in the ONU installation stations (# 1 to #N) (FIG. 1) connected to the own station (the station line termination device OLTIF # 1 in the figure). This is means for managing the status of all ONU # 1 (a, b) to ONU # N (a, b).

  That is, information storage described below by accepting setting information by the user from the subscriber terminal devices (# 1 to #N) via the reception processing unit 55 at the time of device setting, or accepting setting change information after device setting. This is means for executing content setting and content change of the unit 57. Similarly, content setting and content change of the information storage unit 57 to be described next are accepted by accepting setting information by a user connected to the network via the transmission processing unit 54 at the time of device setting, or accepting setting change information after device setting. Is a means for executing.

  The information storage unit 57 is a memory that stores therein an ONU number table 57a, an active / spare type table 57b, and an LLID management table 57c.

  The ONU number table 57a includes an active system and a standby system included in the ONU installation stations (# 1 to #N) (FIG. 1) connected to the local station (the station line termination device OLTIF # 1 in the figure) at the present time. Is a table that stores all numbers of ONU # 1 (a, b) to ONU #N (a, b) that are paired.

  The working / standby type table 57b indicates whether all of the ONUs # 1 (a, b) to ONU #N (a, b) in which the working system and the standby system are paired are currently working. It is a table that stores information as to whether it is a system in association with the ONU number table 57a. Here, as an example, 0 is stored in a predetermined area in the case of the active system, and 1 is stored in the case of the standby system.

  The LLID management table includes an LLID value that is an identifier of a frame destined for an ONU installation station (# 1 to #N (FIG. 1)), a change value thereof, and an ONU installation station (# 1 to #N (FIG. 1)). ) Is a table for storing a set value, a changed value, and the like of information for recognizing the transmission timing assigned to the ONU number table 57a.

The point-to-multipoint system of the first embodiment described above operates as follows.
First, in FIG. 2, the optical switch 1 selects ONU # 1a as the active system. In this state, “1” is stored in the ONU number 10a of the information storage unit 10 and “1” is stored in the working / reserve type 10b. Various information is set from OLTIF # 1 to ONU # 1a by transmission / reception of a transmission / reception control frame between OLTIF # 1 and ONU # 1a and stored in the ONU setting holding unit 11.

  As described above, the various information includes (1) authentication information, (2) encryption information, (3) size setting of the queue buffer for data processing inside the ONU, and (4) the reception processing unit 7 LLID value serving as an identifier for frame recognition destined for the destination, a set value or a changed value of information for the transmission processing unit 8 to recognize the transmission timing assigned to the own station.

  When the duplex structure of the system is adopted, “1” is stored in the ONU number 30a of the information storage unit 30 of the ONU # 1b and “0” is stored in the working / spare type 30b via the transmission / reception control frame. The

  At this time, the monitoring control unit 12 is connected to the monitoring control unit 32 and recognizes that the standby system is connected. Further, the serial number management means 32c of the monitoring control unit 32 indicates that the ONU number 30a is "1" and the working / standby type 30b is "1", and the OLTIF reception processing unit 54 (FIG. 3). Is notified via a transmission / reception control frame.

  When receiving the corresponding transmission / reception control frame, the reception processing unit 54 (FIG. 3) of the OLTIF sends it to the monitoring control unit 58 (FIG. 3). The monitoring control unit 58 (FIG. 3) recognizes the content of the transmission / reception control frame. The ONU management unit 58a changes the content stored in the information storage unit 57 with the recognized content.

  When the monitoring control unit 12 recognizes that the standby system is connected, it copies the contents of the ONU setting holding unit 11 to the ONU setting holding unit 31, and the contents of the ONU setting holding unit 11 and the ONU setting holding unit 31 are the same. Set the status (synchronized). Through the above operation, ONU # 1a and ONU # 1b are synchronized.

  In this state, when the monitoring control unit 12 detects a failure of the active ONU # 1a, the switch switching unit 12a uses the switching unit (I) 2 and the switching unit (O) 3 to switch the optical switch 1 and SEL (1). And SEL (2) are switched to switch the active system from ONU # 1a to ONU # 1b.

  At this time, since the stored contents of the information storage unit 10 are changed, the serial number managing unit 12c generates a transmission / reception control frame and transmits it to the station line terminal unit OLTIF # 1. When receiving the corresponding transmission / reception control frame, the reception processing unit 54 (FIG. 3) of the OLTIF sends it to the monitoring control unit 58 (FIG. 3). The supervisory control unit 58 (FIG. 3) recognizes the content of the transmission / reception control frame, and the ONU management unit 58a changes the content stored in the information storage unit 57 with the recognized content.

  Thereafter, the reception processing unit 54 (FIG. 3) accepts the frames received from the ONU # 1b (FIG. 1) of the ONU installation station # 1, accumulates them in the order of reception, executes a predetermined reception process, and executes a network (for example, To Ethernet (registered trademark).

  Further, the transmission processing unit 55 (FIG. 3) assigns a predetermined identifier as a destination to the frame received from the network, executes a predetermined transmission process, and transmits the frame to the ONU # 1b (FIG. 1) of the ONU installation station # 1. To do. Here, the identifier is given by the transmission processing unit 55 (FIG. 3) acquiring the LLID value stored in the LLID management table 57c (FIG. 3) of the information storage unit 57 and including it in the frame preamble. .

  Thereafter, the operation is continued with ONU # 1b as the active system and ONU # 1a as the standby system. In this way, the point-to-multipoint optical communication system according to this embodiment can minimize the influence on the line at the ONU installation station # 1.

  As described above, according to the present embodiment, it is possible to adopt the duplex structure of ONU # 1 (a, b) without reducing the maximum number of ONU installation stations that can be connected to the station line termination device OLTIF. obtain.

FIG. 4 is a block diagram of an ONU installation station according to the second embodiment.
As shown in the figure, the ONU installation station of the second embodiment includes an optical switch 1, a switching control unit (I) 42, a switching control unit (O) 43, ONU # 1a, ONU # 1b, and SEL ( 1) and SEL (2).

  As shown in the figure, the difference between the ONU installation station of the first embodiment shown in FIG. 2 and the ONU installation station of the present embodiment is that the switching unit (I) 2 and the switching unit (O ) 3 is replaced by a switching control unit (I) 42 and a switching control unit (O) 43 in this embodiment.

  The switching unit control (I) 42 monitors a decrease in the light level to the optical switch 1 and executes switching of the optical switch 1 based on its own judgment when the abnormal state is detected. This is the part that notifies the control unit 32. Further, similarly to the first embodiment, the optical switch 1 is also switched based on the control of the monitoring control unit 12.

  The switching control unit (O) 43 monitors input / output signals to SEL (1) and SEL (2), and when an abnormal state is detected, switches SEL (1) and SEL (2) based on its own judgment. This is a part that is executed and notified to the monitoring control unit 12 and the monitoring control unit 32. Moreover, it is also a part which performs switching of the optical switch 1 of SEL (1) and SEL (2) based on control of the monitoring control part 12 similarly to Example 1. FIG. The other parts, including the OLTIF, are all the same as those in the first embodiment, and thus the description thereof is omitted.

  If only one of the switching control unit (I) 42 and the switching control unit (O) 43 detects an abnormal state, the monitoring control unit 12 and the monitoring control unit 32 are notified of the occurrence of an accident. Therefore, the switch control signal is sent from the monitoring control unit 12 and the monitoring control unit 32 to both the switching control unit (I) 42 and the switching control unit (O) 43, and switching between the active system and the standby system is executed. .

  As described above, according to the present embodiment, in place of the switching unit (I) 2 and the switching unit (O) 3 that do not have the self-determination function in the first embodiment, the self-determination function is provided in this embodiment. Since the switching control unit (I) 42 and the switching control unit (O) 43 are replaced with each other, there is an effect that the reliability is higher and quick switching is possible when an active system accident occurs.

  In the description of the embodiment, the network to which the OLT installation station is connected is limited to Ethernet (registered trademark), but the present invention is not limited to this example. In other words, connection to the Internet network is possible, and further interoperability can be secured in the future.

1 is a system configuration diagram of a point-to-multipoint optical communication system according to the present invention. FIG. FIG. 3 is a block diagram of an ONU installation station according to the first embodiment. It is a block diagram of OLTIF of the present invention. 6 is a block diagram of an ONU installation station according to Embodiment 2. FIG. It is a system configuration | structure figure of the conventional point to multipoint optical communication system.

Explanation of symbols

1 Optical switch 2 Switching part (I)
3 switching part (O)
4 WDM
5 O / E
6 E / O
7 Reception processing unit 8 Transmission processing unit 10 Information storage unit 10a ONU number 10b Current / spare type 11 ONU setting holding unit 12 Monitoring control unit 12a Switch switching unit 12b Synchronization unit 12c Sequential number management unit 24 WDM
25 O / E
26 E / O
27 reception processing unit 28 transmission processing unit 30 information storage unit 30a ONU number 30b current / spare type 31 ONU setting maintenance unit 32 monitoring control unit 32a switch switching unit 32b synchronization unit 32c serial number management unit

Claims (7)

A point-to-multipoint optical communication system in which one OLTIF (station line termination device) and N ONU installation stations are connected via a 1 to N branching optical coupler,
The ONU installation station is
A pair of ONUs (subscriber accommodation units);
A system setting unit for setting one of the pair of ONUs as an active system and the other as a standby system;
A monitoring control unit that monitors the operating state of the active system and switches the active system to the standby system, switches the standby system to the active system and detects the switching result to the OLTIF when an abnormal state is detected;
The OLTIF is
A point-to-multipoint optical communication system comprising transmission / reception means for communication connection with the working system of the pair of ONUs based on a notification result by the monitoring control unit. The system setting section
The point-to-multipoint optical communication system according to claim 1, further comprising a two-branch optical switch that performs system switching based on control of the supervisory control unit. The monitoring controller is
When the abnormal state is detected, the system setting unit is controlled, switch switching means for switching the active system to the standby system and the standby system to the active system,
Serial number management means for notifying the OLTIF of the switching result by the switch switching means;
The point-to-multipoint optical communication system according to claim 1, further comprising synchronization means for sharing communication setting information between the pair of ONUs. Each of the pair of ONUs is
The point-to-multipoint optical communication system according to claim 3, further comprising a first information storage unit that stores a result of switching by the switch switching unit. Each of the pair of ONUs is
The point-to-multipoint optical communication system according to claim 3, further comprising an ONU setting holding unit that stores communication setting information shared between the pair of ONUs. The OLTIF is
The point-to-multipoint optical communication system according to claim 3, further comprising a second information storage unit that stores a notification result by the serial number management unit. The system setting unit
The point-to-multipoint according to claim 2, further comprising: a switching control unit that monitors a two-branch optical switch and detects system failure regardless of control by the monitoring control unit. Optical communication system.

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