JP2000032022A - Optical transmission system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the optical transmission system with a small system scale that can monitor each device independently of number of receivers and of whether or not the receivers are normal or faulty in one-to-multi communication. SOLUTION: The optical transmission system consists of a transmitter 31 that has a transmission means, a reception means receiving again a signal sent from the transmission means after one circulation of a ring, and a transmitter control means that receives communication quality information of an optical signal received by the reception means and can communicate system monitor information with other in-ring devices and of receivers 32, 33 each having a branch means that branches an optical signal propagated in the ring and transmits the one branched optical signal into the ring again, a reception means that receives the other branched optical signal by the branch means, and a receiver control means that communicates the system monitor information with the transmitter control means, and each of the devices above is interconnected as a ring by an optical transmission line 34.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical transmission system suitable for transmitting an optical signal between a transmitting device and one or more receiving devices.

[0002]

2. Description of the Related Art A conventional optical transmission system will be described with reference to FIG. In FIG. 7, reference numerals 11 and 14 denote optical transmission terminal devices, and reference numerals 12 and 13 denote relay terminal stations. 2. Description of the Related Art In a general optical transmission system in the related art, communication is usually performed using a pair of fiber cores in a single system (a system using one of an active transmission line and a backup transmission line). In such a device, monitoring of the device is performed by using SOH (Section over
Head), for example, using a supervisory control channel as performed in an optical amplification relay system, or a communication network for supervisory control (Data Communication Network).
k: DCN. Hereinafter, it is referred to as DCN. ) Or the information transfer channel in the system (Embedded Communication Channel)
l: ECC. Hereinafter, it is called ECC. ) Through. Particularly for urgent information, the two methods before using the SOH or the supervisory control channel are used. However, these two methods are premised on two-way communication and cannot be applied to one-way communication. On the other hand, although the method using DCN or ECC is applicable to one-way communication, the communication speed available for monitoring the device is more limited than the former two methods. However, the delay in data transfer was large, and it was not possible to cope with emergency restoration.

A method for implementing one-to-many communication using a conventional optical transmission device will be described. In FIG. 8, reference numeral 21 denotes a signal branching unit, and reference numerals 22 to 24 denote optical transmission terminals. Here, for the sake of simplicity, a case where one-to-two communication is performed from a certain point to two different points will be described. Usually 21
To 23 are installed close to each other, such as in the same building. 2
3 and 24 are installed at different points from each other. 22 and 24 and 23 and 25 respectively constitute the conventional optical transmission system shown in FIG. Thus, according to the conventional technique, each of the plurality of receiving apparatuses can be monitored, and one-to-many communication can be realized. But,
Usually, one-to-many communication is performed in one direction,
When a system is configured using devices for two-way communication, the communication network cannot be used effectively. On the other hand, in a conventional system suitable for one-way communication, it becomes difficult to quickly monitor devices as the number of devices on the receiving side increases. Further, in such a system configuration, it is necessary to provide an optical transmission terminal station corresponding one-to-one for both transmission and reception, and there is a disadvantage that the apparatus scale is increased.

[0004]

SUMMARY OF THE INVENTION In view of the above prior art, the present invention realizes one-to-many communication without impairing the utilization efficiency of a communication network, as well as the number of receiving devices and whether or not the receiving devices are normal. It is an object of the present invention to provide an optical transmission system that can monitor each device regardless of the state of abnormality and has a small device scale.

[0005]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, according to the first aspect of the present invention, an optical transmission line forming a ring, transmitting means, and a signal transmitted by itself are received again after one round of the ring. A transmitting device having a receiving device, a transmitting device control device capable of capturing communication quality information of an optical signal received by the receiving device, and communicating system monitoring information with another device in the ring; Branching means for branching the signal and transmitting one of the branched optical signals into the ring again; receiving means for receiving the other optical signal branched by the branching means; and transmitting means for controlling the transmitting device and system monitoring information. A receiving device having receiving device control means capable of communication, wherein the transmitting device and the plurality of receiving devices are connected in a ring shape by the optical transmission line. It is set to. According to the second aspect of the present invention, an optical transmission line that forms a ring from two transmission routes, a clockwise route and a counterclockwise route, a transmitting unit capable of transmitting signals in two directions, Receiving means for receiving the signal again after one round of the ring, and capturing communication quality information of the optical signal received by the receiving means;
A transmission device having a transmission device control means capable of communicating system monitoring information with another device in the ring; a light signal propagating in the two rings is partially branched, and one of the branched optical signals is again ring-transmitted. Send to within 2
Two branching units, a receiving unit for receiving an optical signal from a normal ring among the optical signals branched from the respective rings by the two branching units, and communicating the transmission device control unit and system monitoring information. And a receiving device having a possible receiving device control means, wherein the transmitting device and the plurality of receiving devices are connected in a ring shape by the optical transmission line. Further, in the above, the system monitoring information can be communicated using a communication network for monitoring and control or an information transfer channel.

That is, according to the present invention, in order to solve the above problem, each device is connected in a ring shape, and a signal from a transmitting device is branched into two by a branching means provided in each receiving device.
Reception is performed by a receiving device having a receiving means for receiving one of them. In addition, the signal after one round of the ring is received by the transmitting device, and the communication quality is monitored. Further, the monitoring information of the receiving device is also transferred to the transmitting device, and the monitoring of the system is realized.

Further, in order to improve the reliability, two rings for transmitting optical signals in mutually opposite directions are used, a transmitting device transmits an optical signal to each of them, and a receiving device selectively receives a normal optical signal. To increase fault tolerance.

[0010] According to the present invention, the present invention provides a ring-shaped configuration, which can reduce the size of the device, and the transmission source device monitors the signal after one round of the ring to provide a monitoring function. Can be realized.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] For simplicity,
A one-to-two type communication will be described as in the conventional example. FIG.
In the figures, 31, 32 and 33 are optical transmission devices used in the present invention. For explanation, the transmitting device 31 and the receiving devices 32, 3
It is assumed that one-to-two type communication is performed with the communication device 3. The transmitting device 31 and the receiving devices 32 and 33 are connected by a ring-type optical transmission line 34. The transmitting device 31 will be described with reference to FIG.

In FIG. 2, reference numeral 41 denotes a transmitting unit for transmitting an optical signal to the optical transmission line 34; 43, a receiving unit for receiving the optical signal from the optical transmission line 34;
A transmitting device control unit 46 controls the receiving unit 43 and transmits and receives data to and from the receiving unit 43, and performs data communication with another device via the DCN or ECC. Reference numeral 46 denotes a DCN or ECC. The transmitting device 31 converts the information into an optical signal by the transmitting unit 41 and transmits the optical signal. This optical signal is transferred to the transmitting device 31 after making a round around the ring formed by using the optical transmission line 34, and is received by the receiving means 43. When receiving the optical signal, the receiving unit 43 measures an error rate and the like, and the transmitting device control unit 45 captures and monitors the information, and determines whether the information has been correctly transferred into the system. Further, the transmission device control means 45 controls the entire transmission device, and furthermore, a DCN (or ECC) 46.
And exchanges information with the receiving devices 32 and 33 through the.

The configuration of the receivers 32 and 33 shown in FIG. 1 used in the present invention will be described with reference to FIG. In FIG. 3, reference numeral 51 denotes a signal branching unit, 52 denotes a receiving unit, and 46 denotes a DCN.
(Or ECC) 55 is a receiving device control means. The signal transferred through the ring network formed via the optical transmission line 34 is split by the signal splitter 51, and one of the signals is transferred again to another device through the ring network. The other is received by the receiving means 52. The information such as the error rate of the received signal measured by the receiving means 52 is once taken into the receiving apparatus control means 55, and then the DCN (or E
CC) management device and transmission device 31 not shown through 46
And so on. One-to-many communication can be economically realized by connecting one such transmitting device and a plurality of receiving devices in a ring.

[0012] Regarding monitoring, it is possible to confirm in real time that a signal has been transferred to the entire ring by receiving a signal that has traveled around the ring by the transmitting apparatus itself. In addition, the status of each receiving device can be monitored via DCN (or ECC).

[Second Embodiment] In the first embodiment, if a failure occurs somewhere in the ring, the failure can be detected immediately, but the communication can be quickly restored. I could not do it. In the present embodiment, the fault tolerance is increased by providing a standby system, and that point will be described. As shown in FIG. 4, in the present embodiment, the transmitting device 61 includes two rings, a clockwise ring 2 (65) composed of an optical transmission line and each device, and a ring 1 (64) rotating in the opposite direction.
And the receiving devices 62 and 63. For the sake of explanation, only one-to-two communication will be described, but this can be extended to one-to-many communication as in the first embodiment.

FIG. 5 shows the transmitting device 61 shown in FIG. 71 is a transmitting means, 72 and 73 are receiving means, 74 is a transmitting device control means, and 75 is a DCN (or ECC). The transmitting means 71 of the transmitting apparatus of the present embodiment has two outputs, and is in the first operating state for transmitting to the ring 1 and the ring 2;
It operates in one of the second operation states of transmitting to only one of them. The receiving means 72 and 73 respectively
, And the signal returned by one round is received, and its error rate and the like are measured. The information is transmitted to the transmission device control means 7
4 to determine whether the entire ring is operating properly. The information of the receiving devices 62 and 63 is also DCN
(Or ECC), the transmitting device control means 74 can monitor the status of the receiving devices 62 and 63.

FIG. 6 shows the receiving devices 62 and 63 shown in FIG. 81 and 82 are signal branching means, 83 is receiving means, 84 is receiving apparatus control means, and 75 is DCN (or E
CC). The signal branching means 81, 82
, Respectively, is split into two, one is transmitted to the next device through the ring, and the other is received. The receiving device of the present embodiment selects and receives signals transferred from the two rings. The receiving means 83 measures an error rate and the like,
The receiving device control means 84 collects such information, and
And the ECC 75 to the transmission-side control means 74 and a network management and operation device (not shown).

In this embodiment, a recovery function can be realized for a failure such as a transmission line disconnection. First, a case where the transmission path is disconnected will be described. Ring 1 (64) is used, and Ring 2
It is assumed that (65) is used as a spare. Receiving device 6
When a failure occurs in the transmission path between the ring 2 and the ring 63 (only the ring 1 or both the ring 1 and the ring 2), the receiving device 62 can normally receive a signal.
In addition, the receiving means 73 in the transmitting device 61 cannot receive the signal. Here, when the transmitting means 71 is transmitting to the ring 1 and the ring 2 at the same time, the receiving device 63 can recover the communication by selecting and receiving the signal from the ring 2 (65). When the transmitting unit 71 is transmitting only to the active (ring 1), the transmitting unit 71 transmits to both the rings 1 and 2, and the receiving device 63 selects and receives the signal from the ring 2 to perform communication. To recover. Further, the receiving devices 62 and 63 determine which signal of the ring 1 or ring 2 is being received by DCN or E.
It notifies the transmitting device 61 and the network operation device via CC. Thus, it is possible to determine which part of the transmission lines 64 and 65 has been cut off from the information.

Next, a case in which the receiving means of the receiving device fails will be described. If the receiving means 83 of the receiving device 63 fails, the receiving means 73 (or 72) of the transmitting device 61
Then, it continues receiving the signal normally. Therefore, the transmitting device 6
1 performs no operation. Since the signal can be normally received by the receiving device 62, no operation is performed.
In the receiving device 63, the failure of the receiving means is determined by some method (for example, a LOS (Loss of Signal) alarm of the receiver).
The alarm is transmitted to the transmitting device 61 or the network management / operation device using a means such as DCN or ECC. Such a failure can be prevented by duplicating the receiving means.

[0018]

As described above, according to the present invention, receiving means for receiving again a signal transmitted by itself to the transmitting apparatus after one round of the ring, and fetching communication quality information of the optical signal received by the receiving means. And a transmitting device control means capable of communicating system monitoring information with other devices in the ring, and a receiving device comprising a transmitting device control means and a receiving device control means capable of communicating system monitoring information. And multiple receivers are connected in a ring by an optical transmission line, so that one-to-many communication can be achieved without impairing the utilization efficiency of the communication network, and the number of receivers and whether the receivers are normal or abnormal Regardless, each device can be monitored, and the size of the device can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a first embodiment of an optical transmission system according to the present invention.

FIG. 2 is a block diagram illustrating a configuration of a transmission device illustrated in FIG.

FIG. 3 is a block diagram illustrating a configuration of a receiving device illustrated in FIG. 1;

FIG. 4 is a block diagram showing a configuration of a second embodiment of the optical transmission system according to the present invention.

FIG. 5 is a block diagram illustrating a configuration of a transmission device illustrated in FIG.

FIG. 6 is a block diagram showing a configuration of the receiving device shown in FIG.

FIG. 7 is a block diagram illustrating a configuration example of a conventional optical transmission system.

FIG. 8 is a block diagram showing a point-to-multipoint communication device using a conventional optical transmission device.

[Explanation of symbols]

 31, 61 Transmitter 32, 33, 62, 63 Receiver 34 Optical transmission path 41, 71 Transmitter 43, 52, 72, 73, 83 Receiver 45, 74 Transmitter controller 46, 75 DCN / ECC 51, 81 , 82 Signal branching means 55, 84 Receiver control means

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5K002 AA01 AA03 AA05 BA04 DA04 DA11 EA05 EA33 FA01 5K031 AA06 AA09 DA12 DA14 DA19 DB14 EA07 EA12

Claims (3)

[Claims] An optical transmission line forming a ring, a transmitting means, a receiving means for receiving a signal transmitted by itself after one round of the ring, and a communication quality information of an optical signal received by the receiving means. A transmission device having transmission device control means capable of communicating system monitoring information with another device in the ring, a branch for branching an optical signal propagating in the ring, and transmitting one of the branched optical signals again in the ring Means, receiving means for receiving the other optical signal split by the splitting means, and a receiving apparatus having receiving apparatus control means capable of communicating system monitoring information with the transmitting apparatus control means. An optical transmission system, wherein the transmitting device and the plurality of receiving devices are connected in a ring shape by the optical transmission path. 2. An optical transmission path forming a ring from two transmission paths, a clockwise path and a counterclockwise path, transmitting means capable of transmitting signals in two directions, and transmitting the signal transmitted by itself in one ring. A transmitting unit having a receiving unit for receiving again later and a transmitting unit control unit capable of capturing communication quality information of the optical signal received by the receiving unit and communicating system monitoring information with another device in the ring; Two branching means for partially branching the optical signal propagating in the ring and transmitting one of the branched optical signals again into the ring, and the optical signal branched from each ring by the two branching means. home,
Receiving means for receiving an optical signal from the normal ring;
A receiver comprising: the transmitter controller and a receiver controller capable of communicating system monitoring information, wherein the transmitter and the plurality of receivers are connected in a ring by the optical transmission path. An optical transmission system characterized by: 3. The optical transmission system according to claim 1, wherein said system monitoring information is communicated using a communication network or an information transfer channel for monitoring and control.