JPH022732A - Optical transmission system - Google Patents

Abstract

PURPOSE:To smoothly perform the switching of a line even when a fault is generated in a monitor control data bit by providing a monitor control data bit demultiplexer which inserts the monitor control data bit from a monitor controller to a frame at a frame switching device. CONSTITUTION:DS3 frames (c1-cn) at a transmission side 1 are inputted to a DS3 signal demultiplexer 6a in the frame switching(SW) device 7a with a monitor data bit b1 from the monitor controller 5a and monitor data bits (b2-bn) from users. The demultiplexer 6a inserts the bits (b1-bn) to the DS3 frames and sends them to signal demultiplexers 8a and 10a. The demultiplexers 8a and 10a multiplex and output the frames (c1-cn). A signal transmitted to a reception side is inputted to signal demultiplexers 8b and 10b, and a main frame is separated to the frames (c1-cn), and they are outputted to a SW device 7b. The device 7b monitors each DS3 frame, and when it detects the fault in the bit bm in a certain frame cm, the device switches it to the frame having a normal bit bm and outputs it.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an optical transmission system characterized by a frame switching device.

[Conventional technology]

In the conventional optical transmission system, as shown in FIG. 3, n DSa frames a1 to an, which are 45 megabit signals, are sent via a frame switching (SW) device 21a on the transmitting side to a regular signal multiplexing/demultiplexing device 22a and a backup signal demultiplexing device 22a. signal demultiplexer 2 for
3a, and these DS3 frames a are input to signal demultiplexers 22a and 23a.

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . , .

Therefore, the main frame a, which is multiplexed by the signal demultiplexers 22a and 23a, is DSa as shown in FIG.
One of the surplus bits after frames a, to a, 1 was used as the supervisory control data bit b.

The signal of this main frame a is converted into an optical signal by optical 1t (oE) converters 27a and 28a, and is sent to the optical fiber 2.
9.30 in parallel to the receiving side.

On the receiving side, the sent optical signals of the main frame a are converted into electrical signals by OE converters 27b and 28b, and are input to signal multiplexing and demultiplexing devices 22b and 23b. At this time, the standby signal multiplexer/demultiplexer 23b is kept inactive, and the regular signal multiplexer/demultiplexer 22b separates the main frame a into DSa frames a1 to a7 and outputs them to the SW device 21b. Further, the supervisory control device 24b receives the supervisory control data bit b separated by the signal multiplexing/demultiplexing device 22b via the input/output port 25b, and determines whether or not there is a fault in the supervisory control data bit b. If there is a failure in the supervisory control data bit b, the supervisory controller 24b stops the operation of the regular signal multiplexer/demultiplexer 22b and switches to the backup signal multiplexer/demultiplexer 23b, and the signal is separated by the signal multiplexer/demultiplexer 23b. The monitoring and control data bit B was manually generated.

[Problem to be solved by the invention]

The conventional optical transmission system described above has a configuration in which the main frame a to be transmitted has a supervisory control data bit b included in one of the surplus bits other than the DSa frames a1 to a7, and a failure of this supervisory control data bit b is monitored. Control device 24
b (24a) determines that the commonly used signal demultiplexer 2
2b (22a) as a backup signal demultiplexer 23b
(23a), the supervisory control device 24a (24b) has two independent input/output ports 2 for switching between regular and backup lines.
Must have 5a (25b) and 26a (26b). In addition, the monitoring control device 24a (24b
”) must perform the switching itself.

This is because the supervisory control device 24a (24b) determines whether or not there is a failure in the supervisory control data bit b using software and separately from the DSU frames a, ``wa, l'', so it takes a long time to make that determination. This means that there is a drawback that it takes a long time to switch from the regular line to the protection line.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and provide an optical system that can smoothly and efficiently switch from a regular line to a protection line.

[Means to solve the problem]

The optical transmission system of the present invention includes a frame switching device having a supervisory control data bit multiplexing/demultiplexing device connected to a supervisory control device on each of the transmitting side and the receiving side, and regular and standby frames connected to the frame switching device respectively. a pair of signal multiplexing/demultiplexing devices, and a pair of photoelectric converters connected to each of the pair of signal multiplexing/demultiplexing devices and interposed between each signal multiplexing/demultiplexing device and an optical fiber for transmitting/receiving the monitoring control data. The bit multiplexing and demultiplexing device inserts supervisory control data bits from the supervisory control device into a frame on the transmitting side, and separates the supervisory control data bits inserted into the frame on the receiving side and outputs the separated supervisory control data bits to the supervisory control device. The signal demultiplexing device multiplexes frames from the supervisory control data bit demultiplexing device to form a main frame on the transmitting side, and separates the main frame into frames on the receiving side, and the frame switching device On the receiving side, the frame from the regular signal multiplexer/demultiplexer is input to the supervisory control data bit multiplexer/demultiplexer, and this frame is monitored, and if there is a failure in the supervisory control data bit in the frame, the regular signal is demultiplexed. The present invention is characterized in that a frame from the multiplexer/demultiplexer is switched to a frame from the standby signal multiplexer/demultiplexer and inputted to the supervisory control data bit multiplexer/demultiplexer.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

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

The optical transmission system is a system that transmits light between a transmitting side 1 and a receiving side 2 via a regular optical fiber 3 and a backup optical fiber 4. In this embodiment, for the purpose of explanation, the system on the left side of the drawing is used as the transmitting side, and the system on the right side is used as the receiving side, but the system is not limited to this, and the transmitting side and the receiving side can be reversed as necessary.

The transmitting side 1 includes a monitoring control device 5a, a DS3 signal multiplexing/demultiplexing device 6a, a SW device 7a in which the DS3 signal multiplexing/demultiplexing device 6a is provided, and a commonly used signal multiplexing/demultiplexing device 8.
a and an OR converter 9a, a backup signal demultiplexer 10a and an OE converter 11a.

The supervisory control device 5a has a function of inputting supervisory control data bits to the DS3 signal multiplexing/demultiplexing device 6a or outputting supervisory control data bits from the DS3 signal multiplexing/demultiplexing device 6a. The supervisory control data bit signal S from the supervisory control device 5a is output in correspondence with the DSS frame CI.

The DS3 signal multiplexer/demultiplexer 6a receives the supervisory control data bits b1 to b, l input to the DS3 signal multiplexer/demultiplexer 6a.
into DSa frames C2-cn, and when it becomes the receiving side, it separates the supervisory control data bits b1-b, l inserted into DSa frames 01-C7 from DSa frames 01-Cn. has.

The SW device 7a monitors each input DS3 frame,
It has a function of electrically, ie, hardware, switching between the regular signal multiplexer/demultiplexer 8a and the standby signal multiplexer/demultiplexer lOa when a failure occurs in a certain DS3 frame.

Therefore, when the transmitting side 1 becomes the receiving side, DSa frames C1 to C input from the commonly used signal demultiplexing device 8a
, , in a specific DSa frame C1, if a failure occurs in the supervisory control data bits b, , , in a specific DSa frame C1, it is detected and switched to the backup signal multiplexing/demultiplexing device 10a, and the signal demultiplexing device 10a normal supervisory control data bit b;
The DSa frame Ci having the following data is output to the DS3 signal demultiplexer 6a.

The commonly used signal multiplexing/demultiplexing device 8a has the supervisory control data bits b1 to b7 inserted in the DS3 signal multiplexing/demultiplexing device 6a.
DS3 frames C7 to C output from the W device 7a,
The main frame C (FIG. 2) is multiplexed to form the main frame C (FIG. 2), or when it becomes the receiving side, the transmitted main frame C is separated into the DS3 signal demultiplexer C+%Cfi.

Further, the OR converter 9a is provided between the signal multiplexing/demultiplexing device 8a and the optical fiber 3, converts the electrical signal of the main frame C from the signal multiplexing/demultiplexing device 8a into an optical signal, and converts the electrical signal of the main frame C from the optical fiber into an optical signal. It has the function of converting signals into electrical signals.

Reserve signal demultiplexer 10a and OE converter 11
a also includes a commonly used signal demultiplexer 8a and an OR converter 9a.
It has the same function as .

The receiving side 2 also has the same configuration as the transmitting side 1. That is, a supervisory control device 5b, a DS3 signal demultiplexer 6b, a SW device 7b in which the DS3 signal demultiplexer 6b is provided, a regular signal demultiplexer 8b and an OE converter 9b, and a backup signal demultiplexer 10b and OE
It is equipped with a converter 11b.

Next, the operation shown in this embodiment will be explained.

The DSa frame (,
The DS3 signal is input to the DS3 signal demultiplexer 6a. The DS3 signal demultiplexer 6a receives input DSa frames c1~
Supervisory control data bin) b, - in each DSa frame of c,
bfi is inserted and output to the signal demultiplexing devices 8a and 10a. At this time, each DSa frame cl, c2. −
..., cI.

are each supervisory control data bit b+ as shown in FIG.
, bz, . The signal demultiplexing devices 8a and 10a receive input DS3 frames cl"-c
, and multiplex it to the main frame C shown in Figure 2.
It outputs to R converters 9a and lla. OE converter 9a, l
la converts the mainframe C signal as an electrical signal into an optical signal. This optical signal is transmitted to the receiver 2 via an optical fiber 3.4.

The optical signal transmitted to the receiving side 2 is transmitted to the OE converter 9b, ll
b is converted into an electrical signal representing the main frame C, and input to the signal multiplexing and demultiplexing devices 8b and 10b. The signal multiplexing and demultiplexing devices 8b and 10b convert the input main frame C into each DSa frame cI+'Z.

. . , C, and output to the SW device 7b.

The SW device 7b receives each DSa frame CI+CZ+...c, which is input from the commonly used signal multiplexing/demultiplexing device 8b.
are monitored one by one, and each DSa frame c,,c2゜...
・Each supervisory control data bin in +CI'l) tel, b2
゜..., monitors whether or not a failure has occurred in b7.

Supervisory control data bit b in a certain DSa frame C8,
When detecting that a failure has occurred in the signal demultiplexing device 8b, the SW device 7b transmits the DSa frame
1 is the signal from the signal demultiplexer 10b and has the normal supervisory control data bit b1.
The signal is then output to the DS3 signal demultiplexer 6b.

The DS3 signal demultiplexer 6b extracts each supervisory control data (pin) bl, b2 . ..., bl are separated and output sequentially. output supervisory control data bit b;
is input to the supervisory control device 5b, and the other DS3 frames C3 to c7 and supervisory control data bits b2 to b are used as user information.

As described above, the optical transmission system of this embodiment transmits each DSa frame cI+02. ..., c7 contains supervisory control data bits b, , b2 . ..., insert b7 and transmit,
Monitoring control data focus b1. Since this is a system in which the SW devices 7a and 7b monitor failures of bz,...b7 and switch from regular use to standby in the event of a failure, monitoring is not possible in the same way as in conventional optical transmission systems. There is no need for the control device itself to perform the switching. Also, the SW devices 7a, 7
Since the switching by b is performed by hardware, the switching is performed smoothly and quickly.

〔Effect of the invention〕

As explained above, in the optical transmission system of the present invention, the frame switching device is provided with a supervisory control data bit demultiplexer that inserts the supervisory control data bits from the supervisory control device into the frame, and the receiving side frame switching device If there is a failure in the supervisory control data bits in the frame, the frame from the regular signal multiplexer/demultiplexer is switched to the frame from the standby signal multiplexer/demultiplexer, so if there is a failure in the supervisory control data bits. This has the effect that switching from a regular line to a protection line can be performed smoothly and efficiently in the event of a problem.

[Brief explanation of the drawing]

Figure 1 is a block diagram of an optical transmission system according to an embodiment of the present invention, Figure 2 is a block diagram of a main frame used in the optical transmission system of Figure 1, and Figure 3 is a block diagram of a conventional optical transmission system. FIG. 4 is a configuration diagram of a main frame used in the optical transmission system of FIG. 3. ■...Transmission side 2...Reception side 3.4...Optical fibers 5a, 5b...Monitoring control device 5a, 5b...DS3 signal multiplexing/demultiplexing device (supervisory control data bit multiplexing device) type separation device) 7a, 7b-=SW device 8a, 8b, 10a, 10b --- signal multiplexing and demultiplexing device

Claims (1)

[Claims] (1) On each of the transmitting side and the receiving side, a frame switching device having a supervisory control data bit multiplexing/demultiplexing device connected to a supervisory control device, and a pair of signal multiplexing devices for regular use and standby, each connected to this frame switching device. The monitoring control data bit multiplexing and demultiplexing device comprises a demultiplexing device, and a pair of photoelectric converters connected to each of the pair of signal multiplexing and demultiplexing devices and interposed between each signal multiplexing and demultiplexing device and a transmitting/receiving optical fiber. On the transmitting side, the supervisory control data bits from the supervisory control device are inserted into a frame, and on the receiving side, the supervisory control data bits inserted into the frame are separated and output to the supervisory control device, and the signal multiplexing and demultiplexing The device multiplexes the frames from the supervisory control data bit multiplexing and demultiplexing device on the transmitting side to form a main frame, and on the receiving side separates the main frame into frames, and the frame switching device A frame from a regular signal multiplexer/demultiplexer is input to a supervisory control data bit multiplexer/demultiplexer, and this frame is monitored, and if there is a fault in the supervisory control data bit in the frame, the frame from the regular signal multiplexer/demultiplexer is input to the supervisory control data bit multiplexer/demultiplexer. An optical transmission system characterized in that the frame is switched to a frame from the standby signal multiplexing/demultiplexing device and inputted to the supervisory control data bit multiplexing/demultiplexing device.