JPS6357971B2 - - Google Patents

Description

Detailed Description of the Invention (A) Technical Field of the Invention The present invention relates to an optical transmission system, particularly an optical transmission system in which a plurality of working systems are associated with one protection system. This invention relates to an optical transmission system in which the order wire signal is transmitted in the working system and the switch control signal is transmitted in the protection system, so that the working system transmission/reception unit and the protection system transmission/reception unit can have exactly the same configuration.

(B) Technical background and problems For example, in optical transmission systems such as telephones,
Conventionally, a plurality of active systems have generally been associated with one backup system. In addition to main signals such as telephone signals, sub signals such as so-called order wire signals and switch control signals are transmitted. The above-mentioned order wire signal is a voice signal related to a call between end stations located at both ends of an optical transmission system, and when there are multiple working systems, any one of the working systems is used. It may be transmitted by multiple systems, or it may be transmitted in parallel by multiple working systems.

Transmission of the above-mentioned main signal and sub-signal has conventionally been performed as follows. That is, during normal operation, the order wire signal is superimposed on the main signal in the active system and transmitted, and the standby system superimposes the order wire signal and the switch control signal on a specific pattern signal such as an all mark. Both are superimposed and transmitted. When a failure occurs in one of the active systems, the backup system
Instead of the specific pattern signal, the main signal of the failed working system is transmitted, and both the original order wire signal and the switch control signal are superimposed on the signal.

Therefore, in the conventional case, when switching from the active system to the protection system at the time of a failure, the transmission rate changes because the amount of transmission in the protection system is larger. Therefore, the active system and the backup system required transmitting/receiving units corresponding to their respective speeds.

Incidentally, if the switch control signal of the above-mentioned sub-signals is superimposed on the main signal of the working system and transmitted, the following problem occurs. In other words, when the backup system is disconnected for some reason, one of the active systems
If a failure occurs in the system, an attempt to switch to the standby system based on the switch control signal may result in a secondary failure. On the other hand, if the switch control signal is placed only on the standby system as in the conventional case, the following will occur, and no special problem will occur. That is, if one of the working systems becomes a failure, it is possible to switch to the protection system based on the switch control signal on the protection system. Furthermore, if the standby system is disconnected for some reason, even if a failure occurs in one of the active systems, only that system will fail.

For this reason, it can be considered that the main signal and sub signal were transmitted as described above. FIG. 1 shows a configuration diagram showing such a conventional transmission mode. In the figure, 1-0 is the backup system, 1-1 is the active system, which represents multiple active systems,
2A0 and 2B0 are standby transmission/reception units, respectively;
A1 and 2B1 are active transmitting/receiving units, 3
A and 3B are switch circuit sections, 4A and 4B are transmitting and receiving sections, respectively, 5A and 5B are time division processing sections, respectively.
6A and 6B are order wire signal processing units, 7
A and 7B represent switch control signal processing sections, respectively. The switch circuit sections 3A and 3B are controlled by switch control signal processing sections 7A and 7B, respectively. Further, in the backup system 10, both the order wire signal and the switch control signal are superimposed on the above-mentioned specific pattern signal or the switched main signal and transmitted.

Another conventional method of transmitting sub-signals is to transmit the sub-signals using separate metal conductive wires, as shown in FIG. Reference numerals 1, 2, 3, and 4 in the figure correspond to those in FIG. 1, 8A and 8B represent sub-signal interface portions, and 9 represents a metal conducting wire.

(C) Object and Structure of the Invention The present invention provides an optical system in which the operations of a protection transmitting/receiving unit and a working transmitting/receiving unit are substantially the same, and the speed is the same even when switching from the working system to the protection system. The purpose is to provide a transmission system. Therefore, the optical transmission system of the present invention includes an optical transmission line in which a plurality of working systems are associated with one protection system, and a subsystem that includes at least a switch control signal and an order wire signal in addition to a main signal. In an optical transmission system having a configuration in which signals are transferred, the main signal and the order wire signal transmitted in a form superimposed on the main signal are transmitted by the active system during normal operation, and the order wire signal is transmitted to the standby system. Therefore, the switch control signal is configured to be transmitted in a form superimposed on the specific pattern signal, and the order wire signal is configured to be transmitted by the other working system when a failure occurs in one of the working systems. The main signal of the faulty active system and the switch control signal transmitted in a superimposed form on the main signal are transmitted by the backup system. This will be explained below with reference to the drawings.

(D) Embodiment of the Invention FIG. 3 shows the configuration of an embodiment of the present invention, and FIG. 4 shows the configuration of an embodiment of the transmitting/receiving unit.

In FIG. 3, the symbols 1-0, 1-1,
2A0, 2B0, 2A1, 2B1, 3A, 3B,
4A, 4B, 6A, 6B, 7A, 7B are the first
Corresponds to the diagram.

In the illustrated embodiment, the data is transmitted as follows during normal operation. In other words, for the order wire signal among the sub-signals, there are multiple working systems 1-1,
1-2, . . . are configured to be superimposed on the respective main signals and transmitted in an overlapping form. That is, the active transmission/reception units 2A1, 2B1
Order wire signal processing sections 6A and 6B are connected to the order wire signal processing sections 6A and 6B. The switch control signal among the sub-signals is configured to be transmitted on the standby system 1-0 by being superimposed on the above-mentioned specific pattern signal. That is, the standby transmission/reception unit 2A0,
2B0, switch control signal processing section 7A,
7B is connected.

In the above state, if a failure occurs in one of the active systems, switching is performed as follows. That is,
The working system that is not in trouble continues to transmit the order wire signal in the form of being superimposed on the main signal as described above. on the other hand,
The backup system 1-0 transmits the main signal of the faulty working system instead of the above-mentioned specific pattern signal, and at this time, the above-mentioned switch control signal is superimposed on the main signal.

For this reason, regarding the need to transmit the switch control signal through the backup system, which was mentioned in connection with the above-mentioned "Technical Background and Problems,"
There is no difference from the conventional case, and since both the active system and the protection system superimpose one of the sub-signals, the operation mode is substantially the same, and there is no change in the transmission speed.

FIG. 4 shows an embodiment of the configuration of the standby transmitting/receiving unit or the active transmitting/receiving unit shown in FIG. 3. In FIG. Codes 2A0, 2A1, 7A, 6 in the diagram
A corresponds to FIG. 3, 10 is a bipolar/unipolar converter, 11 is a code converter, and 12 is an electric/unipolar converter.
13 represents an optical converter, 13 represents an optical/electrical converter, 14 represents a code converter, and 15 represents a unipolar/bipolar converter.

Assuming that the illustrated unit is the active transmitting/receiving unit 2A1, the output signal from the order wire signal processing section 6A is superimposed with the transmission signal in the code converter 11 and sent out in the form of an optical signal. In addition, order wire signals transmitted in the form of optical signals are
From the code converter 14 to the order wire signal processing unit 6
Guided by A.

Note that in the above, the manner in which the sub signal is superimposed on the main signal or the specific pattern signal may be arbitrary. For example, as is well known in the art, one or more time slots in a frame structure are used to transmit a sub-signal by pulse position and to make the amplitude of the pulse correspond to the amplitude of a main signal in the form of an analog signal. There are many ways to do this, such as assigning a sub-signal to a location, determining the location where a CRV (coding rule violation) should occur, and transmitting a sub-signal depending on whether or not a CRV occurs at that location. The following method can be adopted.

(E) Effects of the Invention As explained above, according to the present invention, the active system transmitting/receiving unit and the protection system transmitting/receiving unit can be made to operate in substantially the same manner, and it is possible to switch from the active system to the backup system. speed fluctuation can be suppressed.

[Brief explanation of drawings]

FIGS. 1 and 2 each show an example of a conventional configuration, FIG. 3 shows a configuration of an embodiment of the present invention, and FIG. 4 shows a configuration of an embodiment of a transmitting/receiving unit. In the diagram, 1-0 is the backup system, 1-1 is the active system, and 2A
0, 2B0 are standby transmission/reception units, 2A1, 2
B1 is the active transmitting/receiving unit, 3A, 3B are the switch circuit sections, 4A, 4B are the transmitting/receiving sections, 6A, 6B
7A and 7B represent an order wire signal processing section, and switch control signal processing sections 7A and 7B.

Claims (1)

[Claims] 1. Optical transmission comprising an optical transmission line in which a plurality of working systems are associated with one protection system, and in which a sub signal including at least a switch control signal and an order wire signal is transferred along with the main signal. In the system, during normal operation, the above-mentioned main signal and the above-mentioned order wire signal transmitted in a form superimposed on the main signal are transmitted by the above-mentioned working system, and the above-mentioned order wire signal is superimposed on a specific pattern signal by the above-mentioned standby system. The switch control signal is configured to be transmitted, and when a failure occurs in one of the working systems, the order wire signal is transmitted by the other working system, and the standby system is configured to transmit the order wire signal when a failure occurs in one of the working systems. An optical transmission system characterized in that it is configured to transmit a main signal of a generating and working system and the switch control signal that is transmitted in a form superimposed on the main signal.