JPS603237A - Multiplexer for optical transmission - Google Patents

Abstract

PURPOSE:To simplify a small or medium capacity line by duplexing a multiplex separating section and an optical interface section in a multiplexer for optical transmission, allowing the multiplexer to generate a switching signal by itself to a fault of line and changing over the line to a spare line. CONSTITUTION:The multiplex separating section 112, the optical interface section 114 and a switching section 113 are provided in the multiplexer 111 for optical transmission. The multiplex separation section 112 consists of an existing section 112A and a spare section 112B and the optical interface section 114 consists of an existing section 114A and a spare section 114B. If a fault occurs in the existing optical line 200A, the existing multiplex separating section 112A or the existing optical interface section 114A detects the fault. The switching section 113 changes over the existing section and the spare section by transmitting the detected fault information to the switching section 113 and the existing multiplex separating section 112A, the existing multiplex separating section 112A transfers the fault information to the opposite side to change over the existing section and the spare section of the opposite side.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical transmission multiplexing device that multiplexes a plurality of low-order group signals into one high-speed signal and converts the high-speed signal into light.

Generally, in line protection of optical transmission lines, a dedicated switching device is used to protect a large number of lines N gathered together. In this method, in the case of a large capacity line, 1
It is economically advantageous because the number of active lines can be N compared to the number of spare lines, but it has the disadvantage that it is uneconomical in terms of system configuration when the number of lines is small and the capacity is medium or small. .

An object of the present invention is to provide an optical transmission multiplexing device that does not require a dedicated line switching device, has a line protection function in itself, and can configure an economical system. The present invention will be described in detail with reference to FIG.

In order to facilitate comparison with the present invention, a conventional optical line system will be described with reference to FIG.

It consists of optical fiber cables 103 to 303 and 503 to 703, backup optical terminal equipment 403 and 803, working optical lines 104 to 304, and protection optical line 404. The line switching procedure in the event of a line failure is first to switch between the current optical terminal equipment 104 and the current optical terminal equipment 104.
~303 or 503-703.

As a result of the detection, a switching command signal is sent to the line switching device 102 or 202. When the line switching device 102 or 202 receives the switching command signal, the line switching device 102 or 202 transfers the signal from the multiplex converter corresponding to the faulty line to the backup optical terminal devices 403 and 803,
Automatically switches to the protection line configured by the protection line 404.

This line switching method uses a dedicated switching device (switching device) to switch one reserved ψi+ft
If a large-capacity line is required to harvest rice using a loop cord, an economical system can be set up for IJ.
On the other hand, in a small or medium capacity line, an uneconomical y'z system configuration results.

Furthermore, in this method, as a method of transmitting line switching information, the speed of the signal from the multiplex converter is increased and the switching information is inserted into the surplus time (time slot). Pukome, who transmits 1n information using dust,
The scale structure is complicated and the scale of the 7i-C device is also increased. or,
The exchange of information between optical terminal equipment and line switching equipment is also becoming more complex.

FIG. 2 is a block diagram showing an embodiment of the present invention.

In FIG. 2, an optical transmission multiplexer 111 of the present invention multiplexes a number of low-speed signals into one high-speed signal, or multiplexes one high-speed signal into a series of low-speed signals. Current use of the optical interface unit 114 (112A, 114A) that converts a high-speed electrical signal multiplexed with the separation unit 112 into a high-speed optical signal or converts a high-speed optical signal into a high-speed electrical signal.
and spare (112B.

114B), and a switching section 113 that controls switching between these active and standby modes. Since each of these parts is arranged within the same device, it is extremely compact. A plurality of low-speed signals are co-fed in parallel to the multiplexing and demultiplexing section 112 which is duplicated, and in the current multiplexing and demultiplexing section 112A,
It is inserted into the allocated time slot in the high-order group multiplex frame structure, and is also used together with the synchronization bit stuffing pit necessary for information transmission or the signal bit (3) for controlling switching between the working and standby of the game equipment. The signals are multiplexed and converted into one high-speed signal. The multiplexed high-speed electrical signals are converted into high-speed optical signals by 114 active optical interface units, and then connected to 20 OA active optical lines.
sent to. In the spare multiplexing and demultiplexing section 112B, the switching control signal from the switching section 113 causes the preliminary multiplexing and demultiplexing section 1 to
The multiplexing circuit in 12B is closed, no multiplexing is performed, and only the pits necessary for the information transmission are multiplexed and converted into high-speed electrical signals. The backup optical interface section 114B converts the high-speed electrical signal from the backup multiplexer/demultiplexer 112B into a high-speed optical signal and sends it to the backup optical transmission line. Current episode 12
Errors due to degradation of 0OA or failures due to line disconnection are caused by the current optical interface section 114A or the current multiplexing/demultiplexing section 1.
Detected by a 12A receiving circuit. The detected fault information is sent to the switching section 113 and the transmission circuit of the current multiplexing/demultiplexing section 112A.

When the switching unit 113 receives the failure information, it generates a switching control signal to switch the current multiplexing/demultiplexing unit 112A and optical interface unit 114A to the spare multiplexing/demultiplexing unit 112B and optical interface unit 114B. Furthermore, in the transmitting circuit of the working demultiplexing section 112A, the working demultiplexing section 112C and the optical interface section 114C on the opposite side are connected to the spare demultiplexing section 112D and the optical interface section 1.
In order to switch to 14D, the failure information is transferred to the opposite side through the working optical line 200A using the X bit provided in the high-order group multiplexing frame. The receiving circuit of the active multiplexing and demultiplexing section 112C on the opposite side detects the X bits in the high-order group multiplexed frame and sends the detection information to the switching section 115. Upon receiving the detection information, the switching unit 115 switches the working multiplexing/demultiplexing unit 112C and the working optical interface unit 114C to the backup multiplexing/demultiplexing unit 112D and the backup optical interface unit 11.
A switching signal is generated to switch to 4D.

Through this series of operations, the working multiplexing/demultiplexing section and the working optical interface section of the own station and the opposing station are switched to the backup multiplexing/demultiplexing section and the backup optical interface section. Then, the blockage state of the multiplexing circuit of the spare multiplexer/demultiplexer 112B is released, and the plurality of low-speed signals are multiplexed into high-speed signals in the spare multiplexer/demultiplexer, and then converted into high-speed optical signals in the spare optical interface part 114B. It is converted and sent to the backup optical transmission line 200B. This protects the working optical line. Furthermore, not only in the case of a failure in the line but also in the case of a failure in the working multiplexing/demultiplexing unit or the working optical interface unit itself, switching is performed using the same means as described above.

As described above, the present invention provides a multiplexing/demultiplexing section, a switching section, and an optical interface section in the same device, thereby making it possible to easily configure a system without using a dedicated line switching device and optical terminal equipment. This is very advantageous for small and medium capacity lines.

Furthermore, the multiplexing and demultiplexing section and the optical interface section are 1:1.
Because it has a grout protection configuration, a highly reliable optical transmission line can be realized.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a system configuration using a conventional optical line switching method, and FIG. 2 is a block diagram showing an embodiment of the present invention. In FIG. 1, 101 to 601, song/multiplex conversion device
02-2G2... Rotating leg switching device, 103-80
3... Quaternary terminal equipment, 104-404... Quaternary line.

Claims (1)

[Claims] a multiplexing and demultiplexing unit that multiplex converts a plurality of low-speed signals into one high-speed signal or separates one high-speed signal into a plurality of low-speed signals; and an optical interface section that converts into signals.
In a multiplexing device in which one of the duplicated multiplexing/demultiplexing section and the optical interface section is configured as a working circuit and the other as a backup circuit, an opposing device is included in the frame of the high-order group multiplexed signal. The multiplexing frame is configured to include signal bits for transferring switching information for switching the working circuit to the protection circuit, and the switching unit controls the switching from the working circuit to the protection circuit, and the high-order group multiplexer A circuit for detecting signal bits in the multiplexing frame is provided in the multiplexing and demultiplexing unit, and in the case of a fault in the working line, the working receiving unit of the own station device detects the fault, and transmits the fault information to the high-order group multiplexing frame. The internal multiplexing/demultiplexing unit and optical interface unit of the local station and the opposing station are transferred to the spare multiplexing/demultiplexing unit and optical interface unit using the switching unit. An optical transmission multiplexing device characterized by protecting an optical transmission line by switching.