JPS6037846A - Order line signal transmission system - Google Patents

Abstract

PURPOSE:To attain transmission/reception of an order line signal even if any transmission line is faulty by transmitting the order line signal while being superimposed on a main signal, receiving the signal, extracting the order line signal from a normal signal and selecting one of the signals. CONSTITUTION:A signal from an order line unit of a station A is transmitted to a code conversion circuit of optical terminal station devices 24-26 and transmitted to a station B together with the main signal by a service bit inserted in the main signal. The order line signal is extracted by a demodulation circuit of optical terminal station devices 27-29 of the station B, and the result is transmitted to a changeover circuit 38, which selects one of the extracted order signals out of the signals transmitted normally and transmits the selected signal to an order line unit 33.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention provides an economical meeting arrangement solution between stations in which a plurality of end station devices are used to superimpose and transmit a meeting line signal on a raw signal.
Regarding the signal transmission method.

(b) Technology background FIG. 1 is a block diagram of an optical fiber transmission system.

6, 12 are input interface circuits, 7, 13 are code conversion circuits, 8, 14 are electrical/optical conversion circuits, 9゜15
10.16 is an output interface circuit, 10.16 is a code demodulation circuit, 11.17 is an optical/electrical conversion circuit, 18.21 is an analog/digital converter (hereinafter referred to as an A/D converter), 1
9.22 is a digital-to-analog converter (hereinafter referred to as a D/A converter), and 20.23 is a telephone set.

In an optical fiber transmission system, since the optical fiber is an insulator, it is less susceptible to the effects of earth potential differences, various electromagnetic rusting, and vibration. It is often done to superimpose or insert the signal into the main signal and transmit it through the optical fiber cable 5.

(c) Prior Art and Problems Main signal transmission between stations is not limited to just one line, but may involve multiple lines placed in parallel. FIG. 2 shows its block diagram. Conventional OW signal transmission and reception will be explained below using FIG.

Figure 2 shows OM between stations that have a conventional example of optical terminal equipment.
1 is a block diagram of a system illustrating signal transmission and reception; FIG.

In the figure, numerals 24 to 29 indicate tip station equipment, 30 to 35 indicate an OW unit, and 1-136 indicates an optical fiber cable.

As shown in FIG. 2, each station has a plurality of yL terminal devices 24 to 26.
．． In a system having 27 to 29, it is unknown to have OW units 30 to 32 and 33 to 35 for each number of times, and it is sufficient to install one in each station. However, if only one specific line is used to transmit the OW multiplied signal, if that line happens to become a failure, the OW multiplied signal cannot be transmitted. For this reason, conventionally, as shown in FIG.
Since it has 35, it has the disadvantage of being uneconomical.

(d) Object of the Invention In view of the above-mentioned drawbacks, the object of the present invention is to provide an economical Toratsukugo transmission system.

(e) Groove formation of the invention In order to achieve the above object, the present invention has the following features:
The OW multiplied signals from the OW units are transmitted superimposed on the main signal of each terminal device, and the normal signals received by each terminal device are extracted to the receiving station. The present invention is characterized in that means is provided for selecting one of the W signals, and the selected OW multiplied signal is received by one 0W unit.

(f) Embodiment of the Invention An embodiment of the present invention will be explained below with reference to the drawings.
FIG. 4 is a block diagram of a system showing transmission and reception of an OW signal of IJ, which is received from a normal transmission line in the embodiment of the present invention. lol
FIG. 2 is a block diagram mainly consisting of a circuit that selectively receives one of the signals.

37. Components in the figure that have the same functions as those in FIG. 2 are indicated by the same symbols.
38 is a switching circuit with the same function, 39 is a D/A converter, 40
is a telephone, 41 to 43 are AND circuits, 44 is an OR circuit,
45 and 46 indicate the V circuit, and rlI to r13 indicate the ALM contacts of the alarm relay that issues a visual report when the receiving state becomes abnormal.

For the contents of OW Units) 30 and 33 and the contents of the optical terminal equipment, use Figure 1, and change the O from A station to B station in Figure 3.
The telephone 20 of the OW unit 3 in FIG. The OW transmission signal 1 is converted into a digital signal by the A/D converter 18, and sent to the code conversion circuit 7 shown in FIG. 1 of each optical terminal equipment 24 to 25 shown in FIG. The inserted service bit is transmitted to station B together with the main signal. At the B station, each of the 0W signals is extracted from the code demodulation circuit 16 shown in FIG. The switching circuit 38 selects one t'' of the OW multiplied signals extracted from the normally transmitted signal and sends it to the OW unit 33.
The signal is converted into an analog signal and sent to the telephone 23.

By doing this, the OW unit is set to 1 for both stations B and B.
Even if one of the lines becomes abnormal, it will work without any problem.
Can send and receive double signals.

Next, the switching circuit 38 will be explained using FIG. 4. The advanced station devices 27 to 29 constantly monitor whether optical signals are being received normally using detection circuits for detecting frame synchronization signals, code errors, input disconnections, etc., and issue an alarm if there is an abnormality. signal! Jl/-'f: tb is activated and the ALM contacts (rl, ~r13) are closed. This ALM contact rl,
~ AND circuit 4 in the switching circuit 38 for the signal line from rim
Connect to numbers 1 to 43. This ALM contact rll~rl
The signal line from B is ij: H level when normal, and L level and null when abnormal. Therefore, if the optical terminal devices 27 to 29 are normal, the optical terminal device 27 is used. w signal is a/
code circuit 41. D/A of OW unit via OR circuit 44
The signal is sent to the converter 39, where it becomes an analog signal and is sent to the telephone set 4o.

Now, for example, if the optical terminal equipment 27 becomes abnormal, the ALM contact rl
l is closed, and the cyanode circuit 41 is blocked.

Therefore, in this case, the 0W (i number) via the optical terminal device 28 is sent to the D/A converter 39 via the AND circuit 42 and the OR circuit 44, and becomes an analog signal and is sent to the telephone 4o. OW extracted from the received signal
Select one from the doubled signals and send it to the OW unit.

As explained above, in the method of the present invention, both A and B stations are equipped with just one OW unit, and even if one of the lines becomes abnormal, OW multiplied signals can be transmitted and received without any trouble, and the switching circuit 37.38 is necessary, but overall it is economical.

(g) Effects of the Invention As explained in detail above, according to the present invention, the main signal is
O between stations with multiple terminal equipment that transmits double signals by superimposing them
When transmitting the W signal, each station uses one OW unit, and even if one of the transmission lines becomes abnormal, the OW multiplied signal can be transmitted and received without any problem, which has the effect of economically performing and refining the OW signal transmission.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an optical fiber transmission system, Fig. 2 is a system diagram showing transmission and reception of communication lines between stations having a plurality of conventional optical terminal equipment, and Fig. 3 is an optical fiber transmission system diagram of an embodiment of the present invention. FIG. 2 is a block diagram showing an arrangement between stations having a plurality of terminal equipment. In the figure, 1, 2, 24-29 are optical terminal equipment, 3, 4, 30-
35 is a meeting line unit, 5 and 36 are optical fiber cables, 6 and 12 are input interface circuits, 7.13 is a code conversion circuit, 8 and 14 are electric '◆ and original conversion circuits, 9 and 1
5 is output/Tough Ace circuit, 10.16 is code compound circuit, 11.17 is optical/electric conversion circuit, 1.8.21 is analog/digital converter, 19, 22゜39 is digital/analog converter , 20, 23.40 is a telephone, 3
7.38 is a switching circuit, 41 to 43 are AND circuits, 44 is an OR circuit, 4-5 and 46 are NOT circuits, r11 to r1
3 is the contact point of the alarm relay.

Claims (1)

[Scope of Claims] Between stations that have multiple terminal devices that superimpose and transmit a communication line signal on a zero main signal, the transmitting station transmits one D line signal from one Ni line unit to each station. The S unit is transmitted by superimposing it on the main signal of the terminal equipment, and the receiving station is provided with a means for selecting one of the stamping line signals extracted from the normal signals received by each terminal equipment. A meeting line signal transmission system characterized in that a selected meeting line signal is received by one meeting line unit≦− port.