JPS6083439A - Optical multiplex transmission system - Google Patents

Abstract

PURPOSE:To reduce the quantity of optical cables and to obtain a transmission line for two routes by laying one multicore optical cable in a loop. CONSTITUTION:This system uses optical cables as many as or more than optical multiplex transmitters. Optical cables 3 are laid in loop form circulating from and to a reception side 1B through all optical multiplex transmitters 1A. The optical cables 3 are sheathed in the transmitters 1A, only cores assigned to the devices are cut selectively, and other cores are not cut. Those cut cores are connected to the transmitters 1A to double the laid route by using one cable.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an optical multiplex transmission system, and particularly to an optical multiplex transmission system suitable for optical multiplex transmission when target signals are scattered over a wide area. Regarding.

[Background of the invention]

Conventionally, when performing optical multiplex transmission, a signal transmitted as shown in FIG. 1 is once transmitted to an optical multiplex transmission apparatus IA via a copper cable 2, which is a general cable, and is converted into an optical signal there. This converted optical signal is transmitted to the receiving side optical multiplex transmission equipment IB via an optical cable. This time, optical multiplex transmission equipment IB
The signal is returned to an electrical signal and transmitted to the receiving device 4B. This configuration realizes a single electric circuit. In this case, if the number of electrical circuits to be targeted is small, even if optical multiplex transmission is implemented, the additional optical multiplex transmission equipment will cost more than the hooked cables that will be removed, and the system will not be effective. If more electrical signals are optically multiplexed and transmitted, it can become an attractive system from a cost perspective, since it requires less copper cables.

The next issue to consider is the placement of the devices 4A and 4B that emit electrical signals to be optically multiplexed.

No matter how many electrical signals there are, if they are not concentrated and are widely scattered, a little here and a little there, the copper cable 2 connecting the optical multiplex transmission device IA and the equipment 4A may become longer. That's too sweet. The fact that the copper cable 2 becomes longer means that the proportion of the copper cable that can be replaced by the optical cable 3 decreases, which means that the merits of optical multiplex transmission are reduced. On the other hand, when the target electrical signals are concentrated, the copper cable 2 can be shortened by arranging the optical multiplex transmission device 1A near the device 4A that outputs the electrical signals. Therefore, the advantage of optical multiplex transmission is that the proportion of copper cables that can be replaced by the optical cable 3 is large.

Based on the above, the decision to apply optical multiplex transmission is made as shown in Figure 2. When taken along the axis, the shaded area in Figure 2 is said to have good freezing conditions.

That is, the use of the optical multiplex transmission device is effective when the following inequality holds true.

Here, Ll: Copper cable length before optical multiplex transmission L2□:
Length L2□ of the copper cable between 4A and IA in Figure 1: Length of the copper cable between 4B and IB in Figure 1, : Length of the optical cable A, , A, , A, , A, : LrIL2゜) L
2m; Unit price of L3p cable A: Unit price of optical multiplex transmission equipment q: Number of optical multiplex transmission equipment Indicates the degree of concentration of electrical signals.
p+ΣAQ)/(ΣA,・Lrl:] If the width becomes larger, no matter how large the number of target electrical signals becomes, the merits of optical multiplex transmission will not come out.On the other hand, as a constant proportional to the electrical signals, Considering B-Σn・L, /ΣA, this is 1 / (1-(ΣAeL2a+ΣA.'L2m+Σ
A p−L sp ) / (Σn・L, )] When the distance becomes smaller, there is no advantage of optical multiplex transmission no matter how concentrated the target signals are. FIG. 2 shows this relationship.

If we rearrange the above equation using A and B, we get: In the prior art, since one optical fiber is used for a fixed electrical signal amount, it is not possible to lower the ratio of Σn·L3p to ΣA,·L below a certain amount. for example,
In the case of 256 points, the maximum number of electrical signals in one optical fiber is 256 points.

In this case, if the copper cable 2 connects at four points on average, 64 copper cables will be used. Therefore, the scope of application of optical multiplex transmission has been narrowed.

[Purpose of the invention]

The purpose of the present invention is to increase the running cape/L"q amount of 6 times, 3 at ?
χmultiφ4Sunoshiλfu4seoriyasu5koto/: * , 3
.

[Summary of the invention]

Optical fibers that transmit light are very thin, less than 1 mm in diameter, and lack mechanical strength on their own. Therefore, when combining them into an optical cable, a core material such as a steel core or high-tensile cablastic fiber is required as a tension member. . A cable sheath material is also provided to protect the outside surface and to facilitate cable installation. Therefore, the optical cable 3 is connected to the tension member 11 as shown in FIG. Spacer 12.
Optical fiber 13 for transmitting light and sheath 1 for protecting the outer surface
It consists of 4. From these points, when combining optical cables, there is not a huge difference in cost between multi-core and single-core optical cables.At the very least, it is better to install a four-core optical cable than a single-core optical cable. It can be said that it is much more economical than installing four cables.

This fact is one of the points of focus of the present invention.

Secondly, in the case of optical cables, although there is attenuation due to its length, it is negligible compared to the voltage drop that occurs with ordinary copper cables, and there are fewer restrictions on the length of installation. Since there are few restrictions on the length, it is not necessary to make the optical cable installation route as short as possible, and other considerations must be taken into account. That is, as in the optical multiplex transmission device 1, multiplexing may be performed in the optical cable 3 to improve reliability. The braided optical cable 3 in which the optical multiplex transmission equipment 1 is multiplied (for example, 21 cables) is also 2.
It is hoped that this will worsen. At this time this optical tape/173
One solution is to make a multi-core cable and use its two core wires, but in that case, the installation route is not duplicated and there is only one cable. Therefore, if you try to duplicate the system by changing the installation route, you will need two optical cables.

The present invention provides a method under such conditions, by laying one multi-core optical cable in a loop shape, thereby achieving a 2N cable in the installation route casing using one optical cable. For this purpose, an optical cable having the same number of fibers as or more than the number of optical multiplex transmission devices constituting the loop is used.

These nine cables are laid in a loop starting from the receiving side, connecting all the optical multiplex transmission devices, and returning to the receiving side. Inside the optical multiplex transmission device M, the sheath 14 of the optical cable 3 is removed, but the optical cable 3 is not cut. With the sheath 14 removed, each core wire can be identified, so only the core wire applied to the optical multiplex transmission device is selected and cut, and the other core wires are not cut. Connect this cut core wire to an optical multiplex transmission device. The present invention can be carried out by curing the remaining core wire from which the sheath 14 is removed using tape or a heat-shrinkable tube.

The situation is shown in FIGS. 7 and 8.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 4 to 7. FIG. 4 shows an example of optical multiplex transmission according to the prior art. This figure will be explained in relation to FIG. 1. In FIG. 1, the signals to be optically multiplexed and transmitted are individually shown as 4A, but in FIG. 4, the entire area in which these signals exist is shown as 401 to 410. Similarly, the area where the receiving side device 4B exists is shown as 420. The signals existing in each area are transferred using general copper cable 2.
a leads to the optical multiplex transmission equipment IA. There, the signal is processed and transmitted to the optical multiplex transmission device IB on the receiving side via the optical cable 3, where the signal is converted and transmitted to the equipment 4B in the area 420 via the copper cable 2b.

In FIG. 4, a large-capacity optical multiplex transmission device IA is used, so the optical cable 3 is short and the copper cables 2a and 2b are long. That is, the second
Corresponding to the hypothetical region shown in the figure (an example where the signal to be optically multiplexed is thick, but the signal arrangement is dispersed),
The benefits of optical multiplex transmission are not being fully utilized.

FIG. 5 shows an example of optical multiplex transmission according to the same prior art, but in this case, an optical multiplex transmission device IA with a small capacity is selected and installed in each area.

In this case, there is a disadvantage that the optical cable 3 is long. Particularly when there are restrictions on the route of the optical cable 3, there is a drawback that the route becomes longer.

FIG. 6 shows an embodiment of the present invention. FIG. 7 shows details of the installation of the optical cable 3 in FIG. 6. Area 40 in Figure 7
Only numbers 7 to 410 are shown. As you can see from Figures 6 and 7, in this case, only one optical cable is required.
Moreover, there is an effect that communication can be carried out in two directions through one optical multiplex transmission device IA. In other words, in the example of FIG. 7, for area 409, the connector of optical multiplex transmission equipment IB!
10ai, the route and connector 1 connecting to the optical multiplex transmission device IA using the optical fiber core wire 13d of the T cable 3'
Two routes can be taken through 10b.

If this was attempted using the conventional technology, it would be necessary to repeat the process once at the optical multiplex transmission device, which is considered undesirable for optical signal transmission. The platform of the present invention can provide 2-1:) transmission paths for the number of optical multiplex transmission devices using one optical cable 3 without relays.

Optical multiplex transmission equipment for realizing this installation method
The method for processing the optical cable 3 in A is shown in Figure 8. The original cable 3 is protected with a conduit 101 and the optical fiber transmission equipment panel 1
Pull in to 04. Optical cable treatment plan 1 for this pulled-in H block
Since 06 is provided, cut the optical cable L4 to a sufficient length and connect the optical 7 eye for the optical multiplex transmission device 1 of this board (cut only the core wire 13 and connect the optical cable installed in the device L). Connect it to the connector 110.The optical cable 3 whose sheath 14 has been peeled off is provided with a tape 111 to protect the optical fiber core 13 other than the above.This allows the 91 original cables to be connected to the connector 110. 3 can be connected to the next optical multiplex transmission device IA without disconnecting the optical fiber.

〔Effect of the invention〕

As described above, according to the present invention, 1. Only a minimum number of optical cables are required, and two transmission routes can be easily provided.

2. If the number of electrical signals to be optically multiplexed and transmitted is more than a certain number, it will not be affected by the placement field Phf of the signals, and the range of applications of the optical multiplexed transmission system will be expanded.

3. In other words, it is possible to maximize the severity of copper goople reduction.

There is an effect.

[Brief explanation of drawings]

Figure 1 is a wiring system diagram showing an overview of the optical multiplex transmission system, Figure 2 is a characteristic diagram showing the decision whether to apply the optical multiplex transmission system, and Figure 3 is a diagram showing the structure of the optical cable. Figure 4 and Figure 5 are a system diagram of a conventional optical multiplex transmission system, Figure 6 is a system diagram of an optical multiplex transmission system that is a preferred embodiment of the present invention, and Figure 7 is a system diagram of a conventional optical multiplex transmission system. , an explanatory diagram showing the connection state of the optical cable in Fig. 6, and Fig. 8 a conceptual diagram showing the connection state of the optical cable in the optical multiplex transmission system shown in Fig. 6. 1... Optical multiplex transmission device, 2...・Cold cable, 3...
・Optical cable, 4... (Electricity to be optically multiplexed (transmits G signal) 4U!'i=, 11... Tension cable (, 12... Spacer, 13... Optical fiber core wire, DESCRIPTION OF SYMBOLS 14... Sheath, 401-410... Area with electrical signals, 420... Area that receives electrical signals, 101... Conduit, 102... Lock nut, 1
03... Bushing, 104... Optical multiplex transmission equipment panel, 105... Partition plate, 106... Optical cable processing plan, 107... Optical multiplex transmission equipment storage room, 108... Copper cable connection space , 109... Terminal block for connecting copper cable, 110... Optical cable No. 1 Figure $ 2 Eye 8. 111 Z/h Kaya 3 Fixture 4 Figure 41 θ No. 2 Tachibana et al. (2)

Claims (1)

[Claims] 1. In an optical multiplex transmission system consisting of multiple optical multiplex transmission devices, each optical multiplex transmission device is connected to a multi-core optical cable with the same or more number of fibers as the number of optical multiplex transmission devices excluding the receiving side. An optical multiplex transmission system characterized by being installed in a loop that crosses the fibers.