JPH0746182A - Optical cable network - Google Patents

Abstract

(57) [Abstract] [Purpose] It is possible to realize a wiring configuration in which the number of branch connection points for subscriber wiring is sufficiently increased and the number of core connection portions in the transmission line to the subscriber is sufficiently small. Provide an optical cable network. [Structure] A long-span cable 1 used for communication or the like is arranged, and a short-span cable 2 is arranged along the long-span cable 1. The long span cable 1 is provided with a plurality of cable coupling portions 3 for connecting the long span cable 1 to the short span cable 2, respectively. Short span cable 2
A plurality of branch wiring units 6 are provided which are connected to subscribers for optical communication and the like.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical cable line network for connecting a long span cable used for optical communication or the like and a subscriber for optical communication or the like.

[0002]

2. Description of the Related Art In recent years, due to the progress of optical communication technology, introduction of optical cables into subscriber systems including general households as well as relay systems connecting stations for optical communication has been studied. For example, as an optical line from a station to a subscriber, like a metal line, a thick bundled base line cable, a wiring cable branched from this base line cable, and a core wire of this wiring cable formed in the middle of this wiring cable. An optical line consisting of a branching part for branching and a connecting part for wiring to a subscriber is being considered.

In the present situation where the demand for optical fiber communication is low, subscribers can only be expected from general companies, and therefore, direct access from a base line cable to a subscriber's building is carried out. Therefore, the base line cable is often laid as loop wiring through a building street where demand is expected to be higher. This loop wiring is a form in which the cable exiting from the station is finally routed back to the station again, while the wiring form in which the cable does not return to the station is called star wiring. This star wiring is used in areas where loop wiring is uneconomical.

The optical fiber core wires in the base line cable are connected to each other by an optical connector for performing connection change and a splice for connecting the optical fiber core wires without assuming the connection change. Regarding the replacement of the connection between the optical fiber cores, in general, the manual work of the optical connector has been prioritized, and the splicing is used for the reconnection as necessary.

[0005]

By the way, since the base line cable is usually routed through an underground pipe, a branchable cable contact (hereinafter, referred to as a branch contact) is located at a place other than a manhole. I can't make it. Therefore, when wiring from the base line cable, there is a problem that the place where the base line cable can branch is limited.
Furthermore, if a branch connection point is provided for each manhole, the connection cost will be high, and the optical loss due to passage through the branch connection point will be large, which is not desirable in terms of transmission characteristics. The current situation is that only one is provided.

Wiring to a subscriber near the branch connection point is easy, but if the subscriber is located far from the branch connection point even if the subscriber is near the installation route of the base line cable,
Since it is necessary to lay a new base line cable from the branch connection point to the building, there is a problem in that it has high responsiveness and costs are high. That is, even when the installation route and connection point position of the base line cable are carefully selected, the positions of the subscribers are often scattered, and an efficient wiring form has been desired.

[0007] Further, as another coping method when wiring to a building far from the branch connection point, when the outer sheath of the base line cable is stripped off in a nearby manhole and a part of the optical fiber core wire of this base line cable is pulled out for branch connection There is also. In such a case, since there is no choice but to touch the optical fiber core wire in the communication service, there are problems that an artificial communication failure often occurs, and that it takes a long working time.

That is, if the number of branch connection points is increased, the wiring work to the subscriber becomes easy, but the cost for laying the base line cable becomes high, and the optical connection loss becomes large. On the other hand, if the number of branch connection points is reduced, there is a problem that the wiring work to the subscriber becomes difficult, the responsiveness is increased, and the cost at that time is increased. Due to such a relationship, in the conventional optical cable line network, the number of branch connection points for wiring to the subscriber must be limited.

The present invention effectively solves the above-mentioned problems. In order to shorten the wiring to the subscriber, the number of branch connection points for the subscriber wiring is sufficiently increased and the core in the transmission path to the subscriber is reduced. An object of the present invention is to provide an optical cable line network capable of realizing a wiring form in which the number of line connection portions can be limited to a sufficiently small number.

[0010]

In order to solve this problem, in the optical cable line network of the present invention, a long span cable used for optical communication or the like is arranged, and a short span cable is arranged along the long span cable. A plurality of cable connecting portions that are arranged in parallel and that connect the long-span cables to the short-span cables, respectively, and the short-span cable is connected to a subscriber for optical communication or the like. Are arranged. Further, the cable coupling section may be the branch wiring section.

[0011]

In the present invention, the light of the long-span cable passes through the cable coupling portion and the short-span cable. Light passing through this short span cable is transmitted to each subscriber or the like through the branch wiring section. That is, the subscriber or the like is connected to the cable coupling portion via the branch wiring portion of the short span cable closest to the subscriber or the like. Therefore, it is possible to connect to the cable coupling portion closest to the subscriber without passing through the short-span cables between the cable coupling portions, so that the number of branch wiring portions through which light passes can be reduced. . on the other hand,
By sufficiently shortening the interval between the branch wiring portions of the short span cable, the wiring section between the subscriber and the branch wiring portion of the short span cable is shortened, and the work of pulling the wiring to the subscriber is facilitated.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of the present invention. Although FIG. 1 shows star wiring, loop wiring may be used. In the figure, reference numeral 1 is a long-span cable, 2 is a short-span cable, and 3 is a cable coupling portion that connects the long-span cable 1 and the short-span cable 2 to each other. The long-span cable 1 is provided with a plurality of cable coupling parts 3 at predetermined intervals from a station 4 for optical communication, and a short-span cable 2 having both ends connected to the cable coupling part 3 is provided. They are juxtaposed along the long-span cable 1. An optical base line cable is composed of the long span cable 1 and the short span cable 2.

Between these cable coupling portions 3, one end is connected to one of the adjacent cable coupling portions 3, and
The short-span cable 2 that connects the other end to the other of the cable coupling portions 3 is arranged. In this short span cable 2, a plurality of branch wiring portions 6 connected to a wiring cable 5a from a subscriber 5 or the like are arranged at predetermined intervals.

The long-span cable 1 and the short-span cable 2 are accommodated in a cave or the like in parallel. A plurality of manholes 7 for allowing people to enter and exit are arranged in the cave, and the cable connecting portions 3 are provided at the positions of the manholes 7.
Is provided, and the branch wiring portion 6 is provided in the manhole 7 located between these cable coupling portions 3. In the figure, the station 4 and the cable coupling portion 3 are short-span cables 2
However, the short-span cable 2 may be directly connected to the station 4 by providing the station 4 with the manhole 7.

Although there are only three cable coupling portions 3 in the figure, the number of cable coupling portions 3 may be 5 or 10. The short-span cable 2 is not provided on the station 4 side of the cable coupling portion 3 close to the station 4, but in this case there is no manhole 7 on the station 4 side, so there is no effect of laying the optical base line cables in parallel. However, it is desirable to increase the number of cores accommodated in the long span cable 1 from the station 4 to the cable coupling portion 3 in consideration of the short span cable 2. If a large number of manholes 7 are located between the station 4 and the cable connection 3, it is possible to install optical baseline cables in parallel up to the station 4. In that case, the main wiring board in the station 5 shares the role of the cable coupling part 3.

Therefore, the wiring from the station 4 to the subscriber 5 goes from the station 4 through the long span cable 1 to the nearby cable coupling portion 3 and from there through the short span cable 2 for the subscriber 5. It is possible to go to the branch wiring section 6 and further to be led to the subscriber 5 from here through the wiring cable 5a. While passing through the long-span cable 1, the connection loss is small because it only passes through the connection part at the cable coupling part 3 installed at a long interval. Therefore, the branch wiring part 6 is installed in the short-span cable 2. Even if the interval is short, the transmission line loss from the station 4 to the subscriber 5 does not become so large. Therefore, since the installation interval of the branch wiring section 6 can be made sufficiently short, the wiring work up to the subscriber 5 can be easily performed.

As shown by the solid line in FIG. 2A, the cable connecting portion 3 connects the long-span cables 1 to each other, and the long-span cable 1 and the short-span cable 2 are connected together.
And connect. Here, in the case of star wiring, at least the long-span cable 1 and the short-span cable 2 need to be connected to the long-span cable 1 on the side closer to the station 4 and the short-span cable 2 on the side far from the station 4. is there. Further, for both the star wiring and the loop wiring, the auxiliary connection shown by the broken line in the figure is useful in operation. When the short span cable 2 is provided only on one side, as in the cable coupling section 3 near the station 4 shown in FIG. 1, the connection function may naturally be small.

Here, FIG. 2B shows a configuration diagram of a specific example of the cable coupling portion 3. As shown in FIG. 2B, the cable connecting portion 3 includes a loop connection board 10 to which all the optical fiber core wires in the cable connecting portion 3 can be connected, and the optical fiber core wires of the long span cable 1. A straight connection board 11 for connecting 1a is housed. Optical connector adapters 10a and 11a are attached to the loop connection board 10 and the straight connection board 11, respectively.
On the other hand, connector plugs (not shown) are attached to the optical fiber core wires 1a and 2a of the long span cable 1 and the short span cable 2, and these connector plugs are attached to the adapters 10a and 11a of the optical connector. .

Here, a part of the optical fiber core wire 1a of the long span cable 1 is attached to the straight connection board 11, and the other part of the optical fiber core wire 1a of the long span cable 1 is attached to the loop connection board 10. There is. A switching fiber 12 for switching the connection of the optical fiber core wires 1 a and 2 a of the long span cable 1 and the short span cable 2 is attached to the loop connection board 10. Connector plugs are attached to both ends of the switching fiber 12, and by switching the connector plug to the adapter 10a of the optical connector of another loop connection board 10, the switching fiber 12 can be switched to another optical fiber core wire. Therefore, all the optical fiber core wires are switched by the switching fiber 12. Then, by forming a thick film that covers the core wire of the switching fiber 12, it is possible to make it difficult for the propagation light to fluctuate due to being touched by the hand. Therefore, the switching fiber 12
Since the connection can be exchanged by simply replacing it, it is possible to prevent the occurrence of an artificial failure such as contact with the optical fiber core wire in the service such as maintenance and inspection work.

It should be noted that a large number of optical fiber cores 1a of the long span cable 1 may be connected to the loop connection board 10 so that the necessary connection can be changed only by replacing the optical fiber cores. As the number of subscribers increases thereafter, the optical fiber core wire 1a of the long span cable 1 is replaced with the optical fiber core wire 1a of the short span cable 2. For example, if the straight connection board 11 is eliminated and all the optical fiber core wires 1a of the long span cable 1 are connected to the loop connection board 10, the optical fiber core wires 1a of the long span cable 1 are connected to the optical fibers of the short span cable 2. It is possible to change the connection to the core wire and cope with the increase in the number of subscribers. However, if it goes through the loop connection board 10, the cable connecting part 3
Since the connection is made in two places, the connection loss is doubled as compared with the case where the straight connection board 11 is used. Therefore, the straight connection board 11 and the loop connection board 10 may be used.

If it is substantially unnecessary to change the connection from the straight connection board 11 to the loop connection board 10, the straight connection board 11 is connected by an inexpensive splice without using an expensive connector. May be. Further, if an automatic switching device is used for switching operation of the loop connection board 10, the switching operation can be automated and remote control can be performed. As this automatic switching device, the optical fiber core wire switching device described in Japanese Patent Application No. 5-121064 can be used. In this optical fiber core wire switching device, it is possible to connect between all terminals without distinguishing between the input terminal and the output terminal. If this optical fiber core wire switching device is used, the wiring work to the subscriber is limited to the work of the branch wiring section 6 in the manhole 7 close to the subscriber and the wiring work from the branch wiring section 6 to the subscriber. The
Wiring work can be speeded up.

Further, if a large number of loop connecting boards 10 are arranged in the cable connecting portion 3, even if the demand is concentrated on the cable connecting portion 3, the cable connecting portion 3 can deal with the demand.
Therefore, it is possible to reduce variations in demand in the plurality of cable coupling portions 3. With the structure in which the straight connection board 11 is eliminated, even if the demand concentrates on one cable connecting portion 3, this can be covered.

Next, the branch wiring unit 6 for branching the subscriber will be described with reference to FIG. As shown in FIG. 3, the branch wiring section 6 is formed in a box shape, and the branch wiring section 6 has a pair of short span cables 2 and a wiring cable 15 for subscribers.
And a straight connection board 11 for connecting the optical fiber cores 2a of the pair of short span cables 2 to each other, and a branch connection for connecting the optical fiber cores 2a of the short span cable 2 to the optical fiber cores 15a of the wiring cable 15. A board 16 is provided. The box-shaped branch wiring portion 6 has a cable mounting port 6a for mounting another wiring cable formed in the lower portion thereof, and the wiring cable 15 is disposed near the cable mounting port 6a. Straight connection board 15 and branch connection board 1
An optical connector 11 for connecting each optical fiber core
Many a and 16a are arranged.

Since the branch wiring section 6 does not require the switching fiber 12 as compared with the cable coupling section 3, the branch wiring section 6 can be manufactured at low cost, but the branch wiring section 6 does not use the optical fiber core wire switching device. Is difficult to automate. However, since the branch wiring section 6 is generated along with the installation work of the wiring cable 15 by the subscriber, even if only the connection change is automated, it is not effective in speeding up the wiring work. do not become. As for the structure of the branch wiring portion 6, it is sufficient that the optical fiber core wires 15a, 2a of the wiring cable 15 and the short span cable 2 can be connected to each other, and the long span cable 1 shown in FIG. The short span cable 2 may be used instead, and the wiring cable 15 may be used instead of the short span cable 2 shown in FIG.

No matter what the structure of the branch wiring section 6 is, the short span cable 2 on both sides is added to the wiring cable 15.
It is sufficient to have a structure in which the core wires can be connected to each other. This way
Since it is possible to wire to the subscriber 5 from both cable joints 3, even if the long span cable 1 has a different route,
Two completely independent paths are wired up to the branch wiring section 6, which is advantageous for ensuring reliability. Also, the demand is 2
Since it can be distributed to the three cable joints 3, it is highly resistant to variations in demand. Furthermore, if the cable joints 3 can connect the short span cables 2, the demand can be distributed to more cable joints 3.

According to such an optical cable line network, a plurality of cable coupling portions 3 for connecting the long span cables 1 to the short span cables 2 are arranged in the long span cable 1 used for optical communication and the like. , Can be wired to the subscriber from both adjacent cable coupling portions 3, and two independent paths are wired to the branch wiring portion 6, so that the reliability of wiring of the long span cable 1 can be secured. Further, since the demand can be distributed to the two cable coupling portions 3, it is possible to deal with the variation in demand. Since the plurality of branch wiring portions 6 connected to the long span cable 1 are arranged in the short span cable 2, the subscribers can be finely dispersed and wired through the branch wiring portions 6.

(Second Embodiment) Next, a second embodiment of the optical cable line network of the present invention will be described with reference to FIG. Figure 4
2, the second embodiment has a structure in which the subscriber wiring cable 15 is attached to the cable coupling portion 3 of the first embodiment shown in FIG. 1 to form a branch wiring portion. That is, the optical fiber core wire 15a of the wiring cable 15 is connected to the loop connection board 10 in the cable coupling portion 3, and the optical fiber core wire 1a of the long span cable 1 is connected via the loop connection board 10 and the switching fiber 12. It is connected.

Since the cable connecting portion 3 is used as the branch wiring portion in this way, the wiring cable 15 is connected to the cable connecting portion 3.
Can be directly connected to the long span cable 1. For this reason, the wiring cable 15 of the subscriber can be wired without excluding the manhole 7 having the cable coupling portion 3, and the wiring work of the wiring cable 15 is further facilitated.

In the above embodiment, the wiring cable 15
Was connected to the loop connection board 10, but the wiring cable 15 may be connected to the straight connection board 11. In such cases,
It becomes difficult to connect to both the optical fiber cores 1a and 1a of the long span cable 1, but there is no problem in star wiring because the connection partner of the long span cable 1 on the station 4 side is determined. Further, the wiring cable 15 branched from the cable coupling portion 3 may be composed of a long span cable and a short span cable. In such a case, the distribution cable 15 is used to distribute the distributed subscribers far.

In the above embodiment, the long-span cable and the short-span cable are each provided in one line, but at least one of the long-span cable and the short-span cable may be provided in a plurality of lines. Further, in the above-mentioned embodiment, the long span cable 1 and the short span cable 2 are arranged in parallel as a whole, but the long span cable 1 arranged at a point distant from the station 4 is provided.
The short span cables 2 may be partially provided side by side. For example, the optical cable line network may be arranged in a wiring system branched from the conventional base line cable. In this case, it is effective when the distribution cable is long and distributed to many subscribers.

Furthermore, the optical fiber core of each cable is
A single core wire having a structure in which a single optical fiber is coated may be used, or a tape core wire having a structure in which a plurality of optical fibers are collectively covered may be used. In such a case, a multicore-to-single-core conversion optical cord having a multicore connector at one end and a plurality of single core connectors at the other end may be mounted on a long span cable. This optical code may be used instead of the switching fiber 12 shown in FIG. At this time, the connectors of the loop connection board 10 include both single-core connectors and multi-core connectors. Even if a tape core wire is used for the short span cable and a single core wire is used for the wiring cable, the conversion optical cord may be similarly mounted in the branch / branch wiring portion for the subscriber.

[0032]

As described above, according to the optical cable line network of the present invention, long-span cables used for optical communication are arranged, and short-span cables are arranged in parallel along the long-span cables. A plurality of cable coupling parts for connecting the long span cables to the short span cables respectively are arranged on the long span cable, and a plurality of branch wiring parts connected to a subscriber for optical communication etc. are arranged on the short span cable. Once installed, the long-span cable transmits light and the short-span cable connects to the subscriber. Therefore, the long-span cable and the short-span cable can be divided into roles, the long-span cable and the short-span cable are connected to each other, and the short-span cable is transmitted to the subscriber through the branch wiring section. As a result, the optical loss transmitted to the subscribers can be reduced, and efficient wiring can be performed from the station to the subscribers. Therefore, it is extremely useful for large-scale introduction of optical fiber transmission lines expected in the future. Further, if the cable coupling portion is the branch wiring portion, it can be directly connected to the cable coupling portion, so that the cable coupling portion can be effectively used.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an optical cable line network of the present invention.

2A and 2B show the cable coupling portion of FIG. 1, in which FIG. 2A is a configuration diagram showing a concept, and FIG. 2B is a configuration diagram showing an embodiment.

3 is a configuration diagram showing a branch wiring section of FIG. 1. FIG.

FIG. 4 is a configuration diagram showing a cable coupling portion as a branch wiring portion according to the second embodiment of the present invention.

[Explanation of symbols]

 1 Long span cable 2 Short span cable 3 Cable coupling part 6 Branch wiring part

Claims (2)

[Claims] 1. A long-span cable used for optical communication or the like is arranged, short-span cables are arranged in parallel along the long-span cable, and the long-span cables are respectively provided with the short-span cables. An optical cable line network characterized in that a plurality of cable coupling portions connected to a span cable are arranged, and that a plurality of branch wiring portions connected to a subscriber for optical communication or the like are arranged in the short span cable. 2. The optical cable line network according to claim 1, wherein the cable coupling portion is the branch wiring portion.