JP2512009B2 - Optical fiber cable with memory and method of constructing optical fiber cable transmission line - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention provides a magnetic recording function to a coating layer of a coated optical fiber to automate work such as on-site connection work such as identification of fiber in a cable. The present invention relates to a high-performance optical fiber cable to be obtained and a method for constructing an optical fiber cable transmission line using the optical fiber cable.

[Problems to be solved by the prior art and the invention]

Recently, various optical fiber cables have been developed. It has been put to practical use. Not only relay systems but also subscriber systems are in full swing, and many types and many optical fiber cables are being put to practical use, from tens of small-fiber cables to hundreds of multi-core cables. . In this case, as in the past,
It would be inevitable to raise costs if inspections during optical fiber cable manufacturing, construction and maintenance at the site were all done manually. Therefore, it is necessary to automate various operations such as inspection, construction, and maintenance to make it more practical and reduce costs. Considering the current state of the art from the viewpoint of labor saving work that occurs when configuring an optical cable route, there are the following problems.

First, in order to clarify the work that should be labor-saving, an outline of the construction at the site will be explained. FIG. 5 shows an example of an optical fiber route for subscribers. One telephone station and two subscriber terminals are connected by an optical fiber. 3 is a line cable from the station 1 and 4 is a wiring cable 5 is a service line for drawing one fiber core to a subscriber. The wiring cable 4 is branched from the feeder cable 3 as needed. In FIG. 1, it is an overhead cable that is connected and branched in a manhole 6 and pulled up on a utility pole. Further, a connecting portion 6'for drawing in to the other subscribers 7 in the building, a connecting portion 9 in the highway 8 and the like are provided as needed. As described above, the feeder cable 3 includes a fiber for a wiring cable that branches in the middle, so that the feeder cable 3 is a multi-fiber cable, and a cable having a maximum of several hundreds to 1000 cores has been developed. (Katsuyama et al. "Optical Fiber Cable for Subscribers and Wiring", Tsuken Jikho, Volume 35, P.763,
1986).

To construct such a route, lay and connect the required optical cables. As work at this time, there is (1) transmission characteristic inspection. Before laying the cable, inspect the transmission characteristics such as optical loss and grasp it as basic data.
After the installation, the optical loss of the cable is measured again, and if there is no change from the value before installation, it can be confirmed that the installation work was completed without problems. After laying, connect the cables to each other. At this time, if the light is emitted from the station 1 and the light emitted from the connection cable is monitored, the optical loss of the line can be measured. If the optical loss of the cable is subtracted from this value, the splice loss of the optical fiber can be inspected. If the cable laying and connection are repeated in this way, the construction of all lines is completed, and the transmission characteristic values of each fiber can be grasped. If it is obvious that the change in optical loss due to laying is small, it is not necessary to measure all cables, and it is possible to represent it with cable data before laying.
In any case, there is an operation to grasp the characteristics of each fiber after construction as data necessary for signal transmission.

(2) The connection work includes the following contents. For connection points, use a cable laying cable with a length of 500 to 800
m, wiring cable is about 800-1000m, average route length is 1-2km, wiring section 1-2km, so the number of connecting points is 2-4 places / feed line, 1-3 places / Wiring. Therefore, a feeder cable for one route requires a great deal of work to connect several hundreds of fibers at two to four locations. In this case, the fiber of the wire number to be connected is selected from the hundreds of fibers and the connection work is performed.

The above is the work at the beginning of the construction of the optical route, but new work is usually added after the construction. That is, at the beginning of construction,
In addition to the actual number of subscribers, we anticipate an increase in demand in the next few years, so we will lay cables with more fibers. After that, when demand occurs, (3) post-branch connection is performed.
This is shown in FIG. 6, for example, at an unbranched connection part, an unused fiber is taken out and connected to a new distribution cable 4 ', a new connection point 6 "is made, and a new subscriber 2'and a station are connected. In this branching work, at the connection point 6 ″, the core number for distinguishing the already used fiber and the unused fiber is identified, and the fiber to be connected is cut and removed. Starting and connecting with the wiring cable 4 ', and complicated work from the beginning of construction. At this time, the optical loss after the post-branch is given by the sum of the optical loss of the existing cable (station 1 to the connection point 6 ″) and the added line. The optical loss of the existing cable can be grasped from the inspection data at the beginning of construction. However, this refers to values such as the management book at the telephone office.
Therefore, (4) In the inspection after the expansion, the data reference is referred to the management book and manpower.

Further, when a new civil engineering work such as road construction or subway construction occurs on the optical route, the pipeline of the section may be removed. At this time, the optical cable of the section is removed and the connection with the optical cable of another route is performed. This is called (5) obstacle transfer. Also in this case, the inspection after the connection change is performed in the same manner as the inspection after the expansion.

With respect to these operations, the problems of the conventional optical cable will be described below.

As mentioned above, it is a multi-core feeder cable that requires much work. In a multi-core cable, several tens to several hundreds of optical fibers are mounted, but in order to make a cable with a small diameter and light weight, the optical fibers are made into a high-density cable. For this purpose, an optical cable has been developed in which optical fibers are arranged in a tape shape and the collectively coated optical fiber tapes are assembled (for example, JP-A-63-11905). FIG. 7 shows a sectional view of a 600-fiber cable as an example of a conventional optical fiber cable. In FIG. 3, 10 is an optical fiber cable, 11 is an optical fiber tape in which a plurality of optical fibers are arranged in parallel with each other in a tape form and collectively coated, 12 is an optical fiber, 13 is a plastic coating layer, 14 is a slot rod, 15
Is a slot, 16 is a unit tension member, 17 is a center tension member, 18 is a press winding, and 19 is a jacket. In this optical fiber cable 10, a plurality of slotted slots 15 each having a substantially rectangular cross section are provided spirally on a plastic rod, and a plurality of optical fiber tension members 11 are laminated in the slots to form a slot rod 14. , A cable structure in which several units are assembled around the central tension member 17.

This type of conventional cable has the following basic problems with respect to the field work in the previous term.

(1) Wire number identification When performing work such as inspection and connection of transmission characteristics, it is necessary to identify the wire number of the fiber in the cable.

In the conventional optical fiber cable, the wire number identification is provided with a colored portion 20 along the longitudinal direction at the end of the optical fiber tape 11. This is a method in which the fiber closest to the colored portion 20 is numbered 1 and the fiber line numbers are determined in order. That is, it was visually identified. This method is easy to identify for small-fiber cables with a few tens of cores, but for multi-core cables with a few hundreds to 1000 fibers,
Accurate identification is difficult in color identification, and it is difficult to perform identification in a short time. Further, it is expected that the connection will be automated in the future, but if the automatic identification by color is difficult and it takes a lot of time to identify the wire number, the merit of the automation becomes small.

(2) Management of transmission characteristics such as optical loss When it is necessary to refer to the transmission characteristics of an existing cable such as branching and transfer of obstacles after a branch, in the conventional optical fiber cable, check the fiber number and the value previously checked in the wire number comparison list. I had to record it and refer to it, and the workability was not good. In particular, in a multi-core feeder cable, information reference work becomes more complicated. This work is inherently unsuitable for mechanization and automation due to human labor.

As described above, the conventional optical fiber cable has poor workability for wire number identification during connection / inspection and transmission characteristic reference at the time of rear branch obstruction transfer, and work is complicated especially for multi-core feeder cables. It is difficult to carry out efficiently. Conventional optical cables have not taken any measures against this problem.

Therefore, it is necessary to eliminate human labor from the above work and automate the work in order to efficiently carry out the work, and as one method therefor, a method of giving a memory function to the coated optical fiber can be considered. Information about wire numbers, inspections, etc. is recorded on the recording medium, and each operation is automated by performing read / write as necessary, and the operation time can be shortened.

Table 1 shows the requirements for the coated fiber with memory, which is necessary to improve the efficiency of the various field work described above.

(1) Recording function conditions It is necessary to rewrite the memory after laying the cable, such as inputting optical loss data after the inspection. Further, from the viewpoint of workability, it is necessary to easily recognize the location where the memory is provided. As a matter of course, the transmission characteristics and mechanical characteristics of the coated optical fiber should not be deteriorated by adding the memory function.

(2) Cable manufacturing The fiber wire number must be written in the memory as data when the cable is manufactured. Further, in order to perform the post-branching work, the coated optical fiber is taken out at the cable intermediate portion and connected to another cable, so that the wire number is also identified by the core wire at the cable intermediate portion. Therefore, the wire number must be recorded over the entire length of the cable. This requires that the memory can be applied online and the wire number data can be applied over the entire length when the coated optical fiber is manufactured.

(3) Installation / Maintenance It is possible to read / write data such as optical loss before and after installation, and it is necessary that the memory contents do not change due to environmental changes after cable installation.

Considering the above requirements, none of the prior arts satisfies this requirement. An example in which a magnetic material is included in the coating of the optical fiber and the wire number is identified by magnetization (Japanese Patent Publication No. 56
Although the fiber number can be identified with this, refer to the transmission characteristics of the existing cable when inspecting the transmission characteristics at the beginning of construction or when connecting with another cable at the time of branching or trouble transfer. I had to make a manual comparison using a wire number comparison book. That is, there was no way to add these data. Also. Post-branch and obstacle transfer works will be added after the construction, but in this case the transmission characteristics will change for each work. However, the prior art has no means for adding or changing the memory contents.
Therefore, it has an essential problem that it is not effective in automating the construction work on site and reducing the labor cost.

An object of the present invention is to enable easy and automated core wire identification and inspection, which took a lot of time in conventional optical fiber cable construction work, and to cover transmission characteristic data necessary for additional work. It can be recorded on the optical fiber itself. It is an object of the present invention to provide an optical fiber cable with a memory and, in addition, to provide a method of constructing an optical fiber cable transmission line which can be quickly and manually omitted by using the optical fiber cable.

[Means for solving problems]

The most important feature of the optical fiber cable of the present invention is to provide the coated optical fiber with a data recording function and appropriately provide data to the memory section. The method of assigning data is different from the conventional technique. A method of constructing an optical fiber cable transmission line according to the present invention is characterized by using the above optical fiber cable.

To explain the present invention in detail, the coated fiber in the optical fiber contains a magnetic substance, and data can be recorded by this magnetization. As a data recording method, a memory section is formed over substantially the entire length of the coated fiber at substantially equal intervals without interruption, and signals indicating the beginning and end of the section are given to both ends of the section. In addition, the numbers (wire numbers) for identifying the fibers in the optical cable are recorded in advance in all the memory sections. The memory capacity in this memory section is set in advance so that data other than the wire numbers in the previous term can be additionally recorded. When the installation of the optical cable is completed and the fiber is connected, the wire number is recorded in every memory section of the coated fiber, so the data reader identifies the wire number of the fiber and automatically detects the pair of fibers to be connected. Can be screened. After connecting,
When light is input from the telephone station and the output light of the connected cable is measured, the total optical loss as the sum of the optical loss of the cable and the connection loss can be evaluated. This value is recorded by the writing device in the additionally recordable memory area of the coated fiber at the connection point. At this time, at the connection point, the cable jacket is stripped off so that connection work is possible, and the coated fiber is 50 to 100c.
About m have been taken out. It may be recorded in any memory section of the coated fiber, but in consideration of reconnection, it is preferable to record in the section closest to the cable side.

As described above, the wire number is recorded in advance on the coated fiber, and the optical loss value of the constructed line is additionally recorded on the coated fiber in the connection point after the connection is completed. With such an optical cable and construction method, even if post-branch or obstacle transfer work occurs after the construction is completed, the optical loss of the existing cable line can be automatically referred to by the reading device. This optical loss value serves as basic data for inspection of a newly laid cable after branching and evaluation of connection loss at the time of branching, compared to the case of referring to the value in the wire number reference book. It is suitable for automation and can save manpower. The optical loss value is recorded in the coated fiber contained within the splice closure, but is not visible to some point. Therefore, the reading device has a driving unit that moves the coated fiber, and reads the data recorded in the coated fiber. At this time, if only the wire number is recorded in the memory section, this is skipped and the data in the next memory section is read. Reading is continued until the section where the optical loss value is recorded in this way. Therefore, in the method of giving data to the coated fiber, it is essential that the section of only the wire number and the section in which the data is additionally recorded can be distinguished.

〔Example〕

<Embodiment 1> FIGS. 1A and 1B are views for explaining a first embodiment of the present invention. The cable structure is similar to that of Fig. 7,
The slot rod 14 is provided with a slot 15 into which the coated optical fiber is inserted. Fiber coating
An optical fiber tape (coated fiber) including 10 cores.
22 is an optical fiber strand, 23 is a tape coating layer of UV curable resin,
24 is a magnetic tape. In the optical fiber tape with memory function shown in FIG. 1, UV curable resin is applied to the optical fiber strands of 10 cores, and the magnetic tape 24 is radiated with ultraviolet rays in a vertically attached state to be cured together with the magnetic tape. Alternatively, it can be manufactured by applying an adhesive and adhering the cured optical fiber tape to the magnetic tape. The magnetic tape 24 may be similar to a high coercive force metal tape used for audio, and the coercive force is 1300 Oersted. The width of the magnetic tape also depends on the shape and size of the magnetic head, but is not particularly limited.

If the tape width is 1 mm or more, you can read and write with a product similar to the existing magnetic card read / write device, but if the width is too narrow, an error is likely to occur during read / write, so the entire surface of one side of the optical fiber tape It is desirable to attach it to. Assuming that the diameter of the optical fiber is 0.25 mmφ, the width of the magnetic tape attached to the optical fiber tape with memory in FIG. 1 is about 2.8 mm. The amount of recorded information does not depend on the width of the magnetic tape but on the length. Consider the data shown in Table 2 as the information required for various construction works. With the known technology, a linear density of 8 bytes / cm is possible with respect to the above-mentioned metal magnetic tape, and with this technology, recording can be performed within 30 cm of the optical fiber tape. Therefore, the memory section is 30 cm
Then, when manufacturing the optical fiber tape with memory function, enter the first and last data of the section every 30 cm to obtain the initial data (wire number).
Is recorded in this 30 cm memory section. Then connect
If necessary, the information shown in Table 2 may be recorded together with the above-mentioned optical loss at the time of maintenance. With this structure,
Using a commercially available read / write device for magnetic cards
There was no error even after 300 consecutive read / writes.

<Embodiment 2> FIG. 2 is a view for explaining a second embodiment of the present invention, and the cable is the same as that of FIG. 1 except for the optical fiber tape. 21 'is a 10-fiber optical tape with memory,
22 is an optical fiber strand, 23 is a UV curable resin tape coating layer, 25
Is a magnetic recording layer. In the optical fiber tape with memory shown in Fig. 2, after the UV curable resin tape coating layer is cured, UV curable resin containing a magnetic material is further applied to one side of the optical fiber tape and irradiated with ultraviolet rays while applying a magnetic field. Then, the magnetic recording layer is cured. The magnetic field is applied to orient the magnetic substance. Its magnetic field strength is several tens of oersteds. The optical fiber tape with a memory described in this embodiment can be read and written exactly as in the first embodiment.

<Embodiment 3> FIG. 3 is a diagram for explaining the third embodiment of the present invention, in which 21 "is a 10-core optical fiber tape with memory, 22 is an optical fiber element wire, and 26 is a magnetically recordable tape. In order to enable magnetic recording, it is necessary to contain a magnetic material in the tape coating layer in a volume fraction of about 30%, and in this embodiment, 30% of γ-Fe ₂ O ₃ is contained. This tape coating is UV
It is made of a cured resin, and it is necessary to apply a magnetic field immediately before irradiating ultraviolet rays to orient the magnetic material. Magnetic field strength is tens
Oersted. The optical fiber tape with a memory function manufactured as described above could be stably read / written.

<Embodiment 4> FIG. 4 is a diagram showing a method of constructing an optical fiber cable transmission line according to the present invention, and 1 is a telephone station. cable
30 is laid first, then cable 31. The cross sections of both cables have the structure shown in FIG. Cable 30 and
31 connects at point 32. At this time, since the memory section is formed at any point on the fiber coating in the cable and the wire number is recorded as the memory, the wire number can be easily identified. The length of one memory section is 30 cm. Usually, at the connecting portion, the outer sheath of 1 to 2 m is removed and the coated fiber inside is taken out. Therefore, if the memory section is 30 cm, there are always a plurality of memory sections in the taken out coated fiber. If light is transmitted from the telephone station 1 at the time of connection, the connection loss can be monitored. After the connection work is completed, the optical loss of the cable 30 and the value of the connection loss are recorded in the coated fiber memory section in the connection point 32. Since a memory capacity for additional recording is provided in the memory section, main recording is possible after installation. By repeating this work, the cables 33, 34 ... Are laid and connected. If, after cable construction, the connection point 32 is opened and post-branching is required, the optical loss from the central office to the connection point can be known by reading the memory of the coated fiber in the connection point. In this reading, it is not possible to visually recognize where the data is recorded, but the reading device is made to read the signals at the beginning and end of each memory section, and if there is no optical loss data in it, the next memory section is read. It suffices to perform sequential reading work such as reading. It is necessary to input a new value of connection loss if the connection work of the branch is performed. At this time, the loss value in the memory section may be rewritten. It is also assumed that the length of the coated fiber is insufficient due to reconnection. At this time, remove the new jacket,
When the coated fiber is taken out, a new memory section appears, so that it can be recorded here. At this time, the old data in the previous memory section can be erased to prevent the data from being confused.

〔The invention's effect〕

As described above, according to the optical fiber cable with a memory of the present invention, since the recording function is provided over the entire length in the longitudinal direction of the optical fiber tape, it is possible to automate each work such as inspection, connection, etc. There is an advantage that the on-site work can be simplified and the cost can be reduced. Further, according to the method of constructing an optical fiber cable transmission line of the present invention, since the above-described optical fiber cable with a memory is used, the work can be performed quickly and manpower can be omitted.

[Brief description of drawings]

FIG. 1 (A) is a sectional view showing a first embodiment of the present invention, FIG. 1 (B) is an enlarged view of an essential part of FIG. 1 (A), and FIG. 2 is a second view of the present invention. FIG. 3 is a sectional view showing an embodiment, FIG. 3 is a sectional view showing a third embodiment of the present invention, FIG. 4 is an explanatory view showing a method of constructing an optical fiber cable transmission line according to the present invention, and FIG. FIG. 6 is an explanatory view of an optical fiber route for subscribers, FIG. 6 is an explanatory view of an optical fiber route for subscribers performing post branching, FIG. 7 (A) is a cross-sectional view of a conventional optical fiber cable, and FIG. 7 (B). FIG. 7 is an enlarged view of a main part of FIG. 7 (A). 1 ... Telephone station, 21,21 ', 21 "... 10-core optical fiber tape (coated fiber) with memory, 30,31 ... Cable, 32 ...
… Connection points, 33,34… cables.

Claims (2)

(57) [Claims] 1. In an optical fiber cable in which a coating layer of a coated fiber obtained by applying a protective coating to an optical fiber includes a magnetic material, the magnetic material is present over the entire length of the coated fiber,
Memory sections are formed in the magnetic material at substantially equal intervals along the length direction without interruption, and signals indicating the beginning and end of the section are recorded at both ends of all the memory sections, and at the same time, in the cable. An optical fiber cable with a memory, in which a number for identifying each fiber is recorded, and an area for additional recording is left in the memory section. 2. A method of constructing an optical fiber cable transmission line by laying or spanning a plurality of optical fiber cables and connecting the optical fiber cables to each other, wherein the optical fiber cables are optical fibers in the optical fiber cables. The protective coating of the fiber includes a magnetic material, the magnetic material is present over the entire length of the coated fiber, and the magnetic material is formed with memory sections at substantially equal intervals along the length direction without interruption, and all the memory sections are provided. A signal indicating the beginning and end of a section is recorded at both ends thereof, a number for distinguishing the fiber in the cable is recorded respectively, and an area for additional recording is left in the memory section. The optical transmission from the signal transmission point of the optical fiber to the connection point when the optical fiber cable is connected after installation. Construction method for the optical fiber cable transmission line, characterized in that to keep the loss recorded additional recordable area provided in the coated optical fiber.