JPH05256730A - Method for identifying line containing optical fiber - Google Patents

Abstract

PURPOSE:To identify the optical-fiber at a remote place without providing a special device in outdoor. CONSTITUTION:Two or more optical cables each including at least one optical fiber 3 are provided in an optical line 1. A plurality of the optical lines 1 are provided in a communication system. In this system, the intervals between connecting points 2-1 to 2-3 of optical cables 1-1 to 1-4 in each optical line 4 are measured and stored beforehand. When the interval between the arbitrary connecting points of the optical-fiber 3 is measured, the result of the measurement is compared with the stored interval between the connecting points of the optical cable. In this way, in which optical line of a plurality of the optical lines the arbitrary optical-fiber is contained can be identified.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of identifying an optical fiber contained line used for facility management of an optical line.

[0002]

2. Description of the Related Art Conventionally, facility management of communication lines has been performed by relying on a database installed at one location.
When introducing new equipment or changing equipment, equipment information was manually input each time. However, this method has problems that the reliability of the database is lowered due to erroneous input and the operation is increased by manual work. Of these, the management of the core wire has been a particular problem because the number thereof is huge.

There are a metal core wire and an optical core wire (optical fiber) as a core wire used for a communication line. In view of such a situation, recently, a semiconductor memory is arranged in a connector portion of the optical core wire. , A method has been proposed in which the identification number of the optical fiber is stored here, and the optical fiber is identified by reading this identification number remotely (Yamashita et al. “Study of real-time optical fiber equipment management system”. ] IEICE Transactions
Vol.J74 B-1 No.1 1991pp48-57).

[0004]

However, in the above-mentioned method, it is necessary to provide a semiconductor memory, which is originally unnecessary for communication, and a communication means for communicating with the semiconductor memory, everywhere in the optical line installed in a wide range outdoors. Yes, there was a problem in terms of economy and reliability.

In view of the above-mentioned conventional problems, it is an object of the present invention to provide a method capable of remotely identifying the optical fiber line without installing a special device outdoors.

[0006]

According to the present invention, in order to achieve the above object, in a communication system in which there are a plurality of optical lines formed by connecting two or more optical cables including at least one optical fiber, each optical line is previously set. When the distance between the connection points of the optical cable is measured and stored, and the distance between the connection points of any optical fiber is measured, the measurement result is compared with the stored distance between the connection points of the optical cable. By doing so, it is proposed a method of identifying the optical fiber line containing line, which identifies which of the plurality of optical lines the arbitrary optical fiber line is housed.

[0007]

The lengths of the two or more optical cables forming the optical line are usually different for each of the plurality of optical lines.
Therefore, when the length of the optical cable, that is, the distance between the connection points is measured and stored in advance, and then the distance between the connection points of the optical fibers that are arbitrarily taken out is measured, this measurement result and the distance between the connection points are the best. It can be identified that the arbitrarily extracted optical fiber is accommodated in the near optical line. According to the method of the present invention, particularly when a plurality of optical lines are laid on different routes, that is, when the lengths of the optical cables forming the optical lines are largely different, the discriminating ability becomes extremely high.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Generally, a plurality of optical fibers are grouped and accommodated in an optical cable, and two or more optical cables are connected in the length direction to form one optical line. To identify the optical fiber, the identification of which optical line the optical fiber belongs to (hereinafter,
This is called optical line identification. ), And which optical fiber in the optical line the optical fiber corresponds to (hereinafter, referred to as optical fiber identification).
However, the present invention provides a method for identifying an optical line.

FIG. 1 shows an embodiment of the method of the present invention. In the figure, 1 is an optical line, 1-1, 1-2, 1-3, 1-.
Reference numeral 4 is an optical cable constituting the optical line 1, 2-1 and 2-2,
2-3 is a connection point, 3 is an optical cable 1-1 to 1-4, that is, an optical core line accommodated in the optical line 1, 4 is an optical pulse tester (OTDR), 5 is a data fold device, and 6 is It is a database.

In the above structure, first, the connection points 2-1 to 2-3 of the optical cables 1-1 to 1-4 forming the optical line 1 are connected.
Is measured by the optical pulse tester 4. The distance between the connection points is a waveform showing the connection points in the backscattered light measured by the optical pulse tester 4 as shown in FIG.
, P2 is easily obtained.

The above-mentioned measurement is carried out for a plurality of other optical lines (not shown), the optical cables are numbered in order from the one closer to the optical pulse tester 4 for each optical line, and the connection points are connected so as to correspond to these numbers. The measurement result of the interval is stored in the database 6.

After that, when it is desired to know the accommodating line of an arbitrary optical core line due to the introduction of new equipment or the change of equipment, the arbitrary optical core line is taken out and the connection point intervals of this optical core line are tested by an optical pulse test. The result of measurement by the instrument 4 and the distance between the connection points of the optical lines stored in the database 6 are compared by using the data folding device 5, and the arbitrary optical core line is connected to any of a plurality of optical lines. Identify if contained.

Next, the comparison method described above will be described. Here, the distance between the connection points of the optical cable measured in advance is a _i = (a _i1 , a _i2 , ..., a _im ), and the distance between the connection points of the optical fiber lines arbitrarily extracted is b = (b ₁ , b _2). , …… b _m )
(Where i is the identification number given to the optical line, i =
1, 2, ... n. ).

Assuming that the standard error of the measurement error of each connection point interval is s, the probability p (b) that the connection point interval of the optical line i is measured and the result is (b ₁ , b ₂ , ..., B _m ). ｜ i) is Given in.

Here, the probability that the optical core line in which w _i is arbitrarily extracted is included in the optical line i (optical line i The number of lines), Bayes' theorem shows that the connection point spacing of the optical cores arbitrarily extracted is b = (b ₁ , b ₂ , ...
b _m ), the probability p (i | b) that the optical core is accommodated in the optical line i is Given in.

Therefore, the connection point spacing is b = (b ₁ , b ₂ ,
.. b _m ) is determined to be accommodated in the optical line i having the highest probability p (i | b).

Erroneous identification rate E when identification is performed by this method
Is given by E = 1−∫max _{(for all i)} {w _i p (b | i)} db (3). However, the integration is a definite integration performed on the entire region of the vector b.

As an example, there are three target optical lines (optical line a, optical line b, optical line c), each of which is composed of three optical cables, and the optical cables of optical line a are all 950 m long. , All optical cables of optical line b are 1000 in length
m, the optical cable of the optical line c is 1050 m in length,
The number of optical fibers contained in each optical line is the same, and the misidentification rate E when the standard deviation s of the measurement error is 10 m (corresponding to the measurement by the optical pulse tester with a pulse width of 100 ns) is expressed by Obtained from (3), it is extremely small at 0.036%,
It turns out that effective identification is possible.

[0019]

As described above, according to the present invention, any optical fiber can be connected to any optical line by only measuring the distance between the connection points of the optical fiber without installing a special device outdoors. It is possible to accurately identify whether or not it is housed, and it is possible to achieve efficient equipment management of the optical line.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a method of the present invention.

FIG. 2 is a waveform diagram of backscattered light of an optical fiber measured by an optical pulse tester.

[Explanation of symbols]

1 ... Optical line, 1-1, 1-2, 1-3, 1-4 ... Optical cable, 2-1, 2-2, 2-3 ... Connection point, 3 ... Optical core line,
4 ... Optical pulse tester (OTDR), 5 ... Data analysis device, 6 ... Database.

Claims (1)

[Claims] 1. In a communication system having a plurality of optical lines formed by connecting two or more optical cables each including at least one optical fiber, the distance between the connection points of the optical cables in each optical line is measured and stored in advance. Every time, when measuring the distance between the connection points of an arbitrary optical fiber, by comparing the measurement result with the distance between the connection points of the optical cable stored in advance, the arbitrary optical fiber A method for identifying an optical fiber contained line, characterized in that it is arranged to identify in which of the optical lines the lines are accommodated.