JPH0785732A - Communication cable - Google Patents

Abstract

PURPOSE:To enhance a crosstalk characteristic while coping with high speed data communication at about 100Mbps. CONSTITUTION:Six units 32A-32F are assembled and stranded, thus providing a communication cable 30. In each unit 32A-32F, four pairs 12A-12D obtained by stranding insulated electric wires 14 of two cores are twisted together in such a manner that the adjacent pairs are arranged at different pitches. A predetermined relation amoung the pitch, an outer diameter of the insulated electric wire, and a twisting rate is established with respect to the two pairs arbitrarily selected from the four pairs 12A-12D of the units 32A-32F and two pairs arbitrarily selected from each of the adjacent two units arbitrarily selected from the units 32A-32F. The pair arbitrarily selected from the adjacent units are twisted at a different pitch.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication cable used for high-speed data communication, for example, a communication cable formed by collecting a plurality of pairs or a unit formed by collecting and twisting a plurality of pairs. The present invention relates to improvement of unit type communication cables.

[0002]

2. Description of the Related Art As a communication cable used in a regionally limited area such as in a business office or a building,
Generally, an indoor line or a premises cable mainly transmitting an audio signal, or a communication cable formed by twisting a plurality of pairs developed for a computer network (LAN) up to 20 Mbps is used. In these cables, conventionally, adjacent pairs are twisted at different pitches, or the relationship between the pitches of each pair is set so as not to be an integral multiple, thereby improving crosstalk characteristics.

In recent years, there has been an increasing demand for high-speed data transmission of about 100 Mbps even in the premises wiring system of business offices and commercial buildings. For communication cables used for such high-speed data communication, see E
IA / TIA (American Electronics Industry Association / American Telecommunications Industry Association) defines the standard. Especially, for electric wires that can be used for data transmission up to 100 Mbps, a unit formed by twisting a plurality of pairs in category 5. The minimum performance standard is stipulated in the performance specifications for unshielded unit type cables that are made by twisting together.

[0004]

Therefore, in the communication cable formed by twisting a plurality of pairs of the prior art, 100M is required.
High frequency of bps or higher, for example, computer network (ATM LAN) in asynchronous transfer mode
In order to obtain the characteristics required for high-speed data communication of about 150 Mbps required in the above, and in order to obtain the characteristics required for high-speed data communication, it is necessary to use a communication cable formed by twisting a plurality of such pairs. It is necessary to make a unit, and twist a plurality of sets of these units to make a unit type cable. However, even if a unit formed by twisting adjacent pairs at different pitches as in the prior art is used, and a plurality of sets are collectively twisted to manufacture a unit type communication cable, the pitch of pairs forming a unit is , If the pitches of pairs forming adjacent units are equal, sufficient crosstalk characteristics cannot be obtained, and EI
The crosstalk characteristic in the standard defined by A / TIA (American Electronics Industry Association / American Telecommunications Industry Association) cannot be cleared. That is, in the unit type cable,
Not only the relationship of pairs within one unit, but also the pitch between a pair forming a unit and a pair forming a unit adjacent to the unit needs to be taken into consideration. However, it has not been possible to obtain sufficient crosstalk characteristics in high-speed data communication of about 100 Mbps. In particular, regarding the unit type communication cable, even when considering the pitch of pairs between a plurality of units, a firm proposal has been made as to what value the pitch should be combined to obtain the optimum crosstalk characteristic. The current situation is that they did not.

The object of the present invention is to avoid the above-mentioned drawbacks and to use a plurality of pairs twisted together, and also to use a plurality of units formed by twisting a plurality of pairs collectively to 100 Mbps or more. It is an object of the present invention to provide a communication cable capable of ensuring a sufficient crosstalk characteristic even in the case of supporting high-speed data communication.

[0006]

The present invention provides, as a first means for solving the above problems, a plurality of pairs formed by twisting two insulated wires together so that adjacent pairs have different pitches. In a telecommunication cable formed by twisting together, two pairs T _i arbitrarily selected from these pairs,
Pitch of one pair T _i of the pitch P _i Toko pair T outer diameter of the insulated wire in the _i D _i versus T _i ratio narrowing twist in the finished cable K _i of and the other pair T _j of Toko of T _j P _{j and} this pair T
outer diameter D _j twist narrowing ratio K _j in the finished cable pair T _j of Toko insulated wire in _j is _{(P i × P j) /} (K i × K j ×
The communication cable is characterized in that D _i × D _j ) ≦ 350.

As a second means for solving the above problems, the present invention comprises twisting a plurality of pairs of insulated wires of two cores so that adjacent pairs have different pitches. in a communication cable that is formed by a plurality of units and twist set of, the pitch P _i of one pair T _i of the two pairs T _i, T _j that is selected in any of a plurality of pairs of the units the outer diameter D of the insulated wire in the pair T _j of the pitch P _j Toko of the pair T _i twisted narrowing ratio of the unit of outside diameter D _i versus T _i of Toko insulated wire in K _i and the other pair T _j twist narrowing ratio K _j in units of pairs T _j of the _j-Toko is _{(P i × P j) /} (K i × K j × D i × D j) ≦ 350
It is set to be (Equation 1), also any of a plurality of pairs constituting one of the unit U _i of any two units neighboring chosen U _i, U _j among the plurality of units Selected pair T _i and the other unit U _j
Pair T _j Togashiki 1 selected arbitrarily among the plurality of pairs constituting configured so as to satisfy, and selected pairs T _i
And T _j are twisted at different pitches to provide a communication cable.

[0008]

When the pitches of a plurality of pairs are numerically limited in this way, a sufficient crosstalk characteristic can be obtained in a communication cable formed by twisting a plurality of pairs, and such a communication cable is regarded as one unit. Even when multiple sets are twisted together to form a unit-type communication cable, the pitch of a pair that constitutes a certain unit and the pitch of the pair that constitutes an adjacent unit to this unit are always different, and each pair is obtained as a result of experiments. Since they are twisted with an optimum value, sufficient crosstalk characteristics can be obtained while supporting high-speed data communication.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, an embodiment of the present invention will be described in detail. FIG. 1 shows a communication cable 10 of the present invention, which is formed by twisting a plurality of pairs 12. . In the embodiment shown in FIG. 1, the communication cable 10
Consists of four pairs 12A to 12D, but may be any other suitable number if desired. Further, if necessary, it may be formed by covering with a push winding 36 via an interposition and covering the push winding 36 with a sheath 38.

The four pairs 12A to 12D are twisted so that adjacent pairs 12 have different pitches so that crosstalk does not occur. Thus, for example, adjacent pairs 12
The pitch P _A of one pair 12A of _A and pair 12B and the pitch P _B of the other pair 12B are different, which means that pair 12B and pair 12C, pair 12C and pair 12D, and pair 12D and pair 12A.
Also holds between. That is, the pitch of the pair 12A is P
_A , the pitch of 12B is P _B , the pitch of 12C is P
_{If C} and the pitch of 12D are P _D , P _A ≠ P _B ,
P _B ≠ P _C , P _C ≠ P _D , P _D ≠ P _A always hold.

As shown in FIG. 2, each pair 12 is formed by twisting two insulated wires 14 together. The insulated wire 14 is formed by covering the conductor 16 with the insulating layer 18. As the conductor 16, for example, annealed copper wire or the like can be used, and the insulating layer 18 can be formed of, for example, polyethylene or the like.

In the present invention, these multiple pairs 12
Two pairs T _i, the finished cable having an outer diameter D _i pairs of Toko T _i of insulated wire 14 in pair T _i of the pitch P _i Toko of one pair T _i of T _j that is arbitrarily selected out of Twist ratio K
_i and the other pair T _j of the pitch P _j outer diameter D _j twist narrowing ratio K _j in the finished cable pair T _j of Toko insulated wire 14 in pair T _j of Toko is (P _i × P _j) / (K _i × K _j × D _i ×
It is set such that D _j ) ≦ 350 (equation 1).
Therefore, for example, when FIG. 1 is taken as an example, the above Expression 1 is established between the pair 12A and the pair 12B that are arbitrarily selected. The twist ratio K in the completed cable indicates the ratio of the length of the insulated wire 14 to the unit length of cable, and K
= (Insulated wire length) / (finished cable length)

By adjusting the different pitches between the plurality of pairs 12 in this way, sufficient crosstalk characteristics can be obtained, and as will be seen from the experimental examples described later, a unit type communication cable used for high speed data communication is used. In this case, the crosstalk characteristic can be improved.

Next, a second embodiment of the present invention will be described with reference to FIG.
The communication cable 30 according to the second embodiment will be described in detail with reference to FIG.
A plurality of units 32 are collectively twisted via
And the sheath 38 is formed on the push-wound 36. That is, the communication cable 30 according to the second embodiment is a so-called unit type communication cable, and is an electric wire that can be used for high-speed data communication of about 100 Mbps defined by the EIA / TIA (American Electronics Industry Association / American Telecommunications Industry Association). It is capable of conforming to the standard. Therefore, the communication cable 3 shown in FIG.
0 can support high-speed data communication in a premises wiring system of a commercial building or the like, which has recently been required.

Each unit 32 has two units as shown in FIG.
A plurality of pairs 12 formed by twisting core insulated wires 14 are twisted together. That is, each unit 32
Corresponds to the communication cable 10 shown in FIG. 1 described above (however, the sheath 38 is not provided). In addition, this FIG.
Also in the embodiment shown in (1), the plurality of pairs 12 constituting each unit 32 are composed of four pairs 12 of pairs 12A to 12C, but other suitable numbers may be used as necessary. The four pairs 12A to 12D are twisted so that adjacent pairs 12 have different pitches so that crosstalk does not occur. Further, in the embodiment shown in FIG. 3, the plurality of units 32 are the units 32A to 32F.
However, other suitable numbers may be used as required.

Also in this second embodiment, in each unit 32, a plurality of pairs 1 forming each unit 32 are formed.
Two pairs T _i which is arbitrarily selected among 2, the insulated wire 14 in pair T _i of the pitch P _i Toko of one pair T _i of T _j
Outer diameter D _i twist narrowing rate in units of pairs T _i of Toko K _i of
And the pitch P _j outer diameter of the insulated wire 14 in pair T _j of Toko D _j twist narrowing ratio K _j in units of pairs T _j of Toko the other pair T _j is _{(P i × P j) /} (K _i × K _j × D _i × D _j )
It is set such that ≦ 350 (Equation 1). Therefore, for example, in FIG. 3, the above Expression 1 is established between the pair 12A and the pair 12B arbitrarily selected in one unit 32A.

[0017] In the communication cable 30 of the present invention, a plurality of pairs constituting one of the unit U _i of which optionally adjacent the selected two unit U _i, U _j among the plurality of units 32 A pair T _i arbitrarily selected from 12 and a plurality of pairs 12 constituting the other unit U _j
A pair T _j arbitrarily selected among the pairs is set so as to satisfy the expression 1, and the pair T _i and T _j selected are twisted at different pitches. In the unit type communication cable 30 shown in FIG. 3, the insulated wire 14 is twisted in each of the pair 12, the unit 32, and the collective twist of the unit 32. The ratio of the lengths, that is, the twisting rate K is calculated by twisting rate K _t of the pair 12 of the insulated wire 14 = (insulated wire length) / (pair length), the unit 32.
Product of three twist ratios of twist ratio K _u = (insulated wire length) / (unit length), twist ratio in collective twist K _r = (insulated wire length) / (communication cable length), that is, K = K _t × K _u × K _r .

Therefore, for example, taking FIG. 3 as an example,
Between the pair 12A arbitrarily selected from the plurality of pairs 12 forming the unit 32A and the pair 12A arbitrarily selected from the plurality of pairs 12 forming the unit 32B adjacent to the unit 32A, The pitch and the like are set so as to satisfy Expression 1. Furthermore, this unit 32A pair 12
It is necessary to set the pitches of A and the pair 12A of the unit 32B to be different. This is to prevent the crosstalk characteristic from being deteriorated when the pair 12A of the unit 32A and the pair 12A of the unit 32B are adjacent to each other.

In this case, in order to obtain a good crosstalk characteristic, it is sufficient to adjust the pitch of the pair 12 between the adjacent units 32. Therefore, as shown in FIG. 4, the units 32 are of type I and type II. 2 types are set and these type I
The unit 32 of 3 and the unit 32 of type II are alternately arranged. For example, the unit 32A in FIG. 3 is a type I (see FIG. 4), the unit 32B is a type II (see FIG. 4), and the following units 32C to 32F are similarly arranged, so that all the adjacent units 32 are connected. ,
The pitch of the pair 12 can be adjusted so as to satisfy the above expression 1.

In addition, as described above, the type I (see FIG. 4)
When setting two types of units 32 of type II and type II (see FIG. 4), as shown in FIG.
In the case of the unit 32 including D, two adjacent units 32 are set by setting eight types of pitch numbers from 4 (pair) × 2 (number of types of units) = 8 (number of pitches).
The pitch of all pairs 12 can be different between them. That is, constituting the optionally selected the pair T _i and the other unit U _j of the plurality of pairs 12 constituting one of the unit U _i of which optionally adjacent the selected two unit U _i, U _j The arbitrarily selected pairs T _{j of the} plurality of pairs 12 can be twisted at different pitches. For example, in FIG. 3, a pair 12A arbitrarily selected from the plurality of pairs 12 constituting the unit 32A and a pair 12A arbitrarily selected from the plurality of pairs 12 constituting the unit 32B adjacent to the unit 32A. And the pitch will always be different.

Next, the process of deriving the above equation 1 is shown in Table 1.
It demonstrates in detail with reference to the experimental example of this invention shown in FIG.

[0022]

[Table 1]

This Table 1 shows the communication cable 3 with various pitches set in order to obtain the optimum set value of the number of pitches of the pair.
This is a comparison of performance specifications of 0. That is, as shown in Table 1, a conductor wire made of an annealed copper wire having an outer diameter of 0.511 mm is covered with an insulating layer made of low density polyethylene and having an outer diameter of 0.92 mm. 6
Communication cable 30 formed by twisting two units 32 together
Was manufactured, and the pitch of the insulated wires 14 forming each pair 12 was set to three from Experimental Example 1 to Experimental Example 3.
In addition, as shown in Table 1, in each of the experimental examples,
The four pairs 12 in the unit 32 are twisted at a pitch of 100 mm for the type I and 130 mm for the type II to form each unit 32, and the plurality of pairs 12 are twisted at a different pitch from the adjacent unit 32. The unit was twisted together. In each of the experimental examples, each unit 32 was collectively twisted at a pitch of 210 mm. Of the three experimental examples shown in Table 1, Experimental example 1 satisfies the above formula 1 in all combinations of pairs 12.

Next, among the three experimental examples shown in Table 1, the experimental examples 1 and 2 have respective units 32.
For all combinations of pairs 12 in each unit, and for all pairs 12 between adjacent units 32 (between Type I and Type II in Table 1), and for Experimental Example 3, all combinations in each unit 32 Near end crosstalk attenuation was measured for each of the 12 pairs.

[0025]

[Table 2]

[0026]

[Table 3]

The crosstalk attenuation amount thus obtained for each experimental example is used for the electric wire of EIA / TIA (American Electronics Industry Association / American Telecommunications Industry Association) 100 Mbps high speed data communication shown in Table 3. It was classified into three evaluations A, B, and C shown in Table 3 in light of the standard (category 5). That is, when the worst value of the crosstalk attenuation amount over all frequency bands is the standard value +11 dB or more shown in Table 2, the evaluation A, and when the worst value of the crosstalk attenuation amount over all frequency bands is the standard value +11 dB or less shown in Table 2 Evaluation B, the worst value of crosstalk attenuation over the entire frequency band is shown in Table 2.
The case of being less than or equal to the standard value shown in was evaluated as C. In Table 3, evaluation A and evaluation B are based on 11 dB.
Is classified because it is appropriate as a margin value when considering multiple crosstalk.

Furthermore, the evaluation based on Table 3 is summarized in the graph shown in FIG.

That is, each point in FIG. 6 indicates a combination of pairs, and the symbols A to C attached to each point indicate the evaluation in Table 3. For example, a combination of a pair of units I twisted at a pitch of 10 mm (see Table 1) in Experimental Example 1 and a pair of units II twisted at a pitch of 11 mm (see Table 1) (Table 4). Indicates that the evaluation was A. In addition, in FIG. 6, the region 1 surrounded by the solid line corresponds to the pair in Experimental Example 1 (see Table 1).
, The region 2 surrounded by a dotted line is the pair in Experimental Example 2 or the range of all combinations (see Table 1), and the region 3 surrounded by a dashed line is the pair in Experimental Example 3. The ranges of all combinations (see Table 1) are shown.

Through the above process, when a boundary line in which all points are evaluated A in FIG. 6 is obtained, the line L shown in FIG. 6, that is, (P _i × P _j ) / (K _i × K _j ×) is obtained. D _i × D
We were able to obtain a function of _j ) = 350. As can be seen from FIG. 6, inside the line L indicating this equation, that is, (P _i
In the range satisfying × P _j ) / (K _i × K _j × D _i × D _j ) ≦ 350 (Equation 1), the crosstalk attenuation is evaluated as A and good crosstalk characteristics are obtained regardless of the combination of any pair. In addition, the EIA / TIA (American Electronics Industry Association / American Telecommunications Industry Association) standard can be satisfied. In particular,
In Experimental Example 2 or Experimental Example 3, depending on the combination of the pair, it may deviate from the region of Expression 1 and the crosstalk characteristic may be evaluated as B or C, but the experimental example satisfying the requirements of the present invention. Region 1 (see FIG. 6) showing the pitch range of the pair of 1s is all included in the region of Expression 1, and all the evaluations are A, so that good crosstalk characteristics can be obtained. I understand. Therefore, it can be said that the pitch combination of the experimental example 1 shown in FIG. 6 is one of the suitable examples.

Although six units 32 are used in FIG. 3, the communication cable 30 may be composed of twelve units 32 as shown in FIG. Also in this case, as shown in FIG. 5, two types of units 3 of type I and type II are used.
2 is set, and 6 sets of these are used, and 2 sets are twisted to the left twist in the center interposition 40 with 2 sets as the center layer, and the other 4 sets of units 32 are placed on the outer periphery of this center layer with the interposition 42 interposed. The pitch of each pair 12 can be set so as to satisfy the expression 1 by alternately arranging them and twisting them in the right twist. In this example, the unit 32 similar to that of the experimental example shown in Table 1 was used to measure the crosstalk attenuation amount.
I was able to get

In the communication cable 10 in which a plurality of pairs 32 shown in FIG. 1 are twisted together, the pitch of each pair 12 is the pair or pairs shown in Experimental Example 1 of Table 1 (see Table 1).
The pitch can be arbitrarily selected within a range satisfying the expression 1 without being limited to the pitch.

[0033]

According to the present invention, since the pitches of a plurality of pairs are numerically limited as described above, it is possible to obtain sufficient crosstalk characteristics in a communication cable formed by twisting a plurality of pairs. Even when such a communication cable is used as one unit and a plurality of sets of the units are collectively twisted to form a unit type communication cable, the pitch of a pair forming a unit and a pitch forming a unit adjacent to this unit are Since they are always different, and each pair is twisted with the optimum value obtained as a result of the experiment, there is a practical advantage that sufficient crosstalk characteristics can be obtained while supporting high-speed data communication.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of a communication cable of the present invention.

FIG. 2 is a sectional view of a pair used in the present invention.

FIG. 3 is a schematic cross-sectional view of another embodiment of the communication cable of the present invention.

FIG. 4 is a schematic view showing an arrangement state of units used in another embodiment of the present invention.

FIG. 5 is a schematic view showing an arrangement state of units used in another embodiment of the present invention.

FIG. 6 is a plot diagram showing a combination of pitches of each pair and a result of near-end crosstalk evaluation based on Table 3 for each combination.

[Explanation of symbols]

 10 Communication Cable 12 Pair 14 Insulated Wire 16 Conductor 18 Insulation Layer 30 Communication Cable 32 Unit 34 Interposition 36 Push Winding 38 Sheath 40 Center Interposition 42 Interposition I Type I Unit II Type II Unit

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kunio Negishi 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd.

Claims (2)

[Claims] 1. A communication cable formed by twisting a plurality of pairs formed by twisting two cores of insulated electric wires so that adjacent pairs have different pitches, and two arbitrarily selected from the plurality of pairs. One of the pair T _i and T _j , T _i
Outer diameter D _i of the insulated wire in the pitch P _i pairs of Toko T _i
Pair T _j of the outer diameter D _j Toko of the insulated wire in the pitch P _j pairs of Toko T _j pairs T _i pair T _j twist narrowing ratio K _i and the other in the finished cable of Toko in the finished cable The twist ratio K _j is (P _i × P _j ) / (K _i × K _j × D _i × D _j ) ≦
A communication cable, which is set to be 350. 2. A communication cable formed by collectively twisting a plurality of units formed by twisting a plurality of pairs formed by twisting two cores of insulated wires so that adjacent pairs have different pitches, a pair of outer diameter D _i Toko of the insulated wire in the pair T _i of the pitch P _i Toko of one pair T _i of the two pairs T _i, T _j that is selected in any of a plurality of pairs of the units T _i pitch P _j outer diameter of the insulated wire in the pair T _j of Toko D _j twist narrowing rate in units of pairs T _j of Toko K _j twisted narrowing ratio K _i and the other pair T _j in units of
Is (P _i × P _j ) / (K _i × K _j × D _i × D _j ) ≦ 35
0 (Equation 1), and two adjacent units U arbitrarily selected from the plurality of units.
_i, a pair T _j that is arbitrarily selected among the plurality of pairs constituting the pair T _i and the other unit U _j which is arbitrarily selected among the plurality of pairs constituting one of the unit U _i of U _j Is set so as to satisfy the above expression 1, and the selected pair T _i and T _j are twisted at different pitches.