JPH08148040A - Communication cable - Google Patents

Abstract

PURPOSE: To improve a crosstalk characteristc without applying particularly a shield to each unit while corresponding to about 100Mbps high speed data communication and high frequency communciation. CONSTITUTION: A communication cable 10 is formed by collectively twisting six units 12A to 12F. Each unit 12A to 12F is formed by twisting together four paired 14A to 14D, formed by twisting together two-core insulated wires 16, in a manner wherein the pairs 14 adjacent to each other are in a different twist pitch. The twist pitch of a plurality of the pairs 14, (1) in the same unit, (2) between adjacent units, (3) between every other unit, is set to be selected from a region where combination of the paired twist pitch is made in a prescribed relation. Further, of the units 12 adjacent to each other, the pair 14 arbitrarily selected is twisted together by a twist pitch different from each other.

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 and the like, and relates to an improvement of a unit type communication cable formed by collectively twisting a unit formed by assembling a plurality of pairs. .

[0002]

2. Description of the Related Art As a communication cable used in a regionally limited area such as in an 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 communication cables, conventionally, adjacent pairs are twisted at different twist pitches, or the relationship between the twist 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 premises wiring systems such as 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]

By the way, the communication cable formed by twisting a plurality of pairs of the prior art is 100
High frequency of about Mbps or higher, for example, a computer network in an asynchronous transfer mode (ATM LA
In N), it is not possible to obtain the characteristics required for high-speed data communication of about 150 Mbps and high-frequency communication of image communication such as cable television (CATV), and eventually to obtain the characteristics required for high-speed data communication and high-frequency communication. Is a communication cable made 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-type communication cable is manufactured by collectively twisting a plurality of units, each of which is formed by twisting adjacent pairs at different twist pitches as in the prior art, the twist pitch of a pair forming a unit And the twist pitches of the pairs forming the adjacent units become equal to each other, sufficient crosstalk characteristics cannot be obtained, resulting in EIA / TI.
The crosstalk characteristic in the standard defined by A (American Electronics Industry Association / American Telecommunications Industry Association) cannot be cleared. That is, in a unit type cable, it is necessary to consider not only the relationship of pairs within one unit, but also the twist pitch between a pair forming a unit and a pair forming an adjacent unit to the unit. .

In this case, by shielding each unit to ensure insulation between the units,
It is conceivable to improve the crosstalk characteristics without considering the twist pitch between the pair forming a certain unit and the pair forming an adjacent unit, but in this way, the diameter of the communication cable is large, In addition to the heavy weight, there is a problem that the communication cable lacks flexibility required to some extent, which further increases the cost.

Therefore, in order to obtain sufficient crosstalk characteristics in high-speed data communication and high-frequency communication, the unit type communication cable has a small diameter, light weight and sufficient flexibility, and in order to obtain sufficient crosstalk characteristics, a pair of units must be connected. Although it is best to consider the twist pitch, in the past, such a point could not be sufficiently dealt with, and sufficient crosstalk characteristics could not be obtained in high-speed data communication of about 100 Mbps. In particular, regarding the unit type communication cable, even if the twist pitch of a pair between multiple units is taken into consideration, a certain proposal is made as to what value of the twist pitch can be combined to obtain the optimum crosstalk characteristic. The current situation is that this has not been done.

Further, for a communication cable having a plurality of units, high-speed data of 100 Mbps defined by EIA / TIA (American Electronics Industry Association / American Telecommunications Industry Association) by ISO / IEC (International Organization for Standardization / International Electrotechnical Commission). To meet the crosstalk attenuation amount in the standard (category 5) of electric wires that can be used for communication, and for the multiple crosstalk characteristics from the signals transmitted at the same time, the following stricter requirements are made. Is desired.

That is, regarding a communication cable having a logarithm n,
(For example, in a communication cable formed by twisting 6 units each having 4 pairs, 4 (pairs) × 6 (units) = 24 (pairs), n = 24) The crosstalk attenuation amounts X ₁ , X ₂ , ..., X _n-1 of the combination with the pair (number: n−1) are measured (in the case of n = 24, 24−1 = 23, the crosstalk attenuation amount of 23), and the respective crosstalk attenuation amounts obtained as
_n-1 = 10log ₁₀ [10 ^{x1 / 10} +10 ^{x2 / 10} ... + 1
[ ^{0xn-1 / 10} ]] for calculation. As a result, the calculated value is called a power sum (hereinafter referred to as a power sum). Then, this power sum is calculated for all pairs (in the case of n = 24, 24 power sums), and the worst value among them is defined by the EIA / TIA (American Electronics Industry Association / American Telecommunications Industry Association) standard ( It is required to pass category 5).

An object of the present invention is to avoid the above-mentioned drawbacks and to use a plurality of units formed by twisting a plurality of pairs as a group to support high-speed high-speed data communication of 100 Mbps or more and high-frequency communication. In addition to being capable of ensuring sufficient crosstalk characteristics while having a small diameter, light weight, and sufficient flexibility, in particular, it can not only meet the EIA (American Electronics Industry Association) standard, but also the power sum mentioned above. It is to provide a communication cable that can meet the requirements of ISO / IEC (International Organization for Standardization / International Electrotechnical Commission) to some extent in terms of characteristics.

[0011]

Means for Solving the Problems As a means for solving the above problems, the present invention provides a unit in which a plurality of pairs are twisted so that adjacent pairs have different twist pitches. In a communication cable that is formed by collectively twisting so that the wires have different twist pitches, two adjacent two arbitrarily selected from a plurality of units
Of the two units U _i and U _j , the twist pitch P _i of the pair T _i arbitrarily selected from the plurality of pairs forming one unit U _i and the plurality of pairs forming the other unit U _j A plurality of pairs that are different in the twist pitch P _j of the arbitrarily selected pair T _j and that constitute the communication cable are twisted from a region that simultaneously satisfies the following conditions (1) to (3). Provided is a communication cable characterized in that a pitch is selected and twisted. However,
In the following condition (1) and condition (2), d is the outer diameter of the insulated wire forming a plurality of pairs.

As the condition (1), the twist pitch P of all the pairs T constituting the communication cable is selected from the range of the following mathematical formula (1). Formula (1) 8.2 ≦ P / d ≦ 30 That is, this condition (1) relates to the upper limit and the lower limit of the twist pitch of a pair in one communication cable,
Twist pitch P of all pairs T that make up the communication cable,
It is necessary to select from within this range and twist the pair T together.

As the condition (2), twisting of two pairs T _i1 and T _i2 arbitrarily selected from a plurality of pairs T _i constituting one unit U _i arbitrarily selected from the plurality of units The pitches P _i1 and P _i2 satisfy the relationship shown in the following formula (2) or formula (2) ′. Formula (2) When P _i1 > P _i2 , P _i2 /d≦(1.5
+ 0.81P _i1 ) / d Formula (2) ′ When P _i1 <P _i2 , P _i2 / d ≧ (−1.
67 + 1.23P _i1 ) / d That is, this condition (2) relates to the relationship of the twist pitch of a pair in one unit, and in each unit that constitutes the communication cable, all the combinations of two pairs are In order to satisfy the condition (2), it is necessary to select the twist pitch of the pair and twist the pair.

As the condition (3), of the two adjacent units U _i and U _j arbitrarily selected from the plurality of units, one of the plurality of pairs forming one unit U _i is arbitrarily selected. a twist pitch P _i pairs T _i, the twisting pitch P _j of an arbitrarily chosen pair T _j of the plurality of pairs constituting the other of the unit U _j is the maximum value of the twisting pitch P _i pairs T _i When P _{i (max) is} the minimum value and P _{i (min)} is the minimum value, and P _{j (min)} is the minimum value of the twist pitch P _j of the pair T _j , the following formula (3) or formula (3) ′ Satisfy the relationship shown in any of Formula (3) When P _{i (max)} <P _{j (min)} , P _{i (max)} /
P _{j (min)} ≤ 0.85 When Formula (3) 'P _{i (min)} > P _{j (min)} , P _{i (min)} /
In P _{j (min)} ≧ 1.04, and the other P _j other than P _{j (min)}
Is greater than P _{i (max)} , and P _{i (max)} / P _j ≦ 0.85, that is, this condition (3) relates to the relationship of the twist pitch of a pair between two adjacent units,
Between two adjacent units, it is necessary for all the combinations of two pairs to be twisted by selecting the twist pitch of the pairs so as to satisfy the condition (3).

[0015]

When the twist pitches of a plurality of pairs are numerically limited in this way, the twist pitches of a pair forming a unit and a pair forming a unit adjacent to this unit are always different, and each pair is obtained as a result of the experiment. Since they are twisted together at the optimum twisting pitch, it is possible to obtain sufficient crosstalk characteristics without specially shielding each unit while supporting high-speed data communication and high-frequency communication at high frequencies of about 100 Mbps or higher. In particular, not only the EIA (American Electronics Industry Association) standard can be cleared, but also the above-mentioned characteristics regarding the power sum are ISO / IE
It is expected that the requirements of C (International Organization for Standardization / International Electrotechnical Commission) can be met to some extent.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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. The communication cable 10 is provided with an interposer 34 provided as necessary.
A plurality of units 12 are collectively twisted via
And the sheath 38 is formed on the push-wrap 36. That is, the communication cable 10 of the present invention is a so-called unit type communication cable, and corresponds to a standard of electric wires that can be used for high-speed data communication of about 100 Mbps defined by EIA / TIA (American Electronics Industry Association / American Telecommunications Industry Association). Is something that can be done. Therefore, the communication cable 10 of the present invention can cope with high-speed data communication in a premises wiring system of a commercial building or the like, which has been increasingly demanded in recent years. In the embodiment shown in FIG. 1, the communication cable 10 is composed of six units 12A to 12F, but other suitable number may be used if necessary.

Each of the plurality of units 12A to 12F is formed by twisting a plurality of pairs 14 as shown in FIGS. In the embodiment shown in FIGS. 1 and 2, each unit 12A-12F consists of four pairs 14A-14D, but other suitable numbers may be used as desired. In this way six units 12A to 1
Since each of the 2Fs consists of four pairs 14A-14D, the communication cable 10 shown in FIG.
Four.

The plurality of units 12 are twisted so that adjacent units 12 have different twist pitches. Here, in the present invention, the twist pitch of the unit 12 means the four pairs 14A constituting each unit 12.
To 14D are twisted together.

Each pair 14 is formed by twisting two insulated wires 16 as shown in FIG. As shown in FIG. 3, the insulated wire 16 is formed by covering the conductor 18 with the insulating layer 20. As the conductor 18, for example,
Annealed copper wire or the like can be used, and the insulating layer 20 can be formed of, for example, polyethylene or the like.

These four pairs 14A to 14D are twisted so that adjacent pairs 14 have different twist pitches so that crosstalk does not occur. Therefore, for example, the twist pitch P _A of one pair 14A of the adjacent pair 14A and 14B shown in FIGS. 1 and 2 and the twist pitch P _B of the other pair 14B are different, which means that the pair 14B and the pair 14C, 1 to
4C and 14D, and also between 14D and 14A. That is, the twist pitch of the pair 14A is P _A , and the twist pitch of the pair 14A is
The twist pitch of _B is P _B , the twist pitch of 14 _C is P _C ,
If the twist pitch of the pair 14D is P _D , P _A ≠ P _B ,
P _B ≠ P _C , P _C ≠ P _D , P _D ≠ P _A always hold.
This is true for all of the units 12A to 12F forming the communication cable 10. In the present invention, the twist pitch of the pair 14 refers to the pitch at which the two insulated wires 16 of each pair 14 are twisted together.

[0021] In the communication cable 10 of the present invention, a plurality of pairs constituting one of the unit U _i of the two units neighboring chosen arbitrarily U _i, U _j among the plurality of units 12 A pair T _i selected arbitrarily from 14 and a plurality of pairs 14 constituting the other unit U _j
Among them, the pair T _j arbitrarily selected is twisted with a different twist pitch.

Therefore, for example, taking FIG. 1 as an example,
A pair 14A arbitrarily selected from the plurality of pairs 14 forming the unit 12A and a pair 14A and a unit 12F arbitrarily selected from the plurality of pairs 14 forming the unit 12B adjacent to the unit 12A are formed. It is necessary to set the twist pitch different from the twisted pair 14A arbitrarily selected from the plurality of pairs 14. This is unit 1
This is to prevent the crosstalk characteristic from being deteriorated when the pair 14A of 2A and the pair 14A of the unit 12B and the pair 14A of the unit 12F are adjacent to each other. In addition, it is needless to say that the twist pitches of the pair 14 arbitrarily selected among the other adjacent units 12B and 12C, the unit 12C and the unit 12D, the unit 12D and the unit 12E, and the unit 12E and the unit 12F are different. .

In this case, in order to obtain a good crosstalk characteristic, it is sufficient to adjust the twist pitch of the pair 14 between the adjacent units 12, so that the units 12 are arranged as shown in FIG.
Are set to two types, a type I having a pair 14 twisted at a predetermined twist pitch, and a type II having a pair 14 twisted at a twist pitch different from the twist pitch of this type I. 12 and type I
The units 12 of I are arranged alternately. For example, FIG.
The unit 12A in FIG. 4 is a type I (see FIG. 4) and the unit 12B is a type II (see FIG. 4), and the following units 12C to 12F are similarly alternately arranged, so that all the adjacent units 12 are The twist pitch of the pair 14 can be adjusted to be different.

In addition, in this way, type I (see FIG. 4)
When setting two types of unit 12 of type II and type II (see FIG. 4), as shown in FIG.
In the case of a unit 12 made up of 4D, two adjacent units can be set by setting 8 types of pitch numbers from 4 (pairs) × 2 (the number of types of units) = 8 (the number of types of twist pitches of a pair) The twist pitches of all the pairs 14 may be different between the 12 pieces. That is, constituting the pair T _i and the other unit U _j arbitrarily chosen among the plurality of pairs 14 constituting one of the unit U _i of which optionally adjacent the selected two unit U _i, U _j Multiple one-to-one
It is possible to twist a pair T _j selected arbitrarily among the four at different twist pitches. For example, in FIG.
The twist pitch between the pair 14A arbitrarily selected from the plurality of pairs 14 forming the unit 12A and the pair 14A arbitrarily selected from the plurality of pairs 14 forming the unit 12B adjacent to the unit 12A is always the same. It will be different.

Further, in the present invention, a plurality of pairs 14
Is twisted by selecting the twist pitch of the pair 14 from a region that simultaneously satisfies the following conditions (1) to (3). However, in the following condition (1) and condition (2), d is the outer diameter of the insulated wire 16 forming the plurality of pairs 14.

As the condition (1), the twist pitch P of all the pairs T (reference numeral 14 in the drawing) constituting the communication cable 10 is used.
Is selected from the range of the following mathematical expression (1). Formula (1) 8.2 ≦ P / d ≦ 30 That is, the condition (1) is one communication cable 10
It relates to the upper and lower limits of the twist pitch of the pair 14 within, and it is necessary to twist the pair 14 by selecting the twist pitch P of the pair T within this range. Therefore, for example, referring to FIG. 1 as an example, all the pairs 14 configuring the communication cable 10 are selected from the range satisfying the mathematical expression (1).

As the condition (2), two arbitrarily selected pairs T _i1 and T out of a plurality of pairs T _i constituting one unit U _i arbitrarily selected from the plurality of units 12 are selected.
pitch P _i1, P _i2 twist _i2 is, satisfies the relationship shown in Equation (2) or formula (2) '. Formula (2) When P _i1 > P _i2 , P _i2 /d≦(1.5
+ 0.81P _i1 ) / d Formula (2) ′ When P _i1 <P _i2 , P _i2 / d ≧ (−1.
67 + 1.23P _i1 ) / d That is, this condition (2) relates to the relationship of the twist pitch of the pair 14 in one unit 12, and in each unit 12 constituting the communication cable 10, 2
The twist pitch of the pair 14 is selected so that all the combinations of the two pairs 14 satisfy the condition (2).
Need to be twisted together.

Therefore, for example, the unit 12 shown in FIG.
In A, the equation (2) or the equation (2) ′ is always established between the pair 14A and the pair 14B. This is, of course, between the other pairs 14A and 14C, 14A and 14D, 14B and 14C, 14B and 14D, 14C in the unit 12A. And 14D
Between all pairs 1 in one unit 12A between
4 combinations (for four pairs 14A-14D,
It is also necessary to be established for 6 types). In addition to the unit 12A, other units 12B to 12F
The same holds true within.

As the condition (3), two adjacent units U _i , U arbitrarily selected from the plurality of units 12 are selected.
a plurality of pairs 14 of one unit U _i of _j
The pitch P _i twisted pair T _i which is arbitrarily selected, the twisting pitch P _j of arbitrarily selected pair T _j of the plurality of pairs 14 constituting the other of the unit U _j is the pair T _i of The maximum value of the twist pitch P _i is P _{i (max)} and the minimum value is P _{i (min)} ,
When the minimum value of the twist pitch P _j of the pair T _j is P _{j (min)} , the relationship shown in the following formula (3) or formula (3) ′ is satisfied. Formula (3) When P _{i (max)} <P _{j (min)} , P _{i (max)} /
P _{j (min)} ≤ 0.85 When Formula (3) 'P _{i (min)} > P _{j (min)} , P _{i (min)} /
In P _{j (min)} ≧ 1.04, and the other P _j other than P _{j (min)}
Is greater than P _{i (max)} and P _{i (max)} / P _j ≦ 0.85 That is, this condition (3) relates to the relationship of the twist pitch of the pair 14 between two adjacent units 12. It is necessary to twist the pair 14 by selecting the twist pitch of the pair 14 so that all the combinations of the two pairs 14 between the two adjacent units 12 satisfy the condition (3).

In particular, in this case, the equation (3) is calculated as follows.
If _i a _{(max) <P j (min} ), i.e., for example, the twisting pitch P _i pairs T _i which constitutes one of the unit U _i 9.0
mm, 10.0 mm, 11.0 mm, 11.9 mm,
Twisted pair T _j which constitutes the other unit U _j pitch P _j
Is 15.9 mm, 18.9 mm, 22.9 mm, 27.
One unit U _j , as when set to 8 mm
Of the twist pitch P _j of the pair T _j of the other unit U _i
It shows the condition when the twist pitch P _i of any pair T _i that composes is larger than the twist pitch P _i .

Further, the mathematical expression (3) 'is P _{i (min)} > P
_In the case of _{j (min)} , that is, for example, one unit U _i
The twist pitch P _i of the pair T _i that composes is 9 mm, 10 m
m, 11 mm, with 11.9 mm, the twisting pitch P _j pair T _j which constitutes the other unit U _j 8.6mm, 15.
As in the case of 9 mm, 18.9 mm, and 22.9 mm, the minimum value P _{j (min)} of the twist pitch P _j of the pair T _j of one unit U _j constitutes the other unit U _i . The condition is shown when the twist pitch P _i of the pair T _i is smaller than the minimum value P _{i (min)} . Further, in this case, of the twist pitch P _j of the pair T _i , the minimum value P
The twist pitch P _j other than _{j (min)} is P _{i (max)} / P _j <
The condition is 0.85, that is, larger than P _{i (max)} . Therefore, the condition (3) 'is towards the twisting pitch P _j pair T _j which constitutes the one of the units U _j is than the twisting pitch P _i pairs T _i constituting the other of the unit U _i adjacent Although generally large, the minimum value of the twisting pitch P _i pair T _i P _{i (min)} P _j when placed pair pair T _j the unit U _j with _(min) is a small twist pitch than This shows the conditions.

Therefore, for example, of the six units 12A to 12F which form the communication cable 10 shown in FIG.
Between two adjacent units 12A and 12B, a twist pitch P _A of a pair 14A arbitrarily selected from a plurality of pairs 14 forming the unit 12A and a unit 12B adjacent to the unit 12A are formed. The twist pitch P _B of the pair 14 B arbitrarily selected from the plurality of pairs 14 is defined by the maximum value of the twist pitch P _A being P _{A (max)} , the minimum value being P _{A (min),} and the twist pitch P _B being When P _{A (max)} <P _{B (min)} when P _{B (min)} is the minimum value, Equation (3) is used, and P _{A (min)} > P _{B (min)} And P
_When P _B other than _{B (min)} is P _{A (max)} <P _B , that is, larger than any twist pitch P _A of the pair 14A, the pair 14A and the pair 14A are satisfied so as to satisfy the equation (3) ′. It is necessary to set the twist pitch of the pair 14B. This is unit 1
The pair 14A of 2A and the pair 14B of the unit 12B are not limited to each other, and other combinations of the pair 14 between the unit 12A and the unit 12B (for example, four pairs 14A to 14D, such as the pair 14A and 14C). In the case of, it is necessary to hold in all of 16 ways). In addition, the other adjacent units 12B, 12C, and 12
C and unit 12D, unit 12D and unit 12
E, unit 12E and unit 12F, unit 12F
It is needless to say that this condition (3) needs to be satisfied even between the twist pitches of the pair 14 arbitrarily selected between the unit 12A and the unit 12A.

When the twist pitches of the plurality of pairs 14 are set by numerically limiting so as to simultaneously satisfy these conditions (1) to (3), as will be understood from the experimental examples and examples described later, about 100 Mbps. Or when used for high frequency high-speed data communication or higher frequency communication,
Sufficient crosstalk characteristics can be obtained, and in particular, not only the standard of EIA (Electronic Industries Association) can be cleared, but also the above characteristics relating to the power sum are ISO / I
It is expected that the requirements of EC (International Organization for Standardization / International Electrotechnical Commission) can be met to some extent.

Next, the above-mentioned conditions (1) to (3)
The process that led to is described in detail below.

[0035]

[Table 1]

In the present invention, in order to meet the requirements of ISO / IEC (International Organization for Standardization / International Electrotechnical Commission), the worst value of the power sum obtained for each pair 14 constituting the communication cable 10 is shown in Table 1 as EIA / TIA
100M defined by (American Electronics Industry Association / American Telecommunications Industry Association)
Since it becomes a problem whether or not the standard (category 5) of the electric wire that can be used for high-speed data communication of bps is passed, it is necessary to study this power sum first in order to derive these conditions. In this case, when considering the power sum for a certain pair 14, as described above, the power sum substitutes the crosstalk attenuation amount of the combination between a certain pair 14 and all other remaining pairs 14 into a predetermined formula. Therefore, the crosstalk attenuation amount between one pair 14 and the other three pairs 14 in the same unit 12 The crosstalk attenuation amount between the four pairs 14 forming the adjacent units 12 Every other one Attenuation amount between four pairs 14 which form the unit 12 of each of the crosstalk attenuation amounts between four pairs 14 which form the unit of every two units between the pair 14 which form the four units 12 of It is necessary to select the twist pitch by examining the crosstalk attenuation amount separately.

Specifically, in the present invention, as described above, the unit 1 of type I and type II shown in FIG. 4 is used.
These two types of units 1 are arranged because the two are arranged alternately.
Considering the relationship from above for each pair 14A to 14D forming part 2, the relationship is the same for the pair 14 forming all other units 12,
no problem. Therefore, the communication cable 10 having the six units 12A to 12F shown in FIGS. 1 and 4 will be described as an example. For example, the unit 1 of type I shown in FIG.
2A and the type 12 unit 12B need only be examined, and the unit 12A (type I),
Adjacent units 12B in the same unit 12A
Or any one of the units 12F, every other unit 12C or one of the units 12E, and between every two units 12D, and the unit 12B.
For (Type II), the same unit 12B
Among them, the crosstalk attenuation amount of the combination of the pair 14 is examined between any one of the adjacent units 12C and 12A, every other unit 12D or unit 12F, and every other unit 12E. It will be.

In the case of the communication cable 10 having the six units 12A to 12F as shown in FIGS. 1 and 4, the pair 14 which is the object of examination in the above example.
Every 3 units for unit 12A with
Since 2 is every other unit 12C or unit 12E, it does not need to be examined redundantly, and if the crosstalk attenuation amount between the units 12 from the above is examined, all other units are There is no problem because the amount of crosstalk attenuation between the pair 14 is considered. This also applies to the type II unit 12B.

Further, in order for the worst value of the power sum obtained for each pair 14 to pass the standard (category 5) defined by the EIA / TIA (American Electronics Industry Association / American Electronics Industry Association) shown in Table 1, , At least each pair 14 above
It is necessary that the actual value of the near-end crosstalk attenuation amount of the combination of 1) has a margin with respect to the value of this standard (category 5). Therefore, the worst value of the near-end crosstalk attenuation amount with respect to the standard value is 1 to 1 in the same unit 12, respectively.
For the combination of 4, the experience shows a margin of 5 dB, and for the combination of the pair 14 between adjacent units 12, the twist pitch value of the pair 14 is close and near-end crosstalk is likely to occur, so a margin of 9 dB is set a little higher. Pair 1 for every other pair 14 between every other unit 12.
It is lower than the distance of 4 is long, but if it is too low as will be described later, the standard value shown in Table 1 cannot be passed at the worst value of the power sum, so that the twist pitch of the pair 14 should have a margin of 5 dB. I examined the selection.

Regarding the near-end crosstalk attenuation amount of the combination of pairs 14 between every two units 12, it has been empirically recognized that there is always a margin of 10 dB or more with respect to the standard value. Did not do. From this, it is presumed that it is not necessary to consider the communication cable 10 having a large number of units 12 as well, for units every two or more units, since empirically little crosstalk occurs.

Further, in this case, as shown in FIG. 4, since the two types of units 12 of type I and type II are alternately arranged, for example, the unit 12A and every other unit 12A are arranged. The unit 12C
In the above, the set twist pitch values of the pair 14 are exactly the same, but since the distance between the unit 12A and the unit 12C is long, it is empirically considered that the influence on the near-end crosstalk is not necessarily large. Therefore, in the present invention, even if two types of units 12 of type I and type II are alternately arranged in order to make the twist pitch of the pair 14 different between the two adjacent units 12, the power sum is the standard. There is no problem, and there is no problem in passing.

From the above, first, the near-end crosstalk of the combination of the pair 14 in the same unit 12 was examined. In considering this point, 7.5mm
Within a range of ˜28.0 mm (the reason for limiting this range will be described later), some pairs 14 for which the twist pitch is selected are twisted together by changing the combination of the twist pitch lengths. Prototypes manufactured and one for each
Near end crosstalk attenuation was measured for the four combinations.

The measurement of this near-end crosstalk attenuation amount was performed for all frequency bands of the standard shown in Table 1 (12 frequencies shown in Table 1). Then, the value obtained by subtracting the standard value shown in Table 1 from the measured value of the near-end crosstalk attenuation amount obtained for each combination of the pair 14 in this way is used as the total frequency band of the standard shown in Table 1 (Table 1 (12 frequencies shown in 1). Then, in the worst case, it becomes a problem to have a margin with respect to the standard values shown in Table 1. Therefore, for each combination of pair 14, 12 kinds of near-end crosstalk attenuation amounts obtained in the entire frequency band are obtained. From the above, the minimum value was used as the crosstalk level for each combination.

As a result of this measurement, as described above, in the same unit 12, it becomes a problem whether or not there is a margin of 5 dB with respect to the standard value shown in Table 1. Therefore, the near-end crosstalk attenuation amount was measured. Among several combinations of 14 pairs, only the combinations of 14 pairs in which the measured value of the near-end crosstalk attenuation amount is 5 dB or less with respect to the standard value are shown in FIG. That is, in FIG. 5, the horizontal axis shows the twist pitch P ₁ of the pair T ₁ on the induction side (transmission side), and the vertical axis shows the twist pitch P ₁ of the pair T ₂ on the guided side.
₂ is taken to show what twist pitch combination of pairs 14 could not have a 5 dB margin to the specified value.

In this case, (1) contrary to the measured values when the pair T ₁ is the guiding side (sending side) and the pair T ₂ is the guided side,
(2) Since the measured values are the same when the pair T ₁ is the guided side and the pair T ₂ is the guiding side (transmission side), the twist pitch of the twist pitch is based on the data actually measured (1). The combination of the numerical values is the same, but the combination of (2), which is the combination of the guiding side (sending side) and the guided side, is also shown in FIG. Therefore, the plots shown in FIG. 5 are arranged in line symmetry.

Based on the experimental results shown in FIG. 5 thus obtained, the boundary line between the combination of the pair 14 having a margin of 5 dB with respect to the standard value shown in Table 1 and the combination of the pair 14 not having the margin is shown. The solid line L shown in FIG.
₁ (see FIG. 5) and solid line L ₂ (see FIG. 5). That is, if a twist pitch combination of pair 14 is selected from the shaded area A ₁ (see FIG. 5) and the shaded area A ₂ (see FIG. 5) shown in FIG. 5, there is always a margin of 5 dB with respect to the standard value. be able to. And this solid line L ₁
(See FIG. 5) is P ₂ = 1.5 + 0.81P ₁ and the solid line L ₂ (see FIG. 5) is P ₂ = −1.67 + 1.
It is represented by 23P ₁ . Also, in FIG. 5, the shaded area A
₁ (see FIG. 5) in the case of P _1> P _2, the hatched area A ₂
(See FIG. 5) is the case where P ₁ <P ₂ . Therefore, from these facts, in order to select the combination of the twist pitches of the pair 14 from the range of the shaded area A ₁ (see FIG. 5) or the shaded area A ₂ (see FIG. 5), P ₁ > P ₂ When P ₂ ≦ 1.5 + 0.81P ₁ (equation (A)), and when P ₁ <P ₂ , P ₂ ≧ −1.67 + 1.23P
₁ ( ₁ ) so that the relationship of ₁ (equation (A) ′) is satisfied
It was found that a twisted pitch combination of 4 should be selected.

Therefore, in order to condition this in relation to the outer diameter d of the insulated wire 16 forming the pair 14, both sides of these formulas (A) and (A) 'are insulated wires forming the pair 14. The following twist pitch relationship was obtained by dividing by the outer diameter d of 16. That is, when P ₁ > P _{2 in} the equation (a), P ₂ /d≦(1.5
+ 0.81P ₁ ) / d When formula (a) ′ P ₁ <P ₂ , P ₂ / d ≧ (−1.
67 + 1.23P ₁ ) / d Then, in order to always have a margin of 5 dB with respect to the standard value in the same unit 12, these formulas (a) and (a) ' Since it is necessary to hold for any of the combinations of pairs 14, P in the formulas (a) and (a) ′
By replacing ₁ with twisting pitch P _i1 of the arbitrarily selected pairs T _i1, also similarly as twist pitch P _i2 pair T _i2 which is arbitrarily selected P _2, equations under the condition (2) (2 ) And mathematical formula (2) '. In this way, the condition (2) is set regarding the relationship of the twist pitch of the pair 14 in the same (one) unit 12.

Next, the near-end crosstalk in the combination between the four pairs 14 forming the adjacent units 12 was examined. In examining this point, in the present invention, since it is necessary to simultaneously satisfy the conditions (1) to (3), eight twist pitches are selected from the range satisfying the condition (1) described in detail later. 8 pairs 14 having these selected twist pitches are used, and four pairs 14 of these are twisted together to form two types of unit 12 of type I and type II shown in FIG. As shown in FIG. 4, three sets of type I and type II units 12 were alternately arranged to manufacture a communication cable 10 having a total of six units 12A to 12F.

[0049]

[Table 2]

Specifically, as shown in Table 2, the outer diameter is 0.
As shown in FIG. 1, six units 12A are used by using four pairs 14 of insulated electric wires 16 in which a conductor 18 made of an annealed copper wire of 511 mm is covered with an insulating layer 20 made of low density polyethylene and having an outer diameter of 0.94 mm. Through 12F 34
A communication cable 10 formed by twisting together via a cable was manufactured. In this case, as Experimental Example 1, first, as shown in Table 2, the twist pitch of four pairs 14A to 14D,
That is, the two-core insulated wire 1 that constitutes each pair 14
The pitch for twisting 6 is 10 mm, 14 mm, 18 mm, and 22 mm for type I, and 12 mm, 16 mm, and 20 for type II, respectively.
mm and 24 mm, and the twist pitch of the adjacent pair 14 in the same unit 12 and the adjacent unit 1
After the twist pitch of the pair 14 between the two was made different, two types of units 12 of type I and type II were alternately arranged as shown in FIG.

As Experimental Example 2, as shown in Table 2 as well, the twist pitch of four pairs 14A to 14D, that is, the pitch of twisting the two insulated wires 16 forming each pair 14 is a type I. About 10.0 mm, 11.5 mm, 13.0 mm, 14.5
mm, for Type II, 10.5 m each
The communication cable 10 set to m, 12.0 mm, 13.5 mm, and 15.0 mm was manufactured.

Next, with respect to the two experimental examples shown in Table 2, all combinations of pairs 14 between adjacent units 12 (between type I and type II in Table 2) (16 ways per experimental example) Therefore, the near-end crosstalk attenuation amount was measured. In this case, the two adjacent units 12 are always a combination of type I and type II as shown in FIG.
One combination (for example, the unit 12 shown in FIG. 4).
It is sufficient to measure the near-end crosstalk attenuation amount only for the combination of A and the unit 12B only) because the result is the same between all the other adjacent units 12.

The near-end crosstalk attenuation amount thus obtained for each experimental example can be used for high speed data communication of 100 Mbps of EIA / TIA (American Electronics Industry Association / American Telecommunications Industry Association) shown in Table 1. The evaluation was performed in the light of the standard (category 5) of electric wires. The evaluation method is based on all combinations (for example, pairs and pairs, between four pairs or pairs forming the type I unit 12 and four pairs or pairs forming the type II unit 12 shown in Table 2). The values obtained by subtracting the standard values shown in Table 1 from the measured values of the near-end crosstalk attenuation obtained for pair-to-pair, pair-to-pair, pair-to-pair, etc.) are calculated. It was obtained over the entire frequency band of the standard shown (12 frequencies shown in Table 1). Then, even in the worst case, it is a problem whether or not it is possible to have a 9 dB margin with respect to the standard values shown in Table 1. Therefore, for each combination of pair 14, there are 12 types of near-end crosstalk obtained in the entire frequency band. From among the attenuation amounts, the minimum value was used as the crosstalk level for each combination.

The evaluations of Experimental Examples 1 and 2 obtained as described above are shown in FIG. That is, in FIG. 6, the twist pitch of the pair T _I constituting the unit _I I of type I is P _I , and the twist pitch of the pair T _II constituting the unit U _{II of} type II is P _II , and the horizontal axis indicates The ratio of the twist pitch, that is, P _I / P _II is taken, and the vertical axis shows a ratio of 1
The minimum value in the entire frequency band of the value obtained by subtracting the standard value shown in Table 1 from the measured value of the near-end crosstalk attenuation amount obtained for each combination of 4 was taken, and the combination of 14 pairs in each experimental example was taken. It shows the evaluation of near-end crosstalk attenuation. Therefore, in this case, when the minimum value has a margin of 9 dB or more with respect to the standard value, the combination of the pair 14 is 9 dB with respect to the standard value in all other frequency bands. It has a margin.

In FIG. 6, the horizontal axis indicates the twisting pitch.
Chi ratio (P_I / P_II) Was taken from the near-end crosstalk
Usually thought to be influenced by the twist pitch ratio of 14
This is because The horizontal axis of FIG. 6 is P_I / P
_IITherefore, if the horizontal axis is less than 1, P
_I <P_IIWhen the horizontal axis is greater than 1,
Is P_I > P_IIIt is shown that. In addition, twist of pair 14
The pitch is set differently as shown in Table 2.
Therefore, in the experimental example shown in Table 2, P_I / P _II= 1
The value of 1 on the horizontal axis in FIG.
There is no plot above.

Further, in FIG. 6, among the data obtained for all the combinations of the pair 14 of Experimental Example 1,
The data in the case where at least one of the combinations of pairs 14 is the pair 14 having a twist pitch of 15 mm or less (that is, the pair of Experiment Example 1, the pair, and the combination of pairs) is shown by a plot ◇, and the pair having a twist pitch of more than 15 mm Data for 14 combinations are shown by plots ♦. In addition, all the data for Experimental Example 2 are shown by plot ◯ in FIG. In this case, Experimental Example 2
As shown in Table 2, the twist pitch of the pair 14 is all 15
Since it is less than or equal to mm, the plot ◯ in FIG. 6 indicates data when both of the combinations of 14 are less than or equal to 15 mm.

In FIG. 6, first, all of the twist pitches P _II of the pair T _II constituting the type II unit U _II are more than the twist pitches P _I of the pair _I constituting the other type I unit U _I. Is larger (that is, the maximum value of the twist pitch P _I is P _{I (max)} , and the minimum value of the twist pitch P _II is P
_{II (min)} , P _{I (max)} <P _{II (min)} )
For, it was determined areas of twist pitch ratio of the pair 14 that can have the margin of 9dB relative to the standard value (P _I / P _II), as indicated by the shaded area in FIG. 6, P _I <
Within the range of the combination of P _II , P _I / P _II ≦
0.85 (vs. T _i is selected arbitrarily, the twisting pitch of _{T j P i, P i /} P j ≦ 0.85 When P _j) by selecting the twist pitch of the pair 14 from the region satisfying a It has been found that it is possible to have a margin of 9 dB with respect to the standard value. In this case, the twist pitch P _I and the twist pitch P _II
When the magnitude relationship with and is taken as P _I > P _II (that is, the ratio of the twist pitch P _I and the twist pitch P _II is P _I / P _II > 1), the above P _I < If 0.85, which is the value relating to the twist pitch ratio in the case of P _II , is set to the reciprocal, the same result is obtained, so P _I / P _II ≧ 1.17
The twist pitch of the pair 14 may be selected from within the area.

Based on the above conclusion, referring to FIG. 6, with respect to Experimental Example 1, Pair 1 in which the twist pitches both exceed 15 mm
The characteristic curve is slightly different between the combination of 4 and the pair of 14 in which at least one has a twist pitch of 15 mm or less, and the characteristic curve regarding the combination of the pair 14 in which the twist pitch exceeds 15 mm (that is, formed by connecting plots ◆). In a region satisfying the margin of 9 dB (see the hatched region in FIG. 6), at least one of them has a twisted pitch of 15 mm or less. The curve is shown in the outer direction of the figure, and all are included in the shaded area shown in FIG. Therefore, if P _I <P _II ,
P _I / P _II ≦ 0.85 (when P _I > P _II , P _I / P _II
If the twist pitch of the pair 14 is selected from the region satisfying P _II ≧ 1.17), the combination of the pair 14 in which at least one has a twist pitch of 15 mm or less,
A combination of pairs 14 each having a twist pitch of more than 15 mm can have a margin of 9 dB with respect to the standard value. Therefore, two adjacent units 12
In the combination of the pair 14 between the two, as in Experimental Example 1 shown in Table 2, all the twist pitches P _II of the pair T _II forming the unit U _{II of the} type II form the other unit U _I of the type I. If greater than the twist pitch P _I pair _I that, always P _I <P _II is satisfied (i.e., P
_{I (max)} <P _{II (min)} ), P _{I (max)} / P _{II (min)} ≤
0.85 (that is, when P _{I (min)} > P _{II (max)} , P
_{If I (max)} / P _{II (min)} ≧ 1.17) (equation (B)) is satisfied, a margin of 9 dB can be provided with respect to the standard value. Then, as in the case of the same unit 12 shown in FIG. 5, P _I in this equation (B) is arbitrarily selected as the twist pitch P _i of the pair T _i , and similarly, P _II is arbitrarily set. By substituting the twist pitch P _{j of the} selected pair T _j , the formula (3) in the condition (3) was derived. In this case, P _{I (max)} / P
If the twist pitch of the pair 14 is set so as to satisfy _{II (min)} ≤ 0.85, the maximum value P _{I (max)} and the minimum value P _{II (min)}
And the other combinations of pair 14, the difference between the twist pitch P _I and the twist pitch P _II becomes large.
In between the units of the type I U _I and units U _II Type II adjacent to this unit U _I, the ratio of any other combination of very twisting pitch of pair 14 (P _I /
P _II ) is always P _I / P _II ≦ 0.85. Therefore, as a condition, when P _{I (max)} <P _{II (min)} , P
_{If I (max)} / P _{II (min)} ≤ 0.85 (Equation (B)) is set, the unit 14 between the unit U _I and the unit U _II
There is no problem because the twist pitch ratio (P _I / P _II ) can be always contained in the shaded area shown in FIG.

Here, empirically, the above equation (B) is used.
However, in the pair T _II which constitutes the type II unit U _II which is the unit 12 having the larger twist pitch of the pair 14 as a whole, the other type I unit U _I
Which is the minimum value of the twist pitch P _I of the pair T _I constituting
It is known that the inclusion of one pair 14 having a twist pitch smaller than _{I (min)} improves the near-end crosstalk level. Then, next, in such a case, that is, P
_{I (min)>} P in _{II (min),} and P _{II (min)} than other P _II
Is to study the optimum twist pitch ratio of the combination of the pair 14 when P _{I (max)} <P _II , as in the formula (B).

In examining this point, in the present invention, as will be described later, it is necessary to select the twist pitch of the pair 14 from the region that simultaneously satisfies the conditions (1) to (3). It is premised that the twist pitch of the pair 14 is selected from a region that simultaneously satisfies (1) and the condition (2). Therefore, first, the condition (1) described later in detail.
The combination of the pair 14 having the twist pitch of the pair 14 within the range of 7.5 mm to 28 mm calculated in the process of deriving the condition (2) and satisfying the condition (2) was searched for. Specifically, P _I <P _II
In such a case, for the combination of the pair 14 in the same unit U _II , since the twist pitch of the pair 14 is 28 mm at the maximum from the condition (1), the above-mentioned mathematical expression ( 28 mm in A)
_Is substituted, P _II2 ≦ 1.5 + (0.81 × 28) =
Since it is 24.18, the next long twist pitch P _II2 in this unit U _II is 24 mm or less. In the unit U _II , the next long twist pitch P _II3 is P _II3 ≦ 1.5 + (0.81 × 24) = 2.
0.94, and the next long twist pitch P _II4 is P _II4 ≦
1.5+ (0.81 × 20) = 17.7. Thus, in the unit U _II type II, in the region that satisfies the conditions (1) and condition (2), when the largest set the twist pitch P _II pair T _II, 28mm, 24
mm, 20 mm, and 17 mm. In other words, vs. T _II
As for the twist pitch P _II , the maximum value of 17 mm is selected as the minimum value even if the twist pitch P _II is set to the maximum value in the range where the condition (1) and the condition (2) are simultaneously satisfied.

In this case, next, paying attention to the relationship of the twist pitch of the pair 14 between the adjacent units 12 (type I and type II) to be examined here, between the adjacent units 12 is as described above. Therefore, it is necessary to consider the above equation (B), and here, P
It is necessary to select a twisting pitch of _{I (min)> P II (} min) and so as to pair 14, when obtaining a more P _I equation that P _I / P _II ≧ 1.17, the minimum P _II Value P _{II (min)}
Is 17 mm, so 17 / 1.17 = 14.5≈
If the twist pitch of the pair T _I that constitutes the unit _I I of type I is selected so as to satisfy the above formula (B) with 15 (mm), the maximum is 15 mm. From this,
To make P _{I (min)} > P _{II (min)} , the twist pitch P _I
Since all are 15 mm or less, the minimum value P _{II (min) of} the twist pitch P _II also needs to be 15 mm or less at the maximum. Therefore, if the _{P I (min)> P II} (min), the minimum value P _II of the twisting pitch P _{II (min),} the minimum value combinations of P _{I (min)} of twisting pitch P _I is Both 15m
It is a combination of pairs 14 having a twist pitch of m or less.

Based on the above points, when attention is paid again to FIG. 6, the vertical axis is 9 even in the range outside the shaded area.
There is data for which plots are shown at locations above dB. This is the case of the combination of the pair 14 both having a twist pitch of 15 mm or less in Experimental Example 2 from the plot ◯, and therefore the twist pitch P _II is a combination of twist pitches of 15 mm or less. In the case of the combination of the minimum value P _{II (min) of the above} and the minimum value P _{I (min)} of the twisting pitch P _I , the twisting pitch ratio (P _I / P _II ) is higher than that shown in the shaded area. Even in the area close to 1 time, Table 1
It is estimated that there are combinations of pairs 14 having a margin of 9 dB or more with respect to the standard value shown in.

Therefore, next, the twist pitches are both 15 mm.
For the following combinations of the pair 14, the area of the twist pitch ratio (P _I / P _II ) of the pair 14 that can have a margin of 9 dB with respect to the standard value was determined, and as shown in FIG. Within the range of P _I <P _II , P _I / P _II
≦ 0.96 was found to be (arbitrarily selected pairs T _i, twist pitch of T _j P _i, when the _{P j P i / P j ≦} 0.96), where a problem P _I Within the range of> P _II , from the reciprocal of this expression, P ₁ / P _II ≧ 1.04 (also P _i / P _j ≧ 1.04) is satisfied, and the pair is 1
It has been found that a twist pitch of 4 can be selected to provide a margin of 9 dB with respect to the standard value. From this, the twist pitch ratio of the pair 14 in the case of P _{I (min)} > P _{II (min)} is P _{I (min)} / P
It has been found that it may be selected from the range of _{II (min)} ≧ 1.04 (formula (B) ′). Incidentally, in this case, other P _II other than P _{II (min)} is, P _{I (max)} <since it is _{P II, P I (max)} / P II ≦ 0.85 (P i (max) / P
_{If j} ≦ 0.85) is satisfied, a 9 dB margin can be provided with respect to the standard value, as described above. Similarly, P _I in the equation (B) ′ is set to the twist pitch P _i of the arbitrarily selected pair T _i , and similarly P _II.
By replacing the twist pitch P _j of an arbitrarily chosen pair T _j, we were led to Equation (3) 'in the condition (3). As described above, the two adjacent units 12
Regarding the relationship of the twist pitch of the pair 14 between the two, the condition (3) including the formulas (3) and (3) ′ was set.

We next considered the near-end crosstalk in the combination between the four pairs 14 that make up every other unit 12. In this case, every other unit 12
As shown in FIG. 4, the pair 12 is a type I unit 12 in which the twist pitches of the pair 14 are the same, or a combination of type II units 12 in the same manner. Therefore, among all 16 combinations, which are all combinations of four pairs 14 between every other unit 12, four combinations are combinations of pairs 14 having the same twist pitch. Then, this is examined for two types of combinations of the type I units 12 and the type II units 12, so that a total of eight combinations of pairs 14 having the same twist pitch will be examined. Further, in this case, a combination of the type I units 12 (for example, the unit 12A and the unit 12 shown in FIG. 4).
C combination only), and type II unit 12
A combination of them (for example, the unit 12B shown in FIG. 4)
And the unit 12D only), the near-end crosstalk is examined one by one without any combination, and the result is the same among all the other units 12 every other, so that it is sufficient.

Based on the above points, five communication cables 10 were prototyped using pairs 14 having various twist pitches, and every other unit 12 (type I and type II. 14 in the combination of types)
The near-end crosstalk attenuation was measured for all combinations of. As a result, the four pairs 14 forming the type I unit U _I are respectively _{designated as} T _{I1 to} T _I4, and for example, the pair T _I1
, The pair T _{I1 to} pair T of the other type I units U _I arranged every other
The near-end crosstalk attenuation with _I4 is the worst among the results obtained for each pair 14 between pairs T _I1 and T _I2 , which are combinations of pairs 14 having the same twist pitch. , A combination with another pair 14 having different twist pitches (for example, pair T _I1 and pair T _I2 , pair T _I1 and pair T _I3 , pair T _I1 and pair T T).
It was confirmed that there was no problem with all of the _I4 etc.) having a margin of 10 dB or more with respect to the standard values shown in Table 1. This was the same when the combination of the units U _II between Type _II. Therefore, only for a combination of pairs 14 having the same twist pitch,
The near-end crosstalk attenuation obtained from the measurement results was evaluated in relation to the standard values shown in Table 1, and the results are shown in FIG. 7.

In FIG. 7, the horizontal axis represents the product (P × P) of the twist pitch P of the pair 14, and the vertical axis represents the measured value of the near-end crosstalk attenuation amount obtained for each combination of the pair 14. The minimum value in the whole frequency band of the value obtained by subtracting the standard value shown in Table 1 from the above is taken on the vertical axis, and the product (P × P) of the twist pitch P of the pair 14 in each case and the near-end crosstalk attenuation amount It shows the relationship of. In this case, the horizontal axis of FIG. 7 indicates the same twist pitch P.
Is the product (P × P), the half of the value on the horizontal axis is the length of the twist pitch P.

Referring to FIG. 7, in selecting the twist pitch of the pair 14, the pair 1 having the same twist pitch is selected.
The combination of 4 is the communication cable 10 shown by the dotted line in FIG.
Considering the cross section D (see FIG. 4) of FIG. 4 as the center, as shown by the arrows in FIG. 4, when considering two symmetrical positions, that is, for example, a type I unit 12A,
As shown in Fig. 4, the pair of the pair of the unit I and the unit 12C of the type I on the right side of the section D (see Fig. 4) and the unit 12E of the type I on the left side of the section D are also paired.
_Since there are combinations of _I1s , for example, each of these combinations is 3 dB against the standard value shown in Table 1.
If it is sufficient to have a margin of (correctly, since it is the amount of attenuation, it is expressed as −3 dB, and dB = 10 * Log (crosstalk power amount / signal power amount), so at −3 dB, (crosstalk power amount / If the two near-end crosstalks that occur at this symmetrical position are taken into consideration, the margin becomes O (0.5 + 0.5 = 1, Log
1 = 0). Therefore, if the margin is set to a minimum value of 5 dB with respect to the standard value, it is possible to still have a certain margin with respect to the standard value even if these two near-end crosstalks are taken into consideration.

From this, in FIG. 7, the limit of the product (P × P) of the twist pitch of the pair 14 which can have a margin of 5 dB with respect to the standard value was obtained, and the near-end crosstalk attenuation amount was measured. From the intersection of the characteristic curve L ₃ (see FIG. 7) regarding the minimum value and the 5 dB line L ₄ (see FIG. 7), it was found that it was about 785 (28.02 ² ). Then, the value of the product (P × P) of the twist pitch of 785 was raised to the power of 1/2, and it was found that 28 mm is appropriate as the upper limit of the twist pitch. That is, if the twist pitch of the pair 14 is selected from the range of 28 mm or less, it is considered that the power sum obtained for the combination of the pair 14 between every other unit 12 can pass the standard values shown in Table 1.

Here, in order to pass the standard shown in Table 1 in terms of power sum, it is necessary to set the upper limit to the value of the twist pitch, and similarly, the lower limit of the twist pitch is also an appropriate value. Is believed to exist. Therefore,
Next, an appropriate value was examined for the lower limit of the twist pitch value. This point was determined from the attenuation standard defined by EIA (Electronic Industries Association) shown in FIG. This Figure 8
Shows the relationship between the twist pitch of the pair 14 and the attenuation amount by taking the value of the twist pitch of the pair 14 on the horizontal axis and the attenuation amount on the vertical axis. From FIG. 8, from the intersection of the line L ₅ (see FIG. 8) of 22 dB which is the upper limit of the attenuation standard set by the EIA (American Electronics Industry Association) and the characteristic curve L ₆ (see FIG. 8) of the attenuation amount. That is, in order to prevent the attenuation from exceeding the upper limit defined by the EIA (American Electronics Industry Association) standard,
When the lower limit of the twist pitch of No. 4 was obtained, it was 7.5 mm as shown in FIG. In this way, 7.5 mm was selected as the lower limit of the twist pitch of the pair 14.

From the above, every other unit 12
Regarding the near-end crosstalk of the pair 14 combination between, 7.
If the twist pitch of the pair 14 is selected from the range of 5 mm ≦ P ≦ 28.0 mm (equation (C)), it is considered that the power thumb can pass the standard shown in Table 1. In this case, since the relationship of the mathematical formula (C) is conditioned on the relationship with the outer diameter d of the insulated wire 16 forming the pair 14, when the mathematical formula (C) is divided by d, the relationship of FIGS. The data obtained regarding the outer diameter d of the insulated wire 16 is
However, since d = 0.92 mm, this formula (C) was divided by 0.92 to derive 8.2 ≦ P / d ≦ 30 (formula (1)).

This equation (1) is calculated for every other unit 1
The range of selection of the twist pitch of the pair 14 calculated in order to pass the standard shown in Table 1 by the power sum in the combination of the twist pitch of the pair 14 between the two is shown in the present invention. As shown in FIG. 4, it suffices to set two types of units 12 of type I and type II, and the combination of every other unit 12 is either type I or type II. In the end, this formula (1)
Are all pairs 14 that make up the communication cable 10 of the present invention.
This will be the case. Therefore, this formula (1)
The condition is not limited to “between every other unit 12”, and the condition (1) is that the twist pitch P of all the pairs T forming the communication cable 10 is expressed by the formula (1 Be selected from within the range of
And it is sufficient. Rather, it is better to select the twist pitches of all pairs 14 from the range of the formula (1) and set two types of units (a total of eight twist pitches of 14 pairs) in this way. Of the pair 14 having a twist pitch that is too large, even between the units 12 that are spaced apart from each other, such as every other unit 12, with respect to the upper limit. Even if the twist pitches are different, it is difficult to have a margin of 5 dB. from these things,
The condition (1) is derived by applying the formula (1) to all pairs 14.

The results derived from FIG. 7 and FIG. 8 in this way are all pairs 1 in one communication cable 10.
Since it applies to the twist pitch of 4, the near-end crosstalk of the combination of the pair 14 in the same unit 12 and the near-end crosstalk of the combination of the pair 14 between the adjacent units 12 are the same as described above. In addition, assuming the formula (C), from 7.5 mm to 2
Select a twist pitch of 14 pairs from the range of 8.0 mm,
We manufactured various prototypes and conducted experiments. Therefore,
An actual procedure for obtaining each of the conditions (1) to (3) is performed by collecting the data shown in FIGS. 7 and 8.

Finally, regarding the near-end crosstalk in the combination between the four pairs 14 that make up every second unit 12, in this regard, the type of every other unit shown in FIG. I unit 12 and type I
With respect to the unit 12 of I, any combination of pairs 14 has a margin of 10 dB or more with respect to the standard shown in Table 1.
Regarding the passing of the standard shown in (1), there was no adverse effect and there was no problem, so no particular evaluation was performed.

As described above, the conditions (1) to (3) are derived from the above four examinations. In the ISO / IEC (International Organization for Standardization / International Electrotechnical Commission), the communication cable It is required that the worst value among the power sums obtained with respect to all pairs 14 constituting 10 pass the standard shown in Table 1. Therefore, all the power sums of the pair 14 must pass the standard. Is required. Therefore, these conditions (1) to (3) relate to the same unit 12, between the adjacent units 12, and between every other unit 12, respectively, and the worst value of the power sum is shown in Table 1. It is not necessary to satisfy only one of these conditions (1) to (3) in order to pass the standard shown, but it is necessary to satisfy these three conditions at the same time. To be done.

Then, two embodiments of the present invention in which the twist pitch of the pair 14 is selected from the region which simultaneously satisfies the above conditions (1) to (3) will be described.

[0076]

[Table 3]

In this embodiment, as shown in Table 3, a conductor 18 made of annealed copper wire having an outer diameter of 0.511 mm was covered with an insulating layer 20 made of low density polyethylene and having an outer diameter of 0.94 mm. As shown in FIG. 1, 24 pairs of communication cables 10 were manufactured by collectively twisting 6 units 12 (outer diameter 3.85 mm of the unit 12) through the interposition 34 by using the 4 pairs 14 formed. . Further, in this case, first, in the first embodiment, four pairs 14
A to 14D twist pitch, ie each pair 14
The pitches for twisting the two insulated wires 16 constituting the above are 9.0 mm for Type I and 10. Pitch for satisfying the conditions (1) to (3) at the same time.
0 mm, 11.0 mm, 11.9 mm, and for Type II, 15.9 mm, 18.9 mm, 2 respectively.
Same unit 1 with 2.9mm and 27.8mm settings
The twist pitch of the four pairs 14 in 2 and the twist pitch of the pairs 14 between adjacent units 12 were all different (see Table 3). In this case, as shown in Table 3, the twist pitch P _II of the pair 14 constituting the type II is larger than any twist pitch P _I of the pair 14 constituting the type I (that is, P _{I (max)} (11.9) <P
_{II (min)} (15.9)), the mathematical expression (3) is applied to the condition (3).

Further, as shown in Table 3, in this case, four pairs 14A to 14D in each unit 12 (Table 3
Type I pair to pair, Type II pair to pair) is 140 mm for Type I, Type II
For each, each unit 12 is configured by twisting two types of twist pitches of 160 mm (twist pitch of the unit 12), and four pairs 14A to 14D are twisted with each other at a twist pitch different from the adjacent unit 12 And As shown in Table 3, all six units 12 were collectively twisted at a pitch of 210 mm. Also,
In this Example 1, as shown in Table 3, all the pairs 14 were twisted to the left and all the units 12 were twisted to the right.

First, according to the first embodiment shown in Table 3, four pairs or more constituting the unit 12 of type I,
For each of the four pairs or a total of eight pairs 14 constituting the type II unit 12, the near-end crosstalk attenuation amount in combination with all other pairs 14 (23 pairs) is measured by a high frequency measuring instrument (network). analyzer)
The power sum is obtained for each measurement range of the measuring device from the measured values, and the results are shown in FIGS. 9 and 10.

That is, FIG. 9 shows the power sums obtained for the pairs or pairs forming the type I unit 12 for the first embodiment shown in Table 3. As can be seen from FIG. 9, the pair 14 constituting the type I unit 12 are all power sum EIA.
It is understood that the product has passed the standard specified by (American Electronics Industry Association) and has a sufficient margin with respect to the standard value even if the worst value of the power sum is taken. In addition, FIG. 10 shows the power sums obtained for the pairs or pairs constituting the type II unit 12 for the first embodiment shown in Table 3. As can be seen from FIG. 10, the pair 14 which composes the type-II unit 12 also passes the power standard in almost all standards, but has almost no margin with respect to the standard value.

Further, in Example 2, as shown in Table 3,
The twist pitches of the four pairs 14A to 14D are 9.0 mm, 10.0 mm, and 1 for Type I, respectively.
1.0 mm and 11.9 mm, and for Type II, 8.6 mm, 15.9 mm and 18.9 m, respectively.
m and 22.9 mm. That is, this Example 2
Is different from Example 1 only in the twist pitch of the pair or pairs forming the type II unit 12, and as for other conditions, as shown in Table 3, twist of the pair 14 of Example 1 and Example 2 The specifications are the same as those of the communication cable 10 of the first embodiment so that the difference in power sum due to the difference in pitch becomes clear. Specifically, the twist pitch of the pair constituting the type II unit 12 in Example 2 shown in Table 3 is set to 8.6 mm, and the twist pitch of the pair 14 constituting the type II unit 12 is set as the minimum value. A twist pitch smaller than the minimum twist pitch of the pair 14 constituting the unit 12 of I is selected (P _{I (min)} (9.0 mm)
> P _{II (min)} (8.6 mm), other P _II is P
_{I (max)} <P _II ), the power sum when the unit 12 is configured by including only one pair 14 having a small twist pitch, and the twist pitch of the pair 14 that constitutes the type II unit 12 is also obtained. But a type I unit 12
The difference from the case where the twist pitch is larger than any of the twist pitches of the pair 14 constituting the above is clarified. Therefore, for the second embodiment, the expression (3) ′ is applied under the condition (3).

Also in the second embodiment shown in Table 3, as in the first embodiment, a total of 8 pairs of 4 pairs or more constituting the type I unit 12 and 4 pairs or more constituting the type II unit 12 are obtained. For each of the 14 types of pairs, the near-end crosstalk attenuation amount in combination with all other pairs 14 (23 pairs) is measured with a high-frequency compatible measuring instrument, and the power sum is calculated from that value for each measuring range of the measuring instrument. The obtained results are shown in FIGS. 11 and 12.

That is, FIG. 11 shows Example 2 shown in Table 3.
Figure 3 shows the power sums obtained for the pairs or pairs that make up the type I unit 12 for.
As can be seen from FIG. 11, with respect to the pair 14 constituting the unit 12 of type I, as in almost the first embodiment, all of the power sums pass the standard specified by EIA (Electronic Industries Association), and It can be seen that even if the worst value is taken, there is a sufficient margin with respect to the standard value.
In addition, FIG. 12 shows the power sums obtained for the pairs or pairs forming the type II unit 12 for the second embodiment shown in Table 3. As can be seen from this FIG. 12, the pair 1 that constitutes the type II unit 12
Also in No. 4, the power sum passed the standard with a sufficient margin with respect to the standard value, and it was confirmed that the power sum in the type II unit 12 was remarkably improved as compared with the first embodiment. (Figs. 10 and 12
Refer to the results shown in). From this Example 2, the minimum value of the twist pitch of the pair 14 (P
_{II (min)} ) includes one pair 14 having a twist pitch smaller than the minimum twist pitch value (P _{I (min)} ) of the pair 14 constituting the type I unit 12, that is, the condition When the twist pitch of the pair 14 is selected so as to satisfy the mathematical expression (3) ′ in (3), the level of the whole near-end crosstalk is improved, and the power sum has a sufficient margin with respect to the standard value. I know what I can do.

From the above, if the twist pitch of the pair 14 is appropriately selected within the region satisfying the conditions (1) to (3), good crosstalk characteristics can be obtained while supporting high-speed data communication. it can. In this case, since good crosstalk characteristics can be obtained without providing a shield to each unit 12, it is possible to sufficiently reduce the diameter, weight and flexibility of the communication cable 10, and particularly , EIA / TIA
It is expected that it will not only be able to meet the standards of (American Electronics Industry Association / American Electronics Industry Association) but also meet the requirements of ISO / IEC (International Standards Organization / International Electrotechnical Commission) to some extent for the above characteristics related to power sum. it can.

[0085]

According to the present invention, as described above, since the twist pitches of a plurality of pairs are numerically limited within a predetermined range,
The twisting pitch of a pair that forms a unit and the pair that forms a unit adjacent to this unit must be different, and since each pair is twisted with the optimum value obtained from the experiment, high-speed data communication, high frequency While supporting communication,
Sufficient crosstalk characteristics can be obtained, especially EIA / TI
Not only can it pass the A (American Electronics Industry Association / American Telecommunications Industry Association) standards, but it can also meet the requirements of ISO / IEC (International Standards Organization / International Electrotechnical Commission) to some extent for the above characteristics related to power sum. There is. Moreover, since the crosstalk characteristics are realized without shielding each unit, the communication cable has a small diameter and light weight, which can reduce the cost and has sufficient flexibility. There are practical benefits such as free access to the underfloor and easy wiring to conduits and trays.

[Brief description of drawings]

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

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

FIG. 3 is a sectional view of a pair used in the present invention.

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

FIG. 5 is a plot diagram showing a pair relationship in the same unit in which the margin of the near-end crosstalk attenuation amount with respect to the standard value defined by EIA is 5 dB or less.

FIG. 6 shows the near-end crosstalk attenuation amounts obtained for all combinations of pairs between adjacent units and the pairs T _I that make up the type I unit U _I for Experimental Example 1 and Experimental Example 2 shown in Table 2. the ratio of the twist pitch P _II pair T _II constituting the unit U _II of twisting pitch P _I and type II (P _I /
It is a plot figure which shows the relationship with _PII ).

FIG. 7 shows the relationship between the near-end crosstalk attenuation amount obtained for a combination of pairs having the same twist pitch between every other unit and the product (P × P) of twist pitches of the pairs at this time. It is a plot figure which shows.

FIG. 8 is a plot diagram showing a relationship between a twisted pair pitch and an attenuation amount.

9 is a plot showing the power sums obtained for the pairs making up the Type I unit for Example 1 shown in Table 3. FIG.

FIG. 10 is a plot showing the resulting power sums for the pairs that make up the Type II unit for Example 1 shown in Table 3.

FIG. 11 is a plot showing the power sums obtained for pairs making up a Type I unit for Example 2 shown in Table 3.

FIG. 12 is a plot showing the power sums obtained for the pairs making up the Type II unit for Example 2 shown in Table 3.

[Explanation of symbols]

10 Communication Cable 12 Unit 14 Pair 16 Insulated Wire 18 Conductor 20 Insulating Layer 34 Interposition 36 Push Winding 38 Sheath I Type I Unit II Type II Unit P ₁ Induction Side (Transmission Side) Pair T ₁ Twist Pitch P ₂ Cover Twisting pitch of pair T ₂ on the induction side P _I Twisting pitch of pair T _I constituting unit _{I I} P _II Twisting pitch of pair T _II constituting unit U _{II of} type II P Twisting pitch of pair

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[Procedure amendment]

[Submission date] June 9, 1995

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 6

[Correction method] Change

[Correction content]

[Figure 6]

Front page continuation (72) Inventor Yoshihiro Yokoyama 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd.

Claims (1)

[Claims] 1. A communication cable formed by collectively twisting a plurality of units in which a plurality of pairs are twisted so that adjacent pairs have different twist pitches so that adjacent units have different twist pitches. , two units adjacent arbitrarily chosen among the plurality of units U _i, of the U _j, twist pitch P of the pair T _i which is arbitrarily selected among the plurality of pairs constituting the one unit U _{i i}
And a twist pitch P _j of a pair T _j arbitrarily selected from a plurality of pairs constituting the other unit U _j , and the plurality of pairs have the following conditions (1) to (3). )
A communication cable characterized in that a twist pitch of a pair is selected and twisted from a region satisfying simultaneously. However, in the conditions (1) and (2), d is the outer diameter of the insulated wire forming the plurality of pairs. Condition (1) The twist pitch P of all the pairs T constituting the communication cable is selected from the range of the following mathematical expression (1). Formula (1) 8.2 ≦ P / d ≦ 30 Condition (2) 1 arbitrarily selected from a plurality of units
Twisting pitches P _i1 , P of two pairs T _i1 and T _i2 arbitrarily selected from a plurality of pairs T _i forming one unit U _i
i2 satisfies the relationship shown in the following formula (2) or formula (2) '. Formula (2) When P _i1 > P _i2 , P _i2 /d≦(1.5+
0.81P _i1) / d Equation (2) 'when the P _i1 <P _i2 is, P _i2 /d≧(-1.6
7 + 1.23P _i1) / d Condition (3) two units U _i adjacent arbitrarily chosen among the plurality of units, among U _j, arbitrarily selected among the plurality of pairs constituting the one unit U _i The pair T
_i twisting pitch P _i and, twist pitch P of the arbitrarily selected pairs T _j of the plurality of pairs constituting the other of the unit U _{j
For j} , the maximum value of the twist pitch P _i of the pair T _i is P _{i (max)} , the minimum value thereof is P _{i ( min),} and the minimum value of the twist pitch P _j of the pair T _j is P _{j (min)} . In this case, the relationship shown in the following formula (3) or formula (3) ′ is satisfied. Formula (3) When P _{i (max)} <P _{j (min)} , P _{i (max)} / P
_{j (min)} ≤ 0.85 When Formula (3) 'P _{i (min)} > P _{j (min)} , P _{i (min)} / P
In _{j (min)} ≧ 1.04, and the other P _j other than P _{j (min)}
Is P _{i (max)} / P _j ≦ 0.85