CN1820427A - Alien crosstalk suppression with enhanced patch cord - Google Patents

Abstract

Systems and methods for decreasing alien crosstalk use enhanced patch cords for introducing additional attenuation. The enhanced patch cords are preferably shielded to reduce alien crosstalk down their lengths and also attenuate signals passing therethrough to a greater extent than standard communication patch cords. The interaction of two enhanced patch cords results in two suppression steps for alien crosstalk and only one suppression step for intended signal passing through a communication cable.

Description

Use different line (alien) cross-talk that strengthens patch cord to suppress

Background technology

The cross-talk that suppresses in the communication system is increasingly important practice for the reliability and the communication quality that increase system.Along with the frequency band increase of communication system, the importance that reduces or eliminates the signal cross-talk is also increasing.

In wired communication system, can cause cross-talk by the electromagnetic interference between telecommunication cable inside or a plurality of cables.Owing to the cross-talk that causes that interacts between the cable is exactly different line (alien) cross-talk.

Can use electronics cross-talk minimizing method to handle though disturb the cross-talk that is caused by another signal coherence in signal that transports in the individual signals cable and the same cable, different line cross-talk also has additional problem, because the character of interference or jammer signal is unknown.In the enforcement such as the communication of the 10Gbps ether on the installation basis of Cat 6 or Cat 5e cable, different line cross-talk is proved to be problematic.In these cables, different line cross-talk can be damaged communication performance significantly.Specially designed cable laying can be used as the different line cross-talk of reduction, but replaces already present cable laying costly with newly-designed cable laying.

Therefore, need can be used on the different line crosstalk inhibition method and the system of having installed on the cable.

Technical field

The present invention relates generally to communication system, especially for the system and method that suppresses different line cross-talk in the communication.

Summary of the invention

According to one embodiment of the invention, have the improved patch cord that strengthens decay and improved the performance that cable laying system is installed.

According to another embodiment of the present invention, can reduce different line cross-talk between telecommunication cable by the method that use is connected to the decay patch cable of telecommunication cable.

According to another embodiment of the present invention, cable laying system uses improved patch cord to reduce the different line cross-talk between the telecommunication cable.

Description of drawings

Fig. 1 is the plane graph of communication system according to an embodiment of the invention;

Fig. 2 has the schematic diagram that the cable laying that is used to provide the improved patch cord that different line cross-talk suppresses is installed;

Fig. 3 illustrates signal that use enhancing patch cord according to the present invention the increases chart to noise ratio in communication system;

Fig. 4 is the conductor and the cross-sectional view that diminishes the conductor insulation body that illustrates according to the embodiment of the invention;

Fig. 5 is the cross-sectional view with the multiple core cord that diminishes conductive coating;

Fig. 6 is the details drawing of Fig. 5 details " A ";

Fig. 7 a and 7b illustrate two comparison cross-sectional views that cable is right, simultaneously the cable of Fig. 7 b to have cross-talk between the distance of increase;

Fig. 8 is the cross-sectional view with cable of peripheral shielding (surrounding shield);

Fig. 9 is the cross-sectional view of cable with periphery shielding of modification;

Figure 10 is the cross-sectional view that has around the cable of the shielding of each wire pair;

Figure 11 is the cross-sectional view with conduction side's bolt;

Figure 12 illustrates the chart of change along the cable lay of cable length direction.

Run through whole accompanying drawing, similarly label refers to similar parts.

Embodiment

Turn to Fig. 1 now, show communication system 10.In communication system 10, the network equipment that switches (switch) 12 such as 10Gb/s ether passes through first and second telecommunication cables 18 and 20 respectively, is connected to a plurality of equipment such as personal computer (PC) 14 and 16.Be appreciated that, though Fig. 1 shows the telecommunication cable 18 and 20 that is stretched over two equipment from single network equipment, but system and a method according to the invention can realize suppressing the different line cross-talk between the telecommunication cable, no matter and the type of the equipment that this cable is connected to.

Usually, because the different line cross-talk that interaction caused between the telecommunication cable 18 and 20 will be along the whole length coupling of cable 18 and 20.Cable 18 and 20 signal suppressing that will transmit by their are to a certain degree, thereby will weaken to some extent in PC 14 and 16 in the cross-talk that is taken place between the nearer cable of ether switch 12.

By using first and second to strengthen patch cord 22 and 24, the cross-talk in the system of Fig. 1 suppresses and can be enhanced.Strengthen patch cord 22 and 24 and be designed to, for example, suppress cross-talk along they length by additional shielding is provided.Strengthen that patch cord 22 and 24 weakens the signal of communication that transmits by them and such as the noise of cross-talk.Can realize the decay in patch cord 22 and 24 in many ways.For example, by using the electric wire in the refining line footpath that strengthens in patch cord 22 and 24, perhaps, increase decay by increasing per inch twisting (twist) quantity in the electric wire that comprises in the patch cord 22 and 24.

The intensity of different line cross-talk depends on the intensity of interference or jammer signal.Therefore, the increase decay that is realized by first patch cord 22 will reduce the signal level in first telecommunication cable 18.As a result, because the decay due to the first enhancing patch cord 22, the different line cross-talk that is coupled to second communication cable 20 from first telecommunication cable will be reduced.Because the different line cross-talk that is caused by first telecommunication cable 18 in second communication cable 20 will transmit along the both direction of second communication cable 20, so different line cross-talk also will experience inhibition in the second enhancing patch cord 24.

For example, if a signal has 1 volt of peak to peak signal strength signal intensity in ether switch 12, and first strengthen patch cord 22 and be attenuated to 10% initial strength, and the signal of delivering to PC 14 from ether switch 12 will have 0.1 volt of peak to peak signal strength signal intensity.If this signal of 10% is coupled to the second communication cable when different line cross-talk, then the different line cross-talk in the second communication cable will have 0.01 volt of peak to peak signal strength signal intensity.Have the attenuation attributes of signal weakening to 10% initial strength if second strengthens patch cord 24, then different line cross-talk will be suppressed to 0.001 volt of peak to peak in second communication cable 20.Therefore, different line cross-talk has experienced twice effect that strengthens patch cord 22 and 24, and has only experienced the effect of second communication cable 24 through the signal of second communication cable 20 from ether switch 12.Select enhancing patch cord 26 to be illustrated and be used to be connected to PC 14 and 16, and similar operation is arranged, to reduce different line cross-talk at the user side that communicates to connect.

Enhancing patch cord according to the present invention can be integrated in a plurality of connections, and as shown in Figure 2, the horizontal cable strain 28 that wherein has a plurality of cables is by enhancing patch cord 30 and 32 enhancings at first and second ends of communication path.

Use enhancing patch cord according to the present invention comes enhancing signal to the ratio of noise as shown in Figure 3.Be shown in dotted line pass communication frequency by strengthening attenuated signal and the noise that patch cord caused.Because the noise ratio signal that is caused by different line cross-talk has weaken largely, in the system that uses according to enhancing patch cord of the present invention, available bandwidth and signal have all increased the ratio of noise.

By the whole bag of tricks, decay is imported in patch cord and other communication cable laying.In the design that diminishes patch cord, to consider two kinds of design parameters.A kind of parameter is included in the amount of the insertion loss (insertionloss) in the cable, and second kind is that different line cross-talk in the cable suppresses or the amount of neurological susceptibility.Preferably in cable design, reserve this two parameters.

By in diminishing conductive insulation 36 and 38, being provided with conductor 34, can increase dielectric loss, as shown in Figure 4.Also can increase dielectric loss by making with the following method: (a) cable jacket dielectric diminishes material; (b) cable spline dielectric diminishes material; And (c) wire pair shielding (it will be concentrated through the electromagnetic field of wire insulator).

Use more difficult conductive electric wire (for example, replacing copper cash) can increase conduction loss equally with aluminum steel.As mentioned above, also can increase conduction loss by the twist number that reduces conductor wire diameter or increase per unit length.The increase of twisting quantity has just increased the effective length of bands and has therefore increased conduction loss.

By metal cords " coating (tinning) " also can be increased conduction loss.Difficult coating of conducting electricity in the electric wire periphery also can increase conduction loss, because current density concentrates near surface (kelvin effect), and is having bigger loss through behind the coating material.Use multiple core cord also can increase conduction loss, for comparable wire gauge, the increment of loss is roughly 20%.Fig. 5 illustrates the cross-sectional view of the cable 40 that uses coating and multiple core cord.In the embodiment of Fig. 5, multicore copper conductors 42 is located in the coating shell 44.Fig. 6 is the details drawing of the details " A " of Fig. 5.The thickness of shell is d _s

The electric wire that use has rough surface also can increase the conduction loss that passes through electric wire.

Fig. 7 a and 7b illustrate a kind of technology, by increase cross-talk between physical distance reduce the neurological susceptibility of cable.First and second cables 46 and 48 are placed with a kind of relation of vicinity.When cable jacket material 50 on thickness, for example be increased to the shell 52 shown in Fig. 7 b, cross-talk between distance from the d shown in Fig. 7 a ₁Be increased to the d shown in Fig. 7 b ₂According to an embodiment, cable jacket material 50 is foamed materials.Cable isolator is also as the isolation that increases between the adjacent cable.

The metallicity shielding also can be used as the different line signal of minimizing and enters into the right neurological susceptibility of signal cable.Fig. 8 shows a kind of by reduce the cross-sectional view of the technology of cable neurological susceptibility in conjunction with conductor screen.In Fig. 8, conductor is located in the overall conductive shield 54 52.Conductive shield 54 is located in the shell 56.(combine detail view) as shown in Figure 9, totally shield 54 layer and can be located between first and second layer 58 and 60 of sheathing material.

Figure 10 illustrates another embodiment, and wherein single shielding 62 is around each wire pair.

Another embodiment is shown in Figure 11, and it illustrates as the conduction side's bolt 64 that reduces neurological susceptibility or conductor isolator.

In another embodiment, can reduce cross-talk by revising along the lay of its length direction.The lay of cable refers to the cable lay along its length direction.In this embodiment, fixed twisted pair length is set as the length direction along cable.Four or more cable lay values are selected to be gone out, and these values provide four pairs of cables with twisted-pair feeder length satisfying on the cable length that suggestion 10Gb/s Ethernet near-end crosstalk (NEXT) requires.Any four or more cable lay values are selected arbitrarily, and the process of selection is as described below:

1. select cable lay (A, B, C, D ...), each lay all satisfies the requirement of 10Gb/s Ethernet.

2. during cable lay was handled, any one was selected in four cable laies, and no longer makes alternative.

3. the cable of selecting is unified or be less than on the cable length at random or equal ten meters.

4. any cable in three or more residue cable lay all can be selected and be applied to as the described construction of cable of step 3.

5. repeat this process, designated up to all cable laies.

Between cable lay changes, use random distance and use the cable length chart of four kinds of different cable laies shown in Figure 12.

Though specific embodiment of the present invention and application have obtained diagram and have described, but be appreciated that, the invention is not restricted to precision architecture described here and composition, and various modifications, variation and change are conspicuous from aforementioned description, and do not break away from the spirit and scope that the present invention defines in claims.

Claims (3)

1. system that is used for reducing outside cross-talk at communication network, comprise: strengthen first telecommunication cable that patch cord is connected to first network equipment by first, the described first enhancing patch cord is a kind of decay patch cord, and it is suitable for making the signal attenuation degree of propagating by described enhancing patch cord greater than the decay in described first telecommunication cable; And

Strengthen the second communication cable that patch cord is connected to second network equipment by second, the described second enhancing patch cord is a kind of decay patch cord, and it is suitable for making the signal attenuation degree of propagating by described enhancing patch cord greater than the decay in the described second communication cable.

2. the system as claimed in claim 1, it is characterized in that, described first patch cord comprises a plurality of twisting communication wires, and described first telecommunication cable also comprises a plurality of twisting communication wires, and the described twisting communication wire of described first patch cord has the per unit length twist number (twists per length) of Duoing than the described twisting communication wire of described first telecommunication cable.

3. the system as claimed in claim 1, it is characterized in that, described first patch cord comprises a plurality of communication wires, and described first telecommunication cable also comprises a plurality of communication wires, and the described communication wire of described first patch cord has the line footpath narrower than the described communication wire of described first telecommunication cable.

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