What is a seven-category line

Category 7 wire is an 8-core shielded wire, each pair has a shielding layer (usually metal foil shielding Foil Shield), and then there is a shielding layer outside the 8 cores (usually metal braided wire mesh shielding Braided Shield), The interface is the same as the current RJ-45. Overall shielding (usually metal braided wire mesh shielding) + pair shielding (usually metal foil shielding) Category 7 line S/FTP Cat.7 (HSYVP-7) The maximum transmission frequency is 600MHz, and the transmission frequency of the super category 7 line is 1000MHz .

There are many significant differences between Category 6 and Category 7 cabling systems, the most obvious being bandwidth. The six types of channels provide a comprehensive attenuation-to-crosstalk ratio of at least 200MHZ and an overall bandwidth of 250MHZ. The seven-category system can provide at least 500MHZ comprehensive attenuation to crosstalk ratio and 600MHZ overall bandwidth.

A large number of broadband applications prompt people to demand more bandwidth. For example, a typical seven-category channel can provide a pair of lines with a bandwidth of 862MHZ to transmit video signals, transmit analog audio signals on another line pair, and then transmit high-speed LAN information on the third and fourth line pairs.

Another difference between Category 6 and Category 7 systems is their structure. The Category 6 cabling system can use either UTP or STP. The Category 7 system is based only on shielded cables. In the seven types of cables, each pair of wires has a shielding layer, and the four pairs of wires together have a common large shielding layer. From the physical structure point of view, the extra shielding layer makes the seven types of wires have a larger wire diameter.

Another important difference lies in its ability to connect hardware. The parameters of the Category 7 system require that all wire pairs provide at least 60DB of comprehensive near-end string winding when the connector is at 600MHZ. The super category five system only requires 43dB at 100MHZ, and the value of category six at 250MHZ is 46dB.

Technical advantages

Rapidly developing network applications have ever-increasing demands on bandwidth. In June 2002, ANSI/TIA/EIA568-B Copper Twisted Pair Category 6 standard [2] satisfies most commercial applications with its bandwidth of 250MHz. However, with the continuous advancement of technology, the 250MHz bandwidth cannot fully meet people's needs.

The choice of cable type should be comprehensively considered from various aspects such as cable use, required transmission capacity, transmission bandwidth, and price. There are three types of cables: unshielded twisted pair, shielded twisted pair, and optical cable.

1) Unshielded twisted pair UTP is currently the most widely used wiring system in China. It is suitable for network applications with transmission bandwidth below 250MHz and no special performance requirements. Its advantages are good overall performance, cheap price, and convenient construction and maintenance. The Category 6 wiring system has reached the performance limit of unshielded twisted pair.

2) The aluminum foil shielded twisted-pair FTP has large bandwidth, strong anti-interference performance, and has the characteristics of low smoke and zero halogen. Relatively, the price and installation cost of shielded wires are higher than that of unshielded wires, and the cable bending performance is slightly worse. This form is often used in Category 6 lines and previous shielding systems.

3) Independently shielded twisted pair STP, each pair has an aluminum foil shielding layer, and four pairs of wires are combined together and there is a common metal braided shielding layer, which is the standard structure of seven types of wires. It is suitable for high-speed network applications, provides highly confidential transmission, supports future new applications, and helps to unify the wiring platform of current network applications, so that various information from emails to multimedia videos can be in the same high-speed system in transmission. The additional shielding layer makes the seven types of wires have a larger wire diameter. These characteristics require special care when designing the installation routing and termination space, leaving a large space and a large bending radius. At present, Corning has Introduced Category 7 cabling system in China.

As early as 1997, wiring standardization organizations and manufacturers had already proposed the idea of seven types of copper cabling systems. It can provide a comprehensive attenuation to crosstalk ratio of at least 500MHz and an overall bandwidth of 600MHz, and its connector requires that all wire pairs provide at least 60dB of comprehensive near-end crosstalk at 600MHz. The super category five system only requires 43dB at 100MHz, and the value of category six at 250MHz is 46dB. Moreover, due to its excellent shielding design and high bandwidth, a typical Category 7 channel can even provide a pair of wires with a bandwidth of 862MHz for transmitting cable TV signals at the same time, and transmit analog audio signals on another wire pair, and then on the third , Four-wire pair transmission of high-speed LAN information.

Compared with the optical fiber LAN, the solution of the seven types of systems provides the expected performance and bandwidth, but its overall cost is only a fraction of the optical fiber. Some people think that fiber optic systems can bring enough bandwidth to people, and the price of fiber optic cables is close to that of Category 7 cables. However, if the cost factors of optical fiber routers, optical switches and optical network cards are considered, the price advantage of optical fiber will be quickly lost.

Compared

The internationally recognized network cable standards are divided into seven categories, and the most common ones we have at present are category five and category six. Category 7 is no longer an unshielded twisted pair, but a shielded twisted pair for applications with a transmission rate higher than 10Gbps.

What is Cat6e

Network cable category

Belden IBDN has developed a high-performance cabling system that can still operate normally at temperatures above 40°C, and officially launched the IBDN 4800LX system at the end of 1999. Its final index reaches 300MHz bandwidth, and it can still reach the 20°C specified by the Category 6 standard at 50°C. ℃ performance index. In order to distinguish it from ordinary Category 6 cabling systems, this kind of wiring whose bandwidth performance far exceeds Category 6 is called Super Category 6.

difference and use

Most Cat 6e cabling uses the same modules and jumpers as Cat 6 cabling of the same brand, so their main difference is in the cables. IBDN's Category 6e cable 4800LX has been set to operate normally at a higher temperature from the very beginning, so one of the characteristics of its cable structure is the large wire diameter, and the diameter of the transmission conductor is changed from 0.5mm (24AWG) of ordinary Category 6 Increased to 0.6mm (23AWG); Some manufacturers also used 24AWG in the initial Category 6 cables to try their best to improve the NEXT method, but in 2002 the improved cable increased its wire diameter to 23AWG. Another feature is that a cross-shaped wire pair separator is added between the 4 twisted wire pairs. Without cross separation, one pair of wires in the cable may become trapped in the gap between the two wires of the other pair, reducing the spacing between the pairs and aggravating the crosstalk problem. At the same time, the spacer and the cable sheath tightly fix the 4 pairs of wires in their designed positions, and can slow down the loosening of the wire pairs caused by the bending of the cable, thereby reducing the performance degradation during installation. The 4800LX was the first Cat 6e cable to feature a cross divider, and subsequent cables followed suit with similar technology.

What is a six-category line

Category 6 line: The transmission frequency of this type of cable is 1MHz to 250MHz. At 200MHz, the Category 6 wiring system should have a large margin for the comprehensive attenuation and crosstalk ratio (PS-ACR). It provides twice the bandwidth of Category 5. Category line is 100M, Category 5 is 155M, Category 6 is 200M. In short-distance transmission, Category 5, Category 5e, and Category 6 can reach 1Gbps. The transmission performance of Category 6 wiring is higher than that of Category 5 and Category 5e. It is most suitable for applications with a transmission rate higher than 1Gbps.

concept

With the rapid development of computer technology, people's demand for fast communication and high-speed broadband transmission is increasing, and the bandwidth of the integrated wiring system, which is the communication platform of the network, is also increasing. In June 2002, the ANSI/TIA/EIA568-B copper cable twisted pair Category 6 line standard has been officially issued. [1]

1. The ANSI/TIA/EIA568-B standard evolved from the ANSI/TIA/EIA568-A standard. The ANSI/TIA/EIA standard belongs to the North American standard series and has been playing the leading role of integrated wiring products all over the world. The new 568-B standard is structurally divided into three parts: 568-B1 General Requirements for Integrated Cabling System, 568-B2 Balanced Twisted Pair Wiring Components and 568-B3 Fiber Optic Wiring Components.

(1) General requirements of 568-B1 integrated wiring system

In this part of the new standard, the design principle of the telecommunications integrated wiring system, the installation criteria and the content related to the field test are included.

(2) 568-B2 Balanced Twisted Pair Cabling Assembly

This part of the new standard covers component specifications, transmission performance, system models and measurement procedures for user verification of telecommunications cabling systems

(3) 568-B3 fiber optic cabling assembly

In this part of the new standard, requirements related to component specification and transmission of fiber optic telecommunications cabling systems are included.

2. The main differences between ANSI/TIA/EIA568-A and ANSI/TIA/EIA568-B

2.1 New terms

(1) The term "attenuation" is changed to "insertion loss", which is used to indicate the amount of signal loss on links and channels. (2) Telecom Room (TC) is changed to Telecom Volume (TR). (3) Change "Basic Link" to "Permanent Link" 2.2 Media Type

(1) Horizontal cable 4 pairs of 100Ω Category 3 UTP or SCTP4 pairs of 100Ω Category 5 UTP or SCTP 2 or more 62.5/125μm or 50/125μm multimode fibers

(2) Backbone cable 100Ω twisted pair, category 3 or higher; 62.5/125μm or 50/125μm multimode fiber; single-mode fiber.

(3) The 568-B standard does not recognize 4 pairs of 4 twisted pair cables and 5 types of twisted pair cables

(4) 150Ω shielded twisted pair is an approved media type, however, it is not recommended for new installations. (5) Hybrid and multi-strand cables are allowed for horizontal wiring, but each cable must meet the corresponding grade requirements and meet the special requirements for hybrid and multi-strand cables.

2.3 Connecting equipment cables and jumpers

(1) The rated attenuation rate of UTP jumper wires and equipment wires composed of 24AWG (0.51mm) multi-strand wires is 20%. SCTP cables with 26AWG (0.4mm) conductors have a 50% attenuation.

(2) Category 5e modular cables need to be connected and tested at the factory.

(3) Stranded cables are recommended for jumper devices due to their greater flexibility.

2.4 Distance change

(1) Now, for UTP patch cords and equipment cords, the horizontal permanent link has a maximum of 5m (16 feet) at both ends to achieve a total channel distance of 100m (328 feet).

(2) For secondary trunk lines, the distance from the intermediate jumper to the horizontal jumper (1C to HC) is reduced to 300m (984 feet). The total trunk distance from the main jumper to the horizontal jumper (MC to HC) still follows the provisions of the 568-A standard.

(3) Equipment wires and patch cords connected to other trunk wiring types in intermediate jumpers are changed from "should not" exceed 20m (66 feet) to "shall not" exceed 20m (66 feet).

2.5 Installation Rules

(1) The bending radius of 4 pairs of SCTP cables under non-stress conditions is specified as 8 times the diameter of the cable

(2) The bending radius of 2-strand or 4-strand fiber is 25mm (1 inch) under non-stressed condition and 50mm (2 inch) during stretching.

(3) The cable manufacturer should determine the bending radius requirements of the optical fiber backbone. If bend radius information is not available from the manufacturer, the bend radius for cables inside buildings is 10 times the cable diameter under non-stressed conditions and 15 times the cable diameter under heavy stress conditions. Under non-stressed/stressed conditions, the bending radius of cables between buildings should be the same as that of cables within buildings.

(4) The cable manufacturer should determine the pulling force for multi-pair optical fiber trunk lines.

(5) The pulling force of 2-core or 4-core fiber is 222N (501bf).

(6) The untwisted distance of category 5e twisted-pair cables should be kept within 13mm (0.5 inches) from the termination point, and category 5 twisted-pair cables should be kept within 75mm (3 inches).

the difference

An important difference between Category 6 and Category 5e is that it improves the performance in terms of crosstalk and return loss. For the new generation of full-duplex high-speed network applications, excellent return loss performance is extremely important. The basic link model is canceled in the six types of standards, and the wiring standard adopts a star topology. The required wiring distance is: the length of the permanent link cannot exceed 90m, and the length of the channel cannot exceed 100m.

In addition, the hard bones of a word or a cross are added to the six categories of lines. There is no category 5e line, and there is a difference in bandwidth. The bandwidth of category 5e is 155M, while the bandwidth of category 6 line can reach 250M.

The elements of purchasing six types of wires

As the infrastructure of network construction, the function of the wiring system is very important. According to statistics, network failures caused by bad wiring systems account for 70% of the number of failures. Therefore, when choosing a real six-category cabling system, we must pay attention to the following 8 elements:

1. The real Category 6 system should meet the performance requirements of Category 6 from connectors, cables, links and channels, including components such as modules, distribution frames, jumpers and cables.

2. The worst-case model defined in the ISO/IEC 11801 and TIA/EIA-568 standards must be used in the system test report, that is, a 90-meter link with 3 connection points or a 100-meter channel with 4 connection points.

3. Manufacturers should provide comprehensive test data for Category 6 products and systems within 250MHz bandwidth, and be able to compare with parameters and indicators required by Category 6 ISO/IEC 11801 and TIA/EIA-568 standards. The test results of some characteristic frequency points cannot represent the performance within the complete test bandwidth. The manufacturer should also provide the test results of some domestic and foreign third parties and official institutions. The product is mature and has been commercialized, and there are already six types of engineering applications in the system. The manufacturer can provide a full line of six types of products for users to choose from, and adapt to any installation method and configuration requirements of users. Users can also request to use a field tester to conduct field tests on the link or channel submitted by the manufacturer in accordance with international standards to see if they can meet the six types of indicators. Manufacturers should provide integrators with special installation training for Category 6, and relevant integrators can participate in the installation and construction of Category 6 projects only after they have passed the training (users can ask integrators to show such training certificates).

Hu Lixiang from Fluke, a manufacturer of field testers for cable systems, said: "What users are most concerned about is how to ensure the performance of the system after the field test, so that the (wiring system) can cope with the development of the next 3 to 5 years." This means , because rewiring is impossible in many cases, the choice of wiring system should focus on future development, and ensure that the constructed six-category system has sufficient transmission margin to meet future network upgrades.