Knowledge of cabling system scheme selection

In today's cabling market, the most hyping media and businesses is "Gigabit ". I remember not long ago I was hyping "over five categories", but with the introduction of the "Gigabit" Ethernet standard, cabling vendors have also successively launched "6 categories" or even "7 categories" cabling systems that support "Gigabit" Ethernet. It is a good thing to launch advanced products, but I still want to remind the majority of users not to be overwhelmed by the hype of the media and manufacturers. when choosing a wiring product, consider it calmly, whether such a high-end system is required.

Cabling System with stars shining

At the beginning, three types of cables were developed. They can reach 10 Mbps and have a thin hand. Generally, cat3 is written on the skin, and "3 types" is injected on the box ", each box is about 305 meters, and there is not much in our network for 4 types of cables;

The continuous improvement of 5E Cable Specifications comes from the Development of Gigabit Ethernet. During the development of Gigabit Ethernet technical specifications, whether Category 5 cables of low-end and low-grade low-end networks can be supported once aroused people's attention, followed by the emergence of level-1 near-end crosstalk (ELFEXT) and return loss and other new key test parameters, therefore, the industry has developed a 5E type cable technical specification, its nominal speed is 100 Mbps, hand leather thick turns, "cat5e" is usually injected on the skin, which is usually 305 meters per case. However, with the introduction of the six types of cable specifications, although existing or emerging networks do not have to rely too much on the support of the six types of solutions, it is foreseeable that the six types of cables are only a matter of time for the mainstream solutions for copper cabling;

Because CAT5E cannot officially support 10 GbaseT, CAT6 also has a distance of 37 m and cannot guarantee signal transmission quality, however, the enhanced type 6 line (AC6) achieves high-speed signal transmission within m;

Seven types of cable technology provide up to MHz bandwidth, which is the highest bandwidth among all types of copper cables. The previous cable technology is based on conservative performance standards, such as 5e 100 MHz and 6 250 MHz, early adopters of new technologies such as 10-Gigabit Ethernet, or companies that focus on environments such as factory workshops) tend to use seven types of cables. The seven types of cables are Fully shielded cables. Each pair of cables is shielded by foil shielding, and the cables themselves use a shield layer that wraps the entire cable. Some seven types of cables also include a fabric Screen Layer Between the cable jacket and the shielded line pair. The cable can also shield external crosstalk, that is, noise from adjacent cables outside the cable jacket. Not long ago, category 5e and Category 6 cables used noise elimination technology to handle noise from the inside of the cable jacket, the biggest problem with copper cables that provide 10G Ethernet transmission is noise from the outside of the jacket.

Seven types of cables are the most balanced cables with the largest capacity, and the cost is about three times that of six types of cables. The latter is generally priced at $1000 feet, enterprises planning for the next 10 years may be able to prove that the cost of installing 7 types of cable and connectors is reasonable, as compared with other alternatives that can handle applications requiring higher bandwidth, seven types of cables save more money. Category 7 provides users with the possibility of selecting based on the installed connector type RJ and non-RJ). When using a non-RJ connector, it provides the application sharing function, when using the RJ connector, the infrastructure has backward compatibility and interoperability.

As this cable technology will gradually enter the mainstream, more and more equipment manufacturers must design seven types of interfaces on their hardware, and enterprise users must gradually adapt to such a different interface, category 7 cables have a larger diameter than Category 6 cables because they use double shielding and typically use the 23AWG U. S. Cable Specification). In contrast to bare copper connector, class 6, category 5e, Category 5, and other types of cables use the 24AWG connector ).

In addition to determining the price of seven types of cables and connectors, the certification of the National Research and Testing Laboratory is also very important, which means that the certification mark of the laboratory will appear on the jacket of the cable, this identifier indicates that the device has passed the nationally approved test chamber test in terms of safety and performance, and complies with the performance specifications of the 7 class international standards. Seven types of products can meet new bandwidth, access, storage, and speed requirements. Based on users' needs and future goals, compare the performance of the latest copper cable technology with competitors, it can help determine what type of cable to use.

Technical Comparison of various cabling systems

The following table compares the performance of Category 5, category 5E, Category 6, and category 7 cables at a MHz normal frequency. We can intuitively see from the table that, comparison results of different technical specifications at the same frequency. Note that the actual values of the six and seven types of cables may be different from the results published in this table. It is estimated that the values of the six types of cables do not change much, there must be a big difference between the seven types of cables and the published standard values. However, the table shows that the six types of cables are improved on the basis of the 5E type. According to the frequency range, the 5E type cable is still limited to 100 MHz, while the six types of cables have been increased to 200 MHz, and additional 25% margin is required on this basis to reach 250 MHz (tentative ).

Unless otherwise specified, all values are measured in dB and all values are measured at MHz (worst case-channel ). The values in the brackets are the measured values of 6 types of cables at MHz and 7 types of cables at MHz respectively.

Integrated Wiring System Solution selection principles

At present, wiring manufacturers have a lot of water in marketing. "Guaranteed applications", "6 categories of cables are the choice of Gigabit Ethernet", "absolutely exclusive supplier solutions", and other market hypes and publicity mislead users confused. After analyzing the characteristics of various integrated wiring systems in detail, what principles should users consider when selecting a system?

Undoubtedly, many users are concerned with the installation, rather than the copper cabling solution. Users can choose from various solutions based on their own needs and economic affordability. Therefore, we recommend that you consider the following issues:

1. What is the purpose of the user's installation of the cabling system and how will the application develop in the future be estimated? Probably Process Planning?

If you only plan to use 100 BaseT in the next five years, the 5E cable is enough, but if you consider using broadband anytime soon, such as real-time video conferencing, 3D mode, desktop printing, etc., it is best to use 6 types of solutions.

2. Are the prospects of the enterprise where the user is located clear? What is the speed of enterprise development?

If the prospects are unclear, you can use six types of solutions for security reasons, or you predict that the enterprise will continue to develop rapidly, in this case, more than six types of solutions can provide a larger "growth space" to support enterprise development through network resizing.

3. What is the importance of Enterprise Networks in daily operations?

For example, the banking network system is the lifeline of its operation. If it is shut down for several minutes, it will cause great losses to its business. Therefore, from the perspective of sufficient balance, easy installation and reliability, the six types of cables are more ideal solutions.

4. How do enterprises consider budgets?

If the budget is not limited, all optical cables are used. The objective environment is realistic and the budget is limited. Therefore, you will certainly consider the economic affordability of the six types of cable solutions. After all, it costs about 20-30% higher than the 5E solution. However, it is important not to focus solely on initial costs when making decisions. Based on the analysis of the above problems and such situations, you can know which solution is most suitable for your needs, and the cost is within the budget range.

Different sounds

When the cabling system entered our country, it gave Chinese people a mysterious feeling that once the cabling system was built in the building, it immediately became a smart building, and each weak current system can use this wiring system. Theoretically, the Integrated Wiring System unifies the transmission medium of various weak current systems in the building as a high-performance transmission medium, which facilitates management, maintenance and future expansion, however, it is unnecessary to select 6 or 7 Generic Cabling systems for three reasons:

1. The cost is too high, and the performance may not be good;

For example, in the security monitoring system, the 75 ohm coaxial cable is currently used at a low price, and its bandwidth is also high when the transmission distance is far (more than 100 meters; the 8-core twisted pair wires used in 6 categories of Integrated Wiring do not have this advantage. First, it is limited by the maximum transmission distance of 100 meters, and the attenuation of the video signal transmitted over 100 meters will be very large. In addition, you need to purchase an impedance pair to make the interface of the monitoring device compatible with the twisted pair cable system. In addition, weak current systems such as building automation have their own cabling systems. Generally, the topological structure of the cabling is bus-type, that is, many control units can be connected in a 2-core line, the Integrated Wiring System uses a star topology, requiring each 8-core cable to be connected to only one device. It can be seen that if the building automation and other weak current systems also adopt a star topology structure, a large number of cables will be required to increase the cost of the entire system.

2. Restrictions on Industry Management in China;

For example, the fire security system is still independently designed, constructed, and managed. It is not suitable for such a system to adopt a good integrated wiring.

3. The advantages of "luxury" Integrated Wiring cannot be fully utilized.

The "luxury" cabling system provides great flexibility for users who often change the types and locations of terminal devices, the weak current terminal devices, such as building automation and security monitoring, are usually fixed in a certain location in a room or corridor for a long time and do not need to be changed frequently.

It can be seen that a good Integrated Wiring System is not omnipotent, and it mainly provides the foundation for high-performance Communication Automation Systems in smart buildings.