Copper cabling - updated important information

REACTION TO FIRE CLASSIFICATION

Euroclasses:



Additional classifications:

Notes:

1. Aca and B1ca euroclasses are not achieavable by copper and fibre optical cables used in structured cabling.
2. Indoor installation of Fca euroclass is forbidden in structured cabling by EN 50174-1/A2:2015.
3. There is no additional classification specified for Eca and Fca euroclasses.
4. National authorities are responsible to specify the appropriate level of fire performance of cables in different environments of the building.

Relationship between transmission properties and performance categories of cables

International standards have defined five cabling categories for horizontal cabling - Cat.5E, Cat.6, Cat.6A, Cat.7, Cat.7A and two categories for data centers - Cat.8.1, Cat.8.2. Despite of this fact there are only two transmission speeds for horizontal cabling - 1Gigabit/s (Cat.5E, Cat.6), 10Gigabit/s (Cat.6A). In case of data centers the situation is different. There are only two transmission speeds for two categories - 25Gigabit/s and 40Gigabit/s but both of them can be transmitted on both categories (Cat.8.1 and Cat.8.2).

Recent results of high-speed protocol development have shown that it is the maximum transmission speed that determines performance of cabling, not the bandwidth. Also the maximum transmission speed is determined by the fastest protocol supported by cabling and the transmission protocol is essential in terms of requirements for cabling and its components.

A transmission speed of 1Gigabit/s complies with the fastest protocol, 1000BASE-T, where a bandwidth of 100MHz is required for the transmission. A transmission speed of 10Gigabit/s complies with the fastest protocol, 10GBASE-T, where a bandwidth of 500MHz is required for the transmission. The diagram illustrates a relationship between the performance of structured cabling and the standardized categories. From the picture, it is clear that the same performance can be achieved by several cabling categories. Cat.5E is efficient for networks with transmission speed of up to 1Gigabit/s. Cat.6A is optimal for networks with transmission speed of up to 10Gigabit/s. A required safety margin of 20% is already included in both 100MHz and 500MHz bandwidths required. Therefore it is not possible to utilize a bandwidth above this value, nor does it contribute to the enhancement of transmission reliability. However, installing Cat.7 and Cat.7A interoperable cables is reasonable and appropriate due to their increased resistance to electromagnetic interference.


 

In the year 2016 two new protocols 2,5GBASE-T and 5GBASE-T were standardized which should allow the transmission speed to be increased to 2,5 or 5Gigabit/s for structured cabling Cat.5E and Cat.6. However, tests on installed cablings showed that it was more of a wish than a real prospect. Because of Alien Crosstalk issue the minimum requirement for reliable transmission of 2,5GBASE-T and 5GBASE-T protocols is Cat.6A cabling. Therefore, the only way to achieve a transmission speed higher than 1Gigabit/s is to install Cat.6A structured cabling. The IEEE 802.3 standardization committee finished a work on new protocols with a transmission speed of 25 and 40Gigabit/s. Due to these protocols, a new performance categories Cat.8.1 and Cat.8.2 have been introduced. The maximum transmission channel length is only 30m. Therefore, Cat.8.1 and Cat.8.2 are practically unusable in horizontal structured cabling. Even in data centers, for which these high-speed protocols have been developed, it would be hard to compete with fiber optics. In addition fiber optics generate less heat which is important since the cooling costs are one of the highest expenses in data centers.