Twisted pair is classified according to frequency and signal to noise ratio

- Jan 10, 2019-

Twisted pair common types are three types of lines, five types of lines and super five types of lines, and six types of lines. The former has a fine wire diameter and the latter has a large diameter. The specific models are as follows:

1) Category 1 line (CAT1): The maximum frequency bandwidth of the cable is 750kHZ, used for alarm systems, or only for voice transmission (one type of standard is mainly used for telephone cables before the early 1980s), not for data transmission. 


2) Class 2 line (CAT2): The highest frequency bandwidth of the cable is 1 MHz, which is used for voice transmission and data transmission with a maximum transmission rate of 4 Mbps. It is commonly used in the old token network using the 4 MBPS specification token transfer protocol.


3) Category 3 line (CAT3): refers to the cable specified in the ANSI and EIA/TIA568 standards. The cable has a transmission frequency of 16MHz and a maximum transmission rate of 10Mbps (10Mbit/s). It is mainly used for voice and 10Mbit/s Ethernet. (10BASE-T) and 4Mbit/s Token Ring, the maximum network segment length is 100m, and the connectors in the form of RJ have faded out of the market.


4) Category 4 line (CAT4): This type of cable has a transmission frequency of 20MHz and is used for voice transmission and data transmission with a maximum transmission rate of 16Mbps (referred to as 16Mbit/s Token Ring). It is mainly used for token-based LAN. And 10BASE-T/100BASE-T. The maximum network segment length is 100m, and connectors in the form of RJ are not widely used.


5) Category 5 (CAT5): This type of cable increases the winding density and is jacketed with a high quality insulation material. The cable has a maximum frequency bandwidth of 100MHz and a maximum transmission rate of 100Mbps. It is used for voice transmission and the maximum transmission rate is 100Mbps data transmission, mainly used for 100BASE-T and 1000BASE-T networks, the maximum network segment length is 100m, using RJ form connectors. This is the most commonly used Ethernet cables. In a twisted pair cable, different pairs have different lay lengths. Generally, the twist length of the four pairs of twisted pairs is within the length of 38.1 mm, twisted in a counterclockwise direction, and the twist length of a pair of pairs is within 12.7 mm.


6) Super Category 5 (CAT5e): Category 5 has low attenuation, low crosstalk, and higher attenuation and crosstalk ratio (ACR) and signal-to-noise ratio (SNR), smaller delay error, and performance. Greatly improved. The Super Category 5 cable is mainly used for Gigabit Ethernet (1000 Mbps).