Industry News

How to Select Private Video Monitoring Network Line

How to Choose Video Surveillance Dedicated Network Cables

  Network surveillance cameras, also known as digital video surveillance cameras (IP Cameras), are the latest generation of cameras that integrate digital video encoding modules within traditional security cameras. These modules compress and encode video images captured by the video sensor according to video encoding standards and transmit them via TCP/IP networks. Network surveillance cameras use network cables (twisted pair cables) for transmission. In surveillance projects, these network cables are primarily used to transmit video surveillance image data, which requires high bandwidth and can operate under high load for extended periods. Therefore, the selection of network cables has higher requirements.

Cable Type

 Currently, video surveillance systems commonly use cameras with resolutions of 2 million pixels or higher. Many applications require 5 million pixels or even 4K ultra-high-definition cameras, with video transmission bitrates typically reaching 4 Mbps or more. Therefore, 100 Mbps network cables are no longer sufficient. We should at least choose Category 5e (CAT5E) network cables that support gigabit speeds, and it is recommended to use Category 6 (CAT6) network cables.

Network cables are mainly divided into shielded (STP) and unshielded (UTP) types. Shielded network cables have better transmission performance than unshielded cables but are more expensive, offering lower cost-effectiveness. It is suggested to choose based on specific conditions.

Copper Core

There are many brands and series of CAT6 network cables available on the market. The network cables used in video surveillance systems must not be made of non-pure copper materials. When choosing, special attention should be paid to the quality of the copper core. There are several methods to determine whether the core is pure copper, the simplest being the burn test. Fake copper cores will produce dense smoke and may even cause flames when burned, while genuine copper cores will not produce smoke, and their color will not change significantly after burning. The diameter of the copper core directly affects the transmission speed, and it should be at least 0.5mm, with 0.55mm or more being recommended.

Twist Length

Network cables consist of four pairs of twisted wires. This structure not only helps resist interference from external electromagnetic waves but also reduces mutual interference between multiple pairs of wires. For Category 5e and above specifications, the twist length should be between 38.1mm and 140mm, twisted counterclockwise, with adjacent pairs having a twist length of 12.7mm or less. Video surveillance projects have higher requirements for network cables, and the twist length of adjacent pairs should be controlled to around 11mm. The length of one twist cycle of twisted pair wires is called the pitch, and a smaller pitch (more tightly twisted) provides stronger interference resistance.

Other Indicators

In addition to the above aspects, when selecting network cables (twisted pair cables) for surveillance projects, the following indicators should also be considered:

Attenuation: The degree of signal loss during transmission.

Near-End Crosstalk (NEXT): The interference level from one pair of wires to another.

Impedance Characteristics: The electrical characteristics of the cable, affecting signal transmission quality.

Distributed Capacitance: The capacitance effect within the cable, impacting signal integrity.

DC Resistance: The conductivity of the cable, affecting current transmission efficiency.

These parameters require professional testing equipment for measurement. Choosing high-quality network cables ensures the stability and reliability of the video surveillance system, reduces fault rates, and enhances overall security.