Coaxial cable

Coaxial cable is a layer of insulated wire wrapped around the central copper conductor cable. It is characterized by good anti-interference ability, stable transmission of data, the price is cheap, so it is widely used in many places, such as closed-circuit television lines.

However, according to the analysis of its own characteristics of coaxial cable, coaxial cable is only suitable for the transmission of image signals at close range, once the transmission distance over 200 meters, the image quality will be significantly decreased, especially the color will becomes dim. We can use coaxial amplifier to extend the transmission distance, 

However, the coaxial amplifier can not be unlimited cascade, usually in a point-to-point system coaxial amplifier can only cascade 2 or 3, or can not guarantee the video transmission quality. Therefore, the use of coaxial cable in the monitoring system, in order to ensure better image quality, the general transmission distance range is limited to four or five hundred meters.

In addition, the coaxial cable in the monitoring system to transmit image signals, there are still some disadvantages:

 The coaxial cable itself is greatly affected by climate change, the image quality is affected to a certain extent;

Coarser coaxial cable, the wiring is not easy to use in intensive monitoring applications;

The coaxial cable can only transmit video signals generally. If the system needs to transmit signals such as control data and audio signals at the same time, it needs additional wiring.

Coaxial cable has limited anti-interference ability and can not be applied to strong interference environment.

Coaxial amplifiers still have the disadvantage of difficult adjustment.

Fiber Optic Cable

Fiber Optic Cable transmits signals in the form of light pulses, so the material is mainly glass or plexiglass. It consists of fiber core, cladding and protective cover.

The structure of the optical fiber is very similar to the coaxial cable. It is also a central optical fiber made of glass or transparent plastic surrounded by a protective material. Multiple optical fibers can be combined in a single optical fiber cable as required. 

According to the different optical signals, optical fibers can be divided into single-mode optical fiber and multimode optical fiber. Multimode fiber is typically used for network connections in the same office building or in relatively close area. 

The single-mode optical fiber to transmit data of higher quality, longer transmission distance, is usually used to connect office buildings or geographically dispersed networks. If the use of optical fiber and cable as a network transmission medium, the need to increase optical transceivers and other equipment, so the cost of investment greater, less commonly used in the application.

The biggest feature of optical fiber is the optical signal is transmitted, so from the external electromagnetic signals, the signal attenuation is very slow, so the signal transmission distance than the various lines of transmission of electrical signals is much farther, and is particularly suitable for Electromagnetic environment in harsh places. 

Due to the optical reflection characteristics of optical fiber, an optical fiber can transmit multiple signals at the same time, so the transmission speed of optical fiber can be very high. However, the use of optical fiber as the network transmission medium requires some specialized knowledge and optical transceivers and other special equipment, so the cost of investment greater, less commonly used in the application.