Overview of security protection system The security protection system that is often said has three defenses: "human defense, physical defense, and technical defense". The main definitions are as follows: Air defense: It is the basis of safety precautions. The traditional "human defense" refers to the display of human's natural ability in security work. That is: use the human senses to detect and respond, and postpone and stop the occurrence of risk events through the exertion of human physical energy. Modern "civil defense" refers to an organized prevention behavior of personnel and/or groups of personnel with corresponding qualities who perform security tasks, including the training of high-quality personnel, the configuration of advanced self-defense equipment, and the organization and management of personnel Wait. Physical defense: various physical protection methods (including buildings (structures), barriers, appliances, equipment, systems, etc.) that are used for security purposes and can delay the occurrence of risk events. Technical defense: the use of various electronic information equipment to form a system and/or network to improve the detection, delay, response capabilities and protection functions of security measures. 2. Purpose of perimeter prevention It mainly realizes that when someone climbs and crosses the predetermined defense zone, it can reliably alarm when invading, and can link the video surveillance system to locate the alarm area, and when no one is climbing, even in severe weather such as wind, rain, snow, and lightning And when vehicles pass and small animals appear, the alarm system will not generate false alarms. According to "Safety Protection Engineering Technical Specification GB 50348-2004" 3.3.3 The functions of the main subsystems of the safety protection system, the important entry of the intrusion alarm subsystem: the system must not have missing alarms, and the false alarm rate should meet the requirements of the engineering contract. 3. Technical classification of perimeter prevention system Classified by signal source According to the change detection of electromagnetic environment: tension net, hydraulic buried detection, vibrating cable, vibrating optical cable. Detection of changes in the electromagnetic environment: microwave radiation, buried leakage cables, electrostatic induction cables, high-voltage pulsed power grids (electronic fences) According to the light intensity change detection: infrared beam, laser beam According to the detector form Tangible: Tension net, vibrating cable, vibrating optical cable, electrostatic induction cable, high-voltage pulse power grid (electronic fence).