Video surveillance

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• detection-based controls
• surveillance is used to improve the resilience of perimeter gateways
  • ensure that attempts to penetrate a barricade are detected
  • may be focused on perimeter areas or within security zones
  • can be performed by
    • security guards
    • security cameras
      • cheaper
      • can be
        • fixed
          • good for recording entrance through an access control vestibule
            • narrow focal length
        • pan-tilt-zoom (PTZ)
          • good for surveying a large room and picking out individual faces
      • closed-circuit television (CCTV) network
        • typically connected to a multiplexer using coaxial cable
          • can
            • display images from the cameras on one or more screens
            • allow operate to control function
            • record images to tape or hard drive
      • newer cameras may use IP networks
        • use regular data cabling
        • can use PoE