Evolution of CCTV

Analog CCTV System with Video Cassette Recorder (VCR) Management

The traditional analog CCTV system was based upon an analog video camera system. Transmitting the video usually traveled over Coaxial Cable or Wireless Analog Video Transmission. A VCR (Video Cassette Recorder) using magnetic tape was used to record and playback these analog signals.

Benefits

At the time, this was the most modern way of transmitting a video signal in a secure network. This video signal transmitted, recorded, and viewed would be entirely analog.

Limitations

Though the video signal in this method was purely analog, the limitations appeared in the recorded video. Interlaced images and degraded picture quality being played back were the most common. Refresh rate displaying the camera images was also an issue when recording and viewing with a multiplexer.

Analog CCTV System with Digital Video Recorder (DVR) Management

The traditional analog CCTV system was based upon an analog video camera system. Transmitting the video usually traveled over Coaxial Cable or Wireless Analog Video Transmission. For PC viewing, this analog video signal was managed by a DVR (Digital Video Recorder). This would store interlaced Analog Video in a digital format.

Benefits

This allows cameras to be managed on one system. Digital recording enabled many new options such as frame rate, compression, motion detection, and advanced storage features.

Limitations

While converting an analog video signal to a digital format, interlaced artifacts as well as analog resolution would still limit the quality of recorded video to only what the analog signal was limited to.

Analog CCTV System with Encoder, Computer Recording, and Network Video Recording (NVR) Management

The traditional analog CCTV system was based upon an analog video camera system. Transmitting the video usually traveled over Coaxial Cable or Wireless Analog Video Transmission. A digital encoder was utilized to digitize analog camera signals into an IP stream for Computer and NVR Software Management. This would store interlaced Analog Video in a digital format.

Benefits

This allows cameras to be managed on one system. Digital recording enabled many new options such as frame rate, compression, motion detection, and advanced storage features. Video streams became accessible any where in the world.

Limitations

While converting an analog video signal to a digital format, interlaced artifacts as well as analog resolution would still limit the quality of recorded video to only what the analog signal was limited to. Recording on a PC with too many cameras can limit bandwidth and recording is limited to hard drive space.

Optimal Digital CCTV System, with Digital IP Transmission, and Network Video Recording (NVR) Management

The most modern CCTV system will employ fully digital transmission via IP (internet protocol) technology. Resolutions from 640x480 pixels to1280x960 (megapixel) allow crisp clear transmission and playback of recorded video. Some cameras incorporate PoE (Power over Ethernet) technology allowing the camera to powered over the same CAT-5 or CAT-6 Ethernet cable the digital video signial is being transmitted on.

IP based Digital signals allow bandwidth efficient transmission for hundreds of digital cameras as well as digital audio and data all at once.

Using a NVR (Network Video Recorder) or Computer with Digital Recording Software, true digital cameras would be viewed and recorded at the highest quality and the highest frame rate allowed. The NVR would employ software for hard drive based recording and intuitive event management. This alleviates old tape based technology to a much more compact, accessible, and scalable medium.

Benefits

A digital system can provide a high quality megapixel image with little to no artifact. Digital IP based transmission enables remote access and management locally and remotely of the NVR as well as each of the camera’s settings. Anywhere in the world you can receive intrusion alarms and easily view live and recorded high quality from your computer or PDA.

Limitations

Video quality can be superb, but too many cameras over one network can limit the bandwidth and effect the frame rate of recorded images. Image compression helps relieve this, but with compression comes a less high quality image. Storing video also depends on the hard disk size.