The Future of CCTV Security Systems

Since the events of September 11, many companies are increasingly concerned about building security and have started to investigate the functionality of their security systems. With the use of a Closed Circuit Television (CCTV) system (i.e., security cameras), the pictures taken could prevent terroristic threats to public and private establishments. But that security is only as reliable as the system supporting it, which has left many IT managers in search of a dependable system that wonâ€™t expend too much bandwidth on existing networks. Understanding the choices out there and how security systems are evolving is key to determining what type of system will work best for a particular environment. The

Evolution of CCTV
Closed circuit television (CCTV) originated in the 1950s and consisted of two low-resolution black and white cameras. Its main objective was to replace humans for visual security surveillance. In the 1980s, solid state cameras and VCRs were introduced. The resolution was better, but the pictures were still in black and white. In the 1990s, came the transformation to color, and eventually digital video recorders (DVRs) were introduced. The DVR allowed video to be recorded in higher resolutions than VCRs and eliminated video tapes, which in turn eradicated the need to physically change the tape. As we venture into the new millennium, the purpose of CCTV is broadening. The DVR is taking analog video and converting it to digital. The digital signal is then compressed using a variety of different methods and sent over the network without bogging it down.

Digital Video Recorders
The DVRâ€™s function is to capture images (from up to 16 cameras per digital recorder), compress them and then store them on the DVRâ€™s hard drive. Since images are stored on the DVR before the LAN, you are not using any bandwidth until you retrieve or view the video remotely.

IP Cameras
IP cameras are similar to DVRs in that they take video, compress it and send it over the LAN. The difference is that the IP camera does not store the video. The IP camera is always streaming video across the LAN to a storage device, possibly to the storage area network (SAN). Therefore, the IP camera is always using bandwidth. Because IP cameras are the route to go today, a parallel or segmented network is suggested. In the future, as different compression methods are developed, it may be possible to use IP cameras on a data network without having bottleneck issues. However, some IP cameras now incorporate both server and DVR functions and limit some of the bandwidth impact.

Compression Technologies
There are many different compression methods out there, including: MJPEG, H263, Wavelet, MPEG2/MPEG4 and JPEG-2000. The major difference between them is the amount of bandwidth they consume. It is highly probable that H263, MPEG2/MPEG4 and JPEG-2000 will prevail in the security industry because of their low bandwidth consumption. The Anixter Levels Lab is currently testing DVRs and IP cameras to determine which product is best for your LAN in terms of bandwidth consumption. This will guarantee that the security products installed on the LAN will not cause bottleneck issues.