CCTV Systems

Closed Circuit Television or CCTV is very important to any total security solution and can augment it in several ways.  First of all, the mere presence of cameras is a deterrence for most illegal behaviors.  Secondly, surveillance can provide three types of event identification; Personal Identification (identifying an object or individual), Action Identification (moving car), and Scene Identification (parking lot). Also, with today's technologies, a CCTV system can increase the speed in prosecution and/or identification of incidents through email and other digital media.

Personal Identification

Personal Identification is the ability to identify something beyond a shadow of a doubt. Whether it is money, objects or people. Personal Identification will give you the specific information on the identity or objects within an image.

Action Identification

Action Identification is the ability to view an act such as property or merchandise removal, exchange, or concealing.

Scene Identification

Scene Identification is the ability to cover a wide-area view such as a parking lot or hallway that will capture information of events.

Evolution of CCTV

As with most technologies, CCTV has inevitably gone digital. 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. 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.

Today and on the horizon of tomorrow, the next step in the evolution of CCTV is Network-IP cameras & broadcasting. This new breed of technology makes use of IP based networks (the core technology of the Internet) and is used in conjunction with DVRs or file servers. Virtually all corporate networks make use of IP technology. Network-IP cameras are remotely accessible over the Internet or private intranet through a company's existing computer network. Network-IP broadcasting is useful for companies that have already made significant investments in analog CCTV technology and allows them to convert analog signals and send them over the network.

Analog Recording

In the past, if a company needed to maintain any type of archived library of surveillance recording, it had to switch tapes on a daily basis. This meant staff had to come in every day to switch the tapes or they would record over the previous day's events. Also, if they wanted to review a tape, they had to use the existing system or buy an identical head-end system. If they used the existing system, they could not record simultaneously. If they bought an additional system for reviewing purposes, they had to assume the additional cost. Consider also that the VCR would need regular maintenance, such as head cleaning and the eventual replacement of all moving parts. Don't forget the quality of the video degraded every time you copied the tape or reviewed it. In the end, a VCR system was a high-maintenance recording medium.

Digital Video Recorders

The DVR’s function is to capture images (from up to 16 cameras per digital recorder), compress them and then store them on the DVR’s hard drive. Since images are stored on the DVR apart from the LAN, you are not using any bandwidth until you retrieve or view the video remotely. Searching for a file is also much easier on a digital system. In the past, a user would have to spend hours going through tapes (provided he/she was looking at the right day). However, digital recorders allow users to search from such criteria as time, date, alarm event, camera, etc. Digital recording has truly revolutionized the CCTV industry, and it is believed by many that digital recording will eliminate traditional analog recording systems very soon. Most digital systems also allow the user to gain access to the system remotely via the Internet, a modem-to-modem connection or a LAN/WAN (local or wide area network). This type of access offers many of the same advantages of phone-line transmission, but with additional features such as the ability to view live or recorded video.

Network-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. Some IP cameras now incorporate both server and DVR functions and limit some of the bandwidth impact. IP cameras are more expensive than standard CCTV cameras and required the use of CAT-5 cable rather than the COAX cable normally used in CCTV. By adding the additional hardware to each camera the price per system acted as a multiplier and quickly became much more expensive than centralizing the digitizing hardware. Installation also requires more expertise in running the CAT-5 cable and setting up each camera, although it is possible to take advantage of existing CAT-5 infrastructure. Another issue to consider is security concerns.  IP cameras are remotely accessible by anyone with access to the network and are usually protected by a username and password.  Care should be taken on segmenting the network and granting access to authorized individuals.

Recent improvements in IP camera technology have made them a more viable alternative to standard CCTV cameras. There is a place for IP cameras in the digital world, and more improvements will make these cameras very competitive to the DVR.

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