The Change in Digital Video Surveillance

No section of the physical security market is going through as much technological change and structural redefinition as video imaging and storage. The concept of what has been called CCTV is being redefined to address new requirements for speed and first response to dangers never before perceived. This technological transition will have a powerful impact on how video is obtained, stored and used.

From Detection to Prevention
In 1997, an article in an ACLU newsletter contrasted the use of video surveillance in the U.K. and the U.S. It stated that the threat of bombs and terrorism in the U.K. made necessary heavy surveillance of public areas, but the absence of such threats in the U.S. meant that our use of surveillance was inappropriate-we used this powerful tool to "fight people who 'spin doughnuts' with their cars, 'loiter' or commit 'nuisance crimes.'" My, how the world has changed. The realities of terror have drastically altered our uses for video surveillance and the number and scope of installations.

Before 2001, camera systems were used primarily to catch the bad guys after a crime had been committed. If you had a very large, well-trained security team, you might even be able to catch them in the act. The list below defines the primary uses of camera systems before the new reality.

  • Catch perpetrators
  • Protect assets
  • Watch workers
  • Protect from litigation
  • Stop cheating in gaming applications
  • Monitor traffic
  • Watch the perimeter
  • The gaming industry was the primary driver of video technology and its most proactive user, with traffic monitoring and control a close second. Although the main drivers of usage are still in gaming and traffic, protection of public spaces and high-occupancy facilities has now taken the use of video to a new level. The end user's perceived needs for video surveillance are heavily weighted toward security and life safety issues, with asset tracking and manufacturing observation as significant secondary requirements. Most video applications have now begun to take a proactive slant, and this has slightly changed our list of primary uses for video:

    • Protect from and catch perpetrators
    • Protect and track assets
    • Watch workers/P.O.S. integration
    • Protect from litigation
    • Stop cheating in gaming applications/Recognition and tracking
    • Monitor roadways, airports, seaports and all vessels of transport
    • Watch the perimeter

    The burgeoning use of video for protection and prevention has forced the development and use of new ways to obtain images, store them and access the data from remote locations.

    The Growth of Digital
    In large installations that require high-quality, fast frame-rate images to be stored for long periods of time-the types of installations that are becoming more common with the growth of proactive security-videotape is neither cost effective nor easily searchable. Digital systems allow users to easily access specific images and send them across a network, and these systems require less maintenance expense than analog videotape systems. It's easy to see why the change to digital has been happening at almost revolutionary speeds.

    The J. P. Freeman 2003 Worldwide CCTV & Digital Video Surveillance Market report projects a decrease of 70 percent in conventional analog recording by 2007, which would decrease its share of the market to 22 percent. The same report projects a 289 percent increase in digital recording in the next three years, which would give it 78 percent of the market. I think you call that a paradigm shift.

    So one of the hot buttons for the past three years has been analog to digital. Although most current CCTV cameras do output an NTSC or PAL analog signal, the imaging is done with a CCD or CMOS digital chip that is then run through a processor to define the image/picture/frame. This is then sent through a digital-to-analog chip to output the NTSC or PAL image. The analog signal must be converted back to a digital image in order to be stored on a digital medium such as a hard drive or CD.

    The transfer of the digital data from a point of storage to another device or site requires some form of transport over a wire or network. This is best accomplished through the Internet Protocol that is now ubiquitous in business enterprises. Digital video and IP have opened the world of network technology to the once stodgy CCTV industry. A digital video system with IP transfer can provide automatic threat detection and warning. It can allow for integrated systems and convergence of networks, where IT infrastructure serves as part of the CCTV network. It can also allow controlled access to recorded and monitored video.

    Transmission Methods
    Because of the dramatic shift away from analog, the transmission medium of choice is moving rapidly away from coax. For IP transport, the medium of choice is usually UTP or unshielded twisted four-pair cabling, with fiber and wireless alternatives for long distances and right-of-way issues. The use of UTP and fiber combined is projected to increase by a factor of two by 2007, with wireless technologies increasing by a factor of five.

    A correctly designed four-pair UTP standards-based system can deliver AC power to analog cameras while bringing back the video to the wiring closet for bulk UTP transport to the head- end equipment. Such a system can also be easily converted to deliver DC voltage as power over Ethernet to IP cameras while bringing back 100 Mbps Ethernet on the same pairs.

    IP-Based Systems
    The next transition is the digital transport of images over an IP-based network using Ethernet as the protocol and IP cameras as the image source.

    An IP-compliant network camera contains a video imaging chip, a compression chip and a computer. The computer is small and specialized for network applications. A network camera has its own IP address. It is connected to a network and does not need to be connected directly to a PC.

    There are many advantages to the implementation of IP surveillance technologies.

    Scalability. IP surveillance scales from one to thousands of cameras in increments of a single camera. There are no 16-channel jumps.

    Life Cycle Costs. IP surveillance uses a more cost-efficient infrastructure. Most facilities are already wired with twisted pair infrastructure. The installation of a future-directed hybrid system for new analog systems will ensure compatibility.

    Network Convergence. Only one type of network-IP-connects and manages the enterprise for data, video and voice, making management more effective and cost efficient.

    Systems Integration. IP surveillance technology provides an open, easily integrated platform.

    Remote Accessibility. Any video stream, live or recorded, can be accessed and controlled from any location in the world over the wired or wireless network.

    Intelligence at the Camera Level. Motion detection, event handling, sensor input, relay output, time and date, and other built-in capabilities allow the camera to make intelligent decisions on when to send alarms, when to send video, and even at what frame rate to send the video.

    The bottom line is availability of video data and the ability to forensically mine this data for evidence or other uses. It is easy to serve out the video in different formats at different frame rates, quality levels, and bandwidths to many users for many different reasons, and still store it centrally somewhere else. Once you are able to collect video in a digital format and store it as a digital data file, all kinds of possibilities open up.

    Content analysis for prevention of incidents, video auditing for retail shrinkage reduction, and other such applications can even pay you back the money invested in all that expensive video gear. You are paying a lot of money hourly to capture and store video, now as useable data. It makes perfect sense to go back after that data and find out what useful things might be buried in the images.

    Pete Lockhart is vice president of new technology with Anixter Inc. He was instrumental in the creation of the original Anixter Levels Program in 1989, and helped to create the Level 5 cable concept in 1991 that led to the Category 5 cables in the current ANSI/TIA/EIA-568-A Standard. Mr. Lockhart is a member of BICSI and IWCS Symposium Committee, and past member of ACUTA, HIMMS, ATM Forum and EIA/TIA.

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