With little fanfare or notice, it's become a digital world. Many of the products we use every day - from cars, microwaves and music players - incorporate digital technology. In the world of security, this shift is also taking place. However, many security professionals believe that digital video recorder (DVR) technology is the most advanced form of digital technology available in the security industry.
However, stopping with DVR technology for security would be the equivalent of the music industry stopping with the CD player. Just as MP3 players offer more functionality than CD players, DVR technology has limitations when compared to truly digital surveillance systems.
Innovation has continued beyond the DVR, and a viable, cost-effective alternative has emerged in IP surveillance. IP surveillance has all the functionality of a DVR and allows users even more performance benefits. In its simplest form, it is video transferred over IP infrastructure - a surveillance concept that is fully digital.
The Digitization of CCTV Technology
Over the past few years, digital technology has become more and more integrated into CCTV systems. DVRs now constitute 80 percent of new CCTV systems. While it is true that DVRs improve upon solely analog systems by adding a digital element, they do not represent an all-digital network technology. End users have started to realize this and some security professionals recognize that DVRs represent just one more step in the digital evolution of surveillance systems.
The DVR is actually a hybrid technology - it is part digital and part analog. DVR systems incorporate digital technology, but maintain the use of coaxial cables. This creates a system where an image is sent over analog cabling, digitized at the DVR, and then presented at a designated viewing station. This processing of the images causes a loss in quality and slows performance. Network cameras and video servers have eliminated this by making the link from the camera to the recorder digitized, using standard computer networks, the Internet, or wireless technologies.
Advantages of IP Surveillance
DVR systems have distinct advantages over a solely analog system, including the elimination of videotapes, consistent recording quality, access to recorded video over IP networks, and more efficient searches for recorded events. However, IP surveillance systems offer all of these same advantages and more:
Scalability - IP surveillance allows users to scale the system from one camera to thousands of cameras in individual increments. In comparison, DVRs usually require users to increase in 16-channel jumps, even if only one additional camera is actually added to the network. This makes IP surveillance a better choice for installations that may need to ramp up in size. For example, the Sooper Stop convenience store in West Fargo, N.D., installed just four network cameras to secure its facility while the New York State Unified Court System installed more than 300 network cameras.
Intelligence at camera level - In DVR systems, most of the "action" takes place within the DVR, including compression, recording and video management. This creates a shortage of computing power and makes it difficult to run intelligent video applications. However, fully digital systems decentralize applications by pushing intelligence out to the camera level, much as PCs did with mainframe computing. Built-in event handling, sensor input, relay output, video motion detection, time and date, and other capabilities allow network cameras to make decisions on when to send alarms and to whom, when to send video, and even at what frame rate or resolution to send the video.