In physical security applications, the CCTV system is in the midst of a fundamental transition. This transition is taking the CCTV function within the integrated security system from one of passive observation to one of active detection. Coupled with advancing video analytic capabilities, it is likely that in the near fouture, the CCTV system will replace many of the detection subsystems that are currently considered essential.
However, the success of this transition is accompanied by ever-increasing video storage requirements. The ease of implementation of IP-addressable, Power over Ethernet (PoE)-enabled CCTV cameras has resulted in a rise in the number of cameras implemented for security applications. Video file retention periods have lengthened from an average of 30 days (common in the late ’90s), to as much as 12 months today. This has resulted in the video storage subsystem becoming a focus of potentially intense capital investment, ongoing data management and maintenance.
In current applications, video storage is typically seen in one or more configurations: on board the CCTV camera, in the digital video recorder/network video recorder (DVR/NVR), or in an external storage device. At the executive level, it is essential to recognize that all of these options may need to be exercised in order to obtain the functional performance needed from the integrated system.
CCTV cameras are currently available that contain onboard storage. This so-called edge storage has some attractive features. First, it enables the trend to push the video analytic activity away from one or more central processing servers and onto the actual camera. Edge processing — operated in the mode that only video of interest is stored and ultimately transmitted to archive — reduces average bandwidth consumption from the CCTV appliance. Second, onboard storage also offers some protection from communication infrastructure failure. These devices are particularly useful when bandwidth availability is limited, communication infrastructure reliability is questionable and the projected level of activity is low.
However, given a robust infrastructure, the trend is to retain all or a significant portion of the available video information for subsequent analysis. This generally leads to dedicated storage devices — either distributed and/or centrally located.