A recent report by IMS Research found the video surveillance storage market is roughly $1.2 billion. This market is growing at more than 60 percent annually based on the facts that more cameras are being installed, higher resolution cameras are in demand and longer retention times are required. The recently thwarted New York City bombing demonstrates the predominant growth of surveillance - 58 private camera views were available following the incident. And this number is far less than the number of views that would potentially be available in London, arguably the city with the most surveillance cameras deployed globally.

As the amount of video data grows, the viability of traditional DVRs and NVR with local storage is breaking down. With these systems, a fixed amount of capacity is available for video streams that may vary in needs over time. Determining what capacity to buy is a challenging task since the amount of storage depends on an estimate of resolution, frame rate, compression and motion detection by camera type. Therefore, the nature of the DVR or NVR infrastructure generally leads resellers to over-provision capacity for each system by up to 50 percent since fixed capacity is not easily expanded and has relatively low reliability.

More advanced compression technologies such as H.264 help bring storage requirements down when there is minimum motion in the field of view. However, the variable nature of the bit rate exacerbates the capacity estimation problem since requirements can be off by as much as 4x if motion is higher than expected. The market will continue to see improvements in compression standards, but the growth in the number of cameras, resolution and retention times will continue to drive the need for scalable and highly reliable storage solutions.

Effective ways to increase storage beyond a DVR or NVR
A storage area network, or SAN, is ideally suited for a centralized site such as an airport, casino or prison where there is plenty of bandwidth on the local area network. In a SAN environment, video recorders or archivers maintain their own file system, such as Windows, and these appliances talk to the shared SAN storage as if it were a local disk. Many archivers can share the storage and the SAN platform introduces more reliability over NVR/DVR systems because there is no single point of failure.