CCTV: Mass Storage

Ten years ago video surveillance was primarily known as a security measure used by major corporations and financial institutions for protecting assets and monitoring perimeters. Analog cameras were strategically placed for remote viewing by security personnel, often in combination with a human guard controlling access to premises.

Videocassette recorders (VCRs) recorded the captured video on tapes.  Tapes were archived for a certain amount of time for post-event analysis and identification, and then reused. The recorded content was often poor because of both the limited resolution of the cameras and the use of worn-out tapes.

Then came 9/11 and, along with it, an increased desire for tougher security measures throughout the world. Fortunately, at around the same time, major technological breakthroughs in the video surveillance world ushered in significant improvements.  On the heels of IP networking for computing came IP networking for video surveillance systems.  IP video surveillance management software makes it possible to centrally manage an unlimited number of networked cameras and store captured video digitally for easy retrieval and export for evidence. Using video encoders, existing analog cameras can easily be made part of the system, in addition to the newer, higher resolution (megapixel) IP network cameras that – because of a variety of advantages – are rapidly taking over the market.

The biggest challenge with closed circuit television (CCTV) systems is the volume of content that is recorded and archived.  As CCTV cameras move from standard definition to high definition and now to 4k resolution, the data rate is growing exponentially and demands massive capacity for storage.

There are basically two approaches to large scale storage systems for CCTV.  The first is the NVR or Network Video Recorder.  It is sometimes called a DVR (Digital Video Recorder) on smaller scaled solutions.  The second options is a large scale, mass storage solution from the IT world.  Depending upon the scale of the network, both have merit in the right circumstances.

Regardless of the video surveillance application that you use, once you record footage, you need a means to store it.  CCTV camera storage can help preserve evidence, beneficial in defending against a case.  The proof can also be used to resolve a robbery or determine the root of an inferno.  In the vast majority of countries, storing surveillance footage for a given period is mandatory.  As a rule of thumb, most security companies store the surveillance videos for one to three months.  Footage is often recorded on a rolling window, meaning after the define time period is achieved, say a 30 day roll-over, the first day of footage is recorded over by the 31st day of footage.  Only the previous 30 days of content is ever available at any one time.  Some key footage can be tagged for longer term preservation, perhaps for years, if it is needed for legal reasons.

Beyond the core storage solution, sometimes regulations require a back-up copy of all footage.  This can be challenging to do.  In most cases, you will want to maintain the back-up copy at a different location to protect it from local events like fire and break-ins.  The cloud is a common place to record back-up footage and longer term archives.