• Enterprise Series drives designed for 24/7 operation with a high MTBF
• High performance Hardware SAS/SATA unified RAID controllers
• Battery backup modules for onboard RAID controller cache
• Redundant power supply units with hot plug replacement modules
• Hot plug hard drives with streamlined and effective cooling for maximum reliability

• Enterprise Series drives designed for 24/7 operation with a high MTBF
• High performance Hardware SAS/SATA unified RAID controllers
• Battery backup modules for onboard RAID controller cache
• Redundant power supply units with hot plug replacement modules
• Hot plug hard drives with streamlined and effective cooling for maximum reliability:

• Enterprise Series drives designed for 24/7 operation with a high MTBF
• High performance Hardware SAS/SATA unified RAID controllers
• Battery backup modules for onboard RAID controller cache
• Redundant power supply units with hot plug replacement modules
• Hot plug hard drives with streamlined and effective cooling for maximum reliability:

CCTV is Closed Circuit Television.  It normally refers to the monitoring of physical areas where security is a concern by individual companies or organizations.  It often implies the presence of a security guard who will monitor the cameras in the control room in real time.

IPVS is Internet Protocol Video Surveillance.  It is a modern version of CCTV by employing the same technologies that support the operations of the Internet.  IPVS can stay as closed circuits if the owner desires and can use the Internet to broadcast camera footage economically.

This paper discusses CCTV and IPVS in the context of physical security and does not include other IPVS applications such as counting the number of consumers interested in a particular product on the supermarket shelf or recording the use of toll roads by vehicles etc.  This paper provides the essential background information for an organization such as a school or a business to draw up a user brief for installing a video surveillance system.
Fitness for Purpose

Most often, we think of CCTV or IPVS because of 2 desires: to accrue evidence of vandalism, threat or misbehaviour and to monitor the state of affairs of remote areas from the comfort of a chair in the office. Vandalism, burglary, and break-in are common concerns or threats to most organizations. Who are involved?  When and under what conditions?  This information is important for operation planning, crime prevention and crime investigation.

To accrue the evidence of vandalism or misbehaviour, the IPVS system shall be able to record the act of the “crime” with clear identification of the “criminal” and the properties being damaged.  The evidence shall be stamped of date and time and provides a trace of the sequence of events.  We need details as well as an overview across space and time.  The task has not been achieved by most analogue based CCTV equipment due to technology limitations.

IPVS is digital based and allows all recorded footage quality to be preserved during copying or transmission over distance and across devices including portable media.  IP camera sensors and chips are manufactured on nanotechnology level.  As of March 2010, IP cameras have attained 1.3 megapixels of resolution and higher whereas analogue cameras stay with the equivalence of 0.4 megapixels max in commercial use.  By thoughtfully designing the type of camera per location and the placement of cameras throughout the campus, IPVS can strike a good balance between details and overview.
Retrieval of Evidence

The biggest challenge of a CCTV or IPVS system is to retrieve evidence from footage quickly.  Most surveillance systems are set up for 24x7 monitoring.  If there are 20 cameras in the system, the video footage would be quite large for 7 days for instance.   Surely we can invest more money in larger storage but the time for searching for the required videos will be longer unless we know the exact date and time of the crime.   If we apply motion detection for recording, the amount of footage would be substantially reduced and the search time would be a lot shorter.  An IPVS system shows when motion was detected, provides fast forward review of footage and exports snapshots or video clips to a portable device such as USB thumb drive. 

A good IPVS will allow play back of several cameras in synchronization.  This enables us to trace movements across space and time for a higher level of evidence. 
Design of IPVS System

A good system should be fit for purpose.  This paper has discussed 2 key factors and they are clarity of images and speed of retrieval of evidence.  In a separate article to be published later, we will discuss the Costs of Owning an IPVS and CCTV system for further consideration.