IP Video Surveillance Fundamentals Overview
This section provides an overview of why video surveillance deployments are migrating from analog-based systems to IP-based systems. The time between 2007 and 2010 represents a market transition in the industry where sales of IP-based components began out-selling analog-based systems. While analog systems have a cost advantage in small deployments (sixteen cameras or less), when larger number of cameras are deployed, IP-based systems may be more cost-effective initially and have a lower ongoing total cost of ownership. IP-based video surveillance systems, especially the end-node (the IP camera), have several operational and technological advantages. Why implement IP video surveillance over analog-based systems? The following subsections provide the answer.
Leveraging VoIP Adoption
Many of the advantages of implementing IP video surveillance are similar to those of VoIP adoption. The fundamental reason is the cost savings of using the IP network for both voice and data. By adding the transport of video surveillance on the existing highly-available IP network, the cost savings realized from eliminating the separate cable plant for voice extends as well to the elimination of the separate cable plant for video.
Not only the wiring for media transport can be eliminated, but also the cabling for electrical power. As is the case with VoIP in the enterprise space, where the IP phone uses PoE, so does many fixed installation IP cameras. While power to some camera deployments continue to be a requirement (Pan-Tilt-Zoom housings, wireless cameras and cameras that require fibre connectivity due to distance), PoE is a substantial cost savings.
IP video surveillance cameras, once connected to the network, may be remotely configured and managed from a central command center. The installing technician must have a laptop to focus the lens and adjust the viewpoint of the camera, but following this initial installation, the camera configuration may be completed by a technician in a central, rather than local, facility.
Access Video Any Time, Any Place
With IP-based systems, video feeds are encoded into Motion JPEG or MPEG-4/H.264 formats and stored as a digital image on a computer disk array. This provides the ability to access the video, by way of the networked digital video recorder, through the IP network at any time, from any place. These digital images do not degrade in quality from duplication like analog recordings on magnetic tape. They can be replicated and posted on web servers, distributed to law enforcement as E-mail attachments, and sent to news outlets. When analog-based systems were the norm, loss prevention/investigations staff may have to visit the location of the incident to view the video or a tape or DVD would need to be shipped by overnight courier. These inefficiencies no longer exist with IP-based systems and WAN connectivity to the physical location.
Intelligence at the Camera
With IP cameras, local processing of the video image may be done during capture and analysis like motion detection and tampering detection logic may raise alerts by communicating with a central server. The alert may use a variety of IP protocols, SMTP (E-mail), Syslog, File Transfer (FTP), or a TCP socket connection with a small keyword in the payload. The Cisco 4500 IP Cameras have an additional DSP capabilities specifically designed to support real-time video analytics on the camera. This option is to allow analytic vendors to develop firmware in the future to run on these resources.
Barriers to Success
While the advantages of an IP-based system are considerable, there are some barriers to success. They mainly revolve around the human element—job responsibilities, training, and education. Typically, the physical security manager and the network manager have no overlapping job responsibilities and therefore have little need to interact with each other. The physical security manager has job responsibilities targeted at loss prevention, employee and customer/visitor safety, security and crime prevention. Because of this, the physical security manager is more confident with a dedicated, reliable, physically separate cable plant.
Many installations of physical security cameras and the accompanying components are solely or partially implemented by value added resellers (VARs) who are specialists in their field, but not yet experts in IP networking. The VAR must become more fluent in internetworking and the network manager must understand the requirements of the physical security processes and applications.
The key elements of video surveillance is the three Rs: resolution, retention, and reliability. For an IP video surveillance deployment to be a success on the IP network, the reliability element must have careful attention by the network manager for the physical security manager to be successful.
Resolution, one of the three Rs of video surveillance, directly influences the amount of bandwidth consumed by the video surveillance traffic. Image quality (a function of the resolution) and frame rate are functions of the amount of bandwidth required. As image quality and frame rate increase, so does bandwidth requirements.