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The current industry-wide transition from analog to an IP networked platform is affecting every aspect of the way video surveillance systems are specified, sold and serviced. The existence of dealers with responsibility for all aspects of this process is diminishing as today's systems are based on the parameters of the information technology (IT) infrastructure. This requires that responsibilities are shared between security and IT departments.
Up until now, security equipment manufacturers and their sales channels have basically controlled their own destiny. This is no longer the case with the emergence of IP networked systems. With IP security systems, security departments no longer control their transmission of signals. In fact, they control very little.
The success of IP video surveillance systems is dependent upon so many factors outside the scope of a typical security dealer that many wonder if it has become more IT than security. The list of what is not controlled is far greater than what is. To start, in almost all cases the network is under the domain of the IT director, who must agree to let you on the network in the first place. Data in the form of access control, reports and alarm notifications present little or no problem, but video is another matter entirely. Quality is a function of bandwidth and the bandwidth required is a function of the compression method used. In general, a reasonable quality CIF (common intermediate format) signal with a resolution of 360 x 240 will usually require about 1 Mbps and a full video frame of D1 or 720 x 480 can require bandwidths approaching 8 Mbps. Apply those figures to one camera operating 24/7 and then by the number of cameras in a system and you can very quickly understand the reluctance of IT directors to allow systems integrators to run video on their systems.
Regardless of what a manufacturer says about how well their codec performs, the simple truth is that the greater the compression, the more a picture degrades. If you have a transmission system with limited bandwidth, your choices are to reduce your picture (file) size, or reduce the number of pictures recorded/views per second, or the reality is that you will have to live with degraded images. Additionally, unlike analog video systems, IP recording and viewing are separate functions defined as video in and video out. In IP systems, there is only one bandwidth pipe, so the requirements for viewing add to those of recording, and most shared networks exist in a constant state of use. Whether it's someone surfing the net or accessing e-mail or office work, you must account for all of these network activities because they consume bandwidth.
As a result, most mid- to large-scale IP video surveillance systems require dedicated networks adding to both installation and material costs. When working with customers on specifying IP systems, it is important to determine security equipment requirements along with the network required to sustain video defined performance parameters. It is far better to delay deployment of a system than to implement a system where you can't view cameras or record footage or do what security is supposed to do.
The good news is that once a network is established, it can be expanded with great cost-efficiencies. Each component in the system can be set up, operated and monitored independently. Multicasting provides the ability for security devices to be monitored in multiple locations and not restricted to the single point-to-point of coaxial cable. Compression levels can be changed to match system limitations. Standardized communication protocols such as SNMP (Simple Network Mail Protocol) allow for interaction throughout the network and via the Internet. Access to the system using user names and passwords can be achieved from any point on the network using standard TCP/IP so that any networked computer can be used as a viewing monitor and operation center. Standardization of databases and protocols also allows for interaction and interfacing with other security components such as access control and alarm systems. This could never be accomplished with analog video components and coaxial cable.
Neil Heller is American Fibertek's director of New Business Development.
author: By Neil Heller