It's becoming harder to believe that VCRs were once the only option for CCTV recording and storage. Digital video recorders (DVRs) revolutionized the industry by putting the process into the digital domain, addressing several issues with respect to reliability, storage capacity, connectivity and
Just in case you have forgotten, VCRs are electromechanical. Consequently, they suffer from the issues that plague all things with wheels, belts and gears. Additionally storage capacity in a VCR is limited by the size of the videocassette and recording speeds. In the lexicon of VCRs and videocassettes, the term connectivity amounted to duplicating cassettes and physically conveying them to other VCRs.
Fast Foward to Third Generation
Network video recorders (NVRs) using IP network video are the third generation—the next step in this evolution of more cost-effective and space-efficient solutions for viewing and storing video. IP-based digital encoders put video onto the network for storage processing and viewing.
The nature of these new techniques permits total or incremental transition from analog to digital technology.
As video moves into the networked world, it permits the use of other IT technologies such as network-attached storage and storage area networks. Rather than individual hard drives, larger systems are using dedicated high-density storage servers which can share their video with anyone anywhere on the network.
Reliability is another benefit of Internet technology. For example IP can automatically redirect video traffic to a backup storage system in the event of a power failure or network outage. Storage devices can be configured into fault tolerant arrays which backup data and enable hot swapping to ensure uninterrupted service.
The convergence of voice, video, and data traffic over a shared network introduces heightened concern over ensuring efficient, reliable application performance, particularly latency-sensitive traffic like Video-over-IP.
Video-over-IP uses an invariable amount of bandwidth but it is highly susceptible to interference from other applications.
Bandwidth is the speed limit which video data must overcome as it travels over networks. Bandwidth issues are somewhat within the LAN, but not as much when the data must ravel over the Internet. When a Video-over-IP system is being contemplated within an enterprise, the network's resources (capacity to support data traffic) becomes a primary concern the same way the hardwired cable sizes, lengths and locations would be addressed in a conventional CCTV infrastructure.
QoS is a term which refers to Quality of Service, an area of network performance and management which network designers and administrators to determine the bottlenecks and loads on their network and employ measures to control it. With video, measurement can be determined by a number of methods, most notably by “user perceived performance.”
Bandwidth throttling is a bandwidth management tool used by cutting-edge manufacturers to self-regulate their equipment's throughput so as to provide the highest level of “user perceived performance.” Other technologies are coming online which place specialized routers at points along the network to monitor the OSI Layer 7 and interactively respond in real-time to latencies which could also adversely affect system performance (video quality).
IP technology offers improved flexibility for enlarging a CCTV system. System scalability includes the ability to add cameras, add storage space and distribute it across the network...Another dramatic change is that Video-over-IP networks are able to support multiple viewers. In the same way that an e-mail server can send the same data to multiple people at the same time, the network switch has the ability to clone the video and use the same data multiple times.
While this month's column brings 2006 to an end, it opens the door to 2007 and the new horizons to be viewed and explored in the New Age of Video-over-IP.