The video world is awash in new terminology: IP addressable, AI, edge devices, network appliances, latency, 4CIF, MPEG4. What does it all mean? To some of us old salts who used to send our CCTV cameras to a shop to be repaired (back when it was cheaper to have them serviced than to buy a new one), it means familiar terms like coax, lines of resolution, real-time video, and closed circuit are being replaced. It means that the gap between leading edge and bleeding edge has gotten smaller. It means that it's easier to be overwhelmed by technology advances and sales claims, and harder to gauge actual performance between devices. It means the video world is running into the information technology playground.
Most people consider the migration of video from analog to digital a good thing. The future of video is clearly in digital, and digital video recording, storage, distribution and search capabilities are driving the market for digital systems. However, not all digital video systems or features are ready for prime time, and not all are yet better than their analog counterparts. In the eyes of someone who has worked with and experienced the performance of analog video systems, the live video viewing and control capabilities of digital systems leave a lot to be desired. Above all, the communications paths or networks are in many cases not ready to handle the load of video viewing to which many security professionals are accustomed.
The most limiting aspect of digital video systems today is that they must be designed to function within the bandwidth limitations of the available networks. Analog systems are unencumbered by this limitation, unless you consider the cost of the cable. Bandwidth limitations can cause performance problems, such as latency of the control functions for networked PTZs. Latency is the delay between the time an operator executes a command and the time the field or edge device (in this case a PTZ motor) responds. Analog system latency is hardly detectable on late-model and best-of-breed systems, but the latency in many of today's digital systems can frustrate a security operator following a suspect in a parking lot or on a casino floor. It may be hard to keep up with a person walking at normal speed.
The most limiting factor of analog systems, on the other hand, is that they require a point-to-point wire connection. One hundred cameras would need 100 coax cables run from the edge device to the controller. That is quite a lot of copper or fiber optic glass.
A Hybrid Solution
Many security professionals consider hybrid video systems the best solutions today. The hybrid configuration includes a dedicated analog transmission (coax or fiber optic cable) from the video camera to the controller and/or DVR. The analog communication allows high-resolution viewing and high-speed control on the local controller. If the DVR device is then connected to the network with an IP address, the system becomes a hybrid of analog and network digital components.
Security or facility managers traveling on the road can, with appropriate authorization as verified by password controls, tap into the recorder and view live or recorded images. However, bandwidth limitations may still limit the video quality and quantity. The limitations can be in the form of resolution, measured today by Common Intermediate Format (CIF) with values of 1CIF, 2CIF, 3CIF and the highest, 4CIF; or by the number of frames per second (fps) that can be viewed (from single-digit fps to a high of 30 fps). Nonetheless, remote viewing of dubious quality is better to many than no remote viewing at all. Future advances in video systems should provide improvements.