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The Battle for Network Bandwidth
By Ray Bernard, PSP, CHS III
Security Technology & Design
There is one area of convergence that has a significantly higher need for physical security and IT collaboration than any other: security video system design and deployment. Unsurprisingly, this is the area in which I receive the most questions and comments.
Specifying a megapixel camera where it is not appropriate can needlessly raise the bandwidth requirement of a particular camera. Even “where a camera points” can have an impact on the amount of network bandwidth required. The more continuous the motion is in the camera’s field of view, the lower the rate of data compression will be for the camera’s video stream, and the higher the bandwidth requirement will be. Including a busy street in the fields of view of multiple cameras — where only one or a few cameras will do for appropriate scene coverage — will needlessly raise the size of the camera’s data stream. These factors were simply not an issue with analog camera system design, with each camera having its own cable connection back to the central monitoring point or recorder.
I recently talked to an IT specialist who used the term video network engineering to describe his work. He was completely unaware of the fact that physical aspects of a camera’s field of view environment — and consequently the camera’s placement — could impact its network requirements.
There are many other factors that also impact a camera’s network bandwidth requirement, such as the video frame rate setting (frames per second), which must be based on the role of the camera and what information the security (or quality or training) application needs to have captured.
Most areas of technology convergence require more IT expertise than they do physical security expertise. Video system design and deployment is the significant exception. This is why IT systems integrators tackling video security projects need a video security specialist on board or as a partner (security consultants take note).
Several of this column’s recent questions have elicited a group of responses all centered around network bandwidth and the performance of networked video systems. There are several aspects of these responses worth special attention. Here is a list of comments that typify the responses, with the most frequent comments listed first:
• “IT wants to know what our network requirements are for our security applications. We ask, ‘What kind of requirements, for example?’ And they reply with technical jargon that we don’t understand.”
