In this converged, digital age, bandwidth (the maximum amount of data that can be sent along a transmission medium) has become one of our most precious resources.
Whether it’s the number of channels your cable-TV system can deliver, or the amount of computers that can use a particular network segment, almost everything we do now is somehow related to the size of that data pipe.
With networked video, we are more concerned about bandwidth than many other industries. As I’m sure you’re already aware, video takes up far more bandwidth than most other networked technologies, such as E-mail and Web browsing.
Calculating the available bandwidth on a network, and how much of it your video system is going to utilize, is both a science and an art. It is also one of the most important factors in any digital video system design.
Unfortunately the art aspect of calculating bandwidth is more pervasive than the science. Camera manufacturers have become better at putting file sizes and bandwidth estimates on spec sheets, but those can only go so far. There are many aspects to look at when determining how much of a network a camera system will take up.
Let’s take a look at a few of the many factors involved with bandwidth estimating.
CONTENDING WITH COMPROMISE
Some things that we need to look at when estimating bandwidth utilization may seem obvious to some people. It is important, though, that they be included here.
Life is full of compromises, and there aren’t many things that involve more compromise than a video network. In a nutshell, the higher the quality of the video, the more bandwidth is used. The less bandwidth used, the lower the video quality (for a given type of compression).
That word, “quality,” has several components, though, and is defined in several ways. There is really no quantifiable way to determine quality (although the emerging pixels-per-inch standard comes close). It is a very subjective term.