Home » Physical Security » Video Surveillance

A Buyers' Guide to IP Surveillance Cameras

IP network-based surveillance cameras offer enticing possibilities. But do you want full or partial IP? How much bandwidth? We'll walk you through the entire process.

By Mary Brandel

Page 2

Second, consider if there is enough bandwidth on the corporate backbone.

Because IP-based surveillance places new demands on existing network infrastructures, the physical security department has to work with IT to implement or even choose the best system, which means overcoming a traditional barrier between the two groups. Network cameras are "forcing these two groups together, but they're kicking and screaming and reluctant to do so," Hunt says.

The best decisions on network design will be made jointly between the two groups, says Jeff Vining, research vice president at Gartner. For instance, because streaming live video is bandwidth-intensive, it can be too costly to upgrade networks or too difficult to use in situations where there are many users. To optimize bandwidth, you may need to use application delivery controllers and/or wide-area-network optimization controllers, he says.

Even when bandwidth is plentiful, the two groups need to communicate, McInturf says. "Because we have a robust network and the cooperation of the network technology group, we were able to use our existing network that we partitioned for security applications," he says.

Evaluation Criteria
The range of features available on network cameras is constantly changing, but here are some basic things to look for, according to analysts.

Field of view: According to Vining, most applications call for a 240-degree field of view and a zoom capability of 500 feet. For those who need more, there are pan/tilt/zoom (PTZ) cameras, which can provide 360-degree views. These can cost more than twice as much as fixed cameras, Vining says, and normally require more maintenance because of their moving parts.

Bandwidth: It's a huge issue, especially as demand grows for more cameras on the network and higher-resolution images. You can reduce bandwidth consumption by putting intelligence into the camera, says Simon Harris, senior analyst at IMS Research, so, for instance, only certain images are forwarded. However, that means you're not recording nonevents that may supply needed context. "You need to use that selectively," he says.

PCamera manufacturers differ in bandwidth consumption, says Anthony Bastian, security-over-IP manager at AMS.Net, an IP convergence integrator. For instance, he says, packets sent from Verint Systems cameras are almost half the size of those sent from Sony equipment. Both use the MPEG4 compression algorithm, but there's more overhead data in Sony's case.

DVTel uses multicasting to reduce bandwidth, McInturf says. In other words, when multiple people are viewing a video, instead of each camera sending out an individual stream, the signal is broadcast from the server without duplicating streams.
Power source: The state-of-the-art approach for network cameras is to use power over Ethernet (POE), which means you power the camera through the same wire that sends the IP signal, saving up to $300 per camera, according to Axis Communications. POE is not always available on PTZ cameras, however, because of the amount of power they consume, Bastian says. Axis also says to ensure that the POE feature complies with the IEEE 802.3af standard so it's compatible with network switches from leading vendors.