IP network-based surveillance cameras offer enticing possibilities. However, you need to evaluate several factors before deciding on the type of IP camera installation you’d like to go for. For example, do you want full or partial IP? How much bandwidth?
Network cameras for IP-based video surveillance systems have been around since 1996. These are attached directly to the network and send video to a network video recorder or to a server equipped with video management software, which stores, displays or broadcasts the images. While it will be another couple of years, according to consultancy and research firm Gartner, before the market favours IP over analogue, IP cameras are considered a fast-growing market.
Experts say the reasons for analogue’s continued dominance centre mainly around upgrade costs and a general lack of knowledge about networking technologies in many physical security departments.
Points to consider when opting for a network video surveillance solution
When looking at your options, the first thing you need to consider is whether you should use full or partial IP. You can still get some of the advantages of IP while maintaining your investment in analogue by using video encoders that convert the analogue signal to one that can run over IP. Though this kind of system works well, it is not architected for growth.
Full IP installations are more streamlined and efficient and require less maintenance. They’re digital from one end to another and are very reliable because there are fewer moving parts. 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. “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 optimise bandwidth, you may need to use application delivery controllers and/or wide-area-network optimisation controllers,” he says.
Evaluation Criteria for a network camera system
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 surveillance 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 cameras 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 non-events that may supply needed context. “You need to use that selectively,” he says.
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. POE is not always available on PTZ cameras, however, because of the amount of power they consume.
Resolution:Many users are moving toward megapixel network cameras, which offer five times the resolution of video graphics array (VGA) cameras. Not only do you get a clearer image, but because of the higher resolution, you can also reduce the number of cameras you need.
Auto filtering: For image clarity in various lighting situations, it’s important to get a network camera with adjustable lenses to control the amount of light that is received. This is especially important, Vining says, when a camera is facing east or west. However, he says, some organisations will simply elevate camera mounts and then angle downward to view the horizon rather than incur the additional costs of adjustable lenses.
Open platforms: Look for vendors that comply 100 percent with industry standards, such as in the areas of security (PSIA or ONVIF) and video compression (H.264), Gartner recommends. Also look for open application programming interfaces and multiple supported software applications.
Scalability: Companies with large installations will want the equipment to be compatible with tools that locate, update and monitor the status of the devices and their IP addresses.
Service/support: Make sure the camera vendor or reseller is able to send replacement parts quickly and can readily offer engineering support. Many network camera manufacturers sell indirectly through channel partners, which is common in the IT industry but not in the security industry. This takes some getting used to among traditional security personnel.
Do’s and Don’ts
Don’t let cost be your guiding light. Most people buy surveillance cameras with cost as their highest priority and effectiveness as the second, which results in grainy, out-of-focus images. There are tools available that help you choose the resolution and lens that fits your needs, based on factors like distance and camera height. Determine what you need to accomplish- whether it’s reading a license plate number or simply knowing whether cars are moving through a tunnel.
Do understand the trade-offs to high-quality images. Industry experts advise people to favour a crisper image over smooth motion.
Do consider the benefits of centralising video surveillance
Don’t assume everything is a mix and match. While many network cameras claim compatibility with many vendors’ video management software, some management software is more open than others.
