Network cameras for IP-based video surveillance systems have been around since 1996, when market leader Axis Communications introduced the first one to the market. 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. It will be another five years, according to consultancy and research firm Gartner, before the market favors IP over analog. However, IP cameras are considered a fast-growing market; according to IMS Research, the global network video market grew 42 percent last year and is expected to reach $2.6 billion by 2010.
Experts say the reasons for analog's continued dominance center mainly around upgrade costs and a general lack of knowledge about networking technologies in many physical security departments.
Two Key Decisions in IP Surveillance Systems
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 analog by using encoders that convert the analog signal to one that can run over IP. Leaders in analog-to-digital systems are Pelco, the "800-pound gorilla of the analog world," according to Steve Hunt, founder of security think tank 4A International; and Bosch Security Systems, another traditional analog supplier.
According to Hunt, these systems work well but are not architected for growth. "With an IP-based system, I can use a 24-port switch to plug in anything I want on the network, but [these companies] are building their own proprietary network," he says. Full IP installations, he says, 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," he says.
But for North Carolina State University, analog-to-digital cameras from Pelco were the best choice for upgrading its previously diverse video surveillance system in mid-2004, according to Scott McInturf, project manager of the AllCampus Network at N.C. State. "It was the early days of IP cameras, so we felt more comfortable with analog," he says.
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At the time, network cameras didn't have features like backlight compensation and a wide selection of lenses. "The advantage of using analog cameras connected to an IP encoder is we can pick any camera we want that will fill our need for lighting and environmental conditions," he says. Network cameras are fast catching up with analog in terms of breadth of features, according to analysts. N.C. State also uses purely IP-network cameras from Axis that other departments had already invested in.
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 for IP Cameras
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.
Camera 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.
Resolution: Many users are moving toward megapixel cameras, which offer five times the resolution of video graphics array (VGA) cameras, according to Jim Gompers, founder of Gompers Technologies Design Group. Not only do you get a clearer image, he says, but because of the higher resolution, you can also reduce the number of cameras you need. On Gompers's recommendation, the Montgomery County Public Schools in Maryland invested in megapixel cameras from IQInvision, and the images are much clearer than the previous analog system, according to Robert Hellmuth, director of security and safety for the school district. "Before, we'd see an incident and play back what we recorded, and we'd see two figures but couldn't identify them," he says.
Auto filtering: For image clarity in various lighting situations, it's important to get a 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 organizations 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 and video compression, 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 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. "The manufacturer doesn't provide the hand-holding of companies like Pelco and Bosch," McInturf says.
IP Surveillance Camera Dos and Don'ts
DON'T let cost be your guiding light. According to Hunt, most people buy cameras with cost as their highest priority and effectiveness as the second, which results in grainy, out-of-focus images.
There are tools available, such as one on IQInvision's website, that help you choose the resolution and lens that fits your needs, based on factors like distance and camera height. "People don't do that calculation; they don't even know how," he says. "They assume all cameras are equal so they buy the cheapest one." Determine what you need to accomplish, he says, whether it's reading a license plate number or simply knowing whether cars are moving through a tunnel.
DON'T think small when upgrading from analog/VCR systems. When the VCRs at the Montgomery County school district began breaking down, Hellmuth first switched to digital video recorders (DVRs). After talking with a consultant, however, he came up with a bigger strategy: centralizing all its security systems, including alarms, access control, visitor management and surveillance, on one platform. As it turned out, the current network infrastructure could support such a system.
Despite the lower cost of the DVR approach, there just weren't a lot of benefits, Hellmuth says. Each could support only 16 cameras, and there was only about two weeks of storage capacity. The school district is now in the middle of a six-year project that will cost $1.5 million per year. "When we decided we wanted to tie all the security components together, we were able to paint a better picture for the funding sources on why we needed more cameras and better quality cameras."
DO understand the trade-offs to high-quality images. Gompers advises people to favor a crisper image over smooth motion.
"Digital quality is not as crisp," McInturf says, but it meets the school's needs, and for now he's choosing not to upgrade to megapixel cameras because of the resulting bandwidth and storage requirements. "It's a balancing act between the storage required and the detail you capture," he says. "If you're capturing the highest quality of video using megapixel cameras and you've set it up perfectly, at that point, you're recording a lot more data than from an analog standpoint."
DO consider the benefits of centralizing video surveillance. Before N.C. State standardized on a single IP surveillance system, each department had invested in its own equipment—some analog, some IP. As a result, it was difficult to locate anyone who knew how to operate the system. "If it was an older system, the tape had run out long ago and no one was looking after it, or they didn't know how to operate the software," he says. Now, campus police can just log in themselves, rather than working with each department to view security footage.
DON'T assume everything is mix and match. While many network cameras claim compatibility with many vendors' video management software, "some management software is more open than others," Harris says. For instance, Bastian points out, the Verint software he uses performs health monitoring of its own cameras, even alerting users to the temperature of cameras. However, with non-Verint hardware, the system can tell you when a camera is out, but not whether it was due to heat. (Editor's note - see the 2009 article How to manage surveillance video.
McInturf has also run into compatibility issues. While he appreciates the fact that he can use multiple cameras with his DVTel management software, each camera poses a learning curve in terms of how it relates to the software. For instance, the motion detection settings in DVTel's software tended to conflict with those settings in the Axis cameras. As a result, the cameras were recording 24/7 and filled up the storage archive in a week. The DVTel software also doesn't currently support megapixel cameras, he says. "The message is that the IP industry for video is still young and fairly proprietary, and everything doesn't work with everything else," he says.##