Don't Roll the Dice

Avoid taking a gamble when installing IP video

• By Oliver Vellacott
• Oct 01, 2007

The IP video market is growing rapidly, having been accepted as a mature technology with a field-proven record. IP networking of security systems will eventually penetrate the majority of the market—it has too many cost and performance advantages not to do so.

Why IP Video?
The advantages of IP video can best be highlighted by looking at the disadvantages of analog CCTV. In many ways, traditional coax or fiber-based video systems are limited. Installation costs over large areas are prohibitive, and the number of monitoring stations is limited due to the investment required to replicate costly switching infrastructure. The analog matrix provides control room flexibility to analog CCTV systems, but this too cannot be easily expanded because it’s location-dependent and requires adding new hardware. Therefore, overall scalability—the cost of expansion—is poor.

Although the introduction of DVRs has improved the recording capabilities of analog CCTV, they too are limited. They have to be physically installed near the analog matrix, and frame rate and image quality is often compromised. Businesses want a single, scaleable, integrated solution that provides high-quality video surveillance across any number of offices or sites—this is what IP video delivers.

For enterprise systems, IP video also offers a high level of redundancy. In the event of an emergency, the control and monitoring capability can easily be transferred to any other point on the network, either on or off site. Redundant networks allow the system to keep operating, even if one link or switch goes down. Redundant NVRs allow recordings to survive, even if one recorder fails or is destroyed. These features allow IP video systems to deliver a level of integrity far higher than what is possible with analog CCTV systems.

Having everything based around a network allows system-wide diagnostics to ensure everything is running smoothly. Every device can be continuously monitored, and an alarm can be raised if anything fails. This is not possible with an analog system, where camera feeds have to be manually monitored to ensure troublefree operation.

Analog systems can perform limited diagnostics, but this depends on the different components used and is not an integral part of the system.

Building and IP System
The key component in an analog CCTV system is the matrix. In an IP system, the network, and the software controlling it, become the virtual matrix. IP video systems operate over standard corporate networks, both of which can span entire organizations. As the traditional control room equipment can be replaced by a PC, it is possible and often desirable to be able to monitor live and recorded video from any camera from any point on the network.

For example, a camera connected to the network via a transmitter/receiver unit compresses the analog video into DVDquality MPEG-4 digital video for transmission over the network. The digital video can then be viewed, analyzed and recorded. This is achieved with Windows®-based PCs running video and alarm management software and NVRs that are installed around the network.

Since access to the system is available from any PC connected to the network, IP video systems implement sophisticated user profiles to manage admittance. These restrict or enable access for users on a camera-by-camera basis.

Transmitter/receiver units allow any type of CCTV camera to be connected to the network, ensuring existing equipment can be fully used. However, for new installations, one option is an IP camera or dome. These combine a professional, fullfunction, high-quality CCTV color camera and an IP video transmitter/receiver in one unit that can be connected directly to the network. Significant cost savings can be achieved by employing integrated camera units in place of traditional analog video cameras and a separate IP transmitter/ receiver unit.

There are now many different IP-ready products available from different manufacturers, including IP cameras and DVRs with network connections. However, to ensure compatibility and to get the most from the advanced features that IP video has to offer, use a single integrated system from one manufacturer.

Network Requirements
Manufacturers of IP video equipment provide excellent tools for helping security and IT professionals design digital CCTV systems and, in particular, compute the bandwidth requirements of a network. It’s fundamentally a simple process—decide how many cameras are required, select the video quality for viewing and recording, and determine how many days of recording are needed. This can then be used to calculate how much bandwidth and recording storage is required.

Each device connected to the network is then assigned an IP address, ensuring they are all on the same sub-net and can therefore see each other. Site Builder software tools provided can then interrogate the network, discover appropriate devices and automatically build a site database and recording schedule.

In many cases, bandwidth requirements can be easily accommodated on the existing corporate LAN/WAN, giving the proposed IP video system another significant advantage over analog CCTV by removing the need for additional cabling. This also means the network can be shared with the normal IT traffic and facilities, such as VoIP.

IP video has many clever features that ensure bandwidth impact is kept to a minimum. Positioning NVRs locally to relevant camera clusters can reduce network traffic and improve redundancy. The compressed video can be transmitted across the network using TCP, UDP Unicast or UDP Multicast protocols. The advantage of Multicast is it uses the same amount of network traffic for 1,000 operators to view a camera as it does for one operator.

Activity controlled frame rate is another feature designed to reduce network traffic. Some facilities rely on processing data at the camera IP transmitter/receiver unit. If no movement is detected in the camera scene, the bandwidth used is dramatically reduced. This feature is most effective in places where low activity occurs, such as in corridors, on fire escapes or in buildings that are unoccupied at night.

Searching recorded video can be a timeconsuming activity with a corresponding increase in network traffic. However, clever thumbnail searches can be provided by the video and alarm management software. The system can analyze movement in a scene and display thumbnail images that represent frames from recordings containing the specified movement. Clicking on a thumbnail then replays that section of video. This feature is designed to search 24 hours of recorded video and display the thumbnails in just a few seconds. Changing the search variables allows the operator to sift through vast quantities of recorded material quickly and efficiently. The use of thumbnails allows a vast amount of video to be analyzed with little extra impact on the network.

Handling Legacy Systems
It is easy to see the advantages of IP video for large enterprise systems. However, it also is an ideal solution for smaller CCTV systems and for upgrades to existing installations.

When upgrading from an existing analog system, the obsolete equipment, such as the matrix and DVRs, can be replaced, but all cameras, domes, monitors and keyboards can remain. Using IP transmitter/receiver units, all existing cameras and monitors can be interconnected; in fact, existing control room configurations can largely remain unchanged. With the addition of a PC or two, all the advanced features of IP CCTV can be made available without the need to change the familiar surroundings of the control room. Once the migration is complete, it’s easy to expand the system in the future. It is now becoming common practice for IP video systems to be used to expand existing analog CCTV systems based on cost alone—it’s often just too costly to cable in new cameras from remote locations.

IP video allows potential end users to easily trial the system first-hand without a commitment to large-scale change from day one. Even though IP video is an established technology, users will always want to convert to new technology at their own pace.

Integration with intruder alarm and access control systems also is providing advantages, as they are now moving to IP networks, as well. These systems also are seeing the benefits and flexibility of replacing cable with a network. CCTV video and data from these systems can share the network without any problems. In fact, this level of integration provides interesting features. For example, a security alarm can provide an input to the IP video system, which automatically moves a camera to cover the incident and displays the video feed on a monitor in the control room with a map of the location, providing multiple perspectives on the incident.

The NVR
It is important to differentiate between DVRs and NVRs, as both are often termed digital. A DVR digitally compresses analog video feeds and stores them on a hard drive. In this instance, digital refers to the compression and storage technology, not the transmitted video images. The DVR has to be located near the analog feeds.

In contrast, an NVR stores digital images directly from the IP network. Therefore, the most obvious difference between the DVR and NVR is that the DVR records analog streams from analog cameras, whereas the NVR records video streams that have already been encoded at the cameras. Thus there are no video connectors anywhere on an NVR; its inputs and outputs are IP data, which is comprised of compressed and encoded video. NVRs can be either PC software-based or dedicated standalone units.

The huge advantage of an architecture based on NVRs is that they can be located anywhere on a network—at the monitoring center, adjacent to camera clusters, on the edge of a network or collected together in a hardened environment. In use, their location is transparent to an operator; the recorded video stream from any camera can be viewed by any operator at any point on the network. NVRs record and replay simultaneously, and recordings on any one machine can be remotely viewed by a number of authorized operators spread across the network simultaneously—all independently and without affecting each other.

Advanced Analytics
Analytics is the processing of video images to detect such events as congestion, stolen objects, cars parked too long outside a building or people moving the wrong way through security checkpoints.

Analytics are available as an add-on to analog systems, making it difficult to realize the true benefits of this technology. In IP systems, however, analytics may be completely integrated so the full benefits can be realized. IP-based analytics can be run in two modes: real time within the IP transmitter/receiver at the camera and postprocessing on any operator’s PC. The realtime mode allows the system to automatically identify events as they occur. Postprocessing allows operators to run many different scenarios on recorded video.

Advanced analytics is one of the outstanding applications of IP video that simply cannot be matched by traditional analog CCTV systems. It offers advantages such that it alone can often justify the IP solution.

It can be expected that huge productivity improvements will result from using analytics software during the searching of recorded material in post-event analysis, and for this, the NVR is key.