An IP World

Digital systems offer numerous advantages over analog technology

Video management systems have evolved considerably since the analog tape-based VCRs that were prevalent nearly 10 years ago. Then, analog CCTV cameras with coaxial cable typically were connected to a multiplexer so multiple video images could be displayed on a video monitor simultaneously. These signals then were recorded for review and archiving.

Today, digital systems afford many advantages over analog-based video recorders. In a digital system, video data is represented by exact numbers in bits. The digital data is processed, stored and distributed by computers. In general, digital video systems offer advantages in information processing, including production of higher-quality information, ease of copying information without quality loss, higher interactivity—ease of manipulation leading to useful product features—ease of storage and retrieval, ease of distribution and higher security.

Going Digital
A DVR, in its simplest form, is a VCR replacement box. A DVR records the same analog video camera signals, not to a tape, but to a computer with hard disk-based storage. Recording with a DVR allows for better video quality capture than older VCRs and provides exponentially more video storage space. The video can be retrieved faster because the computer can find, manage and replay video clips instantaneously. When a DVR is connected to a network, users can view live or recorded video from any computer that has access. DVRs offer all of this improved functionality and conveniently require very little user intervention.

For these reasons, DVRs have proliferated, and the continuing evolution of video management is now tending toward completely digital systems. The goal is the establishment of a fully digital solution from the camera, at the edge of the network; to a computer viewing the video, located anywhere on the network; to a storage device that collects the data for retrieval and historical archiving. The advantages of an all-IP digital video system are numerous, including design, installation and overall flexibility.

The dilemma facing customers and system integrators tasked with installation is how to implement a video surveillance system that is capable of meeting current and future needs while incorporating existing products the customer may have acquired in the past. Security manufacturers have designed systems specifically to address these issues. These systems allow the customer to protect previous investments by using the technology the customer already has and integrating it into current technologies, laying the foundation for an all-digital solution in the future.

DVR Design Advantages
DVRs are being used as transition storage devices between the analog systems of yesterday and the all-digital surveillance systems of the future. Technological developments in storage and computer networks are making the deployment of fully digital IP surveillance more cost-effective, and the benefits of a DVR-based solution are numerous:

• DVR-based solutions are easily understood in design terms. The interface to the video management software is via the network and the DVR manufacturer’s software interface. Connections from camera to recorder are through dedicated cables; the design element simply ensures a cable route is available. In a technical sense, DVR-based systems are easy to deploy.

• Network design is simple; a single network connection point is required by the DVR with a single IP address for high camera concentrations. Network bandwidth is low and only used when the video is being viewed or streamed over the network.

• Most DVRs have a built-in browser so the occasional user can connect to live and stored video with software loaded on the PC.

• No network bandwidth is used when recording because the video is being transmitted to the DVR via a dedicated cable.

• Easy storage calculation for video.

• Easy deployment—many buildings have existing analog CCTV system infrastructure, such as coaxial cable routed to a central location.

• Easy expansion—software can be overlaid on top of the DVR infrastructure without equipment redundancy.

• Where video is required locally, a lowcost monitor can be connected to the DVR for viewing purposes.

THE DEBATE IS ON ETHERNET-BASED IP NETWORKING VERSUS COAXIAL-BASED ANALOG NETWORKING

By Nathan Wheeler
When cable television was introduced to the public, a fierce debate erupted about whether the transmission medium would replace traditional open-air-based antenna television. Those in favor of the new technology largely based their argument on a single precept—consumer demand. To put it simply, people wanted and were ready for the channels, content and options that cable television offered.

For the past several years, a similar debate based on the acceptance of a new transmission technology has been going on in the security industry: traditional coaxial analog video networking versus IP/data video networking. It is a hot topic at trade shows, in conference rooms and at training sessions worldwide, and it will probably continue to be so for years to come.

Consider the fact that basic surveillance networks consist of three primary components— cameras generating content, a wirebased transmission medium for transporting content and a recording device for data. Tune out all of the background noise about functions and feature sets, and what remains is a simple platform of components upon which rests the foundation of nearly every major surveillance network deployed. Once deployed, the question becomes very simple: Which of the two systems offers more?

Security directors are always looking to maximize the performance of a video surveillance system in terms of both coverage and image detail. With IP-based high-definition multi-megapixel cameras, they now have this ability like never before. A few years ago, the concept of zooming in on recorded or archived video to view and recover clear, forensic, detailed information was exclusively reserved to magicians on television shows like “CSI.” Now, with cameras recording at resolutions higher than the best available monitors can display, forensic zooming and analysis of recorded data have become as simple as point and click.

With the introduction of Arecont Vision’s patented 180-degree and 360-degree panoramic cameras last year, it is now possible to put multiple, multi-megapixel high-definition cameras inside of a single camera body—four separate 2 megapixel cameras, each with its own CMOS image processor, all operating over a single Cat-5 connection. For the first time, security personnel can view a sweeping landscape of imagery at amazingly high resolution with a single camera.

The storage and bandwidth requirements of these HD megapixel cameras has been the most common issue preventing widespread acceptance of implementing systems based on IP megapixel technology. With gigabyte switches and terabytes of storage available for hundreds of dollars rather than thousands, a valid argument nearly ceases. Now, with the rollout of megapixel cameras with H.264 compression, the bandwidth and storage requirements for IP megapixel cameras have dropped tremendously. New H.264 megapixel cameras now offer bandwidth that’s 25 times greater than conventional MPEG megapixel devices, along with incomparable resolution. As a result, the longstanding arguments against IP networking no longer apply.

Nathan Wheeler is the Western U.S. sales manager for Arecont Vision.

DVR Design Disadvantages
However, the move to digital recording also can present some negative factors:

• Hidden cost—equipment costs may look favorable, but cabling costs, deployment and disruption may result in higher total costs.

• System availability can be affected by a single equipment failure because, to achieve low equipment costs, DVRs use high camera concentrations—16 cameras or more.

• Equipment setup and programming is required individually on all the DVRs as well as with the management system, which can add time to the configuration. Single configuration changes cannot be made by the management system, thus requiring the user to log on to the DVR and program locally.

• Video is stored on the DVR, and while it can be viewed on the management system, permanent archiving has to be performed at the DVR directly.

• The security management system and the DVR connect via a protocol called an application programming interface. The interconnection is limited by the functionality the DVR manufacturer provides. Often, manufacturers will not expose all of the functionality through the API to protect their intellectual property or to keep their own software solution’s advantage.

• Because the security management system and the DVR are provided by different manufacturers, keeping the products compatible through future upgrades and service packs might be difficult. There is no guarantee that later releases will be backward compatible.

• The system setup is generally static: the DVR is set to a fixed frame rate, resolution and record period prior to any reference to the pictures being viewed. This can lead to a compromise on the retention period of recordings or an increased cost of hardware to achieve the storage required.

Common Ground
Select a video management system platform that supports DVR integration from a variety of manufacturers while supporting IP cameras and edge encoders. By supporting the whole spectrum of CCTV products, the digital video management system can incorporate the advantages of all systems and avoid the disadvantages.

“Superior video management systems support the use of IP/network cameras,” said Bob Sawyer, president of AMAG Technology. “Additional camera support will continue to be offered as technology changes, taking advantage of new technologies as they are introduced.”

There is no single point of failure—as each camera is a separate intelligent entity, there is no one place that can fail and bring the system down. Redundancy or fault tolerance can be built into the management system, ensuring high reliability.

IP Design Disadvantages
When designing a system that uses IP cameras, remember to take the following advantages into consideration:

• Many new construction projects include structured network cable throughout the buildings, making deployment of IP/network cameras a relatively trivial matter. Additional cameras, temporary solutions or single cameras in a location easily can be implemented with minimal installation.

• Improved image performance—As there is no conversion of the video into an analog signal prior to the MPEG-4 compression, the IP cameras generally provide superior image quality. Advanced features such as integrated alarms, audio and motion detection now are being built into the camera and transmitted via IP over the network.

• Network PTZ cameras can be controlled via the network without additional cabling. A fixed camera easily can be replaced by a PTZ model. No extra cables have to be run for PTZ controls.

• PoE availability means a power cable may not be needed. If the network supports PoE, the camera can be powered by the Ethernet connection, meaning only one cable is needed for the entire functionality of the device.

• Plug and play—IP cameras use a protocol called UPnP, which detects the camera when it is on a network. To set up the camera, all the user has to do is plug it into a network and use a PC to detect and configure it. Bringing the camera into a video management system requires a modest amount of configuration, but there is no need to perform the configuration in two locations as is done with DVRs.

• Less cost—While IP/network cameras initially may seem more expensive, prices will come down as they generally do with all technology products. When taking cabling costs into account, there may be a price advantage to installing IP cameras on a network with the additional advantage of reduced installation labor costs.

• Network cameras have built-in browsers, allowing occasional users to connect from anywhere on the network. Network cameras generally support firmware uploads, making functionality improvements possible without equipment redundancy.

• Tight integration with a security management system means the whole power and flexibility of the security system can be applied to system design without giving up on functionality.

IP Design Disadvantages
As with DVR systems, IP solutions also feature their share of shortcomings to consider:

• Network cameras use large amounts of network bandwidth if not correctly configured. Understanding the customer requirements and bandwidth availability is crucial to successful system implementation. However, this disadvantage easily can be rectified by using a video server that provides the ability to buffer video at the edge of the network and intelligently control bandwidth use.

• Without a video management system supporting the network cameras, only live video may be viewed. A good video system supplements the solution by providing a means of storing video and providing video replay.

• The system designer is forced to use the camera manufacturers supported by the software. NTSC and PAL present standards that system designers can use to provide universal support for analog cameras. Presently, all network cameras use different protocols, limiting the ability to support large numbers of cameras from different manufacturers in the video management solution.

• Successful installation requires an understanding of network technology that is not common in the security industry today.

Select a video management platform that supports IP camera integration from a number of product manufacturers and provides the additional components to complement the basic IP camera functionality, such as storing and archiving video deemed of value. The ability to tag, replay and export video files from IP cameras is missing from the basic solution. Furthermore, introduction of video analytics can offload the requirement to stream video over the network. A video analytics engine can determine when there is an alarm in the video stream and send a message to the security management system. Deeply integrated solutions that encompass digital video, video intelligence (analytics) and video management, as well as security management, resolve the shortcomings of a single-product solution.

On the Edge
One of the disadvantages of the network camera is that it requires new investment in camera technology. Video servers, sometimes called encoders, were introduced as a way to make use of an existing analog camera investment, and to provide support for special-purpose cameras that are not available in network camera versions— extreme low light, thermal imaging, license plate readers, extreme high zoom, highspeed PTZ or explosion-proof housings. These servers are boxes that take the analog signal from a traditional CCTV camera and transform—or encode—the signal so it can be connected to a computer network.

A video server that sits on the edge is a departure from the existing solution in a number of important ways, such as onboard storage. This enables many interesting features, including store and forward capability that allows video to be stored at the edge of the network to not burden the LAN with video traffic. The stored video then can be forwarded to long-term storage at times of low bandwidth use, at night or on weekends.

Next, a video server on the edge of the network provides a DSP-based solution to video compression. Since the algorithms are in the software, they can be updated and features can be enhanced. DSP technology will follow general technology trends, providing better performance at lower cost over time. An application- specific integrated circuit solution is constrained to basic functionality that is fixed in time, and dual processor solutions are expensive. A video server that sits on the edge is designed with future capabilities in mind. Bidirectional audio and compact flash interfaces are supported in the hardware and can be implemented in future versions of the device to provide even more capability than is available today.

When selecting a video server, choose a company that has complete control of the product development, functionality and feature set. This gives the most flexibility in designing and engineering solutions for customers. Parameters of the MPEG-4 compression are exposed to the advanced user, for example, allowing the system to be highly customized for different networking conditions.

The Optimal Solution
There are advantages and disadvantages to many of these components. How are video system designers to choose? The answer is, they don’t have to choose. Modern video management systems support multifunctional solutions in which the entire spectrum of products—from analog CCTV camera switcher matrix systems to NVR/DVR systems to IP network cameras—is supported.

This is the optimal solution because it allows all of these components to be fully integrated into a seamless package on the network. Such systems integrate with DVRs, IP cameras and video encoders, including edge of network video servers, to provide support for existing analog infrastructure. Transitioning to digital through a video server while supporting legacy LAN architectures and adding IP cameras allows users a scalable solution both now and into the future. Cameras can be brought into the system from disparate sources, and live video can be displayed simultaneously from all sources side-by-side with stored video from various sources, all while still making user viewing easy.

Furthermore, such video management system architecture is scalable. As the number of cameras grows—from any or all sources—the system remains stable. Storage capacity can grow by simply adding off-the-shelf computer technology. The architecture is distributed to not only allow this scalability but also to provide support over the WAN—video can be stored at the remote location and transferred on-demand or on a schedule. The system offers the ultimate in design flexibility.

Finally, the video management system must be deeply integrated into the security management platform. Thus video management becomes a seamless, integral part of the alarm management, identity management, and reporting and review system.

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