Cabling considerations for network-based video

The cabling installation professional’s role in the deployment of video over IP is crucial; so is the need to perform their tasks well.

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The cabling installation professional’s role in the deployment of video over IP is crucial; so is the need to perform their tasks well.

by Steve Surfaro

Cabling installation professionals typically play a significant role in the installation and deployment of any new video-over-Internet Protocol (IP) project, whether the network is shared or dedicated solely to a single function, such as security operations.

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When building the infrastructure for a network of IP cameras, like Panasonic’s BB-HCM511, cabling installers will recognize the familiar RJ-45 port into which the terminated twisted-pair cables will plug.
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If the system will be run over a shared or public network, information-technology (IT) personnel or a systems integrator who has special expertise in network installations will need to get involved, but even then, cabling installation professionals will play a significant role in the system’s deployment and implementation. There simply is no replacement for the expertise and capabilities of a cabling professional.

The first step in defining system parameters, equipment selection, and means of deployment is a comprehensive site survey, which includes a complete assessment of existing conditions. Security experts should implement this survey, since they have experience with security- and surveillance-related issues, along with awareness of hot spots warranting specific attention and precautions.

Security, IT, and cabling professionals should all be involved in an assessment of infrastructure to assure that objectives and functionality issues are addressed, and to ensure high levels of interoperability among disparate systems and/or means of signal deployment and transmission.

Surveying the landscape

Because cable quality and installation technique have a significant impact on a system’s video refresh rate and throughput, good infrastructure is a necessity for any systems-based installation requiring correctly specified, installed, and connectorized cable:

  • The correct cable must be selected to meet specific application requirements and to assure that it is installed in a manner that minimizes or eliminates crosstalk.
  • Camera and recorder placement is an important consideration as well, particularly with regard to wiring-plant topology and location of network switches. Larger systems may require distributed architecture with network video recorders (NVRs) located throughout the facility to help localize and optimize bandwidth use.
  • Environmental conditions also need careful monitoring to ensure continuous and prolonged equipment life-especially recording devices using hard disk drives that run continuously and generate excessive heat.
  • Lighting conditions and systems should be assessed for specific monitoring assignments and to eliminate troublesome conditions, such as high contrast, and to accommodate specific camera functions, such as day/night switchover or automatic back focus.
  • The potential for external sources of system disruption, such as vandalism, also needs to be weighed to determine the most appropriate cameras for specific site placement.

An effective way to initiate the site survey is by determining zones of protection, beginning at the most remote point of contact with your facility (i.e., the street and/or road and walkway access points), proceeding to actual entry points, followed by internal areas of high importance. The farthest points will require good peripheral coverage, while the middle and interior locations will need more focused protection tailored to your specific security priorities.

Continuing with the site survey, the next step is to determine whether this will be a server-based or an embedded system. This is a critical distinction; server-based recorders equire camera and/or software licenses, have variable network throughput, require additional software to protect files, and require an advanced skill set to maintain. Embedded systems, on the other hand, usually have no camera-licensing costs, have a fixed network throughput, and offer exclusive file protection through a proprietary operating system.

In addition, look at the number and type of cameras that will be deployed to determine the type of recording system, recorder capacity, and recorder type.

How much bandwidth do they eat?

The issue of bandwidth allocation can be tricky. Higher bandwidth correlates to higher resolution and motion, but requires a greater investment. This equation rises exponentially when large numbers of cameras (particularly megapixel cameras) and recorders are added to a network.

A diligent determination will include consideration of how cameras will be monitored, what the user will need to see versus record, available bandwidth, and the functional requirements to determine what type of compression best fits the need. MPEG-4 is best for monitoring and multicast capability, while JPEG is more appropriate for higher-resolution recording.

Bandwidth requirements can be calculated by accumulating total camera bandwidth for each NVR, typical multiple-user monitoring-station bandwidth values for each NVR, totals to nearest network switch, multiple network-switch bandwidth, and individual-user monitoring-station bandwidth values.

Use an estimate of maximum load to determine the area system power requirement, simulating continuous operation of pan/tilt/zoom cameras. Power over Ethernet capability facilitates installation for network video cameras, resulting in lower installation costs and reduced operational overhead. The potential for large expenditures on maintenance and service calls is also reduced because cameras can be adjusted, checked, or even reconfigured remotely without the need for on-site service.

A networked system is more easily scalable than a point-to-point system, because camera locations can freely and safely be added or changed without incurring substantial costs for installation and wiring, and without the potential of having to shut down the system during installation. Whether using analog or network cameras, there is also a need to consider the additional power required for a camera-housing heater/blower based on the site’s exposure to the elements.

Once these determinations have been made and the installation is complete, test the system response by going through the most common network usage scenarios. Simulate as many network conditions and loads as possible for components, edge devices, and infrastructure, and provide recovery scenarios from the most common and reasonable failures. Then publish a network-video commissioning statement to specify the system deployment, including step-by-step staging, programming, installation, and commissioning tasks, as well as division of responsibilities and acceptance-test criteria.

While installation best practices vary between dedicated and shared networks, there are common methods of selecting the system configuration that is best for an individual application. The initial selection criteria for cameras will always remain the same, whether for analog or IP-based video devices: The camera needs to have the ability to produce an image in simple or difficult lighting conditions. Should a specialized camera be required that does not have a network version available, you can use a video encoder and incorporate the analog camera(s) plus encoder into the video-over-IP system.

Options and expertise

Giving users a variety of means to access video streams over a network can enhance the overall security the system provides. For example, video feeds can be linked to access-control events to reduce piggybacking or tailgating. Loss-prevention teams can also use network video recordings with special video analyzers to reduce shrinkage and theft, and human resources personnel may access network video in a distribution center for work habits and safety concerns.

Collaboration is the first step in planning and implementing networked-video deployment. When you allow infrastructure designers to use their expertise for data transport, and IT professionals to use theirs for deployment or shared networks, best practices will become a reality.

STEVE SURFARO is group manager and strategic technical liaison with Panasonic System Solutions Company (www.panasonic.com).

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