The Right Stuff

Organizations investing in IP video technology to take advantage of robust camera functionality, obtain higher quality video

• By Gareth McClean
• Oct 01, 2006

WHEN you consider the investment companies have made in analog devices, moving to IP can be a difficult task. However, there are ways to leverage existing analog technology while moving to IP. There are myriad issues to consider when choosing the kind of network on which to run an IP video system.

The best solution will depend upon what type of environment the cameras will be monitoring, the level of security needed to protect the surveillance footage, the flexibility needed for moving cameras from one location to another and bandwidth requirements, all of which impact the total cost of ownership.

The best solution will depend upon what type of environment the cameras will be monitoring, the level of security needed to protect the surveillance footage, the flexibility needed for moving cameras from one location to another and bandwidth requirements, all of which impact the total cost of ownership. Some organizations will need more flexibility to move cameras from place to place within a facility. This type of application is best served by a wireless network.

Other surveillance environments may require the capture of very fine details and need safeguards against hacking, which is best served by a wired Ethernet environment using an advanced camera and superior compression scheme.

These issues necessitate that security and IT managers work hand in hand to optimize performance and protect the integrity of security systems.

What do you need to know about networks?

Hard-Wired Ethernet
Wired Ethernet is the most prevalent choice for running IP-based devices. This is an attractive option, as it enables organizations to leverage their existing network. Many times, the wired Ethernet infrastructure already is in place or planned for a facility where there is considerable labor and material costs associated with other options such as running cable. Instead of having to run coax cable or power, building planners simply use a standard cabling package such as Cat6E.

With wired Ethernet, a security manager can run power to the device over a network cable without a separate power source to a PoE-enabled device.

While this is a cost-effective option, organizations also must be aware of network limitations. This is particularly important if there are multiple facilities using one network. Companies that use Ethernet must consider whether to segregate their video network from their corporate network, since video files can be quite large. If these files are transmitted on the same network, they may compete with business functions such as e-mail and other applications that can impact performance, particularly during office hours. Creating a dedicated portion of the network for video gives the security planner complete control over how much video can be sent and when. This is easily accomplished using modern routers or L3 switch technology.

Another consideration in provisioning video to run on wired Ethernet is choosing the right compression scheme for peripheral devices. When designing systems, companies should evaluate various compression methods, such as common MPEG-4 or MJPEG, or the more security-tailored active content compression, as the type of compression used will have considerable impact on bandwidth needs.

Unlike MPEG-4 and MJPEG, the patented American Dynamics ACC was developed specifically for security applications and can differentiate between true motion and video noise. This allows the images to be compressed into a file that is one-ninth the size of what it would be if compressed with MPEG-4 technology, which means using far less disk space and less network bandwidth transferring images because the file size is smaller.

Additionally, consider what level of security the video file itself offers. For example, recording formats, such as those provided by the ACC technology, offer more secure files because each image is given a unique identification stamp. Any attempt to overwrite or alter the image renders the video unplayable. The other standardized file formats are much easier to alter, impacting questions on the validity of the video captured.

Wireless Ethernet
Wireless Ethernet has many benefits, but the technology has its challenges. Wireless networks offer flexibility for moving cameras around. For example, retailers can easily move covert cameras from aisle to aisle as needed or place cameras in a parking lot to avoid running cable. However, wireless networks require a separate power source. There also is an added security concern in that intruders can more easily gain access to the video feed. Without the proper security settings, hackers can simply pick up the wireless frequency by "sniffing" the network.

The other issue with wireless Ethernet is bandwidth. Wired Ethernet gets as much as a gigabit connection (or more on fiber), whereas wireless is more limited. This lower bandwidth impacts the size of the video files that are able to run over the network and the speed at which the files are transferred. Wireless standards are improving, but are still not ideal for high-security environments. Wireless networks are likely not the best option in highly active environments with numerous cameras unless they are carefully laid out from the beginning.

Overall, wireless Ethernet is a good solution for low-volume scenarios requiring flexibility of movement or where there is no infrastructure to support cabling. High-volume, high-throughput environments call for wired Ethernet, and users should consider wireless Ethernet only in areas where they can implement proper security measures to ensure only authorized access to the wireless network. You have a network decision, Now what do you need?

Edge Device Choices
IP cameras. Whether using wireless or wired solutions, IP cameras connect directly to the network. With no device between the camera and its storage system, this is the simplest way to achieve an IP solution. While the price of IP cameras has come down, they are still not completely comparable in speed, functionality and cost to their more mature analog counterparts.

The near future of IP holds the promise of enhanced image quality with the integration of mega pixel cameras. Analog supports a maximum resolution of 4 CIF. IP allows for the transmission of even higher quality and larger format images. This is particularly important for high-security applications, such as casinos and high-end retail stores that often require megapixel cameras to make out the fine details of a card in a player's hand or the distinguishing features of a person's face, for example. These cameras also are being deployed at ports to capture images over a long distance and zoom in on details. Since IP allows multiple video streams to be transmitted over a single cable, larger applications may find IP to be a more cost-effective solution. But for now, analog still offers better performance and economy for smaller systems.

IP encoders. As an interim step, many companies opt for IP encoders, which reside between analog devices and the network, converting the analog signals to IP. This allows the company to take advantage of the benefits of IP while still using the investment made in analog. In this model, companies can achieve the benefits of using the network immediately and require less of an investment in cabling down the road.

This will likely be a viable option for many companies looking to take advantage of an IP system while absorbing the costs of transitioning to IP cameras over time.

Network Storage Devices
Many security systems are now incorporating network storage devices where several DVRs connect into the same separate, common storage server.

Security and IT managers should consider how much video they have to store and for what length of time when choosing a network storage device. A casino with many cameras is likely to need a good deal of separate storage that can be transferred to a digital video management system while a smaller corporate environment might not have the same requirements.

Cost Advantages
Wired Ethernet offers numerous cost advantages and is preferable for high-activity scenarios. Wireless Ethernet is a good solution for environments with low numbers of cameras that need to be moved around to different areas. However, it's important to deploy proper security measures to prevent access to video feeds. While IP cameras aren't yet as mature as analog devices, they offer tremendous scalability and are a wise investment for those looking to take advantage of emerging capabilities.

As an interim step between the adoption of an IP system and use of analog, IP encoders offer a good solution to benefit from IP now, while continuing to leverage the investment made in an analog system.

Regardless of the selection of wired or wireless Ethernet, IP cameras or IP encoders, compression scheme considerations are vital in addressing the network impact and speed with which the video data traverses the network.