The anatomy of a 'crime camera' system

Nov. 11, 2008
From cameras to wireless video transmission for municipal surveillance projects

A "crime camera" is essentially an integrated system providing video surveillance tools for law enforcement. The components of such a system include the camera itself, backend hardware and software, monitors, capture and storage devices and ? most critical ? network connectivity to securely and intelligently transport sensitive video data.

When a crime camera is available in the vicinity on an incident, police personnel can accelerate their response by gaining situational awareness within seconds. Instant awareness also translates into better-allocated resources, making sure, as they say, that officers aren't caught bringing a knife to a gunfight. When the stakes are high, only evidence-grade video over highly reliable networks can assure authorities that they'll have the information they need when trouble comes. Evidence-grade video, roughly defined as high-resolution video, is tamper-proof, stands up in court, increases convictions, assists in identification and helps prevent future crime.

Crime camera technologies have come a long way. Slowly the days of "unknown trouble" and vague 911 dispatch call reports are disappearing. What are the components of a crime camera system? How does one get started?

Snapshot: The system as a whole

Although crime camera systems require video technologies that produce high enough resolution for evidence-grade video, the camera itself is just one component of a larger system. "The cameras are only as good as the network that connects them," says Mark Jules, president of Maryland-based Avrio Group, which develops integrated wireless surveillance systems.

Assuming that a camera is connected to a network, what becomes important is the infrastructure that manages the movement and transmission of the significant amount of data the cameras collect. Because of innovations in performance and cost reductions, video surveillance networks are increasingly turning to wireless technologies to both support and supplant existing wired networks.

Let's Think Wireless LLC, a New Jersey-based systems integrator, has been in the municipal video surveillance market for more than eight years. "In the past, if a city wanted to install an IP video camera network, it would typically pay a telco or cable provider for the use of a leased circuit -- provided the circuit was available in the desired location," says Craig Lerman, vice president and founder. "The costs ranged from $40 per month per camera for a cable modem, to a frame relay or shared T1 circuit (hundreds of dollars per month per camera). These public networks did not offer any quality of service mechanisms and the resulting video was of poor quality, with frequent outages on the network. Private fiber infrastructure, while providing excellent quality of transmission, is costly and time consuming to deploy. "

The advantages of wireless mesh

Wireless mesh network-supported crime camera systems are rapidly becoming the go-to option for law enforcement. They offer key benefits lifting its advantages over its complexities.

Flexibility. Where wired cameras must rely on the existence of wires, wireless crime cameras can be positioned almost anywhere to obtain the best point of view. There's no dependence on where the nearest network cable rests. This minimizes the need to drill holes, pull cable, trench ground, etc. Each of those activities is not only costly but also eats valuable time.Throughput. Crime cameras require an extensive amount of bandwidth to transmit data. Without enough bandwidth, cameras cannot deliver evidence-grade video or support video analytics: The better the video, the more effective analytic systems are at detecting shapes, movement and direction.

Not long ago, the demands of video required law enforcement agencies to use wires or costly microwave simply because they provided the necessary data throughput. Now, however, wireless network technologies can rival the results of wired networks. Los-Gatos, California-based Firetide, a developer of wireless mesh networking solutions, routinely delivers quality of wired Ethernet networks. Moreover, the flexibility, cost savings and other advantages alone are enough to justify exploring wireless mesh as a crime camera infrastructure, immediately. It certainly beats digging.

Multi-hop or linear topology. Where fiber points-of-presence aren't readily available, video needs to be transmitted across wireless networks, with mesh offering critical resilience compared to point-to-point network setups. Unfortunately, in the majority of cases, video loses its fidelity to the point of being unusable after two or three hops (a hop is when data move from one network node to the next). Using a combination of high-power radios, load balancing, compression and other innovations, wireless mesh technology enable public safety agencies to flow video across 10 or more hops without significant loss of quality.

Security and privacy of video streams. Secure systems offer what's known as "end-to-end encryption." Most mesh or access point systems need to decrypt feeds on intermediary nodes -- nodes between the source and destination -- to collect routing information that provides instructions about where to send video next. This can add unnecessary chattiness to the network, increasing problematic latency. To silence this, Firetide provides end-to-end encryption while eliminating performance-robbing redundant inspections along the way and also encapsulates packets traveling over secure links. Encapsulation provides an added level of security because only Firetide nodes can see the encapsulated packets.

Multicasting. The idea behind multicasting is to compile information from one or more cameras and send it to multiple destinations for simultaneous viewing and recording. Multicasting is essential for remote monitoring by decision makers, but can severely burden a network. Firetide's encapsulation techniques, in addition to increasing security of data, enable multicasting of video streams across wireless networks -- minimally impacting bandwidth.

A true infrastructure mesh should be able to handle all these capabilities. Firetide's networks function as a fully distributed, virtual Ethernet switch -- distributing intelligence throughout the network to deliver self-healing and self-configuring capabilities.

Deploying successfully

Deploying a crime camera system requires the cooperation of diverse agencies. The details involved might initially sound overwhelming but delivering a positive experience and support from start to finish is the bread and butter of systems integrators such as Chicago-based Technology Consortium Group (TCG). As agencies move from one step to the next, TCG makes sure equipment is placed, tested and optimized according to plan, with necessary support upon completion.

"We run with the ball when our clients have a clear picture of what they want and where they want it," says TCG director of operations, mesh network products group, Ron Norris. "We work with multiple teams focused on implementing design, electrical, installation and connectivity." Norris adds that the primary goal is a solid system but also that his company focuses on "keeping everyone moving in sync" to help clients reduce costs.

Some specific steps any agency should expect when working with vendors and integrators as part of a crime camera system deployment lifecycle include:

• Plan the network
• Deploying the gear and integrating the backend
• Manage network projects and performance
• Scaling the network
• Existing fiber assets

When adding new surveillance coverage, wireless mesh networks can, and should, leverage existing fiber and Ethernet assets to offload video traffic to the wire. This aids in load-balancing and helps optimize how mesh networks use the available radio spectrum.

Even when existing fiber assets are available, the condition of the fiber, its conduits, and policies for accessing can hamper schedules, drive up costs and increase project risk. Wireless mesh can eliminate many of these obstacles, speeding implementation, testing and acceptance by end-users.

The cost savings of using wireless mesh over pulling new fiber, in areas where a fiber infrastructure is not available, is significant. Costs as high as $300 per linear foot are not uncommon for projects requiring trenching. If it costs $300 per linear foot to trench, at 20 feet that's $6,000. For similar cost, two mesh nodes will provide transport over several miles without ever touching a jack hammer or shovel.

About the author: Bo Larsson is CEO of Firetide. He can be reached at [email protected]