Out of Sight
Taking advantage of the latest high-throughput wireless network technologies
- By Ksenia Coffman
- Mar 03, 2009
Out of sight never means “out of mind” for security professionals. But how do you provide security at remote locations without deploying foot patrols 24/7 or burying fiber to extend surveillance reach? Many organizations tasked with ensuring public safety and securing critical infrastructure are increasingly turning to wireless security and surveillance to cover remote areas without breaking the bank.
When wired networking infrastructure is not available, wireless is often the only logical choice, especially compared to trenching, which can run as high as $300 per linear foot. In terms of investment, the advantages of wireless mesh are significant: initial capital and operating expenses can be as low as 1/20th of the total investment for a similar wired infrastructure. Cost reductions of that magnitude are, by themselves, motivating customers to turn to wireless solutions.
On the operational side, video surveillance systems require a great deal of flexibility, and wireless networks offer advantages that wired systems just can’t match. A wireless system can transport real-time wireless video, voice and data from just about any location. Cameras can be installed in buses or trains, fixed on buildings, repositioned, added or replaced, and there’s no need to pull cable, drill holes or disrupt day-to-day operations.
Wireless Saves Time, Money
A major driver for implementing wireless security is to eliminate expensive leased lines, with their recurring service charges, while achieving much higher throughput for video. When fiber assets are available, wireless can be deployed to extend or back up existing fiber infrastructure—resulting in much lower overall project cost. Time to lay fiber—or to secure architectural permits and rights of way—is another important consideration that is driving the use of wireless technologies. Wireless networks can be installed in days and weeks, compared to the months required when trenching and cabling is involved.
Advanced Communications Services, a North Carolina-based security system integrator, has deployed wireless video surveillance at several remote sites, including the PCS Phosphate Mine in Aurora, N.C.
“The mine required real-time monitoring to secure a remote mine operation gate, which was staffed by a fulltime security guard,” said Brandon Hood, project manager at ACS. “After the installation of a remote surveillance camera, the gate could be monitored and controlled from a central station.”
In addition to live monitoring, analytics and intelligent video management play a critical role in shoring up security for remote locations.
“Intelligent video applications, such as motion or object detection, can be easily integrated in most open-architecture video control and management systems,” said Jeff Knapp, vice president of marketing at OnSSI. “Video surveillance systems also can interface with access control systems to allow searches of specific surveillance images to confirm actions or analyze patterns.”
Todd Dieterly, executive vice president of TDK Systems Group, a New Jersey-based security engineering and integration firm, agrees but cautions against 100-percent reliance on video analytics. While the surveillance systems are designed to deliver realtime video streaming, often personnel cannot be dedicated to the constant monitoring of these systems. In these situations, incorporating video analytics into the system design creates a more automated approach.
“In most instances, real-time monitoring is preferred because, typically, a human interface allows for quick responses to issues,” Dieterly said. “Responses in both cases can be swift and efficient, but video analytics only responds to pre-established rules. In contrast, human interface often identifies activities that cannot be easily programmed.”
Choose the Right Technology
Let’s look at the wireless options available for video surveillance, from frequency ranges to network topologies.
Point-to-point wireless systems provide connections between two fixed locations and often offer greater capacities and distances compared to point-to-multipoint and mesh technologies. These connections (bridges) are ideal for backhaul of other wireless networks. For example, point-to-point bridges from BridgeWave Communications deliver throughput of 1,000 MBps over 5 miles.
Point-to-multipoint wireless systems deliver high-speed Ethernet network connections to multiple remote locations. When towers or tall buildings are available, point-to-multipoint systems can offer cost-effective deployments. However, the central base unit creates a single point of failure—should this unit lose power or become inoperative, the entire network goes down.
Multipoint to multipoint (wireless mesh) systems are by their nature selfhealing for resiliency: redundant links eliminate single points of failure associated with conventional wireless networks, while multiple paths overcome line-ofsight issues. On a wireless mesh network, unlike with a point-to-multipoint system, any mesh node can act as a head end— allowing multiple command centers to be set up, at any point on the network.
The flexibility of mesh allows it to be deployed in any of the above scenarios— point-to-point for backhaul, point-to-multipoint or true mesh for complete redundancy. Some deployments start as pointto- multipoint, later to be reconfigured into a mesh topology, when security needs call for ubiquitous coverage. Some integrators deploy mesh equipment in a point-to-multipoint topology, with mesh at the edges to provide reach into remote areas.
Mesh networks from California-based Firetide Inc. support 2.4 GHz, 4.9 GHz and 5 GHz. Firetide mesh seamlessly operates indoors and outdoors and across multiple bands and supports mobility with only 24 milliseconds handoff while roaming from node to node.
This technology delivers up to 70 MBps throughput in bonded mode—both radios operating together—for point-topoint backhaul, or up to 35 MBps in linear mode for sustained throughput over multiple hops, such as along transit corridors or to extend reach into areas with no hard-wire point of presence. Firetide mesh can be deployed rapidly to service temporary events, such as rallies and festivals, to deliver event-mesh capabilities.
Wireless mesh adds layers of data security too. This type of mesh encrypts data from the source to the destination, with no decryption along the way. Firetide also encapsulates packets traveling over secure links. Encapsulation provides another level of security because only Firetide nodes can see the encapsulated packets. Once packets hit the cloud, data is never exposed.
Surveillance systems that use mesh for streaming live video feeds are ideal for monitoring remote facilities. For example, Sage Designs, a California-based SCADA specialist, deployed a wireless mesh network for the La Palma, Calif., Public Works Department to provide video surveillance at water treatment plants. Three or four strategically placed cameras can monitor 12 water tanks without the need to trench and pull expensive cable.
TDK, with many large-scale security integration projects under its belt, chose wireless mesh because it provides the ability to rapidly deploy and expand these types of networks. Additionally, police and emergency vehicles equipped with mobile nodes have the ability to join the local mesh, as well as tap into existing networks over a mesh connection, allowing communities to share assets in case of a large-scale event or emergency. Video quality is paramount, too.
“Our recent surveillance installation for a water treatment facility required a backhaul connection to the Internet, multiple hard-wired Ethernet connections and several wireless mesh nodes, including a one-mile wireless link over water,” Dieterly said. “The wireless mesh portion of this network has been rock solid with excellent performance for nearly a year. In this installation, video transported across the mesh was virtually identical to video transported via a direct Ethernet connection.”
Mesh also has found a niche in heavy industries, such as mining, where conditions change minute by minute. ACS picked wireless mesh for its PCS Phosphate deployment to overcome lineof- site issues created by giant diggers that mine the phosphate. Whenever a digger crossed the wireless paths of a point-topoint network, the mine lost surveillance coverage. ACS solved the problem by installing wireless mesh to create failover paths for wireless signals.
Remote security benefits not only long-distance and out-of-the-way locations but height-intensive ones as well. Samsung Corp. recently deployed a wireless network at the construction site of the tallest free-standing structure in the world, the Burj Dubai (Dubai Tower) in United Arab Emirates. At the start of the Dubai Tower project, communications in and around the construction site were accomplished using traditional walkie-talkies. As the tower grew, the walkie-talkies became less reliable, creating delays and safety concerns. Samsung Corp. installed a mesh network for video surveillance, VoIP and radio over IP applications at the worksite.
“Initially, we expected the Firetide network would only solve the walkietalkie voice communication problem,” said Jerry Jang, Samsung SDS project manager. “But an added benefit was the ability to use IP cameras and VoIP phones over the network. We could monitor the safety status of the top-floor workers inside our ground-level offices.”
Plan to Succeed
Ensuring the success of any wireless video surveillance installation requires thoughtful planning from the start. Organizations must perform site surveys to determine any issues involving line-ofsite obstructions that may be present in the surrounding geography or metro areas that includes buildings, tunnels and trees.
Dieterly said deploying video surveillance at remote sites requires careful attention to logistics, as well as coordinating resources that are often not under the direct control of the customer or integrator, such as public utilities, telephone, cable and private companies. From a technical point of view, line-of-site between nodes becomes critical in mesh applications with longer distances involved.
“When establishing budgets and finalizing network design, consider all contingencies and discuss them with the end user,” Dieterly said.
Hood points to securing power and dealing with line-of-site issues as major challenges at remote sites. Solar or generator power may be required to power remote installations. Line-of-site issues can often be dealt with by going around obstructions; some projects call for construction of a tower or mast.
Planning for scale also is key, especially where IT or security departments expect to add network capacity and camera locations. Video applications can eat bandwidth quickly, and any wireless infrastructure should have plenty of room to grow—even if current requirements appear limited. This might sound obvious, but organizations that focus on narrowband data, such as access control, can easily underestimate the requirements for transmitting high-throughput video data.
This article originally appeared in the March 2009 issue of Security Today.