Video Security Networks
Whether you’re trying to ensure the safety of your citizens, students, employees or property, protect critical infrastructure such as ports and mass transit systems, or provide detailed visibility of a disaster site or large event to enable effective personnel and resource allocation, you’re likely considering an IP-based networked video surveillance system. Networked video surveillance is one of the security industry’s fastest growing markets.
But how do you network the cameras to enable the collection and distribution of video and support monitoring of both real-time and recorded footage? Wiring was the traditional answer but it’s no longer your only option. Wireless mesh technology may provide a number of benefits over wiring, including:
- Cost-effectiveness and installation speed: Wiring requires trenching whereas wireless mesh nodes are quickly and conveniently co-located -- and connected via ethernet -- with the cameras they support.
- Resiliency: Wireline failure will often result in lost video transmissions, while wireless mesh enables continued transmission even in the event of a node failure.
- Flexibility: Without the limitations imposed by a wired network, cameras can be set up anywhere and moved as and when required.
However, to fully realize these benefits, a careful investigation of various mesh architectures is required. While any wireless mesh network can theoretically support video, wireless mesh nodes equipped with either single or dual radios will be limited in their ability to scale. Of course, scalability may not be an issue in a small video surveillance network, provided there’s no likelihood of the network needing to expand in the future. However, for large-scale video surveillance networks and any networks that may need to be expanded, scalability is a technical issue that must be addressed upfront.
What are the scaling limitations of single and dual radio wireless mesh nodes?
First of all, we should acknowledge that single and dual radio wireless mesh nodes are included in the BelAir Networks portfolio, and sometimes our dual radio nodes are deployed within a video surveillance network, where it addresses the requirements of the network. That being said it is important to understand the technical limitations of single and dual radio nodes, regardless of algorithms used to optimize their video delivery capabilities.
Single radio nodes will generally lack the bandwidth required to effectively support video surveillance networks. Where bandwidth is sufficient, it only retains its capacity when used in a point to point configuration – and a single point to point connection is inherently non-resilient. In order to provide resiliency, nodes must be meshed or interconnected with other neighboring nodes on the same channel of the same wireless frequency. When meshed, the available bandwidth is shared among all nodes simultaneously, limiting the available capacity and creating high and unpredictable latency and jitter as traffic grows. This performance is unsuitable for video surveillance networks which require high capacity and low latency and jitter to maintain the quality of the video.
Dual radio nodes improve this situation somewhat. They can be deployed in what may be described as a linear fashion, with each radio in the node dedicated to a separate channel and only interconnecting with radios on that same channel in adjacent nodes – effectively doubling the capacity available on a single radio node when used in point to point mode. While this reduces the contention in the network to make more bandwidth available, it also results in a network of non-resilient links. Effectively you end up with the same lack of resiliency associated with a single radio point-to-point or even a traditional wireline network. And, you’ve eliminated one of the main benefits of a mesh network. Alternatively, dual radio nodes can be deployed such that both radios are combined and interconnected via mesh to the neighboring nodes, effectively operating like a single radio node in mesh mode but with twice the bandwidth. But while the bandwidth is greater, it is still shared among all of the neighboring nodes, which limits its available capacity and increases latency and jitter as traffics grow, resulting again in performance unsuitable for quality video delivery. There’s a workaround for that, too. Just limit the size of the mesh and provide more wireline or high-capacity point to point wireless egress for additional capacity injection. This inherent lack of scalability of the dual radio wireless mesh reduces its cost-effectiveness and flexibility as the video surveillance network grows.
Bringing scalability to the video surveillance network
So, the question is: How do you realize and not compromise the benefits of wireless mesh technology – resilience, flexibility – when you deploy large-scale video surveillance networks or grow existing networks?
In contrast to single and dual radio nodes discussed above, BelAir’s patented switched mesh architecture supports diverse paths between nodes through multiple dedicated and isolated point-to-point connections. Available bandwidth of each separate channel is dedicated to the link to the neighboring node, so total bandwidth is the sum of bandwidth of each link. Each link is on a separate channel so forwarded traffic doesn’t use bandwidth from another link. This enables the network to effectively scale, delivering and maintaining much higher capacities and transmission rates and lower latency and jitter than other mesh nodes. The network also retains its resiliency, cost-effectiveness and flexibility, making switched mesh an ideal solution for large-scale video surveillance networks – or those that may need to be expanded.
For example, the Port of Richmond, northern California’s most diversified cargo handler, researched wireless mesh options for their 15 square miles of perimeter and facilities. They wanted state-of-the-art IP video surveillance with advanced analytics, remote monitoring and storage, and next generation wireless mesh networking capable of expanding. Proven reliability, scalability and high-quality real-time video support were key. After extensive research, the Port deployed 31 BelAir Networks wireless nodes supporting 82 IP cameras.
More than video surveillance
This switched mesh architecture, combined with other advanced networking features uniquely enabled through the BelAirOS operating system, such as QoS and traffic prioritization, enables you to take advantage of that same mesh network to enable police or security personnel to remotely access and monitor video (real-time or recorded) throughout the coverage area. In fact, a whole host of WLAN applications, including high-quality VoWLAN, can be supported on that same network.
Taking video surveillance on the road… and track
Mass transit vehicles and the associated stops, stations, road and trackside areas represent critical infrastructure requiring the protection afforded by video surveillance that supports public safety and defends national security. These video surveillance systems require high-performance mesh capable of maintaining seamless, high capacity connectivity at speed of up to 150 miles/hour. The BelAir100M mobile mesh node is designed for vehicular installations (including buses, trains, and police cars) and provides mobile broadband connectivity using 5 GHz, WiMAX, 4.9GHz Public Safety, or 5.9GHz Intelligent Transportation Services (ITS) bands. Offering true standards-based seamless mobility, the BelAir100M employs 'make before break' handover to ensure uninterrupted broadband connectivity for video surveillance cameras and other WLAN applications.