Houston deploys fixed video surveillance system
The city of Houston has joined other major metropolises such as Chicago, Denver, Phoenix and Dallas in deploying a fixed wireless video-surveillance network that monitors activity in its downtown area. The city worked closely on the project with wireless mesh network vendor Firetide, which previously installed mesh networks in the aforementioned cities, as well as others, to support fixed video implementations.
With 200 nodes operating on 4.9 GHz spectrum that has been allocated to public safety for broadband data communications, the mesh network carries live video feeds on a 24/7 basis from 300 high-definition cameras — provided by Axis Communications — to four network gateways. The footage then is transmitted over fiber to a central location, where it is analyzed and viewed.
Houston opted for a wireless mesh network for a simple reason, according to Denise Barton, Firetide’s vice president of marketing communications.
“They didn’t have fiber everywhere,” Barton said. “Obviously, it would have been far more expensive to run fiber everywhere, so they decided to use their existing infrastructure to backhaul the mesh network. … If you don’t have fiber, wireless mesh is the best solution that you can deploy for video surveillance, which is one of the most demanding applications.”
Barton added that the city also considered deploying a point-to-point system but opted for mesh technology because of its resiliency.
“In a mesh network, every point is connected to multiple points, so there are multiple paths that the packets can take, and if a node fails, the traffic simply is rerouted,” Barton said. “So, from a reliability standpoint, one of the keys is that there are redundant paths built into the network architecture.”
Another advantage of a mesh network is that it is scalable. If an entity wants to increase network capacity or expand the network geographically, all it has to do is add nodes. A significant expansion of a point-to-point network would require the addition of one or more hops, which would be a much more expensive proposition, Barton said.
Each node in Houston’s deployment provides more bandwidth than the video camera needs, according to Barton. This means that the mesh network can be used simultaneously for other purposes — for instance, a police officer could access the city’s data network to pull a mug shot or rap sheet; a hazmat team could download a warehouse manifest to determine whether the facility poses a risk; or a fire chief could download a building blueprint or floor plan while on the fireground to improve incident command — without having a detrimental effect on the video network.
