Wireless Video in Theory and Practice

It’s as important to know some of the nuts and bolts as it is to see what your peers are doing in wireless video for first response.

In 2004, the Texas State Fair at Fair Park in Dallas , TX , used an AgileMesh Video solution and a HotPort ™ wireless mesh network from Firetide ™ to help police monitor video across the fairgrounds.

“The Police Department wanted a portable video monitoring solution because the Fair is a temporary venue and they cannot dig trenches, pull cable, or alter the historic buildings to deploy a solution,” said Bill Dickerson, president of AgileMesh Inc., according to Firetide.

“Rather than dragging a cable out there, you just plug in one of our mesh nodes to your network device. You take the devices and place them in proximity to one another, they connect to each other wirelessly and automatically,” said Mike Downes, vice president of marketing communications for Firetide. The Firetide solution has a completely wireless infrastructure. Existing IP cameras, or analog cameras with encoders, can be connected to nodes anywhere they can be powered to create a self-healing wireless mesh network.

“If you need more cameras, you install more nodes. All you need is a node for the cameras and then you need another node to connect to the wired network. There are no other devices that you need,” said Downes.

The park was so happy with the solution that they decided to keep it up year-round to augment the reach of the security force.

South Sioux City , NE

Lance Martin, communications director for South Sioux City , NE , has overseen a couple of wireless solutions for South Sioux City . The city implemented a Wi-Fi network in 2002 via a technology grant, which funded 12 hot spots. “We covered maybe 25% of the city with Wi-Fi wireless broadband, but it was frustrating because that technology was very line-of-sight, and a police officer had to pretty much know the spots in town where he could park and use it,” said Martin. He'd also become concerned about the security of Wi-Fi, since the commonly used WEP encryption was at the time being outed as easily hackable.

So Martin began looking for a new wireless solution that would cover the entire city, one that was non-line-of-sight. He finally landed upon a WiMax-based system from a Minnesota-based company called NextNet Wireless. The system transmits and receives wireless data through base stations mounted on water towers. It uses a transport protocol called OFDM to achieve communication outside of the line of sight, meaning officers and emergency personnel can pick up the signal anywhere inside the boundaries of the network.

“Wi-Fi is very much punished by a phenomenon called multi-path and reflection,” said Martin. “The signal bouncing back off of buildings and chain link fences is bad for Wi-Fi, and they do everything they can to eliminate that in a Wi-Fi environment. Through OFDM, NextNet's technology is able to capitalize off of multi-path and reflection, and the signal bouncing off of buildings and fences and vehicles is very good. That's what allows you to get the non-line of sight. If you're parked in a spot where you don't have a clear shot from the tower, the signal will go over the vehicle, bounce off a building that's behind it, and reflect back into the vehicle.”

The system is proprietary and works on licensed frequencies, which allows for greater security of the signal. And the system is multi-tenant, so the city works with ISPs to use part of the network for public access to the Internet. The system uses Vicon Kollector Series DVRs and ViconNet software for video management.

Martin has plenty of success stories to tell—of the time they caught a graffiti artist within 24 hours after a motion-activated camera caught images of him, face forward, in front of his car, license plate in full view, with a spray can in his hand; and the time they did a SWAT exercise in the schools and used the video system to pinpoint and apprehend the simulated bad guy within two minutes each time.

As far as drawbacks … “Well, other than having to climb the water tower to clean bird poop off the camera, probably the biggest challenge is keeping the software up to date on everything, keeping the police officers trained on how to use this stuff,” Martin said.

Not All Happy Endings