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.


Command Center Only. If you're interested only in sending video clips of critical events to roving officers or emergency personnel, you don't have to have an enterprise-wide, end-to-end wireless infrastructure. All you need is the capability to send data wirelessly to in-vehicle laptops or PDAs from one point—your command center. Your command center staff makes the call as to what video or other data to send, then broadcasts it securely to the appropriate officers' mobile devices. This option requires limited equipment investment and infrastructure cost.

Hot Spots/Wireless Access Points. If you want broader distribution than that described above, or if you want mobile personnel to be able to view live video from a variety of hardwired points on demand, you can use wireless access points (WAPs). Wireless access points provide an interface between the wired network and wireless devices. For example, your cameras are hardwired to DVRs, which digitize the video and transmit it back along your hardwired LAN. You could place wireless access points on the outer edges on the network at each of these DVRs. If you have a point of video aggregation in each building or each sector, you could place a WAP there for a different level of access. Networks like this are sometimes called hot spot networks.

Mesh—Wired Infrastructure. In a mesh network, individual devices or nodes on the network act as repeaters. This means the wireless signal can “hop” from one node to another to cover longer distances. This configuration also allows the signal to find an open transmission path when the most direct route is compromised or obstructed, making the network stronger. The more nodes, the wider the network coverage. Mesh networks tend to offer more throughput because the network load is shared among multiple paths. Many mesh networks operate in connection with an existing hard-wired network.

Mesh—Wireless Infrastructure. This type of solution allows you to set up a wireless mesh network, as described above, but without an interface back to a wired network. The entire infrastructure is wireless, enabling connectivity in temporary installations and hard-to-reach places.

How have municipalities and businesses used these options to increase security with mobile video? We have three success stories and a few warnings as well.

Spotsylvania County , VA

The Spotsylvania County Public Schools in Virginia , which has been named a Tech Savvy School District by the Center for Digital Education and the National School Boards Association, implemented a hot-spot wireless network to proactively secure itself against a Columbine-esque incident. They hooked IP cameras into a secure wireless network and outfitted local police squad cars with rugged laptops.

“The sheriffs didn't have to be on premises to understand what's going on in the school; they know before they get there what's happening,” said Andy Lausch, director of public sector sales for CDW-G, the federal solutions provider that worked with the schools to implement the network.

But the implementation went beyond the schools, helping county law enforcement in a number of other ways. Greg Call, Rappahannock Regional Criminal Information Network administrator, said the county police force now uses the system for records management, police dispatch and mobile access to mug shots. This last function began increasing police efficiency almost immediately, according to Call:

“The first month the system was in operation, there was a local robbery at a convenience store. The police officer who was testing the new mug shot system responded to the robbery and, from the victim's description, had a hunch about the identity of the perpetrator. The officer was able to retrieve a mug shot of the suspect via the network and also created a lineup of similar mug shots right from his patrol car. He then went back into the convenience store and provided the lineup to the victim—who identified the suspect. The networking capabilities enabled the officer to solve the crime in a few minutes. It used to take police officers anywhere from one hour to a couple of days to build a good lineup. Now, with our network capabilities, we can do it in a matter of mouse clicks.”

The county's network is carefully secured through VPNs and mobile VPNs, with encryption, firewalls and password protection, as well as the ability to set different levels of access for different users based on roles.

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