Wireless Video in Theory and Practice

Wireless technology has become ubiquitous in our day-to-day lives, and it's both a blessing and a curse. We find ourselves calling friends as we pull into their driveways to let them know we've arrived to pick them up. (Why get out of the car?) We can check the weather on our wireless-enabled laptop from nearly any Starbucks. (Why look out the window?)

The omnipresence of personal wireless technology has both bolstered and inhibited development of wireless technology for transmission of video to mobile security staff or first responders. On one hand, it's fueled some municipalities' and companies' interest in using such technologies, and anytime interest grows in a technology, it works to bolster R&D at some level. However, it's been challenging to maintain security on certain types of wireless networks precisely because everyone has access to wireless devices. And even though many solutions have now surmounted those challenges, the perception lingers that all wireless video is unsafe for security use.

We've heard more and more lately about the installation and use of municipal wide-area networks that allow mobile police and first responders to view video from schools, courthouses and businesses in real time. “With heightened threat levels, domestic and international municipalities have a renewed interest in deterring crime and terrorism and enhancing the security of their public spaces,” said Mariann McDonagh, vice president of global marketing for Verint. “Transit system and critical infrastructure facility operators also must work with first responders to secure their operations, respond effectively to emergency situations and share critical intelligence with a wide variety of law enforcement agencies to facilitate investigations after an incident occurs.”

There are a number of local and wide-area wireless options available, not only to municipalities but also to private businesses, that can offer both mobile, actionable intelligence and a return on investment through non-security uses.

If you try to learn about wireless video transmission from one or two Web sites or one or two trade show booths, you might come away with a skewed idea of the breadth of your options. There are several ways to implement wireless transmission for security video, and most of them have unique drawbacks and success stories. In this article, we'll examine some of the options available today and highlight some successful and some not so successful projects.

A Word on Informed Cooperation

If you're looking into a wireless network for video transmission for a municipality or an enterprise, you should know one thing at the outset: Chances are, IT will be in the driver's seat on this one. Wireless networks are usually expected to transmit a variety of data beyond security video, and your IT counterparts will be in charge of making sure the network you end up with will support all these functions adequately. In fact, in many cases, security probably won't be the main driver for the implementation. But even if you are looking at a dedicated security network, IT is probably going to be in charge.

That doesn't mean you should shrug off learning about wireless network features and options. IT's knowledge already has wireless covered, yes, but if you want input at the ground level—if you want to look out for security's best interests through collaboration—then you should learn some of the lingo. There's nothing like sitting in on a planning meeting and watching unfamiliar terms fly across the table and straight over your head. See the sidebar below for a start, and check out some online resources as well, such as www.jiwire.com and www.wirelessweek.com.

Broad Configuration Options

There are many ways to arrange for wireless transmission of video for mobile security forces or emergency personnel.

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.

Texas State Fair

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

Success stories aren't the only stories. There are things to watch out for.

Reliability. Interference has proven a problem in some types of applications. “We have one client that had this whole thing laid out, and when we went into test mode we had to scrap the whole thing because we had it next to an airport and every time certain airplanes came over it just blew the daylights out of the signal,” said Roy Bordes, president of The Bordes Group.

Mike Downes of Firetide offers one solution to this concern: “You eliminate a lot of the interference problems by operating on a 5GHz spectrum. Most wireless devices operate at 2.4 GHZ, so with 5 you get less interference with other devices.”

Distance and Terrain. Many wireless networks aren't made to extend over more than a few miles, and some have a hard time dealing with atmospheres with too many obstructions. “The radio transceivers selected should be either long-range non-line-of-sight products—when supporting more challenging installations with many buildings and trees in the transmission path—or, conversely, higher-bandwidth line-of-sight products for shorter-range applications without obstacles in the transmission path,” said Ray Shilling, vice president of sales and marketing for AvaLAN Wireless.

Shilling goes on to say, however, that technology issues can generally be overcome.

“Today's wireless Ethernet technologies vary widely, are fairly cost effective due to increasing competitive pressures, and can address almost any installation configuration. In short, the technology is NOT in fact the limiting factor. For the most part, it is the constraints of budget and the appropriate alignment of the senior management with the authority to release the necessary funds that becomes the real challenge to the municipality. If the budgets are available, and the senior officials share the vision of the emergency services personnel, then the projects are being readily approved and deployed.”

Marleah Blades is managing editor of Security Technology & Design.