As the city of Chicago expands its network of video surveillance cameras, wireless broadband is slated to play a key role. Within the next two years, thousands of cameras deployed by city agencies could start transmitting video over wired and wireless pipelines to a new operations center run by the city's Office of Emergency Management and Communications, or OEMC. Better still, law enforcement personnel are expected to eventually be able to view the transmissions via in-vehicle systems.

Among those cameras will be about 2000 belonging to OEMC, including 250 new units the office will install over the next two years, and security cameras owned by other city agencies. “Our intent is, we're going to be robust enough that O'Hare Airport, Midway Airport, the Chicago Transit Authority, the Chicago Department of Transportation — some of our sister agencies — can jump onto the network,” said James Argiropoulos, OEMC director of information services.

The expanded network is part of an initiative, announced by Mayor Richard Daley in September 2004, to saturate high-crime sections of the city and areas around critical infrastructure with surveillance technology. City agencies will use the surveillance network both for day-to- day law enforcement and for homeland security initiatives.

Many of the cameras OEMC has in place today transmit over a city-owned network consisting of more than 500 miles of fiber optic cable and 850 miles of copper wire. Last month, OEMC released a request for proposals to augment that network with additional fiber, implement one or more wireless broadband technologies and install OEMC's new cameras.

Intended to support both video and data, the wireless networks will provide flexibility, Argiropoulos said. OEMC will run new fiber off the existing infrastructure, allowing the network to branch into city blocks not currently covered by cameras. Using wireless technology, the city also can place cameras in key locations that aren't close to the main network or can cover certain locations temporarily, he said.

“Maybe we need to hang a camera because of intelligence reasons for a short period of time. We wouldn't want to build a lateral for that,” he said.

The system also might use wireless communications equipment installed in public-safety vehicles to transmit video and data from the scene during incidents, Argiropoulos said. They are keeping the system as flexible as possible to allow for future expansion, he said.

OEMC hasn't chosen the wireless technologies it will deploy. Candidates include mesh radio systems and Motorola's proprietary Canopy technology, Argiropoulos said.

Software built into the cameras will help the Operations Center staff monitor the video. They will analyze the video stream for activities that appear suspicious and, when appropriate, alert human monitors to take a closer look.

For example, a camera might detect someone walking erratically on Michigan Avenue who drops a package and leaves, Argiropoulos said. The camera will zoom in on the package, analyze the image and transmit an alarm to the Operations Center. “The image comes up on a 28-foot video wall and will alarm that frame, giving its exact address,” so staff can analyze it further and decide how to respond, he said.

While the system will channel images from all over the city to OEMC's Operations Center, sister agencies will still be able to view images from their own cameras in their own facilities, Argiropoulos said.

The upcoming project won't be the first time Chicago has used wireless networks to transmit video from the field. The Chicago Police Department already deploys portable video units, known as pod cameras, on downtown streets. Marked with the police department insignia and a flashing blue light, these cameras are designed as a deterrent to crime, as well as a way to give police a better view of what's happening on the streets.

The police began installing the first wave of pod cameras — 30 in all — in July 2003. The first units record video images and transmit them via landline to a central location, but they also include a wireless component. Officers who need to view the images are issued a briefcase containing a monitor, wireless communications equipment and a joystick, which they use to control the camera's pan, tilt and zoom functions, said Gregory Hoffman, a sergeant with the department's Information and Strategic Services Unit.

The department currently is adding another 50 pod cameras, which are equipped to transmit wirelessly to the Operations Center. Each of these units also includes an audio sensor that can detect a gunshot and then point the camera in the direction of the sound. Once the 50 new units are installed this year, the department will retrofit the original 30 to include a wireless link to the Operations Center, Hoffman said. Officers will still be able to view images on their briefcase monitors as well, he said.

Hoffman declined to identify the wireless technology the pod cameras employ or name the radio band on which they operate. The wireless network uses “encrypted and secure technology so that nobody can break into our video streams or view them without having the proper encryption device inside the case and having the proper passcodes,” he said.

RMS Business Systems of Buffalo Grove, Ill., integrated the pod system for the Chicago police. The company's contract prohibits it from divulging details of the technology, said Paul Zucker, vice president of technology for RMS.

Once the police pod cameras and cameras from other city agencies are transmitting video feeds to the Operations Center, officials will have an easier time pursuing suspects, Argiropoulos said. For example, a pod camera could detect a gunshot and then zoom on a fleeing car, he said. As the vehicle leaves that camera's field of vision, “we can now jump on a CTA [Chicago Transit Authority] camera and continue to follow that individual. We leverage the power of existing cameras that are out there with this new technology.”

As Chicago evaluates wireless technologies for its expanded video network, officials must take care that their choices don't leave the network open to interference, spying or malicious attacks, said John Powell, a consulting engineer who works with the U.S. Departments of Justice and Homeland Security.

Today, wireless surveillance systems operate mainly on unlicensed spectrum because that's the spectrum that provides sufficient bandwidth for transmitting video, Powell said. Unfortunately, “using shared spectrum can be problematic because you don't have exclusive use,” he said. “Someone could come in with just as much right to that spectrum as you have and put in a device that totally disrupts your communications.”

Hackers also might intercept or disrupt video images transmitted over unlicensed bands. Even in the security-minded public-safety world, information technology professionals aren't as sensitive as they should be to security issues, Powell said.

“Most of them don't know, for example, that I could take probably a few dozen PDAs and disable all the wireless access points in the [Unlicensed National Information Infrastructure] bands in Chicago” with a denial-of-service attack, Powell said. “If you've got critical areas that you're monitoring, and you can't suffer a loss, you need to be looking at very carefully examining the wireless carriage you're using to make sure it's not susceptible to those kinds of degradation.”

Powell points to the Seal Beach (Calif.) Police Department as one that has implemented wireless video surveillance with high-end equipment and encryption technology to safeguard its transmissions. Police there worked with Cisco Systems and Loronix Information Systems to implement the network, which can transmit images from a bank's security camera to officers' mobile computers during a robbery.

Public-safety agencies generally are not transmitting video in the 4.9 GHz band, which the FCC has dedicated to public-safety use, Powell said, because vendors have not yet produced much equipment for that new band. But as demand grows through projects such as the massive wireless public-safety network on the drawing board in New York City, “I think you'll see a lot of it migrate there,” he said.