Public-safety agencies in the Boston area, led by the city's police department and the Massachusetts State Police, are using 4.9 GHz wireless spectrum for interagency video surveillance of both local police activity and farther-reaching national homeland security matters.

The interagency cooperation is starting to include other local, state and federal agencies using technology that has been modified for use in the band, which was set aside by the FCC specifically for public-safety use.

“We're on the leading edge,” said Lt. Mike Barry, airwing commanding officer in the Massachusetts State Police Bureau of Tactical Operations, who runs the agency's helicopter fleet, the only public-safety aviation squad in New England. “It's light years ahead of the old analog technology that we also used since the late 1990s.”

Microwave Radio Communications (MRC) has transformed its digital radio technology used for electronic news gathering for use in the 4.9 GHz spectrum for public safety. MRC encrypts the signals to secure the transmissions.

Moving traditional gear to public safety was a bit of a chore, but it wasn't the Herculean task some vendors suggest, said Mike Payne, MRC's vice president of marketing and business development.

“All we have to do is adapt the RF side to the new frequency bands,” he said. “It's not a huge technology challenge for us, but it's not easy.”

It's also an opportunity for new business, he said, since the news-gathering business is flattening.

“When the 4.9 gig band opened up, we jumped on it and said this is an opportunity for us to provide the same core technology, same equipment, but with our radio technology scaled to their frequency band,” Payne said.

Boston police use a mobile ground unit that includes equipment in a van while the state police uses a helicopter. The two agencies share the video, which is transmitted over the 4.9 GHz airwaves to a central receive site on the Prudential Building and then on to Boston Police headquarters. Plans are in the works to also link state police headquarters in nearby Framingham.

Helicopter-based video is old hat; news crews have been using it for years. The mobile ground units are a little more space-aged and certainly more specific to the public-safety task.

“It has its own camera system or it can be used as a relay unit where you can have someone in the field with a camera and a radio attached to their body,” said Payne. “The batteries and the radio and the antenna and even the camera are mounted to either the equipment that they're wearing or in pockets. That person can go pretty much anywhere in the general vicinity next to the mobile unit, and that mobile unit will relay the signals back to the central receive site.”

While the Boston Police and Massachusetts State Police spearheaded the effort to get the funding, other agencies are starting to reap the benefits, including the Massachusetts Department of Transportation, Massport — the port authority agency that oversees Boston's seaport and Logan International Airport — and the Massachusetts Emergency Management Agency. The state fire marshal's office and the U.S. Coast Guard are all “interested in jumping on board with this system,” Barry said.

The funds came from the U.S. Department of Homeland Security (DHS) so the surveillance effort is targeting homeland security-type functions such as watching vessels containing hazardous materials, such as liquid natural gas, that arrive and depart three or four times a week in Boston's busy seaport.

“It's no secret that the tanker passes within some 300 yards of the skyline of the city of Boston,” Barry said. “Since September 11, it's been perceived as a palatable target so we're taking great measures along with the Boston police, Massport and the Coast Guard to ensure the transit of that vessel.”

Barry wants the surveillance to include live video feeds to multiple government agencies, including the DHS at some point.

The high-tech cameras currently in use provide real-time views of a 60-square-mile area or show you the pinstripes on a player's uniform in Fenway Park, according to David Troup, director of the Boston Police Department's telecommunications unit.

“The [state police] helicopter was sitting in back of Fenway Park [during a playoff game], and they were zooming in on some players,” said Troup. “When they were at bat, you could almost read the label that's on the bat.”

Live video shows a crowd's size and how unruly it is, which helps police determine how many police should be dispatched to the scene. This capability proved its worth during the Democratic National Convention (DNC), held at the Fleet Center in August. Because of the video, police were able to determine that 200 reportedly unruly protesters were really 20 quiet people with picket signs, Troup said.

The city police owns and operates a mobile van that it first used during the DNC and will now use generally in crowd-control situations.

While much of the Beantown activity is shrouded under the homeland security blanket, other agencies have seen it at work.

“Anybody that was in the unified command center during the DNC saw what we were doing,” Troup said. “The Secret Service watched it; the FBI watched it. The law enforcement agencies we deal with for these special events get to use it.”

They also get to see interagency cooperation that is probably even more remarkable than the technology.

“That's an important point,” said Troup, who said the cooperation began with getting the money. “We had resources that we could contribute, and the state police had the helicopter.”

Both will continue to seek funding to upgrade the system.

“We see this as a long-term project. As funds become available we can enhance what we have,” said Troup.

Improved antennas would be a nice enhancement, as the 4.9 GHz spectrum is quirky and doesn't offer great range. For now, the agencies are using omnidirectional antennas, but Barry would like to see some form of global positioning system (GPS)-based, electronically steerable antennas installed on the aircraft and at the central receive site.

The new antennas would enable one feed to be transmitted to another agency, such as the fire department, while another feed goes to the state police command center.

“That would require receiving independently at two different locations,” he said. Barry added that could be accomplished using the omnidirectional antennas but that the GPS antennas would offer a big improvement.

For now, the system is strictly live video, although audio can and probably will accompany it someday, Barry said, noting that the department's 800 MHz radios will provide audio for the present.

More important, since broadband wireless also is considered a fixed technology, this system is mobile.

“We're just developing the capability to set up portables to receive in one moving vehicle while watching in another,” said Barry. “That's the ultimate that we seek to achieve in Boston Harbor.”

Barry is optimistic that other cities and communities will be taking the same steps as Boston in using the 4.9 GHz spectrum.

“You're going to see it explode over the next few years, not only with airborne technology but with ground-based applications,” he predicted. “You're going to see point-to-point short hauls, long hauls, all of that is going to really expand with the increased need of video surveillance. The digital is going to be the way to go. The analog, in an urban environment, from a mobile application, is very frustrating; digital 4.9 works out much better.”