Faced with the loss of cellular digital packet data (CDPD) service this summer, the city of Garland, Texas, eschewed overtures from wireless carriers to use more expensive GPRS services. Instead, the Dallas suburb is building its own high-speed mesh network that offers enhanced features and future revenue-generating potential.

The end result is going far beyond the initial goal established more than two years ago. At that time, the city just wanted an efficient way to store field video shot by police and avoid having to repair the chronically broken cameras in its squad cars, according to Darrell McClanahan, Garland's telecommunications manager.

“It started out as a way to solve a maintenance problem,” McClanahan said. “Then, one thing led to another.”

Those “things” resulted in the deployment of a $3.9 million converged network designed by Richardson, Texas-based startup NexGen City throughout Garland's 57 square miles that is slated for completion by mid-April. The network provides consistent data throughputs of 1 MB/s for stationary users, with bursts up to 6 MB/s. It also works well on the move. A pilot program last year proved the network delivers minimum throughputs of 200 kb/s to vehicles traveling at more than 100 miles per hour.

The slowest data rate offered by the new network is a quantum leap forward compared to CDPD — a technology that rarely transmits data as fast as 9 kb/s. The network “gives [us] options we don't have now,” McClanahan said.

Indeed, not only will Garland be able to stream field video back to a central location for monitoring and storage purposes, but text, photos and video can be forwarded to officers in the field. This will enable officers to process routine traffic stops more quickly, but the greater value will come in emergency situations after security cameras at various establishments throughout the city are linked to the system, according to NexGen City President Richard Dwelle.

“As the first responder approaches the scene, he has the ability to look at real-time video at the scene,” Dwelle said. “For instance, he can know that the suspect is hiding in back of a rack of donuts with a hostage, which is invaluable information.”

While the data speeds are impressive, the widespread availability of the network may be its greatest asset. Should a portion of the network fail, the mesh architecture allows the rerouting of data streams via 400 nodes attached to streetlights and other fixed locations throughout the city. Additionally, every radio and handheld device also includes a router, which enables the network to be extended or quickly patched.

“Right now, if a tornado hit our main tower, we'd be in trouble — we have a backup, but the coverage isn't as good,” McClanahan said. “[With the mesh network], if a tornado hits a couple of streetlights, you can just park a police car in the area, and you're back in business.”

Such resiliency is a hallmark of the mesh architecture used in the Internet. Like the Internet, the wireless technology deployed in Garland evolved from military research and development, in this case a communications network designed for use by mobile troops in battle scenarios. That technology was licensed exclusively to Maitland, Fla.-based MeshNetworks, which provides the chipsets for all NexGen City devices used in the Garland network. Lockheed Martin is the system integrator for the project.

Rick Rotondo, MeshNetworks' vice president for technical marketing, said he believes more governmental entities like Garland will build their own data networks rather than depend on a private carrier to handle critical transmissions during times of crisis — when commercial wireless carriers' networks generally are besieged with subscriber traffic or severely damaged by environmental or man-made disasters.

“The problem for public-safety organizations is that the time they're going to need [a carrier's data network] most is the time it's going to be available the least,” Rotondo said.

But building a dedicated wireless network using traditional cellular architecture is virtually impossible in a developed area, McClanahan said. Garland first pursued a two-site simulcast that was estimated to cost at least $4 million and would have data transmission speeds slower than NextGen's solution, which cost about the same. Later, a three-site simulcast system was recommended, which McClanahan believes would have cost more than $6 million. None of these costs were ever solidified, because the proposals never got past the substantial hurdle of locating 200-foot towers in a city of 221,000.

“With every site we chose, we went to planning and zoning and were told we couldn't do it,” he said. “It's just a nightmare to build a tower in the city anymore.”

With the NexGen solution, there is no need to find tower sites and installation of the fixed nodes is simple enough that Garland paid its regular light-maintenance contractors $100 per node to install them, McClanahan said. Because installation of each node can be done quickly — 15 minutes for a router, and 40 minutes for an access point — the 325 additional nodes in Garland that were not part of the pilot program are scheduled to be installed in less than four months, Dwelle said.

The tower-based data network concept also would have utilized the 800 MHz band, squeezing spectrum from the city's current radio network. In contrast, NexGen's solution uses the unlicensed 2.4 GHz ISM [Industrial Scientific Medical] band, meaning the 800 MHz frequencies can remain dedicated to voice applications.

In fact, McClanahan said the nodes in the network are located close enough to each other so voice-over-IP calls can be made without introducing latency problems. Public-works and code-enforcement employees will use the VoIP system for their voice communications in the near future. Garland's public-safety personnel will not be switched to VoIP until the bugs are worked out of the system — and the police and fire departments are absolutely sure they want it, McClanahan said.

“I'm not about to try to force it on [fire and police departments],” he said. “I've told them, ‘I'll keep up the 800 MHz system until you come to me because you want something more.’ … And I'm sure that day will come.”

Another day McClanahan hopes will come is when the NexGen network ceases to be a drain on the budget and becomes a revenue producer for the city. Although adjacent to the high-tech haven known as the Telecom Corridor in Richardson, Garland has not seen broadband deployed in its city as rapidly as city officials would like.

There is enough capacity on the mesh-network system for the city of Garland to offer wireless broadband access to its citizens to generate additional revenue for its coffers — something McClanahan believes is in the long-term plans, after ensuring that doing so won't negatively impact public-safety functionality.

Given the mesh network's cost, installation ease, resiliency, data speeds and “phenomenal” security, McClanahan believes Garland is on the cutting edge of wireless networks for public-safety organizations.

“If this isn't the future, I do see it as certainly being on the path,” he said.