Shotspotter recently announced that the city of Birmingham, Ala., will use the company’s patented gunshot-location technology in a 6-square-mile area of the city.

In the Birmingham deployment, telephone-network links will be used to provide backhaul from the Shotspotter sensors that are used to triangulate the location of gunfire, even though the company increasingly has been using broadband wireless networks for this task, said Gregg Rowland, Shotspotter’s senior vice president.

“We chose to go in that [telephone-based] direction because they have a big challenge for wireless because of the terrain and hills in the city,” Rowland said. “Our telephone system is a little cheaper—so they can cover more area for less [money]—and they didn’t have an existing wireless network for us to use.”

Birmingham will leverage a $1 million grant from the U.S. Department of Justice to pay for the system, which is being delivered through a contract with the South Carolina Research Authority. Deployment of the system is expected to be completed by the end of the summer, Rowland said.

In the Shotspotter system, 12 to 20 sensors are deployed per square mile. When a weapon is fired, sensors in the area detect the implosive event and use triagulation technology to determine the location of the shot—always within 25 yards but typically within a few feet, Rowland said. The location information is delivered to designated public-safety agencies within seconds, allowing them to react quickly to the incident.

“Within about 10 seconds, you know exactly where a gunshot has occurred, and you also have the audio that you can listen to—the number of shots fired, the address and everything that you need to dispatch rapidly to that event,” Rowland said.

It’s a capability that the Birmingham officials are glad is being deployed.

“We’ve seen the positive results of the ShotSpotter program in other cities and we are anxious to bring this technology to the city of Birmingham,” Pete Cosgrove, deputy director of the Public Safety and Homeland Security Directorate in Birmingham, said in a prepared statement.

In addition to the Birmingham award, Shotspotter has received notice of a $1.5 million award to provide a 6-square-mile system in Boston, Rowland said. Details of the contract still need to be finalized, including exactly what kind of backhaul system to use. Currently, the considerations are wireless networks operating in the 700 MHz, 900 MHz and 4.9 GHz bands, he said.