Cobb County, Ga., has accepted the first deployed 800 MHz P25 Phase 2 radio system from Motorola Solutions that uses time-division multiple access (TDMA) technology to double the number of channels supported from 18 to 36, according to Tracy Roberts, radio system manager for Cobb County’s department of public safety.

“We have reached a point with our public-safety communications that the number of users on the radio systems and the type of calls that we’re getting is starting to hammer our capacity, utilizing a lot more frequency resources than we had in the past,” Roberts said during an interview with IWCE’s Urgent Communications. “Traditionally, we’ve had to go back to the FCC to add [channels] to our system, so we can handle the extra capacity that we’re having to provide from a service standpoint.

“This new technology allows us to operate that enhanced service without going back to the FCC and asking for more frequencies. From a resource standpoint—just like with water and electricity—we’re being more efficient with what we have and what we’ve been given.”

Although Cobb County accepted the Motorola Solutions ASTRO P25 Phase 2 system in October, it has not yet been able to realize all of the spectrum efficiency enabled by the upgraded network, because not all subscribers have been upgraded to Phase 2 technology. Roberts said. Overall, the system serves about 3,000 Cobb County devices for public-safety and non-public-safety personnel, as well as about 1,800 units for nearby jurisdictions, universities and other entities, she said. 

In the interim, the system will allow P25 Phase 1 subscribers to operate as they did with the previous infrastructure, Roberts said.

“The system is backward compatible, so it can talk [P25] Phase 1, if we have to interoperate with our neighbors,” she said.

Jim Mears, corporate vice president with Motorola Solutions, also noted the importance of interoperability in his prepared statement that was part of a news release announcing the Cobb County system.

“Motorola understands the importance of providing our customers with innovative solutions that enhance information sharing and deliver a unified operational view of incidents to ensure a well-orchestrated and coordinated response,” Mears said in the prepared statement. “Our robust, regional ASTRO 25 Phase 2 TDMA System will enable Cobb County to handle calls faster, allocate resources more efficiently and coordinate seamlessly within its operation and with other departments and agencies in the region.”