Raytheon recently unveiled a new server-based system that is designed to link LTE and P25 systems over the same network.

"This ensures that public-safety officials can all stay connected when they need it most, whether [it is] a firefighter using a legacy FM handheld, an EMS technician with a P25 radio or a police officer with and LTE-linked mobile data computer in a squad car," according to a Raytheon press release.

By using the new interoperable server as a link between networks gateways such as Raytheon's ACU-5000, network operators can perform software upgrades throughout an entire system by updating the software in the server, said Mike Cox, Raytheon's chief engineer for the ACU-5000.

"You can basically have everything on a server," Cox said during an interview with Urgent Communications. "You don't have to worry about updating a PC; everything's on the server itself."

While the server architecture simplifies system maintenance, it does not create a single point of failure, because Raytheon has retained the characteristics of its traditional distributed systems if the server is unavailable, Cox said.

"The only data streams that go between the server and the ACU-5000s that make up a system are for links that have to go to another ACU-5000 or to an operator or something like that," he said. "If the infrastructure goes down, so there's no link to the server, the ACU-5000 can run it autonomously and can be controlled locally."

Demonstrated earlier this month at the Association of Public-Safety Communications Officials (APCO) conference in Philadelphia, a version of the interoperability server is expected to be commercially available by the end of the year, with software feature upgrades being provided throughout 2012, Cox said.