LAS VEGAS—Three companies—ESChat, Tait Communications and Avtec—conducted a joint demonstration at IWCE 2016 highlighting the ability to leverage P25 gateway standards to enable full-featured communications between traditional P25 radio systems and an LTE-based push-to-talk (PTT) solution.

Interoperability between LTE-based PTT and P25 has been achieved before using Bridging System Interface (BSI) technology or radio-over-IP (RoIP) gateways. However, leveraging standardized Inter RF Subsystem Interface (ISSI) and Console Subsystem Interface (CSSI)—components that already exist in many P25 networks—allows for greater functionality between the systems, according to Josh Lober, president of SLA Corp., the developer of ESChat.

“Tait and Avtec have been partners for awhile and already have full-featured communication between the [Avtec] Scout console and the Tait P25 radio network,” Lober said during an interview with IWCE’s Urgent Communications. “In the past, we could have connected ESChat by BSI or RoIP to interoperate, but the level of capability between the systems is quite limited. With the implementation of ISSI to the Scout console, ESChat appears as a P25 radio network, and we’re able to maintain all of the features.”

“It’s a little more of an intimate integration than BSI or a basic RoIP solution. There’s a little bit more information that needs to be put in, but the benefits that you get out of it are tremendous—group calling, private calling and emergency calling, plus you get systemwide radio IDs.”

Bruce Mazza, Tait Communications’ vice president of solutions marketing, echoed this sentiment.

“With the Tait radio network, the extension of [ESChat] push to talk looks like another radio,” Mazza said during an interview with IWCE’s Urgent Communications. “We actually don’t know, when we’re communicating a group call or an individual call between the radio system and push to talk, it’s totally transparent to the system. [The P25 system] thinks it’s another radio, but it’s actually a soft client sitting on a device—that’s the level of interoperability that’s been achieved here.

Lober said the PTT solution was implemented on a Sonim Band 14 handset, which has a dedicated push-to-talk button that was integrated with the ESChat application. Lober said interfacing with Avtec’s IP-based Scout console was “critical” for the demonstration.

Mike Ridge, director of product marketing for Avtec, said the key was the ability for ESChat to communicate via a standard CSSI gateway.

“We didn’t do anything special for it,” Ridge said during an interview with IWCE’s Urgent Communications. “But when you talk about an end-to-end operation, the console plays an important role, especially in a command-and-control kind of application.”

This level of interoperability was achieved with relative quickness, as ESChat officials were able to plug its systems into the P25 gateways and communicate with Tait and Avtec devices in less than a day, according to Lober.

“That’s the whole point of building a standards-based solution, so that—if people take advantage of them—you get this benefit,” Lober said. “You can connect to a console that you’ve never worked with before within hours—and, if you know what you’re doing, even quicker.

“We didn’t invent anything new, but it is the implementation of ISSI into ESChat that has allowed the communication between the LTE users and the radio and between the console position and the LTE users.”