​Push-to-talk-over-cellular (PoC) provide ESChat today announced plans to develop Mission Critical ESChat (MC-ESChat), which will provide “full compliance” with the new 3GPPP mission-critical push-to-talk (MCPTT) standard as it evolves during the next few years.

“We’re committed to it [developing an MCPTT-compliant offering], and we’re doing it,” Josh Lober—president of SLA, which makes ESChat—said during an interview with IWCE’s Urgent Communications. “We’re in the process of building our MCPTT version of ESChat and in the process of testing for interoperability.”

Used by the military and in several 700 MHz Band 14 LTE trials and early-builder deployments, ESChat already offers AES-256 encryption, LMR interoperability and quality of service (QoS) with many carriers and private-network providers, Lober said. But no vendor has a fully MCPTT-compliant product today, because many key components simply don’t exist today, such as eMBMS-based multicast, IMS-based application-server interoperability, Isolated E-UTRAN Operation for Public Safety (IOPS) and proximity services (ProSe), he said.

IOPS allows an LTE base station to continue providing coverage locally when connection to the evolved packet core (EPC) is lost, and ProSe functionality enables direct-mode communication between users that is vital to public safety when a network connection is unavailable

“This is going to be a long process, a long evolution—the [3GPP MCPTT] spec was only released recently,” Lober said. “We’re well into this, but it’s a gated process. As each new feature becomes available, we can test it.”

When asked when IOPS and ProSe functionality might be on the market, Lober said, “That’s up to the chip vendors and infrastructure providers. It’s not scheduled to happen until 2018.”

Although non-mission-critical PoC services have been available commercially for more than a decade, one concern cited by many is that PoC solutions from different vendors are not interoperable without a separate gateway. ESChat has committed to participating in the European Telecommunications Standards Institute’s (ETSI’s) first MCPTT plugfest event in June 2017 that will be designed to let MCPTT vendors test their ability to interoperate with MCPTT solutions from other vendors, Lober said.

Meanwhile, ESChat is not simply waiting until next June’s event to work on MCPTT interoperability, Lober said.

“We have reached out to other MCPTT vendors to being the process of interoperability testing,” he said.

Over the past 20 months ESChat has been tested by first responders on numerous FirstNet Band 14

Deployments, according to a company press release. These include FirstNet Colorado (2015 Alpine World Ski Championships and XPSLTE), New Mexico FirstNet (2015 and 2016 New Mexico State Fair, 2015 and 2016 International Balloon Fiesta and the 2016 Zozobra Festival), Harris County, Texas (2015 Houston Livestock Show and Rodeo) and LA-RICS (2016 Tournament of Roses Parade).