International push expected to ensure that mission-critical PTT standard for LTE will be finalized in 2016

In March, the LTE Release 12 standard was completed, and that standard includes a direct-mode capability—a key prerequisite for public-safety communications. The Release 12 direct-mode functionality largely mirrors current LMR capabilities for “fire-and-forget” communications within the range of initiating device, Thiessen said. As with LMR systems, Release 12 does not include acknowledgement that direct-mode communications are received, other than having other users respond to the communications, he said.

“There’s no acknowledgement in land mobile radio, so the base-level functionality was, ‘What can LMR do?’ Thiessen said.

That is expected to change in Release 13, Thiessen said. In addition to being able to communicate via mission-critical push-to-talk services, LTE Release 13 is expected to include out-of-network discovery capability, so users can know who is within transmission range for direct-mode communications, he said.

“We’re going to get out-of-network discovery in Release 13,” Thiessen said. “Then, we can build in things like a confirmed group call, which is that I know who got it. Discovery is going to give public safety a lot more capability beyond what they have in land mobile radio.”

In the United States, FirstNet officials have committed to offering non-mission-critical voice capability from the first day that its network services are available to public-safety entities. According to the FirstNet draft request for proposal (RFP) that was released this spring, Release 13 capabilities—presumably MCPTT—would have to be implemented in the network within two years of the contract being awarded for the nationwide public-safety broadband network.

FirstNet plans to issue a final RFP by the end of the year, so an award could occur as early as late in 2016 or sometime in 2017.