Mission-critical VoLTE gear could be available in 2018

But there is a lot of work that needs to be done, according to Andrew Thiessen, acting division chief for the Institute of Telecommunications Services (ITS). The biggest challenge to making mission-critical voice a reality over LTE is that first responders need their gear to work in direct mode—known as “talkaround” or “simplex” in the LMR arena—while LTE devices today only work if they can connect to an LTE base station.

“If this one day is ever to replace a land-mobile-radio device, it has to encapsulate the same feature functionality, which is the ability for my UE [user equipment] to be able to talk with somebody else’s UE without traversing the network—that is the direct-mode capability,” Thiessen said during the IWCE session.

This requirement for public safety has been recognized, and solutions are being developed. Budka noted that 3GPP—the global LTE standards body—plans to have most of the key functionality needed to provide mission-critical VoLTE (including direct-mode capability) in Release 12, which is scheduled to be solidified in December of this year. Meanwhile, a formal standard for mission-critical push-to-talk is slated to be part of LTE Release 13, which is scheduled to be solidified in March 2016.

Typically, equipment for a standard hits the market two years after a release version is solidified, Budka said. Given this, Release 12 equipment would be available in late 2016, and Release 13 gear would be in the marketplace in 2018.

One public-safety entity that plans to explore at least some the capabilities of VoLTE is the Los Angeles Regional Interoperable Communications System Authority (LA-RICS), according to Patrick Mallon, LA-RICS executive director. Under current law, LA-RICS will have to abandon its T-Band spectrum in 2021, so the organization is building a P25 network on 700 MHz narrowband spectrum and an LTE network in cooperation with FirstNet, he said.