Crystal ball for mission-critical voice over LTE timeline certainly not crystal clear

For those trying to read the tea leaves about mission-critical push-to-talk services over LTE, here are some places to look for hints that might shed light on the ultimate answer:

(1)     Commercial-carrier networks: After years of running voice calls over older technology, U.S. wireless carriers have announced that they will be transitioning voice calls to their new LTE networks. This will not be mission-critical voice, but a solid launch in the carrier-grade voice space would be an encouraging step in the right direction.

(2)     High-definition voice: This is one of the intriguing capabilities of LTE. With a broadband pipe, more bandwidth can be devoted to transmitting voice signals, allowing for high-definition voice. For carriers, this is expected to be a way to differentiate themselves from various service applications like Skype. For public safety, audio intelligibility is paramount to good voice communications, so effective high-definition voice capability could be very attractive, particularly when compared to LMR voice quality.

(3)     Europe: Based on the timeline announced previously to transition from public-safety TETRA to LTE, the UK or France could be the first place to have mission-critical voice implemented in a real-world situation. If this happens, U.S. officials are eager to leverage the lessons learned in this part of the globe.

There are other indicators that will be worth monitoring, most notably the progress and buildout plans of FirstNet, because I have a difficult time envisioning a scenario in which public safety trusts any application—especially something as important as mission-critical voice—that operates on a commercial-carrier network that is subject to capacity issues within a given cell sector.

What is perhaps most interesting about the debate surrounding mission-critical voice is how the dialog has changed in recent years. Even last year, there was a significant contingent within the public-safety community that questioned whether mission-critical voice over LTE was possible; today, with the necessary standards work well underway and LTE development occurring at a lightning-quick pace for a communications technology, the questions seem to be more a matter of when it will be available in a given location, not whether it will occur.