At first, VoLTE will be used to deliver "Rich Communications Services" (which look like something similar to what Voice over IP/Video over IP outfits offer today) rather than completely replacing narrowband voice. It will be awhile before Verizon is willing to commit to that, due in part to LTE outages in late 2011.
On the flip side is MetroPC, which has pushed VoLTE as hard as it could.
Then there's Sprint, which will stick to voice over 1x for the foreseeable future, but routes Direct Connect over IP. Sprint's latest DC incarnation seems quite similar to one facet of RCS over LTE.
Bellevue, Washington — November 20, 2018 — T-Mobile (NASDAQ: TMUS) plans to bring 5G to everyone, everywhere, and together with Nokia, the Un-carrier just took a big step toward making that a reality. The companies just completed the world's first 5G data transmission on low-band spectrum (600 MHz) … and they did it on the Un-carrier’s live commercial network. Low band 600 MHz spectrum is key to building a nationwide 5G network, as it reaches much farther than other frequencies.
That's certainly a big step forward....