Verizon CFO Matt Ellis in December 2017 said, “it just starts to be significant to our financials in the next 2 to 3 years.” That would be late 2019 or 2020. Since then, Verizon has said everything is going better than expected. Verizon is building a true gigabit millimeter wave network.
After that comment, the industry accepted calling almost everything "5G," including 5G Low in 3.5 GHz spectrum. That's 70%-90% slower, really 4G with a software tweak (New Radio.) Especially in China, 3.5 GHz networks may be built early in 2018.
In July 2018, Skyworks CEO Kris Sennesael didn't see much demand for either type of 5G until late in 2019. Skyworks supplies frontend radio frequency parts to almost all the phone makers and has a clear view of the market.
What we’re seeing today is a lot of design activity on both the infrastructure side and also on really kind of a heartbeat of the connectivity within smartphones. We think, again, you can get different answers, but we see revenue really being posted probably by 2020, maybe late '19. But 2020 is where I think kind of we translate around real revenue. (Seeking Alpha)
Getting the first 5G phones for Xmas, as Ted Rappaport predicts, is very exciting. But it probably will be Xmas 2019 or a little later for enough units to ship to affect any bottom line. It will take at least another year after that until they are in mid-priced phones.