He is very vocal to say that 5G is a technology that it officially hopes to support next year, and back in January, Xiaomi already said that it plans to do 5G with a Qualcomm Snapdragon X50 modem inside.
So if you add two and two together this is one of the first phones running the Snapdragon 855 SoC and Snapdragon X50 5G modem combo seen in action. We would expect that this phone ships in 2019 but not too late into the year. For what it is worth, this can be one of the successors in the Mi Mix series, maybe even Mi Mix 3S (or simply called Mi MiX 5G). It is, of course, up to Xiaomi to brand its phones.
N75 is the TDD band that works between 3300 – 3800 MHz and the phone was using 20 MHz bandwidth while also using the LTE FDD band 5 with 10MHz and frequencies between 869 – 894 MHz.
28GHz mmWaves for super speed
More interestingly, the phone was using at least one of the mmWave frequencies also known as N257 - this is a 28 GHz TD band that is likely to be available globally. The fourth carrier is actually hidden but you can see that it is another 100MHz channel most likely additional 28 GHz N25x band.
This is where the speed will be coming from. 28 GHz can get you really fun speeds with multiple gigabits per second. Even 10s of gigabit speeds are possible down the road with 5G.
Donovan showed the full-view, near bezel-less phone, most likely with a slider camera. This looks like what Xiaomi showcased as the Mi MIX 3 and officially promised for October but unless the company wants to claim to be the first, this is probably some future version of the successful Mix series.
This is one of the trends in 2019 for most high-end phones that have already started in the second half of 2018 and Snapdragon 845 phones out of China. China is betting on 5G in 2019 and so does the USA and a few countries in Europe. Most European countries promised deployment of 5G in the course of 2020 but some advanced thinking carriers like TIM in Italy are already thinking to deploy mm Waves. Some others, like Deutsche Telekom, plan to start with sub 6GHz and grow into mm-waves and really attractive speeds a bit later.