The Helio M70 baseband chipset was showcased at the China Mobile Global Partner Conference in Guangzhou today. This modem, unlike the Snapdragon X50, is backwards-compatible with 4G to 2G. It is also 3GPP-compatible and rated for speeds of 5 gigabits per second.
https://www.notebookcheck.net/MediaTek-launches-its-M70-5G-modem-at-a-tech-conference.374801.0.html