Impending release of USB 4 specification was announced by USB Promoter Group in March 2019.[30] The USB 4 architecture is based on the Thunderbolt 3 protocol specification.[31] It supports 40 Gbit/s speed and is compatible with USB 3.2, USB 2.0 and Thunderbolt 3.[32][33] The architecture defines a method to share a single high-speed link with multiple end device types dynamically that best serves the transfer of data by type and application.
USB 4 specification is on track to be published around the middle of 2019.[34]
Source: Wikipedia.org