The USB4 update complements and builds upon the existing USB 3.2 and USB 2.0 architectures. It is based on the Thunderbolt protocol specification recently contributed by Intel Corporation to the USB Promoter Group. It doubles the maximum aggregate bandwidth of USB and enables multiple simultaneous data and display protocols.
The development of the USB4 specification was first announced in March 2019 by the USB Promoter Group. It is now officially published by USB-IF and available for download at www.usb.org.
Key characteristics of the USB4 solution include:
- Two-lane operation using existing USB Type-C cables and up to 40Gbps operation over 40Gbps certified cables
- Multiple data and display protocols that efficiently share the maximum aggregate bandwidth
- Backward compatibility with USB 3.2, USB 2.0 and Thunderbolt 3
As the USB Type-C connector has evolved into the role as the external display port of many host products, the new USB specification provides the host with the ability to optimally scale allocations for display data flow.
Even as the USB4 specification introduces a new underlying protocol, compatibility with existing USB 3.2, USB 2.0 and Thunderbolt 3 hosts and devices are supported; the resulting connection scales to the best mutual capability of the devices being connected.
The upcoming USB Developer Days 2019 in Seattle and Taipei will include detailed technical training covering the USB4 specification and the latest for USB Type-C, USB Power Delivery, and new USB-IF branding strategies.