The USB Implementers Forum (USB-IF) today announced the publication of the USB4 specification, a major update to deliver the next-generation USB architecture that complements and builds upon the existing USB 3.2 and USB 2.0 architectures.

The USB4 architecture is based on the Thunderbolt protocol specification recently contributed by Intel 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 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 USB4 specification provides the host 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 is supported; the resulting connection scales to the best mutual capability of the devices being connected.