Wireless USB (Universal Serial Bus) was a short-range, high-bandwidth wireless radio communication protocol created by the Wireless USB Promoter Group which intended to increase the availability of general USB-based technologies. It was unrelated to Wi-Fi, and different from the Cypress WirelessUSB offerings. It was maintained by the WiMedia Alliance which ceased operations in 2009. Wireless USB is sometimes abbreviated as "WUSB", although the USB Implementers Forum discouraged this practice and instead prefers to call the technology Certified Wireless USB to distinguish it from the competing UWB standard. Wireless USB was based on the (now defunct) WiMedia Alliance's Ultra-WideBand (UWB) common radio platform, which is capable of sending 480 Mbit/s at distances up to and 110 Mbit/s at up to . It was designed to operate in the 3.1 to 10.6 GHz frequency range, although local regulatory policies may restrict the legal operating range in some countries. The standard is now obsolete, and no new hardware has been produced for many years. Support for the standard was deprecated in Linux 5.4 and removed in Linux 5.7 Overview The rationale for this specification was the overwhelming success of USB as a base for peripherals everywhere: cited reasons include extreme ease of use and low cost, which allow the existence of a ubiquitous bidirectional, fast port architecture. The definition of Ultra-WideBand (UWB) matches the capabilities and transfer rates of USB very closely (from 1.5 and 12 Mbit/s up to 480 Mbit/s for USB 2.0) and makes for a natural wireless extension of USB in the short range (3 meters, up to 10 at a reduced rate of 110 Mbit/s). Still, there was no physical bus to power the peripherals any more, and the absence of wires means that some properties that are usually taken for granted in USB systems need to be achieved by other means. The goal of the specification was to preserve the functional model of USB, based on intelligent hosts and behaviorally simple devices, while allowing it to operate in a wireless environment and keeping security on a par with the levels offered by traditional wired systems. It also seeks to be comparably power-efficient. To accomplish this, it uses an existing standard which defines a suitable physical layer and medium access control, through which the desired performance can be met, and it adds to it a convergence layer to merge both architectural efforts. W-USB was defined as a bus, albeit