Wireless USB (WUSB) is a new wireless extension to USB intended to combine the speed and security of wired technology with the ease-of-use of wireless technology. WUSB is based on ultra wideband wireless technology defined by WiMedia Alliance, which operates in the range of 3.1–10.6 GHz.

IEEE 802.15.3a was an attempt to provide a higher speed UWB PHY enhancement amendment to IEEE 802.15.3 for applications which involve imaging and multimedia. IEEE 802.15.3a UWB standardisation attempt failed due to contrast between WiMedia Alliance and UWB Forum. On January 19, 2006 IEEE 802.15.3a task group (TG3a) members voted to withdraw the December 2002 project authorization request (PAR) that initiated the development of high data rate UWB standards. The IEEE 802.15.3a most commendable achievement was the consolidation of 23 UWB PHY specifications into two proposals using : Multi-Band Orthogonal Frequency Division Multiplexing (MB-OFDM) UWB, supported by the WiMedia Alliance, and Direct Sequence - UWB (DS-UWB), supported by the UWB Forum.

The Wireless USB Promoter Group was formed in February 2004 to define the Wireless USB specification. The group consists of Agere Systems, Hewlett-Packard, Intel, Microsoft, NEC Corporation, Philips and Samsung.

WUSB offers bandwidths of 480 Mbit/s at three meters and 110 Mbit/s at 10 meters. WUSB uses a star topology with up to 127 devices. WUSB also supports so-called dual-role devices, which in addition to being a WUSB client device, can function as a host with limited capabilities. For example, a digital camera could act as a client when connected to a computer, and as a host when transferring pictures directly to a printer.

WUSB will be used in devices that are now connected via regular USB cables, such as game controllers, printers, scanners, digital cameras, MP3 players, hard disks and flash drives, but it is also suitable for transferring parallel video streams.

In May 2005, the Wireless USB Promoter Group announced the completion of the Wireless USB specification. The first WUSB products hit the market at the end of 2005. Companies like Ellisys and LeCroy are supplying development support tools to facilitate early introduction of the technology.

In June 2006, USB Implementers Forum (USB-IF) offered the first five-way, multi-vendor interoperable demonstration of Certified Wireless USB. A laptop with an Intel host adapter using an Alereon PHY was used to transfer high definition video from a Philips wireless semiconductor solution with a Realtek PHY, all using Microsoft Windows XP drivers developed for Wireless USB.

Certified Wireless USB vs WirelessUSB™

Cypress's "WirelessUSB™" is a protocol that uses the 2.4 GHz ISM band with a range from 10 meters (at max 1 Mbit/s) to 50 meters (at max 62.5 kbit/s) and is designed for Human Interface Devices (HIDs), with current offerings from companies such as Belkin, Logitech, and Virtual Ink.

Other forms of Wireless USB such as those to be offered on the competing UWB technology based on Freescale pulse method are also not approved by the USB Sig or the IEEE. The same is also true for other RF based Wire replacement systems which can carry USB. The result is that the name 'Certified Wireless USB' had to be adopted to allow consumers to identify which products would be adherrent to the standard and would support the correct protocol and data rates.

External links

• The Wireless USB Promoter Group home page
• Wimedia/MBOA Alliance
• USB Central

USB

Wireless USB | Wireless USB | Wireless USB | Wireless USB | WUSB