Wireless USB devices due in September

The first devices using a wireless version of the Universal Serial Bus connection technology will begin arriving in the third quarter, the leader of an industry group overseeing the standard said on Monday.

Wireless USB promises help for consumers frustrated with PCs sprouting a profusion of cables linking their PCs with printers, digital cameras, music players and external disk drives, said Jeff Ravencraft, chairman of the USB Implementers Forum and an Intel technology strategist. Wireless USB permits the same 480 megabits-per-second data transfer speed as the current wired USB 2.0 standard, but requires small radios inside PCs or devices rather than the cables.

"Early movers are going to be external hard drives, cameras and printers," Ravencraft said in an interview in San Francisco on the eve of the Intel Developer Forum. "You'll begin to see products move in the third quarter through the back half of the year."

To make wireless USB practical, though, some aspects of the technology had to be ironed out. On Monday, the USB standards group announced a new element to that work, the Wireless Association Specification that makes sure only authorised connections are made between PCs and devices.

USB has caught on widely as a way to connect cameras, scanners, mobile phones, handheld organisers, DVD burners and innumerable other devices to PCs. The Wireless Association Specification governs how the PC end of the wireless USB connection will be able to connect to as many as 127 devices, Ravencraft said.

There will probably be a learning curve in the arrival of wireless USB. The specification requires one of two ways to set up the association between a device and the PC so the connection can be used. In one, the two are connected by a cable initially and set up their association for future wireless links. In the other, the device will show a number that the user then has to type into the PC.

Wireless USB uses an underlying wireless communication technology called ultrawideband (UWB). Where 802.11g uses a relatively narrow frequency range centred on 2.4GHz radio waves, UWB uses a very broad range from 3.1GHz to 10.6GHz, Ravencraft said. The UWB signal levels are low enough that it appears to be noise to other radio communication technology.

Wireless networking using Wi-Fi, or 802.11, has caught on widely in laptop computers. It's even shipping in some cameras from Kodak and Canon, among others. Wireless USB is a different technology, however, and gadget makers are keen to embrace it for its relative simplicity and the fact that it consumes about half the power of Wi-Fi.

"With very high-end phones and cameras, you're starting to see 802.11. The issue in those mobile devices is the battery power and cost of battery life in implementing that," Ravencraft said. "The mobile phone and camera guys see UWB as a very good solution for point-to-point connections with very low power."

Wireless USB runs at full 480Mbps speed only when a device is within about 3m of a computer. Beyond that, but still within the maximum 10m distance, the transfer rate drops to 110Mbps. However, wireless USB will soon reach 1Gb-per-second speeds and faster, Ravencraft said.

The UWB radio communication is useful for more than just wireless USB. It also can be used simultaneously for wireless Bluetooth links, IEEE 1394 FireWire links and even WiNet short-range Internet Protocol networks.

Initially, wireless USB will require an add-in card or plug-in device for a PC to use it. Eventually it will be built in, then integrated gradually more tightly with computing electronics, the same path wired USB took, Ravencraft said.