Wireless USB

Wireless USB aims to eliminate cables and should let wired PC peripherals and multimedia devices interconnect over blazingly fast ultrawideband technology. The major stakeholders in wireless USB are Freescale, with its proprietary Cable-Free USB, and the USB Implementers Forum, with its Certified Wireless USB. The latter uses the radio platform of the WiMedia Alliance, which has the backing of industry giants HP, Intel and Microsoft as well as silicon providers such as Alereon, WiQuest and Wisair. Although wireless USB is proven in the lab, it will take some time for it to replace wired USB interfaces. Initially, products like Belkin's wireless USB hub (based on Certified Wireless USB), will let wired USB products go wireless. After wireless USB interfaces are built into laptops, PCs, cameras and other gadgets, consumers will be able to interconnect them, but the real test will be in this technology's ability to deliver the same ease of use that has made wired USB so successful.

Wired users have long benefited from the common plug-and-play high-speed bus provided by USB 1.0 and 2.0. But while enterprises and consumers have moved to wireless architectures, USB has remained tethered--until now.

Two groups are attempting to design the wireless USB standard. Vendor Freescale is touting its proprietary Cable-Free USB. The USB Implementers Forum's Certified Wireless USB, on the other hand, is an open alternative with backing from industry heavyweights.

Enabling Technology

UWB (ultrawideband) radio technology makes wireless USB possible. In contrast with wireless technologies such as Wi-Fi, which offers maximum speeds of 54 Mbps, UWB uses roughly 25 times the amount of spectrum and offers a much larger "pipe" that tops out at 480 Mbps. By spreading the bitstream over a large bandwidth using low-power pulses, UWB can limit interference and co-exist with other technologies using the same spectrum. In addition, UWB's power consumption is about 10 times more efficient than Wi-Fi, so it improves battery life.