May 23 2007

Eliminate the Need for Cables by Switching to Wireless USBs

Double the reach to USB devices by unplugging the cables.

Since no one seeems to like cables, enter the Universal Serial Bus (USB), invented in 1995 to eliminate the variety of parallel, serial and other cables required to connect computers to peripheral devices. By adding a very fast radio connection to USB, the result is Wireless USB, which offers twice the range as the traditional device but without the rat’s nest of cables.

How Wireless USB Works

What made Wireless USB possible was the development of ultrawideband (UWB) technology. UWB uses a very broad frequency range — 3.1 to 10.6 gigahertz — and a frequency modulation technique that is very efficient and requires half the power of 802.11g. UWB has been used by the military since 1960, but it wasn’t until a 2002 Federal Communications Commission rule change that it became possible to use UWB without a license in the computer industry. You can also customize the frequencies for local regulatory markets.

Like USB, Wireless USB supports up to 127 devices connected to a single host. You can get speeds of up to 480 megabits per second if devices are within 10 feet. At the maximum range of 30 feet, data transfer drops to a still very respectable 110Mbps.

Two groups are working on mutually exclusive versions of Wireless USB. Freescale is developing its proprietary Cable-Free USB. The USB Implementers Forum (USB-IF) ­— the group that gave us USB — is working on a Certified Wireless USB standard. Freescale Semiconductor’s implementation of the USB 2.0 standard in a wireless format is compatible with existing USB devices without additional drivers. Hewlett-Packard, Microsoft, NEC, Intel and more than 200 other companies back the nonproprietary Certified Wireless USB standard.

Wireless USB is different from Bluetooth and 802.11. Bluetooth is limited to eight devices in a net and 802.11 tops out at 54Mbps. Still, all three have applications for which they’re most useful, so don’t expect any of them to go away.

45 Feet of Freedom

The initial value of Wireless USB is that it extends your reach. Although USB cables are 15 feet long, you can set up a Wireless USB hub 30 feet away from a computer and add hardware to extend the range to 45 feet. This allows you to keep noisy or infrequently used peripherals in a more convenient space, perhaps in another room.

In addition to reducing cable clutter, Wireless USB makes it easier to connect. You can plug a Wireless USB dongle into any device with a standard USB port, including printers, cameras, external hard disks and MP3 players. In the next few years, notebooks, computer peripherals, digital cameras and cell phones are expected to have built-in Wireless USB. Other expected future developments are speeds surpassing 1 gigabit per second and devices that can be shared by multiple hosts, which is like having a network server with a bunch of peripherals but without the network server.

IT Takeaway

Wireless USB is still a very young technology that requires you to examine the pros and cons, particularly related
to security.

• If you have a wireless connection, there is a potential security hole. The USB-IF uses 128-bit AES encryption as part of the Certified Wireless USB standard.
• Don’t skip the security setup: All new devices require you to go through a handshaking process the first time you use them or link them to another Wireless USB device.