By Stephen Bucaro
Originally peripherals such as the mouse and the printer were connected to a PC
using the RS232 serial port and the IEEE1284 parallel port, but to connect
and disconnect devices you had to reboot the computer. USB (Universal Serial Bus)
allows hot swapping, which is to connect and disconnect devices from the computer
without rebooting the computer.
But, like RS232 and IEEE1284, USB required peripherals to be connected to the
PC with cables. Some PC users feel they can be more productive if they could
get rid of those cables. This has resulted in the introduction of several
short range wireless connection technologies.
Infrared (IR) Wireless technology uses electromagnetic radiation in the infrared
(heat) wavelength to provide wireless connections. Bluetooth technology uses the
microwave radio frequency spectrum in the 2.4 GHz to 2.4835 GHz range. Wireless
USB uses the 3.1 to 10.6 GHz frequency range to provide wireless connections.
There are two competing versions of wireless USB. CableFree USB, is a system
developed by Motorola spin-off FreeScale Semiconductor. The other version
was developed by WiMedia. The two systems canít talk to each other. The
(USB Implementers Forum) has adopted the WiMedia version as its standard and
wants us to refer to that version as "Certified Wireless USB" to differentiate
it from "uncertified" competitors.
"Certified Wireless USB" works at the 3.1 GHz Ė 10.6 GHz Ultra-WideBand (UWB)
frequency and can provide a bandwidth up to 480 Mbit/s at a distance up to
3 meters. Several vendors, like Belkin and D-Link have come out with 4-port
"Certified Wireless USB" Hubs.
American Cancer Society
has determined that high-frequency radio waves used in microwaves, cellular phones,
and other wireless devices causes cancer and other disease. Unfortunately the
cellular phone industry and other vested interests, in order to protect their
lucrative profits, have sponsored many bogus studies to confuse the public. I
think I'll just live with my annoying, productivity killing cables. But feel
free to wrap your own hand around, or hold next to your brain, a microwave