Asus B and W PCI CARD - Manual (Page 105)

104 ASUS SpaceLink B&W PCI Card
Chapter 6
Chapter 6 - Glossary
IEEE 802.11b (11Mbits/sec)
In 1997, the Institute of Electrical and Electronics Engineers (IEEE) adopted
the 802.11 standard for wireless devices operating in the 2.4 GHz frequency
band. This standard includes provisions for three radio technologies: direct
sequence spread spectrum, frequency hopping spread spectrum, and
infrared. Devices that comply with the 802.11 standard operate at a data
rate of either 1 or 2 Mbps.
In 1999, the IEEE created the 802.11b standard. 802.11b is essentially
identical to the 802.11 standard except 802.11b provides for data rates of
up to 11 Mbps for direct sequence spread spectrum devices. Under 802.11b,
direct sequence devices can operate at 11 Mbps, 5.5 Mbps, 2 Mbps, or 1
Mbps. This provides interoperability with existing 802.11 direct sequence
devices that operate only at 2 Mbps.
Direct sequence spread spectrum devices spread a radio signal over a range
of frequencies. The IEEE 802.11b specification allocates the 2.4 GHz
frequency band into 14 overlapping operating Channels. Each Channel
corresponds to a different set of frequencies. See the Appendix to determine
the center frequency used by each Channel.
If operating multiple 802.11b Wireless PCI Cards in the same vicinity, the
distance between the center frequencies must be at least 25 MHz to avoid
interference. Note that the Channels available to an 802.11b Wireless PCI
Card will vary from country to country. In the United States, the 802.11b
standard allocates 11 operating Channels for direct sequence devices. Channels
1, 6, and 11 are independent and do not overlap with each other. To avoid
interference between 802.11b Wireless PCI Cards, It is recommended that
you configure the Wireless PCI Cards using only Channels 1, 6, and 11.