Intended to retain the error-correction, security, power-management and other advantages of the original, but slower 802.11 standard, 802.11b adds a key ingredient - a technique for increasing bandwidth to 11M bit/sec.
Called Complementary Code Keying (CCK) the technique works only in conjunction with the DSSS technology specified in the original standard. It does not work with frequency-hopping or infrared transmissions.
What CCK does is apply sophisticated mathematical formulas to the DSSS codes, permitting the codes to represent a greater volume of information per clock cycle. The transmitter is now able to send multiple bits of information with each DSSS code, enough to make possible the 11M bit/sec of data rather than the 2M bit/sec in the original standard.
From Wireless LAN speeds get a boost, Network World Tech Update, 02/14/00.
Note: 802.11b is also known as Wi-Fi (short for "Wireless Fidelity")
Also see 802.11a
Additional Resources
Wireless Ethernet Compatibility Alliance
Wi-Fi industry group.
