IEEE 802.11b is a popular standard for wireless networking. It has a theoretical maximum speed of 11Mb/s, though in practice the maximum you will get is just over 6Mb/s. 802.11b is basically an extension on top of 802.11 with emphasis on rate improvement, it introduces modulation techniques to achieve 8 bits/symbol (allowing for 11Mb/s) and optionally shorter frames to reduce overhead. Also, while 802.11 describes three general PHY methods: FHSS, DSSS, and Infrared; 802.11b specifically uses DSSS (DirectSequenceSpreadSpectrum).
802.11b allows for the use of these digital modulation techniques (in order of rate improvement):
Frame headers (and preambles) are always transmitted using DBPSK at 1Mb/s, but the modulation and rate of the data portion is variable.