Binary Phase Shift Keying (BPSK) is a method for representing bits with an analog signal, in our case turning the digital electrical signals in our PCs and APs into wireless radio waves. BPSK is highly clear of multipath propagation, but is unused in high data rate applications because of bandwidth inefficiency. In terms of [802.11b], BPSK is only used when 1Mbps data rates are in use, above this threshold, [QPSK] is generally used. * (http://www.computerpro.com/~lyle/watsbpsk.htm BPSK Basics) * (http://cnx.rice.edu/content/m10280/latest/ Maths behind BPSK) * (http://www.pulsewan.com/data101/802_11_b_basics.htm 802.11B Basics) See also [PHY], [QPSK]