“…It supports several physical layer transmission rates, with 802.11b having four (1, 2, 5.5 and 11 Mb/s), 802.11a having eight (6,9,12,18,24,36,48 and 54 Mb/s), while 802.11g has all twelve of the 802.11b and 802.11a rates, and 802.11n has eight when using two streams at 20 Mhz and a guard interval of 800ns (13,26,39,52,78,104,117, 130 Mb/s). A range of rates are available as their modulation and coding schemes give them distinct robustness characteristics to noise on the medium.…”