11n standard has been slow
in coming. This has had an adverse effect on the widespread adoption of 802.11n to date.
However, the Wi-Fi Alliance recently announced a certification program for 802.11n
Guide to Wireless LAN Analysis
15
hardware based on a draft standard of the IEEE specification, and this is likely to bring
about stability and increased adoption. The IEEE has also recently approved a draft version
of the 802.11n specification, making a significant step towards ratification. Currently, it is
estimated that the 802.11n specification will be ratified by the IEEE sometime in the first
half of calendar year 2008.
Table 2.1: Standards, band, encoding, and data rates.
Year Standard
or revision Band Encoding Data Rates
(Mbps) Comments
Mandatory,
optional
Mandatory data rates shown in Bold, other
rates are optional.
1997 802.11 IR
(infrared)
PPM 1, 2 Never implemented. (PPM = Pulse Position
Modulation)
1997 802.11 2.4 GHz FHSS 1, 2 Commercially insignificant. (FHSS =
Frequency Hopping Spread Spectrum)
1997 802.11 2.4 GHz DSSS 1, 2 Distributed Sequence Spread Spectrum
(DSSS) methods also supported by later
802.11b and 802.
Pages:
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101