801.11b

In 1999, the Institute of Electrical and Electronic Engineers (IEEE) ratified the 802.11b standard which defined a new modulation technique that enabled 5.5 and 11 Mbps in addition to the 1 and 2 Mbps already supported in the original 1997 specification. The B standard uses DSSS; therefore, the original 802.11 1- and 2-Mbps DSSS cards were compatible with the new 802.11b system. Original 802.11 1- and 2-Mbps FHSS cards, however, were not compatible. Table 2.1 outlines the basic operating characteristics of 802.11b.

Table 2.1. 802.11b specifications.
Frequency:2.4 GHz
Channels:11 (3) USA
Speed:11 Mbps
Range:Appx. 300 feet (varies)
Encoding Scheme:DSSS
Modulation Technique:DBPSK (1 Mbps)

DQPSK (2 Mbps)

CCK (5.5 & 11 Mbps)

802.11b operates in ...

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