802.11g

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This new PHY extension to 802.11b will operate in the 2.4 GHz band and specify three available radio channels providing a maximum link rate of 54 Mbps per channel, compared with 11 Mbps for 802.11b. Even though the charter of the 802.11g Task Group is to develop a higher speed extension (up to 54 Mbps) to the 802.11b PHY while operating in the 2.4 GHz band and implementing all mandatory elements of the IEEE 802.11b PHY standard, the Task Group opted not to use 802.11b's DSSS. Instead, OFDM provides the higher data rate extensions. But, to provide backwards compatibility with 802.11b, the specification supports complementary code keying (CCK) modulation and, as an option for faster link rates, allows Packet Binary Convolutional Coding (PBCC) modulation.

The IEEE standards board finalized the 802.11g specification in mid-June 2003. The next step is for the Federal Communications Commission (FCC) to approve the use of OFDM in the 2.4 GHz band (a generally necessary action when messing with the PHY). Also, other national regulatory bodies must approve the operation of 802.11g equipment within their domain. It could take awhile for that to occur.

Despite all of these constraints, leading vendors are racing to introduce new 802.11g compliant gear. But don't jump on the 802.11g bandwagon until products based on a final version of the specification and sport a Wi-Fi certification label are available. Buyers of 802.11g gear that doesn't meet such criteria risk interoperability and performance problems in a multi-vendor environment, particularly with certified 802.11b products installed in PCs in a mixed 802.11b and 802.11g operating environment.

The highly respected market research group, Gartner, Inc. suggests that potential users wait until 802.11g products have been certified by the Wi-Fi Alliance before adding such equipment to their networking environment. (The Wi-Fi Alliance has begun the certification process.)

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