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Wireless LANs
IEEE 802.11a
Author
- Jim
Geier, MobileInfo consultant and author of several books
on wireless networking - modified and enhanced by MobileInfo.Com
The
wireless LAN industry is buzzing with activity as vendors push the
development and delivery of 54 Mbps wireless LAN radios and access
points based on the IEEE 802.11a
standard. In contrast to
the today’s 2.4 GHz, 11 Mbps, 802.11b standard, the 802.11a version
specifies data rates up to 54 Mbps with operation in the 5 GHz
frequency band using OFDM
(orthogonal frequency division multiplexing).
The much higher performing 802.11a wireless LAN radios and
access points should be available by the end of 2001. If you’re
about ready to sink a large amount of money into a wireless LAN, you
might consider waiting for 802.11a products if possible.
Why
would I want to wait for 802.11a?
Here are some advantages to consider:
-
Very
high data rates. The
initial implementations of 802.11a products should operate at the
full 54 Mbps data rates as specified by the standard. Some
companies will even operate at higher (100 Mbps) proprietary data
rate extensions by implementing solutions that combine multiple
OFDM channels. At
these data rates, there’s enough throughput to support a very
high density of bandwidth hungry end users and multimedia
applications.
-
Fewer
transmission impairments.
Because 802.11a products operate in the 5 GHz frequency
band, there is much less potential for RF
interference as compared to the more common 2.4 GHz band
(where many 802.11b wireless LANs, Bluetooth
devices, and the newer wireless phones operate).
In addition, OFDM offers greater tolerance to multi-path
propagation, which can be significant at higher data rates.
This makes wireless LAN implementations more reliable and less
risky.
Product Examples
Comparison with 802.11b and
Bluetooth
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