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The
launch of the three wireless standards have left quite a few
gaping on as to what is the difference between them. Doug
Mohney tries to dissect them and tries to find out which one
is the best
Are
you confused over the three different wireless standards,
802.11a, 802.11b, and 802.11g? Of course, each of these standards
were implemented in different orders, so here’s our snapshot
of the three unlicensed.
802.11a: This standard uses the 5 Ghz wireless band,
but different parts of the 5 Ghz band are approved for use
in North American markets as against the rest of the world.
802.11a is designed to crank data at rates starting at 54
Mbps using an encoding scheme called orthogonal frequency
division multiplexing (OFDM). Some of the hardware is incorporating
proprietary schemes to use two virtual data channels for speeds
of 108 Mbps. Equipment using 802.11a is just starting to hit
the shelves at a list price of around $450 for a notebook
PC card or $700 for an external ‘access point’.
The newly minted trade name for the standard is WiFi-5.
802.11b: Using the 2.4 Ghz wireless scheme, 802.11b
is a worldwide standard that delivers throughputs of up to
11 Mbps. There are literally hundreds of thousands of cards
and devices using the standard worldwide at pricing as low
as $99 for a PC card and under $150 for an access point. The
trade name to cover up geek label 802.11b is WiFi.
802.11g: Just ratified in November, 802.11g works in
the 2.4 Ghz wireless band and is designed to support speeds
at 1.1 Mbps, 5.5 Mbps, 11 Mbps, 22 Mbps, and 54 Mbps. The
standard is designed to be backwards compatible with the 802.11b
standard, but there may be a split of how data rates beyond
11 Mbps are implemented, since the two major wireless chip
manufactures are split on how to do it. TI has a subtle lead
in this race since they managed to incorporate the 22 Mbps
data rate into shipping chip sets AND got their 22 Mbps standard
incorporated into the 802.11g rate. No trade name has been
assigned for the higher standard.
Which standard is the best? From a pure technical standpoint,
802.11a is the best because it delivers the most sheer speed
and is in the 5 Ghz band. The 5 Ghz band is relatively uncluttered
with other devices, but 2.4 Ghz is full of extraneous garbage
from wireless phones, microwave ovens, and even Bluetooth
devices. (Bluetooth is a separate wireless standard designed
to network PC devices) On the other hand, 802.11b is established
and cheap and has an upward growth path to the faster 802.11g
standard.
—
www.ispworld.com
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