Hack 1 802.11: The Mother of All IEEE Wireless Ethernet
While definitely showing its age, the original
802.11 gear still has its uses.The first wireless
standard to be defined in the 802 wireless
family was 802.11. It was approved by the IEEE in 1997, and defines
three possible physical layers: Frequency
Hopping Spread Spectrum (FHSS) at 2.4 GHz,
Direct Sequence
Spread Spectrum (DSSS) at 2.4 GHz, or Infrared. 802.11 could achieve
data rates of 1 or 2 Mbps. 802.11
radios that use DSSS are interoperable
with 802.11b and 802.11g radios at those speeds, while FHSS radios
and Infrared obviously are not.The original 802.11 devices are increasingly hard to come by, but can
still be useful for point-to-point links with low bandwidth
requirements.
Pros
Very inexpensive (a few dollars or even free) when you can find them.DSSS cards are compatible with
802.11b/g.Infrared
802.11 cards (while rare) can offer interference-free wireless
connections, particularly in noisy RF environments.Infrared also offers increased security due to significantly shorter
range.
Cons
No longer manufactured.Low data rate of 1 or 2 Mbps.FHSS radios are incompatible with everything else.
Recommendation
802.11 devices can still be useful,
particularly if you find that you already have a few on hand. But the
ever falling price of 802.11b and 802.11g gear makes the old 802.11
equipment less attractive each day. The
FHSS and
Infrared cards talk
only to cards of the same era, so don't expect them
to work outside of your own projects. Infrared requires an absolutely
clean line of sight between devices and offers limited range, but it
operates well away from the popular ISM and UNII bands. This means
that it won't interfere with (or see interference
from) other networking devices, which can be a huge advantage in some
situations.I probably wouldn't go out of my way to acquire
802.11 equipment, but you can still build a useful network if
it's all you have to work with. They are probably
best used for building point-to-point links, but might be better
avoided altogether. |
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