Post by fred_eg_bowinatuckPost by Brian McIlwrath5GHz band (802.11a) and
such equipment is widely available! (but not as common as 2.4GHz).
I wonder why it is not as common!
http://www.networkcomputing.com/1201/1201ws1.html
The website at
http://www.wi-fiplanet.com/tutorials/article.php/1009431 provides
useful information about the differences between 802.11a, 802.11b and
802.11g.
This situation is not dissimilar to the battle for supremacy that
existed 20 years ago between Betamax and VHS video recorders. The
Sony Betamax system was reputed to be technically superior. However,
major retailers in the UK (who had links with JVC) promoted the VHS
standard and marketed a wide range of pre-recorded tapes. Market
forces restricted the availability of Betamax pre-recorded tapes. The
VHS and Betamax systems were not compatible and eventually, Betamax
died out in the UK.
A wireless LAN that operates under the 802.11a standard uses the 5GHz
frequency band, with twelve separate non-overlapping channels. As a
result, RF interference is much less likely because of the
less-crowded 5 GHz band. 802.11a can support data transmission rates
of up to 54 Mbps and in some respects, it appears to be technically
superior to the competing 802.11b and 802.11g standards.
However virtually all public Wi-fi hotspots operate under the 802.11b
standard (max speed 11 Mbps). A few hotspots operate under the later
802.11g derivative (max speed 54 Mbps). Consequently, the 802.11a
standard has become less common, because it is not compatible with
public Wi-Fi hotspots.
The 802.11b and 802.11g standards both operate within the 2.4 GHz
band. This avoids compatibility issues between b and g. A computer
with a 802.11g wireless LAN card, can use hotspots that operates under
either b or g - but will only achieve the fastest data transmission
speed, if the hotspot has also adopted 802.11g. Similarly, a laptop
with a 802.11b wireless LAN card can use a hotspot that operates under
either b or g - subject to the maximum data transmission speed of 11
Mbps for the 802.11b standard.
Most laptop computers with Wi-Fi capability have a wireless LAN card
that uses the 802.11b or 802.11g standard. A laptop computer with a
802.11a card would be unable to connect to public Wi-Fi hotspots. It
follows 802.11b or 802.11g seem destined to become de facto standards
in most environments.
bob at lucas99 dot freeserve dot co dot uk