THE idea of wirelessly connecting machines together has been out there since the inception of networking, but it wasn’t till 1997 that the first wireless networking standard – simply called 802.11 – was introduced.
The body tasked with coming out with the standard, the IEEE 802 committee, chose the term “802” because all other local area network (LAN) standards had numbers like 802.1, 802.2, and 802.3 up to 802.10.
Therefore, it was only logical that the wireless LAN standard be an extension of that, and so “802.11” was chosen.
The first iteration (802.11) only operated with a data throughput of up to 2Mbps and allowed two different methods of encoding, namely FHSS (Frequency Hopping Spread Spectrum) and DSSS (Direct Sequence Spread Spectrum).
The problem was that the two modes of encoding were totally incompatible with one another, causing quite a bit of confusion when it came to hardware.
Because of this relatively low throughput speed and the hardware confusion, the IEEE 802 committee approved a new standard called 802.11b.
The 802.11b standard was approved in September 1999 by the IEEE 802 committee and it was decided that DSSS would be the standard encoding method.
With more efficient encoding techniques, the throughput of the 802.11b standard allowed for a much better 5.5Mbps, with a maximum of 11Mbps.
802.11 in general works in two modes, either infrastructure or ad hoc.
Infrastructure is where a WiFi card connects to a wireless “infrastructure,” which usually means a network of PCs connected via a wireless access point, thus providing the convenience of file sharing and Internet access. This method allows a user to roam from access point to access point almost seamlessly.
Ad hoc is a mode which allows individual machines (or “nodes”) to connect peer-to-peer without the need for an access point.
Currently in the process of approval is the 802.11g standard, which is the next generation of 802.11. This standard allows a higher data throughput rate of 54Mbps while still being backwards-compatible with 802.11b equipment (though with 802.11b equipment, the data speed will only be 11Mbps).
For a standards body, the IEEE 802 committee has a rather strange habit of approving more than one wireless standard, thus causing even more confusion.
What we’re talking about here is 802.11a, which is yet another specification for 54Mbps wireless networking.
The main difference between 802.11a and 802.11g is that 802.11g works in the 2.4GHz band and thus is interoperable with 802.11b equipment.
802.11a on the other hand, works in the 5GHz and 6GHz band, and is totally incompatible with 802.11b and g.
Hardware supporting 802.11a and 802.11g are already out in the market right now, although the 802.11g standard has not been finalised yet.
In Malaysia though, 802.11a and 802.11b equipment will likely take a bit longer to make an appearance since it will take some time before type approval is received.
Here are a few facts about 802.11b which you may find useful:
a. The further you go from the WiFi access point, the slower your throughput becomes. As you go further, your WiFi card will automatically drop in speed from 11Mbps to 5.5Mbps, then 2Mbps and finally to just 1Mbps. You’ll probably notice a difference if you are copying files from another machine, but probably not when it comes to Internet access, because the fastest T1 Internet access line moves at just 1.544Mbps.
b. Still on the subject of speed, while it is true that WiFi can achieve a theoretical limit of 11Mbps, most of time, WiFi access points only have a 10base-T Ethernet connection (the “wired” part of the network), which means the theoretical maximum is just 10Mbps.
c. WiFi cards that you use in your laptop or PC usually only have one radio in them, which means that only half duplex communications is possible -– i.e. your machine can only talk or listen, but not do both at the same time.
Because of all the factors above, the most you’ll probably be able to squeeze though the WiFi connection is about 8Mbps in the best of conditions.
To get the best signal strength out of your WiFi card, consider that generally, a WiFi access point antenna sends signals out in roughly a horizontal circle, with the hub of the circle being the antenna.
The worst possible place to put your WiFi access point is on your roof, especially if you are going to be right under the antenna, where sensitivity is at its lowest.
With WiFi PC Cards plugged into a notebook PC, the design is unfortunately such that the pattern is just the opposite – a vertically aligned circle, with your sensitivity being up and down instead.
Therefore, if you’re really obsessive compulsive about getting the best possible signal, you’ll probably have to tilt your notebook PC on its side and learn how to type sideways! :-p
These days, however, several PC manufacturers like IBM, Apple and Hewlett-Packard, which have WiFi built into their notebook computers, have integrated an antenna that runs up the side of the LCD panel, thus putting the antenna in the best possible position for maximum range. – TAN KIT HOONG (Blatantly plagiarized from inTech)
https://drsjmc.tripod.com/index.htm
Created:- 23 Mar 2003
Last Updated:- 23 Mar 2003
Author:-tkh