802.11 differences A / B / G

[dubie]

I'm still working on my project that is due tomorrow. I need laymen terms to the differences between A, B, and G standards..

like B is better for distance than A but A is faster...

I need a resource, or just a brief descrition of a pro/con and what each is good for and who is the target audience, any help is greatly appreciated.

[Gregkor1]

802.11 operates In tHE 2.4ghz range and was the original spec of the 802.11 IEEE standard. This spec delivered 1 to 2 Mbps using a technology known as phase-shift keying(PSK) modulation. This spec is no longer used and has largely been replaced by other forms of the 802.11 standard.

802.11A
802.11a operates in the 5-6 ghz range with data rates commonly in the 6mbps, 12mbps, or 24mbps. because 802.11a uses the orthogonal frequency division multiplexing (OFDM) standard, data transfer rates can be as high as 54mbps. OFDM breeaks up fast serial information signals into several slower sub signals that are transferred at the same time via different freqeuncies, providing more resisitance to radio freq. interference. the 802.11a spec is also known as Wi-fi5, and though regionally deployed, it is NOT a global standard like 802.11b. FADING FAST. FAST SPEED BUT VERY VERY LIMITED DISTANCE. MAYBE A CONFERECE ROOM OR BOARD ROOM.

802.11b
The 802.11b standard (also know as wi-fi) operates in the 2.4 ghz range with up to 11mpbs data rantes and is backward compatible with the 802.11 standard. 802.11b uses a technology known as complementary code keying (CCK) modulation, which allows for higher data rates with less chance of multi-path propagation interference (duplicate signals bouncing off walls).
USE IT ANYWHERE. HOT SPOTS ARE ALL OVER THIS.

U.S. Robotics/D-LINK 22mbps 802.11b
REcent developments to 802.11b have seen numberous improvements to this well established and widely deployed wireless standard. New U.S. Robotics 22mbps products are designed to support packet binary convolutional coding (PBCC) in addition to cck modulation. This not only increases performance but also maintains complete 802.11b compatibility with both the 11mbps and 22mbps products. the overall benefits include:

-Up to twice the data rate of conventional 111 mbps standard products

-Greater WLAN coverage up to 70%

-Full interoperability with all 802.11b products and upcoming G products.

-improved security over standard 802.11b products. 256-bit WEP encryption and MAC filtering.

802.11g
is the most recent IEE 802.11 DRAFT standard and operates in the 2.4 ghz range with data rates as high as 54mbps over a limited distance. It is also backwards compatible with 802.11b and will work with both 11 and 22mbps products. 802.11g offers the best features of both 802.11a and b. THIS STANDARD HAS NOT BEEN CERTIFIED!!! THERE HAVE BEEN MANY REPORTED ISSUES WITH IT SO I WOULD STAY AWAY FROM IT TILL IT IS RATIFIED.

HOW IS THAT FOR YOUR ANSWER BUD?

[dubie]

Thanks! :)

:D

[jangeunjun]

Hi Dubie,
Although it's past your homework deadline and your question was answered by Gregkor1, let me add an interesting thing that might do good to others.
As for the data rate difference among 802.11, 802.11a and 802.11b, there is an online calculator that provides an instant prediction of theoretical maximum bandwidth given all the parameters you choose to use. For example, if you choose 802.11b and RTS/CTS as the MAC scheme and DSSS for the physical layer, the maximum bandwidth you will have is around 4.5Mbps. I hope you will get some comparison of the real data rates (not the advertised data rate) using this calculation. Unfortunately, it does not support 802.11g, because the standard is not approved, yet.
The url is:
http://www4.ncsu.edu/~jjun/tmtcal.htm
If you are looking for the background theory for the calculation, it is available at:
http://www4.ncsu.edu/~jjun/research.htm
All the best,
-JJ

[dubie]

Thanks much!

dubie

[Gregkor1]

That is a great point. but even so, the higher the advertised rates the higher the real throughput is anyways....i thought that was too much detail for a starter.