The purpose of this document is to give technical readers a basic overview of the new 802.11 Standard, in such a way that they will be able to understand the basic concepts, the principle of operations, and some of the reasons behind some of the features and/or components of the Standard.
Obviously the document does not cover all the Standard, and does not provide enough information for the reader to implement an 802.11 compliant device (for this purpose the reader should read the Standard
itself which is a several hundred pages document).

source : www.sss-mag.com