Wireless Extensions

Hi!

I need to add Wireless LAN functionality to an embedded Linux environment,
so obviously I've been looking at the "Wireless Extensions" Linux kernel
extension. First of all, I need to write a driver to interface between the
"Wireless Extensions" and the actual hardware since such a driver does not
exist.

My question is, apart from a standardized API what functionality does the
"Wireless Extensions" actually provide? For instance, when a mobile WLAN
Station (STA) moves from one Access Point (AP) to another, it needs to do a
so-called re-association. Where is such a re-association request initiated?
In the driver, the Wireless Extensions, or in some upper application?

I've read all the documentation as well as browsed most of the source code
for the "Wireless Extensions" without being able to determine where such
management functionality is performed, i.e. where do I specify when to
associate/re-associate to which AP, when scan for other APs, etc.?

Also, does the "Wireless Extensions" implement LLC functionality, i.e.
handling the data channel herunder sending data to the TCP/IP stack?

If this functionality is not included in "Wireless Extensions" (I can't find
it there!), does this then mean that each Wireless LAN provider have
implemented their own management entity to handle the above-mentioned tasks
in some custom way?

Best Regards,
Thomas Hjort