Virtual WiFi on Linux?

[Jean Tourrilhes]

On Tue, Oct 18, 2005 at 10:00:10AM -0600, Alejandro Bonilla Beeche wrote:
> Hi Jean,
> 
> 	Did you know about this? Could the wireless-tools support this or is
> just some weird Microsoft feature?
> 
> 
> http://research.microsoft.com/netres/projects/virtualwifi/software.htm
> 
> 
> .Alejandro
> -- 
> UNIX is user friendly, it's just picky about who its friends are 

	I was talking with some HP product people about that a couple
of years ago (for an application they don't discuss here
actually). Basically, you connect to multiple network at once. Of
course, because you have only a single transmitter/receiver in your
hardware, what you really do is time slotted hopping, you periodically
hop between each AP.
	To implement this on Linux, the Wireless Tools would be the
least of your problems. What you would need to do is to extend IP
aliasing. You create multiple virtual interfaces on top of your real
interface (wlan0:0, wlan0:1, wlan0:2). You assign each of this virtual
interface an ESSID (using regular Wireless Tools). Somehow, you need
to put an AP scheduler between the virtual interfaces and the real
interface, the scheduler can control the real interface using regular
Wireless Tools, it check how much traffic there is on each virtual
interface to decide how long to spend with each AP. Obviously, if you
want the performance to not suck, you need fast AP switching
(currently available only with HostAP, doable with any card using the
kernel ieee stack).
	That would be a nice project, however you have to ask yourself
if it is worth the effort (the example they present are far from
compelling). I believe they might be some interesting applications of
that along the line of Connection Diversity, but they are a few years
down the line.

	Good luck...

	Jean