Roaming wifi

[Casey Halverson]

Its really too bad that there are no wifi chipsets with a second radio -- even if it was receive-only for channel scanning.  This would avoid the interface going into a blocking state while it scanned for access points near by, and improve overall performance.  This is especially important as we move into complex things like VoIP over WiFi.

To answer your question, yes, this can be done, with some extensive software trickery.  Your best friend will be interface metrics.  Interface metrics can be adjusted, as you can assign a cost to each one.  The interface with the lowest cost is used as the active interface.  Even windows has this functionality.

Whether you can modify these interface metrics fast enough to make any difference compared to traditional roaming techniques is anyone's guess.  But why are you worried about losing data during a handoff?  Even if there was packet loss, the higher layer protocols have ways to correct this.  



> -----Original Message-----
> From: dev-bounces at seattlewireless.net 
> [mailto:dev-bounces at seattlewireless.net] On Behalf Of Jesús Rodríguez
> Sent: Saturday, September 24, 2005 11:42 AM
> To: dev at seattlewireless.net
> Subject: Roaming wifi
> 
> Hello all,
> 
> I'm thinkin' about be connected while i'm driving. I don't 
> know if anyone has developed software to control 2 wifi cards 
> like one virtual interface. If we can establish 2 connections 
> (active and secondary), we can change between APs without 
> lose data. The software may control the diferent APs in the 
> "active" zone and select the best like active and another 
> like secondary. While we're moving, the software may can 
> detect signal changes from the APs and change the status of 
> the connections (change secondary to active, or connect to 
> another AP without loss connection).
> 
> Is that possible?
> 
> Thanks
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