client - AP preference in 2-AP LAN

[alyarb]

I'm going to try and keep this short. Basically I have 11 ipads and one ipad 2 as my walking around clients. My LAN has two APs; one of them is a Buffalo WHR-HP-G54 running DD-WRT and the other is an Engenius EOA3630. I decided to draw the situation rather than try to explain it.

http://dl.dropbox.com/u/594924/blop.png

Because of the concrete wall and the inevitability of clients passing through the wall we have two APs on each side, which is to assume that the ipads will choose the best access point depending on where they are. What we are encountering instead is that all the clients prefer the Buffalo no matter where they are, and it is screwing up performance in some areas that would be much better served by the EOA3630. Of course when I power down the Buffalo and all the clients use the EOA3630, the opposite is true on the other side of the wall. I've tried running them on a few different channel combinations, I've tried running them on the same channel. I've tried WDS and I've tried reducing the power. If nothing else can work, the next thing I will try is a MAC filter for clients that spend more time on a particular side, but I really want to avoid that. Is there anything else you guys would try? The SSID is (must be) the same on both APs. They are both plugged into the same switch. Encryption is WPA AES with a PSK.

 

[theevilsharpie]

Two options:
1. Turn off the lower data rates advertised by the access point. As the signal becomes marginal, this will force the clients to roam to the other access point.

2. Modify the aggressiveness with which the iPads roam to new AP's. I'm not sure if this is a configurable setting.

 

[alyarb]

The DD-WRT interface in the buffalo only lets me select one rate out of many. I don't want to simply select 54 mbps because that would force anyone who can't get 54 mbps to connect to the Engenius, which isn't necessarily good. The Engenius does not have any configuration like that in its web admin.

 

[imagoon]

Client AP preference is entirely handled by the client. The only way you can "urge it to move" is shutting of the low data rates (IE 1 2 5.5 etc.) The only place I have seen anything about AP's and clients handling hand offs is the "pro" wireless cards like Intel Proset wireless etc. Their is some protocol out there that hasn't been adopted at the consumer level to force hand offs.

 

[alyarb]

Alright no biggy. MAC filter it is.

 

[wlee]

You might also try reducing the power output on one or both of the APs. That should reduce the range and allow them to more readily roam to the second AP. It's not the power level, but the signal/noise ratio that counts for connection quality/speed. Also, if you have them both running DD-WRT, you can try to shorten the beacon length to something under 100 ( but not less than 50 ) and reduce the ACK Timing to something lower than the default 2000.
Be advised, you will still not get "seamless roaming" between the 2 sides.