Wireless users staying on original AP even though SNR is better on closer AP

[Dave Clark_3]

I have a MSM765 with 2 MSM430 AP's. Flat network, all vlan 1. When a client connects to one AP it will stay on that AP and not roam to a closer one with a better SNR. How can you get the MSM to move the client to the better AP?

[Z273]

Hi,

Can you be more specific when you said "SNR better",  can you give the SNR numbers?  The txpower, the channel used on both APs.

Also it is not the AP whom initiates the connection, it is the client device that make that decision.

Under Windows, in Wifi adapter->Advance config there is a setting for Roaming Aggressiveness, you might want to change that setting.  Most clients devices drivers vendor do not disclose what the level means, e.g. Intel has 5 levels where 1 is lowest to 5 most aggressive.

My guess is they are related to SNR too.

From my own experience, the client driver starts to roam when they start to "miss seeing beacon" from the AP, since beacon are tx at lowest rate, you have to be pretty far from the AP to get such low SNR that cause the client to no longer see the AP, in the mean time the client still sticks to the AP.

Another event that cause the client to start roaming is the wifi connection starts to be bad, like lots of retries, bad frames errors, or the client use low data rate to communicate with the AP.

If the client wifi rates are still OK to-from the AP (you can look at this in the client data rates on the MSM AP or MSM controller), if the rates are good then there is no need to roam.

So the wifi has to be pretty bad before the client decides to roam.

MSM engineer.