Hi
I am using KDE 4.13 on arch linux. I have two wifi routers in my home named 'primo' and 'seco'. The router named 'seco' is closer to me so I usually connects to it but sometimes this router is turned off so I have to connect to other router named 'primo'. My question is that what setting i should use in kde network manager applet that;
1. If both routers are available to connect then laptop should connect automatically to 'seco'.
2. If 'seco' is not available then laptop should connect automatically to 'primo'.
3. If 'primo' is not available then laptop should connect automatically to 'seco'.

Regards

Afaik the network applet connects to the strongest signal automagically. I take it the network name is the same?

Yes, both routers are connected to same network. Thats not happening here and the network manager applet is connecting automatically to one network which is selected to connect automatically. If both are selected to connect automatically then it connects to 'primo' which is farther from me.

Do both routers use the same SSID, or is it different?

Both routers have different SSID. By 'name' here I mean SSID which are 'primo' and 'seco'.

I would suggest tailing the NetworkManager log, then enabling wifi on your system (using either a hardware switch or the inbuilt NM functionality) and seeing if it mentions anything about why it chooses one network over another. I suspect it is probably favouring the network it last connected to.