android - Calculating signal strength from wifi on my android device

Question

WifiManager wifi = = (WifiManager) uMobility.getContext().getSystemService(Context.WIFI_SERVICE); 
int rssi = wifi.getConnectionInfo().getRssi(); // for geting RSSI

I want to collect signal strength of the wifi in dbm on my android device. Then i need to pass this value in Java server.

I searched for all the codes on google I came across this. The last line gives me the rssi values.

I am new to android. Could anyone help me but how can I get from which router i am accessing ? What would be the code for that ? WHere should I write the mac address from which it should access ?

Thanks