Who knows, it isn't a standardized value, each chipset maker has their own range.
Compare something that is standardized like dBm if you want to know an absolute good or bad, or compare the rssi among networks using something like inSSIDer, higher would be better in a heads up comparison in terms of the signal strength.
Hello,
what does it mean , is it good or bad result
Actually, the signal strength is stronger the closer it gets to 0 dBm. This is because it is measuring the change in signal from when it is emitted from the base station to when it reaches the client. So if the signal strength is -48 dBm, this means that it is 48 dBm less powerful when it reaches your laptop than when it left the base station. If you want you can download wireless scanning software to see if people in your street are on the same channel as you. If there is then this can weaken the signal strength, change to a different channel your manual or service provider website should tell you how to do this. You can also see what speeds they are getting. I use inSSIDer 2.1 its free and legal.
I range from -40 to -49 my neighbours -80 up so i'd say your dbm wasn't to bad.