What is the unit for RSSI? is it dbm? if not, how to convert it to dbm?

What is the unit for RSSI? is it dbm? if not, how to convert it to dbm?

The older chipsets used RSSI from 0 to 256. The newer chipsets use 0
to 100. The 0 to 100 flavour is what is commonly used to display
"percent signal strength". The conversion between RSSI and dBm is
non-linear. See the graph in the following paper:

Converting Signal Strength Percentage to dBm Values



http://www.wildpackets.com/element [...] rength.pdf
http://www.wildpackets.com/elements/whitepapers/Converting_Signal_Strength.pdf

Thanks to :
http://www.tomshardware.com/forum/9692-43-rssi-received-signal-strength-indication