Checking the Signal Strength
When the Wi-Fi interface is in the associated state (wln.associationstate= 1- PL_WLN_ASSOCIATED), wln.rssi read-only property is constantly updated with the strength of the signal coming from the access point. When the Wi-Fi interface is running its own network (wln.associationstate= 2- PL_WLN_OWN_NETWORK), wln.rssi is updated with the strength of the signal coming from wireless stations (if any stations are currently associated with your device).
The signal strength is expressed in 256 arbitrary levels that do not correspond to any standard measurement unit.
Do not confuse this with the wln.scanresultrssi property, which returns the signal strength of a network detected during scanning.