Re: location acquiring approaches of zigbee/wlan and bluetoo
I think it refers to the sort of technology used by baby locators.
Zigbee and bluetooth devices have a Received Signal Strength Indicator ( RSSI ) pin.
You can use a motor powered antenna and monitor the RSSI pin as the antenna rotates to find the location of a transmitting device. This is similar to the way baby locators work. From what I can gather this approach on it's own is unreliable at best.
A more reliable approach is using triangulation, but for that approach to work you need a minimun of 3 stationed transmitters on known locations, then a receiver device can listen to all the transmitters and use triangulation to calculate it's location based on the strength of the signals coming from different locations This is how GPS works.