Wi-Fi and RFID Convergence

Another trend emerge - the convergence of active RFID and
Wi-Fi.Active RFID involves tags with an
energy source that emit a signal to readers some distance away.It's
provides almost precise
location of tags by coordinates ,designed for use in-inside
neighboring open spaces,as parking lots or courtyards.

http://flying-rugs.com/wi-fi-and-rfid/