\subsection{\docWIFI}

	absolute positioning using wifi (x,y,z)
	no fingerprinting
	uses signal-strength prediction model
	position of access points must be known beforehand
	only 2 parameters for all APs
	only vague position estimation
	
\subsection{\docIBeacon{}s}

	optional
	same as wifi
	but only one param: as txp is broadcasted