A Survey of Crowd Sensing Opportunistic Signals for Indoor Localization

Table 2

Comparison table of state-of-the-art solutions.

System	Signals	Frontend	Algorithm	Accuracy	Participant	Scale	Placement	Publish date
Redpin	W, B, C	MP	DA	90% CR	10	10 RMs	Free	Sept., 2008
OIL	W	MP	PA	4.5 m	19	1400 RMs	Free	June, 2010
WiFi-SLAM	W	PDA	PA	m	N/A	250–500 m	H	Jan., 2007
Zee	W	SP	PF	2.3 m (80%)	N/A	2275m^2	Free	Aug., 2012
LiFS	W	SP	DA	5.88 m	4	1600 m^2	H	Aug., 2012
MagSLAM	M	XSens	PF, SLAM	9 cm–22 cm	N/A	5 Bldgs.	Shoes	Oct., 2013
HiMLoc	W	SP	PF	<3 m	N/A	600 m^2	H/P	Oct., 2013
UnLoc	W, M	SP	DA, PDR	1.69 m	N/A	3 bldgs.	H/P	June, 2012
SmartSLAM	W, M	SP	PDR, KF, PF, SLAM	2.7 m (95%)	N/A	600 m^2	N/A	Sept., 2013
FreeLoc	W	SP	DA	<2 m (Hallway); <4 m (Lab)	15	70 points	Free	April, 2013
Elekspot	W	SP/iPod	DA, PA	91.87% CR	8	3 bldgs.	Free	July, 2012
WicLoc	W	SP	DA	4.65 m	17	1600 m^2	N/A	June, 2015

Abbreviations in the table are list as follows:
() C: Cellular network; W: Wi-Fi; B: Bluetooth; M: Magnetic field;
() MP: Mobile Phone; SP: Smartphone; PDA: Personal Digital Assistant;
() DA: Deterministic Approach; PA: Probabilistic Approaches; PF: Particle Filter; KF: Kalman Filter;
() RM: Room; Bldg: Building;
() H: Hand-held; P: Pocket.
() CR: Correct Rate.