<s>
An	O
indoor	B-Device
positioning	I-Device
system	I-Device
(	O
IPS	O
)	O
is	O
a	O
network	O
of	O
devices	O
used	O
to	O
locate	O
people	O
or	O
objects	O
where	O
GPS	O
and	O
other	O
satellite	O
technologies	O
lack	O
precision	O
or	O
fail	O
entirely	O
,	O
such	O
as	O
inside	O
multistory	O
buildings	O
,	O
airports	O
,	O
alleys	O
,	O
parking	O
garages	O
,	O
and	O
underground	O
locations	O
.	O
</s>
<s>
A	O
large	O
variety	O
of	O
techniques	O
and	O
devices	O
are	O
used	O
to	O
provide	O
indoor	B-Device
positioning	I-Device
ranging	O
from	O
reconfigured	O
devices	O
already	O
deployed	O
such	O
as	O
smartphones	O
,	O
WiFi	O
and	O
Bluetooth	B-Protocol
antennas	O
,	O
digital	O
cameras	O
,	O
and	O
clocks	O
;	O
to	O
purpose	O
built	O
installations	O
with	O
relays	O
and	O
beacons	O
strategically	O
placed	O
throughout	O
a	O
defined	O
space	O
.	O
</s>
<s>
WiFi	O
/	O
LiFi	O
access	O
points	O
,	O
Bluetooth	B-General_Concept
beacons	I-General_Concept
or	O
Ultra-Wideband	O
beacons	O
)	O
,	O
magnetic	O
positioning	O
,	O
dead	O
reckoning	O
.	O
</s>
<s>
Promising	O
direction	O
radio	O
frequency	O
positioning	O
error	O
correction	O
opened	O
by	O
the	O
use	O
of	O
alternative	O
sources	O
of	O
navigational	O
information	O
,	O
such	O
as	O
inertial	O
measurement	O
unit	O
(	O
IMU	O
)	O
,	O
monocular	O
camera	O
Simultaneous	B-Application
localization	I-Application
and	I-Application
mapping	I-Application
(	O
SLAM	O
)	O
and	O
WiFi	O
SLAM	O
.	O
</s>
<s>
Global	O
Positioning	O
System	O
(	O
GPS	O
)	O
and	O
other	O
similar	O
Global	O
navigation	O
satellite	O
systems	O
(	O
GNSS	O
)	O
are	O
generally	O
not	O
suitable	O
to	O
establish	O
indoor	B-Device
locations	I-Device
,	O
since	O
microwaves	O
will	O
be	O
attenuated	O
and	O
scattered	O
by	O
roofs	O
,	O
walls	O
and	O
other	O
objects	O
.	O
</s>
<s>
However	O
,	O
in	O
order	O
to	O
make	O
the	O
positioning	O
signals	O
become	O
ubiquitous	O
,	O
integration	O
between	O
GPS	O
and	O
indoor	B-Device
positioning	I-Device
can	O
be	O
made	O
.	O
</s>
<s>
Many	O
different	O
systems	O
take	O
advantage	O
of	O
existing	O
wireless	O
infrastructure	O
for	O
indoor	B-Device
positioning	I-Device
.	O
</s>
<s>
The	O
localization	O
technique	O
used	O
for	O
positioning	O
with	O
wireless	B-Device
access	I-Device
points	I-Device
is	O
based	O
on	O
measuring	O
the	O
intensity	O
of	O
the	O
received	O
signal	O
(	O
received	O
signal	O
strength	O
in	O
English	O
RSS	O
)	O
and	O
the	O
method	O
of	O
"	O
fingerprinting	O
"	O
.	O
</s>
<s>
To	O
increase	O
the	O
accuracy	O
of	O
fingerprinting	O
methods	O
,	O
statistical	O
post-processing	O
techniques	O
(	O
like	O
Gaussian	B-General_Concept
process	I-General_Concept
theory	O
)	O
can	O
be	O
applied	O
,	O
to	O
transform	O
discrete	O
set	O
of	O
"	O
fingerprints	O
"	O
to	O
a	O
continuous	O
distribution	O
of	O
RSSI	O
of	O
each	O
access	B-Device
point	I-Device
over	O
entire	O
location	O
.	O
</s>
<s>
Typical	O
parameters	O
useful	O
to	O
geolocate	O
the	O
Wi-Fi	B-Application
hotspot	I-Application
or	O
wireless	B-Device
access	I-Device
point	I-Device
include	O
the	O
SSID	O
and	O
the	O
MAC	O
address	O
of	O
the	O
access	B-Device
point	I-Device
.	O
</s>
<s>
Originally	O
,	O
Bluetooth	B-Protocol
was	O
concerned	O
about	O
proximity	O
,	O
not	O
about	O
exact	O
location	O
.	O
</s>
<s>
Bluetooth	B-Protocol
was	O
not	O
intended	O
to	O
offer	O
a	O
pinned	O
location	O
like	O
GPS	O
,	O
however	O
is	O
known	O
as	O
a	O
geo-fence	O
or	O
micro-fence	O
solution	O
which	O
makes	O
it	O
an	O
indoor	O
proximity	O
solution	O
,	O
not	O
an	O
indoor	B-Device
positioning	I-Device
solution	O
.	O
</s>
<s>
Micromapping	O
and	O
indoor	O
mapping	O
has	O
been	O
linked	O
to	O
Bluetooth	B-Protocol
and	O
to	O
the	O
Bluetooth	B-General_Concept
LE	I-General_Concept
based	O
iBeacon	B-General_Concept
promoted	O
by	O
Apple	O
Inc	O
.	O
</s>
<s>
Large-scale	O
indoor	B-Device
positioning	I-Device
system	I-Device
based	O
on	O
iBeacons	B-General_Concept
has	O
been	O
implemented	O
and	O
applied	O
in	O
practice	O
.	O
</s>
<s>
Bluetooth	B-Protocol
speaker	O
position	O
and	O
home	O
networks	O
can	O
be	O
used	O
for	O
broad	O
reference	O
.	O
</s>
<s>
This	O
is	O
usually	O
the	O
case	O
with	O
passive	O
radio-frequency	B-Application
identification	I-Application
(	O
RFID	B-Application
)	O
/	O
NFC	O
systems	O
,	O
which	O
do	O
not	O
report	O
the	O
signal	O
strengths	O
and	O
various	O
distances	O
of	O
single	O
tags	O
or	O
of	O
a	O
bulk	O
of	O
tags	O
and	O
do	O
not	O
renew	O
any	O
before	O
known	O
location	O
coordinates	O
of	O
the	O
sensor	O
or	O
current	O
location	O
of	O
any	O
tags	O
.	O
</s>
<s>
Angle	B-Algorithm
of	I-Algorithm
arrival	I-Algorithm
(	O
AoA	O
)	O
is	O
the	O
angle	O
from	O
which	O
a	O
signal	O
arrives	O
at	O
a	O
receiver	O
.	O
</s>
<s>
AoA	O
is	O
usually	O
used	O
with	O
triangulation	B-Algorithm
and	O
a	O
known	O
base	O
line	O
to	O
find	O
the	O
location	O
relative	O
to	O
two	O
anchor	O
transmitters	O
.	O
</s>
<s>
Indeed	O
,	O
instead	O
of	O
requiring	O
multiple	O
access	O
points	O
and	O
techniques	O
such	O
as	O
triangulation	B-Algorithm
and	O
trilateration	O
,	O
a	O
single	O
access	B-Device
point	I-Device
will	O
be	O
able	O
to	O
locate	O
a	O
user	O
with	O
combined	O
angles	O
and	O
times	O
of	O
arrival	O
.	O
</s>
<s>
MALLY	O
by	O
Geniusmatcher	O
is	O
a	O
hardware-free	O
solution	O
in	O
any	O
indoor	B-Device
location	I-Device
.	O
</s>
<s>
Un-optimized	O
compass	O
chips	O
inside	O
smartphones	O
can	O
sense	O
and	O
record	O
these	O
magnetic	O
variations	O
to	O
map	O
indoor	B-Device
locations	I-Device
.	O
</s>
<s>
Note	O
that	O
this	O
can	O
be	O
a	O
special	O
case	O
of	O
sensor	B-General_Concept
fusion	I-General_Concept
where	O
a	O
camera	O
plays	O
the	O
role	O
of	O
yet	O
another	O
sensor	O
.	O
</s>
<s>
One	O
way	O
to	O
determine	O
position	O
is	O
to	O
match	O
the	O
data	O
from	O
the	O
unknown	O
location	O
with	O
a	O
large	O
set	O
of	O
known	O
locations	O
using	O
an	O
algorithm	O
such	O
as	O
k-nearest	B-General_Concept
neighbor	I-General_Concept
.	O
</s>
<s>
Sequential	B-Algorithm
Monte	I-Algorithm
Carlo	I-Algorithm
method	I-Algorithm
(	O
for	O
approximating	O
the	O
Bayesian	O
statistical	O
models	O
)	O
.	O
</s>
<s>
The	O
major	O
consumer	O
benefit	O
of	O
indoor	B-Device
positioning	I-Device
is	O
the	O
expansion	O
of	O
location-aware	O
mobile	O
computing	O
indoors	O
.	O
</s>
<s>
Applications	O
benefiting	O
from	O
indoor	B-Device
location	I-Device
include	O
:	O
</s>
