An indoor positioning system (IPS) uses wireless technologies like Wi-Fi to locate objects or people inside buildings, as GPS does not work well indoors. IPS relies on nearby nodes with known positions rather than satellites. Wi-Fi fingerprinting involves collecting and storing Wi-Fi signal strengths to develop location fingerprints. IPS has many potential uses including indoor navigation, location-based services, security, and analytics. Researchers are working to increase IPS accuracy by supplementing Wi-Fi with other sensor data.

1. INDOOR
POSITIONING
SYSTEM

2. CONTENTS
What is IPS?
Why not GPS?
GPS vs IPS
Choosing Wi-Fi over other sensor
techniques
Wi-Fi Fingerprinting
Uses of IPS
Conclusion

3. What is IPS?
An indoor positioning system (IPS) is a network
of devices used to wirelessly locate objects or
people inside a building.
Instead of using satellites, an IPS relies on
nearby anchors (nodes with a known position),
which either actively locate tags or provide
environmental context for devices to sense
IPS can be entirely local to your Smartphone (or
other portable navigation device). IPS, like GPS,
can establish a location fix completely
passively.

4. Why not GPS?
A satellite navigation is a system of satellites
that provide autonomous geo-spatial
positioning with global coverage may be
termed a global navigation satellite
system (GNSS or GPS).
GPS has two fundamental laws :
They don’t work indoors
They only really operate in two
dimensions
GPS are generally not suitable to establish
indoor locations, since microwaves will be
attenuated and scattered by roofs, walls and
other objects.

5. GPS vs IPS
Outdoors, navigation relies for the most part on GPS, whose accuracy ranges
from 1 to 10 meters. Indoors, because of attenuation and scattering, GPS
falls apart. And even outdoors, GPS is vertically challenged; it’s about one-
third as accurate at pinpointing your elevation as it is at telling where you are
on the ground.

6. Choosing Wi-Fi over other sensor
techniques
GPS is suitable for the outdoor navigation, as the navigable spaces are wide
enough. The accuracy positioning of GPS is between 6 and 12 meters 95%
of the time. The problem is that the reception of the GPS signals is bad in
densely build areas, including the indoor environment.
Radio Frequency Identification (RFID) makes use of tags and readers, which
allow fast read/write data communication, but there is no real localization
and positioning involved
Ultra Wide Band (UWB) offers fast, low-power and large capacity data
transfer. The advantage is that it is capable of very precise localization
(near 15 cm) but it is rather expensive
Finally, The IEEE 802.11 (Wi-Fi) technology of data exchange proves to be
the most balanced, as the signal range of around 30-40 meter indoor is
acceptable and its economic viability is stable.

7. Technique Range / accuracy Remarks
(A)GPS Accuracy: + Low barrier entry
6.0 m - 10.0 m - Slow computation and processing
time Very susceptible to reflectance
and multi-paths
GSM / UMTS Range: + Globally available
≈ 35.0 km - Cell-based accuracy
Bluetooth Range: + High speed data transfer
≈ 100 m - Positioning via triangulation (no
Accuracy:10 m – 20 objects into account),Explicit links
m between devices required
IR Range: - Short range of detection limits
0.7 m – 2.5 m infrastructure, No penetration of
materials / multipath, Line of sight,
Signal can be disturbed easily
IEEE 802.11 (Wi-Fi) Range: + Large scale available over the
≈ 32 m (indoor) world .Economical viable
≈ 95 m (outdoor) - High power consumption, Slightly
Accuracy: 1 m – 5 m multipath susceptible

8. Wi-Fi Fingerprinting
Fingerprinting is the process of position determination, using the received
signal strength at one point.
This can be stored for each point, at given heights, although in this research
only the height of about 1 metre above the floor is considered. Once
collected in a database, the application can check at which position the
receiver is, and thus position the user.

9. Uses of IPS
Navigation inside buildings, offices, industrial facilities
Location Based Services, such as sales, coupons, sweep stakes, time management
Special offers alerts
Coupons
Sweep stakes
Time management alert
Find your buddy (friends, school classes etc.)
Workforce solutions (personnel)
Security (evacuation, calamities)
Alarms and alerts (know where your colleagues are)
Alarm applications in general
Store usage analysis and store optimization
Statistics, Tracking & Tracing
Hotels
Gaming
Energy Management; climate control and lighting control system
Audio visual info (museums)

10. Conclusion
To increase the accuracy of finding your location, mapping developers
are considering methods of supplementing Wi-Fi signals. Using measured
Wi-Fi signal strengths to develop Wi-Fi fingerprints is an area that has
been receiving attention from researchers, and is certainly a valid
approach for indoor environments.
Not only will it reduce the stress of getting lost, but this technology can
also inspire other services to improve your shopping experience. For
instance, one of your favourite clothing stores at the mall can send a
coupon to your phone when you pass by their doors.
Already, indoor mapping is creating buzz as the hot technology of 2013.