Global Positioning System Reference
In-Depth Information
Cellular Systems
Cell ID
Simple course positioning method
using identity of cellular radio base
station.
Internal parameter used to align
frame timing, which gives
approximate range between base
station and mobile.
Centralized measurement of
distance using signal timing from a
mobile to at least three base
stations.
(Cellular Identity)
GSM Localization:
TA (Timing Advance)
Time Difference Of
Arrival (TDOA)
Enhanced Observed
Time Difference
(EOTD)
Similar to TDOA but with
measurements performed locally at
mobile ( >50m accuracy).
Fourth Generation
Mobile (4G)
Cellular Radar
Experimental.
Hotspots or Picocells
WiFi
(e.g., Ekahau)
By simple proximity (~100m
accuracy).
By timing (under development)
Highly accurate indoor system
(<10cm in three dimensions).
Ultrawideband (UWB)
(e.g., Ubisense)
Sensor Systems
Active RFID
(Radio Frequency
Identification)
Scene Analysis
Battery-powered transponder
(range <100m) positioning by
simple proximity.
Using cameras to recognize and
position objects such as vehicle
number plates (range depends on
lighting and optics).
Wireless Sensor
networks (e.g., ZigBee
[IEEE 802.15.4])
Used for control of buildings and
environments. Positioning by
simple proximity (<100m
accuracy).
Experimental. Furniture and
artifacts with embedded sensing
and wireless (radio and infrared
optical) widely deployed.
Positioning by proximity (accuracy
10s m). Ad hoc approach to
positioning possible. Includes use
of inertial/mechanical sensing.
Very accurate indoor positioning
from transponders but clear line of
sight needed (accuracy <10cm).
“Internet of Things”
Ultrasonics
