How RTLS Works

Learn how different Real-Time Location Systems (RTLS) work including Ubisense Dimension4 Ultra-Wideband (UWB).

Locating with Radio Frequency (RF) Signals

Radio-frequency (RF) systems calculate location using either the distance of a transmitter relative to a receiver, or the angle (direction) of a transmitter relative to a receiver.  Measurements from multiple receivers are cross-referenced to determine location.

How Distance is Measured

There are different ways of determining the distance of a transmitter relative to a receiver using attributes of the RF signal.

How Angles are Measured

The angle at which the RF signal arrives at the receiver from the transmitter can be measured in single or multiple dimensions.

Challenges of locating indoors

Only direct path signals between transmitter and receiver give a reliable basis of measurement.  With conventional RF, reflections of the signal in indoor environments distort the direct path signal.  When direct path and reflected signals overlap it makes interpreting accurate location difficult.

Locating indoors with Ultra-Wideband (UWB)

With Ultra-Wideband (UWB), signal pulses are much shorter and use a wider frequency bandwidth. The shorter UWB pulses don’t overlap with reflected signals, which means the direct path signal is more easily distinguished from reflections, making interpreting accurate location easier.

Not all Ultra-Wideband (UWB) systems are the same

Ubisense Dimension4 UWB is unique in measuring both 2-axis Angle-of-Arrival (AoA) AND Time-Difference-of-Arrival (TDoA) in the same system for superior performance, accuracy and reliability.

Ubisense Dimension4 UWB

Significantly more location measurements than any other UWB RTLS

  • More accurate and precise location data with unrivaled confidence
  • Fewer sensors required for 3D locations than comparable systems

Tag transmitters do not require 2-way measurements

  • Very long tag battery life up to 15 years
  • High quantities of tags can be used without interference

Sophisticated sensor design with edge data processing

  • Capable of scaling to 1000’s of tags with 1000’s of updates per second
  • Real systems deployed with over 2000 sensors operating 24/7
Ubisense Logo

How can we help
transform your business?

Get in touch to discuss how Ubisense SmartSpace and Dimension4 can make your business more productive, flexible, profitable and safe.


Ubisense Limited
St Andrew’s House
St Andrew’s Road
Cambridge, CB4 1DL
United Kingdom

+44 1223 53 5170


Ubisense America LLC
1630 Welton Street, Suite 1000E
Denver, CO 80202
United States

+1 720 549 7553


Ubisense GmbH
Klaus-Bungert-Straße 5B
40468 Düsseldorf

+49 211 2297330

Ubisense SAS
52 Boulevard De Sébastopol
75003 Paris

+33 1 83 79 06 82


Ubisense Japan
Rakuten Crimson House
1-14-1 Tamagawa
Setagaya City Tokyo
158-0094 Japan

+81 3 4577 8372