Real-time location services

Jump to: navigation, search

Real Time Locating Systems (RTLS), also misspelled real time location systems, sometimes named local positioning systems, are electronic systems that are intended to locate people or things by means of small electronic devices carried on these items or persons at any time. None are perfect in this respect but to qualify for the term, they must give real time identity and location most of the time, or when interrogated. Systems without identity report are useless but for the bearer, as they do not discriminate individuals in a pool of objects.

RTLS in the sense of ISO 19762-5 and ISO 24730-1 are widely spread as satellite navoigation systems and offsprings in the type of satellite locating systems. A rapid increase in the market is expected for those applications, where

  • line-of-sight conditions to receive satellite signals are poor
  • motion conditions advertise for faster system response

For such requirements the terrestrial locating with anchor node transmitters in known positions is the first choice.

In general the main applications of RTLS are in manufacturing, military, healthcare, postal/courier, research and development but with increased interest from most other sectors including retail and agricultural. There are many situations calling for RTLS, particularly now that it has become affordable and the mobile devices that are sensed have, in many cases, become small and convenient.

These system can display the location of assets, wireless devices, laptops, PDAs or indeed any item carrying an RFID tag or Wi-Fi tag, on screen, and graphically in real-time. However, RFID tagging alone does not provide any locating.

Real-time Location Systems are highly relevant to healthcare, manufacturing and other industries, where new applications can be almost instantly enabled, and the return on investment can be high. For example, Wayne Memorial hospital has saved $300,000 by tracking for infusion pumps with RFID technology that can piggyback on the Wi-Fi system already in place [1].

Third-party software, and sometime hardware, are usually needed, examples of which include the Cisco 2700 Wireless Location Appliance, the Ekahau Positioning Engine (EPE), and Nanotron's nanoLOC. These systems may also be integrated with other IT systems to provide tracking and logging of movements, from which high-level business management information can be obtained.

The location software calculates the location of tracked devices using techniques such as RF fingerprinting, which uses assesses RF characteristics such as reflection, attenuation, and multi-path, along with the signal strength readings of wireless devices calibrated RF environments.

To understand how RF (radio waves) interact with an a particular environment, including building materials, walls, doors and furniture, an RF calibration is required to determine the characteristics of the RF environment.

See also


  1. Making Business Sense of Real Time Location Systems (RTLS), RFID Radio