WLAN-based location

from Wikipedia, the free encyclopedia
An iPhone near the Brandenburg Gate determining its location using WLAN (red) and GSM radio cells (blue) ( Assisted Global Positioning System )

WLAN-based location is a method of location . It works in a similar way to multilateration with GPS positioning and differently from GSM positioning and calculates the position based on WLAN propagation patterns.

Basics

In metropolitan areas in particular, you usually receive numerous WLAN signals in an individual, location-dependent combination. These signals come from commercial hotspots , company networks or private home networks. Knowing the location of these networks ( routers ) allows you to calculate your own location. The more network signals are received, the more accurately the location can be calculated. In contrast to GPS , WLAN-based positioning also works inside buildings. A prominent example is the iPhone , which uses technology from Skyhook Wireless . In the meantime, there are also free alternatives such as the OpenWLANMap and Mozilla Location Service.

accuracy

There is no general specification of an achievable measurement accuracy . Under (never attainable) ideal conditions, a location accurate to 0.5 m would be possible. None of the equipment suppliers specify the accuracy of their solutions. Even with topological reference measurements, no reliably valid accuracies can be achieved. The cause is the high attenuation by water molecules in the frequency range used around 2.45 GHz and the diverse reflection in closed rooms.

At the 13th USENIX symposium in April 2016, MIT presented the “Chronos” technology , according to which an accuracy in the decimeter range should be possible using a single WLAN hotspot.

Procedure for collecting data

The automatic recording takes place without the consent of the respective operator. WLAN data and their positions from mostly wardriving tools are uploaded to the project pages. Some systems offer their own apps for this. Google Street View Cars collected WiFi data from 2007-2010.

application areas

WLAN-based positioning enables the provision of location-based services for all WLAN-enabled end devices ( notebook , smartphone , modern cell phones, PDAs, etc.) independently of GSM or GPS. In addition, it allows workflows to be optimized by allowing employees and work materials with WiFi tags to be located. The Museum of Industrial Culture (Nuremberg) is the first museum in the world to use a guidance system which, in addition to the navigation function, offers special services and didactics with the help of WLAN-based location.

Lists of located WLAN access points

There are several databases that link WiFi signal information with geographic location:

Surname Unique Wi-Fi networks Observations Free data download Project active? SSID lookup BSSID lookup Data license Opt out annotation
Combain Positioning Service > 602,000,000 > 9,446,000,000 No Yes Yes Yes Proprietary respects _nomap Cell ID database as well.
Geomena 55.013 Yes No Yes Yes CC-BY-SA No editable wiki
LocationAPI.org by Unwired Labs > 709.510.000 > 4,100,000,000 No Yes Yes Yes Proprietary respects _nomap Cell ID database as well.
Mozilla Location Service 272,402,231 > 4,519,830,000 No Yes No No Proprietary respects _nomap and hidden SSID With cell ID database in the public domain .
Navizon 480,000,000 21,500,000,000 No Yes No Yes Proprietary No Based on data via crowdsourcing . Cell ID database as well.
radiocells.org 7,532,779 Yes Yes No Yes ODbL Cell ID database as well.
OpenWLANMap 22,010,794 Yes No No Yes GFDL On demand Enabled manual entry of the access point operator.
WiGLE 563.029.680 8,071,196,633 No Yes Yes Yes Proprietary On demand Cell ID database as well.
Skyhook Wireless No Yes Proprietary
Google No Yes Data collection by Street-View vehicles and google services

Comment on the "Opt-out" column: Some location mapping services promise not to include WLANs and their location data in their databases or to delete them from their databases if their network name ( SSID ) ends with the string "_nomap".

Web links

Individual evidence

  1. ↑ Deepak Vasisht (MIT CSAIL), Swarun Kumar (Carnegie Mellon University), Dina Katabi (MIT CSAIL): Decimeter-Level Localization with a Single WiFi Access Point (pdf, 846kB), accessed on April 20, 2016
  2. ↑ Jemima Kiss: Google admits collecting Wi-Fi data through Street View cars . In: The Guardian . May 15, 2010, ISSN  0261-3077 (English, theguardian.com [accessed January 17, 2020]).
  3. ↑ Combain Positioning Service . Retrieved January 3, 2015.
  4. ↑ Wifi Positioning | Wifi Location | Cell ID - Combain . Retrieved June 23, 2015.
  5. ↑ Wifi Positioning | Wifi Location | Cell ID - Combain . Retrieved June 23, 2015.
  6. ↑ Wifi Location Service . Retrieved February 11, 2015.
  7. ↑ Geomena: Wifi geolocation . Retrieved June 23, 2015.
  8. ↑ Unwired Labs LocationAPI . Retrieved May 11, 2015.
  9. ↑ Unwired API: Unwired Labs Location API - Geolocation API and Mobile Triangulation API, Cell Tower database . Retrieved June 23, 2015.
  10. ^ Mozilla Location Service . Retrieved February 28, 2015.
  11. ^ MLS - Statistics . Retrieved June 24, 2015.
  12. ^ MLS - Statistics . Retrieved June 24, 2015.
  13. ↑ MLS opt-out . In: mozilla.com . Retrieved September 2, 2014.
  14. ↑ Navizon Global Positioning System . Retrieved June 21, 2015.
  15. ↑ Navizon WiFi Coverage Map . Retrieved June 21, 2015.
  16. ↑ openBmap . Retrieved February 23, 2016.
  17. ↑ Openbmap Database Download . Retrieved November 3, 2018.
  18. ↑ Wifi access point finder . Retrieved January 30, 2015.
  19. ↑ Openbmap license . Retrieved January 30, 2015.
  20. ↑ OpenWLANMap . Archived from the original on August 2, 2014. Retrieved June 23, 2015.
  21. ↑ OpenWLANMap Database Download . Retrieved November 3, 2018.
  22. ↑ a b Find WLAN network . Retrieved December 19, 2014.
  23. ↑ OpenWLANMap license . Retrieved December 19, 2014.
  24. ↑ WiGLE . Retrieved December 19, 2014.
  25. ↑ a b WiGLE stats . Retrieved June 28, 2019.
  26. ↑ a b WiGLE Wireless Network Map . Retrieved December 19, 2014.