Wi-Fi positioning system

From Wikipedia, the free encyclopedia
  (Redirected from Wi-Fi Positioning System)
Jump to: navigation, search
Not to be confused with Wi-Fi Protected Setup.

Wi-Fi-based positioning system (WPS) or WiPS/WFPS is used where GPS is inadequate due to various causes including multipath and signal blockage indoors. Such systems include indoor positioning systems. Wi-Fi positioning takes advantage of the rapid growth in the early 21st century of wireless access points in urban areas.

The localization technique used for positioning with wireless access points is based on measuring the intensity of the received signal (received signal strength or RSS) and the method of "fingerprinting".[1][2] Typical parameters useful to geolocate the Wi-Fi hotspot or wireless access point include the SSID and the MAC address of the access point. The accuracy depends on the number of positions that have been entered into the database. The Wi-Fi hotspot database gets filled by correlating mobile device GPS location data with Wi-Fi hotspot MAC addresses.[3] The possible signal fluctuations that may occur can increase errors and inaccuracies in the path of the user. To minimize fluctuations in the received signal, there are certain techniques that can be applied to filter the noise.

In the case of low precision, some techniques have been proposed to merge the Wi-Fi traces with other data sources such as geographical information and time constraints (i.e., time geography).[4]

Privacy concerns[edit]

Citing the specific privacy concerns arising out of WPS, Google suggested a unified approach for opting-out a particular access point from taking part in determining location using WPS.[5] Appending "_nomap" to a wireless access point's SSID excludes it from Google's WPS database. Google hopes that other WPS providers and data collectors, like Apple and Microsoft, follow that recommendation so that it becomes an accepted standard.[6] Mozilla honors _nomap as a method of opting-out of its location service.[7]

Public Wi-Fi location databases[edit]

A number of public Wi-Fi location databases are available:

Name Unique Wi-Fi networks Observations Free database download Active project SSID lookup BSSID lookup Data License Opt-out Comment
Combain Positioning Service[8] >700,000,000[9] >12,117,000,000[10] no yes yes yes Proprietary _nomap supported Also Cell ID database. Coverage map
Geomena[11] 55,013[12] yes yes yes yes CCSA No Wiki editable Coverage map
LocationAPI.org by Unwired Labs[13] >709,510,000[14] >4,100,000,000 no yes yes yes Proprietary _nomap supported Also Cell ID database Coverage map
Mozilla Location Service[15] 357,708,166[16] >6,241,930,000[17] no yes no no Proprietary _nomap[7] Also Cell ID database whose data are public domain. Coverage map
Navizon[18] 480,000,000 21,500,000,000 no yes no yes Proprietary no Based on crowd-sourced data. Also Cell ID database.[19] Coverage map
openBmap[20][21] 1,667,635 yes[22] yes no yes[23] ODbL[24] Also Cell ID database. Coverage map
OpenWLANMap[25][26] 22,010,794 yes[27] yes no yes[28] GFDL[29] _nomap, request[28] Coverage map
WiGLE[30] 198,891,361[31] 2,891,184,857[32] no yes yes[33] yes[33] Proprietary request Also Cell ID database. Coverage map
Mylnikov GEO[34] 76,655,230[35] yes[36] yes no yes MIT[37] Also Cell ID database[38]

See also[edit]

External links[edit]


  1. ^ P. Bahl and V. N. Padmanabhan, “RADAR: an in-building RF-based user location and tracking system,” in Proceedings of 19th Annual Joint Conference of the IEEE Computer and Communications Societies (INFOCOM ’00), vol. 2, pp. 775–784, Tel Aviv.Israel, March 2000.
  2. ^ Y. Chen and H. Kobayashi, “Signal strength based indoor geolocation,” in Proceedings of the IEEE International Conference on Communications (ICC ’02), vol. 1, pp. 436–439, New York, NY, USA, April–May 2002.
  3. ^ How Does a Wi-Fi Positioning System Work?
  4. ^ Danalet, Antonin; Farooq, Bilal; Bierlaire, Michel. "A Bayesian approach to detect pedestrian destination-sequences from WiFi signatures". Transportation Research Part C: Emerging Technologies 44: 146–170. doi:10.1016/j.trc.2014.03.015. 
  5. ^ http://www.infosecurity-magazine.com/blog/2011/11/20/googles-approach-of-a-nomap-wifi-zone/460.aspx.
  6. ^ Google Help - Location-based services - How do I opt out? Obtained 2012-05-30
  7. ^ a b "MLS-Opt-Out". mozilla.com. Retrieved 2 September 2014. 
  8. ^ "Combain Positioning Service". Retrieved 2015-01-03. 
  9. ^ "Wifi Positioning | Wifi Location | Cell ID - Combain". Retrieved 2015-06-23. 
  10. ^ "Wifi Positioning | Wifi Location | Cell ID - Combain". Retrieved 2015-06-23. 
  11. ^ "Wifi Location Service". Retrieved 2015-02-11. 
  12. ^ "Geomena: Wifi geolocation". geomena.org. Retrieved 2015-06-23. 
  13. ^ "Unwired Labs LocationAPI". Retrieved 2015-05-11. 
  14. ^ API, Unwired. "Unwired Labs Location API - Geolocation API and Mobile Triangulation API, Cell Tower database". Unwired Labs Location API - Geolocation & Mobile Triangulation API. Retrieved 2015-06-23. 
  15. ^ "Mozilla Location Service". Retrieved 2015-02-28. 
  16. ^ "MLS - Statistics". location.services.mozilla.com. Retrieved 2015-08-28. 
  17. ^ "MLS - Statistics". location.services.mozilla.com. Retrieved 2015-08-28. 
  18. ^ "Navizon Global Positioning System". Retrieved 2015-06-21. 
  19. ^ "Navizon WiFi Coverage Map". Retrieved 2015-06-21. 
  20. ^ "openBmap". Retrieved 2015-01-30. 
  21. ^ "Wireless Collaborative Map". openbmap.org. Retrieved 2015-07-06. 
  22. ^ "Openbmap Database Download". Retrieved 2015-01-30. 
  23. ^ "Wifi Access Point finder". Retrieved 2015-01-30. 
  24. ^ "Openbmap license". Retrieved 2015-01-30. 
  25. ^ "OpenWLANMap". Retrieved 2015-06-23. 
  26. ^ QXC, VWPDesign/. "Open WLAN Map - free and open WLAN-based location services". openwifi.su. Retrieved 2015-07-06. 
  27. ^ "OpenWLANMap Database Download". Retrieved 2015-02-24. 
  28. ^ a b "Find WLAN network". Retrieved 2014-12-19. 
  29. ^ "OpenWLANMap license". Retrieved 2014-12-19. 
  30. ^ "WiGLE". Retrieved 2014-12-19. 
  31. ^ "WiGLE Stats". www.wigle.net. Retrieved 2015-06-23. 
  32. ^ "WiGLE Stats". www.wigle.net. Retrieved 2015-06-23. 
  33. ^ a b "WiGLE Wireless Network Map". Retrieved 2014-12-19. 
  34. ^ "Mylnikov GEO Wi-Fi". Retrieved 2015-05-19. 
  35. ^ "Mylnikov GEO Wi-Fi". Retrieved 2015-05-19. 
  36. ^ "Mylnikov GEO Wi-Fi Database Download". Retrieved 2015-05-19. 
  37. ^ "Mylnikov GEO license". Retrieved 2014-12-19. 
  38. ^ "Mylnikov GEO Mobile Cells Database". Retrieved 2014-12-19. 
  • Anthony LaMarca, Yatin Chawathe, Sunny Consolvo, Jeffrey Hightower, Ian Smith, James Scott, Tim Sohn, James Howard, Jeff Hughes, Fred Potter, Jason Tabert, Pauline Powledge, Gaetano Borriello, Bill Schilit: Place Lab: Device Positioning Using Radio Beacons in the Wild. In Pervasive (2005)