Wi-Fi positioning system
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. Commercial providers of this type of positioning service include Google, Navizon, AlterGeo, Skyhook Wireless, who was acquired by TruePosition Inc. in 2014, and Combain Mobile.
The localization technique used for positioning with wireless access points is based on measuring the intensity of the received signal (received signal strength in English RSS) and the method of "fingerprinting". 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 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 WiFi traces with other data sources.
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. 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. Mozilla honors _nomap as a method of opting-out of its location service.
- Automatic vehicle location
- Hybrid positioning system
- Indoor positioning system
- MAC address
- Mobile phone tracking
- AlterGeo: About us
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- Google Help - Location-based services - How do I opt out? Obtained 2012-05-30
- "MLS-Opt-Out". Retrieved 2 September 2014.
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