PlaceEngine
PlaceEngine is a technology that uses Wi-Fi information (such as MAC address, RSSI, etc) from the Wi-Fi access points, deployed in large number in urban areas, to estimate current location in reference to the PlaceEngine database. Any device equipped with Wi-Fi can easily estimate its location without utilizing GPS. PlaceEngine enables a device to determine its location even indoors or underground, where it might normally not be possible with GPS. Furthermore, additional information such as landmarks or building floor information can also be tagged to respective Wi-Fi signal data. For example, digital cameras with PlaceEngine are capable of automatically recording the coordinates of the position where each photo has been taken by adding latitude and longitude information to the EXIF files in each photo. This way, locations where each photo was taken can be added to devices without GPS, but only Wi-Fi.
Since Wi-Fi access points are often added, removed and/or randomly moved at any given location, PlaceEngine applies the "collective intelligence" idea used by many Internet services. It implements a realword folksonomy approach where information from users such as "get location" or "registered location" help create a self-maintaining database that keeps on improving in accuracy as more people use it.
The accuracy of the location estimated by PlaceEngine, depends on the Wi-Fi signals that can be sensed at a given time and place which is affected by many factors (one such factor is access point density), as well as the information stored in the Wi-Fi database in the PlaceEngine server. Thus, it is difficult to determine the precise accuracy of the PlaceEngine service, but to give a rough estimation we believe it to be on the order of 5 to 100 meters.
PlaceEngine is not intended to replace GPS, but rather to complement the technology. PlaceEngine cannot estimate location where Wi-Fi signals are not available, and yet, in large cities with many indoor and underground areas, a solution that combines GPS and PlaceEngine may prove more convenient.
Jun Rekimoto, Director of the Interaction Lab, at Sony Computer Science Laboratories, Inc. (Sony CSL) (also Professor, The University of Tokyo) came up with the original concept behind PlaceEngine during the course of his research on real world user interfaces. He was then joined by Taka Sueyoshi (currently at Koozyt, Inc.) and Atsushi Shionozaki (also at Koozyt), who were formerly researchers at Sony CSL, to develop PlaceEngine。Currently, PlaceEngine is licensed by Koozyt, Inc., and the PlaceEngine client is available for use in multiple platforms, inclusive of PCs, mobile devices and portable games. Clients for Windows (XP,