Pinpointing users with location estimation techniques and Wi-Fi hotspot technology

Location awareness is becoming an important capability for mobile computing; however, it has not been possible until now to provide cheap pervasive positioning systems. Wide area coverage is most famously achieved by using global positioning systems (GPS). A constellation of low-orbit satellites cover the earth's surface. Unfortunately GPS does not work indoors and has limited success in big cities because of the 'urban canyon' effect. PlaceLab is a research project that attempts to solve the ubiquity issues surrounding 802.11-based location estimation. PlaceLab, like RADAR, uses a device's 802.11 interface; however, it does not require the area to be pre-calibrated. It predicts location via the known positions of the access points detected by the device. Commonly used systems have a number of drawbacks, including cost, accuracy and the ability to work indoors. PlaceLab is a piece of open source software developed by Intel Research that can pinpoint a user within a Wi-Fi network. We set out here to investigate whether PlaceLab can be used as a means of establishing a user's position. This type of investigation could, if successful, pave the way for the development of other location-based applications. This report documents the efforts to answer the above question. PlaceLab was found to work, but only in ideal locations where factors such as the number of floors and the lack of available APs did not affect its use. It was concluded that these factors prevent the system from being effective as a means of establishing a user's position in most locations on campus.

[1]  Andy Hopper,et al.  Implementing a Sentient Computing System , 2001, Computer.

[2]  Henk L. Muller,et al.  Low Cost Indoor Positioning System , 2001, UbiComp.

[3]  Bill N. Schilit,et al.  Place Lab: Device Positioning Using Radio Beacons in the Wild , 2005, Pervasive.

[4]  Ivan Poupyrev,et al.  Virtual object manipulation on a table-top AR environment , 2000, Proceedings IEEE and ACM International Symposium on Augmented Reality (ISAR 2000).

[5]  Gaetano Borriello,et al.  Particle Filters for Location Estimation in Ubiquitous Computing: A Case Study , 2004, UbiComp.

[6]  Yang Li,et al.  Topiary: a tool for prototyping location-enhanced applications , 2004, UIST '04.

[7]  Matthew Chalmers,et al.  Lessons from the lighthouse: collaboration in a shared mixed reality system , 2003, CHI '03.

[8]  William G. Griswold,et al.  ActiveCampus: experiments in community-oriented ubiquitous computing , 2004, Computer.

[9]  Eric Horvitz,et al.  RightSPOT: A Novel Sense of Location for a Smart Personal Object , 2003, UbiComp.

[10]  Paramvir Bahl,et al.  RADAR: an in-building RF-based user location and tracking system , 2000, Proceedings IEEE INFOCOM 2000. Conference on Computer Communications. Nineteenth Annual Joint Conference of the IEEE Computer and Communications Societies (Cat. No.00CH37064).

[11]  William G. Griswold,et al.  Experiences with place lab: an open source toolkit for location-aware computing , 2006, ICSE '06.

[12]  William G. Griswold,et al.  Challenge: ubiquitous location-aware computing and the "place lab" initiative , 2003, WMASH '03.

[13]  John Krumm,et al.  Location-aware computing comes of age , 2004, Computer.