Organic Indoor Location Discovery
Author(s)
Hicks, Jamey
Curtis, Dorothy
Teller, Seth
Charrow, Ben
Ryan, Russell
Ledlie, Jonathan
Battat, Jonathan
Advisor(s)
Seth Teller
Date Issued
December 30, 2008
Series/Report no.
MIT-CSAIL-TR-2008-075
Abstract
We describe an indoor, room-level location discovery method based on spatial variations in "wifi signatures," i.e., MAC addresses and signal strengths of existing wireless access points. The principal novelty of our system is its organic nature; it builds signal strength maps from the natural mobility and lightweight contributions of ordinary users, rather than dedicated effort by a team of site surveyors. Whenever a user's personal device observes an unrecognized signature, a GUI solicits the user's location. The resulting location-tagged signature or "bind" is then shared with other clients through a common database, enabling devices subsequently arriving there to discover location with no further user contribution.
Realizing a working system deployment required three novel elements: (1) a human-computer interface for indicating location over intervals of varying duration; (2) a client-server protocol for pre-fetching signature data for use in localization; and (3) a location-estimation algorithm incorporating highly variable signature data. We describe an experimental deployment of our method in a nine-story building with more than 1,400 distinct spaces served by more than 200 wireless access points. At the conclusion of the deployment, users could correctly localize to within 10 meters 92 percent of the time.
Subjects
Shared Sensing
Computer Communication Networks
Localization
Location-Based Services
Geo-Tagging
Collaborative Computing
Distributed Systems
Distributed Applications
Pervasive Computing
Algorithms
Experiments
Groups and Organization Interfaces
Measurement
Crowd-Sourcing
Information Interfaces and Presentation
Human Factors
Persistent DSpace Link
