Finding MiMo : Tracing a Missing Mobile Phone using Daily Observations
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This paper presents Finding MiMo, a system designed to trace missing mobile devices using daily observations. The approach addresses challenges in indoor tracking and relies on ambient features and movement detection without needing extensive pre-learned databases. By utilizing GPS, GSM, and WiFi signals, the system constructs paths between known places and current unknown locations, thereby providing real-time tracking and chasing capabilities. The proposed solution overcomes limitations of existing methods while minimizing energy consumption and improving accuracy, resulting in an effective tool for locating lost mobile devices.
Finding MiMo : Tracing a Missing Mobile Phone using Daily Observations
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Presentation Transcript
Finding MiMo: Tracing a Missing Mobile Phone using Daily Observations Hyojeong Shin, Yohan Chon, Kwanghyo Park and Hojung Cha MobiSys2011 - Sowhat2012.03.19
Outline • Introduction • System Design • Evaluation • Discussion • Conclusion
Outline • Introduction • System Design • Evaluation • Discussion • Conclusion
Motivation • Missing handheld device problem • Existing solution • MobileMe, provided by Apple Inc. and Skyhook • GPS, cell tower ID, WiFi fingerprints • Drawbacks - Inaccurate location estimations in indoor • GPS signal not reachable • Pre-learned database for radio fingerprints not available
Challenges • Efficient - limited battery duration • Indoor environment challenge • GPS, floor plan, pre-learned radio map, non-standard hardware not generally available • Room-level accuracy • Not necessary with additional hardware functionality or infrastructure
Outline • Introduction • System Design • Evaluation • Discussion • Conclusion
Idea of FindingMiMo ~ Warn / Cold Game ~ Sim() = Tanimoto coefficient function =
Place-matching Problem • Input • Initial known position • Logged observations • Live observations • Output • Moving path of missing mobile • Moving path of the chaser
LifeMap • Functionality • Monitor user’s physical location with ambient features • Construct nodes (places) & edges (paths) • Sensing • GPS, GSM, WiFi • Activity-based sensor selection (move / stationary) • Detection of movement – Tanimoto Coefficient > threshold • Known place • Stationary state continuously maintained • Role • Provide information of movement and known places
MissingMobile:Daily Ambient Logger • Role • Record ambient radio logs on the path, from last known place to current unknown place • Functionality Log WiFi vectors , LifeMap detect movement & no GPS signal Sleep state , otherwise • Minimize stored information • Collection period < 1 Day • Reset when 1. revisit a known place 2. GPS signal available
SmartSLAM:Indoor Pedestrian Tracking • Role • Provide indoor floor plan & location of the user • Functionality– floor plan construction • Path • Accelermeter step count • Digital compass heading direction • Location • Use WiFi observation to identify locations • Adjust path while revisting identified locations
Chaser: Device TrackingChasing Information • Circumstantial evidence • Approximate missing time & previous known place • Indoor pedestrian tracking • Display map & location of the user • Log similarity • Similarity of current and logged observations • Trace similarity – • Target similarity – • Chasing progress -
Chaser: Device TrackingChasing Information If no specific location (GPS) in log data Visit all possible entrances of last placeto find the one with largest similarity Indoor Chasing
Outline • Introduction • System Design • Evaluation • Discussion • Conclusion
Missing Mobile • Energy consumption & space complexity • Setting • Similarity threshold = 0.7 • 5 students collect 2 weeks • Energy consumption
Missing Mobile • Space complexity • AP – 367 ~ 1573 • Record – 50160~248700 • 4.5 ~ 22.3MB • Reduction: ABCBD ABD
Hide-and-Seek Game • Goal: check if chaser could chase with only the information from chaser app. • Setting • 4 games at 4 different buildings • 36 people • 1 participant hide, chaser group chase
Case Study: Shopping mall • Real environment & case • Setting • 195000 m2 shopping mall • 3 hours log • Extract 6 possible missing place generate logs • User chase at the next day
Outline • Introduction • System Design • Evaluation • Discussion • Conclusion
Discussion • User guide • Move slow while chasing • Places with similar radio signal may be on different floor • Erroneous data • GPS may be read via window • Open space
Outline • Introduction • System Design • Evaluation • Discussion • Conclusion
Conclusion • FindingMiMo with ambient observations to help to trace missing mobile device • Not clear descriptions for detail settings