Towards mobile phone localization

Towards Mobile Phone Localization without War-Driving Location is an IP address for content delivery Is GPS the solution? Pros: Good accuracy Cons: Poor battery lifetime Is GSM the solution? Pros: Long battery lifetime Cons: Poor accuracy What about WiFi Localization? E.g., SkyHook: Basic Basic Idea: Idea: 1 Several Several trucks trucks war-drive war-drive aa place place 2 Create Create Radio Radio map map == 3 Distribute Distribute map map to to phones phones 4 Phone Phone user user goes goes to to war-driven war-driven region, region, overhears overhears WiFi WiFi IDs IDs 5 Reverse Reverse Look Look Up Up IDs IDs against against radio radio map map 6 Obtains Obtains location location Is Skyhook the solution? Middle Ground Lower Accuracy than GPS, Longer Battery lifetime Better Accuracy than GSM, Shorter Battery lifetime but … Is Skyhook the solution? Middle Ground Lower Accuracy than GPS, Longer Battery lifetime Better Accuracy than GSM, Shorter Battery lifetime but … At the cost of:  Degraded location accuracy: walking paths ~ 60m  Reliance on infrastructure (APs)  War-driving ($$ + carbon footprint) “NYTimes: Skyhook fleet 500 trucks/drivers” Visual Representation Of the State of the Art (Duke Campus) No Eng Eff & Acc Solution SkyHook GPS unusable with phone battery GSM too inaccurate Skyhook Better than GPS Eng Eff Eng Eff & Acc Solution CompAcc GPS unusable with GPS unusable phone battery with phone battery GSM too inaccurate Contents  CompAcc  Evaluation  Limitations and Future Work  Conclusion 10 Contents  CompAcc  Evaluation  Limitations and Future Work  Conclusion 35 CompAcc  Today’s localization technologies limited  Energy- Efficiency  Coverage/Accuracy  Rely on simple localization mechanism  Need: Compass, Accelerometer and Maps  Evaluation results:  ALE: 11m  Battery: 23h  CompAcc scales to any mapped part of the world 36 Questions? Thank You! Visit the SyNRG research group @ http://synrg.ee.duke.edu/ 37 Additional Slides 38 Skyhook on walking paths g – GPS position S – Skyhook position Assume GPS is absolute truth 39 Skyhook Coverage 40 Directional trail: displacement  Step count/displacement accuracy 41 Trail/Path Size 42 Fallback Mechanism: A-GPS  What if the dissimilarity metric is large?  Trigger A-GPS 43 Fallback Mechanism 7th Street A 5th Street Estimated Location Main St E 44 Fallback Mechanism 7th Street A 5th Street Estimated Location Main St E 45 Context Pervasive wireless connectivity + Localization technology = Location-based Location-based applications (LBAs) 46 Context Pervasive wireless connectivity + Localization technology = Location-based Location-based applications (LBAs) (iPhone AppStore: 3000 LBAs, Android: 600 LBAs) 47 Location-Based Applications (LBAs)  Examples: Location-based recommendations, geo-tagging GeoLife: shopping list when near a grocery store TrafficSense: real-time traffic conditions  Location expresses context of user  Facilitates content delivery 48 Localization Technology  LBAs executed on mobile phones Accuracy Accuracy 10m 10m 20-40m 20-40m 200-400m 200-400m Technology Technology GPS GPS WiFi WiFi // Skyhook Skyhook GSM GSM Energy-Efficiency Energy-Efficiency 4h-8h 4h-8h 16h 16h ~days ~days 49 ... map == 3 Distribute Distribute map map to to phones phones 4 Phone Phone user user goes goes to to war-driven war-driven region, region, overhears overhears... SkyHook GPS unusable with phone battery GSM too inaccurate Skyhook Better than GPS Eng Eff Eng Eff & Acc Solution CompAcc GPS unusable with GPS unusable phone battery with phone battery GSM too inaccurate...  Location expresses context of user  Facilitates content delivery 48 Localization Technology  LBAs executed on mobile phones Accuracy Accuracy 10m 10m 20-40m 20-40m 200-400m 200-400m Technology