Localization of Wireless Terminals using Smart Sensing Shahrokh Valaee Wireless and Internet Research Lab (WIRLab) Dept of Electrical and Computer Engineering University of Toronto
2 Wireless and Internet Research Laboratory (WIRLab) A laboratory built by funds from: Canadian Foundation for Innovation (CFI) Ontario Innovation Trust (OIT) Several industrial partners The research focus at WIRLab is on Wireless Networks and Signal Processing
3 WIRLab Architecture The equipment is organized into multiple layers to emulate various networking architectures: Core network with high-end L2/L3 switches and soft routers; Several access points with capability for multiple standard support; Numerous wireless devices such as notebooks, PDAs, wireless cameras, etc, for mesh or multi-hop communications; Wireless robots for mobility management; Sensors equipped with localization devices for environmental monitoring and location estimation; DSRC/WAVE devices for fast MAC and rapid network acquisition used in mobile communications at vehicular speeds. The lab can simulate almost all network configurations and various topologies.
4 Team of Researchers last six years Director: Shahrokh Valaee Professors on Sabbatical: 7 Visiting Researchers: 4, (LG Electronics, SONY, ETRI) Post-doctoral Fellows: 6 PhD Students: 15 MASc Students: 15 Visiting PhD Students: 7 Visiting MASc Students: 1 Undergrad students: 40+
5 Sample Projects Localization of Wireless Terminals Vehicle-to-vehicle Communication Cognitive Radios Cellular Networks Sensor networks Mesh networks …. WIRLab
6 Cellular Networks High Bandwidth communication for Maglev Trains PAPR reduction through network coding (LGE) Joint patent Instantly Decodable Network Coding (IDNC) Spectrum Sensing
7 Vehicular Networks Low latency communications for vehicular environment Opportunistic Network Coding for data broadcast Enhanced reliability through Positive Orthogonal Codes V2X (pedestrian, cyclists) communications Localization of vehicles
Localization of Wireless Nodes 8 Localization of mobile phones Compressive Sensing Patent licensed Android and Windows implementation SLAM Crowdsourcing Using Camera for Localization
9 WIRLab Projects Signal Processing Localization Networking Vehicular Networks Communications Cognitive Radios
Localization of Wireless Terminals using Smart Sensing Indoor Localization
11 Objective To design an accurate indoor navigation system that can be easily deployed on commercially available mobile devices without any hardware modification.
Motivation Regulations: E911 Commercial: shopping mall advertisement Assistive: visually challenged Precision increases 12
Where Am I? 13 Sense the environment and find your location
Sensors in Mobile Phones RF Signal Scanner Accelerometer Gyroscope Barometer Magnetometer Thermometer Photometer … 14 Software Sensors Orientation Rotation Matrix Gravity Linear Accelerometer Rotation Vector Game Rotation Vector Camera GPS …
Integrated Solution 15 Localize and Track
RF Sensing & Localization Beacon-based Proximity RSS-based Fingerprinting Time-of-Arrival GPS 16
iBeacon Uses Bluetooth Low Energy (BLE) Small battery-operated transmitters Used in consumer market 17
Localization based on Proximity 18
Localization via RF Fingerprinting Off-line measurements (site survey) On-line localization
20 Fingerprinting Collect fingerprints and store Measure and compare Off-line On-line
21 Received Signal Strength (RSS) ?
22 Fingerprint Matrix
23 Online Localization The problem is underdetermined if L < N infinite solutions L: no. of WiFi access points N: no. of fingerprints Radio map MeasurementUnknown Location Assuming sparsity
Compressive Sensing The location of user can be found via the following convex programming Number of samples: C K log(N) 24
versus EITA-EITC 2012 [Valaee] 25
26 Skip the details Indoor Navigation System
Patents and Licenses S. Valaee, C. Feng, and A. W. S. Au, “System, Method, and Computer Program for Anonymous Localization,” US non-prov patent, EFS ID , Application ID 12/ filed Dec 2010, Notice of Allowance issue on 12/05/2014. S. Valaee, C. Feng, and A, Au, “System, Method, and Computer Program for Anonymous Localization,” Canadian patent, Reference no M, filed Dec S. Valaee and C. Feng, “System, Method, and Computer Program for Dynamic Generation of a Radio Map for Indoor Positioning of Mobile Devices, “US Patent Application, Application number 13/927510, Filed June 26,
CNIB Testbed Demo 28 Canadian National Institute for the Blind
Evaluation Results 29 30 blind subjects interviewed by a doctor 15 testing group 15 control group 3 tests for each subject
30 Bayview Village Shopping Center
31 Accuracy (positioning in BV)
Site Survey via Crowd Sourcing Accelerometer Sensing Step Counter
Off-line Phase A radio map includes A grid of points (labeled points) in the service area RSS measurements at each point 33 AP(2) AP(L) AP(l) AP(1) Access Points (APs) Labelled Points (reference points) Data Points MAC1 MAC2 MAC3 MAC4 MAC5 MAC6 MAC
34 Off-line Phase: Speedup Collect RSS readings while walking Need for a location estimation method AP(2)AP(L)AP(l) AP(1) Access Points (APs) Labelled Points Data Points Auto-Labelled Points
35 Android Motion Sensors Take advantage of various sensors information. Each Android device has a combination of: Accelerometer Gyroscope Magnetic Field sensor (compass) …. Linear Acceleration Information
36 Position Estimation with Step Counter Position can be estimated given the initial location, speed, and heading directions With the help of accelerometer, it is possible to make a step counter to estimate the coordinates of RSS readings Acceleration samples
37 Step Counter Accuracy Test1Test2Test3Test4Test5Test6 PhoneSamsung S1 Samsung Tab Motorola RAZR HTC Desire Z LG Nexus 4 Tester idP1 P2P3 Actual steps: Counted steps: Accuracy97.5%100% 98.75%98%
38 Speedup in Data Acquisition Manually labeled data: 21 labeled points in approx. 15 min. Bahen Centre 4 th floor, 70m x 80m Auto-labeled data: 347 labeled points in approx. 12 min.
39 Reliability of Auto-labeled Data Auto-labeled data is as useful as manually labeled data Manually labelled data Auto-labelled data
40 Crowd Sourcing Traces from casual users The answer to several issues: Removing the training phase Radio map maintenance Using Graph theory, we can build a completely unsupervised system Combine traces from multiple users to build the radio map
Demos 41
Floor Detection Pressure Sensing
Barometer Air pressure of the environment ( ). Barometer is useful in floor detection. Power consumption: 0.003mA Unit: mBars Max. sample rate : 30 Hz 43
Barometric Data Air pressure for different floors of Bahen Centre. 44
Floor detection View of 3D Map 45
Confusion Matrix for Floor Detection Floor 1Floor 2Floor 3Floor 4Floor 5Floor 6Floor 7Floor 8 Floor Floor Floor Floor Floor Floor Floor Floor
Transmit sensor data of the phone to a PC running MATLAB in real-time. We deploy algorithms in MATLAB rather than JAVA. Much Faster! Implementation of Algorithms 47
Conclusion Sensory data from smartphones can be used to localize wireless devices indoors Compressive Sensing is used to enhance sensing and localization Accelerometer and Gyro are used for crowdsourcing Pressure sensor is used for floor detection Direct connection between sensor data and MATLAB reduces the implementation time 48