Table 1.
Different User Location Discovery (ULD) methods. DFL, Device-Free Localization; PIR, Passive InfraRed; DBL, Device-Based Localization; MIMO-UWB, Multiple-Input Multiple-Output Ultra-Wide Band.
| Source | Type | Detection Level | Application | Equipment | Technique(s) | Algorithm(s) |
|---|---|---|---|---|---|---|
| [1] | DFL | Symbolic | Localization and tracking | ZigBee devices equipped with PIRs | Probabilistic filtering, motion detection | Bayes-based algorithm |
| [10] | DBL | Physical | Localization and tracking | Wearable tags, contact sensors | Joint Motion Tracking, Continuous Root Location Update | Sensor mapping calibration, Footprint skeleton calibration |
| [11] | DBL | Symbolic | Localization | Mobile phone and access point(s) | Logical localization (WiFi fingerprints and user movement) | Skeleton mapping and branch knot |
| [12] | DFL | Physical | Localization | Multiple antennas (MIMO-UWB system) | Measuring the propagation channels between the antennas and the human body | Distance estimator (time difference between sending the pulse and reception of the echo) |
| [13] | DFL | Physical | Localization and tracking | Wireless pyroelectric infrared sensors | Motion detection | Distributed localization |
| [14] | DFL | Physical | Localization | PIR sensors | Map-based localization, Bayesian and particle filtering | Data fusion by particle filters |