Study of Activity Tracking through Bluetooth Low Energy-Based Network

Abstract

This paper proposes a proof-of-concept, low-cost, and easily deployable Bluetooth low energy- (BLE-) based localization system which actively scans and localizes BLE beacons attached to mobile subjects in a room. Using the received signal strength (RSS) of a BLE signal and the uniqueness of BLE hardware addresses, mobile subjects can be identified and localized within the hospital room. The RSS measurement of the BLE signal from a wearable BLE beacon varies with distance to the wall-anchored BLE scanner. In order to understand and demonstrate the practicality of the relationship between RSS of a BLE beacon and the distance of a beacon from a scanner, the first part of the paper presents the analysis of the experiments conducted in a low-noise and nonreflective environment. Based on the analysis conducted in an ideal environment, the second half of the paper proposes a data-driven localization process for pinpointing the movements of the subject within the experimental room. In order to ensure higher accuracy like fingerprinting techniques and handle the increased number of BLE-anchored scanners like geometric techniques, the proposed algorithm was designed to combine the best aspects of these two techniques for better localization. The paper evaluates the effects of the number of BLE wall-mounted scanners and the number of packets on the performance of the proposed algorithm. The proposed algorithm locates the patient within the room with error less than 1.8 m. It also performs better than other classical approaches used in localization.

On the High Fluctuations of Received Signal Strength Measurements With BLE Signals for Contact Tracing and Proximity Detection

“…These orientation changes can, in turn, cause RSS fluctuations. Fluctuations of up to 30 dB between maximum and minimum RSS at constant TX-RX distances were observed in [32] when RSS data acquired with different device orientations was aggregated.…”

An Ensemble Filter for Indoor Positioning in a Retail Store Using Bluetooth Low Energy Beacons

“…Due to the nature of Bluetooth and the signals emitted, the most widely used and efficient technique used for Bluetooth-based indoor positioning is fingerprinting (e.g., [4,12,13,14,15,61]). For example, Subedi et al [14] combined fingerprinting with weighted centroid localization aiming to reduce the total number of collected fingerprints to improve the time required for the positioning process.…”

“…For example, Subedi et al [14] combined fingerprinting with weighted centroid localization aiming to reduce the total number of collected fingerprints to improve the time required for the positioning process. One of the most recent studies combined fingerprinting with geometric techniques to pinpoint the movements of patients in a BLE beacon-enabled hospital room [15].…”

“…Lymberopoulos et al [7] argued that the indoor location problem still remains unsolved and stresses the importance of the employment of a realistic approach that would counterbalance the desired localization accuracy with low costs. Most studies have utilized Wi-Fi technology for indoor localization experimenting with a vast variety of indoor positioning techniques (e.g., [8,9,10,11]), while research on Bluetooth technology for indoor positioning is increasing (e.g., [4,12,13,14,15]). However, most works are practically laboratory experiments (e.g., [16,17,18,19,20]) that have not validated their indoor positioning approach in a real, fully operational environment.…”

Improved Method of Bluetooth-low-energy-based Location Tracking Using Neural Networks

“…In a study on the tracking method using fingerprinting, the performance according to the number of receivers is analyzed. (11) Also, an observation model based on Wasserstein distance interpolation combined with the sequential Monte Carlo (SMC) method exhibited good performance. (12) For general use, the indoor tracking system was designed and implemented using Java.…”