# A Comprehensive Review of Indoor Localization Techniques and Applications in Various Sectors
## 3 Methodology and Application of Indoor Localization in Various Fields
### Indoor Localization Applications and Methodologies in Healthcare  
#### 3.1.1 Wi-Fi Based Healthcare Facilities System  
[PERSON] et al. [14] illustrates an implementation and security analysis of an IoT-based RTLS called LoCATE for tracking patients, staff, and assets in healthcare facilities using Wi-Fi (802.11) infrastructure. The system is designed to leverage existing hospital Wi-Fi networks to provide a cost-effective and scalable solution for real-time localization. The LoCATE system uses the Raspberry Pi 3 Model B or Raspberry Pi Zero W as edge nodes. These nodes run on the Raspbian OS and are equipped with a wireless USB dongle for collecting Wi-Fi signals. Each edge node is powered by a 12,000 mAh lithium battery, making it portable for carrying by healthcare staff or patients. The portability of these nodes ensures flexibility in deployment and ease of tracking throughout the hospital environment [14]. As shown in Figure 7, the edge nodes collect RSSI values from nearby Wi-Fi access points (APs). The system scans for Wi-Fi beacon frames every 5 to 7 s. Each data point includes the RSSI value, the media access control (MAC) address of the detected access point, and a timestamp. This continuous scanning provides the necessary data for accurate \begin{table}
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**References** & **Motivation** &
\begin{tabular}{c} **Indoor Localization** \\ **Technology** \\ \end{tabular} & **Measurement Method** & **Application** \\ \hline \multirow{4}{*}{[60]} & To develop & & & \\  & low-complexity & & & \\  & BLE-based localization & & & \\  & algorithms suitable for & & & \\  & large industrial areas & & & \\  & with limited & & & \\  & infrastructure. & & & \\ \hline \multirow{4}{*}{[61]} & To propose a robust & & & RSSI with customized & \\  & and fast setup Wi-Fi & & & signal-strength-to- & \\  & localization system for & localization using RSSI & distance functions & \\  & large exhibition venues & and piecewise linear & using expectation & \\  & with varied device & models & maximization (EM) & \\  & characteristics. & & algorithm & \\ \hline \multirow{4}{*}{[62]} & To enhance indoor & & & \\  & positioning accuracy & & & \\  & for safety and public & & & RSSI measurements & \\  & facility use through a & & with RSS and RBFN & \\  & low-cost ZigBee-based & & & \\  & system. & & & \\ \hline \multirow{4}{*}{[63]} & To improve the & & & \\  & accuracy and response & & & \\  & time of Wi-Fi & & & \\  & fingerprint-based & & & \\  & localization in & & & \\  & dangerous area & & & \\  & monitoring. & & & \\ \hline \multirow{4}{*}{[64]} & To develop a low-cost & & & \\  & BLE-based positioning & & & \\  & system for drones & & & \\  & operating indoors & & & \\  & where GNSS is & & & \\  & unreliable. & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: _Cont._real-time tracking of patients, staff, and medical assets. Once the RSSI data are collected, they are transmitted via the facility's Wi-Fi network to a cloud database hosted on Amazon Web Services (AWS). The cloud infrastructure uses the relational database service (RDS) to store the location data securely. Additionally, an Elastic Compute Cloud (EC2) instance connects the database to a web or mobile application, enabling real-time visualization and access to historical data. This architecture allows for seamless tracking and efficient data retrieval [14]. The system determines the location of the tracked assets or individuals by processing the collected RSSI values. Using triangulation algorithms, the system calculates positions relative to the known locations of Wi-Fi access points. This approach achieves localization accuracy within 3 to 5 feet. The cloud database can be queried for both real-time and historical location data, and the results are displayed through a user-friendly web or mobile interface, enhancing accessibility for healthcare staff. The LoCATE system also incorporates a detailed security analysis to identify vulnerabilities and ensure reliable performance.