# A Comprehensive Review of Indoor Localization Techniques and Applications in Various Sectors
## 1 Introduction
Additionally, IoT-based real-time locating systems (RTLSs), such as LoCATE, offer location accuracy within 3-5 feet. However, these RTLS solutions are vulnerable to security risks, including data breaches and unauthorized access. To mitigate these risks, implementing security measures like data encryption and tamper-proof hardware is crucial to ensure that these systems remain reliable and secure [14]. Another promising advancement is the integration of indoor localization with human activity recognition (HAR) systems. HAR systems use wearable sensors and activity-detection algorithms to monitor the real-time movements and behaviors of mobility-impaired or elderly patients [15]. This capability is particularly valuable for detecting falls or other incidents that require immediate attention. Despite their potential, these systems encounter several challenges, such as signal interference, NLOS conditions, and multipath effects caused by reflections within the environment [16]. These factors can hinder the accuracy and scalability of localization systems. To overcome these limitations, hybrid approaches that combine technologies like BLE and UWB are being explored. UWB, known for its high precision and resilience to interference, can significantly enhance the reliability of indoor localization in healthcare settings [17]. Looking ahead, research must prioritize the development of secure, scalable, and cost-effective indoor localization systems [18]. Innovations in AI-driven analytics, sensor fusion, and advanced encryption protocols hold the potential to address current challenges and further enhance these technologies. AI-driven analytics can process large volumes of location data to optimize decision-making and predict patterns, improving the efficiency of hospital operations [19]. Sensor fusion--the combination of data from multiple sensors--can help mitigate accuracy issues by providing more comprehensive and reliable location information. Meanwhile, advanced encryption ensures data integrity and privacy, addressing concerns around security threats. By incorporating these innovations, indoor localization systems can be seamlessly integrated into healthcare workflows. These advancements promise to transform various aspects of healthcare, including patient monitoring, asset management, and overall service delivery [20]. As these technologies mature, they can pave the way for smarter and more efficient medical environments. For instance, hospitals could automate resource allocation based on real-time data, reduce wait times by locating staff and equipment instantly, and improve patient outcomes through continuous monitoring. The future of healthcare lies in embracing these transformative technologies, which can lead to safer, more efficient, and more responsive medical care [11; 19]. Indoor localization systems are increasingly vital in various sectors, including healthcare, industrial operations, military missions, and emergency response scenarios. These systems are crucial for tracking personnel, assets, and equipment in GNSS-denied environments where GPS signals are unavailable or unreliable due to structural obstructions or interference [21]. The benefits of accurate indoor localization include improved safety, operational efficiency, and decision-making. Whether managing a hospital's workflows, optimizing industrial processes, or coordinating military and first responder missions, reliable localization technology enhances situational awareness and streamlines critical operations [22]. Unlike outdoor environments where GNSS technologies excel, indoor localization faces significant challenges such as signal attenuation, NLOS conditions, and dynamic environmental changes. In industrial settings, the presence of metallic obstructions, moving machinery, and fluctuating environmental factors complicates accurate tracking. For example, military and firefighting operations often occur in unpredictable environments without pre-installed infrastructure, making real-time localization difficult.