# An Overview of Indoor Positioning and Mapping Technology Standards
## 2 Related Work
### Indoor Positioning Technologies
[24] categorize wireless indoor localization schemes into device-based and device-free, where device-based localization refers to a wireless device (e.g., a smartphone) attached to the target that computes its location through cooperation with other deployed wireless devices; in contrast, device-free localization means the target carries no wireless devices, while the wireless infrastructure deployed in the environment determines the target's location by analyzing its impact on wireless signals. The authors also present a performance comparison of smartphone-based, tag-based, and device-free systems. Based on whether an IPS requires the deployment of dedicated infrastructure or not, the existing indoor localization systems can also be classified into infrastructure-based and infrastructure-free systems [22, 23]. [PERSON] et al. [5] provide a detailed survey of indoor localization techniques such as AOA, TOF, return time of flight (RTOF), received signal strength (RSS), RSSI, and channel state information (CSI) based on technologies such as WiFi, RFID, UWB, Bluetooth, and systems that have been proposed in the literature. The authors grouped these technologies and systems as device-based localization (DBL), monitor-based localization (MBL), and proximity detection. In contrast to the existing surveys, they analyzed how novel systems such as Internet of Things (IoT), smart architectures (such as smart cities, smart buildings, smart grids), and machine type communication (MTC) can impact or benefit indoor localization; and, they evaluated different systems from the perspective of energy efficiency, availability, cost, reception range, latency, scalability and tracking accuracy. However, as the authors addressed, there is no system proposed so far that satisfies all these requirements. The authors highlight the use of localization in context-aware location-based marketing, health services, disaster management and recovery, security, asset management/tracking, and IoT. Finally, the authors provide a checklist of the pros and cons of different technologies and highlight their suitability and challenges for indoor localization. One of the biggest problems is that there is no standard that can serve as a guide for designing localization and proximity techniques. [PERSON] et al. [7] revisited the then current literature to present an expansion of the range of technologies and methodologies for assisting the visually impaired in previous works, providing readers and researchers with a more recent version of what was done and the advantages and disadvantages of each approach. The authors reorganized IPS structures into radio-based (range-based and range-free), no radio-based (inertial-based, sound-based, light-based and vision-based), and hybrid indoor positioning systems. Many more comprehensive reviews of various positioning technologies can be found in the literature [4, 5, 6, 16, 17, 20, 21, 25, 26, 27, 28, 29, 30]. The main goal of most surveys is to provide a guideline for readers and IPS developers to better understand the weaknesses and strengths of each technology and system. The performance evaluation metrics usually include accuracy and precision, coverage, cost, latency, complexity, robustness, availability/usability, scalability, lower power, privacy, and security. Currently, the fifth generation (5G) mobile network, big data, and artificial intelligence (AI) are new technologies to improve indoor 3D localization by using new radio (5G NR) technologies, Internet of Things (IoT), and machine learning probabilistic algorithms, among other technologies [31]. In 2019, 5G cellular networks started to be deployed worldwide, and the new technologies have enabled approaches for improving the performance of wireless indoor positioning [32]. For example, [PERSON] et al. [33] proposed (a deep, learning-based cooperative architecture using 5G IoT networks for 3D indoor positioning, and [PERSON] et al.