# A Comprehensive Review of Indoor Localization Techniques and Applications in Various Sectors
## 3 Methodology and Application of Indoor Localization in Various Fields
### Transforming Industrial Operations with Indoor Localization Technologies  
#### 3.2.1 UWB-Based Indoor Localization for Industrial Environments  
[PERSON] et al. [26] evaluate the performance of two indoor localization technologies--UWB and BLE--in a real-world industrial environment. The goal is to assess their accuracy, reliability, and scalability under dynamic conditions often found in industrial settings, such as the presence of metallic structures, moving objects, and signal interference. The study was conducted in the Royal FloraHolland Flower Auction Center in the Netherlands. The testing area covered a large section of the facility, including auction halls, storing zones, buffering zones, and distribution zones. These areas presented challenges such as multipath interference, shadowing, and NLOS conditions caused by the continuous movement of flower trolleys, workers, and machinery [26].  
The anchors were installed at a height of 5.6 m, covering a 60 \(\times\) 46 m area. The system utilized time-of-flight (TOF) measurements to determine the distance between the tag and the anchors. The position of the tag was calculated using a multi-lateration algorithm. The UWB system's performance was evaluated for ranging accuracy, positioning accuracy, and update rate. The system provided update rates between 5 and 50 Hz for a single tag, with the rate divided proportionally when multiple tags were tracked simultaneously [26].  
The BLE-based system used five anchor nodes positioned along the sides of the measurement area, with BLE tags mounted on the flower trolleys. This system estimated positions using the AoA method, where the anchors measured the angle at which the signal arrived. The BLE system was evaluated for coverage range, typically achieving a range of 11-15 m from the nearest anchor. The system's positioning accuracy was measured in both static and dynamic conditions, with static scenarios achieving accuracy around 20 cm. Additionally, the BLE's latency was low, with update rates up to 100 Hz and delays as short as 100 ms [26].  
Several evaluation scenarios were designed to measure system performance, which are shown in Figure 14. The static ranging accuracy test measured the distance between the tag and the anchor under line-of-sight (LOS) conditions, while the dynamic environment test assessed accuracy when objects and people obstructed the signal path. The positioning with mobility scenario evaluated the system's ability to track a moving tag along a predefined path, and the multiple tags tracking scenario tested scalability when monitoring several tags simultaneously. Additionally, the operational range of the localization system and its coverage capabilities for positioning applications were investigated. For this purpose, ranging measurements between the tag and a single anchor were collected at different distances, maintaining LOS, until reaching the system's maximum operational range. These measurements were conducted using the 3244.8-3744 MHz frequency band for ranging signals, with a preamble length of 4096 and a bit rate of 110 kbps [26].  
The key findings revealed that UWB provided high accuracy, often within sub-meter precision, and demonstrated robustness against multipath interference, making it suitable for critical industrial applications. In contrast, BLE offered reasonable accuracy at a lower installation cost but required a denser deployment of anchors to achieve optimal performance. Both systems faced challenges with NLOS conditions and dynamic obstructions. The study highlighted that scalability and deployment costs were critical factors influencing the choice of technology for specific industrial use cases. This evaluation provides valuable insights into the strengths and weaknesses of UWB and BLE for industrial indoor localization, helping industries choose the most appropriate technology for their specific tracking needs [26].