# An Overview of Indoor Localization System for Human Activity Recognition (HAR) in Healthcare
## 2 Ips
#### Evaluation Metrics  
For the best choice of the most suitable system for the requested application, it is advisable to examine a series of performance indices [18]. For example, some applications may require low-cost IPS, while others may require high accuracy, such as healthcare systems. Below are the commonly used parameters.  
1. **Accuracy** is the main feature that evaluates the average difference between the detected and actual positions (ground truth) [19]. Generally, this value is not fixed but oscillates concerning various parameters; thus, the reference is made to minimum and maximum values. Depending on the technology used, we can have the values in meters reported in Table 1.
2. **Coverage** indicates the functional surface within which the examined technology is effective. Depending on the type of technology used, it takes on different values. IPS coverage usually ranges from a few meters to scalable systems that can cover multiple large environments by adding hardware. In the case of challenging-to  
Figure 3: Diagram of the localization process.  
scale technologies, this value represents the maximum local area covered, while, in the application of techniques that can scale (increasing their level of coverage), it represents the distance or area that can be covered by a single cell. Generally, technologies with more excellent coverage typically imply lower accuracy. In Table 1, the values of coverage are reported in meters.
3. **Scalability** indicates the possibility with which the technology can be extended, referring both to the coverage area and to the number of users supported simultaneously [20].
4. **Security and privacy** represent the level of control of access to the subjects' personal information.
5. **Cost** includes all the costs necessary for the implementation and operation of the system, such as infrastructure costs, installation and maintenance, and energy consumption to run the components. The latter represents a fundamental parameter to ensure system continuity and higher mobility [21].
6. **Complexity** represents the level of complexity of designing, constructing, and maintaining an IPS.
7. **Support/infrastructure** represents the hardware necessary for the system to operate, i.e., if specific equipment is needed, or it can refer to the integration of an infrastructure located in the localization area, such as sensors or transmitters. The density and cost of these additional infrastructures weigh on the expansion capacity of the technology if it is necessary to use more nodes of the infrastructure.
8. **Continuity** indicates the property of continuous operation of an IPS over an appropriate time to perform its specific function, including acceptable outage frequency.
9. **Usability/user acceptance** represents how convenient and usable the technology is to the end user. A simpler infrastructure is easier to use.
10. **Privacy** is a crucial aspect to keep in mind that is not always carefully evaluated in IPS systems. Security mechanisms should be in place to improve user privacy, protecting data from intrusion or misuse [22].  
From the analysis of the tabulated values, a broad scenario of adoptable solutions can be seen depending on the specific design needs. In particular, for accuracy, each technology has its own range of applicability, and none overlaps the other.