## 1 Introduction  
Smart health care and smart hospitals are concepts that have emerged as a result of innovation in the healthcare sector with the key supporting of technologies, especially the Internet of Things (IoT), individualized facilities and intelligent devoted machines (in termsof artificial intelligence). IoT is a rapidly evolving technology with potential for distributed computing and rapid information sharing in large-scale networks. Since the COVID-19 pandemic [1], considerable investments have been made in health care, which an important sector in everyday human life. The increasing population and the rise in chronic diseases have increased the demand for hospital resources and monitoring technology [2]. Appropriate solutions and facilities are required to minimize the pressure on healthcare systems and severe patients [3]. A potential solution to minimize the load on healthcare systems is the use of IoT technology. Therefore, efforts have been devoted [4; 5; 6; 7; 8] to the development of innovative healthcare solutions. A large amount of research has been conducted on patient monitoring in specific diseases such as Parkinson's disease and diabetes [7]. Many studies have focused on specific tasks, such as the combination of rehabilitation with regular tracking of patient progress [8]. The importance of emergency healthcare support has also been recognized [9; 10] but has not been widely researched. Various studies have reviewed specific health-related technologies. For example, the authors of [11] conducted a review with a primarily focus on a commercially obtainable solutions, remaining problems and best possible applications. Various topics were considered in [12; 13], including system storage, analysis and data mining, as well as system integration. The authors of [10] investigated big data control and sensing in terms of network-supported communication. This paper represents a crucial contribution in that we explore all key aspects of end-to-end IoT related to health care and suggest a collective model that can be applied to any healthcare system based on IoT. This work is important because no such system for end-to-end communication and remote tracking of health issues has been established to date. Herein, we provide a detailed review of IoT technologies that related to the suggested model. The novelty of this article lies in its focus on aspects of IoT related to healthcare systems. Low-power networks are among the major needs in IoT systems. Herein, we compare standard licensed bands such as low-power Bluetooth, narrowband IoT, etc., with alternatives with specific attentiveness and discuss their suitability for different healthcare applications. Smartphones play an important role in daily life; these devices can be connected to various types of sensors to track the health status of individuals [14]. Such devices can sense and record various types of data for automatic and efficient control of health care [15]. IoT healthcare systems can also be effectively used to track and monitor human resources [16]. Cloud resources can be used to control healthcare data of healthcare through various strategies, such as data integration, storage flexibility and parallel processing, although all these methods are subject security issues [17]. Implanted sensors or wearable devices can be used for IoT healthcare applications using a limited power supply. However, frequent charging may be required, and the use of such technology may result in patient fatigue, requiring additional care support and influencing user involvement [18]. Cloud data centers consume considerable energy resources, increasing costs; on the other hand, cloud service requires minimal energy and provides low latency [19]. Security is one of the major concerns associated with healthcare monitoring, as crucial data can easily be corrupted by hackers. Therefore, data privacy and protection are important considerations in IoT healthcare systems with respect to data transmission [20].