# Design and Evaluation of Large-Scale IoT-Enabled Healthcare Architecture
## 3 Proposed IoT-Enabled Healthcare Architecture
### How the Proposed Healthcare Architecture Works  
The proposed healthcare system comprises the direct related health devices and devices that may be needed for medical systems, such as cars. Hence, these devices are categorized into four main groups. The first group comprises sensing-based devices. The RFID-based devices (often passive), such as equipment, which are stored in the medical inventories are included in the second group. The third group comprises wearable devices related to health, such as blood pressure monitors. The fourth group includes cellular devices, such as smartphones and their applications. Using this categorization, Figure 4 illustrates a general view of the proposed healthcare system, including the numerous health devices of different types and locations. A WSN can connect devices in the first category. The second category of devices can communicate using an RFID network. The third device category can communicate using a MANET. A cellular network can connect the fourth category of devices. The four categories can be communicated using the Internet (or other alternative coverage tools), which leads us to deal with IoT technology. One of the most important goals of the proposed IoT-enabled healthcare is to have a robust communication system in which health devices operate as if they were one device. Therefore, each device in the proposed healthcare system is covered using one of the three coverage tools: satellites, HAPs, and Internet. The priority order of coverage tools is the Internet, then HAPs, then satellites. This priority depends on the tools that are the most popular and easily available for each device. For constant location devices, it is simple to maintain coverage using the first selected tool, but for moving devices, such as ambulances or wearable devices, these tools may change when transferring from one location to another. Active devices, which have a processing unit, can easily connect to any coverage tool. For passive devices without a processing unit, RFID is used to achieve this type of communication [30]. The communication process can be accomplished in three statuses, device-to-device [31; 32], device-to-computing center, and computing center-to  
Figure 4: Simple overall view of the proposed healthcare system. computing center. These communication statuses are accomplished over short (Internet or Bluetooth) and long ranges (Internet, HAPs, or satellites). Using different ranges ensures the healthcare devices are continuously connected to the healthcare system. The detailed description of the communication architecture is presented in [33]. The UM and HM monitor the healthcare system. The main idea of the UM and HM is based on monitoring and action. Monitoring is achieved by gathering data on predetermined parameters. Actions are taken based on the collected data after processing. Further, managers use control messages to execute their functions in the proposed healthcare system architecture. The communication system guarantees that multiple healthcare devices become one device regardless of the type or location, but the data transmission between devices should be organized and managed. Therefore, each device must send regular control data to determine its importance and available power. This information is determined by the management center using control messages. Hence, each device should maintain continuous communication with its HM. If the device moves from one region to another, the new HM detects this device in its region and sends a control message to that device and its old HM informing them of the new state of this device. The control message also informs the device of newly available computing centers (each with its priority). If a new device wants to join a healthcare system, it should send a join message to its HM asking for registration. The HM informs the device using another accept or reject control message.