چكيده به لاتين
Remote health monitoring systems are examples of the use of IoT in the health field that have made great progress and are being developed day by day. Energy consumption of the wearable home-care monitoring systems is a major challenge due to the need for continuous remote monitoring of the patients. Choosing an appropriate communication protocol to reduce energy consumption of these systems is, therefore, a key parameter. Since the recent versions of the IEEE 802.15.1 (Bluetooth) protocol can potentially reduce the energy consumption and provide a better coverage range, they are promising for wearable homecare monitoring systems (WHMS). On the other hand, a deep energy consumption analysis of these protocols for WHMS has not been thoroughly yet conducted. In this survey, using software and hardware-based energy monitoring platform, the energy consumption and maximum coverage range of the Bluetooth Low Energy (BLE) V4.2 and V5 protocols are experimentally evaluated in different homecare scenarios. In our designed architecture, a smart health gadget equipped with Bluetooth 4.2 and 5 sends its data to a mobile phone periodically. Our scenarios designed to measure the maximum coverage range and the power consumption of the mobile phone and the Bluetooth module during the Advertising interval and transmitting and receiving data in various environmental conditions (including direct and indirect visibility conditions which the wireless signal may travel through the wood, metal, brick wall, body, and similar obstacles in various humidity situations), as well as different internal settings (including data transmission rate, signal transmit power, and advertising interval). Our results show that the material, thickness and number of obstacles between the Bluetooth sender and receiver affect the maximum coverage range and the energy consumption of this protocol, especially on the module side. Therefore, the highest energy consumption of the BLE protocol occurs when there is a human body or brick wall obstacle between the transmitter and receiver. About the maximum coverage range, our extensive experiments also reveal that the maximum coverage range of the BLE v5/ 1Mb, is 108m in line of sight scenarios which decline to around 45m and 29m when the signal travels through brick walls and the human body, respectively. In addition to the above results, humidity can also be mentioned as an influential factor on energy consumption. Water molecules increase the energy consumption by absorbing 2.4 GHz signals (Bluetooth frequency). The tangible impact of changing the internal parameters, especially the advertising interval on the energy consumption was also proved. So that the shorter the advertising interval, the more energy consumption. Finally, it is concluded that the energy consumption of the BLE v5/ 2Mb, is less than 1Mb. Also the BLE v5/ 2Mb transmission speed is twice the BLE v5/ 1Mb, while its maximum coverage range is 20% lower.
