A Low-SAR Energy-efficient Transmission Mechanism based on WBAN

• Main Authors: Yu-Wei Wu, 吳昱緯
• Other Authors: Tin-Yu Wu
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/51161658246939501432

碩士 === 國立宜蘭大學 === 資訊工程學系碩士班 === 103 === With the rapid advancement of wireless networks and sensing technology in recent years, researchers have developed Wireless Sensor Network (WSN) to gather data for environmental monitoring. Because the economic growth stimulates people's attention to health-related issues, researchers have changed their observation target from the environment to the human or animal body. Wireless Body Area Network, WBAN, therefore takes shape. Sensors nodes are placed on, in or around the human body to collect biosignals and the bioinformation is transmitted wirelessly to a back-end database for medical diagnosis or treatment. However, in the context of WBAN, power capacity remains a significant problem. The network lifetime is inversely proportional to power consumption. If any one of the sensor nodes stops working, the network could possibly stop working, either. For medical purposes, such a situation can reduce the system reliability, cause significant packet loss and even lead to life-threatening results. The purpose of this study is to investigate a two-hop transmission mechanism for WBAN which computes the average residual energy of sensor nodes to decide whether to switch sensor nodes as the relaying node or not. For WBAN applications that give special consideration to human body, we first measure the signal decay rate between nodes and find the SAR level of each transmission path based on the specific absorption rate (SAR) of each body part. Next, we use Dijkstra's algorithm to balance the power consumption and SAR level of the path for best path selection that not only optimizes sensor nodes lifetime but also prolongs the WBAN network life cycle.