Low-SAR Path Discovery by Particle Swarm Optimization Algorithm in Wireless Body Area Networks

Sensor nodes in wireless body area networks are placed on the surface of the human skin or embedded inside the human body. When a transmitter sends packets, signals reach the receiver through the human body or skin. However, electric and magnetic field (EMF) radiation generated during packet transmission can lead to a negative influence on human health. The specific absorption rate (SAR) is defined as a measure of the amount of radio frequency energy absorbed by human tissue in units of mass. The higher the human body absorbs the value of the specific absorption rate, the more EMF radiation. Also, the degree of harm to human health is greater. This paper uses the particle swarm optimization algorithm to discover the optimal position of the relay node so that sensor nodes can send packets to the hub via the relay node through a path with the lowest SAR and the success rate of packet transmission thus can be improved.