Extended Dynamic Transmission Power Control Algorithm in Wireless Body Sensor Network Systems

In the wireless body sensor network system (WB-SNS), saving energy in sensor nodes is a high priority. As an energy-saving method for sensor nodes, the transmission power control (TPC) algorithm has been developed. The TPC technique is a method of saving energy by adjusting the transmission power of the radio chip inside a sensor node. Numerous TPC algorithms exist, but in this paper, the dynamic TPC algorithm was analyzed intensively. The existing dynamic TPC algorithm utilizes a linear equation to find the optimal transmission power level (TPL). However, the existing dynamic TPC algorithm may operate well when the channel condition is good but it could estimate the TPL inaccurately due to the generation of an incorrect linear equation when the channel conditions are bad. Therefore, to solve the problem described above, this paper proposes an extended dynamic TPC algorithm that can estimate errors earlier based on slope values, which can be extracted at the time of generation of the linear equation, and estimate transmission power better by reutilizing the existing transmission power to create a more accurate equation. Through an experiment, this paper also proves that the extended dynamic TPC algorithm showed better performance compared to the existing dynamic TPC algorithm.