Research on EWMA based link quality evaluation algorithm for WSN

Link quality for WSN is easy to be disturbed by the environment. Link quality not only affects the reliability of data transmission in the network, but also determines the performance of related Upper-layer network protocol. Therefore, link quality evaluation becomes a considering question. The link quality evaluation methods include data package delivery rate and LQI(Link Quality Index). Practical tests show that the delivery rate and LQI value has high dithering and low performance, which can not provide the foundation for Upper-layer protocol. This paper proposed a stable and sensitivity adjustable evaluation algorithm by applying EWMA mathematical model to link quality evaluation. The experimental results prove the validity of the algorithm which can better evaluate actual link quality according to the historical and current data.