Study and Prediction of Wireless Link Quality for Adaptive Channel Hopping

The nature of packet loss of wireless links at 2.4G band was analyzed and a wireless link quality prediction algorithm for wireless sensor networks was proposed. In the proposal, RSSI (Received Signal Strength Indicator) and LQI (Link Quality Indicator) were utilized to produce a couple of metrics of wireless link quality, named Sm and delta respectively, and their distributions were studied. By using SAX (Symbol Aggregation approximately) method, the LQIs were mapped into different symbols, and summarized the preceding symbols of link quality deterioration in collection of patterns. Then the distance of a sample to patterns was used to determine the probability the link deterioration, so that the link quality of the next period was predicted. The proposed method is simple, so it is easy to implement in wireless sensor network. Finally, the experiment using practical link data showed that the proposed method can predict more than 80 percent of the link deteriorations.