1. A device for detecting radio communication anomalies, the device being capable of communicating with a sensor node via radio waves, the device comprising: a memory; and a processor coupled to the memory and configured to: gather and store different kinds of parameters in a storage unit, the different kinds of parameters indicating a quality of radio communication with the sensor node; classify parameter sets into a plurality of clusters, each of the parameter sets containing specific kinds of parameters gathered during a prescribed time period among the parameters stored in the storage unit; estimate that a rapid radio quality degradation has occurred during the prescribed time period when there is a cluster of which all average values of specified kinds of parameters among the different kinds of parameters degrade more than those of another cluster; perform a trend analysis for a time period during which it is not estimated that the rapid radio quality degradation has occurred to determine whether each of the different kinds of parameters gathered during the time period exhibits a trend of degradation; and estimate that a slow radio quality degradation has occurred based on a result of the trend analysis by the trend analyzer.