Method and system for detecting suspicious frame in wireless sensor network

A wireless sensor network that detects suspicious frames, comprising:

• a plurality of hierarchically structured sensor nodes, each sensor node senses at least one of temperature, illumination or humidity, and sending the sensed data and data regarding an upper-level node of the sensor node and a cluster head node;
• a data collecting node that receives data from the sensor nodes, and sends information regarding a source node and at least one upper-level node thereof constituting a routing path, said information being extracted from the data received from the sensor nodes;
• and
• a terminal device that receives the information regarding a source node and upper-level nodes thereof from the data collecting node, computes a first probability of occurrence of the routing path with respect to previous frames, computes a second probability of occurrence of a source routing path passing through the at least one upper-level node and leading to the source node using the first probability, compares the second probability of occurrence of the source routing path with a reference value, and displays an indication notifying abnormality of the source node when the second probability is less than or equal to the reference value.