Sole threshold based monitoring algorithms bring down the accuracy of alarm

hence researching on dual threshold based monitoring technique

that is

constraint violation monitoring with probability guarantee has significant meanings.Firstly

according to the semantics of probability threshold on the monitoring result

dual threshold monitoring of sensor node was investigated.Secondly

a tight upper bound of the probability of the sensing data larger than monitoring threshold was given

and dual threshold based distributed monitoring algorithm was proposed.Thirdly

based on the given accuracy requirement

a mathematical method to determine an optimal sample was provided.A sampling based approximate cluster monitoring algorithm was proposed.The theoretical analysis and performance evaluation demonstrate the efficiency of the proposed algorithms.