Optimal Sleep-Wake Scheduling for Quickest Intrusion Detection Using Wireless Sensor Networks
K. Premkumar, Anurag Kumar · 2008
We consider the problem ofquickestdetectionofanintrusionusing a sensor network, keeping only a minimal number of sensorsactive. By using a minimal number of sensor devices, we ensure that the energy expenditure forsensing,computationandcommunicationis minimized (and the lifetime of the network is maximized). We model the intrusion detection (or change detection) problem as aMarkovdecisionprocess(MDP). Based on the theory of MDP, we develop the following closed loopsleep/wakescheduling algorithms: (1) optimal control of Mk+1, the number of sensors in the wake state in time slot k + 1, (2) optimal control of qk+1, the probability of a sensor in the wake state in time slot k + 1, and an open loopsleep/wakescheduling algorithm which (3) computes q, the optimal probability of a sensor in the wake state (which does not vary with time), based on the sensor observations obtained until time slot k. Our results show that an optimum closed loop control on Mk+1significantly decreases the cost compared to keeping any number of sensors active all the time. Also, among the three algorithms described, we observe that the total cost is minimum for the optimum control on Mk+1and is maximum for the optimum open loop control on q.