Countermeasures Against Jamming Attack in Sensor Networks with Timing and Power Constraints.

In a typical wireless sensor network (WSN), a central controller collects information from multiple sensors which are battery operated. The challenging problem is how to minimize the number of re-transmissions or increase the sleep time of sensors without compromising on the timeliness of the sensed information. The age of information (AoI) is a recently proposed measure of freshness or timeliness of the sensed information at the central controller. The problem becomes even more challenging under the denial of service attack from in-band full duplex jammers. Such jammers can sense the transmissions while injecting interference allowing them to react instantaneously with the transmission strategies. We develop a decision making policy for the central controller to combat such jammers with an aim to minimize the number of re-transmissions without compromising on the AoI. To boost the anti-jamming capability of the WSN, we introduce three modes for sensors: sleep, silent and transmit. We then jointly optimize the decision of when to switch the operating mode of each sensor and when to hop to a new channel using Markov Decision Process. We validate the superiority of the proposed strategy via extensive simulation results considering various parameters such as switching cost, transmission cost, failure to meet AoI cost and channel qualities.