Jamming Power Optimization for Data Freshness in Covert Relay Networks

In this paper, we analyze covert amplify-and-forward (AF) relay networks with a metric for measuring the data freshness, i.e, age of information (AoI), with aid of the cooperative jammer that generates artificial noise (AN) to protect from Warden Willie’s surveillance. We first derive lower boundary of covertness, average AoI and formulate an average AoI minimization problem by optimizing the jamming power of the cooperative jammer. Our analysis shows that the optimal jamming power is the minimum value that satisfies the lower boundary of covertness, which varies depending on the prior probability.