Age of Information Resilience With a Strategic Out-of-Band Relay

The age of information (AoI) is a metric representing the freshness of the information available at the receiver in a system which involves the exchange of status updates over an error-prone time-slotted channel between a sensing source and a receiver. We consider such a system, with the addition of a relay node that is able to assist the transmission to improve the resilience against failures, and compute the expected AoI over a discrete time-slotted channel when both the sensor and relay are intermittently and independently active. Furthermore, we present a game theoretic formulation of the optimization of the activity rate for both nodes when transmissions are expensive, managing the tradeoff between cost and AoI. The Nash equilibrium (NE) of the resulting game is found to be both efficient from the perspective of the resulting performance and computationally lightweight for a distributed robust control implementation.