Strategic Age of Information Aware Interaction Over a Relay Channel

Age of Information (AoI) is a metric often used to represent the freshness of the information exchanged between a sensing source and a receiver. We consider a system where these two nodes are connected through an error-prone time-slotted channel, and a relay node is also present to assist the transmission. We consider both the sensor and the relay as intermittently and independently active nodes, whose activity rate may be adjusted, resulting in different levels of freshness and corresponding energy costs. To this end, the activity pattern can either follow a Bernoulli random process or a periodic duty cycle with adjustable duration. After computing the expected AoI and the complete Peak Age of Information (PAoI) distribution for both cases, we consider a fully distributed game theoretic duty cycle optimization, in which the two nodes independently tune their own activity rate, finding a balance between freshness and cost. The equilibrium 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.