Age Optimal Scheduling for a Network with Relay

In this paper, we study the transmission scheduling problem in a wireless network with a relay. There are two flows of traffic from the source and relay nodes to the destination. The packets need to be sent to the destination node in a timely manner. For stochastic packet arrivals, we pose the transmission scheduling problem in the network, under interference constraints, such that the destination node's expected weighted sum average age of information is minimum. We model the problem as a Markov Decision Process and obtain a policy (AOPT) that is age-optimal. We analyse the optimal policy and propose an efficient near-optimal policy. We compare performances of heuristic policies like Maximum Age First (MAF), Round Robin (RR) and Round Robin based on Queue length (RRQ), and the obtained policy with the age-optimal policy.