Timeliness of wireless sensor networks with random multiple access

In this paper, we consider a wireless sensor network in which N nodes deliver the observed information of interest to remote receiver by competing for sharing channel through Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) protocol or slotted ALOHA protocol. For network, evaluate freshness two random multiple access protocols using age (AoI) metric. order explicitly express average AoI CSMA/CA based establish an equivalent and tractable transmission model probabilities collision are assumed be identical over time among nodes. derive focusing on randomly chosen reference node. Our theoretical results show that 1) probability networks increase both arrival rate number nodes; 2) same probability, is always smaller than no matter how change. Monte Carlo simulation also validate correctness our calculations.