Age of Information of SIC-Aided Massive IoT Networks With Random Access

Abstract

Age of Information (AoI) has turned to be an outright metric to evaluate information freshness in Internet of Things (IoT) networks. In this work, we evaluate the average AoI of an uplink IoT monitoring network where multiple end devices have independent status updates to transmit to a common access point (AP). More specifically, we propose the so-called successive interference cancellation (SIC)-aided age-independent random access (AIRA-SIC) scheme, where the AP performs SIC aiming at recovering collisions of multiple packets that are transmitted simultaneously by different devices in a slotted ALOHA fashion. Our results show that the proposed scheme not only achieves considerably lower AoI levels than the standard AIRA but also outperforms a recently proposed threshold-based age-dependent random access (ADRA) scheme, where the channel access probability (CAP) of each device is dynamically adapted based on each devices’ AoI. Finally, we provide some insights on the optimal CAP that minimizes the network average AoI, as well on the influence of imperfect channel state information (CSI) in the performance of the proposed scheme.