Information Freshness in Random Access Channels for IoT Systems

Abstract

This paper introduces and discusses some recent advances in the field of information freshness for Internet of things (IoT) applications. Focusing on a setup in which a large number of transmitters share a common wireless channel to deliver updates to a common receiver, we tackle in particular the role played by random access policies based on variations of the basic ALOHA protocol, employed in most practical IoT systems. The fundamental trade-offs that emerge are discussed together with the enhancement achieved by a number of novel schemes tailored to optimize age of information. The article aims to trigger discussion and further research on a relevant yet still largely unexplored field, and highlights some important issues and challenges that have yet to be addressed.

On the Value of Retransmissions for Age of Information in Random Access Networks without Feedback

“…In this perspective, first important results have been obtained focusing on grant-free (random) access medium sharing policies [5] which are commonly employed in commercial IoT solutions [6]. Assuming a generate-at-will policy, in which a device can collect new information on the process right before sending a packet, the performance of ALOHA [7], [8] as well as of more advanced variations of the strategy [9] has been extensively studied.…”