Age of Information in Symmetric Broadcast Networks with Stochastic Packet Arrivals

In this work, we study the age of information (AoI) in time-slotted symmetric broadcast networks with d information streams (i.e., source-destination pairs), where all streams have the same parameters, such as packet generation rate. By following a discrete-time stochastic hybrid system (DT-SHS) modeling approach, we derive the average AoI for the max-age-first-with-no-buffer (MAF-WNB) and persistent-round-robin-last-generated-first-served (PRR-LGFS) policies, where the latter does not need any knowledge about the AoI of the streams. We also compare the performance of these policies with the max-age-first-LGFS (MAF-LGFS) and max-value-first-LGFS (MVF-LGFS) policies, which have been shown to achieve near-optimal performance in some special scenarios. Our results indicate that for high values of d or the packet generation rate, the PRR-LGFS and MAF-LGFS policies perform closely, and the MAF-WNB policy outperforms the other ones in general.