Queue-Aware Transmission in S-ALOHA for Delay Fair Access

Abstract

While prioritized random access (RA) systems based on the users' queue length have been researched, much of the existing literature assumes either a saturated condition or necessitates message exchange from the users to the base station (BS) or among the users. Acquiring user weight information without an uplink control channel establishment is challenging in RA systems, particularly when this weight varies over time. To address this, we propose a queue-aware RA system for unsaturated users, which operates without message-passing from the users to the BS. To facilitate this approach, we also develop the BS's weight estimation algorithm based on observing the idle slots in an online manner. The numerical results demonstrate that the proposed algorithm provides fair delay for users of different packet arrival rates while ensuring maximum throughput. In addition, we also introduce a mathematical model to analyze the queueing delay performance of users.