A Dynamic Distributed Queueing-Based Random Access Protocol for Softwarized Internet of Things

In this paper, we propose an efficient random access (RA) protocol based on the dynamic distributed queueing (DQ) mechanism to support massive bursty access for softwarized Internet of Things (IoT). Different from the existing DQ-based protocols, it can flexibly adjust the number of machine-type devices (MTDs) in the divided subgroup according to the occupancy condition of RA preambles, so as to effectively enhance both the resource utilization and access efficiency in the late stage of contention resolution. In addition, a two-phase theoretical model is developed to analyze the average access delay and the number of preamble retransmissions of the proposed protocol. Simulation results verify the validity of mathematical analysis, and demonstrate that our protocol can achieve a remarkably reduced access delay in comparison with the conventional ones, while maintaining a consistently high access success probability.