Modelling, analysis and performance improvement of an SRU's access request queue in multi-channel V2I communications

This paper presents a concise yet comprehensive description of a multi-channel Vehicle-to-Infrastructure (V2I) communication system. Existing mathematical models for such a system overlook some of its essential behavioural characteristics such as the reneging, force-termination and ultimately blocking of service requests. A multi-server queueing model with First-In-First-Out (FIFO) service policy is proposed for the purpose of accurately capturing the dynamics of the above-mentioned communication system and evaluating its performance. Approximations were exploited as a mean to enhance this model's mathematical tractability. Simulations are conducted in the context of a realistic scenario with the objective of validating the proposed approximate model, verifying its accuracy and characterizing the system's performance in terms of several new metrics. The reported results indicate a cataclysmic access request blocking probability ranging from 66% to 85%. An Access Request Deadline-Aware (ARDA) service policy is then proposed to reduce the blocking probability and improve the system's response time. Indeed ARDA achieved an improvement over FIFO of almost 70% in terms of the overall blocking probability and 22% to 66% in terms of the system's response time.