Analyzing Average Age of Information in CRDSA Protocol with Access-Banned Policy

This paper focuses on the analysis of the average age of information (AAoI) of the Contention Resolution Diversity Slotted ALOHA (CRDSA) protocol based on the access-banned policy in massive machine-type communication (mMTC) scenarios. The CRDSA system is modeled as a bipartite graph, and graph theory methods are used to analyze the system performance. At the same time, a comprehensive formula for calculating the packet recovery rate (PRR) in the CRDSA system is derived, considering the spectral characteristics of the bipartite graph. This formula can quantitatively evaluate the system’s ability to successfully decode transmitted data packets. Based on this, the age of information (AoI) in the CRDSA system based on the access-banned policy is studied. The sparse access model and the sampling method at the beginning of each frame are considered, and the expression of the AAoI of the whole system is given. The analysis process considers the probabilities of successful and failed decoding and the impact of decoding on delay, thus gaining a deep understanding of the freshness of information in the CRDSA system. The research results of this paper are of great significance for optimizing the design of the CRDSA protocol based on the access-banned policy. The research results can improve the reliability and efficiency of system performance in mMTC scenarios.