Age of Information With Hybrid-ARQ: A Unified Explicit Result

Delivering timely status updates in a timeliness-critical communication system is of paramount importance to assist accurate and efficient decision making. Therefore, the topic analyzing Age Information (AoI) has aroused new research interest. This paper contributes results this area by systematically AoI two types Hybrid Automatic Repeat reQuest (HARQ) techniques that have been newly standardized Release-16 5G New Radio (NR) specifications, namely reactive HARQ proactive HARQ. Under code-based update with non-trivial coding delay, transmission propagation decoding feedback we derive unified closed-form average Peak expressions for HARQ, respectively. Based on obtained explicit expressions, formulate an minimization problem investigate age-optimal codeblock assignment strategy finite block-length (FBL) regime. Through case studies analytical results, provide comparative insights between from perspective freshness information. The numerical optimization solutions show draws its strength both age performance robustness, thus enabling potential advancement freshness-critical system.