Reliability-Latency Tradeoff Analysis with Random Arrivals in URLLC Networks over Nakagami- m Fading Channels

Abstract

Motivated by URLLC scenarios with stringent reliability and latency requirements, this paper investigates the relationship between the target block error rate (BLER) and the delay violation probability (DVP) in short-packet transmissions over Nakagami- m fading channels under statistical delay constraints. Specifically, for a random-arrival queueing system, an analytical approach integrating finite blocklength (FBL) coding with effective capacity (EC) analysis is developed to connect physical-layer reliability targets with link-layer delay performance. By combining generalized Gauss-Laguerre quadrature with a central-limit-theorem-based approximation, this paper derives an approximate closed-form expression for the DVP in terms of the target BLER, enabling direct delayperformance evaluation. Further theoretical analysis reveals an approximate quadratic relationship between the reliability metric and the delay exponent in the high signal-to-noise ratio (SNR) regime. Simulation results are provided to validate our theoretical analysis.