When xURLLC Meets NOMA: A Stochastic Network Calculus Perspective
To address the stringent requirements of ultra-low latency, ultra-high reliability, and fresh information (quantified by Age of Information, AoI) in xURLLC systems, this paper proposes a NOMA-assisted uplink architecture. It introduces stochastic network calculus (SNC) into the NOMA-xURLLC domain for the first time, establishing a unified theoretical framework that enables joint statistical QoS provisioning (SQP) for latency, AoI, and reliability tail distributions. Furthermore, we propose an SQP-driven power optimization paradigm, leveraging convex optimization and a customized power allocation algorithm to minimize uplink transmit power while satisfying multi-dimensional QoS constraints. Simulation results demonstrate that the proposed scheme outperforms conventional orthogonal multiple access across all key metrics—latency, AoI, reliability, and energy efficiency.