In this article, we propose a novel formulation for the resource allocation problem of a sliced and disaggregated Radio Access Network (RAN) and its transport network. Our proposal assures an end-to-end delay bound for the Ultra-Reliable and Low-Latency Communication (URLLC) use case while jointly considering the number of admitted users, the transmission rate allocation per slice, the functional split of RAN nodes and the routing paths in the transport network. We use deterministic network calculus theory to calculate delay along the transport network connecting disaggregated RANs deploying network functions at the Radio Unit (RU), Distributed Unit (DU), and Central Unit (CU) nodes. The maximum end-to-end delay is a constraint in the optimization-based formulation that aims to maximize Mobile Network Operator (MNO) profit, considering a cash flow analysis to model revenue and operational costs using data from one of the world's leading MNOs. The optimization model leverages a Flexible Functional Split (FFS) approach to provide a new degree of freedom to the resource allocation strategy. Simulation results reveal that, due to its non-linear nature, there is no trivial solution to the proposed optimization problem formulation. Our proposal guarantees a maximum delay for URLLC services while satisfying minimal bandwidth requirements for enhanced Mobile BroadBand (eMBB) services and maximizing the MNO's profit.

翻译：本文针对分离式无线接入网（RAN）及其传输网络的资源分配问题，提出了一种新颖的建模方法。该方案为超可靠低延迟通信（URLLC）场景保障端到端延迟上限，同时联合考虑接纳用户数量、每切片传输速率分配、RAN节点功能分割以及传输网络路由路径。我们采用确定性网络演算理论，计算连接部署无线单元（RU）、分布单元（DU）和集中单元（CU）节点的分离式RAN的传输网络延迟。在基于优化的建模中，最大端到端延迟被设定为约束条件，目标是通过采用全球领先移动网络运营商（MNO）的现金流分析模型来最大化其利润（该模型可量化收入与运营成本）。该优化模型利用灵活功能分割（FFS）方法，为资源分配策略提供了新的自由度。仿真结果表明，由于问题的非线性特性，该优化问题不存在显式解析解。本方案在满足增强移动宽带（eMBB）业务最低带宽需求且最大化运营商利润的同时，可保障URLLC服务的最大延迟。