“…Some works have proposed analytical E2E delay models for virtualized wireless networks and network slices [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ]. Although there are also works providing performance models for a specific network domain (e.g., RAN, TN, and CN) [ 28 , 29 , 30 , 31 ] or component (e.g., gNB and UPF) [ 32 , 33 ], here we will only review E2E delay models, i.e., those considering every network domain. Analytical models are crucial to assist autonomous solutions for the management and operation of the network and to perform offline network performance assessments and optimization.…”