“…• NS architecture: Several papers (Afolabi et al, 2018;Foukas et al, 2017;Kaloxylos, 2018;Barakabitze, Ahmad, Mijumbi, & Hines, 2020) describe the NS architecture, which is composed of infrastructure, network function and service layers (Next Generation Mobile Network (NGMN) Alliance, 2016). Depending on the layer, NS isolation can be done in many ways: software-based isolation, physical isolation, and virtual machine-based isolation (Kostopoulos, Chochliouros, & Spada, 2019). For this purpose, the Next Generation Mobile Networks (NGMN) Alliance ( 2015), establishes for each network layer the following instances: 5G service instance layer (5GSIL), 5G network instances layer (5GNSI), 5G physical resource layer (5GRL).…”