Using network simulators as digital twins of 5G/B5G mobile networks

Digital Twins (DTs) have been proposed as digital replicas of physical entities (e.g., manufacturing plants), which one can observe and interact with, e.g., to perform what-if analysis. In this paper, we argue that mobile networks need DTs as well, and network simulators appear to be promising candidates to fulfill that role. We discuss the challenges that need be addressed to make this happen, e.g., centralized vs. distributed implementation, gathering input from the physical network, security issues and hosting, and the possibilities offered by network simulation in terms of what-if analysis, defining the concepts of lockstep and branching analysis. We exemplify the above concepts using Simu5G, a popular 5G/B5G simulation library for OMNeT++, as a reference case study.