on table, we can see that leveraging the EPC as a core network is just a temporary solution for MNOs to quickly deploy a 5G network. However, in this case, the 5G services provided will be limited to eMBB services. For instance, with EPC, there will be limited support for network slicing, which is a crucial concept in 5G deployments. 5G Deployment Options Summary In this chapter, we discussed two different 5G network deployment architectures, which are called NSA and SA. We've also seen different deployment options that were determined by 3GPP by comparing the architectures of the networks and the differences between the nodes utilized from the perspective of the control plane and user plane. With the knowledge we gained, we made some suggestions for MNOs on what the possible migration strategies from 4G to 5G could be in the future. We finalized the chapter by analyzing the evolution of the EPC to 5GC with the main comparison between them made from the perspective of 5G deployments and IMT-2020 use cases. In the following chapters, we will analyze the NSA and SA network architectures in more technical detail. 5G Non-Standalone Networks The initial trials for 5G networks started as early as 2018, and by 2019, many tier-one operators already had some presence of 5G in their networks. Therefore, the race among service providers to introduce a 5G presence was substantial. The 3GPP standards body already anticipated this; hence specifications were written to enable an architecture that would ensure faster rollouts of 5G. This provision was in the form of 5G Non-Standalone (NSA) networks. In this chapter, we will dig into the details of what an NSA network really means and ask, how is an NSA network designed? What are the various technical aspects of this architecture and what are the various types of NSA networks? In this chapter, we're going to cover the following main topics: Overview of NSA networks Types of NSA networks A deep dive into NSA networks 5G NSA - option 3 call flows Advantages and shortcomings Introdu