5G Standalone (SA) is the target architecture defined by 3GPP. It consists of the NG-RAN (Next Generation Radio Access Network) with gNBs connecting to a cloud-native 5G Core (5GC). The 5GC uses a Service-Based Architecture (SBA) where network functions communicate via HTTP/2-based APIs rather than point-to-point interfaces. This is a fundamental shift from the diameter/GTP-based 4G EPC.