5G NSA (Non-Standalone) uses the existing LTE core (EPC) as the anchor while adding 5G NR as a secondary radio. This is defined as "Option 3" in 3GPP. The LTE eNB is the master node (MN) and the 5G gNB is the secondary node (SN). The UE connects to both LTE and NR simultaneously via EN-DC (E-UTRAN–NR Dual Connectivity), boosting throughput without requiring a new core network.