What is the difference between EN-DC and NE-DC?
EN-DC (E-UTRAN New Radio Dual Connectivity) and NE-DC (NR E-UTRA Dual Connectivity) are two dual connectivity configurations in 5G networks that allow user equipment (UE) to connect simultaneously to both LTE (4G) and NR (5G) networks to improve data throughput and service continuity. While they are conceptually similar, their roles and anchor nodes differ, impacting deployment strategy and performance.
EN-DC (E-UTRAN New Radio Dual Connectivity)
EN-DC is a dual connectivity architecture where the LTE eNodeB serves as the master node (MN) and the 5G NR gNodeB acts as the secondary node (SN). This setup allows a 4G anchor cell to provide control-plane connectivity while 5G NR is used mainly to boost user-plane throughput.
Key characteristics of EN-DC:
- The Master Node (MN) is LTE eNodeB
- The Secondary Node (SN) is NR gNodeB
- Used in NSA (Non-Standalone) 5G deployments
- Signaling and mobility are handled via 4G (EPC – Evolved Packet Core)
- UE connects to LTE first and adds 5G dynamically
EN-DC is commonly used in early 5G rollouts, allowing mobile operators to leverage their existing LTE infrastructure and gradually introduce 5G without overhauling the entire network core.
NE-DC (NR E-UTRA Dual Connectivity)
NE-DC is the reverse of EN-DC, where the 5G NR gNodeB acts as the Master Node and LTE eNodeB is the Secondary Node. This model is typically part of SA (Standalone) 5G deployment, where NR handles both control and user planes using the 5G Core (5GC).
Key characteristics of NE-DC:
- The Master Node (MN) is NR gNodeB
- The Secondary Node (SN) is LTE eNodeB
- Used in SA (Standalone) 5G architectures
- Signaling is managed via the 5G Core (5GC)
- Provides fallback to LTE as needed without switching anchors
NE-DC enables full 5G capabilities with reduced dependency on 4G infrastructure, supporting advanced use cases such as ultra-low latency and network slicing.
What is NR-DC?
NR-DC (NR-NR Dual Connectivity) is a dual connectivity setup where both the Master and Secondary Nodes are 5G gNodeBs. This is used in full 5G networks, especially to aggregate different NR bands like Sub-6 GHz and mmWave for maximum throughput.
Can the same UE support both EN-DC and NE-DC?
Yes, multi-mode UEs compliant with 3GPP Release 15 and above can support multiple dual connectivity options, including EN-DC, NE-DC, and NR-DC. The actual configuration depends on the network’s architecture and operator strategy.
Which one is more common: EN-DC or NE-DC?
EN-DC is more commonly deployed in initial 5G rollouts due to its compatibility with existing LTE infrastructure. NE-DC is expected to become more prevalent as Standalone 5G networks expand globally.