What is eLTE eNB?
An eLTE eNB is an evolved 4G eNodeB that has been upgraded to support connectivity to both the legacy 4G Evolved Packet Core (EPC) and the 5G Next-Generation Core (5GC). This dual-connectivity capability enables operators to provide 5G core network services to LTE users without replacing their existing radio infrastructure, serving as a key element in the migration path from 4G to 5G Standalone architecture.
How Does eLTE eNB Work?
The eLTE eNB connects to the 5GC via the NG interface (specifically NG-C to the AMF and NG-U to the UPF), while maintaining its S1 interface to the legacy EPC. This allows it to serve UEs that support connection to the 5GC through LTE radio access. The eLTE eNB can interwork with gNBs via the Xn interface, enabling handovers and dual connectivity between LTE and NR. It implements the necessary protocol adaptations to support 5GC procedures such as network slicing, policy control via PCF, and registration via AMF, while using the LTE air interface for radio transmission.
Use Cases
4G-to-5G migration without radio hardware replacement, 5GC feature delivery to existing LTE subscribers, interworking with gNB for mobility and load balancing, rural coverage extension using existing LTE sites connected to 5GC, and gradual migration of subscribers from EPC to 5GC.
3GPP / Standards Reference
3GPP TS 37.340 (Multi-connectivity — NR and E-UTRA), 3GPP TS 38.401 (NG-RAN architecture), 3GPP TS 23.501 (5G system architecture)
Related Terms
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