5G X2/Xn Interface Between RAN Nodes

  • The X2 interface is used for communication between RAN nodes in non-standalone operation, such as between eNBs in LTE and between en-gNBs and eNBs in 5G.

  • The Xn interface is a new interface specified for communication between RAN nodes in standalone operation, such as between ng-eNBs and gNBs.

  • The extensions of X2 include functions for EN-DC (Evolved NodeB – Dual Connectivity) and flow control for split bearers in non-standalone operation.

  • X2 interface is used between eNBs in LTE and between RAN nodes in non-standalone operation (between eNB and en‒gNB).

  • Xn interface is newly specified between RAN nodes in standalone operation (between ng‒eNB and ng‒eNB/gNB and gNB/ng‒eNB and gNB).

  • Extensions of X2 include functions adopting EN-DC and flow control for split bearers for non-standalone operation
    Flow control function, which was defined for LTE-DC split bearers in Release 12, is used to split downlink data when using radio resources of multiple RAN nodes.

  • Xn is based on the X2 function but with enhanced UE context management function for adopting new QoS flow framework and network slice.

Credits: :point_down: