ENDC Entity in NSA Deployment

:eyes: Know the important entity of ENDC operation in NSA Deployment (Option 3) through below diagram.

:sparkles: Important Entity

  • NSA: Non Standalone
  • ENDC: E-utran New Radio Dual Connectivity
  • MCG : Master Cell Group
  • SCG: Secondary Cell Group
  • PCell : Primary Cell of Master RAN Node
  • PSCell : Primary Cell of Secondary RAN Node
  • Scell : Secondary Cell of Master and Secondary RAN Node
  • SpCell: Special Cell

:ok_hand: User Plane Radio Bearer: MCG Bearer, SCG Bearer, Split Bearer (MCG Split Bearer, SCG Split Bearer)

:ok_hand: Control Plane SRB Split : SRB 1 & SRB 2 can be configured as a split bearer for control information. SRB 0 and SRB 3 can not be configured for split option.

SRB 3 is optional that can be used in ENDC operation for direct communication between secondary node and UE.

LinkedIn: Pawan Kumar Choudhary on LinkedIn: #nr #lte #5g #nsa #openran #rftechpoint

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please, why has SCG split been more preferred by industry? why can’t we use MCG split instead to avoid switching s1_u path every time 5g leg is being added?

I think because If you use MCG Split bearer, you have to improve the S1 and X2 link to support 5G traffic , instead of only add S1 link to gNb

you mean SCG split helps offloading traffic of s1_u link to enb(SGW-enb) and reducing enb processing load.

1- Less changes in eNB legacy implementation
2- SCG resources will be used for small sessions when split is not needed