5G NR-DC/NRDC Introduction 1.0 #NR #5G

Background: NRDC comes under the umbrella of dual connectivity. Dual connectivity option was first introduced in LTE (Rel 12), where a UE can be connected to two eNB nodes. In rel-15 this feature was expanded to NR as well where connected nodes can be LTE-NR or NR-NR. 2 nodes are connected using non-ideal backhaul.

Earlier this feature was called Multi RAT dual connectivity but now being called Mult Radio Dual Connectivity (MR-DC).

MRDC broadly classified into two types:

                 1. Core node EPC

·        ENDC (EUTRA-NR Dual connectivity) 

2. Core node 5GC

·        NEDC (NR-EUTRA Dual connectivity) 

·        NGENDC (New radio EUTA-NR dual connectivity) 

·        NRDC (NR-NR dual connectivity

Different Deployment options as per 3GPP:

 

NRDC (New Radio-New Radio Dual connectivity): In this deployment option two NR nodes are connected to non-ideal backhaul connection. Connection between the two nodes Xn.

This deployment option can be used mainly for:

•      load balancing of Master node
•      Support for both frequency ranges of NR (FR1 and FR2) at the same time

 

Basic terminologies for NRDC:

1.      Master Node: Node connected to AMF or having major c-plane signaling control.

2.      Secondary Node: Node added to enhance the data or don’t have much c-plane control

3.      PCell: Primary cell of Master node

4.      PScell: Primary cell of the secondary node

5.      MCG: cell/s configured to UE from Master node.

6.      SCG: cell/s configured to UE from secondary node.