NR Dual Connectivity (EN-DC)
Talk about Dual connectivity In a Simple words Dual connectivity means UE can get resources from two different enodeB's that is Master Enodeb and Secondary Enodeb . Sometime back in Rel12 of 3GPP has introduced this Dual connectivity concept but for NR deployment dual connectivity plays major role . In NR , E-Utran NR dual connectivity (EN-DC) will have two nodes 1. First one is Master Enb i.e. Enb (LTE) and 2. second one is Secondary Enb i.e. gNB (NR) So , First UE will connect to one Enb that acts as Master Enb and the other one will act as Secondary Enb . For EN-DC , UE will connect to LTE (i.e Menb ) and later UE will get an access to Senb via SCG addition procedure . For EN-DC 3GPP specifies three different types of bearer i.e. (MCG,SCG,SPLIT). For more details about Multi Rat dual connectivity you can refer spec 37.340