I have very limited knowledge in term of 5G network architecture but I would like to share that limited knowledge. Please correct me if anyone finds content in wrong. Next generation telecom network covers both radio and core network changes. As far as I know, following options have been defined for next generation network:
Option 3
In this option, next generation radio network node would be deployed with LTE eNodeB and LTE EPC. Next generation radio node (gNB) will have control and data path connection through eNodeB.
Option 3A
In this option, network would be deployed with eNodeB and LTE EPC but next generation radio node (gNB) will be having user plane connectivity directory through LTE EPC
Option 2
In this option, next generation radio and core network nodes such as NGCN and gNB would be deployed to create and server the subscribers.
Option 4
In this option, next generation core network (NGCN) will be connected to gNB but along with this network, LTE eNodeB would also be connected to NGCN via gNB.
Option 4A
This option has minor change compared to option 4 as explained above. LTE eNodeB would be connected to NGCN directly for user path but gNB would be connected to NGCN directly.
Option 7
NGCN will be directly connected to LTE eNodeB but gNB will have connection to NGCN through LTE eNodeB.
Option 7 A
gNB node will have data plane connectivity with NGCN directly.