For release R3 to R10, the RAN-Sim RAN Simulator provided an abstraction of network of O-CU and O-DU with a northbound interface aligning to O-RAN O1. As shown in Figure 1, RAN-Sim provides:
- NF modules representing the CU/DU Network Functions (NF)
- Netconf servers to terminate the O1 interface from SDN-R to the CU/DU
- VES agents generating O1-aligned VES messages for PM kpi, FM fault notifiction, and CM update
- RAN-Sim Controller with support for a Web GUI and an internal database of cells and configuration
Figure 1: Rel 10 RAN-Sim functional architecture ONAP Rel 10 with northbound O1 interface support (netconf config and PM/FM/CM VES) from CU/DU RAN NF modules.
Figure 2 shows the release R11 enhancements in RAN-Sim RAN Simulator which add:
- A1 Termination hosting A1 interface to A1 Policy Management Service in SDN-R
- ran-app abstraction of xApp hosted on Near-RT RIC
- Websocket interface from ran-app to RANSim Controller to provide E2-like interaction from xApp to CU/DU.
More details are provided in : A1 Support in RanSim Simulator
Figure 2: Rel11 RAN-Sim functional architecture for ONAP Rel11 with (a) northbound O1 interface support (netconf config and PM/FM/CM VES) from CU/DU RAN NF modules, and (b) northbound A1 interface support from A1 Termination and ran-app abstraction of xApps hosted on Near-RT RIC controlling the CU/DU modules.