Architecture
Existing architecture is leveraged to support the network slicing in Guilin release. It has the below predominant elements.
- Netconf Servers
- Ransim Controller
- Ransim DB
Netconf Servers
1. Each network function in the RAN network is realized by a Netconf server. The network functions are NearRTRIC, gNBCUCPFunction, gNBCUUPFunction, gNBDUFunction. RAN Network’s YANG model is attached.
yang_ran-network@2020-08-06.yang
2. RAN Network’s topology is maintained in ransim DB (mariaDB implementation). Based on the topology defined, netconf servers are spawned. Current topology supports, 2 NearRTRIC, 2 gNBCUCPFunction, 2 gNBCUUPFunction, 6 gNBDUFunction ans 30 cells. It is modifiable.
3. When a netconf server is spawned, it opens a websocket connection to Ransim controller and communicate via websocket messages.
4. Initial configuration for the netconf servers is simulated from ransim controller. Once the netconfserver is configured, it will be mounted to SDN-R.
Ransim Controller
1.Ransim controller acts as the simulator for the Honeycomb netconf servers.
2. Netconf servers ping Ransim Controller with the IP and port.
3. Once the websocket connection is received from the netconf agent, Ransim controller identifies the netconf agent as the specific network function (NEarRTRIC, CUCP, CUUP, DU) based on the topology and maintains the active sessions.
4. It sends the initial configuration to netconf servers via websocket messages.
5. It also takes care of distribution of NearRTRIC configuration to the cells associated with DU function
6. PM data for closed loop and intelligent slicing usecases are generated by Ransim controller.
Ransim DB:
1. MariaDB is used to implement ransim DB.
2. Ransim DB houses the below details:
- Network functions’ topology and Initial configuration details
- Slice configuration of network functions
- RRMPolicy Details
- Tracking Area to Cell mapping
Network Slicing impacts:
When a request is received from SDN-R to Netconf servers, slice configuration and RRM policy updates are done in the yang structures and websocket message is sent to ransim controller to store the details in DB.
REST APIs are exposed in Ransim Controller to Start/Stop the RAN network slice simulation.
Start RAN network slice simulation API:
- It will populate the network function server Id based on the topology that need to be assigned to netconf server when it is spawned.
- Read the dump json file which will preload CUCP config data (PLMNInfo of each cell) in to ransimDB.
- Prepare unassignedServerIds map with RTRIC network function Id, when a netconf server is spawned the server Id from unassignedServerIds map will be assigned and it will load respective cellList from respective entity into unassignedCellIds map. When the subsequent netconf servers are spawned the server Id will be assigned from unassignedCellIds map.
- The client will seed the initial configuration of read/write data for each Node and initial configuration of read/only data for each node will be send as a websocket message to netconf server.
Closed Loop & Intelligent Slicing impacts:
PM data is generated for both the closed loop and intelligent slicing usecases.
PM data simulated in ran sim controller is sent to Netconf server via websocket message. It is parsed, converted to binary data and compressed in Honeycomb. This file is stored at SFTP in compressed form, later it will be read by DFC.
Below REST APIs are exposed for PM data generation.
- Start/Stop generate PM data of the simulated CUCP netconf server - Intelligent slicing
- Start/Stop generate PM data of the simulated DU netconf server – Closed Loop
VES Notification - Fileready event
File ready event is triggered from Honeycomb agent to VES collector. This event contains SFTP location of the PM data file and other details. PM data file name is aligned with 3GPP specification 32.432-5.1.2
Sample file ready event:
$ curl -k -u sample1:sample1 -X POST https://localhost:8443/eventListener/v7 -i -H "Content-Type:application/json" --data '{
"event": {
"commonEventHeader": {
"version": "4.0.1",
"vesEventListenerVersion": "7.0.1",
"domain": "notification",
"eventName": "Notification_RnNode-Slicing_FileReady",
"eventId": "FileReady_1797490e-10ae-4d48-9ea7-3d7d790b25e1",
"lastEpochMicrosec": 8745745764578,
"priority": "Normal",
"reportingEntityName": "otenb5309",
"sequence": 0,
"sourceName": "oteNB5309",
"startEpochMicrosec": 8745745764578,
"timeZoneOffset": "UTC+05.30"
},
"notificationFields": {
"changeIdentifier": "PM_MEAS_FILES",
"changeType": "FileReady",
"notificationFieldsVersion": "2.0",
"arrayOfNamedHashMap": [
{
"name": "A20161224.1045-1100.bin.gz",
"hashMap": {
"location": "ftpes://192.168.0.101:22/ftp/rop/A20161224.1045-1100.bin.gz",
"compression": "gzip",
"fileFormatType": "org.3GPP.32.435#measCollec",
"fileFormatVersion": "V10"
}
}
]
}
}
}'