This page documents the inFlux DB schema used in the E Release for the KPM (and other) information collected from E2 Simulator.

Summary / Goals

The goal is to have a generic schema definition for xApps to access timeseries data obtained via E2SM/KPM and possibly the other E2SM protocols.

References

• E2SM-KPM specs
• TS 28.552 "5G performance measurements"
• InfluxDB glossary - https://docs.influxdata.com/influxdb/v1.8/concepts/glossary
• Viavi RIC Test User Manual

Glossary

• SDL: Shared Data Layer, a term referring to the services and schemas used to share data among xApps

Essential InfluxDB terms:

• Database: the highest level unit of storage
• Measurement: a table inside a database
• Data point: a row inside a Measurement table.
• Field: a sort of column of a Measurement table, with name and type of data.
  • Note that not all fields need to be present in all data points
• Tag: a metadata field that is indexed so queries on them are performant

Guidelines

• For items not explicitly defined in O-RAN specs, look for relevant 3GPP specs.
• Field and tag names should be brief because the may pose a direct impact on InfluxDB performance at high loads.
• For proprietary/enrichment data fields, use a brief vendor prefix e.g. "Viavi."

Proposed Schema for E2SM/KPM data

• Database name: “E2SM-KPM”

For the labelling of fields we will be using names from E2SM/KPM v2.0 (MeasurementLabel) and TS 28.552 "5G performance measurements" as much as possible.

Following the general ideas in from TS 28.552, using short labels, organized in hierarchical form <topic>[.<subtopic>].<name>

KPM Measurement tables:

1. "CellReports" table containing the following fields:

   1. Timestamp

   2. PLMN (tag)
   3. KPMNodeID (tag) - The KPM Node identification in string form to accomodate the many binary variants (maybe an hex dump?)
   4. S-NSSAI (tag?) - useful to identify slices?

   5. NRCellIdentity (tag?)
      
      Any of the fields defined for cell reports in TS 28.552, for example the following are provided by RIC Test scenario generator:

   6. DRB.UEThpDl - Average DL throughput in Kb/s

   7. RRU.PrbUsedDl / RRU.PrbAvailDl

   8. RRU.PrbUsedUl / RRU.PrbAvailUl

   9. QosFlow.PdcpPduVolumeUl - UL PDCP PDU Data Volume (amount of kilobytes in the reporting period)

   10. QosFlow.PdcpPduVolumeDl - DL PDCP PDU Data Volume (amending inconsistency in the case of the final "L" in TS 28.552)
       
       And proprietary extensions:

   11. Viavi.Geo.x - Non standard / Viavi proprietary extension / External enrichment

   12. Viavi.Geo.y

   13. Viavi.Geo.z
       

2. "UeReports" measurement table containing the following fields:

   1. Timestamp

   2. UE.Id - String representation to accomodate the many forms.
      Note: A "UE id resolution" xApp may be needed to match the same UE on different measurements and possibly producing unique ids for this field
      

   3. Slice.Id

   4. DRB.UEThpDl - TS 28.552 Average DL UE throughput

   5. RRU.PrbUsedDl - TS 28.552 DL PRB used for data traffic

   6. Viavi.Geo.x”, .y, .z...  Viavi proprietary extensions

   7. RF.serving.Id - May be just the PCI or resolved into NRCellIdentity

   8. RF.serving.RSRP (Loosely based on LTE specs)

   9. RF.serving.RSRQ

   10. RF.serving.RSSINR

   11. RF.nb1.CellId - 1st neighbour id

   12. RF.nb1.RSRP, etc. 1st neighbour signal levels

   13. RF.nb2.CellId - 2nd neighbour id

   14. RF.nb2.RSRP, etc. 2nd neighbour signal levels

3. "cellMeasReport" cell load measurement table has the following fields:
   1. Timestamp
   2. DLOccupyPRBNum – 3GPP supported
   3. CellDLMACRate – proprietary
   4. ULSINR – proprietary
   5. MCS – proprietary
   6. PDCPOccupBuffer – proprietary
   7. PDCPUnusedBuffer – proprietary
   8. DLPacketDiscardNum – proprietary
   9. DLPacketSDUNum – 3GPP supported
   10. DLPacketLossNum – 3GPP supported
   11. DLMACRate – proprietary