Get measurement report from neighboring cells and the serving cell

[HaoxinSEU]

Hi community,

Thanks for the work on handover! We are trying to get the measurement reports from the connected UE about different cells. We read the tutorial about handover, and understand that it's possible to get reports for multiple DUs that are connected to one CU.

Thus, we are wondering if it's also possible to get the measurement reports for different monolithic gNBs?

Thanks for your help!

[HaoxinSEU]

We managed to change the RRC reconfiguration signaling to include the neighboring cell (measId 2). But the UE report only contains the serving cell... Does anyone have a hint on this? Thanks!

Here is part of the RRC reconfiguration signaling:

                  "measObjectToAddModList": [
                    {
                      "measObjectId": 1,
                      "measObject": {
                        "measObjectNR": {
                          "ssbFrequency": 639648,
                          "ssbSubcarrierSpacing": "kHz30",
                          "smtc1": {
                            "periodicityAndOffset": {
                              "sf10": 0
                            },
                            "duration": "sf5"
                          },
                          "referenceSignalConfig": {
                            "ssb-ConfigMobility": {
                              "deriveSSB-IndexFromCell": true
                            }
                          },
                          "nrofSS-BlocksToAverage": 8,
                          "quantityConfigIndex": 1,
                          "offsetMO": {
                          },
                          "freqBandIndicatorNR": 78
                        }
                      }
                    }
                  ],
                  "reportConfigToAddModList": [
                    {
                      "reportConfigId": 1,
                      "reportConfig": {
                        "reportConfigNR": {
                          "reportType": {
                            "periodical": {
                              "rsType": "ssb",
                              "reportInterval": "ms480",
                              "reportAmount": "infinity",
                              "reportQuantityCell": {
                                "rsrp": true,
                                "rsrq": true,
                                "sinr": true
                              },
                              "maxReportCells": 4,
                              "reportQuantityRS-Indexes": {
                                "rsrp": true,
                                "rsrq": true,
                                "sinr": true
                              },
                              "maxNrofRS-IndexesToReport": 4,
                              "includeBeamMeasurements": true,
                              "useAllowedCellList": false
                            }
                          }
                        }
                      }
                    },
                    {
                      "reportConfigId": 2,
                      "reportConfig": {
                        "reportConfigNR": {
                          "reportType": {
                            "eventTriggered": {
                              "eventId": {
                                "eventA3": {
                                  "a3-Offset": {
                                    "rsrp": 3
                                  },
                                  "reportOnLeave": false,
                                  "hysteresis": 0,
                                  "timeToTrigger": "ms40",
                                  "useAllowedCellList": false
                                }
                              },
                              "rsType": "ssb",
                              "reportInterval": "ms1024",
                              "reportAmount": "infinity",
                              "reportQuantityCell": {
                                "rsrp": true,
                                "rsrq": true,
                                "sinr": true
                              },
                              "maxReportCells": 4,
                              "reportQuantityRS-Indexes": {
                                "rsrp": true,
                                "rsrq": true,
                                "sinr": true
                              },
                              "includeBeamMeasurements": true
                            }
                          }
                        }
                      }
                    }
                  ],
                  "measIdToAddModList": [
                    {
                      "measId": 1,
                      "measObjectId": 1,
                      "reportConfigId": 1
                    },
                    {
                      "measId": 2,
                      "measObjectId": 1,
                      "reportConfigId": 2
                    }
                  ],

And the full RRC log is here:
gnb_rrc.log

[pgawlowicz]

did you configure neighboring cells in the gnb config?:

cu_cp:
mobility:
  trigger_handover_from_measurements: true  # Set the CU-CP to trigger handover when neighbor cell measurements arrive
  cells:                                    # List of cells available for handover known to the cu-cp
    - nr_cell_id: 0x19B0                      # Cell ID for cell 1
      periodic_report_cfg_id: 1               #
      ncells:                                 # Neighbor cell(s) available for handover
        - nr_cell_id: 0x19B1                    # Cell ID of neighbor cell available for handover
          report_configs: [ 1 ]                 # Report configurations to configure for this neighbor cell
    - nr_cell_id: 0x19B1                      # Cell ID for cell 2
      periodic_report_cfg_id: 1               #
      ncells:                                 # Neighbor cell(s) available for handover
        - nr_cell_id: 0x19B0                    # Cell ID of neighbor cell available for handover
          report_configs: [ 1 ]                 # Report configurations to configure for this neighbor cell

[HaoxinSEU]

Hi Piotr,

Thanks for your reply! Yes, we configure the neighboring cells ncells, and it is reflected in RRC reconfiguration messages. But the UE seems to not respond to it... We will investigate more about this and post here if we have any progress.