Intra-gNB handover using two RUs

[radutipurita]

Hello,

I am currently working on a project where I would like to deploy two base stations so that I can gather more channel state information elements. After doing a bit of research I came across this discussion and in the responses it is mentioned that inter gNB handover is not supported. That said, the documentation documents mention that intra handover is supported.
I was curious if it would be possible to run a intra handover setup by using two single channel SDRs instead of the dual channel USRP. The SDR we are using is the BladeRF and we have managed to make it work with just one RU. We have tried to setup with two SDRs but it does not seem to recognize the second SDR. This is our current yaml file:

gnb_id: 411
gnb_id_bit_length: 32
   
cu_cp:
  amf:
    addr: open5gs-amf-ngap.core
    bind_addr: 10.42.0.181
    supported_tracking_areas:
      - tac: 1
        plmn_list:
          - plmn: "00108"
            tai_slice_support_list:
              - sst: 1
                sd: 0
  inactivity_timer: 7200

  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                                 # Set the periodic report configuration ID for this cell
        ncells:                                                   # Neighbor cell(s) available for handover
          - nr_cell_id: 0x19B1                                      # Cell ID of neighbor cell available for handover
            report_configs: [ 2 ]                                   # Report configurations to configure for this neighbor cell
      - nr_cell_id: 0x19B1                                        # Cell ID for cell 2
        periodic_report_cfg_id: 1                                 # Set the periodic report configuration ID for this cell
        ncells:                                                   # Neighbor cell(s) available for handover 
          - nr_cell_id: 0x19B0                                      # Cell ID of neighbor cell available for handover
            report_configs: [ 2 ]                                   # Report configurations to configure for this neighbor cell
    report_configs:                                             # Sets the report configuration for triggering handover
      - report_cfg_id: 1                                          # Report config ID 1 
        report_type: periodical                                   # Sets the report type as periodical
        report_interval_ms: 480                                   # Sets to report every 480ms 
      - report_cfg_id: 2                                          # Report config ID 2
        report_type: event_triggered                              # Sets the report type as event triggered
        event_triggered_report_type: a3                           # Sets the event triggered report type as A3               
        meas_trigger_quantity: rsrp                               # Sets the measurement trigger quantity as rsrp
        meas_trigger_quantity_offset_db: 3                        # Sets the measurement trigger quantity offset to 3dB
        hysteresis_db: 0                                          # Sets the hysteresis to 0dB
        time_to_trigger_ms: 100                                   # Sets the time to trigger to 100ms



cells:
  -
    pci: 1
    prach:
      prach_root_sequence_index: 0
  -
    pci: 2
    prach:
      prach_root_sequence_index: 64
ru_sdr:
  device_driver: bladerf
  srate: 23.04
  otw_format: sc16
  tx_gain: 66
  rx_gain: 15

cell_cfg:
  dl_arfcn: 632628
  band: 78
  channel_bandwidth_MHz: 20
  common_scs: 30
  plmn: "00108"
  tac: 1
  slicing:
    - sst: 1
      sd: 0
  pci: 1
  tdd_ul_dl_cfg:
    dl_ul_tx_period: 4
    nof_dl_slots: 2
    nof_dl_symbols: 10
    nof_ul_slots: 1
    nof_ul_symbols: 0
  nof_antennas_ul: 1
  nof_antennas_dl: 1
  pdsch:
    mcs_table: qam256
  pusch:
    mcs_table: qam64
    max_ue_mcs: 27
  pucch:
    sr_period_ms: 10

log:
  filename: /tmp/gnb.log
  all_level: debug

pcap:
  mac_enable: false
  mac_filename: /tmp/gnb_mac.pcap
  ngap_enable: false
  ngap_filename: /tmp/gnb_ngap.pcap

metrics:
    autostart_stdout_metrics: 1

Thank you in advance for any suggestions, and I apologize if I'm overlooking something obvious, I'm still a beginner in this field.

Best regards,
Radu