Issues regarding handover testing

[laxmandvb]

We are trying intra DU handover. we are able to create two cells with PCI = 1, 2 and connected to RUs. But unable to include mobility related parameters in the gNB configuration file. Under section srsRAN gNB Handover, we are unable to download sample configuarion file "handover_x310.yml".

Request you to provide sample configuration file for handover and guide us for successful hand over testing.

Regards,
Laxmaiah.

[pgawlowicz]

Hi, thanks for pointing this out. The link will be fixed soon.

[brendan-mcauliffe]

@pgawlowicz @laxmandvb this issue has been fixed.

[laxmandvb]

Thanks for the support

[HaoxinSEU]

Hi @brendan-mcauliffe,

Thanks for the update! We are excited to see the new features.

However, with the provided handover_x310.yml, we get the error:

For external cells, the gnb_id_bit_length, pci, band, ssb_arfcn, ssb_scs, ssb_period, ssb_offset and ssb_duration must be configured in the mobility config
srsGNB ERROR: Invalid configuration detected.

It seems that we need to provide more configurations in cu_cp:mobility:cells session. Can you give some hints on this? Thanks so much!

We are using the latest main branch (commit 1483bda3091420cf7270eacdf31de932865c6294), and the configuration is:

gnb_id: 147
gnb_id_bit_length: 32

amf:
  addr: 10.43.31.80
  bind_addr: 10.42.1.79

ru_sdr:
  device_driver: uhd
  device_args: type=x300
  tx_gain: 20
  rx_gain: 15
  srate: 92.16
  lo_offset: 45
  clock: internal
  sync: internal
  time_alignment_calibration: 0

cell_cfg:
  dl_arfcn: 640000
  band: 78
  channel_bandwidth_MHz: 20
  common_scs: 30
  nof_antennas_dl: 1
  nof_antennas_ul: 1
  plmn: "00103"
  tac: 1

cells:
  -
    pci: 1
    prach:
      prach_root_sequence_index: 0
  -
    pci: 2
    prach:
      prach_root_sequence_index: 64

cu_cp:
  mobility:
    trigger_handover_from_measurements: true
    cells:
      - nr_cell_id: 0x19B0
        periodic_report_cfg_id: 1
        ncells:
          - nr_cell_id: 0x19B1
            report_configs: [ 1 ]
      - nr_cell_id: 0x19B1
        periodic_report_cfg_id: 1
        ncells:
          - nr_cell_id: 0x19B0
            report_configs: [ 1 ]
    report_configs:
      - report_cfg_id: 1
        report_type: periodical
        report_interval_ms: 480
      - report_cfg_id: 2
        report_type: event_triggered
        a3_report_type: rsrp
        a3_offset_db: 3
        a3_hysteresis_db: 0
        a3_time_to_trigger_ms: 100

[FabianEckermann]

Hi @HaoxinSEU! Your gnb_id doesn't match the nr_cell_id of the two cells. The nr_cell_id is constructed from the gnb_id (among_others), so you need to change it accordingly.

[HaoxinSEU]

Hi @FabianEckermann ,

Thanks for the information! Very useful!

[yc541]

I have tested HO with the sample HO yml and the UE has been successfully handed over between two cells. However, once the HO happens, the UE loses Internet and can't ping the core. The UE has Internet and can reach the core after the initial attach (but before any HO, automatic or forced). Has anyone seen the same issue?

[andrepuschmann]

@yc541 Please send full logs with all_level=info and PCAPs and we'll have a loo. Please also describe your exact setup. Also it might be worth to open a separate issue for that.