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UE Fails to Complete Synchronization (PSS) Process

Branch: 2023.w41

I'm using CU & DU split mode to set up the gNB, and all components, including nrUE, are in rfsimu mode.

I've confirmed that both CU and DU can start up successfully, and DU can also connect to CU.

When the nrUE attempts to connect du, it keeps trying to sync up, but unfortunately, it can't successfully finish the synchronization.

However, if I use just single gNB, this issue doesn't occur.

Here are the commands I'm using:

Start CU

sudo RFSIMULATOR=server ./nr-softmodem --rfsim --sa -O ../../../targets/PROJECTS/GENERIC-NR-5GC/CONF/cu_gnb.conf --sa -E

Start DU

sudo RFSIMULATOR=server ./nr-softmodem --rfsim --sa -O ../../../targets/PROJECTS/GENERIC-NR-5GC/CONF/du_gnb.conf --sa -E

Start UE

sudo ./nr-uesoftmodem -r 106 --numerology 1 --band 78 -C 3619200000 --rfsim --sa --nokrnmod -O …/…/…/targets/PROJECTS/GENERIC-NR-5GC/CONF/ue.conf --rfsimulator.serveraddr 127.0.0.1

UE log:

[NR_RRC]   create TASK_RRC_NRUE 
[UTIL]   Creating thread TASK_RRC_NRUE with affinity -1 and priority 50
[LOADER] library librfsimulator.so successfully loaded
[LIBCONFIG] rfsimulator: 9/9 parameters successfully set, (8 to default value)
[HW]   sample_rate 61440000.000000
[HW]   Running as client: will connect to a rfsimulator server side
Initializing random number generator, seed 11296701583157242927
[HW]   [RRU] has loaded RFSIMULATOR device.
[HW]   running command "/sbin/sysctl -n -e -q -w net.core.rmem_default=134217728" to increase RFsim performance
[HW]   running command "/sbin/sysctl -n -e -q -w net.core.rmem_max=134217728" to increase RFsim performance
[ITTI]   Created Posix thread TASK_RRC_NRUE
[UTIL]   Creating thread TASK_NAS_NRUE with affinity -1 and priority 50
[HW]   running command "/sbin/sysctl -n -e -q -w net.core.wmem_default=134217728" to increase RFsim performance
[HW]   running command "/sbin/sysctl -n -e -q -w net.core.wmem_max=134217728" to increase RFsim performance
[ITTI]   Created Posix thread TASK_NAS_NRUE
[LIBCONFIG] uicc0: 10/10 parameters successfully set, (4 to default value)
[SIM]   UICC simulation: IMSI=208950000000031, IMEISV=6754567890123413, Ki=0C0A34601D4F07677303652C0462535B, OPc=63bfa50ee6523365ff14c1f45f88737d, DNN=oai, SST=0x01, SD=0x000001
[HW]   Trying to connect to 127.0.0.1:4043
[HW]   Connection to 127.0.0.1:4043 established
[HW]   connect() to 127.0.0.1:4043 failed, errno(0)
[PHY]   [SCHED][UE] Check absolute frequency DL 3619200000.000000, UL 3619200000.000000 (RF card 0, oai_exit 0, channel 0, rx_num_channels 1)
[NR_PHY]   Starting sync detection
[PHY]   [UE thread Synch] Running Initial Synch 
Entering ITTI signals handler
TYPE <CTRL-C> TO TERMINATE
[PHY]   [UE] nr_synchro_time: Sync source = 1, Peak found at pos 428440, val = 448663165 (86 dB) avg 56 dB, ffo 0.000000
[PHY]   PSS execution duration 5173641 microseconds 
[PHY]   [UE0] Initial sync : Estimated PSS position 428440, Nid2 1
[PHY]   sync_pos 428440 ssb_offset 428296 
[PHY]   Calling sss detection (normal CP)
[PHY]   TDD Normal prefix: CellId 199 metric 222, phase 8, pbch 1
[PHY]   [UE] nr_synchro_time: Sync source = 0, Peak found at pos 0, val = 0 (0 dB) avg 0 dB, ffo 0.000000
[PHY]   PSS execution duration 2525856 microseconds 
[PHY]   [UE0] Initial sync : Estimated power: 0 dB
[PHY]   [SCHED][UE] Check absolute frequency DL 3619200000.000000, UL 3619200000.000000 (RF card 0, oai_exit 0, channel 0, rx_num_channels 1)
[NR_PHY]   Starting sync detection
[PHY]   [UE thread Synch] Running Initial Synch 
[PHY]   [UE] nr_synchro_time: Sync source = 1, Peak found at pos 425856, val = 636554957 (88 dB) avg 56 dB, ffo 0.000000
[PHY]   PSS execution duration 2554468 microseconds 
[PHY]   [UE0] Initial sync : Estimated PSS position 425856, Nid2 1
[PHY]   sync_pos 425856 ssb_offset 425712 
[PHY]   Calling sss detection (normal CP)
[PHY]   TDD Normal prefix: CellId 499 metric 9040, phase 8, pbch 1
[PHY]   [UE] nr_synchro_time: Sync source = 0, Peak found at pos 0, val = 0 (0 dB) avg 0 dB, ffo 0.000000
[PHY]   PSS execution duration 2528018 microseconds 
[PHY]   [UE0] Initial sync : Estimated power: 0 dB
[PHY]   [SCHED][UE] Check absolute frequency DL 3619200000.000000, UL 3619200000.000000 (RF card 0, oai_exit 0, channel 0, rx_num_channels 1)
[NR_PHY]   Starting sync detection
[PHY]   [UE thread Synch] Running Initial Synch 
[PHY]   [UE] nr_synchro_time: Sync source = 0, Peak found at pos 0, val = 0 (0 dB) avg 0 dB, ffo 0.000000
[PHY]   PSS execution duration 2868200 microseconds 
[PHY]   [UE] nr_synchro_time: Sync source = 1, Peak found at pos 118656, val = 572060074 (87 dB) avg 56 dB, ffo 0.000000
[PHY]   PSS execution duration 2904164 microseconds 
[PHY]   [UE0] Initial sync : Estimated PSS position 118656, Nid2 1
[PHY]   sync_pos 118656 ssb_offset 118512 
[PHY]   Calling sss detection (normal CP)
[PHY]   TDD Normal prefix: CellId 997 metric 10025, phase 10, pbch 1
[PHY]   [UE0] Initial sync : Estimated power: 0 dB
[PHY]   [SCHED][UE] Check absolute frequency DL 3619200000.000000, UL 3619200000.000000 (RF card 0, oai_exit 0, channel 0, rx_num_channels 1)
[NR_PHY]   Starting sync detection
[PHY]   [UE thread Synch] Running Initial Synch 
[PHY]   [UE] nr_synchro_time: Sync source = 0, Peak found at pos 0, val = 0 (0 dB) avg 0 dB, ffo 0.000000
[PHY]   PSS execution duration 2607531 microseconds 
[PHY]   [UE] nr_synchro_time: Sync source = 2, Peak found at pos 119888, val = 481234370 (86 dB) avg 56 dB, ffo 0.000000
[PHY]   PSS execution duration 2796281 microseconds 
[PHY]   [UE0] Initial sync : Estimated PSS position 119888, Nid2 2
[PHY]   sync_pos 119888 ssb_offset 119744 
[PHY]   Calling sss detection (normal CP)
[PHY]   TDD Normal prefix: CellId 692 metric 5963, phase 11, pbch 1
[PHY]   [UE0] Initial sync : Estimated power: 0 dB
[PHY]   [SCHED][UE] Check absolute frequency DL 3619200000.000000, UL 3619200000.000000 (RF card 0, oai_exit 0, channel 0, rx_num_channels 1)
[NR_PHY]   Starting sync detection
[PHY]   [UE thread Synch] Running Initial Synch 
[PHY]   [UE] nr_synchro_time: Sync source = 0, Peak found at pos 0, val = 0 (0 dB) avg 0 dB, ffo 0.000000
[PHY]   PSS execution duration 5508158 microseconds 
[PHY]   [UE] nr_synchro_time: Sync source = 0, Peak found at pos 119640, val = 494590714 (87 dB) avg 56 dB, ffo 0.000000
[PHY]   PSS execution duration 3453718 microseconds 
[PHY]   [UE0] Initial sync : Estimated PSS position 119640, Nid2 0
[PHY]   sync_pos 119640 ssb_offset 119496 
[PHY]   Calling sss detection (normal CP)
[PHY]   TDD Normal prefix: CellId 234 metric 7089, phase 5, pbch 1
[PHY]   [UE0] Initial sync : Estimated power: 0 dB
[PHY]   [SCHED][UE] Check absolute frequency DL 3619200000.000000, UL 3619200000.000000 (RF card 0, oai_exit 0, channel 0, rx_num_channels 1)
Edited by Nic Tseng