Synchronize multiple gNBs by aligning the slot boundaries
Currently, we derive frame and slot number based on proc->timestamp_rx
using
proc->frame_rx = (proc->timestamp_rx / (fp->samples_per_subframe*10))&1023;
proc->tti_rx = get_slot_from_timestamp(proc->timestamp_rx, fp);
This ignores the samples
proc->timestamp_rx % fp->samples_per_frame
while computing the frame and slot number creating a mis-alignment with
the slot boundaries. A detailed description of the slot misalignment
in a pictorial representation can be seen in an attachment in the MR [1].
We fix this alignment issue by compensating these samples during the
first reception.
We can test the synchronization of the multiple gNBs from the estimated
ToAs from the PRS in the Downlink and the estimated ToAs from the SRS in
the Uplink using rfsim.
In order to test this, make sure you build gNB and nrUE along with the
telnetsrv flag using the option --build-lib telnetsrv.
Also, enable the following log in the function
nr_est_srs_timing_advance_offset() in
openair1/PHY/NR_ESTIMATION/nr_measurements_gNB.c to observe SRS ToAs
LOG_I(NR_PHY, "SRS estimatd ToA %d [RX ant %d]: TA offset %d, TA offset ns %d (max_val %ld, mean_val %ld, max_idx %d)\n", srs_toa, ant, *ta_offset, *ta_offset_nsec, max_val, mean_val, max_idx);
Furthermore, update the option Active_gNBs = 2; in
targets/PROJECTS/GENERIC-NR-5GC/CONF/ue.nr.prs.fr1.106prb.conf to enable
decoding PRS transmitted from two gNBs
To run:
nrUE:
sudo ./nr-uesoftmodem -r 106 --numerology 1 --band 78 -C 3619200000 --uicc0.imsi 001010000000001 --rfsim --phy-test -O ../../../targets/PROJECTS/GENERIC-NR-5GC/CONF/ue.nr.prs.fr1.106prb.conf --rfsimulator.serveraddr server
gNB 0:
sudo ./nr-softmodem -O ../../../targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb0.prs.band78.fr1.106PRB.usrpx310.conf --gNBs.[0].min_rxtxtime 6 --rfsim --phy-test --rfsimulator.[0].serveraddr 127.0.0.1 --rfsimulator.[0].options chanmod --rfsimulator.[0].modelname AWGN --telnetsrv
gNB 1:
sudo ./nr-softmodem -O ../../../targets/PROJECTS/GENERIC-NR-5GC/CONF/gnb1.prs.band78.fr1.106PRB.usrpx310.conf --gNBs.[0].min_rxtxtime 6 --rfsim --phy-test --rfsimulator.[0].serveraddr 127.0.0.1 --rfsimulator.[0].options chanmod --rfsimulator.[0].modelname AWGN --telnetsrv
When we run the nrUE, gNB0 and gNB1, we can see the following logs
nrUE:
[PHY] [gNB 0][rsc 0][Rx 0][sfn 976][slot 2] DL PRS ToA ==> 0.0 / 2048 samples, peak channel power -16.4 dBm, SNR +4.0 dB, rsrp -42.2 dBm
[PHY] [gNB 1][rsc 0][Rx 0][sfn 976][slot 3] DL PRS ToA ==> 0.0 / 2048 samples, peak channel power -16.4 dBm, SNR +4.0 dB, rsrp -42.2 dBm
gNB 0:
[NR_PHY] SRS estimatd ToA 0 [RX ant 0]: TA offset 31, TA offset ns 0 (max_val 99820162, mean_val 80176, max_idx 0)
gNB 1:
[NR_PHY] SRS estimatd ToA 0 [RX ant 0]: TA offset 31, TA offset ns 0 (max_val 98784562, mean_val 79369, max_idx 0)
From the above logs, when we run the rfsim and when no delays introduced, we can observe the following results
In the Downlink at the UE, the estimated ToAs using PRS from both gNB0
and gNB1 are 0 and in the uplink, the ToA estimated from the SRS
transmitted by the UE at both the gNBs are also 0. This indicates that
both the gNBs are synchronized along with their slot boundaries. We also
highlight that this is not the case in the current develop branch since
the slot boundaries are not aligned.
We also can test the multi gNB synchronization by introducing delays
using telnet as follows,
Introduce new_offset (delay) of 4 samples to the gNB 0 from UE in the
uplink as follows,
openairinterface5g$ echo rfsimu setdistance rfsimu_channel_enB0 20 | ncat --idle 1 127.0.0.80 9080
softmodem_gnb> rfsimu_setdistance_cmd: new_offset 4, new (exact) distance 19.518 m, new delay 0.000065 ms
Ncat: Idle timeout expired (1000 ms).
We can oberve this delay of 4 samples being reflected in the estimated
SRS ToAs at gNB 0 while not changing the ToA in gNB 1
[NR_PHY] SRS estimatd ToA 4 [RX ant 0]: TA offset 31, TA offset ns 65 (max_val 98803636, mean_val 79430, max_idx 8)
similarly, Introduce new_offset (delay) of 2 samples to the gNB 1 from
UE in the uplink as follows,
openairinterface5g$ echo rfsimu setdistance rfsimu_channel_enB0 10 | ncat --idle 1 127.0.0.81 9081
softmodem_gnb> rfsimu_setdistance_cmd: new_offset 2, new (exact) distance 9.759 m, new delay 0.000033 ms
Ncat: Idle timeout expired (1000 ms).
We can oberve this delay of 2 samples being reflected in the estimated
SRS ToAs at gNB 1 while not changing the ToA in gNB 0
[NR_PHY] SRS estimatd ToA 2 [RX ant 0]: TA offset 31, TA offset ns 32 (max_val 98962768, mean_val 79552, max_idx 4)
Closes#897
[1] https://gitlab.eurecom.fr/oai/openairinterface5g/-/merge_requests/3892
Remove L1 dependence from NR band number
L1 band information relied on get_band function that couldn't provide an
unambiguous result. Also there is no SCF compliant parameter for L1 and
generally we don't really need that information in L1.
The MR also remove a RU section that used nr_band but was never really
accessed in NR.
Add missing packing for CONFIG.request parameter BetaPSS
Adds the packing procedure for the parameter BetaPSS, as well as adding this
parameter to the utility functions where it is missing
IPV6 support for telnet socket binding
Now, the listening telnet socket is only bound to the dedicated interface IPs in
config file, both for V4 and V6
Closes#834
Fix handling of IPv4v6 PDU sessions
The code previously checked that the supplied PDU sessions's type is
exactly what we requested. However, at least OAI 5GC will only give us
an IPv4 PDU session if we request IPv4v6 (so the check would fail).
Extend the validation to either check exact match, or, if IPv4v6
requested, that it is either IPv4 or IPv6.
Fix error
openair1/SIMULATION/NR_PHY/dlsim.c:1057:37: runtime error: member access within misaligned address 0x7f8a67e01010 for type 'struct NR_Sched_Rsp_t', which requires 32 byte alignment
Prior to this commit, constants NB_ANTENNAS_RX/TX are provided on the
command line to each compiler invocation. This has the drawback (1) that
also files that don't need that get the constants, and (2) it is not
easy to find them using ctags or similar, as the only definition is in
CMakeLists.txt (where it is not found).
In this commit, use cmake configure_file() to write a header file with
these constants. The file will be generated during cmake invocation, and
written to <build-dir>/common/cmake_defs.h. The relevant files that
need this definition will pick it from the header.
This has been used previously also in a commit to write git information.
See-also: 8bffd1666d ("Avoid complete rebuild on cmake run with git info change")
Since the grand-parent commit, if possible, the gNBs synchronize on a
slot-level boundary. Some configuration files/command line overrides
left the same SSB position for two DUs in RFsim-based handover
scenarios, which then makes that the UE cannot decode the SSB.
This commit changes the positions such that this is possible again. In
the F1 HO docker-compose
(ci-scripts/yaml_files/5g_f1_rfsimulator/docker-compose.yaml), we set it
to 2 to send only one SSB (not 2 with bitmap 3).
fix: removed the nssai_sd parameter in the ue.conf file
Following the tutorial in the RF simulator, the PDU session cannot
be established because the Slice Differentiator to request(nssai_sd)
parameter in the ue.conf file is 1(integer) but in the documentation
the default value of the nssai_sd is 0xFFFFF(meaning "no SD")
Now the nssai_sd parameter is removed in the ue.conf to establish the
PDU session.
NR UE: correctly compute writeTimestamp for SCS > 30 kHz with rf-simulator
Contains also two minor cleanups for nr-ue.c:
- make fp point to constant NR_DL_FRAME_PARMS where possible
- use c16_t type for I/Q sample arrays
print better message for rsrp: invalid doesn't mean it is not measured
print better message for rsrp: invalid doesn't mean it is not measured,
it means it is out of usable range
NR UE: fix PRACH k1 calculation at MAC when handover
The k1 for PRACH calculation in config_common_ue() should be the same as in
config_common_ue_sa(), otherwise k1 is wrong when handover to target cell if
msg1-FDM not 0 in reconfigurationWithSync.
Verified with 3rd-party gNB.
The code previously checked that the supplied PDU sessions's type is
exactly what we requested. However, at least OAI 5GC will only give us
an IPv4 PDU session if we request IPv4v6 (so the check would fail).
Extend the validation to either check exact match, or, if IPv4v6
requested, that it is either IPv4 or IPv6.
Following the tutorial in the RF simulator, the PDU session cannot
be established because the Slice Differentiator to request(nssai_sd)
parameter in the ue.conf file is 1(integer) but in the documentation
the default value of the nssai_sd is 0xFFFFF(meaning "no SD")
Now the nssai_sd parameter is removed in the ue.conf to establish the
PDU session.
gNB: Reset NDI only after usage in case of disable HARQ
Solves this warnings seen in the UE trace:
NDI indicates re-transmission but computed TBS 3968 doesn't match with what previously stored 3368
Issue happens only if feature disable_harq is enabled. GNB resets the harq
process (including NDI) as PUCCH will not be sent for this harq process, but
before the harq process is used in DCI payload preparation.
Fix is to reset the harq process after harq process in case of no PUCCH.
Fail early if configuration module can not initialize properly
In the case that the config module cannot load the driver for libconfig or yaml,
currently, there might be a cascade of errors that are difficult for users to
understand. For instance (partially redacted for clarity):
[CONFIG] Error calling dlopen(libparams_libconfig.so): libparams_libconfig.so: cannot open shared object file: No such file or directory
[CONFIG] config module "libconfig" couldn't be loaded
[CONFIG] config_get, section log_config skipped, config module not properly initialized
[LOG] init aborted, configuration couldn't be performed
[CONFIG] config_get, section (null) skipped, config module not properly initialized
[CONFIG] /home/francesco/openairinterface5g/common/config/config_userapi.c 68 nfapi has no processed integer availablle
[CONFIG] config_get, section (null) skipped, config module not properly initialized
Assertion (get_softmodem_params()->default_pdu_session_id == -1) failed!
In get_common_options() /home/francesco/openairinterface5g/executables/softmodem-common.c:161
Use uicc0.pdu_sessions.[0].id to change the requested PDU session ID (is 0)
Here, the error is the missing shared object, but a user is more likely to look
at the last error instead of the first.
This commit addresses it by checking early for CONFIG_ISFLAGSET(CONFIG_ABORT),
and stopping if it is set. Additionally changes include making functions static,
removing late CONFIG_ISFLAGSET() checks, and the CONFIG_ISFLAGSET() in
load_configmodule(), because at that time "uniqCfg" is not set yet and thus does
not do anything (this is likely a regression of an earlier cleanup).
See-also: f50d5f5a ("make multiple config instead of one implicit global")
Currently, we derive frame and slot number based on `proc->timestamp_rx`
using
`proc->frame_rx = (proc->timestamp_rx / (fp->samples_per_subframe*10))&1023;` and
`proc->tti_rx = get_slot_from_timestamp(proc->timestamp_rx, fp);`
This ignores the samples `proc->timestamp_rx % fp->samples_per_frame`
while computing the frame and slot number creating a mis-alignment with the slot boundaries.
We fix this alignment by compensating these samples during the first reception.
Integration: `2026.w08`
* !3934 Fix Ubuntu build: reinstate -Werror
* !3803 remove cblas and atlas dependancy
* !3918 Add a simple GTP unit test
* !3924 T: macpdu2wireshark: gentle exit (and some other minor work in the T tracer)
* !3925 Fix race condition on double RA during RRC reestablishment
* !3930 bugfix: add PCell to serving_cells in fallback path and refactor update logic
* !3936 [FHI72] Remove support for xran E release
* !3893 NR Paging on CU
See merge request oai/openairinterface5g!3939
In the case that the config module cannot load the driver for libconfig
or yaml, currently, there might be a cascade of errors that are
difficult for users to understand. For instance (partially redacted for
clarity):
[CONFIG] Error calling dlopen(libparams_libconfig.so): libparams_libconfig.so: cannot open shared object file: No such file or directory
[CONFIG] config module "libconfig" couldn't be loaded
[CONFIG] config_get, section log_config skipped, config module not properly initialized
[LOG] init aborted, configuration couldn't be performed
[CONFIG] config_get, section (null) skipped, config module not properly initialized
[CONFIG] /home/francesco/openairinterface5g/common/config/config_userapi.c 68 nfapi has no processed integer availablle
[CONFIG] config_get, section (null) skipped, config module not properly initialized
Assertion (get_softmodem_params()->default_pdu_session_id == -1) failed!
In get_common_options() /home/francesco/openairinterface5g/executables/softmodem-common.c:161
Use uicc0.pdu_sessions.[0].id to change the requested PDU session ID (is 0)
Here, the error is the missing shared object, but a user is more likely
to look at the last error instead of the first.
This commit addresses it by checking early for
CONFIG_ISFLAGSET(CONFIG_ABORT), and stopping if it is set. Additionally
changes include making functions static, removing late
CONFIG_ISFLAGSET() checks, and the CONFIG_ISFLAGSET() in
load_configmodule(), because at that time "uniqCfg" is not set yet and
thus does not do anything (this is likely a regression of an earlier
cleanup).
See-also: f50d5f5a9b ("make multiple config instead of one implicit
global")
NR Paging on CU
Implements the NR paging path on the CU:
- NGAP Paging is decoded and passed to RRC
- RRC builds F1AP Paging, and distributes it to DUs via F1 callback
Changes:
- Refactor and extend F1AP Paging encode/decode libraries
* add missing enc/dec/eq/cp functions
* add unit test
* IEs: CN UE 5G-S-TMSI, RAN UE I-RNTI; optional DRX/priority/origin)
- Refactor CU callback CU_send_Paging
- Refactor DU handler DU_handle_Paging
- Refactor old F1 callback for Paging indication, extend it and align
with existing F1 callbacks in stack
- Refactor and extend NGAP Paging encode/decode lib
* add missing enc/dec/eq/cp functions
* add unit test
* Fixes NGAP paging to accept Paging only on SCTP stream 0 per TS
38.412
- Includes supporting refactors (PDU session split, shared 5G-S-TMSI
helpers, NGAP/F1AP cleanups)
Testing
- NGAP and F1AP Paging lib unit tests (enc/dec)
- Stream-0 fix validated with Open5GS AMF
This MR does not address the DU changes besides the F1 handler. F1AP
Paging does not have an RRC container to pass the PCCH message to the
DU, and F1 DL RRC Message Transfer does not apply to PCCH. PCCH-Message
shall be built at DU per TS 38.331 §5.3.2, with padding as per §8.5 and
delivered as RLC SDU per §8.2. For each cell in Paging Cell List that
belongs to this DU, queue for MAC. MAC schedules at PF/PO per TS 38.304
§7.
Refs:
- F1AP 3GPP TS 38.473 version 16.21.0 Release 16
- NGAP 3GPP TS 38.413 version 16.17.0 Release 16
[FHI72] Remove support for xran E release
All the use cases we tested with E release are working end-to-end with F release.
The near future plan is to support K release which is ongoing in the MR !3444.
Robert Schmidt