Handle target DU UE context setup when handover preparation info
is unavailable (i.e. re-establishment scenario) by retrieving
secondary UE ID from F1 UE data.
rrc_f1_ue_context_setup_for_target_du is either applying to
handover or re-establishment. In the latter scenario, populate
DU UE ID, which should be known.
Extract the common RRC container handling logic from
ue_context_setup_request() and ue_context_modification_request() into
a new static function handle_ue_context_rrc_container().
This refactoring:
- Eliminates code duplication between the two functions
- Centralizes RRC container forwarding logic
- Improves code maintainability and consistency
Extract common CellGroupConfig encoding logic from
ue_context_setup_request() and ue_context_modification_request() into
encode_cellgroup_config().
Replace uper_encode_to_buffer() with uper_encode_to_new_buffer() to:
- Remove 1024-byte buffer size limit
- Automatically allocate correct buffer size
- Simplify code (no manual bit-to-byte conversion)
- Align with other protocol encoders
- Add function documentation blocks for `rrc_fill_f1_ue_context_setup`,
`rrc_f1_ue_context_setup_for_target_du`, and `rrc_f1_ue_context_setup_from_e1_response`
explaining their purpose, parameters, and usage scenarios
- Add inline comments throughout these functions
Improve maintainability by centralizing common F1AP UE context setup
logic into reusable helper functions, enabling consistent handling
and clear serving/target DU entry points for different scenarios.
Code duplication prevention is a beneficial side effect, since at
least one helper function is adopted in subsequent commits.
Major changes:
- Move DRB list filler from external file into rrc_gNB.c and rename
fill_drb_to_be_setup to rrc_fill_f1_drb_to_setup for naming
consistency
- Add static helper rrc_fill_f1_ue_context_setup to populate common
fields shared between serving DU and target DU scenarios:
- Rename rrc_gNB_generate_UeContextSetupRequest to
rrc_f1_ue_context_setup_from_e1_response to clarify it prepares
F1AP context setup from E1AP bearer setup response for serving DU
- Add rrc_f1_ue_context_setup_for_target_du (for target DU in
handover/reestablishment scenarios)
- Adopt helper rrc_fill_f1_ue_context_setup in both functions
When processing UL RRC messages from PDCP, the DU association ID (assoc_id)
was not being propagated to RRC, resulting in assoc_id being 0 in
rrc_gNB_decode_dcch.
Fix by setting originInstance in the ITTI message header to the stored
du_assoc_id from ue_data when PDCP creates the F1AP_UL_RRC_MESSAGE.
NR gNB handling TCI state indication for beam switching
This MR implements the procedure to send in DLSCH MAC-CE for TCI state
indication to UE
- if new beam is reported via SSB RSRP, gNB allocates MAC-CE with TCI
indication
- DLSCH is scheduled to be transmitted with priority
- a timer is started when receiving ACK according to the delay mandated
by standard (8.10.3 of 38.133)
- at timer expiry the gNB switches beam
Check for PDSCH overlapping CORESET during RA
CORESET 0 is configured in the configuration file by
'initialDLBWPcontrolResourceSetZero' and PDSCH TDA list is configured based on
the current BWP size.
It may happen that the user configures a 2 symbol CORESET 0 for a BWP >= 48 PRBs
(which is a valid 3GPP configuration) but in function 'nr_rrc_config_dl_tda'
this scenario is not taken in account causing an overlap between PDSCH and PDCCH
symbols during RA.
This leads to very unreliable Msg2 and Msg4 decoding at the UE, but from time to
time it succeeds, which becomes hard to identify this issue.
closes#705
NR UE: add neighboring cell measurements and measurement report of event A3
This is a rework of MR !2385 (closed), the goal is to add neighboring cell
measurements and measurement report of event A3 for NR UE.
This MR was tested with:
- 3rd-party gNB
- 2 OAI-gNB-DUs
The neighboring cell measurements and measurement report of event A3 for OAI-UE
are working as expected.
fix A3 event configuration
See commit message for more information.
As a reference, for comparison purpose, PCAPs and TXT files for various tests
done in develop and in this MR are available in the MR description.
While testing the gNB with two hypotetical neighbors, some issues were found
with A3 event configuration.
The configuration of neighbors is:
neighbour_list = (
{
nr_cellid = 12345679L;
neighbour_cell_configuration = (
{
gNB_ID = 0xba0;
nr_cellid = 720898;
physical_cellId = 1;
absoluteFrequencySSB= 621312;
subcarrierSpacing = 1;
band = 78;
plmn = { mcc = 505; mnc = 01; mnc_length = 2 };
tracking_area_code = 1;
},
{
gNB_ID = 0xea0;
nr_cellid = 1345678L;
physical_cellId = 2;
absoluteFrequencySSB= 640000;
subcarrierSpacing = 1;
band = 78;
plmn = { mcc = 505; mnc = 01; mnc_length = 2 };
tracking_area_code = 1;
}
);
}
);
There were two problems.
The first problem is:
- when only default A3 event is configured, it is duplicated in the
RRC Reconfiguration Report Config To AddMod list with IDs 4 and 5
To test this case, the event configuration is:
nr_measurement_configuration = {
Periodical = {
enable = 1;
includeBeamMeasurements = 1;
maxNrofRS_IndexesToReport = 4;
};
A2 = {
enable = 1;
threshold = 60;
time_to_trigger = 1;
};
A3 = (
{
physCellId = -1;
offset = 15;
hysteresis = 2;
time_to_trigger = 3
}
);
};
The second problem is:
- when configuring an A3 event with an unknown physCellId, the gNB
does not include any A3 event in the RRC Reconfiguration Report
Config To AddMod list (which is correct), but configures some
meas ID with nonexistant Report Config IDs
To test this case, the event configuration is:
nr_measurement_configuration = {
Periodical = {
enable = 1;
includeBeamMeasurements = 1;
maxNrofRS_IndexesToReport = 4;
};
A2 = {
enable = 1;
threshold = 60;
time_to_trigger = 1;
};
A3 = (
{
physCellId = 10;
offset = 15;
hysteresis = 2;
time_to_trigger = 3
}
);
};
Reworking A3 event configuration as done in this commit solves both
issues.
CORESET 0 is configured in the configuration file by 'initialDLBWPcontrolResourceSetZero' and PDSCH TDA list is configured based on the current BWP size.
It may happen that the user configures a 2 symbol CORESET 0 for a BWP >= 48 PRBs (which is a valid 3GPP configuration) but in function 'nr_rrc_config_dl_tda' this scenario is not taken in account causing an overlap between PDSCH and PDCCH symbols.
This leads to very unreliable Msg2 and Msg4 decoding at the UE, but from time to time it succeeds, which becomes hard to identify this issue.
Correct how the slot for SIB1 is computed in case of MUX pattern 2 and 3.
Renamed n_0 to slot for clarity. n_c was never used outside of the function, so
remove it where it is not used.
Reference: 3GPP 38.473 v16.21.0
Mandatory fields:
Transaction ID (supported)
LMF Measurement ID (supported)
RAN Measurement ID (supported)
Add F1AP positioning measurement failure indication message enc/dec + test
Reference: 3GPP 38.473 v16.21.0
Mandatory fields:
Transaction ID (supported)
LMF Measurement ID (supported)
RAN Measurement ID (supported)
Cause (supported)
Reference: 3GPP 38.473 v16.21.0
Mandatory fields:
Transaction ID (supported)
LMF Measurement ID (supported)
RAN Measurement ID (supported)
Positioning Measurement Result List (range: 1)
> Positioning Measurement Result List Item (range: 1..64)
>> Positioning Measurement Result (supported)
>> TRP ID (supported)
Reference: 3GPP 38.473 v16.21.0
Mandatory fields:
Transaction ID (supported)
LMF Measurement ID (supported)
RAN Measurement ID (supported)
Cause (supported)
Optional fields:
Criticality Diagnostics (not supported)
Reference: 3GPP 38.473 v16.21.0
Mandatory fields:
Transcation ID (supported)
LMF Measurement ID (supported)
RAN Measurement ID (supported)
Positioning Measurement Result List (range: 0..1)
> Positioning Measurement Result List Item (range: 1..64)
>> Positioning Measurement Result (supported)
>> TRP ID (supported)
Optional fields:
Criticality Diagnostics (not supported)
Reference: 3GPP 38.473 v16.21.0
Mandatory fields:
Transcation ID (supported)
TRP Information List (range : 1)
> TRP Information Item (range : 1..65535)
>> TRP Information (supported)
Further details of TRP Information:
TRP ID
TRP Information Type Response List (range : 1)
> TRP Information Type Response Item (range : 1..64)
>> CHOICE TRP Information Type Response Item
>>> NR PCI (madatory : supported)
>>> NG-RAN CGI (madatory : supported)
>>> NR ARFCN (madatory : supported)
>>> PRS Configuration (madatory : not supported)
>>> SSB Information (madatory : not supported)
>>> SFN Initialisation Time (madatory : not supported)
>>> Spatial Direction Information (madatory : not supported)
>>> Geographical Coordinates (madatory : supported)
For now, we only use Geographical Coordinates.
Optional fields:
Criticality Diagnostics (not supported)
Reference: 3GPP 38.473 v16.21.0
Mandatory fields:
Transcation ID (supported)
TRP list (range : 0..1)
> TRP list Item (range : 1..65535)
>> TRP ID (supported)
TRP Information Type List (range : 1)
> TRP Information Type Item (range : 1..64)
>> TRP Information Type Item (supported)
While implementing NRPPA-related F1AP messages, we remarked that
extension field "UL-AoA-ExtIEs" needs to be OPTIONAL (e.g., in NRPPA it
is optional in the OAI-compiled version), but it was not marked as such.
This later version 16.21.0 fixes this.
Fix bug "no AMF for UE"
It might happen that the RRC does not know the AMF UE NGAP ID, yet. Even
in that case, we should forward the release request to the NGAP module,
which can either forward a message to the AMF, or reply back to release
the UE. This avoids an error where the CU claims there was no AMF, when
there actually is.
One possible problematic behavior is if a UE disconnects before the gNB
receives an NGAP Initial Context Setup. In this case, the AMF UE NGAP ID
was not forwarded to the RRC (although it was known at NGAP), thus
blocking the release of the UE.
This is the main fix, the rest are minor fixes:
- store AMF UE NGAP ID as early as possible
- warn in MAC if UE unknown for UE context release command
- show TEIDs with correct endianness in GTP
- avoid NG Setup Failure+Setup log.
Guido Casati