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.
Introduce SRS physical simulator and improvements
This MR consists of two parts:
- Introduces SRS physical simulator to test different configurations of
SRS
- Improvements in the SRS channel estimation (Addressing the comments
from old, unfinished MR !2875)
- rewrite nr_srs_channel_estimation() to loop over rx antennas and
antenna ports to be able to parallelize
- Improvements in timing_advance_offset and timing_advance_offset_nsec
computation
- Introduce SRS multi-symbol channel estimation
- The channel impulse response is estimated from the averaged
channel frequency response over multiple symbols
- The channel frequency estimates are left as they are to be able to
estimate doppler in the future
- Simplify SRS channel estimation to handle memory alignment in the
case of different SRS configurations (eg: comboffset)
To use multiple symbols when running gNB, the following parameters needs
to be edited in the function get_srs_resource()
- srs_res->resourceMapping.startPosition with a range from {0,1,..,5}
corresponds to the start symbol {13, 12, .. 8} with in a slot
- srs_res->resourceMapping.nrofSymbols indicates the number of symbols
{n1, n2, and n4}
Make sure the that start symbol + number of symbols is < 14
The timing results for SRS in develop and srs_phy_simulator are as follows:
Command used: sudo ./nr_ulsim -n1000 -s50 -S50 -R273 -W2 -y2 -z2 -E 1 -P
develop
|__ RX SRS time 124.94 us (1000 trials) (124.94 total [ms])
|__ Generate SRS sequence time 0.05 us (1000 trials) ( 0.05 total [ms])
|__ Get SRS signal time 19.41 us (1000 trials) ( 19.41 total [ms])
|__ SRS channel estimation time 89.11 us (1000 trials) ( 89.11 total [ms])
|__ SRS timing advance estimation time 13.10 us (1000 trials) ( 13.10 total [ms])
|__ SRS report TLV build time 2.80 us (1000 trials) ( 2.80 total [ms])
|__ SRS beam report build time 0.00 us ( 0 trials)
|__ SRS IQ matrix build time 2.73 us (1000 trials)
srs_phy_simulator
|__ RX SRS time 211.93 us (1000 trials) (211.93 total [ms])
|__ Generate SRS sequence time 0.04 us (1000 trials) ( 0.04 total [ms])
|__ Get SRS signal time 19.55 us (1000 trials) ( 19.55 total [ms])
|__ SRS channel estimation time 152.05 us (1000 trials) (152.05 total [ms])
|__ SRS timing advance estimation time 36.67 us (1000 trials) ( 36.67 total [ms])
|__ SRS report TLV build time 2.96 us (1000 trials) ( 2.96 total [ms])
|__ SRS beam report build time 0.00 us ( 0 trials)
|__ SRS IQ matrix build time 2.88 us (1000 trials)
Note that in srs_phy_simulator, to compute timing offset ns, an
oversampling factor of 2 is performed. Also, for peak detection, we
average the channel estimates for every port.
In the Initial Context Setup message, the NGAP forwards the AMF UE ID,
but not in the DL NAS Message, although 38.413 says, in $8.3.1.2 either
> The NG-RAN node shall use the AMF UE NGAP ID IE and RAN UE NGAP ID IE
> received in the INITIAL CONTEXT SETUP REQUEST message as identification
> of the logical connection
or in $8.6.2.2
> The NG-RAN node shall use the AMF UE NGAP ID IE and RAN UE NGAP ID IE
> received in the DOWNLINK NAS TRANSPORT message as identification of the
> logical connection
So forward in both cases for harmonization.
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.
Reported-By: Jegor Zelenjak <jzelenjak@proton.me>
maki
Jaroslava Fiedlerova