Our initial CellGroupConfig always contains LCID1, because in normal
connection setup, the DU has to automatically set it up anyway. In
handover/UE Context Setup, the CU requests to set up SRB1 (which we
assume to be LCID1), but we reuse the initial CellGroupConfig. To not
have SRB1 added twice, skip in this case.
This commit implements adding a new UE on the target DU in case of
handover. We identify this case by the fact that the gNB-CU did not send
a gNB-DU UE ID (which is optional in F1AP, but not in our
implementation), such that we know there is no corresponding UE, which
therefore has to be created.
If it happens that there is a handover preparation information, we read
the UE capabilities from this information, and subsequently trigger the
creation of a new UE.
Another change is that for all bearers that we are asked to setup, we
add reestablishRLC so that the UE does a reestablishment during the
reconfiguration.
As we have to remove the reconfigurationWithSync and reestablishRLC IE
after application of the CellGroupConfig (because we might reuse the
CellGroupConfig later), free these IEs. As there are now multiple fields
to free, introduce a separate nr_mac_clean_cellgroup() function that
handles cleaning of the CellGroupConfig.
Co-authored-by: batuhanduyuler <batuhan.duyuler@firecell.io>
Co-authored-by: rmagueta <rmagueta@allbesmart.pt>
The next commit will modify the UE context setup request procedure to
(possibly) receive UE capabilities through Handover Preparation
Information, which extracts the UE capabilities for the UE to be setup.
To avoid code duplication, extract the code that will be needed in UE
capability extraction from Handover Preparation Information.
Implement the Transmission Action Indicator F1AP forwarding logic, and
add it to the F1 internal representation structure. After the
transmission interrupt timer (during which SRB1 can send messages), the
UE will be out-of-sync (we assume it's not there anymore).
Co-authored-by: batuhanduyuler <batuhan.duyuler@firecell.io>
Co-authored-by: rmagueta <rmagueta@allbesmart.pt>
Implement the HandoverPreparationInformation F1AP forwarding logic, and
add it to the F1 internal representation structure.
No logic is implemented in this commit.
Co-authored-by: batuhanduyuler <batuhan.duyuler@firecell.io>
Co-authored-by: rmagueta <rmagueta@allbesmart.pt>
Refactor the RRC processing timer to be a generic "transmission
interrupt" timer, and use NR_timer_t for it. Also,
depending on the kind of RRC processing (see 38.331 table 12.1-1),
timing requirements might be different. However, the DU does not always
know which RRC processing is ongoing, and does not get this information
via F1. Hence, introduce a "worst case" delay time, which aligns with
the spec (it says these times are "minima") and is accepted by COTS UE.
The gNB MAC might need to stop transmission either for some time (RRC
processing), or continuously (transmission stop requested by CU). Those
can be handled in one common timer implementation. The continuous case
will be used in a follow-up commit.
Co-authored-by: Luis Pereira <lpereira@allbesmart.pt>
Currently, sD has not been allocated, so the octet string is empty. Fix the
allocation to correctly write&read NSSAIs in UE context setup/modification
request messages.
This adds DTX detection in PUCCH 2 receiver. This is detected by MAC
already which will drop PUCCH 2 indications that are detected as DTX.
For the moment this uses the same pucch0_dtx_threshold value indicated
in L1 section of the configuration file. The feature firstly reduces
unnecessary logging on stdout and the use of invalid CSI measurements in
the MAC scheduler.
Closes: #547
- Fixes#853, #854, #858, #859, #862
- handle repeated NGAP Initial context setup requests, thereby fixing assert:
Assertion (!ue_p->as_security_active) failed!
In rrc_gNB_generate_SecurityModeCommand() /home/eurecom/raymond/openairinterface5g/openair2/RRC/NR/rrc_gNB.c:2590
logic error: security already activ
- A lot of cleanup: remove almost all use of protocol_ctxt_t in 5G RRC and use
existing pointers instead
Introduce two tests for NR RLC AM entity:
- test_nr_rlc_am_entity
- benchmark_nr_rlc_am_entity
The benchmark can be used to verify processing time improvements for NR RLC AM
entity. The benchmark creates two entities and creates an unbalanced
communication channel between them with 10% loss packet loss and 100:1 PDU sent
ratio. This allows the lists in RLC to build up and triggers RLC AM code
related to looking through the segment/pdu lists.
Example benchmark output:
ubuntu@zeus:~/bpodrygajlo/openairinterface5g/cmake_targets/build$ ./openair2/LAYER2/nr_rlc/tests/benchmark_nr_rlc_am_entity
[LOG] init aborted, configuration couldn't be performed
log init done
CMDLINE: "./openair2/LAYER2/nr_rlc/tests/benchmark_nr_rlc_am_entity"
[CONFIG] debug flags: 0x00400000
2024-10-16T14:58:20+02:00
Running ./openair2/LAYER2/nr_rlc/tests/benchmark_nr_rlc_am_entity
Run on (8 X 4700 MHz CPU s)
CPU Caches:
L1 Data 48 KiB (x4)
L1 Instruction 32 KiB (x4)
L2 Unified 1280 KiB (x4)
L3 Unified 12288 KiB (x1)
Load Average: 0.48, 0.27, 0.20
***WARNING*** CPU scaling is enabled, the benchmark real time measurements may be noisy and will incur extra overhead.
--------------------------------------------------------------------
Benchmark Time CPU Iterations
--------------------------------------------------------------------
BM_nr_rlc_am_entity/100 50096 ns 50097 ns 13101
BM_nr_rlc_am_entity/256 140386 ns 140387 ns 4868
BM_nr_rlc_am_entity/1024 536323 ns 536311 ns 1309
BM_nr_rlc_am_entity/4096 2084464 ns 2084385 ns 338
BM_nr_rlc_am_entity/16384 8309318 ns 8309458 ns 81
BM_nr_rlc_am_entity/20000 9843792 ns 9843774 ns 68
This hotfix removes division by num_antenna_ports in PDSCH precoding matrix generation.
These matrices are defined for CSI reporting in this way but here we are using them for
transmission and this results in an unwanted 10*log10(num_antenna_ports) reduction in
transmit power (3dB for 2 antenna ports, 6dB for 4 antenna ports, etc.)
A UE might send a ULInformationTransfer without the actual content present
(intentionally or not). Check this and handle appropriately to avoid
a segfault when reading the empty NAS message.
Closes: #862
Pass UE context pointer directly. In the switch, do not return to not
create memory leaks (after the switch, memory is freed). Move the
function up to make it appear before the use of the function.
Pass UE context, without protocol_ctxt_t, for cleanup. Remove the return
from within the switch, as this would lead to memory leaks; nothing is
executed after the switch statement (except for freeing memory).
The existing check for the initialization of GTP is wrong; GTP returns
-1 if it could not initialize. Correct this, such that the DU will stop
if GTP cannot be initialize.
If we continue, the DU is requested to set up a GTP tunnel; because GTP
is not initialized, it assumes it is in monolithic/no F1, and does not
set up a tunnel. The F1 UE Context setup response encoder then fails
with this assertion:
Assertion (tnl->teid > 0) failed!
In DU_send_UE_CONTEXT_SETUP_RESPONSE() ../../../openair2/F1AP/f1ap_du_ue_context_management.c:415
Exiting execution
../../../openair2/F1AP/f1ap_du_ue_context_management.c:415 DU_send_UE_CONTEXT_SETUP_RESPONSE() Exiting OAI softmodem: _Assert_Exit_
Aborted
Closes: #853
A UE might send a MeasurementReport without the actual IEs present
(intentionally or not). Check this and handle appropriately to avoid
assertion
Assertion (measurementReport->criticalExtensions.present == NR_MeasurementReport__criticalExtensions_PR_measurementReport && measurementReport->criticalExtensions.choice.measurementReport != ((void*)0)) failed!
In rrc_gNB_process_MeasurementReport() ../../../openair2/RRC/NR/rrc_gNB.c
Closes: #859
A UE might send a UE Capability Information without unsolicitatedly
(intentionally or not). Check this and handle appropriately to avoid
assertion
Assertion (UE->xids[xid] == RRC_UECAPABILITY_ENQUIRY) failed!
In handle_ueCapabilityInformation() ../../../openair2/RRC/NR/rrc_gNB.c
Closes: #858
A UE might send a rrcReestablishmentComplete without the actual IEs
present (intentionally or not). Check this and handle appropriately to
avoid assertion
Assertion (reestablishment_complete->criticalExtensions.present == NR_RRCReestablishmentComplete__criticalExtensions_PR_rrcReestablishmentComplete) failed!
In handle_rrcReestablishmentComplete() ../../../openair2/RRC/NR/rrc_gNB.c:1364
Closes: #854
Prior to this commit, if we receive an Initial Context Setup Request for
a UE that has AS security set up, the gNB asserts with
Assertion (!ue_p->as_security_active) failed!
In rrc_gNB_generate_SecurityModeCommand() openairinterface5g/openair2/RRC/NR/rrc_gNB.c:2590
logic error: security already activ
However, TS 38.413 says:
> The AMF may initiate the Initial Context Setup procedure if a
> UE-associated logical NG-connection exists for the UE
(I interpret this as "it might happen anytime")
> store the received Security Key in the UE context and, if the NG-RAN
> node is required to activate security for the UE, take this security key
> into use.
(I interpret this as "do not set up AS security again")
In this commit, handle if we receive an Initial Context Setup Request
for an existing UE context. As said in the spec, we store the keys. If
security is not active, we trigger RRC Security Mode Command. If it is
active, we skip Security, and directly set up a PDU session. If there is
also no PDU session, we simply forward the NAS message, and acknowledge.
If there was no AS security, after security, the gNB would trigger the
setup of PDU sessions (if any), and then forward any NAS PDUs, which is
stated in the if block if AS security is already active.
rrc_gNB_process_security() does not only set (process) the security
algorithms, but also checks for those. However, we don't use the check.
Simplify the function, to reintroduce the check later. Rename to
set_UE_security_algos() to better reflect what the functions do.
Robert Schmidt