... so if we want to have 1 BWP configured at any given time we need to
reconfigure BWP 1 every time. This means that since the gNB has more
than 1 BWPs (for use for different UEs), that there is a "gNB BWP ID"
(as used by the gNB), which can be any BWP ID X, and one "UE BWP ID",
which is always 1. This commit implements this distinction.
Return from triggering reconfiguration with BWP switch if BWP is the
same as before the switch, and add check to verify if BWP triggered by
switch command exists
The PDUSessionResourceReleaseResponse message was missing the mandatory
pDUSessionResourceReleaseResponseTransfer IE in each released PDU session item. This caused Open5GS to send an error indication.
Changes:
- Add encode_ngap_pdusession_release_response_transfer() function to
properly encode the transfer structure (empty since Secondary RAT Usage
Information is optional and not used, per 9.3.4.21)
- Always include the mandatory PDUSessionResourceReleasedListRelRes IE
- Always encode the pDUSessionResourceReleaseResponseTransfer for each
PDU session item
- Fix Release Command handler to decode and log Cause from command transfer:
instead of incorrectly copying command data to response: the 2 transfer
IEs in the Command and the Response messages are different and should
not be mixed
- Split Command/Response struct type definitions
- Add missing includes
1) Remove UE Context Release Response code: there is no
such thing in the specs, it is either UE Context Release Request
(NG-RAN node initiated) or UE Context Release (AMF initiated)
(3GPP TS 38.413). The former message has only the request, no
response is defined by the specs. The code in the stack had no
purpose at all and was removed.
2) The UE Context Release Request message only contains a PDU
Session Resource List (optional) of PDU Session IDs, therefore
the use of pdusession_release_t was wrong and was refactored
CFRA: mark RA complete when sending Msg2
The current contention-free random access forces a "Msg3" (which does
not exist in CFRA) to be received by a UE. Sometimes, this "Msg3" is not
received (for whatever reason), and the MAC declare that RA failed.
This is problematic, as the spec says that RA is complete once Msg2 is
received by the UE. Since the gNB cannot know when this is, simply mark
it as complete once we sent Msg2.
We still send Msg3 in CFRA, which is explained further in the commits.
Also, improve logging and stabilize an RFsim test by reducing sl_ahead.
Since the parent commit, CFRA is inconditionally marked complete on Msg3
reception (successful or not). This works because the current
implementation still sends a UL grant (see parent commit for details).
In this commit, handle Msg3 if received in CFRA (notably for TA and
power). Note that since we declare RA complete, UE->ra does not exist
anymore, and so an intermediate variable is introduced to capture the
CFRA flag. The code should be such that if we are in CFRA, we never
access any UE->ra variable.
The current contention-free random access forces a "Msg3" (which does
not exist in CFRA) to be received by a UE. Sometimes, this "Msg3" is not
received (for whatever reason), and the MAC declare that RA failed.
This is problematic, as the spec says that RA is complete once Msg2 is
received by the UE. To avoid this, inconditionally mark RA as complete
as soon as we receive an indication of Msg3 (DTX or not).
Note that after this change, we still send a UL grant in Msg2. This is
because 38.321 §5.1.4 is not clear to me whether we should send UL grant
(it does not explicitly exclude it), and it says
> 3> if the Random Access Response includes a MAC subPDU with RAPID only:
> [...]
> 4> indicate the reception of an acknowledgement for SI request to
> upper layers.
which is NOT the case (but then I don't know/think we can have CFRA for
SI request?). Since it also works with COTS UE, I leave Msg3 for the
moment.
The reason to not directly mark RA as complete when sending Msg2 is
because of possible retransmissions in do-ra mode. In fact, in do-ra,
there might already be data awaiting. In that case, the DLSCH scheduler
schedules data _in the same slot as Msg2_, which the UE does not decode,
leading to retransmissions.
Implementation of STOP exchange
This implements the STOP.request/indication for all 3 transport mechanisms, the
VNF will send the STOP.request to the PNF, indicating it will disconnect, and
await a STOP.indication from the PNF
The WLS VNF is reworked to be able to start before the PNF, by calling call
rte_eal_init and rte_dev_probe to determine if dpdk has been initialized
properly, before calling rte_eal_init in the intended process when it is
appropriate to do so
Fix reestablishment after handover
- fix reestablishment by not re-creating LCIDs with priority set to 0 (see first
commit for more details)
- cleanup code
The idea is to reestablish all RLC entities (it's a new UE, and we set
reestablishRLC on all bearerrs), so we should reestablish all RLC
entities on gNB side as well, without any additional loop.
Co-authored-by: Roberto Magueta <rmagueta@allbesmart.pt>
Move the file process_addmod_bearers_cellGroupConfig() to the file where
it is used. Correctly set priorities as requested in RLC bearer
configuration.
In all cases (NSA, HO), we create LCIDs before the UE triggers random
access. Hence, process_addmod_bearers_cellGroupConfig() is not
necessary, as it just tries to recreate an LCID.
Furthermore, it includes a bug, as this function does set a wrong
priority (0), so the sorting of LCIDs is not correct. This in turn
creates problems with reestablishment, as LCID 1/SRB1 is not in the
first position, making reestablishment fail (where we assume LCID 1 be
in first position).
The actual bug of setting priorities is fixed in the next commit.
Fix MIB encoding in F1SetupRequest: use encode_MIB_NR_setup instead of encode_MIB_NR
- The DU was using encode_MIB_NR() while constructing the GNB-DU System
Information for the F1SetupRequest.
- encode_MIB_NR() encodes a full NR_BCCH_BCH_Message_t, causing the MIB to be
wrapped in a BCH container.
- This results in incorrect MIB values in the F1SetupRequest PCAP (e.g., wrong
systemFrameNumber, SCS, DMRS position, cellBarred).
- According to 3GPP TS 38.473, the MIB carried in F1AP must be encoded as a raw
NR_MIB_t.
- The correct function encode_MIB_NR_setup() encodes MIB in the required format
but was not used.
- This patch replaces encode_MIB_NR() with encode_MIB_NR_setup() to ensure correct
and standards-compliant MIB encoding in the F1SetupRequest.
Closes issue #1034.
Fix DRB integrity failures during handover and re-establishment
This MR fixes DRB integrity protection failures that occur during N2 handover
and connection re-establishment scenarios. The issues were caused by incorrect
security key handling and ciphering configuration during these procedures with
DRB integity enabled.
See merge request !3767 for more details.
Avoid measGap configuration on handover in intra-freq scenarios
During the handover, we are incorrectly configuring the measGap, even though
neighboring cells are on the same frequency. Since gNB is not expecting this
measGap, the SRS scheduling is performed. Therefore, we are periodically
receiving these logs after the handover:
[NR_MAC] Invalid timing advance offset for RNTI 58e2
[NR_MAC] Invalid timing advance offset for RNTI 58e2
[NR_MAC] Invalid timing advance offset for RNTI 58e2
[NR_MAC] Invalid timing advance offset for RNTI 58e2
[NR_MAC] Invalid timing advance offset for RNTI 58e2
[NR_MAC] Invalid timing advance offset for RNTI 58e2
These logs occur at a time when UE is performing a MeasGap operation and not
sending the SRS, while gNB thinks it will receive the SRS, but will not receive
any SRS.
This MR resolves this issue, and after the handover, these logs no longer
appear.
Use UL functions for Qm/R determination
During refactoring, the wrong functions and correspondingly tables have
been used to calculate UL TB size. Fix through correct functions.
This should fix these error messages:
3624774.778195 [MAC] E (nr_get_Qm_dl:2034) Invalid MCS table index 3 (expected in range [0,2])
3624774.778207 [MAC] E (nr_get_code_rate_dl:2066) Invalid MCS table index 3 (expected in range [0,2])
3624774.778211 [NR_MAC] E (nr_compute_tbs:63) Error in compute TBS with a NULL input, returning NULL TBS
Fixes: 9449f777 ("Remove TBS table and recompute on demand")
During refactoring, the wrong functions and correspondingly tables have
been used to calculate UL TB size. Fix through correct functions.
This should fix these error messages:
3624774.778195 [MAC] E (nr_get_Qm_dl:2034) Invalid MCS table index 3 (expected in range [0,2])
3624774.778207 [MAC] E (nr_get_code_rate_dl:2066) Invalid MCS table index 3 (expected in range [0,2])
3624774.778211 [NR_MAC] E (nr_compute_tbs:63) Error in compute TBS with a NULL input, returning NULL TBS
Fixes: 9449f777cc ("Remove TBS table and recompute on demand")
- The DU was using encode_MIB_NR() while constructing the GNB-DU System Information for the F1SetupRequest.
- encode_MIB_NR() encodes a full NR_BCCH_BCH_Message_t, causing the MIB to be wrapped in a BCH container.
- This results in incorrect MIB values in the F1SetupRequest PCAP (e.g., wrong systemFrameNumber, SCS, DMRS position, cellBarred).
- According to 3GPP TS 38.473, the MIB carried in F1AP must be encoded as a raw NR_MIB_t.
- The correct function encode_MIB_NR_setup() encodes MIB in the required format but was not used.
- This patch replaces encode_MIB_NR() with encode_MIB_NR_setup() to ensure correct and standards-compliant MIB encoding in the F1SetupRequest.
Closes issue #1034.
Problem:
During N2 handover with integrity protection (NIA1/NIA2), the target gNB
was disabling ciphering when configuring SRB1 security, while the UE
continued using the old security context from the source gNB until it
received and processed the RRC Reconfiguration with masterKeyUpdate. The
first PDUs sent after CFRA were still ciphered with the old keys, but the
target gNB had ciphering disabled, causing it to skip deciphering and
attempt integrity verification on ciphered data, leading to MAC-I
mismatches and integrity failures.
Specification Reference:
According to TS 33.501 section 6.11, "the UE shall keep the K gNB used in
the source cell until the handover or a connection re-establishment has been
completed successfully". This means the UE continues using the old security
context (old KRRCint, KRRCenc) until it receives and processes the RRC
Reconfiguration with masterKeyUpdate. The target gNB must therefore enable
ciphering during handover setup to correctly decipher and verify integrity
of PDUs sent with the old security context before the UE switches to the new
keys.
Root Cause:
The code was calling nr_rrc_pdcp_config_security(UE, false) during
handover setup, which disabled ciphering. This was incorrect because:
1. The UE already has security active from the source gNB
2. The UE continues using old ciphered keys until masterKeyUpdate
3. The UE sends ciphered PDUs immediately after CFRA succeeds
4. The target gNB must be able to decipher these PDUs to verify integrity
Why it only manifested when drb_integrity = "yes":
The bug was always present, but only caused visible failures when
integrity verification was enabled. When drb_integrity = "no", the config
typically also sets integrity_algorithms to only NIA0, resulting in
UE->integrity_algorithm = 0, which causes has_integrity = 0 for SRB1,
skipping integrity verification and hiding the underlying ciphering bug.
When drb_integrity = "yes", integrity_algorithms typically includes
NIA1/NIA2, resulting in has_integrity = 1 for SRB1, causing integrity
checks to run on ciphered data and fail.
Fix:
Change nr_rrc_pdcp_config_security(UE, false) to
nr_rrc_pdcp_config_security(UE, true) during handover setup to enable
ciphering immediately, allowing the target gNB to correctly decipher and
verify integrity of PDUs sent with the old security context.
Note: This fix is specific to handover. During initial context setup,
ciphering should remain disabled until SecurityModeComplete is received,
as the UE hasn't activated ciphering yet at that point.
During re-establishment, new KgNB* is derived, requiring new UP keys (KUPint,
KUPenc) to be sent to CU-UP. When do_drb_integrity = true, CU-UP needs the
updated integrity keys to verify DRB PDUs. Without this update, CU-UP uses
old keys while the UE uses new keys, causing integrity failures.
The fix ensures security info is always sent during re-establishment,
which is critical for DRB integrity.
Instead of trying to estimate N_UE_TA_adj with a second degree polynomial,
we introduce orbit propagation to calculate N_UE_TA_adj with higher accuracy.
When we receive the satellite ephemeris data consisting of the satellite position vector
and the satellite velocity vector, we calculate parameters for orbit propagation, assuming
a circular orbit in the plane created by the satellite position vector and the satellite
velocity vector. This is done in the function prepare_ue_sat_ta().
Every millisecond, we use these parameters together with the time since epoch to calculate
the satellite position on that orbit and from this the reound-trip-time between UE and the
satellite, what corresponds to N_UE_TA_adj. This is done in the function apply_ntn_timing_advance().
In case of Handover, NTNconfig sent in RRCreconfiguration triggering handover contains epoch time wrt
timing of Target cell. NTNconfig in RRC needs to be processed only after timing is acquired on the target cell
In case of Target cell, epoch time is the sfn nearest to the frame timing of the target cell.
PDU Session Release
This MR implements end-to-end PDU Session Release functionality
according to 3GPP TS 38.413 and TS 38.331 specifications.
Reason for Change Previous implementation had incomplete and wrongly
places tunnel cleanup during PDU session release. UP cleanup shall be
done at CUUP, RRCReconfiguration shall be sent after retrieval of
updated CellGroupConfig from the DU. This implies F1 and E1 exchanges
during PDU session release procedure.
Major Changes:
1. RRC PDU Session Release: DRBs and PDU session teardown in NGAP PDU
Session Release Response callback
- Helper Functions: Introduced rm_pduSession,
find_drb_by_pdusession_id and rm_drbs() helpers to locate and clean
up DRBs linked to a specific PDU session
- Targeted Cleanup: RRC PDU Session and per-session DRB removal in
rrc_gNB_send_NGAP_PDUSESSION_RELEASE_RESPONSE()
- Status Cleanup: Removed unused PDU_SESSION_STATUS_RELEASED status
2. RRC PDU Session Release: Refactor
rrc_gNB_process_NGAP_PDUSESSION_RELEASE_COMMAND
- Any PDU session in the pdusession_release_params list that is
present in the RRC list can be set to release, regardless of its
status
- Function Signature Update: Updated function signature and other
minor changes
- Response Handling: rrc_gNB_send_NGAP_PDUSESSION_RELEASE_RESPONSE is
sent upon completion of RRCReconfiguration
3. RRC PDU Session Release: add missing procedures E1AP Integration:
- Populates E1AP Bearer Modification for each to be released session
- PDCP Enhancement: Added nr_pdcp_release_drbs() to remove all DRBs
linked to a given PDU session in CUUP
- GTP-U Cleanup: GTP tunnel teardown handled in CUUP
e1_bearer_context_modif() using correct F1 or N3 GTP instance
4. NR PDCP/GTP:
- Enhanced Tunnel Deletion Logic: Separate handling for N3 tunnels (1
per PDU session) and F1-U tunnels (1 per DRB)
- New PDCP API Function: Added nr_pdcp_get_drb_ids_for_pdusession()
function to retrieve all DRB IDs associated with a specific PDU
session
5. RRC PDU Session Release: F1AP-based UE Context Modification:
- Replaced direct RRC message transfer with F1AP UE Context
Modification Request for proper retrieval from DU
- Cell Group Configuration: handling of updated CellGroupConfig from
DU ensures DRB release at CU
6. Docs and testing:
- Added PDU session add/remove test cases to 25 PRB RFSIM pipeline
- Documentation: Added PDU Session Release sequence diagram
- Telnet Commands: Added ci command to trigger NGAP PDU Session
Release and ciUE command to trigger establishment of a new PDU
Session
7. Additional fixes:
- UE RLC Management: ensure release of RLC entities
- Unify NG delay control before calling the RRC NGAP handler, for both
Setup and Release
8. Code Cleanup: Cleaned up unused GTP teardown functions.
Closes#867
Robert Schmidt