Signal gNB-DU config update CellStatus from DU to CU
Add the cell status to gNB-DU configuration update message, including
test. Use the gNB-DU configuration update to signal the cell status in
the stack.
This IE was not included in a previous refactoring round, but is at
least necessary to be decoded when interoperating with the OSC O-DU.
This is preparatory work to allow NSA-like modes to be used over F1 in
the future. Notably, it fills the F1 message for UE context setup with
GTP TEID, and fills additional information to "make the F1 encoder
happy" (fill in QFI etc). Also, provide some F1 fixes to make this work.
Remove stale UE connections, if relevant.
Issue 947 and compilation improvements
This MR started with a small commit (03c7f151) to close#947. Little did
I know that I would be taken in a long journey through OAI compilation
hell.
- encode all SI containers the encoding function gets (it's not the
encoding function's job to enforce semantics)
-
Fixes: 30628b820c ("Add encoding/decoding lib for F1AP Setup Response
(Interface Management)")
Encapsulate the asn1c call from cmake in a cmake function run_asn1c().
As a notable change to the previous manual add_custom_command()
invocation, in suppresses the output of asn1c by default [1] and stores
it in a log file. In case of asn1c4 error, the output will output on
stdout.
Use the new run_asn1c() in all occasions for code generation.
[1] it is quite verbose, with many warnings that we cannot influence nor
suppress, and lists all generated files which is verified by the build
system automatically, anyway.
[E2 agent] RAN Control SM - support for REPORT Style 1 ("RRC Message" and "UE ID" RAN Parameter IDs)
[Spring of Code 2024] contributions
Extended the RAN Control Service Model at E2 Agent to support all RC
REPORT Styles (1 - 5)
Implemented the following RAN Parameter IDs for REPORT Style 1:
1. "RRC Message": any DL-DCCH, and any UL-DCCH
2. "UE ID": as per spec, when the RRC Setup Complete or F1 UE Context
Setup Request detected
As per spec, UE ID shall be reported when the message event configured by
the Event Trigger Style 1 is set to “RRC Setup Complete" message (UE attach), or
“Xn/NG Handover Request” or “F1 UE Context Setup Request” (Intra gNB Handover).
In OAI RAN, Xn/NG Handover is not yet supported, and therefore not added as the trigger event
in this commit.
Additionally, as the Event Trigger Definition Format 1 is common for both "RRC Message" and "UE ID",
E2 node will report the “RRC Setup Complete" message which the xApp will decode and print.
Co-authored-by: Khanh Toan Pham <khanh.toan.pham@hhi.fraunhofer.de>
Co-authored-by: Shrinish Donde <shrinish.donde@hhi.fraunhofer.de>
Co-authored-by: Theodoros Tsourdinis <theodoros.tsourdinis@sorbonne-universite.fr>
Co-authored-by: Miguel Fuentes <miguel.fuentes@i2cat.net>
Co-authored-by: Teodora Vladic <teodora.vladic@openairinterface.org>
During refactoring, the previously implemented NSSAI field of the cell
info structure was not written to F1AP ASN.1 structures anymore;
eq_f1ap_cell_info() also conveniently omitted the corresponding equality
check. Add this back so the CU can correctly receive the NSSAI in case
of F1 split operation.
Fixes: f278b00837 ("Add encoding/decoding library for F1AP Setup
Request (Interface Management) ")
F1AP IDs: Add update, fix concurrency bug
I suspect a concurrency bug: For instance, during reestablishment, the
CU needs to update the DU UE ID under which the UE is identified in the
DU. Previously, the CU would remove, then add the DU UE ID info. At the
same time, the PDCP thread might look up the information. This can lead
to asserts. Modify the code to do the update under (one) lock.
Also, refactor some code.
Introduce function cu_update_f1_ue_data() which does remove+add under
one lock. This fixes a concurrency bug. For instance, during
reestablishment, the CU needs to update the DU UE ID under which the UE
is identified in the DU. Previously, the CU would remove, then add the
DU UE ID info. At the same time, the PDCP thread might look up the
information. This can lead to asserts. Use the above addmod
functionality to do the remove-add under a mutex.
Modify test to verify this works as expected.
- Refactor SCTP Association Response Handling
- Unified function for both CU-CP and CU-UP handling
- CU-CP: Notifies RRC of E1 connection loss with CU-UP
- CU-UP: Initiates a new SCTP association request to regain E1 connection
- this fix will prevent issue #878 from happening
- Send list of PDU Session Resources to Failed Setup in the (PDU Session
Resource/Initial Context) Setup Response
- depending on different failure scenarios
- e.g. (#878) when No CU-UP is associated and still the CU-CP receives a PDU
Session Setup Request
- add relevant functions to handle NGAP Setup Response messages with failed
list of items
- this is an extra failure handling to make #878 is handled if it ever happens
again
- NGAP Cause Refactoring
- Refactor struct for NGAP cause group and value
- Add extended radio network cause enumeration values
- Refactor redundant code into a new NGAP cause encoding function
- Minor logging, function descriptions improvements
Closes#878
Modify xu_add_f1_ue_data() to be xu_addmod_f1_ue_data(), i.e., "addmod"
behavior in which it is possible to also update f1_ue_data. I do it this
way since an xu_updade_f1_ue_data() function would be almost the same as
the add function (only deleting existing data, whereas the original
add() was asserting in that case).
Modify tests to test for this behavior.
This fixes a concurrency bug. For instance, during reestablishment, the
CU needs to update the DU UE ID under which the UE is identified in the
DU. Previously, the CU would remove, then add the DU UE ID info.
At the same time, the PDCP thread might look up the information. This
can lead to asserts. Use the above addmod functionality to do the
remove-add under a mutex.
* this function is used by both CU-CP and CU-UP
* it behaves differently depending on the type of E1 instance:
CU-CP: inform RRC of E1 connection loss with CU-UP
CU-UP: trigger a new SCTP association request by sending an ITTI to the CU-UP task
* after receiving the E1AP register request, the CU-UP will send a new association request to
SCTP until new E1 connection is achieved by sending a TIMER_HAS_EXPIRED message to the CU-UP
task. The function e1apHandleTimer() is basically triggering a new E1 association request
until new E1 connection is achieved
* print SCTP association state in e1ap.c whenever needed
Related to #878
Need to proper forward declaration, as we otherwise need to make
telnet_o1 module dependent on F1. Make functions publicly accessible,
as the F1 functions are used in an upcoming commit to start the L1.
Split out these functions, to be reused in a follow-up commit to
correctly have gNB-DU configuration update message working.
Change the return type copy_f1ap_served_cell_info(), to return the copy,
which IMO is more intuitive then passing target and source in
parentheses.
Add F1 Handover procedures
- Clean up at RRC and MAC
- Add DU handover procedures, completely handle CellGroupConfig at DU
- Add CU handover procedures
- Maintain reestablishment working between/after handover
- Changes at UE to resync on different frequency DUs
Instructions: see doc/handover-tutorial.md
Things not implemented/open/missing: see #855
Robert Schmidt