E1 Setup enc/dec library and unit test
This MR is adding a library for E1 Setup enc/dec functions:
- E1 CU-UP Setup Request
- E1 CU-UP Setup Response
- E1 Setup Failure
and relevant unit tests
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.
* add function to check whether cu-up is connected
* add functions to send the relevant response messages with the failed list
e.g. to fill PDU Session Resource Failed to Setup items
* set return value of trigger_bearer_setup to bool and handle the
failure by sending setup response messages with list of PDU sessions failed to setup
i.e. send failed list of items when no CU-UP is associated to the CU-CP
note: it considers all PDU Sessions as failed to setup in the considered failure scenarios
* e.g. send a list of failed PDU session resources in the response message to reject
PDU Session Resource Setup in rrc_gNB_process_NGAP_PDUSESSION_SETUP_REQ
* the Initial Context Setup has a Failure message, but for the considered failure scenario
when no CU-UP is available the current design is just sending a list of failed to setup
items in the Response message
* transfer PDU Session Resource/Initial Context Setup Request NAS PDU to UE
closes#878
* new struct definition including both NGAP cause group and value
* add encoding function, temporarily in ngap_common.c
(in the long term to be place in a enc/dec NGAP library)
* extend Radio Network cause enum values
* add cause member to Setup Failure
Introduce ITTI queue in RRC-to-MAC direction
resolve ue rcc to mac race conditions by a itti queue, but it doesn't
resolve the problem of exact slot we should apply the new cell
configurtion
Reduce race conditions through a itti queue, such that RRC-initiated MAC
memory modifications happen at the same time as MAC thread writes.
However, it doesn't resolve the problem of exact slot we should apply
the new cell configurtion.
Add support for O1 in O-DU via telnet
This change set adds a simple telnet interface to nr-softmodem. Together
with oai/o1-adapter>, this implements a part of the O1 interface, for
the DU only. Currently supported uses cases:
- some stats are send to an SMO (such as bandwidth, PLMN, frequency, ...)
- re-configuration of bandwidth, frequency
- stop/start of the softmodem, while keeping the CU and L2 running
- the o1-adapter implements two alarms, load overload and base station
offline, using this interface.
It is possible to use the telnet interface by itself (i.e., "o1" without
the o1-adapter). To do this, compile with telnet support (./build_oai
--build-lib telnetsrv) and start the nr-softmodem with O1 module
(./nr-softmodem --telnetsrv --telnetsrv.shrmod o1). You can then do the
following:
- see some statistics as exposed to o1-adapter, in JSON: echo o1 stats | nc 127.0.0.1 9090 && echo
- stop the L1: echo o1 stop_modem | nc 127.0.0.1 9090 && echo
- reconfigure bandwidth: e.g., echo o1 bwconfig 20 | nc 127.0.0.1 9090 && echo (also supported: 40, 60, 100)
- start the L1: echo o1 start_modem | nc 127.0.0.1 9090 && echo
Note that the reconfiguration works with split-8 radios. Notably, it
does not work yet out-of-the-box with 7.2 radios, because they have to
be manually reconfigured on bandwith/frequency switch. The planned
M-plane should allow such use case, though.
To help with the above, this branch also includes fixes (for more
information, refer to the corresponding commits):
- fixes for stopping the L1, notably stop threads in right order, stop
thread pool of RU
- collect some general MAC metrics, fix some bugs in MAC
- fix problems in F1AP gNB-DU configuration update message, update test
- fix some problems in RRC
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.
For the "restart" feature, earlier versions where creating multiple UL
TDA. This is not a problem (anymore), but to avoid that we call this
multiple times, add this assert.
NGAP-Initial Context Setup Failure
NGAP Failure message - Initial Context Setup Failure. When an Initial
Context Setup Request is received with the UE context as null, it
triggers Initial Context Setup failure
NGAP Failure message - Initial Context Setup Failure.
When an Initial Context Setup Request is received with the UE context as null, it triggers Initial Context Setup failure.
NR UE RRC T304 in phy-test mode
RRC timer T304 is stopped upon completion of the associated RA handover
procedure. There is no RA procedure in phy-test mode so T304 should not
be started to avoid unwanted expiration.
* tac is optional IE, and it was assumed as always present
* is now allocated in DU container by copy_f1ap_served_cell_info
when present in the updated cell info and missing in the
DU container
Refactor of includes in gNB/UE for improved header management
This merge request implements changes suggested by the Include What You Use
(IWYU) open source tool to streamline the project’s header file usage.
The adjustments ensure that each file includes only the necessary headers for
the symbols it uses, making the code more efficient and maintainable.
Unnecessary includes have been removed, and missing headers have been added
where required. This improves modularity and reduces inter-dependencies between
files, helping to avoid future build issues caused by unused or missing includes.
Each output has been manually reviewed.
Followed a similar approach as in !2953 (merged).
Affected folders/files:
- NR_MAC_gNB/main.c
- nr-softmodem.c
- unitary simulators: nr_dlsim, nr_ulsim, prachsim
- openair2/RRC/NR
- openair3/NGAP
- openair2/LAYER2/nr_pdcp
- openair2/SDAP/nr_sdap
Robert Schmidt