If the RLC cannot retransmit a package, 3GPP specs say that we should
declare radio link failure (RLF). Up to this commit, the code did
nothing though. In this commit, add a per-UE RLF callback; the RLC will
call into this function to signal that RLF has been detected through
maximum retransmissions on a particular RLC bearer.
Set SA mode as default
- Set standalone (SA) mode as the default.
- Adjust commands in Docker Compose files by removing --sa flags and
adding --nsa flags where applicable.
- Add a function to verify that only one mode is being used at a time.
- Update all relevant documentation.
csiim_vars/csirs_vars used to be global array for each UE. Now its present
in phy_data which is in dynamically allocated memory.
MAC config was done without mutex while DL and UL threads could be running
at the same time.
get_ue_nas_info was allocating memory possibly from more than one thread.
Moved it into new init function for UE NAS layer.
Addreses most issues in #869
Fix Regression 4G
- Fix various bugs and/or regressions in 4G code
- Also, the CI does not test RFsim 4G with --sanitize, enables this to
detect problems.
Moved some functions around so that instead of a function pointer a function
call is used. This enables inlining of functions which reduces number of function calls.
This commit removes many logs that just show memory addresses, indices,
etc., which, I presume, do not mean anything to the "average user" and
developers alike.
This MR removes limitations on BWP scheduler operation for which only
the information from the first UE of the list was taken into account. To
do so, I moved the VRB map check for DL and UL scheduler out of the
preprocessor and in the scheduler itself.
Closes: #769
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
Prior to this commit, after RA failure, the DU would send a UE context
release complete, without actually requesting one. This could lead to
inconsistent state between DU and CU, because the CU might just discard
this (unrequested) message, and not actually trigger a release [1].
Thus, refactor the release request into a function, and use it to
request release of a UE for which RA has not been completed. If the CU
does not know the UE, release the UE immediately.
[1] One possibility would be that during reestablishment, the CU would
request to look up an old DU UE ID when it has been released, resulting
in
Assertion (oldUE) failed!
In dl_rrc_message_transfer() /home/oaicicd/robert/openairinterface5g/openair2/LAYER2/NR_MAC_gNB/mac_rrc_dl_handler.c:860
CU claims we should know UE bc7f, but we don't
In handover, we might need to remove a UE that we knew under it's
C-RNTI, for which we also have the RA process. Hence, when removing a UE
by RNTI, remove it also from RA.
Bugfix in ue pusch mac pdu creation
When more than one sdu with equal priority is present, there could be
buffer left after serving the lcids and also not enough to equally serve
all lcids. This commit checks for this condition. Before this fix the ue
would send malformed mac pdus when serving multiple lcids.
Instead of hardcoding to 0, instruct the GTP module to send N3 GTP
packets with the right GTP.
We currently only support one QoS Flow, so check that it is really only
one.
When more than one sdu with equal priority is present, there could be
buffer left after serving the lcids and also not enough for equaly
serving all lcids. This commit checks for this condition. Before this
fix the ue would send malformed mac pdus when serving multiple lcids.
After RA, in the case of HO, we need to make sure to use the right radio
configuration (MCS table, etc). This commit is important to make HO
actually work.
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>
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>
francescomani