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.
Fix reestablishment after handover
- fix reestablishment by not re-creating LCIDs with priority set to 0 (see first
commit for more details)
- cleanup code
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.
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")
[MAC] Add UL total/used aggregated MAC stats; [E2 agent] Properly calculate
used UE PRBs in KPM; [CI] Simplify and improve the Undeploy_Object() and
implement Stop_Object()
- Create common dlul_mac_stats_t struct for both DL and UL total/used aggregated
PRBs
- Use correct unit [%] for RRU.PrbTotDl and RRU.PrbTotUl , instead of [PRBs]
- Use correct unit [Mb] for DRB.PdcpSduVolumeDL and DRB.PdcpSduVolumeUL [kb]
- Implement Stop_Object() (docker compose stop = SIGTERM)
- Simplify the Undeploy_Object() function
- Improve the logging for Deploy/Undeploy_Object() functions
- OAI-FlexRIC CI: properly stop all the containers (one by one or a subgroup of
running containers), and rename oai-flexric to nearRT-RIC container
DL stats (aggregated total and used PRBs) previosuly used only for O1 interface,
now finds the purpose for E2 interface as well.
New UL stats (aggregated total and used PRBs) serve for E2 interface only.
Co-authored-by: Teodora Vladić <teodora.vladic@openairinterface.org>
In the current implementation, if UE transmission is interrupted via nr_mac_interrupt_ue_transmission(),
UE_sched_ctrl.ta_frame is modified to be the previous frame avoiding TA scheduling in the measurement gap.
So the next scheduled TA is shifted to be in 99 frames. As there are other measurement gaps before that,
the scheduled TA is always shifted, but actually never reached, effectively disabling the MAC TA commands.
To fix this, UE_sched_ctrl.ta_frame is changed to not indicate the last TA command transmission, but the
next one. This allows to check in nr_mac_interrupt_ue_transmission() if the next TA command transmission
is within the measurement gap and if so shift it to just after that gap.
Check and return, if necessary, that we have enough resources to make
retransmissions. Without, we can asserts in L1, such as
Assertion (NPRB>0 && (NPRB + RBstart <= BWPsize)) failed!
In PRBalloc_to_locationandbandwidth0() openairinterface5g/common/utils/nr/nr_common.c:506
Illegal NPRB/RBstart Configuration (0,51) for BWPsize 51
which indicates that the scheduler requested a transmission with 0 PRBs,
which does not make sense.
Refactor measConfig
- Refactor and minor improvements in get_MeasConfig function;
- Add support for band in neighbourConfiguration (It is currently
possible to handover cells with different frequencies, as long as they
are in the same band, but this MR allows the handover to also be done
between cells in different bands).
Reworking BWP configuration
This MR reworks the configuration via fail of additional BWPs. Moreover, it
allows for a single BWP to be configured for a given UE at a given time (BWP
switch possible only via reconfiguration). It also reworks PTRS configuration
for consistency with the BWP one.
Fixes and updates for UL scheduling, notably DSUUU
Fix a number of problems that stem from !3521, notably regarding Msg3
scheduling, retransmissions in "UL-heavy" TDD scenarios, and BSR
handling. Modify a CI test to run a UL-heavy TDD scenario, and add
documentation for UL-heavy TDD scenarios.
On BSR reception, reset sched_ul_bytes. This change means that we assume
that no data is "in flight" for this UE at time of BSR reception, or,
put differently, that we overestimate the buffer size at UE (in the
worst case).
To illustrate this, consider the following traces before/after this
change.
Before this change: Upon BSR reception, the estimated BSR of the UE is
reset, but the gNB still accounts for data "in flight". It is visible
that the calculated buffer size (estimated - scheduled) quickly goes to
zero, and we don't use all resources, despite the buffer still being
full. The maximum application throughput in this run was ~220Mbps.
[NR_MAC] SHORT BSR at 773.19, est buf 300000
[NR_MAC] ULSCH/PUSCH: 774. 6 RNTI af8e UL sched 774. 9 PRB start 0:162 TDA 2 TBS 32797 est 300000 sched 152704 est BSR 147296 TPC 1
[NR_MAC] ULSCH/PUSCH: 774. 6 RNTI af8e UL sched 774.11 PRB start 0:162 TDA 4 TBS 7172 est 300000 sched 159876 est BSR 140124 TPC 1
[NR_MAC] ULSCH/PUSCH: 774.10 RNTI af8e UL sched 774.12 PRB start 0:162 TDA 0 TBS 32797 est 292845 sched 185501 est BSR 107344 TPC 1
[NR_MAC] ULSCH/PUSCH: 774.10 RNTI af8e UL sched 774.13 PRB start 0:162 TDA 2 TBS 32797 est 292845 sched 218298 est BSR 74547 TPC 1
[NR_MAC] ULSCH/PUSCH: 774.11 RNTI af8e UL sched 774.14 PRB start 0:162 TDA 2 TBS 32797 est 260117 sched 218298 est BSR 41819 TPC 1
[NR_MAC] ULSCH/PUSCH: 774.11 RNTI af8e UL sched 774.16 PRB start 0:162 TDA 4 TBS 7172 est 260117 sched 225470 est BSR 34647 TPC 1
[NR_MAC] ULSCH/PUSCH: 774.15 RNTI af8e UL sched 774.17 PRB start 0: 35 TDA 0 TBS 7172 est 220236 sched 185501 est BSR 34735 TPC 1
[NR_MAC] ULSCH/PUSCH: 774.15 RNTI af8e UL sched 774.18 PRB start 0:162 TDA 2 TBS 32797 est 220236 sched 218298 est BSR 1938 TPC 1
[NR_MAC] ULSCH/PUSCH: 774.16 RNTI af8e UL sched 774.19 PRB start 0: 10 TDA 2 TBS 2017 est 187508 sched 187518 est BSR -10 TPC 1
[NR_MAC] SHORT BSR at 774. 9, est buf 300000
[NR_MAC] ULSCH/PUSCH: 775. 0 RNTI af8e UL sched 775. 2 PRB start 0:162 TDA 0 TBS 32797 est 260117 sched 147549 est BSR 112568 TPC 1
[NR_MAC] ULSCH/PUSCH: 775. 0 RNTI af8e UL sched 775. 3 PRB start 0:162 TDA 2 TBS 32797 est 260117 sched 180346 est BSR 79771 TPC 1
[NR_MAC] ULSCH/PUSCH: 775. 1 RNTI af8e UL sched 775. 4 PRB start 0:162 TDA 2 TBS 32797 est 227389 sched 180346 est BSR 47043 TPC 1
[NR_MAC] ULSCH/PUSCH: 775. 1 RNTI af8e UL sched 775. 6 PRB start 0:162 TDA 4 TBS 7172 est 227389 sched 187518 est BSR 39871 TPC 1
[NR_MAC] ULSCH/PUSCH: 775. 5 RNTI af8e UL sched 775. 7 PRB start 0:162 TDA 0 TBS 32797 est 180353 sched 173174 est BSR 7179 TPC 1
[NR_MAC] ULSCH/PUSCH: 775. 5 RNTI af8e UL sched 775. 8 PRB start 0: 36 TDA 2 TBS 7298 est 180353 sched 180472 est BSR -119 TPC 1
After this change: The gNB resets the number of bytes "in flight"
(sched). Thus, the calculated buffer is larger, and does not "run out"
before a new BSR arrives (which still indicates the maximum). The UE is
thus allocated all resources, but we might overestimate some resources.
The maximum application throughput in this run was ~300Mbps, limited by
MCS and not by estimated buffer size as in the previous case.
[NR_MAC] SHORT BSR at 43. 3, est buf 300000
[NR_MAC] ULSCH/PUSCH: 43.15 RNTI d3ea UL sched 43.17 PRB start 0:162 TDA 0 TBS 36897 est 263180 sched 36897 est BSR 226283 TPC 1
[NR_MAC] ULSCH/PUSCH: 43.15 RNTI d3ea UL sched 43.18 PRB start 0:162 TDA 2 TBS 36897 est 263180 sched 73794 est BSR 189386 TPC 1
[NR_MAC] ULSCH/PUSCH: 43.16 RNTI d3ea UL sched 43.19 PRB start 12:150 TDA 2 TBS 33822 est 263180 sched 107616 est BSR 155564 TPC 1
[NR_MAC] ULSCH/PUSCH: 43.16 RNTI d3ea UL sched 44. 1 PRB start 0:162 TDA 4 TBS 7941 est 263180 sched 115557 est BSR 147623 TPC 1
[NR_MAC] ULSCH/PUSCH: 44. 1 RNTI d3ea UL sched 44. 3 PRB start 0:162 TDA 0 TBS 36897 est 173698 sched 25881 est BSR 147817 TPC 1
[NR_MAC] ULSCH/PUSCH: 44. 1 RNTI d3ea UL sched 44. 4 PRB start 0:162 TDA 2 TBS 36897 est 173698 sched 62778 est BSR 110920 TPC 1
[NR_MAC] ULSCH/PUSCH: 44. 1 RNTI d3ea UL sched 44. 6 PRB start 0:162 TDA 4 TBS 7941 est 173698 sched 70719 est BSR 102979 TPC 1
[NR_MAC] SHORT BSR at 43.13, est buf 300000
[NR_MAC] ULSCH/PUSCH: 44. 5 RNTI d3ea UL sched 44. 7 PRB start 0:162 TDA 0 TBS 36897 est 292079 sched 36897 est BSR 255182 TPC 1
[NR_MAC] ULSCH/PUSCH: 44. 5 RNTI d3ea UL sched 44. 8 PRB start 0:162 TDA 2 TBS 36897 est 292079 sched 73794 est BSR 218285 TPC 1
[NR_MAC] ULSCH/PUSCH: 44. 6 RNTI d3ea UL sched 44. 9 PRB start 0:162 TDA 2 TBS 36897 est 292079 sched 110691 est BSR 181388 TPC 1
[NR_MAC] ULSCH/PUSCH: 44. 6 RNTI d3ea UL sched 44.11 PRB start 0:162 TDA 4 TBS 7941 est 292079 sched 118632 est BSR 173447 TPC 1
[NR_MAC] ULSCH/PUSCH: 44.10 RNTI d3ea UL sched 44.12 PRB start 0:162 TDA 0 TBS 36897 est 213587 sched 39972 est BSR 173615 TPC 1
[NR_MAC] ULSCH/PUSCH: 44.10 RNTI d3ea UL sched 44.13 PRB start 0:162 TDA 2 TBS 36897 est 213587 sched 76869 est BSR 136718 TPC 1
Instead of only saving this information in the first transmission, also
store it on each retransmission. This should ensure that if some
information changes, we always relate to the last transmission. For
instance, power control information might have changed, and should be
considered in subsequent rounds, if necessary. It also simplifies code.
Fixes: 6294ce715e ("Reorder pf_ul to process retransmission")
Previously, the TDA reuse condition was wrong: for multiple TDAs with
different k2, the symbol allocation might be the same, in which the
previous logic was using the wrong TDA. Fix the condition, and insert an
assert to ensure the allocated TDA is correct.
Refactor ULSCH scheduler towards more TDD pattern flexibility
Refactors ULSCH scheduler, notably to support "UL-heavy" TDD patterns,
e.g., DSUUU. Also allows to run TDD pattern2 with UL slots, which was a
limitation in the previous code.
A new function get_best_ul_tda() allows to select the "best" TDA out of
a number of TDA. Specifically, get_best_ul_tda() considers in how many
RBs a given TDA might be allocated, and multiplies this number of RBs
with the number of symbols in the TDA to form a "score". The TDA with
the best "score" is selected, considering it maximizes resource usage.
In phytest scheduler, we use this function to verify that the given TDA
can be really allocated in all selected slots.
Schedule SRS longer in advance, so that it would also be enough even
with big k2 for UL TDA.
Remove useless types: we do not use the information on sched_srs
anymore, so remove it.
Check that the VRB map is free before making allocations.
Add multiple TDAs with k2 larger than the min_rxtxtime, to potentially
allow to allocate all available slots. For this, nr_rrc_config_ul_tda()
inspects the TDD pattern, and allocates as many TDAs as necessary. It
also sorts the TDA list, with smaller k2 and larger symbol lengths
first.
This in turn is now used by get_num_ul_tda() to use a k2 and the slot
configuration to find a suitable TDA, assuming a list as sorted in
nr_rrc_config_ul_tda().
Note that since get_num_ul_tda() does only inspect the available UL
slots, there might be overlap (e.g., when scheduling SRS), which will be
fixed in a follow-up commit.
Also, TDD pattern 2 is not handled here yet, and a follow-up commit will
fix it.
Add a loop to advance slots as determined by current ("DL") slot, and
advance further into the future (for "UL" slots) if TDAs allow. Ensure
to schedule all TDAs if it's the last DL slot, to guarantee a previously
scheduled TDA will also reoccur (i.e., for guaranteeing that
retransmissions can be made).
Note that the check for number of UE being zero is removed, as this
allows to keep "ul_next" close to the "min_next" slot. This way, we can
use fs_get_max(); otherwise, if we did not always execute this loop,
they might diverge far from each other, making the logic inside the loop
more complicated.
This commit introduces a new type "fsn_t" (frame-slot number) that
encapsulates a single frame-slot combination in a single struct. The
helper functions (in gNB_scheduler_ulsch.c) should be moved to a new
file under common/, but we don't do this here to limit the amount of
code changes.
For scheduling multiple ULSCH ahead, we will have to use different k2.
Hence, we will need to check for k2 in the TDA selection as well. The
function get_ul_tda() is renamed to get_num_ul_tda() to reflect that it
might return multiple TDAs (not done in this commit, but in a follow-up
MR). get_num_ul_tda() also returns a pointer to the first suitable TDA.
In the phy-test scheduler, simplify the selection of the TDA to use: do
not hardcode a specific K2, but rather, use the first one (with any k2).
For the multi-UL slot scheduling functionality in a follow-up commit, it
would be important to know if the scheduler allocated any UEs. If
pf_ul() allocated for some UEs, we might run it again on a different
slot. If on the other hand, no UEs were allocated, there is no point in
running it again.
Scheduling for inactivity only deviates in details from the main
scheduling logic: we simply allocate a fixed number of RBs instead of
making it dependent of data.
In this commit, add an additional flag to sort UEs that are scheduled
for inactivity in front of "normal" UEs (with traffic). Then, schedule
those UEs by limiting/fixing the amount of RBs to schedule to
min_grant_prb.
Update the comparator() to properly sort UEs based on this flag and the
coefficient by applying a consistent logic of -1/0/1 (see man qsort) for
smaller/equal/larger. The inactivity flag, if set, will always have
higher priority over the coefficient to schedule these UEs first, as was
the case prior to this commit.
Remove sched_ctrl->sched_ulsch, and call the post-processing function
post_process_ulsch() in the places where sched_ctrl->sched_ulsch has
been assigned. This will have two effects:
- it is not necessary to have the final loop over all UEs, which might
be costly especially towards many UEs.
- till now, there is only a single sched_ulsch; however, a later commit
will allow to schedule multiple PUSCH transmissions from a single (DL)
slot. This would require to make sched_ctrl->sched_ulsch, and
also iterate through all sched_ulsch. In this new scheme, we can
simply call post_process_ulsch() multiple times, which is simpler (and
therefore, implicitly handleded as of this commit).
Write a single NR_sched_pusch_t structure in a single statement (where
possible). Assign to sched_ctrl->sched_pusch in one place, where the
post-processing functionality will be called in a follow-up commit.
Avoid to overwrite the existing retInfo. Instead, create a new
NR_sched_pusch_t and assign to sched_ctrl->sched_pusch in one place. A
follow-up commit will directly trigger the post processor here.
Write a single NR_sched_pusch_t structure in a single statement (where
possible). Assign to sched_ctrl->sched_pusch in one place, where the
post-processing functionality will be called in a follow-up commit.
PF uses MCS and average throughput to decide which UE to schedule. Thus,
the first loop selects the MCS, and the second does the main UE
allocation after sorting by priority, depending on the MCS.
A follow-up commit will remove sched_pusch from NR_UE_sched_ctrl_t.
Thus, we cannot rely on sched_ctrl to store the MCS in the first loop,
and look it up from there in the second. Instead, store it as part of
the UE iterator data, and take it from there.
maki
Robert Schmidt