Integration: `2025.w09`

See merge request !3284

* !3088 Support for long PRACH formats
* !3266 Add optional UTC time stamp to the logging module
* !3280 Changes required for UE to work as a rfsim server with channel modelling
* !3279 Fix UL-MCS when UL inactivity and no data
* !3283 Limit amp_dmrs to 16 bit signed max

Use `rfsimu_channel_ue1`, `rfsimu_channel_ue2`, etc. if you want to
use different channel models for each client. The client connection
order determines its channel model name.

Enable/disable workaround based on a new option "hanging-workaround".
This addresses an issue where the workaround will trigger even if there
is no risk of a permanent lockup of the system.

Remove pthread_mutex_init call from nr_ue_init_mac. The function is
reentrant causing mutex overwrite and possible hanging of the NR UE.

If "utc_time" is selected, log lines are prepended with the UTC time,
formatted as YYYY-MM-DD hh:mm:ss.ssssss UTC.

The documentation has been updated. For other time methods, additional
description of what they show has been added.

As parent.

amp_dmrs is used to scale individual 16bit samples. hence, limit it to
the signed maximum of 16 bits.

Integration: `2025.w08`

Closes #772

See merge request oai/openairinterface5g!3273

* !3263 Free ITTI message after receiving it at MAC from RRC
* !3268 Upgrade SIMDe commit
* !3269 chore(ci): change image rentention from 4weeks to 3weeks
* !3227 fix(nrLDPC_coding): timers in DL encoding, fix(ldpctest): Confusion in sizes
* !3270 Update of gNB-N300-Timing-Phytest threshold
* !3272 Fix: write NSSAI info of F1AP Cell Info struct
* !3259 UE DCI no candidates
* !3264 Fix "Received Nack" log for Msg4/MsgB and minor improvement in RA logs
* !3228 Add option to use global noise power for all RX channels in RFSimulator
* !2725 Use 5G-S-TMSI as UE identity in RRCSetupRequest

NTN test uses long PRACH format (format 0).

set number of prach slots in prach_vars in first slot and set as
inactive in last slot so we can skip OFDM modulation in slots that
already has prach.

Use memcpy in nr_prach.c to fill txdata buffer.

Remove global tables related to PRACH generation.

Add new function to compute modulo multiplicative inverse and use it
directly to get inverse instead of LUT.

Removed nr_ru table and compute the values in-place.

In UE, added new flag root_seq_computed in nrUE_config to only compute
the sequence once after new nrUE_config is received.

t_id for long prach formats is computed with mu = 0.

Long PRACH extends beyond a slot. Changes necessary to mark future slots
that may contain prach in ru, phy and mac functions.

In RU, the PRACH IDFT is done only after receiving last slot and marks
for L1 to start processing. The L1 processes at the last prach slot and
reports to MAC with the first slot index.

In MAC scheduler, the VRB for future slots are also marked as used.
PRACH scheduler is called in advance one frame minus num prach slots.

Use 5G-S-TMSI as UE identity in RRCSetupRequest

This MR includes the following implementation:

- Handle 5G-S-TMSI in RRCSetup:
  - Set the ue-Identity to ng-5G-S-TMSI-Part1 in RRCSetupRequest and
  - If RRCSetup is received in response to an RRCSetupRequest: set the
    ng-5G-S-TMSI-Value to ng-5G-S-TMSI-Part2 in do_RRCSetupComplete

TS 38.331 5.3.3.3 Actions related to transmission of RRCSetupRequest message:

The UE shall set the contents of RRCSetupRequest message as follows:
1> set the ue-Identity as follows:
2> if upper layers provide a 5G-S-TMSI:
3> set the ue-Identity to ng-5G-S-TMSI-Part1;

- Pass 5G-S-TMSI to RRC when NAS receives GUTI in Registration Accept
  - NAS extracts GUTI from Registration Accept
  - send ITTI indication from NAS to RRC when GUTI is available and store
    5G-S-TMSI in RRC instance
- Rework of Initial UE message handling in RRCSetupComplete: simplify code and memory management
- Fix for integrity failure after UE comes back from RRC IDLE
- Other NAS fixes

Note:
- Initial implementation of Initial NAS Message: Service Request -> moved to !3065 (merged)
- Rework of Registration Request added to !3176 (merged)

Closes #772

Add option to use global noise power for all RX channels in RFSimulator

Added new command line option to rfsimulator: noise_power_dBFS. This options
allows the user to configure noise power in dBFS added instead of the
per-channel value.

This makes it so noise is not accumulated per channel reaching higher than
expected values.

The dBFS unit allows easy configuration. The gNB by default uses -36 dBFS
setting. e.g. to reach 3dB SNR one should set the noise_power_dBFS value to -39.

Fix bug in talbe 38.211 6.3.3.2-1 for FR2.

function returns mu of UL BWP if msg1-SubcarrierSpacing absent instead
of asserting. The mu retured by this function is used to compute the
slot number of PRACH. In case of long format, the slot number is as per
UL mu.

Fix "Received Nack" log for Msg4/MsgB and minor improvement in RA logs

Fix "Received Nack" log for Msg4/MsgB, in 4-Step RA. When there is a Msg4 NACK,
we have this log:

[NR_MAC]   (UE 91db) Received Nack in MsgB, preparing retransmission!

This MR fixes the message and now works correctly both in 4-Step RA and 2-Step RA.
Other additional but minor improvement in RA logs.

UE DCI no candidates

Do not schedule DCI in MAC UE if there are no candidates

Fix: write NSSAI info of F1AP Cell Info struct

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: f278b008 ("Add encoding/decoding library for F1AP Setup
Request (Interface Management) ")

Update of gNB-N300-Timing-Phytest threshold

Current results are in some cases well below the current thresholds. We should
periodically adapt them to actual values so that the test is meaningful.

Merge remote-tracking branch 'origin/nrLDPC_coding_improvements_3' into integration_2025_w08 (!3227)

fix(nrLDPC_coding): timers in DL encoding, fix(ldpctest): Confusion in sizes

Main improvements:

1. fix(ldpctest): Confusion in sizes
   IMPORTANT: This fix makes that ldpctest now works with BG2 and K' != K!
   (Worth double checking with more cases than I did check with though)
   The variable block_length had an ambiguous role and was used as both K and
   Kprime. This was leading to arrays with wrong sizes and functions with wrong
   arguments. Now there is not anymore block_length but K and Kprime.
   Kprime can be set with the command line argument -l.
   There was also some problems with array allocation for segments with length
   not divisible by 8. A proper sizing with ((size_in_bits + 7) & ~7) / 8 was
   used.
   A proper masking of the last byte containing payload bits was also added to
   keep filler bits to 0 after random initialization.

2. fix(nrLDPC_coding): timers in DL encoding
   While timers were available for rate matching and interleaving in the new
   interface, these timers were not merged to rate matching and interleaving
   timers in nr_dlsch_coding.

chore(ci): change image rentention from 4weeks to 3weeks

The cluster image registry is getting full. At the moment we have limited
storage so we should reduce the retention period.