Miscelaneous improvements in PHY simulators
1: Add a SIGINT handler to NR PHY simulators
When using T2 virtual functions, it is important to properly stop DPDK
and free the device. Otherwise the virtual functions may be blocked and
a restart of the admin application is necessary.
If not carefully done, such kind of operation can lead to losing cores
to DPDK processes that cannot be stopped. This can lead to situations
where the machine is locked and can only be unlocked by a power cycle.
Always properly stopping DPDK and freeing the device reduces the risk of
such situation to happen.
Up to now, SIGINT was shutting down the PHY simulators without freeing
the device. This commit adds a signal handler to handle SIGINT in a way
that allow to properly free the device.
This feature is added to all the NR PHY simulators whether they use T2
or not in case it is now or later of any use.
2: Make nr_ulschsim functional
There were two issues that were making nr_ulschsim non functional:
1. The channel output was not copied to decoder input (llr array)
2. The test on decoding successful outcome was wrong
The result was that nr_ulschsim was succesfull whatever were its
arguments. This changeset fixes the two issues so that nr_ulschsim is
now functional.
1. Change the name of `openair1/SIMULATION/NR_PHY/nr_dummy_functions.c` into `openair1/SIMULATION/NR_PHY/nr_unitary_common.c` for naming coherence after adding the SIGINT handler which is not a dummy function.
2. Instead of being built once for every NR PHY simulators, the common functions source file is built once as an object and linked to each simulator.
Even though the remaining NR PHY simulators do not use the T2, we may still feature them with a SIGINT handler for proper termination on SIGINT and for a matter of completeness.
The remaining NR PHY simulators are:
* nr_pbchsim
* nr_prachsim
* nr_psbchsim
* nr_pucchsim
There was two issues that were making nr_ulschsim non functional:
1. The channel output was not copied to decoder input (llr array)
2. The test on decoding successful outcome was wrong
The result was that nr_ulschsim was succesfull whatever were its arguments.
This commit fixes the two issues so that nr_ulschsim is now functional.
When using T2 virtual functions, it is important to properly stop DPDK and free the device.
Otherwise the virtual functions may be blocked and a restart of the admin application is necessary.
Up to now, SIGINT was shutting down the PHY simulators without freeing the device.
This commit adds a signal handler to handle SIGINT in a way that allow to properly free the device.
This feature is first added to the PHY simulators that use the T2 which are `nr_ulsim`, `nr_dlsim`, `nr_ulschsim` and `nr_dlschsim`.
fix(nrLDPC_decoder): fix numIter increment
The logs of ./nr_ulsim -n100 -m19 -s12 -S12 -z2 -L4 were showing that sometimes
the decoding of one segment was failing while the CRC check succeeded. This was
happening because the iteration counter numIter was not properly managed so that
when the last iteration was successful to decode the segment still numIter at
the exit was equal to numMaxIter plus 1 so that decoding was considered to have
failed. In other words the last iteration if it occured was always wasted.
This commit offers to solve this problem by simply moving the iteration counter
increment at the end of the iteration loop while remaining careful at fixing the
tests relying on this counter.
Post-Scriptum:
After a first review, we decided to make the counter more standard from a C code
perspective. The counter now counts from 0 to numMaxIter minus 1. If it reaches
numMaxIter, it means that decoding was unsuccessful.
The idea is to make LDPC iteration accounting more standard from a C coding perspective by making two changes:
1. Now the iteration counter starts at 0 for the first iteration and goes up to max_ldpc_iterations - 1 for the last iteration.
If it is equal to max_ldpc_iterations, it means that decoding failed.
2. A chain of useless returns in the UE DLSCH decoding call chain was removed.
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.
E1AP enc/dec lib improvements
This MR is including some fixes and improvements for the E1AP library,
focusing mostly on Bearer Context Management:
- struct reorganization: split setup and modification request messages
into distinct structures, ensuring compliance with 3GPP TS 38.463
specifications
- add encoding/decoding sub-functions for different IEs
- improvements to Bearer Context Management: Implemented various
improvements to the E1 Bearer Context Setup Response and Request,
including the adoption of encoding/decoding sub-functions for
different IEs
- use lib functions whenever need (e.g. cp_bearer_context_setup_request
in cucp_cuup_e1ap.c)
- handle optional struct members as pointers
- updated copy/equality check utility functions
EDIT: The MR is also including the changes from !3222 (closed):
> While testing E1 with security enabled for DRBs, it was found that
> data traffic was not functional.
>
> The problem was that security settings were modified in the PDCP
> reestablishment happening when receiving Bearer Context Modification
> Request.
>
> So some restructuring was done.
>
> The actual fix is in 18176297, the others are for support. Basically
> we introduce a boolean to check if the security settings are present in
> Bearer Context Modification Request and we change PDCP security settings
> only if they are.
>
> (Note that in OAI CU security settings are not sent in Bearer Context
> Modification Request, so we could also remove all this, but we need to
> be compatible with other cu-up and/or cu-cp.)
Bearer context setup request and modification request messages
differ in various IEs according to 9.2.2 of 3GPP TS 38.463, e.g.
the Bearer context setup request does not contain a list of
DRBs to modify and does not contain an UP TL configuration.
Thus, the goal of this commit is to split the setup request message
and the modification request into two different structs:
* adopt e1ap_bearer_mod_req_t where necessary (e.g. fill_e1_bearer_modif)
Also, reorganized existing struct members according to specs:
* remove irrelevant struct members from the setup request
* group members from the same IEs into structs
* set optional struct members IEs as pointers
* add and adopt enc/dec/cp/eq lib functions for single IEs
* add UP_TL_information_t struct with TEID and TL address info and adopt in stack
* use int instead of long for count types
* update the relevant copy/equality check utility functions
Extra:
* add a function to handle Security Information in RRC in the process
* add create_up_tl_info and adopt in unit tests
Changes to support multiple TDD patterns
- Updated the configuration changes for 2 Patterns
- Update the TDD table configuration for NFAPI
- Added the tdd bitmap for the period
- Adapted the bitmap for UL/DL for the multi TDD pattern
- Updated the RACH procedure for multi TDD pattern
- Updated DL and UL scheduler for multi TDD pattern
* assuming num_dl_slots and num_ul_slots are including also
slots with dl/ul symbols respectively
* refactor set_tdd_config_nr
* moved function to MAC
* fill max_num_of_symbol_per_slot_list depending on slot type
* use new set_tdd_config_nr in stack
* minor refactor in config.c to improve readability (scs)
Co-authored-by: Guido Casati <guido.casati@firecell.io>
Repair nFAPI in 5G
Add 5G nFAPI in OAI/Make it it work.
Many commits in this branch are basically bug fixes of things that don't work
properly, such as
- check for correct conditions (e.g. instance numbers in the RAN context)
- remove artificial limitation (e.g. only one PUCCH per TDD period in the PNF)
- improve performance (reduce big mallocs, make some static buffers such as a
global ring buffer for nFAPI messages in the PNF)
- fix bugs in nFAPI (e.g., increase maximum message size to ~64kB instead of
1500 bytes, because the latter is way too small for many TX_data.requests in
5G, and it will delay message arrival unduly)
- fix bugs in message enc/dec (e.g., handle FDD in config.request)
- adjust the L1 such that the condition "we run monolithic" is not necessery
(e.g., some message numbers in nFAPI struct where reset in MAC, instead of
L1, and this breaks when running the PNF)
There are instructions that explain how to set it up. Two CI tests have been
added, one with COTS UE and MIMO in DL+UL in TDD numerology 1 (30kHz), and a
second test with FDD mu=0 (15kHZ) in RFsimulator.
These were some old to-dos that have been addressed.
- test with COTS UE - 4x4 pipeline works good in DL, UL now also work
- test in RFsim
- make PNF status message
- make FDD in u0 work
The L1 receives a pointer to the L1 payload to use for PDSCH generation.
This would overwrite an existing pre-allocated pointer. Remove this
preallocation. Instead, allocate it in the simulator (the only place
that actively uses this buffer allocation; in nr-softmodem, it's lost by
assigning a pointer). Allocate with an extra byte, because the payload
(in bits) might not be a multiple of 8 bits/1 byte, so the CRC is in the
last 3 bytes.
Also, improve the log with frame/slot information if the PDSCH payload
pointer is NULL.
FAPI says these lists should be for MAX_TDD_PERIODICITY (which is maybe
a frame, or a TDD period? but likely not two frames). Reduce to one
frame.
Also, the nFAPI code assumes one entire frame, so use that (this commit
necessary to actually make the PNF work, otherwise, the
packing/unpacking of the FAPI message would need to do 2 frames).
Closes: #876
Bartosz Podrygajlo