This commit introduces X2AP timers (t_reloc_prep, tx2_reloc_overall).
You need to set the values in the configuration file.
X2AP can be enabled or disabled in the configuration file too (disabled
by default).
Some deadcode was removed.
Added the following structs and enums in "defs_gNB.h"
- NR_UL_gNB_HARQ_t
- NR_gNB_ULSCH_t
- NR_SCH_status_t
added the following structs in "nfapi_nr_interface.h"
- nfapi_nr_ul_config_ulsch_pdu
- nfapi_nr_ul_config_ulsch_pdu_rel15_t
- nfapi_nr_ul_srs_config_t
- nr_pusch_freq_hopping_t
added nr_ulsch.h for the ulsch decoding function declarations
- free_gNB_ulsch
- new_gNB_ulsch
- nr_ulsch_decoding
added nr_ulsch_decoding.c for the implementation of the ulsch decoding functions
- free_gNB_ulsch
- new_gNB_ulsch
- nr_ulsch_decoding
Although not used in the UE, we currently need to link the F1 library into it.
This is because we do not define ASN_DISABLE_OER_SUPPORT (otherwise, F1 has
compilation problems). In this case, some functions are apparently not
correctly defined, giving linker errors in the UE. Linking F1 in solves the
problem.
This is a hack. It would be better to be able to define ASN_DISABLE_OER_SUPPORT
and have no compilation errors or compile everything with
ASN_DISABLE_OER_SUPPORT except F1. I did not do this because I did not find
another way than add target_compile_definitions() to every target except F1
which adds many lines just so that one target (F1 ASN.1) compiles correctly (in
other words, F1 needs to be fixed).
Some deadcode was removed.
The implementation of the ID management is not finished.
It will only work if the handover is successful. No error
recovery has been done. For error recovery, we need to
implement the X2AP timers. As it is, in case of error, an ID
might very well never be released.
It has been tested with 1 and 2 UEs doing handover more or less
at the same time.
With the introduction of X2AP into develop, the UEs now have to regularly
send measurement reports.
In the logs of the eNB, we see:
[OSA] Mismatch found in integrity for algorithm 2,
got e0.a0.c2.66, expecting a5.9c.cb.57
[PDCP] [OSA][RB 1] eNB failed to validate MAC-I of incoming PDU
This is a bug in the PDCP layer that uses wrong parameters to compute the
integrity.
This commit fixes this bug.
The function pdcp_is_rx_seq_number_valid was removed. Its processing
has been directly integrated into the function pdcp_data_ind.
The function pdcp_mark_current_pdu_as_received is not called anymore.
Its processing was not used later on, so as of today, not calling it does
not introduce any functional change.
The function pdcp_validate_security takes now as parameters both
SN and HFN. Same for the function pdcp_get_next_count_rx.
Useless constants PDCP_SN_5BIT, PDCP_SN_7BIT and PDCP_SN_12BIT have been
removed.
The compilation option ENABLE_SECURITY has been removed. It's now always
on. (This may impact some use cases.)
The PDCP for DRB using RLC AM is not correct. It was not correct before
this commit (apart from the integrity bug). We should deal with a list
of PDUs and transmit packets to upper layers as detailed in the specs.
Today we transmit the PDU as soon as we get it. We don't care about
duplicates, in-order delivery, timeouts.
Also, we don't deal with "PDCP re-establishment". Not sure how that impacts
the software.
And, last but not least, there is still no ROHC.
Robert Schmidt