From the spec, it does not seem to be mandated to check that the random
identity needs to be unique within a cell. Also, from experience we see
that this only happens when the same UE "comes back"; so since one UE
can only have one connection, the other RRC UE contexts (with the same
identity) should be removed at some point, anyway, leaving only one with
the same identity.
nr_fill_indication() fills CRC and RX requests, to be sent from L1 to
L2. Before this commit, nr_fill_indication() is called when
- we finally decoded LDPC (or not)
- low signal on PUSCH
This might happen at the same time, i.e., nr_fill_indication() might try
to fill both CRC and RX, in the same list, from different threads. This
can lead to this assertion:
Assertion (crc->rnti == rx->rnti) failed!
In handle_nr_ulsch() ../../../openair2/NR_PHY_INTERFACE/NR_IF_Module.c:190
mis-match between CRC RNTI e071 and RX RNTI 5e3b
e.g., e071 is low energy, and while 5e3b related message are filled in
one thread, e071 is being put into the message structure as well.
At least that is my understanding. I could not actually reproduce this
assertion; to be seen if it still happens.
They use 4G NUMBER_OF_UE_MAX, which is not supposed to be present in 5G.
Further, the mutex and variable are global state; for Paging, we should
use F1.
We can only support up to 30 UEs for SRS. In this commit, we change:
- if the total number of UEs is > 32, throw error during compilation to
raise awareness (32 so that a multiple of two still works, everything
else is confusing, see also next point)
- during runtime, handle gracefully if UID is 30 or 31 to not abort (we
can simply not allocate SRS resources)
Also, refactor config_srs() to always give back new memory; the code is
shorter and clearer. Rename to get_contig_srs() to make it explicit.
SCF 222.10.02, Table 3-35: the PDUSize parameter of a DL_TTI.request PDU
includes the 4 bytes required for PDUType and PDUSize parameters (each 2
bytes), not 2.
This is required for the Aerial interoperability.
The original UL max MCS of 9 was chosen for performance reasons. In the
meantime, machines became faster, and the ULSCH decoding faster. Improve
UL max MCS to be 28 by default to use the complete range of possible
MCS.
Doing only 5 LDPC iterations by default leads to a poor reception
performance, and correspondingly many retransmissions. Increase to 8 as
the new default to improve user experience.
francescomani