However, when we free after we encode, fsanitize isnt happy.
Need to clean that up. Also, found an actual bug in LTE.
For the random value issue from fall 2020, we added a fix.
This fix uses ctxt and we were getting ctxt properly.
Lastly, we allocated some memory in processing of the
NR Meas report in the eNB.
At this point we are successfully able to build.
Additionally, we can run the scenario,
however, it does not pass. It seems that the gNB
is not connecting to the proxy correctly. Just
wanted to push the progress so far. FYI, the items
that had to be changed to correct the linking issues
were the following:
- mac_rrc_data_ind_ue vs. nr_mac_rrc_data_ind_ue
- rrc_data_req vs. nr_rrc_data_req
- mac_rrc_data_req_ue vs. nr_mac_rrc_data_req_ue
- rrc_data_req_ue vs. rrc_data_req_nr_ue
- rrc_data_req vs. nr_rrc_data_req
The listed functions should be declard in the LTE/NR
UE directory depending on the functionality. Several
were mixed. i.e.: LTE functions being called in NR UE.
Also, removing siWindowLength, siWindowLength_int,
SIBType, SIBPeriod, and siPeriod_int from the NR UE RRC.
These variable were not used in the NR UE and are defined
for LTE only.
Lastly, in the NR_IF_Module.c of the NR UE, the global
variable def_dci_pdu_rel15 is not accessible. Need to
revisit this. For not it is commented out.
When there is a retransmission, we want to use the same number of RBs.
The RBs are allocated by groups (RBGs).
In some cases (like a cell with 25 PRBs), the last RBG contains less RBs.
So in case of a retransmission, if this last RBG was used before we need
to reuse it to have the same number of RBs. If not, we will use more RBs
for the retransmission than the previous transmission.
In an experiment with two UEs (quectel modules) it was seen that when a
retransmission happens with a different number of RBs then the UE is not
happy at all, leading to way more NACKs in the harq processes than should
happen (actually the first NACK was not a NACK at all, but the eNB did
interpret it as a NACK; so the next transmission should simply be discarded
by the UE that successfully received the first transmission; instead the UE
fails to decode the data and sends a NACK, a real one this time).
Maybe it's not the correct solution, but it improve things, there are
much less NACKs.
The problem is that when using those RBs with MCS 28 we may exceed the
code rate 0.93 and according to 36.213 7.1.7 the UE may skip decoding
PDSCH entirely in this case.
This is a hack. The real solution is to check that the code rate is below
0.93 for each scheduling decision and, I don't know, reduce the MCS if the
code rate is above, so that in the end it is below. That means that we need
a proper resource grid for the configuration of the eNB and this is not an
easy thing (at least from my point of view) given all the possible
configurations for the eNB, so I prefer not to do it rather than do something
incorrect, thus this hack.
The problem of this hack is that we won't use all the available RBs for
scheduling, potentially reducing the maximum throughput achievable.
To be fixed properly at some time, by someone who understands fully the
resource grid and all the possible combinations (fdd/tdd, number of
antennas, whatever else).
This commit properly is filing the dci_format but the
rx_ind and dl_ind has not been updated in the NR UE
prior to sending to gNB. The chnages in this commit
to properly fill the dci_format include:
- filling the dci canidates every slot indiction
- checking for a dl_tti/ul_tti containing a dci
- when dci payload is received we use the filled
dci canidates to update the dci_format
Also, a bug in LTE UE is found where we are indexing
passed the end of ue_sdu array. We added a check for this.
Furthermore, in the nr_ue_scheduler we were utilizing
tx_req but the memory wasnt properly initialized.
The global mbms_rab_id was defined as `uint16_t` in
eNB_scheduler_mch.c but `int` in other places. So, code that
wrotes this global would clobber the two bytes that follow the
variable in memory.
Found by `-fsanitize=address`.
For some reason the htons invocation got deleted which broke
the VNF P7 interface.
Also fixed some build issues, not sure how these got onto the
develop branch to begin with.
Robert Schmidt