For whatever reason, lte-softmodem.c was totally messed up...
We took the version from the branch develop and added
abstraction_flag, which is needed in openair2/LAYER2/MAC/main.c
(this is not clean, previous commit added a comment for this).
This has to be cleaned at some point.
- the option --UE was abused! Let's introduce --UE-conf-nvram and
--UE-gen-nvram
- the option name --UE-OUTPUT was not clear and is now replaced by
--UE-gen-nvram
- the new options are described when running ./build_oai -h
- print_help has been modified (' replaced by ") to print
$conf_nvram_path and $gen_nvram_path
The problem was the following.
Run oaisim with two UEs:
sudo ../cmake_targets/oaisim_build_oai/build/oaisim -O enb.conf -u2 -s15 -AAWGN -y1 -b1 -Q0
Then wait for both UEs to be connected. The interfaces "oip1" and "oip2" are
activated, with IP addresses 192.172.0.2 for the first UE and 192.172.0.3 for
the second.
Then on the EPC machine, do:
ping 192.172.0.3
No reply.
On the oaisim machine, we see that the packets are sent to "oip1" instead
of "oip2".
The fix may break softmodem UE. The inst was forced to "1" for some reason.
To be checked.
The memset was also too big. It should only clear
one subframe.
Only tested without abstraction.
Abstraction does not work for the moment anyway, but just to
keep that in mind.
The idea is as follows.
oaisim waits for all tasks to be done for a TTI.
To do so it waits for last_rx_timestamp == current_rx_timestamp,
for all UEs and eNBs.
When it's done, it increases current_rx_timestamp by samples_per_tti,
to inform UEs and eNBs that a new TTI is ready.
In the functions [UE|eNB]_trx_read, we wait for a new TTI to be ready,
that is we wait for current_rx_timestamp != last_rx_timestamp.
The UE has also to wait for processing threads to be done.
In the eNB it's not necessary because the processing is all
done in one thread, that is: read subframe, process this subframe,
emit subframe+4, and then back to read subframe.
The code is not clean. We should not use usleep but semaphores.
Also, do_[DL|UL]_sig should not read from rxdata and write to txdata,
but use internal buffers.
The functions [UE|eNB]_trx_read should call do_[DL|UL]_sig and then
copy from the internal buffers of the channel simulator into rxdata.
The functions [UE|eNB]_trx_write should write data passed into the
internal buffers of the channel simulator.
Not sure if this is the right thing to do, but it seems to be.
"start_eNB = 1;" is also necessary when the l2l1 task gets INITIALIZE_MESSAGE
otherwise the eNB does not start.
As it is today, I don't think oaisim will work with more than one eNB.
It was probably the result of a bad merge.
At this point eNB_inst is not valid. Plus the T_ENB_MASTER_TICK
is now handled in lte-enb.c, even for oaisim.
Cedric Roux