This commit introduces a 'basic simulator'.
This basic simulator is made of:
- the standard eNB code using a special driver that mimics the USRP driver
- the standard UE code using a special driver that mimics the USRP driver
- no channel simulation
- some special code to deal with faster-than-realtime behaviour of this
basic simulator
It connects one UE to one eNB. It requires an EPC, populated with the
correct configuration for the UE.
This is the initial release and may contain bugs (most probably race
conditions due to the faster-than-realtime behaviour).
To use it, see the documentation at:
targets/ARCH/tcp_bridge/README.tcp_bridge_oai.
It has been tested with 25, 50 and 100 RBs, FDD mode.
(No check at all has been done to know if it could work in TDD mode.)
- fix compilation of dlsim/ulsim/oaisim by defining some needed
global variables
- fix compilation of oaisim: compile coding and params_libconfig
- fix running of if4p5 with low CPU count (oaisim was not working
on the machine 'haswell' because of this)
This work is based on work by NTT.
To use the code, do:
./build_oai --oaisim --ue-nas-use-tun -t ETHERNET -c
This commit only handles oaisim in S1 mode.
We won't handle noS1 mode.
fixes small bug in ulsim which kills one RX antenna in channel simulation.
Another simple but bad bug in ulsch_demodulation.c (bad access of avgU
array). This probably resulted in a performance degradation for non-ideal
channels, even for 1 antenna. The avgU was read in position 1 instead of
0 for 1-antenna and in positions 1 and 2 instead of 0 and 1 for 2-antennas.
When the program exits it has to stop the streaming of the USRP.
The function exit_fun is supposed to do that. When quitting with
control+c (very common case) this function is not called. The
code is very unclear there, so let's add a stop_rf in the RU,
as there is already a start_rf.
If we don't call trx_end_func, then at the next run the USRP
device may be in an unstable state and behave improperly.
If the program crashes then the USRP device may be in an
unstable state. The only solution to this problem is to reset
the USRP device.
Maybe there is a way to clean the state of the device when we
open it, before we start using it. Sort of a cleanup before
use. That could be a better solution to "bad state after program
crash".
What has been tested:
- monolithic eNB only
With value 4 when connecting one UE and doing some downlink
iperf TCP there is a crash. Probably due to the multiple wrong
RA detected leading to uplink failure of fake UE that never
sends Msg3 (because, well, there is no other UE).
This is another problem that will be fixed at some point.
Anyway, this value 4 fails. Let's put back 3.
Doing airplane mode off to connect a cots UE followed by airplane mode on
to disconnect it gives very bad results (bad disconnection with lots of
UL failures followed by lots of logs in the eNB). It used to work properly
after the work done by Xu Bo.
It turns out that in 2018.w04 things were still working okay. But
in 2018.w05 no.
So I ran:
git diff 2018.w04 2018.w05
And I checked all the modifications that I thought were relevant
(everything related to the UE, oaisim, if4 and fapi has not been checked).
This commits takes back the version of 2018.w04.
The modifications in openair2/RRC/LITE/rrc_eNB.c are necessary, I think.
The other modifications may not be necessary or even wrong. To be checked
at some point.
Cedric Roux