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)
It is possible to restart the lte-softmodem via the FlexRAN controller. For
this to work, the end_configmodule() method needs to be called when shutting
the lte-softmodem down so that the configuration can be read again during a
restart.
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
The one in lte-enb.c disrupts the realtime. Using a B200mini with
20MHz bandwidth leads to the UE unable to connect for it seesms like
the UL and DL are not properly time synched because of this sleep
of one second that happens after the USRP streaming has started.
We see some random access attempts but the decoded preamble is
wrong.
This may be dependant on the setup. I had sporadic errors with
a B210, where sometimes the UE could connect and sometimes not.
- add function free_td() -> complements init_td() [seems to not be used, added
for completeness]
- add function free_td8() -> undoes init_td8() [free memory of 8-bit LLR Turbo
decoder]
- add function free_td16() -> undoes init_td16() [free memory of 16-bit LLR
Turbo decoder]
- change function free_tdavx216() -> undoes init_tdavx216() [free memory of
16-bit LLR Turbo decoder, AVX2 version]
- add free_lte_top() -> frees memory allocated by init_lte_top()
- change free_ul_ref_sigs() to set freed pointers to NULL
- add method free_transport() -> frees memory of ULSCH/DLSCH transport channels
- use the above functions when stopping/restarting the lte-softmodem
Through configuration, the lte-softmodem can be halted to await a
reconfiguration from the lte-softmodem. A mutex and condition variable are used
to implement this.
Furthermore, the dependance of lte-softmodem.c on FlexRAN has been reduced to
one include and the flexran_agent_start() call.
- add set_function_spec_param() which configures RU_t instance depending on its
function(al split)
- export more functions like kill_RU_proc() so that they can be reused by
restart functionality
Cedric Roux