basic simulator: initial release

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.)

cmake_targets/CMakeLists.txt

@@ -243,6 +243,7 @@ add_boolean_option(UE_TIMING_TRACE     False "Activate UE timing trace")
 add_boolean_option(DISABLE_LOG_X       False "Deactivate all LOG_* macros")
 add_boolean_option(USRP_REC_PLAY       False "Enable USRP record playback mode")
 add_boolean_option(UE_NAS_USE_TUN      False "Enable UE NAS TUN device instead of ue_ip.ko")
+add_boolean_option(BASIC_SIMULATOR     False "Has to be True when building the basic simulator, False otherwise")
 
 add_boolean_option(DEBUG_CONSOLE False "makes debugging easier, disables stdout/stderr buffering")
 
@@ -563,14 +564,26 @@ add_library(oai_mobipass MODULE ${TPLIB_MOBIPASS_SOURCE} )
 get_target_property(mobipas_cflags oai_mobipass COMPILE_FLAGS)
 set_target_properties(oai_mobipass PROPERTIES COMPILE_FLAGS "${mobipass_cflags} -fvisibility=hidden")
 
+# TCP bridge libraries
+######################################################################
+
+# this one is for internal use at Eurecom and is not documented
 set(HWLIB_TCP_BRIDGE_SOURCE
   ${OPENAIR_TARGETS}/ARCH/tcp_bridge/tcp_bridge.c
   )
-add_library(oai_tcp_bridge MODULE ${HWLIB_TCP_BRIDGE_SOURCE} )
+add_library(tcp_bridge MODULE ${HWLIB_TCP_BRIDGE_SOURCE} )
 
-#get_target_property(tcp_bridge_cflags oai_tcp_bridge COMPILE_FLAGS)
-#set_target_properties(oai_tcp_bridge PROPERTIES COMPILE_FLAGS "${tcp_bridge_cflags} -fvisibility=hidden")
-set_target_properties(oai_tcp_bridge PROPERTIES COMPILE_FLAGS "-fvisibility=hidden")
+#get_target_property(tcp_bridge_cflags tcp_bridge COMPILE_FLAGS)
+#set_target_properties(tcp_bridge PROPERTIES COMPILE_FLAGS "${tcp_bridge_cflags} -fvisibility=hidden")
+set_target_properties(tcp_bridge PROPERTIES COMPILE_FLAGS "-fvisibility=hidden")
+
+# this one is to connect OAI eNB and OAI UE in the basic simulator
+# see targets/ARCH/tcp_bridge/README.tcp_bridge_oai for usage
+set(HWLIB_TCP_BRIDGE_OAI_SOURCE
+  ${OPENAIR_TARGETS}/ARCH/tcp_bridge/tcp_bridge_oai.c
+  )
+add_library(tcp_bridge_oai MODULE ${HWLIB_TCP_BRIDGE_OAI_SOURCE} )
+set_target_properties(tcp_bridge_oai PROPERTIES COMPILE_FLAGS "-fvisibility=hidden")
 
 ##########################################################
 

cmake_targets/build_oai

@@ -68,6 +68,7 @@ DISABLE_LOG_X="False"
 USRP_REC_PLAY="False"
 BUILD_ECLIPSE=0
 UE_NAS_USE_TUN="False"
+BASIC_SIMULATOR=0
 trap handle_ctrl_c INT
 
 function print_help() {
@@ -159,6 +160,9 @@ Options
    Build for I/Q record-playback modes
 --ue-nas-use-tun
    Use TUN devices for the UEs instead of ue_ip.ko
+--basic-simulator
+   Generates a basic [1 UE + 1 eNB + no channel] simulator.
+   See targets/ARCH/tcp_bridge/README.tcp_bridge_oai for documentation.
 Usage (first build):
  oaisim (eNB + UE): ./build_oai -I  --oaisim -x --install-system-files
  Eurecom EXMIMO + COTS UE : ./build_oai -I  --eNB -x --install-system-files
@@ -354,6 +358,10 @@ function main() {
             UE_NAS_USE_TUN="True"
             echo_info "Enabling UE NAS TUN device usage instead of ue_ip.ko"
             shift 1;;
+        --basic-simulator)
+            BASIC_SIMULATOR=1
+            echo_info "Compiling the basic simulator"
+            shift 1;;
         -h | --help)
             print_help
             exit 1;;
@@ -919,6 +927,96 @@ fi
   else
     echo_info "10. Bypassing the Tests ..."
   fi
+
+  # basic simulator
+  #####################
+  if [ "$BASIC_SIMULATOR" = "1" ]; then
+    echo_info "Build basic simulator"
+    [ "$CLEAN" = "1" ] && rm -rf $OPENAIR_DIR/cmake_targets/basic_simulator
+    mkdir -p $OPENAIR_DIR/cmake_targets/basic_simulator
+    mkdir -p $OPENAIR_DIR/cmake_targets/basic_simulator/enb
+    mkdir -p $OPENAIR_DIR/cmake_targets/basic_simulator/ue
+
+    # enb
+
+    cmake_file=$OPENAIR_DIR/cmake_targets/basic_simulator/enb/CMakeLists.txt
+    echo "cmake_minimum_required(VERSION 2.8)"         >  $cmake_file
+    echo "set ( CMAKE_BUILD_TYPE $CMAKE_BUILD_TYPE )"  >> $cmake_file
+    echo "set ( CFLAGS_PROCESSOR_USER \"$CFLAGS_PROCESSOR_USER\" )" >>  $cmake_file
+    echo "set ( RRC_ASN1_VERSION \"${REL}\")"          >>  $cmake_file
+    echo "set ( ENABLE_VCD_FIFO $VCD_TIMING )"         >>  $cmake_file
+    echo "set ( XFORMS $XFORMS )"                      >>  $cmake_file
+    echo "set ( RF_BOARD \"OAI_USRP\")"                >>  $cmake_file
+    echo "set ( TRANSP_PRO \"None\")"                  >>  $cmake_file
+    echo "set(PACKAGE_NAME \"simulator_enb\")"         >>  $cmake_file
+    echo "set (DEADLINE_SCHEDULER \"False\" )"         >>  $cmake_file
+    echo "set (CPU_AFFINITY \"False\" )"               >>  $cmake_file
+    echo "set ( T_TRACER \"True\" )"                   >>  $cmake_file
+    echo "set (UE_AUTOTEST_TRACE $UE_AUTOTEST_TRACE)"  >>  $cmake_file
+    echo "set (UE_DEBUG_TRACE $UE_DEBUG_TRACE)"        >>  $cmake_file
+    echo "set (UE_TIMING_TRACE $UE_TIMING_TRACE)"      >>  $cmake_file
+    echo "set (DISABLE_LOG_X $DISABLE_LOG_X)"          >>  $cmake_file
+    echo "set (USRP_REC_PLAY $USRP_REC_PLAY)"          >>  $cmake_file
+    echo "set (BASIC_SIMULATOR \"True\" )"             >>  $cmake_file
+    echo 'include(${CMAKE_CURRENT_SOURCE_DIR}/../../CMakeLists.txt)' >> $cmake_file
+
+    echo_info "Build eNB"
+    echo_info "logs are in $dlog/basic_simulator_enb.txt"
+    {
+      cd $OPENAIR_DIR/cmake_targets/basic_simulator/enb
+      cmake .
+      make -j`nproc` coding params_libconfig tcp_bridge_oai lte-softmodem
+      ln -sf libtcp_bridge_oai.so liboai_device.so
+      cd ../..
+    } > $dlog/basic_simulator_enb.txt 2>&1
+    check_warnings "$dlog/basic_simulator_enb.txt"
+
+    # ue
+
+    echo_info "Compile conf2uedata"
+    compilations \
+        nas_sim_tools conf2uedata \
+        conf2uedata $dbin/conf2uedata
+
+    cmake_file=$OPENAIR_DIR/cmake_targets/basic_simulator/ue/CMakeLists.txt
+    echo "cmake_minimum_required(VERSION 2.8)"        >  $cmake_file
+    echo "set ( CMAKE_BUILD_TYPE $CMAKE_BUILD_TYPE )" >> $cmake_file
+    echo "set ( CFLAGS_PROCESSOR_USER \"$CFLAGS_PROCESSOR_USER\" )" >>  $cmake_file
+    echo "set ( RRC_ASN1_VERSION \"${REL}\")"         >>  $cmake_file
+    echo "set ( ENABLE_VCD_FIFO $VCD_TIMING )"        >>  $cmake_file
+    echo "set ( XFORMS $XFORMS )"                     >>  $cmake_file
+    echo "set ( RF_BOARD \"OAI_USRP\")"               >>  $cmake_file
+    echo "set ( TRANSP_PRO \"None\")"                 >>  $cmake_file
+    echo "set(PACKAGE_NAME \"simulator_ue\")"         >>  $cmake_file
+    echo "set (DEADLINE_SCHEDULER \"False\" )"        >>  $cmake_file
+    echo "set (CPU_AFFINITY \"False\" )"              >>  $cmake_file
+    echo "set ( T_TRACER \"False\" )"                 >>  $cmake_file
+    echo "set (UE_AUTOTEST_TRACE $UE_AUTOTEST_TRACE)" >>  $cmake_file
+    echo "set (UE_DEBUG_TRACE $UE_DEBUG_TRACE)"       >>  $cmake_file
+    echo "set (UE_TIMING_TRACE $UE_TIMING_TRACE)"     >>  $cmake_file
+    echo "set (DISABLE_LOG_X $DISABLE_LOG_X)"         >>  $cmake_file
+    echo "set (USRP_REC_PLAY $USRP_REC_PLAY)"         >>  $cmake_file
+    echo "set (LINUX True )"                          >>  $cmake_file
+    echo "set (PDCP_USE_NETLINK True )"               >>  $cmake_file
+    echo "set (BASIC_SIMULATOR \"True\" )"            >>  $cmake_file
+    echo "set (UE_NAS_USE_TUN \"True\" )"             >>  $cmake_file
+    echo 'include(${CMAKE_CURRENT_SOURCE_DIR}/../../CMakeLists.txt)' >> $cmake_file
+
+    echo_info "Build UE"
+    echo_info "logs are in $dlog/basic_simulator_ue.txt"
+    {
+      cd $OPENAIR_DIR/cmake_targets/basic_simulator/ue
+      cmake .
+      make -j`nproc` coding params_libconfig tcp_bridge_oai lte-uesoftmodem
+      ln -sf libtcp_bridge_oai.so liboai_device.so
+      cd ../..
+    } > $dlog/basic_simulator_ue.txt 2>&1
+    check_warnings "$dlog/basic_simulator_ue.txt"
+
+    echo_info "Generate UE SIM data"
+    $OPENAIR_DIR/targets/bin/conf2uedata -c $OPENAIR_DIR/openair3/NAS/TOOLS/ue_eurecom_test_sfr.conf -o $OPENAIR_DIR/cmake_targets/basic_simulator/ue
+
+  fi
 }
 
 main "$@"

common/utils/T/T.h

@@ -110,6 +110,16 @@ typedef struct {
 extern volatile int *T_freelist_head;
 extern T_cache_t *T_cache;
 
+/* When running the basic simulator, we may fill the T cache too fast.
+ * Let's not crash if it's full, just wait.
+ */
+#if BASIC_SIMULATOR
+#  define T_BASIC_SIMULATOR_WAIT \
+     while (T_cache[T_LOCAL_slot].busy) usleep(100)
+#else
+#  define T_BASIC_SIMULATOR_WAIT /* */
+#endif
+
 /* used at header of Tn, allocates buffer */
 #define T_LOCAL_DATA \
   char *T_LOCAL_buf; \
@@ -118,6 +128,7 @@ extern T_cache_t *T_cache;
   T_LOCAL_slot = __sync_fetch_and_add(T_freelist_head, 1) \
                  & (T_CACHE_SIZE - 1); \
   (void)__sync_fetch_and_and(T_freelist_head, T_CACHE_SIZE - 1); \
+  T_BASIC_SIMULATOR_WAIT; \
   if (T_cache[T_LOCAL_slot].busy) { \
     printf("%s:%d:%s: T cache is full - consider increasing its size\n", \
            __FILE__, __LINE__, __FUNCTION__); \

common/utils/T/T_defs.h

@@ -8,10 +8,20 @@
 #define T_MAX_ARGS 16
 
 /* maximum size of a message - increase if needed */
-#define T_BUFFER_MAX (1024*64)
+#if BASIC_SIMULATOR
+   /* let's have 100 RBs functional for the basic simulator */
+#  define T_BUFFER_MAX (1024*64*2)
+#else
+#  define T_BUFFER_MAX (1024*64)
+#endif
 
 /* size of the local cache for messages (must be pow(2,something)) */
-#define T_CACHE_SIZE (8192 * 2)
+#if BASIC_SIMULATOR
+   /* we don't need much space for the basic simulator */
+#  define T_CACHE_SIZE 1024
+#else
+#  define T_CACHE_SIZE (8192 * 2)
+#endif
 
 /* maximum number of bytes a message can contain */
 #ifdef T_SEND_TIME

common/utils/T/local_tracer.c

@@ -300,6 +300,20 @@ static void forward(void *_forwarder, char *buf, int size)
   if (f->tail != NULL) f->tail->next = new;
   f->tail = new;
 
+#if BASIC_SIMULATOR
+  /* When runnng the basic simulator, the tracer may be too slow.
+   * Let's not take too much memory in the tracee and
+   * wait if there is too much data to send. 200MB is
+   * arbitrary.
+   */
+  while (f->memusage > 200 * 1024 * 1024) {
+    if (pthread_cond_signal(&f->cond)) abort();
+    if (pthread_mutex_unlock(&f->lock)) abort();
+    usleep(1000);
+    if (pthread_mutex_lock(&f->lock)) abort();
+  }
+#endif /* BASIC_SIMULATOR */
+
   f->memusage += size+4;
   /* warn every 100MB */
   if (f->memusage > f->last_warning_memusage &&

openair1/PHY/LTE_ESTIMATION/lte_adjust_sync.c

@@ -84,6 +84,11 @@ void lte_adjust_synch(LTE_DL_FRAME_PARMS *frame_parms,
   {
       diff = max_pos_fil - (frame_parms->nb_prefix_samples>>3);
 
+#if BASIC_SIMULATOR
+      /* a hack without which the UE does not connect (to be fixed somehow) */
+      diff = 0;
+#endif
+
       if ( abs(diff) < SYNCH_HYST )
           ue->rx_offset = 0;
       else

openair1/PHY/LTE_TRANSPORT/pss.c

@@ -75,6 +75,11 @@ int generate_pss(int32_t **txdataF,
   a = (frame_parms->nb_antenna_ports_eNB == 1) ? amp: (amp*ONE_OVER_SQRT2_Q15)>>15;
   //printf("[PSS] amp=%d, a=%d\n",amp,a);
 
+#if BASIC_SIMULATOR
+  /* a hack to remove at some point (the UE doesn't synch with 100 RBs) */
+  a = (frame_parms->nb_antenna_ports_eNB == 1) ? 4*amp: (amp*ONE_OVER_SQRT2_Q15)>>15;
+#endif
+
   Nsymb = (frame_parms->Ncp==NORMAL)?14:12;
 
   for (aa=0; aa<frame_parms->nb_antenna_ports_eNB; aa++) {

targets/ARCH/tcp_bridge/README.tcp_bridge_oai

+The driver tcp_bridge_oai.c is to be used with the basic simulator.
+
+To build the basic simulator:
+    cd [openair top directory]
+    . oaienv
+    cd cmake_targets
+    ./build_oai --basic-simulator
+    cd ../common/utils/T/tracer
+    make
+
+To use it, you need to run the eNB and the UE.
+
+The eNB requires the T tracer.
+Open two terminals.
+In one terminal, run:
+    cd [openair top directory]
+    cd common/utils/T/tracer
+    ./enb -d ../T_messages.txt
+In the other terminal, run:
+    cd [openair top directory]
+    cd cmake_targets/basic_simulator/enb
+    export ENODEB=1
+    sudo -E ./lte-softmodem -O [configuration file]
+[configuration file] is just a regular configuration file.
+The eNB needs an EPC.
+
+To run the UE, open a terminal and run:
+    cd [openair top directory]
+    cd cmake_targets/basic_simulator/ue
+    sudo ./lte-uesoftmodem -C 2680000000 -r 25
+Adapt the value of -r, it has to match the value N_RB_DL in the configuration
+file of the eNB. (Same for -C which should match the value downlink_frequency
+in the configuration file.)
+
+The UE configuration (security keys) is generated from the file
+openair3/NAS/TOOLS/ue_eurecom_test_sfr.conf. You need to configure
+your EPC to know about the UE. If you change the file
+openair3/NAS/TOOLS/ue_eurecom_test_sfr.conf then you need to
+regenerate the configuration files using the program targets/bin/conf2uedata.
+You run it as:
+    $OPENAIR_DIR/targets/bin/conf2uedata -c $OPENAIR_DIR/openair3/NAS/TOOLS/ue_eurecom_test_sfr.conf -o $OPENAIR_DIR/cmake_targets/basic_simulator/ue

targets/RT/USER/lte-ue.c

@@ -692,6 +692,9 @@ static void *UE_thread_rxn_txnp4(void *arg) {
           exit_fun("noting to add");
         }
         proc->instance_cnt_rxtx--;
+#if BASIC_SIMULATOR
+        if (pthread_cond_signal(&proc->cond_rxtx) != 0) abort();
+#endif
         if (pthread_mutex_unlock(&proc->mutex_rxtx) != 0) {
           LOG_E( PHY, "[SCHED][UE] error unlocking mutex for UE RXTX\n" );
           exit_fun("noting to add");
@@ -751,6 +754,12 @@ void *UE_thread(void *arg) {
         AssertFatal ( 0== pthread_mutex_unlock(&UE->proc.mutex_synch), "");
 
         if (is_synchronized == 0) {
+#if BASIC_SIMULATOR
+            while (!((instance_cnt_synch = UE->proc.instance_cnt_synch) < 0)) {
+              printf("ue sync not ready\n");
+              usleep(500*1000);
+            }
+#endif
             if (instance_cnt_synch < 0) {  // we can invoke the synch
                 // grab 10 ms of signal and wakeup synch thread
                 for (int i=0; i<UE->frame_parms.nb_antennas_rx; i++)
@@ -833,6 +842,17 @@ void *UE_thread(void *arg) {
                 // update thread index for received subframe
                 UE->current_thread_id[sub_frame] = thread_idx;
 
+#if BASIC_SIMULATOR
+                {
+                  int t;
+                  for (t = 0; t < 2; t++) {
+                        UE_rxtx_proc_t *proc = &UE->proc.proc_rxtx[t];
+                        pthread_mutex_lock(&proc->mutex_rxtx);
+                        while (proc->instance_cnt_rxtx >= 0) pthread_cond_wait( &proc->cond_rxtx, &proc->mutex_rxtx );
+                        pthread_mutex_unlock(&proc->mutex_rxtx);
+                  }
+                }
+#endif
                 LOG_D(PHY,"Process Subframe %d thread Idx %d \n", sub_frame, UE->current_thread_id[sub_frame]);
 
                 thread_idx++;