diff --git a/cmake_targets/tools/run_enb_ue_virt_s1 b/cmake_targets/tools/run_enb_ue_virt_s1
index 031df89fea22d578e4ebc840363b090f56ddc31b..003da3dc370db6c4095f008ef4fc6eb0c2968bf8 100755
--- a/cmake_targets/tools/run_enb_ue_virt_s1
+++ b/cmake_targets/tools/run_enb_ue_virt_s1
@@ -86,6 +86,7 @@ function help()
   echo_error "  -g, --gdb                               Run with GDB."
   echo_error "  -h, --help                              Print this help."
   echo_error "  -K, --itti-dump-file   filename         ITTI dump file containing all ITTI events occuring during EPC runtime.(can omit file name if last argument)"
+  echo_error "  -m, --mscgen           directory        Generate mscgen output files in a directory"
   echo_error "  -V, --vcd                               Dump timings of processing in a GTKWave compliant file format."
   echo_error "  -x, --xforms                            Run XFORMS scope windows."
 }
@@ -98,9 +99,11 @@ function main()
   cecho "OPENAIR_DIR    = $OPENAIR_DIR" $green
 
   local -i run_gdb=0
+  local -i run_mscgen=0
   local    exe_arguments=""
   local    DEFAULT_CONFIG_FILE_ENB=$OPENAIR_DIR/targets/PROJECTS/GENERIC-LTE-EPC/CONF/enb.band7.generic.oaisim.local_mme.conf
   local    CONFIG_FILE_ENB=$DEFAULT_CONFIG_FILE_ENB
+  local    MSC_DIR="/tmp"
   
   until [ -z "$1" ]
     do
@@ -145,6 +148,19 @@ function main()
         exe_arguments="$exe_arguments -K $ITTI_DUMP_FILE"
         ;;      
 
+      -m | --mscgen)
+        MSC_DIR=$2
+        # can omit file name if last arg on the line
+        if [ -d  "$MSC_DIR" ]; then
+          echo "setting mscgen log files to dir: $MSC_DIR"
+          run_mscgen=1
+          shift 2;
+        else
+          echo_error "Mscgen log dir does not exist"
+          exit -1
+        fi
+        ;;      
+
       -V | --vcd)
         "setting gtk-wave output"
         exe_arguments="$exe_arguments -V /tmp/oai_gtk_wave.vcd"
@@ -217,12 +233,12 @@ function main()
   $SUDO ip rule add fwmark 5 table lte
   $SUDO ip route add default dev oip1 table lte
 
-  exe_arguments="$exe_arguments -u1 -l9"
+  exe_arguments="$exe_arguments -s15 -AAWGN -y1 -b1 -u1 -Q0"
     
   cd  $OPENAIR_DIR/targets/bin
    
   if [ $run_gdb -eq 0 ]; then 
-    exec $OPENAIR_DIR/targets/bin/oaisim $exe_arguments  
+    exec $OPENAIR_DIR/targets/bin/oaisim $exe_arguments | tee /tmp/enb_ue_s1.log.txt
   else
     touch      ~/.gdb_enb_ue_s1
     chmod 777  ~/.gdb_enb_ue_s1
@@ -232,6 +248,21 @@ function main()
     cat ~/.gdb_enb_ue_s1
     gdb -n -x ~/.gdb_enb_ue_s1 
   fi
+  
+  if [ $run_mscgen -eq 1 ]; then 
+    cd $MSC_DIR
+    last_created_file=`ls -t mscgen* | head -1 | tr -d ':'`
+    $OPENAIR_DIR/targets/SCRIPTS/msc_gen.py
+    sync
+    last_created_file2=`ls -t mscgen* | head -1 | tr -d ':'`
+        
+    if [ x"$last_created_file" != x"$last_created_file2" ]; then
+      if [ -f ./$last_created_file2/oai_mscgen_page_0.png ]; then 
+        command -v eog 2>/dev/null &&  eog ./$last_created_file2/oai_mscgen_page_0.png
+      fi
+    fi 
+  fi
+  
 }
 
 main "$@"