diff --git a/src/main/java/fr/ntr/Main.java b/src/main/java/fr/ntr/Main.java
index df7976a..f71e144 100644
--- a/src/main/java/fr/ntr/Main.java
+++ b/src/main/java/fr/ntr/Main.java
@@ -12,6 +12,7 @@ import java.util.List;
 import java.util.Objects;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
 
 public class Main {
 
@@ -52,27 +53,33 @@ public class Main {
                     });
             Cell.setTimeSlotNb(timeSlotNb);
             Cell.setSubCarrierNb(subCarrierNb);
-            try(ExecutorService executor = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors())) {
-                for(int i = 2; i <= maximumLoad; i += 2) {
-                    List<User> users = generateUsers(i, timeSlotNb, subCarrierNb);
-                    ResourceBlock[][] frame = new ResourceBlock[timeSlotNb][subCarrierNb];
-                    //TODO : changes schedulers
-                    Scheduler schedulerCell1 = new RoundRobin(frame, users);
-                    Scheduler schedulerCell2 = new RoundRobin(frame, users);
-                    try{
-                        FileOutputStream output = new FileOutputStream("export" + File.separator + users.size() + ".csv", true);
-                        output.write("tick;x;y;user;bandwidth;delay;cell;\n".getBytes());
+            ExecutorService executor = Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors());
+            for(int i = 2; i <= maximumLoad; i += 2) {
+                List<User> users = generateUsers(i, timeSlotNb, subCarrierNb);
+                ResourceBlock[][] frame = new ResourceBlock[timeSlotNb][subCarrierNb];
+                //TODO : changes schedulers
+                Scheduler schedulerCell1 = new RoundRobin(frame, users);
+                Scheduler schedulerCell2 = new RoundRobin(frame, users);
+                try{
+                    FileOutputStream output = new FileOutputStream("export" + File.separator + users.size() + ".csv", true);
+                    output.write("tick;x;y;user;bandwidth;delay;cell;\n".getBytes());
 
-                        Cell cell1 = new Cell(0, schedulerCell1, frame, users, output);
-                        Cell cell2 = new Cell(1, schedulerCell2, frame, users, output);
-                        AccessPoint accessPoint = new AccessPoint(cell1, cell2);
-                        executor.submit(() -> accessPoint.startSimulation(numberOfTicks, users));
-                    } catch(IOException e) {
-                        System.err.println(e.getClass().getSimpleName() + " : " + e.getMessage());
-                        System.exit(1);
-                    }
+                    Cell cell1 = new Cell(0, schedulerCell1, frame, users, output);
+                    Cell cell2 = new Cell(1, schedulerCell2, frame, users, output);
+                    AccessPoint accessPoint = new AccessPoint(cell1, cell2);
+                    executor.submit(() -> accessPoint.startSimulation(numberOfTicks, users));
+                } catch(IOException e) {
+                    System.err.println(e.getClass().getSimpleName() + " : " + e.getMessage());
+                    System.exit(1);
                 }
             }
+            executor.shutdown();
+            try {
+                executor.awaitTermination(2, TimeUnit.MINUTES);
+            } catch (InterruptedException e) {
+                e.printStackTrace();
+            }
+            executor.shutdownNow();
         } else {
             System.err.println("Please give launch arguments");
             System.err.println("gradle run --args=\"<number of ticks> <number of users>\"");
diff --git a/src/main/java/fr/ntr/User.java b/src/main/java/fr/ntr/User.java
index d80be5d..e32cacd 100644
--- a/src/main/java/fr/ntr/User.java
+++ b/src/main/java/fr/ntr/User.java
@@ -45,9 +45,9 @@ public class User {
     public void createPackets(int m, int ticks) {
         timeInterval--;
         if(timeInterval == 0) {
-            timeInterval = random.nextInt(50, 101);
+            timeInterval = 50 + random.nextInt(51);
             // On tire un nombre entre 0 et 2 * m
-            mbis = random.nextInt(1, 2 * m + 1) ;
+            mbis = 1 + random.nextInt(2 * m + 1) ;
 
         }
         // On calcule le nombre de paquets qu'on peut transmettre