diff --git a/measurement_main.py b/measurement_main.py
index db10c83..905db65 100755
--- a/measurement_main.py
+++ b/measurement_main.py
@@ -257,6 +257,29 @@ def monitor_gps(ser, output_file):
         return
 
 
+def connect_moden(provider="telekom"):
+    print_message("Connect modem with provider {} ...".format(provider))
+    os.system("/root/connect-modem.py -l {}".format(provider))
+    print_message("...done")
+
+
+def reconnect_modem(provider="telekom"):
+    print_message("Reonnect modem with provider {} ...".format(provider))
+    os.system("/root/connect-modem.py -s")
+    os.system("/root/connect-modem.py -l {}".format(provider))
+    print_message("...done")
+
+
+def is_modem_connected():
+    timeout = 5
+    try:
+        request = requests.get("http://130.75.73.69", timeout=timeout)
+        return True
+    except (requests.ConnectionError, requests.Timeout) as exception:
+        pass
+    return False
+
+
 class Server:
     def __init__(self, config):
         self.config = config
@@ -724,6 +747,8 @@ class Client:
             ws_filter = "{} and port {}".format("tcp", self.config["port"])
             print_message("Use ws filter: {}".format(ws_filter))
             for n in range(1, self.config["number_of_measurements"] + 1):
+                if not is_modem_connected():
+                    reconnect_modem()
                 print_message(
                     "{} of {}".format(n, self.config["number_of_measurements"])
                 )
@@ -778,6 +803,8 @@ class Client:
                 enable_tcp_probe()
                 print_message("tcp probe is now enabled")
             for n in range(1, self.config["number_of_measurements"] + 1):
+                if not is_modem_connected():
+                    reconnect_modem()
                 print_message(
                     "{} of {}".format(n, self.config["number_of_measurements"])
                 )
@@ -975,6 +1002,8 @@ async def start_server(args):
 
 
 async def start_client(args):
+    if not is_modem_connected():
+        connect_moden()
     s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
     s.connect((args.client, args.port))
     s.send(config2json(args))