diff --git a/freedata_server/api/modem.py b/freedata_server/api/modem.py
index 02b140cc..e922842b 100644
--- a/freedata_server/api/modem.py
+++ b/freedata_server/api/modem.py
@@ -785,18 +785,10 @@ async def post_modem_stop_transmission(request:Request):
     Raises:
         HTTPException: If the modem is not running or an error occurs.
     """
-    if not request.app.state_manager.is_modem_running:
-        api_abort("Modem not running", 503)
-    if request.app.state_manager.getARQ():
-        try:
-            for session in request.app.state_manager.arq_irs_sessions.values():
-                # session.abort_transmission()
-                session.transmission_aborted()
-            for session in request.app.state_manager.arq_iss_sessions.values():
-                session.abort_transmission(send_stop=False)
-                session.transmission_aborted()
-        except Exception as e:
-            print(f"Error during transmission stopping: {e}")
+    try:
+        request.app.state_manager.stop_transmission()
+    except Exception as e:
+        print(f"Error during transmission stopping: {e}")
     return api_ok()
 
 
diff --git a/freedata_server/arq_session_irs.py b/freedata_server/arq_session_irs.py
index 31a78692..aa1eb0a7 100644
--- a/freedata_server/arq_session_irs.py
+++ b/freedata_server/arq_session_irs.py
@@ -486,15 +486,16 @@ class ARQSessionIRS(arq_session.ARQSession):
         Returns:
             Tuple[None, None]: Returns None for both data and type_byte.
         """
-        self.log("session aborted")
-        self.session_ended = time.time()
-        self.set_state(IRS_State.ABORTED)
-        # break actual retries
-        self.event_frame_received.set()
+        if self.state not in [IRS_State.ABORTED, IRS_State.ENDED]:
+            self.log("session aborted")
+            self.session_ended = time.time()
+            self.set_state(IRS_State.ABORTED)
+            # break actual retries
+            self.event_frame_received.set()
 
 
-        #self.modem.demodulator.set_decode_mode()
-        self.event_manager.send_arq_session_finished(
-            True, self.id, self.dxcall, False, self.state.name, statistics=self.calculate_session_statistics(self.received_bytes, self.total_length))
-        self.states.setARQ(False)
+            #self.modem.demodulator.set_decode_mode()
+            self.event_manager.send_arq_session_finished(
+                True, self.id, self.dxcall, False, self.state.name, statistics=self.calculate_session_statistics(self.received_bytes, self.total_length))
+            self.states.setARQ(False)
         return None, None
\ No newline at end of file
diff --git a/freedata_server/arq_session_iss.py b/freedata_server/arq_session_iss.py
index 97b45242..43aff52a 100644
--- a/freedata_server/arq_session_iss.py
+++ b/freedata_server/arq_session_iss.py
@@ -464,14 +464,17 @@ class ARQSessionISS(arq_session.ARQSession):
         Returns:
             Tuple[None, None]: Returns None for both data and type_byte.
         """
-        self.log("session aborted")
-        self.session_ended = time.time()
-        self.set_state(ISS_State.ABORTED)
-        # break actual retries
-        self.event_frame_received.set()
 
-        self.event_manager.send_arq_session_finished(
-            True, self.id, self.dxcall, False, self.state.name, statistics=self.calculate_session_statistics(self.confirmed_bytes, self.total_length))
-        #self.state_manager.remove_arq_iss_session(self.id)
-        self.states.setARQ(False)
+        # Only run this part, if we are not already aborted or ended the session.
+        if self.state not in [ISS_State.ABORTED, ISS_State.ENDED]:
+            self.log("session aborted")
+            self.session_ended = time.time()
+            self.set_state(ISS_State.ABORTED)
+            # break actual retries
+            self.event_frame_received.set()
+
+            self.event_manager.send_arq_session_finished(
+                True, self.id, self.dxcall, False, self.state.name, statistics=self.calculate_session_statistics(self.confirmed_bytes, self.total_length))
+            #self.state_manager.remove_arq_iss_session(self.id)
+            self.states.setARQ(False)
         return None, None
diff --git a/freedata_server/state_manager.py b/freedata_server/state_manager.py
index 6b62ead4..44a7058e 100644
--- a/freedata_server/state_manager.py
+++ b/freedata_server/state_manager.py
@@ -412,6 +412,28 @@ class StateManager:
         if id in self.arq_irs_sessions:
             del self.arq_irs_sessions[id]
 
+    def stop_transmission(self):
+        """Stops any ongoing ARQ transmissions.
+
+        This method iterates through all active ARQ Information Sending Station (ISS)
+        and Information Receiving Station (IRS) sessions and aborts their transmissions.
+        ISS sessions are removed after being stopped, while IRS sessions are retained
+        to allow for potential resumption.
+        """
+        # Stop and remove IRS sessions
+        for session_id in list(self.arq_irs_sessions.keys()):
+            session = self.arq_irs_sessions[session_id]
+            session.transmission_aborted()
+            # For now, we don't remove IRS session because of resuming transmissions. 
+            #self.remove_arq_irs_session(session_id)
+
+        # Stop and remove ISS sessions
+        for session_id in list(self.arq_iss_sessions.keys()):
+            session = self.arq_iss_sessions[session_id]
+            session.abort_transmission(send_stop=False)
+            session.transmission_aborted()
+            self.remove_arq_iss_session(session_id)
+
     def add_activity(self, activity_data):
         """Adds a new activity to the activities list.