diff --git a/test_drone_data.py b/test_drone_data.py
index 2f0f2c7..73ceb55 100644
--- a/test_drone_data.py
+++ b/test_drone_data.py
@@ -257,6 +257,53 @@ class DroneSimulator:
         
         return detection
 
+def send_heartbeat(device_id):
+    """Send heartbeat to keep device online"""
+    global DEBUG_MODE
+    url = f"{API_BASE_URL}/heartbeat"
+    headers = {
+        "Content-Type": "application/json"
+    }
+    
+    heartbeat_data = {
+        "type": "heartbeat",
+        "key": f"device_{device_id}",
+        "device_id": device_id,
+        "signal_strength": random.randint(-70, -30),  # Simulate signal strength
+        "battery_level": random.randint(70, 100),     # Simulate battery level
+        "temperature": random.randint(20, 45),        # Simulate temperature
+        "uptime": random.randint(3600, 86400),        # Simulate uptime
+        "memory_usage": random.randint(30, 80),       # Simulate memory usage
+        "firmware_version": "1.0.0"
+    }
+    
+    # Debug output for heartbeat
+    if DEBUG_MODE:
+        print("\n" + "-"*40)
+        print("💓 DEBUG: Sending heartbeat to backend")
+        print("-"*40)
+        print(f"URL: {url}")
+        print("Heartbeat payload:")
+        print(json.dumps(heartbeat_data, indent=2, sort_keys=True))
+        print("-"*40 + "\n")
+    
+    try:
+        response = requests.post(url, json=heartbeat_data, headers=headers, timeout=10)
+        
+        if response.status_code == 201:
+            if DEBUG_MODE:
+                print(f"💓 Device {device_id}: Heartbeat sent successfully")
+            return True
+        else:
+            if DEBUG_MODE:
+                print(f"❌ Heartbeat failed: {response.status_code} - {response.text}")
+            return False
+            
+    except requests.exceptions.RequestException as e:
+        if DEBUG_MODE:
+            print(f"❌ Heartbeat network error: {e}")
+        return False
+
 def send_detection(detection_data):
     """Send detection data to the API"""
     global DEBUG_MODE
@@ -375,18 +422,32 @@ def simulate_orlan_detection_test():
     
     print("\n" + "=" * 70)
     print("STARTING ORLAN APPROACH SIMULATION")
+    print("💓 Sending initial heartbeat to keep device online...")
     print("=" * 70)
     
+    # Send initial heartbeat to target device
+    send_heartbeat(target_device['id'])
+    
     # Simulation parameters
     total_steps = 50
     final_distance = 0.0  # Directly overhead
     drone_id = 3000  # Unique ID for Orlan test
+    last_heartbeat = time.time()
+    heartbeat_interval = 60  # Send heartbeat every 60 seconds
     
     detection_started = False
     critical_alerts_started = False
     
     try:
         for step in range(1, total_steps + 1):
+            current_time = time.time()
+            
+            # Send periodic heartbeat to keep device online
+            if current_time - last_heartbeat >= heartbeat_interval:
+                print("💓 Sending heartbeat to maintain device status...")
+                send_heartbeat(target_device['id'])
+                last_heartbeat = current_time
+            
             # Calculate current distance (exponential approach)
             progress = step / total_steps
             distance_km = start_distance * (1 - progress) ** 1.8 + final_distance * progress ** 1.8
@@ -476,11 +537,19 @@ def simulate_realistic_scenario(duration_minutes=10):
     """Simulate realistic drone scenario with persistent tracking"""
     print(f"🚁 Starting realistic drone simulation for {duration_minutes} minutes...")
     print("📊 Scenario: Multiple drones with persistent tracking, RSSI changes, movement patterns")
+    print("💓 Heartbeat system: Keeping devices online during test")
     print("=" * 80)
     
     simulator = DroneSimulator()
     start_time = time.time()
     end_time = start_time + (duration_minutes * 60)
+    last_heartbeat = start_time
+    heartbeat_interval = 60  # Send heartbeat every 60 seconds (well under 300s limit)
+    
+    # Send initial heartbeats to all devices
+    print("💓 Sending initial heartbeats to all devices...")
+    for device in DEVICES:
+        send_heartbeat(device['id'])
     
     # Force create initial drone for testing
     if len(DEVICES) > 0:
@@ -491,6 +560,7 @@ def simulate_realistic_scenario(duration_minutes=10):
     
     detection_count = 0
     last_update = start_time
+    heartbeat_count = 0
     
     try:
         while time.time() < end_time:
@@ -498,6 +568,14 @@ def simulate_realistic_scenario(duration_minutes=10):
             time_delta = current_time - last_update
             last_update = current_time
             
+            # Send periodic heartbeats to keep devices online
+            if current_time - last_heartbeat >= heartbeat_interval:
+                print(f"💓 Sending heartbeats to {len(DEVICES)} devices...")
+                for device in DEVICES:
+                    if send_heartbeat(device['id']):
+                        heartbeat_count += 1
+                last_heartbeat = current_time
+            
             # Randomly spawn new drones (1-15% chance per cycle)
             if random.random() < 0.15 and len(simulator.active_drones) < 8:
                 device = random.choice(DEVICES)
@@ -531,7 +609,6 @@ def simulate_realistic_scenario(duration_minutes=10):
                     
                     if should_detect:
                         detection = simulator.generate_detection(drone, device, distance)
-                        detection["_distance"] = f"{distance:.1f}"  # For logging only
                         
                         if send_detection(detection):
                             detection_count += 1
@@ -547,7 +624,7 @@ def simulate_realistic_scenario(duration_minutes=10):
             if int(elapsed_minutes) % 2 == 0 and elapsed_minutes > 0:
                 active_count = len(simulator.active_drones)
                 if active_count > 0:
-                    print(f"📍 Status: {active_count} active drones, {detection_count} total detections")
+                    print(f"📍 Status: {active_count} active drones, {detection_count} total detections, {heartbeat_count} heartbeats sent")
             
             time.sleep(3)  # 3 second cycle time