diff --git a/server/sql/tables.sql b/server/sql/tables.sql
index 5788884..96e9328 100644
--- a/server/sql/tables.sql
+++ b/server/sql/tables.sql
@@ -18,8 +18,8 @@ CREATE TABLE IF NOT EXISTS wifi_scan (
     lp_ttn_end_device_uplinks_id UUID,
     mac VARCHAR(255),
     rssi NUMERIC,
-    latitude DOUBLE,
-    longitude DOUBLE,
+    latitude DOUBLE NOT NULL,
+    longitude DOUBLE NOT NULL,
     created_at_utc TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
     updated_at_utc TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
     FOREIGN KEY (lp_ttn_end_device_uplinks_id) REFERENCES lp_ttn_end_device_uplinks(lp_ttn_end_device_uplinks_id)
diff --git a/server/src/eventHandler/ttnMessageReceivedEventHandler.ts b/server/src/eventHandler/ttnMessageReceivedEventHandler.ts
index 9d47ce1..e59893d 100644
--- a/server/src/eventHandler/ttnMessageReceivedEventHandler.ts
+++ b/server/src/eventHandler/ttnMessageReceivedEventHandler.ts
@@ -7,6 +7,7 @@ import { container } from "tsyringe";
 import { LocationService } from "../services/locationService";
 import { WifiScanService } from "../services/wifiScanService";
 import { getLocationForWifiMemoized } from "../proxy/wigle";
+import { WifiScan } from "../models/wifiScan";
 
 const locationService = container.resolve(LocationService);
 const wifiScanService = container.resolve(WifiScanService);
@@ -54,54 +55,52 @@ const CalculateWifiLocation = async (event: TtnMessageReceivedEvent) => {
     console.log("No WiFi scans received!")
   } else {
     // Process Wi-Fi data to compute weighted location
-    const wifiScans = await Promise.all(
+    let wifiScans = await Promise.all(
       event.wifis.map(async (wifi) => {
         // Create new WiFi Scan entry if wigle.net reported location
-        const apiResponse = await getLocationForWifiMemoized(wifi.mac);
-        console.log(apiResponse);
-
+        const apiResponse = await getLocationForWifiMemoized(wifi.mac);;
         // Only return valid data wifiScans (location for MAC was found)
-        if ((apiResponse != undefined) && (apiResponse.success == true) && (apiResponse?.totalResults > 0)) {
-          console.log("Create new wifiScan: " + wifi.mac)
+        if ((apiResponse?.success == true) && (apiResponse.totalResults > 0)) {
           return {
             lp_ttn_end_device_uplinks_id: event.lp_ttn_end_device_uplinks_id,
             mac: wifi.mac,
             rssi: wifi.rssi,
-            latitude: apiResponse.results[0].trilat,
-            longitude: apiResponse.results[0].trilong,
-          };
+            latitude: apiResponse?.results[0].trilat,
+            longitude: apiResponse?.results[0].trilong,
+          }
         }
-        // Return null for invalid cases
-        console.log("Don't create new wifiScan: " + wifi.mac)
-        return null;
+        return undefined;
       })
     );
 
+    const wifiScansFiltered = wifiScans.filter(w => (w !== undefined));
+
     // Store valid wifiScans into DB
-    await wifiScanService.createWifiScans(wifiScans);
+    const locatedWifiScans = await wifiScanService.createWifiScans(wifiScansFiltered);
 
-    const { totalWeight, weightedLatitude, weightedLongitude } =
-      wifiScans.reduce(
-        (acc, { latitude, longitude, rssi }) => {
-          console.log("Current WifiScan: " + latitude + " " + longitude + " " + rssi)
-          const weight = 1 / Math.abs(rssi);
-          acc.totalWeight += weight;
-          acc.weightedLatitude += latitude * weight;
-          acc.weightedLongitude += longitude * weight;
-          return acc;
-        },
-        {
-          totalWeight: 0,
-          weightedLatitude: 0,
-          weightedLongitude: 0,
-        }
-      );
+    if (locatedWifiScans.length !== 0) {
+      const { totalWeight, weightedLatitude, weightedLongitude } =
+        locatedWifiScans.reduce(
+          (acc, { latitude, longitude, rssi }) => {
+            const weight = 1 / Math.abs(rssi);
+            acc.totalWeight += weight;
+            acc.weightedLatitude += latitude * weight;
+            acc.weightedLongitude += longitude * weight;
+            return acc;
+          },
+          {
+            totalWeight: 0,
+            weightedLatitude: 0,
+            weightedLongitude: 0,
+          }
+        );
 
-    // Calculate the weighted average to get the virtual location
-    virtualLocation.latitude = weightedLatitude / totalWeight;
-    virtualLocation.longitude = weightedLongitude / totalWeight;
+      // Calculate the weighted average to get the virtual location
+      virtualLocation.latitude = weightedLatitude / totalWeight;
+      virtualLocation.longitude = weightedLongitude / totalWeight;
 
-    console.log("Tracker location based on WiFi Scan location:", virtualLocation);
+      console.log("Tracker location based on WiFi Scan location:", virtualLocation);
+    }
   }
   return {
     wifi_latitude: virtualLocation.latitude,
diff --git a/server/src/proxy/wigle.ts b/server/src/proxy/wigle.ts
index d2139cd..705c180 100644
--- a/server/src/proxy/wigle.ts
+++ b/server/src/proxy/wigle.ts
@@ -54,9 +54,14 @@ export const getLocationForWifi = async (
         Authorization: `Basic ${process.env.WIGLE_TOKEN}`,
       },
     });
-    return await response.json();
+    if (response.ok) {
+      return await response.json();
+    }
+    console.log(response.status);
+    return undefined;
+
   } catch (error) {
-    console.error("Fehler beim Aufruf des Services:", error);
+    console.error("Error during call of API wigle.net:", error);
   }
 };