diff --git a/app/src/main/java/de/fraunhofer/fokus/OpenMobileNetworkToolkit/DataProvider/DataProvider.java b/app/src/main/java/de/fraunhofer/fokus/OpenMobileNetworkToolkit/DataProvider/DataProvider.java
index a6b83bf0..7bfd06c2 100644
--- a/app/src/main/java/de/fraunhofer/fokus/OpenMobileNetworkToolkit/DataProvider/DataProvider.java
+++ b/app/src/main/java/de/fraunhofer/fokus/OpenMobileNetworkToolkit/DataProvider/DataProvider.java
@@ -98,7 +98,7 @@ public class DataProvider extends TelephonyCallback implements LocationListener,
     // internal data caches
     private List<CellInformation> ci = new ArrayList<>();
     private LocationInformation li = new LocationInformation();
-    private NetworkInformation ni;// = new NetworkInformation();
+    private NetworkInformation ni = new NetworkInformation();
     private List<NetworkInterfaceInformation> nii = new ArrayList<>();
     private ArrayList<CellInformation> ssi = new ArrayList<>();
     private WifiInformation wi = null;
@@ -160,6 +160,14 @@ public void onLocationResult(@NonNull LocationResult locationResult) {
         refreshAll();
     }
 
+    /**
+     * Update the current Telephony Manager reference e.g. after subscription change
+     * @param tm new Telephony Manager reference
+     */
+    public void setTm(TelephonyManager tm) {
+        this.tm = tm;
+    }
+
     /**
      * Refresh Network Information
      */
@@ -888,11 +896,12 @@ public void onUnavailable() {
                         wi = null;
                     }
                 };
-                cm.registerNetworkCallback(request, networkCallback);
-                cm.requestNetwork(request, networkCallback);
+                cm.registerNetworkCallback(request, networkCallback); //todo this call back is already registered
+                //cm.requestNetwork(request, networkCallback);
             }
         } catch (Exception e) {
-            Log.d("Network Callback: Exception in registerNetworkCallback", "Catch exception");
+            Log.d(TAG, "Network Callback: Exception in registerNetworkCallback");
+            Log.d(TAG,e.toString());
         }
     }
 
diff --git a/app/src/main/java/de/fraunhofer/fokus/OpenMobileNetworkToolkit/DataProvider/LocationInformation.java b/app/src/main/java/de/fraunhofer/fokus/OpenMobileNetworkToolkit/DataProvider/LocationInformation.java
index ac911f9f..32d8e2c8 100644
--- a/app/src/main/java/de/fraunhofer/fokus/OpenMobileNetworkToolkit/DataProvider/LocationInformation.java
+++ b/app/src/main/java/de/fraunhofer/fokus/OpenMobileNetworkToolkit/DataProvider/LocationInformation.java
@@ -8,9 +8,6 @@
 
 package de.fraunhofer.fokus.OpenMobileNetworkToolkit.DataProvider;
 
-import android.content.Context;
-import android.widget.TableLayout;
-
 import java.util.List;
 
 public class LocationInformation extends Information {
@@ -33,6 +30,12 @@ public LocationInformation(double longitude, double latitude, double altitude, S
     }
 
     public LocationInformation() {
+        this.longitude = -1;
+        this.latitude = -1;
+        this.altitude = -1;
+        this.provider = "N/A";
+        this.accuracy = -1;
+        this.speed = -1;
     }
 
     public List<String> getProviderList() {
diff --git a/app/src/main/java/de/fraunhofer/fokus/OpenMobileNetworkToolkit/DataProvider/NetworkInformation.java b/app/src/main/java/de/fraunhofer/fokus/OpenMobileNetworkToolkit/DataProvider/NetworkInformation.java
index 2b272078..15074a25 100644
--- a/app/src/main/java/de/fraunhofer/fokus/OpenMobileNetworkToolkit/DataProvider/NetworkInformation.java
+++ b/app/src/main/java/de/fraunhofer/fokus/OpenMobileNetworkToolkit/DataProvider/NetworkInformation.java
@@ -9,15 +9,10 @@
 package de.fraunhofer.fokus.OpenMobileNetworkToolkit.DataProvider;
 
 import android.annotation.SuppressLint;
-import android.content.Context;
 import android.os.Build;
 import android.telephony.AccessNetworkConstants;
+import android.telephony.SubscriptionManager;
 import android.telephony.TelephonyManager;
-import android.widget.TableLayout;
-
-import java.util.Arrays;
-
-import de.fraunhofer.fokus.OpenMobileNetworkToolkit.GlobalVars;
 
 public class NetworkInformation extends Information {
     private final String networkOperatorName;
@@ -39,6 +34,16 @@ public NetworkInformation(String networkOperatorName, String simOperatorName, St
         this.preferredOpportunisticDataSubscriptionId = preferredOpportunisitcDataSubscitptionId;
     }
 
+    public NetworkInformation() {
+        this.networkOperatorName = "N/A";
+        this.simOperatorName = "N/A";
+        this.networkSpecifier = "N/A";
+        this.dataState = TelephonyManager.DATA_UNKNOWN;
+        this.dataNetworkType = TelephonyManager.NETWORK_TYPE_UNKNOWN;
+        this.phoneType = TelephonyManager.NETWORK_TYPE_UNKNOWN;
+        this.preferredOpportunisticDataSubscriptionId = SubscriptionManager.DEFAULT_SUBSCRIPTION_ID;
+    }
+
     /**
      * Get the Network Operator Name
      * @return Operator Name string
diff --git a/app/src/main/java/de/fraunhofer/fokus/OpenMobileNetworkToolkit/MainActivity.java b/app/src/main/java/de/fraunhofer/fokus/OpenMobileNetworkToolkit/MainActivity.java
index 192d8832..ff15e620 100644
--- a/app/src/main/java/de/fraunhofer/fokus/OpenMobileNetworkToolkit/MainActivity.java
+++ b/app/src/main/java/de/fraunhofer/fokus/OpenMobileNetworkToolkit/MainActivity.java
@@ -160,8 +160,10 @@ protected void onCreate(Bundle savedInstanceState) {
                 }
                 // switch the telephony manager to a new one according to the app settings
                 tm = tm.createForSubscriptionId(Integer.parseInt(spg.getSharedPreference(SPType.default_sp).getString("select_subscription", "0")));
+
+                // update reference to tm
                 gv.setTm(tm);
-                dp = new DataProvider(this);
+                dp.setTm(tm);
             }
 
             gv.setSm((SubscriptionManager) getSystemService(Context.TELEPHONY_SUBSCRIPTION_SERVICE));