diff --git a/mpmaster/src/main/java/com/xypower/mpmaster/AppMaster.java b/mpmaster/src/main/java/com/xypower/mpmaster/AppMaster.java
index abea3b3a..5ee17218 100644
--- a/mpmaster/src/main/java/com/xypower/mpmaster/AppMaster.java
+++ b/mpmaster/src/main/java/com/xypower/mpmaster/AppMaster.java
@@ -114,6 +114,14 @@ public class AppMaster {
     public void start() {
 
         new Thread(new Runnable() {
+
+            void sleep(long ms) {
+                try {
+                    Thread.sleep(ms);
+                } catch (Exception ex) {
+                }
+            }
+
             @Override
             public void run() {
 
@@ -121,31 +129,24 @@ public class AppMaster {
 
                 if (separateNetwork) {
                     try {
+                        ConnectivityManager connectivityManager = (ConnectivityManager) mService.getSystemService(Context.CONNECTIVITY_SERVICE);
+                        Network previousNetwork = connectivityManager.getActiveNetwork();
+                        String previousNetworkStr = previousNetwork.toString();
+
                         mService.logger.info("Switch to Simcard 2");
                         SysApi.selectSimCard4Data(mService.getApplicationContext(), 2);
-                        Thread.sleep(100);
+                        sleep(100);
 
                         boolean connected = false;
-                        ConnectivityManager connectivityManager = (ConnectivityManager) mService.getSystemService(Context.CONNECTIVITY_SERVICE);
 
                         for (int idx = 0; idx < 8; idx++) {
-                            Network[] networks = connectivityManager.getAllNetworks();
-                            if (networks != null && networks.length > 0) {
-                                for (Network nw : networks) {
-                                    NetworkInfo ni = connectivityManager.getNetworkInfo(nw);
-
-                                    if (ni.getType() == 0) {
-                                        connected = true;
-                                        break;
-                                    }
-                                }
-                            }
-
-                            if (connected) {
+                            Network network = connectivityManager.getActiveNetwork();
+                            if (!network.equals(previousNetwork)) {
+                                mService.logger.info("Network Changed from " + previousNetworkStr + " to " + network.toString());
                                 break;
                             }
 
-                            Thread.sleep(1000);
+                            sleep(1000);
                         }
 
                         try {
@@ -164,6 +165,15 @@ public class AppMaster {
                         }
                     } catch (Exception ex) {
                         ex.printStackTrace();
+                    } finally {
+                        try {
+                            if (!mService.isMntnMode()) {
+                                mService.logger.info("Switch to Simcard 1");
+                                SysApi.selectSimCard4Data(mService.getApplicationContext(), 1);
+                            }
+                        } catch (Exception ex) {
+                            ex.printStackTrace();
+                        }
                     }
                 } else {
                     try {
diff --git a/mpmaster/src/main/java/com/xypower/mpmaster/MpMasterService.java b/mpmaster/src/main/java/com/xypower/mpmaster/MpMasterService.java
index fd285d8a..b651c8ba 100644
--- a/mpmaster/src/main/java/com/xypower/mpmaster/MpMasterService.java
+++ b/mpmaster/src/main/java/com/xypower/mpmaster/MpMasterService.java
@@ -658,8 +658,8 @@ public class MpMasterService extends Service {
                 }, 5000);
 
                 // Reset Data Network
-                logger.info("Switch to Simcard 1");
-                SysApi.selectSimCard4Data(getApplicationContext(), 1);
+                // logger.info("Switch to Simcard 1");
+                // SysApi.selectSimCard4Data(getApplicationContext(), 1);
 
                 registerHeartbeatTimer();