diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index ce9ea49..9e5c664 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -95,7 +95,8 @@
     <uses-permission android:name="android.permission.SET_PREFERRED_APPLICATIONS" />
     <uses-permission android:name="android.permission.READ_SEARCH_INDEXABLES" />
     <uses-permission android:name="android.permission.DUMP" />
-    <uses-permission android:name="android.permission.REGISTER_PROVIDER_OR_SUBSCRIPTION" />
+    <uses-permission android:name="android.permission.REGISTER_CALL_PROVIDER" />
+    <uses-permission android:name="android.permission.REGISTER_SIM_SUBSCRIPTION" />
 
     <!-- This tells the activity manager to not delay any of our activity
          start requests, even if they happen immediately after the user
diff --git a/res/values-mcc204-mnc04/strings.xml b/res/values-mcc204-mnc04/strings.xml
new file mode 100644
index 0000000..fec694f
--- /dev/null
+++ b/res/values-mcc204-mnc04/strings.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2014 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
+    <string translatable="false" name="config_world_mode">true;BAE0000000000000</string>
+</resources>
diff --git a/res/values-mcc310-mnc004/strings.xml b/res/values-mcc310-mnc004/strings.xml
new file mode 100644
index 0000000..55cbcd6
--- /dev/null
+++ b/res/values-mcc310-mnc004/strings.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2014 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
+    <string translatable="false" name="config_world_mode">true</string>
+</resources>
diff --git a/res/values-mcc311-mnc480/strings.xml b/res/values-mcc311-mnc480/strings.xml
new file mode 100644
index 0000000..55cbcd6
--- /dev/null
+++ b/res/values-mcc311-mnc480/strings.xml
@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2014 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<resources xmlns:xliff="urn:oasis:names:tc:xliff:document:1.2">
+    <string translatable="false" name="config_world_mode">true</string>
+</resources>
diff --git a/res/values/arrays.xml b/res/values/arrays.xml
new file mode 100644
index 0000000..8187ff3
--- /dev/null
+++ b/res/values/arrays.xml
@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+     Copyright (C) 2014 The Android Open Source Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+<resources>
+
+    <!--String arrays for World preferred netwrok modes -->
+    <string-array name="preferred_network_mode_choices_world_mode">
+        <item>Global</item>
+        <item>LTE / CDMA</item>
+        <item>LTE / GSM / UMTS</item>
+    </string-array>
+
+    <string-array name="preferred_network_mode_values_world_mode">
+        <item>"10"</item>
+        <item>"8"</item>
+        <item>"9"</item>
+    </string-array>
+
+</resources>
diff --git a/res/values/strings.xml b/res/values/strings.xml
index 5d9f835..4c7f558 100644
--- a/res/values/strings.xml
+++ b/res/values/strings.xml
@@ -382,7 +382,10 @@
     <string name="preferred_network_mode_global_summary">Preferred network mode: Global</string>
     <!-- Mobile network settings, summary for preferred network mode LTE / WCDMA[CHAR LIMIT=100] -->
     <string name="preferred_network_mode_lte_wcdma_summary">Preferred network mode: LTE / WCDMA</string>
-
+     <!-- Mobile network settings, summary for preferred network mode LTE / GSM / UMTS [CHAR LIMIT=100] -->
+     <string name="preferred_network_mode_lte_gsm_umts_summary">Preferred network mode: LTE / GSM / UMTS</string>
+     <!-- Mobile network settings, summary for preferred network mode LTE / CDMA [CHAR LIMIT=100] -->
+     <string name="preferred_network_mode_lte_cdma_summary">Preferred network mode: LTE / CDMA</string>
 
     <string-array name="preferred_network_mode_choices">
         <item>LTE / WCDMA</item>
@@ -1245,4 +1248,6 @@
     <string name="sim_label_emergency_calls">Emergency calls</string>
     <string name="sim_description_emergency_calls">Emergency calling only</string>
     <string name="sim_description_default">SIM card, slot: <xliff:g id="slot_id">%s</xliff:g></string>
+    <!-- Configuration setting for world mode Format is <true;GID if any to be checked>-->
+    <string translatable="false" name="config_world_mode"/>
 </resources>
diff --git a/src/com/android/phone/CallFeaturesSetting.java b/src/com/android/phone/CallFeaturesSetting.java
index abc0edd..796e3e5 100644
--- a/src/com/android/phone/CallFeaturesSetting.java
+++ b/src/com/android/phone/CallFeaturesSetting.java
@@ -216,6 +216,11 @@
     private static final int MSG_VM_OK = 600;
     private static final int MSG_VM_NOCHANGE = 700;
 
+    /**
+     * @see CallForwardInfo#status
+     */
+    private static final int CALL_FORWARD_INFO_INACTIVE_STATUS = 0;
+
     // voicemail notification vibration string constants
     private static final String VOICEMAIL_VIBRATION_ALWAYS = "always";
     private static final String VOICEMAIL_VIBRATION_NEVER = "never";
@@ -500,7 +505,10 @@
         }
 
         if (preference == mSubMenuVoicemailSettings) {
-            handleVMBtnClickRequest();
+            VoicemailProviderSettings newSettings = new VoicemailProviderSettings(
+                    mSubMenuVoicemailSettings.getPhoneNumber(),
+                    VoicemailProviderSettings.NO_FORWARDING);
+            saveVoiceMailAndForwardingNumber(getCurrentVoicemailProviderKey(), newSettings);
         }
     }
 
@@ -531,20 +539,6 @@
         return getString(R.string.voicemail_abbreviated) + " " + vmDisplay;
     }
 
-
-    // override the startsubactivity call to make changes in state consistent.
-    @Override
-    public void startActivityForResult(Intent intent, int requestCode) {
-        if (requestCode == -1) {
-            // this is an intent requested from the preference framework.
-            super.startActivityForResult(intent, requestCode);
-            return;
-        }
-
-        if (DBG) log("startSubActivity: starting requested subactivity");
-        super.startActivityForResult(intent, requestCode);
-    }
-
     private void switchToPreviousVoicemailProvider() {
         if (DBG) log("switchToPreviousVoicemailProvider " + mPreviousVMProviderKey);
         if (mPreviousVMProviderKey != null) {
@@ -721,21 +715,6 @@
         super.onActivityResult(requestCode, resultCode, data);
     }
 
-    // Voicemail button logic
-    private void handleVMBtnClickRequest() {
-        // normally called on the dialog close.
-
-        // Since we're stripping the formatting out on the getPhoneNumber()
-        // call now, we won't need to do so here anymore.
-
-        saveVoiceMailAndForwardingNumber(
-                getCurrentVoicemailProviderKey(),
-                new VoicemailProviderSettings(mSubMenuVoicemailSettings.getPhoneNumber(),
-                        VoicemailProviderSettings.NO_FORWARDING)
-        );
-    }
-
-
     /**
      * Wrapper around showDialog() that will silently do nothing if we're
      * not in the foreground.
@@ -928,17 +907,18 @@
         return result;
     }
 
-    private boolean isUpdateRequired(CallForwardInfo oldInfo,
-            CallForwardInfo newInfo) {
-        boolean result = true;
-        if (0 == newInfo.status) {
-            // If we're disabling a type of forwarding, and it's already
-            // disabled for the account, don't make any change
-            if (oldInfo != null && oldInfo.status == 0) {
-                result = false;
-            }
+    private boolean isUpdateRequired(CallForwardInfo oldInfo, CallForwardInfo newInfo) {
+        if (oldInfo == null) {
+            return true;
         }
-        return result;
+
+        // If we're disabling a type of forwarding, don't make any change if it's already disabled.
+        if (newInfo.status == CALL_FORWARD_INFO_INACTIVE_STATUS
+                && oldInfo.status == CALL_FORWARD_INFO_INACTIVE_STATUS) {
+            return false;
+        }
+
+        return true;
     }
 
     private void resetForwardingChangeState() {
@@ -1000,9 +980,7 @@
             switch (msg.what) {
                 case EVENT_VOICEMAIL_CHANGED:
                     mVoicemailChangeResult = result;
-                    mVMChangeCompletedSuccessfully = checkVMChangeSuccess() == null;
-                    if (DBG) log("VM change complete msg, VM change done = " +
-                            String.valueOf(mVMChangeCompletedSuccessfully));
+                    mVMChangeCompletedSuccessfully = isVmChangeSuccess();
                     done = true;
                     break;
                 case EVENT_FORWARDING_CHANGED:
@@ -1013,9 +991,8 @@
                     } else {
                         if (DBG) log("Success in setting fwd# " + msg.arg1);
                     }
-                    final boolean completed = checkForwardingCompleted();
-                    if (completed) {
-                        if (checkFwdChangeSuccess() == null) {
+                    if (isForwardingCompleted()) {
+                        if (isFwdChangeSuccess()) {
                             if (DBG) log("Overall fwd changes completed ok, starting vm change");
                             setVMNumberWithCarrier();
                         } else {
@@ -1048,7 +1025,7 @@
                 if (mForwardingChangeResults != null) {
                     dismissDialogSafely(VOICEMAIL_FWD_SAVING_DIALOG);
                 }
-                handleSetVMOrFwdMessage();
+                handleSetVmOrFwdMessage();
             }
         }
     };
@@ -1080,7 +1057,7 @@
             }
             final boolean done =
                 (!mVMChangeCompletedSuccessfully || mVoicemailChangeResult != null) &&
-                (!mFwdChangesRequireRollback || checkForwardingCompleted());
+                (!mFwdChangesRequireRollback || isForwardingCompleted());
             if (done) {
                 if (DBG) log("All VM reverts done");
                 dismissDialogSafely(VOICEMAIL_REVERTING_DIALOG);
@@ -1090,91 +1067,61 @@
     };
 
     /**
-     * @return true if forwarding change has completed
+     * Return true if there is a change result for every reason for which we expect a result.
      */
-    private boolean checkForwardingCompleted() {
-        boolean result;
+    private boolean isForwardingCompleted() {
         if (mForwardingChangeResults == null) {
-            result = true;
-        } else {
-            // return true iff there is a change result for every reason for
-            // which we expected a result
-            result = true;
-            for (Integer reason : mExpectedChangeResultReasons) {
-                if (mForwardingChangeResults.get(reason) == null) {
-                    result = false;
-                    break;
-                }
+            return true;
+        }
+
+        for (Integer reason : mExpectedChangeResultReasons) {
+            if (mForwardingChangeResults.get(reason) == null) {
+                return false;
             }
         }
-        return result;
+
+        return true;
     }
-    /**
-     * @return error string or null if successful
-     */
-    private String checkFwdChangeSuccess() {
-        String result = null;
-        Iterator<Map.Entry<Integer,AsyncResult>> it =
-            mForwardingChangeResults.entrySet().iterator();
-        while (it.hasNext()) {
-            Map.Entry<Integer,AsyncResult> entry = it.next();
-            Throwable exception = entry.getValue().exception;
+
+    private boolean isFwdChangeSuccess() {
+        if (mForwardingChangeResults == null) {
+            return true;
+        }
+
+        for (AsyncResult result : mForwardingChangeResults.values()) {
+            Throwable exception = result.exception;
             if (exception != null) {
-                result = exception.getMessage();
-                if (result == null) {
-                    result = "";
-                }
-                break;
+                String msg = exception.getMessage();
+                msg = (msg != null) ? msg : "";
+                Log.w(LOG_TAG, "Failed to change forwarding setting. Reason: " + msg);
+                return false;
             }
         }
-        return result;
+        return true;
     }
 
-    /**
-     * @return error string or null if successful
-     */
-    private String checkVMChangeSuccess() {
+    private boolean isVmChangeSuccess() {
         if (mVoicemailChangeResult.exception != null) {
-            final String msg = mVoicemailChangeResult.exception.getMessage();
-            if (msg == null) {
-                return "";
-            }
-            return msg;
+            String msg = mVoicemailChangeResult.exception.getMessage();
+            msg = (msg != null) ? msg : "";
+            Log.w(LOG_TAG, "Failed to change voicemail. Reason: " + msg);
+            return false;
         }
-        return null;
+
+        if (DBG) log("VM change completed successfully.");
+        return true;
     }
 
-    private void handleSetVMOrFwdMessage() {
-        if (DBG) {
-            log("handleSetVMMessage: set VM request complete");
-        }
-        boolean success = true;
-        boolean fwdFailure = false;
-        String exceptionMessage = "";
-        if (mForwardingChangeResults != null) {
-            exceptionMessage = checkFwdChangeSuccess();
-            if (exceptionMessage != null) {
-                success = false;
-                fwdFailure = true;
-            }
-        }
-        if (success) {
-            exceptionMessage = checkVMChangeSuccess();
-            if (exceptionMessage != null) {
-                success = false;
-            }
-        }
-        if (success) {
-            if (DBG) log("change VM success!");
-            handleVMAndFwdSetSuccess(MSG_VM_OK);
+    private void handleSetVmOrFwdMessage() {
+        if (DBG) log("handleSetVMMessage: set VM request complete");
+
+        if (!isFwdChangeSuccess()) {
+            handleVmOrFwdSetError(MSG_FW_SET_EXCEPTION);
+        } else if (!isVmChangeSuccess()) {
+            handleVmOrFwdSetError(MSG_VM_EXCEPTION);
         } else {
-            if (fwdFailure) {
-                Log.w(LOG_TAG, "Failed to change fowarding setting. Reason: " + exceptionMessage);
-                handleVMOrFwdSetError(MSG_FW_SET_EXCEPTION);
-            } else {
-                Log.w(LOG_TAG, "Failed to change voicemail. Reason: " + exceptionMessage);
-                handleVMOrFwdSetError(MSG_VM_EXCEPTION);
-            }
+            if (DBG) log("change VM success!");
+            handleVmAndFwdSetSuccess(MSG_VM_OK);
         }
     }
 
@@ -1185,7 +1132,7 @@
      * @param msgId Message ID used for the specific error case. {@link #MSG_FW_SET_EXCEPTION} or
      * {@link #MSG_VM_EXCEPTION}
      */
-    private void handleVMOrFwdSetError(int msgId) {
+    private void handleVmOrFwdSetError(int msgId) {
         if (mChangingVMorFwdDueToProviderChange) {
             mVMOrFwdSetError = msgId;
             mChangingVMorFwdDueToProviderChange = false;
@@ -1201,9 +1148,9 @@
      * Called when Voicemail Provider and its forwarding settings were successfully finished.
      * This updates a bunch of variables and show "success" dialog.
      */
-    private void handleVMAndFwdSetSuccess(int msg) {
+    private void handleVmAndFwdSetSuccess(int msg) {
         if (DBG) {
-            log("handleVMAndFwdSetSuccess(). current voicemail provider key: "
+            log("handleVmAndFwdSetSuccess(). current voicemail provider key: "
                     + getCurrentVoicemailProviderKey());
         }
         mPreviousVMProviderKey = getCurrentVoicemailProviderKey();
diff --git a/src/com/android/phone/MobileNetworkSettings.java b/src/com/android/phone/MobileNetworkSettings.java
index 2c57b47..d618b5c 100644
--- a/src/com/android/phone/MobileNetworkSettings.java
+++ b/src/com/android/phone/MobileNetworkSettings.java
@@ -312,6 +312,12 @@
             } else {
                 throw new IllegalStateException("Unexpected phone type: " + phoneType);
             }
+            if (isWorldMode()) {
+                mButtonEnabledNetworks.setEntries(
+                        R.array.preferred_network_mode_choices_world_mode);
+                mButtonEnabledNetworks.setEntryValues(
+                        R.array.preferred_network_mode_values_world_mode);
+            }
             mButtonEnabledNetworks.setOnPreferenceChangeListener(this);
             int settingsNetworkMode = android.provider.Settings.Global.getInt(
                     mPhone.getContext().getContentResolver(),
@@ -731,6 +737,11 @@
                 }
                 break;
             case Phone.NT_MODE_LTE_GSM_WCDMA:
+                if(isWorldMode()) {
+                    mButtonEnabledNetworks.setSummary(
+                            R.string.preferred_network_mode_lte_gsm_umts_summary);
+                    break;
+                }
             case Phone.NT_MODE_LTE_ONLY:
             case Phone.NT_MODE_LTE_WCDMA:
                 if (!mIsGlobalCdma) {
@@ -745,9 +756,14 @@
                 }
                 break;
             case Phone.NT_MODE_LTE_CDMA_AND_EVDO:
-                mButtonEnabledNetworks.setValue(
-                        Integer.toString(Phone.NT_MODE_LTE_CDMA_AND_EVDO));
-                mButtonEnabledNetworks.setSummary(R.string.network_lte);
+                if(isWorldMode()) {
+                    mButtonEnabledNetworks.setSummary(
+                            R.string.preferred_network_mode_lte_cdma_summary);
+                } else {
+                    mButtonEnabledNetworks.setValue(
+                            Integer.toString(Phone.NT_MODE_LTE_CDMA_AND_EVDO));
+                    mButtonEnabledNetworks.setSummary(R.string.network_lte);
+                }
                 break;
             case Phone.NT_MODE_CDMA:
             case Phone.NT_MODE_EVDO_NO_CDMA:
@@ -820,4 +836,28 @@
         }
         return super.onOptionsItemSelected(item);
     }
+
+    private boolean isWorldMode() {
+        boolean worldModeOn = false;
+        final TelephonyManager tm = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
+        final String configString = getResources().getString(R.string.config_world_mode);
+
+        if (!TextUtils.isEmpty(configString)) {
+            String[] configArray = configString.split(";");
+            // Check if we have World mode configuration set to True only or config is set to True
+            // and SIM GID value is also set and matches to the current SIM GID.
+            if (configArray != null &&
+                   ((configArray.length == 1 && configArray[0].equalsIgnoreCase("true")) ||
+                       (configArray.length == 2 && !TextUtils.isEmpty(configArray[1]) &&
+                           tm != null && configArray[1].equalsIgnoreCase(tm.getGroupIdLevel1())))) {
+                               worldModeOn = true;
+            }
+        }
+
+        if (DBG) {
+            log("World mode is set to" + worldModeOn);
+        }
+
+        return worldModeOn;
+    }
 }