Detecting and Using LTE Networks

    技术2024-04-16  20

    3GPP Long Term Evolution (LTE) is a 4G wireless network technology that supports significantly higher data rates than those supported by existing 3G networks. Because LTE enables video applications on both the downlink and the uplink, Android-powered devices that support LTE on Verizon Wireless—such as DROID BIONIC—are able to provide fast, high-quality web browsing, video streaming, and video conferencing. And because these devices also support traditional 3G (CDMA) and eHRPD (evolved High-Rate Packet Data) networks, the device isn’t limited to operating within LTE coverage areas. Users get the best of all worlds: the greatest degree of coverage and the best network performance possible within a given cell. Working in conjunction with Verizon Wireless, Motorola Mobility has implemented a few Android platform extensions to enable LTE and eHRPD on DROID BIONIC and certain other Android-powered devices intended for use on the Verizon Wireless network. This article describes how Android applications can detect when the device is on the LTE and eHRPD networks, and how they can be notified when the connected network type changes. Detecting the Network Devices on the Verizon Wireless LTE network typically maintain a separate connection each for voice and data. An Android application uses the Connectivity Manager to monitor the state of the data network. Similarly, the Telephony Manager provides APIs that enable apps to check the state of the voice connection. When writing Android applications that make use of a specific feature, you typically add a corresponding <uses-feature> element to your AndroidManifest.xml file. Apps that interact with the telephony features typically include: <uses-feature android:name="android.hardware.telephony"/>

     

    Apps that specifically use the LTE and/or eHRPD capabilities of a device should include one or both of the following: <uses-feature android:name="android.hardware.telephony.lte"/>view sourceprint? <uses-feature android:name="android.hardware.telephony.ehrpd"/>

     

    In addition, you’ll need ACCESS_NETWORK_STATE permission: <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

     

    Data Connection Using the Connectivity Manager, check the active network type to see whether or not the data connection is 4G. Obtain the NetworkInfo object from an instance of the Connectivity Manager. Then, from the NetworkInfo object get the network type and subtype. // get the type and subtype of the data connection ConnectivityManager connMgr =     (ConnectivityManager)getSystemService(Context.CONNECTIVITY_SERVICE); NetworkInfo netInfo = connMgr.getActiveNetworkInfo(); int dNetType = netInfo.getType(); int dNetSubtype = netInfo.getSubtype();

     

    Depending upon the network to which the device is currently connected, the values listed in the following tables are returned when you query the NetworkInfo object: Function Return Value (LTE) getType() 0 (ConnectivityManager.TYPE_MOBILE) getSubtype() 13 getSubtypeName() “LTE”   Function Return Value (eHRPD) getType() 0 (ConnectivityManager.TYPE_MOBILE) getSubtype() 14 getSubtypeName() “eHRPD”   Function Return Value (CDMA) getType() 0 (ConnectivityManager.TYPE_MOBILE) getSubtype() 6 getSubtypeName() “CDMA - EvDo rev. A”   Similar values are returned for the NetworkInfo objects in the array returned by the Connectivity Manager’s getAllNetworkInfo() method. Voice Connection To determine the network currently being used for the voice connection, simply request the network type from an instance of the TelephonyManager object: TelephonyManager telMgr =     (TelephonyManager)getSystemService(Context.TELEPHONY_SERVICE); int vNetType = telMgr.getNetworkType(); if(vNetType == NETWORK_TYPE_LTE){     // on the LTE voice network }

     

    The following table lists return values from the getNetworkType() method, depending upon the current network: Network getNetworkType() return value LTE 13 (NETWORK_TYPE_LTE) eHRPD 14 (NETWORK_TYPE_EHRPD) CDMA 6 (NETWORK_TYPE_EVDO_A) Handling Network Transitions As the connected device moves from cell to cell, it tries to maintain its network connection. It will generally be successful if the network type doesn’t change between cells. However, if the device moves into or out of the 4G coverage area, the data connection will be dropped and your IP address will change. Because this can happen while an app has an active data connection open, Android sends an android.net.ConnectivityManager.CONNECTIVITY_ACTION broadcast whenever there is a change in the network. If your app needs to be aware of network changes, register for this broadcast. When Android sends a CONNECTIVITY_ACTION broadcast, it includes extra data: a NetworkInfo object for the new network. Consult this NetworkInfo object to see what kind of connectivity event occurred. private class ConnectivityRcvr extends BroadcastReceiver {     @Override     public void onReceive(Context context, Intent intent) {         if (intent.getAction()                 .equals(ConnectivityManager.CONNECTIVITY_ACTION)) {             NetworkInfo netInfo =                 (NetworkInfo)intent.getParcelableExtra(ConnectivityManager                     .EXTRA_NETWORK_INFO);             int netType = netInfo.getType();             int netSubtype = netInfo.getSubtype();             boolean isConnected = netInfo.isConnected();             // ...         }         // ...     } }

    Typically you register for the CONNECTIVITY_ACTION broadcast either in your onCreate() method (if you prefer to register from within your app’s source code) or in your AndroidManifest.xml file. Note that there is a similar broadcast intent defined in the TelephonyManager: ACTION_PHONE_STATE_CHANGED is broadcast if the call state changes. Be aware that your app will need READ_PHONE_STATE permission when registering for this broadcast.

     

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    https://developer.motorola.com/docstools/library/detecting-and-using-lte-networks/

     

            IntentFilter intentFilter = new IntentFilter();         intentFilter.addAction(ConnectivityManager.CONNECTIVITY_ACTION);         this.connectivityBroadcastReceiver = new ConnectivityBroadcastReceiver();         this.registerReceiver(this.connectivityBroadcastReceiver, intentFilter);

     

     

            this.unregisterReceiver(this.connectivityBroadcastReceiver);

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