title: How to get android signal strength
body: <p>I just started developing for android and I am trying to figure out how to get a users signal strength. The following code gives me the Dbm for a GSM network:</p>
  
  <pre><code>TelephonyManager telephonyManager = (TelephonyManager)getSystemService(Context.TELEPHONY_SERVICE);
  
  // Get GSM Signal Strength (Dbm)
  CellInfoGsm GSM = (CellInfoGsm)telephonyManager.getAllCellInfo().get(0);
  CellSignalStrengthGsm cellSignalStrengthGsm = GSM.getCellSignalStrength();
  signalStrength = cellSignalStrengthGsm.getDbm();
  </code></pre>
  
  <p>However I want to be able to get the signal strength from any kind of network. May it be GSM, LTE, CDMA, or WCDMA. I have looked at the telephony documentation but I'm lost in how to go about this. I have tried to take the same code as above and just replace Gsm with Lte but that ended up crashing my emulator.</p>
  
  <p>Any help would be greatly appreciated.</p>
  
  <p>Updated and added the listener from the answer below. However now as soon as i run the app it crashes. This is the log file.</p>
  
  <pre><code>05-26 11:25:21.140: D/AndroidRuntime(921): Shutting down VM
  05-26 11:25:21.140: W/dalvikvm(921): threadid=1: thread exiting with uncaught exception (group=0xb3aecba8)
  05-26 11:25:21.170: E/AndroidRuntime(921): FATAL EXCEPTION: main
  05-26 11:25:21.170: E/AndroidRuntime(921): Process: com.example.androidcellinfo, PID: 921
  05-26 11:25:21.170: E/AndroidRuntime(921): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.androidcellinfo/com.example.androidcellinfo.MainActivity}: java.lang.NullPointerException
  05-26 11:25:21.170: E/AndroidRuntime(921):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2195)
  05-26 11:25:21.170: E/AndroidRuntime(921):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2245)
  05-26 11:25:21.170: E/AndroidRuntime(921):  at android.app.ActivityThread.access$800(ActivityThread.java:135)
  05-26 11:25:21.170: E/AndroidRuntime(921):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
  05-26 11:25:21.170: E/AndroidRuntime(921):  at android.os.Handler.dispatchMessage(Handler.java:102)
  05-26 11:25:21.170: E/AndroidRuntime(921):  at android.os.Looper.loop(Looper.java:136)
  05-26 11:25:21.170: E/AndroidRuntime(921):  at android.app.ActivityThread.main(ActivityThread.java:5017)
  05-26 11:25:21.170: E/AndroidRuntime(921):  at java.lang.reflect.Method.invokeNative(Native Method)
  05-26 11:25:21.170: E/AndroidRuntime(921):  at java.lang.reflect.Method.invoke(Method.java:515)
  05-26 11:25:21.170: E/AndroidRuntime(921):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
  05-26 11:25:21.170: E/AndroidRuntime(921):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
  05-26 11:25:21.170: E/AndroidRuntime(921):  at dalvik.system.NativeStart.main(Native Method)
  05-26 11:25:21.170: E/AndroidRuntime(921): Caused by: java.lang.NullPointerException
  05-26 11:25:21.170: E/AndroidRuntime(921):  at com.example.androidcellinfo.CellInfo.&lt;init&gt;(CellInfo.java:74)
  05-26 11:25:21.170: E/AndroidRuntime(921):  at com.example.androidcellinfo.MainActivity.onCreate(MainActivity.java:28)
  05-26 11:25:21.170: E/AndroidRuntime(921):  at android.app.Activity.performCreate(Activity.java:5231)
  05-26 11:25:21.170: E/AndroidRuntime(921):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
  05-26 11:25:21.170: E/AndroidRuntime(921):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2159)
  05-26 11:25:21.170: E/AndroidRuntime(921):  ... 11 more
  05-26 11:25:25.090: I/Process(921): Sending signal. PID: 921 SIG: 9
  </code></pre>
  
  <p>Here is the code for line 74 (CellInfo)
  <img src="https://i.stack.imgur.com/xueSu.png" alt="Code Snippet 1"></p>
  
  <p>Here is the code for line 28 (MainActivity)
  <img src="https://i.stack.imgur.com/v7fRx.png" alt="Code Snippet 2"></p>