How to get android signal strength

Question

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:

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();

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.

Any help would be greatly appreciated.

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.

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.<init>(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

Here is the code for line 74 (CellInfo)

Here is the code for line 28 (MainActivity)

Answer 1

Duplicate question?
How to get cell service signal strength in Android?
Android: How do I get GSM signal strength for all available network operators
Retrieve GSM signal strength in Android

---

Anyway, check those links above or these references:

http://developer.android.com/reference/android/telephony/SignalStrength.html

http://www.firstdroid.com/2010/05/12/get-provider-gsm-signal-strength/

---

If you are lazy to check that, this seems to work (didn't check it):

PhoneStateListener phoneStateListener = new PhoneStateListener() {
    public void onCallForwardingIndicatorChanged(boolean cfi) {}
    public void onCallStateChanged(int state, String incomingNumber) {}
    public void onCellLocationChanged(CellLocation location) {}
    public void onDataActivity(int direction) {}
    public void onDataConnectionStateChanged(int state) {}
    public void onMessageWaitingIndicatorChanged(boolean mwi) {}
    public void onServiceStateChanged(ServiceState serviceState) {}
    //Deprecated
    //public void onSignalStrengthChanged(int asu) 
    public void onSignalStrengthChanged (SignalStrength signalStrength)
    {
         //Do your thing
    }
};

Once you’ve created your own PhoneStateListener, register it with the Telephony Manager using a bitmask to indicate the events you want to listen for, as shown in the following code snippet:

telephonyManager.listen(phoneStateListener,
                        PhoneStateListener.LISTEN_CALL_FORWARDING_INDICATOR |
                        PhoneStateListener.LISTEN_CALL_STATE |
                        PhoneStateListener.LISTEN_CELL_LOCATION |
                        PhoneStateListener.LISTEN_DATA_ACTIVITY |
                        PhoneStateListener.LISTEN_DATA_CONNECTION_STATE |
                        PhoneStateListener.LISTEN_MESSAGE_WAITING_INDICATOR |
                        PhoneStateListener.LISTEN_SERVICE_STATE |
                        PhoneStateListener.LISTEN_SIGNAL_STRENGTH);

How to get a list of all available networks:

Android: How do I get GSM signal strength for all available network operators