getGSMSignalStrength() Always Returns 99

Question

I know there is another question on here relating to this, but I don't think it applies to me, as I'm pretty sure I use GSM (isGSM() returns true). In any case, getCdmaDbm returns -1 for me anyway. I am using Android 4.1.1 and an HTC One X. Here is my code (most of which isn't mine):

MainActivity:

package com.example.receptionlookup;

import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.telephony.PhoneStateListener;
import android.telephony.SignalStrength;
import android.telephony.TelephonyManager;
import android.view.Menu;
import android.widget.Toast;

public class MainActivity extends Activity {

    TelephonyManager        Tel;
    MyPhoneStateListener    MyListener;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        /* Update the listener, and start it */
        MyListener   = new MyPhoneStateListener();
        Tel       = ( TelephonyManager )getSystemService(Context.TELEPHONY_SERVICE);
        Tel.listen(MyListener ,PhoneStateListener.LISTEN_SIGNAL_STRENGTHS);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }

    /* Called when the application is minimized */
    @Override
    protected void onPause()
    {
        super.onPause();
        Tel.listen(MyListener, PhoneStateListener.LISTEN_NONE);
    }

    /* Called when the application resumes */
    @Override
    protected void onResume()
    {
        super.onResume();
        Tel.listen(MyListener,PhoneStateListener.LISTEN_SIGNAL_STRENGTHS);
    }

    /* —————————– */
    /* Start the PhoneState listener */
    /* —————————– */
    private class MyPhoneStateListener extends PhoneStateListener
    {
        /* Get the Signal strength from the provider, each tiome there is an update */
        @Override
        public void onSignalStrengthsChanged(SignalStrength signalStrength)
        {
            super.onSignalStrengthsChanged(signalStrength);
            Toast.makeText(getApplicationContext(), "Go to Firstdroid!!! GSM Cinr = "
                    + String.valueOf(signalStrength.getGsmSignalStrength()), Toast.LENGTH_SHORT).show();
        }

    };/* End of private Class */

}

AndroidManifest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.receptionlookup"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="17" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name="com.example.receptionlookup.MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>
    <uses-permission android:name="android.permission.READ_PHONE_STATE" />
    <uses-permission android:name="android.permission.CHANGE_NETWORK_STATE"/>
</manifest>

Does anyone know what the problem is? If I go to Settings->About->Network, I can see the signal strength there. Isn't there some way to just read this value? I've tried several third party apps, and none of them are able to read my signal strength either. I've also tried the proprietary getGSMSignalBar() method, but I get a NoSuchMethodException.

Answer 1

As you can read in the 3GPP 127 007 8.5 the implementation of the at+csq is optional (the command which suppose to give the signal strength). Apparently HTC hide this value from 3rd party applications and they probably have another way to achieve that value for display in their own proprietary Settings application.

The fact that other applications also cannot get that information justifies my case.

This issue is tightly related to yours - thay said that HTC is one of the OEMs that does not worth the modem related developing time.

Answer 2

Try this:

Class signalStrengthClass = signalStrength.getClass();
            try {
                Method method = signalStrengthClass.getMethod(
                        "getGsmSignalBar", null);
                method.setAccessible(true);
                Integer bars = (Integer) method.invoke(signalStrength,
                        (Object[]) null);
                }
            } catch (Exception e) {
                e.printStackTrace();
            }