Android SmsManager fail to send

Question

I am working with this code -

   private void sendSMS(String phoneNumber, String message)
{        
    String SENT = "SMS_SENT";
    String DELIVERED = "SMS_DELIVERED";

    PendingIntent sentPI = PendingIntent.getBroadcast(this, 0,
        new Intent(SENT), 0);

    PendingIntent deliveredPI = PendingIntent.getBroadcast(this, 0,
        new Intent(DELIVERED), 0);

    //---when the SMS has been sent---
    registerReceiver(new BroadcastReceiver(){
        @Override
        public void onReceive(Context context, Intent arg1) {
            switch (getResultCode())
            {
                case Activity.RESULT_OK:
                    Toast.makeText(context, "SMS sent", 
                            Toast.LENGTH_SHORT).show();
                    break;
                case SmsManager.RESULT_ERROR_GENERIC_FAILURE:
                    Toast.makeText(context, "Generic failure", 
                            Toast.LENGTH_SHORT).show();
                    break;
                case SmsManager.RESULT_ERROR_NO_SERVICE:
                    Toast.makeText(context, "No service", 
                            Toast.LENGTH_SHORT).show();
                    break;
                case SmsManager.RESULT_ERROR_NULL_PDU:
                    Toast.makeText(context, "Null PDU", 
                            Toast.LENGTH_SHORT).show();
                    break;
                case SmsManager.RESULT_ERROR_RADIO_OFF:
                    Toast.makeText(context, "Radio off", 
                            Toast.LENGTH_SHORT).show();
                    break;
            }
        }
    }, new IntentFilter(SENT));

    //---when the SMS has been delivered---
    registerReceiver(new BroadcastReceiver(){
        @Override
        public void onReceive(Context context, Intent arg1) {
            switch (getResultCode())
            {
                case Activity.RESULT_OK:
                    Toast.makeText(context, "SMS delivered", 
                            Toast.LENGTH_SHORT).show();
                    break;
                case Activity.RESULT_CANCELED:
                    Toast.makeText(context, "SMS not delivered", 
                            Toast.LENGTH_SHORT).show();
                    break;                        
            }
        }
    }, new IntentFilter(DELIVERED));        

    SmsManager sms = SmsManager.getDefault();
    sms.sendTextMessage(phoneNumber, null, message, sentPI, deliveredPI);  
}

and can successfully send sms , such as "Hi", "Good", "23782454" . But I got generic error on more lenght sms. not much, only 13/14 char including sms can't go out via this code.

Please check my error - Please kindly help me to my problem. I added all those permissions in manifest well.

  <uses-permission android:name="android.permission.RECEIVE_SMS" />
  <uses-permission android:name="android.permission.READ_SMS" />
  <uses-permission android:name="android.permission.SEND_SMS" />

  <uses-sdk
    android:minSdkVersion="8"
    android:targetSdkVersion="21" />

Android version 5.0.2 . Thank you for interesting my problem.