Sending Pause and DTMF input in android

I am Intercepting outgoing call following is my code of outgoing call interception

public class InterceptCall extends BroadcastReceiver {

    @Override
    public void onReceive(Context context, Intent intent) {

        String calling_number = intent.getStringExtra(Intent.EXTRA_PHONE_NUMBER);
                setResultData("123,"+calling_number );
}
}

in android , is used for pause, but it is not working? how 开发者_如何学JAVAcan I send DTMF input or use pause, wait and symbol? I am stuck in it any help will be appreciated

Use p or w, not comma