Problem calling a Web Service (PHP and NUSOAP) from Android (java) client

require_once('lib/nusoap.php');
// Create the server instance
$server = new soap_server();
// Initialize WSDL support
$server->configureWSDL('hellowsdl', 'urn:hellowsdl');
// Register the method to expose
$server->register('hello',                // method name
    array('name' => 'xsd:string'),        // input parameters
    array('return' => 'xsd:string'),      // output parameters
    'urn:hellowsdl',                      // namespace
    'urn:hellowsdl#hello',                // soapaction
    'rpc',                                // style
    'encoded',                            // use
    'Says hello to the caller'            // documentation
);

function hello($name) {
        return 'Hello, ' . $name;
}

$HTTP_RAW_POST_DATA = isset($HTTP_RAW_POST_DATA) ? $HTTP_RAW_POST_DATA : '';
$server->service($HTTP_RAW_POST_DATA);

private static final String SOAP_ACTION = "urn:hellowsdl#hello";
	private static final String METHOD_NAME = "hello";
	private static final String NAMESPACE = "urn:hellowsdl";
	private static final String URL = "http://127.0.0.1/www/webs.php";


	@Override
	public void onCreate(Bundle icicle)
	{
		super.onCreate(icicle);
		TextView tv = new TextView(this);
		setContentView(tv);


		SoapObject request = new SoapObject(NAMESPACE, METHOD_NAME);


		//SoapObject 
		request.addProperty("name", "name");


		SoapSerializationEnvelope envelope = new SoapSerializationEnvelope(SoapEnvelope.VER11);
		envelope.setOutputSoapObject(request);

		HttpTransportSE httpTransport = new HttpTransportSE(URL);

		try
		{
			httpTransport.call(SOAP_ACTION, envelope);
			Object response = envelope.getResponse();
			tv.setText(response.toString());
		}

		catch (Exception exception)
		{
			tv.setText(exception.toString());
		}

	}