private static LinkedList<CommMode> parseComm(String path)
			throws ParserConfigurationException, SAXException, IOException {
		// xml get root
		Document partXml = XmlReader.getDoc(path);
		Node partNod = partXml.getDocumentElement();
		Element partElem = (Element) partNod;
		// the return
		LinkedList<CommMode> ret = new LinkedList<CommMode>();
		// get comm nodes
		NodeList coms = partElem.getElementsByTagName("comm");

		for (int i = 0; i < coms.getLength(); i++) {
			// the node
			Element node = (Element) coms.item(i);
			// get comm type
			String mode = node.getElementsByTagName("comm_type").item(0)
					.getTextContent();
			// System.out.println("mode:" + mode);
			if (mode.equals(Airsched.MODE_SAMPLING)) {
				
				
				
				//SamplingComm smp = new 
			} else if (mode.equals(Airsched.MODE_QUEUEING)) {

			} else {
				System.out.println("Mode exception:" + mode);
			}
		}
		return ret;
		// return null;
	}