สอบถามเรื่องการเขียน .xsd ในการตรวจสอบ Tag Xml ฝั่ง Server ครับ

$xml_rates='<?xml version="1.0" encoding="utf-8"?>
                  <FTSXML_FAH>
					<VERSION>1.0</VERSION>
					<USER_TOKEN>token</USER_TOKEN>
						<LOGIN_INFO>
							<SYSTEM>'.$loginparam[0].'</SYSTEM>
							<OPERATOR>'.$loginparam[1].'</OPERATOR>
							<POS>'.$loginparam[2].'</POS>
							<AGENCY>'.$loginparam[3].'</AGENCY>
							<PASSWORD>'.$loginparam[4].'</PASSWORD>
						</LOGIN_INFO>
						<SEARCH>
							<FLAGS>
								<RETURNWHEN>R</RETURNWHEN>
								<PRICEDONLY>Y</PRICEDONLY>
								<SHOWROOMS>Y</SHOWROOMS>
								<SHOWBREAK>Y</SHOWBREAK>
							</FLAGS>
							<FORWHOM>
								<FORAGENCY>'.$loginparam[5].'</FORAGENCY>
								<FORCOUNTRY />
							</FORWHOM>
							<SORT>P</SORT>
							<CURRENCY>THB</CURRENCY>
							<STAYPERIOD>
								<CHECKINDATE>'.$checkin.'</CHECKINDATE>
								<DURATION>'.$duration.'</DURATION>
							</STAYPERIOD>
							<CITY>'.$city_code.'</CITY>
							<HOTELPARAMS>
								<SERVICE>'.$service_code.'</SERVICE>
								<SUBSERVICE>---</SUBSERVICE>
							</HOTELPARAMS>
							<ROOMS>
								<ROOM>
								<QUANTITY></QUANTITY>
								<ADULT_NO>'.$nbradults.'</ADULT_NO>
								<CHILD_NO>'.$nbrchildren.'</CHILD_NO>
								</ROOM>
							</ROOMS>
						</SEARCH>
					</FTSXML_FAH>';

$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, "https://xxx.com/xml/xml.php");
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_HEADER, 0);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, "xml_rate=".urlencode($xml_rates));
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 0);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
echo $result = curl_exec($ch);

curl_close($ch);

print_r($_POST['xml_rate'])