try {
        /* Create the Soap Client */
        $client = new ExactTargetSoapClient($wsdl, array('trace'=>1));

        /* Set username and password here */
        $client->username = 'userName';
        $client->password = 'Password';

        $tsd = new ExactTarget_SMSTriggeredSendDefinition();

        $tsd->Name = "ABCDE";
        $tsd->CustomerKey = "xxxxx"; // set external key/unique identifier for the triggered send definition
        $tsd->SendToList = false;
        $tsd->SendToListSpecified = false;
$ts = new ExactTarget_SMSTriggeredSend();

        $ts->SMSTriggeredSendDefinition = new SoapVar($tsd, SOAP_ENC_OBJECT, 'SMSTriggeredSendDefinition', "http://exacttarget.com/wsdl/partnerAPI");
        $subscriber = new ExactTarget_Subscriber();
        $subscriber->SubscriberKey = "validEmail";
        $ts->Number="90909090909";
        $ts->Message="Hello from me";

// create SoapVar object
        $object = new SoapVar($ts, SOAP_ENC_OBJECT, 'SMSTriggeredSend', "http://exacttarget.com/wsdl/partnerAPI");

        // create request object
        $request = new ExactTarget_CreateRequest();
        $request->Options = NULL;
        $request->Objects = array($object);

        // Create the triggered send definition
        $results = $client->Create($request);

["StatusCode"]=>
    string(5) "Error"
    ["StatusMessage"]=>
    string(39) "Single sends must include a subscriber."
    ["OrdinalID"]=>
    int(0)
    ["ErrorCode"]=>
    int(33100)
    ["NewID"]=>
    int(0)