fileref.upload(downloadURL, fileName);

fileref.addEventListener(ProgressEvent.PROGRESS, progressHandler);

var preloaded = 0;

var pretime = getTimer();

function progressHandler(event:ProgressEvent):void {

            var file:FileReference = FileReference(event.target);

            var delta = getTimer() - pretime;

            var speed = (event.bytesLoaded - preloaded )/delta;

            var timetoupload = event.bytesTotal/speed; 

            pretime = getTimer() ;

            preloaded = event.bytesLoaded ;

           trace( "Cкорость : "+speed +"  Время загрузки "+timetoupload +" сек");

        }