According to the invention, a broadcast receiver receives a packetized stream. The broadcast receiver extracts display time information from a header of the packetized stream, and extracts trigger information including a target object identifier from a payload of the packetized stream. The broadcast receiver recognizes the type of the trigger information. If the trigger information is of the preparation trigger type, the broadcast receiver acquires information on the location of the file which belongs to the target object identifier. The broadcast receiver downloads the file which belongs to the target object identifier from the time corresponding to the extracted display time information via said acquired information on the location of the file.