An object is to perform retrial processing according to the allowable volume on communication lines made available at response information receiving equipment. A broadcast unit 140, when broadcasting video and audio, includes retrial information in that broadcast, according to the allowable volume on the communication lines between the television receivers and the response information receiving equipment 150. Television receivers effect display based on the received digital data. Response information input by users is sent to the response information receiving equipment 150. The television receivers make retrial transmissions based on the received retrial information when communications could not be established with the response information receiving equipment 150. This retrial information is responsive to the allowable volume on the communication lines between the television receivers and the response information receiving equipment 150, wherefore retrial transmissions are made according to the allowable volume on the communication lines.