Patent ID: 7024178

Claim:
A message delivery system comprising: mobile terminal devices, each configured to convey speech or communication from a place where the mobile terminal device is located by radio means, and to generate and receive a message; ground facilities, each including a radio station connected to a mobile terminal device by radio means; and a message center configured to receive the message issued from a mobile terminal device via a ground facility and transmit the received message to a specified transmission destination, the message center including retry means responsive to a failure of the transmission of the message configured to retry the transmission according to a communication state of a mobile terminal device of reception side and a term of validity of preservation of the message, wherein the retry means comprises: a transmission failure message preservation section configured to provide a message transmission which has failed with transmission information, set a priority, and store the message; a retry control section configured to control retry transmission of the message transmission which has failed; a timer configured to set an interval of the retry; a retry counter configured to count the number of times of execution of the retry; and a control section configured to control reception and transmission of the message and to manage the whole retry means, and wherein the retry means is configured to change the number of times of retry according to a communication state of a mobile terminal device of a transmission destination of the message and a term of validity of the message; the retry means is configured to shorten the retry interval when a communication failure is judged to be an occurrence of temporary error due to the communication state; the retry means is configured to execute the retry a preset number of times; the retry means is configured to change the priority of the retry to a high value when the term of validity is near at hand; and the retry a low value when the number of times of the retry has exceeded the preset number of times.