PURPOSE: To apply only up-to-date information to the network by selecting one or several destinations of a user relating destination list and limiting a transmission number of the user state message able to be sent for a predetermined optional period.

CONSTITUTION: A broadcast registration processing S1 receives a user state change report and writes a new user state to a database and registers the user to a broadcast registration table. The broadcast registration table T2 is provided with a list of each object user making broadcast processing. The broadcast execution processing S3 processes an entry registered in the broadcast registration table and reports the user state change to each relating destination of each entry user to be processed.