Communication system

摘要

Disclosed is a communication system which improves the system flexibility and serviceability by efficiently controlling presence information. A presence inquiring section makes an inquiry about a presence state of a communicating party. A presence information receiving section receives presence information. A presence information display section displays the received presence information. A presence determining section determines the presence state. A presence information generating section generates the presence information. A presence information sending section sends the presence information upon reception of the inquiry.