Communication system and communication method sharing communication data among a plurality of communication terminals

A communication system in which a plurality of communication terminals, which are connected to a network including a Public Switched Network in a category thereof, mutually communicate through communication data addressed to a common phone number issued by a communication terminal being a management terminal, comprising:

• a phone number management unit, a message management unit and a bulletin board unit provided in said network;
• means for registering, after being accessed by an arbitrary one of said plurality of communication terminals using said issued common phone number and receiving a confirmation by said management terminal, the arbitrary one of said communication terminals in correspondence with said common phone number issued from said management terminal;
• means for sending a message file sent by accessing from a registered communication terminal to said common phone number to other registered communication terminals via the message management unit when a first mode in which the message file to be directly sent to the other communication terminals is selected, and leaving the message file in said message management unit when a second mode in which any registered communication terminal accesses to said message management unit to receive the message file is selected;
• means for leaving a message sent by accessing from a registered communication terminals to said common phone number on said bulletin board unit;
• and
• means for reading at any time the message file left in said message management unit, in a case where the message file is left in said message management unit, and the message left on said bulletin board unit, in a case where the message is left on said bulletin board unit, from an arbitrary one of the other registered communication terminals.

A communication method in which a plurality of communication terminals, which are connected to a network including a Public Switched Network in a category thereof, mutually communicate through communication data addressed to a common phone number issued by a communication terminal being a management terminal, wherein:

• said network is provided with a phone number management unit, a message management unit and a bulletin board unit, and said method comprising the steps of:
• registering a predetermined communication terminal so as to correspond to said issued common phone number by sending an identification name of the predetermined communication terminal of said plurality of communication terminals to said phone number management unit in correspondence with said common phone number issued from said management terminal;
• sending a message file sent by accessing from a registered communication terminal to said common phone number to other registered communication terminals via the message management unit when a first mode in which the message file to be directly sent to the other communication terminals is selected, and leaving the message file in said message management unit and notifying the other registered communication terminals of arrival of the message file when a second mode in which any registered communication terminal accesses to said message management unit to receive the message file is selected;
• leaving a message sent by accessing from a registered communication terminal to the common phone number on said bulletin board unit;
• and
• reading at any time the message file left in said message management unit or the message left on said bulletin board unit from an arbitrary one of the registered communication terminals.

A communication method in which a plurality of communication terminals, which are connected to a network including a Public Switched Network in a category thereof, mutually communicate through communication data addressed to a common phone number issued by a communication terminal being a management terminal, wherein:

• said network is provided with a phone number management unit, a message management unit and a bulletin board unit, and
• said method comprising the steps of:
• registering, after being accessed by an arbitrary one of said plurality of communication terminals using said issued common phone number and receiving a confirmation by said management terminal, the arbitrary one of said communication terminals in correspondence with said common phone number issued from said management terminal;
• sending a message file sent by accessing from a registered communication terminal to said common phone number to other registered communication terminals via the message management unit when a first mode in which the message file to be directly sent to the other communication terminals is selected, and leaving the message file in said message management unit when a second mode in which any registered communication terminal accesses to said message management unit to receive the message file is selected;
• leaving a message sent by accessing from a registered communication terminal to said common phone number on said bulletin board unit;
• and
• reading at any time the message file left in said message management unit, in a case where the message file is left in said message management unit and the message left on said bulletin board unit, in a case where the message is left on said bulletin board unit, from an arbitrary one of the other registered communication terminals.