Method and system for notifying absence in PTT service, and portable terminal adapted thereto

A Push-To-Talk (PTT) service system comprising:

• a first portable terminal the first portable terminal comprises an absence message generating unit operable to transmit an absence notifying message to at least one of a plurality of second portable terminals;
• and
• the plurality of second portable terminals;
• and
• the second portable terminal comprises:
• an absent state setting unit operable to set subscriber information regarding the first portable terminal to an absent state if the second portable terminal has received the absence notifying message;
• and
• an absent state controlling unit operable to output an absent state indication of the first portable terminal if the user of the second portable terminal requests a connection from the first portable terminal.

A portable terminal for use in a wireless communications and for supporting a Push-To-Talk (PTT) service, the portable terminal comprising:

• a memory adapted to store subscriber information including absent state information, absence reason information, and absence time period information;
• an absence message generating unit operable to generate an absence notifying message;
• an absent state setting unit operable to set subscriber information regarding other portable terminal, which have transmitted the absence notifying message to the portable terminal, to an absent state if it receiving the absence notifying message;
• and
• an absence state controlling unit operable to output an absent state indication of subscriber information set to an absent state if a user of the portable terminal requests a connection with the other portable terminal whose subscriber information has set to the absent state.