Patent ID: 7561869

Claim:
A mobile communication system, comprising: a sender terminal configured to input PTT (Push to Talk) voice data; a PTT server configured to receive the PTT voice data from the sender terminal and to convert the PTT voice data into VMS (Voice Mail System) formatted voice data; and a VMS server configured to receive the VMS formatted voice data from the PTT server and to transmit the VMS formatted voice data to non-PTT receiver terminals that do not support a PTT function and are not subscribed to a PTT service the sender terminal is subscribed to, wherein the PTT server is further configured to compare first numbers input at the sender terminal with second numbers of PTT receiver terminals existing in a PTT service area, and wherein for the first numbers that are different from the second numbers, which indicates the first numbers correspond to non-PTT terminals, the PTT server transmits the VMS formatted voice data and the first numbers that are different from the second numbers to the VMS server, and the VMS server transmits the VMS formatted voice data to the non-PTT terminals that correspond to the first numbers that are different from the second numbers.