Patent ID: 7966030

Claim:
A PoC (Push-to-talk over Cellular) system comprising: a PoC portable terminal capable of a group telephone conversation substantially in the same manner as a transceiver; and a PoC server for managing a right of speaking from a user of said PoC portable terminal in a telephone conversation group, wherein said PoC portable terminal comprises: a radio part for receiving data of a common image to be displayed on PoC terminals in said telephone conversation group from said PoC server; a display part for displaying said common image data and a marker specifying a portion of said common image; an input part for receiving an input for said display of said marker; and a control part for controlling said display of said marker on said display part according to said input that is made through said input part while said user's PoC portable terminal has said right of speaking, wherein said radio part transmits data Dm for said marker to said PoC server, and wherein said PoC server transmits said data Dm of said marker to other users' PoC portable terminals if said marker is moved in the screen of said user's PoC terminal while said user's PoC terminal having said right of speaking in said telephone conversation group.