Patent ID: 8880098

Claim:
A communication server, comprising: a communication interface unit configured to connect to a network; a first storage unit configured to store terminal list information containing a terminal identifier for identifying a terminal and a position identifier for identifying a position of the terminal for each terminal, wherein the terminal is connected to the network and is capable of presenting a content including at least one of audio data and image data; a session setting processing unit configured to transmit, upon receiving a first message from the terminal, an instruction to set a session for presenting the content on the terminal to one or a plurality of terminals associated with the session, wherein the first message contains user identifier for identifying a user associated with the session, user position identifier for specifying a current position of the user, and content information about the content associated with the session; a second storage unit configured to store session attribute information containing the user identifier, the user position identifier and the content information associated with the session; and a session roaming processing unit configured to select, when a second message containing the user identifier and the user position identifier of the user is received via the network while the session is maintained after the session is set, and it is then determined based on the second message that the user moved, a terminal having a position identifier corresponding to the user position identifier after the user moved based on the terminal list information, and to transmit, to a plurality of devices associated with session roaming to the selected terminal, an instruction to perform the session roaming.