Method and system for synchronizing content between terminals

A content synchronization method for providing a receiving terminal with content of a sending terminal in a system that includes the sending terminal, the receiving terminal and a server to provide the content to the sending terminal and the receiving terminal, comprising:

• receiving, at the server, a session request message including session information of the sending terminal from the sending terminal to request the server to provide content currently being played back by the sending terminal;
• calculating a first content playback start time point by adding a transmission delay time to a content playback start time point of the sending terminal at the time of transmitting the session information that is included in the session information, the transmission delay time including a session information delivery delay time taken by the session information to be transmitted to the receiving terminal and a content request message delivery time taken by a content request message to be transmitted from the receiving terminal to the server to request the content;
• calculating, at the receiving terminal, a second content playback start time point by adding a content delivery time taken by the content to be transmitted from the server to the first content playback start time point;
• and
• playing back, at the receiving terminal, the content at the second content playback start time point,
• wherein the session information includes identification information of the content, a content playback point at the time of transmitting the session information and session information transmission point information.

A content synchronization method for providing a receiving terminal with content of a sending terminal in a system that includes the sending terminal, the receiving terminal and a server to provide the content to the sending terminal and the receiving terminal, comprising:

• receiving, at the sending terminal, a session request message from the receiving terminal to request the sending terminal to provide content, that is currently being played back at the sending terminal, to the receiving terminal;
• transmitting, at the sending terminal, session information including identification information of the content, a content playback point at the time of transmitting the session information and session information transmission point information to the receiving terminal;
• calculating, at the server, a first content playback start time point by adding a transmission delay time to a content playback time point of the sending terminal at the time of transmitting the session information that is included in the session information, the transmission delay time including a session information delivery delay time taken by the session information to be transmitted from the sending terminal to the receiving terminal and a content request message delivery time taken by a content request message to be transmitted from the receiving terminal to the server to request the content;
• calculating, at the receiving terminal, a second content playback start time point by adding a content transmission time taken by the content to be transmitted from the server to the receiving terminal to the first content playback start time point;
• and
• playing back, at the receiving terminal, the content based on the second content playback start time point.

A content synchronization method for providing a receiving terminal with content of a sending terminal in a system that includes the sending terminal, the receiving terminal and a server to provide the content to the sending terminal and the receiving terminal, the content synchronization method comprising:

• receiving, at the receiving terminal, a session request message including session information from the sending terminal to request the sending terminal to provide content, that is currently being played back at the sending terminal, to the receiving terminal;
• transmitting, at the receiving terminal, a content request message to the server to request the content;
• calculating, at the server, a first content playback start time point of the receiving terminal by adding a transmission delay time to a content playback time point of the sending terminal at the time of transmitting the session information, the transmission delay time including a session information delivery delay time taken by the session information to be transmitted from the sending terminal to the receiving terminal and a content request message delivery time taken by a content request message to be transmitted from the receiving terminal to the server to request the content;
• calculating, at the receiving terminal, a second content playback start time point by adding a content transmission time taken by the content to be transmitted from the server to the receiving terminal to the first content playback start time point;
• and
• playing back, at the receiving terminal, the content based on the second content playback start time point,
• wherein the session information includes identification information of the content, a content playback point at the time of transmitting the session information and session information transmission point information.

A content synchronization system comprising:

• a sending terminal;
• a receiving terminal;
• and
• a server configured to provide the receiving terminal with the content of the sending terminal,
• wherein the server further comprises:
• a communication unit configured to communicate with the sending terminal and the receiving terminal and to transmit a message containing a sending time point of the message, and
• a content playback time point calculating unit configured to calculate a first content playback start time point of the receiving terminal in an effort to provide the content of the sending terminal that is synchronized with the receiving terminal, and
• wherein the content playback time point calculating unit calculates a first content playback start time point of the receiving terminal by adding a transmission delay time to a content playback time point of the sending terminal at the time of transmitting session information, the transmission delay time including a session information delivery delay time taken by the session information to be transmitted from the sending terminal to the receiving terminal and a content request message delivery time taken by a content request message to be transmitted from the receiving terminal to the server to request the content,
• wherein the receiving terminal is configured to calculate a second content playback start time point by adding a content transmission time taken by the content to be transmitted from the server to the receiving terminal to the first content playback start time point and to reproduce the content based on the second content playback start time point,
• wherein the session information includes identification information of the content, a content playback point at the time of transmitting the session information and session information transmission point information.