| 摘要 |
PURPOSE: A synchronization method for a distribution type multimedia service in an asynchronous transfer mode network is provided to secure a packet loss rate requested by a user and be actively adapt to a change of a variable delay of a network. CONSTITUTION: A receiving side user(26) transmits a multimedia data transmission request message for a multimedia service to an expression schedule generation module(20) for a multimedia service together with a QoS parameter like a packet loss ratio. The expression schedule generation module(20) requests time-related information of the multimedia service and position information of a media server(10) from a database(25) form managing time-related information of the multimedia service requested by a user, and receives information as an OPCN type. The expression schedule generation module(20) extracts expression time information of the multimedia service from OPCN information, generates a multimedia media-based expression time schedule from expression time information of the multimedia service, and transmits the expression time schedule to the synchronous module(21). The synchronous module(21) measures a clock synchronization between a transmitting side and a receiving side and an initial delay of a network, and transmits a transmission start request message including related information for calculating a transmission start time of the transmitting side and the expression time schedule transmitted from the expression schedule generation module(20) to a media server(10) of the transmitting side. The media server(10) receives the transmission start request message, calculates the transmission start time, and waits to the transmission start time, and initializes a transmission timer(11). The transmission timer(11) transmits a main stream to a delay estimating module(22) of the receiving side when the transmission start time coincides with the expression time schedule transmitted from the receiving side.
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