Patent ID: 6173329
Filing Date: 2001-01-09
Classification: H04L,H04N

Abstract:
A distributed multimedia server device for delivering requested multimedia data to a plurality of terminals, comprising:a plurality of storage server modules for distributedly storing fixed length multimedia blocks dividing each multimedia data, and reading out multimedia blocks in response to multimedia block read requests;a plurality of communication server modules, each capable of receiving a multimedia data read request for one multimedia data from a terminal through a connection set up with respect to the terminal, issuing the multimedia block read requests to the storage server modules so that the storage server modules read out multimedia blocks corresponding to said one multimedia data, and periodically delivering the multimedia blocks read out and transferred by the storage server modules to the terminal through the connection using a delivery period corresponding to a playback time of one multimedia block; andan inter-server module network for supporting communications between any of the storage server modules and of the communication server modules;wherein each multimedia data is divided into fixed length segments, and segments are stored over the storage server modules in a cyclic order;said device is configured so that segment read requests are issued sequentially from one communication server module to the storage server modules in said cyclic order, in response to a request for one multimedia data of one program from a terminal, said sequential issuance being timed to prevent interruption in a program playback at the terminal upon delivering segments read out by the storage server modules;said device is further configured such that segments for said one multimedia data are read out at the storage server modules in response to the segment read requests from said one communication server module without establishing synchronization among the storage server modules, and segments read out by the storage server modules are delivered from said one communication server module to the terminal; andeach said storage server module includes a plurality of storage devices in which segments are stored cyclically, and each said storage server module reads out segments stored in the storage devices cyclically in response to a segment read request from said one communication server module, by using an idle time-slot selected from a time-slot sequence formed by a prescribed number of time-slots arranged at uniform intervals, in a plurality of time-slot sequences with mutually displaced phases which are provided in correspondence to said plurality of storage devices, independently from other storage server modules.