Video on demand network, including a central video server and distributed video servers with random access read/write memories
First Claim
1. Video on demand network for transmitting video signals to user stations and including at least one central video server for storing a first plurality of video signals, and a plurality of distributed video servers each for storing a second plurality of video signals and for transmitting video signals of said second plurality to said user stations in response to control signals provided by said user stations, said central server for transmitting video signals of said first plurality to said distributed video servers in order to adapt said second pluralities based on said control signals, wherein said distributed video servers include random access read/write memories for storing said second pluralities as pluralities of data packets, wherein predetermined ones of said data packets include timing information relating to required packet transmission rates of video signals of which they form a part, wherein said data packets are retrieved from said random access memories independent from said required transmission rates, and wherein said distributed servers also include pace control means for queuing said data packets under control of said timing information in order to transmit said video signals at said required packet transmission rates.
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Accused Products
Abstract
A video on demand network (VODN), transmits video signals (VS) to user stations (US11, . . . , US2N) pursuant to the receipt of control signals (CS) issued by these user stations. In order to optimize the retrieval costs, this video on demand network maintains a large video library in a central video server (CS) and stores locally popular video signals in a plurality of local distributed video servers (DS1/2) from which the latter video signals are transmitted to the user stations. The video signals provided by the local distributed servers are updated from the central server based upon the changing popularity of the video signals. The present invention proposes in particular to store the video signals in the local distributed servers in random access read/write memories (HDA), e.g., electronic RAMs, magnetic or optical disks, and/or the like, from which the video signals can flexibly be supplied on-line to the user stations and to store the video signals in the central server in sequential access memories, e.g. Digital Audio Tapes (DAT) and CD-ROMs (CDR), providing cheap mass storage.
564 Citations
13 Claims
- 1. Video on demand network for transmitting video signals to user stations and including at least one central video server for storing a first plurality of video signals, and a plurality of distributed video servers each for storing a second plurality of video signals and for transmitting video signals of said second plurality to said user stations in response to control signals provided by said user stations, said central server for transmitting video signals of said first plurality to said distributed video servers in order to adapt said second pluralities based on said control signals, wherein said distributed video servers include random access read/write memories for storing said second pluralities as pluralities of data packets, wherein predetermined ones of said data packets include timing information relating to required packet transmission rates of video signals of which they form a part, wherein said data packets are retrieved from said random access memories independent from said required transmission rates, and wherein said distributed servers also include pace control means for queuing said data packets under control of said timing information in order to transmit said video signals at said required packet transmission rates.
- 9. Video on demand network for transmitting video signals to user stations and including at least one central video server for storing a first plurality of video signals, and a plurality of distributed video servers each for storing a second plurality of video signals and for transmitting video signals of said second plurality to said user stations in response to control signals provided by said user stations, said central server for transmitting video signals of said first plurality to said distributed video servers in order to adapt said second pluralities based on said control signals, wherein said distributed video servers include random access read/write memories for storing said second pluralities as pluralities of data packets, wherein said central server includes a number of read modules smaller than a number of off-line memories on which said first plurality of video signals is stored as a plurality of said data packets and transfer means for transferring a requested video signal of one said off-line memories to one of said read modules, and that said read modules are electronically coupled to input ports of a broadband switch having output ports coupled to said distributed servers.
Specification