Video on demand network, including a central video server and distributed video servers with random access read/write memories
US5550577A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 19, 1994 |
| Grant date | Aug 27, 1996 |
| Priority date | — |
| Expiry date | May 19, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N7/17354
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.