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公开(公告)号:DE69720088D1
公开(公告)日:2003-04-30
申请号:DE69720088
申请日:1997-01-22
Applicant: IBM
Inventor: AGGARWAL CHARU CHANDRA , WOLF JOEL LEONARD , YU PHILIP SHI-LUNG
Abstract: A VOD scheduler maintains a queue of pending performance for each video. Using the notion of queue selection factor, a batching policy is devised that schedules the video with the highest selection factor. Selection factors are obtained by applying discriminatory weighting factors to the adjusted queue lengths associated with each video where the weight decreases as the popularity of the respective video increases and the queue length is adjusted to take defection into account.
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公开(公告)号:DE69634110D1
公开(公告)日:2005-02-03
申请号:DE69634110
申请日:1996-08-12
Applicant: IBM
Inventor: AGGARWAL CHARU CHANDRA , WOLF JOEL LEONARD , YU PHILIP SHI-LUNG
Abstract: Portions (A1-D1) of multimedia program (presentation) are repetitively broadcast to receiving stations (122) with subsequent portions (C1-D1) being broadcast less frequently than preceding portions (A1-C1). Blocks (a-f) of at least one of the portions (A1) are broadcast in varying permutations from one repetition to a next repetition. Further, each portion is of a length which is proportional to a sum of the lengths of all preceding portions. A receiver (122) is provided which selects blocks to be skipped (in a pyramid type broadcast) based on information indicative of the permutation selected by the server (100). The receiver (122) determines the number of blocks to skip before buffering the next block for the video being viewed.
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公开(公告)号:DE69503817T2
公开(公告)日:1999-04-15
申请号:DE69503817
申请日:1995-03-13
Applicant: IBM
Inventor: WOLF JOEL LEONARD , YU PHILIP SHI-LUNG
Abstract: A system and method of supporting pause-resume in a video-on-demand service of a type which can accommodate multiple viewers sharing a common data stream is described. When a video server receives a performance request from one of the viewers for showing a particular video, it identifies and reserves a look-ahead stream. The look-ahead stream is another video stream which is scheduled to become available after a predetermined time period. When the video is commenced, a common data stream for the video is concurrently transmitted from the video server to reception equipment at the viewers' locations. Transmission of the common data stream causes the particular video to be performed on the viewers' reception equipment. When the video server receives a pause request and then a subsequent resume request from one of the viewers, it transmits the video via the look ahead stream instead of the common data stream.
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公开(公告)号:DE69503817D1
公开(公告)日:1998-09-10
申请号:DE69503817
申请日:1995-03-13
Applicant: IBM
Inventor: WOLF JOEL LEONARD , YU PHILIP SHI-LUNG
Abstract: A system and method of supporting pause-resume in a video-on-demand service of a type which can accommodate multiple viewers sharing a common data stream is described. When a video server receives a performance request from one of the viewers for showing a particular video, it identifies and reserves a look-ahead stream. The look-ahead stream is another video stream which is scheduled to become available after a predetermined time period. When the video is commenced, a common data stream for the video is concurrently transmitted from the video server to reception equipment at the viewers' locations. Transmission of the common data stream causes the particular video to be performed on the viewers' reception equipment. When the video server receives a pause request and then a subsequent resume request from one of the viewers, it transmits the video via the look ahead stream instead of the common data stream.
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公开(公告)号:DE69509433D1
公开(公告)日:1999-06-10
申请号:DE69509433
申请日:1995-02-15
Applicant: IBM
Inventor: SHACHNAI HADAS , WOLF JOEL LEONARD , YU PHILIP SHI-LUNG
Abstract: A video on demand computer system includes a plurality of storage media each storing a plurality of videos. The storage media are disks attached to a computer system. The computer system plays the videos on demand by reading out the videos from the disks as data steams to play selected ones of the videos for users responsive to received user performance requests. The computer system is programmed to monitor the numbers of videos being performed for each of the disks. Based on the monitoring function performed by the computer system, the computer system performs a load balancing function by transferring the performance of a video in progress from one of the disks to another disk having a copy of the video in progress. The computer system periodically performs a reassignment function to transfer videos between the disks to optimize load balancing based on the user performance requests for each of the videos. There are two phases to the load balancing performed by the computer system; a static phase and a dynamic phase. In the static phase, videos are assigned to memory and disks, and in the dynamic phase there is provided a scheme for playing videos with minimal and balanced loads on the disks. The static phase supports the dynamic phase which insures optimal real-time operation of the system. Dynamic phase load balancing is accomplished by a process of baton passing.
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公开(公告)号:DE68924013T2
公开(公告)日:1996-04-18
申请号:DE68924013
申请日:1989-06-15
Applicant: IBM
Inventor: STONE HAROLD STUART , WOLF JOEL LEONARD
Abstract: A mechanism within a disk controller that computes the number of distinct sectors referenced as a function of either real or virtual time. This so-called "footprint" function can be used by the disk controller as input for an algorithm that attempts to optimize cache performance.
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公开(公告)号:DE68924013D1
公开(公告)日:1995-10-05
申请号:DE68924013
申请日:1989-06-15
Applicant: IBM
Inventor: STONE HAROLD STUART , WOLF JOEL LEONARD
Abstract: A mechanism within a disk controller that computes the number of distinct sectors referenced as a function of either real or virtual time. This so-called "footprint" function can be used by the disk controller as input for an algorithm that attempts to optimize cache performance.
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公开(公告)号:DE69634110T2
公开(公告)日:2005-07-07
申请号:DE69634110
申请日:1996-08-12
Applicant: IBM
Inventor: AGGARWAL CHARU CHANDRA , WOLF JOEL LEONARD , YU PHILIP SHI-LUNG
Abstract: Portions (A1-D1) of multimedia program (presentation) are repetitively broadcast to receiving stations (122) with subsequent portions (C1-D1) being broadcast less frequently than preceding portions (A1-C1). Blocks (a-f) of at least one of the portions (A1) are broadcast in varying permutations from one repetition to a next repetition. Further, each portion is of a length which is proportional to a sum of the lengths of all preceding portions. A receiver (122) is provided which selects blocks to be skipped (in a pyramid type broadcast) based on information indicative of the permutation selected by the server (100). The receiver (122) determines the number of blocks to skip before buffering the next block for the video being viewed.
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公开(公告)号:DE69720088T2
公开(公告)日:2004-02-26
申请号:DE69720088
申请日:1997-01-22
Applicant: IBM
Inventor: AGGARWAL CHARU CHANDRA , WOLF JOEL LEONARD , YU PHILIP SHI-LUNG
Abstract: A VOD scheduler maintains a queue of pending performance for each video. Using the notion of queue selection factor, a batching policy is devised that schedules the video with the highest selection factor. Selection factors are obtained by applying discriminatory weighting factors to the adjusted queue lengths associated with each video where the weight decreases as the popularity of the respective video increases and the queue length is adjusted to take defection into account.
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公开(公告)号:DE69509433T2
公开(公告)日:1999-12-16
申请号:DE69509433
申请日:1995-02-15
Applicant: IBM
Inventor: SHACHNAI HADAS , WOLF JOEL LEONARD , YU PHILIP SHI-LUNG
Abstract: A video on demand computer system includes a plurality of storage media each storing a plurality of videos. The storage media are disks attached to a computer system. The computer system plays the videos on demand by reading out the videos from the disks as data steams to play selected ones of the videos for users responsive to received user performance requests. The computer system is programmed to monitor the numbers of videos being performed for each of the disks. Based on the monitoring function performed by the computer system, the computer system performs a load balancing function by transferring the performance of a video in progress from one of the disks to another disk having a copy of the video in progress. The computer system periodically performs a reassignment function to transfer videos between the disks to optimize load balancing based on the user performance requests for each of the videos. There are two phases to the load balancing performed by the computer system; a static phase and a dynamic phase. In the static phase, videos are assigned to memory and disks, and in the dynamic phase there is provided a scheme for playing videos with minimal and balanced loads on the disks. The static phase supports the dynamic phase which insures optimal real-time operation of the system. Dynamic phase load balancing is accomplished by a process of baton passing.
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