US 5586264

Summary of U.S. Patent No. 5,586,264 (US5586264A)

Bibliographic data (confirmed via Google Patents, FreePatentsOnline, and USPTO-derived records)

Note: The assignment record on Google Patents contains an apparent OCR typo spelling inventor No. 3 as "FLACON"; the patent itself and inventor databases list him as Lorenzo Falcon, Jr. (San Jose, CA). I have interpreted the identifier literally but flagged the discrepancy.

Abstract (authoritative text)

A data storage system includes a mass storage unit storing a data entity, such as a digital representation of a video presentation, that is partitioned into a plurality N of temporally-ordered segments. A data buffer is bidirectionally coupled to the mass storage unit for storing up to M of the temporally-ordered segments, wherein M is less than N. The data buffer has an output for outputting stored ones of the temporally-ordered segments. The data storage system further includes a data buffer manager for scheduling transfers of individual ones of the temporally-ordered segments between the mass storage unit and the data buffer. The data buffer manager schedules the transfers in accordance with at least a predicted time that an individual one of the temporally-ordered segments will be required to be output from the data buffer. When employed with a media streamer (10) distributed data buffer management techniques are employed for selecting blocks to be retained in a buffer memory, either in a storage node (16, 17) or in a communication node (14). These techniques rely on the predictable nature of the video data stream, and thus are enabled to predict the future requirements for a given one of the data blocks.

Plain-language overview of the independent claim

The patent has one independent claim (claim 1). It claims a media streamer (video server) architecture with three component types:

1. At least one storage node that stores a digital video presentation. The presentation takes total time T to play and is stored as N data blocks, each block being roughly a T/N portion (i.e., a time-slice of the video). The storage node has a first data buffer holding at least one of these blocks.
2. Multiple communication nodes, each having an input port coupled through a circuit switch to the storage node's first buffer output, so blocks can be received sequentially (from the same video or different videos). Each communication node has multiple output ports (each port outputs one video presentation) and a second data buffer that holds a block just before it is output.
3. At least one control node that operates in two modes:
   • First operating condition: a single data block is transferred from the storage node's first buffer directly to output ports of two different communication nodes — i.e., one copy of the block is shared across nodes via the switch ("single copy, multiple stream").
   • Second operating condition: a block is transferred from the first buffer into one communication node's second buffer, and from there to multiple output ports of that same node — i.e., local fan-out within a single node.

In essence, claim 1 covers a distributed video server that lets many viewers share a single copy of a video block, either by broadcasting it from the storage node to multiple communication nodes through a switch, or by caching it in one communication node and feeding several of that node's output ports.

Dependent claims (overview, based on the record retrieved)

• Claim 2 — Means for keeping a block in the storage node's first buffer if it is predicted to be output from a communication node within a predetermined time.
• Claim 3 — Means for keeping a block in a communication node's second buffer if it is predicted to be output from an output port within a predetermined time.
• Claim 4 — For blocks not to be retained in the first buffer: replacement priority is based on predicted demand for the video and the block's position within the video.
• Claim 5 — Higher retention priority for blocks near the beginning of a video than near the end (first-buffer variant).
• Claim 6 — Same replacement-priority mechanism as claim 4, but for the second buffer.
• Claim 7 — Same beginning-vs-end priority rule as claim 5, but for the second buffer.
• Claim 8 — For blocks to be retained in the first buffer: replacement is responsive to the next predicted output time and the number of output ports outputting the associated video.
• Claim 9 — For blocks to be retained in the second buffer: replacement responsive to the next predicted output time and number of output ports (claim text truncated in the retrieved source).

Uncertainty: The full claims section was truncated in the sources I retrieved; I confirmed claims 1–9 verbatim (claim 9 cut off mid-sentence). Google Patents indicates the patent contains 13 claims, but I could not independently verify the exact text of any claims numbered 10–13, so I do not describe them. The sole independent claim is claim 1; all other confirmed claims depend from it.

CAFC 2026 docket / litigation check

Searches for 5586264 (and "5,586,264") against CAFC 2026 dockets, PTAB/IPR, and litigation databases returned no results. Given the patent's expiration on September 8, 2014 (status: Expired – Fee Related), active CAFC litigation in 2026 is highly unlikely. The absence of hits is consistent with that status, though it is not affirmative proof that no docket exists anywhere.

Key sources

• Google Patents: https://patents.google.com/patent/US5586264/en
• FreePatentsOnline (full claims text): https://FreePatentsOnline.com/5586264.html
• USPTO.report grant page: https://uspto.report/patent/grant/5,586,264
• EPO Global Patent Index (EP 0702491 A1, same family/abstract): http://data.epo.org/gpi/EP0702491A1