In Sound View Innovations, Inc., v. Hulu, LLC, [2021-1998] (May 11, 2022), the Federal Circuit, whille agreeing with the district court’s claim construction, the Federal Circuit disagreed with the district court’s application of that construction, so it vacated summary judgment of no infringement of U.S. Patent No. 6,708,213 on a “Method for Streaming Multimedia Information over Public Networks.”

Sound View alleged that, under Hulu’s direction, when an edge server receives a client request for a video not already fully in the edge server’s possession, and obtains segments of the video seriatim from the content server (or another edge server), the edge server transmits to the Hulu client a segment it has obtained while concurrently retrieving a remaining segment. The claim at issue specifies a method, involving a content server and intermediate servers (helper servers), to use when a client requests a streaming multimedia (SM) object.

The district court construed the limitation to require that the same buffer in the helper
server—host both the portion sent to the client and a remaining portion retrieved
concurrently from the content server or other helper server. With that claim construction, Hulu sought and obtained summary judgment of non-infringement, arguing that it was undisputed that, in the edge servers of its content delivery networks, no single buffer hosts both the video portion downloaded to the client and the retrieved additional portion. Sound View argued, in response, that there remained a factual dispute about whether “caches” in
the edge servers met the concurrency limitation as construed. The district court held, however, that a “cache” could not be the “buffer” that its construction of the downloading/
retrieving limitation required, and on that basis, it granted summary judgment of non-infringement.

The Federal Circuit citing theapplicant’s statements in the prosecution history, affirm the district court’s construction of the downloading/retrieving limitation, but rejected the district court’s determination that “buffer” cannot cover “a cache,” and therefore vacated the district court’s grant of summary judgment and remanded for further proceedings.

The Federal Circuit noted that all the district court did in construing “buffer” was to declare that it must exclude a “cache.” It said that the district court did not adopt an affirmative construction of what constitutes a “buffer” in the patent. Although there is no per se rule against negative constructions, which in some cases can be enough to resolve the relevant dispute, the Federal Circuit found the court’s construction was inadequate for the second step of an infringement analysis—comparison to the accused products or methods.

The Federal Circuit said that the district court did not decide, and the record does not establish, that “cache” is a term of such uniform meaning in the art that its meaning in the patent must be relevantly identical to its meaning when used by those who labeled the pertinent components of the accused edge servers. In the absence of such a uniformity-of-meaning determination, the district court’s conclusion that the patent distinguishes its buffers and caches is insufficient to support a determination that the accused-component “caches” are outside the “buffers” of the patent. The Federal Circuit said that what was needed was an affirmative construction of “buffer”— which could then be compared to the accused-component “caches” based on more than a mere name, and the district
court did not supply the needed construction.

The Federal Circuit noted an additional reason why an affirmative construction was needed: even in the patent the terms “buffer” and “cache” did not appear to be mutually exclusive,
but instead seem to have at least some overlap in their coverage.