Sound View Innovations, LLC v. Hulu, LLC

33 F.4th 1326

SOUND VIEW INNOVATIONS, LLC, Plaintiff-Appellant

v.HULU, LLC, Defendant-Appellee

2021-1998

United States Court of Appeals, Federal Circuit.

Decided: May 11, 2022

Alan Kellman, Desmarais LLP, New York, NY, argued for plaintiff-appellant. Also represented by Frederick Ding; Peter Curtis Magic, San Francisco, CA.

Brett Johnston Williamson, O'Melveny & Myers LLP, Newport Beach, CA, argued for defendant-appellee. Also represented by Bradley M. Berg, John C. Kappos, Bo Moon, Cameron William Westin ; Patrick Nack-Lehman, Menlo Park, CA.

Before Prost, Mayer, and Taranto, Circuit Judges.

Taranto, Circuit Judge.

Sound View Innovations, LLC owns now-expired U.S. Patent No. 6,708,213, titled "Method for Streaming Multimedia Information over Public Networks." When Sound View brought the present case against Hulu, LLC, it alleged infringement of six Sound View patents, but only claim 16 of the '213 patent remains at issue. Sound View alleges that Hulu infringed claim 16 by its use of (third party) edge servers, which sit between a central Hulu content server and the video-playing devices of end-user customers (clients). Most significantly for purposes of the infringement dispute currently before us, Sound View alleges 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.

Claim 16 specifies a method, involving a content server and intermediate servers (helper servers), to use when a client requests a streaming multimedia (SM) object. One limitation requires "allocating a buffer" at a helper server "to cache" at least a portion of the SM object. The next limitation (the "downloading/retrieving limitation") requires sending that portion to a requesting client while concurrently retrieving a remaining portion of the SM object from the content server or another helper server. In the first ruling before us, the district court construed the downloading/retrieving limitation not to cover a process in which the downloading occurs from one buffer in the helper server and the (concurrent) retrieving places what is retrieved in another buffer in that server. Rather, the court construed the limitation to require that the same buffer in the helper server—the one allocated in the preceding step—host both the portion sent to the client and a remaining portion retrieved concurrently from the content server or other helper server. Sound View Innovations, LLC v. Hulu, LLC , No. LA CV17-04146, 2020 WL 10758103, at *5 (C.D. Cal. Apr. 13, 2020) ( Claim Construction Opinion ).

With that claim construction in hand, Hulu sought summary judgment of non-infringement of claim 16, 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.

Sound View Innovations, LLC v. Hulu, LLC , No. LA CV17-04146, 2020 WL 6821317, at *6 (C.D. Cal. Oct. 20, 2020) ( Summary Judgment Opinion ). A final judgment followed.

Sound View appeals. It challenges the claim construction and the summary judgment ruling. It also challenges two interlocutory rulings that excluded, under Federal Rule of Evidence 702, portions of Sound View's expert testimony on reasonable-royalty damages. Sound View Innovations, LLC v. Hulu, LLC , No. LA CV17-04146, 2019 WL 9047211, at *9–11 (C.D. Cal. Nov. 18, 2019) ( Damages Opinion I ); Order Re Defendant's Supplemental Motion to Exclude Testimony of Mr. David Yurkerwich, Sound View Innovations, LLC v. Hulu, LLC , No. LA CV17-04146 (C.D. Cal. June 18, 2020), ECF No. 840 (Damages Opinion II ).

We affirm the district court's construction of the downloading/retrieving limitation. But we reject the district court's determination that "buffer" cannot cover "a cache," and we therefore vacate the district court's grant of summary judgment and remand for further proceedings. Because the evidentiary rulings could matter on remand, we address those rulings—which we affirm.

I

A

The '213 patent describes and claims "methods which improve the caching of streaming multimedia data (e.g., audio and video data) from a content provider over a network to a client's computer." '213 patent, col. 1, lines 10– 15. The methods use "helper servers (HS) ... which operate as caching and streaming agents." Id. , col. 2, lines 64– 67. Delay in content delivery, server load, and network load can be reduced by using helper servers to respond to client requests. Id. , col. 5, lines 46–50. In described embodiments, the invention "utilizes ring buffers in the memory of the HS." Id. , col. 5, lines 55–57. When a helper server receives a request for a streaming media (SM) object, and it does not already have the object, it requests the object from, e.g. , the content server, which starts streaming it to the HS. Id. , col. 6, lines 42–46. The HS "allocates a ring buffer in memory," id. , col. 6, line 54, which "is filled with data" from, e.g. , the content server, id. , col. 6, lines 48–51. "The ring buffers represent a type of short term storage to service multiple requests for the same object which occur within a certain time range." Id. , col. 5, lines 57–60. Referring to a ring buffer 57 of Figure 5A, the patent states that "the ring buffer 57 operates as a type of short term cache which stores a portion of an SM object for a fixed time interval," and, because it is emptied out by sending data to a client and replenished with more data, "[i]t is also convenient to view the ring buffer 57 as a sliding window in the sense that portions of an SM object are initially cached in the ring buffer 57 and then deleted to store successive portions of the SM object." Id. , col. 7, lines 20– 26.

Claim 16 of the '213 patent recites:

16. A method of reducing latency in a network having a content server which hosts streaming media (SM) objects which comprise a plurality of time-ordered segments for distribution over said network through a plurality of helpers (HSs) to a plurality of clients, said method comprising:

receiving a request for an SM object from one of said plurality of clients at one of said plurality of helper servers;

allocating a buffer at one of said plurality of HSs to cache at least a portion of said requested SM object;

downloading said portion of said requested SM object to said requesting client, while concurrently retrieving a remaining portion of said requested SM object from one of another HS and said content server; and

adjusting a data transfer rate at said one of said plurality of HSs for transferring data from said one of said plurality of helper servers to said one of said plurality of clients.

Id. , col. 14, lines 31–48.

B

In June 2017, Sound View sued Hulu for infringement of claims of six patents, based on Hulu's Streaming Video on Demand products, which use the edge servers of content delivery networks, including third parties Akamai and Level 3, to deliver content to clients. J.A. 203; J.A. 221–37. As to claim 16 of the '213 patent, Sound View argued that Hulu directed or controlled the content delivery networks to allocate a local buffer at an edge server (the claimed "helper server") to cache at least a portion of a Hulu video and to download that video portion to a client while concurrently pre-fetching (i.e. , retrieving) another portion of the video.

The district court initially construed several claim terms, but the initial constructions are not disputed in this appeal. As the case proceeded, it became clear that the parties disputed the meaning of the downloading/retrieving limitation of claim 16. The district court's resolution of the dispute is on appeal to us.

Sound View argued that the limitation should be construed according to the ordinary meaning of its words, which do not include "buffer" and, more particularly, do not require that the concurrent sending out (downloading) and receiving (retrieving) involve the same buffer. Hulu argued that the concurrent-function requirement must involve the same buffer, and it relied centrally (though not solely) on the prosecution history to support that construction. During prosecution, the applicants added the entire downloading/retrieving limitation to original claim 16 to overcome a rejection over DeMoney ( U.S. Patent No. 6,438,630 ). The district court agreed with Hulu that the applicants' statements accompanying the amendment disclaimed the full scope of the downloading/retrieving limitation, and that the claim required the concurrent downloading from and filling of a single buffer. Claim Construction Opinion , 2020 WL 10758103, at *3–4. It thus construed the downloading/retrieving limitation as "downloading said portion of said requested SM object from said allocated buffer to said requesting client, while concurrently retrieving into the same buffer a remaining portion of said requested SM object from one of another HS and said content server." Id. at *5 (emphases added). Sound View subsequently sought reconsideration of that decision, but the court denied the reconsideration motion. Sound View Innovations, LLC v. Hulu, LLC , No. LA CV1704146, 2020 WL 5356698, at *5 (C.D. Cal. June 18, 2020).

Hulu eventually sought summary judgment of non-infringement, arguing that it could not infringe claim 16 because it was undisputed that the accused edge servers—the edge servers Sound View identified as the "helper...