DCT
2:19-cv-08968
Accelerated Memory Tech LLC v. Hulu LLC
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Accelerated Memory Tech, LLC (Georgia)
- Defendant: Hulu, LLC (Delaware)
- Plaintiff’s Counsel: Hill, Kertscher & Wharton, LLP
- Case Identification: 2:19-cv-08968, D. Del., 06/21/2019
- Venue Allegations: Venue is alleged to be proper in the District of Delaware because Hulu is a Delaware corporation and therefore a resident of the state.
- Core Dispute: Plaintiff alleges that Defendant’s use of Redis technology for its video streaming service infringes a patent related to efficient server response generation through the caching of intermediate state information.
- Technical Context: The technology concerns methods for improving server performance by caching the results of initial processing steps to avoid redundant computation when handling repeated requests for the same digital resource.
- Key Procedural History: The complaint alleges that Plaintiff provided Defendant with notice of the patent-in-suit via a letter dated January 24, 2019. Public records associated with the patent indicate that the patent owner, Accelerated Memory Tech, LLC, filed a terminal disclaimer on January 29, 2020, disclaiming all claims (1-8) of the patent. This disclaimer was filed after the complaint, raising a significant question about the continued viability of the infringement action.
Case Timeline
| Date | Event |
|---|---|
| 1999-05-25 | Patent Priority Date |
| 2003-01-28 | Patent Issue Date |
| 2019-01-24 | Plaintiff sends notice letter to Defendant |
| 2019-06-21 | Complaint Filing Date |
| 2020-01-29 | Plaintiff files disclaimer of all patent claims |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 6,513,062 - "Method, Apparatus, and Computer Program Product for Efficient Server Response Generation Using Intermediate State Caching"
- Patent Identification: U.S. Patent No. 6,513,062, "Method, Apparatus, and Computer Program Product for Efficient Server Response Generation Using Intermediate State Caching," issued January 28, 2003 (the “`’062` Patent”).
The Invention Explained
- Problem Addressed: The patent’s background section identifies an inefficiency in conventional web servers, which must repeatedly perform a computationally expensive "rewrite mapping process" that translates an external resource name (like a URL) to an internal file name for every single request, even for identical resources requested moments apart (Compl. ¶8; ’062 Patent, col. 1:40-58).
- The Patented Solution: The invention proposes a method to improve server efficiency by "caching intermediate states" encountered while generating a response ('062 Patent, Abstract). After a server processes a first request, it saves key information—such as the result of the external-to-internal name mapping—in a cache. For subsequent requests for the same resource, the server can retrieve this cached "intermediate state information" and bypass the redundant mapping step, thereby generating the response more quickly ('062 Patent, col. 2:20-33). The complaint references Figure 1 of the patent, which depicts a hash table architecture for storing this cached data ('062 Patent, Fig. 1; Compl. ¶9).
- Technical Importance: This caching strategy was intended to reduce server load and response times in high-traffic environments, such as serving resources associated with "Enhanced Television" where many viewers might request the same content nearly simultaneously ('062 Patent, col. 1:20-38).
Key Claims at a Glance
- The complaint asserts infringement of at least independent Claim 1 (Compl. ¶13).
- The essential elements of Claim 1 are:
- receiving a first request for a first resource;
- deriving intermediate state information used in generating a first response to said first request, said intermediate state information comprising a result of mapping an external name of the first request for the first resource to an internal name associated with the first resource;
- caching said intermediate state information;
- receiving a second request for said first resource;
- retrieving said intermediate state information; and
- generating a second response to said second request using said intermediate state information.
- The complaint does not explicitly reserve the right to assert other claims in its infringement count, but later sections refer generally to "one or more claims" ('062 Patent, Compl. ¶17).
III. The Accused Instrumentality
Product Identification
- The complaint identifies "Hulu's Redis technology," described as a "data delivery system that enables Application Availability, Acceleration and Control" (Compl. ¶11).
Functionality and Market Context
- The complaint alleges that Hulu uses Redis for caching to accelerate application delivery (Compl. ¶11). Citing an external article (Exhibit B), the complaint describes the accused functionality: when a first request for a user arrives, data is loaded from a primary database (Cassandra) into the Redis cache, and a "flag" is set for that user. For the "next time a request comes in for this user," the system checks the flag and, if it is set, serves data directly from Redis "without hitting Cassandra," which is alleged to reduce database load and improve performance (Compl. ¶13.b, ¶13.f). The complaint includes a diagram from the patent, Figure 1, which it describes as a "graphic example of such hash table" that the patented invention uses to store cached information (Compl. ¶9).
IV. Analysis of Infringement Allegations
'062 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| receiving a first request for a first resource; | The system receives a "first time a request comes for a user," which includes a request for a video provided by the server. | ¶13.b | col. 9:1-2 |
| deriving intermediate state information... comprising a result of mapping an external name... to an internal name...; | The Redis system routes a request by mapping an external name (e.g., a URL) to an internal name (e.g., the location of media content), and a "flag" for a user is alleged to be a result of this mapping. | ¶13.c | col. 9:3-8 |
| caching said intermediate state information; | Redis "creates and manages persistent data storage and caches data for future use," and the "flag is cached in memory." | ¶13.d | col. 9:9-10 |
| receiving a second request for said first resource; | The system receives a subsequent request, described as the "next time a request comes" for the same user. | ¶13.e | col. 9:11-12 |
| retrieving said intermediate state information; | The system checks if the "flag is set" to alert the system to return information for that user stored in Redis. | ¶13.f | col. 9:13-14 |
| generating a second response to said second request using said intermediate state information. | The system returns "whatever it has from Redis without hitting Cassandra" using the information stored in Redis. | ¶13.g | col. 9:15-17 |
- Identified Points of Contention:
- Scope Questions: A central dispute may concern whether the accused "flag" constitutes "intermediate state information comprising a result of mapping an external name... to an internal name." The complaint alleges the flag is a "result" of this mapping, but the defense may argue that a simple binary flag indicating that data is present in a cache is different from the claimed "result of mapping," which the patent specification describes as containing specific data like an "internalname" string ('062 Patent, col. 4:11-12).
- Technical Questions: The infringement theory relies heavily on an external article's description of Hulu's system. A key question for discovery will be what technical information the "flag" actually represents. The court will need to determine if the flag is merely a boolean indicator or if it functions as a pointer or key that contains or directly corresponds to the "internal name" of a resource as required by the claim.
V. Key Claim Terms for Construction
- The Term: "intermediate state information comprising a result of mapping an external name... to an internal name"
- Context and Importance: The entire infringement case rests on the meaning of this term. Whether Hulu's accused use of a "flag" infringes Claim 1 depends directly on whether that flag can be considered to be or to contain the specific "result of mapping" recited in the claim. Practitioners may focus on this term because it defines the core technical element that distinguishes the invention from general caching.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent's Summary section describes "intermediate state information" with illustrative, non-limiting examples, including "an internal name... a type of the first resource; the first resource; or a plurality of response header lines" ('062 Patent, col. 2:28-33). Plaintiff may argue this suggests the term is flexible and that a "flag" which functionally achieves the purpose of the mapping should be included.
- Evidence for a Narrower Interpretation: The Detailed Description and Figure 1 show a specific data structure (1450) for the intermediate state, which includes distinct variables for an "internalname" (1465), file "type" (1460), and "bodylen" (1470) ('062 Patent, col. 4:5-15). A defendant may argue this disclosure limits the "result of mapping" to a data structure that explicitly contains the internal name, not a simple flag that merely indicates that a user's data has been pre-loaded into a cache.
VI. Other Allegations
- Indirect Infringement: The complaint alleges induced infringement, stating Hulu supplies Redis with knowledge and intent to infringe and encourages infringement through the dissemination of "user manuals, articles, and other documentations" (Compl. ¶17). It also pleads contributory infringement, alleging Redis is not a staple article of commerce suitable for substantial non-infringing use (Compl. ¶18). The factual support for these allegations is stated generally.
- Willful Infringement: Willfulness is alleged based on pre-suit knowledge of the ’062 Patent. The complaint states Hulu received a letter from Plaintiff describing the patent on January 24, 2019, five months prior to the lawsuit's filing (Compl. ¶16).
VII. Analyst’s Conclusion: Key Questions for the Case
- A dispositive threshold issue will be one of mootness: Given that the plaintiff filed a disclaimer surrendering all claims of the ’062 Patent after filing the complaint, the primary question is whether any valid basis for an infringement action remains. The surrender of the underlying patent rights would typically extinguish the case.
- A core issue will be one of definitional scope: If the case were to proceed, the dispute would center on claim construction. The key question is whether the accused system's use of a "flag" to signify pre-loaded user data can be construed to meet the claim limitation of "intermediate state information comprising a result of mapping an external name... to an internal name," which the patent specification appears to define as a more complex data structure.
- A key evidentiary question will be one of technical implementation: The complaint's infringement theory is based on a high-level description from a third-party article. The case would depend on whether evidence obtained in discovery shows that Hulu's Redis system actually performs the specific mapping and caching functions as recited in the claim elements, or if its operation is technically distinct.