LS Cloud Storage Tech LLC v. Microsoft Corp

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: LS Cloud Storage Technologies, LLC (Texas)
  • Defendant: Microsoft Corporation (Delaware)
  • Plaintiff’s Counsel: Ramey LLP
• Case Identification: LS Cloud Storage Technologies, LLC v. Microsoft Corporation, 6:22-cv-00321, W.D. Tex., 03/25/2022
• Venue Allegations: Plaintiff alleges venue is proper because Defendant has committed alleged acts of infringement in the district, maintains a regular and established place of business in the district, and conducts substantial business in the forum.
• Core Dispute: Plaintiff alleges that Defendant’s data storage products and services infringe two patents related to distributed data caching in computer networks.
• Technical Context: The technology concerns methods for building scalable data storage systems from standard computers, using a distributed cache to improve performance and manage data consistency between different types of connected hosts.
• Key Procedural History: The complaint states that Plaintiff owns the patents-in-suit by assignment. It explicitly reserves the right to amend its complaint to assert claims for indirect and willful infringement pending discovery into Defendant's knowledge of the patents.

Case Timeline

Date	Event
1999-01-22	Priority Date for ’092 and ’988 Patents
2003-04-15	’988 Patent Issue Date
2018-12-11	’092 Patent Issue Date
2022-03-25	Complaint Filing Date

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 10,154,092, Data Sharing Using Distributed Cache In A Network Of Heterogeneous Computers, issued Dec. 11, 2018

The Invention Explained

• Problem Addressed: The patent describes prior art data storage systems as being built with expensive, proprietary hardware and inflexible, low-level software like microcode or assembler (’092 Patent, col. 1:45-col. 2:14). These systems were costly, difficult to scale, and often required separate, dedicated architectures to handle I/O channel-attached hosts versus network-attached hosts, limiting their utility and increasing expense (’092 Patent, col. 2:50-60).
• The Patented Solution: The invention proposes a data storage system built from a network of standard, off-the-shelf personal computers (PCs) to reduce cost and increase flexibility (’092 Patent, col. 3:41-48). The system uses separate interfaces for distinct traffic types: a “dedicated I/O channel” for local hosts and a network adapter for remote hosts and other storage systems (’092 Patent, col. 3:20-25). A processor manages data access, using a cache memory to fulfill requests and a back-end connection to a persistent storage device, with the back-end communication path being distinct from the front-end I/O channel (’092 Patent, col. 9:28-33).
• Technical Importance: This architecture aimed to provide the performance of specialized storage arrays using cheaper, more adaptable commodity hardware, while concurrently supporting both direct-attached and network-attached computing environments (’092 Patent, col. 3:41-51).

Key Claims at a Glance

• The complaint asserts one or more of claims 1-24 (Compl. ¶9). Independent claim 1 is a system claim containing the following essential elements:
  • A "first interface" for receiving "input/output (I/O) traffic" from a host via a "dedicated I/O channel".
  • A "second interface" for receiving data via a "network".
  • A "cache memory".
  • A "storage device".
  • A "processor" coupled to the cache and storage device, where the communication path to the storage device is "distinct from the dedicated I/O channel".
• The complaint does not specify which dependent claims may be asserted.

U.S. Patent No. 6,549,988, Data Storage System Comprising A Network Of PCs And Method Using Same, issued Apr. 15, 2003

The Invention Explained

• Problem Addressed: The patent addresses the same problems as the ’092 patent: the high cost, inflexibility, and architectural limitations of proprietary data storage systems that rely on specialized hardware and low-level programming (’988 Patent, col. 1:35-col. 2:10).
• The Patented Solution: The invention describes a computer within a networked data storage system that separates front-end I/O and network requests from back-end disk operations (’988 Patent, col. 9:26-33). This is achieved through distinct software modules: front-end software handles incoming requests, a "configuration manager software" decides whether to service a request from cache or disk, and back-end software handles the disk I/O, thereby separating these operations from the host-facing traffic (’988 Patent, col. 9:16-33). The system uses a "volume access table" to manage data consistency across the distributed cache (’988 Patent, col. 10:4-9).
• Technical Importance: The invention provides a software architecture for creating a sophisticated, distributed storage system from commodity PCs, aiming to lower costs while providing advanced features like intelligent caching and data consistency management (’988 Patent, col. 1:40-48).

Key Claims at a Glance

• The complaint asserts one or more of claims 1-6 (Compl. ¶14). Independent claim 1 is a system claim for a computer within a storage system, containing the following key software and hardware elements:
  • An "I/O channel adapter" for I/O requests from a host.
  • "Configuration manager software" that decides how to route the request (to cache, to disk, or reject).
  • A "network adapter" for network traffic.
  • A "cache memory".
  • "Front-end software" for handling incoming requests.
  • "Cache manager software" for handling data in the cache.
  • "Back-end software" for disk I/O, which "separat[es] disk operations from network and I/O traffic".
• The complaint does not specify which dependent claims may be asserted.

III. The Accused Instrumentality

Product Identification

The complaint does not identify any specific accused product or service by name. It refers generally to "data storage products and services" that Defendant "maintained, operated, and administered" (Compl. ¶9, ¶14).

Functionality and Market Context

The complaint alleges that Defendant's unspecified products and services perform infringing methods or processes and were put into service by Defendant (Compl. ¶3, ¶9, ¶14). The complaint does not provide any technical description of the accused instrumentalities' functionality or allegations regarding their market position beyond the general assertion of infringement. Support for the allegations is said to be in Exhibits A and B, which were not included with the complaint document (Compl. ¶10, ¶15).

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint references claim chart exhibits (Exhibits A and B) that were not provided with the filed document (Compl. ¶10, ¶15). Therefore, a claim chart summary cannot be constructed. The infringement allegations are presented in a conclusory manner, stating that Defendant’s "data storage products and services" infringe the asserted claims (Compl. ¶9, ¶14).

• Identified Points of Contention:
  • Evidentiary Questions: The primary question will be what evidence Plaintiff can produce to map the elements of the asserted claims onto Defendant’s modern, highly-distributed cloud storage architectures. The complaint's lack of specificity suggests that identifying the precise components corresponding to claimed elements like the "front-end software" or "configuration manager software" may be a central point of dispute.
  • Scope Questions (’092 Patent): A potential dispute may arise over the term "dedicated I/O channel". The patent contrasts this with general-purpose "network links" and provides SCSI as an example (’092 Patent, col. 5:36-39). The litigation may turn on whether this term can be interpreted to cover the software-defined, virtualized network interfaces used in modern cloud computing, or if its meaning is limited to the physically distinct hardware channels of the era in which it was drafted.
  • Technical Questions (’988 Patent): A key technical question will be whether the accused systems practice the specific architectural separation required by claim 1, which calls for "back-end software" that handles disk I/O while "separating disk operations from network and I/O traffic" (’988 Patent, col. 9:31-33). The analysis will question whether the integrated, multi-layered software stacks of modern storage systems perform this function in the manner claimed.

V. Key Claim Terms for Construction

For the ’092 Patent

• The Term: "dedicated I/O channel" (Claim 1)
• Context and Importance: This term is critical because it defines the primary interface for host communication and is structurally distinguished from the general "network" interface. The patent’s infringement theory rests on the accused system having this specific type of interface. Practitioners may focus on this term to determine if it is limited to legacy hardware interfaces or can encompass modern virtualized interconnects.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The term is not explicitly defined, which may support an argument for a broader meaning covering any channel primarily used for I/O traffic, as opposed to general-purpose networking.
  • Evidence for a Narrower Interpretation: The specification repeatedly contrasts "I/O channels" with "network links" (’092 Patent, col. 1:19-24). It explicitly provides "SCSI channels for I/O traffic and Ethernet link for network traffic" as an embodiment, suggesting the term refers to a specific class of hardware technology distinct from standard TCP/IP networking (’092 Patent, col. 5:36-39).

For the ’988 Patent

• The Term: "configuration manager software" (Claim 1)
• Context and Importance: This software is the decision-making core of the claimed invention, responsible for routing requests to cache or disk. An infringement finding will require Plaintiff to identify a corresponding component with this specific functionality in the accused systems. Its construction will determine the necessary level of intelligence and type of decision-making required to meet the limitation.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The claim language describes the manager's function broadly as deciding whether to route a request to cache, disk, or reject it (’988 Patent, col. 9:17-20). This could arguably cover a wide range of caching and load-balancing algorithms.
  • Evidence for a Narrower Interpretation: The specification links the configuration manager's operation to a "volume access table" that dictates behavior based on an "access mode" (e.g., exclusive, shared) (’988 Patent, col. 10:4-18). This suggests the "configuration manager software" may be construed more narrowly to require a system that uses such a table-driven, mode-based logic for routing requests.

VI. Other Allegations

• Indirect Infringement: The complaint does not currently allege indirect infringement. However, footnotes in the complaint state that "Plaintiff reserves the right to amend to assert claims for indirect... infringement if discovery reveals an earlier date of Defendants' knowledge of the patents" (Compl. p. 3, fn. 1; p. 4, fn. 2).
• Willful Infringement: The complaint does not allege willful infringement but similarly reserves the right to amend its pleading to add such a claim based on facts revealed in discovery (Compl. p. 3, fn. 1; p. 4, fn. 2).

VII. Analyst’s Conclusion: Key Questions for the Case

1. A core issue will be one of definitional scope: Can terms rooted in the late-1990s hardware paradigm, such as "dedicated I/O channel" and "I/O channel adapter", be construed to read on the highly virtualized, software-defined infrastructure of modern cloud data storage products and services?
2. A key evidentiary question will be one of architectural mapping: Given the complaint's lack of specificity, the case will depend on whether Plaintiff can produce evidence identifying discrete components within Defendant's complex systems that perform the specific functions of the claimed "configuration manager software" and demonstrate the architectural separation of "back-end" disk operations from "front-end" I/O traffic as required by the patents.