Southwest Airlines Co v. Intellectual Ventures II LLC

1. Case Identification

• Case #: IPR2026-00043
• Patent #: 7,721,282
• Filed: October 10, 2025
• Petitioner(s): American Airlines, Inc. and Southwest Airlines Co.
• Patent Owner(s): Intellectual Ventures II LLC
• Challenged Claims: 1-30

2. Patent Overview

• Title: Distributing an Application Environment
• Brief Description: The ’282 patent describes a system for distributing application environments to multiple compute nodes in a clustered computing system. The technology uses a branching-store file system where a common, read-only "root" image is stored on a first storage unit, and node-specific changes are stored in a "leaf" image on a second storage unit, with a "union block device" merging them to create a unique environment for each node.

3. Grounds for Unpatentability

Ground 1: Obviousness over Birse - Claims 1, 3-10, 13-16, 19-26, 29, 30 are obvious over Birse.

• Prior Art Relied Upon: Birse (Patent 7,089,300).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Birse teaches all elements of the challenged claims. Birse discloses a network computer system where clients boot from a server using a copy-on-write storage scheme. Petitioner contended that Birse’s read-only "core system volume" is the claimed "root image," its client-specific "shadow system volume" is the claimed "leaf image," and its "block device driver," which transparently redirects read/write requests to the appropriate volume, is functionally identical to the claimed "union block device" that merges the images. Birse's system, therefore, creates a dynamic application environment for each client by merging a base image with client-specific modifications, as claimed.
  • Motivation to Combine (for §103 grounds): As a single-reference ground under 35 U.S.C. §103, Petitioner asserted that Birse's teachings are so comprehensive that only minor, obvious modifications would be needed to arrive at the claimed invention. For example, Petitioner argued it would have been obvious to a person of ordinary skill in the art (POSITA) to recognize that Birse's block device driver, which interfaces between storage units and the file system to merge data, constitutes the claimed "union block device."
  • Expectation of Success: A POSITA would have had a high expectation of success because Birse’s system was designed for the same purpose: efficiently providing customized operating system environments to multiple clients over a network.

Ground 2: Obviousness over Birse and Ballew - Claims 2, 11, 12, 18, 27, and 28 are obvious over Birse in view of Ballew.

• Prior Art Relied Upon: Birse (Patent 7,089,300) and Ballew (Application # 2005/0235092).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Birse provides the core architecture for distributing application environments using root and leaf images, as detailed in Ground 1. Ballew was introduced to supply the context of high-performance computing (HPC) clusters and grid computing. Ballew explicitly discloses using clusters of servers, nodes interconnected in a grid, and dynamically allocating execution environments in an HPC system. This combination allegedly meets the limitations of dependent claims requiring the system to operate in an "HPC cluster" (claims 11, 27), a "grid computing cluster" (claims 12, 28), or for the compute node to be a "server" (claims 2, 18).
  • Motivation to Combine: A POSITA would combine Birse's efficient OS distribution method with Ballew's HPC environment to address the known challenge of deploying and managing operating systems across many nodes in a large-scale cluster. Ballew describes the need for providing unique execution environments to nodes, and Birse provides a well-defined, space-saving mechanism to do so, representing a combination of known solutions to solve a known problem.
  • Expectation of Success: The combination would yield predictable results, as both references address network-based computing environments. A POSITA would expect that applying Birse’s storage scheme to Ballew’s HPC clusters would successfully and efficiently manage node environments.

Ground 3: Obviousness over Birse and Wu - Claims 8 and 24 are obvious over Birse in view of Wu.

• Prior Art Relied Upon: Birse (Patent 7,089,300) and Wu (Patent 6,981,114).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Birse teaches the foundational system, but its "shadow volume" stores entire modified data blocks. Wu was introduced to teach a "block modification log," as required by claims 8 and 24. Wu discloses a copy-on-write snapshot system that uses a modification log to track the addresses and pre- and post-modification values of changed blocks, which is more space-efficient than storing the blocks themselves.
  • Motivation to Combine: A POSITA would combine these references to improve the storage efficiency of Birse's system. Both Birse and Wu address the management of copy-on-write data, and Wu explicitly teaches using a modification log to reduce the storage footprint of snapshots. A POSITA would be motivated to replace or supplement Birse’s shadow volume with Wu’s more efficient logging technique to conserve disk space, a well-known goal in data storage.
  • Expectation of Success: A POSITA would have a high expectation of success, as implementing a logging mechanism to track block changes in a copy-on-write system was a known technique for improving storage efficiency.

Ground 4: Obviousness over Birse and Kleinschnitz - Claims 9, 17, and 25 are obvious over Birse in view of Kleinschnitz.

• Prior Art Relied Upon: Birse (Patent 7,089,300) and Kleinschnitz (Application # 2003/0191911).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner relied on Birse for the base system and introduced Kleinschnitz to teach two specific features. First, Kleinschnitz discloses partitioning a hard disk to store user data and system data in separate partitions, which Petitioner argued meets the limitations of claims 9 and 25. Second, Kleinschnitz teaches "reconciling" an incremental snapshot image with a complete snapshot image to form a new, updated complete image, which Petitioner argued meets the "reconciling" limitation of claim 17.
  • Motivation to Combine: A POSITA would be motivated to apply Kleinschnitz's teachings to Birse for routine system administration and organization. Partitioning the root image (system data) and leaf images (user data) as taught by Kleinschnitz would be an obvious design choice for better data management. Furthermore, reconciling the leaf image into the root image is a common maintenance task in snapshot-based systems to consolidate changes and free up space, a process Kleinschnitz describes.
  • Expectation of Success: The combination would predictably result in a more organized and maintainable system. Disk partitioning and snapshot merging were well-understood techniques, and a POSITA would expect their application to Birse’s system to be straightforward and successful.

4. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 1-30 of Patent 7,721,282 as unpatentable.