Ericsson Inc v. XR Communications LLC

1. Case Identification

• Case #: IPR2024-00613
• Patent #: 10,715,235
• Filed: March 6, 2024
• Petitioner(s): Ericsson Inc., Nokia of America Corporation
• Patent Owner(s): XR Communications LLC
• Challenged Claims: 1-5, 8-12, 15-19

2. Patent Overview

• Title: Directed Wireless Communication
• Brief Description: The ’235 patent relates to a wireless communication system that uses a receiver with multiple antenna elements. The system is configured to simultaneously receive signal transmissions, determine different signal information from those transmissions, and calculate a set of weighting values used to construct subsequent beam-formed signals.

3. Grounds for Unpatentability

Ground 1: Obviousness over Agee and Butler - Claims 1-5, 8-12, and 15-19 are obvious over Agee alone or in combination with Butler.

• Prior Art Relied Upon: Agee (Patent 7,248,841) and Butler (Patent 3,255,450).
• Core Argument for this Ground:
  • Petitioner asserted that the core inventive concept of the ’235 patent hinges on "simultaneously" receiving signals and determining "different signal informations" to calculate beam-forming weights. During prosecution, the Patent Owner allegedly relied on the inherent operation of a "Butler matrix" to provide support for these limitations. Petitioner argued that the primary reference, Agee, discloses the exact same technical approach by teaching a "Butler Mode Form"—a component a person of ordinary skill in the art (POSITA) would recognize as a Butler matrix—used with an antenna array to calculate adaptive weights for beam-formed transmissions. The secondary reference, Butler, which invented the component, was cited to explain the foundational, well-known principles of Butler matrix operation that a POSITA would use to understand Agee’s disclosure.
  • Prior Art Mapping: Petitioner contended that Agee teaches the key limitations of independent claims 1, 8, and 15. For claim 1, Agee’s system comprises a receiver with a multi-element antenna array. The limitation of simultaneously receiving a first and second signal transmission is met by Agee in at least three ways: its use of a Butler matrix, which inherently operates on signals received simultaneously across multiple antenna elements; its use of a Time Division Duplex (TDD) system that requires simultaneous signal reception in defined time slots; and its use of Orthogonal Frequency-Division Multiplexing (OFDM), which involves simultaneously receiving multiple different signal tones. The limitation of determining different signal information is met because Agee’s Butler matrix measures different signal strengths and phases at each spatially separated antenna element, even for the same signal wave. These different measurements constitute "different signal informations." Finally, Agee’s "Multilink Weight Adaptation Algorithm" determines a set of "combiner weights" based on this received signal information, and those weights are then used to construct and transmit beam-formed signals, thereby satisfying the remaining limitations of the independent claims.
  • Motivation to Combine: A POSITA would combine Butler with Agee because Agee expressly references "Butler" technology in its "Butler Mode Form." To fully understand the implementation and operation of this component within Agee's system, a POSITA would naturally refer to the foundational Butler patent, which describes the component's well-established functionality.
  • Expectation of Success: A POSITA would have a high expectation of success because Agee uses the Butler matrix technology for its conventional and intended purpose of beamforming in a wireless communication system. The combination would involve applying known principles to a known system to achieve a predictable result.

4. Key Technical Contentions (Beyond Claim Construction)

• A central technical contention was that the fundamental physics and electrical engineering principles governing a Butler matrix inherently satisfy the key disputed claim limitations. Petitioner argued that when a signal wave propagates across a multi-element antenna array connected to a Butler matrix, each antenna element simultaneously samples the wave at a different phase due to its unique physical location. This necessarily results in different instantaneous amplitude measurements ("different signal informations") at each antenna. The Butler matrix circuitry is specifically designed to process these simultaneous, distinct measurements to form directional receive beams, making the limitations of "simultaneously receiving" and "different signal informations" an intrinsic property of the disclosed prior art structure.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial would be inappropriate.
  • Regarding 35 U.S.C. §325(d), Petitioner asserted that the primary references, Agee and Butler, present arguments and disclosures that were never considered by the examiner or the Board in any prior proceeding.
  • Regarding discretionary denial under 35 U.S.C. §314(a) and the Fintiv factors, Petitioner contended that the petition is particularly strong on the merits, directly addressing the element that provided patentability during prosecution. Petitioner further noted that the related district court litigation is in its early stages, with minimal investment of resources. Crucially, Petitioners stipulated that they would not pursue invalidity in the district court using the specific combination of prior art references and arguments raised in the IPR, thus mitigating concerns of duplicative efforts and promoting efficiency.

6. Relief Requested

• Petitioner requests institution of an inter partes review (IPR) and cancellation of claims 1-5, 8-12, and 15-19 of the ’235 patent as unpatentable.