PTAB

IPR2014-00963

Ericsson Inc v. Intellectual Ventures I LLC

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1. Case Identification

2. Patent Overview

  • Title: Method of Baseband Frequency Hopping
  • Brief Description: The ’408 patent describes a method for frequency hopping in a cellular communication system using a basestation with a broadband transceiver. The method involves switching communications between different physical radio frequency (RF) channels while maintaining the same logical channel for a mobile subscriber.

3. Grounds for Unpatentability

Ground 1: Claims 1-16 are anticipated by the ’480 Patent under 35 U.S.C. §102.

  • Prior Art Relied Upon: ’480 patent (Patent 5,592,480).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the ’480 patent, which was assigned to the same original applicant as the challenged ’408 patent, discloses every limitation of claims 1-16. The ’480 patent describes a wideband digital basestation and explicitly states that it can be used with various wireless standards, including "frequency hopping standards such as the European Groupe Speciale Mobile (GSM)." Petitioner contended that this express reference to the GSM standard would inform a Person of Ordinary Skill in the Art (POSA) that the basestation was capable of performing the fundamental GSM function of changing physical RF channels while maintaining a consistent logical channel, thereby anticipating the method claimed in the ’408 patent. The hardware disclosures, such as the digital channelizer and TDM bus, were also alleged to be disclosed.
    • Key Aspects: This argument hinges on the assertion that a reference to a well-known standard like GSM inherently discloses the fundamental and mandatory operational characteristics of that standard, making a separate, explicit description of the frequency hopping process unnecessary for anticipation.

Ground 2: Claims 1-16 are obvious over the ’480 patent in view of the ’435 patent and GSM 05.02.

  • Prior Art Relied Upon: ’480 patent (Patent 5,592,480), ’435 patent (Patent 5,537,435), and GSM 05.02 (a technical standard).
  • Core Argument for this Ground:
    • Prior Art Mapping: As an alternative to Ground 1, Petitioner argued this combination renders the claims obvious. The ’480 patent provides the foundational broadband basestation architecture. The ’435 patent, another reference from the same original applicant, provides more specific details about implementing the digital channelizer and combiner using Fast-Fourier-transform (FFT) based components. The GSM 05.02 standard explicitly details the frequency hopping algorithm, including methods for generating initial and subsequent hopping sequences and mapping logical channels to physical channels.
    • Motivation to Combine: A POSITA would combine these references because they have overlapping authorship (Airnet) and are directed to the identical technical field of wideband basestations. Both patents expressly reference compatibility with GSM frequency hopping standards, which would directly lead a POSA to the GSM 05.02 standard for specific implementation details. The combination amounted to implementing a known communication protocol (GSM 05.02) on a compatible hardware platform disclosed by the ’480 and ’435 patents.
    • Expectation of Success: A POSITA would have a high expectation of success, as combining the references involved applying a well-documented public standard to a system expressly designed to support it.

Ground 3: Claims 1-16 are obvious over the ’602 patent in view of the ’713 patent and Steele.

  • Prior Art Relied Upon: ’602 patent (Patent 5,428,602), ’713 patent (Patent 5,430,713), and Steele (a 1992 publication titled "Mobile Radio Communications").
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued this combination teaches all elements of the claimed invention. The ’602 patent discloses a GSM-compliant basestation that achieves frequency hopping by switching baseband signals between multiple fixed-frequency transceivers. The ’713 patent teaches a specialized circuit for frequency hopping in a TDMA system, including a dedicated "hopping processor" coupled to a dual-port RAM, which provides the memory and control structure for managing hopping sequences. For claim 11, which recites a GPS receiver, Steele discloses using a GPS signal for timing and synchronization purposes in mobile radio communications.
    • Motivation to Combine: A POSITA would combine the ’602 and ’713 patents because both are directed to implementing GSM-compliant frequency hopping. This combination represents the predictable application of a known processing circuit (’713 patent) to a known system (’602 patent) to achieve the desired functionality. Adding GPS for synchronization as taught by Steele was a well-known technique for improving timing accuracy and represented a simple substitution of one known element for another to obtain predictable results.
  • Additional Grounds: Petitioner asserted additional challenges, including that claims 1-4 are anticipated by the ’729 patent (Patent 6,788,729), and that claims 1-16 are obvious over a combination including the ’480 patent, the ’713 patent, GSM standards, and a publication by Komara.

4. Key Claim Construction Positions

  • "Broadband Transceiver": Petitioner proposed this term be construed as "a transceiver that covers a substantial portion of the bandwidth available to the wireless service provider who is operating the basestation." This construction was based on interchangeable use of "broadband" and "wideband" in the specification.
  • "Basestation": Petitioner proposed this term be construed as "in a wireless communications system, any fixed station that communicates with mobile stations." Critically, Petitioner argued that this term should not be limited to include specific components described in the ’408 patent’s specification (e.g., a digital channelizer, digital combiner, and channel allocator), as these components are not recited in the claim itself. This broader construction was central to Petitioner's argument that the prior art met the claim limitations.

5. Key Technical Contentions (Beyond Claim Construction)

  • Effective Priority Date: A central contention of the petition was that the ’408 patent is not entitled to its claimed October 15, 1998 provisional filing date. Petitioner argued the patent’s effective priority date is its non-provisional filing date of February 20, 2001, due to multiple alleged defects in the priority claim chain, including failure to properly reference the relationship to a prior application and lack of written description support in the priority documents. This later priority date was critical for establishing that certain references, like the ’729 patent, qualify as prior art.

6. Relief Requested

  • Petitioner requested institution of an inter partes review and cancellation of claims 1-16 of Patent 6,952,408 as unpatentable.