PTAB

IPR2018-01689

Ericsson Inc v. Intellectual Ventures II LLC

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Methods and Apparatus for Multi-Carrier Communications with Variable Channel Bandwidth
  • Brief Description: The ’641 patent describes a multi-carrier communication system, such as one using Orthogonal Frequency Division Multiple Access (OFDMA), that transmits broadcast information within a defined portion of the frequency spectrum referred to as a "core-band." The technology focuses on managing variable bandwidth operations by defining how control and data channels are handled within this core-band.

3. Grounds for Unpatentability

Ground 1: Claims 1-4 are obvious over Li, Husted, Cheng, and McFarland

  • Prior Art Relied Upon: Li (Patent 6,904,283), Husted (Application # 2005/0100039), Cheng (Application # 2004/0233936), and McFarland (Patent 7,397,859).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the combination of references taught every element of claims 1-4. Li disclosed the foundational cellular base station operating in an OFDMA system, which partitions subcarriers into groups ("clusters") and allocates them to users to provide variable bandwidth. Husted taught the concept of a "core-band" through its disclosure of a central "master channel" used to broadcast beacons for initiating communication, a method designed to support both legacy (single-channel) and enhanced (multi-channel) devices. This master channel was argued to be centered at an operating frequency and have a fixed bandwidth, meeting key claim limitations. Cheng, which describes beacons in the context of IEEE 802.11 standards explicitly referenced by Husted, was used to show that such beacons conventionally contained "radio network information" like synchronization data and cell identifiers. Finally, McFarland was cited for its teaching of how to realize a variable band in an OFDM system by adjusting the number of usable subcarriers (e.g., by setting unused subcarriers to zero) while maintaining a fixed spacing between them.
    • Motivation to Combine: Petitioner asserted several motivations for a person of ordinary skill in the art (POSITA) to combine the references. A POSITA would combine Husted's control channel strategy (using a centered master channel) with Li's OFDMA data system to solve the known problem of supporting both legacy and new devices as wireless systems evolved to use more spectrum. Because Husted explicitly referenced IEEE 802.11 standards for its beacon generation, a POSITA would have been motivated to look to a reference like Cheng to implement the specific details of beacon content, such as periodic transmission for synchronization. Finally, a POSITA would incorporate McFarland's efficient technique for adjusting the number of subcarriers to implement the variable bandwidth systems of Li and Husted, as it represented a known method for reducing system complexity.
    • Expectation of Success: The combination involved applying known techniques to solve predictable problems, such as using a standard beacon structure for control signaling and an established method for varying bandwidth, leading to a high expectation of success.

Ground 2: Claim 5 is obvious over Li, Husted, Cheng, McFarland, and Dulin

  • Prior Art Relied Upon: Li (Patent 6,904,283), Husted (Application # 2005/0100039), Cheng (Application # 2004/0233936), McFarland (Patent 7,397,859), and Dulin (Application # 2002/0055356).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground incorporated all arguments from Ground 1 and addressed the additional limitation of dependent claim 5, which requires the base station to operate in a frequency division duplex (FDD) or time division duplex (TDD) mode. Petitioner argued that while FDD/TDD operation was implicit in Li's bidirectional cellular system, Dulin explicitly disclosed using both FDD and TDD in an OFDMA system. Dulin taught a flexible scheduler for assigning frequency blocks and time slots, which is characteristic of OFDMA, and specified that its transmission maps were consistent with both FDD and TDD transmissions.
    • Motivation to Combine: A POSITA implementing the bidirectional (uplink and downlink) communication system described in Li would have needed to select a duplexing scheme. Dulin taught that FDD and TDD were the two conventional and well-known options for managing duplexing in OFDMA systems. Therefore, a POSITA would combine Dulin with the Li/Husted/Cheng/McFarland system to implement a necessary and standard feature, filling in an implementation detail not specified by the other references.
    • Expectation of Success: Combining a standard duplexing method like FDD or TDD with an OFDMA communication system was a routine design choice with predictable and successful results.

4. Key Claim Construction Positions

  • Petitioner argued for a specific construction of the term "OFDMA core-band" as used in claim 1.
  • The proposed construction was "core-band in an OFDMA system." Petitioner contended that the patent specification and claims treated "OFDMA" and "core-band" as distinct concepts. "OFDMA" was described as a multiplexing technique, while "core-band" was defined by its bandwidth characteristics. This construction was critical to the invalidity arguments, as it allowed Petitioner to map prior art teaching a "core-band" (like Husted's "master channel") onto a base system that used OFDMA (like Li's).

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-5 of Patent 8,953,641 as unpatentable under 35 U.S.C. §103.