PTAB

IPR2014-00275

ZTE Corp v. InterDigital Technology Corp

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method and System for Providing Channel Assignment Information Used to Support Uplink and Downlink Channels
  • Brief Description: The ’151 patent relates to methods in a wireless communication system for providing both uplink and downlink channel assignment information over a single, shared physical downlink control channel. The technology aims to efficiently manage resources by reusing an existing control channel, the High Speed Shared Control Channel (HS-SCCH), to signal both downlink assignments and new Enhanced Uplink (EU-DCH) assignments, distinguishing between them by using previously undefined values in the channelization code-set field.

3. Grounds for Unpatentability

Ground 1: Anticipation/Obviousness over Siemens 004 - Claims 1-6, 8-9, 16-21, and 23-24 are anticipated by or obvious over Siemens 004.

  • Prior Art Relied Upon: Siemens 004 (Tdoc R1-030004, a submission to the 3GPP TSG-RAN Working Group 1, Jan. 2003).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Siemens 004, a technical proposal submitted to the same standards body the inventors participated in, discloses every element of the challenged claims. Siemens 004 proposed reusing the existing HSDPA downlink control channel (HS-SCCH) to also carry control information for the Enhanced Uplink channel (EU-DCH). It explicitly taught distinguishing between downlink (HS-DSCH) and uplink (EU-DCH) assignments by using the eight previously unused or "redundant" codewords in the channelization code-set field of the HS-SCCH. Petitioner asserted this is identical in substance to the first embodiment of the ’151 patent, noting that the patent’s provisional application copied a figure directly from Siemens 004. Siemens 004 also disclosed that detection would be based on the "implicit UE-ID," which a person of ordinary skill in the art (POSITA) would understand refers to the standard, pre-existing method of using a UE ID-masked Cyclic Redundancy Check (CRC) for user identification on the shared channel.
    • Key Aspects: The central argument was that the inventors claimed an idea publicly disclosed by Siemens months earlier at a standards meeting, which the inventors' employer attended, and failed to submit this dispositive prior art to the USPTO during prosecution.

Ground 2: Obviousness over Siemens 004 and 3GPP TS 25.212 - Claims 1-6 and 16-21 are obvious over Siemens 004 in view of 3GPP TS 25.212.

  • Prior Art Relied Upon: Siemens 004 and 3GPP TS 25.212 (a 3GPP technical specification, Sep. 2002).
  • Core Argument for this Ground:
    • Prior Art Mapping: To the extent Siemens 004 was found not to explicitly disclose every detail, Petitioner argued that 3GPP TS 25.212 provided the necessary context. This reference is the foundational technical specification that defines the structure and coding of the HS-SCCH for HSDPA. It explicitly detailed the use of a UE ID-masked CRC for determining if a transmission on the shared channel was intended for a specific handset (the "first determining" limitation of claim 1).
    • Motivation to Combine: A POSITA would combine these references because Siemens 004 was a proposal for a new feature (Enhanced Uplink signaling) intended to be backward-compatible with the existing system defined by 3GPP TS 25.212. A POSITA implementing the high-level proposal of Siemens 004 would have naturally turned to the 3GPP TS 25.212 specification for the established, underlying details of the HS-SCCH, such as its coding format and the use of a UE-masked CRC.
    • Expectation of Success: The combination was expected to succeed because Siemens 004 explicitly stated its reuse of the HS-SCCH was intended to be identical for decoding, simplifying receiver implementation and ensuring compatibility.

Ground 3: Obviousness over Siemens 004 and Motorola 683 - Claims 8 and 23 are obvious over Siemens 004 in view of Motorola 683.

  • Prior Art Relied Upon: Siemens 004 and Motorola 683 (Tdoc SMG2 UMTS-L1 683/98, a submission to the ETSI SMG2 UMTS L1 Expert Group, Dec. 1998).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground specifically targeted the limitations in dependent claims 8 and 23 requiring the physical downlink control channel to carry both downlink and uplink channel assignment information "simultaneously." While Siemens 004 taught using the same channel for both types of information (in time multiplex), Motorola 683 taught aggregating functions onto a single downlink control channel (the "tertiary CCPCH") that explicitly carried assignment information for both a downlink shared channel (DSCH) and an uplink shared channel (USCH) simultaneously.
    • Motivation to Combine: A POSITA seeking to improve the efficiency of the system taught by Siemens 004 would have been motivated to consider techniques for simultaneous signaling, as taught by Motorola 683, to further conserve control channel resources. Both references were contributions to the same overall effort of developing the UMTS standard and addressed the common problem of efficient resource allocation.
    • Expectation of Success: There was a high expectation of success, as both references dealt with established methods for signaling channel assignments on control channels within UMTS systems.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including combining Siemens 004 with the ’151 patent’s admissions of prior art; with InterDigital 810 (another 3GPP contribution detailing UE-specific CRCs); and with Siemens 010 (another reference teaching simultaneous uplink/downlink signaling).

4. Key Claim Construction Positions

  • "same physical downlink control channel": Petitioner noted that in parallel litigation, Patent Owner proposed a broad construction of "a radio resource used to transmit uplink and/or downlink channel assignment information." Petitioner argued that even under this broad construction, the claims were invalid. Petitioner’s proposed construction was narrower, requiring a "channel used for transfer of downlink control information only."
  • "channel assignment information": Petitioner argued for the plain and ordinary meaning, or "information identifying a channel assigned to the WTRU." This contrasted with the Patent Owner's broader litigation proposal of "information regarding radio resource assignment for the uplink or downlink channel."
  • "based on WTRU identity (ID)-masked cyclic redundancy check (CRC) parity bits": Petitioner argued for a construction requiring the comparison of a received masked CRC with a locally generated masked CRC. This was contrasted with Patent Owner's broader proposal requiring only that the determination be "based on" parity bits masked with a code associated with the WTRU.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-6, 8-9, 16-21, and 23-24 of Patent 7,941,151 as unpatentable.