PTAB

IPR2013-00306

CLearWire Corp v. Mobile Telecommunications Technologies LLC

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Petition
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1. Case Identification

2. Patent Overview

  • Title: Method and System for Efficiently Providing Two Way Communication Between a Central Network and Mobile Unit
  • Brief Description: The ’403 patent discloses a two-way communication system using geographically separated base transmitters controlled by a central operations center. The technology addresses interference in overlapping coverage areas by switching between a "simulcast" transmission method (multiple transmitters sending identical data) and a "cellular" transmission method (neighboring transmitters sending different data) across different time periods to improve communication efficiency.

3. Grounds for Unpatentability

Ground 1: Anticipation over AMPS Reference - Claims 1, 10, and 11 are anticipated by the AMPS Reference.

  • Prior Art Relied Upon: AMPS Reference ("Advanced Mobile Phone Service: Control Architecture," published in The Bell System Technical Journal, Jan. 1978).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued the AMPS Reference, which describes an early wireless cellular system, discloses all limitations of the challenged claims. It taught using a simulcast method for initial call setup where paging messages were broadcast from all base stations simultaneously (first time period). After setup, the system switched to a cellular method where a single serving base station handled the call, freeing other transmitters (second time period). For claims 10-11, Petitioner asserted that AMPS taught dynamically reassigning base stations via "cell splitting" and handoffs based on the number of users in a cell, meeting the limitations for dynamic reassignment and monitoring mobile receivers in overlap regions.

Ground 8: Obviousness over Linquist and Uddenfelt - Claims 1, 10, and 11 are obvious over Linquist in view of Uddenfelt.

  • Prior Art Relied Upon: Linquist (Patent 5,423,056) and Uddenfelt (Patent 5,109,528).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted that Linquist teaches a communication system that explicitly switches between a "cellular mode" and a "simulcast mode" for different types of message transmissions, thereby disclosing the core two-period transmission method of claim 1. Linquist also allegedly discloses dynamically reassigning base transmitters (called "sticks") into different zones to follow a mobile user, which Petitioner mapped to the limitations of independent claim 10.
    • Motivation to Combine: Petitioner argued Uddenfelt taught established techniques for managing handoffs and power control in cellular systems to improve reliability. A person of ordinary skill in the art (POSITA) would combine Uddenfelt's known handoff management techniques with Linquist's dual-mode system to improve performance and efficiently manage network resources, particularly in the overlap regions between zones where handoffs are critical.
    • Expectation of Success: The combination involved applying a well-understood technique (Uddenfelt's handoff management) to a known type of system (Linquist's dual-mode network) to achieve the predictable result of improved communication reliability.

Ground 33: Obviousness over Multiple Gilhousen References - Claims 1, 10, and 11 are obvious over Gilhousen ’472 in view of Gilhousen ’390 and Gilhousen ’501.

  • Prior Art Relied Upon: Gilhousen ’472 (Patent 5,280,472), Gilhousen ’390 (Patent 5,109,390), and Gilhousen ’501 (Patent 5,101,501).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that the Gilhousen patents, which relate to early CDMA cellular systems, collectively disclose all elements of the challenged claims. Gilhousen ’472 taught a system using both cellular transmission (employing different time divisions for signals) and simulcast transmission (sending the same RF signals simultaneously from multiple antennas). Gilhousen ’390 and ’501 further detailed systems where a mobile unit can perform diversity combining of signals from multiple cell-sites (an application of simulcast) and can route calls through multiple sites while in overlap areas, which inherently requires the dynamic assignment of base stations based on mobile unit location and network traffic.
    • Motivation to Combine: All three Gilhousen references are directed to solving similar problems in CDMA systems, share a common inventor, and belong to the same field of technology. A POSITA would naturally look to these related disclosures to implement a robust network, combining their complementary teachings on simulcast, cellular, and diversity techniques to optimize performance.
    • Expectation of Success: Combining these closely related and complementary teachings to build an efficient, dynamic communication system was presented as a straightforward integration for a POSITA, carrying a high expectation of success.
  • Additional Grounds: Petitioner asserted numerous additional anticipation and obviousness challenges based on various combinations of the Gilhousen patents, Paulraj (Patent 5,345,599), Bollinger (Patent 5,195,090), Winters (a 1992 conference paper), and Anderson (a 1991 journal article), but relied on similar arguments regarding the combination of known cellular, simulcast, and dynamic reassignment techniques.

4. Key Claim Construction Positions

  • Petitioner dedicated a section to the construction of "transmitting... in simulcast" and "transmitted in simulcast," arguing these terms were central to the dispute.
  • Petitioner's Proposed Construction: "broadcasting identical signals simultaneously."
  • Relevance: Petitioner argued that the Patent Owner advocated for a broader construction ("transmitting information over two or more channels"). The petition asserted that the challenged claims are unpatentable even under its own narrower and proper construction, and that the cited prior art also rendered the claims invalid under the Patent Owner's broader interpretation.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1, 10, and 11 of Patent 5,590,403 as unpatentable.