PTAB

IPR2014-00916

St Jude Medical Inc v. Atlas IP LLC

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1. Case Identification

2. Patent Overview

  • Title: Medium Access Control Protocol For Wireless Network
  • Brief Description: The ’734 patent discloses a Medium Access Control (MAC) protocol for wireless computer networks designed to conserve power in battery-operated devices. The protocol uses a central "hub" to establish a repeating "communication cycle" with defined intervals for inbound and outbound transmissions, allowing remote stations to power down their radios when not scheduled to transmit or receive.

3. Grounds for Unpatentability

Ground 1: Anticipation of Claims 6, 14, and 21 under §102 over Natarajan 1992

  • Prior Art Relied Upon: Natarajan 1992 (an IEEE 802.11 Working Group paper titled "Medium Access Control Protocol for Wireless LANs (An Update)").
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Natarajan 1992 disclosed every limitation of independent claims 6, 14, and 21. The paper described a MAC protocol where an "Access Point" (hub) coordinates communications within a structured "frame" (communication cycle). This frame was divided into intervals for outbound data from the hub to "mobile units" (remotes) and inbound data from the remotes to the hub. Petitioner asserted that Natarajan 1992 explicitly taught broadcasting scheduling information in headers (e.g., Header AH, BH), enabling mobile units to know when to power on their transmitters or receivers, thereby minimizing battery consumption, which directly maps to the core power-saving features of the challenged claims.

Ground 2: Obviousness of Claim 11 under §103 over Natarajan 1992 in view of Bella

  • Prior Art Relied Upon: Natarajan 1992 (IEEE paper), Bella (Patent 4,542,499).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Natarajan 1992 established the base system for claim 11. The claim’s distinguishing features require the hub to monitor a remote's transmissions and revoke its allocated transmission opportunity if the remote fails to transmit for a predetermined period. Petitioner contended that Bella taught this exact concept for managing TDMA-like time slots in a local area network. Bella disclosed monitoring reserved slots and canceling the reservation if a communicator failed to transmit, thereby freeing up network resources.
    • Motivation to Combine: A POSITA would combine Bella's resource management technique with Natarajan's wireless protocol to improve efficiency. Natarajan's system provided for reserved, repeating timeslots for "isochronous" data like voice. A predictable problem was that a mobile remote might stop transmitting (e.g., move out of range), leaving its reserved slot unused. Bella offered a simple, known solution to this problem by revoking the allocation of inactive remotes.
    • Expectation of Success: The combination involved applying a known, simple cancellation method to a known system to achieve a predictable improvement in network efficiency, leading to a high expectation of success.

Ground 3: Obviousness of Claims 6, 14, and 21 under §103 over Natarajan ’542 in view of Bantz

  • Prior Art Relied Upon: Natarajan ’542 (Patent 5,241,542), Bantz (Patent 5,123,029).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner asserted that the Natarajan ’542 patent, which describes a system substantively similar to the Natarajan 1992 paper, taught most limitations of the claims. However, it lacked the specific limitation of "designating one of the communicators...as a hub." Petitioner argued this was taught by Bantz, which disclosed a protocol for an ad-hoc network where one of the remote stations is dynamically designated as the base station, particularly to provide robustness in case the currently designated base station fails.
    • Motivation to Combine: A POSITA would combine the references because they were highly relevant to each other; both patents originated from IBM, shared a co-inventor, were filed within two months of each other, and addressed the same subject of MAC protocols for frequency-hopping wireless LANs. Bantz’s dynamic hub designation was a known method to improve network fault tolerance and would have been a natural and advantageous feature to incorporate into the very similar system of Natarajan ’542.
    • Expectation of Success: Because the combination involved integrating a known feature for robustness into a nearly identical system, a POSITA would have had a reasonable expectation of success.

  • Additional Grounds: Petitioner asserted additional obviousness challenges, including a combination adding Wilson (Patent 4,841,526) for a selective-reject error control method (Ground 3), and applying the teachings of Bella and Wilson to the Natarajan ’542 and Bantz combination (Grounds 5 and 6).

4. Key Claim Construction Positions

  • "communication cycle": Petitioner proposed this term means "a series of intervals for outbound and inbound communications." This construction was crucial for mapping the term to the prior art concept of a "frame" as used in the Natarajan references, which similarly described a repeating structure with defined transmission periods.
  • "designating one of the communicators...as a hub": Petitioner proposed this means "the communicators using the MAC protocol to dynamically select one of the group to function as a hub." This construction distinguished a static, pre-assigned hub from a dynamically selected one, supporting Petitioner's argument that this limitation was met by Bantz's disclosure of a dynamic designation process for ad-hoc networks.

5. Relief Requested

  • Petitioner requests institution of inter partes review and cancellation of claims 6, 11, 14, 21, and 44 of Patent 5,371,734 as unpatentable.