PTAB

IPR2013-00125

ReSearch In Motion Corp v. Wi LAN Inc

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1. Case Identification

2. Patent Overview

  • Title: Method for Frequency Sharing and Frequency Punchout in Frequency Hopping Communications Network
  • Brief Description: The ’369 patent discloses a method for managing wireless communications in a frequency hopping network where multiple nodes share a set of frequencies. The system assigns each node a unique channel-hopping plan using a seed value and a "channel punchout mask" to eliminate channels experiencing interference, thereby preventing interference between nodes.

3. Grounds for Unpatentability

Ground 1: Anticipation by Munday - Claim 5 is anticipated by Munday.

  • Prior Art Relied Upon: Munday (Patent 5,377,221).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Munday discloses every element of claim 5. Munday describes a frequency hopping radio communications system with multiple radios (nodes) that monitor a set of channel frequencies to measure signal strength and identify a subset of channels with the lowest interference. This process of identifying a subset of usable channels was argued to be equivalent to the claimed "determining a channel punchout mask." Munday’s system then uses a unique "key of the day" and timing sync data to seed a keystream generator, which creates a pseudo-random hopping sequence over the low-interference channels. Petitioner contended this "key of the day" and sync data constitute the claimed "unique seed value." Finally, Munday teaches transmitting the identities of the selected channels and the sync data to other radios so they can derive the hopping plan, which Petitioner asserted meets the limitation of "communicating said unique channel-hopping band plan."

Ground 2: Anticipation by Jackson - Claims 5 and 9 are anticipated by Jackson.

  • Prior Art Relied Upon: Jackson (“Advanced HF Anti-Jam Network Architecture”).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner contended that Jackson, a publication describing a high-frequency anti-jam network, anticipates claims 5 and 9. Jackson teaches a multi-node network where each user is assigned a unique hopping pattern. The system monitors channel quality over a large set of frequencies (512) to select a smaller, preferred hop set (64 frequencies), which Petitioner equated to the claimed "channel punchout mask." The assignment of a unique hopping pattern to each user, generated via a pseudo-random sequence, was argued to inherently require a "unique seed value" as would be understood by a person of ordinary skill in the art (POSITA). To satisfy claim 9, Petitioner asserted that Jackson teaches communicating data from which other nodes can derive the band plan, and that this data necessarily includes the mask (the 64-frequency hop set) and the unique seed value to reduce transmission overhead compared to sending the entire hopping sequence.

Ground 3: Obviousness over Jackson and Flammer - Claim 6 is obvious over Jackson in view of Flammer.

  • Prior Art Relied Upon: Jackson (“Advanced HF Anti-Jam Network Architecture”) and Flammer (Patent 5,079,768).

  • Core Argument for this Ground:

    • Prior Art Mapping: Petitioner argued that Jackson teaches all elements of claim 5, upon which dependent claim 6 is based. Claim 6 adds the specific limitation that the "seed value is derived from an address of the node." While Jackson teaches using a unique seed value, it does not specify its origin. Flammer, which also describes a frequency hopping communication system, was asserted to explicitly teach this missing element. Flammer discloses that a random offset "seed" value for generating a unique hopping plan "is derived from a node address."
    • Motivation to Combine: A POSITA would combine Jackson and Flammer because both address the same problem of creating unique channel-hopping plans in a frequency hopping network. Petitioner argued a POSITA would be motivated to incorporate Flammer's elegant and well-known technique of deriving a seed from a node's unique address into the Jackson system to predictably and efficiently generate the unique hopping patterns that Jackson requires for each user.
    • Expectation of Success: A POSITA would have a reasonable expectation of success in this combination, as it involves applying a known technique (deriving a seed from a node address) to a similar system (Jackson's frequency hopping network) for its intended and predictable purpose (generating a unique hopping plan).

  • Additional Grounds: Petitioner asserted additional challenges, including that claim 7 is obvious over Munday and that claim 7 is obvious over Jackson. These arguments relied on the assertion that it was well-known at the time to use a binary bit mask (using 0s and 1s) to represent channel availability to reduce transmission overhead.

4. Key Claim Construction Positions

  • "channel punchout mask": Petitioner argued this term should be given its broadest reasonable interpretation and not be limited to a specific structure. Based on the file history of the ’369 patent, where the Patent Owner allegedly acquiesced to the examiner's interpretation that a "table" of invalid channels constituted a mask, Petitioner contended the term simply means any data that indicates which channels are undesirable or unusable due to interference. This broad construction is critical to their argument that the subset of low-interference channels in Munday and the selected hop set in Jackson meet this limitation.

5. Key Technical Contentions (Beyond Claim Construction)

  • Petitioner's arguments relied heavily on the general knowledge of a POSITA in the field of frequency hopping communications at the time of the invention. Key contentions included that a POSITA would have understood that:
    • Using a binary mask to represent usable/unusable channels is more efficient and reduces overhead compared to transmitting a full list of channel frequencies.
    • Generating unique pseudo-random hopping sequences for different nodes requires supplying a pseudo-random number generator with a unique seed value for each node.
    • Communicating a band plan is most efficiently done by transmitting the seed and mask, from which a receiving node can reconstruct the full hopping sequence.

6. Relief Requested

  • Petitioner requested that the Board institute an inter partes review and cancel claims 5-7 and 9 of the ’369 patent as unpatentable.