PTAB

IPR2016-01310

Samsung Electronics Co Ltd v. Evolved Wireless LLC

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method and Apparatus for Transmitting Signal Via Random Access Channel in Mobile Communication System
  • Brief Description: The ’965 patent describes a method for a user equipment (UE) in a wireless communication system to perform a random access procedure. The invention modifies prior art methods by dividing a set of available preamble signatures into subsets based on criteria such as path loss or information size, from which the UE selects a preamble.

3. Grounds for Unpatentability

Ground 1: Anticipation over Schulist - Claims 1, 3, and 8 are anticipated by Schulist under 35 U.S.C. §102.

  • Prior Art Relied Upon: Schulist (International Publication No. WO 2004/030392).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Schulist discloses every limitation of claims 1, 3, and 8. Schulist teaches a modification to the WCDMA random access procedure where the complete set of sixteen preamble signatures is divided into subsets, or "individual path loss classes." A UE first estimates its path loss to the base station, which determines the appropriate path loss class. The UE then selects the corresponding subset of preamble signatures and randomly selects one signature from within that subset for transmission on the random access channel (RACH). This process directly maps to the claimed method of selecting a sequence set based on a "degree of path loss" and then randomly selecting a sequence from within that set.
    • Key Aspects: This ground relies on Petitioner's proposed claim construction that "considering at least one of a size of information... and a degree of a path loss" should be interpreted disjunctively (i.e., OR), allowing a reference that only considers path loss to meet the limitation.

Ground 2: Obviousness over Schulist and Popovic - Claims 2 and 9 are obvious over Schulist in view of Popovic under 35 U.S.C. §103.

  • Prior Art Relied Upon: Schulist and Popovic (International Publication No. WO 2007/082409).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground addresses dependent claims 2 and 9, which further require the specific random access sequence to be a Constant Amplitude Zero Auto-Correlation (CAZAC) sequence. Schulist teaches using orthogonal sequences, specifically Walsh sequences, for the preamble signatures. Popovic addresses improving prior art systems that use Hadamard sequences (which Petitioner asserted are mathematically related and often used interchangeably with Walsh sequences) by replacing them with CAZAC sequences. Popovic explicitly teaches that CAZAC sequences provide better properties, such as improved mutual cross-correlation and higher detection probability, especially at low signal-to-interference ratios.
    • Motivation to Combine: A POSITA would combine Schulist and Popovic to improve the performance of Schulist’s random access system. A POSITA would have recognized the known benefits of CAZAC sequences described in Popovic and would have been motivated to replace the Walsh sequences in Schulist with the superior CAZAC sequences to achieve more reliable preamble detection.
    • Expectation of Success: The combination would have been a predictable substitution of one known type of sequence for another to achieve a known benefit, leading to a high expectation of success.

Ground 3: Obviousness over Schulist and Rao - Claims 1-3 and 8-9 are obvious over Schulist in view of Rao under 35 U.S.C. §103.

  • Prior Art Relied Upon: Schulist and Rao (Application # 2007/0291708).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground was presented as an alternative argument in case Petitioner’s primary claim construction was rejected in favor of a conjunctive reading requiring consideration of both path loss and information size. Schulist teaches partitioning preamble sequences based on path loss. Rao teaches a similar method where preamble sequences are partitioned into subsets based on the "initial data packet size" to implicitly signal the data type and reduce latency in resource allocation. This combination, therefore, discloses a system where preamble subsets are selected based on both path loss (from Schulist) and data packet size (from Rao).
    • Motivation to Combine: A POSITA would combine Schulist and Rao to further reduce latency and improve the efficiency of the random access procedure. Both references teach using preamble subset selection to implicitly convey information to the base station. A POSITA would have been motivated to combine the criteria from both references to implicitly transmit more information (both path loss and data packet size) with the preamble. This would allow the base station to make more efficient resource allocation decisions immediately upon preamble receipt, reducing latency.
    • Expectation of Success: Both references suggest their criteria could be combined with other parameters. The combination represented a straightforward application of known techniques to achieve the predictable benefits of increased efficiency and reduced latency.

  • Additional Grounds: Petitioner asserted an additional obviousness challenge (Ground 4) for claims 2 and 9 over the combination of Schulist, Rao, and Popovic, relying on the same motivations to combine all three references.

4. Key Claim Construction Positions

  • Petitioner argued for a disjunctive construction of the phrase "considering at least one of a size of information to be transmitted by the specific UE and a degree of a path loss."
    • Petitioner proposed this should be construed to mean "considering at least one of a size of information... or a degree of a path loss."
    • This construction was critical to their primary anticipation ground, as Schulist discloses consideration of path loss but not information size. Petitioner argued the patent’s specification discloses an embodiment where sequence sets are allocated based only on path loss, supporting a disjunctive reading.

5. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1-3, 8, and 9 of the ’965 patent as unpatentable.