Samsung Electronics Co Ltd v. Evolved Wireless LLC

1. Case Identification

• Case #: IPR2021-00950
• Patent #: RE48,326
• Filed: May 16, 2021
• Petitioner(s): Samsung Electronics Co., Ltd. and Samsung Electronics America, Inc.
• Patent Owner(s): Evolved Wireless LLC
• Challenged Claims: 14-16, 18-20

2. Patent Overview

• Title: Method for Performing a Random Access Procedure During Handover
• Brief Description: The ’326 patent describes a method for managing a random access procedure during the handover of a mobile terminal from a source base station to a target base station in a wireless communication system. The disclosed method aims to avoid collisions on the random access channel by having the target base station assign a specific preamble to the mobile terminal for the handover.

3. Grounds for Unpatentability

Ground 1: Claims 14-16 and 18-20 are obvious over Nokia in view of Hu.

• Prior Art Relied Upon: Nokia (3GPP Draft R2-061135) and Hu (Chinese Patent Application Publication No. CN159602A).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Nokia taught most of the claimed features for a handover procedure in a Long Term Evolution ("LTE") system. Nokia’s disclosed handover sequence included a User Equipment ("UE") sending a measurement report, a source base station deciding to hand off, an exchange of context data with the target station, and the source station sending a "Handover Command" to the UE. The UE then performs a random access channel ("RACH") procedure to connect to the target. Petitioner contended that while Nokia disclosed a complete handover framework, it did not specify the details of the RACH procedure beyond mentioning it was a "non contention based access burst." Hu, however, explicitly taught a method to improve handover success by addressing this very issue. Hu disclosed that a target base station designates a specific, dedicated "random access resource" (i.e., a preamble) for a single mobile terminal undergoing handover. This dedicated preamble is then used on a shared RACH to ensure a contention-free connection. Petitioner asserted that combining Hu's dedicated preamble solution with Nokia's handover framework rendered the challenged claims obvious.
  • Motivation to Combine: Petitioner argued a person of ordinary skill in the art (POSITA) would combine Nokia and Hu to improve the reliability and speed of the handover process. Nokia’s disclosure of a handover using a shared RACH would have presented the well-known problem of potential signal collisions. A POSITA seeking to implement Nokia's procedure would have been motivated to find a solution for contention avoidance. Hu addressed this exact problem by teaching the use of a dedicated preamble for a specific UE on a shared channel. Therefore, a POSITA would combine Hu’s specific, contention-free RACH implementation into Nokia's general handover framework to create a more efficient and robust system.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success in this combination. Both references operated in the same technical field of mobile communication handovers and addressed the same problem. Implementing a known contention-avoidance technique (dedicated preambles from Hu) within a standard handover procedure (from Nokia) was a predictable design choice with foreseeable results.

4. Key Claim Construction Positions

• Petitioner argued that key terms challenged in the patent, such as "handover" and "target base station," are well-understood by a POSITA and require no special construction.
• To the extent construction is deemed necessary, Petitioner contended that the Patent Owner’s previously proposed construction for "handover" in a related district court case—requiring a "break-before-make" connection—was improperly narrow. Petitioner asserted that the term should encompass multiple known types of handovers, including "soft handovers," and that nothing in the intrinsic evidence limited the claims to only hard handovers.

5. Key Technical Contentions (Beyond Claim Construction)

• Priority Date Challenge: Petitioner contended that the ’326 patent was not entitled to the October 31, 2005 priority date of its provisional application. Petitioner argued the provisional application failed to disclose key limitations recited in the challenged claims, including the "handover command message" containing preamble information and the "handover confirm message" sent from the target to the source base station. As a result, Petitioner asserted the earliest possible priority date for the challenged claims was the filing date of the Korean application, July 5, 2006. This later priority date is critical because it renders the Nokia reference, published on or before May 3, 2006, eligible as prior art under 35 U.S.C. §102(a).

6. Arguments Regarding Discretionary Denial

• §314(a) (Fintiv Factors): Petitioner argued against discretionary denial based on parallel district court and ITC proceedings. The key reasons were that the co-pending district court action was stayed, mitigating concerns of inefficiency. Furthermore, Petitioner stipulated that if the inter partes review (IPR) was instituted, it would not pursue the same invalidity grounds based on Nokia in the parallel ITC proceeding, thus eliminating any overlap of issues.
• §325(d): Petitioner argued against denial under §325(d), which allows the Board to reject petitions raising the same or substantially the same art or arguments previously presented to the Office. Although Nokia and Hu were cited during prosecution, Petitioner argued they were part of a list of hundreds of references and that the Examiner never substantively analyzed them or considered them in combination. Petitioner asserted that the Examiner materially erred by overlooking the specific teachings of the Nokia/Hu combination, which directly address the patentability of the challenged claims.

7. Relief Requested

• Petitioner requested the institution of an IPR trial and the cancellation of claims 14-16 and 18-20 of Patent RE48,326 as unpatentable.