PTAB

IPR2025-00446

Samsung Electronics Co Ltd v. Vasu Holdings LLC

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Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method for Seamless Roaming of a Mobile Communication Device
  • Brief Description: The ’181 patent discloses a method for a mobile communication device to roam between different types of wireless networks, such as from a Wi-Fi network to a cellular network, without disrupting an in-progress call. The method uses an "interface server" to facilitate the switching process when the signal strength of the first network drops below a threshold.

3. Grounds for Unpatentability

Ground 1: Obviousness over Iizuka - Claims 1, 4, and 8 are obvious over Iizuka.

  • Prior Art Relied Upon: Iizuka (Application # 2005/0282541).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued Iizuka discloses a nearly identical method for a mobile terminal to roam between a wireless LAN and a wireless telephone network using a "call-management server" that functions as the claimed interface server. Iizuka taught monitoring the signal strength ("intensity of a radio wave") of an ongoing VoIP call on the wireless LAN. When the signal "deviates from a predetermined criterion," the mobile terminal notified the call-management server, which then established a second communication link (a voice call) through the telephone network while the original VoIP call "still continues," thus not disrupting the first link. Iizuka further disclosed re-directing the call by establishing a connection between the server and the mobile terminal over the telephone network and then terminating the original wireless LAN session.
    • Key Aspects: This ground asserted that Iizuka alone taught every limitation of independent claim 1 and that any minor differences, such as the specific notification method for terminating the first link, would have been obvious modifications.

Ground 2: Obviousness over Iizuka and Preston - Claims 1, 4, and 8 are obvious over Iizuka in view of Preston.

  • Prior Art Relied Upon: Iizuka (Application # 2005/0282541) and Preston (Application # 2002/0126654).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground incorporated the teachings of Iizuka from Ground 1 and argued that to the extent Iizuka did not explicitly teach "notifying the mobile communication device to terminate transmission" (limitation 1[d]), Preston supplied this teaching. Preston disclosed terminating a Session Initiation Protocol (SIP) session by having a SIP proxy server transmit a "SIP BYE message" to a SIP telephone, which then replied with an "OK" message to end the communication.
    • Motivation to Combine: A POSITA would combine Preston with Iizuka's roaming method to implement a standard, well-known procedure for terminating the initial SIP-based VoIP call. Since Iizuka's server already managed VoIP communications using a SIP server, it would be a simple and advantageous step to add Preston's explicit SIP BYE message to ensure the mobile terminal was properly informed to cease transmission, thereby preventing lost data and potential call disruption.
    • Expectation of Success: The combination was argued to be a straightforward application of a standard protocol (SIP termination) to an existing system (Iizuka's roaming method), which would predictably improve the robustness of the call handoff.

Ground 3: Obviousness over Iizuka and Orava - Claims 2 and 3 are obvious over Iizuka in view of Orava.

  • Prior Art Relied Upon: Iizuka (Application # 2005/0282541) and Orava (Application # 2003/0177267).

  • Core Argument for this Ground:

    • Prior Art Mapping: Dependent claim 2 requires the first wireless network to be an IEEE 802.11 standard-based network and access point. While Iizuka disclosed a wireless LAN, it did not specify the IEEE 802.11 standard. Orava was cited for its explicit disclosure of a WLAN network comprising access points that operate according to the IEEE 802.11 standard to provide "very fast data transmission." Claim 3, which requires the second network to be a cellular network, was argued to be met by Iizuka's disclosure of a "wireless telephone network."
    • Motivation to Combine: A POSITA would combine Orava's teachings with Iizuka's system because the IEEE 802.11 standard was the dominant, industry-wide protocol for wireless LANs at the time. Implementing Iizuka's system using this standard would have been a natural design choice to maximize performance, compatibility, and interoperability with other devices, and to take advantage of a protocol designed to minimize delays and collisions.
    • Expectation of Success: Given the widespread adoption and well-understood nature of the IEEE 802.11 standard, applying it to Iizuka's generic wireless LAN would have been a routine modification with a high expectation of success.

  • Additional Grounds: Petitioner asserted additional obviousness challenges for claim 9 based on combinations of Iizuka and Gallagher (Application # 2004/0192211), optionally with Preston, to teach providing a specific "routing association" to a mobile switching center to uniquely identify the mobile device and interface server during handover.

4. Arguments Regarding Discretionary Denial

  • Petitioner argued against discretionary denial under §325(d) because the primary references (Iizuka, Orava, Gallagher) were not cited or considered during the original prosecution of the ’181 patent, and the petition presented new arguments and expert testimony.
  • Petitioner further argued against discretionary denial under Fintiv, stating that the co-pending district court case was in its very early stages with a trial date more than three months after the statutory deadline for an institution decision. Petitioner expressed its intent to seek a stay of the litigation if the IPR is instituted, thereby conserving judicial and party resources.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1-4, 8, and 9 of the ’181 patent as unpatentable.