PTAB

IPR2020-00841

Ericsson Inc v. Cellular Evolution LLC

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method and Apparatus for Interfacing Among Mobile Terminal, Base Station and Core Network in Mobile Telecommunications System
  • Brief Description: The ’783 patent discloses a method for enabling a mobile terminal to connect to different types of core networks (e.g., GSM-MAP or ANSI-41). The system achieves this by having a radio network determine the operating type of the connected core network and send this information in a message to the mobile terminal.

3. Grounds for Unpatentability

Ground 1: Obviousness over OHG and Im - Claim 7 is obvious over OHG in view of Im.

  • Prior Art Relied Upon: OHG (an Open Letter from the Operators Harmonization Group, RP-99358) and Im (Korean Publication # 1999-0038697).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that OHG discloses a flexible 3G network architecture where various radio access networks (e.g., W-CDMA) can connect to different core networks (GSM-MAP and ANSI-41). OHG states that a "mobile terminal will have the ability to determine the network environment it is accessing" but does not provide the implementation details for how this determination is made. Im allegedly supplies this missing detail by teaching a system where a mobile terminal determines the core network type based on "core network configuration information" it receives in a broadcasted system information message from the base station.
    • Motivation to Combine: A POSITA implementing the flexible architecture of OHG would be motivated to look to related art like Im to supply the necessary implementation details for how a terminal determines the core network type. This combination would predictably allow a terminal to roam between the different core networks contemplated by OHG, a beneficial result.
    • Expectation of Success: Success would be expected because both references address the same problem of interfacing different radio and core network types and describe the benefits of such a flexible architecture.

Ground 2: Obviousness over OHG and TS-25.331 - Claims 1, 2, and 8 are obvious over OHG in view of TS-25.331.

  • Prior Art Relied Upon: OHG and TS-25.331 (3GPP Technical Specification 25.331 v3.1.0).
  • Core Argument for this Ground:
    • Prior Art Mapping: As in Ground 1, OHG provides the high-level framework for a flexible network. Petitioner asserted that TS-25.331, a well-known 3GPP standard for W-CDMA radio interfaces, provides the specific implementation details that OHG lacks. TS-25.331 allegedly discloses broadcasting a Master Information Block (MIB) which contains a mandatory "CN Type" field to identify the core network as either "GSM-MAP" or "ANSI-41." Critically, Petitioner argued that the MIB format detailed in TS-25.331 includes, verbatim, all elements of the message structure recited in challenged claims 1, 2, and 8, including the "MIB Value Tag," "Scheduling information," and the conditional presence of "PLMN Identity" or "ANSI-41 Information elements" based on the CN Type.
    • Motivation to Combine: A POSITA implementing the W-CDMA-based system described in OHG would naturally and logically consult the governing 3GPP standard, TS-25.331, for the standardized method of communicating system information. Using the predefined MIB structure from TS-25.331 is an efficient, well-known, and standardized technique for implementing the terminal's need to determine the core network type as required by OHG.
    • Expectation of Success: The combination would have been predictable because it involves applying a specific, detailed standard (TS-25.331) directly to the type of system (a W-CDMA network) generally described in the primary reference (OHG).

Ground 3: Obviousness over OHG, Im, and R2-99414 - Claims 1 and 8 are obvious over OHG in view of Im and R2-99414.

  • Prior Art Relied Upon: OHG, Im, and R2-99414 (a 3GPP contribution titled "Structure of System Information").
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground builds on the combination of OHG and Im. While Im teaches broadcasting core network type information, it lacks detail on the message format. R2-99414 allegedly provides this missing detail by describing a mechanism for structuring the transmission of system information in a W-CDMA network. It teaches using a Master Information Block (MIB) that is broadcast first and contains key information like the "PLMN id," "Value tag" for updates, and "Scheduling information" that points to other system information blocks. The combination of OHG's architecture, Im's teaching to broadcast core network type, and R2-99414's MIB structure allegedly renders the claimed message format obvious.
    • Motivation to Combine: A POSITA seeking to implement the system of OHG and Im would be motivated to use the technique from R2-99414 because it provides an efficient and flexible structure for broadcasting the required system information. R2-99414's proposal for an MIB containing scheduling information and value tags was a known technique to improve system information broadcasting, making it a logical addition.
    • Expectation of Success: Implementing R2-99414's technique in the combined OHG/Im network represents the application of a known method (structured broadcasting via an MIB) to improve a similar system, yielding predictable results.

4. Key Technical Contentions (Beyond Claim Construction)

  • Priority Date Challenge: Petitioner dedicated a substantial portion of the petition to arguing that claims 1, 2, and 8 are not entitled to the filing date of their Korean priority applications (filed in 1999). Petitioner contended that key claimed elements, such as "MIB value tag," "scheduling information," and the specific conditional logic for including "PLMN IDENTITY" (C-GSM), were not disclosed in the Korean applications. Instead, these details were allegedly added to the U.S. application's specification from later-published 3GPP standards (e.g., TS-25.331), meaning the claims' effective priority date is the U.S. filing date of May 4, 2000, making TS-25.331 available as prior art.

5. Arguments Regarding Discretionary Denial

  • No Fintiv Issues: Petitioner argued that the Board should not exercise its discretion to deny institution under §314(a). Petitioner asserted that because it is not a party to the two pending parallel district court lawsuits involving the ’783 patent, there is no tactical advantage gained by the IPR filing. Furthermore, because the invalidity contentions in the co-pending litigation remain in flux, it is uncertain whether the "same prior art and arguments" will be presented at trial, making an IPR an efficient alternative. Petitioner also noted that the ’783 patent is alleged to be a standard essential patent, and lawsuits against two industry participants should not foreclose a challenge by another, such as Ericsson.

6. Relief Requested

  • Petitioner requested that the Board institute an inter partes review of claims 1, 2, 7, and 8 of the ’783 patent and cancel those claims as unpatentable.