CelluPlex LLC v. Binatone Electronics Intl Ltd

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: CelluPlex LLC (New Mexico)
  • Defendant: Binatone Electronics International Limited (Hong Kong)
  • Plaintiff’s Counsel: Rabicoff Law LLC
• Case Identification: 2:25-cv-00061, E.D. Tex., 01/27/2025
• Venue Allegations: Plaintiff alleges venue is proper because Defendant has an established place of business in the Eastern District of Texas and has committed acts of infringement in the district.
• Core Dispute: Plaintiff alleges that Defendant infringes a patent related to an interface device that connects a Bluetooth-enabled cellular phone to a conventional wired telephone network.
• Technical Context: The technology addresses the desire to integrate the functionality of a mobile cellular phone with the convenience and infrastructure of a landline telephone system, such as a home or office phone network.
• Key Procedural History: No prior litigation, Inter Partes Review (IPR) proceedings, or licensing history is mentioned in the complaint.

Case Timeline

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 7,177,664 - "Bluetooth interface between cellular and wired telephone networks"

• Patent Identification: U.S. Patent No. 7,177,664, "Bluetooth interface between cellular and wired telephone networks," issued February 13, 2007.

The Invention Explained

• Problem Addressed: The patent addresses the inconvenience that arises when a cellular phone user is at home or in an office with a conventional wired telephone system. Users may turn off their cell phones to conserve battery, thereby missing calls, or must physically retrieve the cellular phone to place or receive calls, even when a more convenient wired handset is nearby (ʼ664 Patent, col. 1:11-29).
• The Patented Solution: The invention is an "interconnect device" that serves as a bridge between a Bluetooth-enabled cellular phone and a wired telephone network (ʼ664 Patent, col. 1:36-40). The device contains a Bluetooth transceiver to communicate with the cellular phone and an interface that "emulates the behavior of a standard wired telephone trunk line" to the wired phones (ʼ664 Patent, col. 2:16-19). This allows a user to make outgoing calls on a standard wired telephone that are routed through the cellular network and to answer incoming cellular calls on any connected wired telephone, which will ring as if the call came over a traditional landline (ʼ664 Patent, col. 2:25-46; Fig. 1).
• Technical Importance: The technology aimed to unify a user's communication experience, allowing a single cellular number to be the primary point of contact while leveraging the superior ergonomics and features (e.g., multiple handsets, speakerphones) of a wired system when the user was at a fixed location (ʼ664 Patent, col. 2:25-35).

Key Claims at a Glance

• The complaint does not identify specific asserted claims, instead referencing "Exemplary '664 Patent Claims" in an unprovided exhibit (Compl. ¶13). Independent claim 1 is representative of the apparatus claims.
• Independent Claim 1: An interconnect device comprising, in combination:
  • A first short-range radio transceiver for exchanging voice and data signals with a second short-range radio transceiver in a cellular telephone.
  • An interface connected between the wired network and the first transceiver for emulating a wired line connection.
  • The interface includes "means for handling an outgoing call," which comprises:
    • "means for indicating the availability of an idle line."
    • "means for receiving a telephone number to be called."
    • "means for transmitting said telephone number" to the cellular phone to initiate the call.
  • The interface also includes "means for handling an incoming call," which comprises:
    • "means for applying a ringing signal" to the wired network.
    • "means responsive to said wired telephone... for establishing an audio transmission channel."
    • "means responsive to said wired telephone... for disconnecting said audio transmission channel."
• The complaint does not explicitly reserve the right to assert dependent claims, but infringement allegations are made as to "one or more claims of the '664 Patent" (Compl. ¶11).

III. The Accused Instrumentality

Product Identification

The complaint does not name any specific accused products. It refers generally to "Exemplary Defendant Products" that are allegedly identified in charts within an unprovided "Exhibit 2" (Compl. ¶11, 13).

Functionality and Market Context

The complaint does not provide sufficient detail for analysis of the accused instrumentality's specific functionality or market context.

IV. Analysis of Infringement Allegations

The complaint alleges that infringement is detailed in claim charts provided as Exhibit 2, which was not included with the filed complaint (Compl. ¶13-14). The complaint’s body does not contain a narrative description of how any specific product functions infringe the patent claims. No probative visual evidence provided in complaint.

Identified Points of Contention

• Means-Plus-Function Limitations: Claim 1 is dominated by "means-plus-function" limitations (e.g., "means for applying a ringing signal"). For each such element, infringement analysis will require identifying the corresponding structure disclosed in the '664 patent specification and then determining whether the accused products contain that same structure or a structural equivalent that performs the identical function. For example, the court will have to determine what structure corresponds to the "means for indicating the availability of an idle line" and whether the accused products contain an equivalent structure (ʼ664 Patent, col. 10:2-4).
• Technical Questions: A primary technical question will be whether the accused products, if they are modern smart home or VoIP devices, "emulat[e] a wired line connection to a telephone central office" as described in the patent (ʼ664 Patent, col. 10:29-32). The specific signaling and interface protocols used by the accused products will be compared against the patent's disclosure of emulating analog telephone behaviors like dial tones and ringing signals (ʼ664 Patent, col. 4:38-44).
• Scope Questions: A potential dispute may arise over the scope of "short-range radio transceiver." While the patent’s preferred embodiment discloses using the Bluetooth standard (ʼ664 Patent, col. 2:51-54), the claim term itself is not so limited. The litigation may involve whether other short-range protocols (e.g., Wi-Fi, Zigbee) fall within the claim's scope.

V. Key Claim Terms for Construction

The Term

"means for indicating the availability of an idle line" (from Claim 1)

Context and Importance

This is a means-plus-function limitation under 35 U.S.C. § 112. Its construction is critical because it defines a core function of the claimed invention: alerting the user of a wired phone that the cellular link is available for making a call. The outcome of the infringement analysis depends on what specific structure from the patent is identified as performing this function and what range of equivalents that structure is afforded.

Intrinsic Evidence for Interpretation

• Evidence for a Broader Interpretation: The summary of the invention describes this function more generally as "indicating the availability of an idle line... when the second transceiver in the cellular phone is within communicating range... and the cellular telephone is not already in use" (ʼ664 Patent, col. 1:59-63). This language could support an argument that any method of indicating line availability performs the function.
• Evidence for a Narrower Interpretation: The specification explicitly links this function to a specific structure and action: "The interconnect device further includes means for... indicating the availability of an idle line (typically by transmitting a dial tone to the connected wired telephone)" (ʼ664 Patent, col. 1:59-62). Furthermore, the detailed description identifies a "dial tone source" within the "interface 14" as the structure that performs this function (ʼ664 Patent, col. 4:38-40). This suggests the corresponding structure is the dial tone source, potentially limiting the claim to devices that generate an audible dial tone.

VI. Other Allegations

Indirect Infringement

The complaint does not include a count for indirect infringement and pleads no specific facts to support the elements of inducement or contributory infringement, such as knowledge or intent (Compl. ¶1-16).

Willful Infringement

The complaint does not allege willful infringement in its counts for relief. The prayer for relief requests that the case be "declared exceptional" and for an award of attorneys' fees and "all appropriate damages under 35 U.S.C. § 284," which allows for enhancement of damages (Compl. p. 4, ¶D-E). However, the complaint pleads no specific facts regarding pre-suit or post-suit knowledge of the patent or infringement that would typically support a claim for willfulness.

VII. Analyst’s Conclusion: Key Questions for the Case

• A central issue will be one of structural correspondence: As the asserted claims are drafted in means-plus-function format, can Plaintiff identify corresponding structures in the patent's specification for each claimed "means for..." function and then prove that the accused products contain those exact structures or their equivalents?
• A key evidentiary question will be one of technical operation: Does the accused technology, which is not identified in the complaint, actually "emulat[e] a wired line connection" as contemplated by the patent, or does it operate on fundamentally different principles (e.g., as a native VoIP system) that fall outside the claimed invention?
• A threshold procedural question will be one of pleading sufficiency: Given the complaint’s reliance on an unprovided external exhibit to identify the accused products and explain its infringement theory, the case may face early challenges regarding whether the allegations meet the plausibility standards required by federal pleading rules.