CelluPlex LLC v. AT&T Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: CelluPlex LLC (NM)
  • Defendant: AT&T, Inc. (DE)
  • Plaintiff’s Counsel: Rabicoff Law LLC
• Case Identification: 2:24-cv-00789, E.D. Tex., 09/27/2024
• Venue Allegations: Venue is alleged to be proper based on Defendant having an established place of business in the district and having committed acts of patent infringement there.
• Core Dispute: Plaintiff alleges that certain unidentified AT&T products and services infringe a patent related to interfacing a cellular telephone with a wired telephone network.
• Technical Context: The technology concerns devices that allow a user to make and receive cellular calls using a conventional wired telephone handset, effectively treating the cellular connection as an additional landline.
• Key Procedural History: The complaint does not mention any prior litigation, inter partes review proceedings, or licensing history related to the patent-in-suit.

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" (Issued Feb. 13, 2007)

The Invention Explained

• Problem Addressed: The patent describes the inconvenience faced by cellular telephone users when at home or in the office. Users often turn off their cell phones to conserve battery, causing them to miss calls, or must retrieve the phone from a different room to use it, forgoing the convenience of their wired telephone system (’664 Patent, col. 1:11-29).
• The Patented Solution: The invention is an "interconnect device" that links a Bluetooth-enabled cellular phone to a home or office's existing wired telephone network (’664 Patent, Abstract). This device emulates a standard telephone company trunk line, allowing a user to pick up any wired telephone on the network to make an outgoing call through the cellular network or answer an incoming call to their cellular number (’664 Patent, col. 2:16-34). The core components are a Bluetooth transceiver for communicating with the cell phone and an interface for connecting to the wired telephone network (’664 Patent, Fig. 1).
• Technical Importance: This approach allows users to consolidate their communications, using a single cellular number while leveraging the superior ergonomics, audio quality, and multi-phone access of a conventional wired system (’664 Patent, col. 2:35-44).

Key Claims at a Glance

• The complaint alleges infringement of "one or more claims," including "exemplary method claims," but does not specify any particular claims (Compl. ¶11). The patent’s broadest independent apparatus claim is Claim 1.
• Claim 1 Elements:
  • 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.
  • The interface emulates a wired line connection to a telephone central office.
  • The interface includes means for handling an outgoing call, which comprises:
    • Means for indicating an idle line is available when the transceivers are in range and the cellular phone is not in use.
    • Means for receiving a telephone number from the wired telephone.
    • Means for transmitting that number via the transceivers to the cellular phone to initiate the call.
  • The interface also includes means for handling an incoming call.

III. The Accused Instrumentality

Product Identification

• The complaint does not identify any specific accused products, methods, or services by name in its main body (Compl. ¶¶1-16). It refers to "Exemplary Defendant Products" that are purportedly identified in an "Exhibit 2" (Compl. ¶11, 13). This exhibit was not filed with the complaint.

Functionality and Market Context

• The complaint does not provide sufficient detail for analysis of the accused instrumentality's functionality or market context. It alleges only that the unidentified "Exemplary Defendant Products practice the technology claimed by the '664 Patent" (Compl. ¶13).

IV. Analysis of Infringement Allegations

The complaint alleges that Defendant infringes by "making, using, offering to sell, selling and/or importing" the accused products and that Defendant's employees also directly infringe by "internally test[ing] and use[ing]" these products (Compl. ¶¶11-12). The complaint’s substantive infringement allegations are contained entirely within a referenced "Exhibit 2," which was not provided with the public filing (Compl. ¶13). The complaint states that these charts show that the "Exemplary Defendant Products satisfy all elements of the Exemplary '664 Patent Claims" (Compl. ¶13). No probative visual evidence provided in complaint.

• Identified Points of Contention:
  • Given the lack of specific allegations, any analysis is preliminary. However, disputes in cases involving this technology often center on the following questions:
  • Scope Questions: Does the accused system's method for connecting a cellular device to other hardware constitute "emulating a wired line connection" as described in the patent, which focuses on mimicking a traditional central office trunk line? (’664 Patent, col. 2:16-18).
  • Technical Questions: What specific hardware and software components in the accused system perform the functions of the claimed "interface"? How does the accused system technically achieve the claimed "means for indicating the availability of an idle line," and does it correspond to the dial tone mechanism described in the patent? (’664 Patent, col. 1:59-62; col. 4:38-44).

V. Key Claim Terms for Construction

The complaint does not provide a basis for identifying specific claim construction disputes. However, based on the technology, the following term from independent claim 1 of the ’664 Patent may be central to the litigation.

• The Term: "emulating a wired line connection...to a telephone central office"
• Context and Importance: This term appears foundational to what the "interface" element must achieve. The scope of "emulating" will be critical. A narrow definition might require the accused device to replicate specific electrical and signaling characteristics of a traditional POTS (Plain Old Telephone Service) line, while a broader definition might cover any system that functionally makes a cellular connection accessible via a wired handset. Practitioners may focus on this term because modern VoIP and digital systems may achieve a similar result without strictly "emulating" a legacy central office connection.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The patent’s "Summary of the Invention" describes the device in functional terms, stating it "emulates the behavior of a standard wired telephone trunk line to a central office," suggesting the focus is on the user-perceived behavior rather than the underlying technical method (’664 Patent, col. 2:16-18).
  • Evidence for a Narrower Interpretation: The detailed description repeatedly references specific legacy telephone system behaviors, such as providing a "dial tone," responding to an "off hook" condition, and applying a "ringing signal," which could support a narrower construction tied to these specific analog signals (’664 Patent, col. 4:30-44; col. 5:11-13).

VI. Other Allegations

• Indirect Infringement: The complaint does not contain an explicit count for indirect infringement and does not allege specific facts supporting inducement or contributory infringement, such as knowledge or intent based on user manuals or advertising (Compl. ¶¶1-16).
• Willful Infringement: The complaint does not use the term "willful." However, the prayer for relief requests that the case be "declared exceptional within the meaning of 35 U.S.C. § 285" (Compl. p. 4, ¶E.i). The complaint does not plead any facts to support a finding of exceptionality, such as pre-suit knowledge of the patent or egregious conduct.

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

1. Question of Specificity: The initial phase of litigation will likely center on the complaint’s lack of factual detail. A primary question is whether the complaint, which relies entirely on an unfiled exhibit to identify the accused products and infringement theory, provides sufficient notice under federal pleading standards.
2. Question of Claim Scope: Assuming the case proceeds, a core issue will be one of definitional scope: can the term "emulating a wired line connection," which is described in the patent with reference to legacy telephone network signals, be construed to cover the functionality of modern digital communication systems that may be accused of infringement?
3. Question of Technical Operation: A key evidentiary question will be one of functional correspondence: what specific structures within the accused products, once identified, perform the functions recited in the patent's means-plus-function limitations (e.g., "means for indicating the availability of an idle line"), and do they operate in a way that is structurally equivalent to the implementations disclosed in the patent's specification?