CommPlex Systems LLC v. CommScope Holding Co Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: CommPlex Systems LLC (NM)
  • Defendant: CommScope Holding Company, Inc. (DE)
  • Plaintiff’s Counsel: Rabicoff Law LLC
• Case Identification: 2:25-cv-00342, E.D. Tex., 04/07/2025
• Venue Allegations: Venue is alleged to be proper in the Eastern District of Texas because the Defendant maintains an established place of business in the district and has allegedly committed acts of patent infringement there.
• Core Dispute: Plaintiff alleges that Defendant’s communication products infringe a patent related to high-data-rate transmission systems that use multiple orthogonal frequencies to encode digital data.
• Technical Context: The technology at issue relates to digital modulation techniques, specifically methods for increasing the amount of data that can be transmitted within a given frequency bandwidth, a critical factor in modern wireless and wired communications.
• Key Procedural History: The complaint does not mention any prior litigation, Inter Partes Review (IPR) proceedings, or licensing history related to the patent-in-suit.

Case Timeline

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

U.S. Patent No. 7,864,900 - "Communication system for sending and receiving digital data," issued January 4, 2011

The Invention Explained

• Problem Addressed: The patent describes a problem in conventional Frequency Shift Keying (FSK) systems where inaccuracies in determining the center frequency—caused by component aging or temperature changes—can lead to a "distorted mark/space ratio in the demodulated data," resulting in transmission errors (’900 Patent, col. 1:56-65). The background also suggests a need for systems that can achieve higher data rates and greater "code density" within a limited bandwidth (’900 Patent, col. 3:12-17).
• The Patented Solution: The invention proposes a "Multiple Orthogonal locked frequencies Narrow Band Frequency Shift Keying (Mary-NBFSK) system" (’900 Patent, col. 4:9-11). Instead of transmitting a single frequency to represent a data bit (e.g., one frequency for a '0' and another for a '1'), the system simultaneously transmits a combination of frequencies selected from a larger set of available orthogonal frequencies to represent a block of data bits (’900 Patent, Abstract). For example, the system can use a look-up table to map a 10-bit data block to a specific pair of frequencies out of 32 available frequencies, which are then transmitted together (’900 Patent, col. 6:62-67). This approach claims to increase the data rate for a given bandwidth.
• Technical Importance: This method of encoding data using combinations of multiple frequencies, rather than single frequencies, represents a technique for increasing spectral efficiency, allowing more information to be sent over the same communication channel.

Key Claims at a Glance

• The complaint asserts infringement of one or more claims, referring to them as the "Exemplary '900 Patent Claims" without specifying claim numbers (Compl. ¶11). Independent claim 1 is representative.
• The essential elements of independent claim 1 include:
  • A communication system with a transmitter and a receiver.
  • A "general binary coded Orthogonal Frequency-Division Multiplexing carrier scheme" to increase code density and data rate.
  • A plurality of "narrow band carrier frequencies" that are orthogonal and "transmitted in a binary code to represent data."
  • The narrow band carrier frequencies having a separation "of the order of 0.1 MHz" and providing a bandwidth "of the order of 3.2 MHz for 32 carriers."
  • The system allows the bandwidth to transmit "at least 6 Mbps in a 2 of 32 Orthogonal Frequency-Division Multiplexing" scheme.
• The complaint does not explicitly reserve the right to assert dependent claims, but the general reference to "one or more claims" suggests this possibility (Compl. ¶11).

III. The Accused Instrumentality

Product Identification

The complaint identifies the accused instrumentalities as "the Defendant products identified in the charts incorporated into this Count below (among the 'Exemplary Defendant Products')" (Compl. ¶11).

Functionality and Market Context

The complaint does not describe the specific functionality or market context of the accused products. It alleges that infringement details are provided in "charts comparing the Exemplary '900 Patent Claims to the Exemplary Defendant Products" contained in Exhibit 2 (Compl. ¶16). This exhibit was not filed with the complaint and is not available for analysis. No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint alleges that the "Exemplary Defendant Products practice the technology claimed by the '900 Patent" and "satisfy all elements of the Exemplary '900 Patent Claims" (Compl. ¶16). However, it does so by incorporating by reference the claim charts in Exhibit 2, which are not provided (Compl. ¶17). As such, a detailed element-by-element analysis based on the complaint's allegations is not possible.

Identified Points of Contention

Based on the language of claim 1 of the ’900 Patent, the infringement analysis will likely raise several technical and legal questions:

• Scope Questions: The complaint's theory appears to depend on a broad reading of "Orthogonal Frequency-Division Multiplexing carrier scheme" (’900 Patent, col. 8:62). A central dispute may be whether the accused products, which may use standardized technologies like modern OFDM, fall within the specific scheme described and claimed in the patent, particularly as detailed in the "Mary-NBFSK" embodiments (’900 Patent, col. 4:9-11).
• Technical Questions: The claims recite specific numerical limitations. A key factual question will be whether the accused products operate with a frequency separation "of the order of 0.1 MHz," a bandwidth "of the order of 3.2 MHz for 32 carriers," and a data rate of "at least 6 Mbps" under the claimed "2 of 32" transmission scheme (’900 Patent, col. 9:1-10). The complaint provides no evidence to support these specific technical parameters.

V. Key Claim Terms for Construction

• The Term: "Orthogonal Frequency-Division Multiplexing carrier scheme" (’900 Patent, col. 8:62)

  • Context and Importance: This term defines the core technology of the invention. The outcome of the case may depend on whether this term is construed broadly to cover any system using OFDM principles or narrowly to cover only the specific "Mary-NBFSK" system detailed in the patent's preferred embodiments.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The claim uses the general term "Orthogonal Frequency-Division Multiplexing," a well-known term of art, which could support an argument that it should be given its plain and ordinary meaning in the field (’900 Patent, col. 8:62).
    • Evidence for a Narrower Interpretation: The specification repeatedly describes the invention as a "Multiple Orthogonal locked frequencies Narrow Band Frequency Shift Keying (Mary-NBFSK)" system, which involves mapping data bits to combinations of frequencies via a look-up table (’900 Patent, col. 4:9-11; col. 6:49-54). A defendant may argue this specific implementation limits the scope of the more general claim term.

• The Term: "of the order of" (’900 Patent, col. 9:7, 9:8)

  • Context and Importance: This term qualifies two critical numerical limitations: the frequency separation ("0.1 MHz") and the total bandwidth ("3.2 MHz"). Practitioners may focus on this term because its inherent imprecision makes it a likely subject for disputes over indefiniteness or non-infringement.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: The use of "of the order of" suggests the patentee did not intend to be limited to the exact numerical values recited, but to a range reasonably close to them. The patent provides an example of 100 KHz (0.1 MHz) separation, but does not state this is the only possibility (’900 Patent, col. 4:38-39).
    • Evidence for a Narrower Interpretation: A defendant may argue that without a more precise definition in the specification, the term is ambiguous and fails to inform a person of ordinary skill about the bounds of the claim, potentially rendering it indefinite. Alternatively, they may argue their own product's parameters fall outside any reasonable interpretation of this range.

VI. Other Allegations

Indirect Infringement

The complaint alleges induced infringement, stating that Defendant distributes "product literature and website materials inducing end users and others to use its products in the customary and intended manner that infringes the '900 Patent" (Compl. ¶14).

Willful Infringement

The complaint alleges that service of the complaint itself provides "actual knowledge of infringement" and that Defendant's subsequent activities constitute ongoing infringement despite this knowledge (Compl. ¶¶13, 14). The prayer for relief requests enhanced damages under 35 U.S.C. § 284, the statutory basis for a willfulness finding (Compl. p. 4, ¶D).

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

This dispute, as framed by the high-level complaint, will likely center on two fundamental types of questions for the court:

• A core issue will be one of definitional scope: can the claim term "Orthogonal Frequency-Division Multiplexing carrier scheme," as used in the patent, be construed to cover the potentially standardized technologies used in Defendant's modern communication products, or is it limited to the specific "Mary-NBFSK" look-up table architecture described in the specification?
• A key evidentiary question will be one of technical and numerical compliance: assuming the complaint survives a motion to dismiss, discovery will be required to determine whether the accused products actually operate within the specific numerical constraints recited in the claims, such as the frequency separation "of the order of 0.1 MHz" and the data rate of "at least 6 Mbps" in a "2 of 32" configuration.