DCT

2:25-cv-00628

Optimnet LLC v. Verizon Communications Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:25-cv-00628, E.D. Tex., 06/12/2025
  • Venue Allegations: Plaintiff alleges venue is proper in the Eastern District of Texas based on Defendants' commission of infringing acts within the district, the presence of regular and established places of business such as retail stores, and the derivation of substantial revenue from Texas.
  • Core Dispute: Plaintiff alleges that Defendant’s fiber-optic network infrastructure and services, which are compliant with the NG-PON2 and OTN industry standards, infringe five patents related to optical network data transmission and management.
  • Technical Context: The lawsuit concerns technologies foundational to high-speed telecommunications, including Passive Optical Networks (PON) and Optical Transport Networks (OTN), which are critical for services like 5G wireless backhaul and fiber-to-the-home broadband.
  • Key Procedural History: The asserted patents, originally assigned to the Electronics and Telecommunications Research Institute (ETRI), were declared as potentially essential to the ITU-T G.989.3 (NG-PON2) and G.709/Y.1331 (OTN) standards. The complaint alleges ETRI made a commitment to license these patents on reasonable and non-discriminatory (RAND) terms, and that Defendant, despite participating in and implementing these standards, did not seek a license.

Case Timeline

Date Event
2009-03-06 Priority Date for ’085 Patent
2009-10-15 ETRI makes OTN IPR Declaration for G.709/Y.1331 standard
2009-12-21 Priority Date for ’323 Patent
2012-11-28 Priority Date for ’968 Patent
2013-02-05 Priority Date for ’351 Patent
2014-04-01 ’085 Patent Issued
2014-04-30 Priority Date for ’710 Patent
2014-07-15 ’323 Patent Issued
2015-01-19 ETRI makes NG-PON2 IPR Declaration for G.989.3 standard
2015-09-15 ’968 Patent Issued
2015-11-24 ’351 Patent Issued
2017-06-30 Verizon publishes OpenOMCI Specification Version 1.00
2017-11-21 ’710 Patent Issued
2018-08-22 Verizon's Network Roadmap is stated to include NGPON-2
2019-06-06 Verizon announces plans to deploy NG-PON2 for 5G mobile services
2020 Verizon and Infinera test 800G transport on network between Dallas and Atlanta
2025-06-12 Complaint Filed

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

U.S. Patent No. 9,136,968 - “Time and wavelength division multiplexing—passive optical network (TWDM-PON) system and communication link method thereof”

  • Patent Identification: U.S. Patent No. 9,136,968, titled “Time and wavelength division multiplexing—passive optical network (TWDM-PON) system and communication link method thereof,” issued September 15, 2015 (Compl. ¶68).

The Invention Explained

  • Problem Addressed: In a Time and Wavelength Division Multiplexing Passive Optical Network (TWDM-PON) with multiple Optical Line Terminals (OLTs), traffic loads can become imbalanced. Some OLTs may be heavily loaded while others are underutilized, leading to inefficient use of network resources and potentially degraded service quality for users connected to the congested OLTs (Compl. ¶72; ’968 Patent, col. 2:45-61).
  • The Patented Solution: The patent describes a method for dynamically reassigning an Optical Network Unit (ONU) from one OLT to another to balance traffic loads. The method involves the ONU receiving a "wavelength change instruction," changing its operating wavelength to match that of a different, less-congested OLT, and then establishing a new communication link with that new OLT after receiving a discovery grant signal (’968 Patent, Abstract; col. 4:10-54).
  • Technical Importance: This dynamic OLT-switching allows for flexible management of network capacity in response to fluctuating traffic demands, improving overall network efficiency and service reliability (’968 Patent, col. 2:55-61).

Key Claims at a Glance

  • The complaint references infringement of at least independent claim 10 (via its reference to an unattached exhibit for a method claim) (’968 Patent, col. 17:21-36).
  • The essential elements of independent claim 10 are:
    • Receiving from a first OLT a wavelength change instruction to change to an operating wavelength of a second OLT.
    • In response, changing the wavelength to synchronize to a downstream signal of that operating wavelength.
    • Receiving an upstream discovery grant signal from the second OLT and transmitting a signal to notify receipt of that grant.
  • The complaint does not explicitly reserve the right to assert dependent claims for this patent.

U.S. Patent No. 9,197,351 - “Method of selecting wavelength of optical network unit in passive optical network”

  • Patent Identification: U.S. Patent No. 9,197,351, titled “Method of selecting wavelength of optical network unit in passive optical network,” issued November 24, 2015 (Compl. ¶83).

The Invention Explained

  • Problem Addressed: When an ONU first joins a complex passive optical network with multiple OLTs using different protocols (e.g., EPON and GPON), it is difficult for the ONU to determine the correct initial wavelength to use for communication. Conventional methods required a central "master OLT" to manage the status of all other OLTs, which is complex and difficult to implement (Compl. ¶87; ’351 Patent, col. 1:58-2:11).
  • The Patented Solution: The patent discloses a method for an ONU to autonomously select its initial operating wavelength. The ONU selects an "available wavelength candidate" from a pre-loaded default list, attempts to synchronize with the corresponding downstream signal, and then transmits a registration request to the OLT. If this process fails, the ONU selects a different wavelength candidate and repeats the process until a connection is established (’351 Patent, Abstract; col. 3:1-17).
  • Technical Importance: This autonomous selection process simplifies network initialization for ONUs, enhancing interoperability in multi-vendor, multi-protocol environments without requiring complex, centralized management (’351 Patent, col. 2:7-11).

Key Claims at a Glance

  • The complaint alleges infringement of at least independent claim 1 (Compl. ¶90).
  • The essential elements of independent claim 1 are:
    • Selecting an "available wavelength candidate" from a pre-loaded default or a changed wavelength.
    • Acquiring frame synchronization for a downstream signal matching the candidate wavelength.
    • Transmitting a registration request message to the corresponding OLT.
    • Registering the ONU in the OLT.
  • The complaint does not explicitly reserve the right to assert dependent claims for this patent.

U.S. Patent No. 9,825,710 - “Method and system for determining and controlling power of optical transmitter of optical network unit for time and wavelength division multiplexing passive optical network”

  • Patent Identification: U.S. Patent No. 9,825,710, “Method and system for determining and controlling power of optical transmitter of optical network unit for time and wavelength division multiplexing passive optical network,” issued November 21, 2017 (Compl. ¶98).
  • Technology Synopsis: The patent addresses signal degradation caused by crosstalk between different wavelength channels in a TWDM-PON. It discloses a method for an OLT to collect Received Signal Strength Indication (RSSI) data from all connected ONUs, determine the optimal optical transmitter power for each ONU to minimize interference, and then transmit control messages to the ONUs instructing them to adjust their power levels accordingly (Compl. ¶102; ’710 Patent, Abstract).
  • Asserted Claims: Claim 1 is referenced (Compl. ¶105).
  • Accused Features: Verizon's NG-PON2 network and its associated management systems are alleged to infringe by performing power control of ONU optical transmitters (Compl. ¶¶25, 27).

U.S. Patent No. 8,781,323 - “Packet transport layer passive optical network (PTL-PON) providing system and method”

  • Patent Identification: U.S. Patent No. 8,781,323, “Packet transport layer passive optical network (PTL-PON) providing system and method,” issued July 15, 2014 (Compl. ¶113).
  • Technology Synopsis: The patent addresses the challenge of managing and monitoring connections across a network that combines a managed Packet Transport Layer (PTL) in the core with a typically unmanaged PON access network. The invention makes the end-user's ONT/ONU an endpoint of the PTL connection itself, enabling end-to-end connection state management and quality control from one subscriber to another (Compl. ¶117; ’323 Patent, Abstract).
  • Asserted Claims: Claim 1 is referenced (Compl. ¶120).
  • Accused Features: Verizon's end-to-end fiber network architecture, which provides managed services over a PON infrastructure, is alleged to infringe (Compl. ¶¶32, 38).

U.S. Patent No. 8,689,085 - “method and apparatus for transmitting data in optical transport network”

  • Patent Identification: U.S. Patent No. 8,689,085, “method and apparatus for transmitting data in optical transport network,” issued April 1, 2014 (Compl. ¶128).
  • Technology Synopsis: The patent addresses the need for stronger forward error correction (FEC) for high-speed (100+ Gbit/s) OTU4 signals without degrading performance by increasing the overall bit rate. The invention proposes a novel OTU4 frame structure with a first "in-band area" for client data and a second "out-band area" for parity information, which allows for a more powerful error correction code to be implemented efficiently (Compl. ¶132; ’085 Patent, Abstract).
  • Asserted Claims: Claim 1 is referenced (Compl. ¶135).
  • Accused Features: Verizon’s OTU4 network infrastructure, which allegedly implements the ITU-T G.709/Y.1331 standard, and associated hardware like Infinera transponders and muxponders are accused of infringement (Compl. ¶21).

III. The Accused Instrumentality

Product Identification

The accused instrumentalities are Verizon's fiber-optic networks and the services provided over them, including the NG-PON2 and OTU4 networks that support services like "5G Ultra Wideband," "Fios," and cellular backhaul (Compl. ¶¶21, 25, 32). Specific hardware identified includes Optical Line Terminals (OLTs) such as the Calix AXOS E9-2, Optical Network Terminals (ONTs) like the Nokia TW-210X-A, and OTN hardware from Infinera (Compl. ¶¶21, 25).

Functionality and Market Context

The complaint alleges these networks implement the ITU-T G.989.3 (NG-PON2) and G.709/Y.1331 (OTN) standards (Compl. ¶¶4, 7). Their accused functionality includes the ability to dynamically manage ONU connections to different OLTs, control ONU transmitter power levels, and transmit data using OTU4 framing. The complaint emphasizes the commercial importance of this infrastructure, particularly Verizon's "One Fiber" project, as foundational to its 5G and advanced broadband strategies (Compl. ¶¶22, 30, 34-35).

No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint references but does not attach exhibits containing claim charts. The following analysis is based on the complaint's narrative allegations and the patent claims.

  • ’968 Patent Infringement Allegations
Claim Element (from Independent Claim 10) Alleged Infringing Functionality Complaint Citation Patent Citation
receiving from the first OLT a wavelength change instruction requesting to change a wavelength to an operating wavelength allocated to the second OLT; Verizon's NG-PON2 network management system allegedly sends instructions to an ONU to switch its operating wavelength to connect to a different OLT, for purposes such as load balancing. ¶¶72, 74 col. 17:22-25
in response to the wavelength change instruction, changing the wavelength to synchronize to a downstream signal of the operating wavelength; The accused tunable ONUs, upon receiving the instruction, allegedly change their operating wavelength and synchronize to the downstream signal of the new OLT. ¶¶25, 74 col. 17:26-29
receiving an upstream discovery grant signal from the second OLT and transmitting a signal notifying receipt of the upstream discovery grant signal to the second OLT. After tuning, the ONU allegedly receives a discovery grant from the new OLT, enabling it to establish a communication link, and sends an acknowledgement. ¶¶72, 74 col. 17:30-33

  • Identified Points of Contention:

    • Technical Question: What evidence demonstrates that Verizon's network actually performs the claimed dynamic, load-balancing-driven OLT switching in practice, as opposed to merely possessing equipment with such a capability?
    • Scope Question: Does a general network management command issued under a standard protocol, such as Verizon's OpenOMCI specification (Compl. ¶28), constitute the specific "wavelength change instruction" as contemplated by the patent?

  • ’351 Patent Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
selecting, as an available wavelength candidate, a pre-loaded default wavelength or a wavelength corresponding to a wavelength changed in response to a preset wavelength changing condition being satisfied; Accused ONUs, when initializing on Verizon's multi-wavelength NG-PON2 network, allegedly select an initial wavelength from a pre-loaded or default set of candidates to attempt connection. ¶¶28, 87, 89 col. 15:15-20
acquiring frame synchronization for a downstream signal having a same wavelength as the selected available wavelength candidate; After selecting a candidate wavelength, the ONU allegedly synchronizes with the corresponding downstream signal being broadcast by an OLT on that wavelength. ¶¶87, 89 col. 15:21-24
transmitting a registration request message to an optical line terminal (OLT) from which the downstream signal has been transmitted...; and Once synchronized, the ONU allegedly transmits a message to the OLT to request formal registration on the network. ¶¶87, 89 col. 15:25-29
registering the ONU in the OLT. The OLT allegedly processes the request and registers the ONU, completing the connection process. ¶¶87, 89 col. 15:30-31
  • Identified Points of Contention:
    • Technical Question: Does the boot-up sequence of the accused ONUs follow the specific iterative logic of the claim, including the implied step of selecting a new candidate wavelength if a prior registration attempt fails?
    • Scope Question: Does the term "available wavelength candidate" require the ONU to select from a plurality of options, and if so, does the accused ONU's operation meet this requirement, or does it simply use a single, non-selectable factory default?

V. Key Claim Terms for Construction

  • The Term: "wavelength change instruction" (’968 Patent)

  • Context and Importance: The infringement reading for the ’968 Patent depends on whether general network management commands within Verizon's system constitute this specific instruction. Its construction will determine if routine, standards-based network configuration messages can be mapped to the claim language. Practitioners may focus on this term because the patent describes it within the context of dynamic load balancing, which may be more specific than the general capabilities of the accused network.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: Claim 10 describes the instruction's function as "requesting to change a wavelength to an operating wavelength allocated to the second OLT" (’968 Patent, col. 17:23-25), which could be argued to encompass any message that achieves this outcome.
    • Evidence for a Narrower Interpretation: The specification suggests the instruction may contain more specific information, such as "information on a point of time when the first ONU starts a tuning process to change a wavelength" (’968 Patent, col. 4:15-18), potentially narrowing its scope beyond a simple command.

  • The Term: "available wavelength candidate" (’351 Patent)

  • Context and Importance: This term is central to the ’351 Patent infringement theory, as it requires an act of selection by the ONU. The case may turn on whether the accused ONUs perform a selection from multiple options or simply use one fixed default. Practitioners may focus on this term to distinguish the patented method from a conventional, single-default boot-up process.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The claim recites selecting either a "pre-loaded default wavelength" or a changed wavelength, which could be interpreted broadly to cover any initial wavelength an ONU uses to attempt connection (’351 Patent, col. 15:16-20).
    • Evidence for a Narrower Interpretation: The use of "candidate" and the condition-based logic for changing the wavelength imply a structured selection process from a set of possibilities, not just the use of a single, immutable default. The process described is iterative, suggesting a choice is made if a prior attempt fails (e.g., '351 Patent, col. 5:35-49).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that Verizon induces infringement by supplying the accused network equipment and providing instructions, specifications (e.g., the "Verizon OpenOMCI Specification"), and services that direct and encourage network operators and end-users to operate the equipment in an infringing manner (Compl. ¶¶28, 77, 92).
  • Willful Infringement: Willfulness allegations are based on Verizon’s alleged knowledge of the asserted patents, stemming from ETRI's public declarations to the ITU-T standards-setting body that the patents were potentially essential to the NG-PON2 and OTN standards. The complaint alleges that Verizon participated in developing and implementing these standards and therefore knew, or was willfully blind to the fact, that its standards-compliant network infringed the patents (Compl. ¶¶4-8, 78-79, 138-139).

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

  • A central issue will be one of standards, licensing, and notice: Given the patents were declared to a standards body with a RAND licensing commitment, the case will raise questions of whether implementing the standard constitutes infringement, what constitutes good-faith negotiation, and whether Verizon’s alleged awareness of the declarations satisfies the knowledge requirement for willful infringement.
  • A key evidentiary challenge will be one of proving infringing operation: Can the Plaintiff demonstrate that Verizon's network actively and regularly performs the specific, dynamic methods claimed in the patents (e.g., load-balancing via OLT-switching), or will the evidence only show that the network components merely possess a latent, standards-based capability to do so?
  • The outcome may hinge on claim construction and technical scope: The dispute will likely focus on whether the generalized functions of a standards-compliant system meet the specific limitations of the claims. For instance, can a generic "configure" command be construed as the specific "wavelength change instruction" of the ’968 patent, or does a standard boot-up sequence embody the iterative "selection" process of the ’351 patent?