US 11431431

Patent Analyst Report: US 11,431,431 B2

Date of Analysis: May 6, 2026

This report provides a concise summary of United States Patent No. 11,431,431 B2, including its key bibliographical data, abstract, and a plain-language overview of its independent claims. The analysis also notes any relevant legal proceedings found in the public record.

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I. Patent Overview

Title:	Add/drop multiplexer, network system, transmission method, non-transitory computer readable medium, and management device
Assignee:	Radiant Patents LLC
Inventor:	Yurie Matsuyama
Filing Date:	June 23, 2021
Priority Date:	January 27, 2015
Issue Date:	August 30, 2022
Abstract:	Provided is a wavelength path communication node device with no collision of wavelengths and routes, capable of outputting arbitrary wavelengths, and capable of outputting them to arbitrary routes. An add/drop multiplexer (11) includes a communication unit (101) that communicates an optical signal with at least one client device and at least one network and a control unit (102) that indicates a transfer destination of the optical signal according to an attribute of the received optical signal to the communication unit (101). The control unit (102) indicates an attenuation amount of the optical signal to the communication unit (101) for each connected device. When a connected device is changed, the control unit (102) instructs the communication unit (101) to change the attenuation amount. The communication unit (101) attenuates the optical signal with the attenuation amount indicated by the control unit (102) and transfers the attenuated optical signal to a transfer destination.

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II. Plain-Language Summary of Independent Claims

US Patent 11,431,431 B2 contains three independent claims (1, 4, and 7). Below is a simplified explanation of the core invention protected by each.

• Independent Claim 1: This claim describes an optical communication device. The device is designed to take a combined light signal (a "wavelength multiplexed signal") and separate it into multiple individual light signals. It then uses an attenuator to adjust the power of one of these individual signals before sending it to a connected optical device. A key feature is a controller that receives information about what type of device is connected (e.g., a "first optical device" versus a "second optical device"). Based on this information, the controller tells the attenuator how much to weaken the signal, using a specific attenuation amount that is appropriate for the identified device.

• Independent Claim 4: This claim broadens the scope to an entire optical communication system. This system includes the optical communication apparatus described in Claim 1, along with a separate "network management apparatus" that controls it. In this setup, the network management device is what sends the "connection information" about the connected target device to the optical communication apparatus. The optical communication apparatus then adjusts the signal attenuation based on this remotely provided information, applying different levels of attenuation for a "first optical device" compared to a "second optical device."

• Independent Claim 7: This claim outlines a method, or a series of steps, for optical communication. The method involves: 1) separating a combined light signal into individual signals; 2) weakening one of these individual signals before sending it to a connected optical device; and 3) receiving information about the specific type of device that is connected. The core of the method is that the amount of signal weakening (attenuation) is chosen based on this received information, with a different amount used if the connected device is a "first optical device" versus a "second optical device."

In essence, the patent protects the idea of an intelligent optical communication device or system that can adapt the power of the light signals it sends out based on the specific type of equipment it is connected to. This allows for more flexible and efficient network configurations.

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III. Legal Status and Litigation

As of the date of this report, US Patent 11,431,431 B2 is active and has been asserted in litigation.

• Litigation: Public records indicate that Radiant Patents LLC has filed a complaint for patent infringement against Nokia Corporation and Nokia of America Corporation in the U.S. District Court for the Eastern District of Texas (Case 2:26-cv-00074, filed January 26, 2026). US Patent 11,431,431 is one of the patents asserted in this case.

• Re-examination: A search of the USPTO's public records did not indicate any current or past ex parte or inter partes re-examination proceedings for this patent.

Disclaimer: This summary is based on publicly available information and is intended for informational purposes only. It does not constitute legal advice. For a complete understanding of the patent and its legal implications, consultation with a qualified patent attorney is recommended.

Based on the public record and previously generated information, here is the known litigation involving US Patent 11,431,431 as of May 8, 2026.

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Litigation History for US Patent 11,431,431

• Case 1
  • Plaintiff(s): Radiant Patents LLC
  • Defendant(s): Nokia Corporation; Nokia of America Corporation
  • Jurisdiction: U.S. District Court for the Eastern District of Texas
  • Case Number: 2:26-cv-00074
  • Filing Date: January 26, 2026
  • Outcome or Current Status: This case is currently active. As of the date of this report, the litigation is in its early stages.

Proceedings overview

The USPTO ODP API returns no AIA trial proceedings for this patent as of the most recent ingest. There is no PTAB activity on file for US Patent 11,431,431. This means all claims (1-9) of the patent remain untested at the PTAB.

Strategic summary

Currently, all claims of US 11,431,431 (claims 1-9) are UNTESTED at the PTAB. This means there are no claims that have been canceled or sustained in an AIA trial.

Since there are no PTAB proceedings, the estoppel landscape under § 315(e)(2) is currently clear. No petitioner, nor their privies, has been barred from raising any ground they raised or reasonably could have raised against this patent. For a defendant currently being asserted against, all prior-art grounds remain available for a potential IPR petition. There are no patterns of multiple IPR filings on this patent, nor has the patent owner pursued PTAB appeals related to IPRs. There is no indication of a defensive aggregator like Unified Patents in any PTAB proceedings for this patent.

Recommended next steps

If you are a defendant facing assertion of US 11,431,431, the absence of PTAB activity suggests that the patent has not yet faced a direct challenge to its validity through this forum. This could mean that potential prior art arguments have not been fully explored or tested in an efficient administrative setting. As such, considering an IPR petition against the patent's claims would be a viable defensive strategy.

Inventors

• Yurie Matsuyama: The sole inventor listed on the patent. At the time of the original Japanese filing (January 27, 2015), the original assignee was NEC Corporation, making it highly probable that Yurie Matsuyama was an employee of NEC Corporation. There are no unusual patterns, such as inventor departure, discernible from the public record.

Original assignee

• NEC Corporation: The original assignee is NEC Corporation, a major Japanese multinational information technology and electronics corporation headquartered in Tokyo, Japan. NEC is an operating company that develops and sells products in areas including telecommunications, semiconductors, and IT services. They have historically developed and shipped optical networking equipment, which would embody the claims of this patent. The company remains a major operating entity.

Assignment timeline

The USPTO Patent Assignment database records a clear chain of transfers from the original operating company to the current asserting entity.

• 2024-03-13 (executed) / recorded 2024-03-21 — Reel 066867/0886

  • Conveyance: Assignment
  • Assignor: NEC CORPORATION
  • Assignee: NEC Asia Pacific Pte Ltd.
  • Correspondent: Suzanne K. Henderson, Henderson, Franklin, Starnes & Holt, P.A., Fort Myers, FL
  • Context: Internal corporate reorganization, moving the patent from the Japanese parent company to a Singapore-based subsidiary.

• 2024-09-30 (executed) / recorded 2024-10-03 — Reel 068783/0632

  • Conveyance: Assignment
  • Assignor: NEC Asia Pacific Pte Ltd.
  • Assignee: IP WAVE PTE. LTD.
  • Correspondent: Andrea Hence Evans, The Law Firm of Andrea Hence Evans, LLC, Forestville, MD
  • Context: A portfolio sale from the operating company's subsidiary to a known patent monetization firm that acquires patents from Japanese corporations for subsequent sale to asserting entities.

• 2025-02-17 (executed) / recorded 2025-03-20 — Reel 070575/0077 (Corrected by Reel 073349/0966)

  • Conveyance: Assignment
  • Assignor: IP WAVE PTE. LTD.
  • Assignee: PLS XLIV LLC
  • Correspondent: Kunal P. Shah, Leydig, Voit & Mayer, Ltd., Chicago, IL. This correspondent recurs on subsequent transfers in this chain.
  • Context: Transfer from the monetization firm to a special purpose LLC, likely created specifically to hold and assert this patent portfolio.

• 2025-04-29 (executed) / recorded 2025-10-01 — Reel 072987/0619

  • Conveyance: Change of Name
  • Assignor: PLS XLIV LLC
  • Assignee: RADIANT PATENTS LLC
  • Correspondent: Kunal P. Shah, Leydig, Voit & Mayer, Ltd., Chicago, IL. The same correspondent from the prior transaction.
  • Context: A simple change of name for the holding LLC, establishing the final entity name that would be used for litigation.

Timeline diagram

timeline
    title Ownership of US 11431431
    2015 : Priority date via NEC Corp
    2022 : Issued to NEC Corp
    2024 : Assigned to NEC Asia Pacific
         : Sold to IP WAVE PTE LTD
    2025 : Sold to PLS XLIV LLC
         : Renamed to Radiant Patents LLC
    2026 : First infringement suit filed

NPE / troll-pattern signals

1. Shell-entity transfer — Present. The patent was moved from an operating company (NEC Corporation) to a series of LLCs and private limited companies (IP WAVE PTE. LTD., PLS XLIV LLC, Radiant Patents LLC) that do not appear to have commercial products. Radiant Patents LLC, the current assignee and plaintiff, is a Delaware LLC with a name indicating a patent-holding function. (Reels 068783/0632, 070575/0077, 072987/0619).

2. Known asserter in the chain — Present. Radiant Patents LLC is the plaintiff in litigation (Case 2:26-cv-00074) asserting this patent, making it a known asserter by definition.

3. Repeat correspondent across the chain — Present. The correspondent Kunal P. Shah of Leydig, Voit & Mayer, Ltd. handled the critical transfer from IP WAVE PTE. LTD. to PLS XLIV LLC (Reel 070575/0077), the subsequent corrective assignment (Reel 073349/0966), and the change of name to the final asserting entity, Radiant Patents LLC (Reel 072987/0619). This indicates a single agent managing the setup of the assertion vehicle.

4. Cascading transfers — Present. The patent was transferred from NEC's subsidiary to IP WAVE in October 2024, then from IP WAVE to PLS XLIV LLC in March 2025, followed by a name change to Radiant Patents LLC recorded in October 2025. This sequence of three transfers/name changes occurred within approximately 12 months.

5. Pre-litigation transfer — Present. The final change of name to Radiant Patents LLC was executed on April 29, 2025, and the litigation was filed on January 26, 2026. The transfer establishing the asserting entity's direct predecessor (PLS XLIV LLC) occurred on February 17, 2025. Both events fall within a year of the litigation filing, showing the patent was acquired for the purpose of assertion.

6. Bankruptcy fire-sale — Not present. The original assignee, NEC Corporation, is a solvent and operating company.

7. Privateering — Unclear. While this is a transfer from an operating company (NEC) to an NPE (Radiant Patents) that is now suing a competitor (Nokia), there is no public evidence of an ongoing financial relationship or agreement for NEC to share in the litigation proceeds.

8. Defensive aggregator (anti-NPE) — Not present. The chain does not terminate at a known defensive entity.

Verdict

• NPE — high confidence

This verdict is based on the presence of at least five strong, classic signals of NPE activity. The patent was transferred from its original creator, operating company NEC, through a monetization firm (IP WAVE) to a purpose-built LLC (PLS XLIV LLC, now Radiant Patents LLC) in a rapid cascade of transactions handled by a recurring correspondent (Reels 070575/0077 and 072987/0619). This entity then initiated litigation within a year of acquiring the patent, confirming the intent to assert without commercializing the invention.

Verify at the USPTO Patent Assignment Search Center (search for patent no. 11431431)

IV. Prior Art Analysis for US 11,431,431

This section evaluates the prior art references cited by the USPTO examiner during the prosecution of US Patent 11,431,431. The analysis focuses on the potential for these references to anticipate the patent's claims under 35 U.S.C. § 102. A claim is anticipated if every element of that claim is found in a single prior art reference. The independent claims (1, 4, 7) are the primary focus, as the invalidity of an independent claim typically renders its dependent claims invalid as well.

The core invention of US 11,431,431 is an optical communication apparatus (and corresponding system and method) that includes:

1. A demultiplexer to split a wavelength multiplexed signal.
2. An attenuator to adjust the power of a demultiplexed optical signal.
3. A controller that receives "connection information" about a "connected target" (i.e., the type of device connected to an output port).
4. The controller then sends a specific attenuation amount to the attenuator based on the type of device connected (e.g., a different amount for a "first optical device" vs. a "second optical device").

The following analysis examines the most relevant examiner-cited prior art in view of these core elements.

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Key Prior Art References

1. US Patent No. 6,959,149 B2 ("Nortel '149")

• Full Citation: US 6,959,149 B2, "Power balancing in DWDM optical networks," assigned to Nortel Networks Limited.
• Dates: Filed March 29, 2002; Published October 25, 2005.
• Brief Description: The Nortel '149 patent describes a method for power balancing in a dense wavelength division multiplexing (DWDM) optical network. It discloses a reconfigurable optical add-drop multiplexer (OADM) that includes variable optical attenuators (VOAs). A control system adjusts these attenuators to equalize the power levels of different wavelength channels. The system can adjust power levels based on factors like the number of active channels and the desired optical signal-to-noise ratio (OSNR).
• Potential Anticipation Analysis:
  • Claim 1 & 7: The Nortel '149 patent discloses a demultiplexer, an attenuator, and a controller that adjusts the attenuation amount. However, it does not appear to explicitly disclose receiving "connection information on a connected target" and then selecting an attenuation amount based on whether the target is a "first optical device" or a "second optical device." The adjustments in Nortel are based on internal network characteristics (like OSNR or channel count) rather than the identity or type of the external device connected to the output port. Therefore, Nortel '149 likely does not anticipate claims 1 and 7 as it is missing the key limitation of adjusting attenuation based on the type of connected device.
  • Claim 4: Since the base apparatus is not fully disclosed, the system claim also is not anticipated.

2. US Patent No. 7,257,288 B1 ("Nistica '288")

• Full Citation: US 7,257,288 B1, "Tunable optical routing systems," assigned to Nistica, Inc.
• Dates: Filed April 23, 2004; Published August 14, 2007.
• Brief Description: The Nistica '288 patent details a tunable optical routing system, such as a ROADM, that can route WDM signals. The system includes wavelength-selective switches (WSS) and arrays of variable optical attenuators (VOAs). A controller manages the VOAs to adjust the power of optical signals as they are routed through the system to different output ports.
• Potential Anticipation Analysis:
  • Claim 1 & 7: Similar to Nortel '149, the Nistica '288 patent teaches the use of a controller to manage variable attenuators for power balancing within an optical node. It describes routing different wavelengths to different ports and adjusting their power. However, the control logic described is for managing signal integrity within the network (e.g., equalization). The patent does not explicitly describe a controller that receives information identifying the type of external device connected to an output port and then sets the attenuation level based on that specific device's requirements (e.g., setting one attenuation level for a cross-connect and a different level for a client-side transponder). This critical element of the claims in US 11,431,431 appears to be absent.
  • Claim 4: The system claim is not anticipated for the same reasons.

3. US Patent Application Publication No. 2009/0297149 A1 ("Fujitsu '149")

• Full Citation: US 2009/0297149 A1, "Optical add/drop multiplexer," assigned to Fujitsu Limited.
• Dates: Filed May 28, 2008; Published December 3, 2009.
• Brief Description: The Fujitsu '149 publication describes an OADM with a wavelength selective switch (WSS) that includes a variable attenuator. It aims to suppress signal degradation by controlling the optical power of signals being added, dropped, or passed through. A control unit sets the attenuation loss of the variable attenuator.
• Potential Anticipation Analysis:
  • Claim 1 & 7: Fujitsu '149 discloses all the basic hardware components: a demultiplexer (within the WSS), an attenuator, and a controller. The controller's function is to maintain optimal power levels for network performance. However, like the other references, the crucial step of receiving "connection information on a connected target" and choosing an attenuation amount specifically based on the type of that target device (first vs. second device type) is not explicitly taught. The control is based on internal power monitoring and pre-set levels for network operation, not on adapting to different categories of external equipment.
  • Claim 4: The system claim is not anticipated for the same reasons.

4. US Patent Application Publication No. 2013/0315580 A1 ("Ciena '580")

• Full Citation: US 2013/0315580 A1, "Software defined networking photonic routing systems and methods," assigned to Ciena Corporation.
• Dates: Filed February 13, 2012; Published November 28, 2013.
• Brief Description: The Ciena '580 publication describes a software-defined networking (SDN) approach to controlling optical networks. It discloses a centralized controller that manages network elements like ROADMs. The controller can configure paths and set parameters, including power levels, on various components. This reference explicitly mentions controlling components based on the requirements of a connection.
• Potential Anticipation Analysis:
  • Claim 1, 4, & 7: Ciena '580 comes closer to the claimed invention by disclosing a centralized network management or SDN controller (as in claim 4) that sends instructions to an optical apparatus. The controller sets parameters for a connection. It is plausible that setting up a connection to a specific device would involve setting appropriate power levels for that device. However, the reference may not explicitly state the specific logic claimed: receiving "connection information" that identifies a "connected target" as a "first optical device" versus a "second optical device," and sending a corresponding attenuation amount based on that classification. While an SDN controller could be programmed to do this, the anticipation standard under § 102 requires the reference to explicitly or inherently disclose this feature. A defense for US 11,431,431 would argue that Ciena '580 teaches generalized SDN control without disclosing the specific claimed logic for adaptive attenuation based on device type.

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Summary of Analysis

The prior art cited by the examiner describes the fundamental building blocks of the claimed invention, including optical add/drop multiplexers, wavelength selective switches, variable optical attenuators, and controllers for power management. However, none of the reviewed references appear to explicitly disclose the key inventive concept of US 11,431,431: a controller that receives information identifying the type of device connected to an output and then adaptively sets a specific attenuation amount from a set of pre-determined amounts corresponding to different device types.

The prior art generally teaches power balancing for internal network reasons (e.g., OSNR, equalization) rather than for compatibility with different categories of external devices. While the Ciena '580 reference discusses high-level SDN control for setting up connections, it may lack the specific, granular detail required to anticipate the claims. Therefore, a strong argument can be made that the claims of US 11,431,431 are novel over these references.

Obviousness Analysis of US 11,431,431 under 35 U.S.C. § 103

Date of Analysis: May 8, 2026

Patent at Issue: US 11,431,431 B2 ("the '431 patent")

This analysis evaluates the obviousness of the independent claims of the '431 patent in view of prior art cited during its prosecution. Under 35 U.S.C. § 103, a patent claim is invalid if the differences between the claimed invention and the prior art are such that the subject matter as a whole would have been obvious at the time the invention was made to a person having ordinary skill in the art (POSITA).

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I. Summary of the Invention

The core concept of the '431 patent is an optical communication apparatus (such as an add/drop multiplexer) that dynamically adjusts the power level of an optical signal using a variable attenuator. The key feature is that the specific attenuation amount is selected by a controller based on "connection information" it receives about the target device to which the signal is being sent. The claims specify that a different attenuation amount is used if the connected target is a "first optical device" versus a "second optical device," allowing the apparatus to adapt to the different power requirements of various types of network equipment. Claim 4 extends this to a system where a central "network management apparatus" provides this connection information to the optical apparatus.

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II. Combination of Prior Art and Motivation to Combine

The independent claims of the '431 patent would have been obvious to a POSITA at the time of invention in view of the combination of the following prior art references cited in the patent's file history:

• Primary Reference: US 6,959,149 B2 to Nortel Networks Limited (hereinafter "'149 patent"), titled "Power balancing in DWDM optical networks."
• Secondary Reference: US 2013/0315580 A1 to Ciena Corporation (hereinafter "'580 application"), titled "Software defined networking photonic routing systems and methods."

A. Summary of Prior Art Teachings

• The '149 patent discloses an optical network node (like a reconfigurable optical add/drop multiplexer or ROADM) that performs power balancing on different wavelength channels in a Dense Wavelength Division Multiplexing (DWDM) system. It explicitly teaches using an array of variable optical attenuators (VOAs) to adjust the power of individual optical signals after they have been demultiplexed. A control processor calculates and applies the necessary attenuation to each channel to equalize power levels, preventing signal degradation. This reference establishes the common practice of using controlled attenuators within an optical node to manage signal power on a per-channel basis.

• The '580 application describes a Software-Defined Networking (SDN) architecture for controlling optical (photonic) networks. It teaches a centralized SDN controller (a "network management apparatus") that has a global view of the network topology and can dynamically configure network elements like optical switches and routers. This controller makes decisions based on high-level policies and knowledge of the network's state, including information about the various interconnected devices and their capabilities. The '580 application discloses that the SDN controller manages path computation and provisioning, which necessarily involves controlling physical layer parameters of the optical devices along the path.

B. Motivation to Combine

A person of ordinary skill in the art, when faced with the problem of managing optical power levels in a flexible and heterogeneous network, would have been motivated to combine the teachings of the '149 patent and the '580 application for the following reasons:

1. Automation of a Known Practice: The '149 patent teaches that power balancing is a critical function in DWDM systems and that it can be achieved with controllable attenuators. The '580 application teaches that modern networks are moving towards centralized, software-defined control for greater flexibility and automation. A POSITA would have found it obvious to apply the advanced control architecture of the '580 application to automate the necessary physical-layer task of power balancing taught in the '149 patent.

2. Addressing Heterogeneity: A key benefit of the SDN architecture in the '580 application is the ability to manage a network composed of diverse equipment. A POSITA would know that different types of optical devices (e.g., a short-reach client transceiver vs. a long-haul coherent transponder, or devices from different manufacturers) have different optimal input power requirements. Manually configuring attenuation for each connection is inefficient and error-prone, especially in a reconfigurable network. It would have been an obvious design choice to leverage the SDN controller's knowledge of the connected devices to automatically set the appropriate power levels.

3. Predictable Result: Combining the systems would yield the predictable result of a more efficient and robust network. The SDN controller from the '580 application would use its network inventory/topology data (the "connection information") to determine the type of device connected at a given port. It would then command the VOA controller in the optical node from the '149 patent to apply a pre-determined attenuation value suitable for that specific device type. This is not an inventive leap but rather the application of a known control paradigm (SDN) to a known optical component (VOA) to solve a well-understood problem (power balancing for heterogeneous devices).

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III. Claim-by-Claim Obviousness Analysis

Independent Claim 1: Optical Communication Apparatus

• "a demultiplexer configured to demultiplex a wavelength multiplexed signal...": Disclosed by the '149 patent (e.g., Fig. 2, demultiplexer 12). This is a fundamental component of any WDM node.
• "an attenuator configured to attenuate one of the plurality of optical signals...": Disclosed by the '149 patent (e.g., Fig. 2, VOA array 14).
• "a controller configured to receive a connection information on a connected target and send, to the attenuator, an attenuation amount according to the received connection information": The '149 patent discloses a control processor (16) that sends attenuation amounts to the VOAs (14). The '580 application discloses an SDN controller that has "connection information" about network devices and uses it to manage network elements. Combining these teaches a controller that uses connection information to set attenuation. The SDN controller of the '580 application provides the connection information, and the node controller of the '149 patent acts upon it to control the attenuator.
• "wherein the controller sends the attenuation amount corresponding to a first optical device when the connected target...is the first optical device, and...a second optical device...": This is an obvious implementation detail that would result from the motivation to combine. A POSITA, seeking to automate power balancing for a heterogeneous network using the SDN controller of the '580 application, would inherently program the controller to apply different settings for different device types. Storing a profile or lookup table with attenuation values for "Device Type A," "Device Type B," etc., would be a standard and obvious engineering practice.

Therefore, claim 1 is obvious over the combination of the '149 patent and the '580 application.

Independent Claim 4: Optical Communication System

This claim recites a system comprising a "network management apparatus" and the optical communication apparatus of claim 1, where the management apparatus controls the optical apparatus.

• This system is expressly taught by the combination. The SDN controller described in the '580 application is precisely a "network management apparatus." The combination involves this controller sending control information (the connection information and resulting attenuation amount) to the optical node disclosed in the '149 patent. This directly maps to the elements of claim 4, rendering it obvious for the same reasons as claim 1.

Independent Claim 7: Optical Communication Method

This claim recites the method steps performed by the apparatus of claim 1.

• The steps of "demultiplexing," "attenuating," "receiving a connection information," and "attenuating the optical signal with an attenuation amount according to the received connection information" are the inherent operations of the obvious apparatus and system described above. Since the apparatus that performs the method is obvious, the method itself is also obvious.

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IV. Conclusion

The independent claims of US Patent 11,431,431 are rendered obvious by the combination of US 6,959,149 B2 and US 2013/0315580 A1. The combination teaches all elements of the claims, and a person of ordinary skill in the art would have been motivated to combine their teachings to achieve a more automated and flexible optical network with optimized power levels, which is a predictable and expected outcome.

V. Patent Term, Adjustments, and Family Status for US 11,431,431

This section details the term of US Patent 11,431,431, including any adjustments or extensions, and outlines its relationship to other patent applications.

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Patent Term and Expiration

• Patent Term Adjustment (PTA): A review of the prosecution history for US Patent 11,431,431 indicates that there has been no Patent Term Adjustment granted by the USPTO. The application did not experience delays attributable to the USPTO that would warrant such an adjustment under 35 U.S.C. § 154(b).

• Patent Term Extension (PTE): There is no indication that this patent is eligible for or has received any Patent Term Extension under 35 U.S.C. § 156, which typically applies to patents covering products that undergo a lengthy pre-market regulatory review (e.g., by the FDA).

• Projected Expiration Date: The patent was granted from an application (US 17/355,469) filed on June 23, 2021. This application claims priority to an earlier non-provisional application filed on January 27, 2015. Under 35 U.S.C. § 154, the term of a US patent is 20 years from the filing date of the earliest U.S. non-provisional application to which priority is claimed.

  Therefore, the projected expiration date is January 27, 2035. This date is contingent on the timely payment of all required maintenance fees.

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Continuity and Family Data

US Patent 11,431,431 is part of a larger family of patents and applications that share a common priority claim.

• Continuation Applications:

  • This patent (issued from application US 17/355,469) is a continuation of application US 16/446,272 (now US Patent 11,095,387).
  • Application US 16/446,272 is itself a continuation of application US 15/545,588 (now US Patent 10,374,740).
  • A subsequent continuation application, US 17/871,382 (now US Patent 11,973,579), was filed that also claims continuity from this family.

• Divisional Applications: There are no divisional applications related to US 11,431,431.

• Domestic and Foreign Priority:

  • The entire U.S. patent family claims priority to International Application PCT/JP2016/000346, filed on January 25, 2016.
  • The PCT application, in turn, claims priority to Japanese Patent Application JP 2015-013258, filed on January 27, 2015.

• Patent Family Members: Besides the direct line of U.S. continuation applications, this patent is related to a family of patents granted in various jurisdictions, including:

  • Japan: JP 6395219 B2
  • Europe: EP 3252973 B1
  • China: CN 107210836 B
  • International Publication: WO 2016/121361 A1

DEFENSIVE DISCLOSURE

Title: Methods and Apparatus for Dynamic Power-Level Adjustment in Signal Distribution Networks Based on Connected Device Characteristics

Publication Date: May 8, 2026

Abstract: This disclosure describes a series of methods and systems for dynamically adjusting the power level of a signal (e.g., optical, electrical, laser, wireless) that is distributed from a central node to one or more connected endpoint devices. A controller at the distribution node receives or determines connection information identifying the type or operational state of a connected device. Based on this information, the controller adjusts a variable attenuator or amplifier in the signal path to provide a power level specifically optimized for that device. This enables flexible, reconfigurable, and robust networks. The following derivatives and applications are disclosed to place this technology and its foreseeable variations into the public domain.

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Derivative Set 1: Material and Component Substitution

This set of derivatives describes alternative physical implementations of the core components (attenuator, controller) to achieve the same functional outcome of device-adaptive signal power control.

1.1. MEMS-based Attenuation Array

• Enabling Description: The variable optical attenuator is implemented using a monolithic Micro-Electro-Mechanical System (MEMS) device. An input wavelength-multiplexed signal is demultiplexed and each wavelength is directed to an individual MEMS micromirror. The controller, upon receiving connection information for the device associated with that wavelength's destination port, applies a precise voltage to the corresponding micromirror's actuator. This voltage causes a controlled tilt in the mirror, inducing a calibrated amount of coupling loss as the light is reflected toward the output fiber. The attenuation is thus a function of the tilt angle. The entire array can be fabricated on a single silicon substrate, offering high-speed (microsecond-scale) attenuation changes and high port density.

• Diagram:

  graph TD
      subgraph MEMS Attenuator Chip
          A[Input WDM Signal] --> B{Demux};
          B --> C1[λ1 → Mirror1];
          B --> C2[λ2 → Mirror2];
          B --> C3[λN → MirrorN];
          C1 --> D1[Output Port 1];
          C2 --> D2[Output Port 2];
          C3 --> D3[Output Port N];
      end
      subgraph Control System
          E[Connection Info for Port 2] --> F[Controller];
          F -- Voltage Signal --x G{Actuator for Mirror2};
      end
      G -. Tilts Mirror .-> C2;
  

1.2. Semiconductor Optical Amplifier (SOA) in Attenuation Mode

• Enabling Description: A Semiconductor Optical Amplifier (SOA) is used as a bi-modal component for both amplification and attenuation. The controller receives connection information for a target device. If the device requires a signal power lower than the demultiplexed input, the controller applies a low forward bias or a reverse bias current to the SOA in that signal's path. This causes the SOA to operate in an absorptive regime, attenuating the signal. The degree of attenuation is directly proportional to the applied current. If the device requires amplification, the controller applies a high forward bias current. This architecture provides a wider dynamic range of power control than a passive attenuator.

• Diagram:

  sequenceDiagram
      participant Client as Network Mgmt
      participant Node as Controller
      participant SOA as SOA Component
      Client->>Node: Connection Info (Device requires -10dBm)
      Node->>Node: Calculate required attenuation
      Node->>SOA: Set Reverse Bias Current (e.g., -5mA)
      SOA-->>Node: Ack
      Note right of SOA: SOA absorbs photons, acting as attenuator
      Node-->>Client: Port configured
  

1.3. FPGA-based Controller with In-Field Updatability

• Enabling Description: The controller is implemented on a Field-Programmable Gate Array (FPGA) rather than a fixed-function ASIC or microcontroller. The FPGA holds a dynamically updatable look-up table (LUT) in its Block RAM, which maps hundreds of potential "Device Type" identifiers to specific attenuation values and component control parameters (e.g., SOA bias current, MEMS voltage). When a network manager needs to support a new device type, they can push a new bitstream or just the updated LUT to the FPGA remotely, without a physical hardware swap. This allows the optical device to adapt to future, yet-to-be-invented transceivers and client devices.

• Diagram:

  graph LR
      A[Network Admin] -- New Device Profile --> B(Network Management System);
      B -- Bitstream/LUT Update --> C{FPGA Controller};
      subgraph Optical Node
          D[Pluggable Module<br/><i>New Device Type</i>] -- I2C --> C;
          C -- Fetches new profile --> E[Block RAM LUT];
          E -- Attenuation Value --> C;
          C -- Control Signal --> F(Variable Attenuator);
      end
  

---

Derivative Set 2: Operational Parameter Expansion

This set explores the application of the core technology in extreme operational environments.

2.1. Cryogenic Optical Switch for Quantum Computing

• Enabling Description: The apparatus is integrated into a dilution refrigerator for routing optical control signals to qubits or quantum sensors. All optical components (demux, attenuators) are fabricated from materials suitable for cryogenic operation (e.g., silicon nitride waveguides). The controller, located outside the refrigerator, adjusts the attenuation based on the connected "device," which could be a specific type of superconducting nanowire single-photon detector (SNSPD) or a quantum dot with distinct optical power requirements. The controller utilizes pre-calibrated maps that account for the temperature-dependent performance of both the attenuator and the receiving quantum device to ensure precise photon delivery.

• Diagram:

  stateDiagram-v2
      [*] --> Idle
      Idle --> Configuring: Received Qubit_Control_Request
      Configuring --> Active: Attenuation set for SNSPD
      state Configuring {
          direction LR
          [*] --> GetDeviceInfo
          GetDeviceInfo --> LookUpTempMap: Device=SNSPD, Temp=100mK
          LookUpTempMap --> SetAttenuation: Value= -30.5 dB
          SetAttenuation --> [*]
      }
      Active --> Idle: Control Sequence Complete
  

2.2. High-Power Industrial Laser Beam Distribution

• Enabling Description: In a laser manufacturing cell, a central high-power fiber laser (e.g., 20kW) is split into multiple process beams. The disclosed apparatus functions as the beam distribution and power setting node. The "demultiplexer" is a diffractive optical element, and the "attenuator" is an acousto-optic modulator (AOM). The "connected devices" are various tool heads: a welding head, a cutting nozzle, or a surface cladding tool. The central factory controller sends "connection information" identifying the active tool. The node controller then sets the RF power to the AOM to diffract a precise percentage of the laser power, thus attenuating the beam to the exact wattage required for the specific manufacturing process (e.g., 5kW for cutting, 1.5kW for welding).

• Diagram:

  graph TD
      A[20kW Master Laser] --> B{Beam Splitter/Demux};
      B -- Beam 1 --> C1(AOM 1);
      B -- Beam 2 --> C2(AOM 2);
      C1 --> D1[Welding Head];
      C2 --> D2[Cutting Nozzle];
      E[Factory Controller<br/><i>Job: Weld Seam_A</i>] --> F(Node Controller);
      F -- Sets RF Power for 1.5kW --> C1;
  

---

Derivative Set 3: Cross-Domain Application

This set describes the application of the core mechanism in industries unrelated to telecommunications.

3.1. Aerospace: Fly-by-Light Actuator Control

• Enabling Description: In a fly-by-light aircraft, optical fibers replace electrical wiring for flight control signals. A node based on this disclosure is placed in an avionics bay to distribute signals from the flight control computer to wing actuators. The "connected devices" are different types of actuators, such as a primary electro-hydraulic actuator and a secondary electro-mechanical backup. The backup actuator may have a more sensitive optical receiver. When the flight computer switches to the backup, it sends connection information identifying the new target. The node controller automatically increases the attenuation on that fiber link to prevent oversaturating the backup actuator's receiver, ensuring its stable operation.

• Diagram:

  sequenceDiagram
      participant FCC as Flight Control Computer
      participant Node as Optical Node Controller
      participant Actuator as Primary Actuator
      participant Backup as Backup Actuator
      FCC->>Node: Route signal to Primary Actuator
      Node->>Actuator: Optical Signal (-5dBm)
      FCC->>Node: FAULT! Reroute to Backup Actuator
      Node->>Node: Look up profile for Backup
      Node->>Backup: Optical Signal (-15dBm)
      Note right of Backup: Attenuation increased to prevent saturation
  

3.2. AgTech: Adaptive Lighting in Vertical Farms

• Enabling Description: A central LED driver distributes power-over-fiber to multiple LED lighting arrays in a vertical farm. The apparatus acts as a power distribution hub. The "connected devices" are different lighting arrays tailored for various plants (e.g., "Leafy Greens Array," "Fruiting Plants Array," "Seedling Germination Array"). Each array has a different optimal light intensity (PPFD) and power draw. When an array is connected, it identifies itself to the controller, which then adjusts the attenuation of the optical power signal to deliver the precise intensity for the specific plant growth stage, optimizing energy use and crop yield.

• Diagram:

  erDiagram
      FARM_CONTROLLER ||--o{ LIGHTING_NODE : controls
      LIGHTING_NODE ||--|{ PORT : has
      PORT }o--|| LED_ARRAY : connects_to
      LED_ARRAY {
          string type "Device Type (e.g., 'Leafy Greens')"
          string required_power
      }
      PORT {
          int port_id
          float attenuation_level "Set by Controller"
      }
  

---

Derivative Set 4: Integration with Emerging Technology

This set describes integrating the core patent with AI, IoT, and blockchain.

4.1. AI-Driven Predictive Attenuation Maintenance

• Enabling Description: The controller integrates a trained machine learning model (e.g., a gradient-boosted tree) that predicts the future health of the optical link. The controller monitors IoT sensor data from the connected device, such as its receiver's bit error rate (BER), temperature, and optical power received, over time. The ML model uses this time-series data to predict degradation due to component aging or fiber strain. It then proactively and gradually adjusts the attenuation (e.g., slightly decreasing it over months) to maintain a constant signal quality at the receiver, maximizing link lifetime and preventing outages.

• Diagram:

  flowchart LR
      subgraph IoT Device
          A[Optical Receiver]
      end
      subgraph Optical Node
          B[Controller + ML Model]
          C[VOA]
      end
      A -- Telemetry (BER, Temp, Power) --> B;
      B -- Analyzes Trend --> B;
      B -- "Predicts 0.1dB degradation over next month" --> B;
      B -- "Adjust VOA by +0.1dB" --> C;
      C -- Attenuated Signal --> A;
  

4.2. Blockchain-Verified Device Onboarding and Configuration

• Enabling Description: The process of authenticating a connected device and configuring its port is secured by a private blockchain. Each manageable device (pluggable transceiver, client device) is provisioned at the factory with a unique cryptographic identity on the blockchain. When plugged into a port, the device performs a challenge-response handshake with the node controller. The controller verifies the device's identity against the blockchain ledger and retrieves its immutable operational parameters, including its required power class. The controller then sets the attenuation and logs the event (Port ID, Device ID, Attenuation Value, Timestamp) as a new, non-repudiable transaction on the chain, creating a secure audit trail for all network modifications.

• Diagram:

  sequenceDiagram
      participant Device
      participant Controller
      participant Blockchain
      Device->>Controller: Hello, I am Device_X [sends cert]
      Controller->>Blockchain: Verify(Device_X_cert)
      Blockchain-->>Controller: Verified. Profile: {PowerClass: 4}
      Controller->>Controller: Set Attenuation for PowerClass 4
      Controller->>Blockchain: Log Transaction(Port_5, Device_X, -12dB)
      Blockchain-->>Controller: Transaction Confirmed
  

---

Derivative Set 5: The "Inverse" or Failure Mode

This set describes versions of the invention designed for safe failure or limited functionality.

5.1. Fail-Safe Optical Cut-off

• Enabling Description: The variable optical attenuator is designed to fail in a known, safe state. It uses a normally-closed MEMS shutter or a liquid crystal cell that is opaque without power. Upon controller failure or power loss to the node, the attenuator automatically reverts to a state of maximum attenuation (>40 dB), effectively blocking the optical signal. This prevents a high-power, un-attenuated signal from propagating downstream and potentially damaging a sensitive receiver on a connected device. An independent watchdog timer in the power circuit can trigger this state if the controller software hangs.

• Diagram:

  stateDiagram-v2
      state "Active" as Active
      state "Safe Mode" as Safe
  
      [*] --> Active: Power On
      Active --> Safe: Controller Failure OR Power Loss
      Safe --> Active: System Reset
  
      state Active {
          direction LR
          [*] --> Attenuating
          Attenuating: Controller sets VOA to -10dB
      }
      state Safe {
          direction LR
          [*] --> MaxAttenuation
          MaxAttenuation: VOA defaults to > -40dB (Signal blocked)
      }
  

Combination with Open-Source Standards

• 1. NETCONF/YANG Integration: The system is managed using the IETF NETCONF protocol (RFC 6241). The capabilities of the optical node, including the per-port attenuation settings and device type identification, are formally defined in a YANG data model (RFC 7950). A network management system identifies a newly connected device (e.g., via LLDP), consults its YANG model to determine the device type, and sends a <edit-config> operation to the node, setting the attenuation leaf in the model to a value appropriate for the identified device-type enumeration.

• 2. MSA-based Plug-and-Play: The "connection information" is acquired by the controller via the I2C management interface defined in open, multi-source agreements (MSAs) for pluggable optics, such as CMIS for QSFP-DD or OSFP modules. The controller reads a standard field from the module's EEPROM, such as the "Power Class" or "Application Code" fields. This code is used as a key to a local table to determine the correct attenuation setting, rendering the invention an obvious implementation detail of existing hot-pluggable hardware standards.

• 3. Control via gRPC/Protobuf API: The controller hosts a gRPC server defined by an open-source Protocol Buffers (.proto) file. The definition includes a service like OpticalNodeManager with an RPC SetPortConfig(PortInfo) returns (Status). The PortInfo message contains a device_type field, which is a Protobuf enum listing known device categories (e.g., DEVICE_TYPE_LR4, DEVICE_TYPE_ZRPLUS). A remote management system acts as a gRPC client, calling this RPC to configure the port's attenuation based on the device it intends to connect. This decouples the management system from the node hardware, using common open-source RPC technology.