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.