Cisco Systems, Inc. v. Oyster Optics, LLC

1. Case Identification

• Case #: Unassigned
• Patent #: 8,374,511
• Filed: July 27, 2017
• Petitioner(s): CISCO SYSTEMS, INC. AND OCLARO, INC.
• Patent Owner(s): OYSTER OPTICS, LLC
• Challenged Claims: 1-7 and 9-15

2. Patent Overview

• Title: Optical Fiber Network Power Monitoring
• Brief Description: The ’511 patent pertains to systems and methods for transmitting and receiving signals in a fiber optic network. While the specification describes security-focused improvements like optical time-domain reflectometry (ODTR) and tap detection, the challenged claims are directed more broadly to conventional methods of operating an optical transceiver, including using a power monitor to measure the average power of a received optical signal.

3. Grounds for Unpatentability

Ground 1: Claim 1 is obvious over Treyz, Ade, and Hardcastle.

• Prior Art Relied Upon: Treyz (Patent 6,529,316), Ade (Patent 5,347,601), and Hardcastle (Patent 6,178,025).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Treyz discloses a modular optical equipment card system capable of power monitoring but lacks specific structural details for the transceiver. Ade supplies these missing details by teaching a conventional optical transceiver on an integrated circuit, suitable for implementation as a module on Treyz's card. Hardcastle provides the specific circuitry for the power monitor itself—a function only generally described in Treyz—by teaching a loss-of-signal detector that uses a photodetector, amplifier, and low-pass filter to generate an average power signal from a tapped optical signal.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Treyz and Ade to implement a complete, known transceiver architecture within Treyz’s flexible and space-saving card-based system, thereby reducing cost and complexity. A POSITA would further combine this with Hardcastle's specific detector circuit to implement the generic power monitoring function of Treyz, as Hardcastle taught a well-understood and standard method for measuring average optical power.
  • Expectation of Success: The combination involved integrating known components (Ade's transceiver, Hardcastle's monitor) into a known system (Treyz's optical card) to perform their established and predictable functions, creating no new or unexpected results.

Ground 2: Claim 9 is obvious over Treyz, Ade, Hardcastle, and Hooijmans.

• Prior Art Relied Upon: Treyz (Patent 6,529,316), Ade (Patent 5,347,601), Hardcastle (Patent 6,178,025), and Hooijmans (a 1994 textbook on coherent optical systems).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground builds on Ground 1 to address independent claim 9, which adds the limitation that the optical signals be "phase-modulated." Petitioner argued the base combination of Treyz/Ade/Hardcastle teaches all other elements of the claim. Hooijmans, a comprehensive survey of known optical technologies, explicitly discloses various modulation schemes, including phase-shift keying (PSK) and differential phase-shift keying (DPSK).
  • Motivation to Combine: Because the primary references do not specify a modulation scheme, a POSITA would have considered well-known, advantageous options. A POSITA would combine the teachings of Hooijmans, as phase modulation was a routine design choice known to provide benefits such as higher data rates and improved performance over longer transmission distances, making it an obvious and desirable feature for the Treyz/Ade/Hardcastle system.
  • Expectation of Success: Adapting a conventional transceiver to use a well-known modulation scheme like PSK was a matter of ordinary skill and would have yielded the predictable benefit of improved signal transmission.

Ground 3: Claims 2-4 are obvious over Treyz, Ade, Hardcastle, and Kobayashi.

• Prior Art Relied Upon: Treyz (Patent 6,529,316), Ade (Patent 5,347,601), Hardcastle (Patent 6,178,025), and Kobayashi (Patent 6,404,281).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground builds on Ground 1 to address dependent claims 2-4, which add limitations for "scaling the electrical signal after filtering with a...linear amplifier" (claim 2), with the scaling being a function of expected power level (claim 3) or fiber span length (claim 4). Petitioner argued Kobayashi discloses an improved transimpedance amplifier (a type of linear amplifier) that linearly scales a detected current to solve known non-linearity problems in power monitors. Kobayashi’s circuit provides both filtering and linear scaling.
  • Motivation to Combine: A POSITA implementing the power monitor of Hardcastle would be motivated to improve its accuracy and linearity, a known problem that Kobayashi directly addressed. It would have been obvious to select Kobayashi's scaling factor based on expected optical power or span length—factors that directly influence signal strength—to ensure that power fluctuations were easily and accurately detectable across the system's dynamic range.
  • Expectation of Success: Substituting the basic amplifier in Hardcastle with Kobayashi's improved linear amplifier for the known purpose of enhancing measurement accuracy would have had a high expectation of success.
• Additional Grounds: Petitioner asserted additional obviousness challenges, including multiple grounds that substituted Corke (Patent 5,510,917) for Treyz as the primary system reference, and combinations including Ikeda (Patent 7,016,612) for its teachings on comparators and programmable thresholds for alarm generation.

4. Key Technical Contentions (Beyond Claim Construction)

• Priority Date Dispute: Petitioner contended that the ’511 patent is not entitled to the priority date of its provisional application (July 9, 2001). The argument was based on the assertion that substantial new matter, including the core limitation of "filtering the electrical signal to produce an average optical power," was added to the later utility application. Therefore, Petitioner argued the correct priority date for all challenged claims is no earlier than the utility application's filing date of July 3, 2002. This contention makes references like Treyz (filed June 12, 2001) prior art under 35 U.S.C. §102(e).

5. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 1-7 and 9-15 of Patent 8,374,511 as unpatentable.