Silver Spring Networks Inc v. Acoustic Technology Inc

1. Case Identification

• Case #: IPR2017-01024
• Patent #: 6,509,841
• Filed: March 3, 2017
• Petitioner(s): Silver Spring Networks, Inc.
• Patent Owner(s): Acoustic Technology, Inc.
• Challenged Claims: 8

2. Patent Overview

• Title: System and Method for Communication Between Remote Locations
• Brief Description: The ’841 patent discloses a communication system for utility providers to remotely read utility meters. The system comprises a central control, multiple servicing means (e.g., metering devices at customer locations), and at least one relay means that facilitates two-way communication between the control and the servicing means, optionally using Code-Division Multiple Access (CDMA).

3. Grounds for Unpatentability

Ground 1: Anticipation - Claim 8 is unpatentable under 35 U.S.C. § 102(b) over NetComm.

• Prior Art Relied Upon: NetComm (a 1990 Southern California Edison research newsletter).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that NetComm, which describes a system for automated two-way meter reading, discloses every limitation of claim 8. NetComm teaches a "head-end" computer (the control) that sends read requests to and receives readings from electronic meters (the metering devices). Communication is facilitated by packet radios (the relays) that shuttle data between the meters (via powerline carrier) and the head-end computers (via radio waves). Petitioner contended that NetComm’s radio communication, described as using a "programmable, pseudo-random pattern" to "dynamically 'hop' over any unusable channel," constitutes Frequency-Hopping CDMA (FH-CDMA), thereby satisfying the "CDMA communication" limitation under Petitioner's proposed claim construction.
  • Key Aspects: This ground's success depends on the construction that "CDMA" encompasses FH-CDMA and that the communication path need only be partially CDMA.

Ground 2: Anticipation - Claim 8 is unpatentable under 35 U.S.C. § 102(b) over Gastouniotis.

• Prior Art Relied Upon: Gastouniotis (Patent 5,438,329).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Gastouniotis teaches a system for two-way utility meter reading that meets all limitations of claim 8. Gastouniotis discloses a "remote station" (the control) that interrogates an "instrument link" associated with a "data gathering device" like a utility meter (the metering device). Gastouniotis explicitly teaches that multiple remote stations can be configured to communicate with each other, allowing one remote station to act as a "relay" for another. Crucially, Gastouniotis expressly states that its use of spread spectrum modulation with unique spreading functions for simultaneous transmission "is referred to as Code Division Multiple Access (CDMA)," directly teaching the claimed communication method.

Ground 3: Obviousness - Claim 8 is obvious over Nelson in view of Roach.

• Prior Art Relied Upon: Nelson (UK Patent Application Publication No. 2,230,629) and Roach (Patent 5,546,444).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Nelson discloses a complete two-way automated meter reading system with all elements of claim 8 except for the use of CDMA. Nelson teaches electronic meter readers ("EMRs," the metering device) that are interrogated by electronic meter interrogators ("EMIs," the control). Nelson explicitly teaches using intermediate EMRs as communication "relays" to extend range, a practice it calls "meterstringing." However, Nelson uses conventional wireless communication. Roach remedies this deficiency by teaching the collection of data from utility meters using a cellular mobile radiotelephone system, and it explicitly lists "IS 95-CDMA" as a compatible system.
  • Motivation to Combine: A POSITA would combine the references because both address automated utility meter reading. A POSITA seeking to improve the communication reliability and range of Nelson's system—an explicit goal of Nelson—would have looked to known, robust communication technologies. Roach provided a clear solution by teaching the use of commercially available cellular CDMA systems for the exact same purpose: collecting data from utility meters.
  • Expectation of Success: A POSITA would have had a high expectation of success because Roach demonstrated that CDMA was already being applied to utility meter data collection. Modifying Nelson's transceivers to use CDMA instead of conventional coded radio transmission would have been a predictable substitution of one known wireless technology for a superior one to achieve the known benefits of increased range and interference resilience.

4. Key Claim Construction Positions

• "code-division multiple access (CDMA) communication": Petitioner argued for a broad construction that encompasses both Direct-Sequence CDMA (DS-CDMA) and Frequency-Hopping CDMA (FH-CDMA). This interpretation was asserted to be consistent with the understanding of a POSITA at the time of the invention and was critical to the anticipation argument over NetComm, which discloses an FH-CDMA system.
• "CDMA communication between said metering device and said control": Petitioner argued this phrase does not require the entire communication path to be CDMA. Instead, it only requires that CDMA is used along at least some part of the path. This position was supported by intrinsic evidence, including the ’841 patent’s specification (which describes exchanging signals between radio frequency and power lines) and file history diagrams from a field trial that depicted a hybrid communication path using both CDMA and wired connections (e.g., RS-232, copper-wire).

5. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claim 8 of the ’841 patent as unpatentable.