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 relates to communication systems for utility providers to remotely read utility meters. The system includes a central control station, multiple remote servicing means (e.g., meters), and at least one relay means that facilitates two-way communication, including via Code-Division Multiple Access (CDMA), between the control station and the servicing means.

3. Grounds for Unpatentability

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

• Prior Art Relied Upon: NetComm Matures as Advanced Communication and Metering System, Research Newsletter, 19 So. Cal. Edison 4 (1990) (“NetComm”).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that NetComm, a 1990 newsletter, describes every element of claim 8. NetComm discloses a two-way automated meter reading system with "head-end" computers (the control), electronic meters (the metering device), and a network of packet radios that shuttle data packets between the computers and meters (the relay). Critically, Petitioner contended that NetComm’s disclosure of spread-spectrum radio communication that "dynamically ‘hop[s]’ over any unusable channel... using a programmable, pseudo-random pattern" constitutes Frequency Hopping CDMA (FH-CDMA). Based on Petitioner’s proposed claim construction, which includes FH-CDMA within the scope of "CDMA communication," NetComm was alleged to teach this limitation. The communication path in NetComm, involving radio waves and powerline carriers, was argued to satisfy the claim because CDMA is present on at least part of the path.

Ground 2: Anticipation over Gastouniotis - 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, which issued more than one year before the ’841 patent's priority date, explicitly discloses all elements of claim 8. Gastouniotis describes a two-way utility meter reading system with "instrument links" combined with data gathering units (the metering device) and "remote stations" (the control). Gastouniotis expressly teaches that these remote stations can be configured to communicate with each other and act "as a relay" to communicate data to a central location. Most significantly, Gastouniotis explicitly discloses that "The simultaneous transmission of several signals using different spreading functions is referred to as Code Division Multiple Access (CDMA)," directly teaching the CDMA communication limitation of claim 8.

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

• Prior Art Relied Upon: Nelson (UK Patent Application Publication No. 2,230,629 A) and Roach (Patent 5,546,444).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued Nelson discloses a two-way meter reading system with all elements of claim 8 except for the explicit use of CDMA communication. Nelson teaches a system with electronic meter readers ("EMRs," the metering device), electronic meter interrogators ("EMIs," the control), and teaches that EMRs can function as communication relays ("meterstringing"). Nelson uses conventional wireless communication. Roach teaches a system for collecting data from remote sources, including utility meters, via a cellular mobile radiotelephone system. Roach explicitly discloses that its system can be compatible with various cellular standards, including "IS 95-CDMA." Petitioner contended it would have been obvious to replace Nelson's conventional wireless communication with the CDMA communication taught by Roach.
  • Motivation to Combine: A person of ordinary skill in the art (POSITA), seeking to improve the reliability and range of Nelson's automated meter reading system, would have been motivated to combine it with Roach's teachings. Nelson acknowledges limitations like interference and distance. Roach teaches that using a cellular system, specifically including CDMA, overcomes the range and quality limitations of conventional radio systems. Thus, a POSITA would combine the references to achieve the known benefits of CDMA (greater range, better interference resilience) in Nelson's relay-based meter reading architecture.
  • Expectation of Success: A POSITA would have had a reasonable expectation of success because Roach taught that CDMA was commercially available and already being used for data collection from utility meters. Substituting Nelson's coded radio transmission with the more advanced CDMA technology taught by Roach would have been a straightforward implementation to achieve predictable improvements in performance.

4. Key Claim Construction Positions

• "code-division multiple access (CDMA) communication": Petitioner argued this term should be construed to include both Direct Sequence CDMA (DS-CDMA) and Frequency Hopping CDMA (FH-CDMA). This construction was critical for the anticipation argument over NetComm, which Petitioner asserted discloses FH-CDMA. Petitioner supported this with expert testimony and technical articles, like Pickholtz, which describe FH-CDMA as an alternative to DS-CDMA.
• "CDMA communication between said metering device and said control": Petitioner argued this phrase does not require the entire communication path between the meter and control to use CDMA. Citing the patent’s specification and file history (specifically, diagrams from a declaration filed during prosecution), Petitioner contended the claim is satisfied if CDMA is used on at least some portion of the communication path. This construction was essential, as both the patent's own examples and the prior art (like NetComm) showed hybrid paths using both radio frequency (like CDMA) and other media (like power lines or wired connections).
• "means for measuring usage": As a means-plus-function term, Petitioner argued the claimed function is "measuring usage" and the corresponding structure disclosed in the specification is an "incremental type metering device or equivalents." This construction aligned the claim with standard utility meters disclosed in the prior art.

5. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claim 8 of Patent 6,509,841 as unpatentable.