Cisco Systems Inc v. ChanBond LLC

1. Case Identification

• Case #: IPR2016-01900
• Patent #: Patent 8,341,679
• Filed: September 28, 2016
• Petitioner(s): Cisco Systems, Inc.
• Patent Owner(s): ChanBond LLC
• Challenged Claims: 36-37

2. Patent Overview

• Title: Intelligent Device System and Method for Distribution of Digital Signals on a Wideband Signal Distribution System
• Brief Description: The ’679 patent relates to radio frequency (RF) transmission devices that divide a high-rate data stream into smaller streams, select multiple channels for transmission, and use modulators to transmit the smaller streams over the selected channels as a multi-channel RF signal.

3. Grounds for Unpatentability

Ground 1: Obviousness over Tiedemann, Gilhousen, and Jacobs - Claim 36 is obvious over Tiedemann in view of Gilhousen and Jacobs.

• Prior Art Relied Upon: Tiedemann (Patent 5,859,840), Gilhousen (Patent 5,103,459), and Jacobs (Patent 5,414,796).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that the base and mobile stations in Tiedemann’s multi-channel cellular RF system constitute the “intelligent device” of independent claim 12, from which claim 36 depends. Tiedemann was asserted to disclose the core components: a demodulator unit for receiving multi-channel signals, a combiner (multiplexer) to reassemble data, a second input for receiving data to be transmitted, a traffic sensor to measure data throughput, and a modulator unit to transmit data across multiple channels. Gilhousen, incorporated by reference in Tiedemann, was cited to explicitly teach that mobile stations are addressable. Jacobs, also incorporated by reference, was cited to teach a variable-rate vocoder that functions as a traffic sensor by determining the data rate of a digital stream through sampling. For dependent claim 36, Petitioner argued Tiedemann’s base station inherently performs the claimed repeater-like functions (receiving a wireless signal from one mobile station and re-transmitting it to another).
  • Motivation to Combine: Petitioner contended that a person of ordinary skill in the art (POSITA) would have been motivated to combine the teachings because Tiedemann expressly incorporates both Gilhousen and Jacobs by reference. The combination was presented as applying known techniques (addressing from Gilhousen, traffic sensing from Jacobs) to a known system (Tiedemann) to improve its functionality and achieve predictable results, such as allowing mobile stations to be individually addressed and efficiently allocating channel resources based on data rate.
  • Expectation of Success: A POSITA would have had a high expectation of success because the combination involved integrating components within their intended environment (a CDMA cellular system) as explicitly suggested by the primary reference, Tiedemann.

Ground 2: Obviousness over Tiedemann, Gilhousen, Jacobs, and Gorsuch - Claims 36-37 are obvious over Tiedemann in view of Gilhousen, Jacobs, and Gorsuch.

• Prior Art Relied Upon: Tiedemann (Patent 5,859,840), Gilhousen (Patent 5,103,459), Jacobs (Patent 5,414,796), and Gorsuch (Patent 6,081,536).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground added Gorsuch to provide further support and, critically, to teach limitations required by claim 37. Gorsuch was cited for its teaching of a cellular system that transmits high-rate data to multiple addressable devices (e.g., computers) by dynamically allocating RF subchannels. Petitioner argued Gorsuch’s input buffer, which detects its fill rate to request additional channels, explicitly teaches the claimed "traffic sensor." For claim 37, which requires receiving and combining first and second separate digital information streams (e.g., from different sources), Gorsuch was argued to teach this explicitly. Its base station processor is described as receiving separate voice and data streams, combining them, measuring the combined throughput, and modulating the combined stream for transmission.
  • Motivation to Combine: A POSITA would combine Gorsuch with the Tiedemann system to satisfy the known market demand for high-speed cellular modems capable of connecting devices like computers to the internet. Gorsuch provided a known method for handling multiple data types and connecting multiple devices, which would predictably enhance Tiedemann’s foundational multi-channel system. The fact that both systems utilize the same CDMA transmission protocols would further motivate the combination.
  • Expectation of Success: Success was predictable because the combination involved integrating standardized communication protocols (CDMA, ISDN) and known components (protocol converters, modems) from Gorsuch into the analogous cellular framework of Tiedemann.

4. Key Claim Construction Positions

• "RF Channel": Petitioner argued for a broad construction of "an RF path for transmitting electric signals." This construction was asserted to encompass channels defined not only by frequency bands but also by time slots (TDMA) or codes (CDMA), as disclosed in the prior art. This was crucial to prevent a narrow reading that might exclude the primary references.
• "Address" and "addressable device": Petitioner proposed that "address" should be construed as "information identifying a device or location," and an "addressable device" as "a device identifiable by its address." This construction supported the argument that devices in the prior art, such as mobile stations identified by phone numbers or user IDs (as in Gilhousen), met this claim limitation.

5. Key Technical Contentions (Beyond Claim Construction)

• Analogous Art: Petitioner asserted that all cited references were analogous art to the ’679 patent. It was argued they are in the same field of endeavor—multi-channel or multiplexed data transmission using modulated RF signals to addressable devices—and are also found in the same patent classification groups. This contention was foundational to the validity of combining these references for the obviousness arguments under §103.

6. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under 35 U.S.C. §325(d) would be inappropriate. While similar prior art was considered during prosecution, Petitioner contended that Tiedemann is a superior reference because it, unlike the cited Zehavi references, discloses dynamic channel allocation—a key concept of the invention. Therefore, Petitioner argued the Examiner did not previously consider the specific teachings relied upon in the petition.

7. Relief Requested

• Petitioner requests institution of an inter partes review and cancellation of claims 36 and 37 of the ’679 patent as unpatentable.