Cisco Systems Inc v. XR Communications LLC

1. Case Identification

• Case #: IPR2018-00762
• Patent #: 6,611,231
• Filed: March 15, 2018
• Petitioner(s): Cisco Systems, Inc.
• Patent Owner(s): XR Communications LLC
• Challenged Claims: 1-9, 12

2. Patent Overview

• Title: Wireless Communication System with Adaptive Antenna Arrays
• Brief Description: The ’231 patent describes an apparatus for a wireless routing network that uses an adaptive antenna array. The system selectively controls the placement of transmission peaks toward desired mobile stations and transmission nulls toward interference sources to route data packets.

3. Grounds for Unpatentability

Ground 1: Obviousness of Claims 1, 3-6, 9, and 12 over Kuwahara, Patel, and Swales

• Prior Art Relied Upon: Kuwahara (Patent 6,597,678), Patel (Patent 7,031,266), and Swales (an IEEE article from Feb. 1990).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Kuwahara teaches the core apparatus: a base station with an adaptive antenna array that forms transmission beams and nulls based on routing information. The combination with Patel taught implementing Kuwahara's base station as a "wireless router" for use in a "wireless routing network," as recited in the preamble of claim 1. The further combination with Swales taught transmitting multiple simultaneous beams to increase user capacity, disclosing the claimed "outgoing multi-beam electromagnetic signals" with a plurality of peaks and nulls.
  • Motivation to Combine: A POSITA would combine Kuwahara with Patel to gain the known benefits of an IP-based routing network, including improved flexibility and efficient traffic processing. A POSITA would have been further motivated to incorporate Swales's multi-beam techniques to predictably increase the user capacity and spectral efficiency of the system, a well-understood goal in wireless communications.
  • Expectation of Success: The combination involved applying known techniques (IP routing, multi-beam antennas) to analogous wireless communication systems to achieve predictable improvements in performance and flexibility.

Ground 2: Obviousness of Claim 2 over Kuwahara, Patel, Swales, and Kanterakis

• Prior Art Relied Upon: Kuwahara (Patent 6,597,678), Patel (Patent 7,031,266), Swales (an IEEE article from Feb. 1990), and Kanterakis (Patent 6,169,759).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground built upon the combination in Ground 1 to address the limitations of dependent claim 2, which requires that cross-correlated signal information be based on a data sequence from a "synchronization packet." Petitioner argued that while Kuwahara generally mentioned using pilot signals, Kanterakis provided the necessary detail, teaching that packets with preambles and pilots are used by a receiver for packet detection and synchronization, thus satisfying this limitation.
  • Motivation to Combine: A POSITA implementing Kuwahara's system would look to a reference like Kanterakis for technical details on implementing pilot signals. Kanterakis provided a known and suitable method for generating and using pilot and preamble signals for synchronization, a common requirement in packet-based systems.
  • Expectation of Success: Petitioner asserted that incorporating Kanterakis's detailed description of synchronization packets into Kuwahara's system was a straightforward application of a known technique to achieve the predictable result of receiver synchronization.

Ground 3: Obviousness of Claim 2 over Kuwahara, Patel, Swales, and IEEE 802.11-1997

• Prior Art Relied Upon: Kuwahara (Patent 6,597,678), Patel (Patent 7,031,266), Swales (an IEEE article from Feb. 1990), and IEEE 802.11-1997 (a technical standard).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground presented an alternative basis for finding claim 2 obvious, focusing on the claim's other options for cross-correlatable data sequences: those from a "header portion" or a "PLCP header portion" of a received packet. The IEEE 802.11-1997 standard explicitly defined PLCP headers containing data sequences (e.g., SYNC field, SIGNAL field) used for updating routing information such as timing, frequency, and data rate.
  • Motivation to Combine: The motivation was explicit, as Patel suggested that its wireless router may communicate using "802.11 based WLAN" technologies. This would have directly led a POSITA to consult the IEEE 802.11-1997 standard for implementation details regarding packet structure and signaling.
  • Expectation of Success: A POSITA would have reasonably expected to successfully implement the packet structures defined in the IEEE standard within the Kuwahara/Patel wireless routing system to ensure interoperability and proper functionality.
• Additional Grounds: Petitioner asserted that claims 5-8 are obvious over the combination of Kuwahara, Patel, Swales, and Khalab (U.K. Application # GB2349045A). Khalab was introduced for its teaching of dynamically determining, storing, and regularly updating user information (e.g., signal direction, power level) to create a more intelligent transmission beam pattern.

4. Key Claim Construction Positions

• "control logic" and "search receiver logic": Petitioner proposed that for the purposes of the IPR, these terms should not be construed as means-plus-function terms. This approach, consistent with the Patent Owner's position in co-pending litigation, would result in a broader, and still reasonable, interpretation of the claims.
• "an adaptive antennas": Petitioner contended that this phrase should be construed to require only a single adaptive antenna. This interpretation was based on the singular article "an" and subsequent singular references ("said adaptive antenna") within claim 1.
• "cross-correlated signal information that is received by said receiver": Petitioner argued this phrase should be interpreted as "cross-correlated signal information based on information that is received by said receiver." This construction was proposed because the patent's specification describes performing cross-correlation on received signals, not receiving signals that have already been cross-correlated.

5. Arguments Regarding Discretionary Denial

• Petitioner argued that discretionary denial under 35 U.S.C. §314(a) was not warranted. It noted that while a third-party petition challenging the ’231 patent existed (IPR2018-00701), Petitioner Cisco was not a party to that proceeding. Therefore, key factors concerning the "same petitioner" or "time elapsed" that might weigh in favor of denial were not implicated in this case.

6. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 1-9 and 12 of the ’231 patent as unpatentable.