PTAB

IPR2018-01724

Cisco Systems, Inc. v. TracBeam LLC

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1. Case Identification

2. Patent Overview

  • Title: Gateway and Hybrid Solutions for Wireless Location
  • Brief Description: The ’484 patent describes systems and methods for locating people or objects using a wireless communication system. The technology uses measurements from wireless signals communicated between mobile stations and network base stations to provide location capabilities, which can be incorporated into existing commercial wireless telephony systems.

3. Grounds for Unpatentability

Ground 1: Obviousness over Sheffer II and Cisneros - Claim 49 is obvious over Sheffer II in view of Cisneros.

  • Prior Art Relied Upon: Sheffer II (Patent 5,218,367) and Cisneros (Patent 5,774,829).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Sheffer II teaches a vehicle tracking system that uses two independent techniques to approximate a vehicle's location, thereby disclosing the claimed "first and second mobile station location estimators." Sheffer II's first estimator performs a cell triangulation calculation based on signal strength from multiple cell sites to generate a geographical approximation ("Area A"). The second estimator uses a sector-based triangulation technique, employing cell sector information and relative signal strengths, to generate a second geographical approximation ("Area A1"). Petitioner asserted that while Sheffer II discloses generating these two separate approximations, Cisneros teaches the claimed method for combining them. Cisneros describes a navigation system that combines location estimates from different sources by weighting each estimate according to its quality or uncertainty to produce a more accurate composite result. Petitioner contended that applying Cisneros's combination technique to Sheffer II's two approximations satisfies the claim limitation of "combining said first and second likely geographical approximations so that said resulting location estimate is dependent on each."
    • Motivation to Combine: A POSITA would combine the teachings to improve the accuracy and robustness of the Sheffer II system. Petitioner contended that a POSITA would recognize that Sheffer II's two estimation techniques could have varying levels of accuracy depending on the operational environment (e.g., urban versus rural). To create a more consistently accurate system, a POSITA would be motivated to apply Cisneros’s method of weighting and combining the two location approximations from Sheffer II. This would allow the final location estimate to be adapted based on which technique is likely to be more accurate in a given situation.
    • Expectation of Success: Petitioner argued a POSITA would have a reasonable expectation of success in combining the references. Both Sheffer II and Cisneros operate in the predictable field of location determination using wireless signals. Applying Cisneros's well-understood mathematical technique of weighted averaging to the location data generated by Sheffer II's established methods would be a straightforward implementation with predictable results.

4. Key Claim Construction Positions

  • "mobile station location estimator": Petitioner argued this term, as used in claim 49, is a means-plus-function term under 35 U.S.C. §112, ¶ 6, because it uses purely functional language without reciting a corresponding structure. Petitioner proposed the function should be construed as "estimating [a] mobile station location." The corresponding structure identified in the ’484 patent specification was a "location hypothesizing model (FOM) implemented on or by a location center or mobile base station." This construction was critical to mapping the central monitoring station computer in Sheffer II, which performs location calculations, to the claimed "estimators."
  • "at least one of the substeps (B1) through (B2)": Claim 49 requires "determining a resulting location estimate" by performing at least one of two alternative substeps. Petitioner argued this phrase should be construed to mean "at least substep (B1) or at least substep (B2)," rather than requiring both. This interpretation was central to Petitioner's strategy, as its obviousness argument focused exclusively on demonstrating that the combination of Sheffer II and Cisneros teaches the alternative recited in substep (B1), which involves combining the first and second geographical approximations.

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that institution should not be discretionarily denied. It acknowledged that it was filing two other IPR petitions against the ’484 patent concurrently. However, Petitioner asserted the petitions were not redundant because they challenge different claims of the patent. This approach was described as necessary due to the unusual length of the challenged claims and the PTAB's word-count limits for petitions, which prevented consolidating all challenges into a single filing. Petitioner also noted that while prior IPRs had been filed against the ’484 patent by other parties (Apple, T-Mobile), Cisco was not a party to those terminated proceedings and therefore should not be penalized.

6. Relief Requested

  • Petitioner requests that the Board institute an inter partes review of claim 49 of the ’484 patent and cancel the claim as unpatentable under 35 U.S.C. §103.