PTAB

IPR2018-01726

CISCO SYSTEMS, INC. v. TracBeam LLC

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1. Case Identification

2. Patent Overview

  • Title: Methods for Locating Communication Devices
  • Brief Description: The ’327 patent describes systems and methods for locating wireless communication devices (e.g., mobile phones) using a communications network. The invention utilizes measurements from wireless signals communicated between mobile stations and network base stations, and can incorporate a plurality of different location estimation technologies.

3. Grounds for Unpatentability

Ground 1: Claims 1 and 47 are obvious over Sheffer in view of Cisneros and Sanderford.

  • Prior Art Relied Upon: Sheffer (Patent 5,844,522), Cisneros (Patent 5,774,829), and Sanderford (Patent 5,717,406).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that the combination of references taught every element of the challenged claims. Sheffer was asserted to disclose a base wireless location system that uses multiple independent techniques to locate a mobile phone, including azimuth triangulation, Received Signal Strength Information (RSSI), and cell/sector data. Sheffer also disclosed assessing a "confidence level" for the determined location based on the agreement between these techniques. Cisneros was argued to teach combining a GPS-based location technique with other methods, such as those using commercial radio broadcasts. Critically, Cisneros taught improving accuracy by weighting or averaging the position solutions from different techniques based on their estimated quality. Sanderford was introduced for its teaching of using a neural network as a sophisticated location technique. This neural network is specifically trained to account for and mitigate multi-path signal distortion common in urban environments, thereby improving location accuracy in such settings. The combination, therefore, provided a system with multiple, independent location determiners (from Sheffer, Cisneros, and Sanderford) and a method for combining or selecting among their outputs to produce a more reliable final location (from Cisneros and Sheffer).
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine the references to improve the accuracy and reliability of mobile device location, particularly for emergency services in varied environments. Sheffer provided a foundational multi-technique system. A POSITA would have been motivated to incorporate the GPS technique from Cisneros as another independent and widely used location method. To resolve potential conflicts or inaccuracies between Sheffer's techniques and the added GPS, a POSITA would have looked to Cisneros's method of weighting different location estimates according to their quality. Furthermore, to address the known problem of multi-path distortion degrading location accuracy in urban areas, a POSITA would have been motivated to incorporate Sanderford’s neural network technique, which is specifically designed to overcome this issue. The combination represented a predictable aggregation of known techniques to create a more robust and accurate location system.
    • Expectation of Success: A POSITA would have had a reasonable expectation of success in combining these teachings. All three references operated in the same field of wireless communication and device location. Integrating a known GPS module (Cisneros) and a known signal processing technique like a neural network (Sanderford) into Sheffer's existing framework for handling multiple location inputs was presented as a straightforward application of known engineering principles to achieve a predictable improvement in performance.

4. Key Claim Construction Positions

  • "location determiners": Petitioner argued this term is subject to §112, ¶ 6 (means-plus-function). Citing agreement in co-pending litigation, Petitioner asserted the function is "determining communication device location" and the corresponding structure disclosed in the specification is a "location hypothesizing model (FOM) implemented on or by a location center or mobile base station," which could include various specific techniques like GPS or signal pattern matching.
  • "at least one of: a potential geographic location and a potential geographic extent": Petitioner contended this phrase should be construed with its plain meaning of "at least one of a potential geographic location or at least one of a potential geographic extent." This construction is critical because it allows for location determiners that output different types of information (a point or an area), which Petitioner argued was consistent with the alternative recitations throughout claim 1.
  • "said second estimator": This term appears in dependent claim 47 without a proper antecedent basis in either claim 1 or 47, which both recite a "second location determiner." Petitioner argued that for the claim to be coherent, "said second estimator" must be construed as referring to the previously recited "second location determiner."

5. Arguments Regarding Discretionary Denial

  • Petitioner argued that this petition was not redundant with two other petitions it was filing concurrently against the ’327 patent. Although all three petitions challenged claim 1, Petitioner asserted this was necessary because the other challenged claims (2, 6, 9, and 47) depend from claim 1. Because the requirements of these dependent claims differ, the analysis of claim 1 in each petition is necessarily different. Petitioner requested that the Board institute trial on all three petitions to address the full scope of the co-pending litigation.

6. Relief Requested

  • Petitioner requested the institution of an inter partes review and the cancellation of claims 1 and 47 of the ’327 patent as unpatentable.