Google LLC v. Geoscope Technologies Pte Ltd

1. Case Identification

• Case #: IPR2023-01210
• Patent #: 8,400,358
• Filed: August 10, 2023
• Petitioner(s): Google LLC
• Patent Owner(s): Geoscope Technologies PTE. LTD.
• Challenged Claims: 1, 15, 18, 41, and 52

2. Patent Overview

• Title: Method to modify calibration data used to locate a mobile unit
• Brief Description: The ’358 patent discloses a method for determining the location of a mobile device, particularly indoors where accuracy is a challenge. The core concept involves modifying observed network signal measurements before comparing them to a pre-existing database of calibration data (a signal fingerprint map) to improve location accuracy.

3. Grounds for Unpatentability

Ground 1: Claims 1, 15, and 18 are anticipated by Shkedi under §102.

• Prior Art Relied Upon: Shkedi (Patent 7,706,811).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Shkedi taught every element of the challenged claims. Shkedi disclosed a "Signal-Comparison Based Location-Determining Method" specifically for improving location accuracy in areas with poor signal reception, such as multi-story buildings. The method involved: (1) creating a database of previously-gathered signal strength measurements for selected locations (the claimed "database of calibration data"); (2) collecting current "observed network measurement data" by monitoring signals from various antenna stations; (3) "modifying" this observed data by normalizing it, for instance, by dividing weaker signals by the single strongest signal; and (4) "comparing" the modified data to the database to determine the mobile device's location. This process directly maps to the method steps of claim 1 and the system elements of claim 15. For claim 18, Petitioner asserted that Shkedi's method of building its database by recording user-selected locations and extrapolating from them inherently results in "non-uniform grid points."

Ground 2: Claims 1, 15, 18, 41, and 52 are anticipated by Zhu under §102.

• Prior Art Relied Upon: Zhu ("Indoor/outdoor location of cellular handsets based on received signal strength," 2005 IEEE 61st Vehicular Technology Conference).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner asserted that Zhu, a conference paper on location techniques, also anticipated the challenged claims. Zhu disclosed a Received Signal Strength (RSS) method using a pre-constructed RF Map Database (the "calibration data"). The system collected observed network measurement reports (NMRs) from a handset and then "modified" them. Critically, Zhu's modification involved normalizing the observed data by subtracting the average dBm-power of the "N strongest" received signals. This modified data was then compared to the RF Map Database to estimate the handset's location. Petitioner argued this taught all limitations of claims 1 and 15. For claim 41, which specifies modification using an "average value," Zhu's use of the average of the N strongest signals was a direct disclosure. For claim 52, which requires at least one transmitter to be outside the wireless network, Zhu's test setup explicitly included transmitters both inside and outside the primary measurement area.

Ground 3: Claims 41 and 52 are obvious over Shkedi in view of Zhu under §103.

• Prior Art Relied Upon: Shkedi (Patent 7,706,811) and Zhu (2005 IEEE paper).

• Core Argument for this Ground:

  • Prior Art Mapping: Petitioner argued that while Shkedi taught the overall location determination method, its specific modification technique involved normalizing by the single strongest signal. Claim 41 requires modification using an "average value." Zhu expressly taught this missing element by disclosing the normalization of signal strengths using an average value of multiple strong signals to improve accuracy.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA), seeking to improve the accuracy of Shkedi's location system, would have been motivated to substitute Zhu's superior normalization technique (using an average value) into Shkedi's framework. Both references addressed the same problem of signal-based location, and using an average is a known method to smooth data and improve results. This would have been a simple substitution of one known element for another to obtain predictable results.
  • Expectation of Success: A POSITA would have had a high expectation of success, as combining a known averaging technique with a known signal fingerprinting system to improve accuracy was a routine and predictable design choice.

• Additional Grounds: Petitioner asserted additional obviousness challenges, including that claim 18 is obvious over Shkedi in view of Spain (Application # 2003/0064735) for its explicit teaching of interpolating grid points; claim 18 is obvious over Zhu in view of Spain for the same reason; and claim 52 is obvious over Zhu in view of Laitinen ("Database Correlation Method for GSM Location," 2001 IEEE paper) for its teaching of using data from multiple different network types (e.g., GSM, UMTS, WLAN) to improve accuracy.

4. Key Claim Construction Positions

• "calibration data": Petitioner proposed this term be construed as "modified or unmodified network measurement data associated with a geographic location." This broad construction, which includes signal strength, is central to arguing that the prior art's signal fingerprint databases meet this limitation.
• "observed network measurement data": Petitioner proposed construing this as "measurement data from a network measurement report (i.e., a report used in cellular networks which provides the results of a measurement from a mobile device on one or more cells)." This links the claim term directly to standard cellular technology described in the prior art.
• "positioning determining equipment": Petitioner argued this term is a means-plus-function limitation under §112, ¶6, with the function being "comparing said modified network measurement data with said database of calibration data." Petitioner contended the patent fails to disclose adequate corresponding structure, rendering the term indefinite. However, for the purposes of the IPR, Petitioner proceeded by mapping the prior art to the structure alleged by the Patent Owner in co-pending litigation (e.g., a processor).

5. Arguments Regarding Discretionary Denial

• Arguments against §314(a) Fintiv Denial: Petitioner argued against discretionary denial based on the parallel district court litigation. Key reasons included that the litigation was in its early stages with no trial date set, petitioner filed the IPR expeditiously after the asserted claims were finalized, and the compelling merits of the petition weigh strongly in favor of institution.
• Arguments against §325(d) Denial: Petitioner argued that the primary prior art references, Shkedi and Zhu, were never considered or substantively discussed by the examiner during prosecution. Petitioner contended this represented a "material error" by the Patent Office, as these references disclose the purported "inventive feature" of the patent (modifying observed data). Because the art is not cumulative and presents new questions of patentability, Petitioner argued the Board should not exercise its discretion to deny the petition.

6. Relief Requested

• Petitioner requested the institution of an inter partes review and the cancellation of claims 1, 15, 18, 41, and 52 of Patent 8,400,358 as unpatentable.