PTAB

IPR2019-01116

Microsoft Corp v. Uniloc 2017 LLC

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Key Events
Petition
petition

1. Case Identification

2. Patent Overview

  • Title: Method, Network and Control Station for the Two-Way Alternate Control of Radio Systems of Different Standards in the Same Frequency Band
  • Brief Description: The ’676 patent discloses an interface-control protocol method where a central control station manages access to a common frequency band for alternate use by radio stations operating under at least two different radio interface standards, aiming to improve the efficiency of radio spectrum use.

3. Grounds for Unpatentability

Ground 1: Obviousness over HomeRF - Claims 1 and 2 are obvious over HomeRF.

  • Prior Art Relied Upon: HomeRF ("HomeRF: Wireless Networking for the Connected Home," a February 2000 article from IEEE Personal Communications).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that HomeRF, which describes the Shared Wireless Access Protocol (SWAP), discloses every limitation of the challenged claims. HomeRF teaches a system combining two radio standards (TDMA/DECT for voice and CSMA/802.11 for data) in a single frequency band, managed by a "control point" (CP), which functions as the claimed "control station." The system uses a fixed-duration "superframe" divided into time slots. The CP allocates "contention-free periods" for priority voice traffic (first standard) and a "contention period" for data traffic (second standard). Petitioner contended that because the superframe duration is fixed, if fewer voice connections are requested by first-standard stations, the time for the data contention period for second-standard stations necessarily increases. This directly teaches the key limitation of claim 1, wherein the control station "renders the frequency band available for access by the stations working in accordance with the second radio interface standard if stations working in accordance with the first radio interface standard do not request access." For claim 2, the CP's role in defining the superframe structure and allocating slots inherently determines the "respective duration" of the contention period available for data traffic.
    • Motivation to Combine: Not applicable (single reference ground).
    • Expectation of Success: Not applicable (single reference ground).

Ground 2: Obviousness over HomeRF in view of HomeRF Tutorial - Claims 1 and 2 are obvious over HomeRF in view of HomeRF Tutorial.

  • Prior Art Relied Upon: HomeRF (the Feb. 2000 article) and HomeRF Tutorial ("HomeRF: Bringing Wireless Connectivity Home," a March 1999 presentation).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground relied on the same core teachings of HomeRF as Ground 1. The HomeRF Tutorial was introduced to provide additional, explicit confirmation of the system's operation. Petitioner highlighted that the Tutorial describes the same SWAP superframe structure and explicitly states that with "no voice," the system provides "Data for entire frame." This disclosure directly corroborates the argument that when the first-standard stations (voice) do not request access, the entire frequency band becomes available for the second-standard stations (data), thus reinforcing the obviousness of claim 1's primary limitation.
    • Motivation to Combine: A POSITA would combine the references because they both describe different aspects and development stages of the very same HomeRF SWAP system. A person implementing or studying the HomeRF standard would naturally consult related articles and tutorial presentations to gain a complete understanding of the technology.
    • Expectation of Success: A POSITA would have a high expectation of success, as the references are not being combined to create something new but are being used together to understand a single, coherent, pre-existing system.

Ground 4: Obviousness over Lansford - Claims 1 and 2 are obvious over Lansford.

  • Prior Art Relied Upon: Lansford (Patent 6,937,158).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner asserted Lansford discloses a controller device that manages wireless communication between devices using at least two different protocols (e.g., HomeRF and Bluetooth) within a common frequency band. The controller allocates time within a communication block, creating "contention-free periods" during which a first class of devices (e.g., Bluetooth) can communicate with the controller. During these periods, communication with a second class of devices (e.g., HomeRF) is "suspended." The second class of devices can communicate during the remaining time (the contention periods). Petitioner argued this maps directly to claim 1, as the controller makes the band available to the second-protocol stations (HomeRF) when the first-protocol stations (Bluetooth) do not require access (i.e., outside of their designated contention-free period). For claim 2, Lansford's controller determines the "time frame for a contention-free period" by sending a beacon, which directly teaches the control station determining the "respective duration" for network access.
    • Motivation to Combine: Not applicable (single reference ground).
    • Expectation of Success: Not applicable (single reference ground).
  • Additional Grounds: Petitioner asserted an additional obviousness challenge (Ground 3) based on HomeRF in view of the HomeRF Liaison Report, which further confirmed that with no voice connections, the data contention period occupies the entire superframe.

4. Key Claim Construction Positions

  • "stations which operate in accordance with a first radio interface standard and/or a second radio interface standard" (Claim 1): Petitioner proposed this term means "two or more devices in a wireless network, each of which operates in a manner that is in agreement with or conforms to a first radio standard, a second radio standard, or both..., or variants thereof." This construction was important to establish that prior art systems with devices conforming to different standards, like HomeRF's voice and data nodes, meet the claim language.
  • "renders the frequency band available for access by the stations working in accordance with the second radio interface standard if stations working in accordance with the first radio interface standard do not request access to the frequency band" (Claim 1): Petitioner proposed this should be interpreted as "makes the frequency band available for transmissions by stations working in accordance with the second radio interface standard for periods during which the common frequency band is not being used by stations operating in accordance with the first radio interface standard that have requested access to the band." This construction was central to mapping the dynamic time-slot allocation schemes of HomeRF and Lansford to the claim language.

5. Relief Requested

  • Petitioner requests institution of an inter partes review and cancellation of claims 1 and 2 of the ’676 patent as unpatentable.