PTAB

IPR2017-01099

T-MOBILE US, INC. v. Barkan Wireless Access Technologies, L.P.

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1. Case Identification

2. Patent Overview

  • Title: Wireless Network Hot-Spot and Routing
  • Brief Description: The ’306 patent describes a computing device (e.g., a laptop) that functions as a Wi-Fi hot-spot, providing network access to other wireless devices. The hot-spot itself connects to an IP-based network through a separate wireless connection (e.g., a cellular network) and uses standard networking techniques like Network Address Translation (NAT), Dynamic Host Configuration Protocol (DHCP), and Mobile IP-like functionality to manage connections.

3. Grounds for Unpatentability

Ground 1: Obviousness over Buddhikot and Lord - Claims 1-12, 14-22, 26-31, 34-37, 39-40, 43, 47-53, 56-63, 65-66 are obvious over Buddhikot in view of Lord.

  • Prior Art Relied Upon: Buddhikot (Patent 7,562,393) and Lord (Patent 6,763,012).
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Buddhikot teaches a "MobileHotSpot Gateway" (the computing device) that provides Wi-Fi connectivity for client devices and connects to the internet via a cellular base station. Buddhikot disclosed providing the client device with a unique public IP address via either a "Simple IP" (using DHCP) or "Mobile IP" scheme. Lord similarly taught a mobile terminal that functions as a hot-spot, preferably providing unique public IP addresses via DHCP to connected devices. The core of the argument was that the combination explicitly taught the key feature allegedly allowing the ’306 patent to issue: a system where both the hot-spot computing device and the client device have distinct public IP addresses.
    • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine Buddhikot and Lord because they addressed the same problem of integrating WLAN and cellular networks. A POSITA would have been motivated to augment Buddhikot’s system, which focused more on security features like IPSec/VPN, with Lord’s more detailed teachings on providing public IP addresses via DHCP to create a more robust and feature-complete mobile hot-spot.
    • Expectation of Success: A POSITA would have a high expectation of success as both references taught compatible methods for assigning IP addresses (public IPs via DHCP or private IPs via NAT) and described similar hot-spot architectures.

Ground 2: Obviousness over Buddhikot, Lord, and Moran - Claims 23-25, 41-42, 44-46, and 67-68 are obvious over Buddhikot, Lord, and Moran.

  • Prior Art Relied Upon: Buddhikot (Patent 7,562,393), Lord (Patent 6,763,012), and Moran (WO 2005/069577).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground built upon Ground 1 and addressed claims reciting more specific Mobile IP functionality, such as a proxy server allocating an IP address and forwarding data packets to a roamed device. Petitioner asserted that while Buddhikot taught using a proxy server and Mobile IP, Moran provided explicit detail on implementing an IPSec/VPN tunnel with Mobile IP where the home agent acts as the tunnel endpoint, VPN gateway, and proxy. Moran taught that the home agent allocates the mobile node’s home address and forwards packets to the mobile node’s new care-of address when it roams.
    • Motivation to Combine: A POSITA, implementing the hot-spot of Buddhikot/Lord, would have been motivated to look to a reference like Moran to improve the Mobile IP and security implementation. Since Buddhikot disclosed using a home agent but did not specify the tunnel endpoint location, a POSITA would consult Moran to learn that the home agent should be the endpoint, thereby providing a more secure and efficient implementation.
    • Key Aspects: The incremental contribution of Moran was its teaching of an improved Mobile IP home agent that acts as the IPSec/VPN tunnel endpoint, which directly maps to the claimed proxy server functionality.

Ground 3: Obviousness over Buddhikot, Lord, and Abhishek - Claims 32-33 and 54-55 are obvious over Buddhikot, Lord, and Abhishek.

  • Prior Art Relied Upon: Buddhikot (Patent 7,562,393), Lord (Patent 6,763,012), and Abhishek (Application # 2004/0103278).

  • Core Argument for this Ground:

    • Prior Art Mapping: This ground addressed claims where a third device connects to the network through the second device (acting as a bridge), rather than directly to the primary hot-spot. Petitioner argued that Abhishek taught a network of 802.11 access points that can act as bridges to extend the range of a wireless network.
    • Motivation to Combine: A POSITA building the hot-spot of Buddhikot/Lord would be motivated to incorporate Abhishek's teachings on Wi-Fi bridging to extend the hot-spot's effective range or overcome signal obstructions, which is a common and predictable design goal in wireless networking. Abhishek's focus on large-scale Wi-Fi deployments made it a natural reference for improving the hot-spot taught by the primary references.
    • Expectation of Success: Combining these technologies was straightforward, as it involved using a standard Wi-Fi bridging function, taught by Abhishek, to connect an additional device in a linear chain, which would be a predictable modification.

  • Additional Grounds: Petitioner asserted an additional obviousness challenge (Ground 4) for claims 13, 38, and 64 based on Buddhikot, Lord, and Kim (Application # 2004/0218611). This ground relied on a theory of obviousness to implement the NAT taught by Buddhikot using the well-known extension of Network Address Port Translation (NAPT) as taught by Kim to differentiate traffic for multiple devices using port numbers.

4. Key Claim Construction Positions

  • "access point”/“AP”: Petitioner proposed the construction "a device that connects a computer to a network." This construction was argued to be critical because it is not limited to a single protocol like 802.11 Wi-Fi. Petitioner contended that dependent claims and the specification supported that an AP could also be a cellular base station, which was necessary for their mapping of the "first AP" to the cellular network connection in the prior art.
  • "proxy server”: Petitioner proposed the construction "a server (a computer system or an application) that acts as an intermediary for requests from clients seeking resources from other servers." Petitioner argued that in the context of the patent, this referred to a trusted network site at the end of a secure tunnel, consistent with the specification's description of tunneling and Mobile IP. This construction was key to mapping the home agent or VPN gateway in the prior art to the claimed proxy server.
  • "communication module" / "AP module": Petitioner argued no construction was necessary for these terms. However, if the Board deemed them means-plus-function terms under §112, Petitioner proposed the function is "wireless communication" or "providing an access point," respectively, and the corresponding structure is "software in a computing device." This was to ensure the terms were not unduly narrowed and could be mapped to software components described in the prior art.

5. Relief Requested

  • Petitioner requested the Board institute an inter partes review and cancel claims 1-68 of the ’306 patent as unpatentable.