PTAB

IPR2018-00727

Ericsson Inc. v. Intellectual Ventures I LLC

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1. Case Identification

2. Patent Overview

  • Title: Wireless Telecommunications Network
  • Brief Description: The ’629 patent describes a method for managing data transmission in a wireless telecommunications network. The core of the invention is an "advanced reservation algorithm" that assigns future transmission slots to data packets based on the priority and characteristics of the associated IP data flow, with a focus on isochronous (i.e., consistently timed) reservations for jitter-sensitive traffic.

3. Grounds for Unpatentability

Ground 1: Claims 1, 3, and 4 are obvious over Dyson in view of Raychaudhuri.

  • Prior Art Relied Upon: Dyson ("A Dynamic Packet Reservation Multiple Access Scheme for Wireless ATM") and Raychaudhuri ("WATMnet: A Prototype Wireless ATM System for Multimedia Personal Communication").
  • Core Argument for this Ground:
    • Prior Art Mapping: Petitioner argued that Dyson discloses a Dynamic Packet Reservation Multiple Access (DPRMA) scheme for a wireless ATM network that reserves future time slots for users. For constant bit rate (CBR) traffic like voice, Dyson taught reserving the same slot in every subsequent frame until the transmission is complete. This maps to the limitations of claim 1 concerning a method for assigning future slots using a reservation algorithm. Raychaudhuri taught the transmission of IP packets over a similar wireless ATM network, providing the "IP flow" context missing from Dyson. The combination thus taught a method of reserving slots for an IP flow. For claim 3, Dyson’s reservation of the same slot in successive frames met the "no periodic variation" limitation, per Petitioner’s proposed claim construction. For claim 4, Petitioner asserted that Dyson’s DPRMA scheme distinguished between CBR (voice) and variable bit rate (VBR) traffic. Since voice traffic was well-known to be jitter-sensitive, the algorithm’s act of identifying traffic as voice/CBR inherently "determines whether said IP flow is jitter-sensitive."
    • Motivation to Combine: A person of ordinary skill in the art (POSITA) would combine the teachings because of the market-driven need to transmit the increasingly ubiquitous IP packets (taught by Raychaudhuri) over efficient wireless reservation systems like Dyson's DPRMA. Both references described compatible wireless ATM systems that handled CBR traffic similarly, making the integration straightforward and predictable.
    • Expectation of Success: A POSITA would have a high expectation of success, as the combination involved applying a known reservation protocol (Dyson) to a known packet type (IP packets from Raychaudhuri) within a common and compatible technological framework (wireless ATM).

Ground 2: Claim 2 is obvious over the combination of Dyson and Raychaudhuri in view of Chennakeshu.

  • Prior Art Relied Upon: Dyson, Raychaudhuri, and Chennakeshu (Patent 5,020,056).
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground specifically addressed claim 2, which required a "periodic variation" between the placement of packets in successive frames. The base combination of Dyson and Raychaudhuri taught reserving the same slot, which corresponds to "no periodic variation." Petitioner argued that this technique was known to be susceptible to synchronous signal fading. Chennakeshu was introduced because it explicitly taught a solution to this exact problem by "varying the position of the time slot... in each success frame." Chennakeshu described a "cyclic shifting" of the assigned slot, which directly mapped to the "periodic variation" limitation as construed by Petitioner.
    • Motivation to Combine: A POSITA, recognizing the known problem of synchronous fading in a system like that proposed by Dyson/Raychaudhuri, would be motivated to implement the known solution taught by Chennakeshu. The combination represented a simple substitution of one known slot allocation method for another to gain a well-understood benefit (fade resistance).
    • Expectation of Success: Success would be expected because Chennakeshu provided an explicit solution to a known problem that could arise in the base system, with both technologies operating in the same field of time-division multiplexing.

Ground 3: Claim 4 is obvious over the combination of Dyson and Raychaudhuri in view of Goodman and Yang.

  • Prior Art Relied Upon: Dyson, Raychaudhuri, Goodman ("Packet Reservation Multiple Access for Local Wireless Communications"), and Yang ("A Multimedia Synchronization Model...").
  • Core Argument for this Ground:
    • Prior Art Mapping: This ground presented an alternative argument for the unpatentability of claim 4. Petitioner argued that Dyson’s DPRMA was an extension of the PRMA scheme first detailed in Goodman. A POSITA would look to Goodman for implementation details. Goodman taught using a "packet assembler" that explicitly identified a packet's category (e.g., periodic/voice vs. random/data) by marking a bit in the packet header. Yang was cited as background art explicitly stating that audio data is "very jitter sensitive." Therefore, implementing Goodman's packet assembler into the Dyson/Raychaudhuri system would provide an explicit mechanism for the reservation algorithm to identify a packet as voice, which is equivalent to determining that the IP flow is "jitter-sensitive."
    • Motivation to Combine: A POSITA implementing Dyson's system would naturally consult Goodman, the foundational reference for PRMA, for implementation details like traffic differentiation. Incorporating Goodman's explicit packet assembler into Dyson's framework was an obvious design choice to enable the system's disparate treatment of CBR and VBR traffic. Yang simply represented the common knowledge of a POSITA.
    • Expectation of Success: The combination yielded predictable results, as it involved incorporating a component (Goodman's packet assembler) into a system (Dyson) for its intended purpose of traffic identification.

4. Key Claim Construction Positions

Petitioner argued that the following claim constructions were central to its unpatentability arguments:

  • "isochronous manner": Should be construed as "consistent timed access interval." This broad construction was argued to encompass both reservations in the same slot and reservations that vary periodically.
  • "no periodic variation": Should be construed as "a consistent time interval equal to the frame duration interval." This construction was key to mapping Dyson's teaching of reserving the same slot in successive frames to the language of claim 3.
  • "periodic variation": Should be construed as "a consistent time interval other than the frame duration interval." This was essential for mapping Chennakeshu's slot-shifting technique to the language of claim 2.

5. Relief Requested

  • Petitioner requested that the Board institute an inter partes review and cancel claims 1-4 of the ’629 patent as unpatentable under 35 U.S.C. §103.