More on Reasonable Expectation of Success from the Federal Circuit

by Dennis Crouch

In Sisvel v. TCT Mobile and Honeywell, the Federal Circuit has affirmed the PTAB’s IPR findings that the claims are obvious.  The non-precedential decision provides further insight into the Federal Circuit’s reasonable expectation of success test.

Sisvel’s U.S. Patent 8,971,279 covers a method of sending Semi-Persistent Scheduling (SPS) deactivation signals that essentially “piggyback” on existing messages. SPS is a technique used in LTE networks to more efficiently allocate radio resources to user equipment (UE) for periodic transmissions, such as Voice over IP (VoIP). In SPS, the base station pre-allocates resources to the UE for a set period of time, reducing the need for frequent scheduling requests and grants. SPS deactivation signals are messages sent by the base station to the UE to indicate that the pre-allocated resources are being released and are no longer available for the UE’s periodic transmissions. These signals are necessary to free up the resources when they are no longer needed, allowing them to be reassigned to other UEs or used for other purposes.

In the context of Sisvel’s ‘279 patent, the invention was directed to a specific method of sending SPS deactivation signals by filling a preexisting binary field (the resource indication value or “RIV”) with all “1”s. This 111111111 technique was intended to provide a more efficient way of signaling SPS deactivation while still ensuring that the deactivation message would not be mistaken for a valid resource allocation message.  In the patented system, the string of ones would always be processed as an invalid value and never mistaken for a valid resource allocation message, providing stability to the network, regardless of size.

TCT Mobile and others petitioned for IPR, asserting that the challenged claims were obvious based on various combinations of prior art, including Samsung and Dahlman. The PTAB found the claims unpatentable as obvious, and Sisvel appealed.

Obviousness is the central patent law concept and is usually the determining doctrine on whether an invention is patentable over the prior art. To assess obviousness, courts consider several factors, including the scope and content of the prior art, the differences between the prior art and the claimed invention, and the level of ordinary skill in the art.  Graham v. John Deere Co., 383 U.S. 1 (1966). When multiple prior art references are combined to challenge obviousness, there must be both a motivation to combine the references and a reasonable expectation of success in  the proposed combination. The Federal Circuit has elaborated on these principles, noting that the motivation to combine need not be explicitly stated in the prior art and can be based on the knowledge and creativity of a person of ordinary skill in the art. As emphasized in Sisvel, the expectation of success need only be reasonable, not absolute, and obviousness does not require a guarantee or certainty on the part of PHOSITA that the combination of prior art references will be successful.

Nexus between the Claims and the Nonobviousness Argument: Sisvel’s main argument was that a person of ordinary skill in the art would not have had a reasonable expectation of success in the proposed combinations because of the allegedly extensive calculations that would have been required to ensure that filling the field entirely with ones would be invalid in all circumstances, regardless of network size. Sisvel relied on the testimony of its expert witness, who asserted that a skilled artisan in this field would have demanded mathematical certainty that the solution would work for all size networks.

As seen below, a key problem with this argument is that it lacks nexus with the patented claims. In rejecting Sisvel’s argument, Federal Circuit particularly noted that the claims at issue did “not require performing any calculations prior to filling the ‘first field’ entirely with 1s,” nor did they require any particular field size. Therefore, the court found no need to resolve the parties’ dispute as to whether a person of ordinary skill would have been capable of performing such calculations.

Reasonable Expectation of Success: Federal Circuit also found that the IPR petitioners had demonstrated a reasonable expectation of success in combining the two references: Samsung and Dahlman. The court pointed to the fact that Samsung (1) describes its solution as “simple,” (2) states that “all 1s could be a good candidate,” and (3) uses the same DCI format for signaling SPS deactivation as Dahlman.

Significantly, the court emphasized that “the expectation of success need only be reasonable, not absolute,” rejecting Sisvel’s argument that a skilled artisan would have demanded certainty of success. See Pfizer, Inc. v. Apotex, Inc., 480 F.3d 1348 (Fed. Cir. 2007).  The court found that there was nothing in the record showing that using all ones would not work or would be exceedingly difficult to implement. Impact on Innovation

Different Fields – Different Expectations?: The Judge Lourie opinion also noted as dicta that “different fields of art may have differences in what constitutes a ‘reasonable’ expectation of success.”  This statement suggests that the bar for establishing a reasonable expectation of success will be higher or lower depending on the predictability and maturity of the field in question. For example, in fields such as mechanical engineering or electrical circuits, where the underlying principles are well-established and outcomes are more predictable, a lower level of explicit guidance in the prior art may be sufficient to establish a reasonable expectation of success. In contrast, in fields such as biotechnology or advanced materials science, where the behavior of complex systems is less predictable and the success of combinations is more uncertain, a higher level of specificity and experimental validation in the prior art may be necessary to meet the reasonable expectation threshold.

17 thoughts on “More on Reasonable Expectation of Success from the Federal Circuit

  1. 5

    What’s the test for the predictability or maturity of the field of endeavor?

    1. 5.1

      I think it aligns with “how grown up” your understanding is.

  2. 4

    > This statement suggests that the bar for establishing a reasonable expectation of success will be higher or lower depending on the predictability and maturity of the field in question.

    I kinda read it the opposite way (albeit, w/o reading the full opinion). In fields were weird corner cases *really* matter, a POSITA might be more skeptical of certain proposals.

  3. 3

    Notably, the primary reference here, Samsung, is a technical proposal from a 3G meeting. The inventors on the 279 are originally from LG, a Samsung competitor that also typically attends such meetings. So one could speculate that the inventors saw the Samsung proposal at the time of the meeting and decided they would just go ahead and patent the technique themselves.

    1. 3.1

      I doubt it as the inventors file provisionals before presenting their inventions.

      1. 3.1.1

        But if that were the case here, had the 279 inventors from LG filed their own earlier provisional, the Samsung proposal should not have been prior art.

        But it’s also just as likely that both companies independently came up with the same solution, which can happen when multiple companies are simultaneously implementing the same standard. Standards are often vague on technical details and actually implementing them may present problems, whereas the other requirements of the standard constrain the universe of solutions to those problems. In this case, populating a preexisting field with a value known to be invalid was a pretty obvious way to convey a deactivation signal.


          There is no way to “invent” a patentable “deactivation signal”.


            Are you parsing claims again?

            Or are you referring to the controlling (albeit reality-rejecting) on re Nuitjen case?

  4. 2

    Re: The indicated Judge Lourie dicta that suggests the bar for establishing a “reasonable expectation of success” will be higher or lower depending on the predictability and maturity of the field in question.”
    This is consistent with the many prior decisions re the “unpredictable arts.”

  5. 1

    I’m surprised that “use a bunch of 1’s as a signal to indicate X” survived an eligibility challenge but perhaps a proper challenge was not raised

    1. 1.1

      This is an IPR proceeding, you can only bring 102/103 challenges.

    2. 1.2

      The interplay between a lawsuit defendant’s use of an “unpatentable subject matter” claim defense and/or an IPR claim defense, as here, is interesting, and would be worth comments by others more involved. The two defenses are obviously very different, yet theoretically both could used in many cases. But as a practical matter it seems often to be just one or the other being chosen, depending on the judge, the attorneys, the prior art found, and other factors? Typically, “unpatentable subject matter” [misleadingly aka 101] is asserted by a FRCP 12(b)(6) motion very early, well before any trial date. If decided favorably to the defendant, early enough, there would, of course, then be no need to also prepare an IPR petition.
      On the other hand, if the judge is one who regularly agrees to stay litigation for IPRs, and the defendant has found good patent or publication prior art, and the claims are not clearly “abstract,” and are not claiming something naturally occurring, filing an IPR petition should be more likely?
      Also note that there is a one year bar date for filing IPRs. In contrast, arguing “unpatentable subject matter” as a defense can be done later on in a trial if it was listed as a potentially asserted defense in the answer to the complaint.

      1. 1.2.1

        Rah Rah

    3. 1.3

      It (101) couldn’t be raised in an IPR given the restriction of IPRs to 102 and 103 grounds based on patent literature and NPL.

    4. 1.4

      I’m surprised that

      One question for you Malcolm: Have you recovered from that attempt to reformat your hard drive with that Britney Spears CD?

    5. 1.5

      “perhaps a proper [eligibility] challenge was not raised”

      Funny guy. Since the improper Mayo / Alice, there are of course no such proper challenges.

      1. 1.5.1

        + 1

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