When 'Very Simple' Isn't Enough: Proving Patent Obviousness

The Federal Circuit has affirmed decisions by the Patent and Trademark Appeal Board (PTAB or Board) that upheld the validity of a communications networking patent. The court agreed with the Board that the opposing party’s expert’s testimony that it would be “very simple” for a person skilled in the art to combine prior art references wasn’t a credible basis for finding that such a person would have a reasonable likelihood of success in making such a combination.

The case is Juniper Networks, Inc. v. Correct Transmission, LLC.

Correct Transmission owns the ’465 patent and the ’150 patent, both of which pertain to improvements in communications networks to protect against failures in those networks.

As the court explained,

For every primary core node (i.e., data communication device) in the network, the patent describes having “one or more standby core nodes,” where “[e]ach standby core node has the same topological image in the network (i.e., the same connections) as a corresponding primary core node which it protects.” … “[I]f the primary core node fails, the remaining nodes in the network simply redirect all connections from the failed primary core node to the corresponding standby core node.” …

The specification explains that the forwarding tables (i.e., the databases of known addresses for each node) of the primary and standby nodes can be synchronized regularly using “[a] simple communications protocol” to keep the forwarding table of the standby node updated with all the addresses in the primary node. … This way, if the primary core node were to fail, the standby core node would know all the same addresses as the primary core node, except those learned by the primary core node after the last update. Because the standby core nodes have the same connections as their corresponding primary core nodes, the other nodes in the network may seamlessly connect to it without there being a change in the network topology.

Juniper argued that certain claims of the patents were unpatentable as obvious over combinations of prior art.

For example,

Juniper contended that Kuo and Casey, individually, recited every limitation in claim 1, except the limitation of periodically synchronizing the forwarding tables between the primary and backup virtual bridges. Juniper argued that “such periodic synchronization would have been obvious to [the skilled artisan] in view of Balakrishnan’s teachings” of periodically synchronizing forwarding tables or “in conjunction with what was generally known in the art.”

The Board determined that the prior art disclosed the patented features and that Juniper had shown evidence of a motivation to combine the features. However, the Board concluded that Juniper had not shown “a reasonable expectation of success in modifying [Casey or] Kuo [with Balakrishnan] to periodically synchronize forwarding tables.”

As an article from the American Intellectual Property Law Association explains,

Even if [an] invention is deemed novel, it must also satisfy the requirement of non-obviousness to be patentable. The test for non-obviousness is outlined in 35 U.S.C. §103, which aims to prevent the granting of patents for inventions that merely make an insignificant departure from what is already known in the prior art. An invention fails this test if a combination of two or more prior art references teaches the same invention. Since the obviousness test often involves combining references, the Examiner must demonstrate that a person skilled in the relevant field (1) would have been motivated to make such a combination and (2) would have had a reasonable expectation of success in arriving at the claimed invention.

Under 35 U.S.C. §103,

A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains.

The Federal Circuit recently addressed the “reasonable expectation of success” test in the case of Sisvel v. TCT Mobile and Honeywell (also involving communications networks), noting that “the expectation of success need only be reasonable, not absolute.”

Also, said the court in Sisvel, “Although different fields of art may have differences in what constitutes a “reasonable” expectation of success, such differences are not determinative…”

“[M]athematical certainty that [a] solution would work” is not required, said the court in Sisvel.

The Board found Juniper’s expert’s testimony about combining prior art references to be conclusory and not credible.

Said the court,

To be sure, testimony that combining references would be difficult or require substantial work does not, in and of itself, establish a lack of reasonable expectation of success. Such a finding also requires evidence demonstrating that making the combination would be beyond the skill level of a POSA [person of ordinary skill in the art] or lead to unpredictable results….

[I]t was Juniper’s burden to offer proof that the combination could be made with a reasonable expectation of success.

Juniper appealed the two decisions by the PTAB.

The court noted that in a previous case, it had held that expert testimony stating that certain software modifications were “straightforward” and “simple” was sufficient to establish a reasonable expectation of success. However, in that previous case, there was no challenge to the expert’s testimony as being conclusory or not credible, and the expert testimony was uncontradicted.

In the present case, Juniper’s expert’s evidence was challenged by Correct Transmission’s expert.

The court agreed with the Board, saying that

It was Juniper’s burden to establish a reasonable expectation of success, and Juniper presented no theory other than that the combination was simple. We conclude the Board’s decision to credit [Correct Transmission’s expert’s] testimony and reject Juniper’s theory was supported by substantial evidence and that it was not an error to conclude that Juniper had not established a reasonable expectation of success.

The court thus affirmed the Board’s decision that the challenged claims of the patents at issue were nonobvious.