Addressing the proper construction for two claim terms construed by the Patent Trial and Appeal Board (PTAB) as part of related inter Partes review (IPR) proceedings, the US Court of Appeals for the Federal Circuit affirmed the PTAB’s decision invalidating certain claims, but vacated and remanded as to other claims because the PTAB erred by improperly reading limitations from a preferred embodiment into the claims in its claim construction. TQ Delta, LLC v. Dish Network LLC, Case No. 18-1799 (Fed. Cir. Jul. 10, 2019) (Wallach, J); Cisco Systems, Inc. v. TQ Delta, LLC, Case No. 18-1806 (Fed. Cir. Jul. 10, 2019) (Wallach, J).

TQ Delta owns a patent directed to multicarrier transmission systems that provide high-speed data links between communication points. The patent claims an apparatus for waking up a transmission system from low power mode using a “synchronization signal,” and allowing the system to rapidly exit low power mode “without needing to reinitialize” by using parameters stored prior to entering low power mode. Dish filed an IPR petition seeking to invalidate claims 6, 11, 16 and 20 of the patent. Cisco filed an IPR petition seeking to invalidate those same claims over the same prior art, and also to invalidate claims 1–5, 7–10, 12–15 and 17–19 of the patent based on different prior art.

The PTAB instituted IPR and ultimately found claims 6, 11, 16 and 20 unpatentable, but determined that claims 1–5, 7–10, 12–15 and 17–19 of the patent were not unpatentable. TQ Delta appealed the findings as to claims 6, 11, 16 and 20 (TQ Delta v. Dish), and Cisco appealed the findings as to claims 1–5, 7–10, 12–15 and 17–19 (Cisco v. TQ Delta).

In TQ Delta v. Dish, TQ Delta challenged the PTAB’s construction of the term “without needing to reinitialize.” The PTAB construed the term “without needing to reinitialize” as being satisfied “if any step of the initialization is avoided and does not require that every step of initialization be avoided.” TQ Delta argued that the PTAB erred and that the plain and ordinary meaning of the term is “without needing to perform any step of the initialization process.”

The Federal Circuit upheld the PTAB’s construction, concluding that it was supported by the intrinsic evidence. In terms of the claim language itself, the Court noted that the claims use the term “reinitialize” but do not refer to a prior or first initialization. Thus, the Court reasoned that the term “reinitialize” must refer to the full initialization process described in the specification, noting that the specification indicates that upon waking from low power mode, it is not necessary to “repeat the initialization that was earlier required to establish the requisite parameters.” The specification explains that transceivers, when waking from inactivity, performed “full . . . initialization.” The Court also noted that nothing in the specification suggested a way to rapidly exit low power mode while avoiding the initialization process entirely. Using the PTAB’s construction, the Court found that substantial evidence supported the PTAB’s obviousness finding of the challenged claims.

In Cisco v. TQ Delta, the Federal Circuit found error in the PTAB’s construction of the term “synchronization signal.” The PTAB had construed the term to mean “a signal allowing synchronization between the clock of the transmitter of the signal and the clock of the receiver of the signal.” The Court found that the intrinsic evidence did not support this narrow construction, given that the term is not limited to describing what a signal must synchronize or to a particular type of synchronization. The Court found that while the preferred embodiment indicates that clock-based synchronization is “advantageous,” it is improper to read limitations from a preferred embodiment into the claims, absent clear indication by the patentee to do so. Having found sufficient alternate embodiments in the specification that support both timing and frequency synchronization, the Court found that the term “synchronization signal” means “used to establish or maintain a timing relationship between transceivers between the transmitter of the signal and the receiver of the signal.” The Court vacated the PTAB’s decision and remanded with instructions to determine whether the prior art invalidated the challenged claims under the proper construction.

Practice Note: In TQ Delta v. Dish, TQ Delta also argued that the PTAB violated TQ Delta’s rights by relying on a new claim construction for “without needing to synchronize” between the institution and final written decision phases. The Federal Circuit found that TQ Delta’s rights were not violated because TQ Delta was provided with notice of the construction at the oral hearing and further had an opportunity to respond through the ability to “seek a sur-reply or rehearing.” This decision indicates that it is entirely possible for the PTAB to construe or reconstrue a term in the final written decision, if proper notice and an opportunity to be heard is provided.