The US Court of Appeals for the Federal Circuit affirmed a Patent Trial and Appeal Board (PTAB) decision, finding that the PTAB did not need to explicitly construe a claim term. HTC Corp. v. Cellular Communications Equipment, LLC, Case No. 16-1880 (Fed. Cir., Dec. 18, 2017) (Reyna, J).

Cellular Communications owns a patent directed to a communications system where the mobile device is assigned a plurality of codes for transmitting messages. When transmission conditions deteriorate, such as when there is a high amount of interference, the base station may command the mobile device to increase transmit power in order to send the message. To avoid operating at maximum transmission power, the patent’s claimed solution sets a “transmit power difference” for the plurality of codes in the mobile device at the start of a message transmission. Setting this transmit power difference allows the mobile device to increase transmit power to overcome interference and avoid aborting the message transmission.

HTC and ZTE filed inter partes review (IPR) petitions challenging several claims in Cellular Communications’ patent. The PTAB instituted IPR on three grounds:

• Anticipation by Baker
• Obviousness over Reed in view of Baker
• Obviousness over Reed in view of Love

Ultimately, the PTAB issued a final written decision concluding that HTC failed to show that any of the challenged claims were unpatentable. HTC appealed.

On appeal, HTC argued that the PTAB failed to construe the term “message” according to its broadest reasonable construction. Specifically, HTC argued that the PTAB’s application of the term improperly excluded single frame EDCH messages, which were an embodiment disclosed in the specification of the challenged patent. The Federal Circuit rejected HTC’s argument and found that while neither the parties nor the PTAB explicitly construed the term “message,” the PTAB agreed in its analysis that a message transmission can occur over a single frame or over multiple frames, and thus properly understood “message” to encompass EDCH messages that last a single frame.

HTC also argued that the PTAB’s anticipation and obviousness findings were not supported by substantial evidence. However, the Federal Circuit rejected HTC’s argument, finding that the PTAB’s decision was supported by substantial evidence from the prior art references, expert declarations and admissions from HTC’s witnesses. The Court thus affirmed the PTAB’s finding of patentability.