The Federal Circuit has affirmed most of a ruling by the Patent Trial and Appeal Board (PTAB or Board) that invalidated claims related to radio communications in a patent owned by Philips.

The case is KONINKLIJKE PHILIPS N.V. v. QUECTEL WIRELESS SOLUTIONS CO. LTD.

Quectel petitioned the PTAB for inter partes review (IPR) of claim 9 of U.S. Patent No. 8,195,216 (’216 patent), owned by Philips. The Board determined the challenged claim to be unpatentable under 35 U.S.C. § 103.

As the Federal Circuit explained,

The ’216 patent relates to techniques for radio communication systems to regulate the power of communications transmitted between base stations and mobile stations. Uplink communications are those transmitted from a mobile station to a base station, and downlink communications are those transmitted from a base station to a mobile station….. The mobile and base stations exchange two types of information: (1) user traffic, such as speech or packet data, and (2) control information, which sets and monitors various parameters of the transmission channel to enable the base and mobile stations to exchange user traffic.

As the patent itself explains,

power control of signals transmitted from a mobile station to the base station is needed “so that the [base station] receives signals from different [mobile stations] at approximately the same power level, while minimi[z]ing the transmission power required by each [mobile station].”

Quectel’s IPR petition challenged the validity of claim 9 of the patent for obviousness based on two prior art references: “Agin” and “Chen.”

Agin teaches a method for improving mobile radio communications that may be subject to interruptions, via the use of a power control algorithm.

Chen teaches a method and apparatus for adjusting the power of base stations that are communicating with a mobile station.

The PTAB found that claim 9 of the patent was invalid as obvious based on the combination of these two prior art references.

As the Federal Circuit noted,

Problems with closed-loop power control arise if there is an interruption in data transmission. “[A]fter the transmission is interrupted, the power control loops may take some time to converge satisfactorily. Until such convergence is achieved data transmissions are likely to be received in a corrupted state if their power level is too low, or to generate extra interference if their power level is too high.” … The ’216 patent purports to address these problems by providing means “for setting the initial transmission power after a pause in transmission to that before the pause adjusted by an offset.”

On appeal, Philips argued that the Board failed to construe its claim term “offset.”

According to Philips, the Board should have explicitly construed “offset” to mean “a one time adjustment applied to initial transmission power following an interruption.”

The court found that Philips didn’t raise this argument in a timely manner.

Philips also contended that Agin didn’t disclose the claimed “initial transmission power” and “offset” limitations of claim 9. 

The court noted that Agin discloses a “power control step” and agreed with the Board that “an offset applying a single step size alteration is not distinguishable from the application of a step size.”

Philips also argued that the Board erred in concluding that Agin teaches applying an offset to an “initial transmission power,” saying that “Agin is silent as to the initial transmission power after an interruption” and, moreover, “the specific teachings of Agin . . . demonstrate that Agin’s step size adjustment could not be applied to the initial transmission.”

On this point, the court was more receptive and found that the Board

failed to address Philips’s argument as to how Agin’s system would adjust the initial transmission following an interruption without having received any power control commands during the interruption.

Philips argued that a skilled artisan would not have been motivated to modify Agin in view of Chen, but the court found its arguments unpersuasive.

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