HTC Corp. v. Cellular Communications Equipment, LLC

877 F.3d 1361
Court of Appeals for the Federal Circuit·Decided December 18, 2017·No. 2016-1880·Published·Cited by 71 cases

Opinion

REYNA, Circuit Judge.

HTC Corporation and ZTE (USA), Inc. appeal a final written decision of the Patent Trial and Appeal Board in an inter partes review. Appellants argue that the. Board improperly construed the claim term “message” and erred in finding that HTC failed to show that the prior art anticipated or rendered obvious the challenged claims. We find no error in the Board’s claim construction, and substantial evidence supports the Board’s patentability determination. We affirm.

Background

A. The ’174 Patent

U.S. Patent No. 7,941,174 (“ ’174 patent”) is directed to methods and apparatuses for a radio communications system where a subscriber station, i.e., a'mobile device, is assigned a plurality of codes for transmitting méssages. T74 Patent Abstract, col. 2 11. 1-6. The assigned codes correspond to data transmission channels in a Universal Mobile Telecommunications System (“UMTS”), in particular here, a Dedicated Uplink Channel (“DCH”) for transmitting messages and an Enhanced Dedicated Uplink Channel (“EDCH”) for transmitting high bit rate messages. Id. col. 4 11. 26-40. To send messages to a UMTS base- station, the subscriber station requires “transmit” or “transmission” power. When radio transmission conditions deteriorate, • such as when there is a high amount , of interference in the communications cell, the base station may--command the subscriber station to increase transmit power in order to send the message, Id. col. 7 11. 20-26, 31-33; J.A. 2125. But the subscriber station is limited in the amount of transmission power it can use, called the “maximum transmission power,” which is “preferably predetermined by the hardware of the subscriber station” or “predefined on the network side.” Id. col. 211. 50-51, 57-58. According to the ’174 patent, operating at maximum transmission power is undesirable because the subscriber station cannot increase transmission power to overcome poor transmission conditions, which in turn results in incomplete and aborted message transmissions. See id. col. 6 11. 20-27.

To avoid operating at maximum transmission power, the ’174 patent’s claimed solution sets a “transmit power difference” or “power headroom” for the plurality of codes in the subscriber station at the beginning of a message transmission. Id. col. 6 11. 40-47. Setting this power headroom permits the subscriber station when'sending messages to increase transmit power to overcome interference and thus avoid aborted message transmission. The transmit power difference “corresponds to an unused transmit power at the start of the transmission” of a message, such as a message transmitted over EDCH. Id. col. 6 11. 47-49.

Illustrative of the method claims, independent claim 1 teaches:

1. A'method for operating a radio communication system in which a subscriber station is assigned a plurality of codes for transmitting messages, comprising:

determining a transmit power difference which is to be maintained by the subscriber station between on one hand a total maximum transmit power of the subscriber station for the codes and on another hand a total transmit power of the subscriber station for the codes at a start of a message transmission using a first one of the codes.

Id. col. 9 11. 56-64.

' Illustrative of the apparatus claims, in-dependerit claim 18 teaches:-

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Id. Fig. 1.

Relevant to this appeal, the ’174 patent recognizes- that an EDCH message is measured in intervals of 10 milliseconds, which is comprised of 15 timeslots. Id. col. 5 11. 29-31. The 10 ms transmission time interval is referred to as a “frame.” See J.A. 1181-82, 2130. . In UMTS systems available around 1999,. transmission tipie 18. A subscriber station for a radio communication system, the subscriber station assigned a plurality of codes for transmitting messages, comprising:

at least one processor programmed to determine a transmit power difference which is to be maintained by the subscriber station between on one hand a total maximum transmit power of the subscriber station for the codes and on another hand a total transmit power of ,the subscriber station for the codes at a start of a message transmission using a first one of the codes.

Id. col. 1211.1-10.

The sole figure in the specification depicts the relationship between the mobile station, UE, which transmits messages over the DOH and EDCH channels, and base station, NODE B, in a UMTS system: intervals could either be 10 ms, 20 ms, 40 ms, or 80 ms. J.A. 2128.

B. Prior Art

1. Baker

U.S. Patent Application Pub. No. 2008/0151840 (“Baker”) is directed to a UMTS communication system in which a mobile station transmits acknowledgement (“ACK”) or non-acknowledgement (“NACK”) signals to a base station upon receiving data from the base station.. J.A. 909. To allow for the transmission of ACK/ NACK signals, the mobile station must .scale down'the maximum transmit power allocated to its transmission codes: a dedicated physical data channel (“DPDCH”) and a dedicated physical control channel (“DPCCH”). Id, Figure 4 depicts this process in a timing diagram, with PCJ and VD1 representing the transmit power associated with each of the two transmission channels, ¿PDCH and DPCCH, operating at maximum transmission power for the mobile station, Pw¡ttr. When the ACK/NACK signal is to be transmitted, PCJ and Vm are scaled down to PC2 and Pm, respectively, for the duration of the ACK/NACK transmission. '

See J.A. 911, 914.

As Baker explains, “at the boundary of the frame or time slot immediately preceding the sending of an ACK or NACK, these amplitudes [Pffl and P^] are adjusted by for example reducing DPCCH whilst maintaining the power ratio P¿/Pc constant.” Id. Baker thus leaves capacity for the transmission of the ACK/NACK signal, or other types of signaling information. J.A. 914-15.

2. Réed

U.S. Patent No. 7,689,239 (“Reed”) is directed to a system, method, and apparatus for “establishing headroom for a mobile station” based on “specific channel variance conditions and battery conditions.” J.A. 901 Abstract. Reed defines “headroom” as “the difference between the maximum power of the transmitter and the transmission power level required for a particular data rate.” J.A. 905 col. 111. 29-31. Headroom is therefore a “margin built in” to the maximum data rate “to provide some protection against varying channel conditions.” Id. col. 1 11. 36-38. In the sole portion of the written description discussing a mobile station with multiple data streams, Reed states:

If the mobile station desires to send two or more data streams (or hold voice and data connections at the same time), an addition [sic] degree of freedom allows the mobile station to deliberately increase the headroom on one of the data streams to de-prioritize that data stream.

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HTC Corp. v. Cellular Communications Equipment, LLC, 877 F.3d 1361 (Fed. Cir. 2017).

877 F.3d 1361 (HTC Corp. v. Cellular Communications Equipment, LLC) — published by Counsel Stack Legal Research, free access to 12M+ legal documents.

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