Interdigital Communications, LLC v. International Trade Commission

690 F.3d 1318, 103 U.S.P.Q. 2d (BNA) 1610, 2012 WL 3104597, 34 I.T.R.D. (BNA) 1841, 2012 U.S. App. LEXIS 15893
CourtCourt of Appeals for the Federal Circuit
DecidedAugust 1, 2012
Docket2010-1093
StatusPublished
Cited by39 cases

This text of 690 F.3d 1318 (Interdigital Communications, LLC v. International Trade Commission) is published on Counsel Stack Legal Research, covering Court of Appeals for the Federal Circuit primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Interdigital Communications, LLC v. International Trade Commission, 690 F.3d 1318, 103 U.S.P.Q. 2d (BNA) 1610, 2012 WL 3104597, 34 I.T.R.D. (BNA) 1841, 2012 U.S. App. LEXIS 15893 (Fed. Cir. 2012).

Opinions

Opinion for the court filed by Circuit Judge BRYSON.

Dissenting opinion filed by Circuit Judge NEWMAN.

BRYSON, Circuit Judge.

InterDigital Communications, LLC, and InterDigital Technology Corporation (collectively, “InterDigital”) appeal from an order of the International Trade Commission finding that InterDigital’s patents, U.S. Patent Nos. 7,190,966 (“the '966 patent”) and 7,286,847 (“the '847 patent”), were not infringed by Nokia Inc. and Nokia Corporation (collectively, “Nokia”). We hold that the Commission erred in construing certain critical claim terms in both patents. We therefore reverse the Commission’s order finding no infringement and remand this case to the Commission for further proceedings.

I

The patents in suit, which are directed to wireless cellular telephone technology, are both entitled “Method and Apparatus for Performing an Access Procedure.” They share a common specification. The patents focus on apparatus and methods for controlling transmission power during the “handshake” portion of a wireless cellular communication, which is the portion of the communication in which a cellphone establishes contact with a cellular base station in order to initiate a cellphone call. The claimed invention operates within a system that uses Code Division Multiple Access (“CDMA”) to allow multiple cellphones (referred to as “subscriber units”) within a certain geographical area to use the same portion of the radio frequency spectrum simultaneously. Unlike its predecessor systems, CDMA does not separate communications from different subscriber units by assigning them different time slots or different frequencies on the radio frequency spectrum. Instead, it assigns a unique code to each communication link, which is known as a CDMA channel. That code is then used to encode and decode the data-carrying signal that trans[1321]*1321mits the telephonic messages between the cellphone and the base station. The encoding process allows data signals from multiple sources to be transmitted at the same time and over the same frequency, while enabling the base station to use the special codes to separate the data signals from each source for further processing.

The CDMA system is able to use a single portion of the frequency spectrum for multiple simultaneous communications by employing a process known as “spreading.” As described in the common specification, each subscriber unit’s baseband data signal (the signal that carries the telephonic communications) “is multiplied by a code sequence, called the ‘spreading code,’ which has a much higher rate than the data.” '966 patent, col. 2, 11. 3-5. In other words, the spreading code modifies the data signal so that the modified signal is transmitted at a faster rate and contains more information. That process results in “a much wider transmission spectrum than the spectrum of the baseband data signal,” id., col. 2,11. 7-9, which enables the system to carry multiple communications over the same frequency at the same time and allows the base station to more easily extract the constituent baseband data signals.

One problem associated with such a system is that signals within the same geographical area can interfere with one another, causing data loss. To combat that problem and to reduce unnecessary power consumption, the '966 and '847 patents use a “power ramp-up” strategy, which limits the power level of initiation messages sent during the handshake period. The power ramp-up begins when the subscriber unit transmits a unique code signal at a power level known to be below the power level needed for detection by the base station. The subscriber unit then transmits the code signal at successively higher power levels; once the power level reaches the point at which the base station is able to detect the signal, the base station sends an acknowledgement signal to the subscriber unit. When the subscriber unit receives the acknowledgment signal, it fixes the current power level as the designated power level for future communications. The connection is then completed, the subscriber unit and the base station are synchronized, and the data constituting the telephonic message is ready to be transmitted.

The '847 patent is a continuation of the '966 patent. Claim 1 of the '966 patent, which is representative in pertinent part of all the claims asserted in this action, recites:

1. A wireless code division multiple access (CDMA) subscriber unit comprising:
a transmitter configured such that, when the subscriber unit is first accessing a CDMA network and wants to establish communications with a base station associated with the network over a communication channel to be indicated by the base station, the transmitter successively transmits signals until the subscriber unit receives from the base station an indication that a transmitted one of the signals has been detected by the base station, wherein each transmission of one of the signals by the transmitter is at an increased power level with respect to a prior transmission of one of the signals;
the transmitter further configured such that the transmitter transmits to the base station a message indicating to the base station that the subscriber unit wants to establish the communications with the base station over the communication channel to be indicated by the base station, the message being transmitted only subsequent to the subscriber unit receiving the indication,
[1322]*1322wherein each of the successively transmitted signals and the message are generated using a same code; and
wherein each of the successively transmitted signals is shorter than the message.

The common specification describes an embodiment of the invention in which the base station transmits a “pilot code” to all of the subscriber units within the transmitting range of the base station. The “pilot code” is described as a “spreading code which carries no data bits.” '966 patent, col. 5, line 10. The subscriber unit then synchronizes its “transmit spreading code” to the base station pilot code. Id., col. 5, 11. 22-32. Once the subscriber unit and the base station are synchronized, the subscriber unit can initiate a communication by transmitting an “access code,” which is “a known spreading code transmitted from a subscriber unit ... to the base station ... during initiation of communications and power ramp-up.” Id., col. 6, 11. 21-23. Upon receipt of the access code, the base station searches through the possible phases of the access code in order to acquire the correct phase so as to enable the initiation of data communication. Id., col. 6,11. 23-38.

When initiating a communication in that embodiment, the subscriber unit “continuously increases the transmission power while retransmitting the access code ... until it receives an acknowledgement from the base station.” '966 patent, col. 6, 11. 67-62. After the minimum power for reception is reached and the base station acquires the access code, the base station transmits an access code detection acknowledgment signal to the subscriber unit. Upon receipt of that signal, the subscriber unit stops the power increase, and two-way communication is established. Id., col. 6, line 62 to col. 7, line 5.

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690 F.3d 1318, 103 U.S.P.Q. 2d (BNA) 1610, 2012 WL 3104597, 34 I.T.R.D. (BNA) 1841, 2012 U.S. App. LEXIS 15893, Counsel Stack Legal Research, https://law.counselstack.com/opinion/interdigital-communications-llc-v-international-trade-commission-cafc-2012.