Case: 19-2072   Document: 40     Page: 1   Filed: 04/07/2020




        NOTE: This disposition is nonprecedential.


   United States Court of Appeals
       for the Federal Circuit
                 ______________________

  UNILOC USA, INC., UNILOC LUXEMBOURG S.A.,
               UNILOC 2017 LLC,
               Plaintiffs-Appellants

                            v.

     SAMSUNG ELECTRONICS AMERICA, INC.,
       SAMSUNG ELECTRONICS CO., LTD.,
              Defendants-Appellees
             ______________________

                       2019-2072
                 ______________________

    Appeal from the United States District Court for the
 Eastern District of Texas in No. 2:18-cv-00042-JRG-RSP,
 Judge J. Rodney Gilstrap.
                  ______________________

                  Decided: April 7, 2020
                 ______________________

     JAMES J. FOSTER, Prince Lobel Tye LLP, Boston, MA,
 for plaintiffs-appellants.

    ALLAN A. KASSENOFF, Greenberg Traurig LLP, New
 York, NY, for defendants-appellees. Also represented by
 RICHARD A. EDLIN.
                 ______________________
Case: 19-2072     Document: 40      Page: 2   Filed: 04/07/2020




 2          UNILOC USA, INC.   v. SAMSUNG ELECTRONICS AMERICA



     Before MOORE, CLEVENGER, and CHEN, Circuit Judges.
 MOORE, Circuit Judge.
      Uniloc USA, Uniloc Luxembourg and Uniloc 2017 (col-
 lectively, Uniloc) appeal the United States District Court
 for the Eastern District of Texas’ judgment of invalidity as
 to claim 18 of U.S. Patent No. 6,868,079. Because the dis-
 trict court did not err in holding claim 18 indefinite, we af-
 firm.
                        BACKGROUND
      Uniloc Luxembourg, S.A. and Uniloc USA, Inc. sued
 Samsung Electronics Co., Ltd. and Samsung Electronics
 America, Inc. (collectively, Samsung), alleging infringe-
 ment of claims of the ’079 patent. 1 The ’079 patent is di-
 rected to a radio communication system in which a
 secondary station (e.g., a mobile phone) requests services
 from a primary station (e.g., a cellular base station). ’079
 patent at Abstract;

According to the speci-
 fication, a secondary station communicates with a primary
 station over an uplink communication channel divided into
 frames, where each secondary station registered with the
 primary station is allocated a time slot within each frame.

In conventional signaling schemes, a sec-
 ondary station would use that time slot to make a request
 for services to a base station and then wait for an acknowl-
 edgement from the base station.

If the sec-
 ondary station did not receive an acknowledgment within
 a predetermined period of time, the secondary station
 scheduled another request.

The claimed
 invention purportedly improves upon response times in



      1   In May 2018, Uniloc Luxembourg assigned the ’079
 patent to Uniloc 2017, which then joined the suit as a plain-
 tiff in September 2018. Uniloc Luxembourg and Uniloc
 USA no longer hold an interest in the patent or this appeal.
Case: 19-2072       Document: 40    Page: 3     Filed: 04/07/2020




 UNILOC USA, INC.   v. SAMSUNG ELECTRONICS AMERICA             3



 conventional signaling schemes by sending requests from
 the secondary stations in at least a majority of the time
 slots allocated to it, until an acknowledgment is received
 from the primary station.

Claim 18 recites:
     18. A radio communication system, comprising:
         a primary station and a plurality of respec-
         tive secondary stations,
         the primary station having means for allo-
         cating respective time slots in an uplink
         channel to the plurality of respective sec-
         ondary stations to transmit respective re-
         quests for services to the primary station to
         establish required services,
         wherein the respective secondary stations
         have means for re-transmitting the same
         respective requests in consecutive allo-
         cated time slots without waiting for an
         acknowledgement until said acknowledge-
         ment is received from the primary station,
         wherein said primary station determines
         whether a request for services has been
         transmitted by at least one of the respec-
         tive is [sic] secondary stations by determin-
         ing whether a signal strength of the
         respective transmitted request of the at
         least one of the respective secondary sta-
         tions exceeds a threshold value.
 (emphases added).
     The parties agree that the term “means for allocating
 respective time slots . . . to establish required services” is a
 means-plus-function term under 35 U.S.C. § 112 ¶ 6, hav-
 ing a function of “allocating respective time slots to estab-
 lish required services.” In April 2019, the magistrate judge
 issued a Claim Construction Memorandum and Order,
Case: 19-2072    Document: 40      Page: 4    Filed: 04/07/2020




 4         UNILOC USA, INC.   v. SAMSUNG ELECTRONICS AMERICA



 holding indefinite claim 18 of the ’079 patent because
 “Uniloc ha[d] pointed to nothing in the specification that
 links the claimed function to [the structural] elements”
 Uniloc identified. J.A. 26. The magistrate judge also held
 the claim indefinite “for failure to provide an algorithm.”
 J.A. 27. The district court adopted the magistrate judge’s
 Claim Construction Memorandum and Order on May 20,
 2019. J.A. 3. Following the district court’s May 20 order,
 the parties stipulated to the entry of judgment of invalidity
 as to claim 18. 2 J.A. 291. The district court entered final
 judgment based on the parties’ stipulation. Uniloc appeals,
 arguing that the district court erred in holding claim 18 in-
 definite.     We have jurisdiction under 28 U.S.C.
 § 1295(a)(1).
                         DISCUSSION
     We review a district court’s indefiniteness determina-
 tion de novo, except for necessary subsidiary fact findings,
 which we review for clear error. Cox Commc’ns v. Sprint
 Commc’n Co., 

, 1228 (Fed. Cir. 2016). Under
 35 U.S.C. § 112, patent claims must “particularly point[ ]
 out and distinctly claim[ ] the subject matter” regarded as
 the invention. Pre-AIA section 112 ¶ 6 allows a patentee
 to express an element of a claim as a means for performing
 a specified function. 35 U.S.C. § 112 ¶ 6 (2006). In ex-
 change for using this form of claiming, the patent specifi-
 cation must disclose with sufficient particularity the
 structure for performing the claimed function and clearly
 link that structure to the function. See Ibormeith IP, LLC
 v. Mercedes–Benz USA, LLC, 

, 1379 (Fed.
 Cir. 2013). For a computer-implemented invention claimed


     2   The parties also stipulated to the dismissal with
 prejudice of Uniloc’s claims of infringement against Sam-
 sung, except as to claim 18, and the dismissal without prej-
 udice of Samsung’s counterclaims.
Case: 19-2072       Document: 40   Page: 5    Filed: 04/07/2020




 UNILOC USA, INC.   v. SAMSUNG ELECTRONICS AMERICA           5



 in means-plus-function format, the specification must dis-
 close the algorithm that the computer performs to accom-
 plish the claimed function. Aristocrat Techs. Australia Pty
 Ltd. v. Int’l Game Tech., 

, 1333 (Fed. Cir.
 2008). Failure to disclose the corresponding algorithm for
 a computer-implemented means-plus-function term ren-
 ders the claim indefinite. Ergo Licensing LLC v. Care-
 Fusion 303, Inc., 

, 1363 (Fed. Cir. 2012).
     Uniloc argues that the district court erred in holding
 that “means for allocating respective time slots . . . to es-
 tablish required services” lacks definite corresponding
 structure in the specification. It argues the ’079 patent dis-
 closes several algorithms for allocating the respective time
 slots that provide enough direction for a person of skill in
 the art to create an operative software program. We do not
 agree.
     The specification does not disclose an algorithm de-
 scribing how the claimed “allocating respective time
 slots . . . to establish required services” is performed. In-
 stead, the specification merely restates the claimed func-
 tion. For example, the specification discloses that each
 secondary station is allocated a time slot in each frame of
 the uplink channel and that each secondary station can de-
 termine the time slot it is allocated. ’079 patent at 3:25–
 32; see also

(describing that the base station
 can increase the capacity of an uplink channel “by not allo-
 cating a time slot for every [secondary station] in every
 frame”). Merely describing the results of an unspecified al-
 gorithm in this manner, however, is not sufficient to satisfy
 the requirements of § 112 ¶ 6. See Aristocrat 

–35; see also Ergo 

 (holding indefinite a claim reciting a computer-imple-
 mented means-plus-function term where “[t]he specifica-
 tion merely provide[d] functional language and d[id] not
 contain any step-by-step process” for performing the
 claimed function). And the failure to disclose an algorithm
Case: 19-2072     Document: 40     Page: 6    Filed: 04/07/2020




 6         UNILOC USA, INC.   v. SAMSUNG ELECTRONICS AMERICA



 is not excused merely because a person of ordinary skill
 purportedly “would be able to devise a means to perform
 the claimed function.” Function Media, L.L.C. v. Google,
 Inc., 

, 1319 (Fed. Cir. 2013). We therefore
 agree with the district court that the specification fails to
 provide sufficient structure to satisfy the requirements of
 § 112 ¶ 6. Accordingly, we affirm the district court’s judg-
 ment that claim 18 of the ’079 patent is invalid for indefi-
 niteness.
                         CONCLUSION
     We have considered the parties’ remaining arguments
 and find them unpersuasive. Because the district court
 correctly held that claim 18 of the ’079 patent is indefinite,
 we affirm the district court’s judgment of invalidity.
                         AFFIRMED