Court Opinion

ID: 4658736
Source: CourtListenerOpinion
Date Created: 2021-02-09 16:00:53.934591+00
Date Added: 2024-06-11T08:01:55.472926
License: Public Domain

Case: 19-1151    Document: 80     Page: 1   Filed: 02/09/2021

        NOTE: This disposition is nonprecedential.

   United States Court of Appeals
       for the Federal Circuit
                  ______________________

  APPLE INC., FACEBOOK, INC., WHATSAPP, INC.,
                   Appellants

                             v.

                   UNILOC 2017 LLC,
                      Cross-Appellant
                  ______________________

             2019-1151, 2019-1179, 2019-1203
                 ______________________

     Appeals from the United States Patent and Trademark
 Office, Patent Trial and Appeal Board in Nos. IPR2017-
 00222, IPR2017-01635.
                  ______________________

                Decided: February 9, 2021
                 ______________________

     LAUREN B. FLETCHER, Wilmer Cutler Pickering Hale
 and Dorr LLP, Boston, MA, for appellant Apple Inc. Also
 represented by HEATH BROOKS, Washington, DC; S. CALVIN
 WALDEN, New York, NY.

     HEIDI LYN KEEFE, Cooley LLP, Palo Alto, CA, for appel-
 lants Facebook, Inc., WhatsApp, Inc. Also represented by
 LOWELL D. MEAD, MARK R. WEINSTEIN; PHILLIP EDWARD
 MORTON, Washington, DC.
Case: 19-1151    Document: 80     Page: 2      Filed: 02/09/2021

 2                              APPLE INC.   v. UNILOC 2017 LLC

    JAMES ETHERIDGE, Etheridge Law Group, Southlake,
 TX, for cross-appellant. Also represented by RYAN S.
 LOVELESS, BRETT MANGRUM, JEFFREY A. STEPHENS.
                 ______________________

     Before LOURIE, WALLACH, and CHEN, Circuit Judges.
 LOURIE, Circuit Judge.
      Apple Inc. (“Apple”) petitioned for inter partes review
 of U.S. Patent 8,243,723 (“the ’723 patent”), owned by
 Uniloc Luxembourg S.A. (“Uniloc”). The United States Pa-
 tent and Trademark Office Patent Trial and Appeal Board
 (“the Board”) held that claims 1 and 2 of the ’723 patent
 would have been obvious over the prior art but that Apple
 failed to demonstrate by a preponderance of the evidence
 that claims 3–8 would have been obvious. See Apple Inc. v.
 Uniloc Luxembourg S.A., No. IPR2017-00222, 2018 WL
 2355988 (P.T.A.B. May 23, 2018) (“Decision”). Apple ap-
 peals the Board’s holding that it failed to demonstrate un-
 patentability of claims 3–8, and Uniloc cross-appeals the
 Board’s holding that claims 1 and 2 would have been obvi-
 ous. We affirm the Board’s decision in all respects.
                        BACKGROUND
      Uniloc owns the ’723 patent, which is directed to sys-
 tems and methods for delivering instant voice-over-IP
 (“VoIP”) messages over the Internet. Traditional telephony
 is based on a public switched telephone network (“PSTN”).
 ’723 patent col. 1 ll. 20–21. The patent acknowledges that
 voice messaging in both PSTN and VoIP as well as instant
 text messaging over an IP network were known. Id. col. 2
 ll. 18–30. But the patent asserts that at the time of the
 invention there remained a need for instant VoIP messag-
 ing with PSTN support. Id. col. 2 ll. 43–49.
     The ’723 patent purports to address this need by
 providing a local instant voice messaging (“IVM”) system
 that includes an IVM server and one or more IVM clients,
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 APPLE INC.   v. UNILOC 2017 LLC                              3

 such as VoIP telephones. Id. col. 6 ll. 48–55. The IVM
 server stores users that are known to the server, including
 IVM clients and legacy telephone clients. Id. col. 13 ll. 56–
 58. The server stores a record for each user, including a
 contact list that indicates other users with which the user
 wishes to exchange instant voice messages. Id. col. 13
 ll. 58–62. The server also maintains a record of the connec-
 tivity status of each IVM client (i.e., whether the client is
 connected to the IVM server and available to receive mes-
 sages), id. col. 12 ll. 46–52, and facilitates the transmission
 of messages between clients, id. col. 7 ll. 59–61.
      To initiate transmission of a voice message, an IVM cli-
 ent displays a user’s contact list, and the user selects one
 or more IVM recipients to whom to transmit a voice mes-
 sage. Id. col. 7 ll. 61–67. “The user selection also generates
 a start signal to the IVM client that the user is ready to
 begin instant voice messaging.” Id. col. 8 ll. 1–3. The pa-
 tent discloses two modes of operation—a “record mode” and
 an “intercom mode.” Id. col. 7 ll. 53–57. In record mode, in
 response to the start signal, the IVM client records the
 user’s speech into a digitized audio file stored on the IVM
 client. Id. col. 8 ll. 3–7. If a recipient IVM client is con-
 nected to the IVM server, the audio file is immediately
 transmitted to the recipient client. Id. col. 8 ll. 28–30. If a
 recipient client is not connected to the server (i.e., if the
 recipient client is “unavailable”), the audio file is temporar-
 ily stored on the server and transmitted to the recipient
 client when the client connects to the server. Id. col. 8
 ll. 30–35.
     Unlike record mode, according to the patent, intercom
 mode implements real-time instant voice messaging. In in-
 tercom mode, instead of recording the user’s speech to an
 audio file, the IVM client uses one or more buffers to write
 and transmit successive portions of the user’s speech to the
 IVM server. Id. col. 11 ll. 33–43.
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 4                                  APPLE INC.   v. UNILOC 2017 LLC

     Apple petitioned for inter partes review of claims 1–8 of
 the ’723 patent. Claim 1 is the only independent claim at
 issue, with claims 2–8 depending directly or indirectly from
 claim 1. Claims 1, 3, and 8 are specifically relevant to this
 appeal and are reproduced below.
     1. A method for instant voice messaging over a
     packet-switched network, the method comprising:
     monitoring a connectivity status of nodes within
     the packet-switched network, said connectivity sta-
     tus being available and unavailable;
     recording the connectivity status for each of the
     nodes;
     associating a sub-set of the nodes with a client;
     transmitting a signal to a client including a list of
     the recorded connectivity status for each of the
     nodes in the sub-set corresponding to the client;
     receiving an instant voice message having one or
     more recipients;
     delivering the instant voice message to the one or
     more recipients over a packet-switched network;
     temporarily storing the instant voice message if a
     recipient is unavailable; and
     delivering the stored instant voice message to the
     recipient once the recipient becomes available.
 Id. col. 23 l. 56–col. 24 l. 16.
     3. The method for instant voice messaging over a
     packet-switch network according to claim 1, fur-
     ther comprising the step of:
     controlling a method of generating the instant
     voice message based upon the connectivity status
     of said one or more recipient.
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 APPLE INC.   v. UNILOC 2017 LLC                            5

 Id. col. 24 ll. 17–26.
     8. The method for instant voice messaging over a
     packet-switch network according to claim 6,
     wherein said intercom mode comprises the steps of:
     buffering each of a plurality of successive portions
     of the instant voice as the instant voice message is
     recorded;
     transmitting from each successive buffered por-
     tion; and
     delivering each successive portion to the recipients
     wherein the recipients audibly playing each succes-
     sive portion as it is delivered.
 Id. col. 24 ll. 46–54.
     Relevant to this appeal, Apple alleged that (1) claim 1
 would have been obvious over U.S. Patent App. Pub.
 2002/0146097 (“Vuori”), (2) claims 2–7 would have been ob-
 vious over Vuori in view of U.S. Patent App. Pub.
 2003/0219104 (“Malik”), and (3) claim 8 would have been
 obvious over Vuori in view of Malik and U.S. Patent
 6,192,395 (“Lerner”).
     Vuori discloses systems and methods for sending short
 voice messages (“SVMs”) between mobile devices. To
 transmit an SVM, a user device records a message spoken
 by the user. Vuori ¶ 32. The user selects one or more re-
 cipients of the SVM, and the user device transmits the rec-
 orded message to an SVM service center (“SVMSC”), which
 determines the availability of the recipients. Id. ¶ 33–34.
 Vuori discloses an SVM presence service that accepts,
 stores, and distributes presence information among clients.
 Id. ¶ 43. Presence information can include a status indi-
 cating that a user is online (available), offline (unavaila-
 ble), or other information. Id. ¶ 47. The SVMSC is able to
 check the availability of the recipient. Id. ¶ 50. If the re-
 cipient is available, the SVMSC sends the message
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 6                               APPLE INC.   v. UNILOC 2017 LLC

 immediately; if the recipient is unavailable, it continues at-
 tempting to send the message until the recipient either be-
 comes available or a time out occurs. Id. ¶ 50–51. In one
 embodiment, the recipient receives a notification of the re-
 ceived message, which the recipient can accept or reject.
 Id. ¶ 36. In another embodiment, the sender first deter-
 mines whether the intended recipient is available by
 means of a presence service and whether the intended re-
 cipient has effectively acquiesced to availability by previ-
 ously joining a “buddy list.” If so, the recipient immediately
 receives the SVM. Id.
     Malik discloses systems and methods for sending in-
 stant voice messages where clients receive and play voice
 messages received from other clients. Malik ¶ 25. Malik
 describes a voice instant message (“VIM”) server that mon-
 itors presence information of clients. Id. ¶ 26. To initiate
 transmission of a voice message, a user speaks into a mi-
 crophone of a client device, which generates a voice record-
 ing. Id. ¶ 33. The client then sends the voice recording to
 a server. Id. ¶ 36. If a recipient client is unavailable to
 receive the message, the message is stored in a queue and
 delivered when the recipient client connects to the net-
 work. Id.
      Lerner discloses a method of visually identifying
 speaking participants in a multi-participant event, such as
 an audio conference. Lerner describes a sound control
 module that routes sound between participants using a
 plurality of buffers. Lerner col. 5 ll. 27–30. To transmit
 sound, a router breaks a signal in a transmit buffer into
 packets that are routed to the participants by a server. Id.
 col. 5 ll. 44–54. To receive sound from remote participants,
 the sound control module includes a plurality of receive
 sound buffers. Id. col. 5 ll. 30–34. The identity of the par-
 ticipant associated with each packet is used to route the
 packet to the appropriate receive sound buffer. Id. col. 5
 ll. 37–40.
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 APPLE INC.   v. UNILOC 2017 LLC                             7

      The Board instituted trial on all grounds and issued a
 final written decision concluding that Apple had demon-
 strated that claims 1 and 2 would have been obvious but
 failed to demonstrate by a preponderance of evidence that
 claims 3–8 would have been obvious. The Board first con-
 strued “list” as recited in claim 1. The Board agreed with
 Uniloc that the “list” must record the connectivity status of
 more than one node, reasoning that to conclude otherwise
 would ignore the recitation of recording a connectivity sta-
 tus for each of the nodes. Decision, 2018 WL 2355988,
 at *6. Applying its construction, the Board determined
 that Vuori’s use of a buddy list and tracking of presence
 information of users discloses the claimed “transmitting a
 signal to a client including a list of the recorded connectiv-
 ity status for each of the nodes in the sub-set corresponding
 to the client.” Id. at *12.
     With respect to claim 3—as well as claims 4–8, which
 depend directly or indirectly from claim 3—the Board re-
 jected Apple’s argument that both Vuori and Malik disclose
 “controlling a method of generating the instant voice mes-
 sage based upon the connectivity status of said one or more
 recipient.” Id. at *16. Specifically, the Board found that
 both Vuori and Malik describe different methods for send-
 ing messages based on connectivity status but fail to dis-
 close different modes of generating messages, as required
 by claim 3. Id.
     Finally, with respect to claim 8, the Board noted that
 Apple had failed to demonstrate unpatentability based on
 claim 8’s dependency from claim 3. Id. at *17. Nonethe-
 less, the Board concluded that Apple had not demonstrated
 that Lerner discloses “buffering each of a plurality of suc-
 cessive portions of the instant voice as the instant voice
 message is recorded.” Id. Specifically, the Board found
 that Lerner’s receive sound buffers buffer packets as they
 are received by the recipient, not as the messages are rec-
 orded, id. at *18, and noted that Apple’s petition did not
 rely on any other buffer in Lerner as disclosing the
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 8                               APPLE INC.   v. UNILOC 2017 LLC

 buffering limitation, id. The Board denied requests for re-
 hearing from both parties. See Apple Inc. v. Uniloc Luxem-
 bourg S.A., No. IPR2017-00222, 2018 WL 4263073
 (P.T.A.B. Sep. 6, 2018); Apple Inc. v. Uniloc Luxembourg
 S.A., No. IPR2017-00222, 2018 WL 4279645 (P.T.A.B. Sep.
 6, 2018).
     Apple appealed, and Uniloc cross-appealed. We have
 jurisdiction under 28 U.S.C. § 1295(a)(4)(A).
                         DISCUSSION
      Obviousness is a question of law that “lends itself to
 several basic factual inquiries,” Graham v. John Deere Co.,
 383 U.S. 1, 17–18 (1966) (citing Great Atl. & Pac. Tea Co.
 v. Supermarket Equip. Corp., 340 U.S. 147, 155 (1950)), in-
 cluding the scope and content of the prior art, the level of
 ordinary skill in the art, differences between the prior art
 and the claimed invention, and any relevant secondary con-
 siderations. Id. “We review the PTAB’s factual findings
 for substantial evidence and its legal conclusions de novo.”
 Redline Detection, LLC v. Star Envirotech, Inc., 811 F.3d
 435, 449 (Fed. Cir. 2015) (citing Rambus Inc. v. Rea, 731
 F.3d 1248, 1251 (Fed. Cir. 2013)). A finding is supported
 by substantial evidence if a reasonable mind might accept
 the evidence as adequate to support the finding. Consol.
 Edison Co. v. NLRB, 305 U.S. 197, 229 (1938). “If two ‘in-
 consistent conclusions may reasonably be drawn from the
 evidence in record, the PTAB’s decision to favor one conclu-
 sion over the other is the epitome of a decision that must
 be sustained upon review for substantial evidence.’” Elbit
 Sys. of Am., LLC v. Thales Visionix, Inc., 881 F.3d 1354,
 1356 (Fed. Cir. 2018) (quoting In re Cree, Inc., 818 F.3d 694,
 701 (Fed. Cir. 2016) (internal brackets omitted)).
                      I. APPLE’S APPEAL
     On appeal, Apple argues that the Board erred in im-
 plicitly construing claim 3 as requiring two modes of gen-
 erating a voice message. Under a correct interpretation in
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 APPLE INC.   v. UNILOC 2017 LLC                             9

 which claim 3 requires only one method of generating a
 voice message based on connectivity status, according to
 Apple, Malik discloses the additional limitation of claim 3.
 However, even under the Board’s construction, Apple ar-
 gues that the Board’s conclusion that Malik fails to disclose
 the controlling limitation was unsupported by substantial
 evidence.
     Apple also argues that the Board’s conclusion that Ler-
 ner fails to disclose the buffering limitation of claim 8 was
 unsupported by substantial evidence. We address Apple’s
 arguments in turn.
                           1. Claim 3
     Claim 3 depends from claim 1 and further recites “con-
 trolling a method of generating the instant voice message
 based upon the connectivity status of said one or more re-
 cipient” (the “controlling limitation”). Apple argues that,
 although neither party sought construction of any element
 of claim 3 and the Board provided none, the Board in its
 obviousness analysis implicitly construed claim 3 “as re-
 quiring two modes of generating instant voice messages.”
 Appellants’ Br. 35. According to Apple, claim 3 does not
 require selecting a method of generating an instant voice
 message from more than one method, but requires only
 controlling “one method of generating the instant voice
 message based on connectivity status.” Id. at 37.
     Apple offers two explanations why Malik satisfies its
 proposed interpretation: first, because it discloses detect-
 ing whether the recipient is available before generating a
 voice recording, id. at 39–40 (citing Malik Fig. 4); second,
 because, in some embodiments, a user is given a choice
 whether to generate a voice message if the recipient is un-
 available, while in other embodiments a voice message is
 generated regardless of the availability of the recipient. Id.
 at 41 (citing Malik ¶ 31). Even under the Board’s alleged
 construction, Apple argues, Malik discloses the controlling
 limitation because it describes delivering messages
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 10                             APPLE INC.   v. UNILOC 2017 LLC

 immediately if the recipient is available, while storing and
 delivering messages later if the recipient is unavailable.
 Id. at 42.
     As an initial matter, we disagree with Apple that the
 Board engaged in implicit construction of claim 3 in its ob-
 viousness analysis. Rather, the Board made factual find-
 ings regarding the content of Malik’s disclosure, and
 considered whether that content satisfied the claims. Ap-
 ple points to a single statement as evidence of the Board’s
 alleged implicit construction in which the Board found that
 Malik does not “control[] the ‘generating’ of the voice in-
 stant message because it is always generated in the same
 manner—recording mode.” Decision, 2018 WL 2355988, at
 *16. Rather than engaging in implicit claim construction,
 the Board merely made a factual finding that, when Malik
 describes generating a voice instant message, the message
 is always generated by recording and storing the voice of
 the sender, akin to the recording mode of the ’723 patent.
      Whether asserted prior art discloses the claim limita-
 tions of a challenged patent is a factual question reviewed
 for substantial evidence, see Elmer v. ICC Fabricating, Inc.,
 67 F.3d 1571, 1575 (Fed. Cir. 1995), and we reject Apple’s
 attempt to bootstrap its argument into one of claim con-
 struction in order to receive de novo review. See also Gra-
 ham, 383 U.S. at 17–18 (establishing the “basic factual
 inquiries” underlying obviousness, including “the scope
 and content of the prior art” and the “differences between
 the prior art and the claims at issue”). Accordingly, we con-
 sider only whether the Board’s determination that Malik
 fails to disclose the controlling limitation was supported by
 substantial evidence.
      Apple offers three theories of how Malik discloses “con-
 trolling a method of generating the instant voice message
 based upon the connectivity status” of a recipient. First, in
 its petition, Apple argued that Malik discloses the control-
 ling limitation because “when a client is online and
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 APPLE INC.   v. UNILOC 2017 LLC                           11

 available, a client generates and sends messages in real
 time,” while “when the recipient is not present and/or is not
 available online VIMs are recorded.” J.A. 5032. The Board
 concluded that the cited portions of Malik describe “send-
 ing [messages], not generating them.” Decision, 2018 WL
 2355988, at *16.
      We agree with the Board. Whether the message is de-
 livered immediately or at a later time, the message is gen-
 erated in the same manner—by a voice recording. See
 Malik ¶¶ 32–33 (“[I]n blocks 430-435, the VIM client 320 of
 the second user checks to see if the computing device of the
 VIM client 320 is capable of generating a voice recording.”);
 (“[I]f the second user accepts the VIM invitation, then the
 VIM client 320 of the second user starts a voice recorder.”);
 (“[T]he VIM client 320 of the second user generates a voice
 recording for the first user.”). Because the voice message
 is generated in the same manner regardless whether its
 delivery is immediate or delayed, the method of generation
 cannot be said to be “controlled” based on connectivity sta-
 tus.
      Apple suggests that, because Malik does not expressly
 state that a voice recording is generated in the same man-
 ner when the message is delivered immediately as when
 the message is stored and delivered later, Malik must dis-
 close some other manner of generating voice message when
 it is delivered in real time. Appellants’ Br. 44. To the ex-
 tent that Apple argues that Malik’s “real time” delivery in-
 herently discloses that the voice message is generated in a
 different manner, we disagree. Apple, holding the burden
 of persuasion, presented no evidence that real time mes-
 sage delivery requires the voice message to be generated in
 a manner other than voice recording—the only method dis-
 closed in Malik—and Malik provides no suggestion that
 generating the message by voice recording would be inade-
 quate or incompatible with real time message delivery.
 “The mere fact that a certain thing may result from a given
 set of circumstances is not sufficient [to establish
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 12                             APPLE INC.   v. UNILOC 2017 LLC

 inherency.]” In re Rijckaert, 9 F.3d 1531, 1534 (Fed. Cir.
 1993) (quoting In re Oelrich, 666 F.2d 578, 581–82 (CCPA
 1981)). Accordingly, based on the disclosure of Malik, we
 conclude that the Board’s finding that the messages are
 generated by voice recording in both cases was supported
 by substantial evidence.
     Second, Apple argues that Figure 4 of Malik (repro-
 duced below) discloses the controlling limitation because it
 discloses detecting whether the recipient is available before
 generating a voice recording. Appellant Br. 39–40.

 We note that Apple did not advance this theory in its peti-
 tion, and it cannot be raised for the first time on appeal.
 See Wasica Finance GmbH v. Continental Automotive Sys.,
 Inc., 853 F.3d 1272, 1286–87 (Fed. Cir. 2017). 1 In any

      1   Apple did not explicitly reference Figure 4 of Malik
 in its original petition, nor did it make nearly as compre-
 hensive an argument regarding the disclosure of Figure 4
 before the Board until it sought rehearing. See J.A. 5020–
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 APPLE INC.   v. UNILOC 2017 LLC                            13

 event, we disagree with Apple. The fact that the determi-
 nation of availability occurs before the generation of the
 voice message does not demonstrate that the method of
 generation is controlled by the connectivity status. In fact,
 because Figure 4 does not show any logical decision regard-
 ing generation at step 425—where availability is deter-
 mined—the determination of availability cannot be said to
 exert control over any aspect of generating the voice mes-
 sage. Further, Malik explains, in the portion cited by Ap-
 ple in its petition, that the only action in response to the
 determination in step 425 that the user is not present
 and/or available is that the “sending of the instant mes-
 sage” is not initiated. See Malik ¶ 32 (emphasis added).
 Accordingly, we disagree that Figure 4 demonstrates that
 the determination of connectivity status controls the
 method of generating the voice message, and we reject Ap-
 ple’s argument.
      Third, Apple points to the disclosure in ¶ 31 of Malik
 that, in other embodiments, a voice message is generated
 “regardless of the presence and/or availability” of the recip-
 ient. Appellants’ Br. 41 (quoting Malik ¶ 31). According to
 Apple, this demonstrates that, in the Figure 4 embodiment,
 “the voice instant message is generated based upon connec-
 tivity status.” Id. at 42. As above, Apple did not present
 this theory in its petition, and we consider this argument
 forfeited. But as above, we also disagree with Apple’s read-
 ing-through-negative-implication argument. Consistent
 with the Board’s finding, when read in the full context of
 Malik’s discussion of Figure 4, Malik describes only that
 the sending of the message is controlled by the connectivity

 23. In its petition, Apple did point to a portion of the spec-
 ification in Malik describing in part the embodiment in Fig-
 ure 4; however, the discussion was limited to two sentences
 of Malik, which reference only blocks 425, 430, and 435.
 J.A. 5032.
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 14                              APPLE INC.   v. UNILOC 2017 LLC

 status of the receiver, not the generating of that message.
 Accordingly, we reject this argument as well and affirm the
 Board’s decision that Apple failed to demonstrate that
 claim 3 would have been obvious over the prior art.
                          2. Claim 8
      Because we affirm the Board’s conclusion that Apple
 failed to demonstrate that Malik discloses the controlling
 limitation of claim 3 and Apple does not dispute the Board’s
 conclusion that Vuori fails to disclose the limitation, we af-
 firm the Board’s conclusion that Apple did not demonstrate
 that claim 8 would have been obvious based on claim 8’s
 dependency from claim 3. Accordingly, we need not ad-
 dress Apple’s argument that the Board erred in determin-
 ing that Lerner does not disclose the buffering limitation of
 claim 8.
                 II. UNILOC’S CROSS-APPEAL
      In its cross-appeal, Uniloc argues that the Board erred
 in concluding that claims 1 and 2 would have been obvious
 over the prior art. Specifically, Uniloc argues that the
 Board’s determination that Vuori discloses “transmitting a
 signal to a client including a list of the recorded connectiv-
 ity status for each of the nodes in the sub-set corresponding
 to the client” as recited in claim 1 was unsupported by sub-
 stantial evidence.
     Uniloc makes two principal arguments. First, Uniloc
 argues that Vuori fails to disclose transmitting a single sig-
 nal that includes a list of connectivity statuses for multiple
 users. Instead, according to Uniloc, the SVM presence ser-
 vice of Vuori distributes presence information one value at
 a time, rather than including multiple values in a single
 signal. Referring to Figure 7 (reproduced below), Uniloc
 asserts that Vuori describes that SVM watcher 256 re-
 quests either “the current value of some SVM presentity’s
 presence information” or “notification from the SVM pres-
 ence service 248 of (future) changes in some SVM
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 APPLE INC.   v. UNILOC 2017 LLC                            15

 presentity’s presence information.”         Cross-Appellant’s
 Br. 22 (quoting Vuori ¶ 44). In either case, according to
 Uniloc, status information is distributed for only a single
 client device, rather than a list of statuses for multiple us-
 ers.

      Apple responds that the Board’s conclusion that the
 SVM presence service distributes presence information for
 multiple nodes in a single signal was supported by substan-
 tial evidence, and we agree. The Board considered the tes-
 timony of Uniloc’s expert, William Easttom, that the SVM
 presence service “distributes presence information . . . one
 value at a time,” but found that Uniloc’s evidence was con-
 tradicted by other aspects of Vuori’s disclosure. Decision,
 2018 WL 2355988, at *14. Specifically, referring to Figure
 10, the Board found that Vuori illustrates presence infor-
 mation comprising multiple “presence tuples,” each with a
 status marker. Id. Vuori explains that “presence infor-
 mation comprises an arbitrary number of elements,” and
 “[e]ach such element comprises a status marker.” Vuori
 ¶ 47. Based on this disclosure, the Board determined that
 it was not reasonable to restrict Vuori’s teaching to distrib-
 uting only one status value at a time, as suggested by
 Easttom. It was within the Board’s discretion to assess the
 credibility of Easttom’s testimony, see Yorkey v. Diab, 601
 F.3d 1279, 1284 (Fed. Cir. 2010) (citing Velander v. Garner,
 348 F.3d 1359, 1371 (Fed. Cir. 2003)), and, based on Vuori’s
 disclosure of the presence information as comprising mul-
 tiple status markers, we cannot conclude that it was error
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 16                              APPLE INC.   v. UNILOC 2017 LLC

 for the Board to determine that Vuori’s transmission of
 presence information includes status information for mul-
 tiple users.
     Second, Uniloc argues that the Board erred in deter-
 mining that Vuori discloses transmitting a signal to a cli-
 ent. Again referring to Figure 7, Uniloc argues that
 presence information is distributed only to SVM watcher
 256, not to either of the “user agents” (i.e., clients, denoted
 as 276 and 278). Apple responds that the Board’s conclu-
 sion that a person of ordinary skill would understand that
 the presence information is transmitted to the user agents
 was supported by substantial evidence, relying on the tes-
 timony of its expert, Dr. Leonard Forys.
     Before the Board, Uniloc presented the same argu-
 ment, relying on Easttom’s declaration that “SVM watcher
 256 is not a user-facing ‘client’” and, relying on the unidi-
 rectional arrows in Figure 7, that “presence information is
 not distributed to a ‘user agent.’” J.A. 3014 ¶ 29. Apple
 responded with Forys’s supplemental declaration that the
 SVM watcher is client-facing because (1) Vuori suggests
 that it is coupled to the user agent, and (2) the presence
 status must be distributed to a user agent because the sta-
 tus markers are interpretable by “programs or persons.”
 J.A.2335–37 ¶¶ 18–19, 21. After weighing the experts’
 competing theories, the Board “credit[ed] Dr. Forys’s testi-
 mony as being more consistent with and supported by
 Vuori’s teachings.” Decision, 2018 WL 2355988, at *15.
 Specifically, the Board found that Forys’s testimony is con-
 sistent with Vuori’s disclosure that “a user agent is purely
 coupling between a principal and some core entity of the
 system,” such as SVM watcher 256, and we agree.
     Ultimately, Uniloc’s arguments on appeal amount to a
 request to reweigh the evidence presented to the Board.
 For example, Uniloc argues that “a more plausible inter-
 pretation” of Vuori’s statement that presence status is in-
 terpretable by “programs or persons” is that the SVM
Case: 19-1151      Document: 80    Page: 17   Filed: 02/09/2021

 APPLE INC.   v. UNILOC 2017 LLC                           17

 watcher enables an administrator, rather than a user, to
 access the status information. But our task is not to deter-
 mine which interpretation we find more plausible. “[I]t is
 not for us to second-guess the Board’s assessment of the
 evidence.” Velander, 348 F.3d at 1371. Rather, the only
 question before us is whether the conclusion adopted by the
 Board was supported by substantial evidence. Here, based
 on Vuori’s disclosure that the user agents are “coupl[ed]” to
 the SVM watcher and that the status must be reviewable
 by “persons,” as well as Forys’s testimony that a person
 having ordinary skill would understand that the status in-
 formation is transmitted to the user agents, we conclude
 that the Board’s finding that a skilled artisan would under-
 stand that presence information is transmitted to the user
 agents via the SVM watcher was supported by substantial
 evidence. Accordingly, we affirm the Board’s conclusion
 that claims 1 and 2 would have been obvious over the prior
 art.
                          CONCLUSION
     We have considered the parties’ remaining arguments
 but find them unpersuasive. For the foregoing reasons, the
 decision of the Board is affirmed.
                          AFFIRMED