       NOTE: This disposition is nonprecedential.


  United States Court of Appeals
      for the Federal Circuit
                ______________________

      GOOGLE LLC, LG ELECTRONICS, INC.,
                  Appellants

                           v.

 CONVERSANT WIRELESS LICENSING S.A.R.L.,
                 Appellee
          ______________________

                      2017-2456
                ______________________

    Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in No. IPR2015-
01715.
                 ______________________

             Decided: November 20, 2018
               ______________________

   NAVEEN MODI, Paul Hastings LLP, Washington, DC,
argued for appellants. Also represented by STEPHEN
BLAKE KINNAIRD, JOSEPH PALYS, DANIEL ZEILBERGER.

   TAREK N. FAHMI, Ascenda Law Group, PC, San Jose,
CA, argued for appellee. Also represented by HOLLY J.
ATKINSON.
                ______________________

   Before O’MALLEY, CHEN, and STOLL, Circuit Judges.
2            GOOGLE LLC v. CONVERSANT WIRELESS LICENSING




CHEN, Circuit Judge.
    Google LLC and LG Electronics, Inc. (Petitioners) ap-
peal from the final written decision of the U.S. Patent and
Trademark Office, Patent Trial and Appeal Board (Board)
in an inter partes review (IPR) proceeding finding that
Appellants did not show claims 1–15 of U.S. Patent No.
7,072,667 (the ’667 patent), assigned to Conversant Wire-
less Licensing S.A.R.L. (Patent Owner), to be unpatenta-
ble as anticipated or obvious.
    Because the Board’s final written decision failed to
consider Petitioners’ primary argument, we vacate and
remand.
                       BACKGROUND
     The ’667 patent, entitled “Location Information Ser-
vice for a Cellular Telecommunications Network,” was
filed on December 31, 2001. According to the ’667 patent,
prior art mobile devices used commercial location finding
services, such as Finder™. J.A. 28 at 1:31–34. A user
could find the location of other members of a group of
subscribers by defining a list of friends that they wanted
to be able to locate. Id. at 1:34–37. This system involved
pre-registration with the vendor of the Finder™ service.
Id. at 1:37–39. When a user wanted to know the location
of a friend, the user initiated a request and selected the
name of the friend. Id. at 1:39–42. The Finder™ service
then located both the user and the friend and calculated
the distance and direction between them, which was
communicated back to the user. Id. at 1:42–45.
    The ’667 patent states that a disadvantage of the pri-
or art system is that the user needed to pre-register with
the system. Id. at 1:46–48. The ’667 patent describes the
invention as providing location service information “inde-
pendently of aforesaid vendor.” Id. at 1:52–54. The
patent claims capture this feature by reciting that the
GOOGLE LLC v. CONVERSANT WIRELESS LICENSING               3



method is performed without pre-registering the mobile
station for the location finding service. Claim 1 recites:
   1. A method of providing a location finding ser-
   vice to mobile stations in a cellular telecommuni-
   cations network, comprising:
   sending a request for location finding information
   from a mobile station as a message through the
   network to a location message server;
   retrieving data from a data store corresponding to
   the location finding information based on the cell
   occupied by at least one mobile station; and
   sending the data through the network from the lo-
   cation message server as a message to the mobile
   station that requested the location finding infor-
   mation; and wherein
   the method is performed without pre-registering
   the mobile station for the location finding service.
J.A. 30 (emphasis added).
    In their IPR petition, Petitioners argued that PCT
Publication No. WO 00/36430 (Staack) discloses every
limitation of claim 1. As to the claim limitation “without
pre-registering the mobile station for the location finding
service,” Petitioners contended it was a negative limita-
tion that Staack satisfies because “Staack nowhere dis-
closes that pre-registration is required to access the
location-based services.” J.A. 61. Petitioners cited two
PTAB decisions as supporting this conclusion. See CLIO
USA, Inc. v. The Procter and Gamble Company, IPR2013-
00448, Paper No. 15 at 3 (Feb. 4, 2014) (stating that
“[n]egative limitations may be satisfied by silence in the
prior art”); Palo Alto Networks, Inc. v. Juniper Networks,
Inc., IPR2013-00466, Paper No. 17 at 18 (Jan. 28, 2014)
(stating that, “[a]lthough a negative limitation is permis-
sible, it merely recites what a claim lacks and, therefore,
4            GOOGLE LLC v. CONVERSANT WIRELESS LICENSING




is likely to be broad by its very nature. Consequently, a
negative limitation requiring the absence of an element
may be adequately described by a cited prior art reference
if that reference does not otherwise require the presence
of the element recited in the negative limitation.”); see
also J.A. 61. Petitioners also cited a declaration by their
expert to support their argument. J.A.61; see also J.A.
723–24.
     To further support its position that Staack meets the
“without pre-registering” limitation, the petition next
went on to explain, preemptively, why a particular pas-
sage in Staack does not teach a pre-registering require-
ment:      “to the extent Patent Owner proposes that
maintaining and using a list of entities that are permitted
to receive location finding information is considered
registering, Staack makes clear that such features are
optional.” J.A. 62 (emphasis in original). Staack discloses
that, for confidentiality reasons, the second (target user)
mobile station may store a list of entities, which may
include the first (requesting user) mobile station, that are
allowed to view the second mobile station’s location. See
J.A. 533. Staack describes this list as “preferred.” Ac-
cordingly, Petitioners argued, Staack discloses that the
list is optional, and under the case law explaining that a
prior art reference that discloses “optional inclusion” of a
feature encompasses a disclosure of embodiments that
“both do and do not contain” the feature, Staack discloses
a method “without pre-registering.”        J.A. 62 (citing
Upshur-Smith Labs., Inc. v. Pamlab, 412 F.3d 1319, 1322
(Fed. Cir. 2005)).
    The Patent Owner’s preliminary response argued that
Staack does explicitly disclose pre-registration through
the use of a “mobile subscriber’s home location data from
a billing center or subscriber database.” J.A. 129. The
Board found this argument unpersuasive, noting in its
institution decision that registration of mobile users,
including identifying users’ phone numbers or subscrip-
GOOGLE LLC v. CONVERSANT WIRELESS LICENSING                5



tion information, “is not commensurate with registration
for a location finding service, as recited in claim 1.” J.A.
156 (emphasis in original). The Patent Owner also ar-
gued that Staack’s second mobile station list—the list
Petitioners referred to in their preemptive argument—is
“not germane” to pre-registration because “[t]hese consid-
erations of confidentiality exist whether or not the MS1
user is pre-registered for the mobile location service or
not.” J.A. 132.
     In its institution decision, the Board clearly under-
stood that Petitioners raised two arguments in their
petition (the second one being conditional): (1) that
Staack’s silence as to pre-registration constitutes disclo-
sure of the negative limitation (the “negative-limitation
argument”); and (2) if the Patent Owner argues that the
second mobile station’s list constitutes pre-registration,
then the pre-registration is optional and therefore Staack
still meets the “without pre-registering” limitation under
Upshur-Smith (the “optional-feature” argument). J.A.
154–58. The Board used the language “argue” to describe
Petitioners’ first argument and “further argue” to describe
Petitioner’s second argument. J.A. 154. The Board
concluded that it was persuaded based on the record
before it that Staack does satisfy the “without pre-
registering” limitation. J.A. 155–56. The Board stated
that (1) it was not persuaded by Patent Owner that
Staack explicitly discloses pre-registering; (2) it was
persuaded that Staack’s methods are performed without
pre-registration; and (3) “without pre-registering” is a
negative limitation. J.A. 156–57. The Board finally noted
that the Petitioners’ second, conditional argument was of
no moment because Staack’s discussion of the second
mobile station list does not constitute pre-registration of
the first mobile station, as recited in the claims. J.A. 158.
The Board instituted the proceeding, finding that Peti-
tioners showed a reasonable likelihood that they would
prevail in establishing that Staack anticipates claims 1–3
6             GOOGLE LLC v. CONVERSANT WIRELESS LICENSING




and 8–14 based on, among other things, Petitioners’
argument as to the negative limitation, and renders
claims 4–7 and 15 obvious in view of Staack combined
with additional references. See J.A. 158, 160, 163.
    In its response, the Patent Owner repeated many of
the same arguments it raised in its preliminary response,
and it noted an additional passage in Staack that it
believed discloses pre-registration: Staack’s citation to
GSM 03.71. J.A. 219. The Patent Owner cited its expert’s
declaration to conclude that a person of ordinary skill in
the art reading Staack would understand the citation to
GSM 03.71, which provides mechanisms to support mo-
bile location services of operators, to mean that mobile
users must be pre-registered with location finding ser-
vices. J.A. 219–21 (citing J.A. 1190–93). In their reply,
Petitioners disagreed, focusing in part on Staack’s state-
ment that an embodiment “could be in accordance with
GSM 03.71.” J.A. 265 (emphasis in original). Because the
word “could” is optional in nature, Petitioners argued,
Staack still discloses a method being performed without
pre-registration. Id.
     Without explanation, the Board’s final written deci-
sion diverged from its institution decision and conflated
its analysis for Petitioners’ negative-limitation argument
into its analysis for the non-instituted optional-feature
argument. J.A. 8–11. The Board repeated its concerns
about the optional-feature argument it identified in its
institution decision, that Staack’s second mobile station
list does not constitute pre-registration of the first mobile
station. J.A. 10–11. The logical result of this finding was
that this feature in Staack could not defeat Petitioners’
claim that Staack satisfies the “without pre-registering”
limitation. Without addressing the negative-limitation
argument or making a finding that Staack does disclose
pre-registration, the Board concluded that the Petitioners
did not meet their burden of proving that Staack discloses
the “without pre-registering” element. Id. The Board did
GOOGLE LLC v. CONVERSANT WIRELESS LICENSING                  7



not explain why it reached the opposite conclusion that it
reached in its institution decision with respect to the
negative-limitation argument. See id.
   Petitioners appeal.     We have jurisdiction under 28
U.S.C. § 1295(a)(4)(A).
                   STANDARD OF REVIEW
     “We review the Board’s IPR decisions [under the APA]
to ensure that they are not arbitrary, capricious, an abuse
of discretion, . . . otherwise not in accordance with law . . .
[or] unsupported by substantial evidence.” Personal Web
Techs., LLC v. Apple, Inc., 848 F.3d 987, 992 (Fed. Cir.
2017). “We review the PTAB’s factual findings for sub-
stantial evidence and its legal conclusions de novo.”
Redline Detection, LLC v. Star Envirotech, Inc., 811 F.3d
435, 449 (Fed. Cir. 2015).
                         DISCUSSION
                        A. Standing
    Although the Patent Owner did not argue that Peti-
tioners lack standing in its original briefing, we asked for
supplemental briefing from both parties to determine
whether Google and LGE have standing to bring this
appeal. “Standing requires an appellant to have ‘(1)
suffered an injury in fact, (2) that is fairly traceable to the
challenged conduct of the defendant, and (3) that is likely
to be redressed by a favorable judicial decision.’” E.I.
DuPont de Nemours & Co. v. Synvina C.V., 904 F.3d 996,
1004 (Fed. Cir. 2018). “As the party seeking judicial
review, the appellant bears the burden of proving that it
has standing.” Id. One typical way for a petitioner-
appellant to prove standing is by establishing “that its
product creates a concrete and substantial risk of in-
fringement or will likely lead to claims of infringement.”
JTEKT Corp. v. GKN Auto. LTD., 898 F.3d 1217, 1221
(Fed. Cir. 2018).
8            GOOGLE LLC v. CONVERSANT WIRELESS LICENSING




     In DuPont, we agreed that DuPont had standing be-
cause it operated a plant that was capable of infringing
the patent at issue, and thus there was a substantial risk
of future infringement.      DuPont, 904 F.3d at 1005.
DuPont had never been sued on the patent at issue, but it
was a competitor of the patent owner, who alleged before
the Board that DuPont’s processes were “embraced by the
claims in the ’921 patent.” Id. at 1003–04. The patent
owner also denied DuPont’s request for a covenant not to
sue, which we found further confirmed that DuPont’s risk
of injury was not “conjectural” or “hypothetical.” Id.
    The record on appeal presents an even stronger basis
for standing here than that in DuPont. In 2014, LGE was
sued for infringement of the ’667 patent. The Patent
Owner’s infringement contentions implicated both LGE
and Google: “LG Maps-Enabled Devices . . . and the
Google Maps application (typically pre-installed) perform
the claimed method.” Petitioners’ Oct. 16, 2018 Ltr. at
Ex. C, p. 1. Although the infringement contentions de-
picted only claims 12–15 (which have been since canceled
in a separate inter partes review proceeding), the Patent
Owner “expressly reserve[d] the right to supplement or
modify” them, and the complaint was not limited to any
particular claims. See id. The Patent Owner similarly
reserved the right to substitute “appropriate claims in the
remaining patents” for claims 12 and 13 of the ’667 patent
in its Election of Asserted Claims. Id. at Ex. D, p. 2.
Ultimately, the Patent Owner withdrew the ’667 patent
“without losing rights,” and the district court dismissed
the ’667 patent without prejudice. The Patent Owner
refused to grant a covenant not to sue to LGE or Google.
    We find LGE’s and Google’s risk of infringement to be
concrete and substantial. LGE was previously accused of
infringing the ’667 patent, and, throughout litigation, the
Patent Owner continually reserved its right to assert the
claims that are at issue in this appeal. The Google Maps
application was directly implicated in the Patent Owner’s
GOOGLE LLC v. CONVERSANT WIRELESS LICENSING               9



infringement contentions. As in DuPont, the Patent
Owner here refused to grant a covenant not to sue. And,
unlike in JTEKT where there was no product yet final-
ized, LGE and Google both currently market and sell the
accused products. See JTEKT, 898 F.3d at 1220–21.
     Moreover, if LGE or Google were to be sued on the
’667 patent in the future, LGE may be prohibited from
filing an IPR under 35 U.S.C. § 315(b). And both LGE
and Google would potentially be collaterally estopped
under 35 U.S.C. § 315(e) from making certain anticipation
and obviousness arguments. See, e.g., Deposit Guar. Nat.
Bank, Jackson, Miss. v. Roper, 445 U.S. 326, 337 (1980);
Shaw Indus. Grp., Inc. v. Automated Creel Sys., Inc., 817
F.3d 1293, 1300 (Fed. Cir. 2016). We therefore conclude
that Google and LGE have Article III standing to bring
this appeal.
          B. Sufficiency of the Board’s Decision
    In its institution decision, the Board clearly and cor-
rectly understood that Petitioners made two distinct
arguments in their petition: (1) the “negative-limitation”
argument and (2) the contingent “optional-feature” argu-
ment. J.A. 154–58. The Board instituted IPR proceed-
ings because it found that the negative-limitation
argument was likely to prevail and stated that it need not
consider the contingent optional-feature argument be-
cause that feature in Staack did not disclose pre-
registration as that term was used in the ’667 patent.
J.A.158. Yet, in its final written decision, the Board
concluded that Petitioners’ arguments failed without even
discussing Petitioners’ negative-limitation argument. See
J.A. 8–11. Instead, the Board simply reiterated that the
“optional” feature that Petitioners said the Patent Owner
may argue (and that the Patent Owner ultimately did not
argue) constitutes pre-registration does not in fact consti-
tute pre-registration. See J.A. 8–11.
10           GOOGLE LLC v. CONVERSANT WIRELESS LICENSING




    We have previously found that the appropriate course
of action when the Board’s analysis is incomplete and fails
to address key arguments and issues properly before it is
to vacate and remand the findings for further considera-
tion. See, e.g., Vicor Corp. v. SynQor, Inc., 869 F.3d 1309,
1321 (Fed. Cir. 2017). Accordingly, we vacate and remand
the Board’s decision for the Board to consider Petitioners’
negative-limitation argument consistent with this opinion
and the Board’s institution decision. On remand, the
Board should also consider all arguments and evidence
raised in the Patent Owner’s response and the Petitioners’
reply as to whether Staack satisfies the “without pre-
registering” limitation.
             VACATED AND REMANDED
