Court Opinion

ID: 4184378
Source: CourtListenerOpinion
Date Created: 2017-07-07 15:01:52.806487+00
Date Added: 2024-06-11T07:47:20.241947
License: Public Domain

United States Court of Appeals
      for the Federal Circuit
                ______________________

                IPCOM GMBH & CO.,
                     Appellant

                           v.

                HTC CORPORATION,
                       Appellee
                ______________________

                      2016-1474
                ______________________

    Appeal from the United States Patent and Trademark
Office, Patent Trial and Appeal Board in No. 95/001,192.
                  ______________________

                 Decided: July 7, 2017
                ______________________

    MITCHELL G. STOCKWELL, Kilpatrick Townsend &
Stockton LLP, Atlanta, GA, argued for appellant. Also
represented by MICHAEL S. PAVENTO, DAVID A. REED.

   MICHAEL A. OBLON, Perkins Coie, LLP, Washington,
DC, argued for appellee. Also represented by TYLER R.
BOWEN, JONATHAN M. JAMES, Phoenix, AZ; DAN L.
BAGATELL, Hanover, NH.
                ______________________

Before PROST, Chief Judge, CLEVENGER and CHEN, Circuit
                        Judges.
2                      IPCOM GMBH & CO.   v. HTC CORPORATION

CHEN, Circuit Judge.
    IPCom GmbH & Co. (IPCom) is the owner of U.S. Pa-
tent No. 6,879,830 (’830 patent), which describes and
claims a method and system for handing over a mobile
phone call from one base station to another base station.
After IPCom sued HTC Corporation (HTC) for infringing
the ’830 patent, HTC requested that the U.S. Patent and
Trademark Office (PTO) conduct inter partes reexamina-
tion of claims 1, 5–26, and 28–37 of the ’830 patent, which
the PTO granted. The reexamination went through two
rounds of review by the Examiner and the Patent Trial
and Appeal Board (Board). In the first round, the Exam-
iner concluded that the claims were patentable, but HTC
appealed to the Board, which issued a new ground of
rejection for claims 1 and 5–30. In the second round,
IPCom amended claims 1, 5–26, and 28–37, 1 but the
Board found that these amended claims were obvious
under 35 U.S.C. § 103 in view of various combinations of
McDonald, 2 Anderson, 3 GSM, 4 and PACS. 5
    In its appeal, IPCom alleges that, even though it had
amended the scope of claims 31–37 during its second
round before the Examiner, the Board lacked jurisdiction
to review the Examiner’s patentability determination of
these amended claims in the Board decision now on

    1   IPCom cancelled claim 27. J.A. 3.
    2   U.S. Patent No. 5,222,248.
     3  U.S. Patent No. 6,088,590.
     4  Digital cellular telecommunications system
(Phase 2+); Mobile radio interface layer 3 specification
(GSM 04.08 version 6.1.1 Release 1997). J.A. 13225; see
infra Background Part III.
     5  American National Standard for Telecommunica-
tions-Personal Access Communications System Air Inter-
face Standard (approved November 16, 1998). J.A. 13823;
see infra Background Part IV.
IPCOM GMBH & CO.   v. HTC CORPORATION                      3

appeal. IPCom also argues that the Board’s obviousness
rejections were based on a flawed claim construction,
because the Board never identified the structure in the
patent specification that corresponds to the “arrangement
for reactivating the link” means-plus-function claim
limitation. IPCom also appeals the Board’s factual find-
ings for several other claim limitations and the motiva-
tion to combine the prior art references in the manner
claimed by the ’830 patent.
    We conclude that, under the circumstances of this
case, the Board properly had the authority to consider the
patentability of claims 31–37 and thus reject IPCom’s
procedural challenge to the Board’s rejection of these
claims. But we agree with IPCom that the Board failed to
conduct a proper claim construction of the “arrangement
for reactivating the link” claim limitation, and we vacate
and remand the obviousness rejections based on that
limitation. We affirm the Board’s findings in all other
respects.
                       BACKGROUND
     The ’830 patent describes a method for performing
handover (or handoff) of a cellular telephone or mobile
station (MS) in a cellular telephone network from a first
base station (BS1) to a second base station (BS2). ’830
patent col. 1 ll. 14–62. Mobile stations communicate with
a network by exchanging signals with a base station,
where the base station is part of a wired network of base
stations, fixed lines, and switching units. Id. col. 2 l. 64–
col. 3 l. 3. Handover occurs in a network when the mobile
station switches from one base station to another. Id. col.
1 ll. 25–28.
    The ’830 patent describes forward and forced hando-
ver techniques. Id. col. 5 ll. 10–15, 61–64. A forward
handover is one in which the mobile station, rather than
the first base station, determines a handover is necessary,
and seeks out the second base station. Id. col. 1 ll. 37–38.
4                      IPCOM GMBH & CO.   v. HTC CORPORATION

A forced handover is one in which the first base station
initiates the handover, e.g., by sending a message to the
mobile station instructing the mobile station to perform a
handover to a second base station. Id. col. 1 ll. 53–56, col.
2 ll. 24–31.
    To reduce the chance of interrupted service when a
mobile station must perform a handover, the claimed
invention calls for the first base station to maintain, for a
period of time, the link data for the mobile station as well
as hold in reserve link resources required to maintain a
link between the mobile station and the first base station.
When a handover of the mobile station to a second base
station is unsuccessful, the mobile station reactivates the
link with the first base station, e.g., by continuing to
maintain the link. Id. col. 2 ll. 38–40, col. 5 ll. 10–15, 61–
64, col. 6 ll. 13–53. By providing this feature, if the mo-
bile station cannot establish a link with a second base
station, the mobile station’s link with the first base sta-
tion can be maintained without the mobile base station
having to resend link information to the first base station.
Id. col. 5 ll. 24–26, col. 6 ll. 40–52. This feature is claimed
in the “arrangement for reactivating the link” limitation
in independent claims 1, 18, 30, and 34. J.A. 12565–74.
Claim 1 is reproduced below:
    1. (Unamended) A mobile station for use with a
    network including a first base station and a sec-
    ond base station that achieves a handover from
    the first base station to the second base station by:
        storing link data for a link in a first base
        station,
        holding in reserve for the link resources of
        the first base station, and
        when the link is to be handed over to the
        second base station:
IPCOM GMBH & CO.   v. HTC CORPORATION                     5

       initially maintaining a storage of the link
       data in the first base station,
       initially causing the resources of the first
       base station to remain held in reserve, and
       at a later timepoint determined by a fixed
       period of time predefined at a beginning of
       the handover, deleting the link data from
       the first base station and freeing up the
       resources of the first base station, the mo-
       bile station comprising:
       an arrangement for reactivating the link
       with the first base station if the handover
       is unsuccessful.
J.A. 12565 (emphasis added). Independent claims 18, 30,
and 34 also recite three additional limitations of (1) a
“forced handover request message” from the first base
station to the mobile station; (2) a “handover query” from
the mobile station to a second base station; and (3) a
“rejection message” from the second base station if the
second base station cannot support the mobile station.
Appellant Br. 10–11; J.A. 12570–74.
     The ’830 patent also describes a flexible type of hand-
over, in which a handover is handled in different ways,
depending on whether a network can support handover by
transferring “link data” directly between the first and
second base stations, or whether that information must be
communicated directly from the mobile station to the
second base station. ’830 patent col. 2 ll. 32–38, col. 3
ll. 10–16. This feature is the “informing the mobile sta-
tion” limitation recited in independent claims 5, 12, and
16. J.A. 12566–70. Claim 5, for example, recites “inform-
ing the mobile station whether the network is capable of
transferring the link data from the first base station to
the second base station.” J.A. 12567. The last relevant
limitation in the challenged claims covers a network using
6                     IPCOM GMBH & CO.   v. HTC CORPORATION

different generations of radio communication standards
and is recited in claims 23 and 25. J.A. 12571–72. These
claims recite that “the first base station and the second
base station operate in respective parts of the network
using different generations of radiocommunications
standards for radio communication with the mobile sta-
tion.” J.A. 12571–72.
    For purposes of this appeal, the challenged claims can
be separated into five categories. First, independent
claims 1, 18, 30, and 34 recite the “arrangement for
reactivating the link” means-plus-function limitation.
Second, independent claims 18, 30, and 34 recite the
“forced handover request message,” “handover query,”
and “rejection message” limitations. Third, independent
claims 5, 12, and 16 recite the “informing the mobile
station” limitation. Fourth, dependent claims 23 and 25
recite using different generations of radio communications
standards. Fifth, claims 31–37 are challenged based on
jurisdiction.
                       I. McDonald
     As noted, the Board considered four prior art refer-
ences. McDonald describes a technique for dealing with
failed handovers. When a mobile station moves from one
cell to a neighboring cell in a cellular telephone network,
the mobile station searches for a second base station in
the neighboring cell and sends an inbound signaling word
(ISW) message to inquire whether a handover is possible.
McDonald col. 1 ll. 30–33, col. 2 l. 66–col. 3 l. 9. If the
second base station cannot support a handover, the net-
work sends the mobile station a busy outbound signaling
word (OSW) rejection message. Id. col. 1 ll. 42–46, col. 2
ll. 1–3). The “busy OSW” signal informs the mobile
station that the network cannot transfer link data from
the first base station to the second base station. J.A. 7.
The mobile station “can then choose to return” to the first
base station by “deregister[ing]” from the second base
IPCOM GMBH & CO.   v. HTC CORPORATION                      7

station, “inform[ing]” the network that it is “returning to
the previous channel,” and “attempt[ing] to receive” at the
first base station. McDonald col. 3 ll. 14–21.
                        II. Anderson
     Anderson describes “mobile directed” or “mobile cen-
tric” handover techniques. Anderson col. 17 ll. 45–52.
Anderson describes integrating multiple cellular network
technologies, including GSM (prior art reference described
infra at Background Part III) into a single network. Id.
col. 4 ll. 40–61. It also describes several types of success-
ful handovers, including a “make before break” handover.
Id. col. 15 l. 25–col. 18 l. 25. In this handover, the mobile
station initiates a handover attempt based on a drop in
link quality below a predetermined threshold level be-
tween the mobile station and a first base station. Id. col.
16 ll. 26–33. To initiate the handover, the mobile station
scans for potential new base stations and measures the
received signal quality from the potential new base sta-
tions to identify a base station with the highest signal
quality (the second base station). Id. col. 16 ll. 6–30. The
mobile station then sends a handover request message to
the second base station and waits for a response. Id. col.
16 ll. 26–33. If the second base station accepts the mobile
station’s handover request, the second base station sends
a response requesting transfer of the link data from the
first base station to the second base station, and the
network transfers the link data. Id. col. 16 ll. 36–60. By
transferring the link data from the first base station to
the second base station, the network informs the mobile
station that the network can transfer the link data.
     Anderson also describes a “break before make” embod-
iment to prevent interrupted service. Anderson col. 18
ll. 16–21. In this embodiment, a mobile station that
suddenly loses its connection with a first base station can
quickly reacquire the first base station, or acquire a
different base station (even if no information is available
8                      IPCOM GMBH & CO.   v. HTC CORPORATION

after the link with the first base station is lost).     Id.
col. 18 ll. 16–21.
    III. Global System for Mobile (GSM) Communications
    The Global System for Mobile (GSM) communications
standard was developed by the European Telecommunica-
tions Standards Institute (ETSI) to standardize telecom-
munications protocols.     J.A. 13225.      GSM describes
reactivating a link with a first base station when a hand-
over attempt to a second base station is unsuccessful. The
mobile station sends a “channel request” message to a
second base station, which responds, in some circum-
stances, with an “immediate assignment reject” message.
J.A. 13303. The mobile station then sends a “handover
failure” message to the first base station and “resumes
normal operation as if no handover attempt had oc-
curred.” Id. GSM also describes the use of base stations
that can operate using different generations of radio
communications standards because it discloses a mobile
station that can communicate with both “upgraded GPRS
[General Packet Radio Service] or 2.5G base stations” and
“pre-existing GSM or 2G-only base stations.” J.A. 19–20.
    IV. Personal Access Communications System Air Inter-
                    face Standard (PACS)
     The American National Standards Institute (ANSI)
adopted and promoted wireless telecommunications
standards such as the Personal Access Communications
System Air Interface Standard (PACS) in 1998.
J.A. 13823, 14842. PACS describes a communications
system using an Automatic Link Transfer (ALT) handover
procedure to transfer a mobile station from one base
station to another base station. J.A. 13969–71. When a
first base station deems that a handover attempt to a
different base station is necessary, the first base station
sends a PERFORM_ALT message to the mobile station to
force the mobile station to attempt a handover.
J.A. 13969. The mobile station then issues a handover
IPCOM GMBH & CO.   v. HTC CORPORATION                   9

query by sending an ALT_REQ message to a second base
station. J.A. 13987–88. If the network cannot perform
the requested transfer, the network responds with an
ALT_DENY message, and the mobile station “resume[s]
the conversation on the old link.” J.A. 13976–77. Thus,
PACS discloses, among other things, (i) a forced handover
request message (PERFORM_ALT), (ii) a handover query
message (ALT_REQ), and (iii) a rejection message
(ALT_DENY). J.A. 11, 13. It also discloses interfacing
with other networks, such as GSM. J.A. 13885.
   We have jurisdiction under 28 U.S.C. § 1295(a)(4).
                        DISCUSSION
                   I. Standard of Review
     In construing claims, the Board applies the broadest
reasonable interpretation consistent with the specifica-
tion. Cuozzo Speed Techs., LLC v. Lee, 136 S. Ct. 2131,
2142 (2016). “We review intrinsic evidence and the ulti-
mate construction of the claim de novo.” SightSound
Techs., LLC v. Apple Inc., 809 F.3d 1307, 1316 (Fed. Cir.
2015). “We review the Board’s conclusions of law de novo
and its findings of fact for substantial evidence.” Blue
Calypso, LLC v. Groupon, Inc., 815 F.3d 1331, 1337 (Fed.
Cir. 2016). Substantial evidence “means such relevant
evidence as a reasonable mind might accept as adequate.”
Id. (quoting Consol. Edison Co. of N.Y. v. NLRB, 305 U.S.
197, 229 (1938)).
                   II. Claim Construction
    We begin with claim construction. Following our
opinion in HTC Corp. v. IPCom GmbH & Co., KG, 667
F.3d 1270 (Fed. Cir. 2012), the claim limitation “an ar-
rangement for reactivating the link with the first base
station” in the ’830 patent is a means-plus-function limi-
10                     IPCOM GMBH & CO.   v. HTC CORPORATION

tation. 6 While the Board recognized that ruling, it failed
to properly construe that limitation. The Board rejected
IPCom’s proposed three-step algorithm allegedly disclosed
in the ’830 specification for performing the “arrangement
for reactivating the link” function, but the Board failed to
identify what it believed to be the correct algorithm from
the specification; that omission led to an incomplete
construction of the claim limitation and is incompatible
with our holding in In re Donaldson Co., 16 F.3d 1189,
1193 (Fed. Cir. 1994) (en banc).
    In Donaldson, the PTO rejected Donaldson’s claims by
construing a means-plus-function limitation to encompass
any means capable of performing the recited function,
giving no consideration to the content in the specification.
Id. The PTO argued that such a practice was permissible
under the broadest reasonable interpretation standard
used by the agency. Id. at 1194–95. We rejected the
PTO’s view, holding that the agency must follow the plain
language of §112 ¶ 6. 7 Id. at 1193. We explained that the
construction of a means-plus-function limitation under
§ 112 ¶ 6 “must look to the specification and interpret
that language in light of the corresponding structure,
material, or acts described therein, and equivalents
thereof, to the extent that the specification provides such

     6   In related district court litigation, IPCom asserted
infringement of the ’830 patent against HTC, and the
district court case has been stayed pending completion of
the inter partes reexamination.
    7    Because the ’830 patent was filed before the effec-
tive date of revisions to 35 U.S.C. § 112 made by The
Leahy-Smith America Invents Act, Pub. L. No. 112-29,
§§ 4(c) & 4(e), 125 Stat. 284, 296–97 (2011), the prior
version of § 112 controls, see MobileMedia Ideas LLC v.
Apple Inc., 780 F.3d 1159, 1168 n.3 (Fed. Cir. 2015)
(applying the pre-AIA version of 35 U.S.C. § 112 ¶ 6).
IPCOM GMBH & CO.   v. HTC CORPORATION                    11

disclosure.” Id. We “h[e]ld that paragraph six applies
regardless of the context in which the interpretation of
means-plus-function language arises, i.e., whether as part
of a patentability determination in the PTO or as part of a
validity or infringement determination in a court.” Id. In
other words, § 112 ¶ 6 “sets a limit on how broadly the
PTO may construe means-plus-function language under
the rubric of ‘reasonable interpretation,’” and “the PTO
may not disregard the structure disclosed in the specifica-
tion corresponding to such language when rendering a
patentability determination.” 8 Id. at 1194–95.
    In HTC Corp., we explained that HTC and IPCom
agreed that the “arrangement for reactivating the link”
recited in the ’830 patent was a means-plus-function
limitation. 667 F.3d at 1278. Section 112 ¶ 6 thus re-
quired the Board to perform a two-step analysis. Id.
First, the Board had to “identif[y] the particular claimed
function.” Id. Second, the Board had to “look[] to the
specification and identif[y] the corresponding structure,
material, or acts that perform that function.” Id. In HTC
Corp., the district court “concluded that the structure
corresponding to the ‘arrangement for reactivating [the
link]’ limitation was ‘a processor connected to a transceiv-
er and programmed to formulate and send messages to
reactivate the link, if the handover is unsuccessful.’” Id.
We held that the district court misstated the law when it
“stated that disclosure of a processor and transceiver

   8     We also explained that “if one employs means-
plus-function language in a claim, one must set forth in
the specification an adequate disclosure showing what is
meant by that language,” because “[i]f an applicant fails
to set forth an adequate disclosure, the applicant has in
effect failed to particularly point out and distinctly claim
the invention as required by the second paragraph of
section 112.” Donaldson, 16 F.3d at 1195.
12                     IPCOM GMBH & CO.   v. HTC CORPORATION

alone was sufficient to provide structure to these claims”
because “[t]he processor and transceiver amount[ed] to
nothing more than a general-purpose computer.” Id. at
1280. We explained that “[r]ather than relying on the
processor and transceiver, IPCom had to identify an
algorithm that the processor and transceiver execute.” Id.
We noted that although IPCom argued that the ’830
patent contains such an algorithm, the district court
never addressed that question “because HTC never asked
it to do so.” Id. “HTC had an opportunity to argue the
algorithm issue—at IPCom’s invitation—during briefing
on claim construction and HTC’s summary judgment
motion, and at oral argument before the district court,”
yet HTC did not do so. Id. at 1282. We held that
“[b]ecause HTC never attacked the adequacy of the algo-
rithm in the ’830 patent when given an opportunity to do
so before the district court,” HTC waived any opportunity
to raise it on appeal as a basis for invalidating the claims.
Id. at 1283.
    Here, the issue of identifying in the ’830 patent the
algorithm for performing the “arrangement for reactivat-
ing the link” function was front and center during the
reexamination. The Board rejected IPCom’s proposed
three-step algorithm of: (1) “receiving a rejection from the
second (i.e., target) base station”; (2) “sending a message
to the first (i.e., old) base station to maintain the link with
the first base station”; and (3) “re-establishing the link
with the first base station by receiving a message from
that first base station.” J.A. 15. Rather than inquiring
further into what algorithm (if any) the specification
actually discloses, however, the Board only questioned
whether each individual step of IPCom’s proposed algo-
rithm was separately necessary. For step one, the Board
found that the specification described an example of an
“algorithm structure” that “does not involve receiving a
rejection from the second base station” because “in some
cases . . . no other base station is receiving.” J.A. 16. For
IPCOM GMBH & CO.   v. HTC CORPORATION                     13

step two, the Board cited the specification’s discussion of a
timer mechanism that purportedly obviated the need for a
message to be sent to the first base station to reactivate
the link with the first base station. Id. For step three,
the Board pointed to the specification’s explanation that
the mobile station “re-registers at its old [base station]
and keeps its previous settings,” purportedly without
requiring a receipt of an acknowledgement message from
the first base station. J.A. 17. The Board then concluded
its analysis by stating that it “need not consider whether
or not the combination of Anderson and McDonald dis-
closes or suggests these method steps.” J.A. 18.
     The Board’s analysis was erroneous because it never
specified what it believed was the actual algorithm dis-
closed in the ’830 patent for performing the “arrangement
for reactivating the link” function. It was not enough for
the Board to reject the individual steps of IPCom’s pro-
posed three-step algorithm. As we explained in Don-
aldson, “the PTO may not disregard the structure
disclosed in the specification corresponding to such lan-
guage when rendering a patentability determination.”
Donaldson, 16 F.3d at 1195. And in HTC Corp., we held
that “the functional claiming in claims 1 and 18 of the
’830 patent must include an adequate algorithm.” HTC
Corp., 667 F.3d at 1283. Here, as in Donaldson, the
Board never engaged in a comparison of the asserted prior
art’s disclosure to the “structure” disclosed in the ’830
patent, due to the Board’s failure to determine what the
’830 patent describes as the structure (i.e., the algorithm
in combination with the processor and transceiver) for
performing the “arrangement for reactivating the link”
function. Like Donaldson, the Board here impermissibly
treated the means-plus-function limitation in its patenta-
bility analysis as if it were a purely functional limitation.
   We vacate the Board’s claim construction of the “ar-
rangement for reactivating the link” limitation, and we
remand for the Board to identify the corresponding algo-
14                    IPCOM GMBH & CO.   v. HTC CORPORATION

rithm (if any) in the specification in the first instance,
consistent with our holdings in Donaldson and HTC Corp.
Because it never identified any algorithm for the “ar-
rangement for reactivating the link” limitation, the Board
also erred by failing to evaluate whether the prior art
disclosed that algorithm (or its equivalents). J.A. 15–18.
We therefore vacate and remand the Board’s finding of
obviousness of claims 1, 18, 30, and 34, and their corre-
sponding dependent claims.
                     III. Obviousness
    We also address here the Board’s findings on the oth-
er claim limitations—the “forced handover request mes-
sage,” “handover query,” and “rejection message”—which
are each recited in claims 18, 30, and 34. J.A. 9–13. We
then discuss the Board’s rejections of claims 5–17 based
on the “informing the mobile station” limitation, and the
Board’s rejections of claims 23 and 25 based on the limita-
tion reciting different generations of radio communication
standards, before addressing the motivation to combine
McDonald, Anderson, GSM, and PACS to arrive at the
claimed inventions.
                            A.
    We first address IPCom’s procedural argument that
the Board could not rely on GSM and PACS as prior art
references because HTC did not explain why those refer-
ences could not have been presented earlier in the pro-
ceeding. [JA5] After the Board’s decision in the first
round of review finding the challenged claims of the ’830
patent unpatentable, IPCom reopened prosecution under
37 C.F.R. § 41.77(b) and amended its claims in the second
round of review. Under 37 C.F.R. § 41.77(c), HTC filed
comments on IPCom’s response and claim amendments,
raising the GSM and PACS references along with the
previously relied upon Anderson and McDonald refer-
ences. J.A. 2–5. IPCom argued to the Board that HTC
did not explain why the additional prior art could not
IPCOM GMBH & CO.   v. HTC CORPORATION                   15

have been raised previously in the proceeding, but the
Board explained that § 41.77(c) does not require HTC to
“explain why the additional prior art could not have been
presented earlier,” when HTC’s comments were filed in
response to IPCom’s request to reopen prosecution. J.A.
6.
    We apply “the standards set forth in the Administra-
tive Procedure Act, 5 U.S.C. § 706” in reviewing the
Board’s interpretation of PTO regulations. Microsoft
Corp. v. Proxyconn, Inc., 789 F.3d 1292, 1306 (Fed. Cir.
2015). “[W]e set aside actions of the Board that are
arbitrary, capricious, an abuse of discretion, or otherwise
not in accordance with law.” Id. “We accept the Board’s
interpretation of [PTO] regulations unless that interpre-
tation is ‘plainly erroneous or inconsistent with the regu-
lation.’” Id. (quoting In re Sullivan, 362 F.3d 1324, 1326
(Fed. Cir. 2004)).
    We agree with the Board, which properly applied its
regulations to consider GSM and PACS because they were
cited in response to IPCom’s election to reopen prosecu-
tion and amend the challenged claims. J.A. 12564–74.
The Board correctly explained that § 41.77(c) does not
require HTC to “explain why the additional prior art
could not have been presented earlier.” J.A. 6. Section
41.77(c) requires only that HTC’s comments be limited to
the Board’s decision and issues raised by IPCom’s request
to reopen prosecution. 9 37 C.F.R. § 41.77(c). When it

   9    Similarly, contrary to IPCOM’s position,
§ 1.948(a) uses the disjunctive “or,” which makes it un-
necessary for HTC to explain why the additional prior art
could not have been raised previously.           37 C.F.R.
§ 1.948(a)(2). Section 1.948(a) provides that a third party
requester may only cite additional prior art:
16                      IPCOM GMBH & CO.   v. HTC CORPORATION

reopened prosecution, IPCom amended claims 5, 12, 16,
18, 23, 25, 30, and 34 (and their dependent claims) to
include the “forced handover request message,” the
“handover query,” the “rejection message,” the “informing
the mobile station” limitation, and different generations
of radio communications standards. 10 J.A. 12564–74. We
affirm the Board’s finding that it could properly consider

     (1) which is necessary to rebut a finding of fact by
     the examiner;
     (2) which is necessary to rebut a response of the pa-
     tent owner; or
     (3) which for the first time became known or
     available to the third party requester after the fil-
     ing of the request for inter partes reexamination
     proceeding. Prior art submitted under paragraph
     (a)(3) of this section must be accompanied by a
     statement as to when the prior art first became
     known or available to the third party requester
     and must include a discussion of the pertinency of
     each reference to the patentability of at least one
     claim.
37 C.F.R. § 1.948 (emphasis added). Thus, § 1.948(a)
allows HTC to cite additional prior art if that prior art “is
necessary to rebut a response of the patent owner.” Id.
    10  Although the “arrangement for reactivating the
link” limitation was not an amendment to the challenged
claims, IPCom sought a new construction of this limita-
tion based on “new evidence in th[e] reexamination; it was
not available when [IPCom] filed its [earlier] responses.”
J.A. 12473–75, 12582. HTC properly responded to IP-
Com’s new argument on the “arrangement for reactivat-
ing the link” limitation. On remand, the Board should
identify the correct algorithm for this limitation and
determine whether the prior art discloses that algorithm.
IPCOM GMBH & CO.   v. HTC CORPORATION                  17

GSM and PACS against IPCom’s request to reopen prose-
cution and amend the claims. 11
                             B.
     We now turn to whether the prior art discloses the
claim limitations in dispute other than the “arrangement
for reactivating the link” limitation. The Board agreed
with HTC that PACS discloses a “forced handover request
message” by describing a PERFORM_ALT message that
is transmitted from the network to a mobile station. J.A.
11. It also agreed that PACS discloses a “handover query”
by describing an ALT_REQ message and a “rejection
message” by describing an ALT_DENY message. J.A. 13.
    We agree with the Board. We note that IPCom con-
cedes that PACS discloses that the PERFORM_ALT
message is forced, i.e., mandatory, but IPCom argues that
PACS never teaches the possibility of reactivating the
link if the handover is unsuccessful, which, in IPCom’s
view, is part of the “forced handover request message”
limitation. Appellant Br. 54; Reply Br. 24. IPCom is
incorrect; the Board correctly explained that reactivating
the link and the forced handover request message are
separate claim limitations. J.A. 11. It also noted that
IPCom did not challenge HTC’s argument that PACS
discloses the “handover query” and “rejection message,”

   11  IPCom argues that it had no opportunity to sub-
mit rebuttal evidence with respect to GSM and PACS.
Reply Br. 21–23. The Board explained to IPCom in its
second round decision, however, that the rejections based
on GSM and PACS were new grounds of rejection that
would allow IPCom to reopen prosecution. J.A. 20–21.
IPCom had the opportunity to reopen prosecution just as
IPCom did after the first round before the Board in which
the Board adopted new grounds of rejection, but IPCom
chose not to do so.
18                   IPCOM GMBH & CO.   v. HTC CORPORATION

id. at 13, and IPCom does not challenge these findings on
appeal. Appellant Br. 42–44; Reply Br. 13–16, 24. Thus,
we affirm the Board’s findings that PACS discloses the
“forced handover request message,” the “handover query,”
and the “rejection message” limitations.
                           C.
     Next, we turn to claims 5–17 and find no error in the
Board’s analysis of the “informing the mobile station”
limitation. The Board explained that claim 5, as amend-
ed, recites “informing the mobile station whether the
network is capable of transferring the link data from the
first base station to the second base station.” J.A. 6.
IPCom argued independent claims 5, 12, and 16 and their
dependent claims to the Board as a group, and the Board
treated claim 5 as representative. Id. The Board found
that McDonald’s “busy OSW” signal informs the mobile
station that the network cannot transfer the link data
from the first base station to the second base station.
J.A. 7. It also found that Anderson disclosed a successful
handover, which informs the requesting mobile station
that the network could perform the transfer. Id. The
Board found that combining Anderson and McDonald
would have disclosed informing the mobile station wheth-
er a network was capable of handover because it would
achieve both alternatives: successful and unsuccessful
handover messages. J.A. 7–8.
    We agree that substantial evidence supports the
Board’s finding that the combination of Anderson and
McDonald teaches the recited “informing the mobile
station” limitation because Anderson teaches a successful
handover, and McDonald describes cases in which hando-
ver is unsuccessful by using a busy OSW signal. Under
the broadest reasonable construction, a combined system
that can indicate either a successful handover using the
features of Anderson or that no handover is possible using
the features of McDonald is sufficient to meet the re-
IPCOM GMBH & CO.   v. HTC CORPORATION                   19

quirements of the claims, which only recite that the
network informs the mobile base station whether a hand-
over is possible. We affirm the Board’s findings that
combining Anderson and McDonald discloses the inform-
ing the mobile station limitation.
                             D.
    We next address the claim limitations calling for the
use of different generations of radio communications
standards recited in claims 23 and 25. 12 These claims
recite that “the first base station and the second base
station operate in respective parts of the network using
different generations of radiocommunications standards
for radio communication with the mobile station.” J.A.
12571–72. The Board rejected claims 23 and 25 in view of
Anderson, McDonald, and GSM. J.A. 18–20. The Board
credited HTC’s argument that GSM disclosed “a mobile
station that is capable of communicating with upgraded
GPRS or 2.5G base stations, as well as pre-existing GSM
or 2G-only base stations.” J.A. 19–20. It found that the
base stations need not be incapable of communicating
among themselves to facilitate handover, even if the
specification discloses such an example, because the
example from the specification should not be imported
into the claims. J.A. 19–20.
    IPCom argues on appeal that because the specifica-
tion shows an example of different base stations that
cannot communicate directly with each other when the
base stations use different generations of radio communi-
cation standards, ’830 patent col. 6 ll. 57–64, a person of
ordinary skill in the art would understand claims 23 and
25 to require that those base stations be unable to com-
municate directly. Appellant Br. 52, 54–56. IPCom also

   12  Claim 23 depends on claim 1 and claim 25 de-
pends indirectly on claim 5. J.A. 12565–72.
20                    IPCOM GMBH & CO.   v. HTC CORPORATION

argues that claim 5 (from which claim 25 indirectly de-
pends) requires the same result because claim 5 recites
that the mobile station transmits link data to a second
base station “if the network cannot transfer the link
data.” Appellant Br. 54; J.A. 12567. IPCom contends
that this limitation is missing from GSM because the base
stations with and without GPRS in GSM can communi-
cate directly with each other. Appellant Br. 55.
    We disagree. We find that substantial evidence sup-
ports the Board’s findings that GSM teaches the recited
limitation of using different generations of radio commu-
nications standards because, as the Board found, GSM
discloses using a mobile station that can communicate
with both GSM/2G and GPRS/2.5G base stations, a find-
ing that IPCom does not challenge. J.A. 19–20. Contrary
to IPCom’s position, claims 23 and 25 do not require that
the base stations be incapable of communicating with
each other; the claims simply require that the first and
second base stations operate “using different generations
of radiocommunications standards for radio communica-
tion with the mobile station.” J.A. 12571–72. We agree
that the specification’s example of base stations incapable
of communicating among themselves to facilitate hando-
ver should not be imported into claims 23 and 25. 13
     We also address IPCom’s argument relating to claim
5, from which claim 25 indirectly depends through claim
11. Claim 5 does not require that the base stations be
unable to transfer link data directly because it covers both
networks that are capable of transferring link data and
ones that are not capable of transferring link data.
J.A. 12567. Claim 5 recites “causing the mobile station to

     13 Because claim 23 depends from claim 1, which re-
cites the “arrangement for reactivating the link” limita-
tion, the Board must resolve this limitation from claim 1
before it can determine claim 23’s patentability.
IPCOM GMBH & CO.   v. HTC CORPORATION                    21

transmit the link data to the second base station, if the
network cannot transfer the link data.” Id. Claim 11
depends on claim 5, and claim 11 recites “causing the first
base station to transfer the link data to the second base
station if the network can transfer link data.”
J.A. 12567–68. Thus, claim 5 does not require that the
network be unable to transfer link data, but it encom-
passes both types of networks—ones that can transfer the
link data and ones that cannot transfer the link data—
because claim 5 must include the scope of claim 11. We
reject IPCom’s argument that the base stations “using
different generations of radiocommunications standards
for radio communication with the mobile station” must be
incapable of communicating directly with each, and we
affirm the Board’s finding that GSM discloses this limita-
tion.
                             E.
    We turn last to the motivation to combine McDonald,
Anderson, GSM, and PACS. The Board rejected IPCom’s
arguments that it would not have been obvious to a
person of ordinary skill in the art to combine either GSM
or PACS with Anderson and McDonald based on the
length of the references or because the combination would
be inoperable.       J.A. 13.     The Board found that
(1) Anderson and McDonald disclose methods of handover
in a mobile telephone system; (2) GSM discloses a tech-
nical specification for handover procedures for mobile
stations; and (3) PACS discloses mobile applications that
include communications and handover methods among
network components (e.g., PERFORM_ALT). J.A. 14. It
further found that combining the known systems of
handover for mobile stations in Anderson or McDonald
with systems for handover discussed in GSM and PACS
would have been obvious because it would have yielded no
more than a predictable result. Id. (citing KSR Int’l Co. v.
Teleflex Inc., 550 U.S. 398, 416 (2007)).
22                     IPCOM GMBH & CO.   v. HTC CORPORATION

    IPCom argues that the Board engaged in impermissi-
ble hindsight to combine the references in the precise
manner claimed by the ’830 patent. IPCom contends that
combining these references would not have yielded pre-
dictable results because Anderson relates to a system
where the mobile system controls the handover, McDon-
ald relates to a system where the user enters input that
guides the handover, and GSM relates to a handover in
which the network is in control. IPCom does not argue
which entity is in control in PACS.
    Substantial evidence supports the Board’s motivation
to combine findings. Both Anderson and McDonald teach
solutions for solving the problem of an unsuccessful
handover in a cellular telephone network, and each teach
a means for returning to a first base station after a failed
handover attempt to a second base station. As discussed
above, McDonald teaches a method for a mobile station to
return to the first base station after a failed handover
attempt. McDonald col. 3 ll. 14–21. Similarly, Anderson
discloses a “break before make” embodiment to prevent
interrupted service, in which a mobile station that sud-
denly loses its connection with a first base station can
quickly reacquire the first base station or acquire a differ-
ent base station after a failed handover attempt. Ander-
son col. 18 ll. 16–24. A person of ordinary skill in the art
would have been motivated to combine these teachings to
solve the common problem of unsuccessful handovers.
J.A. 13–14. Combining McDonald with Anderson’s “make
before break” embodiment also teaches the “informing the
mobile station” limitation, as we discuss above. J.A. 6–8.
     Anderson further discloses that its communication
system can be combined with a GSM network. Anderson
col. 4 ll. 40–44. McDonald contains a similar disclosure in
its reference to “TDM time slots” because HTC’s expert
explained that at the time of the invention, “GSM was a
common cellular protocol using TDM time slots.” J.A.
12791–92; McDonald col. 1 ll. 24–26. Adding GSM to
IPCOM GMBH & CO.   v. HTC CORPORATION                    23

Anderson and McDonald teaches the limitation of using
different generations of radio communication standards in
a cellular telephone network because GSM discloses using
a mobile station that can communicate with both GSM/2G
and GPRS/2.5G base stations. J.A. 19–20.
    A person of ordinary skill would also have been moti-
vated to combine Anderson or McDonald with PACS.
Anderson describes a mobile-centric system designed to
connect with different networks. Anderson col. 1 ll. 18–
21, col. 4 ll. 40–51. The crossover between McDonald and
PACS was also readily apparent for the same reasons. As
discussed above, PACS discloses a “forced handover
request message” by describing a PERFORM_ALT mes-
sage transmitted from the network to a mobile station, a
“handover query” by describing an ALT_REQ message,
and a “rejection message” by describing an ALT_DENY
message. J.A. 11, 13–14. PACS itself further discloses
interfacing with GSM. J.A. 13885.
    The Board correctly explained that both McDonald
and Anderson disclose methods of handover for mobile
telephone systems (including the “informing the mobile
station” limitation), GSM discloses using a mobile station
that can communicate with both GSM/2G and GPRS/2.5G
base stations (which are different generations of radio
communication standards), and PACS discloses using
communication messages between base stations and
mobile stations (including a forced handover request
message, a handover query, and a rejection message).
J.A. 14. In light of their interrelated teachings, combin-
ing these four known systems for handover and handoff
for cellular telephone systems would have resulted in no
more than the predictable result for a system for handing
over mobile stations between base stations, consistent
with the GSM and PACS industry standards. Id.
    For these reasons, we affirm the Board’s factual find-
ings that the prior art discloses all the limitations of the
24                     IPCOM GMBH & CO.   v. HTC CORPORATION

challenged claims on appeal, except for the “arrangement
for reactivating the link” means-plus-function limitation.
We also affirm the Board’s finding of a motivation to
combine McDonald, Anderson, GSM, and PACS to arrive
at the combinations recited in the challenged claims
except for the “arrangement for reactivating the link”
limitation. We vacate and remand the Board’s findings on
the “arrangement for reactivating the link” limitation.
          IV. The Board’s Rejection of Claims 31–37
     We briefly address IPCom’s arguments that the Board
lacked jurisdiction to consider the patentability of claims
31–37 during its second round of review. In its first
decision in the reexamination proceeding, the Board did
not address whether claims 31–37 should be regarded as
obvious, J.A. 12475–76, as HTC had not expressly chal-
lenged those claims for obviousness in its first Notice of
Appeal to the Board. 14 J.A. 8670–71. After the Board’s
first decision, IPCom reopened prosecution of claims 1, 5–
26 and 28–37 and amended these claims, and HTC re-
sponded that the amended claims were unpatentable.
J.A. 3, 5.
    After IPCom filed its request to reopen prosecution in
view of the Board’s initial decision, the Board issued its
Order Remanding Inter Partes Reexamination under 37
CFR 41.77(d) to the Examiner, granting IPCom’s request
to enter “claim amendments to claims 5, 12, 16, 18, 23, 25,
30, and 34” and ordering that “[t]his matter will be re-
manded to the Examiner for consideration of claims 1 and
5–37 in view of the newly submitted claim amendments,

     14 HTC’s first Notice of Appeal did challenge the Ex-
aminer’s refusal to maintain rejections of claims 30–37
under 35 U.S.C. § 305 as enlarging the scope of the
claims, J.A. 8671, but HTC did not maintain this argu-
ment in its appeal brief to the Board. J.A. 8814–25.
IPCOM GMBH & CO.   v. HTC CORPORATION                   25

the declaration of [IPCom’s expert], and Requester’s
response pertaining to the new grounds of rejection as
enumerated in our prior Decision.” J.A. 14422. The
Board expressly explained that “[a]s Patent Owner ob-
serves (Request, p. 14), the new ground of rejection ap-
plies to claims 1 and 5–37.” J.A. 14422 n.1. The
Examiner then reviewed claims 1 and 5–37 in light of the
new amendments, J.A. 14541, 14754, and found, as rele-
vant here, claims 31–37 patentable based on IPCom’s
amendments. 15 J.A. 14547–48, 14757–61.
    IPCom argues that when the reexamination returned
to the Board for the second time, the Board lacked juris-
diction to consider the obviousness of claims 31–37 be-
cause, even though IPCom amended those claims when it
reopened prosecution, claims 31–37 had not been part of
the first Board appeal. There certainly was some confu-
sion below about the impact of the Board’s first decision
on claims 31–37. For example, IPCom itself stated on the
record below, after receiving the Board’s first decision,
that it “presume[d] that the Board intended to reject all
claims that were subject to appeal, namely claims 1 and
5–37.” J.A. 12577 n.1. IPCom’s initial reaction to the
Board’s first decision is not surprising, since the Board’s
logic in rejecting claims 1, 5–26, and 28–30, appears to
apply equally to claims 31–37. J.A. 12471–75.
    More importantly, when IPCom reopened prosecution,
it amended all of the pending claims, including claims 31–
37. J.A. 12565–76. IPCom amended independent claims
30 and 34 to add the forced handover request, handover

   15   When the reexamination returned to the Board,
the Board reversed, initially addressing only claims 1 and
5–30, J.A. 15688, 15692, but it later issued a replacement
decision, clarifying that IPCom had reopened prosecution
of claims 1, 5–26, and 28–37, and it found those claims
unpatentable. J.A. 2–5.
26                    IPCOM GMBH & CO.   v. HTC CORPORATION

query, and rejection message limitations. J.A. 12572–74.
IPCom also for the first time raised its claim construction
argument on the “arrangement for reactivating the link”
limitation in claims 1 and 18, a limitation that is also
recited in both claims 30 and 34. J.A. 12565–74. IPCom
explained that this construction was “new evidence in this
examination; it was not available when the Patent Owner
filed its [prior] responses.” J.A. 12582. Although depend-
ent claims 31–33 and 35–37 were not directly amended,
they were indirectly amended because they depend on
amended claim 30 or 34. J.A. 12572–74. By amending
claims 31–37, IPCom altered the scope of these claims,
and this opened the door to permit HTC to challenge the
amended claims.
    IPCom also argues that the Board lacked jurisdiction
to consider claims 31–37 because HTC’s notice of appeal
in the first Board appeal did not challenge claims 31–37
as to obviousness. J.A. 8670–71. However, IPCom cites
no authority (other than an inapposite Board decision
that found that a proposed obviousness rejection was
waived) 16 to support IPCom’s argument that the Board’s
jurisdiction in the second round before the Board is lim-
ited by HTC’s Notice of Appeal in the first round. Reply
Br. 26–27. We find that in its second decision (which is
the one on appeal), the Board properly considered HTC’s
challenge to claims 31–37 after IPCom had reopened
prosecution and amended those claims.

     16 Google Inc. v. Netlist, Inc., No. 2014-007777, 2015
WL 799035, at *8 (P.T.A.B. Feb. 24, 2015) (finding that a
requester’s arguments opposing an examiner’s nonadop-
tion of a proposed rejection for obviousness were waived
because the requester did not identify that issue in its
Notice of Cross Appeal).
IPCOM GMBH & CO.   v. HTC CORPORATION                    27

                        CONCLUSION
     For the foregoing reasons, we affirm in part, vacate in
part, and remand for consideration in light of this opinion.
We vacate and remand the Board’s finding of obviousness
of independent claims 1, 18, 30, and 34, and their corre-
sponding dependent claims based on the “arrangement for
reactivating the link” means-plus-function limitation. We
affirm the Board’s findings that the prior art discloses all
the other limitations of the challenged claims on appeal,
and the motivation to combine McDonald, Anderson,
GSM, and PACS to arrive at claims 5–17 and 25. We
affirm the Board’s finding of obviousness with respect to
claims 5–17 and 25.
  AFFIRMED-IN-PART, VACATED-IN-PART, AND
                REMANDED
                           COSTS
   No costs.