Mentone Solutions LLC v. Digi International Inc.

N OTE: This disposition is nonprecedential.
United States Court of Appeals
for the Federal Circuit
______________________
MENTONE SOLUTIONS LLC,
Plaintiff-Appellant
v.
DIGI INTERNATIONAL INC.,
Defendant-Appellee
______________________
2021-1202
______________________
Appeal from the United States District Court for the
District of Delaware in No. 1:20-cv-00280-LPS, Judge
Leonard P. Stark.
-------------------------------------------------
MENTONE SOLUTIONS LLC,
Plaintiff-Appellant
v.
ELO TOUCH SOLUTIONS, INC.,
Defendant-Appellee
______________________
2021-1203
______________________
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MENTONE SOLUTIONS LLC v. DIGI INTERNATIONAL INC. 2
Appeal from the United States District Court for the
District of Delaware in No. 1:20-cv-00281-LPS, Judge
Leonard P. Stark.
______________________
Decided: November 15, 2021
______________________
G EORGE P AZUNIAK, O'Kelly, Ernst, & Bielli, LLC, Wil-
mington, DE, for plaintiff-appellant.
AMR O. ALY , Jenner & Block LLP, New York, NY, for
defendant-appellee Digi International Inc. Also repre-
sented by YUSUF ESAT , Chicago, IL; ADAM G. U NIKOWSKY ,
Washington, DC.
RICARDO B ONILLA, Fish & Richardson P.C., Dallas, TX,
for defendant-appellee Elo Touch Solutions, Inc. Also rep-
resented by N EIL J. MCN ABNAY , MICHAEL V INCENT .
______________________
Before M OORE, Chief Judge, L OURIE and D YK, Circuit
Judges.
MOORE, Chief Judge.
Mentone Solutions LLC appeals an order from the Dis-
trict of Delaware holding the claims of U.S. Patent No.
6,952,413 invalid under 35 U.S.C. § 101 and dismissing
Mentone’s claim of patent infringement. For the following
reasons, we reverse.
BACKGROUND
I
The ’413 patent relates to dynamic resource allocation
in general packet radio systems. ’413 patent at 1:8–10. In
those systems, a number of mobile stations communicate
with a single network through physical links called Packet
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Data Channels (PDCHs). Id. at 1:13, 19–24. When the mo-
bile stations receive information from the network, they
are engaging in downlink (DL) communication, and when
the mobile stations are transmitting information to the
network, they are engaging in uplink (UL) communication.
Id. at 1:28–32. These mobile stations communicate within
time frames, each divided into eight timeslots. Id. at 1:24–
26. Figure 1 of the patent depicts the numbering conven-
tion used for uplink and downlink slots in two successive
frames:
Each corresponding pair of slots (e.g., uplink slot 0 and
downlink slot 0) represents a PDCH. Id. at 1:55–58.
To control access to the PDCHs, which are shared
among mobile stations, the network uses an uplink status
flag (USF). Id. at 1:50–54. That flag can take eight values,
0 through 7, allowing allocation of resources for up to eight
mobile stations. Id. at 1:60–62. When a mobile station re-
ceives a USF, it may recognize the value as valid, which
communicates exclusive use of resources to that station.
Id. at 1:63–64. In systems using an extended dynamic al-
location method, a mobile station’s reception of a valid USF
in a certain downlink timeslot indicates the availability for
that station to begin transmission in the corresponding up-
link slot. Id. at 1:65–2:5.
To “utilize most effectively the available bandwidth,”
access to PDCHs may be dynamically allocated. Id. at
1:33–38. “The amounts of time that the mobile station re-
ceives downlink or transmits uplink may be varied and
slots allocated accordingly.” Id. at 1:39–41. However, as
explained below, at the time of the alleged invention,
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MENTONE SOLUTIONS LLC v. DIGI INTERNATIONAL INC. 4
certain multislot patterns or configurations were not avail-
able due to restrictions in mobile stations.
II
The ’413 patent identifies two restrictions. First, “the
mobile station is not able instantly to switch from a receive
condition to a transmit condition or vice versa.” Id. at 2:11–
12. This turn-around time, along with the time needed to
perform certain measurements, prevents certain multislot
patterns from functioning. Id. at 4:1–8. Figure 3 depicts
an example of an impermissible multislot pattern, specifi-
cally a steady state single-downlink and 5 uplink slot allo-
cation for a class 34 mobile station:
Id. at 2:11–14; 4:5–7. Between uplink timeslot 4 of the first
frame and downlink timeslot 0 of the second frame (shown
as letter A), there is insufficient time for the mobile station
to change from a transmit state to a receive state. Id. at
4:5–7.
Second, in systems using an extended dynamic alloca-
tion method, there is a fixed relationship between the
downlink slot in which a valid USF is received and the up-
link slot in which transmission begins; a mobile station’s
receipt of a valid USF in a certain downlink timeslot indi-
cates the availability for that station to begin transmission
in the corresponding uplink slot. Id. at 1:65–2:5. For ex-
ample, if a valid USF indicating the availability of four up-
link slots is received at downlink timeslot 0, the mobile
station begins transmission in the corresponding uplink
timeslot 0. Id. at 2:1–10, 27–35. Figure 2 illustrates this
fixed relationship:
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MENTONE SOLUTIONS LLC v. DIGI INTERNATIONAL INC. 5
Id. at 3:61–67. Due to these two restrictions, certain mul-
tislot configurations were not possible.
III
The ’413 patent’s purported invention focuses on eas-
ing the latter restriction. It allows a mobile station access
to previously restricted multislot configurations through
“altering the fixed relationship in the timing of the down-
link allocation signalling [sic] and subsequent uplink
transmission for certain classes of mobile station.” Id. at
2:46–49. For example, it purports to allow configurations
that would otherwise be impossible due to insufficient
turnaround time. Compare id. at Fig. 3 with id. at Fig 4.
The ’413 patent specification purports to alter this fixed re-
lationship through shifting, to the second downlink slot,
the USF indicating the mobile station may begin uplink
transmission at the first uplink slot, as shown in Figure 4:
Id. at 4:8–19. Any USF corresponding to the second uplink
slot is also placed in the second downlink slot. Id. at 4:12–
14. Through this shifted USF, the invention purports to
“reduce restrictions affecting extended dynamic allocation
with minimal effect on the existing prescript.” Id. at 2:44–
46. It allows the mobile station to “transmit up to its phys-
ical slot limit.” Id. at 5:17–18. The present invention in-
creases the capacity of networks to communicate data by
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allowing the network to use timeslots for transmission
which, according to the patent, were not available in the
prior art. The result is a system capable of a higher rate of
data transmission. Claim 5 is representative and recites:
5. A multiple access communication method in a
mobile station, comprising the steps of:
receiving an assignment of at least a first
PDCH (packet data channel) and a second
PDCH;
monitoring an assigned PDCH to detect a
USF; and
transmitting on an assigned PDCH corre-
sponding to the USF,
wherein (i) if shifted USF operation is not
used then a first assigned PDCH is moni-
tored to detect a USF corresponding to the
first assigned PDCH and (ii) if the shifted
USF operation is used then a second as-
signed PDCH is monitored to detect the
USF corresponding to the first assigned
PDCH and a USF corresponding to the sec-
ond assigned PDCH.
IV
Mentone sued Digi International Inc. and Elo Touch
Solutions, Inc. (collectively Appellees) for infringement of
at least claim 5 of the ’413 patent. Appellees moved to dis-
miss under Federal Rule of Civil Procedure 12(b)(6), argu-
ing the ’413 patent claims are patent ineligible under 35
U.S.C. § 101. The district court held that claim 5, which
the parties agreed is representative, is patent ineligible.
The district court held claim 5 is “directed to the abstract
idea of receiving a USF and transmitting data during the
appropriate timeslots.” J.A. 7. It further held that the
shifted uplink status flag combined with the “abstract idea,
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MENTONE SOLUTIONS LLC v. DIGI INTERNATIONAL INC. 7
functional limitations, and anything else” is not signifi-
cantly more than a claim to the abstract idea. J.A. 8. Ac-
cordingly, the district court dismissed Mentone’s
infringement claims. Mentone timely appeals. We have
jurisdiction under 28 U.S.C. § 1295(a)(1).
D ISCUSSION
We review a district court’s Rule 12(b)(6) dismissal un-
der regional circuit law, here the Third Circuit. In re TLI
Commc’ns LLC Pat. Litig., 823 F.3d 607, 610 (Fed. Cir.
2016). The Third Circuit reviews such orders de novo, ac-
cepting as true the facts alleged and drawing all reasonable
inferences in favor of the nonmoving party. Vallies v. Sky
Bank, 432 F.3d 493, 494 (3d Cir. 2006). Applying our law,
we review a district court’s patent eligibility determination
under § 101 de novo. OIP Techs., Inc. v. Amazon.com, Inc.,
788 F.3d 1359, 1362 (Fed. Cir. 2015). Patent eligibility un-
der § 101 is a question of law, based on underlying factual
findings. SAP Am., Inc. v. InvestPic, LLC, 898 F.3d 1161,
1166 (Fed. Cir. 2018). It may be resolved on a Rule 12(b)(6)
motion “when there are no factual allegations that, taken
as true, prevent resolving the eligibility as a matter of law.”
Aatrix Software, Inc. v. Green Shades Software, Inc., 882
F.3d 1121, 1125 (Fed. Cir. 2018).
Section 101 provides that “[w]hoever invents or discov-
ers any new and useful process, machine, manufacture, or
composition of matter, or any new and useful improvement
thereof,” may obtain a patent. 35 U.S.C. § 101. However,
“[l]aws of nature, natural phenomena, and abstract ideas
are not patent eligible.” Alice Corp. v. CLS Bank Int’l, 573
U.S. 208, 216 (2014). We apply the Supreme Court’s two-
step framework to determine patent eligibility. See id. at
217. First, we determine whether the claims are directed
to a “patent-ineligible concept,” such as an abstract idea.
Id. If they are, we examine “the elements of [each] claim
to determine whether it contains an ‘inventive concept’ suf-
ficient to ‘transform’ the claimed abstract idea into a
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patent-eligible application.” Id. at 221 (quoting Mayo Col-
laborative Servs. v. Prometheus Labs., Inc., 566 U.S. 66, 72,
79–80 (2012)).
I
At Alice step one, we determine whether the claims are
directed to an abstract idea. Alice, 573 U.S. at 217. In
cases involving software, step one often “turns on whether
the claims focus on specific asserted improvements in com-
puter capabilities or instead on a process or system that
qualifies [as] an abstract idea for which computers are in-
voked merely as a tool.” Uniloc USA, Inc. v. LG Elecs. USA,
Inc., 957 F.3d 1303, 1306–07 (Fed. Cir. 2020) (citing Cus-
tomedia Techs., LLC v. Dish Network Corp., 951 F.3d 1359,
1364 (Fed. Cir. 2020)). “We have routinely held software
claims patent eligible under Alice step one when they are
directed to improvements to the functionality of a computer
or network platform itself.” Id. at 1307 (collecting cases).
Here, claim 5 is directed to a patent-eligible improve-
ment to computer functionality, namely permitting addi-
tional multislot configurations for certain classes of mobile
stations using extended bandwidth allocation. See ’413 pa-
tent at 2:36–53; 4:5–19. It adds this capability through us-
ing a shifted USF that breaks the fixed relationship in the
timing of downlink allocation signaling (i.e., receipt of a
USF on a timeslot) and subsequent uplink transmission.
First, a mobile station receives two assignments for PDCHs
and then monitors them to detect a shifted USF. If a
shifted USF operation is used, then the mobile station
monitors the second assigned PDCH to “detect the USF
corresponding to the first assigned PDCH and a USF cor-
responding to the second assigned PDCH,” and transmits
on both PDCHs accordingly. The specification shows how
using the shifted USF, as in Figure 4, allows a mobile sta-
tion to utilize the otherwise impermissible configuration of
Figure 3 because the mobile station has sufficient
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turnaround time to switch from a receive condition to a
transmit condition.
See ’413 patent at 4:1–19. And this newly allowed multislot
configuration provides an additional uplink slot compared
to the configuration of Figure 2. Id. at 3:61–67. The
claimed invention, therefore, improves communication ca-
pabilities in certain mobile stations using extended band-
width allocation. Like the claims we held patent eligible in
DDR Holdings, LLC v. Hotels.com, L.P., claim 5 improves
the normal operation of the communication system itself to
“overcome a problem specifically arising in the realm of
computer networks.” 773 F.3d 1245, 1257 (Fed. Cir. 2014).
We reject the district court’s holding and Appellees’ po-
sition that claim 5 does not recite “when, how, or why one
would . . . shift the USF or how a shifted USF would spe-
cifically improve the functioning of a prior art system.” See
J.A. 7; Appellees’ Br. 12. The claim does not merely recite
generalized steps to be performed on a computer. Nor does
it recite data manipulation on a generic computer as Ap-
pellees argue. Appellees’ Br. 12. Claim 5 recites a partic-
ular method of breaking the fixed relationship between the
timing of a downlink USF and subsequent uplink trans-
mission: the mobile station receives an assignment of two
distinct PDCHs, and, if the shifted USF operation is used,
it monitors the second PDCH for USFs corresponding to
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the first and second PDCH and transmits on those PDCHs
accordingly.
The specification also provides important details on the
technological problem and how the claimed invention
solves that problem. The specification is of particular im-
portance here, as “shifted USF” appears to be a coined term
by the inventor.1 See Intervet Inc. v. Merial Ltd., 617 F.3d
1282, 1287 (Fed. Cir. 2010) (“[T]erms coined by the inven-
tor are best understood by reference to the specification.”
(citing Phillips v. AWH Corp., 415 F.3d 1303, 1315 (Fed.
Cir. 2005) (en banc)). Figure 2 provides a prior art “steady
state single downlink and 4 uplink slot allocation” in which
there is a fixed relationship between a downlink in which
the USF is received and transmission availability on the
corresponding uplink slot. Id. at Fig. 2; 1:50–2:5; 3:61–67.
Figure 3 shows how the prior art’s use of a USF does not
permit a 5 uplink slot allocation due to constraints in
switching a mobile station from a transmitting configura-
tion to a receiving configuration. Id. at 3:1–4. Accordingly,
as the patent explains, there was a need to reduce re-
strictions with minimal effect on the existing system to en-
able desirable multislot configurations. Id. at 2:32–46.
Figure 4 permits the 5 uplink slot allocation through
altering the fixed timing relationship of the prior art Fig-
ure 3 system. It has the network send USFs for both the
first and second uplink slots in the second downlink slot.
Through using a shifted USF, a mobile station is able to
utilize a desirable and previously restricted multislot con-
figurations. Figure 7 depicts a detailed flow chart of how a
mobile station may implement the shifted USF in a mobile
station:
1 Appellees do not contest that shifted USF is a
coined term.
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As shown, the mobile station receives assignment infor-
mation relating to the first and second downlink and up-
link slots (i.e., assignments for the first two PDCHs), and,
if a shifted USF is to be used, monitors the second downlink
slot for the first and second USF, and utilizes the uplink
slots accordingly. Thus, the specification shows how the
elements of claim 5 work together to solve a technological
problem in network communication.
To the extent either the Appellees or the district court
believe claim 5 must expressly mention the additional
timeslots available or enabled by this achievement, they
are mistaken. “Claims need not articulate the advantages
of the claimed combinations to be eligible.” Uniloc, 957
F.3d at 1309.
This case is nothing like the claims we held ineligible
in Two-Way Media Ltd. v. Comcast Cable Communications,
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LLC, 874 F.3d 1329 (Fed. Cir. 2017). There, the claims re-
cited a method of transmitting packets of information over
a communications network comprising: converting infor-
mation into streams of digital packets; routing the streams
to users; controlling the routing; and monitoring the recep-
tion of packets by the users. Id. at 1334. We held the
claims ineligible because they merely recited a series of ab-
stract steps (“converting,” “routing,” “controlling,” “moni-
toring,” and “accumulating records”) using “result-based
functional language” without the means for achieving any
purported technological improvement. Id. at 1337. Here,
there is no functional claiming, nor are there abstract
steps.
Instead, the claims here are like those in Packet Intel-
ligence LLC v. NetScout Sys., Inc., 965 F.3d 1299 (Fed. Cir.
2020). In that case, the claim presented a solution to a
“challenge unique to computer networks, identifying dis-
jointed connection flows in a network environment,” and
provided detail on how the solution was “achieved in sev-
eral steps.” Id. at 1309. To inform our understanding of
the claimed invention and the technological solution, we
relied on the specification which made it clear that “known
network monitors were unable to identify disjointed con-
nection flows to each other,” and that the focus of the
claims was “a more granular, nuanced, and useful classifi-
cation of network traffic.” Id. at 1309–10. We also relied
on the specification to inform our understanding of how the
elements in the claim functioned together to provide that
“granular, nuanced, and useful classification of network
traffic, rather than an abstract result.” Id. at 1310.
Like the claim in Packet Intelligence, claim 5 purports
to solve a challenge unique to computer networks, or, more
specifically, certain mobile stations using extended band-
width allocation in a network: reducing restrictions to ena-
ble additional multislot configurations. It increases the
rate of data transmission by enabling the use of timeslots
for transmission that were not previously available.
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Likewise, the specification informs our understanding of
the claimed invention, the technological solution, and how
the elements of the claim work together to provide that so-
lution. The specification explains the restrictions on mo-
bile stations and how use of a shifted USF permits these
configurations. Further, the specification through at least
Figure 7 shows how the elements of claim 5, including re-
ceiving and monitoring information in two separate
PDCHs, function together to provide that inventive solu-
tion. Accordingly, we hold that claim 5 is directed to pa-
tent-eligible subject matter.
The district court held that claim 5 was directed to the
abstract idea of “receiving a USF and transmitting data
during the appropriate timeslots.” J.A. 7 We do not agree.
The district court’s formulation of the abstract idea ap-
pears to be a high-level description of how USFs operate in
mobile stations using extended bandwidth allocation gen-
erally. See ’413 patent at 1:67–2:8. However, the claimed
invention departs from this conventional use through a
shifted USF, which breaks the fixed relationship between
USFs in a downlink slot and the availability for transmis-
sion in the corresponding uplink slot. The district court’s
abstract idea fails to mention a shifted USF, nor does it
capture the receipt of two PDCH assignments that permit
monitoring and detecting the PDCHs for a shifted USF and
transmission based thereon. Accordingly, it is untethered
to the invention as claimed. Because we hold the claims
patent eligible under Alice step one, we need not proceed to
the second step of Alice. Uniloc, 957 F.3d at 1309.
CONCLUSION
Because we hold claim 5 is directed to patent-eligible
subject matter, we reverse the district court’s judgment
and its dismissal of Mentone’s infringement claims.
REVERSED
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COSTS
Costs to Mentone.
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