By: Mark Magas

Mentone Sols. LLC v. Digi Int’l Inc. provides patent owners with additional guidance on the pendulum swinging away from the widespread, successful challenges to validity, which sprung from Alice and its progeny. [1]. In Mentone, the U.S. Court of Appeals for the Federal Circuit reversed a decision by Judge Stark from the District of Delaware that found claims of U.S. Patent No. 6,952,413 (the “’413 Patent”) invalid under 35 U.S.C. § 101. [2]

The Technology

The ’413 Patent relates to dynamic resource allocation in mobile communication systems. In prior art systems, mobile stations, such as cell phones, may communicate with a network through Packet Data Channels (PDCHs) having uplink and downlink slots for sending and receiving information, respectively. This is shown below in Figure 2 of the ’413 Patent. An uplink status flag (USF) sent by the network to a mobile station indicates that the mobile station may send information to the network in predetermined future timeslots (the striped boxes). However, the prior art systems had various limitations. (1) New USFs could not be received in a timeslot directly after transmitting information because changing from transmitting to receiving takes some amount of changeover time, and (2) USFs received in a particular download timeslot required data to be sent in a corresponding upload timeslot. These limitations caused certain multislot configurations to be impermissible, reducing the amount of bandwidth that could be used.

The ’413 Patent enables additional multislot configurations by using shifted USFs. As shown below in Figure 4, the invention teaches shifting the USF to other timeslots to allow for changeover time and removes the requirement that the downlink timeslot the USF is received in must correspond to the uplink timeslot information is sent. This allows for additional multislot configurations that were previously impermissible. [3] In layman’s terms, this technology improves how cell phones communicate with cell towers by using more available bandwidth.

The Law

Alice Corp. Pty. Ltd. v. CLS Bank Int’l established a two-step test for determining patent eligibility under § 101. Under step one, “the Court must first determine whether the claims at issue are directed to a patent-ineligible concept.” If so, the Court must proceed to step two, where the Court “asks whether the claim’s elements, considered both individually and as an ordered combination, transform the nature of the claim into a patent-eligible application.” [4] A number of cases following Alice have applied the two-step test. Uniloc USA, Inc. v. LG Elecs. USA, Inc. and McRO, Inc. v. Bandai Namco Games Am. Inc., for example, set forth that in software cases, claims that cover specific technological improvements over conventional practices are eligible under step one of the test, as compared to claims that merely automate existing practices on a computer. [5]

The Court’s Decision

The Federal Circuit Court in Mentone applied the two-step test from Alice, holding the claims of the ’413 Patent to be patent-eligible under step one. [6] Continuing the trend of Uniloc and McRO towards a narrower application of Alice, the Court found that the claims were directed to a patent-eligible improvement in computer functionality. [7] The Court reasoned that the claims recite a specific technological improvement for “breaking the fixed relationship between the timing of a downlink USF and subsequent uplink transmission.” [8]

In support, the Court credited the specification as providing “important details on the technological problem and how the claimed invention solves that problem.” [9] The Court pointed to specific disclosure in the specification about the need to reduce restrictions in multislot configurations.[10] The Court also pointed to various figures and text in the specification that explain how the claim elements “work together to solve” the technological problem by shifting the USF. [11]

The Court contrasted claims of the ’413 Patent with claims held ineligible in other cases under step one of Alice, which merely used abstract steps (e.g., converting, routing, controlling, etc.) and results-based functional language without the means for achieving any technological improvement. [12] The Court disagreed with Judge Stark’s analysis, which considered the invention at too high of a level and failed to consider the technological improvements, and ultimately held the ’413 Patent to be patent-eligible under step one. [13]

Key Takeaway

The Mentone decision demonstrates the importance of including specific factual details in the patent specification about the technological problem an invention addresses in addition to solutions to the problem. At some level of abstraction, all computer-implemented inventions can be reduced to abstract steps, such as converting, routing, or controlling data. Pointing to specific evidence in the specification about the technological problem and how the patent solves the problem helps prove that an invention is more than just abstract steps. In litigation, these advances and details should be pled in the complaint and identified during discovery, either in initial disclosures, responses to interrogatories, or in any required disclosures under local patent rules.

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[1] Alice Corp. Pty. Ltd. v. CLS Bank Int’l, 573 U.S. 208, 208-09 (2014).

[2] Mentone Sols. LLC v. Digi Int’l Inc., Nos. 2021-1202, 2021-1203, 2021 U.S. App. LEXIS 33793, at *1 (Fed. Cir. Nov. 15, 2021).

[3] U.S. Patent No. 6,952,413.

[4] Alice, 573 U.S. at 208-09.

[5] Uniloc USA, Inc. v. LG Elecs. USA, Inc., 957 F.3d 1303, 1306-07 (Fed. Cir. 2020) (clarifying that in software cases, step one “often turns on whether the claims focus on specific asserted improvements in computer capabilities or instead on a process or system that qualifies an abstract idea for which computers are invoked merely as a tool”); McRO, Inc. v. Bandai Namco Games Am. Inc., 837 F.3d 1299, 1312-13 (Fed. Cir. 2016) (finding claims directed to “technological improvement over the existing, manual 3-D animation techniques” patentable).

[6] Mentone Sols. LLC v. Digi Int’l Inc., Nos. 2021-1202, 2021-1203, 2021 U.S. App. LEXIS 33793, at *15.

[7] Id. at *8.

[8] Id. at *10.

[9] Id.

[10] Id. at *11.

[11] Id. at *12.

[12] Id.

[13] Id. at *14-15.


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Posted in: Intellectual Property - Patents

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