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Strengthen Software Claims Against Alice Challenges through Coined Terms and Depicting Technical Advantages in Figures

The Federal Circuit recently provided strategic guidance for defending software claims against Alice challenges that claims recite ineligible patent subject matter under 35 U.S.C. § 101. In Mentone Solutions LLC v. Digi International Inc., defendants alleged that representative claim 5 of U.S. Patent No. 6,952,413, directed towards allocating data channels using shifted uplink status flags in cellular mobile stations, claimed only an abstract idea. The District Court agreed and dismissed. On appeal, the Federal Circuit reversed, holding that claim 5 is not directed to an abstract idea because the claim improved the functionality of a computer.

Guidance Based on the CAFC Decision

The Mentone decision, while non-precedential, provides further insight into how to overcome § 101 challenges, such as using coined terms by the inventor in the claim language, depicting the technical deficiencies in the figures, depicting the technical advantages in the figures, and reciting specific claim language that captures the technical advantages of the specific technical problem. Once the patent application’s specification has been drafted and submitted, long before litigation commences, the strategies can no longer be implemented. Practitioners should therefore be mindful while drafting the specification to address these areas that may build in natural Alice immunity, thereby enhancing the value of the patent assets.

The Patent-Eligible Claim of U.S. Patent No. 6,952,413

The claim at issue provided a series of method steps related to allocating resources on packet data channels:

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 corresponding to the USF,

wherein (i) if shifted USF operation is not used then a first assigned PDCH is monitored to detect a USF corresponding to the first assigned PDCH and (ii) if the shifted USF operation is used then a second assigned PDCH is monitored to detect the USF corresponding to the first assigned PDCH and a USF corresponding to the second assigned PDCH.

The claim covers a method for cellular mobile stations. The cellular mobile stations can have packet data channels (PDCHs) for downlink and uplink operations between cell phones and a network. The mobile stations can allocate a PDCH to be used for downlink and uplink operations. Downlink operations include receiving information from the network and uplink operations include transmitting information to the network.

Uplink status flags can indicate whether a packet data channel is to switch from receiving information from a network (e.g., downlink operations) to transferring information to a network (e.g., uplink operations) via an assignment. But sometimes the turn-around time and the fixed timing relationship between the downlink signaling and the subsequent uplink operation means that the assignment cannot be carried out. The inability to assign a PDCH for uplink operations reduces the availability of uplink operations, thereby reducing the flow of data and flexibility of response to changing conditions.

The claim utilizes shifted uplink status flags (“shifted USFs”) to control access to the PDCHs. The shifted USFs overcome the limitations of USFs by altering the fixed timing relationship of the downlink signaling and enabling the mobile station to switch to uplink operations given the turn-around time.

Claim 5 is Not Directed to an Abstract Idea – Court Reasoning and Analysis

The Federal Circuit rejected the view that the claim was simply the abstract idea of “receiving an uplink status flag and transmitting data during the appropriate timeslots.” Instead, the Federal Circuit found the patent improved computers, specifically mobile devices, by claiming USFs that broke the fixed timing relationship between the receipt of the USF during a downlink operation and the subsequent uplink operations. These improvements addressed the data-network problem triggered by the fixed relationship between USFs in a downlink slot and the availability for transmission in the corresponding uplink slot. As established precedent shows, improving existing computer systems demonstrates that an idea is not a patent ineligible abstract idea.

The Court relied on several features of the claim language and specification to establish claim 5 as patent eligible under § 101. First, the claim recited “shifted USF,” which was a term coined by the inventor. Second, the claim recited specific capabilities such as monitoring, in response to detecting a shifted USF operation, a second assigned PDCH to “detect the USF corresponding to the first assigned PDCH and a USF corresponding to the second assigned PDCH” and transmitting on both PDCHs accordingly. Third, claim 5 improved existing systems by breaking the fixed relationship in the timing of downlink allocation signaling (i.e., receipt of a USF on a timeslot) and subsequent uplink transmission. Finally, the specification showed an example of the deficiency in the prior art (such as the impermissible configuration of Figure 3) and proposed a solution: a new configuration using a shifted USF that enables the mobile station sufficient turn-around time to switch from downlink operations to uplink operations.

The Federal Circuit’s reversal of the District Court also relied on the technical problems and technical advantages presented in the figures of the challenged patent. More specifically, the figures depicted the limitations of the prior art and how the fixed timing relationship made some uplink configurations unavailable. For example, Figures 2 and 3 detail the limitations of a USF due to slot allocation constraints related to the fixed timing relationship. Additionally, the figures show how the technical improvement of the shifted USFs overcome the specific problem related to the fixed timing relationship. For example, Figures 4 and 5 show the mobile stations monitoring the 2nd downlink slot for the shifted USF instead of the 1st downlink slot for the first USF. Further, Figure 7 shows how the elements of claim 5, including receiving and monitoring information in two separate PDCHs, function together to provide that inventive solution. The technical advantages articulated by the figures demonstrate that claim 5 is not abstract by eliminating restrictions to mobile station configurations.


The decision provides direction regarding techniques patent practitioners can employ to refute arguments that unfairly reduce software claims to a mere abstract idea ineligible under § 101. Patent drafters may benefit from depicting justifications (where possible) using diagrams of the claimed advantages over the prior art. Litigants can later point to these figures depicting the technical problems and technical solutions to overcome Alice and support a conclusion of patent eligible claims. In addition, the patent drafters may include discussions of: (1) coined terms used in the claims that address the problems identified in the specification, (2) how the invention improves on prior art, and (3) the figures that depict the specific steps to carry out the technical advantages.

©1994-2022 Mintz, Levin, Cohn, Ferris, Glovsky and Popeo, P.C. All Rights Reserved.National Law Review, Volume XII, Number 31

About this Author

Daniel B. Weinger Patent Litigation Attorney Mintz Law Firm

Daniel's practice in intellectual property focuses on patent litigation, both at the International Trade Commission and the Federal District Courts. Daniel has participated in all phases of patent litigation, including active engagement in multiple evidentiary hearings at the International Trade Commission. He has done work in a variety of technology areas, including computer software, software architecture, GPS, network devices, semiconductors, converged devices, and LED lighting.

Prior to joining Mintz Levin, Daniel worked as a database...

Mark D. Hammond Intellectual Property Attorney Mintz, Levin, Cohn, Ferris, Glovsky and Popeo San Diego, CA

Mark is an intellectual property attorney and registered patent agent with a background in engineering. He focuses his practice on patent prosecution, patent office proceedings, and patent litigation support. He works primarily with clients in the semiconductors, electronics, software, and medical devices industries.

Prior to joining Mintz, Mark worked as an associate in the San Diego office of a Seattle-based international law firm. He also worked as a summer associate with intellectual property law firms in Houston and Salt Lake City and served as a summer intern in the Madrid...