Missed Call LLC v. Sangoma US Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Missed Call, LLC (Texas)
  • Defendant: Sangoma US, Inc. (Delaware)
  • Plaintiff’s Counsel: David J. Hoffman
• Case Identification: 1:25-cv-00467, W.D.N.Y., 05/30/2025
• Venue Allegations: Plaintiff alleges venue is proper because Defendant has a regular and established place of business in the district and has committed acts of infringement there.
• Core Dispute: Plaintiff alleges that Defendant’s telecommunication systems and services infringe a patent related to methods for providing a user with an indication about the reason for a missed telephone call.
• Technical Context: The technology concerns telecommunication systems that can distinguish between a missed call terminated by the caller versus one terminated by a network timeout, and then convey the urgency of the call to the end-user.
• Key Procedural History: Plaintiff states it is a non-practicing entity and that it and its predecessors have entered into settlement licenses with other entities, which it argues do not trigger marking requirements under 35 U.S.C. § 287(a).

Case Timeline

Date	Event
2010-07-21	’872 Patent Priority Date (PCT)
2016-12-27	’872 Patent Issue Date
2025-05-30	Complaint Filing Date

II. Technology and Patent(s)-in-Suit Analysis

U.S. Patent No. 9,531,872 - "Communication Apparatus For Providing An Indication About A Missed Call, And Method Thereof"

• Patent Identification: U.S. Patent No. 9,531,872, "Communication Apparatus For Providing An Indication About A Missed Call, And Method Thereof," issued December 27, 2016.

The Invention Explained

• Problem Addressed: The patent’s background section notes that prior art systems could not provide a reliable indication of why a missed call was disconnected (e.g., whether the caller hung up or the network timed out), preventing the user from recognizing the call's potential importance or urgency (’872 Patent, col. 5:11-18).
• The Patented Solution: The invention is a communication apparatus (e.g., a phone) that, upon receiving a missed call, extracts a specific "cause value" from a "cause information element" sent by the telecommunications network. This value explicitly states whether the call was terminated by the caller or the network, allowing the apparatus to provide the user with a corresponding indication of urgency (’872 Patent, Abstract; col. 6:10-16). Figure 2 illustrates the logic of receiving the call, extracting the cause value, and outputting an indication of urgency (e.g., "urgent" if network-terminated, "not urgent" if caller-terminated).
• Technical Importance: This approach aimed to add a layer of intelligence to missed call notifications by leveraging standardized network signaling data that was previously used primarily by network operators for statistical analysis (’872 Patent, col. 6:7-9).

Key Claims at a Glance

• The complaint asserts claims 1-13 (’872 Patent, col. 7:24-8:50; Compl. ¶10).
• Independent Claim 1, a system claim, recites the following essential elements:
  • "receiving means" for receiving an incoming call;
  • a "control unit" to process the call;
  • "output means" for user-facing information;
  • "processing means" for extracting a "cause value" from a "cause information element" sent by a network and outputting an indication related to the missed call;
  • Wherein if a "caller ends the... call", the "cause value" indicates this, and the apparatus outputs an indication that the call was "caused by the caller";
  • Wherein if the "network automatically ends the... call", the "cause value" indicates this, and the apparatus outputs an indication that the call was "caused by the network and was urgent".

III. The Accused Instrumentality

Product Identification

• The complaint does not name specific accused products. It broadly accuses "systems, products, and services that facilitate providing of an indication of a missed telephone call" that are maintained, operated, and administered by Defendant Sangoma US, Inc. (Compl. ¶10).

Functionality and Market Context

• The complaint does not describe the specific functionality of any accused product. It alleges in general terms that Defendant’s products and services perform infringing methods and directs the court to Defendant's general corporate website (Compl. ¶4, ¶12). No probative visual evidence provided in complaint. The complaint does not provide sufficient detail for analysis of the accused instrumentality's specific operation or market context.

IV. Analysis of Infringement Allegations

The complaint alleges that Defendant’s products and services infringe claims 1-13 of the ’872 patent (Compl. ¶10). It states that support for these allegations "may be found in the exemplary table included as Exhibit A" (Compl. ¶11). However, Exhibit A was not filed with the complaint. As a result, the complaint provides only a conclusory narrative of infringement without mapping specific features of any accused product to the limitations of the asserted claims.

• Identified Points of Contention:
  • Pleading Sufficiency: A primary issue may be whether the complaint’s infringement allegations, which rely on a missing exhibit, meet the plausibility standard required by Federal Rule of Civil Procedure 8(a) as interpreted by Bell Atl. Corp. v. Twombly and Ashcroft v. Iqbal.
  • Technical Questions: A central factual question for the case will be whether Defendant’s systems actually receive and process a "cause information element" from a network to determine the reason for a missed call, as required by claim 1 of the '872 Patent.

V. Key Claim Terms for Construction

• The Term: "processing means for extracting a cause value..." and other "means-plus-function" terms (e.g., "receiving means", "output means").

• Context and Importance: Claim 1 is written in means-plus-function format under 35 U.S.C. § 112(f). The scope of these limitations is not their literal functional language but is instead restricted to the specific structures, materials, or acts described in the specification that perform the function, and their equivalents. The construction of these terms, particularly the "processing means," will be foundational to the infringement analysis.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The parties might dispute the full range of equivalents for the disclosed structures.
  • Evidence for a Narrower Interpretation: The specification links the "processing means" to "processing means 40 associated to said control unit 20" (’872 Patent, col. 6:42-44, Fig. 1). The function performed by this structure is the specific algorithm detailed in the specification and illustrated in the flowchart of Figure 2, including the steps of verifying the cause value and outputting an urgency indication (’872 Patent, col. 7:1-56, Fig. 2). This provides a concrete but potentially limiting definition of the corresponding structure and its function.

• The Term: "cause value"

• Context and Importance: This term is the core technical concept of the invention. The infringement analysis will depend on whether the data allegedly used by Defendant's systems constitutes a "cause value" as contemplated by the patent. Practitioners may focus on this term because its definition could either confine the claim to specific telecommunication standards or allow it to cover a broader range of functionally similar data.

• Intrinsic Evidence for Interpretation:

  • Evidence for a Broader Interpretation: The claim language itself is general, referring to a "cause value contained in a cause information element sent from a network" (’872 Patent, col. 7:38-40). Plaintiff may argue this covers any data field that communicates the reason for call termination.
  • Evidence for a Narrower Interpretation: The specification gives specific examples of cause values, such as "RECOVERY ON TIME EXPIRY," "NORMAL, UNSPECIFIED," and "NORMAL CLEARING," and ties the invention to established standards like ITU-T Q.931 and 3GPP TS 24.008 (’872 Patent, col. 6:20-22, col. 6:45-46, col. 6:58-64). Defendant may argue that the term should be limited to these specific, standardized codes or their close equivalents.

VI. Other Allegations

• Indirect Infringement: The complaint alleges inducement by asserting that Defendant "actively encouraged or instructed" customers on how to use its systems to infringe, citing Defendant's website (Compl. ¶12). It also alleges contributory infringement with a conclusory statement that there are "no substantial noninfringing uses" for the accused products and services (Compl. ¶13).
• Willful Infringement: The complaint alleges Defendant has known of the ’872 patent "from at least the filing date of the lawsuit," which supports a claim for post-filing willfulness (Compl. ¶12, ¶13). The prayer for relief also seeks a finding of willfulness based on any pre-suit knowledge that may be revealed in discovery (Compl., Prayer for Relief ¶e).

VII. Analyst’s Conclusion: Key Questions for the Case

1. A central procedural question will be one of pleading sufficiency: Does the complaint, which makes general allegations and references a missing exhibit, provide sufficient factual detail to state a plausible claim for relief, or will it be vulnerable to a motion to dismiss?
2. A core issue will be one of claim scope: How will the court construe the "means-plus-function" limitations, particularly the "processing means"? The outcome will depend on identifying the corresponding structure in the specification—likely the control unit and its associated algorithm—and determining the scope of its equivalents.
3. A key evidentiary question will be one of technical mechanism: Does the accused Sangoma technology actually "extract a cause value from a cause information element" sent by a network, as required by the claims, or does it use an alternative method to determine and display the reason for a missed call?