Mobility Workx LLC v. Microsoft Corp

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Mobility Workx, LLC (Florida)
  • Defendant: Microsoft Corporation (Delaware)
  • Plaintiff’s Counsel: Machat & Associates, PC; Zeisler PLLC
• Case Identification: 4:25-cv-01367, E.D. Tex., 12/09/2025
• Venue Allegations: Plaintiff alleges venue is proper in the Eastern District of Texas based on Defendant’s operation of regular and established places of business, specifically identifying three retail store locations in Plano, Frisco, and Lewisville.
• Core Dispute: Plaintiff alleges that certain unidentified Microsoft products and services related to wireless network handoffs infringe two patents concerning the proactive allocation of communication resources for mobile devices.
• Technical Context: The technology at issue addresses methods for minimizing latency and data loss when a mobile device transitions between different wireless network access points, a foundational challenge for ensuring seamless mobile connectivity.
• Key Procedural History: The complaint notes that U.S. Patent No. 8,213,417 was subject to an Inter Partes Review (IPR), after which asserted claims 3 and 6 were found to remain valid and enforceable. The provided IPR certificate confirms this outcome and further specifies that independent claim 1, from which claims 3 and 6 depend, was cancelled. This procedural history suggests that the asserted dependent claims were likely amended into independent form during the IPR, a factor that will be central to claim construction and infringement analysis for this patent.

Case Timeline

Date	Event
2003-07-31	Priority Date for ’508 and ’417 Patents
2010-04-13	U.S. Patent No. 7,697,508 Issues
2012-07-03	U.S. Patent No. 8,213,417 Issues
2025-12-09	Complaint Filed

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

U.S. Patent No. 7,697,508 - "System, Apparatus, and Methods for Proactive Allocation of Wireless Communication Resources" (Issued Apr. 13, 2010)

The Invention Explained

• Problem Addressed: The patent addresses the "registration delays and associated information losses" that occur when a mobile device moves between the coverage areas of different wireless access points (termed "foreign agents") (Compl. ¶2; ’508 Patent, col. 2:20-22). Conventional systems typically initiate the handoff process only after the mobile device has arrived in the new coverage area, which can cause service interruptions and dropped data packets, particularly for fast-moving devices (’508 Patent, col. 2:25-35).
• The Patented Solution: The invention proposes a "preemptive and predictive solution" that uses two novel software constructs: a "ghost-mobile node" and a "ghost-foreign agent" (’508 Patent, col. 2:42-43). The ghost-mobile node predicts the mobile device’s future location and pre-registers it with the next foreign agent before the device physically enters that agent's coverage area (’508 Patent, col. 2:58-62). Concurrently, a ghost-foreign agent, operating from a neighboring access point, advertises the upcoming foreign agent’s presence to the mobile device, making the device aware of the next connection point in advance (’508 Patent, col. 3:1-6; Fig. 2A). This proactive allocation of network resources is designed to make handoffs seamless.
• Technical Importance: This approach sought to enhance the performance and reliability of mobile communications by minimizing handoff latency, which was a significant technical barrier to providing continuous, high-quality data services for mobile users (’508 Patent, col. 2:50-53).

Key Claims at a Glance

• The complaint asserts independent claim 14 and dependent claim 7 (Compl. ¶11).
• The essential elements of independent claim 14 include:
  • A method for handling mobile devices in a network, comprising steps of:
  • Determining a mobile node's current geographical state;
  • Predicting a future geographical state of the mobile node based on GPS data from a linked GPS unit;
  • Identifying a foreign agent corresponding to that future state;
  • Creating a "ghost foreign agent" that can announce the presence of the identified foreign agent;
  • Registering the mobile node (or a "ghost mobile node") with the foreign agent while the mobile node is still in its current location; and
  • Linking the mobile node with that foreign agent when it enters the future geographical state.
• The complaint reserves the right to assert additional claims (’508 Patent, claim 14; Compl. ¶11).

U.S. Patent No. 8,213,417 - "System, Apparatus, and Methods for Proactive Allocation of Wireless Communication Resources" (Issued Jul. 3, 2012)

The Invention Explained

• Problem Addressed: As a continuation of the application leading to the ’508 Patent, the ’417 Patent shares the same specification and addresses the identical technical problem of latency and data loss during mobile network handoffs (Compl. ¶3; ’417 Patent, col. 2:20-39).
• The Patented Solution: The patented solution is likewise a system for preemptive handoff management using a "ghost-mobile node" to predict movement and pre-register the device with an upcoming "foreign agent," and a "ghost-foreign agent" to provide advance notification of network topology (’417 Patent, col. 2:41-58).
• Technical Importance: The technology aimed to provide more robust and uninterrupted mobile data services, a key enabler for the expanding ecosystem of mobile applications and devices (’417 Patent, col. 2:50-53).

Key Claims at a Glance

• The complaint asserts claims 3 and 6, which survived an Inter Partes Review where the original independent claim 1 was cancelled (Compl. ¶19, ¶20). Assuming these claims were rewritten in independent form during the IPR, their essential elements combine the limitations of original claim 1 with their own.
• The essential elements of effective independent claim 3 include:
  • A system using proxy mobile IP comprising a mobile node, home agent, foreign agent, a "ghost-foreign agent" for advance advertisement, and a "ghost-mobile node" for predictive signaling;
  • Wherein the signaling triggers allocation of resources via a tunnel or network communication based on the mobile node reaching a "threshold distance" to a foreign agent, with the distance being based on a "projected trajectory and a speed."
• The essential elements of effective independent claim 6 include:
  • A system with the same components as claim 3;
  • Wherein the "ghost-foreign agent populates mobile IP Advertisement messages with at least one care-of-address of neighboring foreign agents" to extend their effective range.
• The complaint reserves the right to assert additional claims (’417 Patent, claims 1, 3, 6; Compl. ¶20).

III. The Accused Instrumentality

Product Identification

• The complaint refers generally to "Accused Handover Products/Services" without identifying any specific Microsoft product, software, or service by name (Compl. ¶11, ¶20).

Functionality and Market Context

• The complaint does not provide sufficient detail for analysis of the technical functionality or market context of the accused instrumentalities. It alleges only that Microsoft makes, uses, and sells products and services, offered via its website, that infringe the patents-in-suit (Compl. ¶5, ¶11). No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint references preliminary infringement claim charts (Exhibits 2 and 4) that were not provided with the publicly filed document (Compl. ¶11, ¶20). In their absence, the infringement theory is summarized from the complaint’s narrative allegations.

The complaint alleges that Microsoft's "Accused Handover Products/Services" infringe the asserted claims of the ’508 and ’417 patents, either literally or under the doctrine of equivalents (Compl. ¶11, ¶20). However, the complaint does not contain factual allegations describing how any specific feature or function of a Microsoft product or service meets the limitations of the asserted claims. The allegations remain conclusory and tied to the generic "Accused Handover Products/Services" category.

• Identified Points of Contention:
  • Evidentiary Questions: A threshold issue for discovery will be for Plaintiff to identify the specific Microsoft products or services at issue. Further, what evidence does the complaint provide that these products perform the functions required by the claims, such as creating "ghost foreign agents" or "predicting... future states" based on GPS data? The complaint itself provides no such evidence.
  • Architectural Questions: Does any accused Microsoft technology for managing network handoffs operate according to the specific "ghost entity" architecture described and claimed in the patents, or does it utilize fundamentally different, non-infringing methods (e.g., standardized reactive protocols)?

V. Key Claim Terms for Construction

• The Term: "ghost-mobile node"

  • Context and Importance: This term, apparently coined by the inventors, is foundational to the claimed proactive handoff mechanism. Its construction will determine whether an accused system must contain a discrete, identifiable component performing the predictive and registration functions, or if these functions can be met by a more distributed or integrated software architecture.
  • Intrinsic Evidence for a Broader Interpretation: The specification suggests this can be a "virtual node" and a "set of software instructions running on a device that is remote from the mobile node," which may support a construction not tied to a specific physical location or hardware component (’508 Patent, col. 6:21-26).
  • Intrinsic Evidence for a Narrower Interpretation: Figure 2A depicts the "Ghost Mobile Node" as a distinct block within the same logical entity as the "Mobile Node." The specification also describes a "wireless node pair" as including "a ghost-mobile node... in addition to the mobile node," which may support a narrower construction requiring a more discrete or closely associated component (’508 Patent, col. 5:22-24, Fig. 2A).

• The Term: "predicting... based upon Global Positioning System (GPS) data" (’508 Patent, claim 14)

  • Context and Importance: This limitation in claim 14 of the ’508 Patent ties the predictive element to a specific data source. The scope of this term will be critical in determining whether modern location-awareness technologies that do not rely solely on direct GPS input (e.g., Wi-Fi triangulation, cellular network positioning, cached location data) fall within the claim's scope.
  • Intrinsic Evidence for a Broader Interpretation: The specification mentions that "other systems for determining location information can be used" and that foreign agents could "triangulate the position of the mobile node... using signal strength," which could support an argument that "based upon" does not require exclusive or direct use of GPS data (’508 Patent, col. 6:60-67).
  • Intrinsic Evidence for a Narrower Interpretation: The claim language is specific, requiring prediction "based upon Global Positioning System (GPS) data obtained from a GPS unit communicatively linked to the mobile node." This explicit recitation of a "GPS unit" may support a narrower construction limited to systems that directly process data from such a unit (’508 Patent, claim 14).

VI. Other Allegations

• Indirect Infringement: The complaint alleges both induced and contributory infringement. Inducement is based on allegations that Microsoft "actively encourage[s] users" to use the accused services in an infringing manner (Compl. ¶12, ¶21). Contributory infringement is based on the allegation that the accused products "have no substantial non-infringing uses" (Compl. ¶14, ¶22).
• Willful Infringement: Willfulness is alleged based on infringement occurring after Defendant gained knowledge of the patents, with the complaint asserting that knowledge was established at the latest by the filing and service of the complaint itself (Compl. ¶15, ¶23). This framing suggests a primary reliance on post-suit conduct to establish willfulness.

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

1. The Identification Question: The case's initial and most significant hurdle is the complaint's failure to identify any accused product. The central question for the early stages of litigation will be: can Plaintiff connect its infringement allegations to specific, concrete functionalities within Microsoft’s vast ecosystem of operating systems, cloud services, and communication platforms, or will the claims fail for lack of specificity?
2. The Architectural Equivalence Question: A core technical dispute will be whether Microsoft's technology for managing network transitions, once identified, maps onto the specific "ghost-mobile node" and "ghost-foreign agent" architecture claimed in the patents. The case may turn on whether the accused system employs a "predictive" and "proactive" registration model as claimed, or if it relies on fundamentally distinct handoff mechanisms.
3. The IPR Estoppel and Claim Scope Question: For the ’417 Patent, a key legal and technical question will be the interpretation of claims 3 and 6 in light of the IPR proceeding that cancelled their parent independent claim. The analysis will focus on construing these narrower, surviving claims and determining if the accused system infringes their more specific limitations related to "threshold distance" triggers and the populating of "IP Advertisement messages."