DCT

2:23-cv-00247

Dali Wireless Inc v. T-Mobile US Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 2:23-cv-00247, E.D. Tex., 05/30/2023
  • Venue Allegations: Venue is alleged based on T-Mobile operating wireless networks, maintaining retail stores, and operating R&D facilities within the Eastern District of Texas. For CommScope, venue is based on an allegedly regular and established place of business in Richardson, Texas.
  • Core Dispute: Plaintiff alleges that Defendant T-Mobile's LTE and 5G networks, which use Defendant CommScope's distributed antenna system and small cell products, infringe a patent related to remotely reconfigurable wireless signal distribution.
  • Technical Context: The technology concerns Distributed Antenna Systems (DAS), which are used to extend and improve wireless network coverage and capacity within large structures or campuses by dynamically allocating radio resources.
  • Key Procedural History: The complaint alleges that the Patent Trial and Appeal Board (PTAB) previously denied institution of an inter partes review (IPR) petition challenging the validity of the patent-in-suit. Such a denial can be noted by a court as a factor weighing against a defendant's invalidity defenses.

Case Timeline

Date Event
2010-09-14 U.S. Patent No. 9,820,171 Priority Date
2016-07-22 Date of "Webinar Introduction to ION E" cited in complaint
2017-11-14 U.S. Patent No. 9,820,171 Issue Date
2023-05-30 Complaint Filing Date

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

U.S. Patent No. 9,820,171 - “Remotely Reconfigurable Distributed Antenna System and Methods,” issued November 14, 2017

The Invention Explained

  • Problem Addressed: The patent describes the challenge of designing indoor wireless networks that can efficiently handle fluctuating subscriber loads (’171 Patent, col. 1:26-46). For example, a large number of users may move from their offices to a cafeteria during lunchtime, overwhelming the network resources in that specific area while leaving resources in other areas underutilized (’171 Patent, col. 1:36-46). Traditional "fixed" or manually reconfigured Distributed Antenna Systems (DAS) are inefficient and slow to adapt to these dynamic changes (’171 Patent, col. 2:4-24).
  • The Patented Solution: The invention is a software-defined radio (SDR) based DAS that allows for the remote and dynamic reconfiguration of radio resources (’171 Patent, Abstract). The system comprises a central Digital Access Unit (DAU) connected to multiple Remote Radio Units (RRUs). The DAU digitizes and packetizes wireless signals corresponding to specific carriers. It can then route and switch these packetized signals to different RRUs based on real-time demand, a capability the patent calls "Flexible Simulcast" (’171 Patent, col. 3:9-19; Fig. 1). This allows the system to change the number of carriers assigned to a specific RRU to match shifting user traffic patterns (’171 Patent, col. 6:45-60).
  • Technical Importance: This approach enables a DAS to automatically perform traffic load-balancing, enhancing network efficiency and performance by allocating capacity where it is needed most at any given time (’171 Patent, col. 4:1-9).

Key Claims at a Glance

  • The complaint asserts independent claims 1 (a method) and 15 (a system) (Compl. ¶¶ 35, 56).
  • Independent Claim 1 recites a method with the essential elements of:
    • Providing a plurality of remote radio units (RRUs) and at least one digital access unit (DAU).
    • Translating signals between RF and baseband.
    • Packetizing the signals, where the signals correspond to a plurality of carriers and each RRU is configured for a subset of those carriers.
    • Routing and switching the packetized signals among the RRUs via the DAU.
    • "Reconfiguring" at least one RRU by increasing or decreasing the number of carriers in its subset.
    • "Thereafter", routing and switching the signals according to the result of the reconfiguration.
  • Independent Claim 15 recites a system with the essential elements of:
    • A plurality of RRUs and at least one DAU, where the units are configured to packetize uplink and downlink signals corresponding to a plurality of carriers, with each RRU configured for a respective subset.
    • During a "first time period", each RRU is configured to transmit or receive its respective subset of carriers.
    • During a "second time period", at least one RRU is "reconfigured" to increase or decrease the number of carriers in a first subset and is configured to operate with that reconfigured subset.
  • The complaint does not explicitly reserve the right to assert dependent claims.

III. The Accused Instrumentality

Product Identification

The complaint accuses T-Mobile's LTE and 5G networks that incorporate CommScope's ION®-E/ERA platform and/or CommScope's OneCell product (Compl. ¶2).

Functionality and Market Context

  • ION®-E/ERA Platform: The complaint describes this as a DAS for in-building wireless coverage (Compl. ¶35). It allegedly consists of a Central Area Node (CAN), which functions as a "digital access unit," and a range of "remote access points," which function as "remote radio units" (Compl. ¶¶ 39, 41). The CAN is alleged to digitize RF signals and distribute them to the access points (Compl. ¶37). The system is alleged to allow the creation of "signal sets" (subsets of carriers) that can be sent to specific access points and can "dynamically adjust system resources to maintain efficiency" as user populations move (Compl. ¶¶ 46, 50). A diagram in the complaint illustrates the alleged architecture of the ION-E/ERA system, showing a Central Area Node connected to remote units (Compl. p. 12).
  • OneCell Product: This is described as a small cell solution comprising a "baseband controller" and multiple "Radio Points" (Compl. ¶¶ 56, 62). The baseband controller allegedly performs "baseband processing and scheduling across all Radio Points" (Compl. ¶62). The complaint alleges that this system utilizes a feature called "Cell Virtualization," where the system dynamically allocates physical resource blocks (PRBs) to different users and areas in millisecond intervals (Compl. ¶62, 65).

IV. Analysis of Infringement Allegations

’171 Patent Infringement Allegations (Claim 1 vs. ION-E/ERA)

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
providing a plurality of remote radio units... The networks include CommScope's ION-E/ERA platform, which provides "[a] range of remote access points that convert the digital signal back to radio frequency (RF)." ¶39 col. 12:56-63
providing at least one digital access unit... The ION-E/ERA platform includes a Central Area Node (CAN) that "digitizes baseband RF signals, combines signals from different operators and distributes them throughout a building or campus." ¶41 col. 12:52-55
packetizing the uplink and downlink base band signals, wherein the packetized signals correspond to a plurality of carriers... Signals are packetized for transport over LAN cables. Marketing materials allegedly describe creating "signal sets" from different channels and assigning a signal set to a remote unit (UAP). ¶¶45-46 col. 11:56-64
routing and switching the packetized signals among the plurality of remote radio units via the at least one digital access unit; The CAN is alleged to route and switch packetized signals from the operator's network to the Access Points in the downlink, and from the Access Points to the network in the uplink. ¶48 col. 11:59-62
reconfiguring at least one of the plurality of remote radio unit by increasing or decreasing the number of carriers in the respective subset... The platform allegedly "can dynamically adjust system resources to maintain efficiency" by assigning radio resources to different access points as users move. A screenshot from a marketing video shows how the "system adapts to user movements for example between University classrooms." ¶¶50-52, p. 13 col. 11:3-13
routing and switching the packetized signals... according to a result of the reconfiguring. After reconfiguring as described above, the CAN allegedly continues to route and switch signals based on the new allocation of resources. ¶¶53-54 col. 13:1-4

’171 Patent Infringement Allegations (Claim 15 vs. OneCell)

Claim Element (from Independent Claim 15) Alleged Infringing Functionality Complaint Citation Patent Citation
a plurality of remote radio units; and at least one digital access unit configured to communicate with the plurality of remote radio units... The OneCell system has multiple "[r]adio [p]oints" (RRUs) and a "baseband controller" (DAU) that "perform[s] baseband processing and scheduling across all Radio Points." ¶¶60, 62 col. 14:10-14
wherein the packetized signals correspond to a plurality of carriers, and each of the plurality of remote radio units is configured to receive or transmit a respective subset of the plurality of carriers, The complaint alleges that packetized signals correspond to carriers, and that each remote radio unit is configured for a subset of carriers in the form of physical resource blocks (PRBs). A visual from a product video shows different PRBs being allocated. ¶62, p. 17 col. 14:21-26
wherein during a first time period, each of the plurality of remote radio units is configured to receive or transmit the respective subset of the plurality of carriers, A video screenshot at "MILLISECOND 001" is used to allege that during a first time period, the OneCell system configures each remote unit to transmit or receive a specific subset of PRBs, forming virtual sectors. ¶65, p. 20 col. 14:27-31
wherein during a second time period, at least one remote radio unit... is reconfigured to increase or decrease the number of carriers in a first subset... and... is configured to receive or transmit the first subset... according to the reconfiguration. A subsequent video screenshot at "MILLISECOND 002" is used to allege that the number of carriers (PRBs) has changed for certain remote units, showing a reconfiguration between time periods. ¶¶66-67, p. 24 col. 14:32-39

Identified Points of Contention

  • Scope Questions: The infringement theory against the OneCell product equates the patent's term "carrier" with an LTE/5G "physical resource block (PRB)" (Compl. ¶62). A central dispute will likely be whether "carrier", as defined and used in the patent, can be construed so broadly. The patent frequently refers to "RF carriers" and "RF bands," which may suggest a narrower meaning tied to distinct radio frequencies rather than scheduling units within a single frequency.
  • Technical Questions: Does the "dynamic adjustment" and "sector remapping" of the ION-E/ERA platform constitute "reconfiguring... by increasing or decreasing the number of carriers in the respective subset" as required by claim 1? The defense may argue that this functionality is a form of dynamic load balancing within a fixed carrier-to-RRU configuration, rather than a structural reconfiguration of which carriers are available to an RRU.

V. Key Claim Terms for Construction

  • The Term: "reconfiguring"

  • Context and Importance: This term is the central active step of the asserted claims. The outcome of the case may depend on whether the accused systems' dynamic resource allocation and load balancing functions are found to be a form of "reconfiguring." Practitioners may focus on this term because its construction will determine if the accused products' ordinary, dynamic operation falls within the claim scope.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The patent abstract states the invention enables "automatic traffic load-balancing, network and radio resource optimization," which could support a functional interpretation where any dynamic change in resource allocation is "reconfiguring" (’171 Patent, Abstract).
    • Evidence for a Narrower Interpretation: The specific language of claims 1 and 15 defines reconfiguration as "increasing or decreasing the number of carriers in the respective subset." The detailed description and figures show this as changing which of several distinct "Carriers" (e.g., "Carriers 1-8") are present at a given RRU, suggesting a more structural change to the system's routing map rather than just shifting traffic load (’171 Patent, Fig. 1; col. 6:45-60).

  • The Term: "carrier"

  • Context and Importance: The infringement case against the OneCell product hinges on this term encompassing a "physical resource block" (PRB). If "carrier" is construed more narrowly, this infringement theory may be significantly weakened or fail.

  • Intrinsic Evidence for Interpretation:

    • Evidence for a Broader Interpretation: The complaint does not cite specific intrinsic evidence from the patent to support equating "carrier" with "PRB". A party might argue that in the context of a flexible, SDR-based system, "carrier" should be understood to mean any discrete, transportable unit of radio resource.
    • Evidence for a Narrower Interpretation: Dependent claim 2 specifies that "each carrier corresponds to a respective RF band" (’171 Patent, col. 13:4-5). The specification repeatedly discusses transporting signals from different "base stations" as distinct groups of "Carriers" (e.g., Carriers 1-4 and Carriers 5-8), which strongly supports a definition related to a full RF channel or frequency band, not a smaller scheduling unit like a PRB (’171 Patent, col. 6:29-32).

VI. Other Allegations

  • Indirect Infringement: The complaint alleges that CommScope induces and contributes to T-Mobile's direct infringement (Compl. ¶69). The inducement theory is based on CommScope allegedly providing T-Mobile with the accused products along with instructions on how to use their infringing routing and switching features (Compl. ¶70). The contributory infringement theory alleges the accused hardware and software are "especially adapted for use in the infringing distributed antenna system, and they have no substantial non-infringing uses" (Compl. ¶72).
  • Willful Infringement: Willfulness is alleged based on knowledge of the patent from at least the filing of the complaint (Compl. ¶73). The allegation is strengthened by the claim that Defendants faced an "objectively high likelihood" of infringement because the patent is presumed valid and, notably, the PTAB has already denied a petition for inter partes review of the patent (Compl. ¶74).

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

  • A core issue will be one of definitional scope: can the term "carrier", which the patent repeatedly associates with an "RF band", be construed to cover a "physical resource block" (PRB), which is a granular time-frequency scheduling unit within an RF band? The viability of the infringement allegations against the OneCell product may depend entirely on the answer.
  • A key evidentiary question will be one of functional distinction: does the accused ION-E/ERA platform's "dynamic adjustment" of system resources constitute the claimed act of "reconfiguring" by "increasing or decreasing the number of carriers" available to a remote unit? The case may turn on whether the court views this as a true structural reconfiguration, as described in the patent's embodiments, or as a distinct form of operational load balancing.
  • A third question will relate to willfulness: given the prior denial of an IPR petition against the '171 patent, what level of pre- or post-suit investigation would be required for Defendants to form a good-faith belief of non-infringement or invalidity, and can they meet that standard?