DCT
2:23-cv-00123
Daingean Tech Ltd v. AT&T Inc
Key Events
Amended Complaint
I. Executive Summary and Procedural Information
Parties & Counsel:
- Plaintiff: Daingean Technologies Ltd. (Ireland)
- Defendant: AT&T Corp., AT&T Mobility LLC, AT&T Mobility II LLC, and AT&T Services Inc. (collectively "AT&T") (USA)
- Plaintiff’s Counsel: Alavi & Anaipakos PLLC; Heim Payne & Chorush LLP
Case Identification: 2:23-cv-00123, E.D. Tex., 05/07/2024
Venue Allegations: Plaintiff alleges venue is proper in the Eastern District of Texas due to Defendant's commission of infringing acts within the district and the presence of regular and established places of business, including numerous AT&T retail stores and a foundry innovation center.
Core Dispute: Plaintiff alleges that Defendant’s 5G and 5G+ wireless telecommunications networks infringe three patents related to interference management, uplink data transmission procedures, and efficient signaling of system information.
Technical Context: The dispute centers on core technologies for 5G wireless networks, a critical infrastructure for modern high-speed mobile communications and emerging applications.
Key Procedural History: This Second Amended Complaint follows an original complaint and involves Intervenors Ericsson Inc. and Nokia of America Corporation, suggesting a broader dispute involving major telecommunications equipment suppliers. The '803 Patent was assigned to Plaintiff from Mitsubishi Electric Corporation in August 2022.
Case Timeline
| Date | Event |
|---|---|
| 2006-04-28 | '803 Patent Priority Date |
| 2013-11-05 | '803 Patent Issue Date |
| 2016-07-28 | '958 Patent Priority Date |
| 2017-01-06 | '976 Patent Priority Date |
| 2019-11-19 | '976 Patent Issue Date |
| 2020-11-17 | '958 Patent Issue Date |
| 2022-08-23 | '803 Patent assigned to Daingean Technologies Ltd. |
| 2024-05-07 | Second Amended Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 8,576,803 - Communication System
- Patent Identification: U.S. Patent No. 8,576,803, "Communication System," issued November 5, 2013.
The Invention Explained
- Problem Addressed: The patent's background describes the technical challenge of interference between base stations operating in contiguous or adjacent areas in a wireless communication system (Compl. ¶41; ’803 Patent, col. 2:1-2).
- The Patented Solution: The invention proposes a communication system where a base station transmits data to a mobile device using a directed beam. The characteristics of this beam are determined "on the basis of" three inputs: channel estimation signals from the intended mobile device, channel estimation signals from mobile devices in adjacent areas, and an "interference amount" at those adjacent mobile devices (Compl. ¶41). This approach aims to focus transmission energy on the target user while actively avoiding interference with users in neighboring cells (’803 Patent, col. 2:54-61).
- Technical Importance: Managing inter-cell interference is a fundamental aspect of cellular network design, directly impacting network capacity, data rates, and reliability.
Key Claims at a Glance
- The complaint asserts independent claim 12 (Compl. ¶44).
- Essential elements of claim 12 include:
- A base station for a communication system with a plurality of base stations and mobile subscriber stations.
- Each mobile station transmits a channel estimation signal to its corresponding base station and to base stations in contiguous areas.
- The base station transmits data using a transmission beam directed to its mobile stations and not directed to adjacent mobile stations.
- The data transmission is based on: (1) the channel estimation signal from the mobile station in its area, (2) channel estimation signals from adjacent mobile stations, and (3) an interference amount at the adjacent mobile stations.
- Plaintiff explicitly reserves the right to assert additional claims (Compl. ¶44).
U.S. Patent No. 10,484,976 - Signaling, Procedures, User Equipment and Base Stations for Uplink Ultra Reliable Low Latency Communications
- Patent Identification: U.S. Patent No. 10,484,976, "Signaling, Procedures, User Equipment and Base Stations for Uplink Ultra Reliable Low Latency Communications," issued November 19, 2019.
The Invention Explained
- Problem Addressed: The patent is directed to managing uplink data transmissions to meet the stringent latency and reliability requirements of Ultra Reliable Low Latency Communications (URLLC), a key service category in 5G networks (Compl. ¶67; ’976 Patent, col. 1:18-22).
- The Patented Solution: The invention describes a multi-step signaling procedure between a base station and user equipment (UE) to manage uplink data grants. This involves the base station sending a Radio Resource Control (RRC) message to configure transmission periodicity and numerology, followed by a Downlink Control Information (DCI) message on a physical control channel to activate or deactivate the transmission. The UE then sends confirmation via a Medium Access Control (MAC) Control Element (CE) (Compl. ¶67; ’976 Patent, Abstract). This structured activation/deactivation mechanism is designed for the efficiency and low latency required by URLLC.
- Technical Importance: URLLC enables mission-critical applications such as industrial automation, remote surgery, and autonomous vehicle communication, which depend on highly reliable and near-instantaneous data exchange.
Key Claims at a Glance
- The complaint asserts representative independent claim 2 (Compl. ¶70).
- Essential elements of claim 2 include:
- A base station apparatus with transmitting and receiving circuitry.
- Transmitting circuitry sends RRC messages to configure "periodicity" and "numerology."
- Transmitting circuitry sends a DCI format in a common search space, with its CRC scrambled by a first Radio Network Identifier (RNTI) that is different from a Cell-RNTI and a semi-persistent scheduling C-RNTI, to indicate activation/deactivation of an uplink transmission.
- Receiving circuitry receives a confirmation MAC CE for both activation and deactivation, with the MAC CE being identified by a MAC Protocol Data Unit (PDU) subheader with a logical channel identifier (LCID).
- Plaintiff reserves the right to assert additional claims (Compl. ¶70).
Multi-Patent Capsule: U.S. Patent No. 10,841,958
- Patent Identification: U.S. Patent No. 10,841,958, "Access Node, a Method for an Access Node, a Wireless Terminal, and a Method for a Wireless Terminal," issued November 17, 2020.
- Technology Synopsis: The patent addresses the problem of network inefficiency caused by base stations periodically broadcasting all System Information Blocks (SIBs), even non-essential ones, which wastes radio resources (Compl. ¶95). The solution involves using a "value tag" within an essential SIB (e.g., SIB1) to indicate whether non-essential SIBs have been updated. This allows a wireless terminal to check the value tag and request the non-essential SIBs on-demand only when necessary, rather than receiving them continuously via broadcast (Compl. ¶95; '958 Patent, Abstract).
- Asserted Claims: The complaint asserts representative independent claim 1 (Compl. ¶98).
- Accused Features: The accused features are the systems and methods within AT&T's 5G networks for managing and transmitting SIBs, which allegedly conform to 3GPP standards that implement the claimed invention of using a "valueTag" in SIB1 to manage the broadcast or on-demand delivery of other SIBs (Compl. ¶103-105).
III. The Accused Instrumentality
Product Identification
- The accused instrumentalities are AT&T's 5G and 5G+ wireless networks ("AT&T 5G Networks") and the associated products, hardware, software, and services used to operate them (Compl. ¶28, 43, 69).
Functionality and Market Context
- The complaint alleges that AT&T's 5G networks operate nationwide, covering over 288 million people and generating substantial revenue, with the Mobility unit alone generating over $81 billion in 2022 (Compl. ¶29, 31). The networks are alleged to operate using both 5G Non-Standalone (NSA) and 5G Standalone (SA) architectures, which are depicted in a diagram within the complaint (Compl. ¶35, p. 14). Functionality is alleged to conform to various 3rd Generation Partnership Project (3GPP) 5G standards, which form the basis for many of the infringement allegations (Compl. ¶37, 48, 74, 100). The complaint provides visual evidence of the network's extensive 5G+ coverage across the United States and within the judicial district (Compl. p. 4, p. 12).
IV. Analysis of Infringement Allegations
'803 Patent Infringement Allegations
| Claim Element (from Independent Claim 12) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A base station for a communication system that includes a plurality of said base stations and mobile subscriber stations... | AT&T's 5G network includes a plurality of base stations (gNodeBs or gNBs) and serves mobile subscriber stations (e.g., smartphones). | ¶50-51 | col. 10:7-13 |
| each mobile subscriber station...transmitting a channel estimation signal to each said base station corresponding to the area and to base stations corresponding to areas contiguous to the area... | Mobile stations on the 5G network transmit Sounding Reference Signals (SRS), which are used for channel estimation by both the home cell and neighboring cells. | ¶52-53 | col. 10:14-19 |
| said base station transmits data to the mobile subscriber stations using a transmission beam that is directed to the mobile subscriber stations in the corresponding area and is not directed to adjacent mobile subscriber stations... | The 5G base stations (gNBs) use beamforming to direct energy toward a target user device while simultaneously directing nulls to avoid interfering with other users, including those in adjacent areas. A complaint figure illustrates this concept (Compl. p. 21). | ¶54 | col. 10:20-25 |
| the data being transmitted...on the basis of the channel estimation signal received from the mobile subscriber station in an area corresponding to said base station... | The base station calculates downlink precoding weights for beamforming based on the SRS received from the target mobile station in its own cell. | ¶55 | col. 10:25-29 |
| the channel estimation signals received from the adjacent mobile subscriber stations...that are outside of the area corresponding to said base stations... | The base stations assess "pilot contamination" by receiving and identifying SRSs from neighboring cells to inform scheduling and generate nulling weights for both uplink and downlink. | ¶57 | col. 10:29-33 |
| an interference amount at the adjacent mobile subscriber stations in the areas contiguous to the area corresponding to the base station. | Interference levels from adjacent cells are determined from measurements on Channel State Information – Interference Measurement (CSI-IM) resources or Channel State Information – Reference Signal (CSI-RS) resources. | ¶58 | col. 10:30-33 |
- Identified Points of Contention:
- Scope Questions: A central question may be whether the term "not directed to," in the context of a transmission beam, requires the active placement of a null in the direction of an adjacent user, as suggested by the complaint's visual evidence (Compl. p. 21). The defense may argue that standard beamforming techniques, which focus energy, inherently do not direct energy to non-target users without meeting the specific claim limitation.
- Technical Questions: The claim requires data transmission to be "on the basis of" three distinct inputs, including "an interference amount at the adjacent mobile subscriber stations." It raises the question of whether the 3GPP-standardized use of general CSI-IM measurements constitutes the specific "interference amount at the adjacent mobile subscriber stations" as contemplated by the patent, and whether this measurement is directly used as a basis for the beamforming of a specific data transmission as required by the claim.
'976 Patent Infringement Allegations
| Claim Element (from Independent Claim 2) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A base station apparatus that communicates with a user equipment (UE), comprising: transmitting circuitry configured to transmit a radio resource control (RRC) message comprising first information used for configuring a periodicity... | The accused network uses RRC messages to configure "Type 2" uplink grants, which include a "periodicity" parameter as defined in 3GPP TS 38.321 and TS 38.331. | ¶76-77 | col. 39:15-20 |
| the transmitting circuitry configured to transmit a RRC message comprising second information used for configuring a numerology... | The network's RRC information elements include the BWP element, which contains the "subcarrierSpacing" parameter that defines the numerology per TS 38.331. | ¶78 | col. 39:21-23 |
| the transmitting circuitry configured to transmit in a common search space...a downlink control information (DCI) format with cyclic redundancy check (CRC) scrambled by a first radio network identifier (RNTI), the first RNTI being different from a Cell-RNTI (C-RNTI) and a semi-persistent scheduling C-RNTI, the first RNTI being used for indicating an activation and a deactivation for an uplink data transmission... | The network uses a Type3-PDCCH Common Search Space (CSS) for DCI formats scrambled by a Configured Scheduling RNTI (cs-RNTI) to activate and deactivate uplink grants, as specified in TS 38.213 and TS 38.321. | ¶79-81 | col. 39:24-38 |
| receiving circuitry configured to receive confirmation information Medium Access Control (MAC) Control Element (CE) in a case that third information used for indicating the activation for the uplink data transmission on the PUSCH is comprised in the DCI format... | Per TS 38.321, upon receiving a DCI indicating a configured grant Type 2 activation via cs-RNTI, the MAC entity triggers a configured uplink grant confirmation, which is a MAC CE. | ¶82 | col. 39:39-46 |
| the receiving circuitry is configured to receive confirmation information MAC CE in a case that fourth information used for indicating the deactivation for the uplink data transmission on the PUSCH is comprised in the DCI format... | Per TS 38.321, a DCI indicating configured grant Type 2 deactivation also triggers a configured uplink grant confirmation MAC CE. | ¶85 | col. 39:50-56 |
| the confirmation information MAC CE for the DCI format comprising the third information is identified by a MAC protocol data unit (MAC PDU) subheader with a logical channel identifier (LCID)...and the same index of the LCID is used... | Per TS 38.321, the "Configured Grant Confirmation MAC CE" is identified by a MAC subheader with a specific LCID value (index 55), which is used for both activation and deactivation confirmations. | ¶86 | col. 39:57-60; col. 40:1-6 |
- Identified Points of Contention:
- Scope Questions: The infringement theory relies heavily on the network's conformance to 3GPP standards. A key point of contention may be whether compliance with the cited standards necessarily results in infringement of every claim limitation, or if an operator could implement the standard in a non-infringing manner.
- Technical Questions: A potential dispute may arise over the claim language "the first RNTI being different from a Cell-RNTI (C-RNTI) and a semi-persistent scheduling C-RNTI." The defense could argue that the cs-RNTI used in its network does not meet the specific definitional requirements or distinctions from a "semi-persistent scheduling C-RNTI" as understood in the context of the patent's specification and prosecution history.
V. Key Claim Terms for Construction
'803 Patent
- The Term: "on the basis of"
- Context and Importance: This term is central to the infringement analysis for claim 12, as it links the act of data transmission to three distinct informational inputs: channel quality from the target user, channel quality from adjacent users, and the interference amount at adjacent users. The case may turn on whether the accused beamforming calculation uses all three specified inputs in a manner that satisfies this causal link.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification might describe a general process where these factors are inputs to a precoding weight calculation algorithm, which could support an interpretation where any consideration of these factors meets the "on the basis of" requirement (’803 Patent, col. 8:1-15).
- Evidence for a Narrower Interpretation: Specific embodiments in the patent may disclose a direct mathematical relationship or a specific multi-step logical process where all three inputs are explicitly and sequentially required, potentially supporting a narrower construction that requires more than just general consideration (’803 Patent, Fig. 5; col. 8:55-67).
'976 Patent
- The Term: "confirmation information Medium Access Control (MAC) Control Element (CE)"
- Context and Importance: Practitioners may focus on this term because the entire claim hinges on the specific mechanism for acknowledging activation and deactivation commands for uplink grants. The dispute will likely involve whether the "Configured Grant Confirmation MAC CE" defined in the 3GPP standards and allegedly used by AT&T is coextensive with the claimed "confirmation information."
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent's detailed description may refer to the MAC CE in functional terms, suggesting that any MAC layer control message that serves the purpose of confirming the DCI command would meet the limitation (’976 Patent, col. 24:38-41).
- Evidence for a Narrower Interpretation: The specification may define or illustrate the "confirmation information" with a specific structure, content, or triggering condition that is narrower than the 3GPP standard's implementation, potentially creating a basis for a non-infringement argument (’976 Patent, col. 25:53-55, noting the use of a specific LCID index).
VI. Other Allegations
- Indirect Infringement: The complaint alleges both induced and contributory infringement for all three patents. The theory is based on AT&T providing and promoting its 5G network and services, thereby encouraging and enabling its customers to use 5G-compliant devices in a way that directly infringes the asserted claims (Compl. ¶61-63, 89-91, 113-115).
- Willful Infringement: Plaintiff alleges that AT&T's infringement is willful since at least the filing of the original complaint, which allegedly provided AT&T with knowledge of the patents and its ongoing infringement (Compl. ¶117(e)).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of functional mapping: for the pre-5G '803 Patent, can Plaintiff demonstrate that the standardized interference management techniques in AT&T's 5G network perform the specific, multi-input beamforming calculation required by the claims, or will Defendant show a fundamental mismatch in technical operation?
- A key evidentiary question will be one of standards-essentiality: for the '976 and '958 patents, which appear to map closely to 3GPP standards, does compliance with the cited technical specifications inevitably result in infringement, or can AT&T prove its specific network implementation is standards-compliant yet avoids one or more claim limitations?
- The case also presents a question of temporal scope and claim construction: how will claim terms from patents filed across a wide span of wireless technology development (from 2006 to 2017) be interpreted by the court in the context of a modern, standardized 5G network that evolved after some of the patents were filed?