Cellular Communications Equipment LLC v. AT&T Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Cellular Communications Equipment LLC (Texas)
  • Defendant: AT&T Inc. (Delaware), et al.
  • Plaintiff’s Counsel: Bragalone Conroy PC; Nelson Bumgardner, P.C.
• Case Identification: 2:15-cv-00576, E.D. Tex., 04/30/2015
• Venue Allegations: Plaintiff alleges venue is proper because each Defendant is deemed to reside in the district, has committed acts of infringement in the district, has purposely transacted business in the district, and/or has a regular and established place of business in the district.
• Core Dispute: Plaintiff alleges that Defendants’ LTE-compatible mobile devices and network infrastructure infringe three patents related to efficient data signaling, power management, and channel reporting in 4G LTE wireless networks.
• Technical Context: The technology at issue addresses fundamental challenges in modern cellular communications, focusing on optimizing the use of radio spectrum and device power to ensure reliable network performance.
• Key Procedural History: The complaint alleges that U.S. Patent No. 8,457,022 is essential to the 3GPP LTE standard and that Defendants had notice of it via its disclosure to a standards body. For U.S. Patent Nos. 8,570,957 and 8,867,472, notice is alleged as of the filing of the complaint. Post-filing, U.S. Patent No. 8,867,472 was subject to Inter Partes Review (IPR) proceedings (IPR2016-01480, IPR2017-00982), which resulted in the cancellation of several claims, including asserted independent claim 1.

Case Timeline

Date	Event
2008-03-26	Priority Date for ’957 Patent
2008-09-22	Priority Date for ’022 Patent
2010-03-25	Priority Date for ’472 Patent
2012-12-31	Alleged Pre-Suit Knowledge of ’022 Patent (approx.)
2013-06-04	’022 Patent Issue Date
2013-10-29	’957 Patent Issue Date
2014-10-21	’472 Patent Issue Date
2015-04-30	Complaint Filing Date
2016-07-22	IPR Filed against ’472 Patent

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

U.S. Patent No. 8,457,022 - Method and Apparatus for Providing Signaling of Redundancy Versions (issued Jun. 4, 2013)

The Invention Explained

• Problem Addressed: The patent describes the challenge of efficiently signaling retransmission information in LTE networks. Specifically, for broadcast control channel (BCCH) data, a receiver (user equipment) does not know in advance when or how a network base station will retransmit parts of a data packet, which can lead to inefficient use of network resources and delays in communication. (’022 Patent, col. 1:26-35, col. 5:11-21).
• The Patented Solution: The invention proposes a structured method for assigning a "redundancy version" (RV) sequence, which tells the receiver how a retransmitted packet is encoded. The method assigns a predetermined sequence of RVs at the start of a specific transmission window, but intelligently skips certain time slots (subframes) that are reserved for other essential signals or are otherwise unavailable, ensuring a predictable and efficient signaling scheme. (’022 Patent, Abstract; col. 7:10-25).
• Technical Importance: This method was designed to improve the reliability and speed of delivering essential system information in LTE networks, which is a foundational step for a mobile device to connect to and operate on the network. (’022 Patent, col. 5:46-60).

Key Claims at a Glance

• The complaint asserts "one or more claims" of the ’022 patent (Compl. ¶26). Independent claim 1 is representative.
• Essential Elements of Independent Claim 1:
  • A method for detecting the start of a system information message transmission window.
  • Assigning a redundancy version sequence at the start of that window.
  • The assignment process includes excluding predetermined subframes in even-numbered radio frames if they fall within the window.
  • The assignment also excludes uplink and multi-cast subframes.
  • The assignment ensures the RV sequence is continuous over adjacent radio frames.
  • The RV sequence is calculated according to a specific formula defined in the claim.

U.S. Patent No. 8,570,957 - Extension of Power Headroom Reporting and Trigger Conditions (issued Oct. 29, 2013)

The Invention Explained

• Problem Addressed: In wireless communications, a user device (UE) reports its available "power headroom" to the network. The patent notes that conventional systems only report zero or positive headroom, failing to quantify how much power a device is lacking if it has insufficient power for a required transmission. This ambiguity forces the network to make less-informed decisions about resource allocation. (’957 Patent, col. 5:1-14).
• The Patented Solution: The invention extends power headroom reporting to include negative values. A negative report explicitly informs the network of the power deficit in decibels (dB), indicating the "missing power" required to meet the transmission requirements. This allows the network to make a more precise and efficient adjustment, such as reducing the data rate or allocated bandwidth for that UE. (’957 Patent, Abstract; col. 2:1-8, col. 5:15-24).
• Technical Importance: Providing negative headroom values gives the network scheduler more granular feedback, enabling more sophisticated and efficient management of radio resources, thereby improving overall network capacity and user experience, particularly for devices at the cell edge. (’957 Patent, col. 6:5-11).

Key Claims at a Glance

• The complaint asserts "one or more claims" of the ’957 patent (Compl. ¶38). Independent claim 1 is representative.
• Essential Elements of Independent Claim 1:
  • An apparatus (e.g., a UE) with a processor and transmitter.
  • The processor is configured to determine a power headroom report.
  • The processor determines the report with "both positive and negative values."
  • The negative values "indicate the missing power in dB to fulfill transmission requirements."
  • The determination is made by subtracting the nominal maximum transmission power from the power the device would use if not for power limitations, where the result is not limited to zero or positive values.

U.S. Patent No. 8,867,472 - Signalling of Channel Information (issued Oct. 21, 2014)

• Technology Synopsis: This patent addresses the issue of excessive uplink signaling when devices report channel quality in systems using carrier aggregation (i.e., communicating over multiple frequency bands at once) (’472 Patent, col. 3:1-9). The invention provides a mechanism for the network to request a detailed channel state information (CSI) report for a single, selected frequency band, rather than requiring a report for all bands, thus conserving uplink resources (’472 Patent, Abstract).
• Asserted Claims: The complaint asserts "one or more claims" (Compl. ¶50). Post-filing IPR proceedings cancelled claims 1, 10, 11, 14, 28, 37, 38, and 41 (’472 Patent, K1 Cert., p. 2).
• Accused Features: The complaint accuses Defendants' LTE-Advanced User Equipment and Network Equipment that are capable of carrier aggregation of infringing the patent (Compl. ¶50-51).

III. The Accused Instrumentality

Product Identification

The complaint names the "AT&T LTE User Equipment and Network Equipment" (Compl. ¶26, ¶38, ¶50). The accused user equipment is an extensive list of smartphones and tablets from major manufacturers, including the Apple iPhone 5/6 series, Samsung Galaxy S3/S4/S5/S6 and Note series, and various devices from HTC, LG, and ZTE (Compl. ¶26). The accused network equipment includes base stations supplied by Alcatel-Lucent and Ericsson (Compl. ¶26).

Functionality and Market Context

The accused products are devices and infrastructure that constitute AT&T's 4G LTE network. The complaint alleges that these products are designed to operate according to 3GPP LTE standards and that this standards-compliance is the basis for infringement (Compl. ¶2, ¶29). The complaint frames the functionality of the accused products as essential for AT&T to provide a competitive national cellular network (Compl. ¶ Introduction).
No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

The complaint provides high-level allegations that the accused products, by virtue of complying with the 3GPP LTE standard, necessarily infringe the asserted patents. It does not contain detailed element-by-element mappings.

’022 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
detecting start of a system information message transmission window;	The complaint alleges that Defendants' LTE User Equipment and Network Equipment practice the claimed methods by operating on AT&T's LTE network. This functionality is implied by the devices' need to receive system information.	¶26-27	col. 2:40-41
and assigning a redundancy version sequence at the start of the transmission window...	The complaint's infringement theory is that devices compliant with the 3GPP LTE standard inherently perform the claimed assignment of RV sequences.	¶27, ¶29	col. 2:42-44
wherein the assignment includes excluding one or more of the predetermined subframes in even-numbered radio frames...and...excluding uplink subframes and multi-cast subframes...	The complaint does not specify how the accused products perform these exclusions, relying instead on the allegation that such functionality is required by the LTE standard that the products implement.	¶27, ¶29	col. 7:18-35

Identified Points of Contention (’022 Patent)

• Scope Question: The plaintiff's case appears to depend on whether compliance with the 3GPP LTE standard requires practicing every element of the asserted claims. A central question for the court will be whether the standard allows for non-infringing alternative implementations.
• Technical Question: What evidence demonstrates that the accused base stations assign RV sequences using the specific exclusion and continuity rules required by the claim? The complaint relies on the assertion of standards-compliance rather than direct evidence of the equipment's specific operation.

’957 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
a processor configured to determine a power headroom report...	Accused User Equipment (smartphones, tablets) contain processors that determine power headroom reports as part of their normal operation on an LTE network.	¶38-39	col. 1:49-51
wherein the processor is configured to determine the power headroom report with both positive and negative values...in which negative values indicate the missing power in dB...	The complaint alleges infringement by the accused devices operating on the LTE network, but does not specifically allege that they are configured to report negative values.	¶38-39	col. 2:1-8
wherein the processor is configured to determine the power headroom by subtracting the nominal maximum transmission power and the power that the apparatus would use if it did not apply maximum power limitations...	The complaint does not detail the specific calculation algorithm used by the accused devices; infringement is alleged based on their general compliance with LTE standards.	¶39, ¶44	col. 4:1-12

Identified Points of Contention (’957 Patent)

• Technical Question: Do the accused user devices, in fact, calculate and transmit negative power headroom values? The core of the invention is this specific extension beyond conventional reporting, and infringement will likely hinge on evidence of this capability in the accused products.
• Scope Question: Does the term "negative values" require a literal numerically negative number, or could it be construed to cover other indicators of a power deficit? The claim's specificity may limit its scope to literal negative values.

V. Key Claim Terms for Construction

’022 Patent: "assigning a redundancy version sequence"

• Context and Importance: This phrase defines the central action of the claimed method. The construction will determine whether the operation of the accused base stations falls within the claim scope. Practitioners may focus on this term because the associated wherein clauses add significant limitations to what "assigning" entails.
• Intrinsic Evidence for a Broader Interpretation: The specification generally describes the invention as a way to provide "signaling of redundancy versions" (’022 Patent, Title), which could support a construction focused on the general act of allocation.
• Intrinsic Evidence for a Narrower Interpretation: Claim 1 itself and the detailed description explicitly link the act of "assigning" to a series of specific constraints, including excluding certain subframes and ensuring continuity over adjacent frames (’022 Patent, Claim 1; col. 7:18-35). This suggests "assigning" is not a generic allocation but a highly constrained process.

’957 Patent: "power headroom report with both positive and negative values"

• Context and Importance: This term is the core of the asserted invention, distinguishing it from prior art that allegedly only reported positive or zero headroom. Proof of infringement rests almost entirely on whether the accused devices generate reports that meet this "positive and negative" limitation.
• Intrinsic Evidence for a Broader Interpretation: The background section focuses on the problem that the network lacks knowledge of "missing" power, suggesting the purpose is to convey this information generally (’957 Patent, col. 5:1-14). A party might argue any mechanism that quantifies a power deficit meets the spirit of the invention.
• Intrinsic Evidence for a Narrower Interpretation: The summary and detailed description repeatedly refer to extending the reporting range to "negative values" and calculating a result that is "not limited to zero and positive values" (’957 Patent, col. 2:5-8; Claim 1). This language strongly supports a literal interpretation requiring the capability to report actual numerically negative values.

VI. Other Allegations

Indirect Infringement

The complaint alleges that Defendants induce infringement by providing customers with instructional materials, user guides, and online support that "specifically teach" users to operate the accused devices in an infringing manner (Compl. ¶31, ¶43, ¶55). It further alleges contributory infringement on the basis that the accused functionalities are a material part of the inventions and not staple articles of commerce suitable for substantial non-infringing use (Compl. ¶32, ¶44, ¶56).

Willful Infringement

For the ’022 patent, willfulness is alleged based on pre-suit knowledge dating to "as early as December 2012" from the patent's disclosure to the 3GPP standards body (Compl. ¶29). For the ’957 and ’472 patents, willfulness is based on knowledge acquired "at least as early as service of this Complaint," establishing a basis for potential post-filing willfulness (Compl. ¶41, ¶53).

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

This case, filed with a notice-style pleading, presents several fundamental questions for the court that span claim interpretation, evidentiary proof, and the impact of post-filing administrative proceedings.

• A primary issue for the ’022 patent will be one of standards-based infringement: Can the plaintiff prove that compliance with the 3GPP LTE standard, as implemented in the accused products, necessarily requires performing the specific, constrained method of assigning redundancy versions recited in the claims, or does the standard permit non-infringing alternatives?
• A key evidentiary question for the ’957 patent will be one of technical implementation: Does discovery show that the accused smartphones and tablets were actually configured to calculate and transmit negative power headroom values, or did they use a more conventional reporting scheme? The viability of this infringement count hinges on demonstrating this specific, non-standard capability.
• The most significant question for the ’472 patent concerns the impact of the IPR cancellation: Given that the IPR proceedings invalidated the core independent claim and numerous other claims after the complaint was filed, a threshold issue is whether the plaintiff has any remaining valid and asserted claims on which it can proceed, or if this count is effectively moot.