Bandspeed LLC v. Espressif Systems Shanghai Co Ltd

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Bandspeed, LLC (Texas)
  • Defendant: Espressif Systems (Shanghai) Co., Ltd. (China)
  • Plaintiff’s Counsel: DINOVO PRICE LLP
• Case Identification: 1:22-cv-00716, W.D. Tex., 07/19/2022
• Venue Allegations: Plaintiff alleges that because Defendant is not a resident of the United States, venue is proper in any judicial district pursuant to 28 U.S.C. § 1391(c)(3).
• Core Dispute: Plaintiff alleges that Defendant’s integrated circuits that comply with Bluetooth wireless communication standards infringe a portfolio of eleven patents related to adaptive frequency hopping.
• Technical Context: The technology at issue is adaptive frequency hopping (AFH), a technique used in wireless protocols like Bluetooth to mitigate interference by dynamically selecting and using communication channels with better performance.
• Key Procedural History: The complaint alleges that Plaintiff provided Defendant with notice of its patent portfolio and infringing activities via letters on April 29, 2020, and April 6, 2021, and that Defendant responded to both communications. These allegations form the basis for Plaintiff's claim of willful infringement.

Case Timeline

Date	Event
2001-01-25	Earliest Priority Date for all Asserted Patents
2006-04-11	U.S. Patent No. 7,027,418 Issued
2009-01-13	U.S. Patent No. 7,477,624 Issued
2009-08-04	U.S. Patent No. 7,570,614 Issued
2011-03-08	U.S. Patent No. 7,903,608 Issued
2013-09-24	U.S. Patent No. 8,542,643 Issued
2014-10-28	U.S. Patent No. 8,873,500 Issued
2016-06-28	U.S. Patent No. 9,379,769 Issued
2018-01-30	U.S. Patent No. 9,883,520 Issued
2020-03-24	U.S. Patent No. 10,602,528 Issued
2020-04-29	Plaintiff sends first notice letter to Defendant
2020-09-29	U.S. Patent No. 10,791,565 Issued
2020-09-30	Defendant responds to first notice letter
2021-01-05	U.S. Patent No. 10,887,893 Issued
2021-04-06	Plaintiff sends supplemental notice letter to Defendant
2021-05-28	Defendant responds to supplemental notice letter
2022-07-19	Complaint Filed

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

U.S. Patent No. 7,027,418 - "Approach for Selecting Communications Channels Based on Performance"

The Invention Explained

• Problem Addressed: The patent addresses "coexistence problems" that arise when frequency hopping (FH) communication systems, such as Bluetooth, operate in the same frequency band as non-frequency hopping (NFH) systems, like Wi-Fi (Compl. ¶36). This co-location can cause interference, leading to data transmission errors, reduced performance, and the need to retransmit data (’418 Patent, col. 3:44-61).
• The Patented Solution: The invention proposes a method of "adaptive frequency hopping" where a communication system actively manages its channel usage (Compl. ¶37). It involves testing a plurality of channels to determine their performance, selecting a subset of channels that meet certain performance criteria (i.e., "good" channels), and then communicating only over this selected subset to avoid interference on "bad" channels ('418 Patent, col. 4:44-54). The system periodically re-evaluates channel performance to adapt to changing interference conditions.
• Technical Importance: This approach allows wireless devices in crowded, unlicensed radio bands to dynamically avoid interference, improving reliability and efficiency without requiring increased transmission power (Compl. ¶38).

Key Claims at a Glance

• The complaint asserts dependent claim 5, which incorporates independent claim 1 (Compl. ¶65).
• Essential elements of independent claim 1 include:
  • selecting, based upon performance of a plurality of communications channels at a first time and channel selection criteria, a first set of two or more communications channels;
  • selecting, based upon performance of the plurality of communications channels at a second time that is later than the first time and the channel selection criteria, a second set of two or more communications channels;
  • wherein the communications system is a frequency hopping communications system and the channels correspond to a set of frequencies used according to a frequency hopping protocol; and
  • wherein at each hop in the hopping sequence, only one communications channel is used for communications between a pair of participants.
• The complaint states that other claims of the '418 Patent are also infringed (Compl. ¶66).

U.S. Patent No. 7,477,624 - "Approach for Managing the Use of Communications Channels Based on Performance"

The Invention Explained

• Problem Addressed: Like the '418 Patent from the same family, this patent addresses the problem of interference in shared frequency bands between different wireless communication systems (’624 Patent, col. 3:45-54).
• The Patented Solution: This patent claims a communications device (comprising a memory, processor, and transceiver) that embodies the adaptive frequency hopping method ('624 Patent, col. 5:1-17). The device is configured to select a first set of channels at a first time, use them for a period, and then select a second set of channels at a later time to be used instead of the first set, thereby adapting to changing channel conditions ('624 Patent, col. 17:17-18:12). The patent also describes loading the selected channel sets into registers for use in the communication protocol.
• Technical Importance: The invention provides a specific device architecture for implementing an adaptive frequency hopping system, making such systems more practical for integration into wireless products.

Key Claims at a Glance

• The complaint asserts dependent claim 15, which incorporates independent claim 13 (Compl. ¶82).
• Essential elements of independent claim 13 include:
  • A communications device comprising a memory, a processor communicatively coupled to the memory, and a transceiver communicatively coupled to the memory.
  • The processor is caused to execute instructions for selecting a first set of channels based on performance at a first time, and a second set of channels based on performance at a later second time.
  • The transceiver is configured to use the first set of channels for a first period and the second set of channels for a second period instead of the first set.
  • The processor is further caused to load the first selected set of channels into registers of the communicating devices, and subsequently load the second selected set of channels into those registers.
• The complaint states that other claims of the '624 Patent are also infringed (Compl. ¶83).

U.S. Patent No. 7,570,614 - "Approach for Managing Communications Channels Based on Performance"

• Technology Synopsis: This patent describes a method for managing channel selection in a master-slave frequency hopping system. It involves a master device selecting a channel based on performance, notifying a slave device not to use that channel, and then receiving performance quality data back from the slave to update its channel data (Compl. ¶99).
• Asserted Claims: Claim 100 (dependent on claim 1) (Compl. ¶99).
• Accused Features: The complaint alleges that "Infringing Bluetooth Classic Products" practice the claimed methods (Compl. ¶98).

U.S. Patent No. 7,903,608 - "Approach for Managing the Use of Communications Channels Based on Performance"

• Technology Synopsis: This patent claims a communications device that adaptively selects different sets of channels at different times, with the specific requirement that the number of channels in the first set varies from the number of channels in the second set (Compl. ¶116).
• Asserted Claims: Claim 1 (Compl. ¶116).
• Accused Features: The complaint alleges that "Infringing Products," which includes both Bluetooth Classic and LE products, infringe the ’608 Patent (Compl. ¶115).

U.S. Patent No. 8,542,643 - "Approach for Managing the Use of Communications Channels Based on Performance"

• Technology Synopsis: This patent claims a method involving loading default channels and good channels into separate registers. If a "selection kernel" addresses a bad channel in the default register, that bad channel is replaced with a good channel from the good channel register (Compl. ¶135).
• Asserted Claims: Claim 5 (dependent on claim 1) (Compl. ¶135).
• Accused Features: The complaint alleges that "Infringing Products" (Bluetooth Classic and LE) practice this method (Compl. ¶134).

U.S. Patent No. 8,873,500 - "Approach for Managing the Use of Communications Channels Based on Performance"

• Technology Synopsis: This patent claims a frequency hopping device that communicates on a default hopping sequence, tests channels, selects a subset of good channels for an "adapted hopping sequence," communicates on that subset, monitors them, and then reverts back to the default sequence based on monitoring results or a timer (Compl. ¶154).
• Asserted Claims: Claim 28 (dependent on claim 16) (Compl. ¶154).
• Accused Features: The complaint alleges that "Infringing Products" (Bluetooth Classic and LE) constitute the claimed device (Compl. ¶153).

U.S. Patent No. 9,379,769 - "Approach for Managing the Use of Communications Channels Based on Performance"

• Technology Synopsis: This patent claims a wireless device that monitors channels, classifies them as good or bad, transmits this classification information to another device, and then communicates over the good channels while avoiding the bad ones (Compl. ¶173).
• Asserted Claims: Claim 1 (Compl. ¶173).
• Accused Features: The complaint alleges that "Infringing Products" (Bluetooth Classic and LE) constitute the claimed device (Compl. ¶172).

U.S. Patent No. 9,883,520 - "Approach for Managing the Use of Communications Channels Based on Performance"

• Technology Synopsis: This patent claims a wireless device configured to send packet data specifying a subset of channels and timing information to another device. It then describes logic for using an identified channel versus a channel from the subset depending on certain conditions (Compl. ¶192).
• Asserted Claims: Claim 1 (Compl. ¶192).
• Accused Features: The complaint alleges that "Infringing Products" (Bluetooth Classic and LE) are the claimed device (Compl. ¶191).

U.S. Patent No. 10,602,528 - "Approach for Managing the Use of Communication Channels Based on Performance"

• Technology Synopsis: This patent claims a device adapted to manage power levels by determining and using subsets of communication channels that meet a target performance threshold. The device assesses channel performance, excludes channels outside a threshold, and sends packet data defining the current subset of channels to another device (Compl. ¶211).
• Asserted Claims: Claim 1 (Compl. ¶211).
• Accused Features: The complaint alleges that "Infringing Products" (Bluetooth Classic and LE) are the claimed device (Compl. ¶210).

U.S. Patent No. 10,791,565 - "Approach for Managing the Use of Communications Channels Based on Performance"

• Technology Synopsis: This patent is similar to the ’528 Patent, claiming a device adapted to manage power level by determining a subset of available channels, excluding those outside a performance threshold, and sending packet data defining that subset to another device for use in frequency hopping (Compl. ¶230).
• Asserted Claims: Claim 1 (Compl. ¶230).
• Accused Features: The complaint alleges that "Infringing Products" (Bluetooth Classic and LE) are the claimed device (Compl. ¶229).

U.S. Patent No. 10,887,893 - "Approach for Managing the Use of Communications Channels Based on Performance"

• Technology Synopsis: This patent claims a device that manages power consumption by assessing whether using a different communication channel would enable improved performance compared to the presently-selected channel, and causing a switch to that different channel if the assessment is positive (Compl. ¶249).
• Asserted Claims: Claim 1 (Compl. ¶249).
• Accused Features: The complaint alleges that "Infringing Bluetooth Classic Products" are the claimed device (Compl. ¶248).

III. The Accused Instrumentality

Product Identification

The accused instrumentalities are broadly defined as "Infringing Bluetooth Classic Products" and "Infringing Bluetooth LE Products" (Compl. ¶41). These are described as integrated circuits or sets of integrated circuits for wireless communication devices that practice, use, or comply with specific versions of the Bluetooth Core Specification (Compl. ¶¶ 39-40).

Functionality and Market Context

• The relevant functionality of the "Infringing Bluetooth Classic Products" is the provision of capabilities including adaptive frequency hopping in compliance with Version 2.0+EDR or later of the Bluetooth Core Specification (Compl. ¶59).
• The relevant functionality of the "Infringing Bluetooth LE Products" is the provision of capabilities including the Bluetooth Low Energy protocol in compliance with Version 4.0 or later of the Bluetooth Core Specification (Compl. ¶60).
• The complaint alleges that Defendant manufactures, sells, offers for sale, and imports these products throughout the United States and within the Western District of Texas (Compl. ¶¶ 21, 58). It further alleges that Defendant provides these products as components for use in end-products and markets them on its website (Compl. ¶¶ 51, 54). No probative visual evidence provided in complaint.

IV. Analysis of Infringement Allegations

'418 Patent Infringement Allegations

Claim Element (from Independent Claim 1)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
selecting, based upon performance of a plurality of communications channels at a first time and channel selection criteria, a first set of two or more communications channels from the plurality of communications channels;	The accused products allegedly perform adaptive frequency hopping as defined in the Bluetooth standard, which involves an initial classification and selection of usable channels based on performance.	¶¶ 59, 65	col. 7:4-24
selecting, based upon performance of the plurality of communications channels at a second time that is later than the first time and the channel selection criteria, a second set of two or more communications channels from the plurality of communications channels;	The accused products allegedly re-evaluate channel performance over time and adapt their set of usable channels to account for changing interference conditions, as required by the Bluetooth standard.	¶¶ 59, 65	col. 7:40-50
wherein the communications system is a frequency hopping communications system and the plurality of communications channels correspond to a set of frequencies to be used based on a hopping sequence according to a frequency hopping protocol;	The accused products are alleged to operate as frequency hopping systems under the Bluetooth protocol, which uses a defined sequence of frequencies (channels) for communication.	¶¶ 39, 59, 65	col. 3:1-10
wherein at each hop in the hopping sequence, only one communications channel is used for communications between a pair of participants.	The Bluetooth protocol allegedly uses a single channel for transmission at each time slot or "hop" in its frequency hopping sequence.	¶¶ 59, 65	col. 3:20-24

'624 Patent Infringement Allegations

Claim Element (from Independent Claim 13)	Alleged Infringing Functionality	Complaint Citation	Patent Citation
A communications device for use in a network of devices, comprising: a memory for storing instructions; a processor that is communicatively coupled to the memory...	The accused integrated circuits are alleged to be communications devices containing memory and a communicatively coupled processor that stores and executes instructions for Bluetooth functionality.	¶¶ 39, 82	col. 10:11-20
...wherein the memory includes instructions which, when processed by the processor, causes: selecting, based upon performance... a first set of two or more communications channels... selecting, based upon performance... a second set of two or more communications channels...	The processor in the accused products allegedly executes instructions to perform the adaptive frequency hopping channel selection method at different times, as specified by the Bluetooth standard.	¶¶ 59, 82	col. 17:17-30
a transceiver that is communicatively coupled to the memory and that is configured to transmit to and receive from another communications device...	The accused products allegedly contain a transceiver for wireless communication that operates according to the instructions stored in memory.	¶¶ 39, 82	col. 10:21-25
...wherein... for a first period of time, the first set... is used to transmit to and receive... and for a second period of time... the second set... is used... instead of the first set...	The accused products allegedly use an initial set of channels and then switch to a new set of channels at a later time to adapt to interference, in accordance with the Bluetooth protocol.	¶¶ 59, 82	col. 18:1-8
...wherein the memory further includes instructions, which when processed by the processor, causes: after selecting... causing the first set... to be loaded into a first register... and a second register...	The accused products allegedly load the selected channel map information into registers for use by the local device and the other communicating device, as part of the Bluetooth protocol's operation.	¶¶ 59, 82	col. 18:9-20

Identified Points of Contention

• Scope Questions: A central question may be whether compliance with the Bluetooth Core Specification necessarily amounts to infringement of the asserted claims. The dispute may focus on whether the specific steps and structures recited in the claims, such as the two distinct "selecting" steps at different times or the loading of channels into specific registers, are mandatory elements of the standard or merely optional implementations.
• Technical Questions: The complaint bases its infringement allegations on the accused products' compliance with a standard rather than on a detailed analysis of their specific operation. A key technical question will be what evidence demonstrates that Defendant's products actually perform the claimed steps. For example, regarding claim 15 of the '624 Patent, what evidence shows that the accused products use a "channel selection criteria" that "specifies that for a particular communications channel to be selected, the particular communications channel receives a specified number of votes"?

V. Key Claim Terms for Construction

The Term: "selecting, based upon performance" ('418 Patent, claim 1)

• Context and Importance: This term is the core of the claimed invention. The infringement case may depend on whether the Bluetooth standard's process for channel classification and mapping qualifies as "selecting" based on "performance" as the patent contemplates. Practitioners may focus on this term because the defendant may argue that its products simply follow a pre-determined or master-dictated channel map rather than actively "selecting" channels based on real-time performance metrics in the claimed manner.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The specification describes "performance" broadly to include a variety of metrics such as "bit error rate (BER)," "packet loss ratio (PLR)," and "received signal strength indicator (RSSI)" ('418 Patent, col. 11:4-47). This could support an interpretation where any channel classification based on a quality metric constitutes selecting based on performance.
  • Evidence for a Narrower Interpretation: The detailed description provides specific examples of testing channel performance using "special test packets" sent between master and slave devices ('418 Patent, col. 11:10-14). A defendant may argue that "selecting, based upon performance" should be limited to this type of active, detailed testing protocol, rather than a more passive channel classification system.

The Term: "channel selection criteria specifies that for a particular communications channel to be selected, the particular communications channel receives a specified number of votes" ('624 Patent, claim 15)

• Context and Importance: This limitation from an asserted dependent claim is highly specific. The viability of the infringement allegation against claim 15 will likely turn on whether the channel classification scheme in the accused Bluetooth products can be characterized as a "voting" process.
• Intrinsic Evidence for Interpretation:
  • Evidence for a Broader Interpretation: The specification explicitly describes a "referendum" approach where multiple participants can "vote" on whether a channel is "good" or "bad," and a "passing mark" of a certain number of votes is required for a channel to be judged "good" ('624 Patent, col. 17:15-44, Table 2). This language provides direct support for a voting-based interpretation.
  • Evidence for a Narrower Interpretation: The patent's primary example of voting involves multiple slave devices and a master all contributing to the decision ('624 Patent, Table 2). A defendant may argue that this term requires a multi-participant voting scheme and does not cover a scenario where a master device unilaterally assesses channel quality and dictates a channel map to a slave, even if that assessment is based on performance data.

VI. Other Allegations

Indirect Infringement

The complaint alleges both induced and contributory infringement. Inducement allegations are based on Defendant allegedly providing products with infringing functionality enabled and providing instructions, datasheets, user manuals, and software development kits (SDKs) that direct and encourage customers to use the infringing Bluetooth features (Compl. ¶¶ 48-49, 74). Contributory infringement is alleged on the basis that the accused components are a material part of the patented inventions, are especially made or adapted to infringe, and have no substantial non-infringing uses (Compl. ¶¶ 78, 95).

Willful Infringement

The complaint alleges willful infringement based on pre-suit knowledge of the patents. It specifically cites notice letters sent to Defendant on April 29, 2020 and April 6, 2021, and responses from Defendant's intellectual property manager, as evidence of actual knowledge (Compl. ¶¶ 265-267). Plaintiff alleges that Defendant continued its infringing conduct despite this knowledge (Compl. ¶268).

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

• A central issue will be one of standards interpretation: does compliance with the Bluetooth Core Specifications (v2.0+EDR and v4.0 and higher) necessarily require infringement of the specific claim limitations, or can the standards be implemented in a non-infringing manner? The case may turn on whether the patent claims cover the mandatory aspects of the Bluetooth AFH protocol or describe a more specific, optional implementation.
• A key evidentiary question will be one of technical proof: what evidence will Plaintiff present to demonstrate that Defendant's products practice the specific, and sometimes detailed, limitations of the claims (e.g., the "voting" mechanism of claim 15 of the '624 patent) beyond asserting general compliance with the Bluetooth standard?
• A third core question will relate to damages and willfulness: given the allegations of pre-suit notice and Defendant's engagement, the dispute may focus significantly on whether Defendant's continued sales after receiving notice were objectively reckless, potentially exposing it to enhanced damages if infringement and validity are established.