2:21-cv-00193
Stingray IP Solutions LLC v. eero LLC
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Stingray IP Solutions, LLC (Texas)
- Defendant: Amazon.com, Inc., Amazon.com Services LLC, Ring LLC, eero LLC, and Immedia Semiconductor LLC (Delaware / Washington)
- Plaintiff’s Counsel: Bragalone Olejko Saad PC; Ward, Smith, & Hill, PLLC
- Case Identification: 2:21-cv-00193, E.D. Tex., 06/01/2021
- Venue Allegations: Plaintiff alleges venue is proper in the Eastern District of Texas because Defendants maintain a regular and established place of business in the district, including at least one fulfillment facility, and have committed acts of infringement there.
- Core Dispute: Plaintiff alleges that Defendant’s smart home devices and systems (including the Echo, Ring, eero, and Blink product lines) infringe four patents related to methods for managing communication, routing, and network organization in wireless ad hoc networks.
- Technical Context: The patents address foundational technologies for organizing and managing data traffic in dynamic, multi-node wireless networks, which are central to the operation of modern smart home ecosystems that rely on protocols like Wi-Fi, ZigBee, and Z-Wave.
- Key Procedural History: The complaint alleges that Defendant Amazon was notified of its infringement of the asserted patents at least as early as May 2, 2018, via a letter from Harris Corporation, the original assignee of the patents. This alleged pre-suit notice forms the basis for the willfulness claims.
Case Timeline
| Date | Event |
|---|---|
| 1999-11-12 | ’537 Patent Priority Date |
| 2002-01-10 | ’986 Patent Priority Date |
| 2002-08-05 | ’426 Patent Priority Date |
| 2002-08-08 | ’310 Patent Priority Date |
| 2005-10-25 | ’986 Patent Issue Date |
| 2005-11-01 | ’310 Patent Issue Date |
| 2005-12-27 | ’537 Patent Issue Date |
| 2006-04-11 | ’426 Patent Issue Date |
| 2017 | Amazon acquires Blink |
| 2018-05-02 | Harris Corporation sends letter to Amazon alleging infringement |
| 2018 | Amazon acquires Ring |
| 2019 | Amazon acquires eero |
| 2021-06-01 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 6,958,986 - "Wireless Communication System with Enhanced Time Slot Allocation and Interference Avoidance/Mitigation Features and Related Methods" (Issued Oct. 25, 2005)
The Invention Explained
- Problem Addressed: The patent addresses the complexity of scheduling communication time slots in mobile wireless networks that use directional antennas, particularly in dynamic environments where interference must be avoided and communication demands vary (’986 Patent, col. 1:64–2:4).
- The Patented Solution: The invention proposes a method where a network controller schedules a combination of "semi-permanent" time slots to establish stable, baseline communication links, and "demand assigned" time slots for additional data transmission capacity. The allocation of these demand-based slots is determined by "link utilization metrics" and data priority levels, allowing the network to adapt dynamically to changing traffic needs (’986 Patent, Abstract; col. 2:22-41).
- Technical Importance: This hybrid scheduling approach offered a more flexible and efficient method for managing bandwidth in mobile ad hoc networks (MANETs), balancing the need for stable connectivity with the ability to handle unpredictable bursts of high-demand traffic.
Key Claims at a Glance
- The complaint asserts independent claim 25 (Compl. ¶75).
- Essential elements of Claim 25:
- A communication method for a wireless network with multiple mobile nodes, each having a data queue.
- Scheduling "semi-permanent time slots" to establish communication links between pairs of nodes for transmitting data from the queues.
- Determining "link utilization metrics" for each link based on the quantity of data previously sent and the data in the queues.
- Scheduling "demand assigned time slots" for additional links based on the determined link utilization metrics.
U.S. Patent No. 6,961,310 - "Multiple Path Reactive Routing in a Mobile Ad Hoc Network" (Issued Nov. 1, 2005)
The Invention Explained
- Problem Addressed: Conventional on-demand (reactive) routing protocols in mobile ad hoc networks typically identify and use only a single path for data transmission. The patent notes that if this single path fails, significant delays occur while a new route is discovered, making the network unreliable (’310 Patent, col. 2:41-51).
- The Patented Solution: The invention describes a method where a source node discovers multiple potential routes to a destination. These routes are then ranked according to one or more "link metric[s]" (e.g., delay, capacity, reliability). The source node then "simultaneously distribute[s]" the message data to the destination along a "plurality" of these discovered routes, enhancing reliability and timeliness (’310 Patent, Abstract; col. 3:3-16).
- Technical Importance: This multi-path routing strategy provides greater resilience to link failures in dynamic wireless environments, offering a significant improvement in robustness compared to traditional single-path routing protocols.
Key Claims at a Glance
- The complaint asserts independent claim 13 (Compl. ¶95).
- Essential elements of Claim 13:
- A method for routing message data from a source to a destination node in a mobile ad hoc network.
- At the source node, discovering routing to the destination node.
- At the source node, ranking the discovered routes according to at least one link metric.
- At the source node, "simultaneously distribut[ing]" the message data to the destination "along a plurality of the discovered routes" based on the ranking.
U.S. Patent No. 6,980,537 - "Method and Apparatus for Communication Network Cluster Formation and Transmission of Node Link Status Messages with Reduced Protocol Overhead Traffic" (Issued Dec. 27, 2005)
Technology Synopsis
The patent describes a method for organizing a wireless network into clusters by using topology information to designate certain nodes as "cluster heads" for relaying traffic and others as "member nodes." This hierarchical structure aims to improve routing efficiency and reduce protocol overhead (Compl. ¶47; ’537 Patent, Abstract).
Asserted Claims
Independent claim 16 (Compl. ¶112).
Accused Features
The complaint alleges that Ring home security products using the Z-Wave protocol infringe by configuring network units to transmit and receive messages, examining network connectivity to identify isolated units, and designating certain units as fixed "routing units" in response to this analysis (Compl. ¶¶113-115).
U.S. Patent No. 7,027,426 - "Multi-channel Mobile Ad Hoc Network" (Issued Apr. 11, 2006)
Technology Synopsis
The patent discloses a method for operating a mobile ad hoc network across multiple, electrically separate wireless channels. The method involves a source node sending a route request over each of the available channels to discover potential routes to a destination and then selecting an optimal route on at least one of those channels for data transmission (Compl. ¶48; ’426 Patent, Abstract).
Asserted Claims
Independent claim 8 (Compl. ¶129).
Accused Features
Amazon's smart home products utilizing ZigBee and/or Z-Wave are accused of infringing by operating over a plurality of channels, sending route requests across these channels to discover routing, and selecting a route on at least one of the channels for data transmission (Compl. ¶¶130-132).
III. The Accused Instrumentality
Product Identification
The complaint identifies the "Accused Products" as Amazon’s smart home devices, components, and related systems from the Echo, Ring, eero, and Blink brands that utilize Wi-Fi, ZigBee, and/or Z-Wave communication protocols (Compl. ¶51). The complaint provides a screenshot from Amazon's website showing a variety of these devices for sale under the "Amazon Smart Home" brand (Compl. ¶20, p. 9).
Functionality and Market Context
The Accused Products create dynamic, ad hoc wireless networks within a home, enabling communication and coordination for services such as security, automation, and whole-home Wi-Fi coverage (Compl. ¶11). For example, the Echo Show 10 is identified as a smart home hub that can directly control compatible Zigbee devices (Compl. ¶51, p. 22). The Ring Base Station is described as using Wi-Fi, Z-Wave, and Zigbee to connect and manage security devices (Compl. ¶53, p. 23). The complaint asserts that these products represent a significant portion of Amazon's business, which had worldwide net product sales of $213 billion in 2020 (Compl. ¶49).
IV. Analysis of Infringement Allegations
’986 Patent Infringement Allegations
| Claim Element (from Independent Claim 25) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A communication method for a wireless communication network comprising a plurality of mobile nodes each comprising a data queue | The Accused Products operate on Wi-Fi and ZigBee networks, which comprise multiple communicating nodes. The Quality of Service (QoS) scheme in Wi-Fi stores data frames in a traffic queue before transmission. | ¶76 | col. 2:22-26 |
| scheduling respective semi-permanent time slots to establish communication links between respective pairs of the mobile nodes for transmitting data stored in the data queues therebetween | Accused Products using ZigBee utilize "contention access period ('CAP') time slots" for data transmission. Products using Wi-Fi employ a "contention-based channel access mechanism" where nodes compete for transmit opportunities (TXOPs) in a contention period (CP). | ¶¶77-78 | col. 2:27-32 |
| determining link utilization metrics for each communication link based upon a quantity of data previously sent over the communication link... and the data queues | In Wi-Fi, a hybrid coordinator (HC) allocates TXOPs based on the size of traffic queues. In ZigBee, pending transactions are stored in queues and transmitted based on algorithms, which the complaint equates to link utilization metrics. | ¶¶79-80 | col. 2:32-35 |
| and scheduling demand assigned time slots for establishing additional communication links... based upon the link utilization metrics | Accused Products using ZigBee schedule "guaranteed time slots ('GTS')" for nodes requiring specific bandwidth. In Wi-Fi, a station can request and be granted specific TXOPs for contention-free transfer of QoS data. | ¶¶81-82 | col. 2:35-41 |
Identified Points of Contention
A primary point of contention may be whether the standardized access methods in Wi-Fi and ZigBee meet the definitions of the claimed "semi-permanent time slots" and "demand assigned time slots." The defense could argue that a shared "contention access period," where access is probabilistic, is technically distinct from a scheduled "semi-permanent time slot" which may imply a more deterministic or reserved allocation.
’310 Patent Infringement Allegations
| Claim Element (from Independent Claim 13) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A method for routing message data from a source node to a destination node in a mobile ad hoc network... | The Accused Products utilize ZigBee and Z-Wave protocols, which create mobile ad hoc networks for communication between smart home devices. | ¶96 | col. 1:13-20 |
| at the source node, discovering routing to the destination node | Accused Products using ZigBee employ "route request" and "route reply" commands to discover routes. Products using Z-Wave utilize Ad-Hoc On-demand Distance Vector ("AODV") routing to discover routes from source to destination. | ¶97 | col. 4:1-3 |
| at the source node, ranking discovered routes according to at least one link metric | Accused Products using ZigBee utilize a "path cost metric" for route comparison and ranking. Products using Z-Wave rank AODV-discovered routes based on metrics such as shortest path derived from link-state information. | ¶98 | col. 4:3-5 |
| and at the source node, simultaneously distributing the message data to the destination node along a plurality of the discovered routes based upon the ranking | The complaint alleges that Accused Products using ZigBee "distribute message data (e.g., relay messages or deliver packets)" and that products using Z-Wave "distribute message data by making a selection among multiple alternative routes." | ¶99 | col. 4:5-8 |
Identified Points of Contention
A key technical question will be whether the accused protocols actually "simultaneously distribute" data "along a plurality" of routes. The complaint's allegation for Z-Wave—"making a selection among multiple alternative routes"—raises the question of whether the protocol simply chooses one best path for transmission rather than using multiple paths at the same time, which may be required by the claim language.
V. Key Claim Terms for Construction
’986 Patent (Claim 25)
The Term
"semi-permanent time slots"
Context and Importance
This term is foundational to the patent's two-tiered scheduling approach. Its construction will be critical because the infringement theory maps this term onto the standardized "contention access periods" of ZigBee and Wi-Fi. Practitioners may focus on this term because if it is construed to require a dedicated, non-contention-based allocation, the infringement allegations may be significantly undermined.
Intrinsic Evidence for Interpretation
- Evidence for a Broader Interpretation: The patent does not appear to provide a lexicographical definition, contrasting it mainly with "demand assigned" slots. This lack of a specific, limiting definition could support a construction that covers any regularly recurring time interval where communication is permitted.
- Evidence for a Narrower Interpretation: The term "semi-permanent" itself implies a degree of stability and reservation not typically associated with a contention period where access is competitive and not guaranteed. The description of the protocol for assigning these slots involves a multi-step request, reply, and confirmation process, suggesting a more formal allocation than a simple contention mechanism (’986 Patent, FIG. 6).
’310 Patent (Claim 13)
The Term
"simultaneously distribut[ing] ... message data ... along a plurality of the discovered routes"
Context and Importance
This phrase captures the core multi-path action of the invention. The infringement case depends on whether the accused products' routing behavior meets this functional requirement. If the products merely select one "best" route from a list of possibilities for each transmission, they may not infringe.
Intrinsic Evidence for Interpretation
- Evidence for a Broader Interpretation: The specification suggests this can include distributing "duplicate message data along the plurality of discovered routes" or "distributing different portions of the message data," which might be argued to cover a range of multi-path utilization schemes (’310 Patent, col. 3:5-8).
- Evidence for a Narrower Interpretation: The word "simultaneously" and the phrase "along a plurality" strongly imply that data from a single logical message is actively transmitted over more than one path at or near the same time. The patent's background explicitly criticizes prior art that "uses only a single path," suggesting the invention requires a fundamental departure from single-path selection (’310 Patent, col. 2:44-46).
VI. Other Allegations
- Indirect Infringement: The complaint alleges that Amazon induces infringement by, among other things, providing instructions, user manuals, and technical support for the Accused Products, thereby encouraging customers to use them in an infringing manner (Compl. ¶¶85, 102, 119, 135).
- Willful Infringement: The complaint alleges willful infringement based on pre-suit knowledge. It specifically cites a letter dated May 2, 2018, from Harris Corporation (the original patent assignee) to Amazon, which allegedly provided notice of infringement of the asserted patent portfolio by products including at least the Amazon Echo Plus (Compl. ¶¶84, 101, 118, 134). Continued sales after this date are alleged to be willful.
VII. Analyst’s Conclusion: Key Questions for the Case
- Definitional Scope: A central issue will be one of claim construction: can the term "semi-permanent time slots," as described in the ’986 Patent, be construed to encompass the shared, contention-based access periods defined by the ZigBee and Wi-Fi standards, or does the term require a more dedicated, non-competitive allocation?
- Functional Operation: A key evidentiary question will be one of technical function: do the Accused Products, by implementing standard Z-Wave and ZigBee protocols, actually perform the "simultaneously distribut[ing]" of data "along a plurality of... routes" as required by claim 13 of the ’310 Patent, or do they operate by selecting a single best path for each data transmission from a list of available options?
- Willfulness and Damages: A critical question for damages will be the impact of the alleged May 2, 2018 notice letter. The case will likely examine what steps, if any, Amazon took after receiving this notice, which will be central to determining whether any infringement was willful and thus subject to potential enhancement of damages.