Centre One v. Cable One Inc

I. Executive Summary and Procedural Information

• Parties & Counsel:
  • Plaintiff: Centre One (Nevada)
  • Defendant: Cable One, Inc. (Delaware)
  • Plaintiff’s Counsel: Friedman, Suder & Cooke; Farnan LLP
• Case Identification: 1:20-cv-00631, D. Del., 05/11/2020
• Venue Allegations: Venue is asserted in the District of Delaware based on Cable One being a Delaware limited liability company, and therefore residing in the district.
• Core Dispute: Plaintiff alleges that Defendant’s Voice over IP (VoIP) telecommunications services infringe five patents related to systems and methods for interfacing traditional public switched telephone networks (PSTN) with Internet Protocol (IP) networks.
• Technical Context: The technology at issue involves the foundational architecture of VoIP systems that bridge legacy circuit-switched telephone networks with modern packet-switched IP networks to enable integrated, real-time voice communications.
• Key Procedural History: The complaint notes that two of the asserted patents, U.S. Patent Nos. 7,068,668 and 7,486,667, were the subject of inter partes reexamination proceedings and were subsequently confirmed as patentable or amended. The complaint also lists prior infringement litigations involving the patent family against other major telecommunications providers, including AT&T, Comcast, and Charter, which reportedly resolved.

Case Timeline

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

U.S. Patent No. 7,068,668 - "Method and Apparatus for Interfacing a Public Switched Telephone Network and an Internet Protocol Network for Multi-Media Communication"

• Issued: June 27, 2006

The Invention Explained

• Problem Addressed: At the time of the invention, real-time voice communication was not seamlessly possible between the traditional circuit-switched PSTN and the emerging packet-switched IP networks; prior attempts were limited to non-real-time messaging systems ('668 Patent, col. 1:43-55).
• The Patented Solution: The patent describes a system architecture that unifies the two networks. The core components are a computer-controlled switch connected to the PSTN, and "gate interface circuitry" (comprising a gateway and a gatekeeper) connected to both the switch and the IP network ('668 Patent, Fig. 2; col. 4:56-65). This allows the system to receive a call from either network and route it to one or more pre-programmed destination addresses on either the PSTN or the IP network, enabling "follow-me" services ('668 Patent, col. 6:1-12).
• Technical Importance: This architecture represented an early, comprehensive solution for bridging the PSTN and IP worlds for real-time voice, enabling advanced calling features that are now common in VoIP services (Compl. ¶20).

Key Claims at a Glance

• The complaint asserts at least independent claim 3, as amended by reexamination (Compl. ¶50).
• Essential elements of claim 3 include:
  • A computer-controlled switch for receiving and routing calls between the PSTN and an IP network.
  • Gate interface circuitry (including gateway and gatekeeper functions) to interface the two networks.
  • The switch stores destination addresses on both the PSTN and IP network for a subscriber.
  • The switch can simultaneously route an incoming call to a plurality of a subscriber's pre-designated destination addresses.
  • A voice response unit connected between the gateway and the switch to convert voice signals into digital tones for the switch.
• The complaint expressly reserves the right to assert additional claims of the ’668 Patent (Compl. ¶50).

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U.S. Patent No. 7,486,667 - "Method and Apparatus for Interfacing a Public Switched Telephone Network and an Internet Protocol Network for Multi-Media Communication"

• Issued: February 3, 2009

The Invention Explained

• Problem Addressed: The patent addresses the same technical problem as its parent, the ’668 Patent: the lack of seamless, real-time voice integration between PSTN and IP networks ('667 Patent, col. 1:42-54).
• The Patented Solution: This patent claims a method for providing advanced call routing. The method involves assigning a subscriber multiple destination addresses across both the PSTN and IP networks, receiving a call from the internet, and automatically routing it to those addresses ('667 Patent, Abstract; col. 8:17-36 [original claim 1]). The method relies on the same underlying system architecture described in the shared specification, including a gateway, switch, and voice response unit ('667 Patent, Fig. 2).
• Technical Importance: This claimed method provided the operational logic for "follow-me" and unified communication services, allowing a user's single inbound number to ring multiple disparate devices (e.g., a desk phone and a computer-based client) simultaneously (Compl. ¶15).

Key Claims at a Glance

• The complaint asserts at least claim 14 (Compl. ¶57).
• Claim 14 was added during inter partes reexamination, while original claims 1-13 were cancelled ('667 Reexam. Cert., col. 2:5-7).
• The claim is for a method that includes:
  • Converting, at a voice response unit connected at a gateway to a switch, voice signals received by the gateway to digital tones for the switch.
  • Transmitting the digital tones to the switch.
• Critically, the claim text states it is "[t]he method of claim 4 or 6, further comprising..." even though claims 4 and 6 were cancelled. This unusual phrasing suggests an intent to incorporate the limitations of the original, cancelled claims, which related to routing calls to an IP address and handling messages.
• The complaint expressly reserves the right to assert additional claims of the ’667 Patent (Compl. ¶57).

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U.S. Patent No. 8,125,982 - "Method and Apparatus for Interfacing a Public Switched Telephone Network and an Internet Protocol Network for Multi-Media Communication"

• Issued: February 28, 2012
• Technology Synopsis: This patent claims systems and methods for real-time voice communication between IP and PSTN networks, with an added focus on providing caller identification upon the routing of a call (Compl. ¶63). The system uses a computer-controlled switch that stores at least one destination address for a subscriber on both a PSTN and an IP network (Compl. ¶63).
• Asserted Claims: At least claim 1 (independent system claim) (Compl. ¶64).
• Accused Features: The accused functionality is Cable One’s VoIP network and infrastructure, which provides caller identification features (Compl. ¶¶ 42, 64).

U.S. Patent No. 8,724,643 - "Providing Real-Time Voice Communication Between Devices Connected to an Internet Protocol Network and Devices Connected to a Public Switched Telephone Network"

• Issued: May 13, 2014
• Technology Synopsis: This patent claims systems and methods for routing calls between IP and PSTN networks by converting voice signals to packetized data and using hardware and software components for call control functions (e.g., address translation, bandwidth management) (Compl. ¶70). The technology routes calls to one or more destination addresses stored for a subscriber on either the IP network or PSTN (Compl. ¶70).
• Asserted Claims: At least claims 10 and 11 (Compl. ¶71).
• Accused Features: The accused functionality is Cable One's network and infrastructure that routes calls to stored destination addresses, such as through its "simultaneous ring" feature (Compl. ¶¶ 44, 71).

U.S. Patent No. 10,063,710 - "Providing Real-Time Voice Communication Between Devices Connected to an Internet Protocol Network and Devices Connected to a Public Switched Telephone Network"

• Issued: August 28, 2018
• Technology Synopsis: This patent claims systems and methods focusing on the IP-to-PSTN call path. The system employs "gate interface circuitry" to receive a call from the IP network and depacketize the voice data (Compl. ¶77). A "voice response unit" then converts the data to digital tones, which a computer-controlled switch uses to route the call to a subscriber's destination address on the PSTN (Compl. ¶77).
• Asserted Claims: At least claim 1 (independent system claim) (Compl. ¶78).
• Accused Features: The accused functionality is Cable One's network and infrastructure used to route calls originating on an IP network to its subscribers on the PSTN (Compl. ¶78).

III. The Accused Instrumentality

Product Identification

• The complaint identifies two categories of accused services: "Accused Residential Products" (e.g., Sparklight Economy and Standard) and "Accused Business Products" (e.g., Sparklight Business Phone Unlimited, Hosted Voice, SIP and PRI Trunking), including prior versions sold under the "Cable One" brand (Compl. ¶¶ 24-26).

Functionality and Market Context

• The accused services are VoIP telephone offerings provided over Cable One's hybrid fiber-coax (HFC) network (Compl. ¶26). The complaint alleges this network operates in accordance with industry standards like DOCSIS and PacketCable (Compl. ¶30). The complaint includes a diagram of the PacketCable reference architecture, alleging that Cable One's network utilizes corresponding components to provide its services (Compl. p. 11, Fig. 1). Key alleged functionalities include:
  • Providing customer premise gateways (e.g., Arris e-MTAs or modems with phone adapters) that convert voice for IP transmission (Compl. ¶¶ 38, 41).
  • Utilizing network switches (allegedly Nortel softswitches) for call processing and routing (Compl. ¶37).
  • Offering advanced features via application servers, including "simultaneous ring," which routes an inbound call to multiple designated phone numbers, and voicemail-to-email services (Compl. ¶¶ 42-44). The "simultaneous ring" feature appears central to the infringement allegations for the patents' "follow-me" functionality (Compl. ¶44).

IV. Analysis of Infringement Allegations

'668 Patent Infringement Allegations

'667 Patent Infringement Allegations

The complaint asserts claim 14, which was added during reexamination and depends on cancelled claims. The elements below are reconstructed from the original claims referenced by claim 14 and the limitations added by claim 14 itself.

Identified Points of Contention

• Architectural Mapping: A likely point of dispute will be whether Cable One's allegedly modern, integrated HFC network architecture, with components like softswitches and multifunction gateways (MTAs), maps onto the more modular system described in the patents, which depicts a distinct "computer controlled switch," "gateway," "gatekeeper," and "voice response unit."
• Scope of Claim 14 of the '667 Patent: The primary legal and technical challenge for the ’667 patent will be the proper interpretation of claim 14. Because it expressly depends on claims 4 and 6, which were cancelled during the same reexamination proceeding, its scope and even its validity are open questions that the court must resolve.
• Functional Equivalence: A key technical question is whether the "signal conversions" generally alleged to occur in the accused network (Compl. ¶37) perform the specific function of the claimed "voice response unit" converting signals into "digital tones for use by the... switch," or if there is a fundamental operational difference.

V. Key Claim Terms for Construction

The Term: "computer controlled switch"

Context and Importance

This term is foundational to the asserted system claims. The Plaintiff alleges that Cable One's Nortel softswitches meet this limitation (Compl. ¶37). The definition will be critical to determining if a modern, software-based and distributed switching architecture falls within the scope of a claim drafted in an era of more centralized, hardware-based "Class 5" switches.

Intrinsic Evidence for Interpretation

• Evidence for a Broader Interpretation: The term itself is general. The specification describes the switch's function—routing calls between PSTN and IP networks—without strictly limiting its implementation, which may support a functional definition covering any component that performs this role ('668 Patent, col. 6:21-30).
• Evidence for a Narrower Interpretation: The specification repeatedly uses "Class 5 switching" and T-1/DS3 lines as the primary example, which could be used to argue the inventor contemplated a traditional telecommunications switch, not a modern softswitch ('668 Patent, col. 6:21-25).

The Term: "voice response unit"

Context and Importance

This limitation was added during reexamination to distinguish the invention from prior art and is present in the asserted claims of the '668 and '667 patents. Practitioners may focus on this term because the complaint's allegations for it are less specific than for other components.

Intrinsic Evidence for Interpretation

• Evidence for a Broader Interpretation: The patent describes the unit's function: "takes the depacketized voice signal received at the gateway 105 and converts it to digital tones for use by the switch 101" ('668 Patent, col. 6:44-48). A party could argue this is a broad functional description that reads on any component, like a Digital Signal Processor (DSP) in a gateway, that performs this conversion.
• Evidence for a Narrower Interpretation: Figure 2 of the patent depicts the "VOICE RESPONSE UNIT" (107) as a distinct box, separate from the "GATEWAY" (105). A party could argue this requires a physically or logically separate component, not a function that is integrated into a gateway device as is common in modern systems.

VI. Other Allegations

• Indirect Infringement: While no separate counts for indirect infringement are pleaded, the complaint lays a factual basis for inducement. It alleges that "Cable One provides instructions in its user guides for activating and configuring" features like readable voicemail and simultaneous ring, which allegedly cause subscribers to directly infringe (Compl. ¶¶ 42-44).
• Willful Infringement: The complaint alleges willful infringement for all five asserted patents. The basis for willfulness is alleged pre-suit knowledge of the patents and infringement, based on a notice letter Plaintiff allegedly sent to Defendant on December 11, 2018, more than sixteen months prior to the filing of the lawsuit (Compl. ¶¶ 45, 51, 58, 65, 72, 79).

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

• A core issue will be one of technological translation: can the patent claims, which describe a seemingly modular system architecture from the early days of VoIP (e.g., a distinct switch, gateway, and voice response unit), be construed to cover the integrated and distributed components of the modern HFC/PacketCable network that Cable One allegedly operates?
• A key legal question will be the viability and scope of claim 14 of the '667 patent. The court must first determine how to interpret a claim that was added during reexamination yet facially depends on parent claims that were simultaneously cancelled, a significant ambiguity that may impact the entire infringement theory for that patent.
• A central evidentiary question will be one of infringement proof: beyond architectural diagrams from industry standards, what specific evidence will Plaintiff produce to show that Cable One’s accused products—particularly its switches and gateways—actually operate in a way that meets the specific functional limitations of the asserted claims, such as the "voice response unit" converting signals to "digital tones for the switch"?