DCT
8:19-cv-02317
Centre One v. Charter Communications LLC
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Centre One (Nevada)
- Defendant: Charter Communications, LLC (Delaware)
- Plaintiff’s Counsel: Umberg Zipser LLP; Friedman, Suder & Cooke
- Case Identification: 8:19-cv-02317, C.D. Cal., 12/02/2019
- Venue Allegations: Venue is asserted based on Defendant's operation of a nationwide network and maintenance of regular and established places of business within the Central District of California, from which it offers for sale and sells the accused products.
- Core Dispute: Plaintiff alleges that Defendant’s Spectrum-branded residential, business, and mobile VoIP services infringe six patents related to interfacing traditional public switched telephone networks (PSTN) with internet protocol (IP) networks.
- Technical Context: The lawsuit concerns Voice over IP (VoIP) technology, which enables voice communication over packet-switched data networks like the internet, and its integration with legacy circuit-switched telephone networks.
- Key Procedural History: The complaint notes that two of the asserted patents, the ’667 and ’668 patents, were the subject of a 2009 lawsuit against other telecommunications companies. It states these patents underwent inter partes reexamination during that litigation and were subsequently "confirmed as patentable," which may be raised to suggest the patents' resilience to validity challenges.
Case Timeline
| Date | Event |
|---|---|
| 2000-01-07 | Priority Date for all Asserted Patents |
| 2006-06-27 | U.S. Patent No. 7,068,668 Issued |
| 2009-02-03 | U.S. Patent No. 7,486,667 Issued |
| 2012-02-28 | U.S. Patent No. 8,125,982 Issued |
| 2013-06-12 | Reexamination Certificate Issued for '668 Patent |
| 2013-09-16 | Reexamination Certificate Issued for '667 Patent |
| 2014-05-13 | U.S. Patent No. 8,724,643 Issued |
| 2017-09-26 | U.S. Patent No. 9,774,745 Issued |
| 2018-08-28 | U.S. Patent No. 10,063,710 Issued |
| 2019-12-02 | Complaint Filed |
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”
The Invention Explained
- Problem Addressed: At the time of invention, integrating the circuit-switched PSTN with packet-switched IP networks for real-time voice communication was difficult (Compl. ¶23). The patent background notes that while computers could communicate over IP networks, this "excluded from the communication loop" the vast, existing PSTN infrastructure, and that attempts to merge them were hindered by technical challenges like propagation and handling delays (’668 Patent, col. 2:38-60).
- The Patented Solution: The invention provides a central communication system that acts as an intelligent bridge between the PSTN and an IP network (’668 Patent, Abstract). As depicted in Figure 2 of the patent, this system uses a computer-controlled switch, a gateway, and a gatekeeper to manage calls, translate addresses, and convert voice signals between the two disparate network types, enabling features like routing a single incoming call to multiple destinations on both the PSTN and the IP network simultaneously (’668 Patent, col. 6:4-40).
- Technical Importance: The technology aimed to unify the global PSTN with the burgeoning internet, allowing for enhanced services (e.g., "follow me" calling, unified messaging) and cost savings through toll bypass without requiring users to abandon their existing telephone devices (Compl. ¶¶ 9, 12, 16).
Key Claims at a Glance
- The complaint asserts at least Claim 3 (Compl. ¶43). The patent's reexamination certificate cancelled original claims 1-2 and amended claim 3, making it a standalone independent claim.
- Essential elements of amended Claim 3 (a system claim) include:
- A computer-controlled switch operable to receive and route calls between a PSTN and an IP network.
- Gate interface circuitry, which itself includes gateway circuitry (for interfacing voice circuits) and gatekeeper circuitry (for address translation, admission control, etc.).
- A voice response unit connected between the gate interface circuitry and the switch to convert voice signals to digital tones for the switch.
- The switch stores destination addresses on both the PSTN and IP network for subscribers and can simultaneously route an incoming call to a plurality of those addresses.
- The complaint expressly reserves the right to assert additional claims (Compl. ¶43).
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”
The Invention Explained
- Problem Addressed: The patent addresses the need for methods to provide advanced, real-time calling features to subscribers across both IP and PSTN networks, such as routing a call from an internet-connected device to multiple subscriber endpoints and handling the call if it is not answered (Compl. ¶48).
- The Patented Solution: The invention describes a method for routing a real-time voice call to a subscriber by assigning them both an IP address and a PSTN phone number (’667 Patent, Claim 1). Upon receiving a call, the system automatically routes it to each pre-designated destination and, if the call is unanswered, takes a message for later delivery in various formats (e.g., voice, e-mail), as determined by the subscriber (’667 Patent, Claim 1).
- Technical Importance: This method enabled "follow-me" functionality where a user could be reached on any of their devices, regardless of network type, from a single inbound call, a significant enhancement over standard telephony (Compl. ¶12).
Key Claims at a Glance
- The complaint asserts at least Claim 14 (Compl. ¶49). The patent’s reexamination certificate added Claim 14 as a new, independent claim.
- Essential elements of Claim 14 (a method claim) include:
- Converting, at a voice response unit connected to a gateway and a switch, voice signals to digital tones for the switch.
- Transmitting, at the voice response unit, the digital tones to the switch.
- The complaint does not explicitly reserve the right to assert additional claims for this patent but does so generally.
Multi-Patent Capsule: U.S. Patent No. 8,125,982 B2, “Providing Real-Time Voice Communication Between Devices Connected to an Internet Protocol Network and Devices Connected to a Public Switched Telephone Network,” issued February 28, 2012.
- Technology Synopsis: This patent discloses systems and methods for providing real-time voice communication and caller identification between IP and PSTN networks (Compl. ¶54). The system uses a computer-controlled switch that stores at least one destination address on each network type for a subscriber and performs call control functions like address translation and bandwidth management (Compl. ¶54).
- Asserted Claims: At least independent system Claim 1 (Compl. ¶55).
- Accused Features: The complaint alleges that Charter's network infrastructure, which provides the Accused Products, comprises the components and functionality of the claimed system (Compl. ¶55).
Multi-Patent Capsule: U.S. Patent No. 8,724,643 B2, “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 covers systems and methods for enabling real-time voice communication between devices on an IP network and a PSTN (Compl. ¶60). The invention entails converting voice signals to packetized digital data (and vice-versa) and using hardware/software components to perform call control functions, routing calls to one or more stored destination addresses for a subscriber on either network (Compl. ¶60).
- Asserted Claims: At least method Claims 10 and 11 (Compl. ¶61).
- Accused Features: The complaint alleges that Charter's Accused Products, operating on its network, comprise the components and perform the functional steps of the claimed method (Compl. ¶61).
Multi-Patent Capsule: U.S. Patent No. 9,774,745 B2, “Providing Real-Time Voice Communication Between Devices Connected to an Internet Protocol Network and Devices Connected to a Public Switched Telephone Network,” issued September 26, 2017.
- Technology Synopsis: This patent claims a system for packetizing voice information from a telephone via a local gateway device, transmitting it over an IP network to a computer-controlled switch, and enabling communication with the PSTN (Compl. ¶66). A key aspect is that this transmission is effected without using a private branch exchange (PBX) (Compl. ¶66).
- Asserted Claims: At least independent system Claim 1 (Compl. ¶67).
- Accused Features: The complaint alleges that Charter’s network and infrastructure for the Accused Products comprise the components and functionality of the claimed system (Compl. ¶67).
Multi-Patent Capsule: U.S. Patent No. 10,063,710 B2, “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 discloses systems and methods using gate interface circuitry to receive a call from an IP network device and depacketize it (Compl. ¶72). A voice response unit converts the voice data to digital tones, which a computer control and switch then use to route the call to one of a plurality of stored destination addresses for a subscriber (Compl. ¶72).
- Asserted Claims: At least independent system Claim 1 (Compl. ¶73).
- Accused Features: The complaint alleges that Charter’s networks and infrastructure for the Accused Products comprise the components and functionality of the claimed system (Compl. ¶73).
III. The Accused Instrumentality
Product Identification
The Accused Products are identified as Charter's Spectrum-branded residential and business VoIP services (e.g., Spectrum Voice, Spectrum Business Voice) and its mobile phone service (Spectrum Mobile) (Compl. ¶¶ 24-27).
Functionality and Market Context
The complaint alleges that the Accused Products operate over Charter's Hybrid Fiber Coaxial (HFC) network, which uses the PacketCable standard to transmit voice as data packets and to interconnect with the PSTN (Compl. ¶¶ 27-28). The network architecture is alleged to include components like Multimedia Terminal Adapters (MTA) at the customer premise, which act as gateways, and network-side components like Media Gateway Controllers (MGC), Breakout Gateway Control Functions (BGCF), and soft switches that collectively manage call routing and signaling between the IP and PSTN domains (Compl. ¶¶ 29-31). The complaint includes a diagram of the PacketCable architecture to illustrate this functionality. The "Figure 1 - PacketCable Reference Architecture" shows the relationship between customer equipment (UE), access network components (CMTS), and core network elements that interface with the PSTN (Compl. p. 9). Additionally, the complaint references a diagram showing a successful interoperability test configuration between Avaya equipment and Charter's SIP trunking service, offered as evidence of the network's capability to interface with enterprise systems and the PSTN (Compl. p. 12, Figure 1). The products are alleged to offer enhanced features such as simultaneous ring and readable voicemail (Compl. ¶¶ 35-37).
IV. Analysis of Infringement Allegations
'668 Patent Infringement Allegations
| Claim Element (from Independent Claim 3) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a computer controlled switch operable for use by subscribers and adapted for connection to a local public switched telephone network... | Charter's network allegedly uses a "soft switch" to manage calls between its subscribers and the PSTN. | ¶31 | col. 6:4-10 |
| gate interface circuitry connected to the computer controlled switch and adapted for connection to the IP network; wherein said gate interface circuitry includes gateway circuitry... and gatekeeper circuitry... | The PacketCable architecture allegedly used by Charter includes Media Gateways (MG) and Media Gateway Controllers (MGC) that perform the claimed interfacing, address translation, and admission control functions. | ¶¶29-30, 42 | col. 6:26-40 |
| a voice response unit connected between the gate interface circuitry and the switch for receiving voice signals and converting them to digital tones for the switch. | The complaint alleges the accused systems include a voice response unit that converts voice signals for use by the computer-controlled switch. | ¶42 | col. 6:41-48 |
| said computing controlled switch containing, for each subscriber, destination addresses on the PSTN and the IP network; | Charter’s "simultaneous ring" feature allegedly allows a subscriber to store multiple phone numbers, including those on the PSTN and IP networks, within a Charter switch. | ¶37 | col. 6:4-10 |
| wherein said computer controlled switch receives an incoming call... and simultaneously routes the call to a plurality of pre-designated destination addresses... | The "simultaneous ring" feature allegedly routes an incoming call to the multiple stored numbers on both the PSTN and IP networks. | ¶37 | col. 6:4-10 |
'667 Patent Infringement Allegations
| Claim Element (from Independent Claim 14) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| 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; | Charter's network infrastructure is alleged to include a voice response unit that converts voice signals for use by its switch, as part of its overall VoIP architecture. | ¶42 | col. 4:47-51 |
| and transmitting, at the voice response unit, the digital tones to the switch. | The system architecture described in the complaint implies that once converted, these tones are transmitted to the switch to facilitate call routing. | ¶42 | col. 4:47-51 |
Identified Points of Contention
- Scope Questions: A central dispute may arise over whether the patent term "computer controlled switch," described in a 2000-era context, can be read to cover the modern, distributed, and often software-defined switching elements (e.g., "soft switch") alleged to be used in Charter's PacketCable network (Compl. ¶31). The defense may argue for a narrower construction tied to the specific hardware of that period.
- Technical Questions: The complaint maps the claimed "gatekeeper circuitry" functions to PacketCable components like the Media Gateway Controller (MGC) (Compl. ¶30). A technical question will be whether the specific functions performed by Charter's MGC and related components are coextensive with the functions required by the claim language, such as "address translation, admission control, bandwidth management, and zone management" (’668 Patent, col. 6:33-40).
V. Key Claim Terms for Construction
"computer controlled switch" ('668 Patent, Claim 3)
- Context and Importance: This term is the central component of the claimed system. Its construction will be critical because the nature of switching technology has evolved significantly since the patent's priority date. Practitioners may focus on this term because its scope will determine whether Charter's modern, potentially distributed "soft switch" (Compl. ¶31) infringes.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The specification describes the switch in functional terms, stating it is "operable for use by subscribers and adapted for connection to a local public switched telephone network, receiving calls from the IP network and the PSTN, and routing calls to the PSTN and the IP network" (’668 Patent, Claim 3 as amended). Plaintiff may argue this functional language is not limited to a specific hardware implementation.
- Evidence for a Narrower Interpretation: The specification states that the switch "is capable of Class 5 switching" and names specific manufacturers of the era (’668 Patent, col. 6:21-25). Defendant may argue this language ties the claim to the specific functionalities and architecture of a traditional Class 5 switch, which may differ from a modern soft switch.
"gatekeeper circuitry" ('668 Patent, Claim 3)
- Context and Importance: This element performs several key management functions. The infringement analysis depends on mapping this claimed circuitry to specific components in Charter's accused PacketCable architecture. The precise meaning of the functions it must perform (e.g., "zone management") will be litigated.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent uses the general term "circuitry" and describes its functions in a list, which a plaintiff might argue covers any combination of hardware or software that performs those roles, such as the Media Gateway Controller (MGC) and Breakout Gateway Control Function (BGCF) in the PacketCable standard (Compl. ¶¶ 29-30).
- Evidence for a Narrower Interpretation: The specification refers to the H.323 standard when discussing gatekeepers, which performs "address translation, admission control, bandwidth management and zone management" (’668 Patent, col. 3:32-35). A defendant could argue that infringement requires practicing all of these specific H.323-defined functions, and that Charter's system, which also relies on other protocols like SIP and NCS, does not perform the identical "zone management" function as contemplated by the patent.
VI. Other Allegations
Indirect Infringement
The complaint alleges that Charter induces infringement by providing instructions to its subscribers for activating and configuring features like "readable voicemail" and "simultaneous ring," which allegedly cause the system to operate in an infringing manner (Compl. ¶¶ 36-37). These allegations of providing instructions and enabling infringing use directly support a claim for induced infringement.
Willful Infringement
The complaint requests enhanced damages, which requires a finding of willful infringement (Compl. p. 22, ¶b). While the complaint does not allege specific pre-suit knowledge by Charter, it does detail a prior lawsuit and subsequent successful reexaminations of the '668 and '667 patents against other major telecommunications companies, including Verizon (Compl. ¶19). Plaintiff may argue that a sophisticated entity like Charter was or should have been aware of these widely-publicized patents and the litigation surrounding them, creating at least a basis for post-filing willfulness.
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of definitional scope: can the term "computer controlled switch," which the patent links to "Class 5" switches of the late 1990s, be construed to cover the distributed, software-based switching architecture alleged to be used in Charter's modern, standards-based VoIP network?
- A key evidentiary question will be one of architectural mapping: does Charter’s infrastructure, which is based on the complex, multi-component PacketCable standard, contain discrete components that perform the specific combination of functions recited for the claimed "gatekeeper circuitry," or is there a technical mismatch between the patent’s system and the accused network architecture?
- A third question will concern patent validity in light of industry standards: given that the accused system is based on industry standards like PacketCable, the case will likely involve significant arguments over whether the claims are invalid as anticipated or rendered obvious by the prior art that formed the basis for those standards. The prior successful reexaminations of the '668 and '667 patents will be a central point of contention in this validity dispute.