DCT

8:19-cv-00708

Rembrandt Wireless Tech LP v. Broadcom Inc

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I. Executive Summary and Procedural Information

  • Parties & Counsel:
  • Case Identification: 8:19-cv-00708, C.D. Cal., 04/15/2019
  • Venue Allegations: Venue is alleged to be proper based on Defendants having regular and established places of business in the Central District of California, including offices in Irvine, and committing acts of infringement within the district.
  • Core Dispute: Plaintiff alleges that Defendant’s semiconductor products that are compliant with certain Bluetooth specifications supporting Enhanced Data Rate (EDR) infringe two patents related to communication systems that use multiple modulation methods.
  • Technical Context: The technology concerns methods for enabling devices in a master-slave network to communicate using different, otherwise incompatible, data modulation techniques, a key feature for ensuring both backward compatibility and support for higher data rates in standards like Bluetooth.
  • Key Procedural History: The complaint heavily references prior litigation involving the patents-in-suit against Samsung and BlackBerry, which resulted in licenses. Notably, a jury found the patents valid and infringed by Samsung's use of Bluetooth EDR, a verdict affirmed by the U.S. Court of Appeals for the Federal Circuit. The complaint also states that the U.S. Patent and Trademark Office declined to institute inter partes review (IPR) and separately confirmed the validity of the asserted claims in ex parte reexamination proceedings. Both patents expired before the complaint was filed; consequently, the lawsuit seeks only past damages.

Case Timeline

Date Event
1997-12-05 Priority Date for ’228 and ’580 Patents
2011-09-20 U.S. Patent No. 8,023,580 Issued
2013-06-04 U.S. Patent No. 8,457,228 Issued
2013-12-03 Broadcom allegedly knew of patents via subpoena in Rembrandt v. Samsung
2014-12-04 Rembrandt disclaimed certain claims of the '580 Patent
2018-08-27 Samsung became licensed to the patents-in-suit
2018-12-04 ’228 and ’580 Patents Expired
2019-04-15 Complaint Filed

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

U.S. Patent No. 8,457,228 - "System and Method of Communication Using at Least Two Modulation Methods"

  • Patent Identification: U.S. Patent No. 8,457,228, "System and Method of Communication Using at Least Two Modulation Methods," issued June 4, 2013.

The Invention Explained

  • Problem Addressed: In prior master-slave communication networks, all devices (transceivers) were required to use a single, common modulation method. This created incompatibility issues, preventing a network from seamlessly incorporating newer devices that used different, often more efficient, modulation methods alongside older devices (’228 Patent, col. 1:29-67, col. 2:20-25).
  • The Patented Solution: The invention describes a master transceiver that can manage communications with slave devices (or "tributaries") using different modulation types. The master can transmit a "first message" using a first modulation method to communicate with one type of slave. Crucially, it can also transmit a "second message" that begins with information modulated in the first method but includes a notification of an "impending change" to a second modulation method, followed by data modulated in that second method for a different type of slave (’228 Patent, col. 6:4-36; Compl. ¶18). This allows a single master to orchestrate a network with heterogeneous devices.
  • Technical Importance: This approach allows for backward compatibility and greater network efficiency by permitting the selection of a modulation type best suited for a particular application (e.g., a low-rate method for simple controls and a high-rate method for data-intensive transfers) without disrupting the entire network (’228 Patent, col. 3:9-14).

Key Claims at a Glance

  • The complaint asserts claim 21, which depends on independent claim 1 (Compl. ¶28).
  • The essential elements of independent claim 1 include:
    • A master communication device with a master transceiver.
    • The transceiver transmits a "first message" comprising: (i) first information modulated via a first method, (ii) second information (payload) modulated via the first method, and (iii) first message address data for a slave device.
    • The transceiver also transmits a "second message" comprising: (i) third information modulated via the first method indicating an impending change to a second modulation method, (ii) fourth information (payload) modulated via the second, different method, and (iii) second message address data for a different, single slave transceiver.
    • The second modulation method provides a higher data rate than the first.
  • The complaint does not explicitly reserve the right to assert other claims, but standard practice suggests this possibility remains.

U.S. Patent No. 8,023,580 - "System and Method of Communication Using at Least Two Modulation Methods"

  • Patent Identification: U.S. Patent No. 8,023,580, "System and Method of Communication Using at Least Two Modulation Methods," issued September 20, 2011.

The Invention Explained

  • Problem Addressed: The patent shares its specification with the ’228 Patent and thus addresses the same problem: the incompatibility and inefficiency of communication networks where all devices must use a single modulation method (’580 Patent, col. 1:25-col. 2:21; Compl. ¶35).
  • The Patented Solution: The solution is functionally identical to that of the ’228 Patent. It describes a master device that can dynamically manage communications with different slave devices by using a first modulation scheme to signal an upcoming switch to a second modulation scheme for a specific data transmission (’580 Patent, col. 6:3-36). The complaint's description of the patented technology in paragraphs 9-27 is explicitly incorporated for the ’580 Patent (Compl. ¶35).
  • Technical Importance: As with the ’228 Patent, the invention enables more flexible, efficient, and backward-compatible networks by allowing different modulation types to coexist under the control of one master device (’580 Patent, col. 2:51-58).

Key Claims at a Glance

  • The complaint asserts claims 2 and 59 (Compl. ¶36). Claim 2 depends on independent claim 1, and claim 59 depends on independent claim 58.
  • The essential elements of independent claim 1 include:
    • A communication device with a master transceiver for sending transmissions.
    • Transmissions are structured with a first portion and a payload portion.
    • The first portion uses a first modulation method and indicates an impending change to a second modulation method.
    • The payload portion is transmitted after the first portion and is modulated according to the second method.
  • The essential elements of independent claim 58 include:
    • A communication device with a master transceiver.
    • It transmits messages with a "first sequence" and a "second sequence."
    • The first sequence is modulated in a first method and indicates which modulation method will be used for the second sequence.
    • In at least one message, the first sequence indicates an "impending change" to a second modulation method, and the second sequence is modulated accordingly.

III. The Accused Instrumentality

Product Identification

  • The accused instrumentalities are Broadcom's semiconductor products (chips) that are compliant with Bluetooth specifications supporting Enhanced Data Rate ("EDR"), including but not limited to versions 2.0+EDR, 2.1+EDR, 3.0+HS, 4.0+LE, 4.1, 4.2, and 5.0 (Compl. ¶28). The complaint provides a non-exhaustive list of over two dozen specific "BCM"-series product numbers (Compl. ¶29). These are collectively referred to as the "Broadcom Bluetooth EDR Products."

Functionality and Market Context

  • The accused products are alleged to function as "master communication devices" in a master-slave network (Compl. ¶30, ¶37). Their core accused functionality is the ability to transmit data using at least two different modulation methods as defined by the Bluetooth EDR standard: a basic rate method, Gaussian Frequency Shift Keying (GFSK), and a higher-rate method, Differential Phase Shift Keying (DPSK) (Compl. ¶30, ¶37).
  • The complaint alleges that these products are used in a vast number of consumer electronics and that Broadcom is a major supplier to companies like Samsung, which was the defendant in prior litigation over these same patents and this same technology (Compl. ¶31, ¶41).

IV. Analysis of Infringement Allegations

The complaint's central theory is that the standard operation of Bluetooth EDR maps directly onto the patented method of switching between modulation types. A lower-rate packet ("Basic Rate packet") corresponds to the "first message," while a higher-rate packet ("Enhanced Rate packet") corresponds to the "second message" that signals a modulation change.

The complaint includes an annotated diagram, adapted from the patent's Figure 8, to illustrate how a communication can use a first modulation method for both a training signal and a data signal (170), while another communication (172) can use that first method for the training signal but switch to a second method for the data signal (Compl. p. 8).

U.S. Patent No. 8,457,228 Infringement Allegations

Claim Element (from Independent Claim 1) Alleged Infringing Functionality Complaint Citation Patent Citation
A master communication device configured to communicate with one or more slave transceivers... Broadcom's Bluetooth EDR Products can operate as a master in a master-slave relationship. ¶30 col. 10:20-24
...transmits a "first message"... comprising... second information... modulated according to a first modulation method... The products transmit a Basic Rate packet, where the payload is modulated using the GFSK method. ¶30 col. 10:31-34
...transmits a "second message"... comprising... third information modulated according to the first modulation method... indicative of an impending change in modulation to a second modulation method... The products transmit an Enhanced Rate packet, where the access code/header is modulated using the GFSK method and allegedly indicates a change in modulation for the payload. ¶30 col. 10:43-49
...and fourth information... being modulated according to the second modulation method... the second modulation method being of a different type than the first modulation method... The payload of the Enhanced Rate packet is modulated using the DPSK method, which is different from GFSK. ¶30 col. 10:52-55

U.S. Patent No. 8,023,580 Infringement Allegations

Claim Element (from Independent Claim 58) Alleged Infringing Functionality Complaint Citation Patent Citation
A communication device capable of communicating according to a master/slave relationship... Broadcom's Bluetooth EDR Products operate in a master-slave relationship. ¶37 col. 11:50-54
...transceiver is configured to transmit messages with: a first sequence, in the first modulation method, that indicates at least which of the first modulation method and the second modulation method is used for modulating a second sequence... The products transmit packets where a GFSK access code/header (the "first sequence") allegedly has fields (LT_ADDR and TYPE) that indicate the modulation method of the payload (the "second sequence"). ¶37 col. 12:5-14
...wherein, in at least one message, the first sequence indicates an impending change from the first modulation method to the second modulation method... In an Enhanced Rate packet, the GFSK header ("first sequence") allegedly indicates an impending change to DPSK modulation for the payload. ¶37 col. 12:6-9
...and the second sequence, modulated in accordance with the modulation method indicated by the first sequence... is modulated using the second modulation method... The payload ("second sequence") of an Enhanced Rate packet is modulated using DPSK, as indicated by the header. ¶37 col. 12:11-14
  • Identified Points of Contention:
    • Scope Questions: A central question is whether the packet structure of the Bluetooth EDR standard constitutes the specific "message" or "sequence" structure required by the claims. The defense may argue that a standard Bluetooth packet is a single, integrated unit, not the multi-part, sequentially processed message described in the patent. The complaint uses an annotated diagram from the patent's Figure 4 to depict the system having a master transceiver capable of communicating with both "Type A" (e.g., AM) and "Type B" (e.g., FM) slave devices simultaneously (Compl. p. 7).
    • Technical Questions: The infringement theory hinges on whether the header of an Enhanced Rate packet performs the claimed function of "indicat[ing] an impending change" in modulation. A key technical question for the court will be whether the header fields simply define a static packet type (an "Enhanced Rate packet") or if they actively signal a dynamic change in modulation from a baseline state, as the patent specification appears to describe. The complaint's depiction of a master transmitting a "Training - Change To Type B" signal (Compl. p. 9, Fig. 5) suggests a more explicit notification than may be present in the accused standard.

V. Key Claim Terms for Construction

  • The Term: "indicative of an impending change in modulation" (’228 Patent, cl. 1) / "indicates an impending change" (’580 Patent, cl. 1, 58).
  • Context and Importance: This term is the crux of the infringement case. The dispute will likely focus on whether the information in a Bluetooth EDR packet header merely identifies the payload's modulation type as a static fact or if it performs the more active, forward-looking function of signaling a change from a different, default modulation method.
  • Intrinsic Evidence for Interpretation:
    • Evidence for a Broader Interpretation: Plaintiff may argue that in the context of a system supporting multiple modulation types, any information that specifies a non-default or higher-rate modulation type for an upcoming payload is inherently "indicative of a change."
    • Evidence for a Narrower Interpretation: The specification describes transmitting a "training sequence... in which these tribs are notified of an impending change" (’228 Patent, col. 6:27-30). This language, along with diagrams like Figure 5 showing an explicit "Training - Change To Type B" step (Compl. p. 9), could support a narrower construction requiring a specific, explicit notification of a change, not just the use of a different packet format.

VI. Other Allegations

  • Indirect Infringement: The complaint alleges active inducement based on Broadcom selling the accused products to its customers, marketing their infringing capabilities (i.e., their compliance with Bluetooth EDR), and providing instructions and technical support that encourage their use in an infringing manner (Compl. ¶31, ¶38).
  • Willful Infringement: The willfulness claim is supported by strong allegations of pre-suit knowledge. The complaint alleges Broadcom was served a subpoena in the Rembrandt v. Samsung litigation on December 3, 2013, which identified the patents-in-suit. It further alleges a Broadcom employee was deposed in that case and attended the trial (Compl. ¶31). This alleges direct, specific knowledge of the patents and the infringement theory years before the current suit was filed.

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

  1. Technical Mapping and Claim Construction: Will the court find that the static structure of a Bluetooth EDR packet (header + payload) meets the dynamic, process-oriented claim limitations requiring a signal that "indicates an impending change" in modulation? The case may turn on whether the function of the Bluetooth header is equivalent to the explicit "notification of change" described in the patent's preferred embodiments.
  2. Impact of Litigation History: How will the extensive and successful litigation history against Samsung—involving the same patents, the same accused technology (Bluetooth EDR), an affirmed jury verdict of validity and infringement, and subsequent validation at the USPTO—influence this case? While not legally binding on Broadcom, this history creates a significant precedential and persuasive challenge for the defense, particularly on issues of validity and the general applicability of the patents to the Bluetooth EDR standard.