Comcast Cable Communications, LLC et al. v. Entropic Communications, LLC

Prosecution History analysis

Examiner Search analysis

Invalidity Framework analysis

Petition

Petition summary

## 1. Case Identification
- Case Number: [IPR2025-00184](https://ai-lab.exparte.com/case/ptab/IPR2025-00184)
- Patent #: [9,866,438](https://ai-lab.exparte.com/patent/9866438)
- Filed: December 6, 2024
- Petitioner(s): Comcast Cable Communications, LLC
- Patent Owner(s): [Entropic Communications, LLC](https://ai-lab.exparte.com/party/entropic-communications-llc)
- Challenged Claims: 1-18

## 2. Patent Overview
- Title: Method and System for Service Group Management in a Cable Network
- Brief Description: The ’438 patent discloses a method for managing groups of cable modems (CMs) in a network. A cable modem termination system (CMTS) determines signal-to-noise ratios (SNRs) for the CMs, assigns them to service groups, and then generates a "composite SNR-related metric" based on the "worst-case SNR profile" within a group to select communication parameters for all modems in that group.

## 3. Grounds for Unpatentability
#### Ground 1: Claims 1-2 and 6 are obvious over Prodan in view of Cooper840.
- **Prior Art Relied Upon:** [Prodan](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1111) (Application # 2012/0269242), [Cooper840](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1130) (’840 application, Application # 2008/0291840).
- **Core Argument for this Ground:**
    - **Prior Art Mapping:** Petitioner argued that [Prodan](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1111), which was considered during prosecution, discloses most limitations of independent claim 1, including a CMTS that determines SNR metrics for CMs and assigns them to service groups. However, the Examiner allowed the claims based on the limitation requiring the generation of a composite metric based on a "worst-case SNR profile." Petitioner asserted that [Cooper840](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1130), which was not considered by the Examiner, explicitly teaches this missing element by disclosing a system that sets the modulation profile for a group of network elements as a function of the *lowest* Modulation Error Ratio (MER), a type of SNR metric, within that group.
    - **Motivation to Combine:** A person of ordinary skill in the art (POSITA) would combine [Cooper840](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1130)'s teaching with [Prodan](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1111)'s system to further [Prodan](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1111)'s stated goal of optimizing network performance. Using the worst-case SNR ensures that all CMs in a service group can reliably communicate, which is a predictable improvement.
    - **Expectation of Success:** A POSITA would have a reasonable expectation of success, as the combination involves applying a known technique (using worst-case SNR for group parameters) to a known system ([Prodan](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1111)'s) via straightforward CMTS programming to achieve a predictable result.

#### Ground 2: Claims 1-2 and 6 are obvious over Prodan in view of Azenkot.
- **Prior Art Relied Upon:** [Prodan](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1111) (Application # 2012/0269242), [Azenkot](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1131) (’996 application, Application # 2005/0122996).
- **Core Argument for this Ground:**
    - **Prior Art Mapping:** This ground presented an alternative to Ground 1. Petitioner argued that [Azenkot](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1131), which was cited but not applied during prosecution, also supplies the "worst-case" limitation missing from [Prodan](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1111). [Azenkot](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1131) taught setting a common burst profile for a group of CMs based on the "least capable cable modem" in the group, which a POSITA would understand corresponds to the modem with the lowest SNR.
    - **Motivation to Combine:** The motivation was identical to Ground 1: to apply a known technique for ensuring reliable communication to [Prodan](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1111)'s system to solve the known problem of optimizing communication parameters for a group of devices with varying channel qualities.
    - **Expectation of Success:** Success would be expected because it would merely require modifying [Prodan](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1111)'s CMTS programming, a routine task for a POSITA, to implement [Azenkot](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1131)'s established method.

#### Ground 3: Claims 3-5 and 12-14 are obvious over Prodan and Cooper840/Azenkot in view of Jalali.
- **Prior Art Relied Upon:** [Prodan](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1111) (Application # 2012/0269242), [Cooper840](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1130) (’840 application), [Azenkot](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1131) (’996 application), and [Jalali](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1114) (Patent 6,952,454).
- **Core Argument for this Ground:**
    - **Prior Art Mapping:** This ground built upon the combinations in Grounds 1 and 2 to address dependent claims requiring communication using orthogonal frequency division multiplexing (OFDM). Petitioner asserted that while the primary combinations teach setting parameters based on worst-case SNR, [Jalali](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1114) taught the benefits of using OFDM to transmit data over multiple sub-carriers, including selecting modulation schemes on a per-sub-carrier basis to improve flexibility and efficiency.
    - **Motivation to Combine:** A POSITA would be motivated to incorporate [Jalali](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1114)'s OFDM techniques into the [Prodan](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1111)-based system to increase network capacity and performance, as OFDM was a well-known method for achieving these benefits in communication systems.
    - **Expectation of Success:** A POSITA would have a reasonable expectation of success because implementing OFDM in a CMTS was a widely used and routine practice at the time of the invention.

- **Additional Grounds:** Petitioner asserted numerous other obviousness challenges against all 18 claims. These grounds relied on the same core arguments from [Prodan](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1111)-[Cooper840](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1130) and [Prodan](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1111)-[Azenkot](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1131), adding further references to teach limitations in other dependent claims. Key additions included:
    - **[Pai](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1120)** (Application # 2010/0061235) to teach the system claim limitations of a CMTS with a processor and network interface (Claims 10-11, 15-18).
    - **[Cooper](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1105)** (Application # 2007/0223512) to teach assigning CMs to service groups based on physical distance or amplifier location (Claims 7-8, 16-17).
    - **[Monk](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1115)** (Patent 7,573,822) and **[Cooper437](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1116)** (Patent 6,772,437) to teach using probe messages from the CMTS to instruct CMs to measure and report back SNR metrics (Claims 9, 18).
    - **[Currivan](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1128)** (Application # 2005/0097617) as a final addition to all combinations to further teach selecting other physical layer parameters like transmit power and forward error correction (FEC) strength based on SNR.

## 4. Key Claim Construction Positions
- Petitioner argued that all claim terms should be given their plain and ordinary meaning. However, it noted that a district court in related litigation issued a tentative construction for "CMTS" as "hardware and accompanying software, with the hardware located at the point at which the cable modem's connection to the hybrid-fiber coaxial network terminates." Petitioner asserted that the prior art met this construction.

## 6. Arguments Regarding Discretionary Denial
- **§314(a) / Fintiv:** Petitioner argued that discretionary denial under *Fintiv* is not warranted. It asserted that the district court case is at an early stage with no trial date set and limited investment by the court. Further, the petition challenges all 18 claims of [the ’438 patent](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1101), whereas the patent owner has only sought to assert a subset (claims 1-5 and 9) in litigation, meaning the IPR is more comprehensive.
- **§325(d):** Petitioner argued that denial under §325(d) is inappropriate because the petition raises new grounds based on prior art that the Examiner did not previously consider or apply. Specifically, Petitioner contended that [Cooper840](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1130) and [Azenkot](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1131) were not applied during prosecution and directly teach the "worst-case SNR profile" limitation that was the basis for allowance, representing a material error by the Examiner.

## 7. Relief Requested
- Petitioner requested institution of an inter partes review and cancellation of claims 1-18 of [the ’438 patent](https://ai-lab.exparte.com/case/ptab/IPR2025-00184/doc/1101) as unpatentable.

Comcast targets cable modem service group patent: Cooper & Azenkot art cited for all 18 claims as obvious over using a worst-case SNR metric.

IPR2025-00184

Comcast Cable Communications, LLC v. Entropic Communications, LLC