Apple Inc. v. INVT SPE, INC.

1. Case Identification

• Case #: IPR2018-01474
• Patent #: 7,206,587
• Filed: August 21, 2018
• Petitioner(s): Apple Inc., ZTE(USA) Inc.
• Patent Owner(s): INVT SPE LLC
• Challenged Claims: 3-4

2. Patent Overview

• Title: Cellular Communication System with Error-Resistant Channel Quality Feedback
• Brief Description: The ’587 patent describes a cellular communication system where a handset measures downlink channel quality, such as a carrier to interference ratio (CIR), and reports it back to a base station. The invention addresses potential errors in transmitting this feedback by representing the quality value with multiple digits (e.g., an upper and lower digit) and applying stronger error correction to the more significant digit, making it less susceptible to transmission errors.

3. Grounds for Unpatentability

Ground 1: Claim 3 is obvious over Bender in view of Jarvinen

• Prior Art Relied Upon: Bender (a 2000 article titled "CDMA/HDR: A Bandwidth-Efficient High-Speed Wireless Data Service for Nomadic Users") and Jarvinen (Patent 6,470,470).
• Core Argument for this Ground:
  • Prior Art Mapping: Petitioner argued that Bender, a printed publication publicly available before the ’587 patent's priority date, discloses a CDMA system where a mobile terminal measures channel quality as a signal-to-noise-plus-interference ratio (SNR) and reports it to the base station. These SNR values are presented as two-digit numbers (e.g., 7.2), comprising a more significant upper digit (the whole number) and a less significant lower digit (the fractional part). Petitioner contended that Jarvinen teaches a well-known method of Unequal Error Protection (UEP), where data is divided into more important and less important bits. Jarvinen applies stronger error correction coding to the more important bits, resulting in a longer code word. Petitioner asserted that applying Jarvinen's teaching to Bender's two-digit SNR value satisfies the limitation of claim 3, which requires converting each digit to a "code word whose length is proportional to the digit's degree of significance." The more significant upper digit from Bender would be encoded with a longer code word (e.g., 378 bits for 182 important bits in Jarvinen's example) while the less significant digit would receive a shorter code word or no additional error correction.
  • Motivation to Combine: A Person of Ordinary Skill in the Art (POSITA) would combine these references to improve the reliability of channel quality feedback. Bender established that its SNR values have parts with different levels of importance; an error in the upper digit (e.g., misreading 7.2 as 8.2) is far more impactful than an error in the lower digit (misreading 7.2 as 7.3). Jarvinen provided a known solution for this exact problem by teaching the use of stronger encoding for more significant data. Petitioner argued this was not hindsight, as Jarvinen itself provides an express motivation to increase the bit count proportionally to the significance of the information to protect it from transmission errors. The combination was presented as a simple application of an available tool (Jarvinen's UEP) to improve a known system (Bender's feedback mechanism).
  • Expectation of Success: Petitioner argued a POSITA would have a high expectation of success. The combination involved applying a standard, well-understood error correction technique (UEP) to a known data transmission problem. This modification would predictably increase the robustness of the feedback signal without requiring undue experimentation.

Ground 2: Claim 4 is obvious over Bender in view of Piret

• Prior Art Relied Upon: Bender (a 2000 article titled "CDMA/HDR: A Bandwidth-Efficient High-Speed Wireless Data Service for Nomadic Users") and Piret (Patent 4,747,104).
• Core Argument for this Ground:
  • Prior Art Mapping: This ground again relied on Bender's disclosure of a two-digit SNR value with differing levels of significance. Petitioner argued that Piret teaches an alternative UEP method to make certain bits "less susceptible to errors," as required by claim 4. Piret discloses encoding more significant bits with a larger minimum code word distance compared to less significant bits. A larger minimum distance provides stronger error detection and correction capabilities. For example, Piret teaches encoding more significant bits into a proto-code word with a minimum distance of six (providing double bit error correction) and less significant bits with a minimum distance of three (providing only single bit error correction). Petitioner mapped Bender's more significant upper digit to Piret's "more significant bits," arguing that encoding it with a larger minimum distance would render it less susceptible to errors than the lower digit, thus meeting the claim limitation.
  • Motivation to Combine: The motivation was similar to Ground 1. A POSITA, understanding from Bender that the upper digit of the SNR value is more critical, would have been motivated to find a way to protect it from transmission errors. Petitioner noted that a POSITA would have been well-versed in various UEP techniques and that the teachings of Bender effectively direct a skilled artisan to employ such techniques. Piret provides an express motivation to increase the code word minimum distance for more important information, making it a natural choice for a POSITA looking to solve the problem presented in Bender.
  • Expectation of Success: Petitioner asserted the combination would yield predictable results. Applying Piret's established encoding scheme to Bender's data would straightforwardly result in a system where the most significant part of the channel quality report is better protected. This would be a natural and logical design choice for a POSITA seeking to improve communication reliability.

4. Key Technical Contentions (Beyond Claim Construction)

• A central technical argument was that a POSITA would inherently understand that an SNR value constitutes a measure of "reception quality."
• Petitioner consistently argued that for a multi-digit numerical value representing a physical measurement like SNR, the higher-order digit (e.g., the "7" in 7.2 dB) is subjectively and objectively more significant than the lower-order digit. An error in the higher-order digit creates a much larger deviation from the true value.
• The petition contended that Unequal Error Protection (UEP) was a prevalent and well-understood field of art, and a POSITA would have readily considered applying UEP techniques, such as varying code word length or minimum distance, to any data transmission where parts of the data had different levels of importance.

5. Relief Requested

• Petitioner requested institution of an inter partes review and cancellation of claims 3 and 4 of the ’587 patent as unpatentable.