Obviousness

Obviousness Analysis of US Patent 11664926 under 35 U.S.C. § 103

This analysis identifies combinations of prior art references that could render the claims of US Patent 11664926 obvious to a person having ordinary skill in the art (POSA). The motivation to combine these references stems from the common objective in wireless communication to improve efficiency and throughput, especially in high-density environments, which is a well-known problem in the field.

A claim is obvious if, at the time of invention, a POSA would have been motivated to combine prior art teachings, or to modify prior art without a combination, to arrive at the claimed invention with a reasonable expectation of success. Motivation to combine can arise from the knowledge of those skilled in the art, the prior art reference itself, or the nature of the problem to be solved. Generalized assertions of technological predictability alone are insufficient.

Independent Claims 1 and 9 (Terminal and Method for Transmitting A-MPDU and Determining Success)

Claims 1 and 9 describe a wireless communication terminal and method for generating and transmitting an A-MPDU soliciting an immediate response, receiving a response frame, and determining transmission success based on the response.

Combination 1: IEEE 802.11 Standards (n/ac/ax) + US20170272138A1 + Common General Knowledge in WLAN

• IEEE 802.11n/ac/ax Standards: These standards widely disclose the use of A-MPDU aggregation to improve throughput and efficiency in WLANs by reducing overhead. A-MPDU aggregates multiple MPDUs, each with its own MAC header and FCS, allowing for selective retransmission of corrupted MPDUs. Block Acknowledgement (BA) mechanisms are also a key feature in these standards, enabling the acknowledgment of multiple received packets with a single BA frame, which is particularly relevant for A-MPDUs. The IEEE 802.11ax standard (non-legacy wireless LAN system) further enhances these capabilities, including increased A-MPDU sizes and support for multi-user (MU-MIMO) and Orthogonal Frequency Division Multiple Access (OFDMA) transmissions. The concept of an A-MPDU containing one or more MPDUs is fundamental to these standards. The patent itself notes that "the non-legacy wireless LAN system may refer to a wireless LAN system conforming to an IEEE 802.11ax standard."
• US20170272138A1 (Method for uplink multi-user transmission in wireless communication system and apparatus therefor): This reference explicitly mentions the use of an ACK frame as a response to an MPDU and a block ACK frame as a response to an A-MPDU. It also discusses the inclusion of padding bits for MPDU/A-MPDU configuration and the indication of A-MPDU length. This document, published in 2017, predates US11664926's priority date of 2016-12-21, making it relevant prior art.
• Motivation to Combine: A POSA in wireless communication would be motivated to combine the general A-MPDU aggregation techniques and BlockAck mechanisms of IEEE 802.11n/ac/ax with the explicit response frame definitions (ACK for MPDU, Block ACK for A-MPDU) found in US20170272138A1. The goal would be to efficiently manage acknowledgments for aggregated frames, especially in the context of high-throughput and multi-user environments addressed by 802.11ax. The problem of efficiently confirming successful transmission of aggregated data and managing retransmissions is inherent in these systems. The "nature of the problem to be solved" drives the combination, as optimizing data communication by effectively handling immediate responses for A-MPDUs is a continuous goal in WLAN development. A POSA would understand that a system transmitting A-MPDUs would require a robust mechanism for determining successful transmission, and that existing ACK/BlockAck frameworks could be adapted.

Independent Claims 10 and 18 (Terminal and Method for Receiving A-MPDU, Determining and Transmitting Response Frame Format)

Claims 10 and 18 describe a wireless communication terminal and method for receiving an A-MPDU, determining the format of a response frame, and transmitting that response.

Combination 2: IEEE 802.11 Standards (n/ac/ax) + KR20190089936A + Common General Knowledge in WLAN

• IEEE 802.11n/ac/ax Standards: As mentioned above, these standards lay the groundwork for A-MPDU structures, including MPDU delimiters, EOF fields, and the concept of different types of MPDUs (e.g., QoS data frames, Action frames, those soliciting immediate responses). They also establish the need for various response mechanisms like ACK and BlockAck (including Multi-STA BlockAck in 802.11ax). The evolution of A-MPDU formats, including multi-TID A-MPDUs, and the corresponding response mechanisms are discussed within the context of these standards.
• KR20190089936A (A set MPDU and a response frame transmission method therefor and a wireless communication terminal using the same): This patent application, with inventors identical to US11664926 and a priority date of 2016-12-21, describes generating an A-MPDU including MPDUs requesting an immediate response, transmitting it, receiving a response frame, and determining transmission success. While it is a similar invention, its publication date of July 26, 2019, makes it prior art to the filing date of US11664926 (January 25, 2021). Its claims directly mirror the independent claims of US11664926, indicating a very close relationship.
• Motivation to Combine: A POSA would be motivated to combine the established A-MPDU aggregation and response frame types of the IEEE 802.11 standards with the explicit methods for determining and transmitting response frame formats based on the content of the received A-MPDU as taught by KR20190089936A. This combination directly addresses the problem of efficiently handling various A-MPDU configurations and providing appropriate acknowledgments. The increasing complexity of A-MPDUs (e.g., multi-TID A-MPDUs) in newer standards like 802.11ax naturally leads to a need for intelligent determination of response frame formats to optimize channel utilization and reduce overhead. A POSA would aim to build on existing aggregation and acknowledgment schemes to create more flexible and efficient communication protocols in dense wireless environments. The shared problem of optimizing data communication in WLANs provides a strong motivation for such a combination.

Further Considerations for Obviousness:

• Increased A-MPDU Complexity: The patent US11664926 specifically addresses the challenges of "setting various formats of the aggregate MPDU and the response frame thereto" and dealing with "high-density environments." The evolution of WLAN standards, particularly with 802.11ax, has seen increased complexity in A-MPDU structures, including the aggregation of MPDUs from multiple Traffic IDs (TIDs) and various acknowledgment policies. This increasing complexity would inherently motivate a POSA to develop more sophisticated methods for processing received A-MPDUs and generating appropriate response frames.
• Efficiency and Overhead Reduction: A recurring theme in WLAN development is the reduction of overhead and improvement of efficiency. A-MPDU aggregation itself is a technique for reducing overhead. Therefore, any system that can intelligently adapt its response frame format based on the received A-MPDU content (e.g., number of TIDs, presence of immediate response requests) would be seen by a POSA as a desirable improvement to minimize unnecessary signaling and maximize throughput.
• Trigger Frames: The patent US11664926 also discusses the use of trigger frames to indicate information such as the maximum number of TIDs in an A-MPDU or to instruct channel sensing. The 802.11ax standard utilizes trigger frames for uplink multi-user transmissions, where an AP can trigger multiple stations to transmit. This pre-existing concept of using trigger frames to control station behavior in aggregated transmissions provides additional motivation for a POSA to use such information to optimize A-MPDU transmission and response mechanisms.

In conclusion, the core aspects of US Patent 11664926, involving flexible A-MPDU structures and intelligent response frame generation, appear to be a logical extension of existing IEEE 802.11 standards and common knowledge in the field, further supported by specific teachings in prior art such as US20170272138A1 and KR20190089936A, all driven by the continuous need to enhance efficiency and performance in wireless networks.