Obviousness

Obviousness Analysis of US11516879 under 35 U.S.C. § 103

This analysis evaluates the obviousness of US patent 11516879 based on the information presented within the patent document itself, particularly the "Prior art keywords" and the "Definitions" and "Description of the Related Art" sections, which represent the knowledge available to a person having ordinary skill in the art (POSITA) at the priority date of 2016-09-07.

Problem Recognized in the Prior Art:
The patent explicitly states that in environments with high-density terminals and base terminals, providing high-efficiency and high-performance wireless communication requires various technologies. It identifies a specific problem: "Therefore, when the uplink multi-user (UL-MU) transmission is scheduled, it is necessary to adjust the EDCA parameter value." [cite: US11516879B2, "Definitions"] The patent notes that "when the base wireless communication terminal and one or more wireless communication terminals simultaneously access the channel for the same transmission, the channel access efficiency may decrease." [cite: US11516879B2, "Definitions"] A POSITA would be motivated to improve this channel access efficiency.

Known Elements and Motivation to Combine:

The following elements, foundational to the claims of US11516879, are described within the patent as known or as straightforward necessities in the art:

1. Enhanced Distributed Channel Access (EDCA): EDCA is a standard mechanism for wireless communication terminals to access a channel according to the priority of data to be transmitted. It involves parameters such as a Contention Window (CW), including CWmin and CWmax, and Arbitration Interframe Space (AIFS). [cite: US11516879B2, "Definitions", "EDCA", "AIFS"] This forms the basis for "accessing a channel according to a priority of data to be transmitted."
2. Multi-User Uplink (UL-MU) Transmission and Triggers: The concept of a base wireless communication terminal triggering uplink transmission for one or more wireless communication terminals is explicitly described. This triggering can occur via a "trigger frame or a MAC header." [cite: US11516879B2, "Definitions", "the base wireless communication terminal may trigger uplink transmission of one or more wireless communication terminals to the base wireless communication terminal."]
3. Need for EDCA Parameter Adjustment during UL-MU: The patent clearly articulates the necessity of adjusting EDCA parameters when UL-MU transmission is scheduled to avoid decreased channel access efficiency. [cite: US11516879B2, "Definitions", "when the uplink multi-user (UL-MU) transmission is scheduled, it is necessary to adjust the EDCA parameter value."] This provides a direct motivation for a POSITA to implement such adjustments.
4. Using a Separate EDCA Parameter Set for UL-MU: The patent directly teaches that a "wireless communication terminal scheduled for UL MU transmission may use a separate EDCA parameter set," referred to as an "MU EDCA parameter set." [cite: US11516879B2, "FIG. 6 shows that a wireless communication terminal according to an embodiment of the present invention adjusts EDCA parameters according to UL MU transmission", "a separate EDCA parameter set used by a wireless communication terminal scheduled for UL MU transmission is referred to as an MU EDCA parameter set."] This demonstrates that the idea of switching from a "first parameter set" (general EDCA) to a "second parameter set" (MU EDCA) when triggered for UL-MU was within the realm of a POSITA's knowledge or straightforward solution space.
5. Transmission of Physical Layer Protocol Data Units (PPDUs) and MAC Protocol Data Units (MPDUs) with Immediate Responses: PPDUs are fundamental units of transmission. MPDUs are included in PPDUs. The concept of an "immediate response" is also known, where a recipient transmits a response (e.g., an ACK) within a predetermined time during the same transmit opportunity (TXOP). [cite: US11516879B2, "Definitions", "PPDU", "MPDU", "an immediate response"]
6. Use of Timers in Wireless Communication: Timers are universally employed in communication protocols to manage the duration of states, operations, and timeouts. The patent describes setting an "MU EDCA timer for terminating the MU EDCA parameter set application." [cite: US11516879B2, "FIG. 14 shows an operation in which a wireless communication terminal according to an embodiment of the present invention terminates the MU EDCA parameter application."]

Obviousness of Independent Claims 1 and 6:

Independent Claim 1 (Method):
The method claim describes a series of steps for a wireless communication terminal:

• Accessing a channel and transmitting data based on priority: This is directly taught by the known EDCA operation. [cite: US11516879B2, "Definitions", "EDCA"]
• Switching from a first parameter set to a second parameter set based on a base terminal triggering multi-user uplink transmission participation: Given the recognized problem of reduced efficiency during UL-MU transmissions and the explicit teaching that "it is necessary to adjust the EDCA parameter value" [cite: US11516879B2, "Definitions"] and that a "separate EDCA parameter set" [cite: US11516879B2, "FIG. 6 shows that a wireless communication terminal according to an embodiment of the present invention adjusts EDCA parameters according to UL MU transmission"] may be used, a POSITA would be motivated to switch to a specialized EDCA parameter set (the second set) upon being triggered for UL-MU.
• Accessing a channel using the second set of parameters: This is the natural and logical consequence of switching to the second parameter set; one would then use it for channel access.
• Transmitting a trigger-based PPDU: This is part of the triggered UL-MU transmission process, involving known PPDU structures.
• Setting a second parameter set timer according to an immediate response reception based on whether an immediate response to an MPDU included in the trigger-based PPDU is received: The patent states that the "wireless communication terminal may set an MU EDCA timer upon receiving a response to the transmission of a trigger-based physical layer protocol data unit (PPDU)." [cite: US11516879B2, "FIG. 14 shows an operation in which a wireless communication terminal according to an embodiment of the present invention terminates the MU EDCA parameter application."] Considering that the specialized MU EDCA parameter set is "more disadvantageous than a typical EDCA parameter set" [cite: US11516879B2, "The MU EDCA parameter is a channel access condition that is more disadvantageous than a typical EDCA parameter set. Therefore, the wireless communication terminal needs to terminate the MU EDCA parameter set application. The wireless communication terminal switches the MU EDCA parameter set to the normal EDCA parameter set when terminating the MU EDCA parameter application."], a POSITA would be motivated to precisely control its duration. Using an immediate response to the transmitted PPDU/MPDU (a known mechanism for transmission confirmation [cite: US11516879B2, "Definitions", "an immediate response"]) as the trigger for starting a timer to manage the duration of this temporary state is a logical and obvious design choice. It ensures the specialized parameters are applied only for the necessary period of the successful UL-MU transmission.
• Terminating the application of the second parameter set when the second parameter set timer expires: This is the inherent function of a timer set to manage the duration of a specific operating mode. Once the specialized (and less favorable for general access) MU EDCA parameter set's purpose is served and its associated timer expires, reverting to the default (first) EDCA parameter set would be obvious to restore normal channel access conditions.

Therefore, the combination of these known elements and logical design choices, driven by the explicit motivation to improve channel access efficiency during UL-MU transmissions, renders Claim 1 obvious to a POSITA.

Independent Claim 6 (Wireless Communication Terminal):
Claim 6 describes a wireless communication terminal comprising a transceiver and a processor configured to perform the method steps of Claim 1. Given that transceivers and processors are standard components of wireless communication terminals (as depicted in FIGS. 3 and 4 of the patent [cite: US11516879B2, "FIG. 3", "FIG. 4"]), and if the method steps of Claim 1 are obvious, then configuring a standard processor to execute these obvious steps using a standard transceiver would also be obvious to a POSITA. The implementation merely involves routine programming or design choices based on the obvious method.