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US-12628040-B2 - Wi-fi device and associated transmission control method

US12628040B2US 12628040 B2US12628040 B2US 12628040B2US-12628040-B2

Abstract

A Wi-Fi (Wi-Fi) device and a transmission control method are provided. The Wi-Fi device selectively transmits at least a data division of a transmission data on a low performance link based on several parameters. The parameters include a start time point of a backoff procedure of the low performance link, a duration information associated with another Wi-Fi device on a high performance link, and some predefined exception conditions. By overhearing status of another Wi-Fi device on the high performance link, the Wi-Fi device attempts to acquire the duration information. If the duration information can be acquired, the Wi-Fi device calculates a coherent remnant-duration accordingly. Then, the Wi-Fi device determines whether the transmission data should be transmitted immediately on the low performance link, transmitted later on the high performance link, or partially transmitted on the low performance link.

Inventors

  • Yang-Hung Peng
  • Cheng-Yi Chang

Assignees

  • MEDIATEK INC.

Dates

Publication Date
20260512
Application Date
20231011

Claims (18)

  1. 1 . A Wi-Fi device, wherein the Wi-Fi device and another Wi-Fi device are in an overlapping basic service set, and the another Wi-Fi device transmits a first physical layer protocol data unit (PPDU) frame on a first link between a first-first time point and a third-first time point, wherein the Wi-Fi device comprises: a media access control address (MAC) module, comprising: a receiving circuit, configured for acquiring a duration information associated with a first payload portion of the first PPDU frame at a second-first time point, wherein the second-first time point is between the first-first time point and the third-first time point; a first transmission circuit corresponding to the first link; a second transmission circuit, configured for selectively transmitting a second PPDU frame on a second link between a first-second time point and a second-second time point, wherein performance of the second link is lower than performance of the first link; and a link selection module, electrically connected to the receiving circuit, the first transmission circuit, and the second transmission circuit, configured for selectively controlling the first transmission circuit and the second transmission circuit to perform transmission according to statuses of the first link and the second link.
  2. 2 . A transmission control method employed by a Wi-Fi device, wherein the Wi-Fi device and another Wi-Fi device are in an overlapping basic service set and the another Wi-Fi device transmits a first physical layer protocol data unit (PPDU) frame on a first link between a first-first time point and a third-first time point, wherein the transmission control method comprises steps of: acquiring a duration information associated with a first payload portion of the first PPDU frame at a second-first time point, wherein the second-first time point is between the first-first time point and the third-first time point; and selectively transmitting a second PPDU frame on a second link between a first-second time point and a second-second time point, wherein performance of the second link is lower than performance of the first link.
  3. 3 . The transmission control method of claim 2 , wherein the Wi-Fi device stops performing transmission on the first link when the another Wi-Fi device transmits the first PPDU frame.
  4. 4 . The transmission control method of claim 2 , wherein the Wi-Fi device stops transmitting the second PPDU frame if the Wi-Fi device is incapable of acquiring the duration information.
  5. 5 . The transmission control method of claim 4 , wherein the Wi-Fi device is incapable of acquiring the duration information if the second-first time point is later than the first-second time point.
  6. 6 . The transmission control method of claim 4 , wherein the Wi-Fi device is incapable of acquiring the duration information if the first-second time point is within a duration of distributed inter-frame spacings on the first link.
  7. 7 . The transmission control method of claim 2 , wherein the Wi-Fi device refers the duration information to obtain the third-first time point, wherein a coherent remnant-duration is defined as a difference between the third-first time point and the first-second time point.
  8. 8 . The transmission control method of claim 7 , wherein the Wi-Fi device stops transmitting the second PPDU frame if the coherent remnant-duration is shorter than a minimum PPDU duration, and the Wi-Fi device transmits the second PPDU frame on the second link within the coherent remnant-duration if the coherent remnant-duration is longer than or equivalent to the minimum PPDU duration.
  9. 9 . The transmission control method of claim 8 , wherein the second PPDU frame comprises a second head portion and a second payload portion, wherein a duration of the second head portion starts at the first-second time point, and a duration of the second payload portion ends at the second-second time point.
  10. 10 . The transmission control method of claim 9 , wherein the second payload portion carries at least part of a transmission data for an access point device.
  11. 11 . The transmission control method of claim 10 , wherein the second payload portion comprises M subframes, the transmission data comprises N data subsets, and each of the M subframes comprises a subframe header and a subframe payload carrying one of the N data subsets, wherein M and N are positive integers, and M is smaller than or equivalent to N.
  12. 12 . The transmission control method claim 11 , wherein the second payload portion is an aggregated MAC protocol data unit (A-MPDU), and the M subframes are A-MPDU subframes.
  13. 13 . The transmission control method of claim 12 , wherein the minimum PPDU duration represents a duration of a physical layer protocol data unit that contains only a first A-MPDU subframe that is qualified for being transmitted.
  14. 14 . The transmission control method of claim 11 , wherein M is smaller than N, and the second payload portion transmits M of the N data subsets with the M subframes if the coherent remnant-duration is shorter than a summation of a duration of the second header portion and a duration required for transmitting all of the N data subsets.
  15. 15 . The transmission control method of claim 14 , wherein the second payload portion further comprises at least one padding bit if a summation of the duration of the second header portion and durations of the M subframes is shorter than the coherent remnant-duration.
  16. 16 . The transmission control method of claim 11 , wherein M is equivalent to N, and the second payload portion transmits all the N data subsets with the M subframes if the coherent remnant-duration is longer than or equivalent to a summation of a duration of the second header portion and a duration required for transmitting all of the N data subsets.
  17. 17 . The transmission control method of claim 16 , wherein the second payload portion further comprises at least one padding bit if a summation of the duration of the second header portion and durations of the M subframes is shorter than the coherent remnant-duration.
  18. 18 . The transmission control method of claim 2 , wherein the first PPDU frame comprises a first header portion and the first payload portion, and the transmission control method further comprises steps of: detecting the first header portion on the first link; and parsing the duration information from the first header portion.

Description

This is a continuation-in-part of U.S. application Ser. No. 17/964,045, filed Oct. 12, 2022. This continuation-in-part application claims the benefit of U.S. provisional application Ser. No. 63/383,114, filed Nov. 10, 2022, the subject matter of which is incorporated herein by reference. TECHNICAL FIELD The disclosure relates in general to a Wi-Fi device and an associated transmission control method, and more particularly to a Wi-Fi device and an associated transmission control method capable of enhancing throughput with a multi-link coherent operation. BACKGROUND In a Wi-Fi multi-link operation (MLO), there may exist several links between two MLDs, including one access point (AP) and one non-AP station (STA), that occupy different radio-frequency (RF) bands. These links can operate independently to increase the overall throughput and/or to improve the connection stability. However, each link has its own capacity that is based on several parameters, including bandwidth (BW), number of spatial streams (NSS), modulation and coding mechanism (MCS), etc. In addition, each link has its own condition that is based on several parameters, including loading, interference, etc. Capacities and conditions of links can be very different. Hence, it is desirable to optimally utilize these asymmetric links to maximize the overall system performance. SUMMARY The disclosure is directed to a Wi-Fi device and an associated transmission control method capable of enhancing throughput with a multi-link coherent operation. According to one embodiment, a Wi-Fi device is provided. The Wi-Fi device and another Wi-Fi device are in an overlapping basic service set (BSS). The another Wi-Fi device transmits a first physical layer protocol data unit (PPDU) frame on a first link between a first-first time point and a third-first time point. The Wi-Fi device includes a MAC module, and the media access control address (MAC) module includes a receiving circuit, a first transmission circuit corresponding to the first link, a second transmission circuit, and a link selection module. The receiving circuit acquires duration information associated with a first payload portion of the first PPDU frame at a second-first time point, wherein the second-first time point is between the first-first time point and the third-first time point. The second transmission circuit selectively transmits a second PPDU frame on a second link between a first-second time point and a second-second time point, wherein the performance of the second link is lower than the performance of the first link. The link selection module is electrically connected to the receiving circuit, the first transmission circuit, and the second transmission circuit. The link selection module selectively controls the first transmission circuit and the second transmission circuit to perform transmission according to the statuses of the first link and the second link. According to another embodiment, a transmission control method employed by the Wi-Fi device is provided. The Wi-Fi device and another Wi-Fi device are in an overlapping basic service set (BSS), and the another Wi-Fi device transmits a first PPDU frame on a first link between a first-first time point and a third-first time point. The transmission control method includes the following steps. Firstly, duration information associated with a first payload portion of the first PPDU frame is acquired at a second-first time point. The second-first time point is between the first-first time point and the third-first time point. Then, a second PPDU frame is selectively transmitted on a second link between a first-second time point and a second-second time point. The performance of the second link is lower than the performance of the first link. These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram illustrating an occasion when multiple access points and multiple stations coincidently select the same links for the frame exchange process. FIG. 2 is a schematic diagram illustrating a Wi-Fi system according to an embodiment of the present disclosure. FIG. 3 is a schematic diagram illustrating the classification of transmission configurations according to the embodiment of the present disclosure. FIG. 4 is a flow diagram illustrating the transmission control method capable of adaptively selecting the transmission mode in response to the satisfaction of the predefined quality condition according to the embodiment of the present disclosure. FIG. 5 is a schematic diagram illustrating an exemplary construction of the PPDU_22 frame. FIGS. 6A and 6B are schematic diagrams illustrating the exemplary construction of an A-MPDU subframe subF[m]. FIG. 7 is a schematic diagram illustrating that the W