US-12621758-B2 - Multi-link spatial multiplexing signaling with power saving

Abstract

A method for performing wireless communication in MLO architecture is applicable to an AP MLD connected with a non-AP MLD through multiple links. The multiple links include at least a first link and a second link, the non-AP MLD operates in ML-SMPS mode. The method includes transmitting an initial control frame to the non-AP MLD via the first link, to trigger at least one link of the multiple links to be activated at the non-AP MLD to support a reception with respective negotiated number of spatial streams, receiving a response frame via the first link in response to the transmission of the initial control frame, and initiating frame exchange between the AP MLD and the non-AP MLD via a target link of the at least one link. The target link is selected from the at least one link according to the response frame. The first link is a primary link.

Inventors

• Hao-Hua KANG
• Cheng-Ying Wu
• Chien-Fang Hsu
• Chih-Chun KUO

Assignees

• MEDIATEK INC.

Dates

Publication Date

20260505

Application Date

20231031

Claims (20)

1. 1 . A method for performing wireless communication in multi-link operation (MLO) architecture, the method being applicable to an access point (AP) multi-link device (MLD) connected with a non-AP MLD through multiple links, the multiple links comprising at least a first link and a second link, the non-AP MLD being operated in Multi-Link Spatial Multiplexing Power Save (ML-SMPS) mode, and the method comprising: transmitting an initial control frame to the non-AP MLD via the first link, to trigger at least one link of the multiple links to be activated at the non-AP MLD to support a reception with respective negotiated number of spatial streams, wherein the first link is a primary link; receiving a response frame via the first link in response to the transmission of the initial control frame; and initiating frame exchange between the AP MLD and the non-AP MLD via a target link of the at least one link, wherein the target link is selected from the at least one link according to the response frame.
2. 2 . The method of claim 1 , wherein transmitting an initial control frame comprises: transmitting an initial control frame with a bitmap or a field for indicating the at least one link of the multiple links to be activated at the non-AP MLD.
3. 3 . The method of claim 1 , wherein: when the response frame carries information for indicating which link of the at least one link to be accepted or rejected, the target link comprises an accepted link; and when the response frame does not carry information for indicating whether to accept or reject any link in the at least one link, the target link comprises all of the at least one link or the pre-negotiated link during enabling the ML-SMPS mode.
4. 4 . The method of claim 1 , wherein: the initial control frame is a Buffer Status Report Poll (BSRP) frame and the response frame is a Buffer Status Report (BSR) frame; or the initial control frame is a Multi-User Request to Send (MU-RTS) frame and the response frame is a Clear to Send (CTS) frame.
5. 5 . The method of claim 1 , wherein: the target link comprises the first link; and the step of initiating frame exchange between the AP MLD and the non-AP MLD comprises transmitting at least one data frame to the non-AP MLD via the first link after receiving the response frame.
6. 6 . The method of claim 1 , wherein: the target link comprises the second link; and the step of initiating frame exchange between the AP MLD and the non-AP MLD comprises transmitting at least one data frame from the second AP to the non-AP MLD via the second link following a predefined delay period; wherein the predefined delay period occurs after the response frame has been received, or after exchanging a MU-RTS frame and a CTS frame between the AP MLD and the non-AP MLD via the second link, or after exchanging a quality of service (QoS) null frame or Power-save poll (PS-Poll) frame and an acknowledge (ACK) frame between the non-AP MLD and the AP MLD via the second link.
7. 7 . The method of claim 1 , wherein the step of initiating frame exchange between the AP MLD and the non-AP MLD comprises: transmitting a data frame to the non-AP MLD that carries a More Data (MD) bit to indicate whether there is more data to be transmitted; and when there is no more data to be transmitted, the MD bit carried in the data frame indicating to the non-AP MLD to deactivate the at least one link.
8. 8 . A method for performing wireless communication in multi-link operation (MLO) architecture, the method being applicable to a non-access point (AP) multi-link device (MLD) connected with an AP MLD through multiple links, the multiple links comprising at least a first link and a second link, the non-AP MLD being operated in Multi-link Spatial Multiplexing Power Save (ML-SMPS) mode, the method comprising: receiving an initial control frame from the AP MLD via the first link, the initial control frame being used to trigger at least one link of the multiple links to be activated at the non-AP MLD to support a reception with respective negotiated number of spatial streams, wherein the first link is a primary link; transmitting a response frame via the first link in response to the reception of the initial control frame; activating a target link of the at least one link by enabling receiving chains for the target link to support reception with respective negotiated number of spatial streams; and initiating frame exchange between the non-AP MLD and the AP MLD via the target link in the at least one link, wherein the target link is selected from the at least one link according to the response frame.
9. 9 . The method of claim 8 , wherein receiving an initial control frame comprises: receiving an initial control frame with a bitmap or field for indicating the at least one link of the multiple links to be activated at the non-AP MLD.
10. 10 . The method of claim 8 , wherein: when the response frame carries information for indicating the at least one link being accepted and/or rejected, the target link comprises an accepted link; and when the response frame does not carry information for indicating whether to accept or reject the at least one link, the target link comprises all of the at least one link or the pre-negotiated link during enabling the ML-SMPS mode.
11. 11 . The method of claim 8 , wherein the initial control frame is a Buffer Status Report Poll (BSRP) frame and the response frame is a Buffer Status Report (BSR) frame; or the initial control frame is a Multi-User Request to Send (MU-RTS) frame and the response frame is a Clear to Send (CTS) frame.
12. 12 . The method of claim 8 , the step of initiating frame exchange between the non-AP MLD and the AP MLD comprises: receiving at least one data frame from the non-AP MLD that carries one More Data (MD) bit to indicate whether there is more data after a current data frame; and when the one MD bit carried in the at least one data frame indicates there is no more data, deactivating the target link.
13. 13 . The method of claim 8 , wherein: the target link comprises a first link; and the step of activating a target link of the at least one link by enabling receiving chains for the target link to support reception with respective negotiated number of spatial streams comprises activating the first link after receiving the initial control frame or transmitting the response frame by enabling other receiving chains for the first link to support the reception with negotiated number of spatial streams via the first link.
14. 14 . The method of claim 8 , wherein: the target link comprises a second link; and the step of activating a target link of the at least one link by enabling receiving chains for the target link to support reception with respective negotiated number of spatial streams comprises activating the second link after transmitting the response frame by enabling receiving chains for the second link to support the reception with negotiated number of spatial streams via the second link.
15. 15 . The method of claim 14 , wherein the step of activating the second link after transmitting the response frame comprises: activating the second link immediately after transmitting the response frame; or activating the second link immediately after receiving the initial control frame transmitted from the AP MLD; activating the second link after a predefined delay period after transmitting the response frame; or activating the second link and transmitting a QoS null frame or a PS-Poll frame to the AP MLD via the second link when a backoff timer for the second link at the non-AP MLD decreases to 0.
16. 16 . The method of claim 8 further comprising deactivating the target link, wherein deactivating the target link comprises: if the non-AP MLD has not received any frame for a predefined period via certain link in the target link, deactivating the certain link.
17. 17 . An access point (AP) multi-link device (MLD) comprising: a first AP and a second AP configured to establish multi-link connection between the AP MLD and a non-AP MLD, the connected multiple links comprising at least a first link between a first station (STA) of the non-AP MLD and a first AP of the AP MLD and a second link between the second STA of the non-AP MLD and a second AP of the AP MLD; a processor coupled to the first AP and the second AP, configured to: transmit an initial control frame to the non-AP MLD via the first link, to trigger at least one link of the multiple links to be activated at the non-AP MLD to support a reception with respective negotiated number of spatial streams, wherein the first link is a primary link; receive a response frame via the first link in response to the transmission of the initial control frame; and initiate frame exchange between the AP MLD and the non-AP MLD via a target link of the at least one link; wherein the target link is selected from the at least one link according to the response frame.
18. 18 . The AP MLD of claim 17 , wherein: when the response frame carries information for indicating which link of the at least one link to be accepted or rejected, and the target link comprises an accepted link; and when the response frame does not carry information for indicating whether to accept or reject any link in the at least one link, and the target link comprises all of the at least one link or the pre-negotiated link during enabling the ML-SMPS mode.
19. 19 . A non access point (non-AP) multi-link device (MLD) comprising: a first station (STA) and a second STA configured to establish multi-link connection between an AP MLD and the non-AP MLD, the connected multiple links comprising at least a first link between a first station (STA) of the non-AP MLD and a first AP of the AP MLD, and a second link between a second STA of the non-AP MLD and the second AP of the AP MLD; a processor coupled to the first STA and the second STA, configured to: receive an initial control frame from the AP MLD via the first link, the initial control frame being used to trigger at least one link of the multiple links to be activated at the non-AP MLD to support a reception with respective negotiated number of spatial streams, wherein the first link is a primary link; transmit a response frame via the first link in response to the reception of the initial control frame; activate a target link of the at least one link by enabling receiving chains for the target link to support reception with respective negotiated number of spatial streams, wherein the target link is selected from the at least one link according to the response frame; and initiate frame exchange between the non-AP MLD and the AP MLD via the target link in the at least one link.
20. 20 . The non-AP MLD of claim 19 , wherein: when the response frame carries information for indicating the at least one link being accepted and/or rejected, and the target link comprises an accepted link; and when the response frame does not carry information for indicating whether to accept or reject the at least one link, and the target link comprises all of the at least one link or the pre-negotiated link during enabling the ML-SMPS mode.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 63/383,713, filed on Nov. 15, 2022. The content of the application is incorporated herein by reference. BACKGROUND Wireless-Fidelity (Wi-Fi) is among the greatest successes of this new technology era. Wi-Fi has created new technologies, industries and careers around the globe. Since Wi-Fi has become an essential part of everyday life, its economic value is expecting to increase, as more capable Wi-Fi 6 based on the most recent Institute of Electric and Electronic Engineers (IEEE) 802.11ax specification becomes widely available. However, the demand for wireless data services continues to increase in many scenarios beyond the capabilities of Wi-Fi 6. To address such demand, the IEEE 802.11 Working Group, which is responsible for developing standards and recommended practices of 802.11 architecture, has already initiated the development on the next generation of Wi-Fi, referred to as IEEE 802.11be Extremely High Throughput (EHT). IEEE 802.11be EHT is being developed to meet the throughput demands by the upcoming applications. The IEEE 802.11be EHT is currently being developed as the next generation Wi-Fi standard to achieve higher data rate, lower latency, and more reliable connection to enhance user experience. The final version of the IEEE 802.11be specification is expected to be published by late 2023, and ratified in 2024. Meanwhile, the Wi-Fi Alliance has initiated the related development toward Wi-Fi 7 certification based on the IEEE 802.11be draft specification. The next generation Wi-Fi 7 includes a number of new features. These features include Multi-Link Operation (MLO), Directional Beamforming, and Orthogonal Frequency Division Multiple Access (OFDMA). The MLO allows devices to connect to multiple Wi-Fi bands simultaneously, which can improve performance in crowded areas. The Directional Beamforming allows routers to focus their signal on specific devices, which can improve performance and reduce interference. The OFDMA allows multiple devices to share the same Wi-Fi channel without interfering with each other. The Multi-Link Operation (MLO) is a key feature of Wi-Fi 7. As the current access point (AP) and station (STA) have dual-band or tri-band transmission capabilities, the newly developed MLO feature enables packet-level link aggregation in the media access control (MAC) layer across different physical (PHY) links. By performing load balancing according to traffic requirements, MLO achieves significantly higher throughput and lower latency for enhanced reliability in a heavily loaded network. With MLO capability, a Multi-Link Device (MLD) comprised of multiple “affiliated” devices to the upper logical link control (LLC) layer, allowing concurrent data transmission and reception in multiple channels across a single or multiple frequency bands in 2.4 GHz, 5 GHz and 6 GHz. Thus, there is an opportunity to add or improve aspects of a wireless local area network (WLAN) as the communication protocols evolve. SUMMARY An embodiment provides a method for performing wireless communication in multi-link operation (MLO) architecture. The method is applicable to an access point (AP) multi-link device (MLD) connected with a non-AP MLD through multiple links comprising at least a first link and a second link. The non-AP MLD operates in Multi-link Spatial Multiplexing Power Save (ML-SMPS) mode. The method comprises transmitting an initial control frame to the non-AP MLD via the first link to trigger at least one link of the multiple links to be activated at the non-AP MLD to support a reception with respective negotiated number of spatial streams, receiving a response frame via the first link in response to the transmission of the initial control frame, and initiating frame exchange between the AP MLD and the non-AP MLD via a target link of the at least one link. The first link is a primary link. The target link is selected from the at least one link according to the response frame. An embodiment provides a method for performing wireless communication in multi-link operation (MLO) architecture. The method is applicable to a non-access point (AP) multi-link device (MLD) connected with an AP MLD through multiple links comprising at least a first link and a second link. The non-AP MLD operates in Multi-link Spatial Multiplexing Power Save (ML-SMPS) mode. The method comprises receiving an initial control frame from the AP MLD via the first link. The initial control frame is used trigger at least one link of the multiple links to be activated at the non-AP MLD to support a reception with respective negotiated number of spatial streams. The method further comprises transmitting a response frame via the first link in response to the reception of the initial control frame, activating a target link of the at least one link by enabling receiving chains for the target link to support the reception with respectiv