US-20260129704-A1 - MULTI-LINK DEVICE OPERATING IN MULTIPLE LINKS AND METHOD FOR OPERATING MULTI-LINK DEVICE

US20260129704A1US 20260129704 A1US20260129704 A1US 20260129704A1US-20260129704-A1

Abstract

Disclosed is a multi-link device comprising multiple stations operating in multiple links, respectively. The multi-link operation device comprises: a transceiver; and a processor. The processor transmits a target wake time (TWT) element from a first station which is one of the multiple stations and is coupled to a first AP in a first link, so as to request a TWT agreement with a second station operating in a second link, for a second AP coupled to the second station.

Inventors

Sanghyun Kim
Geonjung KO
Juhyung Son
Jinsam Kwak

Assignees

WILUS INSTITUTE OF STANDARDS AND TECHNOLOGY INC.

Dates

Publication Date: 20260507
Application Date: 20251230
Priority Date: 20210317

Claims (6)

1 . A multi-link device including a first station and a second station operating in a first link and a second link, respectively, the multi-link device comprising: a transceiver; and a processor configured to: transmit a target wake time (TWT) element from the first station associated to a first AP in the first link, so as to request a TWT agreement for the second station and a second AP associated to the second station, when the second link is disabled, tear down the TWT agreement for the second station and the second AP without reception or transmission of a TWT teardown frame for tearing down the TWT agreement for the second station and the second AP, wherein the TWT element comprises a bitmap including information indicating that a link to which the TWT agreement to be established by the TWT element is to be applied, wherein the indicated link is to the second link, and when receiving a TWT teardown frame from or transmitting a TWT teardown frame to the first AP successfully, tear down the TWT agreement for the second station and the second AP, wherein the TWT agreement for the second station and the second AP is identified by the TWT teardown frame received from or transmitted to the first AP based on a link identifier (ID) of the second link, a medium access control (MAC) address of a TWT requesting station, a MAC address of a TWT responding station of the TWT agreement for the second station and the second AP, and a TWT Flow ID of the TWT agreement for the second station and the second AP, and wherein the TWT requesting station of the TWT agreement for the second station and the second AP is the second station, and the TWT responding station of the TWT agreement for the second station and the second AP is the second AP.
2 . The device of claim 1 , wherein the processor is configured to, when receiving a TWT teardown frame from or transmitting a TWT teardown frame to the second AP successfully, tear down the TWT agreement for the second station and the second AP.
3 . The device of claim 1 , wherein the processor is configured to, when tearing down the TWT agreement for the second station and the second AP, inherit the TWT agreement for the second station and the second AP to the first station and the first AP.
4 . The device of claim 3 , wherein the processor is configured to, when inheriting the TWT agreement for the second station and the second AP to the first station and the first AP, apply a TWT parameter of the TWT agreement for the second station and the second AP to a TWT agreement for the first station and the first AP.
5 . A method of operating a multi-link device including a first station and a second station operating in a first link and a second link, respectively, the method comprising: transmitting a target wake time (TWT) element from a first station associated to a first AP in a first link, so as to request a TWT agreement for a second station, and a second AP associated to the second station, when the second link is disabled, tearing down the TWT agreement for the second station and the second AP without reception or transmission of a TWT teardown frame for tearing down the TWT agreement for the second station and the second AP, wherein the TWT element comprises a bitmap including information indicating that the TWT agreement to be established by the TWT element is to be applied, wherein the indicated link is to the second link, and when the multi-link device receives a TWT teardown frame from or transmits a TWT teardown frame to the first AP successfully, tearing down the TWT agreement for the second station and the second AP, wherein the TWT agreement for the second station and the second AP is identified by the TWT teardown frame received from or transmitted to the first AP based on a link identifier of the second link, a medium access control (MAC) address of a TWT requesting station, a MAC address of a TWT responding station of the TWT agreement for the second station and the second AP, and a TWT Flow ID of the TWT agreement for the second station and the second AP, and wherein the TWT requesting station of the TWT agreement for the second station and the second AP is the second station, and the TWT responding station of the TWT agreement for the second station and the second AP is the second AP.
6 . The method of claim 5 , further comprising, when receiving the TWT teardown frame from the second AP or transmitting the TWT teardown frame to the second AP successfully, tearing down the TWT agreement for the second station and the second AP.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation under 35 U.S.C. § 120 of U.S. application Ser. No. 18/369,193, filed Sep. 17, 2023, which is a continuation of International Application No. PCT/KR2022/003704, filed Mar. 16, 2022, which claims priority to Korean Application No. 10-2021-0034964, filed Mar. 17, 2021, Korean Application No. 10-2021-0036273, filed Mar. 19, 2021, and Korean Application No. 10-2021-0038379 filed Mar. 24, 2021, under 35 U.S.C. § 119 (a). Each of the above-referenced patent applications is incorporated by reference in its entirety. TECHNICAL FIELD The disclosure relates to a multi-link device operating in multiple links and a method for operating a multi-link device. DESCRIPTION OF RELATED TECHNOLOGY In recent years, with supply expansion of mobile apparatuses, a wireless LAN technology that can provide a rapid wireless Internet service to the mobile apparatuses has been significantly spotlighted. The wireless LAN technology allows mobile apparatuses including a smart phone, a smart pad, a laptop computer, a portable multimedia player, an embedded apparatus, and the like to wirelessly access the Internet in home or a company or a specific service providing area based on a wireless communication technology in a short range. Institute of Electrical and Electronics Engineers (IEEE) 802.11 has commercialized or developed various technological standards since an initial wireless LAN technology is supported using frequencies of 2.4 GHz. First, the IEEE 802.11b supports a communication speed of a maximum of 11 Mbps while using frequencies of a 2.4 GHz band. IEEE 802.11a which is commercialized after the IEEE 802.11b uses frequencies of not the 2.4 GHz band but a 5 GHz band to reduce an influence by interference as compared with the frequencies of the 2.4 GHz band which are significantly congested and improves the communication speed up to a maximum of 54 Mbps by using an OFDM technology. However, the IEEE 802.11a has a disadvantage in that a communication distance is shorter than the IEEE 802.11b. In addition, IEEE 802.11g uses the frequencies of the 2.4 GHz band similarly to the IEEE 802.11b to implement the communication speed of a maximum of 54 Mbps and satisfies backward compatibility to significantly come into the spotlight and further, is superior to the IEEE 802.11a in terms of the communication distance. Moreover, as a technology standard established to overcome a limitation of the communication speed which is pointed out as a weak point in a wireless LAN, IEEE 802.11n has been provided. The IEEE 802.11n aims at increasing the speed and reliability of a network and extending an operating distance of a wireless network. In more detail, the IEEE 802.11n supports a high throughput (HT) in which a data processing speed is a maximum of 540 Mbps or more and further, is based on a multiple inputs and multiple outputs (MIMO) technology in which multiple antennas are used at both sides of a transmitting unit and a receiving unit in order to minimize a transmission error and optimize a data speed. Further, the standard can use a coding scheme that transmits multiple copies which overlap with each other in order to increase data reliability. As the supply of the wireless LAN is activated and further, applications using the wireless LAN are diversified, the need for new wireless LAN systems for supporting a higher throughput (very high throughput (VHT)) than the data processing speed supported by the IEEE 802.11n has come into the spotlight. Among them, IEEE 802.11ac supports a wide bandwidth (80 to 160 MHz) in the 5 GHz frequencies. The IEEE 802.11ac standard is defined only in the 5 GHz band, but initial 11ac chipsets will support even operations in the 2.4 GHz band for the backward compatibility with the existing 2.4 GHz band products. Theoretically, according to the standard, wireless LAN speeds of multiple stations are enabled up to a minimum of 1 Gbps and a maximum single link speed is enabled up to a minimum of 500 Mbps. This is achieved by extending concepts of a wireless interface accepted by 802.11n, such as a wider wireless frequency bandwidth (a maximum of 160 MHz), more MIMO spatial streams (a maximum of 8), multi-user MIMO, and high-density modulation (a maximum of 256 QAM). Further, as a scheme that transmits data by using a 60 GHz band instead of the existing 2.4 GHz/5 GHZ, IEEE 802.11ad has been provided. The IEEE 802.11ad is a transmission standard that provides a speed of a maximum of 7 Gbps by using a beamforming technology and is suitable for high bit rate moving picture streaming such as massive data or non-compression HD video. However, since it is difficult for the 60 GHz frequency band to pass through an obstacle, it is disadvantageous in that the 60 GHz frequency band can be used only among devices in a short-distance space. As a wireless LAN standard after 802.11ac and 802.11ad, the IEEE 802.11ax (high efficiency WLAN, HEW) standard for prov