EP-4742754-A1 - COMMUNICATION METHOD AND APPARATUS

Abstract

Embodiments of this application relate to a communication method and apparatus. The method includes: An AP MLD receives first downlink data from a current AP MLD; a target AP MLD encrypts the first downlink data by using a second key, to obtain second downlink data, where the second key is a key negotiated by the target AP MLD and a non-access point non-AP MLD, and the target AP MLD is an AP MLD of the non-AP MLD after a basic service set BSS transition; and the target AP MLD sends the second downlink data to the non-AP MLD. According to the method in embodiments of this application, roaming performance of the non-AP MLD can be improved.

Inventors

• HUANG, Guogang

Assignees

• Huawei Technologies Co., Ltd.

Dates

Publication Date

20260513

Application Date

20240719

Claims (20)

1. A communication method, comprising: receiving, by a target access point AP multi-link device MLD, first downlink data from a current AP MLD; encrypting, by the target AP MLD, the first downlink data by using a second key, to obtain second downlink data, wherein the second key is a key negotiated by the target AP MLD and a non-access point non-AP MLD, and the target AP MLD is an AP MLD of the non-AP MLD after a basic service set BSS transition; and sending, by the target AP MLD, the second downlink data to the non-AP MLD.
2. A communication method, comprising: receiving, by a target access point AP multi-link device MLD, first uplink data from a non-access point non-AP MLD; decrypting, by the target AP MLD, the first uplink data by using a second key, to obtain second uplink data, wherein the second key is a key negotiated by the target AP MLD and the non-AP MLD, and the target AP MLD is an AP MLD of the non-AP MLD after a basic service set BSS transition; and sending, by the target AP MLD, the second uplink data to a current AP MLD.
3. The method according to claim 1 or 2, wherein a first transmission link exists between the non-AP MLD and the current AP MLD, and the method further comprises: receiving, by the target AP MLD, a first request, wherein the first request is used to request to establish a second transmission link between the non-AP MLD and the target AP MLD; and establishing, by the target AP MLD, the second transmission link with the non-AP MLD.
4. The method according to claim 3, wherein the first request comprises indication information for enabling dual-link transmission of the non-AP MLD, and the dual links comprise the first transmission link and the second transmission link.
5. The method according to any one of claims 1 to 4, further comprising: sending, by the target AP MLD, a second request to the current AP MLD, wherein the second request is used to request to enable the dual-link transmission of the non-AP MLD.
6. The method according to any one of claims 1 to 5, further comprising: receiving, by the target AP MLD, a third request, wherein the third request is used to request to trigger path switching of the non-AP MLD; and sending, by the target AP MLD, a fourth request to a distributed system DS, wherein the fourth request is used to request the DS to update a stored mapping relationship between the non-AP MLD and the current AP MLD to a mapping relationship between the non-AP MLD and the target AP MLD.
7. The method according to any one of claims 3 to 6, wherein one or both of the first request and the third request are from the non-AP MLD, and one or both of the first request and the third request are transmitted through an air interface between the non-AP MLD and the target AP MLD or are transmitted through the current AP MLD and the DS.
8. The method according to claim 7, wherein the first request does not comprise operating channel information OCI when the first request is transmitted through the current AP MLD and the DS.
9. The method according to any one of claims 6 to 8, wherein after receiving, by the target AP MLD, the third request, and before sending, by the target AP MLD, the fourth request to the DS, the method further comprises: sending, by the target AP MLD, a context transfer request to the current AP MLD; and receiving, by the target AP MLD, a context transfer response from the current AP MLD, wherein the context transfer response comprises context information of the non-AP MLD.
10. The method according to claim 9, wherein the context transfer response further comprises at least one of the following: a block acknowledgement protocol of a traffic identifier TID, a window start position of a transmit buffer of the TID, a window size of the transmit buffer of the TID, a window start position of an uplink receive end scoreboard, a window size of the uplink receive end scoreboard, a window start position of a receive reordering buffer, a window size of the receive reordering buffer, a currently received maximum packet number PN value, or an uplink replay counter.
11. The method according to any one of claims 1 to 10, wherein after a transmission path of the non-AP MLD is switched from the first transmission path to the second transmission path, the non-AP MLD and the target AP MLD encrypt/decrypt uplink data and/or downlink data by using the second key negotiated by the non-AP MLD and the target AP MLD.
12. A communication method, comprising: receiving, by a current access point AP multi-link device MLD, third downlink data from a distributed system DS; performing, by the current AP MLD, upper-medium access control MAC layer processing on the third downlink data, to obtain first downlink data, wherein the upper-MAC layer processing does not comprise encrypting the third downlink data; and sending, by the current AP MLD, the first downlink data to a target AP MLD, wherein the target AP MLD is an AP MLD of a non-access point non-AP MLD after a basic service set BSS transition.
13. A communication method, comprising: receiving, by a current access point AP multi-link device MLD, second uplink data from a target AP MLD, wherein the second uplink data is data decrypted by using a second key, the second key is a key negotiated by the target AP MLD and a non-access point non-AP MLD, and the target AP MLD is an AP MLD of the non-AP MLD after a basic service set BSS transition; performing, by the current AP MLD, upper-medium access control MAC layer processing on the second uplink data, to obtain third uplink data, wherein the upper-MAC layer processing does not comprise decrypting the second uplink data; and sending, by the current AP MLD, the uplink data to a distributed system DS.
14. The method according to claim 12, wherein the upper-MAC layer processing comprises: performing duplicate detection on the uplink data packet.
15. The method according to any one of claims 12 to 14, wherein a first transmission link exists between the current AP MLD and the non-AP MLD, and the method further comprises: receiving, by the current AP MLD, a second request from the target AP MLD, wherein the second request is used to request to enable dual-link transmission of the non-AP MLD, and the dual links comprise the first transmission link and a second transmission link between the non-AP MLD and the target AP MLD.
16. The method according to any one of claims 12 to 15, further comprising: receiving, by the current AP MLD, a fifth request from the non-AP MLD, wherein the fifth request is used to request to disconnect the first transmission link between the non-AP MLD and the current AP MLD, the fifth request comprises first indication information, and the first indication information indicates the current AP MLD to reserve block acknowledgement BA information and/or context information of the non-AP MLD and buffer data that is not from the non-AP MLD; and sending, by the current AP MLD, a sixth request to the DS, wherein the sixth request is used to request to delete a mapping relationship that is between the non-AP MLD and the current AP MLD and that is stored in the DS.
17. The method according to any one of claims 12 to 16, further comprising: receiving, by the current AP MLD, a context transfer request from the target AP MLD; and sending, by the current AP MLD, a context transfer response to the target AP MLD, wherein the context transfer response comprises context information of the non-AP MLD.
18. The method according to claim 17, wherein the context transfer response further comprises at least one of the following: a block acknowledgement protocol of a traffic identifier TID, a window start position of a transmit buffer of the TID, a window size of the transmit buffer of the TID, a window start position of an uplink receive end scoreboard, a window size of the uplink receive end scoreboard, a window start position of a receive reordering buffer, a window size of the receive reordering buffer, a currently received maximum packet number PN value, or an uplink replay counter.
19. The method according to any one of claims 12 to 18, further comprising: sending, by the current AP MLD, a beacon measurement request to the non-AP MLD, wherein the beacon measurement request comprises indication information of a corresponding link of a serving AP.
20. The method according to any one of claims 12 to 19, further comprising: sending, by the current AP MLD, a seventh request to the non-AP MLD, wherein the seventh request comprises second indication information, and the second indication information indicates the non-AP MLD to reserve the BA information and/or the context information of the non-AP MLD and buffer the data that is not from the non-AP MLD.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to Chinese Patent Application No. 202310952314.0, filed with the China National Intellectual Property Administration on July 29, 2023 and entitled "COMMUNICATION METHOD AND APPARATUS", which is incorporated herein by reference in its entirety. TECHNICAL FIELD Embodiments of this application relate to the field of communication technologies, and in particular, to a communication method and apparatus. BACKGROUND Due to factors such as movement of a non-access point (non-access point, non-AP) multi-link device (multi-link device, MLD), the non-AP MLD needs to switch an access point (access point, AP) MLD associated with the non-AP MLD. During roaming, the non-AP MLD often encouters a rate drop (to be specific, a transmission rate decreases). How to improve roaming performance of the non-AP MLD is an important research direction of next-generation wireless fidelity (wireless fidelity, Wi-Fi) roaming. SUMMARY Embodiments of this application provide a communication method and apparatus. During roaming, data transmission may be performed between a current AP MLD and a target AP MLD, to improve roaming performance of a non-AP MLD. According to a first aspect, a communication method is provided, including: A target access point AP multi-link device MLD receives first downlink data from a current AP MLD; the target AP MLD encrypts the first downlink data by using a second key, to obtain second downlink data, where the second key is a key negotiated by the target AP MLD and a non-access point non-AP MLD, and the target AP MLD is an AP MLD of the non-AP MLD after a basic service set BSS transition; and the target AP MLD sends the second downlink data to the non-AP MLD. According to a second aspect, a communication method is provided, including: A target access point AP multi-link device MLD receives first uplink data from a non-access point non-AP MLD; the target AP MLD decrypts the first uplink data by using a second key, to obtain second uplink data, where the second key is a key negotiated by the target AP MLD and the non-AP MLD, and the target AP MLD is an AP MLD of the non-AP MLD after a basic service set BSS transition; and the target AP MLD sends the second uplink data to a current AP MLD. In a design, a first transmission link exists between the non-AP MLD and the current AP MLD, and the method further includes: The target AP MLD receives a first request, where the first request is used to request to establish a second transmission link between the non-AP MLD and the target AP MLD; and the target AP MLD establishes the second transmission link with the non-AP MLD. In a design, the first request includes indication information for enabling dual-link transmission of the non-AP MLD, and the dual links include the first transmission link and the second transmission link. In a design, the method further includes: The target AP MLD sends a second request to the current AP MLD. The second request is used to request to enable dual-link transmission of the non-AP MLD. In a design, the method further includes: The target AP MLD receives a third request, where the third request is used to request to trigger path switching of the non-AP MLD; and the target AP MLD sends a fourth request to a distributed system DS, where the fourth request is used to request the DS to update a stored mapping relationship between the non-AP MLD and the current AP MLD to a mapping relationship between the non-AP MLD and the target AP MLD. In a design, one or both of the first request and the third request are from the non-AP MLD, and one or both of the first request and the third request are transmitted through an air interface between the non-AP MLD and the target AP MLD or are transmitted through the current AP MLD and the DS. In a design, the first request does not include operating channel information OCI when the first request is transmitted through the current AP MLD and the DS. In a design, after the target AP MLD receives the third request, and before the target AP MLD sends the fourth request to the DS, the method further includes: The target AP MLD sends a context transfer request to the current AP MLD; and the target AP MLD receives a context transfer response from the current AP MLD. The context transfer response includes context information of the non-AP MLD. In a design, the context transfer response further includes at least one of the following: a block acknowledgement protocol of a traffic identifier TID, a window start position of a transmit buffer of the TID, a window size of the transmit buffer of the TID, a window start position of an uplink receive end scoreboard, a window size of the uplink receive end scoreboard, a window start position of a receive reordering buffer, a window size of the receive reordering buffer, a currently received maximum packet number PN value, or an uplink replay counter. In a design, after a transmission path of the non-AP