CN120614661A

CN120614661A - Multi-link device communication method, communication device, chip, computer-readable storage medium, and computer program product

Info

Publication number: CN120614661A
Application number: CN202410266240.XA
Authority: CN
Inventors: 淦明; 黄国刚; 赵悦; 张茂礼
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2024-03-07
Filing date: 2024-03-07
Publication date: 2025-09-09
Also published as: WO2025185645A8; WO2025185645A1

Abstract

The present application provides a method for multi-link device communication, which can be applied to support IEEE protocols, such as 802.11be/Wi-Fi 7/Wi-Fi 8 protocols, IEEE 802.11 Integrated mmWave protocols, IEEE 802.11bf/perception protocols, or IEEE 802.15/UWB protocols; the method can also support the Star Flash protocol. The method includes: generating a request frame, the request frame being used to request roaming to a target AP MLD, the request frame including first indication information, the first indication information being used to determine the target AP MLD; and sending the request frame to the first AP MLD. In an embodiment of the present application, a non-AP MLD sends a request frame to the first AP MLD to enable roaming of the non-AP MLD to the target AP MLD.

Description

Method, communication device, chip, computer readable storage medium and computer program product for multi-link device communication

Technical Field

The present application relates to the field of communications, and in particular, to a method, a communication apparatus, a chip, a computer readable storage medium and a computer program product for multi-link device communication.

Background

Wireless local area network (wireless local area network, WLAN) roaming or wireless fidelity (WIRELESS FIDELITY, wi-Fi) roaming refers to the process of a wireless terminal or Station (STA) transferring from one Access Point (AP) to another AP, i.e., the wireless terminal or STA moving from one Basic Service Set (BSS) to another BSS. WLAN roaming or Wi-Fi roaming means that an STA can move arbitrarily in a Wi-Fi network belonging to the same Extended Service Set (ESS), such as switching from one BSS to another BSS in the same ESS. WLAN roaming or Wi-Fi roaming includes roaming of STAs and roaming of non-access point multi-link devices (non-AP multi-LINK DEVICE, non-AP MLD), i.e. non-AP MLD switches from one access point multi-link device (AP multi-LINK DEVICE, AP MLD) to another APMLD.

The roaming mechanism defined in the current protocol does not support packet continuous transmission, that is to say, the problems of packet loss and overlong transmission interruption time occur in the roaming process, which results in poor user experience. How to improve the user roaming experience is a problem to be solved at present.

Disclosure of Invention

The embodiment of the application discloses a method, a communication device, a chip, a computer readable storage medium and a computer program product for multi-link equipment communication, which can realize roaming supporting packet continuous transmission.

In a first aspect, an embodiment of the present application provides a method for multi-link device communication, where the method is applied to a non-access point multi-link device (non-AP multi-LINK DEVICE, non-AP MLD), and the method includes generating a request frame for requesting roaming to a target AP MLD, where the request frame includes first indication information, where the first indication information is used to determine the target AP MLD, and sending the request frame to the first AP MLD.

In the embodiment of the application, the non-AP MLD sends the request frame to the first AP MLD, and the request frame is used for requesting roaming to the target AP MLD, so that the first AP MLD realizes that the transmission of the non-AP MLD is not interrupted in the process of roaming the non-AP MLD to the target AP MLD in a context transfer mode and the like, namely, realizes the roaming supporting the continuous transmission, can reduce packet loss, and further improves the roaming experience of users.

In one possible implementation, the first indication information is used to indicate the target AP MLD, or the first indication information is a wild card basic service set identifier (basic SERVICE SET IDENTIFIER, BSSID).

In this implementation, the first indication information is used to indicate the target AP MLD, so that the first AP MLD can learn the AP MLD to which the non-AP MLD is to roam. The first indication information is a wild-card BSSID so that the first AP MLD decides to which AP MLD the non-AP MLD is to be roamed.

In a possible implementation manner, the request frame further includes one or more second indication information, where each second indication information is used to indicate a first link, and the first link is a link that the non-AP MLD requests the target AP MLD to establish. Or the request frame further includes second indication information, where the second indication information is used to indicate a first link, and the first link includes one or more links that the non-AP MLD requests the target AP MLD to establish.

In this implementation, the request frame further includes one or more second indication information, which may indicate that the non-AP MLD requests the link established by the target AP MLD.

In a possible implementation manner, the request frame further includes at least one of third indication information and parameters for establishing one or more of the first links, where the third indication information is used to indicate a primary link of the one or more first links.

In this implementation, the third indication information is used to indicate the primary link of the one or more first links, so that the target AP MLD knows the primary link that the non-AP MLD requests to establish. The request frame also includes parameters for establishing one or more first links, which may be determined more quickly.

In a possible implementation manner, the request frame further includes fourth indication information, where the fourth indication information is used to indicate a link state of the first link after receiving the response frame.

In this implementation, the fourth indication information is used to indicate the link state of the first link after receiving the response frame, which may facilitate data transmission between the non-AP MLD and the current AP MLD and the target AP MLD.

In one possible implementation, the link state includes enabled and disabled, or the link state includes an awake state and a sleep state.

In a possible implementation manner, the request frame further includes timeout information, where the timeout information is used to feed back the determination of the effective time of the response frame corresponding to the request frame.

In the implementation, the request frame further comprises timeout information, the timeout information is used for feeding back the determination of the effective time of the response frame corresponding to the request frame, and long-time waiting of the non-AP MLD can be avoided, so that roaming experience is prevented from being influenced.

In one possible implementation, the request frame is a link reconfiguration request frame.

In this implementation, multiplexing the link reconfiguration request frame has the advantage that the first AP MLD can be triggered to perform context transfer while establishing a link with the target AP MLD, so that signaling overhead can be saved while switching to the target AP MLD interaction is reduced.

In one possible implementation manner, the method further includes receiving a response frame from the first AP MLD, where the response frame includes fifth indication information, where the fifth indication information is used to indicate a status code corresponding to the first link and/or a critical update count value, where the status code is used to indicate that a request for establishing the first link is denied or received, and the critical update count value is a number of times that a Basic Service Set (BSS) critical parameter of the AP where the first link is currently updated, and when the BSS critical parameter of the AP where the first link is located changes, the critical update count value is increased by 1.

In this implementation manner, the fifth indication information is used to indicate the status code and/or the critical update count value corresponding to the first link, so that the non-AP MLD may learn whether the request for establishing the first link is received and/or whether the BSS critical parameter of the AP where the first link is located needs to be updated.

In a possible implementation manner, the response frame further includes sixth indication information, where the sixth indication information is used to indicate the target AP MLD.

In one possible implementation, the response frame is a link reconfiguration response frame.

In this implementation, multiplexing the link reconfiguration response frames may save signaling overhead.

In a second aspect, an embodiment of the present application provides a method for multi-link device communication, where the method is applied to a first AP MLD, and the method includes receiving a request frame from a non-AP MLD, where the request frame is used to request roaming to a target AP MLD, where the request frame includes first indication information, where the first indication information is used to determine the target AP MLD, and performing a context transfer to the target AP MLD. The purpose of the context transfer is to roam the non-AP MLD to the target AP MLD. Alternatively, the performing context transfer is used to roam the non-AP MLD to the target AP MLD. Illustratively, the context is used to configure MLDMAC sublayers.

In the embodiment of the application, the context transfer is carried out to the target AP MLD, and the roaming of the non-AP MLD to the target AP MLD can be realized. The context transfer to the target AP MLD can realize that the transmission of the non-AP MLD is not interrupted in the process of roaming the non-AP MLD to the target AP MLD, namely, the roaming supporting the continuous transmission of the packet is realized, and the packet loss can be reduced, thereby improving the roaming experience of the user.

In one possible implementation, the context includes Block ACK (BA) session related parameters and/or security related parameters.

In this implementation, if the context includes parameters related to the BA session, the context transfer is performed to the target AP MLD, so that packet loss of the non-AP MLD during roaming may be reduced or avoided, thereby improving the roaming experience of the user. If the context includes the security-related parameters, the target AP MLD may be enabled to implement encryption and decryption-related operations, thereby improving the security of the data.

In a possible implementation manner, the first indication information is used to indicate the target AP MLD, or the first indication information is a wild card BSSID.

In a possible implementation manner, the request frame further includes one or more second indication information, where each second indication information is used to indicate a first link, and the first link is a link that the non-AP MLD requests the target AP MLD to establish.

In one possible implementation manner, the method further comprises sending a response frame to the non-AP MLD, wherein the response frame comprises fifth indication information, the fifth indication information is used for indicating a state code and/or a key update count value corresponding to a first link, the state code is used for indicating that a request for establishing the first link is refused or received, the key update count value is the current update times of a Basic Service Set (BSS) key parameter of an AP where the first link is located, and when the BSS key parameter of the AP where the first link is located is changed, the key update count value is increased by 1.

In this implementation, sending the response frame to the non-AP MLD may enable the non-AP MLD to learn the status code and/or the key update count value corresponding to the first link.

In one possible implementation, the request frame further includes fourth indication information, where the fourth indication information is used to indicate a link state of a first link after receiving the response frame, where the first link is a link that the non-AP MLD requests the target AP MLD to establish, and after sending the response frame to the non-AP MLD, the method further includes:

And when the last sequence number SN associated with the non-AP MLD on the first AP MLD is refreshed or overtime, transmitting link deletion information to the non-AP MLD, wherein the link deletion information is used for indicating the non-AP MLD to delete the link of the first AP MLD. Transmitting link deletion information to the non-AP MLD may be replaced by transmitting link disabling information to the non-AP MLD, the link disabling information indicating that the non-AP MLD disables a link with the first AP MLD. Or transmitting link deletion information to the non-AP MLD may be replaced by transmitting link dormancy information to the non-AP MLD, where the link dormancy information is used to instruct the non-AP MLD to configure (switch) a link with the first AP MLD to a dormant state.

In this implementation, the remaining data packets in the transmission queue are sent to the non-AP MLD in case the link state of the first link is a disabled or sleep state, so that the non-AP MLD receives complete downstream data from the first AP MLD.

Possible implementations of the second aspect may be found in various possible implementations of the first aspect.

With respect to the technical effects brought about by the various possible implementations of the second aspect, reference may be made to the description of the technical effects of the various possible implementations of the first aspect.

In a third aspect, an embodiment of the present application provides a communication device having a function of implementing the behavior in the method embodiment of the first aspect described above. The communication device may be a terminal device, a component of a terminal device (for example, a processor, a chip, or a chip system), or a logic module or software that can implement all or part of the functions of the terminal device. For example, the communication device is a second access point. The functions of the communication device may be implemented by hardware, or may be implemented by executing corresponding software by hardware, where the hardware or software includes one or more modules or units corresponding to the functions described above. In one possible implementation manner, the communication device comprises a transceiver module and a processing module, wherein the processing module is used for generating a request frame, the request frame is used for requesting roaming to a target AP MLD, the request frame comprises first indication information, the first indication information is used for determining the target AP MLD, and the transceiver module is used for sending the request frame to the first AP MLD.

In a possible implementation manner, the transceiver module is further configured to receive a response frame from the first AP MLD, where the response frame includes fifth indication information, where the fifth indication information is used to indicate a status code and/or a critical update count value corresponding to the first link, where the status code is used to indicate that a request for establishing the first link is denied or received, where the critical update count value is a number of times that a BSS critical parameter of the AP where the first link is currently updated, and where when the BSS critical parameter of the AP where the first link is located is changed, the critical update count value is increased by 1.

Possible implementations of the third aspect may be found in various possible implementations of the first aspect.

Regarding the technical effects brought about by the various possible implementations of the third aspect, reference may be made to the description of the technical effects of the various possible implementations of the first aspect.

In a fourth aspect, an embodiment of the present application provides another communication device having a function of implementing the behavior in the method embodiment of the second aspect described above. The communication device may be a network device, a component of a network device (e.g., a processor, a chip, or a system on a chip), or a logic module or software that can implement all or part of the functions of the network device. For example, the communication device is a second access point. The functions of the communication device may be implemented by hardware, or may be implemented by executing corresponding software by hardware, where the hardware or software includes one or more modules or units corresponding to the functions described above. In one possible implementation, the communication device comprises a transceiver module and a processing module, wherein the transceiver module is configured to receive a request frame from a non-AP MLD, the request frame is configured to request roaming to a target AP MLD, the request frame includes first indication information, the first indication information is configured to determine the target AP MLD, and the processing module is configured to perform context transfer to the target AP MLD. Illustratively, the processing module is configured to perform a context transfer to the target AP MLD in response to the request frame.

In a possible implementation manner, the transceiver module is further configured to send a response frame to the non-AP MLD, where the response frame includes fifth indication information, where the fifth indication information is used to indicate a status code and/or a critical update count value corresponding to the first link, where the status code is used to indicate that a request for establishing the first link is rejected or received, where the critical update count value is a number of times that a BSS critical parameter of the AP where the first link is currently updated, and where when the BSS critical parameter of the AP where the first link is located is changed, the critical update count value is increased by 1.

In one possible implementation manner, the request frame further includes fourth indication information, where the fourth indication information is used to indicate a link state of a first link after receiving the response frame, where the first link is a link established by the non-AP MLD requesting the target AP MLD, and the transceiver module is further configured to send, to the non-AP MLD, a remaining data packet in a transmission queue, where the transmission queue includes a data packet to be sent to the non-AP MLD, where the last sequence number SN associated with the non-AP MLD on the first AP MLD is refreshed or overtime, and where the link deletion information is used to indicate that the non-AP MLD deletes the link of the first AP MLD.

Possible implementations of the fourth aspect may be found in various possible implementations of the second aspect.

With respect to the technical effects brought about by the various possible implementations of the fourth aspect, reference may be made to the description of the technical effects of the various possible implementations of the second aspect.

In a fifth aspect, embodiments of the present application provide another communications apparatus comprising one or more processors configured to process data and/or signalling such that the method of the first or second aspect described above is implemented.

Optionally, the communication device further comprises a memory storing a computer program or instructions which, when executed by the processor, cause the communication device to perform the method of the first or second aspect as described above. The communication means may be, for example, a chip, the processor being a processing unit in the chip, the memory being a random access memory or a cache in the chip.

In the embodiment of the present application, in the process of executing the above method, the process of sending information (or signals) in the above method may be understood as a process of outputting information based on a computer program or instructions of a processor. In outputting the information, the processor outputs the information to the transceiver for transmission by the transceiver. After output by the processor, this information may also be subjected to other processing and then to the transceiver. Similarly, when the processor receives input information, the transceiver receives the information and inputs it to the processor. Further, after the transceiver receives the information, the information may be further processed before being input to the processor.

With respect to operations such as sending and/or receiving, etc., as referred to by a processor, if not explicitly stated or if not contradicted by actual or inherent logic in the relevant description, may generally be understood as processor-based computer program or instruction output.

In implementation, the processor may be a processor dedicated to performing the methods, or may be a processor that executes a computer program or instructions in a memory to perform the methods, such as a general-purpose processor. For example, the processor may also be configured to execute a program stored in the memory, which when executed, causes the communication device to perform the method as described above in the first aspect or any possible implementation of the first aspect.

In one possible implementation, the memory is located outside the communication device. In one possible implementation, the memory is located within the communication device.

In one possible implementation, the processor and the memory may also be integrated in one device, i.e. the processor and the memory may also be integrated together.

In one possible implementation, the communication device further comprises a transceiver for receiving signals or transmitting signals, etc.

In a sixth aspect, the present application provides a further communications device comprising processing circuitry and interface circuitry, the interface circuitry being for obtaining data or outputting data, the processing circuitry being for performing the method of the first or second aspects as described above.

In a seventh aspect, the present application provides a computer readable storage medium having stored therein a computer program comprising program instructions which when executed cause a computer to perform the method of the first or second aspects as described above.

In an eighth aspect, the present application provides a computer program product comprising a computer program comprising program instructions which, when executed, cause a computer to perform the method of the first or second aspect as described above.

In a ninth aspect, the present application provides a chip comprising a communication interface for signal transceiving of the chip, and a processor for executing a computer program or instructions to cause a communication device comprising the chip to perform the method of the first or second aspect as described above.

In a tenth aspect, embodiments of the present application provide a communication system, including a communication device according to any possible implementation manner of the third aspect or the third aspect, and a communication device according to any possible implementation manner of the fourth aspect or the fourth aspect.

Drawings

Fig. 1 is a schematic diagram of a roaming scenario applicable to an embodiment of the present application;

fig. 2 is an example of a schematic structural diagram of a multi-link device according to an embodiment of the present application;

Fig. 3 shows an example of a schematic structural diagram of multiple links between multiple link devices according to an embodiment of the present application;

FIG. 4 shows a schematic diagram of the format of a basic multilink element;

fig. 5 shows a schematic diagram of a format of a reconfiguration multi-link element (Reconfiguration Multi-LINK ELEMENT);

Fig. 6 is a schematic diagram of a connection manner between a multi-link AP and a multi-link STA according to an embodiment of the present application;

fig. 7 is a schematic architecture diagram of a communication system according to an embodiment of the present application;

FIG. 8 illustrates an example of a reconfiguration status list;

Fig. 9 shows an example of multicast key data;

fig. 10 is a schematic diagram of a KDE format according to an embodiment of the present application;

FIG. 11-1 shows an MLO GTK KDE format according to an embodiment of the present application;

FIG. 11-2 shows a MLO IGTK KDE format provided by an embodiment of the present application;

Fig. 11-3 shows a MLO BIGTK KDE format provided by an embodiment of the present application;

FIG. 12 is a diagram illustrating an OCI element format in accordance with an embodiment of the present application;

Fig. 13 is a flowchart of BA session establishment according to an embodiment of the present application;

fig. 14 is a flowchart of a method for multi-link device communication according to an embodiment of the present application;

fig. 15 is an example of a frame structure of a request frame according to an embodiment of the present application;

fig. 16 is an example of a frame structure of another request frame provided in an embodiment of the present application;

fig. 17 is an example of a frame structure of a response frame according to an embodiment of the present application;

fig. 18 is a flowchart of another method for multi-link device communication according to an embodiment of the present application;

Fig. 19 is a flowchart of another method for multi-link device communication according to an embodiment of the present application;

Fig. 20 is a schematic block diagram of a communication device 10 provided by an embodiment of the present application;

FIG. 21 is a schematic diagram of another communication device 20 according to an embodiment of the present application;

Fig. 22 is a schematic diagram of a chip system 30 according to an embodiment of the present application.

Detailed Description

The terms "first," "second," and various numerical numbers (e.g., "#1", "#2", etc.) and the like in the description, claims, and drawings of the present application are used for distinguishing between different objects only and not for describing a particular sequential order. It will be appreciated that the various numerical numbers referred to in the embodiments of the present application are merely for ease of description and are not intended to limit the scope of the embodiments of the present application. The sequence numbers of the processes below do not mean the sequence of execution, and the execution sequence of the processes should be determined by the functions and the internal logic, and should not be construed as limiting the implementation process of the embodiments of the present application. Furthermore, the terms "comprising," "including," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion. Such as a process, method, system, article, or apparatus that comprises a list of steps or elements is not limited to the list of steps or elements but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly understand that the embodiments described herein may be combined with other embodiments. Some of the steps in the embodiments described herein may be implemented as separate embodiments. In the present application, the naming of messages (frames) is used only to distinguish between different messages (frames) and should not be construed as limiting. That is, the names of any messages or frames in the present application may be replaced by other names, and the present application is not limited thereto.

The terminology used in the following embodiments of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the specification of the present application and the appended claims, the singular forms "a," "an," "the," and "the" are intended to include the plural forms as well, unless the context clearly indicates to the contrary. It should also be understood that the term "and/or" as used in this disclosure refers to and encompasses any or all possible combinations of one or more of the listed items. For example, "A and/or B" may mean that only A, only B, and both A and B are present, where A, B may be singular or plural. The term "plurality" as used in the present application means two or more. In the text description of the present application, the character "/", generally indicates that the front-rear associated object is an or relationship.

It will be appreciated that in the embodiments of the present application, "B corresponding to a" means that there is a correspondence between a and B, and B may be determined according to a. It should also be understood that determining (or generating) B from (or based on) a does not mean determining (or generating) B from (or based on) a alone, but may also determine (or generate) B from (or based on) a and/or other information.

It should be understood that in the present application, the indication includes a direct indication (also referred to as an explicit indication) and an implicit indication. The direct indication information A comprises the information A, and the implicit indication information A indicates the information A through the corresponding relation between the information A and the information B and the direct indication information B. The correspondence between the information a and the information B may be predefined, pre-stored, pre-burned, or pre-configured.

It should be understood that in the present application, information C is used for the determination of information D, including both information D being determined based on information C alone and based on information C and other information. In addition, the information C is used for determination of the information D, and a case of indirect determination is also possible, for example, the information D is determined based on the information E, and the information E is determined based on the information C.

In embodiments of the application, words such as "exemplary" or "such as" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "for example" should not be construed as preferred or advantageous over other embodiments or designs. Rather, the use of words such as "exemplary" or "such as" is intended to present related concepts in a concrete fashion.

In addition, the "network element a sends the information a to the network element B" in the embodiments of the present application may be understood that the destination end of the information a or an intermediate network element in a transmission path between the destination end is the network element B, and may include directly or indirectly sending the information to the network element B. "network element B receives information a from network element a" is understood to mean that the source of the information a or an intermediate network element in the transmission path with the source is network element a, and may include receiving information directly or indirectly from network element a. The information may be subjected to necessary processing, such as format change, etc., between the source and destination of the information transmission, but the destination can understand the valid information from the source. Similar expressions in the present application can be understood similarly, and are not repeated here.

Some of the figures relating to the structure of a message (frame) in the embodiments of the present application show examples of the lengths of fields in the message. It should be understood that the lengths of the fields shown in the drawings in the embodiments of the present application are merely examples, and that in practical applications, the lengths of any one of the fields may vary. In the drawings related to the structure of a message (frame) in the embodiments of the present application, the positions of the fields are not limited.

The embodiments of the present application relate to the drawings of a message structure, and some examples of names of fields in a message are given. It should be understood that the names of the fields shown in the drawings in the embodiments of the present application are merely examples, and in practical applications, the names of any one field may vary.

Some embodiments of the present application relate to the drawing of a message structure, and some embodiments show that a field in a message has a length of 0 or variable (variable) indicates that the field is an optional field, that is, when the field is not included in the message, the field has a length of 0. If the length of the field is variable (variable), the actual design process may indicate the specific length of the field through other indication information, or the receiving end may negotiate the length of the field in advance, or the length of the field is predefined, or the receiving end may determine the length of the field based on other auxiliary information when receiving the message carrying the field, and parse the message. The specific length determination method of the variable length field in the present application is not limited in any way. The length of the variable length field referred to in the message is not repeated hereinafter.

The technical scheme provided by the embodiment of the application can be applied to WLAN systems, such as Wi-Fi and the like. The method provided by the embodiment of the application can be suitable for IEEE protocols, such as IEEE 802.11be/Wi-Fi 7/EHT protocol, IEEE 802.11bn/UHR/Wi-Fi 8 protocol, IEEE INTEGRATED MMWAVE/integrated millimeter wave/IMMW protocol, IEEE 802.15/Ultra Wideband (UWB) protocol or IEEE 802.11bf/sensing protocol, and can also support star flash/SPARK LINK/nearlink standard protocol. The technical scheme provided by the embodiment of the application can also be applied to a wireless personal area network (wireless personal area network, WPAN) based on UWB technology. The method provided by the embodiment of the application can be suitable for IEEE802.15 series protocols, such as 802.15.4a protocol, 802.15.4z protocol or 802.15.4ab protocol, or future UWB WPAN protocol of some generation, and the like, and is not listed one by one. The technical scheme provided by the embodiment of the application can be applied to a communication system such as an internet of things (internet of things, ioT) system, a vehicle to X (V2X), a narrowband internet of things (narrow band internet of things, NB-IoT) system, devices in the internet of things, internet of things nodes, sensors and the like in the internet of things (IoT, internet of things), intelligent cameras in smart homes, intelligent remote controllers, intelligent water meter meters, sensors in smart cities and the like, or a long term evolution (long term evolution, LTE) system, a fifth generation (5 th-generation, 5G) communication system, a new communication system in future communication development and the like.

The WLAN system can provide high-rate low-delay transmission, and with the continuous evolution of WLAN application scenarios, the WLAN system will be applied to more scenarios or industries, such as the internet of things industry, the internet of vehicles industry or banking industry, enterprise offices, stadium stadiums, concert halls, hotel rooms, dormitories, wards, classrooms, super-merchants, squares, streets, production workshops, warehouses, and the like. Of course, the devices supporting WLAN communication or awareness (such as access points or sites) may be sensor nodes in a smart city (such as smart water meters, smart air detection nodes), smart devices in a smart home (such as smart cameras, projectors, display screens, televisions, stereos, refrigerators, washing machines, etc.), nodes in the internet of things, entertainment terminals (such as wearable devices of augmented reality (augmented reality, AR), virtual Reality (VR), etc.), smart devices in a smart office (such as printers, projectors, microphones, stereos, etc.), internet of vehicles in the internet of vehicles, infrastructure in everyday life scenarios (such as vending machines, super self-service navigation stations of merchants, self-service cashing devices, self-service ordering machines, etc.), devices in large sports and music stadiums, etc. Illustratively, the access points and sites may be devices applied in the internet of things, internet of things nodes, sensors, etc. in the internet of things, intelligent cameras in the smart home, intelligent remote controllers, intelligent water meter and electricity meter, sensors in the smart city, etc.

Although the embodiments of the present application are mainly exemplified by WLAN, and are particularly applied to networks of IEEE 802.11 series standards, such as a system supporting Wi-Fi7, which may also be referred to as very high throughput (EHT), and a system supporting Wi-Fi8, which may also be referred to as ultra high reliability (ultra high reliability, UHR) or ultra high reliability and throughput (ultra high reliability and throughput, UHRT). Those skilled in the art will readily appreciate that aspects of embodiments of the present application may be extended to other networks employing a variety of standards or protocols. Such as bluetooth (blue), high performance wireless LANs (high performance radio LAN, HIPERLAN), a wireless standard similar to the IEEE 802.11 standard and used principally in europe, and Wide Area Networks (WANs) or other now known or later developed networks.

The above-mentioned communication system to which the present application is applied is merely illustrative, and the communication system to which the present application is applied is not limited thereto, and is generally described herein, and will not be described in detail.

The method provided by the application is mainly applied to a roaming scene, wherein the roaming scene comprises at least two Access Point (AP) multi-link devices (MLD) and at least one Non-access point (Non-AP) MLD. Fig. 1 is a schematic diagram of a roaming scenario applicable to an embodiment of the present application.

In the roaming scenario shown in fig. 1, when the non-AP MLD associated with the AP MLD 1 moves from the coverage of the AP MLD 1 to the coverage of the AP MLD 2, the non-AP MLD establishes an association relationship with the AP MLD 2, for example, STA1 of the non-AP MLD associates AP1 of the AP MLD 2 and STA2 of the non-AP MLD associates AP2 of the AP MLD 2. Fig. 1 is merely an example, and the number of non-AP MLDs and the number of AP MLDs in a roaming scenario are not limited.

One key technology of the Institute of Electrical and Electronics Engineers (IEEE) 802.11be (Wi-Fi alliance called Wi-Fi 7, also known as the very high throughput (extremely high throughput, EHT) standard) is the multi-link (multi-link) technology, which, in turn, requires multi-link devices (multi-LINK DEVICE, MLD) to support. MLD is a device that supports (has) multilink co-transmission. In the embodiment of the application, the device supporting multiple links and supporting the IEEE 802.11 standard is called a multi-link device. MLD may have the ability to establish multiple links simultaneously. For example, the multi-link device may be an AP MLD, or may also be a non-AP MLD, such as a station multi-link device (STA MLD). It should be noted that the names of the above-mentioned multi-link devices are merely examples, and the protection scope of the present application is not limited in any way, for example, the AP MLD may also be called a multi-link AP, or with the development of communication technology, the AP MLD may also have other names, which are not illustrated herein.

In the IEEE 802.11be (Wi-Fi 7) protocol, MLD can use multiple links simultaneously. In one possible implementation, the MLD has a plurality of radio frequency modules that can operate in different frequency bands, respectively, e.g., the frequency band in which the MLD operates can be, for example, all or a portion of 2.4GHz,5GHz,6GHz, and high frequency 60 GHz. When the distance between channels operated by two radio frequency modules in one MLD is large enough, the two radio frequency modules do not interfere with each other and can independently operate. If any two links support transmission over one link while the other is receiving, we call the two links to support Simultaneous Transceiving (STR) capability, otherwise call the two links not have simultaneous transceiving (Non-STR). The multilink device includes one or more affiliated stations (AFFILIATED STA), which are logical stations that can operate on a link. The station to which the station is affiliated may be an Access Point (AP) or a non-Access Point station (non-Access Point Station, non-AP STA). For convenience of description, the multi-link device with the affiliated station being an AP may be referred to as a multi-link AP or multi-link AP device or AP multi-link device (AP multi-LINK DEVICE), and the multi-link device with the affiliated station being a non-AP STA may be referred to as a multi-link STA or multi-link STA device or STA multi-link device (STA multi-LINK DEVICE). For convenience of description, "multi-link device including affiliated STA" is also briefly described as "multi-link device including STA" in the embodiment of the present application.

Notably, the multi-link device includes multiple logical stations, each operating on one link, but allowing multiple logical stations to operate on the same link. The link identifiers mentioned below characterize a station operating on a link, i.e. if there are more than 1 station on a link, more than 1 link identifier is required to characterize them. The links referred to below are sometimes also representative of stations operating on the links.

The multi-link AP device and the multi-link STA may use link identification to identify a link or a station on a link during data transmission. Prior to communication, the multi-link AP device and the multi-link STA device may negotiate or communicate a link identifier to a link or a station on a link. Therefore, in data transmission, a large amount of signaling information is not required to be transmitted to indicate a link or a station on the link, and the link identification is carried, so that the signaling overhead is reduced, and the transmission efficiency is improved.

In one example, when the multi-link AP device establishes a BSS, a transmitted management frame, such as a beacon (beacon) frame, may carry an element that includes a plurality of link identification information fields, each of which may suggest a link identification to station operating on a link. Each link identification information field includes a link identification and further includes one or more of a media access control (MEDIA ACCESS control, MAC) address, an operation set, and a channel number, where one or more of the MAC address, the operation set, and the channel number may indicate a link. In another example, the multi-link AP device and the multi-link station device negotiate multiple link identification information fields during the multi-link establishment association process. In subsequent communications, the multi-link AP device or multi-link station device may characterize a station in the multi-link device by using a link identification that may also characterize one or more attributes in the MAC address, operational set, channel number of the station. The MAC address may also be replaced by an association identifier of the associated multilink AP device.

If multiple stations operate on a link, the link identification (a digital ID) is characterized in a sense that it includes, in addition to the set of operations on which the link is located, the channel number, and the station identification, such as the station's MAC address or AID, that operates on the link.

The multi-link device may enable wireless communications following the 802.11 family of protocols, for example, following an extremely high throughput (Extremely High Throughput, EHT) station, or following an 802.11 be-based or compatible 802.11 be-capable station, to enable communications with other devices, which may or may not be multi-link devices.

The non-AP MLD related to the application can be a wireless communication chip, a wireless sensor or a wireless communication terminal. Such as a user terminal, user equipment, access device, subscriber station, subscriber unit, mobile station, user agent, user equipment supporting Wi-Fi communication functions, where the user terminal may include various handheld devices, in-vehicle devices, wearable devices, internet of things (internet of things, ioT) devices, computing devices, or other processing devices connected to a wireless modem, as well as various forms of User Equipment (UE), mobile Station (MS), terminal (terminal), terminal device (terminal equipment), portable communication device, handset, portable computing device, entertainment device, gaming device or system, global positioning system device, or any other suitable device configured for network communication via a wireless medium, etc. In addition, the non-AP MLD can support 802.11be system or the next generation of 802.11be, such as WLAN system of Wi-Fi 8. The non-AP MLD can also support a plurality of WLAN systems such as 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, 802.11a and the like.

The AP MLD according to the embodiment of the present application may be a device deployed in a wireless communication network to provide a wireless communication function for its associated non-AP, and is mainly deployed in a home, a building, and a campus, where a typical coverage radius is several tens meters to hundreds meters, and of course, may also be deployed outdoors. The AP MLD corresponds to a bridge connecting a wired network and a wireless network, and mainly serves to connect each wireless network client together and then access the wireless network to the ethernet. Specifically, the AP MLD may be a base station with a Wi-Fi chip, a router, a gateway, a repeater, a communication server, a switch, or a bridge, where the base station may include various macro base stations, micro base stations, relay stations, and so on. In addition, the AP MLD may support 802.11be system or the next generation of 802.11be, such as WLAN system like Wi-Fi 8. The AP MLD may also support WLAN standards such as 802.11ax, 802.11ac, 802.11n, 802.11g, 802.11b, and 802.11 a.

The MAC layer of MLD is divided into an MLD high MAC sublayer (MLD Upper MAC subLayer) and an MLD low MAC sublayer (MLD lower MAC sublayer). Each secondary site included in the MLD has a respective Media Access Control (MAC) address, which may be referred to as a lower layer (low) MAC address, and the MLD has a higher layer (upper) MAC address. The lower layer MAC address corresponds to the MLD lower MAC sublayer and the higher layer MAC address corresponds to the MLD higher MAC sublayer. Fig. 2 is an example of a schematic structural diagram of a multi-link device according to an embodiment of the present application. As shown in fig. 2, the affiliated stations of the AP MLD include AP1 and AP2, the lower layer (low) MAC address of AP1 (corresponding to the MLD lower MAC sublayer 1) is MAC address #1, the lower layer MAC address of AP2 (corresponding to the MLD lower MAC sublayer 2) is MAC address #2, and the AP MLD has a higher layer (upper) MAC address, which is called MLD MAC address. The lower layer (low) MAC address of AP1 may be the MAC address of the link associated (supported) by AP1 and the lower layer (low) MAC address of AP2 may be the MAC address of the link associated by AP 2.

In order to facilitate understanding of the technical solutions of the embodiments of the present application, first, a description will be briefly given of techniques that may be related to the embodiments of the present application.

1) Multilink establishment AP MLD and non-AP MLD can establish multilink connection through signaling interactions on any link. Fig. 3 shows an example of a schematic structure of multiple links between multiple link devices according to an embodiment of the present application. As shown in fig. 3, the AP MLD includes AP1 and AP2, the AP1 includes an AP1 physical layer (PHYSICAL LAYER, PHY), an AP1 low MAC (i.e., an MLD low MAC sublayer) and an MLD high MAC (i.e., an MLD high MAC sublayer), the AP2 includes an AP2 PHY, an AP2 low MAC and an MLD high MAC, wherein the MLD high MAC is shared between the AP1 and the AP2, the non-AP MLD includes STA1 and STA2, the STA1 includes an STA1 PHY, an STA1 low MAC and an MLD high MAC, the STA2 includes an STA2 PHY, an STA2 low MAC and an MLD high MAC, wherein the MLD high MAC is shared between the STA1 and the STA2, the AP1 and the STA1 are connected through a link 1, and the AP2 and the STA2 are connected through a link 2. Fig. 3 is only an example, and the number of APs included in the AP MLD, the number of STAs included in the non-AP MLD, and the number of links between the AP MLD and the non-AP MLD are not limited.

For non-AP MLD, it can implement simultaneous association with multiple links of AP MLD by performing a multi-link establishment operation on one of the links. In one possible implementation, at the time of multilink establishment, an association may be established between the non-AP MLD and the AP MLD through an association procedure. In connection with fig. 3, the flow of multilink establishment may include the steps of 1) non-AP MLD transmitting an association request (Association Request) frame on link 1, the association request frame carrying STA-side information of link 1 and STA-side information of link 2. For example, the association request frame may carry a Multi-link element (Multi-LINK ELEMENT) field, where the Multi-LINK ELEMENT field is used to carry information of the non-AP MLD and information of stations in the non-AP MLD, and step 2) the AP MLD sends an association response (Association Response) frame on the link 1, where the association response frame carries AP side information of the link 1 side and further carries AP side information of the link 2, so as to implement that STA1 and STA2 of the non-AP MLD respectively establish association (or complete association) with AP1 and AP2 of the AP MLD. In the process of multilink establishment, the link (e.g., link 1) on which the association request/response frame exchange is performed is called a transmission link (TRANSMITTED LINK), and the corresponding other link (e.g., link 2) is called a Non-transmission link (Non-TRANSMITTED LINK).

In order to carry non-AP MLD related information in the existing association request frame, the IEEE 802.11be protocol defines a Basic Multi-link element (Basic Multi-LINK ELEMENT) that carries MLD related information in an inherited manner, similar to the Multi-Basic Service Set Identifier (BSSID) element (Multi-BSS IDENTIFIER ELEMENT) in the existing protocol. BSS refers to an abbreviation for Basic service set (Basic SERVICE SET). In a possible implementation manner, the basic multilink element includes a multilink Control (Multi-Link Control) field, a Common information (Common Info) field and a Link information (Link Info) field, wherein the Common Info field carries information Common to a plurality of stations in the MLD, and information of the MLD itself. The Link Info field carries information about the stations on each Link in the MLD, such as the Per-STA Profile shown in FIG. 4. Illustratively, the single STA configuration (Per-STAProfile) includes subelements ID (Subelement ID), length, STA control (STAControl) and STA information (STA Info) and STA configuration (STAProfile). Fig. 4 shows a schematic diagram of the format of a basic multilink element. The meaning of the fields in fig. 4 can be referred to in the existing protocol and will not be described in detail here. The multilink control field carries the type of multilink element (as various variants such as Basic variant, reconfiguration variant (Reconfiguration variant), and probe request variant (Probe Request variant) are now defined), and a status Bitmap (Presence Bitmap) field, indicating which fields are not present. The inheritance mode refers to that the corresponding element of the corresponding link in the Per-STA Profile is carried in the Per-STA Profile only if the content of the corresponding element of the corresponding link in the frame body is different from that of the corresponding link in the frame body. If the contents of the corresponding elements are the same, the Per-STA Profile need not be carried repeatedly.

Fig. 5 shows a schematic diagram of a format for reconfiguring a multi-link element (Reconfiguration Multi-LINK ELEMENT). As shown in fig. 5, the reconfiguration multilink element includes a multilink Control (Multi-Link Control) field, a Common information (Common Info) field, and a Link Info field. Illustratively, the multilink control field includes a type, a presence bit map, and a reservation. Illustratively, the single STA configuration (Per-STAProfile) includes the subelement ID (Subelement ID), length, STA control (STA control), and STA information (STAinfo). The STA control field may include, among other things, a link Identification (ID), a complete profile, STAMAC address presence (STA MAC ADDRESS PRESENT), a remove timer presence (remote TIMER PRESENT), an Operation parameter presence (Operation PARAMETERS PRESENT), and a reservation. The STA information may include at least one of a STA Info Length (STA Info Length), a STA MAC address (STAMAC ADDRESS), an AP Removal Timer (AP remove Timer), and an operation parameter (Operation Parameters). The meaning of the fields in fig. 5 can be referred to in the existing protocol and will not be described in detail here.

2) The MLD MAC layer unicast data plane architecture the MLD MAC layer can be divided into an MLD high MAC sublayer (MLD Upper MAC subLayer, which can be abbreviated as high MAC layer) and an MLD low MAC sublayer (MLD lower MAC sublayer, which can be abbreviated as low MAC layer). The affiliated APs under the same AP MLD share a MLD high MAC sublayer, each affiliated AP having a respective MLD low MAC sublayer, as shown in fig. 6 below. Fig. 6 is a schematic diagram of a connection manner between a multi-link AP and a multi-link STA according to an embodiment of the present application. The 802.11 standard focuses on the 802.11PHY and MAC layer portions of a multi-link device, so fig. 6 shows only the PHY and MAC layers by way of example.

As shown in fig. 6, the multi-link device (e.g., multi-link AP and multi-link STA) may include PHY (PHY #1, PHY #2, and PHY #n as shown in fig. 6) and MAC layer, the physical layer may be used to process the physical layer signal, and the MAC layer may be used to process the MAC layer signal. Further, in the MAC layer, it is also possible to divide one high MAC (high-MAC) layer (high MAC as shown in fig. 6) and a plurality of low MAC (low-MAC) layers (low mac#1, low mac#2 to low mac#n as shown in fig. 6). As shown in fig. 6, a plurality of APs included in the multi-link AP share a high MAC layer at a low MAC layer and a PHY independently of each other. Multiple STAs included in the multi-link STA share a high MAC layer at a low MAC layer and a PHY independent of each other. The high MAC layer is connected to the plurality of low MAC layers, respectively, i.e., the high MAC layer is shared by the plurality of links. By way of example, the high MAC layer may perform one or more of Sequence Number (SN) and Packet Number (PN) assignment of MAC service data units (MAC SERVICE DATA units, MSDUs), MAC protocol data unit (MAC protocol data unit, MPDU) encryption, mapping of traffic identifications (TRAFFIC IDENTIFIER, TIDs) to links (TIDs-to-links), etc., when the MLD transmits data, and one or more of block acknowledgement scoreboard maintenance, duplicate detection, MPDU decryption, packet reordering, replay attack detection, etc.

In fig. 6, the phy#1 layer, the low mac#1 layer, and the high MAC layer in the multi-link AP may be regarded as ap#1, the phy#2 layer, the low mac#2 layer, and the high MAC layer may be regarded as ap#2. In a multi-link STA, the situation is similar in that the high MAC layer in the multi-link STA is also shared by a plurality of links, the phy#1 layer, the low mac#1 layer, and the high MAC layer are regarded as sta#1, the phy#2 layer, the low mac#2 layer, and the high MAC layer are regarded as sta#2, and the phy#n layer, the low mac#n layer, and the high MAC layer are regarded as sta#n, that is, it can be understood that n STA entities are included in the multi-link STA. As shown in fig. 6, phy#1 of ap#1 of the multi-link AP and phy#1 of sta#1 of the multi-link STA operate on one same channel, ap#1 of the multi-link AP and sta#1 of the multi-link STA communicate through a link (link#1 shown in fig. 6), phy#2 of ap#2 of the multi-link AP and phy#2 of sta#2 of the multi-link STA operate on another same channel, ap#2 of the multi-link AP and sta#2 of the multi-link STA communicate through a link (link#2 shown in fig. 6), phy#n of ap#n of the multi-link AP and phy#n of sta#n of the multi-link STA operate on another same channel, and ap#n of the multi-link AP and sta#n of the multi-link STA communicate through a link (link#n shown in fig. 6).

Illustratively, the high MAC layer or the low MAC layer may be implemented by a processor in a chip system of the multi-link device, or may be implemented by different software processing modules in a chip system, respectively, which are not listed in the embodiments of the present application. It will be appreciated that fig. 6 may be understood as a division of functional modules of a multi-link device, and each module shown in fig. 6 may be implemented in a form of hardware, or may be implemented in a form of a software functional module, etc. The PHY and MAC layers shown in fig. 6 can be understood as a division of logic functions, and other division manners are possible in practical implementation. N shown in fig. 6 may be equal to 1, or n may be an integer greater than 1, or the like.

For a multi-link device, each multi-link device has a MLD MAC address (MLD MAC ADDRESS) in addition to a respective MAC address (MAC ADDRESS) on each link. As illustrated in the architecture of fig. 6, the upper MAC layer may be uniquely identified by the MAC address of the corresponding MLD, and the lower MAC layer may be uniquely identified by the MAC address of the corresponding link, e.g., the lower MAC #1 and the lower MAC #2 may respectively correspond to the MAC addresses of the corresponding links. The multi-link device in the embodiment of the application can be a single-antenna device or a multi-antenna device. For example, a device with more than two antennas may be used. The number of antennas included in the multi-link device is not limited in the embodiments of the present application.

In one possible implementation, all links in the same MLD share a pairwise temporal key (PAIRWISE TRANSIENT KEY, PTK), but each link has a respective group temporal key (group temporal key, GTK), an integrity group temporal key (INTEGRITY GROUP TEMPORAL KEY, IGTK) and a beacon integrity group temporal key (beacon integrity group temporal key, BIGTK).

3) Non-co-located AP MLD (Non-collocated AP MLD) or roaming AP MLD (RoamingAP MLD) architecture IEEE 802.11be is currently discussing a new AP MLD architecture, referred to as Non-collocated AP MLD. The non-co-located AP MLD may also be referred to as a logical AP MLD (logical AP MLD), and the co-located AP MLD may also be referred to as a physical AP MLD (PHYSICAL AP MLD). One possible deployment form of the non-co-located AP MLD architecture is that MLD Upper MAC sublayer and MLD Lower MAC sublayer of the AP MLD are not within the same device, which communicates by wire, as shown in fig. 7 below. Fig. 7 is a schematic architecture diagram of a communication system according to an embodiment of the present application. The architecture shown in fig. 7 includes a UHR system, an EHT system, and a pre-EHT system (e.g., referred to as a pre-EHT). It will be appreciated that the various thickness lines or broken lines shown in fig. 7 are intended to represent various transmission paths. Generally, an interface between an upper layer (which may also be referred to as a higher layer, such as a radio resource control (radio resource control, RRC) layer) and a MAC layer may be referred to as a MAC service access point (SERVICE ACCESS point, SAP) (MAC SAP1 to MAC SAP7 shown as 7 black points in fig. 7). The MAC address may uniquely identify the MAC SAP. It will be appreciated that the representation of the MAC SAP (e.g., represented by black dots) and the representation of the location (e.g., where the black dots are located) shown in fig. 7 are merely examples, and should not be construed as limiting embodiments of the present application.

As an example, for the data of the Pre-EHT STA, since it is associated with an AP to which it belongs, the data of the Pre-EHT STA needs to be transceived through the MAC SAPs (e.g., MAC SAP1, MAC SAP3, MAC SAP4, MAC SAP6 shown in fig. 7) of the corresponding APs to which it belongs. As shown in fig. 7, for data from or transmitted to the pre-EHT STA, a certain AP may process the data through a non-MLD high MAC layer (MAC SAP1, MAC SAP3, MAC SAP4, MAC SAP6 as shown in fig. 7).

As another example, for the data of the EHT non-AP MLD, since it is associated with a certain co-located AP MLD, the data of the EHT non-AP MLD needs to be transceived through the MAC SAP (e.g., MAC SAP2, MAC SAP5 shown in fig. 7) of the corresponding co-located AP MLD. As shown in fig. 7, for data from or transmitted to the EHT non-AP MLD, the co-located AP MLD may perform data processing through the AP MLD high MAC sub-layers (MAC SAP2, MAC SAP5 as shown in fig. 7) and then perform data processing through the AP MLD low MAC sub-layers. Each AP MLD low MAC sublayer may correspond to one PHY, such as each AP MLD low MAC sublayer may correspond to PHY 1 (which may also be referred to as link 1 or PHY corresponding to link 1) in turn, to PHY N (which may also be referred to as link N or PHY corresponding to link N) for co-located AP MLD a, and each AP MLD low MAC sublayer may correspond to PHY 1 (which may also be referred to as link 1 or PHY corresponding to link 1) in turn, to PHY M (which may also be referred to as link M or PHY corresponding to link M) for co-located AP MLD B. Wherein A and B are used for distinguishing different co-located APs MLD, and M and N are positive integers.

As yet another example, for data of the UHR non-AP MLD, since it is associated with a certain non-co-located AP MLD, data related to the UHR non-AP MLD all needs to be transceived through the MAC SAP (e.g., MAC SAP7 shown in fig. 7) of the corresponding non-co-located AP MLD. As shown in fig. 7, for data from or transmitted to the UHR non-AP MLD, the non-co-sited AP MLD is forwarded out through the MAC SAP7 or to the corresponding co-sited AP MLD after processing through the AP MLD high MAC sublayer. The co-located AP MLD delivers the data to the relevant module of TID and link mapping or link merging.

Illustratively, the division of the high and low MAC sublayer functions for non-co-sited AP MLDs may depend on whether a certain traffic identification (TRAFFIC DENTIFIER, TID) is allowed to map onto links of different co-sited AP MLDs. For example, when a certain traffic identification (TRAFFIC DENTIFIER, TID) is allowed to map onto links of different co-located AP MLDs, a Block ACK (BA) session of the TID needs to be maintained at the high MAC sublayer of the non-co-located AP MLD, which session may be refreshed according to BA information fed back by the corresponding co-located AP MLD.

It can be understood that the AP MLD high MAC sublayer functional block may be placed in a certain co-located AP MLD, or may also be placed in an access point controller, etc., and the embodiment of the present application does not limit the manner of setting the high MAC sublayer of the non-co-located AP MLD. Communication between the AP MLD high MAC sublayer and the AP MLD low MAC sublayer may be via a network cable or other techniques. By way of example, a non-co-sited AP MLD may be understood as an AP MLD that is made up of a plurality of co-sited AP MLDs. Or the non-co-located AP MLD may be understood as a device for centrally or uniformly managing (or controlling) a plurality of co-located APs MLD.

Taking the relationship between the MAC address of the MLD and the MAC address of the link affiliated to the MLD as shown in fig. 2 as an example, the non-co-sited AP MLD also has a similar relationship with the co-sited AP MLD. Each non-co-located AP MLD has a non-co-located MLD MAC address (e.g., the high MAC sublayer of the non-co-located AP MLD shown in fig. 7) and the MLD MAC address of the co-located AP MLD affiliated with the non-co-located AP MLD, as well as the MAC address of the link affiliated with the co-located AP MLD. It is understood that the non-co-sited MLD MAC address may be understood as the MAC address of the AP MLD high MAC sublayer shown in fig. 7 (e.g., the MAC address of the AP MLD high MAC sublayer may identify MAC SAP 7). The n co-located AP MLDs belonging to the non-co-located AP MLD may also be referred to as the non-co-located AP MLD including the n co-located AP MLDs, or the non-co-located AP MLD corresponds to the n co-located AP MLDs, etc.

It will be appreciated that, with respect to the relationship between non-co-located AP MLD and co-located AP MLD, there may be different descriptions as the standard progresses, and thus embodiments of the present application are not limited with respect to the description of the relationship between non-co-located AP MLD and co-located AP MLD.

In a non-co-sited AP MLD architecture, UHR non-AP MLD with roaming requirements may be associated with UHR non-collocated AP MLD, whereas EHT non-AP MLD may only be associated with AP MLD, and Pre-EHT STA may only be associated with a certain AFFILIATED AP. When the UHR non-AP MLD associated with UHR non-collocated AP MLD moves from the coverage of one AP MLD to the coverage of another AP MLD and both AP MLDs are affiliated with the UHR non-collocated AP MLD, data transmission is not interrupted at roaming by adding links and assigning the multicast key of the added link without updating the PTK or re-associating.

It should be noted that the non-collocated AP MLD architecture is sometimes referred to as Roaming (Roaming) AP MLD, meaning that the AP MLD architecture is proposed to improve the Roaming performance of the non-AP MLD.

However, no agreement is currently made on the specific implementation (deployment) form of the non-co-sited AP MLD architecture. It is thought that if MLD Upper MAC sublayer and MLD lower MAC sublayer of the non-co-located AP MLD are deployed in different locations, the communication latency between MLD Upper MAC sublayer and MLD lower MAC sublayer can be significant, resulting in poor data transfer performance for this implementation. Another possible deployment scenario for Non-co-sited AP MLD architecture is proposed, namely MLD Upper MAC sublayer and MLD lower MAC sublayer of the Non-co-sited AP MLD must be deployed in the same device, and MLD Upper MAC sublayer of the Non-co-sited AP MLD moves MLD Upper MAC sublayer from one AP MLD to another AP MLD with the movement of Non-AP MLD, i.e. by Context (Context). The context transfer here may include MLD Upper MAC sublayer parameters required for data transmission and reception, PTKSA, and the like. The benefit of this deployment is that MLD Upper MAC sublayer and MLD Lower MAC sublayer are always within the same device, and the communication latency between MLD Upper MAC sublayer and MLD Lower MAC sublayer is small. For purposes of describing aspects, we refer to the former deployment form as deployment form I, and the latter deployment form as deployment form II.

4) BSS parameter critical update (BSSParameter Critical Update) to avoid clients (e.g., STAs) parsing the Beacon (Beacon) frame content each time, existing protocols define a BSS parameter critical update mechanism. Under this mechanism, the AP maintains a critical update count value (criticalupdate counter) and is carried in the Beacon frame, and the STA locally stores the last criticalupdate counter. If the local criticalupdate counter is different from criticalupdate counter carried in the current Beacon frame, the BSS parameters are considered to be changed, the Beacon frame content is further analyzed, and if the local criticalupdate counter is the same as criticalupdate counter carried in the current Beacon frame, the BSS parameters are considered to be unchanged, and the Beacon frame content is not required to be analyzed. The protocol defines which elements' content changes are defined as critical updates (critical updates), and when the content of these elements changes, then criticalupdate value is added.

5) Link reconfiguration request/Response (Link Reconfiguration Request/Response) frame the current IEEE 802.11be draft defines a multi-link reconfiguration operation that allows non-AP MLD to add/delete one or more links without re-association in the case of current AP MLD association. The multi-link reconfiguration operation does not need to update the PTK, but only negotiates key information of each link (per-link) such as GTK/IGTK/BIGTK for the newly added link. Specifically, the multi-link reconfiguration operation is accomplished using a path reconfiguration request/response, the specific frame format of which is shown in tables 1 and 2 below.

Table 1 multilink reconfiguration request frame

Sequential order	Information processing system
		1	Category class
2	Protected EHT Action protected EHT action frame
		3	Dialogtoken Dialog Token
4	Reconfiguration Multi-LINK ELEMENT reconfiguration of multilink elements
		5	OCI element operation channel information element

The meaning of the fields in table 1 can be referred to in the existing protocol. When the Complete Profile subfield in the multi-link element is reset to 1, then the Per-STA Profile carries all the fields and elements in the (re) association request frame.

Table 2 multilink reconfiguration response frame

Sequential order	Information processing system
		1	Category class
2	Protected EHT Action protected EHT action frame
		3	Dialogtoken Dialog Token
4	Count of Count
		5	Reconfiguration Status List Reconfiguration State List
6	Group Key Data multicast Key Data
		7	OCI element operation channel information element
8	Basic Multi-LINK ELEMENT Basic multilink element

In table 2, count is used to indicate the number of reconfiguration status tuple (Reconfiguration Status Tuple) fields in the reconfiguration status list, the reconfiguration status list is used to indicate the status code of the corresponding link, the format of which is shown in fig. 8 below, and the multicast Key Data (Group Key Data) field is used to carry the multicast Key Data, the format of which is shown in fig. 9 below. Fig. 8 shows an example of a reconfiguration status list. As shown in fig. 8, the reconfiguration status list includes a plurality of reconfiguration status tuple fields, each including a link Identification (ID) and a status code, each of the reconfiguration status tuple fields indicating a status of a link.

Fig. 9 shows an example of multicast key data. As shown in fig. 9, the multicast Key Data includes a multicast Data length (KEY DATA LENGTH) indicating the length of the Key Data and a Key Data (Key Data) subfield. The meaning of the fields in table 2 can be referred to in the existing protocol. The key data subfield contains one or more multi-link operation (MLO) key data packages (key data encapsulation,KDE)(The Key Data subfield contains one or more MLO KDEs for group keys corresponding to added links). corresponding to the multicast key of the added link, each MLO KDE being packaged using a KDE format as shown in fig. 10 (Each MLO KDE is encapsulated using the KDE format shown in Figure). Fig. 10 is a schematic diagram of a KDE format according to an embodiment of the present application. For each added link, including the MLO GTK KDE (MLO GTK KDE format) defined in fig. 11-1, MLO IGTK KDE (MLO IGTK KDE format) defined in fig. 11-2, and MLO BIGTK KDE(MLO BIGTK KDE)(For each added link,an MLO GTK KDE is included as defined in Figure 12-1(MLO GTK KDE format),an MLO IGTK KDE is included as defined in Figure 12-2(MLO IGTK KDE format),and an MLO BIGTK KDE is included as defined in Figure 12-3(MLO BIGTK KDE)). defined in fig. 11-3, fig. 11-1 is an MLO GTK KDE format provided by an embodiment of the present application. Fig. 11-2 shows a MLO IGTK KDE format provided by an embodiment of the present application. Fig. 11-3 shows a MLO BIGTK KDE format provided by an embodiment of the present application. Referring to FIG. 10, DATA FIELD is shown in FIG. 11-1 when the Data type is MLO GTK KDE only. Referring to fig. 10, when the Data type is MLO IGTK KDE only, DATA FIELD is shown in fig. 11-2. Referring to fig. 10, when the Data type is MLO BIGTK KDE only, DATA FIELD is shown in fig. 11-3.

The operation channel information (Operating Channel Information, OCI) element is used to indicate operation channel information, the format of which is shown in fig. 12 below. Fig. 12 is a format of an OCI element according to an embodiment of the present application.

6) Block ACK session establishment-in a multi-link scenario, a Block ACK session must be established before transmission using multi-link aggregation. The 802.11n protocol defines a BA mechanism that increases channel efficiency by aggregating multiple acknowledgements (acklegments) into one frame. The BA mechanism is initiated by exchanging an add block acknowledgement (addBA) request (request) frame and an addBA acknowledgement (response) frame. Specifically, the BA session establishment flow is shown in fig. 13 below. Fig. 13 is a flowchart of BA session establishment according to an embodiment of the present application. Referring to fig. 13, the ba session establishment procedure includes a data transmitting end (originator) (abbreviated as "transmitting end") transmitting an addrequest frame to a data receiving end (receiver) (abbreviated as "receiving end"), and the receiving end replying to ADDBAResponse frames to the transmitting end. Through the above procedure, the BA mechanism (or "BA session") between the sender and the receiver is successfully established. Next, the transmitting end transmits a plurality of mac layer protocol data units (MACprotocoldataunit, MPDU) to the receiving end. A plurality of MPDUs transmitted from a transmitting end to a receiving end may be changed into one aggregated medium access control layer protocol data unit (aggregationMPDU, a-MPDU) in an aggregated manner. The transmitting end transmits a BA request (BAR) frame to the receiving end. The receiving end replies a BA frame to the sending end, and the BA frame is used for confirming the receiving condition of all MPDUs in the A-MPDUs sent by the sending end. The initiator or responder may send a DELBA to terminate the block acknowledgment session for the corresponding TID.

Currently, there are two BA mechanisms, a full state BA mechanism and a partial state BA mechanism, respectively. The former requires maintaining the scoreboard state throughout the BA session, so the receiving end needs to maintain all active BA session states, which can place a large burden on the receiving end. The latter only needs to store the most recently active BA session state in a cached manner, which can ensure that the memory used to store the BA state can be reused by a different BA session and can be backwards compatible with the full state BA mechanism.

A block acknowledgment session established between two stations has a specific communication identifier (TRAFFIC IDENTIFIER, TID) and is used only for unidirectional data transfer from the originating to the responding end. For example, for downlink data transmission, only BA session establishment can be initiated by the AP. For uplink data transmission, only the BA session establishment can be initiated by the STA. Specifically, the initiator establishes a BA session for a certain TID by an addbar request/Response frame exchange with the STA. The initiator or responder may send a DELBA to terminate the block acknowledgment session for the corresponding TID.

The block acknowledgment session of the sender includes one or more of the following parameters:

TID;

SN (sequence number) allocated to each MSDU, whether to allow MSDU aggregation, whether to allow fragmentation, and whether to support HE fragmentation operation;

WinStart_O (window starting position), winSize_O (window size) of the transmission buffer;

the success or failure state of each MPDU in the window and the retransmission times.

The block acknowledgment session at the receiving end includes one or more of the following parameters:

TID;

A block acknowledgement policy, whether MSDU aggregation is allowed, fragmentation is allowed, HE fragmentation operation is supported (HE fragmentation operation);

A bit map of a scoreboard at a receiving end, and WinStart_R (window starting position), winSize_R (window size), wherein the scoreboard bit map is used for recording which MSDUs are successfully received;

WinStart_B (window starting position), winSize_B (window size) of the reorder buffer is received. The receive reorder buffer is used to buffer the received MSDUs because the MAC layer must forward the received MSDUs to the LLC layer in order. If a packet is not successfully received, other MSDUs following the MSDU cannot be delivered to the LLC layer even if the reception is successful.

For a certain TID, both its sender and receiver may send DELBAs to delete block sessions.

The frame structure of an existing ADDBA Request/Response is shown in FIG. 13 below. Fig. 13 shows a frame structure of the ADDBA Request/Response. The roles of the fields in fig. 13 can be referred to in the existing protocol. The Frame Body of the ADDBA Request Frame contains the fields shown in table 3. The Frame Body of ADDBAResponse frames contains the fields shown in table 4.

TABLE 3 Table 3

Order	Information
		1	Category, category
2	Block ACK Action, block acknowledgement Action
		3	Dialog Token
4	Block ACK PARAMETER SET, set of Block acknowledgement parameters
		5	Block Ack Timeout Value block acknowledgement timeout value
6	Block ACK STARTING Sequence Control, block acknowledgement initiation Sequence Control
		7	ADDBA Extension (optional), adding a block acknowledgement Extension field

TABLE 4 Table 4

Order	Information
		1	Category
2	Block ACK Action
		3	Dialog Token
4	Status Code, status Code
		5	Block ACK PARAMETER SET, set of Block acknowledgement parameters
6	Block Ack Timeout Value block acknowledgement timeout value
		7	ADDBA Extension (optional), adding a block acknowledgement Extension field

In order to realize the roaming of the multi-link equipment, the application provides a scheme for realizing the roaming of the multi-link equipment by carrying out context transfer operation between different AP MLDs. The scheme provided by the application is suitable for deployment form II of the Roaming AP MLD (i.e. non-collocated AP MLD) architecture. Alternatively, when the Roaming AP MLD (i.e., non-collocated AP MLD) architecture is deployment type II, roaming of the multi-link device can be achieved using the scheme of the present application. The general flow of the scheme provided by the present application is shown in figure 14 below. Fig. 14 is a flowchart of a method for multi-link device communication according to an embodiment of the present application. As shown in fig. 14, the Non-AP MLD triggers Roaming from the current AP MLD (i.e., the AP MLD with which the Non-AP MLD is currently associated) to the target AP MLD by sending a Roaming Request (Roaming Request) frame, optionally including the current AP MLD transferring Context to the target APMLD. After context transfer is completed, current AP MLD or target AP MLD returns Roaming Response frame to Non-AP MLD. As shown in fig. 14, the method includes:

1401. The Non-AP MLD generates a request frame.

The request frame is used to request roaming to the target AP MLD.

In one possible implementation, the request frame is used to trigger roaming from the first AP MLD to the target AP MLD. The request frame may be considered a roaming request. Alternatively, the request frame is used to trigger the first AP MLD to roam the non-AP MLD to the target AP MLD.

In one possible implementation, the request frame is used to trigger the first AP MLD to perform a context transfer to the target AP MLD, thereby implementing roaming of the non-AP MLD to the target AP MLD. The request frame may be considered a roaming context transfer request. The above context is used to configure an MLD high MAC sublayer, e.g., an MLD high MAC sublayer of a target (target) AP MLD. The uplink may include one or more of parameters MLD Upper MAC sublayer, PTK, or PN required for data transmission and reception. Illustratively, the uplink may include at least one of BA session-related parameters and security-related parameters. Parameters related to the BA session (also referred to as BA session context) are parameters of MLD Upper MAC sublayer required for data transmission and reception, such as SN (sequencenumber), parameters related to security (also referred to as security context), such as one or more of information related to encryption and decryption including PTKSA, and such as PN (packetnumber). In a possible implementation, the context further includes one or more link indication information, where the link indication information is used to indicate a first link, and the first link includes a link that the non-AP MLD requests the target AP MLD to establish. The step of uplink transfer in the embodiment of the present invention is optional.

1402. The Non-AP MLD transmits a request frame to the first AP MLD.

Accordingly, the first AP MLD receives a request frame from the Non-AP MLD. The first AP MLD is the AP MLD with which the Non-AP MLD is currently associated. Alternatively, the first AP MLD currently has at least one link with the Non-AP MLD. In still another alternative, the Non-AP MLD establishes an association with one or more links of the first AP MLD. The request frame may include first indication information for determining the target AP MLD.

In a possible implementation, the first indication information is used to indicate the target AP MLD. For example, the first indication information includes an MLD MAC address or an MLD ID of the target AP MLD (i.e., an ID of the target AP MLD). The first indication information may further include other information for uniquely identifying the target AP MLD, which is not limited herein.

In a possible implementation, the first indication information includes Wildcard (wild card) MLD MAC ADDRESS field or Wildcard BSSID. In this case, it is not clear to which AP MLD the non-AP MLD roams, or the first AP MLD decides the target AP MLD to roam. Illustratively, the WILDCARD MLD MAC ADDRESS field includes a broadcast address or Wildcard BSSID, for example, this field is set to all 1 s. The broadcast address or Wildcard BSSID is used to indicate to which AP MLD the non-AP MLD is not clear to roam. The embodiment of the present application is not limited to the broadcast address or Wildcard BSSID. Illustratively, wildcard BSSID is a special value specified by the protocol, such as all 0s or all 1 s, which represents the decision by the first AP MLD as to which AP MLD to roam the non-AP MLD to, i.e., the decision by the first AP MLD as to the target AP MLD to which the non-AP MLD roams. The embodiment of the application is not limited to this particular value.

In a possible implementation, the first indication information indicates an AP MLD set (including a plurality of AP MLDs), and the first indication information is used to indicate that the first AP MLD decides to select an AP MLD from the AP MLD set as a target AP MLD to which the non-AP MLD roams. That is, when the first indication information indicates one set of AP MLDs (including a plurality of AP MLDs), the first indication information implicitly indicates that the non-AP MLD does not clearly roam to which AP MLD, and at this time, the first AP MLD may decide which AP MLD in the set of AP MLDs to roam to. Illustratively, the first indication information includes a plurality of AP MLDs, i.e., one AP MLD set. Illustratively, the first indication information includes an index that is associated with a set of AP MLDs.

In a possible implementation, the request frame further includes one or more second indication information, where each second indication information is used to indicate a first link, and the first link is a link that the non-AP MLD requests the target AP MLD to establish. Illustratively, each second indication information includes a link ID of the first link. The link that the non-AP MLD requests the target AP MLD to establish may include one or more first links, with different stations associated with different first links. Or, the request frame further includes second indication information, where the second indication information is used to indicate a first link, and the first link includes one or more links that the non-AP MLD requests the target AP MLD to establish. Illustratively, the second indication information includes an identification of the first link, i.e., an identification of one or more links that the non-AP MLD requests the target AP MLD to establish. Optionally, the request frame further includes third indication information, where the third indication information is used to indicate a primary link in the first link. Or, the third indication information is used to indicate a primary link in the one or more first links. The request frame further includes a main link indication field corresponding to each link in the first link, and the main link indication field corresponding to each link is used to indicate whether the link is a main link. Optionally, the request frame further includes an information parameter for establishing the first link.

In a possible implementation, the request frame further includes fourth indication information, where the fourth indication information is used to indicate a link state of the first link after the non-AP MLD receives the response frame. Or the fourth indication information is used to indicate the link state of the first link after the first AP MLD completes the context transfer with the target AP MLD. Or the fourth indication information is used for the link state of the first link after the first AP MLD or the target AP MLD replies the response frame. Illustratively, each link ID in the first link is followed by an enable/disable (enable/disable) status indication. The link ID followed by the enable status indication indicates that the link corresponding to the link ID is enabled after the non-AP MLD receives the response frame, or that the link corresponding to the link ID is an enable link after the non-AP MLD receives the response frame. Or the link ID is followed by an enable state indication indicating that the link corresponding to the link ID is in an enable state after the non-AP MLD receives the response frame. The link ID followed by the disable state indication indicates that the link corresponding to the link ID is disabled after the non-AP MLD receives the response frame, or that the link corresponding to the link ID is a disable link after the non-AP MLD receives the response frame. Or the link ID is followed by a disable state indication indicating that the link corresponding to the link ID is in a disable state in the non-AP MLD reception response frame. Or a link ID (e.g., corresponding to a link between the first AP MLD and the non-AP MLD) followed by a Delete status indication indicates that the link corresponding to the link ID was deleted after the first AP MLD replies to the response frame. Illustratively, each link ID in the first link is followed by an awake/sleep awake/doze status indication. The link ID followed by an awake state indication indicates that the link to which the link ID corresponds is in an awake state after the non-AP MLD receives the response frame. The link ID followed by a sleep state indication indicates that the link to which the link ID corresponds is in a sleep state after the non-AP MLD receives the response frame.

Optionally, the request frame further includes fourth indication information, where the fourth indication information is used to indicate a link state of the second link after the first AP MLD replies with the response frame. Or the fourth indication information is used to indicate the link state of the second link after the first AP MLD completes the context transfer with the target AP MLD. The second link includes a link between the first AP MLD and the non-AP MLD. Illustratively, each link ID in the second link and/or the first link is followed by an enable/disable status indication. The link ID followed by the enable status indication indicates that the link corresponding to the link ID is enabled after the first AP MLD reply response frame, or that the link corresponding to the link ID is an enable link in the first AP MLD reply response frame. The link ID followed by a disable status indication indicates that the link to which the link ID corresponds is disabled after the first AP MLD reply response frame. Of course, the fourth indication information may not indicate the link state of the second link after the first AP MLD replies to the response frame, but infer the link state of the second link from the link state of the first link, for example, if the first link is in a disabled state, and then the second link between the station of the non-AP MLD operating on the first link (for the target AP MLD) and the AP of the first AP MLD is in an enabled state. For another example, the first link is in an enabled state, and then a second link between a station of the non-AP MLD operating on the first link (for the target AP MLD) and an AP of the first AP MLD is in a disabled state. The enabling/disabling of the enable/disable in the link state may be replaced by wake/sleep (awake/doze).

When the request frame further includes fourth indication information, the main link in the first link may be indicated by the first link including an enable state indication after only one of the links, the link being the main link. When the request frame further comprises fourth indication information, the main link in the first link can be indicated in a manner that the first link comprises an enable state indication after a plurality of links exist in the link, and the request frame further comprises a main link indication field corresponding to each enable link in the first link and used for indicating whether the enable link is the main link. In one possible implementation, the Non-AP MLD requires that its primary link requesting establishment of the target AP MLD must be received, otherwise all links established by the target AP MLD are rejected, thus avoiding that the target AP MLD establishes links that do not meet the requirements of the Non-AP MLD. In this implementation, data transmission between the Non-AP MLD and the current AP MLD and the target AP MLD may be facilitated by indicating at least one of a link state of the second link and a link state of the first link after the first AP MLD replies to the response frame.

In a possible implementation, the request frame further includes timeout information, where the timeout information is used to feed back a determination of an effective time of a response frame corresponding to the request frame. The timeout information is used for determining, by the first AP MLD or the target AP MLD, an effective time for feeding back a response frame corresponding to the request frame. The timeout information may be a timeout value. Illustratively, the timeout information includes a time length (duration) and is used to indicate that the first AP MLD or the target AP MLD needs to feed back the response frame within the time length after receiving the request frame, otherwise, the roaming request or the context transfer request fails. Illustratively, the timeout information indicates an absolute time before which the first AP MLD or the target AP MLD needs to feed back the response frame, and if no response frame is fed back before this time, the roaming request or the context transfer request is considered to fail. In the implementation, the request frame further comprises timeout information, the timeout information is used for feeding back the determination of the effective time of the response frame corresponding to the request frame, and long-time waiting of the Non-AP MLD can be avoided, so that roaming experience is prevented from being influenced.

In one possible implementation, the request frame is a management frame, such as a link reconfiguration request frame. Alternatively, the request frame may multiplex the link reconfiguration request frame. In one possible implementation, a new element is added to the link reconfiguration request frame (Link Reconfiguration Request) to carry one or more of the above-mentioned first indication information, second indication information, third indication information, fourth indication information, or timeout information, and when the first AP MLD receives the link reconfiguration request frame, context transfer is performed in addition to link reconfiguration operation. In this implementation, multiplexing the link reconfiguration request frame has the advantage that the first AP MLD can be triggered to perform context transfer while establishing a link with the target AP MLD, so that signaling overhead can be saved while switching to the target AP MLD interaction is reduced.

Fig. 15 is an example of a frame structure of a request frame according to an embodiment of the present application. As shown in fig. 15, the request frame includes a class (Category) field, an MLD MAC Address (Address), link information (Link Info) (optional), and a timeout value (optional). The class field in embodiments of the present application may be used to represent the type of frame/message, i.e. to distinguish between different types of action frames. The type indicated by the class field in fig. 15 corresponds to a request frame for requesting roaming to the target AP MLD, for example, a request frame for triggering a transfer of the uplink. The MLD MAC address field is used to indicate the MLD MAC address or MLDID of the target AP MLD. The MLD MAC ADDRESS field is an example of the first indication information. Referring to fig. 15, the link information field includes a second field, and optionally includes a first field. The first field is used to indicate a link state of the second link after the first AP MLD reply response frame. Referring to fig. 15, the first field includes a Link ID (Link ID), a Link status indication (e.g., enable/disable), wherein each Link ID is an ID of one of the second links, and x1 and y1 are integers greater than or equal to 0. If a certain link ID is associated with an enable state indication, a link corresponding to the link ID is not disabled after the first AP MLD replies to the response frame, and if a certain link ID is associated with a disable state indication, a link corresponding to the link ID is disabled after the first AP MLD replies to the response frame. The second field is used for indicating the link state of the first link and the main link in the first link after the first link and the first AP MLD reply response frame. The second field may include a Link ID, a Link status indication (such as enable/disable), a main Link indication (optional). Referring to fig. 15, the second field includes a Link ID (Link ID), a Link status indication, and a main Link indication, wherein each Link ID is an ID of one of the first links, and each Link ID-associated main Link indication is used to indicate whether the Link is a main Link, and x2 and y2 are integers greater than 0. For example, when the value of the main link indication associated with one link ID is 1, the corresponding link of the link ID is the main link. The second indication information includes each link ID in the second field, i.e., the link ID of the first link. In other words, each link ID in the second field is an example of the second indication information. The third indication information includes a main link indication associated with each link ID in the second field. Alternatively, the main link indication associated with each link ID in the second field is an example of the third indication information. The fourth indication information includes a link state indication associated with each link ID in the second field, and optionally includes a link state indication associated with each link ID in the first field. Alternatively, at least one of the link state indication associated with each link ID in the first field and the link state indication associated with each link ID in the second field is an example of the fourth indication information. The timeout value is the timeout information described above. the timeout value represents a length of time or an absolute time.

Fig. 16 is an example of a frame structure of another request frame provided in an embodiment of the present application. As shown in fig. 16, the request frame includes a class (Category) field, WILDCARD MLD MAC address/WildcardBSSID, link Info (optional), and a timeout value (optional). WILDCARD MLD MAC ADDRESS or WildcardBSSID are used to indicate that the non-AP MLD does not know which AP MLD to roam to. Or WILDCARD MLD MAC ADDRESS or WildcardBSSID is used to represent any one of the target AP MLDs, or the target AP MLD for which the first AP MLD determines to perform the context transfer. The roles of the other fields in fig. 16 can be referred to the description for each field in fig. 15.

1403. And the first AP MLD receives the request frame and performs context transfer to the target AP MLD.

The request frame is used to request roaming to the target AP MLD. The first indication information in the request frame is used to determine the target AP MLD.

In one possible implementation, the request frame is used for triggering the first AP MLD to perform context transfer to the target AP MLD, the first indication information is used for indicating the target AP MLD, and the first AP MLD can determine the target AP MLD for the context transfer based on the request frame and perform the context transfer to the target AP MLD.

In one possible implementation, the request frame includes first indication information, where the first indication information indicates an AP MLD set (including a plurality of AP MLDs), and the first indication information is used to indicate that the first AP MLD decides to select one AP MLD from the AP MLD set as a target AP MLD for context transfer, and the first AP MLD selects one AP MLD from the AP MLD set as a target AP MLD for context transfer based on the request frame, and performs context transfer to the target AP MLD. The implementation of selecting one AP MLD from the set of AP MLDs as the target AP MLD for the context transfer by the first AP MLD based on the request frame is not limited. The first AP MLD first estimates the distance between each AP MLD in the set of AP MLDs and the non-AP MLD, and then selects one of the AP MLDs closest to the non-AP MLD as the target AP MLD for the context transfer. Illustratively, the first AP MLD selects one AP MLD with the greatest signal strength between itself in the set of AP MLDs as the target AP MLD for the context transfer. Illustratively, the first AP MLD selects the least loaded one of the set of AP MLDs as the target AP MLD for the context transfer.

In one possible implementation, the request frame includes first indication information, where the first indication information includes WILDCARD MLD MAC ADDRESS field or WildcardBSSID, and indicates that there is no designated target AP MLD, or is used to indicate that the first AP MLD decides to perform a context transfer, and the first AP MLD selects, based on the request frame, one AP MLD as a target AP MLD for the context transfer, and performs the context transfer to the target AP MLD. The manner in which the first AP MLD selects the target AP MLD as the context transfer is not limited. Illustratively, the first AP MLD selects, from among nearby AP MLDs, one AP MLD nearest to the non-AP MLD as a target AP MLD for the context transfer. Illustratively, the first AP MLD selects one AP MLD closest to the first AP MLD as the target AP MLD for the context transfer. Illustratively, the first AP MLD selects, from among nearby AP MLDs, the one AP MLD with the lightest load as the target AP MLD for the context transfer.

The context transfer by the first AP MLD to the target AP MLD may be that the first AP MLD transmits at least one of a BA session context and a security context to the target AP MLD. In one possible implementation, to prevent packet loss when the non-AP MLD roams from the current AP MLD to the target AP MLD, the BA session context may be transferred from the current AP MLD to the target AP MLD. The transfer of the context (including the BA session context) to the target AP MLD can prevent packet loss, so that the transmission of the non-AP MLD is not interrupted in the process of roaming the non-AP MLD to the target AP MLD, and a roaming mechanism supporting packet continuous transmission can be realized. In a multilink scenario, a block acknowledgment session needs to be established before using multilink aggregate transmissions. The first AP MLD transmits the BA session context to the target AP MLD, so that the BA session establishment procedure does not need to be performed before the multi-link aggregation transmission is used between the non-AP MLD and the target AP MLD, and the delay of roaming of the non-AP MLD to the target AP MLD can be reduced. for example, for the transmission of the downlink tid#n, the first AP MLD may transfer the BA session context of the transmitting end of tid#n (i.e., the AP MLD end) to the target AP MLD, where the BA session context includes at least one of SN Counter, winstart_o of the transmission buffer, winsize_o, whether the transmission of each MSDU/MPDU in the transmission window is successful or not, the retransmission times, whether to open the a-MSDU, whether the block acknowledgement policy is immediate block acknowledgement or delayed block acknowledgement, a timeout value of the block session, whether to allow fragmentation, and whether to support HE (High efficiency) fragmentation operations. For example, for the transmission of the uplink tid#n, the first AP MLD may transfer a BA session context of a receiving end (i.e., AP MLD end) of tid#n to the target AP MLD, where the BA session context includes at least one of a receiving end scoreboard, and a corresponding winstart_r (window Size), where the scoreboard is used to record which MSDUs are successfully received, a winstart_b (window starting position) of a receiving reorder Buffer, and a receiving reorder Buffer is used to Buffer the received MSDUs, because the MAC layer must submit the received MSDUs to the LLC layer in order. If a certain packet is not successfully received, other MSDUs behind the MSDU cannot be submitted to the LLC layer even if the reception is successful, whether the A-MSDU is started, whether the block acknowledgement policy is immediate block acknowledgement or delayed block acknowledgement, the timeout value of the block session, whether the fragmentation is allowed, and whether the HE fragmentation operation is supported. The security context may include one or more of a PTK, PN Counter (Counter), or Replay Counter (Replay Counter).

In one possible implementation, the target AP MLD configures an MLD high MAC sublayer employed for data transmission with the non-AP MLD itself based on a context from the first AP MLD, including at least one of a BA session context and a security context, for example, and parameters of the configured MLD high MAC sublayer may be the same as parameters of an MLD high MAC sublayer employed for data transmission with the non-AP MLD by the first AP MLD. The realization can achieve the effect equivalent to transferring the MLD high MAC sublayer from the first AP MLD to the target AP MLD, thereby realizing the roaming of the non-AP MLD.

In one possible implementation, the target AP MLD establishes one or more link associations with the non-AP MLD based on context from the first AP MLD, e.g., including at least one of BA session context and security context, and the second indication information, and transmits with the non-AP MLD using a multi-link aggregation transmission.

1404. The first AP MLD or the target AP MLD transmits a response frame to the non-AP MLD.

Accordingly, the non-AP MLD receives a response frame from the first AP MLD or the target AP MLD. In one possible implementation, the first AP MLD sends a response frame to the non-AP MLD after completing the context transfer to the target AP MLD (i.e., sending context to the target AP MLD). In one possible implementation, the target AP MLD sends a response frame to the non-AP MLD after receiving the context from the first AP MLD. Two dashed boxes in fig. 14 illustrate two possible schemes for step 1404.

The response frame includes sixth indication information (optional) and fifth indication information. The sixth indication information is used to indicate the target AP MLD. In a possible implementation, the first indication information in the request frame is used to indicate the target AP MLD performing the context transfer, and the response frame may or may not include the sixth indication information. In a possible implementation, the first indication information in the request frame is used to indicate roaming from the first AP MLD to the target AP MLD, e.g. including the first AP MLD transferring the context to the target AP MLD. The response frame includes sixth indication information and fifth indication information. The fifth indication information is used for indicating a status code (status code) and/or a key update count value (critical update counter) corresponding to the first link. The status code is used for indicating that the request for establishing the first link is refused or received, and the key update count value is the current update times of the BSS key parameters of the AP where the first link is located. When the BSS key parameter of the AP where the first link is located is changed, the BSS key parameter update count value is increased by 1 or other values. The receiving end (a site of the non-AP MLD) maintains or retains the BSS key parameter update count value (which may be simply referred to as a key update count value). And broadcasting a BSS key parameter update count value of the AP where the first link is located by any AP which receives the MLD at the next time, and comparing the BSS key parameter update count value received or maintained at the last time. If the parameters are the same, the BSS key parameters of the AP where the first link is located are unchanged, otherwise, the BSS key parameters of the AP where the first link is located are changed. Illustratively, the fifth indication information further includes a link ID of each of the first links, and a status code and a critical update count value (or critical update counter) corresponding to each link. The status code corresponding to each link is used to indicate that the request to establish the link is denied or received. The key update count value corresponding to each link is used for indicating whether the key parameters of the BSS of the AP where the link is established are updated. And carrying a key update count value of the newly added link in the response frame so that the Non-AP MLD can know whether the key parameters of the corresponding BSS change or not according to the key update count value.

In one possible implementation, the non-AP MLD requires that its requested (designated) primary link must be accepted, otherwise all requested links (i.e., links established by the requesting target AP MLD) are rejected. For example, the protocol specifies that the primary link requested (specified) by the non-AP MLD must be accepted by the target AP MLD, otherwise all requested links (i.e., links that the target AP MLD is requested to establish) are rejected by the target AP MLD. Illustratively, the target AP MLD may perform one of three operations, namely receiving all requested links (ACCEPT ALL THE LINKS THAT ARE requested), or receiving part of the requested links, including the primary link (accept a subset of the links that are requested,and the subset of the links include the primary link that is requested in the Roaming Request frame),or rejecting all requested links.

The critical update count value is a non-negative integer count value, and when the BSS critical parameter (which may be named as a critical BSS parameter) of the AP where the corresponding link ID is located is updated, the corresponding critical update count value is increased, for example, by 1, wherein the BSS critical parameter may include one or more of a channel change notification element (CHANNEL SWITCH announcement element), an extended channel change notification element (extended CHANNEL SWITCH announcement element), an enhanced distributed channel access (enhanced distributed CHANNEL ACCESS, EDCA) parameter element (PARAMETERS ELEMENT), a channel change notification element (CHANNEL SWITCH announcement element), A muting element (quiet element), a DSSS parameter set (DSSS PARAMETER SET), an HT operation element (HT operation element), a wide bandwidth channel change element (wide bandwidth CHANNEL SWITCH ELEMENT), a wide bandwidth channel change envelope element (CHANNEL SWITCH WRAPPER ELEMENT), an operation mode notification element (operating mode notification element), a bandwidth channel change envelope element (not shown), Silent channel element (quiet CHANNEL ELEMENT), VHT (very high throughput) operation element (operation element), HE (high efficient) operation element (operation element), broadcast TWT element (broadcast TWT ELEMENT), BSS color change notification element (BSS color change announcement element), MU EDCA parameter set element (MU EDCA PARAMETER SET ELEMENT), spatial reuse parameter set element (spatial reuse PARAMETER SET ELEMENT), UORA parameter set element (UORA PARAMETER SET ELEMENT), The index adjustment factor field (Index Adjustment Factor field in a Multiple BSSID Configuration element)、EHT(extremely high throughput) of the multiple BSSID configuration element operates on the element (operation element), the transmission power includes the element (Transmit Power Envelope element, IF THE AP IS AN EHT AP), and UHR (ultra high reliability) operates on the element (operation element). one or more of the BSS key parameters may also be listed as key parameters for the link. Additionally, the BSS critical parameter occurrence update event comprises one or more of a channel change notification element (including of CHANNEL SWITCH announcement element), an extended channel change notification element (inclusion of extended CHANNEL SWITCH announcement element), a modified enhanced distributed channel access (Modification of enhanced distributed CHANNEL ACCESS, EDCA) parameter element (PARAMETERS ELEMENT), a channel change notification element (including of CHANNEL SWITCH announcement element), Including a quieter element (inclusion of quiet element), modifying a DSSS parameter set (Modification ofDSSS PARAMETER SET), an HT operation element (Modification of HT operation element), including a wide bandwidth channel change element (inclusion ofwide bandwidth CHANNEL SWITCH ELEMENT), including a wide bandwidth channel change envelope element (inclusion of CHANNEL SWITCH WRAPPER ELEMENT), comprises an operation mode notification element (inclusion of operating mode notification element), a silent channel element (inclusion of quiet CHANNEL ELEMENT), a modify VHT (very high throughput) operation element (Modification of VHT operation element), a modify HE (high efficient) operation element (Modification of HE operation element), Includes a Broadcast TWT element (inclusion of Broadcast TWT ELEMENT), inserting or removing a Broadcast TWT parameter field (Insertion or removal of a Broadcast TWT PARAMETER SET FIELD IN A Broadcast TWT ELEMENT) in the Broadcast TWT element, includes a BSS color change notification element (inclusion of BSS color change announcement element), Modifying MU EDCA parameter set element (Modification of MU EDCA PARAMETER SET ELEMENT), modifying spatial multiplexing parameter set element (Modification of spatial reuse PARAMETER SET ELEMENT), modifying UORA parameter set element (Modification of the UORA PARAMETER SET ELEMENT), index adjustment factor field (Insertion of an Index Adjustment Factor field in a Multiple BSSID Configuration element)、EHT(extremely high throughput) operation element (Modification of the EHT operation element) inserted into multi-BSSID configuration element, A transmit power envelope element (include, modification or removal of Transmit Power Envelope element, IF THE AP IS AN EHT AP) is inserted, modified or removed, and a UHR (ultra high reliability) operation element is modified (Modification of the UHRoperation element).

In one possible implementation, a station (one of the non-AP MLDs) locally maintains a critical update count value corresponding to a link ID based on the link ID and the critical update count value in the response frame. For example, after obtaining the key update count value corresponding to the link ID by receiving a management frame, such as a beacon frame, a probe response frame, etc., the station compares the local key update count value with the latest received key update count value, if the local key update count value is the same, the key parameters of the BSS where the AP corresponding to the link ID is located are not updated, otherwise, the key parameters of the BSS where the AP corresponding to the link ID is located are updated. At this time, the non-AP MLD where the station is located may send a probe request frame to the AP MLD where the AP corresponding to the link ID is located through any station, to request the key parameters of the BSS where the AP corresponding to the link ID is located. And then the latest parameters are obtained after receiving the detection response frame. Or receiving the beacon frame sent by the AP corresponding to the link ID to obtain the latest parameters.

In a possible implementation, the response frame further includes eighth indication information, where the eighth indication information is used to indicate that roaming between different AP MLDs in the same roaming domain or mobile domain, such as including a context transfer operation, or roaming between different AP MLDs in different roaming domains or mobile domains, such as including a context transfer operation. The eighth indication information includes one bit or more. The method is used for indicating roaming between different AP MLDs in the same roaming domain or mobile domain when the value of the eighth indication information is 1, and indicating roaming between different AP MLDs in different roaming domains or mobile domain when the value of the eighth indication information is 0. Wherein the roaming or mobile domain may also be expressed as non-co-located AP MLD or roaming roamingAP MLD, which non-co-located AP MLD or roaming roamingAP MLD is comprised of a plurality of AP MLDs.

Step 1404 is optional. In one possible implementation, the first indication information in the request frame is used for indicating the target AP MLD performing the context transfer, and if the first AP MLD or the target AP MLD refuses the request of the request frame or does not complete the context transfer to the target AP MLD within a first time period when the request frame is received, a response frame for indicating that the request of the request frame is refused is sent to the non-AP MLD.

In one possible implementation, the response frame is a link reconfiguration response frame. Alternatively, the response frame may multiplex the link reconfiguration response frame. In one possible implementation, a new element is added to the link reconfiguration response frame (Link Reconfiguration Response) to carry the sixth indication information and the fifth indication information. In this implementation, multiplexing the link reconfiguration response frames may save signaling overhead.

Fig. 17 is an example of a frame structure of a response frame according to an embodiment of the present application. As shown in fig. 17, the response frame includes a class (Category) field, an MLD MAC address field (optional), link information (Link Info), and a scene indication field (optional). The MLD MAC address field is used to indicate the MLD MAC address or MLD ID of the target AP MLD. The MLD MAC ADDRESS field is an example of sixth indication information. Referring to fig. 17, the link information field includes a link ID of a link requested to be established (or added) in a request frame, and a status code (statuscode) and a critical update count value (criticalupdatecounter) corresponding to each link ID. The scene indication field, that is, the eighth indication information, is used to indicate whether to perform a context transfer operation between different AP MLDs under the same roaming AP MLD or a context transfer operation under different roaming AP MLDs.

In the embodiment of the application, the Non-AP MLD sends the request frame to the first AP MLD, the first AP MLD receives the request frame and carries out context transfer to the target AP MLD, and the context associated with the Non-AP MLD can be transferred to the target AP MLD so that the target AP MLD can establish link association with the Non-AP MLD based on the context, namely the roaming of the Non-AP MLD is realized. The context transfer to the target AP MLD can ensure that the transmission of the non-AP MLD is not interrupted in the process of roaming the non-AP MLD to the target AP MLD, namely, the roaming supporting the continuous transmission of the packet is realized, and the packet loss can be reduced.

Fig. 18 is a flowchart of another method for multi-link device communication according to an embodiment of the present application. The method flow of fig. 18 is based on the method flow of fig. 14, and after the first AP MLD transmits the response frame, non-AP MLD related transmission operations are added. As shown in fig. 18, the method includes:

1801. the Non-AP MLD generates a request frame.

1802. The Non-AP MLD transmits a request frame to the first AP MLD.

1803. The first AP MLD performs a context transfer to the target AP MLD based on the request frame.

1804. The first AP MLD transmits a response frame to the non-AP MLD.

Steps 1801 to 1804 may refer to steps 1401 to 1404 in fig. 14, and are not described herein.

1805. And carrying out data transmission between the non-AP MLD and the target AP MLD.

In one possible implementation, after receiving the response frame, the non-AP MLD establishes a link and/or association with the target AP MLD and performs data transmission. The target AP MLD may establish a link and/or association with the non-AP MLD based on the context from the first AP MLD and enable data transfer with the non-AP MLD. Illustratively, the fifth indication information in the response frame is used to indicate the status code and/or the key update count value corresponding to the first link, and the non-AP MLD may determine, based on the fifth indication information, that the target AP MLD accepts the established link, and further establish a link and/or association with the target AP MLD.

1806. The first AP MLD transmits downlink data to the non-AP MLD.

In one possible implementation, the fourth indication information in the request frame is used to indicate that the link state of the second link after the reply response frame is an enabled or awake state, and in another possible implementation, the fourth indication information in the request frame is used to indicate that the link state of the first link after the reply response frame is a disabled or dormant state, where a station of the non-AP MLD operating on the first link may communicate with the first AP MLD. And the first AP MLD sends the rest data packets (namely downlink data) in a transmission queue to the non-AP MLD when the link state of the second link is enabled or awakened, wherein the transmission queue comprises the data packets to be sent to the non-AP MLD. In the embodiment of the present application, after the first AP MLD transmits the response frame to the non-AP MLD, the first AP MLD may continue to transmit downlink data to the non-AP MLD. The order of steps 1806 and 1805 is not limited. Step 1805 and step 1806 may be performed in parallel. Step 1806 is optional.

1807. The first AP MLD transmits link deletion information to the non-AP MLD.

Accordingly, the non-AP MLD receives link deletion information from the first AP MLD. The link deletion information is used to instruct the non-AP MLD to delete (or disable) the link of the first AP MLD. In one possible implementation, the link deletion information is sent to the non-AP MLD when the last SN associated with the non-AP MLD on the first AP MLD is refreshed or timed out, so that the link can be released in time to fully utilize the link resources.

1808. The non-AP MLD deletes the link associated with the first AP MLD based on the link deletion information.

In a possible implementation, the steps 1807 and 1808 are replaced by deleting the link associated with the first AP MLD when the link quality between the non-AP MLD and the first AP MLD is lower than a certain threshold, and sending a message to the first AP MLD to instruct the first AP MLD to delete the link between the non-AP MLD, so that the resource utilization rate can be improved. The threshold may be set according to actual requirements.

In the embodiment of the application, after the first AP MLD sends the response frame to the non-AP MLD, the first AP MLD continues to send the downlink data to the non-AP MLD until the last SN (sequence number) associated with the non-AP MLD on the first AP MLD is refreshed or overtime, and the first AP MLD can send the rest data packet in the transmission queue to the non-AP MLD so that the non-AP MLD receives the complete downlink data from the first AP MLD. Roaming of Non-AP MLD is achieved by context transfer to target AP MLD, and packet loss can be reduced.

Fig. 19 is a flowchart of another method for multi-link device communication according to an embodiment of the present application, which is optionally applicable to a single radio multi-link device (single radio MLD). The method flow of fig. 19 is based on the method flow of fig. 14, and after adding the response frame sent by the first AP MLD, a Non-AP MLD related transmission operation is added. The method flow in fig. 19 and the method flow in fig. 18 are two parallel method flows. The difference between the method flow of fig. 19 and the method flow of fig. 18 is that the first AP MLD in the method flow of fig. 19 does not transmit downlink data to the Non-AP MLD after transmitting the response frame, and the first AP MLD in the method flow of fig. 18 may continue to transmit downlink data to the Non-AP MLD after transmitting the response frame. As shown in fig. 19, the method includes:

1901. The Non-AP MLD generates a request frame.

1902. The Non-AP MLD transmits a request frame to the first AP MLD.

1903. The first AP MLD performs a context transfer to the target AP MLD based on the request frame.

Steps 1901 to 1903 may refer to steps 1401 to 1403 in fig. 14, and will not be described here.

1904. The first AP MLD transmits downlink data to the non-AP MLD.

In another possible implementation, the fourth indication information in the request frame is used for indicating that the link state of the second link after the first AP MLD or the target AP MLD replies to the response frame is in a disabled (or dormant) state, and in another possible implementation, the fourth indication information in the request frame is used for indicating that the link state of the first link after the response frame replies to the first link is in an enabled or awake state, and at this time, a station of the non-AP MLD working on the first link after the response frame replies to the first link is in a disabled or dormant state. And if the link state of the second link is disabled or dormant, the first AP MLD transmits the remaining data packets (i.e., downlink data) in a transmission queue to the non-AP MLD before transmitting a response frame to the non-AP MLD, where the transmission queue includes the data packets to be transmitted to the non-AP MLD.

1905. The first AP MLD transmits a response frame to the non-AP MLD.

Step 1905 may refer to step 1404 in fig. 14, and is not described herein.

1906. The non-AP MLD deletes the link of the first AP MLD.

In a possible implementation, the request frame may further optionally include fourth indication information, where the fourth indication information is used to indicate a link state of a second link after the reply response frame, where the second link includes a link between the first AP MLD and the non-AP MLD, and the link state of the second link is a disabled or dormant state, or the fourth indication information is used to indicate a link state of the first link after the reply response frame, and the non-AP MLD learns, according to a corresponding rule, the link state of the second link between the first AP MLD and the non-AP MLD. In a possible implementation, the response frame further includes seventh indication information, where the seventh indication information is used to instruct the non-AP MLD to delete the link of the first AP MLD, and the non-AP MLD deletes the link of the first AP MLD based on the seventh indication information. In one possible implementation, the protocol specifies that the link established with the first AP MLD is deleted after the non-AP MLD receives the response frame.

1907. And carrying out data transmission between the non-AP MLD and the target AP MLD.

Step 1907 may refer to step 1805 in fig. 18, and will not be described herein.

In the embodiment of the application, before the first AP MLD sends the response frame to the non-AP MLD, the first AP MLD sends the residual data packet in the transmission queue to the non-AP MLD, so that the first AP MLD can send the residual data packet in the transmission queue to the non-AP MLD, and the non-AP MLD can receive complete downlink data from the first AP MLD.

It should be understood that the sequence numbers of the above processes do not mean the order of execution, and the execution order of the processes should be determined by the functions and internal logic of the processes, and should not be construed as limiting the implementation process of the embodiments of the present application.

It is also to be understood that in the various embodiments of the application, where no special description or logic conflict exists, the terms and/or descriptions between the various embodiments are consistent and may reference each other, and features of the various embodiments may be combined to form new embodiments in accordance with their inherent logic relationships.

It should also be understood that in some of the above embodiments, the devices in the existing network architecture are mainly described as examples, and it should be understood that the embodiments of the present application are not limited to specific forms of the devices. For example, devices that can achieve the same functions in the future are applicable to the embodiments of the present application.

It will be appreciated that in the various method embodiments described above, the methods and operations implemented by a device (e.g., non-AP MLD, first AP MLD, target AP MLD) may also be implemented by components (e.g., chips or circuitry) that may be used in the device.

It will also be appreciated that some optional features of the various embodiments of the application may, in some circumstances, be independent of other features or may, in some circumstances, be combined with other features, without limitation.

Those of skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as hardware or combinations of hardware and computer software. Whether a function is implemented as hardware or computer software driven hardware depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

The following describes in detail the communication device provided in the embodiment of the present application with reference to fig. 20 to 22. It should be understood that the descriptions of the apparatus embodiments and the descriptions of the method embodiments correspond to each other, and thus, descriptions of details not shown may be referred to the above method embodiments, and for the sake of brevity, some parts of the descriptions are omitted.

The embodiment of the application can divide the function modules of the sending end device or the receiving end device according to the method example, for example, each function module can be divided corresponding to each function, and two or more functions can be integrated in one processing module. The integrated modules may be implemented in hardware or in software functional modules. It should be noted that, in the embodiment of the present application, the division of the modules is schematic, which is merely a logic function division, and other division manners may be implemented in actual implementation. The following description will take an example of dividing each functional module into corresponding functions.

Fig. 20 is a schematic block diagram of a communication device 10 provided by an embodiment of the present application. The device 10 comprises a transceiver module 11 and a processing module 12. The transceiver module 11 may implement a corresponding communication function, the processing module 12 is configured to perform data processing, or the transceiver module 11 is configured to perform operations related to reception and transmission, and the processing module 12 is configured to perform operations other than reception and transmission. The transceiver module 11 may also be referred to as a communication interface or a communication unit.

Optionally, the apparatus 10 may further include a storage module 13, where the storage module 13 may be configured to store instructions and/or data, and the processing module 12 may read the instructions and/or data in the storage module, so that the apparatus implements the actions of the devices in the foregoing method embodiments.

In one design, the apparatus 10 may correspond to the non-AP MLD in the method embodiments above, or may be a component (e.g., a chip) of the non-AP MLD.

The apparatus 10 may implement steps or procedures performed corresponding to the non-AP MLD in the above method embodiment, where the transceiver module 11 may be configured to perform operations related to the transceiver of the non-AP MLD in the above method embodiment, and the processing module 12 may be configured to perform operations related to the processing of the non-AP MLD in the above method embodiment.

It should be understood that the specific process of each unit performing the corresponding steps has been described in detail in the above method embodiments, and is not described herein for brevity.

In another design, the apparatus 10 may correspond to the first AP MLD in the above method embodiments, or may be a component (e.g., a chip) of the first AP MLD.

The apparatus 10 may implement steps or processes performed by the first AP MLD in the above method embodiment, where the transceiver module 11 may be configured to perform operations related to the transceiver of the first AP MLD in the above method embodiment, and the processing module 12 may be configured to perform operations related to the processing of the first AP MLD in the above method embodiment.

It should also be appreciated that the apparatus 10 herein is embodied in the form of functional modules. The term module herein may refer to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (e.g., a shared, dedicated, or group processor, etc.) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that support the described functionality.

The apparatus 10 of each of the above aspects has a function of implementing the corresponding steps performed by the device (e.g., the first AP MLD) in the above method. The functions can be realized by hardware, and can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the functions described above, for example, the transceiver module may be replaced by a transceiver (for example, a transmitting unit in the transceiver module may be replaced by a transmitter, a receiving unit in the transceiver module may be replaced by a receiver), and other units, such as a processing module, may be replaced by a processor, to perform the transceiver operations and related processing operations in the respective method embodiments, respectively.

The transceiver module 11 may be a transceiver circuit (for example, may include a receiving circuit and a transmitting circuit), and the processing module may be a processing circuit.

Fig. 21 is a schematic diagram of another communication device 20 according to an embodiment of the present application. The apparatus 20 comprises a processor 21, the processor 21 being arranged to execute computer programs or instructions stored in a memory 22 or to read data/signalling stored in the memory 22 for performing the methods of the method embodiments above. Optionally, the processor 21 is one or more.

Optionally, as shown in fig. 21, the apparatus 20 further comprises a memory 22, the memory 22 being for storing computer programs or instructions and/or data. The memory 22 may be integrated with the processor 21 or may be provided separately. Optionally, the memory 22 is one or more.

Optionally, as shown in fig. 21, the apparatus 20 further comprises a transceiver 23, the transceiver 23 being used for receiving and/or transmitting signals. For example, the processor 21 is configured to control the transceiver 23 to receive and/or transmit signals.

As an alternative, the apparatus 20 is configured to implement the operations performed by the non-AP MLD or the first AP MLD in the method embodiments above.

It should be appreciated that the processor referred to in the embodiments of the present application may be a central processing unit (central processing unit, CPU), but may also be other general purpose processors, digital signal processors (DIGITAL SIGNAL processors, DSPs), application Specific Integrated Circuits (ASICs), off-the-shelf programmable gate arrays (field programmable GATE ARRAY, FPGAs) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

It should also be understood that the memory referred to in embodiments of the present application may be volatile memory and/or nonvolatile memory. The nonvolatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an erasable programmable ROM (erasable PROM), an electrically erasable programmable EPROM (EEPROM), or a flash memory. The volatile memory may be random access memory (random access memory, RAM). For example, RAM may be used as an external cache. By way of example, and not limitation, RAM includes various forms of static random access memory (STATIC RAM, SRAM), dynamic random access memory (DYNAMIC RAM, DRAM), synchronous Dynamic Random Access Memory (SDRAM), double data rate synchronous dynamic random access memory (doubledata RATE SDRAM, DDR SDRAM), enhanced synchronous dynamic random access memory (ENHANCED SDRAM, ESDRAM), synchronous link dynamic random access memory (SYNCHLINK DRAM, SLDRAM), and direct memory bus random access memory (direct rambus RAM, DR RAM).

It should be noted that when the processor is a general purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware components, the memory (storage module) may be integrated into the processor.

It should also be noted that the memory described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

Fig. 22 is a schematic diagram of a chip system 30 according to an embodiment of the present application. The system-on-chip 30 (or may also be referred to as a processing system) includes logic circuitry 31 and an input/output interface 32.

The logic circuit 31 may be a processing circuit in the chip system 30. Logic circuitry 31 may be coupled to the memory unit to invoke instructions in the memory unit so that system-on-chip 30 may implement the methods and functions of embodiments of the present application. The input/output interface 32 may be an input/output circuit in the chip system 30, and outputs information processed by the chip system 30, or inputs data or signaling information to be processed into the chip system 30 for processing.

As an alternative, the chip system 30 is configured to implement the operations performed by the non-AP MLD or the first AP MLD in the various method embodiments above.

For example, the logic circuit 31 is configured to implement the processing-related operations performed by the non-AP MLD or the first AP MLD in the above method embodiment, and the input/output interface 32 is configured to implement the transmission-and/or reception-related operations performed by the non-AP MLD or the first AP MLD in the above method embodiment.

The embodiments of the present application also provide a computer readable storage medium having stored thereon computer instructions for implementing the method performed by the apparatus in the method embodiments described above.

For example, the computer program, when executed by a computer, enables the computer to implement the method performed by the non-AP MLD or the first AP MLD in the above-described method embodiments.

The embodiments of the present application also provide a computer program product containing instructions that, when executed by a computer, implement the method performed by the non-AP MLD or the first AP MLD in the method embodiments described above.

The embodiment of the application also provides a communication system which comprises the non-AP MLD, the first AP MLD and the target AP MLD.

The explanation and beneficial effects of the related content in any of the above-mentioned devices can refer to the corresponding method embodiments provided above, and are not repeated here.

In the several embodiments provided by the present application, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Furthermore, the coupling or direct coupling or communication connection shown or discussed with each other may be through some interface, device or unit indirect coupling or communication connection, which may be in electrical, mechanical or other form.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, produces a flow or function in accordance with embodiments of the present application, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a computer network, or other programmable apparatus. For example, the computer may be a personal computer, a server, or a network device, etc. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another, for example, by wired (e.g., coaxial cable, optical fiber, digital Subscriber Line (DSL)), or wireless (e.g., infrared, wireless, microwave, etc.). The computer readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that contains an integration of one or more available media. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid State Disk (SSD) STATE DISK, etc.. For example, the aforementioned usable medium includes but is not limited to: a U-disk, a removable hard disk, a read-only memory (ROM), a random access memory (random access memory, RAM), a magnetic disk, or an optical disk, or the like, which can store program codes.

The foregoing is merely illustrative of the present application, and the present application is not limited thereto, and any person skilled in the art will readily recognize that variations or substitutions are within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A method for multi-link device communication, characterized in that the method is applied to a non-access point multi-link device (non-AP MLD), the method comprising:

Generate a request frame, the request frame being used to request roaming to a target access point multi-link device (AP MLD), the request frame including first indication information, the first indication information being used to determine the target AP MLD;

The request frame is sent to the first AP MLD.

2. The method according to claim 1, wherein the first indication information is used to indicate the target APMLD, or the first indication information is a wildcard basic service set identifier (BSSID).

3. The method according to claim 1 or 2, characterized in that the request frame further includes one or more second indication information, each second indication information is used to indicate a first link, and the first link is the link that the non-AP MLD requests the target AP MLD to establish.

4. The method according to claim 3 is characterized in that the request frame also includes one or more of the following: third indication information or parameters for establishing one or more of the first links, and the third indication information is used to indicate the main link among the one or more first links.

5. The method according to any one of claims 1 to 4, characterized in that the request frame further includes fourth indication information, and the fourth indication information is used to indicate the link status of the first link after receiving the response frame.

6 . The method according to claim 5 , wherein the link status includes enabled and disabled, or the link status includes awake and sleep states.

7. The method according to any one of claims 1 to 6, characterized in that the request frame further includes timeout information, and the timeout information is used to feed back the determination of the valid time of the response frame corresponding to the request frame.

8. The method according to any one of claims 1 to 7, characterized in that the request frame is a link reconfiguration request frame.

9. The method according to any one of claims 1 to 8, further comprising:

Receive a response frame from the first AP MLD, the response frame including fifth indication information, the fifth indication information being used to indicate a status code and/or a key update count value corresponding to the first link, the status code being used to indicate that the request to establish the first link is rejected or received, the key update count value being the number of times the basic service set BSS key parameters of the AP where the first link is located are currently updated, and when the BSS key parameters of the AP where the first link is located change, the key update count value increases by 1.

10 . The method according to claim 9 , wherein the response frame further comprises sixth indication information, and the sixth indication information is used to indicate the target AP MLD.

11. The method according to claim 9 or 10, wherein the response frame is a link reconfiguration response frame.

12. A method for multi-link device communication, characterized in that the method is applied to a first access point multi-link device (AP MLD), the method comprising:

receiving a request frame from a non-AP MLD, the request frame being used to request roaming to a target AP MLD, the request frame including first indication information, the first indication information being used to determine the target AP MLD;

Perform context transfer to the target AP MLD.

13. The method according to claim 12, wherein the context includes Block Acknowledgement (BA) session-related parameters and/or security-related parameters.

14. The method according to claim 12 or 13, wherein the first indication information is used to indicate the target AP MLD, or the first indication information is a wildcard basic service set identifier (BSSID).

15. The method according to claims 12 to 14, characterized in that the request frame further includes one or more second indication information, each second indication information is used to indicate a first link, and the first link is the link that the non-APMLD requests the target AP MLD to establish.

16. The method according to claim 15 is characterized in that the request frame further includes third indication information and at least one of the parameters used to establish one or more of the first links, and the third indication information is used to indicate a main link among the one or more first links.

17. The method according to any one of claims 12 to 16, characterized in that the request frame further includes fourth indication information, and the fourth indication information is used to indicate the link status of the first link after receiving the response frame.

18 . The method according to claim 17 , wherein the link state includes enabled and disabled, or the link state includes awake and sleep states.

19. The method according to any one of claims 12 to 18, characterized in that the request frame further includes timeout information, and the timeout information is used to feed back the determination of the valid time of the response frame corresponding to the request frame.

20. The method according to any one of claims 12 to 19, wherein the request frame is a link reconfiguration request frame.

21. The method according to any one of claims 12 to 20, further comprising:

A response frame is sent to the non-AP MLD, where the response frame includes fifth indication information, where the fifth indication information is used to indicate a status code and/or a key update count value corresponding to the first link, where the status code is used to indicate that the request to establish the first link is rejected or received, and where the key update count value is the number of times the basic service set (BSS) key parameters of the AP where the first link is located are currently updated. When the BSS key parameters of the AP where the first link is located change, the key update count value increases by 1.

22. The method according to claim 21, wherein the response frame further comprises sixth indication information, and the sixth indication information is used to indicate the target AP MLD.

23. The method according to claim 22, wherein the request frame further includes fourth indication information, the fourth indication information being used to indicate a link status of a first link after receiving the response frame, the first link being the link that the non-AP MLD requested the target AP MLD to establish; after sending the response frame to the non-AP MLD, the method further includes:

When the link state of the first link is disabled or in a dormant state, remaining data packets in a transmission queue are sent to the non-AP MLD, where the transmission queue includes data packets to be sent to the non-AP MLD. When the last sequence number SN associated with the non-AP MLD on the first AP MLD is refreshed or times out, link deletion information is sent to the non-AP MLD, where the link deletion information is used to instruct the non-AP MLD to delete the link of the first AP MLD.

24. The method according to any one of claims 21 to 23, characterized in that the response frame is a link reconfiguration response frame.

25. A communication device, characterized in that it comprises a processor, the processor is coupled to a memory, the memory is used to store computer programs or instructions, and the processor is used to execute the computer program or instructions in the memory, so that the communication device performs the method according to any one of claims 1 to 11; or, the communication device performs the method according to any one of claims 12 to 24.

26. A communication system, characterized in that the communication system comprises a first communication device and a second communication device; wherein the first communication device is used to execute the method according to any one of claims 1 to 11, and the second communication device is used to execute the method according to any one of claims 12 to 24.

27. A computer-readable storage medium, characterized in that a computer program or instruction is stored on the computer-readable storage medium, and when the computer program or instruction is executed on a computer, the computer is caused to execute the method according to any one of claims 1 to 24.

28. A chip, characterized in that it comprises: a communication interface and a processor; the communication interface is used for sending and receiving signals of the chip; the processor is used for executing a computer program or instruction so that a communication device including the chip executes the method according to any one of claims 1 to 24.

29. A computer program product, characterized in that when the computer program product is run on a computer, the computer is enabled to perform the method according to any one of claims 1 to 24.