CN116634607A - Multilink device and communication method - Google Patents

Abstract

Handover operations are described that provide greater reliability for multi-link operation between access point multi-link devices (AP MLDs) and non-AP MLDs in a wireless communication network. The AP MLD announces one of a plurality of links necessary for the AP MLD to switch the multi-link operation. The non-AP MLD determines whether an AP operating on the handover link has resumed Basic Service Set (BSS) operation on the target channel.

Description

Multilink device and communication method

technical field

The invention relates to the field of communication technology, in particular to multi-link equipment.

Background technique

In recent years, the demand for high-speed and reliable wireless communication technology has been increasing. For example, in wireless technologies such as wireless local area networks, the need for ever-increasing data speeds and reliability is unabated.

To support these needs, WLANs consider the use of multiple links between access points and client devices. For example, access points and client devices use two or more radios to maintain corresponding links between each other. These multiple links may be in different channels or different frequency bands. Given the close physical proximity of multiple radios, challenges exist in ensuring increased data throughput and reliability is achieved. These multiple links typically use the IEEE 802.11 standard, which recently considered the challenges and opportunities of multiple links.

Contents of the invention

An aspect of the present invention provides a non-access point (AP) multilink device (MLD) configured to send data to or receive data from the AP MLD over multiple links, the multiple links Including at least a first link and a second link, the non-AP MLD includes: processing circuitry; a transceiver coupled to the processing circuitry; and a memory coupled to the processing circuitry, the memory storing instructions, When executed by the processing circuit, a plurality of operations are performed, the plurality of operations including: detecting an indication that a handover link is to be handed over by the AP MLD to a target channel, wherein the handover link for one of the plurality of links; and determining whether an AP affiliated with the AP MLD and operating on the handover link has resumed Basic Service Set (BSS) operation on the target channel.

Another aspect of the present invention provides an access point (AP) multilink device (MLD) configured to send data to or receive data from a non-AP MLD over multiple links, the multiple The links include at least a first link and a second link, the AP MLD includes: a processing circuit; a transceiver coupled to the processing circuit; and a memory coupled to the processing circuit, the memory storing instructions , when executed by the processing circuit, perform a plurality of operations, the plurality of operations comprising: determining to switch the second link to the target channel, and determining to switch the second link to the target channel After the target channel is selected, an announcement is sent on the first link, instructing the AP MLD to switch the second link to the target channel.

Yet another aspect of the present invention provides a method performed by a non-access point (AP) multi-link device (MLD) and an AP MLD to transmit or receive data over multiple links comprising at least The first link and the second link, the method includes: the AP MLD sends an announcement to the non-AP MLD, the announcement indicates that the switching link will be switched to the target channel, and the switching link is a plurality of links and the non-AP MLD determines whether the AP affiliated with the AP MLD and operating on the handover link has resumed BSS operation on the target channel.

Wherein, the AP MLD sends the maximum channel switching time element corresponding to the second link to the non-AP MLD in at least one of a beacon frame and a probe response frame on the first link until until the AP operating on the second link resumes BSS operation on the target channel; and after the AP operating on the second link resumes BSS operation on the target channel, the AP MLD Stop sending max channel switch time elements.

Wherein, the non-AP MLD detects that the AP belonging to the same AP MLD and operating on a link other than the handover link stops sending the maximum channel corresponding to the AP operating on the handover link After switching time elements, it is determined that the AP operating on the switching link has resumed BSS operation on the target channel.

Still another aspect of the present invention provides a communication method, performed on the side of a non-access point (AP) multi-link device (MLD), and the non-AP MLD is used to send data to or from the AP MLD on multiple links. The AP MLD receives data, the multiple links include at least a first link and a second link, the method includes: detecting an indication that the switching link will be switched to a target channel by the AP MLD, Wherein, the switching link is one of the multiple links; and determining whether the AP belonging to the AP MLD and operating on the switching link has restored the basic service set on the target channel ( BSS) operation. Wherein, the communication method executed on the non-access point (AP) multi-link device (MLD) side is executed by a processor.

Another aspect of the present invention provides a communication method, which is executed on the side of an access point (AP) multi-link device (MLD), and the AP MLD is used to send data to or from a non-AP MLD on multiple links. The AP MLD receives data, the multiple links include at least a first link and a second link, and the AP MLD includes: determining that the second link is to be switched to a target channel, and determining that the second link is to be switched to a target channel, and determining that the After the second link is switched to the target channel, an announcement is sent on the first link, instructing the AP MLD to switch the second link to the target channel. Wherein, the communication method executed on the access point (AP) multi-link device (MLD) side is executed by a processor.

Description of drawings

The present invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar components. In addition, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears.

In the attached picture:

Figure 1 shows an overview of a wireless communication system using multiple links according to some embodiments of the present invention.

Figure 2 shows a block diagram of a wireless communication system according to some embodiments of the present invention.

Fig. 3 shows a block diagram of a non-access point (non-access point, non-AP) multilink device (multilink device, MLD) according to some embodiments of the present invention.

FIG. 4 shows a block diagram of an access point (AP) MLD according to some embodiments of the present invention.

FIG. 5 shows a flowchart of the operation of a non-AP MLD according to an embodiment of the present invention.

FIG. 6 shows a flowchart of the operation of a non-AP MLD according to an embodiment of the present invention.

FIG. 7 shows a flowchart of the operation of the AP MLD according to an embodiment of the present invention.

FIG. 8 shows a flowchart of the operation of a non-AP MLD according to an embodiment of the present invention.

9 is an example processor system for implementing some aspects or portions.

The present invention will now be described with reference to the accompanying drawings.

Detailed ways

The following description provides many different embodiments, or examples, for implementing different features of the presented subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. Of course, these are only examples and not limiting. For example, in the description below, forming a first feature over a second feature may include embodiments where the first and second features are formed in direct contact, and may also include embodiments where additional features may be formed between the first and second features. Embodiments of features such that the first feature and the second feature may not be in direct contact. Furthermore, the present invention may repeat reference numerals and/or letters in various examples. This repetition does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

As noted above, wireless local area networks allow for the use of multiple links between access points and client devices to provide increased data throughput and reliability. The IEEE 802.11 standard, which provides specifications governing the operation and performance of wireless LANs, has begun to consider the use of multilink. Such multiple links typically use different channels and/or different frequency bands. However, the physical proximity between multiple radios needs to be considered to ensure that any interference between multiple radios is properly addressed.

Figure 1 illustrates exemplary multi-link operation in a wireless communication network, where multiple access points and multiple non-access points work together. In multi-link operation, multiple links are formed between a device 110 (eg, a client device) having multiple non-access points 112 , 114 and a device 120 having multiple access points 122 , 124 . Devices 110, 120 may communicate using multiple links 130, 140 for fast and/or reliable communication. The devices 110, 120 are referred to as multilink devices (MLD).

1. Overview of multi-link operation

The present invention is applicable to devices, systems and methods for performing multi-link operations. In the following, FIG. 2 is used to illustrate an example of multi-link operation.

Figure 2 shows a block diagram of a wireless communication system according to some embodiments of the present invention.

System 200 is a system for multi-link operation. System 200 includes non-access point multi-link device (non-AP MLD) 210, access point multi-link device (AP MLD) 220, a primary link (primary link) formed wirelessly between non-AP MLD 210 and AP MLD 220 link) 230 and non-primary link (non-primary link) 240.

The non-AP MLD 210 has a first station (STA) 212 and a second STA 214 . Each STA has necessary components for communicating with an access point (AP), such as an antenna, a radio frequency (radio frequency, RF) transceiver module, and a baseband processor. Details of the non-AP MLD will be explained below with reference to FIG. 3 .

Figure 3 shows a block diagram of a non-AP MLD according to some embodiments of the invention. In addition to the first STA 212 and the second STA 214 , the non-AP MLD 210 also has a processor 300 , a memory 302 and a detector (Sensor) 304 . The processor 300 controls components constituting the non-AP MLD 210 . The memory 302 temporarily or permanently stores information not necessary for the operation of the AP MLD 210 . The detector 304 detects signal strength to monitor the quality of wireless communications performed by the non-AP MLD 210 . Components are omitted for simplicity in FIG. 2 , and the non-AP MLD 210 may also have a third STA 306 . In various embodiments of the invention, an MLD may have two or more STAs or APs.

Returning to FIG. 2 , the AP MLD 220 has a first access point (AP) 222 and a second AP 224 . Each AP has the necessary components for communicating with STAs, such as antennas, RF transceiver modules, and baseband processors. Details of the non-AP MLD will be explained below with reference to FIG. 4 . In the present invention, each link may include the antenna and RF transceiver modules of the non-AP MLD 210 and the AP MLD 220 .

Figure 4 shows a block diagram of an AP MLD according to some embodiments of the invention. The description of each component of the AP-MLD 220 is substantially similar to the description of the corresponding components in the non-AP MLD 210 described in FIG. 3 , and thus the description of these components is omitted.

Returning to FIG. 2 , the primary link 230 is a wireless link formed between the first STA 212 and the first AP 222 . Non-primary link 240 is a wireless link formed between second STA 214 and second AP 224 . Each link uses its assigned channel operating class (operating class) and the channel corresponding to the channel number or the channel corresponding to the assigned channel number as its communication channel, where the operating class indicates the information of the channel set, and indicates the starting point of the channel set. Frequency, channel spacing, and the channel number of each channel in the set. For example, the operation category is 1, which includes four channel numbers 36, 40, 44, and 48. The link can use the channel corresponding to the channel number (eg, 36). In the present invention, a plurality of links established between the non-AP MLD 210 and the AP MLD 220 for multi-link operation may be referred to as multi-link. In the present invention, the main link 230 may also be called a first link, the non-main link 240 is called a second link, and the additional links described below are called a third link.

As shown in FIG. 2, a communication operation using multiple links is called a multi-link operation. Multilink operation can include two modes of operation.

A simultaneous transmit and receive operation (STR) mode is a mode of operation. In STR mode, multiple links operate independently. Therefore, each link can send and receive data simultaneously.

Non-STR (NSTR) mode is another mode of operation. In NSTR mode, multiple links do not operate independently of each other. For example, operation in STR mode is not guaranteed if data cannot be successfully sent and received. In this case, STR mode is not feasible and NSTR mode becomes necessary.

One criterion for choosing which of these modes to use is potential or actual in-device coexistence (IDC) interference. For example, MLD devices have IDC interference when multiple links of multi-link operation are close to each other. An MLD operating on multiple links with IDC interference may not support the STR mode of operation. Therefore, in this case, the NSTR mode of operation is preferred.

As will be appreciated by those of ordinary skill in the art, it is desirable to use the STR mode of operation whenever feasible because simultaneous use of the links maximizes data throughput. However, interference may prevent the use of the STR mode of operation.

When MLD operates using NSTR mode, non-AP MLD and AP MLD can avoid IDC interference by performing contention-based channel access on their respective links and starting transmissions simultaneously with the following constraints, as described below.

An example of non-AP MLD 210 transmitting data to AP MLD 220 in NSTR mode is shown in FIG. 1 . In NSTR mode, at least one link is designated as the main link, and other links are defined as non-main links. As already explained, in the example of FIG. 2 one link is the primary link 230 and the other link is the non-primary link 240 . In order to transfer data from the non-AP MLD 210 to the AP MLD 220, the first STA 212 and the second STA 214 should initiate PPDUs of the primary link (or first link) 230 and the non-primary link (second link) 240 ( PLCP Protocol Data Unit, PLCP protocol data unit) transmission, where PLCP is a physical layer convergence protocol (Physical Layer Convergence Protocol). However, in the NSTR mode, only the first STA 212 (operating on the main link and belonging to the same MLD as the second STA) as the holder of the transmission opportunity (transmit opportunity, TXOP) with the same start time initiates PPDU transmission, The second STA may initiate a PPDU transmission for the second link 240 . This is because there is a risk of IDC if one STA transmits a signal while another STA belonging to the same MLD receives the signal independently at the same time. Therefore, in the NSTR mode, one STA among multiple STAs becomes a reference, the reference STA transmits a signal, and other STAs transmit signals simultaneously.

As shown in FIG. 2 , the first STA 230 and the second STA 240 as TXOP initiators initiate enhanced distributed channel access (EDCA) backoff 232 and 242 on each link. In the example shown in FIG. 2, the first link 230 is assigned a random backoff (RBO) count of four slots, and the second link 240 is assigned an RBO count of six slots. When the RBO count of the first link 230 is decremented to zero, the first STA 212 becomes idle to wait for the RBO count of the second link 240 to decrement, a wait period 234 as shown in FIG. 2 . Thereafter, when the RBO count of the second link 240 is decremented to zero, and if the first STA 212 is still idle, the first STA 212 and the second STA may transmit messages 236 and 244 with the first and second APs. The second STA 214 may use its detector to detect whether the first STA 212 is still idle. Messages 236 and 244 may include uplink data PPDU and Block Ack (Block Ack, BA). The start of the PPDU on the waiting link (primary link 230 in the example of FIG. 2) should be aligned with the start of the PPDU on the other link (secondary link 240 in the example of FIG. 2). The ends of the PPDUs on the first link 230 and the second link 240 also need to be aligned.

However, if a link needs to switch its channel operating class/channel number due to interference, regulatory requirements, or other reasons, the non-AP MLD 210 affiliated with the AP MLD 220 may not be able to switch to the new channel indicated by the AP MLD 220, or the non-AP MLD 220 may not switch to the new channel indicated by the AP MLD 220. AP MLD 210 may not know when AP MLD 220 resumes basic service set (BSS) operation on the new channel, so transmissions on the new channel initiated by non-APMLD 210 or AP MLD 220 may will fail and the spectrum efficiency will be reduced. To solve this problem, an exemplary channel switching scheme is proposed in the present invention. According to an example of the present invention, the non-AP MLD 210 may notify whether handover is possible and request to continue communication according to its own situation. According to one example of the present invention, AP MLD 220 may announce switchover of non-primary link 240 over primary link 230 even though they are operating in NSTR mode. According to an example of the present invention, after the channel switch of the non-primary link 240 has been completed, the AP MLD 220 can stop sending the Max Channel Switch Time (Max Channel Switch Time) element in the STA profile (Per STAprofile) sub-element , to indicate in the beacon frame and probe response frame on the primary link 230 that the BSS operation has resumed on a new channel other than the primary link 240 . According to an example of the present invention, non-AP MLD 210 and AP MLD 220 can maintain communication even if AP MLD 220 decides not to switch non-primary link 240 to a new channel. It is emphasized here again that the present invention is not only applicable to systems running in NSTR mode. In systems operating in non-NSTR mode, it is preferable to define the behavior of the associated non-AP MLD if the channel of the AP MLD scheduled link is switched to a new channel operation class/channel number.

2. Channel switching scheme for non-AP MLD

2.1 Switching non-primary links

This section shows the operation of the non-AP MLD 210 when the AP MLD 220 switches the non-primary link 240 .

FIG. 5 shows a flowchart of the operation of a non-AP MLD according to an embodiment of the present invention. Unless otherwise stated, the processing of each operation is performed by the processor 300 of the non-AP MLD 210 in cooperation with other components.

In operation 500 , the non-AP MLD 210 transmits/receives data to/from the AP MLD 220 .

In operation 502 , the non-AP MLD 210 determines whether the non-AP MLD 210 detects a handover of the non-primary link 240 . Non-AP MLD 210 may detect the switch of non-primary link 240 in a number of ways. One example of detecting the handover of the non-primary link 240 is the method described later in the present invention. The switching method of the non-primary link 240 is not limited to the method described in the present invention; for example, the APMLD may directly or indirectly notify the non-AP MLD of the switching, and the system administrator may automatically or manually notify the non-APMLD.

If the non-AP MLD 210 does not detect a handover of the non-primary link 340 , the process returns to operation 500 .

When the non-AP MLD 210 detects a handover, the process moves to operation 504 . The non-AP MLD 210 can also detect the target channel at the same time. The target channel is the channel to which the operating channel of the non-primary link 240 will be switched. The target channel is identified by information indicating, for example, channel operation class/channel number. The non-AP MLD 210 can also detect the target switching time at the same time. The target switching time is information providing the time at which the AP MLD 220 starts switching the non-primary link 240 to the target channel.

In operation 504, the non-AP MLD 210 determines whether the non-AP MLD 210 switches to the target channel. There are many reasons for not switching to the target channel. For example, one reason for not switching to the target channel includes interference, regulatory requirements, or other similar reasons.

If the non-AP MLD 210 determines to switch to the target channel, the process moves to operation 506 . In operation 506, the non-APMLD 210 determines whether the target switching time is reached, and if not, continues to wait for the target switching time to arrive.

In operation 508 (the non-AP MLD 210 determines "No" in operation 504), the non-AP MLD 210 determines whether the target switching time is reached.

If the non-AP MLD 210 determines in operation 508 that the target handover time has not elapsed, the process moves to operation 510 . In operation 510 , the non-AP MLD 210 sends a request to the AP MLD 220 .

This request is a message instructing the non-AP MLD 210 to remove the handover link from the links already established between the AP MLD 220 and the non-AP MLD 210 . Here, the switching link refers to the link to be switched (referred to as the non-primary link 240 in this section). Requests can take various forms. Some examples of these are described below.

An example of the request is a request for mapping from a traffic identifier (Traffic Identifier, TID) to a link. A TID is an identifier that identifies a frame of data to be transmitted on a link. A TID-to-Link Mapping Request indicates a mapping between a TID and a link carrying a data frame with that TID. At operation 510, the non-AP MLD 210 may send a TID to link mapping request that maps the TID to a link of a non-handover link to avoid communication on the handover link where the non-AP MLD 210 has decided not to handover to the target channel of the handover link. The TID-to-link mapping request may preferably include a target timer indicating the point in time at which the non-AP MLD 210 will start the requested mapping, eg, transition from an existing mapping approach to the requested mapping approach. It may be better to use a TID-to-link mapping request as an example of a request for the following reasons. Since the connections between the non-AP MLD 210 and the AP MLD 220 do not have to be re-associated, handover can be accomplished quickly and easily.

Another example of a request is a reassociation request. A reassociation request is a request to establish a new link or a new multi-link. During performing re-association, AP MLD 220 or non-AP MLD 210 may avoid including the handover link operating on the target channel in the new link or new multi-link.

Another example of a request is a link reconfiguration request or a removal request. A link reconfiguration request or remove request is a request to remove a handover link from a multi-link configuration. The request may include a delete timer to indicate when to delete the link. There are advantages to using link reconfiguration requests or removal requests as examples of requests. Since the connections between the non-AP MLD 210 and the AP MLD 220 do not have to be re-associated, handover can be done quickly and easily.

The link that sends the request can be a primary link or a non-primary link. However, in some cases, the AP MLD 220 forces the non-AP MLD 210 to stop transmitting until the channel switch occurs by setting the channel switch mode in the Channel Switch Announcement element or the Extended Channel Switch Announcement element until. In this case, requests can only be sent on other links that are not being used by the AP MLD 210.

If the target handover time has elapsed, then at operation 512, the non-AP MLD 210 sends a request using a link other than the handover link because the handover link is not available at this time.

If the non-AP MLD 210 determines that the target switching time arrives in operation 506 , the non-AP MLD 210 switches the non-primary link 240 to the target channel in operation 513 . After the target switching time is reached, the non-AP MLD 210 receives the maximum channel switching time element of the AP 224 (AP operating on the switching link) corresponding to the AP MLD 220 in operation 514 . The maximum channel switching time element indicates the estimated time between when the maximum channel switching time element is sent and when the second AP 224 of AP MLD 220 resumes BSS operation on a new channel other than primary link 240 . Beacon frames and probe response frames sent by AP MLD 220 include multilink elements. The multi-link element includes an STA profile (Per STAprofile) sub-element corresponding to a non-primary link. Since the first AP 222 of the AP MLD 220 (the AP operating on the non-handover link) is still transmitting beacon frames or probe response frames, the AP MLD 220 can notify the non-AP MLD 210 that BSS operation resumes on the target channel of the handover link estimated time.

In operation 516, the non-AP MLD 210 determines whether the AP 222 of the AP MLD 220 stops transmitting the maximum channel switching time element.

If the non-AP MLD 210 determines that the AP 222 stopped transmitting the maximum channel switching time element, then at operation 518 the non-AP MLD 210 determines that the AP 224 of the AP MLD 220 has resumed BSS operation. This is because AP MLD 220 may stop sending this element after detecting that AP 224 has resumed BSS operation. After determining that AP 224 of the AP MLD has resumed BSS operation, non-AP MLD 210 may resume multi-link operation.

2.2 Switch the main link

This section shows the operation of the non-AP MLD 210 when the AP MLD 220 switches the primary link 230 . In this section, multi-link operation is performed by using NSTR mode non-AP MLD 210 and AP MLD 220 .

FIG. 6 shows a flowchart of the operation of a non-AP MLD according to an embodiment of the present invention. Unless otherwise stated, the processing of each operation is performed by the processor 300 of the non-AP MLD 210 in cooperation with other components.

In operation 600 , the non-AP MLD 210 transmits data to the AP MLD 220 or the non-AP MLD 210 receives data from the AP MLD 220 .

In operation 602 , the non-AP MLD 210 determines whether the non-AP MLD 210 detects a handover of the primary link 230 . Non-APMLD 210 can detect the handover of non-primary link 230 in a number of ways.

If the non-AP MLD 210 does not detect a switch of the primary link 230, the process returns to operation 600.

The process moves to operation 604 when the non-AP MLD 210 detects a handover. The non-AP MLD 210 can also detect the target channel at the same time.

In operation 604, the non-AP MLD 210 determines whether the non-AP MLD 210 is to switch to the target channel.

If the non-AP MLD 210 determines to switch to the target channel, the process moves to operation 606 . In operation 606, the non-AP MLD 210 switches the main link 230 to the target channel.

In operation 608 (non-AP MLD 210 determines "No" in operation 604), non-AP MLD 210 determines whether non-AP MLD 210 and AP MLD 220 have established additional links other than primary link 230 and non-primary link 240 road. For example, non-APMLD 210 and AP MLD 220 may establish a third link between third STA 306 and third AP 406 .

If the non-AP MLD 210 determines that additional links exist, the process moves to operation 610 . At operation 610, the non-APMLD 210 sends a request to the AP MLD 220 on the additional link.

The requested examples are in principle similar to the examples given in Section 2.1, but differ from them in several respects as follows.

In operation 610, if the non-AP MLD 210 sends a TID-to-link mapping request as a request, the non-AP MLD 210 may send a TID-to-link mapping request, which maps the TID to a link that is not a primary link and a non-primary link (e.g. additional link). This is because, as already explained, the non-primary link 240 cannot initiate communication without the primary link 230 .

If the non-AP MLD 210 sends a re-association request as a request, then at operation 610, the AP MLD 220 or the non-AP MLD 210 may attempt not to include the primary and non-primary links into the new link or In the new multilink.

If the non-AP MLD 210 sends a link reconfiguration request or a removal request as a request, in operation 610, the delete timer indicates when both links are to be deleted. If the non-AP MLD 210 determines that there are no additional links, then the process moves to operation 612 . At operation 612 , the non-AP MLD 210 sends a disassociation frame on the primary link 230 . After sending the disassociation frame, the non-AP MLD 210 initiates a multilink teardown procedure.

3. Channel switching scheme of AP MLD.

This section shows the operation of AP MLD 220 when AP MLD 220 determines to switch non-primary link 240 . In this section, non-AP MLD 210 and AP MLD 220 perform multi-link operation by using NSTR mode.

FIG. 7 shows a flowchart of AP MLD operation according to an embodiment of the present invention. The processing of each operation is performed by the processor 400 of the AP MLD 220 in cooperation with other components unless otherwise noted.

In operation 700, the AP MLD 220 transmits data to the non-AP MLD 210, or the AP MLD 220 receives data from the non-AP MLD 210.

In operation 702, the AP MLD 220 determines whether the AP MLD 220 is to switch the non-primary link 240 to the target channel. If the AP MLD 220 is not about to switch the non-primary link 240 to the target channel, the process returns to operation 700 .

In operation 704 , the AP MLD 220 sends an announcement to the non-AP MLD 210 . This announcement instructs APMLD 220 to switch the non-primary link to the target channel. The announcement indicates the operating class/channel number of the target channel. The announcement may further indicate the target switching time.

Announcements can take various forms, some examples of which are described below.

An example of an announcement is a Channel Switch Announcement element or an Extended Channel Switch Announcement element sent on the main link 230 . AP MLD 220 periodically sends beacon frames on primary link 230 . AP MLD 220 also sends probe response frames on primary link 230 in response to probe requests from non-AP MLD 210 . Beacon frames and probe response frames include multilink elements. The multilink element includes a STA profile sub-element. The STA profile sub-element corresponding to the non-primary link of the multi-link element carries the profile of the non-primary link 240 . In operation 704, the AP MLD 220 may indicate switching of the non-primary link 240 by including a channel switching announcement element or an extended channel switching announcement element in the STA configuration file sub-element corresponding to the non-primary link. In this way, announcements can be sent in beacon frames or probe response frames.

The channel switching announcement element or the extended channel switching announcement element may be carried in the channel switching announcement frame or the extended channel switching announcement frame transmitted on the main link 230 . These frames are not sent in beacon frames or probe response frames.

The Channel Switch Announcement Element, Extended Channel Switch Announcement Element, Channel Switch Announcement Frame, and Extended Channel Switch Announcement Frame may be sent on a link to indicate channel switching for the link. However, in the present invention, the scheme uses elements/frames to indicate channel switching for other links.

A frame carrying a channel switching announcement element or an extended channel switching announcement element may indicate link ID information of the non-primary link 240 to indicate which link is to be switched. AP MLD 220 may indicate the link ID in various ways.

The link ID information may be the MAC address of the second AP 224 described as the A3 address in the MAC header of the corresponding frame. AP MLD 220 may indicate link ID information by indicating the MAC addresses of APs operating on non-primary link 240 affiliated to AP MLD 220 . Accordingly, the AP MLD 220 may indicate the MAC address of the second AP 224 as the A3 address.

The AP MLD 220 can also indicate link ID information by using a link ID subfield of a corresponding frame. The link ID information corresponds to the link ID of the non-main link 240 .

Another example of the announcement is that the content of the announcement is described in the neighbor AP information field corresponding to the non-main link 240 in the Reduced Neighbor Report (RNR) element in the beacon frame on the main link 230 . AP MLD 220 periodically transmits beacon frames over primary link 230, as described above. A beacon frame includes various elements. The RNR element is one of multiple elements, and is used to notify the state of neighboring APs. The RNR may include the status of the second AP 224 corresponding to the non-primary link 240 . The neighbor AP information field of the RNR has an operating class (Operating Class) field and a channel number (Channel Number) field. In operation 704, the AP MLD 220 includes the operation class/channel number of the target channel at the target switching time in the operation class field or the channel number field of the neighbor AP information field corresponding to the non-primary link 240 in the RNR element.

In operation 706, the AP MLD 220 determines whether the AP MLD 220 fails or decides not to switch to the target channel. If the AP MLD 220 has not failed to switch or has not decided not to switch to the target channel, the process moves to operation 708 . In operation 708, the AP MLD 220 determines whether the target switching time is reached, and if not, continues to wait for the target switching time to arrive.

In operation 711, the AP 222 of the AP MLD 220 switches to the target channel after reaching the target switching time. After reaching the target switching time, in operation 712, the AP MLD 220 may transmit a maximum channel switching time element corresponding to the AP 224 by using a beacon frame or a probe response frame, indicating the time at which the maximum channel switching time element is transmitted and the AP 224 at The estimated time between when BSS operation resumes on the new channel of the non-primary link 240. As previously mentioned, beacon frames or probe response frames sent by AP MLD 220 include multilink elements. The multi-link element includes a STA profile sub-element corresponding to the non-primary link 240 . Since the first AP 222 of the AP MLD 220 (the AP operating on the non-handover link) is still able to transmit beacon frames or probe response frames, the AP MLD 220 can notify the non-AP MLD 210 to resume BSS operation on the target channel of the handover link estimated time of .

In operation 714, the AP MLD 220 determines whether the second AP 224 has resumed BSS operation on the non-primary link (the switched link).

After determining that the second AP 224 resumes BSS operation on the non-primary link (the switched link), the AP MLD 220 stops sending the maximum channel switching time elements. In this way, the AP MLD 220 can inform the non-AP MLD 210 that the second AP 224 resumes BSS operation on the non-primary link (the switched link). Corresponding to the operations 712 to 716 described above, the non-AP MLD 210 also performs operations 810 to 814 described later.

Note that operations 712 through 716 are also applicable to multi-link operations operating in modes other than NSTR mode. If the AP MLD 220 switches one of the links, the AP operating on the link other than the switched link of the AP MLD 220 transmits a message corresponding to the AP operating on the switched link by using a beacon frame or a probe response frame. Maximum channel switching time element.

If the AP MLD 220 fails to switch to the target channel or decides not to switch to the target channel and the AP MLD 220 includes the operation class/channel number of the target channel into the operation class field or the channel number field, the process moves to operation 710 . At operation 710, the AP MLD 220 sends a new announcement. AP MLD 220 may maintain the current operating class/channel number of non-primary link 240 in the operating class field or channel number field at or after the target switch time. In other words, the AP MLD 220 sets the operation category and channel number field in the RNR element corresponding to the non-primary link 240 to the original operation category and channel number of the non-primary link 240 (secondary link), the original operation category and channel number The number is the operation category and channel number that the switching link (such as the non-primary link 240) is operating on before performing the operation of switching to the target channel.

When the AP MLD 220 performs operation 710, the non-AP MLD 210 may detect that the AP MLD 220 is not switching. The operation of the non-AP MLD 210 at this time will be explained with reference to FIG. 8 .

FIG. 8 shows a flowchart of the operation of a non-AP MLD according to an embodiment of the present invention. Unless otherwise stated, the processing of each operation is performed by the processor 300 of the non-AP MLD 210 in cooperation with other components.

In operation 800 , the non-AP MLD 210 transmits data to the AP MLD 220 , or the non-AP MLD 210 receives data from the AP MLD 220 .

At operation 802 , the non-AP MLD 210 receives the announcement sent at operation 704 . In this case, at operation 704, the AP MLD 220 proceeds by including the operation category/channel number of the target channel at the target handoff time into the operation category field of the neighbor AP information field corresponding to the non-primary link 240 in the RNR element or channel number field, send announcement.

In operation 804, the non-AP MLD 210 determines whether the target handover time is reached. If the target switching time has not been reached, the process returns to operation 800 .

If the target switching time has elapsed, the process moves to operation 806 . In operation 806, the non-AP MLD 210 determines whether the latest announcement data shows that the AP MLD 220 is switching the handover link (non-primary link in this embodiment) to the target channel. When the non-AP MLD 210 recognizes that the target operation category/channel number of the non-primary link is shown in the operation category field and channel number field of the neighbor AP information field corresponding to the non-primary link 240 in the RNR element, the non-AP MLD 210 It is determined that the most recent announcement shows the AP MLD 220 switching the handover link to the target channel.

If the non-AP MLD 210 determines that the latest announcement shows that the AP MLD 220 did not switch the handover link to the target channel, then the process returns to operation 800 .

If the non-AP MLD 210 determines that the latest announcement shows the AP MLD 220 switching the handover link to the target channel, then the process moves to operations 808 and 810 . In operation 808, the non-AP MLD 210 switches the non-primary link 240 to the target channel.

Operation 810, operation 812, and operation 814 are basically the same as operations 514 to 518, and thus descriptions are omitted.

As mentioned in the previous section, the reliability of multi-link operation is improved even if one link needs to switch the channel operation class/channel number for any reason. The non-AP MLD 210 may notify whether it is possible to switch and request to continue communication according to its own situation. AP MLD 220 may announce switchover of non-primary links 240 over primary link 230 even though they are operating in NSTR mode. Even if AP MLD 220 decides not to switch links, non-AP MLD 210 and AP MLD 220 can maintain communication.

Various aspects disclosed above may be implemented, for example, using one or more processor systems, such as processor system 900 shown in FIG. 9 . Processor system 900 may be any well-known computer capable of performing the functions described herein, such as devices 210 and 220 of FIG. 2 . Processor system 900 includes one or more processors (also referred to as central processing units or CPUs), such as processor 904 . The processor 904 is connected to a communication infrastructure 906 (eg, a bus). Processor system 900 also includes user input/output devices 903 , such as monitors, keyboards, pointing devices, etc., which communicate with communication infrastructure 906 through user input/output interfaces 902 . Processor system 900 also includes main memory or main memory 908, such as random access memory (RAM). Main memory 908 may include one or more levels of cache memory. Main memory 908 has stored therein control logic (eg, computer software) and/or data.

Processor system 900 may also include one or more secondary storage devices or memories 910 . Secondary storage 910 may include, for example, a hard drive 912 and/or a removable storage device or drive 914 . Removable storage drive 914 may be a floppy disk drive, tape drive, optical disk drive, optical storage device, tape backup device, and/or any other storage device/drive.

Removable storage drive 914 may interface with removable storage unit 918 . Removable storage unit 918 includes a computer usable or readable storage device having computer software (control logic) and/or data stored thereon. Removable storage unit 918 may be a floppy disk, magnetic tape, compact disk, DVD, optical storage disk, and/or any other computer data storage device. Removable storage drive 914 reads from and/or writes to removable storage unit 918 in a known manner.

According to some aspects, secondary memory 910 may include other means, tools, or other methods for allowing computer programs and/or other instructions and/or data to be accessed by processor system 900 . Such devices, tools, or other methods may include, for example, removable storage unit 922 and interface 920 . Examples of removable storage unit 922 and interface 920 may include program cartridges and cartridge interfaces (such as those found in video game devices), removable memory chips (such as EPROM or PROM) and associated sockets, memory sticks and USB ports, memory cards and associated memory card slots, and/or any other removable storage unit and associated interfaces.

Processor system 900 may also include a communication or network interface 924 . Communication interface 924 enables processor system 900 to communicate and interact with any combination of remote devices, remote networks, remote entities, etc. (separately and collectively referenced by reference numeral 928). For example, communication interface 924 may allow processor system 900 to communicate with remote device 928 via communication path 926, which may be wired and/or wireless, and may include any combination of LAN, WAN, Internet, etc. Control logic and/or data may be sent to and from processor system 900 via communication path 926 .

Operations in the foregoing aspects can be implemented in a wide variety of configurations and architectures. Therefore, some or all of the operations of the foregoing aspects may be performed in hardware, software, or both. In some aspects, a tangible, non-transitory apparatus or article includes a tangible, non-transitory computer-usable or readable medium having control logic (software) stored thereon, also referred to herein as a computer program product or program storage device. This includes, but is not limited to, processor system 900, main memory 908, secondary memory 910, and removable storage units 918 and 922, as well as tangible articles of manufacture embodying any combination of the foregoing. Such control logic, when executed by one or more data processing devices (eg, processor system 900), causes such data processing devices to operate as described herein.

Based on the teachings contained herein, it will be apparent to a person skilled in the relevant art how to make and use aspects of the invention using data processing apparatus, computer systems and/or computer architectures other than the components in FIG. 9 . In particular, aspects may operate with software, hardware, and/or operating system implementations other than those described herein.

It should be understood that the Detailed Description and not the Summary and Abstract are intended to be used for interpreting the claims. The Summary and Abstract sections may set forth one or more, but not all, exemplary embodiments of the invention and, therefore, are not intended to limit the invention and the appended claims in any way.

The invention has been described above with the aid of functional building blocks illustrating the implementation of specified functions and relationships thereof. The boundaries of these functional building blocks have been arbitrarily defined herein for the convenience of the description. Alternative boundaries may be defined provided the specified functions and their relationships are appropriately performed.

The above description of specific embodiments will sufficiently reveal the general characteristics of the invention so that, without departing from the general concept of the invention, it can be readily modified by others for various applications by applying the knowledge of those skilled in the art and/or tinker without undue experimentation. Therefore, such modifications and/or modifications are intended to be within the meaning and range of equivalents of the disclosed embodiments, based on the teaching and guidance presented herein. It should be understood that the terms or terms herein are for the purpose of description rather than limitation, so that the terms or terms in this specification will be interpreted by those skilled in the art according to the teaching and guidance.

The breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the appended claims and their equivalents.

Claims (22)

1. A communication method, executed on the side of a non-access point AP multi-link device MLD, the non-AP MLD is used to send data to the AP MLD or receive data from the AP MLD on multiple links, the multiple The link includes at least a first link and a second link, characterized in that, detecting an indication that a handover link is to be handed over by the AP MLD to a target channel, wherein the handover link is one of the plurality of links; and Determining whether the AP belonging to the AP MLD and operating on the handover link has resumed basic service set (BSS) operation on the target channel. 2. The communication method according to claim 1, wherein: Determining whether the AP affiliated with the AP MLD and operating on the handover link has resumed BSS operation on the target channel includes: After detecting that an AP belonging to the same said AP MLD and operating on a link of a non-handover link stops transmitting the maximum channel switching time element corresponding to said AP operating on said handover link, determining to operate The AP on the handover link has resumed BSS operation. 3. The communication method according to claim 2, wherein the maximum channel switching time element indicates that the time at which the maximum channel switching time element is sent is on the target channel with the AP on the switching link Estimated time between times when BSS operation resumes. 4. The communication method according to claim 1, further comprising: determining whether the non-AP MLD switches the handover link to the target channel, and After determining that the non-AP MLD has not switched the handover link to the target channel, sending a request for instructing the non-AP MLD to remove the handover link from the plurality of links. 5. The communication method according to claim 4, further comprising: Detecting a target switching time, where the target switching time is the time when the switching link is scheduled to start switching to the target channel; sending a request on at least one of the plurality of links prior to the target switch time; and/or, Sending the request on at least one of the plurality of links other than the handover link after the target handover time. 6. The communication method according to claim 4, wherein the request is at least one of the following: Mapping request from service identifier TID to link; reassociation request; A link reconfiguration request, where the link reconfiguration request is used to request to delete the handover link from the plurality of links. 7. The communication method according to claim 1, wherein: The non-AP MLD is configured to send data to the AP MLD or receive data from the AP MLD, wherein the AP MLD works in a non-simultaneous transmission and reception operation NSTR mode; the first link is the switching the link and the primary link; and the second link being a non-primary link. 8. The communication method according to claim 4, wherein: The non-AP MLD is configured to send data to or receive data from the AP MLD operating in NSTR mode; the first link is the handover link and the main link; the second link is a non-primary link; said request is a disassociation frame that initiates the teardown procedure, and Also methods include: detecting whether the plurality of links includes only primary links and non-primary links, Sending said request includes: The request is sent after detecting that the plurality of links only include the primary link and the non-primary link. 9. The communication method according to claim 4, wherein: The non-AP MLD is configured to send data to or receive data from the AP MLD operating in NSTR mode; the first link is the handover link and the main link; the second link is a non-primary link; The request is at least one of the following: TID to link mapping request; reassociation requests; and a link reconfiguration request requesting deletion of the primary link and the non-primary link, and The method also includes: detecting whether a plurality of links includes additional links other than said primary link and non-primary links, Sending said request includes: The request is sent after detecting that the plurality of links include the additional link, where the request is used to request that the TID be mapped to the additional link. 10. The communication method as claimed in claim 4, characterized in that, The non-AP MLD is configured to send data to or receive data from the AP MLD operating in NSTR mode; the first link is a primary link; said second link is said handover link and a non-primary link; and The method also includes: Detecting a target switching time, the target switching time being the time when the switching link is scheduled to start switching to a target channel, the target channel being indicated by the target channel operation category and channel number; and After the target switching time arrives, after detecting that the target channel operation category and channel number indicated in the simplified neighbor report element corresponding to the non-primary link are the original channel operation category and channel number of the non-primary link , keep the non-primary link. 11. A communication method for executing on the side of an access point AP multi-link device MLD, characterized in that the AP MLD is used to send data to a non-AP MLD or receive data from a non-AP MLD on multiple links For data, the multiple links include at least a first link and a second link, and the AP MLD includes: determining that the second link is to be switched to a target channel, and After it is determined that the second link is to be switched to the target channel, an announcement is sent on the first link to instruct the AP MLD to switch the second link to the target channel. 12. The communication method according to claim 11, wherein the AP MLD is used to send data to or receive data from a non-AP MLD using NSTR mode; the first link is a main link; and the The secondary link mentioned above is a non-primary link. 13. The communication method according to claim 11, wherein sending an announcement on the first link comprises: including an announcement in a beacon frame and a probe response frame sent on the first link to send the announcement in at least one of . 14. The communication method according to claim 11, wherein the announcement indicates link ID information of the second link. 15. The communication method according to claim 11, characterized in that, the announcement indicates at least one of an operating class and a channel number of the target channel; and The operations also include sending the announcement by including the announcement in a beacon frame sent on the first link. 16. The communication method according to claim 13 or 15, further comprising: sending an announcement indicating a target switching time to the non-AP MLD, and the target switching time is when the second link is scheduled to start connecting to the target channel switching time; At the target switching time or after the target switching time, after determining that the AP MLD has not switched the second link to the target channel, the simplified neighbor report element corresponding to the second link The channel operation category and channel number fields in are set to the original channel operation category and channel number of the second link. 17. The communication method according to claim 11, further comprising: sending to the non-AP MLD in at least one of a beacon frame and a probe response frame on the first link A maximum channel switching time element corresponding to the second link until the AP operating on the second link resumes basic service set BSS operation on the target channel; and After the AP operating on the second link resumes BSS operation on the target channel, stop sending maximum channel switch time elements. 18. The communication method according to claim 17, wherein: The maximum channel switch time element indicates an estimated time between when the maximum channel switch time element is sent and when the AP on the second link resumes BSS operation on the target channel. 19. A non-access point AP multi-link device MLD, characterized in that it is configured to send data to the AP MLD or receive data from the AP MLD on multiple links, and the multiple links include at least the first link and a second link, the non-AP MLD includes: processing circuit; a transceiver coupled to the processing circuit; and a memory coupled to the processing circuit, the memory storing instructions that when executed by the processing circuit perform a plurality of operations, the plurality of operations including: detecting an indication that a handover link is to be handed over by the AP MLD to a target channel, wherein the handover link is one of the plurality of links; and Determining whether the AP belonging to the AP MLD and operating on the handover link has resumed basic service set (BSS) operation on the target channel. 20. The non-AP MLD of claim 19, wherein, After detecting that an AP belonging to the same said AP MLD and operating on a link of a non-handover link stops transmitting the maximum channel switching time element corresponding to said AP operating on said handover link, determining to operate The AP on the handover link has resumed BSS operation. 21. An access point AP multi-link device MLD, characterized in that it is configured to send data to a non-AP MLD or receive data from a non-AP MLD on multiple links, and the multiple links include at least the first A link and a second link, the AP MLD includes: processing circuit; a transceiver coupled to the processing circuit; and a memory coupled to the processing circuit, the memory storing instructions that, when executed by the processing circuit, perform a plurality of operations, the plurality of operations including: determining that the second link is to be switched to a target channel, and After it is determined that the second link is to be switched to the target channel, an announcement is sent on the first link to instruct the AP MLD to switch the second link to the target channel. 22. The AP MLD of claim 21, wherein, The plurality of operations further includes: Send the maximum channel switching time element corresponding to the second link to the non-AP MLD in at least one of a beacon frame and a probe response frame on the first link until operating on the second link APs on the link resume Basic Service Set BSS operation on the target channel; and After the AP operating on the second link resumes BSS operation on the target channel, stop sending maximum channel switch time elements.