Roaming method and system of wireless local area network

Abstract

The embodiment of the invention provides a roaming method and system of a wireless local area network, which are applied to the technical field of wireless communication, and the method comprises the following steps: sending a message containing a roaming access point information element, receiving a multi-link reconfiguration request message sent by a multi-link terminal, and sending a roaming preparation request message to a second multi-link access device to which the roaming target access point belongs, receiving a roaming preparation response message, and according to state parameters in the roaming preparation response message, keeping BA parameter setting in an original BA protocol with the multi-link terminal or sending a BA parameter updating request message to the multi-link terminal, and thus, the multi-link terminal can perform data transmission with the roaming target access point based on the BA parameter setting in the original BA protocol or the changed BA parameter setting. When the terminal roams from one access point to another access point to carry out data transmission, the terminal does not need to carry out BA negotiation with a new access point again, and the data transmission delay caused by signaling interaction is reduced.

Description

Roaming method and system for wireless local area network Technical Field

[0001] The present application relates to the field of wireless communication technology, and in particular to a roaming method and system for a wireless local area network, and more particularly to a roaming method and a roaming system for a wireless local area network. Background Art

[0002] A wireless local area network (WLAN) includes access points (APs) and stations (STAs). STAs refer to terminals with WLAN capabilities, such as smartphones and laptops. When a terminal in a WLAN moves, the link quality will decrease as the distance between the terminal and the associated AP increases or as obstructions appear. At this time, the terminal can roam to an AP that provides a higher-quality link to meet the service's demand for communication quality. During the roaming switching process, after the terminal establishes a connection with a new AP, if data needs to be transmitted with the new AP through block transmission, it is usually necessary to re-negotiate the BA with the new AP. The signaling interaction will increase the delay in data transmission, which will have a certain impact on service transmission. Therefore, how to make the terminal roam and switch smoothly is a problem that needs to be solved at present.

[0003] Summary of the Invention

[0004] To overcome the above-mentioned problems, an embodiment of the present application provides a roaming method and system for a wireless local area network. When a multi-link terminal roams from one access point to another access point and needs to transmit data, the multi-link terminal does not need to re-negotiate the BA with the new access point, thereby reducing the data transmission delay caused by signaling interaction and enabling the multi-link terminal to complete roaming switching more smoothly.

[0005] In one aspect, the present application proposes a roaming method for a wireless local area network, the method comprising:

[0006] Sending a message including a roaming access point information element, wherein the roaming access point information element includes information of adjacent access points that can support roaming, so that the multi-link terminal device determines a roaming target access point according to the roaming access point information element;

[0007] receiving a multi-link reconfiguration request message sent by a multi-link terminal, where the multi-link reconfiguration request message includes an identifier of the roaming target access point;

[0008] Sending a roaming preparation request message to the second multi-link access device to which the roaming target access point belongs, where the roaming preparation request message includes a BA parameter;

[0009] receiving a roaming preparation response message sent by the second multi-link access device, where the roaming preparation response message includes a status parameter;

[0010] The method further comprises: maintaining the BA parameter settings in the original BA protocol with the multi-link terminal or sending a BA parameter update request message to the multi-link terminal according to the state parameters, so that the multi-link terminal transmits data with the roaming target access point based on the BA parameter settings in the original BA protocol or the changed BA parameter settings; or sending a terminate BA protocol message to the multi-link terminal according to the state parameters, so that the multi-link terminal terminates the BA protocol.

[0011] As a feasible implementation manner, the multi-link reconfiguration request includes a first reconfiguration information element, where the first reconfiguration information element includes the following parameters: a reconfiguration type, an access point identifier AP ID, and a multi-link device identifier MLD ID, where the value of the AP ID is set to correspond to the roaming target access point; the value of the Reconfiguration type is set to a first preset value, indicating a request to add a new link; and the value of the MLD ID is set to uniquely identify the second multi-link access device.

[0012] The sending a roaming preparation request message to the second multi-link access device to which the roaming target access point belongs includes:

[0013] Obtaining the first reconfiguration information element from the multilink reconfiguration request;

[0014] If it is determined according to the value of the MLD ID in the first reconfiguration information element that the link requested to be added and the first multi-link access device do not belong to the same device, a roaming preparation request message is sent to the multi-link access device corresponding to the value of the MLD ID.

[0015] As a feasible implementation manner, maintaining the BA parameter settings in the original BA protocol with the multi-link terminal according to the state parameter includes:

[0016] If the state parameter indicates that the second multi-link access device accepts the BA parameter in the roaming preparation request message, the BA parameter setting in the original BA protocol is maintained with the multi-link terminal.

[0017] As a feasible implementation manner, the sending a BA parameter update request message to the multi-link terminal according to the state parameter to instruct the multi-link terminal to change the BA parameter includes:

[0018] If the state parameter indicates that the second multi-link access device recommends changing the BA parameters, obtaining the recommended BA parameters;

[0019] If the recommended BA parameters are accepted, a BA parameter update request message is sent to the multi-link terminal, instructing the multi-link terminal to update the BA parameters to the recommended BA parameters.

[0020] As a feasible implementation manner, sending a terminate BA protocol message to the multi-link terminal according to the state parameter so that the multi-link terminal terminates the BA protocol includes:

[0021] If the state parameter indicates that the second multi-link access device does not accept the BA parameter in the roaming preparation request message, sending a terminate BA protocol message to the multi-link terminal;

[0022] Alternatively, if the state parameter indicates that the second multi-link access device recommends changing the BA parameters, and the first multi-link access device does not accept the recommended BA parameters, a terminate BA protocol message is sent to the multi-link terminal.

[0023] As a feasible implementation manner, if the recommended BA parameters are accepted, sending a BA parameter update request message to the multi-link terminal to instruct the multi-link terminal to update the BA parameters to the recommended BA parameters includes:

[0024] If the first multi-link access device is the initiator of the original BA protocol and accepts the suggested BA parameters, it sends a BA parameter update request message to the multi-link terminal, instructing the multi-link terminal to update the BA parameters to the suggested BA parameters.

[0025] As a feasible implementation manner, the method further includes:

[0026] sending the data packet reception status information to the second multi-link access device, so that the second multi-link access device generates BA data packet reception status information based on the data packet reception status information sent by the first multi-link access device and its own data packet reception status information, and sends a BA message to the multi-link terminal, where the BA message includes the BA data packet reception status information;

[0027] Alternatively, the device receives data packet reception status information sent by the second multi-link access device; generates BA data packet reception status information based on the data packet reception status information sent by the second multi-link access device and its own data packet reception status information, and sends a BA message to the multi-link terminal, wherein the BA message includes the BA data packet reception status information.

[0028] As a feasible implementation manner, the method further includes:

[0029] receiving BA data packet reception status information generated according to received data packets sent by the multi-link terminal;

[0030] The BA data packet reception status information is sent to the second multi-link access device, so that the first multi-link access device and / or the second multi-link access device delete the successfully sent data packet according to the BA data packet reception status information.

[0031] As a feasible implementation method, the message containing the roaming access point information element is: a connection response message sent by the first multi-link access device to the multi-link terminal, a broadcast message sent by the first multi-link access device, or a response message returned by the first multi-link access device after receiving a proprietary information request message sent by the multi-link terminal.

[0032] According to another aspect of an embodiment of the present application, a roaming system for a wireless local area network is further provided, the system including a multi-link terminal, a first multi-link access device and a second multi-link access device, wherein:

[0033] The multi-link terminal is configured to send a connection request message to the first multi-link access device;

[0034] The first multi-link access device is configured to send a connection response message to the multi-link terminal, where the connection response message indicates that the connection is successfully established;

[0035] The first multi-link access device is further configured to send a roaming access point information element, where the roaming access point information element includes access point information of each neighboring access point that can support roaming;

[0036] The multi-link terminal is further configured to determine a roaming target access point from the neighboring access points according to the roaming access point information element, and send a multi-link reconfiguration request including an identifier of the roaming target access point to the first multi-link access device;

[0037] The first multi-link access device is further configured to send a roaming preparation request message to a second multi-link access device to which a roaming target access point belongs according to the multi-link reconfiguration request, where the roaming preparation request message includes a BA parameter;

[0038] The second multi-link access device where the roaming target access point is located is configured to return a roaming preparation response message to the first multi-link access device, where the roaming preparation response message includes a status parameter;

[0039] The first multi-link access device is further configured to maintain the BA parameter settings in the original BA protocol with the multi-link terminal according to the state parameter, send a BA parameter update request message to the multi-link terminal, or send a BA protocol termination message to the multi-link terminal;

[0040] The multi-link terminal is further configured to perform data transmission with the roaming target access point based on the BA parameter settings in the original BA protocol and the changed BA parameter settings, or terminate the BA protocol established with the first multi-link access device.

[0041] In an embodiment of the present application, a message including a roaming access point information element is sent, a multilink reconfiguration request message sent by a multilink terminal is received, a roaming preparation request message is sent to a second multilink access device to which a roaming target access point belongs, a roaming preparation response message is received, and based on a status parameter in the roaming preparation response message, the BA parameter settings in the original BA protocol are maintained with the multilink terminal or a BA parameter update request message is sent to the multilink terminal, so that the multilink terminal can perform data transmission with the roaming target access point based on the BA parameter settings in the original BA protocol or the modified BA parameter settings. This allows the multilink terminal to roam from one access point to another access point for data transmission without having to re-negotiate the BA with the new access point, thereby reducing data transmission delays caused by signaling interaction and completing roaming handover more smoothly. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] FIG1 is a flow chart of a roaming method for a wireless local area network provided according to an embodiment of the present application. DETAILED DESCRIPTION

[0043] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the embodiments described are only a part of the embodiments of the present invention, rather than all the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Although the disclosure in the present invention is introduced according to one or more exemplary examples, it should be understood that each aspect of these disclosures can also constitute a complete technical solution independently. In the absence of conflict, the features in the following embodiments and embodiments can be combined with each other.

[0044] To facilitate a clear description of the technical solutions of the embodiments of the present invention, in the embodiments of the present invention, the words "first" and "second" are used to distinguish between identical or similar items with substantially the same functions and effects. Those skilled in the art will understand that the words "first" and "second" do not limit the quantity or order of execution. They are merely used to illustrate and distinguish the objects being described. They do not have any order, do not represent any specific limitation on the number of devices or messages in the embodiments of the present invention, and do not constitute any limitation on the embodiments of the present invention. The term "comprising" is used to indicate the presence of the features subsequently claimed, but does not preclude the addition of other features.

[0045] Example 1

[0046] An embodiment of the present application provides a roaming system for a wireless local area network, the system including a multi-link terminal, a first multi-link access device, and a second multi-link access device. The multi-link terminal may include multiple logical terminals, each logical terminal operating on a different communication link. The first multi-link access device and the second multi-link access device each include multiple logical access points, each logical access point operating on a different communication link.

[0047] in:

[0048] The multi-link terminal is configured to send a connection request message to the first multi-link access device;

[0049] The first multi-link access device is configured to send a connection response message to the multi-link terminal, where the connection response message indicates that the connection is successfully established;

[0050] The first multi-link access device is further configured to send a roaming access point information element, where the roaming access point information element includes access point information of each neighboring access point that can support roaming;

[0051] The multi-link terminal is further configured to determine a roaming target access point from each neighboring access point according to the roaming access point information element, and send a multi-link reconfiguration request including an identifier of the roaming target access point to the first multi-link access device;

[0052] The first multi-link access device is further configured to send a roaming preparation request message to a second multi-link access device to which a roaming target access point belongs according to the multi-link reconfiguration request, where the roaming preparation request message includes a BA parameter;

[0053] The second multi-link access device where the roaming target access point is located is configured to return a roaming preparation response message to the first multi-link access device, where the roaming preparation response message includes a status parameter;

[0054] The first multi-link access device is further configured to maintain BA parameter settings in the original BA protocol with the multi-link terminal based on the state parameter, or send a BA parameter update request message to the multi-link terminal to instruct the multi-link terminal to change the BA parameters, or send a terminate BA protocol message to the multi-link terminal so that the multi-link terminal terminates the BA protocol;

[0055] The multi-link terminal is further configured to perform data transmission with the roaming target access point based on the BA parameter settings in the original BA protocol and the changed BA parameter settings, or terminate the BA protocol established with the first multi-link access device.

[0056] Example 2

[0057] Applied to the above-mentioned roaming system, referring to FIG1 , the present application proposes a roaming method for a wireless local area network. The method can be performed by a first multi-link access device. It should be noted that the steps shown in the flowchart of the accompanying figure can be executed in a computer system such as a set of computer-executable instructions. Moreover, although a logical order is shown in the flowchart, in some cases, the steps shown or described can be performed in a different order than here. The method includes:

[0058] S10: Send a message including a roaming access point information element, where the roaming access point information element includes information of adjacent access points that can support roaming, so that the multi-link terminal device can determine a roaming target access point according to the roaming access point information element.

[0059] In which, the first multi-link access device establishes a connection with the multi-link terminal on any link, and the first multi-link access device sends a roaming access point information element. The roaming access point information element can be a new parameter added to the neighboring area information element to indicate that the adjacent access point can support roaming, or it can be an independent information element dedicated to indicating information of the roaming access point.

[0060] The roaming access point information element includes information about adjacent access points that support roaming. Each access point information includes the AP ID of the corresponding access point. The AP ID is used by a multi-link terminal to uniquely identify an access point. It can be an independent identifier of an access point, such as the access point number, BSSID, MAC address, etc., or the link identifier Link ID of the link where the AP operates. It can also be a set of identifiers, such as (MLD ID, Link ID). The MLD ID is used to identify a multi-link device.

[0061] As a feasible approach, the message including the roaming access point information element may be a connection response message sent by the first multi-link access device to the multi-link terminal. In this case, the multi-link terminal sends a connection request message to the first multi-link access device, and the first multi-link access device includes the roaming access point information element in a connection response message and sends it to the multi-link terminal. The connection response message indicates that the connection is successfully established.

[0062] As another feasible embodiment, the message including the roaming access point information element may be a broadcast message sent by the first multi-link access device. In this case, the first multi-link access device may include the roaming access point information element in the broadcast message. After the multi-link terminal reads the broadcast message, it may obtain the roaming access point information element therefrom.

[0063] As another feasible embodiment, the message including the roaming access point information element may be a response message returned by the first multi-link access device after receiving a dedicated information request message sent by the multi-link terminal. In this case, after the first multi-link access device and the multi-link terminal establish a connection, the multi-link terminal may send a dedicated information request message, such as a roaming request message or a multi-link detection request message, to the first multi-link access device. The first multi-link access device then adds the roaming access point information element to the response message and returns it to the multi-link terminal.

[0064] When a multi-link terminal moves and needs to roam to an access point covering the new location, or when the service quality of the currently connected access point is poor and the terminal needs to roam to an access point that provides higher service quality, the multi-link terminal measures other access points (i.e., the adjacent access points that support roaming indicated in the roaming access point information element) and selects a roaming target access point based on the measured signal strength or load status of the access points. For example, the access point with the strongest signal strength or the lowest load is selected as the roaming target access point.

[0065] S11: Receive a multi-link reconfiguration request message sent by a multi-link terminal, where the multi-link reconfiguration request message includes an identifier of a roaming target access point.

[0066] S12: Send a roaming preparation request message to the second multi-link access device to which the roaming target access point belongs. The roaming preparation request message includes BA parameters, which are parameters of the BA protocol established between the first multi-link access device and the multi-link terminal.

[0067] As a feasible approach, the multi-link reconfiguration request includes a first reconfiguration information element, which includes the following parameters: reconfiguration type, access point identifier AP ID, and multi-link device identifier MLD ID. The value of AP ID is set to correspond to the roaming target access point; the value of Reconfiguration type is set to a first preset value (such as add), indicating a request to add a new link; the value of MLD ID is set to uniquely identify the second multi-link access device.

[0068] The value of the AP ID in the first reconfiguration information element may be, for example, the number, BSSID, MAC address, etc. of the roaming target access point, or the link ID of the link on which the roaming target access point operates. It may also be a set of identifiers, such as (MLD ID, Link ID), where the value of the MLD ID is set to uniquely identify the multi-link device (i.e., the second multi-link access device) to which the roaming target access point belongs.

[0069] As a feasible approach, step S12 includes:

[0070] The first reconfiguration information element is obtained from the multi-link reconfiguration request. If it is determined based on the value of the MLD ID in the first reconfiguration information element that the link requested to be newly added and the first multi-link access device do not belong to the same device, a roaming preparation request message is sent to the multi-link access device corresponding to the value of the MLD ID.

[0071] As another feasible way, when there are no idle links in the multi-link terminal (that is, all links have been connected to other devices), if you want to switch to a connection with a roaming target access point, you need to disconnect a connected link. In order to deal with this situation, in addition to the first reconfiguration information element, the above-mentioned multi-link reconfiguration request may also include a second reconfiguration information element. The second reconfiguration information element includes the following parameters: reconfiguration type, access point identifier AP ID, and multi-link device identifier MLD ID. The value of AP ID is set to correspond to the target access point. The target access point can be a logical access point operated by the first multi-link access device on the target communication link; the value of Reconfiguration type is set to a second preset value (such as delete), indicating a request to delete the link. In the second reconfiguration information element, in addition to being set to the identifier of the corresponding multi-link device, the MLD ID can also be set to other values ​​(such as 0), indicating the multi-link device currently connected to the multi-link terminal. Among them, the target communication link corresponds to the communication link operated by the target roaming access point in the second multi-link access device. Assume that both the first multi-link access device and the second multi-link access device include two logical access points that can operate on two links, namely Link 1 and Link 2. Between the first multi-link access device and the second multi-link access device, Link 1 corresponds to Link 1, and Link 2 corresponds to Link 2. Therefore, when the target roaming access point is the logical access point operated by the second multi-link access device on Link 2, the target access point is the logical access point operated by the first multi-link access device on Link 2.

[0072] S13: Receive a roaming preparation response message sent by the second multi-link access device, where the roaming preparation response message includes a status parameter.

[0073] S14: Maintaining the BA parameter settings in the original BA protocol with the multi-link terminal according to the state parameters, or sending a BA parameter update request message to the multi-link terminal to instruct the multi-link terminal to change the BA parameters so that the multi-link terminal can perform data transmission with the roaming target access point based on the BA parameter settings in the original BA protocol or the changed BA parameter settings; or sending a terminate BA protocol message to the multi-link terminal so that the multi-link terminal can terminate the BA protocol.

[0074] As a feasible approach, the roaming preparation request message includes BA parameters, indicating the parameters of the BA protocol that need to be continued during roaming. The BA parameters include TID (service identifier of the data packet), buffer size (buffer data size corresponding to the TID), start sequence number (start sequence number of the data packet), BA timeout timer duration, etc.

[0075] As another feasible approach, the Roaming Preparation Request message may further include a Negotiation parameter, which indicates whether BA parameters need to be negotiated. If the parameter is set to a first threshold (e.g., 1), it indicates that the message recipient can provide different BA parameters; if the parameter is set to a second threshold (e.g., 0), it indicates that different BA parameters provided by the message recipient are not accepted.

[0076] Alternatively, when the first multi-link access device is the initiator of the BA protocol established with the multi-link terminal, the Negotiation value is set to the first threshold; when the first multi-link access device is the responder of the BA protocol, the Negotiation value is set to the second threshold.

[0077] When the Roaming Preparation Request message does not include the Negotiation parameter, it indicates that different BA parameters provided by the message recipient are not accepted.

[0078] After receiving the roaming preparation request message, the second multi-link access device may perform a response operation in one of the following ways:

[0079] 1) If the parameters of the BA protocol that need to be continued during roaming are accepted, a roaming preparation response message is sent to the first multi-link access device, where the message includes a status parameter indicating acceptance;

[0080] 2) If the BA protocol parameters that need to be continued during roaming are not accepted, a roaming preparation response message is sent to the first multi-link access device, where the message includes a status parameter indicating rejection;

[0081] 3) If the parameters of the BA protocol that needs to be continued during roaming are not accepted, the roaming request message includes a Negotiation parameter, and the parameter value is a first threshold, sending a roaming preparation response message to the first multi-link access device, the message including a status parameter indicating rejection and recommended BA parameters;

[0082] 4) If the parameters of the BA protocol that need to be continued during roaming are not accepted, the roaming request message includes the parameter Negotiation, and the parameter value is the second threshold, then a roaming preparation response message is sent to the first multi-link access device, and the message includes a status parameter indicating rejection.

[0083] After the first multi-link access device receives the roaming preparation response message including the status parameter, there are the following processing methods:

[0084] 1. If the status parameter indicates that the second multi-link access device accepts the BA parameters in the roaming preparation request message, the BA parameter settings in the original BA protocol are maintained with the multi-link terminal. If the multi-link terminal does not receive instructions related to BA parameter update, it will also transmit data with the roaming target access point based on the BA parameter settings in the original BA protocol by default.

[0085] 2. If the status parameters indicate that the second multi-link access device recommends changing the BA parameters, the recommended BA parameters are obtained. If the first multi-link access device accepts the recommended BA parameters, a BA parameter update request message is sent to the multi-link terminal, instructing the multi-link terminal to update the BA parameters to the recommended BA parameters. If the multi-link terminal accepts the change, both parties use the new BA parameters, and the multi-link terminal performs data transmission with the roaming target access point based on the changed BA parameter settings. If the multi-link terminal refuses the change, a BA protocol termination message is sent to the first multi-link access device to terminate the BA protocol established with the first multi-link access device. After roaming is completed, a new BA protocol is negotiated with the second multi-link access device.

[0086] Alternatively, if the first multi-link access device does not accept the recommended BA parameters, the first multi-link access device sends a terminate BA protocol message to the multi-link terminal. When the multi-link terminal receives the terminate BA protocol message, it terminates the BA protocol established with the first multi-link access device and negotiates with the second multi-link access device to establish a new BA protocol after roaming is completed.

[0087] Alternatively, as a feasible approach, after the first multi-link access device accepts the recommended BA parameters, it can further determine whether the first multi-link access device is the initiator of the original BA protocol. If the first multi-link access device is the initiator of the original BA protocol and accepts the recommended BA parameters, it sends a BA parameter update request message to the multi-link terminal, instructing the multi-link terminal to update the BA parameters to the recommended BA parameters. If the first multi-link access device is not the initiator of the BA protocol, the first multi-link access device sends a terminate BA protocol message to the multi-link terminal. Upon receiving the terminate BA protocol message, the multi-link terminal terminates the BA protocol established with the first multi-link access device and negotiates with the second multi-link access device to establish a new BA protocol after roaming is completed.

[0088] 3. If the status parameter indicates that the second multi-link access device does not accept the BA parameter in the roaming preparation request message, a terminate BA protocol message is sent to the multi-link terminal.

[0089] When a multi-link terminal roams from one access point to another access point and needs to transmit data, the roaming method proposed in the embodiment of the present application does not require the multi-link terminal to re-negotiate the BA with the new access point, thereby reducing the data transmission delay caused by signaling interaction and enabling the multi-link terminal to complete roaming switching more smoothly.

[0090] Example 3

[0091] Another wireless local area network roaming method proposed in this application, based on steps S10 to S14 included in embodiment 2, further includes step S15: sending data packet reception status information to the second multi-link access device, so that the second multi-link access device generates BA data packet reception status information based on the data packet reception status information sent by the first multi-link access device and its own data packet reception status information, and sends a BA message to the multi-link terminal, the BA message including the BA data packet reception status information. The data packet reception status information indicates which data packets have been successfully received by the corresponding receiver.

[0092] For example, assume that a multi-link terminal establishes a connection with a first multi-link access device on a first link and a connection with a second multi-link access device on a second link. The multi-link terminal sends data to the first multi-link access device on the first link and to the second multi-link access device on the second link. The service type of the transmitted data is identified by the parameter TID in the previous step. After receiving the data, the first multi-link access device and the second multi-link access device each maintain a scoreboard to track which data packets have been successfully received. Subsequently, the first multi-link access device can directly use the scoreboard as BA packet reception status information, or generate BA packet reception status information based on the scoreboard and send the data packet reception status information to the second multi-link access device. The second multi-link access device combines the data packet reception status information sent by the first multi-link access device and its own data packet reception status information to form a BA packet reception status information indicating which data packets have been successfully received by the first and second multi-link access devices. Furthermore, the second multi-link access device sends a BA message containing the BA packet reception status information to the STA MLD. After receiving the BA message, the multi-link terminal deletes the successfully transmitted data packets based on the BA packet reception status information.

[0093] Alternatively, based on steps S10 to S14 included in Example 2, step S16 is further included: receiving data packet reception status information sent by the second multi-link access device; generating BA data packet reception status information based on the data packet reception status information sent by the second multi-link access device and its own data packet reception status information, and sending a BA message to the multi-link terminal, wherein the BA message includes the BA data packet reception status information.

[0094] For example, assume that a multi-link terminal establishes a connection with a first multi-link access device on a first link and a connection with a second multi-link access device on a second link. The multi-link terminal sends data to the first multi-link access device on the first link and to the second multi-link access device on the second link. The service type of the transmitted data is identified by the parameter TID in the previous step. After receiving the data, the first and second multi-link access devices each maintain a scoreboard to track which data packets have been successfully received. Subsequently, the second multi-link access device can directly use the scoreboard as BA packet reception status information, or generate BA packet reception status information based on the scoreboard and send the data packet reception status information to the first multi-link access device. The first multi-link access device combines the data packet reception status information sent by the second multi-link access device and its own data packet reception status information to form a BA packet reception status information indicating which data packets have been successfully received by the first and second multi-link access devices. Furthermore, the first multi-link access device sends a BA message containing the BA packet reception status information to the STA MLD. After receiving the BA message, the multi-link terminal deletes the successfully transmitted data packets based on the BA packet reception status information.

[0095] As another feasible approach, if the multi-link terminal only sends data to the second multi-link access device or the first multi-link access device, the data receiving device, the second multi-link access device or the first multi-link access device, can directly add its own data packet reception status information as BA data packet reception status information in a BA message and send it to the STA MLD. After receiving the BA message, the multi-link terminal deletes the successfully sent data packets based on the BA data packet reception status information. Alternatively, the multi-link terminal can forward the data packets to another multi-link access device, which then forwards the data packets to the multi-link terminal.

[0096] Example 4

[0097] Another wireless local area network roaming method proposed in this application, based on steps S10 to S14 included in embodiment 2, further includes:

[0098] Step S17: receiving BA data packet reception status information generated according to the received data packets sent by the multi-link terminal.

[0099] Step S18: Sending the BA packet reception status information to the second multi-link access device, so that the first multi-link access device and / or the second multi-link access device can delete the successfully sent data packets based on the BA packet reception status information. The BA packet reception status information indicates which data packets the multi-link terminal has successfully received.

[0100] Exemplarily, assuming that the multi-link terminal establishes a connection with a first multi-link access device on a first link and establishes a connection with a second multi-link access device on a second link, the multi-link terminal receives data sent by the first multi-link access device on the first link and / or receives data sent by the second multi-link access device on the second link.

[0101] As a feasible method, the multi-link terminal generates BA data packet reception status information based on the received data packet, and sends a BA message to the first multi-link access device, where the BA message includes the BA data packet reception status information; the first multi-link access device sends the BA data packet reception status information to the second multi-link access device; the first multi-link access device and / or the second multi-link access device deletes the successfully sent data packet based on the BA data packet reception status information.

[0102] Alternatively, as another feasible method, the multi-link terminal sends a BA message to the second multi-link access device, where the BA message includes BA data packet reception status information; the second multi-link access device sends the BA data packet reception status information to the first multi-link access device; the first multi-link access device and / or the second multi-link access device deletes the successfully sent data packets based on the BA data packet reception status information.

[0103] To better understand the roaming method proposed in this application, the following further illustrates the roaming method proposed in this application, assuming that the first multi-link access device, the second multi-link access device, and the multi-link terminal are represented as AP MLD1, AP MLD2, and STA MLD1, respectively. It is assumed that STA MLD1 and AP MLD1 establish a connection on link Link1. The method steps include:

[0104] Step 1: STA MLD1 obtains the roaming access point information element.

[0105] Step 2: STA MLD1 determines the roaming target access point; assume it is the logical access point operated by AP MLD2 on link Link2.

[0106] Step 3: STA MLD1 sends a link reconfiguration request message (or a roaming request message, or other control message, which will be described below using the link reconfiguration request message as an example) to AP MLD1. The link reconfiguration request message includes the first reconfiguration information element, which includes:

[0107] In addition to the first reconfiguration information element, the link reconfiguration request message may also include a second reconfiguration information element. The second reconfiguration information element includes:

[0108] Step 4: After receiving the multi-link reconfiguration request message, if it contains the corresponding information with the Reconfiguration type value of add, AP MLD1 determines whether the newly added link requested by the multi-link terminal belongs to the same device as AP MLD1 based on the MLD ID information. If not, it sends a roaming preparation request message to the access device AP MLD2 corresponding to the MLD ID.

[0109] The roaming preparation request message contains:

[0110] BA parameters: Indicates the parameters of the BA protocol that need to be continued during roaming, including TID (service identifier of the data packet), buffer size (buffer size corresponding to the TID), start sequence number (start sequence number of the data packet), BA timeout timer duration, etc.

[0111] Negotiation: Indicates whether BA parameters need to be negotiated. If set to 1 (i.e., the first threshold is set to 1), the message recipient can provide different BA parameters. If set to 0 (i.e., the second threshold is set to 0), different BA parameters provided by the message recipient are not accepted. When AP MLD1 is the initiator of the BA protocol established with STA MLD1, this value is set to 1, and when AP MLD1 is the responder of the BA protocol, this value is set to 0. The Negotiation parameter can also be omitted. If not included, it indicates that different parameters provided by the message recipient are not accepted.

[0112] Step 5: After receiving the request message, AP MLD2 responds in one of the following ways:

[0113] 1) If the BA protocol parameters that need to be continued during roaming are accepted (i.e., the BA parameters in the Roaming Preparation Request message are accepted), a Roaming Preparation Response message is sent to AP MLD1, indicating acceptance.

[0114] 2) If the BA protocol parameters that need to be continued during roaming are not accepted, a roaming preparation response message is sent to AP MLD1, indicating rejection;

[0115] 3) If the BA protocol parameters that need to be continued during roaming are not accepted, the Roaming Request message contains the parameter Negotiation with a value of 1. Then, a Roaming Preparation Response message is sent to AP MLD1, which contains the recommended BA parameters, indicating that the BA parameters are recommended to be changed.

[0116] 4) If the BA protocol parameters required for roaming continuation are not accepted, the Roaming Request message contains the parameter Negotiation with a value of 0. Then, a Roaming Preparation Response message is sent to AP MLD1, indicating rejection.

[0117] Step 6: After receiving the roaming response message, AP1 performs a response operation in one of the following ways:

[0118] 1) If the indication is accepted, AP MLD1 and STA maintain the parameter settings in the original BA protocol;

[0119] 2) If the indication is rejection, AP MLD1 sends a DELBA message (i.e., BA protocol termination message) to STA MLD1, instructing STA MLD1 to terminate the BA protocol;

[0120] 3) If the message contains recommended BA parameters (i.e., indicates that it is recommended to change the BA parameters), perform one of the following operations:

[0121] A) If AP MLD1 accepts the new parameters, it sends an ADDBA request message (i.e., a BA parameter update request message) to STA MLD1, instructing it to change the BA parameters.

[0122] B) Based on method A), it can be further specified that if AP MLD1 is the initiator of the BA protocol and AP MLD1 accepts the new parameters, AP MLD1 sends an ADDBA request message to STA MLD1 to instruct it to change the BA parameters;

[0123] C) After executing method A) or method B), if STA MLD1 accepts the change, both parties use the new parameters. If STA MLD1 rejects the change, a DELBA message is sent to AP MLD1.

[0124] D) If AP MLD1 is not the initiator of the BA protocol, or AP MLD2 provides acceptable parameters but AP MLD1 does not accept the new parameters, AP MLD1 sends a DELBA message to STA MLD1.

[0125] Step 7: If STA MLD1 receives the DELBA message, it terminates the BA agreement established with AP MLD1 and negotiates with AP MLD2 to establish a new BA agreement after roaming is completed.

[0126] The above is only a preferred embodiment of the present application. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present application. These improvements and modifications should also be regarded as the scope of protection of the present application.

Claims

1. A roaming method for a wireless local area network, characterized in that: The method is applied to a first multi-link access device, and the method includes: Sending a message including a roaming access point information element, wherein the roaming access point information element includes information of adjacent access points that can support roaming, so that the multi-link terminal device determines a roaming target access point according to the roaming access point information element; receiving a multi-link reconfiguration request message sent by a multi-link terminal, where the multi-link reconfiguration request message includes an identifier of the roaming target access point; Sending a roaming preparation request message to a second multi-link access device to which the roaming target access point belongs, where the roaming preparation request message includes a BA parameter; receiving a roaming preparation response message sent by the second multi-link access device, where the roaming preparation response message includes a state parameter; According to the state parameters, the BA parameter settings in the original BA protocol are maintained with the multi-link terminal or a BA parameter update request message is sent to the multi-link terminal, so that the multi-link terminal transmits data with the roaming target access point based on the BA parameter settings in the original BA protocol or the changed BA parameter settings; or, according to the state parameters, a BA protocol termination message is sent to the multi-link terminal, so that the multi-link terminal terminates the BA protocol.

2. The method according to claim 1, characterized in that The multi-link reconfiguration request includes a first reconfiguration information element, which includes the following parameters: a reconfiguration type, an access point identifier AP ID, and a multi-link device identifier MLD ID, wherein the value of the AP ID is set to correspond to the roaming target access point; the value of the Reconfiguration type is set to a first preset value, indicating a request to add a new link; the value of the MLD ID is set to identify the second multi-link access device; The sending a roaming preparation request message to the second multi-link access device to which the roaming target access point belongs includes: Acquire the first reconfiguration information element from a multilink reconfiguration request; If it is determined according to the value of the MLD ID in the first reconfiguration information element that the link requested to be added and the first multi-link access device do not belong to the same device, a roaming preparation request message is sent to the multi-link access device corresponding to the value of the MLD ID.

3. The method according to claim 1, characterized in that The maintaining the BA parameter setting in the original BA protocol with the multi-link terminal according to the state parameter comprises: If the state parameter indicates that the second multi-link access device accepts the BA parameter in the roaming preparation request message, the BA parameter setting in the original BA protocol is maintained with the multi-link terminal.

4. The method according to claim 1, characterized in that The sending a BA parameter update request message to the multi-link terminal according to the state parameter to instruct the multi-link terminal to change the BA parameter includes: If the state parameter indicates that the second multi-link access device recommends changing the BA parameter, acquiring the recommended BA parameter; If the recommended BA parameters are accepted, a BA parameter update request message is sent to the multi-link terminal to instruct the multi-link terminal to update the BA parameters to the recommended BA parameters.

5. The method according to claim 1, characterized in that The sending a BA protocol termination message to the multi-link terminal according to the state parameter so that the multi-link terminal terminates the BA protocol includes: If the state parameter indicates that the second multi-link access device recommends changing the BA parameters, and the first multi-link access device does not accept the recommended BA parameters, sending a terminate BA protocol message to the multi-link terminal; or, If the state parameter indicates that the second multi-link access device does not accept the BA parameter in the roaming preparation request message, a terminate BA protocol message is sent to the multi-link terminal.

6. The method according to claim 4, characterized in that If the recommended BA parameters are accepted, sending a BA parameter update request message to the multi-link terminal to instruct the multi-link terminal to update the BA parameters to the recommended BA parameters, comprising: If the first multi-link access device is the initiator of the original BA protocol and accepts the proposed BA parameters, a BA parameter update request message is sent to the multi-link terminal, instructing the multi-link terminal to update the BA parameters to the recommended BA parameters.

7. The method according to claim 1, characterized in that The method further comprises: Sending data packet reception status information to the second multi-link access device, so that the second multi-link access device generates BA data packet reception status information according to the data packet reception status information sent by the first multi-link access device and its own data packet reception status information, and sends a BA message to the multi-link terminal, wherein the BA message includes the BA data packet reception status information; Alternatively, receiving data packet reception status information sent by a second multi-link access device; generating BA data packet reception status information according to the data packet reception status information sent by the second multi-link access device and its own data packet reception status information, and sending a BA message to the multi-link terminal, wherein the BA message includes the BA data packet reception status information.

8. The method according to claim 1, characterized in that The method further comprises: receiving BA data packet receiving state information generated according to received data packets and sent by the multi-link terminal; The BA data packet reception status information is sent to the second multi-link access device, so that the first multi-link access device and / or the second multi-link access device deletes the successfully sent data packet according to the BA data packet reception status information.

9. The method according to claim 1, characterized in that The message containing the roaming access point information element is: a connection response message sent by the first multi-link access device to the multi-link terminal, a broadcast message sent by the first multi-link access device, or a response message returned by the first multi-link access device after receiving a proprietary information request message sent by the multi-link terminal.

10. A roaming system for a wireless local area network, the system comprising a multi-link terminal, a first multi-link access device and a second multi-link access device, wherein: The multi-link terminal is used to send a connection request message to the first multi-link access device; The first multi-link access device is used to send a connection response message to the multi-link terminal, wherein the connection response message indicates that the connection is successfully established; The first multi-link access device is further configured to send a roaming access point information element, wherein the roaming access point information element includes access point information of each neighboring access point that can support roaming; The multi-link terminal is further configured to determine a roaming target access point from the neighboring access points according to the roaming access point information element, and send a multi-link reconfiguration request including an identifier of the roaming target access point to the first multi-link access device; The first multi-link access device is further configured to send a roaming preparation request message to a second multi-link access device to which a roaming target access point belongs according to the multi-link reconfiguration request, wherein the roaming preparation request message includes a BA parameter; The second multi-link access device where the roaming target access point is located is used to return a roaming preparation response message to the first multi-link access device, where the roaming preparation response message includes a state parameter; The first multi-link access device is further configured to maintain the BA parameter settings in the original BA protocol with the multi-link terminal according to the state parameter, send a BA parameter update request message to the multi-link terminal, or send a BA protocol termination message to the multi-link terminal; The multi-link terminal is further configured to perform data transmission with the roaming target access point based on the BA parameter settings in the original BA protocol and the changed BA parameter settings, or terminate the BA protocol established with the first multi-link access device.

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