A seamless roaming method and system

Abstract

This application relates to the field of wireless networks and discloses a seamless roaming method and system. The seamless roaming method includes: a terminal sending a seamless roaming request to a target access point device (APD); after receiving a response to the seamless roaming request from the target APD; establishing a connection with the target APD; sending a seamless roaming confirmation frame to the terminal's original access point device (OAP); and disconnecting from the OAP after receiving a response to the OAP's seamless roaming confirmation frame. This application enables a terminal to switch from its OAP to the target AP while maintaining at least a partial connection with the OAP during the switch, only disconnecting after the switch. This reduces the number of steps required for switching access points and minimizes packet loss during the switch.

Description

Technical Field

[0001] This application relates to the field of wireless networks, and in particular to a seamless roaming method and system. Background Technology

[0002] Wireless Fidelity (WiFi) systems are a type of wireless network implementation that uses wireless hotspots. When a terminal uses a wireless network, the wireless hotspot converts the network signal into a Wi-Fi signal and then broadcasts it into the air for the terminal to connect to.

[0003] Wireless hotspots exist within a certain area, and when a terminal moves, the access point of the wireless hotspot may switch. In existing technologies, when a terminal switches access points, it first disconnects from the current access point and then establishes a connection with the target access point. After the terminal completes authentication and association and establishes a connection with the target access point, the terminal and the target access point perform a four-way handshake to generate a key and begin transmitting encrypted data. Therefore, the existing disconnect-then-reconnect switching method involves many steps and is prone to packet loss. Summary of the Invention

[0004] The purpose of this application is to provide a seamless roaming method and system that can reduce the number of steps a terminal takes when switching access points and reduce packet loss.

[0005] To address the aforementioned technical problems, embodiments of this application provide a seamless roaming method applied to a terminal, the method comprising:

[0006] Send a seamless roaming request to the target access point device, and establish a connection with the target access point device after receiving the response to the seamless roaming request transmitted by the target access point device;

[0007] Send a seamless roaming confirmation frame to the original access point device of the terminal, and disconnect from the original access point device after receiving the response of the seamless roaming confirmation frame transmitted by the original access point device.

[0008] Embodiments of this application also provide a seamless roaming method, wherein before sending a seamless roaming request to the target access point device, the method further includes:

[0009] Send a seamless roaming alternative target access point query frame to the original access point device;

[0010] Receive a seamless roaming suggestion frame from the original access point device in response to a seamless roaming candidate target access point query frame, wherein the seamless roaming suggestion frame contains at least the information of the target access point device;

[0011] The target access point device and the original access point device are located in the same seamless roaming domain.

[0012] Embodiments of this application also provide a seamless roaming method, wherein sending a seamless roaming request to a target access point device and establishing a connection with the target access point device after receiving a response to the seamless roaming request transmitted by the target access point device includes:

[0013] The original access point device sends the seamless roaming request to the target access point device, and receives the response to the seamless roaming request transmitted by the target access point device through the original access point device, thereby establishing a connection with the target access point device.

[0014] Embodiments of this application also provide a seamless roaming method, wherein sending a seamless roaming request to a target access point device and establishing a connection with the target access point device after receiving a response to the seamless roaming request transmitted by the target access point device includes:

[0015] Send a request to the original access point device that includes changing the number of connections supported by the terminal.

[0016] If, after sending a seamless roaming related frame to the target access point device or after sending a seamless roaming related frame to the original access point, a response frame is received from the original access point device requesting a change in the number of connections supported by the terminal, seamless roaming with the target access point device is first completed according to the number of connections supported by the terminal before the change, and then the number of connections between the terminal and the target access point device is adjusted according to the number of connections supported by the terminal after the change.

[0017] If, before sending a seamless roaming-related frame to the target access point device or before sending a seamless roaming-related frame to the original access point, a response frame for the request to change the number of connections supported by the terminal is received from the original access point device, seamless roaming is initiated and completed with the target access point device according to the changed number of connections supported by the terminal.

[0018] Embodiments of this application also provide a seamless roaming method, wherein sending a seamless roaming request to a target access point device and establishing a connection with the target access point device after receiving a response to the seamless roaming request transmitted by the target access point device includes:

[0019] If, after sending a seamless roaming-related frame to the target access point device, or after sending a seamless roaming-related frame to the original access point, the latest multi-connection information is received from the original access point device, seamless roaming with the target access point device is first completed according to the number of connections maintained by the terminal before receiving the latest multi-connection information, and then the connection between the terminal and the target access point device is adjusted according to the latest multi-connection information.

[0020] If the terminal receives the latest multi-connection information from the original access point device before sending the seamless roaming related frame to the target access point device or before sending the seamless roaming related frame to the original access point device, the terminal initiates and completes seamless roaming with the target access point device according to the latest multi-connection information and the changed number of connections of the original access point device.

[0021] The multi-connection information refers to a basic multi-connection element, a reconfigured multi-connection element, or a TTLM element.

[0022] Embodiments of this application also provide a seamless roaming method, wherein sending a seamless roaming request to a target access point device and establishing a connection with the target access point device after receiving a response to the seamless roaming request transmitted by the target access point device includes:

[0023] If the latest multi-connection information broadcast by the target access point device is received after a preset time point, seamless roaming with the target access point device is first completed according to the number of connections maintained by the terminal before the target access point device received the latest multi-connection information. Then, the connection between the terminal and the target access point device is adjusted according to the latest multi-connection information.

[0024] If the latest multi-connection information broadcast by the target access point device is received before the preset time point, the terminal initiates and completes seamless roaming with the target access point device according to the latest multi-connection information and the changed number of connections of the target access point device.

[0025] Wherein, the multi-connection information is a basic multi-connection element, or a reconfigured multi-connection element, or a TTLM element;

[0026] The preset time point is any time point after the terminal sends a seamless roaming related frame to the original access point device or the target access point device, and before the terminal establishes a connection with the target access point device; or, the preset time point is pre-configured according to the terminal's capabilities.

[0027] Embodiments of this application also provide a seamless roaming method applied to the original access device, the method comprising:

[0028] The receiver sends a seamless roaming confirmation frame to the terminal, sends a response to the seamless roaming confirmation frame to the terminal, and disconnects from the terminal.

[0029] Embodiments of this application also provide a seamless roaming method, the method further comprising:

[0030] Send a seamless roaming request to the target access point device through a distributed system;

[0031] The response to the seamless roaming request sent by the target access point device is sent to the terminal.

[0032] Embodiments of this application also provide a seamless roaming method, wherein the original access device and the target access device constitute a seamless roaming domain, and the method further includes:

[0033] If the original access point device is the access point device group leader in the seamless roaming domain, or a MAC layer-high local device, it receives the access seamless roaming domain access request sent by the access point device to be accessed, and sends a response to the access seamless roaming domain access request to the access point device to be accessed.

[0034] Embodiments of this application also provide a seamless roaming system, the system comprising: a terminal, an original access point device connected to the terminal, and a target access point device; the terminal, the original access point device, and the target access point device all support seamless roaming;

[0035] The terminal is configured to send a seamless roaming request to the target access point device, and establish a connection with the target access point device after receiving a response to the seamless roaming request from the target access point device; the terminal is also configured to send a seamless roaming confirmation frame to the original access point device, and disconnect from the original access point device after receiving a response to the seamless roaming confirmation frame from the original access point device.

[0036] In this embodiment, the terminal sends a seamless roaming request to the target access point device, and after receiving the response to the seamless roaming request from the target access point device, establishes a connection with the target access point device, sends a seamless roaming confirmation frame to the terminal's original access point device, and disconnects from the original access point device after receiving the response to the seamless roaming confirmation frame from the original access point device. This application enables the terminal to switch from the original access point device to the target access point device, while maintaining at least a part of the connection with the original access point device during the switch, and disconnecting from the original access point device only after the switch. This reduces the steps required for the terminal to switch access points and reduces packet loss during the switch. Attached Figure Description

[0037] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, and these illustrative descriptions do not constitute a limitation on the embodiments.

[0038] Figure 1 This is a schematic diagram of the structure of the first seamless roaming system provided in the embodiments of this application;

[0039] Figure 2 This is a flowchart of the first seamless roaming method provided in the embodiments of this application;

[0040] Figure 3 This is a flowchart of the second seamless roaming method provided in the embodiments of this application;

[0041] Figure 4 This is a flowchart of the third seamless roaming method provided in the embodiments of this application;

[0042] Figure 5 This is a schematic diagram of the structure of the second seamless roaming system provided in the embodiments of this application;

[0043] Figure 6 This is a schematic diagram of the structure of the third seamless roaming system provided in the embodiments of this application;

[0044] Figure 7 This is a flowchart of the fourth seamless roaming method provided in the embodiments of this application;

[0045] Figure 8 This is a schematic diagram of the first seamless roaming time node provided in the embodiments of this application;

[0046] Figure 9 This is a schematic diagram of the second type of seamless roaming time node provided in the embodiments of this application;

[0047] Figure 10 This is a schematic diagram of the third seamless roaming time node provided in the embodiments of this application;

[0048] Figure 11 This is a flowchart of the fifth seamless roaming method provided in the embodiments of this application.

[0049] Figure 12 This is a schematic diagram of the terminal structure provided in the embodiments of this application;

[0050] Figure 13 This is a schematic diagram of the original access point device provided in the embodiments of this application. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the various embodiments of this application will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the various embodiments of this application to help readers better understand this application. However, the technical solutions claimed in this application can be implemented even without these technical details and various changes and modifications based on the following embodiments. The division of the various embodiments below is for the convenience of description and should not constitute any limitation on the specific implementation of this application. The various embodiments can be combined with and referenced by each other without contradiction.

[0052] To address the packet loss issues that often occur in existing technologies where terminals disconnect and then reconnect during access point switching, embodiments of this application relate to a seamless roaming system, such as... Figure 1 As shown, the seamless roaming system includes: a terminal, the original access point device connected to the terminal, and the target access device.

[0053] In one example implementation, the terminal communicates with the original access point device (IPN). Both the IPN and the target IPN share a common MAC upper layer, which can also be called the CommonMedia Access Control upper layer. Furthermore, the IPN and the target IPN can be multiple-connection IPNs. Establishing a common MAC upper layer between IPNs requires new signaling support.

[0054] The original access point device and the target access point device are also connected via a distributed system (DS), which is a wired network for communication between access point devices.

[0055] In one example implementation, the source access point device and the target access point device are either a regular access point device (AP) or a multi-connection access point device (AP MLD).

[0056] Seamless roaming of a terminal needs to occur within a range consisting of access point devices such as the original access point device and the target access point device. Specifically, each access point device has its own communication range. The communication ranges of multiple access point devices with the same MAC layer constitute a seamless roaming domain, and seamless roaming of the terminal can occur within this seamless roaming domain.

[0057] For a terminal to perform seamless roaming, both the terminal and the access point device must support it simultaneously. Therefore, in this embodiment, the terminal, the original access point device, and the target access point device all support seamless roaming. Supporting seamless roaming is a capability of either the access point device or the terminal. The identifiers indicating whether the terminal or the access point device supports seamless roaming can be included in the MIB (Management Information Base), and / or in the TxVector (parameters contained in the transmitted frame), and / or in the RxVector (parameters contained in the received frame), and / or in the management frame, and / or in the negotiation frame, and / or in the authentication request frame, and / or in the authentication response frame, and / or in the (re)association request frame, and / or in the (re)association response frame, and / or in the beacon frame, and / or in the probe response frame. The MIB is located in the attributes of each terminal and access point device.

[0058] In one example implementation, an existing Mobility Domain Element (MDE) can be modified to carry a field or subfield that supports seamless roaming. Typically, a Mobility Domain Element exists if the parameter `dot11FastBSSTransitionActivated` is true. The modified Mobility Domain Element appears in the association request frame if the parameter `dot11SeamlessTransitionActivated` is true and if an association request frame is sent to an access point device that advertises its seamless roaming capability in its Fast Handover Element in its beacon or probe response frame.

[0059] In one example embodiment, additional subdomains can be set in the fast transition element to support seamless roaming capability. Specifically, the original MDE includes four parts: Element ID, Length, Mobility Domain ID (MDID), and Fast Transition Capability and Policy. The modified fast transition element may include five parts: Element ID, Length, Fast Transition Domain ID, Fast Transition Capability and Policy, and Seamless Roaming Capability and Policy. The Element ID is formatted as 1 octet, the Length is formatted as 1 octet, the Fast Transition Domain ID is formatted as 2 octets, the Fast Transition Capability and Policy is formatted as 1 octet, and the Seamless Roaming Capability and Policy is formatted as 1 octet.

[0060] In one example embodiment, a new seamless roaming domain element or seamless roaming element can be defined to indicate that a terminal or access point device supports seamless roaming capability. This new seamless roaming domain element or seamless roaming element may contain information to be exchanged, such as the seamless roaming domain. When the terminal first associates with the access point device, this element is published in beacons, probe request frames, and probe response frames, and the access point device has the parameter `dot11seamlesstransitionactivated` set to true. Specifically, the new seamless roaming domain element or seamless roaming element may include four parts: element identifier, length, identifier of the fast handover element, seamless roaming capability, and policy. The element identifier is formatted as one octet, the length as one octet, the identifier of the fast handover element as two octets, and the seamless roaming capability and policy as one octet.

[0061] Seamless roaming capabilities and policies can include four parts: whether seamless roaming over a distributed system (DS), resource request protocol capability, whether seamless roaming is supported, and reserved. The format for whether seamless roaming over a distributed system is 1 byte, the format for resource request protocol capability is 1 byte, the format for whether seamless roaming is supported is 1 byte, and the format for reserved is 5 bytes. A value of 1 for seamless roaming over a distributed system indicates seamless roaming initiated by the distributed system; a value of 0 indicates seamless roaming initiated by the terminal. A resource request protocol capability of 1 indicates that seamless roaming is supported during handover. A resource request protocol capability of 0 indicates that seamless roaming is not supported during handover. A value of 1 for whether seamless roaming is supported indicates that seamless roaming is supported; a value of 0 indicates that seamless roaming is not supported. In some cases, reserved includes at least one of the following: whether seamless roaming over a distributed system, resource request protocol capability, and whether seamless roaming is supported.

[0062] In one example embodiment, some fast roaming elements are identified as belonging to seamless roaming, while others belong to fast roaming. For instance, in a certain generation of WiFi devices, such as UHR (Ultra High Reliability) devices, fast roaming element identifiers exceeding binary 000000001111111 belong to the mobility domain of seamless roaming. Fast roaming element identifiers less than or equal to binary 000000001111111 belong to the fast roaming domain. In this embodiment, the value 000000001111111 is merely an example and may be other values, such as 0000000100000000, and is not specifically limited in this embodiment.

[0063] During the movement of the terminal, it can switch from the original access point device to the target access point device. Specifically, the terminal sends a seamless roaming request to the target access point device. After receiving the response to the seamless roaming request from the target access point device, it establishes a connection with the target access point device. After establishing a connection with the target access point device, it needs to disconnect from the original access point device. Therefore, the terminal also sends a seamless roaming confirmation frame to the original access point device. After receiving the response to the seamless roaming confirmation frame from the original access point device, it disconnects from the original access point device, thereby realizing seamless roaming of the terminal from the original access point device to the target access point device.

[0064] In one example implementation, due to different area requirements in different scenarios, it is necessary to further divide the original seamless roaming domain to determine the final seamless roaming area. In this embodiment, a new element called a Seamless Transition Element can be defined to divide the working area. This Seamless Transition Element can further divide the range consisting of multiple access point devices with the same MAC layer to determine the final seamless roaming area. The Seamless Transition Element carries context information, which includes at least one of the following: TTLM, terminal capability, packet number, and session number.

[0065] The seamless roaming system provided in this application embodiment enables the terminal to maintain at least a part of the connection with the original access point device during the seamless roaming connection between the terminal and the target access point. This can reduce the number of steps the terminal takes when switching access points and reduce the occurrence of packet loss when switching access points.

[0066] In the above Figure 1 Based on the existing seamless roaming system embodiments, this application provides a seamless roaming method, such as... Figure 2 As shown, the seamless roaming method specifically includes the following steps.

[0067] Step 101: Send a seamless roaming request to the target access point device, and after receiving the response to the seamless roaming request transmitted by the target access point device, establish a connection with the target access point device.

[0068] Seamless roaming can be initiated by the terminal. The terminal can obtain information about the target access point device through reduced neighbor report elements, beacons, or probe response frames.

[0069] In one example implementation, when a terminal wants to switch access point devices, it sends a probe request frame. All access point devices that receive the probe request frame will send back probe response frames. The terminal will select one of the access point devices from the multiple probe response frames as the target access point device based on signal strength, artificial intelligence algorithms, and other factors.

[0070] After identifying the target access point device, the terminal sends a seamless roaming request to it. Specifically, this seamless roaming request can be a seamless roaming request frame. Upon receiving the seamless roaming request, the target access point device returns a response. After receiving the response, the terminal establishes a connection with the target access point device, enabling seamless roaming handover and establishing communication between them.

[0071] Step 102: Send a seamless roaming confirmation frame to the original access point device of the terminal, and disconnect the connection with the original access point device after receiving the response of the seamless roaming confirmation frame transmitted by the original access point device.

[0072] After the terminal establishes a connection with the target access point device, since it has not yet completely disconnected from the original access point device, it needs to send a seamless roaming confirmation frame to the original access point device to inform it that the terminal needs to completely disconnect from it. Upon receiving the seamless roaming confirmation frame, the original access point device sends a response back to the terminal, informing it that it will actively disconnect after a preset time following the response, thus breaking the connection between the terminal and the original access point device. The preset time can be 5ms, etc., and is not specifically limited in this embodiment.

[0073] The seamless roaming confirmation frame can be a disassociation frame or other disconnection frames, and no specific restrictions are imposed in this application embodiment.

[0074] The seamless roaming method provided in this application involves a terminal sending a seamless roaming request to a target access point device (APD). After receiving a response to the seamless roaming request from the target APD, the terminal establishes a connection with the target APD, sends a seamless roaming confirmation frame to its original APD, and disconnects from the original APD after receiving a response to the same frame. This method enables the terminal to switch from its original APD to the target APD while maintaining at least a partial connection with the original APD during the switch, and disconnecting only after the switch is complete. This reduces the number of steps required for the terminal to switch access points and minimizes packet loss during the switch.

[0075] In the above Figure 2 Based on the aforementioned seamless roaming method embodiments, this application provides a seamless roaming method, such as... Figure 3 As shown, before step 101, that is, before sending a seamless roaming request to the target access point device, the following steps are also included.

[0076] Step 301: Send a seamless roaming alternative target access point query frame to the original access point device.

[0077] The terminal can determine the target access point device by probing request frames, or by using the suggestions of the original access point device.

[0078] When a terminal determines a target access point device based on the suggestion of the original access point device, it may optionally first query the original access point device, that is, send a seamless roaming alternative target access point query frame to the original access point device. This seamless roaming alternative target access point query frame is used to enable the original access point device to determine the access point device that the terminal can connect to based on multiple access point devices in the same seamless roaming domain.

[0079] Step 302: Receive a seamless roaming suggestion frame from the original access point device in response to the seamless roaming alternative target access point query frame.

[0080] In one example implementation, the seamless roaming proposal frame includes information about the target access point device. In this case, the original access point device assists the terminal in determining the target access point device, and the terminal can perform seamless roaming with the target access point device. The target access point device and the original access point device are located in the same seamless roaming domain.

[0081] In one example implementation, the seamless roaming suggestion frame includes information on multiple access point devices. The terminal selects one of these access point devices as the target access point device. Of course, the terminal may also reject the suggestion from the original access point device and determine the target access point device by scanning.

[0082] In one example implementation, the seamless roaming suggestion frame does not contain information about any access point device; that is, the original access point device does not provide suggestions, and the terminal needs to scan for access point devices and determine the target access point device.

[0083] In one example implementation, the response frames to the Seamless Roaming Proposal Frame, Seamless Roaming Request Frame, and Seamless Roaming Confirmation Frame include the address of the wireless roaming initiating device, and / or the address of the target device, and / or a fast handover element, and / or a seamless roaming element, and / or a basic multi-link element, and / or a TID-to-link mapping element, and / or a Resource Information Container (RIC) and / or a Dialog Token. The resource information container is defined by 802.11-202013.11 resource request procedures. The address of the wireless roaming initiating device can be an access point multiple access device (APM), a non-access point multiple access device (NMP), a non-access point terminal address, or an access point. The target device address is either the target access point multiple access device address or the target access point address. The resource information container is used by the target access point device to determine the terminal's service flow, QoS parameters, etc., in the seamless roaming request initiated by the terminal, thereby completing TID-to-link mapping. The session token is used to identify the current frame and match the current response frame and request frame.

[0084] The seamless roaming method provided in this application embodiment involves the original access point device sending a seamless roaming candidate target access point inquiry frame before the terminal sends a seamless roaming request to the target access point device. The terminal then receives a seamless roaming suggestion frame from the original access point device in response to the seamless roaming candidate target access point inquiry frame, thereby enabling the terminal to determine the target access point device based on the seamless roaming suggestion frame.

[0085] In the above Figure 2 Based on the aforementioned seamless roaming method embodiments, this application embodiment provides a seamless roaming method, step 101, sending a seamless roaming request to the target access point device, and establishing a connection with the target access point device after receiving the response to the seamless roaming request transmitted by the target access point device, including the following steps.

[0086] The original access point device sends a seamless roaming request to the target access point device, and receives the response to the seamless roaming request transmitted by the target access point device through the original access point device, thus establishing a connection with the target access point device.

[0087] After the terminal sends a seamless roaming request to the target access point device, the target access point device sends a response to the seamless roaming request to the terminal through the distributed system and forwarded by the original access point device, thus establishing a connection with the target access point device.

[0088] In one example implementation, the terminal may also send a seamless roaming request frame to the original access point device, which then sends the seamless roaming forwarding request frame to the target access point device through a distributed system.

[0089] In one example implementation, seamless roaming via a distributed system is as follows: Figure 4 As shown, the original access point device and the target access point device share a common MAC layer, managing seamless roaming of the terminal. The seamless roaming action request and response contain seamless roaming related information and parameters, such as seamless roaming elements.

[0090] The Station Management Entity (SME) of the wireless roaming initiator / terminal sends a wireless roaming request frame to the target access point device by issuing the primitive: MLME-REMOTEREQUEST.request. This primitive contains configuration parameters for setting up a seamless roaming action frame, indicating that the seamless roaming action frame is a seamless roaming request frame. The terminal's MAC layer (link layer) transmits this wireless roaming action frame.

[0091] When the terminal's MAC layer receives a wireless roaming action frame from the terminal's SME layer (the wireless roaming field of the wireless roaming action frame represents a wireless roaming response; for example, a field of 0 indicates a wireless roaming request frame, and a field of 1 indicates a wireless roaming response frame), it sends a Seamless Roaming Action Request (Elements) to the higher MAC layer. The higher MAC layer instructs the MAC layer to respond to the Seamless Roaming Action Request by passing the parameters contained in the instruction to the original access point device's device management entity SME via the primitive MLME-REMOTE-REQUEST.indication. The original access point device initiates a Remote Request (elements) to the target access point device. The target access point device's device management entity processes the request and provides a remote response. The original access point device sends a request MLME-REMOTEREQUEST.request to the higher MAC layer; the higher MAC layer responds with a Seamless Roaming Action repose (Elements), and the terminal's MAC layer instructs the terminal's device management entity with MLME-REMOTEREQUEST.indication.

[0092] The `elements` are the elements contained in a seamless roaming request frame or a seamless roaming response frame. The device management entity of the target access point device processes the remote request, including determining the target connection for access and completing the TID-to-link mapping. The remote request and response lack a pre-authentication step; they simply relay the wireless roaming request frame and relay the target access point device's response to the response frame. The access authentication process is included in the common MAC layer.

[0093] In one example implementation, to simplify the design, a Basic Multi-Link element is included in the Seamless Roaming Request and Response frames, or in the Seamless Roaming Action frame. This Basic Multi-Link element is configured in at least one of the following ways: the STA (Station, where an STA is an access point device attached to a multi-link device) in the Common Info field of the Basic Multi-Link element contains the MAC address of the MLD (Multi-link Device); the Presence Bitmap in the Multi-LinkControl field of the STA is set to 0; or the STA does not contain the Link Info field of the Basic Multi-Link element.

[0094] The seamless roaming method provided in this application embodiment sends a seamless roaming request to a target access point device through the original access point device, and receives the response to the seamless roaming request transmitted by the target access point device through the original access point device, and establishes a connection with the target access point device, so that the terminal determines the target access point device according to the seamless roaming suggestion frame, and realizes the forwarding of the seamless roaming request and the response to the seamless roaming request through the original access device.

[0095] After a terminal switches from the original access point device to the target access point device, in one example implementation, all connections before and after the seamless handover are in active mode. In another example implementation, on the terminal side, the connection between the terminal and the original access point device is in power-saving mode, and the corresponding connection between the terminal and the target access point device remains in power-saving mode after the seamless handover. In this case, the connection between the terminal and the target access point device is a corresponding connection, where a corresponding connection refers to a connection between the terminal and the original access point. Switching to the connection between the terminal and the target access point does not change the number of connections before and after the handover.

[0096] like Figure 5As shown, the connections between the terminal's auxiliary STA1 and STA2 and the original access point device AP MLD1 (which can be a multi-connection device) include Connection 1 and Connection 2. Auxiliary STA1 sends and receives data on Connection 1, and auxiliary STA2 sends and receives data on Connection 2. After seamless roaming handover, the terminal and the target access point device AP MLD2 establish Connection 3 and Connection 4. At this time, auxiliary STA1 sends and receives data on Connection 3, and auxiliary STA2 sends and receives data on Connection 4. Therefore, Connection 3 is the corresponding connection to Connection 1, and Connection 4 is the corresponding connection to Connection 2. In one example implementation, if there is an active connection between the terminal and the original access point device, the corresponding connection between the terminal and the new access point device will remain active after seamless handover; if auxiliary STA1 is in power-saving mode, it will remain in power-saving mode after seamless handover. AP MLD1 or AP MLD2 is not limited to WiFi 7 devices and can be future WiFi 8 devices.

[0097] The change in the number of terminal connections before and after seamless handover refers to the fact that the number of connections between the terminal and the original access point is not equal to the number of connections between the terminal and the target access point. Specifically, before seamless roaming, the number of terminal connections may change due to changes in the terminal's operating mode, terminal energy saving, TiD-to-link mapping reconfiguration / new TiD-to-link mapping with the target access point device, TiD-to-link mapping completion, link enablement, link disablement, reconfiguration or parameter changes of the auxiliary APs of the original access point device, multi-connection re-setup, sudden arrival of low-latency services on the terminal or access point requiring the activation of an auxiliary STA / AP, or the activation of a connection. Alternatively, some auxiliary APs of the original or target access point device may enter sleep mode, or the operating mode of the original or target access point device may change to save energy, resulting in a change in the number of auxiliary APs it supports.

[0098] Specifically, during seamless roaming, some connections between the terminal and the original access point device are associated with the target access point device. All data is mapped to the connections between the terminal and the target access point device. The number of connections between the terminal and the target access point device is less than the number of connections between the terminal and the original access point device. For example, before seamless roaming, there were 3 connections between the terminal and the original access point device; after seamless roaming, there are only 2 connections between the terminal and the target access point device, meaning the services from the 3 connections are mapped to 2 connections. In one example implementation, during seamless roaming, all connections between the terminal and the original access point device are associated with the target access point device, and additional connections are established. All data is mapped to the connections between the terminal and the target access point device. The number of connections between the terminal and the target access point device is greater than the number of connections between the terminal and the original access point device. For example, before seamless roaming, there were 2 connections between the terminal and the original access point device; after seamless roaming, there are 3 connections between the terminal and the target access point device, meaning the services from the 2 connections are mapped to 3 connections.

[0099] In one example implementation, if the number of connections of the terminal changes before and after seamless roaming, the corresponding connection between the terminal and the target access point device remains in active mode. Connections with new services remain active; new services mean that the original TTLM (Tid-To-Link Mapping) has been mapped to different corresponding connections. For example, before wireless roaming, there were two connections between the terminal and the original access point device; after seamless roaming, each service is mapped to three connections, meaning that now each service between the terminal and the target access point device is mapped to three connections. Connections with mapping changes remain active. For example, if the services on new connections 2 and 3 between the terminal and the target access point device are split from the original connection 2 between the terminal and the original access point device, then both new connections 2 and 3 are active. If the original connection 1 between the terminal and the original access point device corresponding to connection 1 is in power-saving mode, the new connection 1 continues to maintain power-saving mode.

[0100] In one example implementation, such as Figure 6 As shown, the terminal is a Wi-Fi STA device that can maintain three connections, such as a non-AP MLD with auxiliary STA1, STA2, and STA3. Auxiliary STA1 and STA2 maintain two connections with the original access point device AP MLD1. Because auxiliary STA3 is in sleep mode (or in a specific operating mode), it does not maintain a connection with the original access point device AP MLD1. During seamless roaming handover, if auxiliary STA3 receives a service and becomes active, it will establish a connection with the target access point AP MLD2. Figure 5 Some or all of the devices in the list are Wi-Fi 8 devices.

[0101] Based on the above embodiments, this application provides a seamless roaming method, such as... Figure 7 As shown, step 101 involves sending a seamless roaming request to the target access point device and establishing a connection with the target access point device after receiving a response to the seamless roaming request from the target access point device, including the following steps.

[0102] S701 sends a request to the original access point device containing a request to change the number of connections supported by the terminal.

[0103] Before seamless roaming, various reasons may cause a change in the terminal's operating mode, such as power saving, the sudden arrival of low-latency services requiring the activation of a secondary STA, or the initiation of a connection, thus changing the number of connections the terminal can support. For example, the number of supported connections can be the number of connections corresponding to the terminal's new operating mode. Specifically, a change in the number of supported connections means a change in the number of connections that the terminal's secondary STAs can establish with the access point device. For instance, if the terminal has three secondary STAs, due to the change in operating mode, the terminal can only maintain two connections between its two secondary STAs and the access point device, respectively. Here, the requested number of supported connections refers to the maximum number of connections the terminal can request.

[0104] Before changing the number of supported connections, the terminal needs to report to the original access point device. Therefore, it needs to send a request to the original access point device containing the request to change the number of supported connections. In some cases, this request is a terminal operating mode indication frame negotiation frame, a TTLM negotiation frame, or an access point power saving related frame.

[0105] In one example implementation, the number of connections supported by the terminal may be included in the seamless roaming request frame or in the seamless roaming response frame. In another example implementation, the number of connections supported by the terminal may be included in the multi-link element of the seamless roaming request frame or in the multi-link element of the seamless roaming response frame.

[0106] S702: If, after sending a seamless roaming related frame to the target access point device or after sending a seamless roaming related frame to the original access point, a response frame is received from the original access point device requesting a change in the number of connections supported by the terminal, seamless roaming with the target access point device is first completed according to the number of connections supported by the terminal before the change, and then the number of connections between the terminal and the target access point device is adjusted according to the number of connections supported by the terminal after the change.

[0107] like Figure 8 As shown, time T1 is when the terminal receives a response frame from the original access point device requesting a change in the number of connections supported by the terminal. The number of connections between the terminal and the original access point device changes, possibly increasing or decreasing. T2 is the start time of establishing a connection between the terminal and the target access point device. The initial point of t2 is the time when the terminal sends a seamless roaming-related frame to the target access point device, or when it sends a seamless roaming-related frame to the original access point. T3 is the time when the terminal disconnects from the original access point device.

[0108] Here, t2 is a time threshold, and different terminals can have different t2 values. In one example implementation, t2 is determined by the terminal based on its own capabilities and reported to the original access point device. In another example implementation, t2 is configured and sent to the terminal by the access point device. In yet another example implementation, t2 is determined through negotiation between the terminal and the access point device; the terminal sends a range of supported values ​​to the access point device, which then configures a specific value and sends it back to the terminal. In one example implementation, t2 is included in a newly defined seamless roaming element. In another example implementation, t2 is included in a newly defined seamless roaming element and is one of its fields. In yet another example implementation, t2 is included in a newly defined seamless roaming request frame or a newly defined seamless roaming response frame. In one example implementation, the access point device stores the t2 value in the UHR MAC higher layer (common MAC higher layer), so that the t2 value is determined as soon as the terminal or access point device first accesses the seamless roaming domain, and it is not necessary to re-determine the t2 value every time seamless roaming (handover).

[0109] After the terminal sends seamless roaming-related frames to the target access point device or after sending seamless roaming-related frames to the original access point, it receives an acknowledgment frame for the request to change the number of connections that the terminal supports for work transmitted by the original access point device, that is, T1 appears after the initial point of t2 (T2 - T2 < t2). The acknowledgment frame for the request to change the number of connections that the terminal supports for work is used to confirm that the terminal can change the supported number of connections. Among them, the seamless roaming-related frames refer to the frames related to seamless roaming sent and received between the terminal and the original access point device and between the terminal and the target access point device during the seamless roaming process, such as seamless roaming request frames, seamless roaming acknowledgment frames, seamless roaming inquiry frames, seamless roaming suggestion frames, seamless roaming confirmation frames, etc.

[0110] If the terminal receives an acknowledgment frame for the request to change the number of connections that the terminal supports for work transmitted by the original access point device after sending seamless roaming-related frames to the target access point device or after sending seamless roaming-related frames to the original access point, it first continues with seamless roaming, that is, completes seamless roaming with the target access point device according to the number of connections that the terminal supported for work before the change, and then performs the change in the number of connections, that is, adjusts the number of connections between the terminal and the target access point device according to the number of connections that the terminal supports for work after the change, that is, the adjustment action occurs at T4 after T3.

[0111] In an exemplary implementation, T1 is the time of the signaling for the change in the number of connections between the terminal and the original access point device, and the number of connections between the terminal and the original access point device has not changed yet.

[0112] In an exemplary implementation, T1 is the time when the operation of changing the number of connections between the terminal and the original access point device is completed, rather than the time when the terminal receives the signaling (command, management frame) for the change in the number of connections. For example, there is a timer, or the service transmission is not completed. T1 is the time when the timer is completed, or the time when the service transmission in the TXOP is completed.

[0113] In an exemplary implementation, T2 is the time when the original access point device sends the first seamless roaming-related frame, such as the time of the seamless roaming suggest frame, or the time when the terminal receives the first seamless roaming-related frame, such as the time of the seamless roaming suggest frame, or the time when the terminal sends the first seamless roaming-related frame, such as the time of the seamless roaming inquiry frame, or the time when the original access point receives the first seamless roaming-related frame, such as the time of the seamless roaming inquiry frame.

[0114] In one example implementation, T2 is the time when the terminal establishes the first connection with the target access point device during seamless roaming, or, T2 is the time when the terminal disconnects the first connection with the original access point device during seamless roaming, or, T2 is the time when the terminal sends a seamless roaming request frame during seamless roaming, or, T2 is the time when the terminal receives a seamless roaming response frame during seamless roaming.

[0115] In one example implementation, T3 is the time when the terminal receives the seamless roaming response frame, or, T3 is the time when the target access point device sends the seamless roaming response frame, or, T3 is the time when the originating access point device receives the seamless roaming ACK frame (a seamless roaming acknowledgment frame sent by the terminal to the originating access point device).

[0116] In one example implementation, t2 is a time threshold for determining the number of connections between the current connection and the original access point. The number of connections between the terminal and the original access point device remains unchanged before the seamless roaming occurs at time T3. If the terminal receives a response frame within time t2 requesting a change in the number of connections supported by the terminal, the terminal executes a handover command after the seamless roaming.

[0117] In one example implementation, the connection change command between the terminal and the original access point device is to increase the number of connections between the terminal and the original access point device, and the method of this embodiment is executed; or, the connection change command between the terminal and the original access point device is to decrease the number of connections between the terminal and the original access point device, and the method of this embodiment is executed.

[0118] S703: If, before sending a seamless roaming related frame to the target access point device or before sending a seamless roaming related frame to the original access point device, a response frame is received from the original access point device requesting a change in the number of connections supported by the terminal, seamless roaming is initiated and completed with the target access point device according to the changed number of connections supported by the terminal.

[0119] The terminal determines whether to request or enable a connection with a target multi-access point device (affiliated APs, or a subset of affiliated APs) based on multiple factors. Changes in the number of connections affect the terminal's selection of affiliated APs or a subset of affiliated APs for the target access point. In some cases, the connection number change command affects the number of connections broadcast / advertised by the target access point device, or changes in parameters.

[0120] like Figure 9As shown, before the terminal sends a seamless roaming related frame to the target access point device, or before sending a seamless roaming related frame to the original access point, it receives a response frame from the original access point device requesting a change in the number of connections supported by the terminal. That is, T1 (T2-T2>t2) appears before the initial point of t2.

[0121] If, before sending a seamless roaming-related frame to the target access point device (APP) or before sending a seamless roaming-related frame to the APP, the terminal receives a response frame from the APP requesting a change in the number of connections it supports, the terminal first changes the number of connections it supports before the initial point t2 and after T1. After the change is complete, it initiates and completes seamless roaming with the target APP according to the changed number of connections it supports. Specifically, the changed number of connections the terminal supports can be carried in its transmitted seamless roaming request.

[0122] The seamless roaming method provided in this application embodiment enables seamless roaming between the terminal and the target access device when the number of connections supported by the terminal changes.

[0123] Based on the above embodiments, this application provides a seamless roaming method. Step 101 involves sending a seamless roaming request to a target access point device and establishing a connection with the target access point device after receiving a response to the seamless roaming request transmitted by the target access point device. This includes the following steps.

[0124] If, after sending a seamless roaming-related frame to the target access point device, or after sending a seamless roaming-related frame to the original access point device, the latest multi-connection information is received from the original access point device, seamless roaming with the target access point device is first completed according to the number of connections maintained by the terminal before receiving the latest multi-connection information. Then, the connection between the terminal and the target access point device is adjusted according to the latest multi-connection information.

[0125] Among them, the multi-connection information is a basic multi-connection element, or a reconfigured multi-connection element, or a TTLM (Tid-to-link mapping) element, or energy-saving information of the access point device, or the access point device is a multi-connection device and its working mode changes.

[0126] The latest multi-connection information includes the latest number of available connections in the original access point device.

[0127] If, after sending a seamless roaming-related frame to the target access point device, or after sending a seamless roaming-related frame to the original access point, the latest multi-connection information is received from the original access point device, seamless roaming will continue first. That is, the terminal will complete seamless roaming with the target access point device according to the number of connections maintained by the terminal before receiving the latest multi-connection information and the information received by the terminal from the target access point device. Then, the connection number will be changed, that is, the connection between the terminal and the target access point device will be adjusted according to the number of connections in the latest multi-connection information.

[0128] If the latest multi-connection information is received from the original access point device before sending a seamless roaming-related frame to the target access point device, or before sending a seamless roaming-related frame to the original access point device, the number of connections between the terminal and the original access point device is first adjusted according to the latest multi-connection information. Then, seamless roaming is initiated and completed with the target access point device based on the changed number of connections. The changed number of connections can be included in the seamless roaming request frame.

[0129] In one example implementation, the terminal receives the latest multi-connectivity information from the original access point device, which is the beacon of the current access point device. The beacon advertises information about the affiliated APs of the current access point. In some cases, the terminal receives the latest multi-connectivity information from the original access point device that is related to the target access point device, such as a reduced neighbor report. In other cases, the terminal receives the latest multi-connectivity information from the target access point device that is related to the target access point device, such as the target access point device's beacon or probe response frame. In still other cases, the terminal receives the latest multi-connectivity information from the target access point device that is related to the target access point device itself, such as the target access point device's operating mode or power-saving information for the AP or affiliated APs.

[0130] The seamless roaming method provided in this application embodiment enables seamless roaming between the terminal and the target access device when the number of connections of the original access point device changes.

[0131] Based on the above embodiments, this application provides a seamless roaming method. Step 101 involves sending a seamless roaming request to a target access point device and establishing a connection with the target access point device after receiving a response to the seamless roaming request transmitted by the target access point device. This includes the following steps.

[0132] If the terminal receives the latest multi-connection information broadcast by the target access point device after the preset time point, it first completes seamless roaming with the target access point device according to the number of connections the terminal maintained before the target access point device received the latest multi-connection information, and then adjusts the connection between the terminal and the target access point device according to the latest multi-connection information.

[0133] In this embodiment, the change in the number of connections refers to a change in the number of connections that the target access point device's auxiliary APs can support establishing with the terminal. For example, if the target access point device originally had two auxiliary APs, due to the power-saving mode being disabled or ML resetup, the target access point device may suddenly be able to establish three connections with the terminal. For instance, the change in the number of connections refers to a change in the maximum number of connections supported by the target access point device, such as from two to three.

[0134] In one example implementation, when the number of connections to the target access point device changes, a Beacon frame is broadcast and periodically sent to the terminal. The Beacon frame contains information about the target access point device's associated APs.

[0135] In one example implementation, a change in the number of connections refers to a change in the number of acceptable connections requested by terminals connected to that target access point device, as indicated in the target access point device's transmitted seamless roaming response frame. In one example implementation, the number of access points attached to the target access point device, or a subset of access points attached to the target access point device, changes.

[0136] In one example implementation, a change in the number of connections means a change in the link(s) to which the service flow is mapped, i.e., a change in the TID-to-link mapping.

[0137] The preset time point is any time point after the terminal sends a seamless roaming-related frame to the original access point device or the target access point device, but before the terminal establishes a connection with the target access point device; or, the preset time point is pre-configured according to the terminal's capabilities.

[0138] In one example implementation, the preset time point is pre-configured based on the capabilities of the original access point device or the target access point device.

[0139] Among them, the multi-connection information is a basic multi-connection element, or a reconfigured multi-connection element, or a TTLM element.

[0140] The latest multi-connection information includes the latest number of connections for the target access point device.

[0141] If the terminal receives the latest multi-connection information broadcast by the target access point device before the preset time point, it initiates and completes seamless roaming with the target access point device based on the updated multi-connection information and the changed number of connections. Specifically, the terminal adjusts the number of connections between itself and the target access point device to the updated number of connections (the latest connection number) based on the latest multi-connection information, and then initiates and completes seamless roaming with the target access point device using the updated number of connections.

[0142] In one example implementation, a change in the number of connections refers to a change in the number of connections requested by a terminal to the target access point device in its transmitted seamless roaming request frame during seamless roaming. In some cases, the number of access points (APs) associated with the target AP, or a subset of APs associated with the target AP, may change. In other cases, the number of connections may be determined by the latest multi-connection information; comparing the latest multi-connection information with the previously received second-latest multi-connection information reveals a change in the number of connections.

[0143] The seamless roaming method provided in this application embodiment enables seamless roaming between the terminal and the target access device when the number of connections to the target access point device changes.

[0144] In the above embodiments, the connection number change and seamless roaming are separate modes; in an example implementation, the connection number change and seamless roaming are merged modes.

[0145] like Figure 10 As shown, the terminal receives the latest multi-connection information sent by the original access point device or the target access point device at time T1, and T2-T1>t3, where t3 is a period of time before the terminal establishes a connection in seamless roaming, and the start time of t3 can be the preset time point mentioned above.

[0146] In one example implementation, the initial point of t2 is the time when the terminal sends a seamless roaming related frame to the target access point device, or when it sends a seamless roaming related frame to the original access point. t3 is the seamless roaming start time, which is the time when the terminal sends a seamless roaming request to the target access point device. T2 is the time when the terminal establishes a connection with the target access point device, and T3 is the time when the terminal disconnects from the original access point device.

[0147] In one example implementation, T1 is the time of the signaling for the change in the number of connections between the terminal and the original access point device, while the number of connections between the terminal and the original access point device has not yet changed.

[0148] In an exemplary implementation, T1 is the time when the operation of changing the number of connections between the terminal and the original access point device is completed, rather than the time when the terminal receives the signaling (command, management frame) of the latest multi-connection information. In an exemplary implementation, there is a timer, or the service transmission is not completed. T1 is the time when the timer is completed, or the time when the service transmission in the TXOP is completed.

[0149] In an exemplary implementation, t2 is a time threshold. One difference between t2 and t3 is that t2 is closer to the time when the seamless roaming handover starts. Some commands, such as TID-to-link mapping, can be completed during the seamless roaming process or outside the seamless roaming process. t2 can indicate that the TID-to-link mapping (update, expiration) occurs at time T1, and if T2 - T1 > t3, then the TID-to-link mapping is immediately executed. In an exemplary implementation, if the occurrence time of the TID-to-link mapping is less than T2 - T1 < t3, then the TID-to-link mapping (update) command is not executed, waiting for the seamless roaming to establish a new TID-to-link mapping, or using the default TID-to-link mapping during the seamless roaming. After the seamless roaming ends, the terminal and the target access point device negotiate a new TID-to-link mapping.

[0150] The terminal receives the latest multi-connection information at T1, and if T2 - T1 > t3, the connection number configuration of the terminal is completed during the seamless roaming handover. For example, there are 3 connections between the terminal and the original access point device. The terminal receives the latest multi-connection information at T1, and the latest multi-connection information is that only two connections are retained between the terminal and the original access point device. Then during the seamless roaming handover process, the terminal and the target access point device complete the handover according to two connections, or complete the configuration of the new TID-to-link mapping. When the seamless roaming is completed, two connections are maintained between the terminal and the target access point device.

[0151] In an exemplary implementation, the latest connection number of the target access point device is included in the seamless roaming response frame, or in the seamless roaming request frame. The latest connection number of the target access point device is included in the multi-link element in the seamless roaming response frame, or in the multi-link element in the seamless roaming request frame, or in the OM (operation mode) control subfield.

[0152] In one example implementation, t2 and t3 are the same threshold with a single, unique value; or, t2 and t3 are different thresholds with two separate values, where t2 > t3. In some cases, t2 or t3 may be included in a beacon, a probe response frame, or a (re)association request / response frame.

[0153] In one example implementation, t3 is a time threshold, and different devices can have different t3 values. In one example implementation, t3 is determined by the terminal based on its own capabilities and reported to the access point device. In one example implementation, t3 is configured and sent to the terminal by the access point device. In one example implementation, t3 is determined through negotiation between the terminal and the access point device; the terminal sends its supported value range to the access point device, which then configures a specific value and sends it to the terminal. In one example implementation, t3 is included in a newly defined seamless roaming element. In one example implementation, t3 is included in a newly defined seamless roaming element and is one of its fields. In one example implementation, the access point stores the t3 value at a higher MAC layer, so that the t3 value is determined the first time the access point enters the seamless roaming domain, and it does not need to be re-determined for each roaming.

[0154] In one example implementation, handover during seamless roaming is performed based on the number of active connections on the terminal. If only one connection on the terminal is active, only that connection is switched during seamless roaming, while other doze connections remain doze and do not participate in the seamless roaming handover.

[0155] The seamless roaming method provided in this application embodiment enables seamless roaming between the terminal and the target access point device when the number of connections changes and seamless roaming is in converged mode, based on the latest multi-connection information.

[0156] Based on the above embodiments, this application provides a seamless roaming method applied to the original access device, including the following steps.

[0157] The receiver sends a seamless roaming confirmation frame to the terminal, sends a response frame to the terminal, and disconnects from the terminal.

[0158] After establishing a connection with the target access point device, the terminal needs to disconnect from the original access point device. Therefore, the terminal sends a final frame to the original access point device, which is a seamless roaming acknowledgment frame, to inform the original access point device that the terminal needs to disconnect. In some cases, the seamless roaming acknowledgment frame does not need to be transmitted, and the seamless roaming process does not include a seamless roaming acknowledgment frame.

[0159] After receiving the seamless roaming confirmation frame, the original access point device sends a response of the seamless roaming confirmation frame back to the terminal, informing the original access point that it will actively disconnect the connection after a preset time following the return of the seamless roaming confirmation frame response. The preset time can be 5ms, etc.

[0160] In some cases, the Seamless Roaming Inquiry Frame and / or the Seamless Roaming Recommendation Frame are not included in the Seamless Roaming Step.

[0161] In some cases, the following roaming methods are supported: i) roaming methods suggested by the access point; ii) roaming methods assisted by the original access point; or iii) roaming methods where the terminal interacts directly with the target access point (over the air). Whether at least one of these roaming methods is supported is included in the seamless roaming element. This field can be a bitmap, where a bit of 1 indicates support for the corresponding seamless roaming method, and 0 indicates no support; or it can be represented in binary format, where 00 indicates support for i), 01 indicates support for ii), 10 indicates support for iii), and 11 indicates reserved. Similarly, a field can be defined in the seamless roaming element to indicate whether seamless roaming initiated by the terminal or by the access point is supported, which can be represented in bitmap or binary format.

[0162] The seamless roaming method provided in this application embodiment enables seamless roaming on the original access device side.

[0163] Based on the above embodiments, this application provides a seamless roaming method, such as... Figure 11 As shown, it includes the following steps.

[0164] Step 1101: Send a seamless roaming request to the target access point device through the distributed system.

[0165] The original access point device and the target access point device transmit data through a distributed system. Therefore, the original access point device needs to send the seamless roaming request to the distributed system first, and the distributed system forwards the seamless roaming request to the target access point device.

[0166] After receiving the seamless roaming request, the target access point device sends a response to the seamless roaming request to the distributed system, which then forwards the response to the seamless roaming request to the original access point device.

[0167] Step 1102: Send the response to the seamless roaming request sent by the target access point device to the terminal.

[0168] The original access point device sends the response to the seamless roaming request forwarded by the distributed system to the terminal.

[0169] The seamless roaming method provided in this application embodiment enables seamless roaming on the original access device side through a distributed system that forwards requests and responses.

[0170] Based on the above embodiments, this application provides a seamless roaming method, including the following steps.

[0171] The original access device and the target access device constitute a seamless roaming domain. If the original access point device is the access point device group leader in the seamless roaming domain, or a co-located AP (MAC layer co-location AP), it receives the seamless roaming domain access request sent by the target access point device and sends a response to the seamless roaming domain access request to the target access point device. A co-located AP refers to an AP whose MAC layer responsible for managing seamless roaming is deployed on an access point device (AP). Optionally, the MAC layer can be deployed on any physical AP, and a co-located AP refers to an AP device that has deployed this MAC layer.

[0172] When an access point device (APD) supports seamless roaming, it needs to access a mobile / seamless roaming domain. Within this seamless roaming domain, APDs share a (common) MAC layer. This (common) MAC layer is responsible for managing seamless roaming of terminals between multiple APDs. APD support for a common MAC layer is a capability contained in a beacon, probe response frame, or MIB.

[0173] Access point devices sharing a common MAC layer can form an access point device group. The group head of the access point device group is responsible for adding and removing new access point devices; that is, the access point device group is responsible for managing the addition and removal of access point devices.

[0174] When a new access point device requests to join a seamless roaming domain, a request frame is sent to the access point device group leader. The request frame contains: the MAC address of the access point device to join the domain, and / or, the MAC address of the access point device group leader, and / or, support for seamless roaming capability, and / or, support for common MAC layer, and / or, basic multi-link element, and / or, MDE, and / or, seamless roaming element.

[0175] In one example implementation, the access point device group leader is the co-located AP in the seamless roaming domain, meaning that the logical entity of the access point device group leader is one of the access point devices in the seamless roaming domain.

[0176] When the access point device group leader receives the request frame, it sends a response frame. If the request is granted, the response allows joining the domain. Otherwise, joining the domain is not allowed.

[0177] The response frame contains one of the following: the MAC address of the access point device to join the domain, and / or the MAC address of the access point device group leader sending the response frame, and / or support for seamless roaming capability, and / or support for common MAC layer, and / or basic multilink element, and / or MDE, and / or status code (1 for allowed joining, 0 for disallowed joining).

[0178] In one example implementation, the response frame includes a rejection reason status code: 01 indicates allow joining, 00 indicates disallowed (seamless roaming not supported), 11 indicates disallowed (fast switching not supported), 10 indicates disallowed (other reasons).

[0179] In one example implementation, the device receiving the request frame and sending the response frame is any access point device within the MDE (Mobility Domain element) domain. This access point device then transmits the relevant information to the access point device leader via wired / wireless backhaul.

[0180] The seamless roaming method provided in this application embodiment enables the management of the device to be accessed by the seamless roaming domain composed of the original access device and the target access device through the access point device side.

[0181] Based on the above embodiments, this application provides a seamless roaming method, including the following steps.

[0182] In one example implementation, handover occurs during seamless roaming based on the number of active connections on the terminal. The power state of the terminal's associated STAs remains unchanged before and after roaming is complete.

[0183] In one example implementation, seamless roaming is performed by handing over the connection to the target access point device during the roaming process, based on the number of connections supported by the terminal. Upon completion of the roaming, connections in power-saving mode are forcibly activated and put into a wake-up state.

[0184] In one example implementation, it is optional whether the terminal performs seamless roaming handover based on the number of active connections or the number of connections supported by the terminal. The capability-based number of connections for seamless roaming handover is included in the probe request frame, or the seamless roaming request frame, or the seamless roaming response frame, or the seamless roaming element, or the multi-link element, or in the seamless roaming inquiry frame.

[0185] In one example implementation, whether the terminal performs seamless roaming handover based on the number of active connections or the number of connections supported by the terminal is optional and depends on the service. If the current connection is transmitting a low-latency service, all dormant connections are forcibly activated during seamless roaming.

[0186] In this application, whether or not to allow the establishment of new connections during roaming is a capability.

[0187] In one example implementation, the maximum number of connections supported by the terminal and the target access point device are inconsistent, but the ability to establish fewer connections than that is a capability. For example, the terminal's ability to establish fewer connections with the target access point device than the number of STAs to which it is attached is a capability of that terminal. In one example implementation, this capability is contained in a probe request frame, a roaming request frame, or a roaming response frame. In one example implementation, the terminal's ability to establish fewer connections than the number of STAs to which it is attached is an operating mode of that terminal, which can be configured and is contained in the operating mode control field.

[0188] In one example implementation, the number of connections between the terminal and the originating access point device differs from the number of connections supported by the target access point device. In another example implementation, the number of connections between the terminal and the access point device is inconsistent before and after seamless roaming; supporting this type of seamless roaming is a capability of either the terminal or the access point device. In one example implementation, a description of this capability is included in the probe request frame, or the roaming request frame, or the roaming response frame, or the beacon, or the MIB.

[0189] In one example implementation, the corresponding connection between the terminal and the original access point device is maintained between the terminal and the target access point device. And a new connection is established during the handover process, such as... Figure 6 As shown. Establishing a new connection, in addition to the existing connection, between the terminal and the target access point device during seamless roaming is a capability. In one example implementation, a description of this capability is included in a probe request frame, a roaming request frame, a roaming response frame, a beacon, or a MIB.

[0190] In one example implementation, a connection exists between the terminal's associated STA and the original access point device, and the STA is in power-saving mode. A connection between the terminal and the original access point device becomes disabled due to a TTLM update or other reasons. During seamless roaming, the TTLM terminates, enabling the connection. After seamless roaming, the terminal operating on the connection corresponding to that connection between the terminal and the target access point device is in power-saving mode, with its power state set to sleep.

[0191] In one example implementation, a connection exists between the terminal's associated STA and the original access point device, and the STA is in power-saving mode. A connection between the terminal and the original access point device becomes disabled due to a TTLM update or other reasons. During seamless roaming, the TTLM terminates, making the connection enabled again. After seamless roaming, the terminal operating on the connection corresponding to that connection between the terminal and the target access point device is in power-saving mode, with its power state set to "wake".

[0192] In one example implementation, a connection between the terminal and the original access point becomes disabled due to a TTLM update or other reasons. During seamless roaming, the TTLM terminates, making the connection enabled again. After seamless roaming, the terminal operating on the connection corresponding to that connection between the terminal and the target access point device is in active mode.

[0193] In one example implementation, a primary connection is responsible for transmitting seamless roaming signaling during seamless roaming. This primary connection remains active both before and after seamless roaming. Non-primary connections maintain their power state before and after seamless roaming. Before seamless roaming, some non-primary connections are in power-saving or active mode; after seamless roaming, the corresponding non-primary connections established between the terminal and the target access point device retain their previous connection states.

[0194] The steps of the various methods described above are only for clarity. In practice, they can be combined into one step or some steps can be split into multiple steps. As long as they include the same logical relationship, they are all within the scope of protection of this patent. Adding insignificant modifications or introducing insignificant designs to the algorithm or process, but without changing the core design of the algorithm and process, are also within the scope of protection of this patent.

[0195] This application relates to a terminal, such as... Figure 12 As shown, it includes: at least one first processor 1201; and a first memory 1202 communicatively connected to the at least one first processor 1201; wherein the first memory 1202 stores instructions that can be executed by the at least one first processor 1201, the instructions being executed by the at least one first processor 1201 to enable the at least one first processor 1201 to execute the seamless roaming method executed by the terminal in the above embodiments.

[0196] The first memory 1202 and the first processor 1201 are connected by a bus. The first bus may include any number of interconnected buses and bridges, and the first bus connects various circuits of one or more first processors and the first memory together.

[0197] This application's embodiments relate to a primary access device, such as... Figure 13 As shown, it includes: at least one second processor 1301; and a second memory 1302 communicatively connected to the at least one second processor 1301; wherein the second memory 1302 stores instructions that can be executed by the at least one second processor 1301, the instructions being executed by the at least one second processor 1301 to enable the at least one second processor 1301 to execute the seamless roaming method executed by the original access point device in the above embodiments.

[0198] The second memory 1302 and the second processor 1301 are connected by a bus. The second bus may include any number of interconnected buses and bridges, and the second bus connects various circuits of one or more second processors and the second memory together.

[0199] This application relates to a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, it implements the method embodiments described above.

[0200] That is, those skilled in the art will understand that all or part of the steps in the methods of the above embodiments can be implemented by a program instructing related hardware. This program is stored in a storage medium and includes several instructions to cause a device (which may be a microcontroller, chip, etc.) or processor to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk.

[0201] Those skilled in the art will understand that the above embodiments are specific embodiments for implementing this application, and in practical applications, various changes can be made to them in form and detail without departing from the spirit and scope of this application.

Claims

1. A seamless roaming method, characterized in that, Applied to a terminal, the method includes: Send a seamless roaming request to the target access point device, and establish a connection with the target access point device after receiving the response to the seamless roaming request transmitted by the target access point device; Send a seamless roaming confirmation frame to the original access point device of the terminal, and disconnect from the original access point device after receiving the response of the seamless roaming confirmation frame transmitted by the original access point device; The original access point device and the target access point device have a common MAC layer, which is responsible for handling seamless roaming requests and seamless roaming responses. Both the original access point device and the target access point device are multi-connection access point devices. During seamless roaming handover, when the number of connections supported by the target access point device changes, the number of connections between the terminal and the target access point device is adjusted.

2. The seamless roaming method according to claim 1, characterized in that, Before sending the seamless roaming request to the target access point device, the method further includes: Send a seamless roaming alternative target access point query frame to the original access point device; Receive a seamless roaming suggestion frame from the original access point device in response to a seamless roaming candidate target access point query frame, wherein the seamless roaming suggestion frame contains at least the information of the target access point device; The target access point device and the original access point device are located in the same seamless roaming domain.

3. The seamless roaming method according to claim 1, characterized in that, The step of sending a seamless roaming request to the target access point device and establishing a connection with the target access point device after receiving a response to the seamless roaming request from the target access point device includes: The original access point device sends the seamless roaming request to the target access point device, and receives the response to the seamless roaming request transmitted by the target access point device through the original access point device, thereby establishing a connection with the target access point device.

4. The seamless roaming method according to claim 1, characterized in that, The step of sending a seamless roaming request to the target access point device and establishing a connection with the target access point device after receiving a response to the seamless roaming request from the target access point device includes: Send a request to the original access point device that includes changing the number of connections supported by the terminal. If, after sending a seamless roaming related frame to the target access point device or after sending a seamless roaming related frame to the original access point, a response frame is received from the original access point device requesting a change in the number of connections supported by the terminal, seamless roaming with the target access point device is first completed according to the number of connections supported by the terminal before the change. Then, the number of connections between the terminal and the target access point device is adjusted according to the number of connections supported by the terminal after the change. The related frames include seamless roaming request frames, seamless roaming response frames, seamless roaming inquiry frames, seamless roaming suggestion frames, or seamless roaming confirmation frames. If, before sending a seamless roaming-related frame to the target access point device or before sending a seamless roaming-related frame to the original access point, a response frame for the request to change the number of connections supported by the terminal is received from the original access point device, seamless roaming is initiated and completed with the target access point device according to the changed number of connections supported by the terminal.

5. The seamless roaming method according to claim 1, characterized in that, The step of sending a seamless roaming request to the target access point device and establishing a connection with the target access point device after receiving a response to the seamless roaming request from the target access point device includes: If, after sending a seamless roaming-related frame to the target access point device, or after sending a seamless roaming-related frame to the original access point, the latest multi-connection information is received from the original access point device, seamless roaming with the target access point device is first completed according to the number of connections maintained by the terminal before receiving the latest multi-connection information, and then the connection between the terminal and the target access point device is adjusted according to the latest multi-connection information. If the terminal receives the latest multi-connection information from the original access point device before sending the seamless roaming related frame to the target access point device or before sending the seamless roaming related frame to the original access point device, the terminal initiates and completes seamless roaming with the target access point device according to the latest multi-connection information and the changed number of connections of the original access point device. The multi-connection information refers to a basic multi-connection element, a reconfigured multi-connection element, or a TTLM element.

6. The seamless roaming method according to claim 1, characterized in that, The step of sending a seamless roaming request to the target access point device and establishing a connection with the target access point device after receiving a response to the seamless roaming request from the target access point device includes: If the latest multi-connection information broadcast by the target access point device is received after a preset time point, seamless roaming with the target access point device is first completed according to the number of connections maintained by the terminal before the target access point device received the latest multi-connection information. Then, the connection between the terminal and the target access point device is adjusted according to the latest multi-connection information. If the latest multi-connection information broadcast by the target access point device is received before the preset time point, the terminal initiates and completes seamless roaming with the target access point device according to the latest multi-connection information and the changed number of connections of the target access point device. Wherein, the multi-connection information is a basic multi-connection element, or a reconfigured multi-connection element, or a TTLM element; The preset time point is any time point after the terminal sends a seamless roaming related frame to the original access point device or the target access point device, and before the terminal establishes a connection with the target access point device; or, the preset time point is pre-configured according to the terminal's capabilities.

7. A seamless roaming method, characterized in that, Applied to the original access point equipment, the method includes: The receiver sends a seamless roaming confirmation frame to the terminal, sends a response to the seamless roaming confirmation frame to the terminal, and disconnects from the terminal. The original access point device and the target access point device for seamless roaming of the terminal have a common MAC layer, which is responsible for handling seamless roaming requests and seamless roaming responses. Both the original access point device and the target access point device are multi-connection access point devices. During seamless roaming handover, when the number of connections supported by the target access point device changes, the number of connections between the terminal and the target access point device is adjusted.

8. The seamless roaming method according to claim 7, characterized in that, The method further includes: Send a seamless roaming request to the target access point device through a distributed system; The response to the seamless roaming request sent by the target access point device is sent to the terminal.

9. The seamless roaming method according to claim 8, characterized in that, The original access point device and the target access point device constitute a seamless roaming domain, and the method further includes: If the original access point device is the access point device group leader in the seamless roaming domain, or a MAC layer-high local device, it receives the access seamless roaming domain access request sent by the access point device to be accessed, and sends a response to the access seamless roaming domain access request to the access point device to be accessed. The device to be accessed is the device that needs to access the seamless roaming domain.

10. A seamless roaming system, characterized in that, The system includes: a terminal, a source access point device connected to the terminal, and a target access point device; the terminal, the source access point device, and the target access point device all support seamless roaming; The terminal is configured to send a seamless roaming request to the target access point device, and establish a connection with the target access point device after receiving a response to the seamless roaming request sent by the target access point device; the terminal is also configured to send a seamless roaming confirmation frame to the original access point device, and disconnect from the original access point device after receiving a response to the seamless roaming confirmation frame sent by the original access point device. The original access point device and the target access point device have a common MAC layer, which is responsible for handling seamless roaming requests and seamless roaming responses. Both the original access point device and the target access point device are multi-connection access point devices. During seamless roaming handover, when the number of connections supported by the target access point device changes, the number of connections between the terminal and the target access point device is adjusted.

Images