A seamless handover method and terminal supporting connection reconfiguration

Abstract

The embodiment of the present application relates to the field of wireless communication technology, and discloses a seamless handover method and terminal supporting connection reconfiguration, wherein the connection reconfiguration is realized during seamless roaming by carrying the connection reconfiguration information in the seamless roaming related frames transmitted between the original access point and / or the target access point during seamless roaming; and the seamless handover from the original access point to the target access point is realized by carrying the seamless roaming information in the seamless roaming related frames. Thus, the multi-connection reconfiguration and the seamless handover are effectively coordinated during seamless roaming.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and in particular to a seamless switching method and terminal that supports connection reconfiguration. Background Technology

[0002] In future Wi-Fi systems, seamless roaming has become a hot research topic to reduce connection interruptions during terminal handover and ensure continuous data transmission and service continuity. Current Wi-Fi handover methods involve first disconnecting from the current serving device and then connecting to the target device. This causes service interruptions. Seamless roaming manages the handover process by establishing a common MAC layer between the current serving device and the target device. During seamless roaming, the terminal remains in STATE4, the associated state, enhancing terminal reliability.

[0003] During seamless roaming, when a terminal switches from the current serving device to the target device, from the terminal's perspective, it's simply a matter of adding a new connection and deleting an existing one. Simultaneously, data previously cached on the original serving device is forwarded to the target device and transmitted back to the terminal, or uplink data cached on the terminal is transmitted to the target access point. In this process, a context is defined; the context must at least contain the sequence number (SN), packet number (PN), and batch acknowledgment (BA). The context is forwarded from the current serving device to the target device. In some cases, the terminal and the target device reconstruct the context content. In other cases, both the current device and the target device, or the terminal, are multi-connection devices.

[0004] Multiple link reconfiguration, for AP-MLD (Access Point Multiple Connection Device), includes the addition and removal of affiliated APs. For non-AP MLD (Non-Access Point Multiple Connection Device), it involves the dynamic establishment and deletion of connections without requiring association or re-association. Therefore, one way to achieve seamless roaming is to reference or enhance the link reconfiguration steps. For example, using seamless roaming request frames and seamless roaming response frames similar to the Link Reconfiguration Request frame and Link Reconfiguration Response frame. Seamless handover is then achieved using these frames. The handover process may also include other frames, such as the target access point suggestion frame transmitted from the current access point to the terminal.

[0005] The inventors have discovered at least the following problems in the relevant technologies: the relationship between multi-connection reconfiguration and seamless roaming is still a technical gap in this field. It is necessary to further clarify how to effectively coordinate multi-connection reconfiguration and seamless switching during seamless roaming to ensure that the two functions do not affect each other, or that the two functions are integrated and coexist. Summary of the Invention

[0006] The purpose of this invention is to provide a seamless handover method and terminal that supports connection reconfiguration, enabling effective coordination of multiple connection reconfigurations and seamless handover during seamless roaming.

[0007] To address the aforementioned technical problems, embodiments of the present invention provide a seamless handover method supporting connection reconfiguration, comprising: implementing connection reconfiguration during seamless roaming by means of connection reconfiguration information carried in seamless roaming-related frames transmitted between the original access point and / or the target access point during seamless roaming; and seamlessly handing over from the original access point to the target access point by means of the seamless roaming information carried in the seamless roaming-related frames.

[0008] Embodiments of the present invention also provide a terminal, comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the above-described seamless switching method supporting connection reconfiguration.

[0009] In this embodiment of the invention, connection reconfiguration is achieved during seamless roaming by carrying connection reconfiguration information in seamless roaming-related frames transmitted between the original access point and / or the target access point; seamless handover from the original access point to the target access point is achieved through the seamless roaming information carried in the seamless roaming-related frames. This enables effective coordination of multiple connection reconfigurations and seamless handover during seamless roaming. Attached Figure Description

[0010] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0011] Figure 1 This is a flowchart of a seamless switching method supporting connection reconfiguration provided according to an embodiment of the present invention;

[0012] Figure 2 This is a schematic diagram of configuration operations for a subfield of a reconstruction operation type according to an embodiment of the present invention;

[0013] Figure 3 This is a schematic diagram of seamless roaming operation at the MLD level according to an embodiment of the present invention;

[0014] Figure 4 This is a schematic diagram of the terminal structure according to another embodiment of the present invention. Detailed Implementation

[0015] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details are presented in the various embodiments of the present invention to facilitate a better understanding of 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 ease of description and should not constitute any limitation on the specific implementation of the present invention. The various embodiments can be combined with and referenced by each other without contradiction.

[0016] One embodiment of the present invention relates to a seamless handover method supporting connection reconfiguration, which can be applied to any terminal (STA) associated with an access point (AP), such as mobile phones, computers, and other terminal devices. Connection reconfiguration is achieved during seamless roaming by carrying connection reconfiguration information in seamless roaming-related frames transmitted between the original access point and / or the target access point; seamless handover from the original access point to the target access point is achieved using the seamless roaming information carried in the seamless roaming-related frames. This enables effective coordination of multiple connection reconfigurations and seamless handover during seamless roaming. The implementation details of the seamless handover method supporting connection reconfiguration in this embodiment are described below. These details are provided for ease of understanding and are not essential for implementing this solution.

[0017] like Figure 1 As shown, in step 101, the terminal performs connection reconfiguration during seamless roaming by using connection reconfiguration information carried in the seamless roaming-related frames transmitted between the original access point and / or the target access point during seamless roaming;

[0018] Seamless roaming-related frames refer to frames involved in the seamless roaming process, including at least one of the following: Link Reconfiguration Request frame / Link Reconfiguration response frame, Seamless Roaming Request frame / Seamless Roaming Response frame, Seamless Handover Confirmation frame (transmitted by the original access point to the terminal to indicate handover completion), or Seamless Handover Target Access Point Proposal frame, Initial Control Frame (ICF), Initial Control Response Frame (ICR), etc. Among these, the Seamless Roaming Request frame / Seamless Roaming Response frame is a newly defined frame used for seamless handover, used to request and respond to seamless roaming.

[0019] Connection reconfiguration information refers to the information or parameters required to implement connection reconfiguration. In one example, connection reconfiguration information is contained in one or any combination of the following elements: Basic multi-link element, Link reconfiguration element, newly defined Seamless roaming element, and Enhanced connection reconfiguration element.

[0020] The basic multi-link element is the most fundamental component of connection reconfiguration. In some cases, seamless roaming-related frames may contain the basic multi-link element of the target access point, the basic multi-link element of the current serving access point, or the basic multi-link element of the terminal itself. In one example, under certain circumstances, seamless roaming-related frames containing basic multi-link elements indicate the frame's purpose. For instance, a seamless roaming request frame containing the terminal's basic multi-link element, sent to the target access point, indicates a request to connect to the target access point and establish a connection with the AP attached to that access point. Similarly, a seamless roaming response frame containing the target access point's basic multi-link element, sent to the terminal access point, indicates a request to connect to the target access point and establish a connection with the terminal or its attached STA.

[0021] In the current Wi-Fi 7 standard, the connection reconfiguration element can be included in beacon and probe response frames to indicate the removal and addition of affiliated APs. It's used for reconfiguring multiple connections, allowing the addition or removal of links or affiliated APs. Seamless handover related frames must contain at least the original access point's Link reconfiguration element and / or the target access point's Link reconfiguration element. Setting the `reconfiguration operation type subfield` to `delete` in the original access point's Link reconfiguration element indicates that the connection with the original access point is being deleted. Setting the `reconfiguration operation type subfield` to `add` in the target access point's Link reconfiguration element indicates that a connection with the target access point is being established.

[0022] The newly defined seamless roaming element is formed by enhancing the basic multi-link element and the link reconfiguration element, integrating the characteristics of the basic multi-link element and the link reconfiguration element. The newly defined seamless roaming element or enhanced link reconfiguration element contains a reconfiguration operation type subfield, and the enabled reserved value is one of {5, 6, ..., 15} within the reconfiguration operation type subfield encoding. The corresponding type (name) is seamless roaming add, seamless roaming delete, or seamless roaming. Seamless roaming add indicates that the terminal adds the connection during seamless roaming and establishes the connection with the target access point. Seamless roaming delete indicates that the terminal deletes the connection during seamless roaming and removes the connection from both the original access point and the target access point. The corresponding value Name is "seamless roaming", which means that the connection, or the attached AP or attached STA, is about to or is in the process of seamless switching, or that the attached STA is performing seamless roaming, including the deletion of the connection and / or the addition of a new connection.

[0023] There are many different variations of the newly defined seamless roaming element, which will be further illustrated below:

[0024] In one example, the newly defined Seamless roaming element, or the enhanced Linkreconfiguration element, contains both "2" (add link) and "3" (delete link) subfields in its configuration operation type subfield, indicating that the connection is about to or is in the process of seamless switching. This is because seamless switching is not simply about deleting or establishing a connection, but rather about switching a terminal connected to the current access point to the target access point, involving both connection addition and deletion actions for the same terminal or the same affiliated STA.

[0025] In one example, the newly defined Seamless roaming element, or the enhanced Linkreconfiguration element, contains both "2" (add link) and "3" (delete link) in its configuration operation type subfield, indicating that the connection is about to or is undergoing a seamless handover. This is because a seamless connection is not simply about deleting or establishing a connection, but rather about switching a terminal connected to the current access point to the target access point. This involves adding and deleting connections for the same terminal or the same affiliated STA. In some cases, the connection corresponding to the configuration operation type subfield is the connection to the target access point (the connection to the AP affiliated with the target access point); "3" (delete link) corresponds to the connection that the terminal is about to disconnect from the current serving access point.

[0026] In one example, such as Figure 2 As shown, the reconstruction operation type subfield is contained within the information or field of each associated STA. Each reconstruction operation type subfield can have different configurations.

[0027] In one example, the newly defined seamless roaming element, or the enhanced Link reconfiguration element, or the improved basic multi-link element contains a reconfiguration operation type subfield. The connection of the associated STA is represented by a combination of the link ID and the device MAC address, such as [MAC address + link ID], as well as the status of the connection, such as "2" for add link and "3" for delete link.

[0028] This applies not only to the newly defined Seamless roaming element, but also, in one example, a Seamless roaming-related frame containing at least one Seamless roaming element, or an enhanced Link reconfiguration element, or a basic multi-link element, where the reconfiguration operation type subfield contains both "2" for "add Link" and "3" for "delete link," indicating that the connection is about to or undergoing a seamless handover. The corresponding attached STA's link ID uses the original 4-bit link ID. Alternatively, in another example, a Seamless roaming-related frame containing at least one Seamless roaming element, or an enhanced Link reconfiguration element, or a basic multi-link element, where the reconfiguration operation type subfield contains "2" for "add Link" and / or "3" for "delete link," indicating that the connection is about to or undergoing a seamless handover. The corresponding attached STA's connection is represented by a combination of the link ID and the device MAC address, such as [MAC address + link ID].

[0029] In some cases, it is necessary to inform or change the status of the AP, such as when the AP is saving energy. Therefore, a reconfiguration operation type subfield encoding is defined for energy saving indication or energy saving management. For example: {5, 6, ..., 15} where one of them is doze; {5, 6, ..., 15} where one of them is wake; {5, 6, ..., 15} where one of them is high capability mode or low capability mode; {5, 6, ..., 15} where one of them is a newly defined capability model, such as high capability mode 1 and high capability mode 2; and {5, 6, ..., 15} where one of them is a newly defined capability model, such as low capability mode 1 and low capability mode 2. In some cases, seamless switching within frames related to seamless roaming is achieved through identifiers in a subdomain: adding a link and / or deleting a link. Seamless roaming changes the current terminal's connection status and can simultaneously include the connection's energy identifier (e.g., capability model) in a subdomain, such as a high-performance mode (the connection was established in high-capability mode). For example, including both an "add link" identifier and a low-capability mode identifier indicates that the connection was established or switched to in low-capability mode. In some cases, newly established connections at the default target access point retain the capability mode of the original access point connection.

[0030] In some cases, unless specifically stated or identified in the seamless roaming-related frame, the newly established connection of the target access point will use the capability mode of the original access point connection. If the terminal requests, or the original access point requests, via the seamless roaming-related frame to the target access point to change the capability mode, the target access point will respond with whether or not it agrees. The capability mode requested or responded to is contained in the seamless roaming-related frame, or in a subdomain of the seamless roaming element, the enhanced link reconfiguration element, or the improved multi-link element. In some cases, the subdomain includes the AP power-saving information corresponding to the aforementioned number.

[0031] The high capability mode or low capability mode corresponds to different wake-up cycles, operating bandwidth, available modulation methods, and allowed PPDU types.

[0032] In some cases, the aforementioned AP behaviors—wake, doze, high capability mode, or low capability mode—or capability mode switching are collectively referred to as operation parameter updates. These specific behaviors are triggered, executed, completed, or notified by the ICF (Initial Control Frame) and / or ICR (Initial Control Response Frame). The link reconfiguration element containing a reconfiguration operation type subfield value of 1 is included in the ICF or ICR. That is, during capability mode switching, the ICF and / or ICR complete the capability mode switching, including the link ID of the corresponding link / AP, and the link reconfiguration element where the corresponding AP's reconfiguration operation type subfield value is 1.

[0033] In step 102, the terminal seamlessly switches from the original access point to the target access point using the seamless roaming information carried in the seamless roaming related frame.

[0034] In some cases, link reconfiguration and seamless roaming occur simultaneously on the AP or terminal side. In this case, seamless roaming information and link reconfiguration information appear together in the seamless roaming-related frame. The seamless roaming-related frame carries elements containing both link reconfiguration and seamless roaming information, for example, the following combinations: the seamless roaming-related frame carries both basic multi-connectivity elements and seamless roaming elements; the seamless roaming-related frame carries both link reconfiguration elements and enhanced link reconfiguration elements; the seamless roaming-related frame carries only the enhanced link reconfiguration element; the seamless roaming-related frame carries only the newly defined seamless roaming element. In other words, at least one seamless roaming-related frame needs to contain the following types of element combinations:

[0035] 1. At least one seamless roaming-related frame contains both a link reconfiguration element and a seamless roaming element. The link reconfiguration element is used for link reconfiguration, where the reconfiguration operation type subfield indicates the addition and deletion of connections; the seamless roaming element is used for seamless roaming and contains a reconfiguration operation type subfield. In the seamless roaming element, the Maximum supported link (hereinafter referred to as No.) represents the maximum number of connections, calculated based on the connection situation before the reconfiguration. For example, if a terminal has three connections and wants to delete one while performing a seamless handover, then the Maximum supported link No. is 3. In some embodiments, the Maximum supported link No. represents the maximum number of connections, calculated based on the link situation after the reconfiguration. For example, if a terminal has three connections and wants to delete one while performing a seamless handover, then the Maximum supported link No. is 2. The case of adding a link is similar and will not be elaborated further.

[0036] 2. At least one seamless roaming-related frame contains both a Link reconfiguration element and an enhanced Link reconfiguration element. The Link reconfiguration element is used for Link reconfiguration, where the reconfiguration operation type subfield indicates the addition and deletion of connections; the enhanced Link reconfiguration element is used for seamless roaming and contains a reconfiguration operation type subfield. In the seamless roaming element, Maximum supported linkNo. represents the maximum number of connections, calculated based on the link configuration before the reconfiguration.

[0037] 3. At least one seamless roaming-related frame contains only an enhanced Link reconfiguration element or a newly defined seamless roaming element. One of the attached STAs contains multiple reconfiguration operation type subfields. One of these subfields is used for link reconfiguration; a value of 2 or 3 indicates adding or removing a connection. Another subfield has a newly enabled reserved value, such as 5, indicating seamless switching. In the seamless roaming element or enhanced Link reconfiguration element, Maximum supported link No. indicates the maximum number of connections, calculated based on the link configuration before the connection reconfiguration associated with the seamless roaming element.

[0038] 4. During seamless handover, the terminal requests access to the target access point and informs the target access point of its maximum supported links. The target access point then connects to the target access point based on its maximum supported links, and determines the final number of connections. In some cases, the maximum supported link number is called the maximum number of simultaneous connections (Maximum Number of Simultaneous Links), indicating the maximum number of STAs attached to that MLD that can simultaneously transmit or receive on their respective connections.

[0039] In one example, the enhanced link reconfiguration element or the newly defined seamless roaming element carries a Multi-Connection Device (MLD) level indication; in other words, in some cases, seamless roaming is at the MLD level, and the MLD level indication is used to inform the receiver corresponding to the MLD level indication that the sender corresponding to the MLD level indication is about to perform seamless roaming, or to inform the receiver corresponding to the MLD level indication that the sender corresponding to the MLD level indication is about to perform connection reconfiguration. The enhanced link reconfiguration element or the newly defined seamless roaming element does not specify a particular attached STA representation identifier, but directly indicates the MLD level, meaning that the current device is about to perform seamless roaming. The MLD level indication includes at least one of the following: roaming, handover, joining a connection, deleting a connection, disconnecting a connection, or capability mode.

[0040] Multi-connected device (MLD) level indication, such as Figure 3As shown, in some cases, such as with the original service access point, the seamless roaming suggestion frame containing its own multi-connection seamless roaming element or enhanced link reconfiguration element indicates that the terminal needs to disconnect from all connections of its affiliated AP. This indication can be an MLD-level indicator; 0 indicates seamless roaming joining or establishing a connection (seamless roamingadd), and 1 indicates disconnecting from the original service node (seamless roaming delete) during seamless roaming. In some cases, this indication is called a reconfiguration operation type subfield, or an enhanced reconfiguration operation type subfield, or the seamless roaming operation type subfield is an MLD-level element contained in the seamless roaming element or enhanced link reconfiguration element. In some cases, during seamless roaming, the seamless roaming related frame contains a newly defined seamless roaming element, or an enhanced link reconfiguration element, or an enhanced multi-link element. At least one of these elements contains basic information or a profile of the terminal device node's affiliated STA. And / or the status of the STA attached to the terminal device node, such as being set to seamless roaming, handover, delete, or add in Link ReconfigurationOperation Support, to indicate the addition and deletion of a link during seamless handover, or the seamless handover of the STA attached to the terminal.

[0041] In some cases, seamless roaming-related frames contain seamless roaming elements, enhanced link reconfiguration elements, or multi-link elements that improve seamless roaming. In these cases, seamless switching is not performed. Instead, the connection status of the current terminal is changed by using the identifier in a subfield of the aforementioned element: add link, delete link, etc., to reconfigure the current connection.

[0042] In some cases, the Multiple Connectivity Device (MLD) level indication is implicitly tied to the seamless roaming element. In other cases, the implicit indication means there is no seamless roaming operation type subfield. The presence of a seamless roaming element in any frame indicates that the endpoint is switching all connections from the current serving access point to the target access point. In some cases, the Multiple Connectivity Device (MLD) level indication is included in seamless roaming-related frames or in the enhanced link reconfiguration element.

[0043] In one example, the enhanced connection reconfiguration element or the newly defined seamless roaming element carries a multi-connection device attached STA level indication; the multi-connection device attached STA level indication is used to inform the corresponding receiver that the multi-connection device attached STA is about to perform seamless roaming or connection reconfiguration.

[0044] In some cases, when seamless roaming is performed, link reconfiguration can occur simultaneously. The appearance of link configuration information along with seamless handover information on the AP or terminal side is optional. For example, when the aforementioned seamless roaming element appears, the link reconfiguration element is optional. Alternatively, if the seamless roaming element includes a subordinate STA containing multiple reconfiguration operation type subfields, the value of 2 or 3 for link reconfiguration indicates adding or deleting a connection and is optional.

[0045] In some cases, seamless roaming can be viewed as a link reconfiguration, involving the addition of new links and the deletion of existing links. Traditional link reconfiguration, as seen in the current Wi-Fi 7 standard 802.11be, refers to the addition and removal of auxiliary APs or terminal connections between an AP-MLD and its associated non-AP MLD. Connection reconfiguration refers to this traditional link reconfiguration. Seamless roaming, on the other hand, involves adding new connections (between the terminal and the target access point) and deleting old links (between the terminal and the original access point) while maintaining a constant connection.

[0046] In one example, seamless handover from the original access point to the target access point using the seamless roaming information carried in the seamless roaming-related frame can be achieved by: selecting a seamless handover method and using the selected seamless handover method to seamlessly handover from the original access point to the target access point based on the seamless roaming information carried in the seamless roaming-related frame; wherein, selecting a seamless handover method can be: determining a seamless handover method through negotiation when initially accessing the seamless roaming domain, or determining a seamless handover method based on the seamless roaming information carried in the seamless roaming-related frame.

[0047] Seamless handover methods include: over-the-air, over-the-distribution system (Over-the-DS), or basic service set (BSS) handover management.

[0048] One implementation of the Over-the-Air method involves the terminal directly requesting the target access point to initiate a connection, complete the handover, and finally inform the original access point that the handover is complete, or disconnect from the original access point.

[0049] One implementation method of the Over-the-DS approach involves the current access point initiating a seamless handover, communicating with the target access point, and informing the terminal that the seamless handover is complete.

[0050] One implementation method of BSS management involves the terminal or current access point suggesting a target access point and then switching to that target access point. The suggested access point and the final target access point do not necessarily have to be the same access point.

[0051] The seamless handover method mainly involves the following seamless roaming-related frames: Link Reconfiguration Request frame / Link Reconfiguration Request frame, seamless roaming Request frame / seamless roaming response frame, seamless handover confirmation frame (sent by the original access point to the terminal to indicate handover completion), or seamless handover target access point suggestion frame, initial control frame (ICF), and initial control response frame (ICR). The initial control frame (ICF) refers to the seamless connection initiation frame, request frame, or trigger frame; the initial control response frame (ICR) is the response frame to the seamless transmission initial control frame (ICF). ICF / ICR can appear in pairs, or the initial control frame (ICF) can appear alone.

[0052] In one example, seamless switching is a capability where the switching method can be selected. Specifically:

[0053] In some cases, the seamless roaming element, the enhanced link reconfiguration element, or the seamless roaming related frame or the seamless switching context may contain a seamless roaming type subfield / field. This field contains two bits: 00 indicates over-the-Air mode, 01 indicates over-the-DS mode, and 10 indicates BSS management seamless roaming mode. 11 is reserved.

[0054] In some cases, this domain (or subdomain) is included in the beacon or configured together with the seamless roaming domain, indicating the roaming methods supported by the access point device in this domain. In other cases, this domain or subdomain is included in the relevant frame, the seamless roaming element, or the link reconfiguration element upon initial access to the seamless roaming domain. Upon initial access to the seamless roaming domain, this domain, or anything containing it, is included in the relevant frame, the seamless roaming element, or the link reconfiguration element, and in the (re)association request frame / (re)association response frame. The terminal's (re)association request frame indicates the seamless roaming methods it supports, and the access point determines the roaming method for seamless roaming by responding in the (re)association response frame based on the terminal's situation. In some cases, this domain or subdomain, or the domain or subdomain included in the relevant frame, the seamless roaming element, or the link reconfiguration element, is included in the ICF / ICR. After the terminal is connected to the seamless roaming domain, it can be reconfigured or the seamless roaming method can be changed.

[0055] In some cases, supporting seamless over-the-Air roaming is a capability contained in the PHY capability element, the MAC capability element, or the Management Information Base (MIB), which can be enabled or disabled.

[0056] In certain circumstances, if the terminal has this capability enabled and receives a seamless roaming-related frame configured to include a seamless roaming type subfield / field of 00, the terminal will perform over-the-air seamless roaming.

[0057] In some cases, if this capability is enabled on the terminal, the terminal will proactively initiate seamless roaming, including seamless roaming-related frames configured to contain seamless roaming type subfield / field with a value of 00, to perform over-the-air seamless roaming.

[0058] Similarly, in some cases, supporting seamless roaming over-the-DS is a capability contained in the PHYcapability element, or the MAC capability element, or the MIB, which can be enabled or disabled.

[0059] In some cases, if the terminal has this capability enabled and receives a seamless handover related frame configured to include a seamless roaming type subfield / field of type 01, the terminal performs over-the-DS seamless roaming. In other cases, if the terminal has this capability enabled, the terminal actively initiates seamless roaming, including a seamless roaming related frame configured to include a seamless roaming type subfield / field of type 01, and performs over-the-DS seamless roaming.

[0060] Similarly, in some cases, supporting seamless roaming of BSS management is a capability contained in the PHY capability element, or the MAC capability element, or the MIB, which can be enabled or disabled.

[0061] In some cases, if the terminal has this capability enabled and receives a seamless roaming-related frame configured to include a seamless roaming type subfield / field of type 10, the terminal performs seamless roaming based on BSS management. In other cases, if the terminal has this capability enabled, the terminal proactively initiates seamless roaming, including the aforementioned seamless roaming-related frame configured to include a seamless roaming type subfield / field of type 10, and performs seamless roaming based on BSS management.

[0062] Regarding the context of seamless roaming-related frames, in one example, the context of a seamless roaming-related frame includes one or any combination of the following: frame sequence number information, packet number information, batch acknowledgement (BA) information, target wake-up time (TWT) information, traffic identifier (TID) to link mapping information, and connection reconfiguration information included in the connection reconfiguration element; wherein, the TID to link mapping information is used to map the seamlessly switched service to the connection corresponding to the target access point according to the TID to the link. A specific example is as follows:

[0063] In some cases, seamless roaming and link reconfiguration occur simultaneously. In some situations, seamless roaming information and link reconfiguration information are contained within the seamless roaming-related frames, along with TID-to-link mapping (or a TID-to-link element). The traffic after the handover is mapped to the target access point's connection according to the TID-to-link mapping. If no TID-to-link mapping is negotiated during seamless roaming, or if the related frames do not contain a TID-to-link mapping element, then the target access point's TID-to-link mapping is assumed to be the default setting, and a single TID can be mapped to any connection on the target access point.

[0064] In some cases, the ICF, or the Seamless Roaming Request frame, or the Enhanced Link Reconfiguration Request frame, requests TID-to-link mapping or contains a TID-to-link mapping element. Then, the ICR, or the Seamless Roaming Response frame, or the Enhanced Link Reconfiguration Response frame, has a TID-to-link mapping negotiation function, responding based on the requested TID-to-link mapping, agreeing to the requested TID-to-link mapping, or suggesting or applying a new TID-to-link mapping.

[0065] In some cases, the ICF, or Seamless Roaming Request Frame, or Enhanced Link Reconfiguration Request Frame, is sent by the terminal to the target access point, and the target access point responds with an ICR, or Seamless Roaming Response Frame, or Enhanced Link Reconfiguration Response Frame.

[0066] In some cases, the ICF, or Seamless Roaming Request Frame, or Enhanced Link Reconfiguration Request Frame, is sent by the endpoint to the current service access point, and then the current service access point responds with an ICR, or Seamless Roaming Response Frame, or Enhanced Link Reconfiguration Response Frame.

[0067] Context refers to the parameters or information exchanged between the terminal and the original access point (or current serving access point) during seamless roaming, such as batch acknowledgements. This information can be carried by the terminal and transmitted to the target access point via a seamless roaming-related frame. Alternatively, this information can be transmitted from the terminal or the current access point to the upper MAC layer, and then from the upper MAC layer to the target access point.

[0068] In one example, the context in a seamless roaming-related frame is divided into a context that supports reconstruction and a context that does not support reconstruction. The context that supports reconstruction will renegotiate and determine some or all of the information contained in the context after receiving the corresponding reconstruction instruction. The context can support reconstruction regardless of whether there is connection reconfiguration information in the seamless roaming-related frame.

[0069] Whether the context of a frame related to seamless roaming contains TID-to-link mapping information can be a capability. In some cases, TID-to-link mapping is a context for seamless roaming.

[0070] In some cases, TWT information, such as the TWT period or TWT element, serves as a seamless roaming context. In other cases, the context during seamless roaming includes TID-to-link mapping information, or TWT information, a TID-to-link mapping element, or a TWT element. This TID-to-link mapping information or TWT information describes the TID mapping state between the terminal and the originating access point, or the TWT operation between the terminal and the originating access point. In some cases, TWT information refers to the TWT element. In other cases, TID-to-link mapping information refers to the TID-to-link mapping element.

[0071] In some cases, the presence of a TID-to-link mapping element in seamless roaming-related frames or within the seamless roaming context is configurable, optional, or a capability. In some situations, TID-to-linkmappingduirngSeamlessRoaming (which may be called by other names) indicates whether TID-to-link element information is included in seamless roaming-related frames, or whether TID-to-link mapping negotiation occurs during seamless roaming. TID-to-linkmappingduirngSeamlessRoaming is contained within a PHY capability element, MAC capability element, or MIB, and can be enabled or disabled.

[0072] In some cases, the variable TID-to-linkmappingduirngSeamlessRoaming is enabled, indicating that the TID-to-link mapping information is contained in the seamless handover-related frame, or that the TID-to-link mapping element is a seamless handover context, contained in the seamless handover context, or contained in the frame or the corresponding defined element of the seamless handover context.

[0073] In some cases, the functionality of TID-to-link mapping during Seamless Roaming is represented by TID-to-Link Mapping Negotiation Support and implemented by TID-to-Link Mapping Negotiation Support. TID-to-Link Mapping Negotiation Support is contained in the MLD Capabilities and Operations subfield within the common info field of the Basic multi-link element. In some cases, the reserved value 2 for this subfield is enabled, indicating that TID-to-Link Mapping negotiation will occur during seamless handover, or the existing design will continue, either within a link reconfiguration element included in the seamless handover-related frame, or in a newly defined seamless roaming element, or within the basic multi-link element.

[0074] Similarly, the TWT element, whether included in seamless roaming-related frames or negotiated during seamless handover, is configurable, optional, or a capability. In some cases, TWTduirngSeamlessRoaming (which may be called by other names) indicates whether TWT information is included in seamless handover-related frames or whether TWT negotiation occurs during seamless handover. TWTduirngSeamlessRoaming is included in the PHYcapability element, MAC capability element, or MIB and can be enabled or disabled.

[0075] In some cases, TWTduirngSeamlessRoaming is enabled, indicating that the TWT information is contained in the seamless handover-related frame, or that the TWT element is a context for seamless handover, or is contained in the frame or the defined element corresponding to the seamless handover context.

[0076] In some cases, if certain configurations, such as TID-to-link mapping during Seamless Roaming, are enabled, or the MLD Capabilities And Operations subfield in the common info field is 2, or the current configuration indicates that TID-to-link mapping negotiation should be performed during seamless roaming, but at least one seamless roaming-related frame does not contain TID-to-link mapping information, or the negotiation fails, then after seamless roaming (or seamless handover) is completed, or during the seamless handover process, the terminal negotiates TID-to-link mapping with the target access point. In some cases, this process is called context re-reconstruction.

[0077] Similarly, if TWT negotiation information is indicated, or configured to occur simultaneously with seamless roaming, but fails to appear in at least one seamless roaming-related frame, or if TWT negotiation fails, the terminal negotiates TWT with the target access point after seamless handover or during the seamless handover process. In some cases, this process is called context re-evaluation.

[0078] In some cases, the context during seamless handover includes at least one of the following: {SN, PN, BA, TWT information, link reconfiguration information, TID-to-link mapping information}. Here, SN is the sequence number, PN is the packet number, BA is the batch acknowledgement, the link reconfiguration information includes the link reconfiguration element, the TID-to-link mapping information includes the TID-to-link mapping element, and the TWT information includes the TWT element.

[0079] In some cases, at least one of the aforementioned contextual information pieces does not support reconstruction; in others, it does. Whether or not the aforementioned contextual information pieces support reconstruction is configurable in some cases. A field, occupying one bit, or a bitmap, is contained within the context, in an enhanced link reconfiguration element, in a newly defined seamless roaming element, or in a frame containing seamless roaming. The corresponding bit indicates whether an item in the context can be reconstructed. For example, 1 indicates that the item is reconstructable, and 0 indicates that the item is not reconstructable.

[0080] In some cases, seamless roaming frames contain implicit indications about whether items (or certain contexts) within a context can be reconstructed. Certain contexts or items within a context that are included in the frame indicate that these contexts do not need to be reconstructed or do not support reconstruction. Other items not included in the frame or context but that do belong to the context indicate that they can be reconstructed. Context reconstruction refers to renegotiating and determining some or all of the information in the context, or renegotiating and determining some or all of the items in the context.

[0081] In one example, when a seamless roaming-related frame carries a connection reconfiguration support indication, the system determines whether connection reconfiguration is allowed during this seamless roaming period based on this indication. From the terminal's perspective, this means that link reconfiguration does not occur during seamless roaming; that is, the terminal does not request to join or delete links during seamless roaming. Specifically:

[0082] In some cases, the number of connections for the terminal, or the number of active affiliated STAs, remains unchanged during seamless roaming. This means that no connection reconfiguration occurs outside of seamless roaming during seamless roaming. Alternatively, no link reconfiguration request frame is transmitted during seamless roaming. Seamless roaming refers to the terminal switching from its current serving AP MLD to another AP MLD while maintaining state 4. State 4 is the associated state. In some cases, seamless roaming refers to the time it takes for the terminal to complete the seamless handover, a time interval such as 10ms or 20ms. In other cases, it refers to the time from when the seamless handover is initiated by the terminal or the currently serving AP MLD until the handover ends.

[0083] To prevent link reconfiguration from occurring during seamless roaming, in one example, the configuration of the corresponding field in the standard should be as follows: LinkReconfiguration Operation Support should be reused or used in the MLD Capabilities And Operations subfield of the common info field in a basic multi-link element, a link reconfiguration element enhanced for seamless roaming, or a newly defined seamless roaming element. If a basic multi-link element, a link reconfiguration element enhanced for seamless roaming, or a newly defined seamless roaming element is included in a frame related to seamless roaming, and Link Reconfiguration OperationSupport is 1, it indicates that multi-link reconfiguration (or link reconfiguration) can be performed during seamless handover; otherwise, it should be 0. In some cases, if MLReconfigurationinSeamlessRoaming is enabled, the above Link Reconfiguration Operation Support should be 1; otherwise, it should be 0. MLReconfigurationinSeamlessRoaming is a variable, or a capability representation, contained in PHYcapability, MAC capability, or MIB, and can be enabled or disabled. For example, if a terminal uses a seamless roaming-related frame and Link Reconfiguration OperationSupport is 1, it means that the terminal can perform connection reconfiguration simultaneously during seamless roaming. Otherwise, LinkReconfiguration Operation Support is 0, indicating that it is not supported.

[0084] It's necessary to prevent link reconfiguration from occurring during seamless roaming. In one example, seamless roaming is made a capability. Specifically: In some cases, the common info field of the seamless roaming element, basic multi-link element, or newly defined link reconfiguration element contains MLD capabilities, and the newly defined seamless roaming support is included in the MLD Capabilities and Operations subfield. This indicates that the device supports seamless handover or seamless roaming. It can be enabled or disabled, set to 1 for enabled, or 0 for disabled. In some cases, this capability is included in the PHY capability element, MAC capability element, or MIB, and can be called Seamless Roaming Supported or Seamless Roaming Enabled. A device can only access a seamless roaming domain if Seamless Roaming Enabled is configured to be enabled, or configured to 1 (indicating support for seamless roaming). If SeamlessRoamingEnabled is configured to 0 (indicating seamless roaming is not supported) or is disabled, the device does not support seamless roaming. During handover, it must fall back to the normal handover method, i.e., first disconnect from the current access point, then establish a connection with the target access point. If a device's SeamlessRoamingEnabled is configured to 0 (indicating seamless roaming is not supported) or is disabled, the device is out of (all) seamless roaming domains and cannot perform seamless roaming operations. If a device receives a seamless roaming-related frame or other management or control frame containing SeamlessRoamingSupported or SeamlessRoamingEnabled configured to 0 or disabled, the device falls back to the normal (or traditional) handover method. In some cases, access points may connect to multiple devices, or an access point may transmit seamless roaming-related frames or other management or control frames containing SeamlessRoamingSupported or SeamlessRoamingEnabled to a single terminal device. The seamless roaming capability of the terminal is configured to be enabled or disabled.In some cases, the terminal's seamless roaming capability is determined by the terminal itself, through seamless roaming-related frames or other management frames, control frames, and reported to the AP. During the initial access for seamless roaming, the terminal can only access a certain seamless roaming domain if SeamlessRoamingEnabled is enabled; otherwise, it cannot access that seamless roaming domain.

[0085] Does the terminal or access point have seamless roaming capability, or does it support seamless roaming as part of a beacon, probe response frame, or probe response frame? In some cases, does the terminal or access point have seamless roaming capability, or does it support seamless roaming as a UHR capability (UHR stands for Wi-Fi 8)? In some cases, this capability is included in the PHY capability element or MAC capability element.

[0086] In this embodiment, connection reconfiguration is achieved during seamless roaming by carrying connection reconfiguration information in seamless roaming-related frames transmitted between the original access point and / or the target access point; seamless handover from the original access point to the target access point is achieved through the seamless roaming information carried in the seamless roaming-related frames. This enables effective coordination of multiple connection reconfigurations and seamless handover during seamless roaming.

[0087] The steps described above are for clarity only. 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 application. 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 application.

[0088] Another embodiment of the present invention relates to a terminal, such as Figure 4 As shown, it includes at least one processor 401; and a memory 402 communicatively connected to the at least one processor; wherein the memory 402 stores instructions executable by the at least one processor 401, the instructions being executed by the at least one processor 401 to enable the at least one processor 401 to perform the seamless switching method supporting connection reconfiguration as described above.

[0089] The memory 402 and processor 401 are connected via a bus, which may include any number of interconnecting buses and bridges. The bus connects various circuits of one or more processors 401 and memory 402 together. The bus can also connect various other circuits, such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. A bus interface provides an interface between the bus and the transceiver. The transceiver can be a single element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices over a transmission medium. Data processed by processor 401 is transmitted over a wireless medium via an antenna, which further receives data and transmits it to processor 401.

[0090] Processor 401 is responsible for managing the bus and general processing, and can also provide various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. Memory 402 can be used to store data used by processor 401 during operation.

[0091] Those skilled in the art will understand that the above embodiments are specific examples of implementing the present invention, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the present invention.

Claims

1. A seamless switching method supporting connection reconfiguration, characterized in that, include: Connection reconfiguration is achieved during seamless roaming by carrying connection reconfiguration information in seamless roaming-related frames transmitted between the original access point and / or the target access point during seamless roaming; The original access point and the target access point are located in a Wi-Fi system; The connection reconfiguration includes adding and / or deleting connections in a Wi-Fi multi-connection device; The seamless roaming information carried in the seamless roaming related frames allows for a seamless switch from the original access point to the target access point.

2. The seamless switching method supporting connection reconfiguration according to claim 1, characterized in that, The connection reconfiguration information is included in one or any combination of the following elements: Basic multi-connection element, connection reconfiguration element, newly defined seamless roaming element, enhanced connection reconfiguration element; The newly defined seamless roaming element is formed by enhancement based on the basic multi-connection element and / or the connection reconfiguration element.

3. The seamless handover method supporting connection reconfiguration as described in claim 2, characterized in that, The elements carrying the connection reconfiguration information and the seamless roaming information in the seamless roaming-related frames include the following combinations: The seamless roaming-related frame carries both the basic multi-connection element and the seamless roaming element; the seamless roaming-related frame carries both the connection reconfiguration element and the enhanced connection reconfiguration element; the seamless roaming-related frame carries only the enhanced connection reconfiguration element; and the seamless roaming-related frame carries only the newly defined seamless roaming element.

4. The seamless handover method supporting connection reconfiguration according to claim 2, characterized in that, The enhanced connection reconfiguration element or the newly defined seamless roaming element carries a multi-connection device level indication; The multi-connection device level indication is used to inform the receiver corresponding to the multi-connection device level indication that the sender corresponding to the multi-connection device level indication is about to perform seamless roaming, or to inform the receiver corresponding to the multi-connection device level indication that the sender corresponding to the multi-connection device level indication is about to perform connection reconfiguration. The multi-connection device level indication includes at least one of the following: roaming, switching, joining a connection, deleting a connection, disconnecting a connection, and capability mode.

5. The seamless handover method supporting connection reconfiguration according to claim 4, characterized in that, The enhanced connectivity reconfiguration element or the newly defined seamless roaming element carries a multi-connected device associated STA level indication; The Multi-Connection Device Auxiliary STA Level Indicator is used to inform the corresponding receiver that the Multi-Connection Device Auxiliary STA is about to perform seamless roaming or the upcoming connection reconfiguration.

6. The seamless handover method supporting connection reconfiguration according to claim 1, characterized in that, The seamless switching from the original access point to the target access point via the seamless roaming information carried in the seamless roaming related frame includes: Select a seamless handover method, and use the selected seamless handover method to seamlessly hand over from the original access point to the target access point based on the seamless roaming information carried in the seamless roaming related frame; The seamless handover method mentioned above is a capability, including: over-the-air method, over-the-DS method, or basic service set (BSS) handover management method. The selection of a seamless handover method includes: determining a seamless handover method through negotiation when initially accessing the seamless roaming domain, or determining a seamless handover method based on the seamless roaming information carried in the seamless roaming related frames.

7. The seamless switching method supporting connection reconfiguration according to claim 1, characterized in that, The context in the seamless roaming-related frame contains one or any combination of the following: Frame sequence number information, packet number information, batch acknowledgment (BA) information, target wake-up time (TWT) information, service identifier (TID) to link mapping information, and connection reconfiguration information included in the connection reconfiguration element; The service identifier (TID) to link mapping information is used to map the seamlessly switched service to the connection corresponding to the target access point according to the service identifier (TID) to link.

8. The seamless handover method supporting connection reconfiguration according to claim 1, characterized in that, The context in the seamless roaming related frames is divided into contexts that support reconstruction and contexts that do not support reconstruction; The context supporting reconstruction will be renegotiated to determine some or all of the information contained in the context supporting reconstruction after receiving the corresponding reconstruction instruction.

9. The seamless handover method supporting connection reconfiguration according to claim 1, characterized in that, The method further includes: When the seamless roaming related frame carries a connection reconfiguration operation support indication, determine whether the connection reconfiguration is allowed during this seamless roaming based on the connection reconfiguration operation support indication.

10. A terminal, characterized in that, include: At least one processor; as well as, A memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor to enable the at least one processor to perform the seamless switching method supporting connection reconfiguration as described in any one of claims 1 to 9.

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