Method for enhancing roaming performance and communication equipment

Abstract

A method of enhancing roaming performance is provided. The method is implemented by a station multilink device (MLD) and includes: communicating with a current access point (AP) over at least two links, where the at least two links include a first link and a second link; disabling the second link connected to the current AP; establishing association with the target AP through a new second link; sending a message to the target AP over the new second link for notifying a network node site (STA) to reside in a cell served by the target AP and disabling the new second link connected to the target AP; obtaining the cached data packet from the current AP through the first link in a time period; disconnecting from the current AP after the time period; and enabling the new first link and the new second link to obtain the data packet from the target AP.

Description

[Technical field]

[0001] The present invention generally relates to the field of wireless communication technology, and more particularly to a method and a communication device for enhancing roaming performance. [Background technology]

[0002] Wireless local area network (WLAN) roaming or Wi-Fi roaming refers to the process of a station (STA) moving from one access point (AP) to another AP. During WLAN roaming or Wi-Fi roaming, a STA can move freely in the same Wi-Fi network including multiple APs to achieve uninterrupted service.

[0003] When a STA roams from a current AP to a target AP, the STA may first disconnect from the current AP. Before the connection with the target AP is established, the current AP and the STA cannot transmit data to each other, and the buffered data packets in the current AP may be lost. In addition, the transition time of the STA switching from the current AP to the target AP affects the duration of the service interruption.

[0004] Institute of Electrical and Electronics Engineers (IEEE) 802.11be, also known as Wi-Fi 7, introduces the concept of Multi-Link Device (MLD), which enables STA to communicate with AP through multiple links. The roaming of multi-link devices is expected to enable uninterrupted data transmission. However, since non-AP MLDs are not allowed to connect to two AP MLDs, the problem of how to implement roaming of multi-link devices under IEEE 802.11be, reduce the interruption time of data transmission during roaming, or ensure uninterrupted data transmission during roaming has not been solved.

[0005] Therefore, a method and a communication device for enhancing roaming performance are needed to solve these problems. [Summary of the invention]

[0006] The following summary is provided for informational purposes only and is not intended to be limiting in any way. That is, the following summary is intended to introduce the concepts, highlights, advantages, and benefits of the novel and non-obvious techniques described herein. Moreover, not all embodiments are described in detail in the following detailed description. Therefore, the following summary is not intended to determine the essential features of the protected subject matter, nor is it intended to determine the scope of the protected subject matter.

[0007] Therefore, the main object of the present invention is to provide a method and apparatus for enhancing roaming performance to achieve uninterrupted data transmission during roaming.

[0008] In an exemplary embodiment, a method for enhancing roaming performance is provided. The method is implemented by a station (STA) multi-link device (MLD). The method includes: communicating with a current access point (AP) through at least two links, wherein the at least two links include a first link and a second link; disabling the second link connected to the current AP; establishing an association with a target AP through a new second link, wherein the association includes a new first link and a new second link; sending a message to the target AP through the new second link to notify the network node that the STA resides in a cell served by the target AP and disabling the new second link connected to the target AP; obtaining a cached data packet from the current AP through the first link within a time period; disconnecting from the current AP after the time period; and enabling the new first link and the new second link associated with the target AP to obtain a data packet from the target AP, wherein the first link and the new first link correspond to the same radio, the second link and the new second link correspond to the same radio, and the new first link and the new second link correspond to different radios.

[0009] In some embodiments, the step of disabling the second link connected to the current AP includes sending a QoS Null frame with PS_mode=1 to the current AP through the second link to disable the second link connected to the current AP.

[0010] In some embodiments, after establishing the association, the new first link is set to the power saving mode by default.

[0011] In some embodiments, the step of enabling a new first link and a new second link associated with the target AP includes: enabling the new first link by sending a first QoS Null frame with PS_mode=0 to the target AP via the new first link; and enabling the new second link by sending a second QoS Null frame with PS_mode=0 to the target AP via the new second link.

[0012] In some embodiments, the method further includes: after disabling the second link connected to the current AP or establishing association with the target AP through a new second link, stopping sending an uplink (UL) data packet of the STA MLD to the current AP through the first link.

[0013] In some embodiments, the message is sent after the current AP sends all buffered uplink (UL) data packets of the STA MLD to the network node.

[0014] In some embodiments, the message is a first broadcast message, used to trigger the target AP to send a second broadcast message to the network node, so that the path of the DL data packet related to the STA MLD in the network node is switched from the current AP to the target AP; the first broadcast message is a QoS Null frame with PS_mode=1, used to disable the new second link connected to the target AP.

[0015] In some embodiments, the step of enabling a new first link and a new second link associated with the target AP to obtain a data packet from the target AP includes: enabling a new first link and a new second link associated with the target AP to obtain a data packet cached by the target AP, wherein the cached data packet is sent by the network node to the target AP after receiving a second broadcast message.

[0016] The present invention provides a method for enhancing roaming performance. The method is implemented by a station (STA). The method includes: communicating with a current AP through a first link; disabling the first link connected to the current AP; establishing an association with a target AP through a new first link; sending a message to the target AP through the new first link to notify the network node that the STA resides in a cell served by the target AP and disabling the new first link connected to the target AP; enabling the first link within a time period and obtaining a cached data packet from the current AP through the first link; disconnecting from the current AP after the time period; and enabling the new first link connected to the target AP to obtain a data packet from the target AP; wherein the first link and the new first link correspond to the same radio.

[0017] In some embodiments, disabling the first link connected to the current AP includes: sending a QoS Null frame with PS_mode=1 to the current AP through the first link to disable the first link connected to the current AP.

[0018] In some embodiments, the method includes: after disabling the first link connected to the current AP, stopping sending UL data packets to the current AP through the first link.

[0019] In some embodiments, the message is a first broadcast message, used to trigger the target AP to send a second broadcast message to the network node, so that the path of the DL data packet related to the STA in the network node is switched from the current AP to the target AP; and the first broadcast message is a QoS Null frame with PS_mode=1, used to disable the new first link connected to the target AP.

[0020] In some embodiments, the step of enabling a new first link associated with the target AP to obtain a data packet from the target AP includes: enabling a new first link associated with the target AP to obtain a cached data packet of the target AP, wherein the cached data packet is sent by the network node to the target AP after receiving the second broadcast message.

[0021] In some embodiments, the step of enabling the first link includes sending a QoS Null frame with PS_mode=1 through the first link to enable the first link connected to the current AP.

[0022] In an exemplary embodiment, a communication device is provided. The communication device includes a processor and a plurality of radio devices. The processor is configured to: communicate with a current AP through at least two links, wherein the at least two links include a first link and a second link; disable the second link connected to the current AP; establish an association with a target AP through a new second link; wherein the association includes a new first link and a new second link; send a message to the target AP through the new second link to notify the network node STA to reside in a cell served by the target AP and disable the new second link connected to the target AP; obtain a cached data packet from the current AP through the first link within a time period; disconnect from the current AP after the time period; and enable a new first link and a new second link associated with the target AP to obtain a data packet from the target AP; wherein the first link and the new first link use the same radio device, the second link and the new second link use the same radio device, and the new first link and the new second link use different radio devices.

Brief Description of the Drawings

[0023] The accompanying drawings are used to help further understand the present invention and are incorporated into and constitute a part of the present invention. The accompanying drawings illustrate embodiments of the present invention and are used together with the description to explain the principles of the present invention. It should be understood that the drawings are not necessarily drawn to scale, because in order to clearly illustrate the concepts of the present invention, some components may not be proportional to the sizes in the actual implementation.

[0024] Figure 1 is a schematic diagram of a wireless communication system architecture according to an embodiment of the present invention.

[0025] Figure 2 2 is an example of a Media Access Control (MAC) protocol stack of an access point multi-link device (AP MLD) 210 and a station multi-link device (STA MLD) 220 according to an embodiment of the present invention.

[0026] Figures 3A to 3EThe process of enhancing roaming performance implemented by STA MLD according to an embodiment of the present invention is shown.

[0027] Figure 4 is a schematic diagram showing a time period T according to an embodiment of the present invention.

[0028] Figure 5 is an exemplary flow chart showing a method for enhancing roaming performance according to an embodiment of the present invention.

[0029] Figures 6A to 6E The process of enhancing roaming performance implemented by a STA according to an embodiment of the present invention is shown.

[0030] Figure 7 FIG. 4 is a flowchart illustrating a method for enhancing roaming performance according to an embodiment of the present invention.

[0031] Figure 8 An exemplary wireless communication device implementing aspects of the present invention is shown. [Specific implementation method]

[0032] Reference will now be made in detail to several embodiments. Although the subject matter will be described in conjunction with alternative embodiments, it should be understood that they are not intended to limit the protected subject matter to these embodiments. On the contrary, the protected subject matter is intended to cover substitutions, modifications and equivalents, which may be included in the spirit and scope of the desired subject matter defined by the appended claims.

[0033] Furthermore, in the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the subject matter protected. However, those skilled in the art will recognize that embodiments can be implemented without these specific details or with their equivalents. In other cases, well-known methods, procedures, components, and circuits are not described in detail to avoid unnecessarily obscuring aspects and features of the subject matter.

[0034] The following detailed description is presented and discussed in terms of methods. Although the diagrams (e.g., Figure 5 and 7 ) discloses the steps and their order, but these steps and order are only exemplary.

[0035] Figure 1 is a schematic diagram of the architecture of a wireless communication system 100 according to an embodiment of the present invention. Figure 1 Using a wireless local area network as an example, the wireless communication system 100 includes one or more access point multi-link devices (e.g., Figure 1 The access point multi-link device 112 and the access point multi-link device 114) and the site multi-link device 120.

[0036] The communication area (or coverage area) 112A or 114A of the access point multi-link device 112 or 114 may be referred to as a “cell.” The site multi-link device 120 may be located within the cell or coverage area 112A of the access point multi-link device 112 .

[0037] The access point multi-link device is a multi-link device that provides services for the site multi-link device. The site multi-link device can use multiple links to communicate with the access point multi-link device to improve throughput. Figure 1 The number of access point multi-link devices and station multi-link devices in is just an example.

[0038] For example, a multilink device (e.g. Figure 1 Any one of the access point multi-link device 112, the access point multi-link device 114, and the station multi-link device 120 in the embodiment of the present invention is a device with a wireless communication function. The device can be a complete device, or can be a chip, a processing system, or a similar device installed in a complete device. The devices installed by these chips or processing systems can be controlled by these chips or processing systems to implement the methods and functions in the embodiments of the present invention. For example, the access point multi-link device in the embodiment of the present invention is a device that provides services for the station multi-link device, and can support the 802.11 series of protocols.

[0039] The site multi-link device in the embodiment of the present invention has a wireless transceiver function, can support the 802.11 series of protocols, and can communicate with an access point multi-link device or another site multi-link device. For example, the site multi-link device is any user communication device that allows a user to communicate with an access point. For example, the site multi-link device can be a user device that can be connected to a network, such as a tablet computer, a desktop computer, a laptop computer, a notebook computer, an ultra-mobile personal computer (UMPC), a handheld computer, a netbook, a personal digital assistant (PDA) or a mobile phone, can be an Internet of Things node in the Internet of Things, or can be a vehicle-mounted communication device in the Internet of Vehicles. The site multi-link device can also be a chip or processing system in the above-mentioned terminal. Of course, the site multi-link device can also be a chip and processing system in various forms of devices to implement the methods and functions in the embodiments of the present application. The 802.11 protocol can be a protocol that supports 802.11be or is compatible with 802.11be.

[0040] Figure 2 It is an example of a Media Access Control (MAC) protocol stack of the access point MLD 210 and the station MLD 220 according to an embodiment of the present invention.

[0041] like Figure 2 As shown, the MLD lower MAC sublayer in the access point MLD includes AP 1 and AP 2 which are independent of each other. AP 1 and AP 2 in the MLD lower MAC sublayer can transmit information or data to the MLD upper MAC sublayer. The MLD upper MAC sublayer transmits the information or data of AP 1 and AP 2 to the upper layer through the MAC service access point (SAP). The MLD upper MAC sublayer can also receive information or data from the upper layer through the MAC SAP and transmit the information or data to AP 1 and AP 2.

[0042] Similarly, the MLD lower MAC sublayer in the site MLD includes STA 1 and STA 2 which are independent of each other. STA 1 and STA 2 in the MLD lower MAC sublayer can transmit information or data to the MLD upper MAC sublayer. The MLD upper MAC sublayer transmits the information or data of STA 1 and STA 2 to the upper layer through MAC SAP. The MLD upper MAC sublayer can also receive information or data from the upper layer through MAC SAP and transmit the information or data to STA1 and STA2.

[0043] The AP multi-link device (AP MLD) 210 and the STA multi-link device (STA MLD) 220 can transmit over multiple links (link 1 and link 2). STA1 can be connected to AP1. STA2 can be connected to AP2. The connection between STA1 and AP1 is link 1. The connection between STA2 and AP2 is link 2. Link 1 uses one radio. Link 2 uses another radio. Link 1 and link 2 use different radios. In addition, the AP MLD 210 and the STA MLD 220 can operate on two or more links at the same time. Different links can be on different frequency bands, such as the 2.4 GHz, 5 GHz, and 6 GHz bands reserved for unlicensed operation.

[0044] Figures 3A to 3E The process of enhancing roaming performance implemented by STA MLD according to an embodiment of the present invention is shown.

[0045] exist Figure 3AIn the embodiment, STA MLD is connected to the current AP MLD, and STA MLD communicates with the current AP MLD through link 1 and link 2. The router can send the DL data packet of STA MLD to the current AP MLD through the switching node, and receive the UL data packet of STA MLD from the current AP MLD through the switching node, wherein the DL data packet includes a MAC destination address (DA) (i.e., the address of STA MLD) and a MAC source address (SA) (i.e., the address of the router), and the UL data packet includes a MAC DA (i.e., the address of the router) and a MAC SA (i.e., the address of STA MLD). STAMLD can receive DL data packets from the current AP MLD through link 1 and link 2, and send UL data packets to the current AP MLD. Link 1 and link 2 can be in different frequency bands. Link 1 can be a link in the 2G frequency band. Link 2 can be a link in the 5G frequency band.

[0046] exist Figure 3B In step S301, the STA MLD sends a QoS Null frame with PS_mode=1 to the current AP MLD through link 2 to disable link 2 connected to the current AP MLD. Then, in step S302, the STA MLD establishes an association with the target AP MLD through the new link 2, wherein the association includes the new link 1 and the new link 2. Specifically, in some embodiments, the STA MLD may send a message (e.g., an association request) to the AP through the new link 2 to notify the target AP MLD that the STA MLD has the new link 1 and the new link 2 available for communication with the target AP MLD. Because the new link 2 is a setup link for establishing an association, the new link 2 is in an awake state. Because the new link 1 is a non-setup link, after the new link 1 is established, the new link 1 is set to a power saving mode by default. In other words, the STA MLD disables the new link 1 after the new link 1 is established.

[0047] exist Figure 3CIn step S304, the STA MLD stops sending UL packets through link 1. In other words, the STA MLD can only receive DL packets from the current AP MLD through link 1. In step S305, the current AP MLD sends all cached UL packets of the STA MLD to the switching node, and caches the DL packets of the STA MLD from the switching node. In step S306, the STA MLD sends a first message to the target AP MLD through the new link 2 to trigger the target AP to send a second message to the switching node to notify the switching node that the STA MLD is residing in the cell served by the target AP MLD. The first message carries an indication for disabling the new link 2 connected to the target AP MLD. The first message and the second message can be broadcast Address Resolution Protocol (ARP) messages. The first broadcast ARP message is sent by the STA MLD. In the first broadcast ARP message, the TA address (sender address) is the STA MLD address, the RA address (receiver address) is the target AP MLD address, and the DA (final destination address) is FF:FF:FF:FF:FF:FF. The target AP MLD sends a second broadcast ARP message after receiving the first broadcast ARP message. In the second broadcast ARP message, the TA address is the STA MLD address, and the DA is FF:FF:FF:FF:FF:FF. The switching node receives the second broadcast ARP message. The switching node can learn that the STA MLD is residing in the cell served by the target AP MLD, and the DL data packet of the STAMLD should be transmitted to the target AP MLD. The first ARP message can be a QoS Null frame with PS_mode=1, which is used to disable the new link 2 connected to the target AP MLD. In some embodiments, the first broadcast ARP message is an 802.11 unicast packet, and the second broadcast ARP message is an 802.3 packet.

[0048] STAMLD can estimate the amount of UL packets of STA MLD stored in the current AP MLD. STAMLD can estimate a time length based on the amount of UL packets of STAMLD stored in the current AP MLD, and wait at least the estimated time length before sending the first broadcast ARP. Because the switching node determines the DA of the DL packets of STAMLD based on the SA of the last received UL packet of STAMLD, STAMLD needs to wait for the estimated time length before sending the first ARP message to the target AP MLD so that the current AP MLD completes the transmission of the UL packets stored in the current AP MLD, and the second ARP message from the target AP MLD is the last UL packet received by the STA MLD. Through this arrangement, the switching node can learn that the DL packets of the STA MLD should be sent to the target AP MLD.

[0049] exist Figure 3D In the example, the STA MLD obtains the DL data packet buffered in the current AP MLD from the current AP MLD through link 1.

[0050] Before the switching node receives the second broadcast ARP from the APMLD, the switching node sends a DL packet of STAMLD to the current AP MLD. After receiving the second broadcast ARP from the target AP MLD, the switching node sends a DL packet of STAMLD to the target AP MLD. The current AP MLD caches the old DL packet of STA MLD, and the target AP MLD caches the new DL packet of STAMLD. Because STA receives the old DL packet from the current AP MLD through link 1 and disables the new link 2 with the target AP MLD, STAMLD does not receive the old DL packet from the current AP MLD and the new DL packet from the target AP MLD at the same time to avoid out-of-order received packets.

[0051] exist Figure 3E In step S307, the STA MLD disconnects from the current AP MLD after a period of time. Specifically, because the STA MLD does not know the cache status of the current AP MLD, the STA MLD will wait for a period of time T to obtain the DL data packet cached by the current AP MLD from the current AP MLD. Figure 4 FIG. 1 is a schematic diagram of a time period T according to an embodiment of the present invention. Figure 4 As shown, t0 is the time when STA MLD sends the first ARP message to the target AP, and the time period t NoDataThe time when the last buffered DL data packet is received from the current AP MLD plus the threshold NoData_TH. The threshold NoData_TH may represent a time period during which no data packet is received from the current AP MLD. In addition, the maximum waiting time t may be preset through experience or experimentation. max When time period t NoData Less than t max When time period T is equal to time period t NoData , and STA MLD is in time period t NoData Then disconnect from the current AP MLD; otherwise, the time period T is equal to t max , and the STA needs to wait for the maximum waiting time t before disconnecting from the current AP MLD max .

[0052] In step S308, the STA MLD sends a QoS Null frame with PS_mode=0 to the target AP MLD through the new link 1 and the new link 2, respectively, to enable the new link 1 and the new link 2 associated with the target AP MLD. Therefore, the STA MLD can send UL packets to the target AP MLD and receive DL packets from the target AP MLD through the new link 1 and the new link 2.

[0053] This enhanced roaming performance process can reduce delay and improve reliability when the STA MLD roams to the target AP MLD.

[0054] Figure 5 is an exemplary flowchart 500 of a method for enhancing roaming performance according to an embodiment of the present invention, wherein the method is performed by a STA or Figures 3A to 3E STA MLD implementation in .

[0055] In step S505 , the STA communicates with the current AP through at least two links, where the at least two links include a first link and a second link.

[0056] Then, in step S510, the STA disables the second link connected to the current AP.

[0057] Specifically, the STA may send a QoS Null frame with PS_mode=1 to the current AP through the second link to disable the second link connected to the current AP.

[0058] In step S515, the STA establishes an association with the target AP through the new second link, where the association includes the new first link and the new second link.

[0059] In some embodiments, after the STA disables the second link connected to the current AP in step S510 or establishes an association with the target AP through a new second link in step S515, it stops sending UL data packets of the STA MLD through the first link.

[0060] In step S520, the STA sends a message to the target AP through the new second link, to inform the switching node that the STA resides in the cell served by the target AP and disables the new second link connected to the target AP.

[0061] In some embodiments, the message sent by the STA is a message. The message is a first broadcast Address Resolution Protocol (ARP) message, which is used to trigger the target AP to send a second broadcast ARP message to the switching node, so as to switch the DL path of the DL data packet related to the STA MLD in the switching node from the current APMLD to the target APMLD. The second broadcast ARP message is used for the switching node to learn that the DL data packet of the STA MLD should be delivered to the target AP MLD. In one embodiment, the first broadcast ARP message is a QoS Null frame with PS_mode=1, which is used to disable the new second link connected to the target AP, and the first broadcast ARP message is an 802.11 unicast packet, and the second broadcast ARP message is an 802.3 packet.

[0062] In some embodiments, the message sent by the STA includes two messages, one of the two messages is used to trigger the target AP to send a second broadcast ARP message to the switching node, so that the DL path of the DL data packet related to the STA MLD in the switching node is switched from the current APMLD to the target AP MLD, and the other message of the two messages is used to disable the new second link.

[0063] Then, in step S525, the STA obtains the buffered data packets from the current AP via the first link within a time period.

[0064] In step S530, the STA disconnects from the current AP after the time period.

[0065] In step S510, the STA disables the second link connected to the current AP. However, the current AP does not delete the association of the second link and maintains the association of the second link until the STA is disconnected from the current AP.

[0066] In step S535 , the STA enables a new first link and a new second link associated with the target AP to obtain a data packet from the target AP.

[0067] Specifically, the STA can send a first QoS Null frame with PS_mode=0 to the target AP via the new first link to enable the new first link associated with the target AP, and send a second QoS Null frame with PS_mode=0 to the target AP via the new second link to enable the new second link associated with the target AP.

[0068] The first link and the new first link correspond to the same radio, the second link and the new second link correspond to the same radio, and the new first link and the new second link correspond to different radios. Specifically, the first link and the new first link use the same radio, the second link and the new second link use the same radio, and the new first link and the new second link use different radios.

[0069] Combined with reference Figure 1 , the first link and the new first link are created by STA 1 in the STA MLD, and the first link and the new first link use the first radio. The second link and the new second link are created by STA 2 in the STA MLD, and the second link and the new second link use the second radio.

[0070] Figures 3A to 3E and Figure 5 The description is made using STA which is an MLD as an example. Figures 6A to 6E and Figure 7 An example of using a STA that is not an MLD is shown. It should be noted that a STA that is not an MLD can only communicate with the current AP or the target AP through a single link, and the STA is suitable for environments such as Wi-Fi 5 / 6. The STA may include an enhanced Multi-Link-Single-Radio (eMLSR) STA.

[0071] Figures 6A to 6E The process of enhancing roaming performance implemented by a STA according to an embodiment of the present invention is shown.

[0072] exist Fig. 6A In the example, the STA is connected to the current AP and communicates with the current AP through link 1. The router can transmit DL packets to the current AP through the switching node and receive UL packets from the current AP through the switching node. The DL packets may include MACDA (i.e., the address of the STA) and MACSA (i.e., the address of the router), and the UL packets may include MAC DA (i.e., the address of the router) and MAC SA (i.e., the address of the STA). The STA can receive DL packets from the current AP through link 1 and send UL packets to the current AP.

[0073] exist Figure 6BIn step S601, the STA sends a QoSNull frame with PS_mode=1 to the current AP through link 1 to disable link 1 connected to the current AP. Then, in step S602, the STA establishes an association with the target AP through the new link. In other words, the STA switches from link 1 to the new link 1. The first link and the new first link share the same radio.

[0074] exist Figure 6C In step S603, the STA stops sending the STA's UL data packets through link 1. In step S604, the current AP sends all the cached UL data packets to the switching node and caches the DL data packets from the switching node. In step S605, the STA sends a first message to the target AP through the new link 1, and the target AP sends a second message to the switching node to inform the switching node that the STA resides in the cell served by the target AP. The first message may carry an indication for disabling the new link 1 connected to the target AP. The first message and the second message are broadcast ARP messages. The first broadcast ARP message is sent by the STA. In the first broadcast ARP message, TA is the STA address, RA is the target AP address, and DA is FF:FF:FF:FF:FF:FF. The target AP sends a second broadcast ARP message after receiving the first broadcast ARP message. In the second broadcast ARP message, TA is the address of the target AP, and DA is FF:FF:FF:FF:FF:FF:FF. The switching node receives the second broadcast ARP message. The switching node can learn that the STA resides in the cell served by the target AP, so the STA's DL data packet should be delivered to the target AP MLD. Therefore, the first broadcast ARP message is used to trigger the target AP to send a second broadcast message to the switching node, so that the DL path of the DL data packet related to the STA in the switching node is switched from the current AP to the target AP. The first broadcast ARP message is a QoS Null frame with PS_mode=1, which is used to disable the new link 1 connected to the target AP. In some embodiments, the first broadcast ARP message is an 802.11 unicast packet, and the second broadcast ARP message is an 802.3 packet.

[0075] exist Fig.6D In the embodiment, the STA enables link 1 and obtains the DL data packets cached in the current AP from the current AP through link 1. In some embodiments, the STA sends a QoS Null frame with PS_mode=1 through link 1 to enable link 1 connected to the current AP. At the same time, because the new link 1 is disabled, the target AP caches new DL data packets from the switching node, and the STA caches UL data packets.

[0076] exist Fig. 6EIn step S606, the STA disconnects from the current AP after a period of time. Specifically, because the STA does not know the cache status of the current AP, the STA can wait for a period of time T to obtain a cached DL data packet from the current AP within the period of time T. The period of time T in this embodiment is the same as Figure 4 The time period T in is the same or similar, so the detailed information about the time period T will be omitted.

[0077] In step S607, the STA sends a QoS Null frame with PS_mode=0 to the target AP through the new link 1 to enable the new link 1 connected to the target AP. Therefore, the STA can send UL packets to the target AP and receive DL packets from the target AP through the new link 1.

[0078] This enhanced roaming performance process can reduce delay and enhance reliability when the STA roams toward a target AP.

[0079] Figure 7 A flowchart 700 of a method for enhancing roaming performance according to an embodiment of the present invention is described, wherein the method is performed by a STA or Figures 6A to 6E STA implementation in .

[0080] In step S705, the STA communicates with the current AP through the first link.

[0081] In step S710 , the STA disables the first link connected to the current AP.

[0082] Specifically, the STA sends a QoS Null frame with PS_mode=1 to the current AP via the first link to disable the first link connected to the current AP. In some embodiments, after the STA disables the first link connected to the current AP in step S710, it stops sending uplink (UL) packets to the current AP.

[0083] In step S715, the STA establishes an association with the target AP through the new first link.

[0084] In step S720, the STA sends a message to the target AP through the new first link to notify the switching node that the STA resides in the cell served by the target AP and disables the new first link connected to the target AP.

[0085] In some embodiments, the message is a first broadcast ARP message, which is used to trigger the target AP to send a second broadcast ARP message to the switching node, so that the DL path of the DL data packet related to the STA in the switching node is switched from the current AP to the target AP. In some embodiments, the first broadcast ARP message is a QoS Null frame with PS_mode=1, which is used to disable the new first link connected to the target AP, and the first broadcast ARP message is an 802.11 unicast packet, and the second broadcast ARP message is an 802.3 packet.

[0086] In some embodiments, the message sent by the STA may include two messages, one of which is used to trigger the target AP to send a second broadcast ARP message to the switching node, so that the DL path of the DL data packet related to the STA in the switching node is switched from the current AP to the target AP. The other of the two messages is used to disable the new first link.

[0087] In step S725, the STA enables the first link within a period of time and obtains the buffered data packet from the current AP through the first link.

[0088] Specifically, the STA sends a QoS Null frame with PS_mode=1 through the first link to enable the first link connected to the current AP.

[0089] In step S730, the STA disconnects from the current AP after the time period.

[0090] In step S735 , the STA enables a new first link connected to the target AP to obtain a data packet from the target AP.

[0091] In this step, the STA can enable the new first link associated with the target AP to obtain the target AP cached data packet from the target AP, wherein the cached data packet is sent to the target AP by the switching node after receiving the second broadcast ARP message. Specifically, the STA sends a QoS Null frame with PS_mode=1 through the new first link to enable the new first link connected to the target AP.

[0092] In some embodiments, the first link and the new first link correspond to the same radio. Specifically, the first link and the new first link use the same radio.

[0093] Embodiments of the present invention provide systems, devices, and methods for enhancing the roaming performance of STAs of multiple links or a single link. The present invention has the following advantages: (1) STA MLD complies with the Wi-Fi 7 specification. (2) No proprietary design needs to be added to AP / AP MLD. (3) STA / STA MLD can reduce packet loss when roaming. (4) STA / STA MLD can shorten the switching time. (5) MAC address conflicts and out-of-order reception of data packets can be avoided on the switching node. (6) STA / STA MLD does not require Layer 3 (IP layer) rebinding in Layer 2 (MAC layer) roaming scenarios.

[0094] Example Computer Control System

[0095] Figure 8 An exemplary wireless communication device 800 is shown in which embodiments of the present invention may be implemented. Embodiments of the present invention relate to a wireless communication device capable of performing a method for enhancing roaming performance.

[0096] The wireless communication device 800 includes a processor 805 for running software applications and optionally running an operating system. The wireless communication device 800 may include a memory 810, which may be a read-only memory and / or a random access memory, for example, for storing applications and data (e.g., an index value table) used by the processor 805 and data received or sent by radios 815 and 820. Radios 815 and 820 may communicate with other electronic devices via a wireless network (e.g., WLAN) using multiple spatial streams (e.g., multiple antennas), and generally operate according to IEEE standards (e.g., IEEE 802.11ax, IEEE802.11ay, IEEE 802.11be, etc.). The processor may perform multi-link operations including multi-link transmissions. According to an embodiment of the present invention, the wireless device 800 may include more than two radios or only one radio. The radio may include a signal processing module, an antenna, or an amplifier, etc. The radio may be located inside or outside the processor. Alternatively, a portion of the radio may be located inside the processor and another portion may be located outside the processor.

[0097] It should be understood that any specific order in any disclosed method is an example of an example method. It should be understood that the order of steps in the method can be rearranged based on design needs, and these modifications are all within the scope of protection of the present invention.

[0098] Although the present disclosure has been described by way of examples and preferred embodiments, it should be understood that the present disclosure is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and similar arrangements (which are obvious to those skilled in the art). Therefore, the scope of the appended claims should be given the broadest interpretation to cover all such modifications and similar arrangements.

Claims

1. A method for enhancing roaming performance, characterized in that: The method is implemented by a station STA multi-link device MLD, and includes: Communicate with a current access point AP through at least two links, wherein the at least two links include a first link and a second link; Disable the second link connected to the current AP; establishing an association with the target AP through the new second link, wherein the association includes the new first link and the new second link; Sending a message to the target AP through the new second link to notify the network node that the STA is camped in the cell served by the target AP and disables the new second link connected to the target AP; Obtaining cached data packets from the current AP via the first link within a time period; Disconnect from the current AP after the period of time; and enabling a new first link and a new second link associated with the target AP to obtain a data packet from the target AP, The first link and the new first link correspond to the same radio, the second link and the new second link correspond to the same radio, and the new first link and the new second link correspond to different radios.

2. The method according to claim 1, characterized in that The steps to disable the second link connected to the current AP include: A QoS Null frame with PS_mode=1 is sent to the current AP through the second link to disable the second link connected to the current AP.

3. The method according to claim 1, characterized in that After the association is established, the new first link is set to power saving mode by default.

4. The method according to claim 3, characterized in that The steps of enabling a new first link and a new second link associated with the target AP include: enabling the new first link by sending a first QoS Null frame with PS_mode=0 to the target AP via the new first link; and The new second link is enabled by sending a second QoS Null frame with PS_mode=0 to the target AP via the new second link.

5. The method according to claim 1, characterized in that Further including: After disabling the second link connected to the current AP or establishing association with the target AP through a new second link, stopping sending the uplink UL data packet of the STA MLD to the current AP through the first link.

6. The method according to claim 1, characterized in that The message is sent after all uplink UL data packets of the STA MLD buffered in the current AP are sent to the network node.

7. The method according to claim 1, characterized in that The message is a first broadcast message, used to trigger the target AP to send a second broadcast message to the network node, so that the path of the DL data packet related to the STA MLD in the network node is switched from the current AP to the target AP; the first broadcast message is a QoS Null frame with PS_mode=1, used to disable the new second link connected to the target AP.

8. The method according to claim 7, characterized in that The step of enabling a new first link and a new second link associated with the target AP to obtain a data packet from the target AP includes: enabling a new first link and a new second link associated with the target AP to obtain a data packet cached by the target AP, wherein the cached data packet is sent by the network node to the target AP after receiving a second broadcast message.

9. A method for enhancing roaming performance, characterized in that: The method is implemented by the STA and comprises: Communicate with the current AP via a first link; Disable the first link connected to the current AP; Establishing an association with the target AP through a new first link; Sending a message to the target AP through the new first link to notify the network node that the STA resides in the cell served by the target AP and disables the new first link connected to the target AP; enabling the first link within a time period and obtaining a cached data packet from the current AP through the first link; Disconnect from the current AP after the period of time; and enabling a new first link connected to the target AP to obtain a data packet from the target AP; The first link and the new first link correspond to the same radio.

10. The method according to claim 9, characterized in that Disabling the first link connected to the current AP includes: A QoS Null frame with PS_mode=1 is sent to the current AP through the first link to disable the first link connected to the current AP.

11. The method according to claim 9, characterized in that Further including: After disabling the first link connected to the current AP, stopping sending UL data packets to the current AP through the first link; The message is sent after all UL data packets of the STA buffered in the current AP are sent to the network node.

12. The method according to claim 9, characterized in that The message is a first broadcast message, used to trigger the target AP to send a second broadcast message to the network node so that the path of the DL data packet related to the STA in the network node is switched from the current AP to the target AP; and the first broadcast message is a QoS Null frame with PS_mode=1, used to disable the new first link connected to the target AP.

13. The method according to claim 9, characterized in that The step of enabling a new first link associated with the target AP to obtain a data packet from the target AP includes enabling a new first link associated with the target AP to obtain a cached data packet from the target AP, wherein the cached data packet is sent by the network node after receiving the second broadcast message.

14. The method according to claim 9, characterized in that The step of enabling the first link further comprises: A QoS Null frame with PS_mode=1 is sent over the first link to enable the first link connected to the current AP.

15. A communication device, characterized in that: include: processor; A plurality of radio devices, wherein the processor is configured to: Communicating with the current AP via at least two links, wherein the at least two links include a first link and a second link; Disable the second link connected to the current AP; Establishing an association with the target AP via a new second link; wherein the association includes a new first link and a new second link; Sending a message to the target AP through the new second link to notify the network node that the STA resides in a cell served by the target AP and disables the new second link connected to the target AP; Obtaining cached data packets from the current AP via the first link within a time period; Disconnect from the current AP after this period of time; as well as enabling a new first link and a new second link associated with the target AP to obtain a data packet from the target AP; The first link and the new first link use the same radio device, the second link and the new second link use the same radio device, and the new first link and the new second link use different radio devices.

16. The device according to claim 15, characterized in that The processor is configured to: A QoS Null frame with PS_mode=1 is sent to the current AP through the second link to disable the second link connected to the current AP.

17. The device according to claim 15, characterized in that The processor can be further configured to: After disabling the second link connected to the current AP or establishing an association with the target AP through a new second link, stopping sending the UL data packet of the STA MLD to the current AP through the first link.

18. The device as claimed in claim 15, wherein the message is a first broadcast message, used to trigger the target AP to send a second broadcast message to the network node so that the path of the DL data packet related to the STAMLD in the network node is switched from the current AP to the target AP; the first broadcast message has a QoS Null frame with PS_mode=1, which is used to disable the new second link connected to the target AP.

19. The device according to claim 15, characterized in that The processor is further configured to: Sending a first QoS Null frame with PS_mode=0 to the target AP via the new first link to enable the new first link associated with the target AP; as well as A second QoS Null frame with PS_mode=0 is sent to the target AP through the new second link to enable the new second link associated with the target AP.

20. The device according to claim 15, characterized in that The message is sent after all uplink UL data packets of the STA MLD buffered in the current AP are sent to the network node.

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