Zero-packet-loss fast roaming method, device, and system based on C-WAN architecture

Abstract

The present invention provides a zero-packet-loss fast roaming method, device, and system based on a C-WAN architecture, relating to the field of communications technology. The method comprises: in response to a handover decision instruction, instructing an original SFU to send a block acknowledgment request (BAR) to a STA to be roamed, to obtain a block acknowledgment (BA) fed back by the STA to be roamed; processing all pending downlink data frames in a buffer array based on the starting sequence number and binary bitmap in the block acknowledgment (BA), and generating a retransmission queue based on all unacknowledged data frames; updating the corresponding transmit queue of the original SFU based on the retransmission queue to obtain an updated transmit queue, and mapping the updated transmit queue to the hardware queue of a target SFU. When the target SFU accesses the STA to be roamed, data frame retransmission is implemented according to the hardware queue of the target SFU. The present invention aims to improve data transmission continuity and overall network performance, effectively simplify the roaming decision and execution process, avoid data loss and delay when switching SFUs, and optimize the user experience.

Description

Technical Field

[0001] The present invention relates to the field of communication technologies, and in particular to a method, device, and system for zero-packet-loss fast roaming based on a C-WAN architecture. Background Art

[0002] 802.11k and 802.11v are two protocol standards in Wi-Fi networks. 802.11k is a technology in wireless local area networks (WLANs) designed to improve roaming performance, while 802.11v is designed to improve wireless network management and optimization capabilities. 802.11r is a protocol standard in Wi-Fi networks that enables fast and secure roaming on wireless networks.

[0003] Most fiber-to-the-telecommunications-room (FTTR) products introduced by related technologies support 802.11k / v, but few support 802.11r. 802.11r requires support from both the AP and the end device. While 802.11k / v simplifies the scanning process, it still requires reassociation and key exchange, making truly seamless roaming impossible. During roaming, a mobile terminal (STA) must reconnect to the destination access point (AP). This process can cause brief network interruptions due to channel contention, particularly impacting real-time services such as Voice over Internet Protocol (VoIP). Furthermore, different Basic Service Set Identifier (BSSID) settings and channel selection between APs can affect roaming efficiency and network performance, such as channel overlap or co-channel interference. To achieve lossless roaming, unfinished data forwarding between APs must be handled, which also consumes time.

[0004] However, there is currently no technical solution that can solve the above technical problems, and there is no method, device, or system for zero-packet-loss fast roaming based on the C-WAN architecture. Summary of the Invention

[0005] The present invention provides a zero-packet-loss fast roaming method, device, and system based on a C-WAN architecture, which reduces the packet loss rate in the downlink direction during roaming, achieving zero packet loss as much as possible, while accelerating the roaming process and achieving zero network waiting as much as possible.

[0006] In a first aspect, the present invention provides a method for fast roaming with zero packet loss based on a C-WAN architecture, characterized by comprising:

[0007] In response to a handover decision instruction, instructing the original SFU to send a block acknowledgement request BAR to the STA to be roamed, so as to obtain a block acknowledgement BA fed back by the STA to be roamed, wherein the handover decision instruction is generated before the original SFU initially accessed by the STA to be roamed roams to the target SFU;

[0008] According to the starting sequence number and the binary bitmap in the block acknowledgment (BA), all downlink data frames to be confirmed in the buffer array are processed to determine all confirmed data frames and all unconfirmed data frames. A retransmission queue is generated based on all the unconfirmed data frames, and all confirmed data frames are released after confirmation.

[0009] Update the sending queue corresponding to the original SFU according to the retransmission queue to obtain an updated sending queue, and map the updated sending queue to the hardware queue of the target SFU, so that when the target SFU accesses the STA to be roamed, data frame retransmission is realized according to the hardware queue of the target SFU.

[0010] According to the zero-packet-loss fast roaming method based on the C-WAN architecture provided by the present invention, before responding to the handover decision instruction, the method further includes:

[0011] If it is determined that the uplink signal quality of the STA to be roamed is lower than a preset value, a Beacon request is generated;

[0012] Using the original SFU to send the Beacon request to the STA to be roamed, so as to obtain signal measurement results of all SFUs fed back by the STA to be roamed;

[0013] The SFU with the strongest signal among the signal measurement results of all SFUs is determined as the target SFU.

[0014] According to the zero-packet-loss fast roaming method based on the C-WAN architecture provided by the present invention, when the STA to be roamed does not support 802.11k, before responding to the handover decision instruction, the method further includes:

[0015] When it is determined that the uplink signal quality of the STA to be roamed is lower than a preset value, all adjacent SFUs within a preset range of the original SFU trigger channel measurement;

[0016] Each adjacent SFU transmits the uplink RF signal strength information corresponding to the adjacent SFU to the MFU when performing channel measurement;

[0017] The SFU with the highest signal strength among all uplink radio frequency signal strength information is determined as the target SFU.

[0018] According to the zero-packet-loss fast roaming method based on the C-WAN architecture provided by the present invention, after mapping the updated sending queue to the hardware queue of the target SFU, the method further includes:

[0019] Sending the physical layer configuration information of the STA to be roamed in the original SFU to the hardware MAC of the target SFU;

[0020] The target SFU sends all the unconfirmed data frames to the STA to be roamed according to the physical layer configuration information of the original SFU.

[0021] According to the zero-packet-loss fast roaming method based on the C-WAN architecture provided by the present invention, after responding to the handover decision instruction, the method further includes:

[0022] Instruct the target SFU to send the target Beacon frame and the original Beacon frame to the STA to be roamed in turn in a time division manner;

[0023] The target Beacon frame is determined according to the BSSID corresponding to the target SFU;

[0024] The original Beacon frame is determined according to the BSSID corresponding to the original SFU;

[0025] The BSSID corresponding to the target SFU and the BSSID corresponding to the original SFU are in the same networking mode.

[0026] The zero-packet-loss fast roaming method based on the C-WAN architecture provided by the present invention processes all downlink data frames to be confirmed in the buffer array according to the starting sequence number and the binary bitmap in the block acknowledgment (BA), and determines all confirmed data frames and all unconfirmed data frames, including:

[0027] Processing each data frame starting from the starting sequence number, and determining the confirmation status of each data frame according to the bit value in the binary bitmap Bitmap, wherein the bit value includes 1 or 0, 1 indicates that the data frame with the corresponding sequence number has been confirmed, and 0 indicates that the data frame with the corresponding sequence number has not been confirmed;

[0028] Traverse all data frames until all confirmed data frames and all unconfirmed data frames are determined.

[0029] According to the zero-packet-loss fast roaming method based on the C-WAN architecture provided by the present invention, before processing all downlink data frames to be confirmed in the buffer array according to the starting sequence number and the binary bitmap in the block acknowledgment (BA), the method further includes:

[0030] For each data frame, after the original SFU sends a block confirmation request BAR to the roaming STA, if no confirmation ACK is received for the data frame, the sequence number corresponding to the data frame is recorded and the bit value of the binary bitmap Bitmap is marked as 0;

[0031] After the original SFU sends a block acknowledgement request BAR to the STA to be roamed, when receiving an acknowledgement ACK of the data frame, it records the sequence number corresponding to the data frame and marks the bit value of the binary bitmap Bitmap as 1.

[0032] According to the C-WAN architecture-based zero-packet-loss fast roaming method provided by the present invention, after retransmitting the data frame according to the hardware queue of the target SFU, the method further includes:

[0033] The roaming of the STA to be roamed from the original SFU to the target SFU is completed, and the STA to be roamed and the target SFU are re-associated using the 802.11v mechanism.

[0034] In a second aspect, a zero-packet-loss fast roaming device based on a C-WAN architecture is provided, comprising:

[0035] a responding unit, configured to, in response to a handover decision instruction, instruct an original SFU to send a block acknowledgement request BAR to the STA to be roamed, so as to obtain a block acknowledgement BA fed back by the STA to be roamed, wherein the handover decision instruction is generated before the original SFU to which the STA to be roamed initially accesses roams to a target SFU;

[0036] a processing unit configured to process all downlink data frames to be confirmed in the buffer array according to the starting sequence number and the binary bitmap in the block acknowledgment (BA), determine all confirmed data frames and all unconfirmed data frames, generate a retransmission queue based on all unconfirmed data frames, and release all confirmed data frames after confirmation;

[0037] A mapping unit, wherein the mapping unit is used to update the sending queue corresponding to the original SFU according to the retransmission queue to obtain an updated sending queue, and map the updated sending queue to the hardware queue of the target SFU, so as to realize data frame retransmission according to the hardware queue of the target SFU when the target SFU accesses the STA to be roamed.

[0038] In a third aspect, a zero-packet-loss fast roaming system based on a C-WAN architecture is provided, including a zero-packet-loss fast roaming device based on a C-WAN architecture, wherein the zero-packet-loss fast roaming device based on the C-WAN architecture is an MFU;

[0039] It also includes multiple SFUs, the MFU is in communication connection with all the SFUs, and in a working state, the STA to be roamed is connected to any of the SFUs.

[0040] Before a STA to be roamed roams from the original SFU it initially accesses to a target SFU, the present invention instructs the original SFU to send a block acknowledgment request (BAR) to the STA to be roamed, obtains the block acknowledgment (BA) fed back by the STA to be roamed, determines the retransmission queue corresponding to all unacknowledged data frames based on the starting sequence number and binary bitmap in the block acknowledgment (BA), obtains an updated send queue based on the retransmission queue, and maps the updated send queue to the hardware queue of the target SFU. Thus, when the target SFU accesses the STA to be roamed, data frame retransmission is implemented according to the hardware queue of the target SFU. The roaming process in the present invention is transparent to the roaming STA, aiming to improve data transmission continuity and overall network performance. It effectively simplifies the roaming decision-making and execution process, avoids data loss and delay when switching SFUs, and optimizes the user experience.

[0041] The present invention can also achieve zero-packet-loss fast roaming based on the C-WAN architecture, complete fast roaming decisions through signal quality detection and control, optimize data transmission efficiency through data frame processing and confirmation status determination, and ensure roaming efficiency and accuracy through Beacon frame transmission and physical layer configuration information transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1 This is a flow chart of a method for zero-packet-loss fast roaming based on a C-WAN architecture provided by the present invention;

[0044] Figure 2 Schematic diagram of the handover decision method provided by the present invention;

[0045] Figure 3 This is a schematic diagram of the dynamic mapping of queues provided by the present invention;

[0046] Figure 4 This is a schematic diagram of module connections of a zero-packet-loss fast roaming device based on a C-WAN architecture provided by the present invention;

[0047] Figure 5 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0048] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0049] Figure 1 : This is a flow chart of a zero-packet-loss fast roaming method based on a C-WAN architecture provided by the present invention. The zero-packet-loss fast roaming method based on a C-WAN architecture includes:

[0050] Step 101: In response to a handover decision instruction, instruct the original SFU to send a block acknowledgement request (BAR) to the STA to be roamed to obtain a block acknowledgement (BA) fed back by the STA to be roamed, wherein the handover decision instruction is generated before the STA to be roamed roams from the original SFU initially accessed to the target SFU;

[0051] Step 102: Process all downlink data frames to be confirmed in the buffer array according to the starting sequence number and the binary bitmap in the block acknowledgment (BA), determine all confirmed data frames and all unconfirmed data frames, generate a retransmission queue based on all unconfirmed data frames, and release all confirmed data frames after confirmation.

[0052] Step 103: Update the sending queue corresponding to the original SFU according to the retransmission queue to obtain an updated sending queue, and map the updated sending queue to the hardware queue of the target SFU, so that when the target SFU accesses the STA to be roamed, data frame retransmission is realized according to the hardware queue of the target SFU.

[0053] In step 101, the MFU software MAC receives the uplink signal quality of the STA based on multiple selective forwarding units (SFUs) or reports the measurement of multiple basic service sets (BSSs) by the STA. The MFU is a mobile-dedicated SFU. When it is determined that the uplink signal quality of the STA to be roamed is poor or the currently accessed SFU has a fault, the present invention can find a target SFU with better uplink signal quality, thereby enabling the STA to be roamed to roam from the original SFU initially accessed to the target SFU. Before roaming, the present application needs to dynamically map the transmit and receive queues of the original SFU to the hardware MAC of the target SFU to improve the continuity of data transmission.

[0054] Optionally, a BAR stands for Block Acknowledgement Request, which requests the receiver to send a Block Acknowledgement frame to confirm received data frames, thereby supporting more efficient data transmission. BAR is commonly used for data frame confirmation and retransmission in Wi-Fi networks. BA stands for Block Acknowledgement. The receiver sends a frame with confirmation information for received data frames in response to a BAR request, informing the sender which data frames have been successfully received and which need to be retransmitted to ensure data transmission reliability. Therefore, the original SFU sends a BAR request to the STA to obtain the BA information fed back by the STA. This helps the original SFU determine which data frames have been successfully received and which need to be retransmitted, thereby maintaining the continuity and reliability of data transmission.

[0055] In step 102, the present invention processes all pending downlink data frames in the buffer array based on the starting sequence number and binary bitmap contained in the block acknowledgment (BA). By analyzing the bitmap, it determines which data frames have been successfully confirmed and which have not yet been confirmed. A retransmission queue is then generated based on the unconfirmed data frames to be retransmitted, and confirmed data frames are released. The retransmission queue has the highest priority, ensuring that data is sent first.

[0056] In step 103, the present application updates the sending queue of the original SFU based on the retransmission queue generated previously, adds the data frames that need to be retransmitted to the sending queue, obtains an updated sending queue, and then maps the updated sending queue to the hardware queue of the target SFU, that is, transmits the data frame information in the sending queue to the hardware layer of the target SFU, and prepares to perform the sending and retransmission operations of the data frames. In the case where the target SFU accesses the STA to be roamed, the retransmission operation of the data frame is implemented according to the hardware queue of the target SFU, ensuring that the data frames that have not been successfully transmitted can be accurately sent to the STA to be roamed. The present invention ensures that in the event of errors or losses during the data transmission process, the data frames can be retransmitted through the retransmission mechanism, thereby ensuring reliable data transmission. By updating the sending queue and mapping it to the hardware queue, the retransmission operation of the data frame on the target SFU is implemented to meet the data transmission requirements for the roaming STA.

[0057] Figure 3 This is a schematic diagram of the dynamic mapping of queues provided by the present invention, such as Figure 3As shown, the software MAC includes a list of transmit descriptors for the STA to be roamed. In the hardware MAC, the hardware queue of the original SFU is dynamically mapped to the hardware queue of the target SFU. Before the STA to be roamed roams from the original SFU it initially accesses to the target SFU, the present invention instructs the original SFU to send a block acknowledgment request (BAR) to the STA to be roamed, obtains the block acknowledgment (BA) fed back by the STA to be roamed, and determines the retransmission queue corresponding to all unacknowledged data frames based on the starting sequence number and binary bitmap in the block acknowledgment (BA). Based on the retransmission queue, an updated transmit queue is obtained, and the updated transmit queue is mapped to the hardware queue of the target SFU. Thus, when the target SFU accesses the STA to be roamed, data frame retransmission is implemented according to the hardware queue of the target SFU. The roaming process of the present invention is transparent to the roaming STA, aiming to improve data transmission continuity and overall network performance. It effectively simplifies the roaming decision-making and execution process, avoids data loss and delay when switching SFUs, and optimizes the user experience.

[0058] Optionally, before responding to the switching decision instruction, the method further includes:

[0059] If it is determined that the uplink signal quality of the STA to be roamed is lower than a preset value, a Beacon request is generated;

[0060] Using the original SFU to send the Beacon request to the STA to be roamed, so as to obtain signal measurement results of all SFUs fed back by the STA to be roamed;

[0061] The SFU with the strongest signal among the signal measurement results of all SFUs is determined as the target SFU.

[0062] Optionally, the present invention monitors the uplink signal quality of the STA to be roamed based on a pre-set threshold. Once the signal quality falls below the set threshold, the system generates a Beacon request signal. The original SFU sends the generated Beacon request signal to the STA to be roamed via a channel. The Beacon request carries system-specific information used to obtain the signal measurement results of each SFU reported by the STA. Upon receiving the Beacon request, the STA to be roamed measures the signal of each SFU, records the signal strength of each SFU, and feeds it back to the MFU. Based on the signal measurement results of all SFUs reported by the STA to be roamed, the MFU determines the SFU with the strongest signal and designates it as the target SFU. This redirects data transmission to the SFU with better signal quality, improving data transmission quality and stability. This embodiment monitors and determines the signal quality of the STA to be roamed in real time, promptly detecting when the signal quality falls below the set threshold, and ensuring data transmission stability and reliability. By selecting the SFU with the strongest signal as the target SFU, data transmission efficiency and speed can be improved, avoiding data loss or delay. Automatically switching SFUs when signal quality is poor provides the STA to be roamed with a better network connection experience and increased user satisfaction.

[0063] Optionally, when the STA to be roamed does not support 802.11k, before responding to the handover decision instruction, the method further includes:

[0064] When it is determined that the uplink signal quality of the STA to be roamed is lower than a preset value, all adjacent SFUs within a preset range of the original SFU trigger channel measurement;

[0065] Each adjacent SFU transmits the uplink RF signal strength information corresponding to the adjacent SFU to the MFU when performing channel measurement;

[0066] The SFU with the highest signal strength among all uplink radio frequency signal strength information is determined as the target SFU.

[0067] Optionally, if the uplink signal quality of the STA to be roamed is determined to be below a preset value, all neighboring SFUs within a preset range of the original SFU trigger channel measurement. This embodiment sends a channel measurement instruction to all neighboring SFUs within the preset range to measure signal strength. Upon receiving the channel measurement instruction, each neighboring SFU begins measuring the uplink signal strength of the STA to be roamed and feeds the measurement results back to the MFU. The MFU collects and compares the uplink signal strength information transmitted by all neighboring SFUs, selects the SFU with the strongest signal as the target SFU, and executes the handover decision instruction. In this embodiment, even when 802.11k is not supported, SFU handover decisions are implemented through signal measurement and comparison of neighboring SFUs, improving the intelligence and accuracy of network handover. This not only effectively and efficiently locates the SFU with the strongest signal when the signal quality of the STA to be roamed is poor, providing the STA with a better network connection experience, but also avoids redundant signal interference through the comparison and selection of signal strength information, ensuring stable and reliable data transmission.

[0068] Optionally, after mapping the updated send queue to the hardware queue of the target SFU, the method further includes:

[0069] Sending the physical layer configuration information of the STA to be roamed in the original SFU to the hardware MAC of the target SFU;

[0070] The target SFU sends all the unconfirmed data frames to the STA to be roamed according to the physical layer configuration information of the original SFU.

[0071] Optionally, to ensure data format consistency, after the target SFU is determined, the original SFU will send the physical layer configuration information (e.g., channel settings, data transmission rate, etc.) of the STA to be roamed in the original SFU to the hardware MAC of the target SFU to ensure that the target SFU can correctly configure the physical layer parameters. After receiving the physical layer configuration information of the STA to be roamed, the target SFU will send a descriptor containing the physical layer configuration information to ensure that the PPDU is constructed and sent according to the original format. All unconfirmed data frames will be sent to the roaming STA based on this information to ensure data integrity and timeliness. This embodiment ensures that the target SFU can accurately configure the physical parameters required for communication with the STA to be roamed by sending the physical layer configuration information, avoiding communication problems caused by configuration mismatch. The target SFU sends unconfirmed data frames based on the physical layer configuration information of the original SFU, ensuring the continuity and stability of data transmission and avoiding communication delays caused by data loss or retransmission. This embodiment integrates the transmission of physical layer configuration information and the sending process of unconfirmed data frames, improving the seamless connection experience and data transmission efficiency for roaming STAs after SFU handover.

[0072] Figure 2 Schematic diagram of the switching decision method provided by the present invention, such as Figure 2 As shown, each SFU hardware MAC reports to the MFU software MAC via RSSI. Specifically, the SFU hardware MAC can obtain the signal strength information between the adjacent device (which may be a STA or other SFU) through the signal strength indication it receives. The SFU hardware MAC sends the obtained RSSI information to the MFU software MAC, and can transmit this data to the MFU software MAC via Ethernet or other communication methods. By reporting the RSSI information to the MFU software MAC, the MFU software MAC can obtain the signal strength information of different SFU hardware MACs, which helps the network management system to perform more accurate signal coverage evaluation and optimization. Furthermore, after determining the target SFU, the STA can roam from the original SFU initially accessed to the target SFU.

[0073] Optionally, after responding to the switching decision instruction, the method further includes:

[0074] Instruct the target SFU to send the target Beacon frame and the original Beacon frame to the STA to be roamed in turn in a time division manner;

[0075] The target Beacon frame is determined according to the BSSID corresponding to the target SFU;

[0076] The original Beacon frame is determined according to the BSSID corresponding to the original SFU;

[0077] The BSSID corresponding to the target SFU and the BSSID corresponding to the original SFU are in the same networking mode.

[0078] Optionally, after receiving the switching decision instruction, the target SFU will be instructed to send the target Beacon frame and the original Beacon frame to the STA to be roamed in a time-division manner, so that the STA to be roamed can receive the Beacon frames of the two SFUs. The BSSID of the target Beacon frame is determined according to the unique identifier of the target SFU, and the BSSID of the original Beacon frame is determined according to the unique identifier of the original SFU. The roaming target SFU will first send a Beacon frame with its own BSSID (the unique identifier corresponding to the SSID) so that the surrounding STAs can see the signal so that the STA can connect to the target SFU. In order to deceive the STA, the target SFU A Beacon frame with the same BSSID as the original SFU will also be sent, so that the STA receives Beacon frames from both the original SFU and the target SFU simultaneously. The target SFU will then take turns sending its own Beacon frame and the Beacon frame with the same BSSID as the original SFU in a time-division manner. This way, the STA will receive signals from different SFUs in a short period of time. However, due to the time-division transmission method, the STA may only receive signals from the target SFU or the original SFU within a period of time. By allowing the STA to receive signals from both the target SFU and the original SFU at the same time, the STA will believe that the target SFU and the original SFU belong to the same access point and will not be aware that a change of access point has actually occurred. Therefore, during roaming, the STA will not actively initiate a reassociation process, thereby achieving a switching process between access points. In this embodiment, by simultaneously sending its own Beacon and a Beacon with the same BSSID as the original SFU and sending them in a time-division manner, the roaming target SFU can deceive the STA into believing that no access point change has occurred, thereby preventing the STA from initiating a reassociation process and achieving a seamless roaming process.

[0079] Optionally, according to the starting sequence number and the binary bitmap in the block acknowledgment BA, all downlink data frames to be confirmed in the buffer array are processed to determine all confirmed data frames and all unconfirmed data frames, including:

[0080] Processing each data frame starting from the starting sequence number, and determining the confirmation status of each data frame according to the bit value in the binary bitmap Bitmap, wherein the bit value includes 1 or 0, 1 indicates that the data frame with the corresponding sequence number has been confirmed, and 0 indicates that the data frame with the corresponding sequence number has not been confirmed;

[0081] Traverse all data frames until all confirmed data frames and all unconfirmed data frames are determined.

[0082] Optionally, this embodiment starts with the starting sequence number obtained from the block acknowledgment BA and processes the downlink data frames to be confirmed in the cache array one by one. According to the bit value in the bitmap Bitmap, 1 indicates that the data frame with the corresponding sequence number has been confirmed, and 0 indicates that it has not been confirmed. The confirmation status of the data frame is determined by comparing the bitmap and the sequence number. According to the above processing procedure, all downlink data frames to be confirmed in the cache array are traversed and processed to determine the status of all confirmed and unconfirmed data frames. This embodiment can efficiently process the data frames to be confirmed in the cache array by using the starting sequence number and bitmap Bitmap of the block acknowledgment BA, avoiding the inefficiency caused by querying the confirmation status one by one, traversing all data frames until all confirmed and unconfirmed data frames are confirmed, ensuring the processing integrity and accuracy of all data frames, and facilitating further data processing and transmission control.

[0083] Optionally, before processing all downlink data frames to be confirmed in the buffer array according to the starting sequence number and the binary bitmap in the block acknowledgment (BA), the method further includes:

[0084] For each data frame, after the original SFU sends a block confirmation request BAR to the roaming STA, if no confirmation ACK is received for the data frame, the sequence number corresponding to the data frame is recorded and the bit value of the binary bitmap Bitmap is marked as 0;

[0085] After the original SFU sends a block acknowledgement request BAR to the STA to be roamed, when receiving an acknowledgement ACK of the data frame, it records the sequence number corresponding to the data frame and marks the bit value of the binary bitmap Bitmap as 1.

[0086] Optionally, an unacknowledged data frame refers to a data frame sent by a sender to a receiver during a data transmission process, but for which an acknowledgment message (e.g., ACK) has not yet been received from the receiver (e.g., a STA). A data frame that has been acknowledged by the STA refers to a data frame sent by a sender to a receiver and for which an ACK has been received from the receiver. During a data transmission process, once the receiver successfully receives and acknowledges a data frame, the sender can mark the data frame as acknowledged by the STA and deem the data transmission successful. If no acknowledgment message is received, the data frame is marked as unacknowledged and may need to be retransmitted to ensure data transmission reliability. This embodiment records the sequence numbers of data frames that have not received ACKs and marks the corresponding bits as 0, which helps clarify the status of unacknowledged data frames in subsequent processing and improves the controllability and reliability of data transmission. Simultaneously, marking the sequence numbers of data frames that have received ACKs with a bit value of 1 allows for rapid determination of the status of acknowledged data frames, avoids repeated processing, and improves data transmission efficiency. The recording and marking process ensures that the acknowledgement status of the data frame is accurately reflected in the binary bitmap, providing an accurate basis and judgment for subsequent data processing.

[0087] Optionally, after retransmitting the data frame according to the hardware queue of the target SFU, the method further includes:

[0088] The roaming of the STA to be roamed from the original SFU to the target SFU is completed, and the STA to be roamed and the target SFU are re-associated using the 802.11v mechanism.

[0089] Optionally, after the data frame retransmission is complete, the STA to be roamed needs to achieve smooth roaming from the original SFU to the target SFU through the wireless network. 802.11v is a protocol used to enhance roaming performance in Wi-Fi networks. It can help the STA to be roamed reassociate with the target SFU more quickly during roaming, thereby improving roaming efficiency and success rate. This embodiment ensures the transmission continuity of data frames between different SFUs by completing the roaming of the STA to be roamed from the original SFU to the target SFU, avoiding data loss and transmission interruption. Using the 802.11v mechanism for reassociation can help the STA to be roamed establish a connection with the target SFU more quickly, reduce delays during roaming, and improve user experience and network performance.

[0090] The present invention aims to optimize the user experience in wireless communication networks by improving data continuity and overall network performance. It provides a zero-packet-loss fast roaming method based on a C-WAN architecture. This method simplifies remote deployment by fully integrating the MAC layer of a slave device into the master device. When the master device detects deteriorating uplink signal quality of a STA or a better access point in the STA's measurement reports for multiple BSSs, it directly schedules downlink data not sent by the original slave device to a more suitable slave device for transmission. The STA's unsent uplink data is also directly received by the more suitable slave device. Due to the highly centralized nature of the C-WAN architecture, this process eliminates the need for data forwarding between the original slave device and the destination slave device on the physical link. Instead, the master device only needs to dynamically schedule the STA's data at the MAC layer. During roaming, if the STA loses connection with the original slave device, the STA's transmit queue on the software MAC is not released. Instead, the queue is mapped to the hardware MAC of the destination slave device, which then continues to transmit the data. This avoids disconnection and packet loss during the handover process caused by the slave device releasing unfinished data, thereby achieving zero downlink packet loss and improving roaming stability.

[0091] Furthermore, the present invention does not perform a reassociation process during roaming. Instead, it uses the same BSSID networking method to deceive the STA, making it believe that the access point has not been changed, and therefore does not initiate a reassociation process with the destination slave device. After waiting for data transmission to be completed, the STA needs to re-establish a connection with the destination slave device. The association process after roaming needs to be actively notified to the STA by the slave device. Since the reassociation process does not occur during roaming, the exchange of reassociation information is avoided, the network waiting time is reduced, and the roaming process is accelerated. Through this centralized data scheduling and intelligent mapping strategy, the present invention significantly improves the stability and efficiency of the wireless network during roaming, achieves zero packet loss and fast roaming in the downlink direction, and thus improves network performance and user satisfaction.

[0092] Figure 4 This is a schematic diagram of module connections of a zero-packet-loss fast roaming device based on a C-WAN architecture provided by the present invention. The zero-packet-loss fast roaming device based on a C-WAN architecture includes:

[0093] A response unit 1 is configured to, in response to a handover decision instruction, instruct the original SFU to send a block acknowledgment request BAR to the STA to be roamed, so as to obtain a block acknowledgment BA fed back by the STA to be roamed. The handover decision instruction is generated before the STA to be roamed roams from the original SFU initially accessed to the target SFU. The working principle of the response unit 1 can be referred to the aforementioned step 101 and will not be repeated here.

[0094] The zero-packet-loss fast roaming device based on the C-WAN architecture further includes a processing unit 2, which is configured to process all downlink data frames to be confirmed in a buffer array based on a starting sequence number and a binary bitmap in a block acknowledgment (BA), determine all confirmed data frames and all unconfirmed data frames, generate a retransmission queue based on all unconfirmed data frames, and release all confirmed data frames after confirmation. The operating principle of the processing unit 2 can be referred to in the aforementioned step 102 and is not further described here.

[0095] The zero-packet-loss fast roaming device based on the C-WAN architecture also includes a mapping unit 3, which is used to update the sending queue corresponding to the original SFU according to the retransmission queue to obtain an updated sending queue, and map the updated sending queue to the hardware queue of the target SFU, so that when the target SFU accesses the STA to be roamed, data frame retransmission is implemented according to the hardware queue of the target SFU. The working principle of the mapping unit 3 can be referred to the aforementioned step 103 and will not be repeated here.

[0096] On the other hand, the present invention further provides a zero-packet-loss fast roaming system based on a C-WAN architecture, comprising the zero-packet-loss fast roaming device based on a C-WAN architecture, wherein the zero-packet-loss fast roaming device based on a C-WAN architecture is an MFU;

[0097] It also includes multiple SFUs, the MFU is in communication connection with all the SFUs, and in a working state, the STA to be roamed is connected to any of the SFUs.

[0098] Before a STA to be roamed roams from its initial SFU to a target SFU, the present invention instructs the original SFU to send a block acknowledgement request (BAR) to the STA to be roamed, obtains a block acknowledgement (BA) fed back by the STA to be roamed, and determines the retransmission queue corresponding to all unacknowledged data frames based on the starting sequence number and binary bitmap in the block acknowledgement (BA). An updated transmit queue is obtained based on the retransmission queue, and the updated transmit queue is mapped to the hardware queue of the target SFU. Thus, when the target SFU accesses the STA to be roamed, data frame retransmission is achieved based on the hardware queue of the target SFU. The roaming process of the present invention is transparent to the roaming STA, aiming to improve data transmission continuity and overall network performance. It effectively simplifies the roaming decision-making and execution process, avoids data loss and delays when switching SFUs, and optimizes the user experience. It also enables zero-packet-loss fast roaming based on the C-WAN architecture. Fast roaming decisions are made through signal quality detection and control, data transmission efficiency is optimized through data frame processing and confirmation status determination, and roaming efficiency and accuracy are ensured through Beacon frame transmission and physical layer configuration information transmission.

[0099] Figure 5 Schematic diagram of the structure of the electronic device provided by the present invention. Figure 5 As shown, the electronic device may include: a processor (processor) 510, a communication interface (Communications Interface) 520, a memory (memory) 530 and a communication bus 540, wherein the processor 510, the communication interface 520, and the memory 530 communicate with each other through the communication bus 540. The processor 510 may invoke logic instructions in the memory 530 to execute a zero-packet-loss fast roaming method based on a C-WAN architecture, the method comprising: instructing an original SFU to send a block acknowledgment request (BAR) to a STA to be roamed in response to a handover decision instruction to obtain a block acknowledgment (BA) fed back by the STA to be roamed, wherein the handover decision instruction is generated before the STA to be roamed roams from the original SFU initially accessed to the target SFU; processing all downlink data frames to be confirmed in a buffer array based on a starting sequence number and a binary bitmap in the block acknowledgment (BA) to determine all confirmed data frames and all unconfirmed data frames, generating a retransmission queue based on all the unconfirmed data frames, and releasing all confirmed data frames after confirmation; updating a send queue corresponding to the original SFU based on the retransmission queue to obtain an updated send queue, mapping the updated send queue to a hardware queue of a target SFU, so that when the target SFU accesses the STA to be roamed, data frames are retransmitted based on the hardware queue of the target SFU.

[0100] In addition, the logic instructions in the above-mentioned memory 530 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when sold or used as an independent product. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0101] On the other hand, the present invention further provides a computer program product, comprising a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute a zero-packet-loss fast roaming method based on a C-WAN architecture provided by each of the above methods. The method comprises: in response to a handover decision instruction, instructing an original SFU to send a block acknowledgment request (BAR) to a STA to be roamed to obtain a block acknowledgment (BA) fed back by the STA to be roamed, wherein the handover decision instruction is generated before the STA to be roamed roams from the original SFU initially accessed to a target SFU; processing all downlink data frames to be confirmed in a buffer array based on a starting sequence number and a binary bitmap in the block acknowledgment (BA) to determine all confirmed data frames and all unconfirmed data frames, generating a retransmission queue based on all the unconfirmed data frames, and releasing all confirmed data frames after confirmation; updating a send queue corresponding to the original SFU based on the retransmission queue to obtain an updated send queue, and mapping the updated send queue to a hardware queue of a target SFU, so that when the target SFU accesses the STA to be roamed, data frames are retransmitted based on the hardware queue of the target SFU.

[0102] In yet another aspect, the present invention further provides a non-transitory computer-readable storage medium having a computer program stored thereon. When executed by a processor, the computer program is implemented to perform the zero-packet-loss fast roaming method based on the C-WAN architecture provided by the above methods. The method includes: in response to a handover decision instruction, instructing an original SFU to send a block acknowledgment request (BAR) to a STA to be roamed to obtain a block acknowledgment (BA) fed back by the STA to be roamed, wherein the handover decision instruction is generated before the STA to be roamed roams from the original SFU to which it initially accessed to a target SFU; processing all downlink data frames to be confirmed in a buffer array based on a starting sequence number and a binary bitmap in the block acknowledgment (BA), determining all confirmed data frames and all unconfirmed data frames, generating a retransmission queue based on all unconfirmed data frames, and releasing all confirmed data frames after confirmation; updating a send queue corresponding to the original SFU based on the retransmission queue to obtain an updated send queue, and mapping the updated send queue to a hardware queue of a target SFU, so that when the target SFU accesses the STA to be roamed, data frames are retransmitted based on the hardware queue of the target SFU.

[0103] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0104] Through the description of the above embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus a necessary general hardware platform, or of course, by hardware. Based on this understanding, the essence of the above technical solution or the part that contributes to the existing technology can be embodied in the form of a software product. The computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a magnetic disk, an optical disk, etc., and includes a number of instructions for enabling a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or certain parts of the embodiments.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A zero-packet-loss fast roaming method based on C-WAN architecture, characterized by: include: In response to a handover decision instruction, instructing the original SFU to send a block acknowledgement request BAR to the STA to be roamed, so as to obtain a block acknowledgement BA fed back by the STA to be roamed, wherein the handover decision instruction is generated before the STA to be roamed roams from the original SFU initially accessed to the target SFU; According to the starting sequence number and the binary bitmap in the block acknowledgment (BA), all downlink data frames to be confirmed in the buffer array are processed to determine all confirmed data frames and all unconfirmed data frames. A retransmission queue is generated based on all the unconfirmed data frames, and all confirmed data frames are released after confirmation. Update the sending queue corresponding to the original SFU according to the retransmission queue to obtain an updated sending queue, and map the updated sending queue to the hardware queue of the target SFU, so that when the target SFU accesses the STA to be roamed, data frame retransmission is realized according to the hardware queue of the target SFU.

2. The zero-packet-loss fast roaming method based on C-WAN architecture according to claim 1, characterized in that: Before responding to the switching decision instruction, the method further includes: If it is determined that the uplink signal quality of the STA to be roamed is lower than a preset value, a Beacon request is generated; Using the original SFU to send the Beacon request to the STA to be roamed, so as to obtain signal measurement results of all SFUs fed back by the STA to be roamed; The SFU with the strongest signal among the signal measurement results of all SFUs is determined as the target SFU.

3. The zero-packet-loss fast roaming method based on C-WAN architecture according to claim 2, characterized in that: In a case where the STA to be roamed does not support 802.11k, before responding to the handover decision instruction, the method further includes: When it is determined that the uplink signal quality of the STA to be roamed is lower than a preset value, all adjacent SFUs within a preset range of the original SFU trigger channel measurement; Each adjacent SFU transmits the uplink RF signal strength information corresponding to the adjacent SFU to the MFU when performing channel measurement; The SFU with the highest signal strength among all uplink radio frequency signal strength information is determined as the target SFU.

4. The zero-packet-loss fast roaming method based on C-WAN architecture according to claim 1, characterized in that: After mapping the updated send queue to the hardware queue of the target SFU, the method further includes: Sending the physical layer configuration information of the STA to be roamed in the original SFU to the hardware MAC of the target SFU; The target SFU sends all the unconfirmed data frames to the STA to be roamed according to the physical layer configuration information of the original SFU.

5. The zero-packet-loss fast roaming method based on C-WAN architecture according to claim 1, characterized in that: After responding to the switching decision instruction, the method further includes: Instruct the target SFU to send the target Beacon frame and the original Beacon frame to the STA to be roamed in turn in a time division manner; The target Beacon frame is determined according to the BSSID corresponding to the target SFU; The original Beacon frame is determined according to the BSSID corresponding to the original SFU; The BSSID corresponding to the target SFU and the BSSID corresponding to the original SFU are in the same networking mode.

6. The zero-packet-loss fast roaming method based on C-WAN architecture according to claim 1, characterized in that: Based on the starting sequence number and binary bitmap in the block acknowledgment (BA), all downlink data frames to be confirmed in the buffer array are processed to determine all confirmed data frames and all unconfirmed data frames, including: Processing each data frame starting from the starting sequence number, and determining the confirmation status of each data frame according to the bit value in the binary bitmap Bitmap, wherein the bit value includes 1 or 0, 1 indicates that the data frame with the corresponding sequence number has been confirmed, and 0 indicates that the data frame with the corresponding sequence number has not been confirmed; Traverse all data frames until all confirmed data frames and all unconfirmed data frames are determined.

7. The zero-packet-loss fast roaming method based on C-WAN architecture according to claim 6, characterized in that: Before processing all downlink data frames to be confirmed in the buffer array according to the starting sequence number and the binary bitmap in the block acknowledgment BA, the method further includes: For each data frame, after the original SFU sends a block confirmation request BAR to the roaming STA, if no confirmation ACK is received for the data frame, the sequence number corresponding to the data frame is recorded and the bit value of the binary bitmap Bitmap is marked as 0; After the original SFU sends a block acknowledgement request BAR to the STA to be roamed, when receiving an acknowledgement ACK of the data frame, it records the sequence number corresponding to the data frame and marks the bit value of the binary bitmap Bitmap as 1.

8. The zero-packet-loss fast roaming method based on C-WAN architecture according to claim 1, characterized in that: After retransmitting the data frame according to the hardware queue of the target SFU, the method further includes: The roaming of the STA to be roamed from the original SFU to the target SFU is completed, and the STA to be roamed and the target SFU are re-associated using the 802.11v mechanism.

9. A zero-packet-loss fast roaming device based on C-WAN architecture, characterized in that: include: a responding unit, configured to, in response to a handover decision instruction, instruct the original SFU to send a block acknowledgement request BAR to the STA to be roamed, so as to obtain a block acknowledgement BA fed back by the STA to be roamed, wherein the handover decision instruction is generated before the STA to be roamed roams from the original SFU initially accessed to the target SFU; a processing unit configured to process all downlink data frames to be confirmed in the buffer array according to the starting sequence number and the binary bitmap in the block acknowledgment (BA), determine all confirmed data frames and all unconfirmed data frames, generate a retransmission queue based on all unconfirmed data frames, and release all confirmed data frames after confirmation; A mapping unit, wherein the mapping unit is used to update the sending queue corresponding to the original SFU according to the retransmission queue to obtain an updated sending queue, and map the updated sending queue to the hardware queue of the target SFU, so as to realize data frame retransmission according to the hardware queue of the target SFU when the target SFU accesses the STA to be roamed.

10. A zero-packet-loss fast roaming system based on C-WAN architecture, characterized by: The device comprises the zero-packet-loss fast roaming device based on the C-WAN architecture as claimed in claim 9, wherein the zero-packet-loss fast roaming device based on the C-WAN architecture is an MFU; It also includes multiple SFUs, the MFU is in communication connection with all the SFUs, and in a working state, the STA to be roamed is connected to any of the SFUs.

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