Communication method and apparatus, and storage medium

Abstract

The present application relates to the field of communications, and discloses a communication method and apparatus, and a storage medium. The method is applied to a master access point in a communication system. The communication system further comprises a first slave access point and a second slave access point. A station accesses the first slave access point. The method comprises: receiving a first roaming message, the first roaming message comprising context information of a service transmitted between the station and the first slave access point; and sending a second roaming message to the second slave access point, the second roaming message comprising the context information, and the context information being used for the second slave access point to transmit the service of the station. The present application can avoid service interruption.

Description

Communication methods, devices and storage media

[0001] This application claims priority to Chinese Patent Application No. 202411565237.4, filed November 4, 2024, entitled "Communication Method, Apparatus and Storage Medium"; this application claims priority to Chinese Patent Application No. 202510042548.0, filed January 9, 2025, entitled "Communication Method, Apparatus and Storage Medium"; and this application claims priority to Chinese Patent Application No. 202510223012.9, filed February 26, 2025, entitled "Communication Method, Apparatus and Storage Medium", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of communications, and in particular to a communication method, apparatus and storage medium. Background Technology

[0003] A wireless local area network (WLAN) may include multiple access points that can provide access services. Stations (STAs) within the coverage area of ​​the WLAN can connect to one access point. For ease of explanation, this access point will be referred to as the first access point. STAs can transmit services with the first access point.

[0004] In a wireless LAN, a STA (Station) can move, potentially from the coverage area of ​​a first access point to the coverage area of ​​a second access point. In this case, the STA can switch its access point from the first to the second. After switching to the second access point, the STA needs to resume service transmission on that second access point. However, in related technologies, it takes a considerable amount of time to resume service transmission on the second access point, which may cause service interruption. Summary of the Invention

[0005] This application provides a communication method, apparatus, and storage medium to avoid service interruption. The technical solution is as follows:

[0006] In a first aspect, this application provides a communication method applied to a primary access point of a communication system. The communication system further includes a first secondary access point and a second secondary access point. A site is connected to the first secondary access point, and the site is located within the coverage area of ​​the second secondary access point. In the method, a first roaming message is received, which includes context information of services transmitted between the site and the first secondary access point. A second roaming message is sent to the second secondary access point, carrying the context information of the services used by the second secondary access point to transmit the site's services.

[0007] Since the site is connected to the first secondary access point and transmits services with it, when the site moves to the coverage area of ​​the second secondary access point, the primary access point can receive the first roaming message sent by the first secondary access point and send a second roaming message to the second secondary access point. Because the second roaming message includes context information describing the services transmitted between the site and the first secondary access point, when switching the access point the site connects to from the first secondary access point to the second secondary access point, the transmission of the site's services can be resumed on the second secondary access point based on the context information, avoiding interruption of the site's services and achieving seamless roaming.

[0008] In one possible implementation, when a site moves into the coverage area of ​​a second access point, it sends a request message to the first access point, requesting the context information. The primary access point then receives a response message from the first access point, which includes the context information. This allows the primary access point to proactively obtain the context information, enriching the methods and flexibility for acquiring it.

[0009] In another possible implementation, when the site moves to the coverage area of ​​the second access point, it receives an update request message from the first access point, which includes the context information. This allows the primary access point to passively receive the context information, enriching the methods and flexibility for obtaining it.

[0010] In another possible implementation, the context information in the first roaming message includes one or more of the following: key update information used for the transmission service, the station's sleep state, the sequence number of the first message in the sending window, the sequence number of the last message in the sending window, the sequence number of the first message in the receiving window, the sequence number of the last message in the receiving window, a bitmap of the receiving window, or the sequence number of a message that the first access point did not send to the station. The service includes downlink services sent from the first access point to the station and / or uplink services received from the station by the first access point. The sending window is the window used by the first access point to send downlink service messages to the station, the receiving window is the window used by the first access point to receive uplink service messages from the station, and the bitmap is used to describe the reception status of the messages included in the receiving window. This allows the context information to describe the context of the service, enabling the second access point to recover the transmission station's service based on this context information.

[0011] In another possible implementation, the communication system includes a fiber-to-the-room (FTTR) system, with the main access point being the main FTTR device included in the FTTR system, and the first and second slave access points being slave FTTR devices included in the FTTR system.

[0012] In another possible implementation, the first roaming message is a service shutdown completion message, and the second roaming message is a service start indication.

[0013] In another possible implementation, the first roaming message or the second roaming message includes a message type and message content, wherein the message content includes the context information.

[0014] In another possible implementation, the first roaming message or the second roaming message includes a message type, message content, and a sequence number, wherein the message content includes the context information.

[0015] In another possible implementation, the first roaming message or the second roaming message includes a message type, message content, sequence number, length, and processing requirements, wherein the message content includes the context information.

[0016] In another possible implementation, the content field of the first roaming message or the second roaming message includes a parameter format and parameter content, wherein the parameter content includes the context information.

[0017] In another possible implementation, the context information includes at least one of the following: message sequence number, IP message identifier, and OMI status information of the site.

[0018] In another possible implementation, the method also includes:

[0019] The primary access point can instruct the secondary access points (first or second secondary access point) to disable multicast key updates in a cooperative roaming enable message or other messages;

[0020] The master access point updates the multicast key during the multicast key update cycle, and then encrypts the updated multicast key GTK and sends it to all slave access points in the network. The master access point uses the key between itself and the slave access points to encrypt the multicast key information to be transmitted to each slave access point.

[0021] After receiving the latest encrypted multicast key GTK from the master access point, the slave access point decrypts the multicast key using the key it shares with the master access point, and then updates the multicast key information. It then performs multicast key updates with all STAs associated with the slave access point, and each slave access point uses the updated multicast key GTK to send broadcast and multicast messages to its associated STAs.

[0022] In this implementation, the multicast key update in the FTTR network is controlled by the master access point. The multicast keys between the master access point and the slave access points are kept consistent, which avoids the STA being unable to receive or send data due to different multicast keys after roaming to different access points, thus improving the efficiency of STA roaming.

[0023] In another possible implementation, the method also includes:

[0024] During the roaming process of a site, the primary access point sends a service shutdown instruction message to the first secondary access point, which is the source access point of the site. This service shutdown message is used to instruct the first secondary access point to shut down service interactions with the site.

[0025] The primary access point receives a service shutdown feedback message from the first secondary access point. This service shutdown feedback message indicates whether the service interaction with the site has been successfully shut down.

[0026] In one possible implementation, the service shutdown instruction message includes the site's identification information.

[0027] In one possible implementation, the service shutdown instruction message is also used to instruct the first access point to report context information about the service interaction with the site.

[0028] In one possible implementation, the service shutdown feedback message indicates that the first access point has successfully shut down service interaction with the site.

[0029] In one possible implementation, the service shutdown feedback message includes context information about the service interaction between the first access point and the site.

[0030] In one possible implementation, the context information includes one or more of the following: unicast packet sequence number PN, sequence number SN, context, message sequence number, or station operation mode indication OMI status information.

[0031] In one possible implementation, the OMI status information of the site includes one or more of the following: receive spatial stream count, channel bandwidth, uplink multi-user transmission disabled, transmit spatial stream count, extended distance single-user transmission disabled, recommendation to re-perform downlink multi-user multiple-input multiple-output transmission channel probing, and uplink data multi-user transmission disabled.

[0032] In one possible implementation, a first multicast key synchronization message is sent to the first slave access point and the second slave access point. The first multicast key synchronization message includes one or more of the following parameters: multicast key, length of the multicast key, integrity group temporary key (IGTK), length of the IGTK, random number (Gnonce), receive sequence counter (RSC) or key replay counter.

[0033] Secondly, this application provides a communication method applied to a main access point of a communication system. The communication system further includes a first slave access point and a second slave access point. A station is connected to the first slave access point, and the station is located within the coverage area of ​​the second slave access point. In the method, a third roaming message is received, which includes connection information establishing a connection between the station and the first slave access point; a fourth roaming message is sent to the second slave access point, which includes the connection information used by the second slave access point to establish a connection with the station.

[0034] Since the site is connected to the first secondary access point and transmits services with it, when the site moves to the coverage area of ​​the second secondary access point, the primary access point can send a fourth roaming message to the second secondary access point. Because the fourth roaming message includes connection information between the site and the first secondary access point, when the access point to which the site is connected is switched from the first secondary access point to the second secondary access point, the transmission of the site's services can be resumed on the second secondary access point based on this connection information, avoiding interruption of the site's services and achieving seamless roaming.

[0035] In one possible implementation, the connection information in the third roaming message includes one or more of the following: aggregation information used to transmit the service or key information used to transmit the service.

[0036] In one possible implementation, the key information includes a unicast key PTK and a multicast key GTK.

[0037] In another possible implementation, the communication system includes a fiber-to-the-room (FTTR) system, the primary access point being a primary FTTR device included in the FTTR system, and the first and second secondary access points being secondary FTTR devices included in the FTTR system.

[0038] In another possible implementation, the connection information in the third roaming message includes one or more of the following: a reassociation request message received from the site by the first access point, an association request message received from the site by the first access point, or an authentication request message received from the site by the first access point.

[0039] In another possible implementation, the third roaming message is an association request reporting message, and the fourth roaming message is an association request sending message.

[0040] In another possible implementation, a first multicast key synchronization message is sent to the first slave access point and the second slave access point. The first multicast key synchronization message includes one or more of the following parameters: multicast key, length of the multicast key, integrity group temporary key IGTK, length of the IGTK, random number Gnonce, receive sequence counter RSC or key replay counter.

[0041] Thirdly, this application provides a communication method applied to a second slave access point of a communication system. The communication system further includes a master access point and a first slave access point. A site is accessed at the first slave access point, and the site is located within the coverage area of ​​the second slave access point. In the method, a second roaming message sent by the master access point is received, the second roaming message including context information of services transmitted between the site and the first slave access point; and the services of the site are transmitted based on the context information.

[0042] Because the site is connected to the first secondary access point and transmits services with it, when the site moves to the coverage area of ​​the second secondary access point, the second secondary access point receives a second roaming message. Since the second roaming message includes contextual information describing the services transmitted between the site and the first secondary access point, when the access point to which the site is connected is switched from the first secondary access point to the second secondary access point, the second secondary access point can resume transmitting the site's services on the second secondary access point based on the contextual information, avoiding interruption of the site's services and achieving seamless roaming.

[0043] In one possible implementation, the context information includes one or more of the following: key update information used to transmit the service, the dormant state of the site, the sequence number of the first message in the sending window, the sequence number of the last message in the sending window, the sequence number of the first message in the receiving window, the sequence number of the last message in the receiving window, the bitmap of the receiving window, or the sequence number of the first message not sent from the access point to the site.

[0044] The service includes downlink service sent from the first access point to the site and / or uplink service received from the site by the first access point. The sending window is the window used by the first access point to send the downlink service message to the site, and the receiving window is the window used by the first access point to receive the uplink service message from the site. The bitmap is used to describe the receiving status of the messages included in the receiving window.

[0045] In another possible implementation, the context information includes at least one of the following: message sequence number, IP message identifier, sequence number (SN) context information, or site OMI status information.

[0046] In another possible implementation, a downlink message is sent to the station based on the message sequence number, or...

[0047] Based on the SN context information, an aggregated message is sent to the site, or...

[0048] The channel bandwidth and number of streams are determined based on the OMI status information of the site.

[0049] In another possible implementation, the OMI status information of the site includes one or more of the following: receive spatial stream count, channel bandwidth, uplink multi-user transmission disabled, transmit spatial stream count, extended distance single-user transmission disabled, recommendation to re-perform downlink multi-user multiple-input multiple-output transmission channel probing, and uplink data multi-user transmission disabled.

[0050] In another possible implementation, if the hibernation state is used to indicate that the station is in a sleep state, then the station is woken up; and / or,

[0051] Based on the sequence number of the first message in the sending window, the sequence number of the last message in the sending window, and / or the sequence number of the first message not sent from the access point to the site, the message to be sent belonging to the downlink service is determined; or,

[0052] Based on the sequence number of the first message in the receive window, the sequence number of the last message in the receive window, and the bitmap of the receive window, the station is instructed to determine the messages to be sent that belong to the uplink service; and / or,

[0053] The multicast data to be sent to the site is encrypted based on the key update information.

[0054] In another possible implementation, the third or fourth roaming message includes a message type and message content, the message content including the connection information.

[0055] In another possible implementation, the first roaming message or the second roaming message includes a message type, message content, and a sequence number, wherein the message content includes the connection information.

[0056] In another possible implementation, the first roaming message or the second roaming message includes a message type, message content, sequence number, length, and processing requirements, wherein the message content includes the connection information.

[0057] In another possible implementation, the content field of the first roaming message or the second roaming message includes a parameter format and parameter content, wherein the parameter content includes the connection information.

[0058] In another possible implementation, the context information includes at least one of the following: message sequence number, IP message identifier, and OMI status information of the site.

[0059] In another possible implementation, a first multicast key synchronization message is received, which includes one or more of the following parameters: multicast key, length of the multicast key, integrity group temporary key suite (IGTK), length of the IGTK, random number Gnonce, receive sequence counter (RSC) or key replay counter; a second multicast key synchronization message is sent to the station, which includes some or all of the parameters in the first multicast key synchronization message.

[0060] Fourthly, this application provides a communication method applied to a second slave access point of a communication system. The communication system further includes a master access point and a first slave access point. A site is connected to the first slave access point, and the site is located within the coverage area of ​​the second slave access point. In the method, a fourth roaming message sent by the master access point is received, the fourth roaming message including connection information establishing a connection between the site and the first slave access point; and services of the site are transmitted based on the connection information.

[0061] Because the site is connected to the first secondary access point and transmits services with it, when the site moves to the coverage area of ​​the second secondary access point, the second secondary access point receives a fourth roaming message. Since the fourth roaming message includes connection information between the site and the first secondary access point, when the access point to which the site is connected is switched from the first secondary access point to the second secondary access point, the second secondary access point can resume transmitting the site's services on its own based on this connection information, avoiding interruption of the site's services and achieving seamless roaming.

[0062] In one possible implementation, the connection information includes one or more of the following: a reassociation request message received from the site by the first access point, an association request message received from the site by the first access point, or an authentication request message received from the site by the first access point.

[0063] In another possible implementation, the transmission of the site's services based on the connection information includes:

[0064] A connection with the site is established based on the association request message, the reassociation request message, and the authentication request message. The connection is used to transmit the site's services.

[0065] In another possible implementation, a first multicast key synchronization message is received, which includes one or more of the following parameters: multicast key, length of the multicast key, integrity group temporary key (IGTK), length of the IGTK, random number (Gnonce), receive sequence counter (RSC) or key replay counter; a second multicast key synchronization message is sent to the station, which includes some or all of the parameters in the first multicast key synchronization message.

[0066] Fifthly, this application provides a communication method, wherein the communication system includes a master access point, a first slave access point, and a second slave access point, wherein a station is connected to the first slave access point, and the station is located within the coverage area of ​​the second slave access point, and the method includes:

[0067] The primary access point obtains a first roaming message, which includes context information of the service transmitted between the site and the first secondary access point;

[0068] The primary access point sends the first roaming message to the second secondary access point, and the context information in the first roaming message is used by the second secondary access point to transmit the services of the site.

[0069] In one possible implementation, the context information in the first roaming message includes: multicast key update information used for transmitting multicast services;

[0070] The second step is to disable multicast key updates from the access point, that is, to disable the local multicast key update function from the access point.

[0071] After receiving the multicast key update information from the primary access point, the second access point updates its local multicast key information.

[0072] The second access point updates the multicast key with its subordinate sites.

[0073] Subsequently, the second access point uses the updated multicast key to send broadcast and multicast messages to the downstream sites.

[0074] Sixthly, this application provides a communication device having the functionality to implement the first aspect and the optional methods of the first aspect described above. The device includes at least one module for implementing the methods provided by the first aspect and the optional methods of the first aspect. Alternatively, the device includes at least one module for implementing the methods provided by the second aspect and the optional methods of the second aspect. Alternatively, the device includes at least one module for implementing the methods provided by the third aspect and the optional methods of the third aspect. Alternatively, the device includes at least one module for implementing the methods provided by the fourth aspect and the optional methods of the fourth aspect.

[0075] In a seventh aspect, this application provides an access point, the access point including a processor, a memory, and a communication interface, the processor being configured to execute program instructions in the memory to implement the methods provided by the first aspect, the second aspect, the third aspect, the fourth aspect, the fifth aspect, any possible implementation of the first aspect, any possible implementation of the second aspect, any possible implementation of the third aspect, any possible implementation of the fourth aspect, or any possible implementation of the fifth aspect, and the communication interface being configured to communicate with the access point.

[0076] Eighthly, this application provides a computer-readable storage medium storing at least one program instruction that is read by a processor to cause an access point to perform the method provided by the first aspect, second aspect, third aspect, fourth aspect, fifth aspect, any possible implementation of the first aspect, any possible implementation of the second aspect, any possible implementation of the third aspect, any possible implementation of the fourth aspect, or any possible implementation of the fifth aspect.

[0077] Ninthly, this application provides a computer program product including program instructions stored in a computer-readable storage medium. A processor at an access point reads the program instructions from the computer-readable storage medium and executes the program instructions, causing the access point to perform the methods provided by the first, second, third, fourth, and fifth aspects, or any possible implementation of the first, second, third, fourth, or fifth aspects. Attached Figure Description

[0078] Figure 1 is a schematic diagram of the structure of a communication system provided in an embodiment of this application;

[0079] Figure 2 is a schematic diagram of another communication system provided in an embodiment of this application;

[0080] Figure 3 is a flowchart of a communication method provided in an embodiment of this application;

[0081] Figure 4 is a schematic diagram of a sending window provided in an embodiment of this application;

[0082] Figure 5 is a schematic diagram of a receiving window provided in an embodiment of this application;

[0083] Figure 6 is a flowchart of another communication method provided in an embodiment of this application;

[0084] Figure 7a is a schematic diagram of a management channel in a data link layer provided in an embodiment of this application;

[0085] Figure 7b is a schematic diagram of the structure of a multicast key provided in an embodiment of this application;

[0086] Figure 8 is a flowchart of another communication method provided in an embodiment of this application;

[0087] Figure 9 is a flowchart of another communication method provided in an embodiment of this application;

[0088] Figure 10 is a flowchart of another communication method provided in an embodiment of this application;

[0089] Figure 11 is a schematic diagram of a communication device structure provided in an embodiment of this application;

[0090] Figure 12 is a schematic diagram of a device structure provided in an embodiment of this application;

[0091] Figure 13 is a schematic diagram of a communication device structure provided in an embodiment of this application;

[0092] Figure 14 is a schematic diagram of a communication device structure provided in an embodiment of this application;

[0093] Figure 15 is a schematic diagram of a communication device structure provided in an embodiment of this application. Detailed Implementation

[0094] A wireless LAN comprises multiple access points, and its coverage area includes the coverage area of ​​each of these access points. The importance of seamless roaming in a wireless LAN lies in its ability to provide users with a continuous and uninterrupted wireless network connection, ensuring stable and reliable network connectivity in homes, offices, and public places. From a user experience perspective, seamless roaming avoids network interruptions. Imagine a user enjoying a smooth online video or participating in an important online meeting, only to suddenly lose their internet connection as they move from one room or area to another; this would significantly degrade the user experience. Seamless roaming technology intelligently senses user movement and changes in signal strength, automatically switching to the optimal access point to avoid such interruptions and allow users to enjoy a continuous and stable network connection. The following examples will illustrate the technology of seamless roaming in detail.

[0095] Referring to Figure 1, this application embodiment provides a communication system 100, which includes a master access point 101, a first slave access point 102, and a second slave access point 103. The master access point 101 can communicate with the first slave access point 102, and the master access point 101 can communicate with the second slave access point 103. The access point can be referred to as an access device; that is, the master access point can be a master access device, and the slave access point can be a slave access device. Both the master and slave access devices can access the STA device via a wireless local area network.

[0096] In the communication system provided in this application, all access points (master access point and slave access point) have the same basic service set identifier (BSSID). A STA device can roam from one master access point to one slave access point, or from one slave access point to another. Optionally, the STA device may include a terminal, etc.

[0097] Optionally, the number of second slave access points 103 included in the communication system 100 may be one or more, that is, the communication system 100 includes at least one second slave access point 103.

[0098] The coverage area of ​​the communication system 100 includes the coverage area of ​​the main access point, the coverage area of ​​the first slave access point 102, and / or the coverage area of ​​each second slave access point 103.

[0099] Referring to Figure 1, the first STA104 is located within the coverage area of ​​the first slave access point 102. The first STA104 can access the first slave access point 102 and transmit services with the first slave access point 102.

[0100] Optionally, the service may include downlink services and / or uplink services. Downlink services are those sent from the first access point 102 to the first STA 104, and are therefore downlink services. Uplink services are those sent from the first STA 104 to the first access point 102, and are therefore uplink services.

[0101] The first STA104 accesses the first slave access point 102 by authenticating, associating and negotiating a key with the first slave access point 102, and then transmits services with the first slave access point 102.

[0102] Optionally, during the authentication, association, and key negotiation process, the first STA104 may send an association request message to the first slave access point 102, send an authentication request message to the first slave access point 102, negotiate with the first slave access point 102 the key information used for the transmission service, and / or negotiate with the first slave access point 102 the aggregation information used for the transmission service, etc.

[0103] Optionally, the aggregation information includes aggregation parameters, such as the size of the aggregation window and / or the aggregation strategy. Key information includes unicast keys (pairwise transit key, PTK) and multicast keys (group temporal key, GTK), etc.

[0104] In some embodiments, when the first STA104 accesses the first slave access point 102, the first slave access point 102 may send a third roaming message to the master access point 101. The third roaming message includes connection information, which may include one or more of the following: association request message, reassociation request message, authentication request message, key information, or aggregation information.

[0105] Optionally, the connection information can be used to indicate a first connection established between the first STA104 and the first slave access point 102.

[0106] In some embodiments, the primary access point 101 may receive a third roaming message and send a fourth roaming message to at least one second secondary access point 103, the fourth roaming message including the connection information. The first STA 104 may move within the wireless local area network. When the first STA 104 moves to the coverage area of ​​another secondary access point, the other secondary access point may establish a second connection with the first STA 104 based on the connection information included in the fourth roaming message, and use the second connection to transmit the services of the first STA 104.

[0107] In some embodiments, the master access point 101 includes a first Wi-Fi management and control interface (WMCI) interface, the first slave access point 102 includes a second WMCI interface, and each second slave access point 103 includes a third WMCI interface. The master access point 101 and the slave access points (102 or 103) communicate via the WMCI interface; that is, messages between the master access point 101 and the slave access points (102 or 103) are transmitted through the WMCI interface.

[0108] The first slave access point 102 can send a third roaming message to the primary access point 101 via the second WMCI interface. The primary access point 101 receives the third roaming message via the first WMCI interface, saves the connection information in the third roaming message, and sends a fourth roaming message, including the connection information, to at least one second slave access point 103 via the first WMCI interface. The second slave access point 103 receives the fourth roaming message via the third WMCI interface and saves the connection information in the fourth roaming message.

[0109] Optionally, the third roaming message can be encapsulated as a WMCI message and then sent by the first slave access point 102 to the master access point 101 through the second WMCI interface. The fourth roaming message can be encapsulated as a WMCI message and then sent by the master access point 101 to the second slave access point 103 through the first WMCI interface.

[0110] The first STA 104 can move within the coverage area of ​​the wireless local area network (the aforementioned communication system 100). When the first STA 104 moves within the coverage area of ​​the second slave access point 103, the primary access point 101 can receive a first roaming message from the first slave access point 102 (the first roaming message includes context information of the services transmitted between the first STA 104 and the first slave access point 102), and send a second roaming message to the second slave access point 103, the second roaming message including the context information. The second slave access point 103 transmits the services of the first STA 104 based on the context information in the second roaming message.

[0111] In some embodiments, the context information in the first roaming message includes one or more of the following: key update information used for transmission services, the sleep state of the first STA104, the sequence number of the first message in the first sending window, the sequence number of the last message in the first sending window, the sequence number of the first message in the first receiving window, the sequence number of the last message in the first receiving window, the bitmap of the first receiving window, or the sequence number of the first message not sent from the access point 102 to the first STA104, the message sequence number, the identifier of the Internet Protocol (IP) message, or the operating mode indication (OMI) status information of the first STA104.

[0112] The service includes downlink service sent from access point 102 to first STA 104 and / or uplink service received from first STA 104 by access point 102. The first sending window is the window used by the first access point 102 to send downlink service messages to first STA 104, and the first receiving window is the window used by the first access point 102 to receive uplink service messages from first STA 104. The bitmap is used to describe the receiving status of the messages included in the first receiving window.

[0113] In some embodiments, the primary access point 101 may instruct the second secondary access point 103 to establish a second connection with the first STA 104 based on connection information, instruct the first secondary access point 102 to close the transmission of services of the first STA 104, and instruct the second secondary access point 103 to start transmitting services of the first STA 104 through the second connection based on context information, thereby switching the access point currently accessed by the first STA 104 from the first secondary access point 102 to the second secondary access point 103.

[0114] During the access point switching process, the first STA104 is unaware of the access point switching process, and when instructing the first slave access point 102 to shut down the transmission of the first STA104's services, it instructs the second slave access point 103 to start transmitting the first STA104's services based on the first roaming message, thereby avoiding interruption of the transmission of the first STA104's services, thus achieving seamless roaming.

[0115] Referring to Figure 1, the second STA 105 is located within the coverage area of ​​the main access point 101. The second STA 105 can access the main access point 101 and transmit services with the main access point 101. A description of the second STA 105 can be found in the description of the first STA 104, and will not be elaborated upon here.

[0116] In some embodiments, the communication system 100 can be a passive optical network (PON) structure system, and the master access point 101 can communicate with the first slave access point 102 and / or at least one second slave access point 103 via optical fiber. Additionally, the master access point 101 can also wirelessly communicate with the slave access points via the aforementioned WMCI interface.

[0117] Optionally, referring to Figure 2, the communication system 100 further includes a splitter 106, with the main access point 101 communicating with the splitter 106. The splitter 106 also communicates with the first slave access point 102 and / or each of the second slave access points 103. Thus, the main access point 101 can communicate with the first slave access point 102 and / or each of the second slave access points 103 through the splitter 106.

[0118] In some embodiments, the communication system 100 includes a Fiber To The Room (FTTR) system, where the main access point 101 is the main FTTR unit (MFU) included in the FTTR system, and the first slave access point 102 and the second slave access point 103 are slave FTTR units (SFUs) included in the FTTR system.

[0119] The SFU is connected to the MFU via optical fiber, and the MFU is connected to the optical line terminal (OLT) via optical fiber.

[0120] SFU and MFU can communicate via the WMCI interface, and the communication messages can be in the WMCI message format.

[0121] In a communication system, the MFU and SFU have the same Basic Service Set Identifier (BSSID) and / or the same Service Set Identifier (SSID).

[0122] When a STA moves within an FTTR network, the channel quality with its currently associated SFU deteriorates, necessitating roaming to an SFU with better channel quality to ensure service continuity. However, during roaming, the terminal needs to re-establish a connection on the new SFU, leading to service interruptions. To ensure timely and continuous roaming, a cooperative roaming control method (WMCI) is employed. Roaming between SFUs involves service shutdown and startup delays.

[0123] In this embodiment, a first STA accesses a first slave access point and transmits services with the first slave access point. When the first STA moves to the coverage area of ​​a second slave access point, the primary access point can receive a first roaming message sent by the first slave access point and send a second roaming message to the second slave access point. Since the first roaming message includes context information describing the services transmitted between the first STA and the first slave access point, the second slave access point can transmit the first STA's services based on the context information when the first slave access point stops transmitting the first STA's services. Thus, when the access point accessed by the first STA is switched from the first slave access point to the second slave access point, the transmission of the first STA's services can be resumed on the second slave access point, avoiding interruption of the first STA's services and achieving seamless roaming.

[0124] Referring to Figure 3, this application embodiment provides a communication method 300. The communication method 300 is applied to the communication system 100 shown in Figure 1 or Figure 2. In the communication method 300, a first STA accesses a first slave access point and transmits services with the first slave access point. When the first STA moves to the coverage area of ​​a second slave access point, the master access point requests the first slave access point to provide context information for the service and sends the context information to the second slave access point, enabling the second slave access point to transmit the first STA's service based on the context information. The communication method 300 includes the following process.

[0125] Step 301: The first STA accesses the first slave access point and transmits services with the first slave access point.

[0126] The first STA is located within the coverage area of ​​the first slave access point, thus enabling the first STA to access the first slave access point. Optionally, in implementation, the first STA can access the first slave access point through a process of authentication, association, and key negotiation.

[0127] Optionally, the first STA is located within the coverage area of ​​the first slave access point, and the signal quality between the first STA and the first slave access point is higher than the quality threshold, so that the first STA can access the first slave access point and then transmit services with the first slave access point.

[0128] Step 302: When the first STA moves to the coverage area of ​​the second slave access point, the primary access point sends an acquisition request message to the first slave access point. The acquisition request message is used to request the context information of the service.

[0129] Within the coverage area of ​​the wireless LAN, the first STA may move into the coverage area of ​​the second slave access point, causing the signal quality between the second slave access point and the first STA to gradually increase, while the signal quality between the first slave access point and the first STA to gradually decrease. If the first STA moves into the coverage area of ​​the second slave access point and the signal quality between the second slave access point and the first STA is higher than a quality threshold, the master access point sends an acquisition request message to the first slave access point.

[0130] Step 303: The first slave access point receives the acquisition request message and sends an acquisition response message to the master access point. The acquisition response message includes context information describing the service transmitted between the first STA and the first slave access point.

[0131] Optionally, the response message is the first roaming message, which is a WMCI message.

[0132] Step 304: The primary access point receives the acquisition response message and sends an update request message to the second secondary access point. The update request message includes the context information.

[0133] Optionally, the retrieval response message and / or the update request message are second roaming messages, which are WMCI messages.

[0134] In some embodiments, the update request message may also include identification information of the first STA.

[0135] In some embodiments, the primary access point receives a response message through a first WMCI interface and sends an update request message to the second secondary access point through the first WMCI interface. The update request message may be a WMCI message.

[0136] Step 305: The second STA receives the update request message from the access point and transmits the services of the first STA based on the context information included in the update request message.

[0137] Regarding step 301 of method 300, in step 301, during the authentication, association and key negotiation process, the first STA may negotiate with the first access point the key information used for transmitting the service, and / or negotiate with the first access point the aggregation information used for transmitting the service, etc.

[0138] Optionally, during the authentication, association, and key negotiation process, the first STA may send an association request message to the first slave access point, send an authentication request message to the first slave access point, and establish a first connection with the first slave access point based on the key information, the association request message, and / or the authentication request message.

[0139] Optionally, the first STA may also send a reassociation request message to the first slave access point.

[0140] In some embodiments, when a first STA accesses a first slave access point, the first slave access point can synchronize the connection information of the first connection with other access points in the communication system. Optionally, in implementation: the first slave access point can send a third roaming message to the master access point, the third roaming message carrying the connection information of the first connection. This connection information includes one or more of the following: association request message, reassociation request message, authentication request message, key information, or aggregation information, etc. The master access point receives the third roaming message and sends a fourth roaming message to a second slave access point in the communication system other than the first slave access point, the fourth roaming message including the connection information. The first slave access point, the master access point, and / or the second slave access point receiving the fourth roaming message can store the connection information.

[0141] Optionally, the first slave access point can send a third roaming message to the primary access point via the second WMCI interface. The primary access point receives the third roaming message via the first WMCI interface, saves the connection information in the third roaming message, and sends a fourth roaming message to the second slave access point via the first WMCI interface. The second slave access point receives the fourth roaming message via the third WMCI interface and saves the connection information in the fourth roaming message.

[0142] Multiple pieces of information in the connection information can be encapsulated in multiple third roaming messages, that is, the first access point sends multiple third roaming messages to the primary access point, and the primary access point sends multiple fourth roaming messages to the second access point.

[0143] For example, see Table 1 below for roaming messages (third roaming message or fourth roaming message) used to encapsulate authentication request messages, association request messages, or reassociation request messages.

[0144] Table 1

[0145] For example, see Table 2 below for roaming messages (third roaming message or fourth roaming message) used to encapsulate key messages. Optionally, the request message shown in Table 1 and the key information shown in Table 2 can be encapsulated in a single roaming message.

[0146] Table 2

[0147] For example, see Table 3 below for roaming messages (third roaming message or fourth roaming message) used to encapsulate aggregation messages.

[0148] Table 3

[0149] Optionally, the aggregation information in Table 3 may exclude frames but include aggregation parameters.

[0150] Multiple pieces of information from the connection information of the first connection can be encapsulated in a third roaming message and a fourth roaming message. That is, the third roaming message includes multiple pieces of information from the connection information of the first connection, and the fourth roaming message includes multiple pieces of information from the connection information of the first connection. In this way, multiple pieces of information can share the three fields of access point identification information, interface identification information, and first STA identification information.

[0151] The first STA can use the first connection to transmit services with the first access point.

[0152] Optionally, the third and fourth roaming messages are WMCI messages.

[0153] The service may include downlink traffic sent from the first access point to the first STA. And / or, the service may include uplink traffic received from the first STA by the first access point.

[0154] The first access point includes a first sending window and / or a first receiving window. The first sending window is the window used by the first access point to send downlink service messages to the first STA, and the first receiving window is the window used by the first access point to receive uplink service messages from the first STA.

[0155] For the first message included in the aforementioned downlink service, the first access point can send the first message to the first STA. The first message has a sequence number. The sequence number of the currently sent first message is obtained by incrementing the sequence number of the previous first message sent by the first access point to the first STA. Both the previous first message and the currently sent first message belong to the downlink service.

[0156] Optionally, the sequence number of the currently sent first message can be obtained by adding 1 to the sequence number of the previous first message.

[0157] Optionally, the sequence number of the first message can be the sequence number (SN) of the first message, etc. For the 0th first message of the downlink service, the first access point initializes the initial value of the SN of the 0th first message. For the nth first message of the downlink service, the SN of the nth first message is equal to the SN of the (n-1)th first message + P1, where P1 is an integer greater than or equal to 1, and n is an integer greater than or equal to 1.

[0158] Optionally, the first message may include multiple data units aggregated based on aggregation information, so that multiple data units can be sent through a single first message, improving transmission efficiency. In implementation, the aggregation information includes an aggregation window size and / or an aggregation strategy. The first access point can aggregate multiple data units into a single first message based on the aggregation strategy, wherein the number of multiple data units is less than or equal to the aggregation window size, and send the first message to the first STA.

[0159] Referring to Figure 4, the first access point sends the first downlink service message to the first STA using a first sending window. An example of sending the first downlink service message is given below. In this example, the first access point initializes the SN of the 0th first downlink service message to 0, assuming P1 = 1. Thus, the SN of the 1st first message is 1, the SN of the 2nd first message is 2, and so on. Referring to Figure 4(a), the first sending window includes multiple first downlink service messages (e.g., the size of the first sending window is 4, including four first messages, namely first messages 0, 1, 2, and 3). The first access point sends multiple first messages from the first sending window to the first STA. Referring to Figure 4(b), after sending multiple first messages from the first sending window, the first access point moves the first sending window so that it includes multiple other first messages from the downlink service (e.g., the first sending window includes first messages 4, 5, 6, and 7), and sends these multiple first messages from the first sending window to the first STA. By repeating the above process, the first access point can continuously send the first message of downlink service to the first STA.

[0160] Regarding the second message included in the aforementioned uplink service, the first slave access point can receive the second message sent by the first STA, and the second message has a sequence number. The sequence number of the second message currently sent by the first STA is obtained by incrementing the sequence number of the previous second message sent by the first STA to the first slave access point. Both the previous second message and the currently sent second message belong to the uplink service.

[0161] Optionally, the sequence number of the currently sent second message can be obtained by adding 1 to the sequence number of the previous second message.

[0162] Optionally, the sequence number of the second message can be the SN of the second message, etc. For the 0th second message of the uplink service, the first STA initializes the initial value of the SN of the 0th second message. For the mth second message of the uplink service, the SN of the mth second message is equal to the SN of the (m-1)th second message + P2, where P2 is an integer greater than or equal to 1 and m is an integer greater than or equal to 1.

[0163] Optionally, the second message may include multiple data units aggregated based on the aggregation information, so that multiple data units can be sent through a single second message, thereby improving transmission efficiency.

[0164] Referring to Figure 5, the first slave access point uses the first receive window to receive the second uplink service message sent by the first STA. The following is an example of receiving the second uplink service message. In this example, the first STA initializes the SN of the 0th second uplink service message to 0, assuming P2 = 1. Thus, the SN of the 1st second message is 1, the SN of the 2nd second message is 2, and so on. Referring to Figure 5(a), assuming the size of the first receive window is 4, the first slave access point uses the first receive window to receive four second uplink service messages, namely second messages 0, 1, 2, and 3, and sends the bitmap of the first receive window to the first STA.

[0165] This bitmap includes four bits corresponding one-to-one with the four second messages. For a second message successfully received using the first receive window, the bit value corresponding to the successfully received second message in this bitmap is the first bit value. For a second message not successfully received using the first receive window, the bit value corresponding to the unsuccessfully received second message in this bitmap is the second bit value. Therefore, this bitmap is used to describe the reception status of the second messages included in the first receive window. Optionally, the first bit value is 1 and the second bit value is 0; or, the first bit value is 0 and the second bit value is 1. For a second message that is not successfully received, the first STA needs to retransmit the second message, and the first STA then receives the retransmitted second message from the access point.

[0166] Referring to Figure 5(b), the first slave access point moves its first receiving window so that its starting position is equal to the SN+1 of the third second message. It then uses the first receiving window to receive four second messages, namely second messages 4, 5, 6, and 7, and sends a bitmap of the first receiving window to the first STA. Repeating this process, the first slave access point can continuously receive second messages from the first STA for uplink services.

[0167] The first STA can move within the coverage area of ​​the wireless LAN. When the first STA moves within the coverage area of ​​at least one second access point, the second access point can transmit the services of the first STA through the following process.

[0168] Regarding step 302 of method 300, in step 302, the first STA may move to the coverage area of ​​at least one second slave access point, and the signal quality between the first STA and the at least one second slave access point is higher than a quality threshold. For each second slave access point, if the second slave access point detects that the signal strength with the first STA is gradually increasing and that the signal strength is higher than the quality threshold, the second slave access point sends roaming decision information to the master access point. The roaming decision information may include the signal quality between the second slave access point and the first STA, etc. Then, the master access point can request a roaming message from the first slave access point.

[0169] In some embodiments, referring to FIG6, when a first slave access point detects that the signal quality between the first slave access point and the first STA is lower than a quality threshold, it sends a roaming trigger event to the master access point. The master access point receives the roaming trigger event and sends roaming decision collection information to each second slave access point in the communication system. The second slave access points receive the roaming decision collection information and send roaming decision information to the master access point based on the roaming decision collection information.

[0170] Optionally, signal quality can be the received signal strength indication (RSSI), etc.

[0171] In some embodiments, the primary access point sends an acquisition request message to the first secondary access point through a first WMCI interface. The acquisition request message may be a WMCI message.

[0172] In some embodiments, the primary access point may receive roaming decision information from at least one second slave access point, which allows it to determine the signal quality between at least one second slave access point and the first STA, and select a second slave access point with the best signal quality or one that exceeds a quality threshold with the first STA. Referring to Figure 6, the primary access point may send a roaming start message to the first slave access point and the selected second slave access point.

[0173] After receiving the roaming start message, the first and second slave access points send a roaming start confirmation message to the primary access point.

[0174] After receiving the roaming start confirmation messages from the first and second slave access points, the primary access point sends a roaming preprocessing instruction to the second slave access point.

[0175] The second step is to receive a roaming preprocessing instruction from the access point and initiate the roaming preprocessing process. There are two possible roaming preprocessing steps:

[0176] The first type of roaming preprocessing is simulated aggregation. The simulated aggregation process is as follows: the second access point establishes an aggregation with the first STA based on the aggregation information, and then sends an aggregation frame to the first STA, or receives an aggregation frame from the first STA, and replies to the first STA with a block acknowledgement (BA) frame. The BA frame is used to indicate frames that were successfully received and frames that were not successfully received.

[0177] The second type of roaming preprocessing involves: establishing a second connection between the second access point and the first STA, and then performing a simulated aggregation process.

[0178] After completing the roaming preprocessing, the second access point sends a roaming preprocessing completion message to the primary access point. Upon receiving the roaming preprocessing completion message, the primary access point can perform the following steps.

[0179] The roaming preprocessing instruction includes parameters used for simulating aggregation. These may include aggregation parameters used to implement aggregated transmission with the STA, or aggregated frames. These parameters, or roaming preprocessing context information, are used for simulating aggregation.

[0180] As an example, aggregation parameters are shown in Table 4-1 or Table 4-2. Tables 4-1 and 4-2 are applicable to aggregation scenarios. The parameters in the following tables can be partially or fully included as needed.

[0181] Table 4-1

[0182] Table 4-2

[0183] In one possible implementation, the Key field may also include an encryption mode.

[0184] Regarding step 303 of method 300, in step 303, the context information used to describe the service transmitted between the first STA and the first access point includes one or more of the following: key update information used for transmitting the service, the sleep state of the first STA, the sequence number of the first packet in the first sending window, the sequence number of the last packet in the first sending window, the sequence number of the first packet in the first receiving window, the sequence number of the last packet in the first receiving window, the bitmap of the first receiving window, the sequence number of the packets not sent by the first access point to the first STA, the packet sequence number, the identifier of the IP packet, or the OMI status information of the first STA, etc.

[0185] Optionally, the sequence number of a message that the first access point did not send to the first STA may include the sequence number of the first second message that the first access point did not send to the first STA, etc.

[0186] In some embodiments, the first slave access point receives an acquisition request message through a second WMCI interface and sends an acquisition response message to the primary access point through the second WMCI interface. Optionally, the acquisition response message is a WMCI message.

[0187] In some embodiments, referring to Figure 6, the primary access point receives a roaming preprocessing completion message and sends a service shutdown indication message to the first secondary access point. The service shutdown indication message may be an instance of a retrieval request message.

[0188] The first STA receives a service shutdown instruction message from the access point, shuts down the service of the first STA, and sends a service shutdown completion message to the primary access point. This service shutdown completion message includes a first roaming message and is an instance of obtaining a response message.

[0189] Regarding step 304 of method 300, as shown in Figure 6, the primary access point receives a service closure completion message and sends a service activation indication to the second secondary access point. The service activation indication message includes service context information and is an example of an update request message.

[0190] In some embodiments, multiple pieces of information from the context of a service can be encapsulated within an update request message. For example, see Table 4-3 below for an update request message used to encapsulate the context information of a service.

[0191] Table 4-3

[0192] Regarding step 304 of method 300, in step 304, the second party obtains the connection information of the first connection from the access point, establishes a second connection with the first STA based on the connection information of the first connection, and transmits the service of the first STA through the second connection based on the context information of the service.

[0193] Optionally, the second access point establishes a second connection with the first STA based on an association request message (or a reassociation request message) and key information; alternatively, the second access point establishes a second connection with the first STA based on an association request message (or a reassociation request message), key information, and an authentication request message. Optionally, the key information includes PTK and GTK, etc.

[0194] In some embodiments, the second access point receives a service initiation indication message, starts transmitting the service of the first STA based on the first roaming message, and sends part or all of the service context information to the first STA. The second access point then sends a service initiation indication completion message to the primary access point.

[0195] Optionally, the service context information includes the sleep state of the first STA. If the sleep state of the first STA indicates that the first STA is currently in a sleep state, the second access point can wake up the first STA and then start transmitting the first STA's service. If the sleep state of the first STA indicates that the first STA is currently awake, the second access point can transmit the first STA's service.

[0196] Optionally, the service context information includes the sequence number of the first message in the first sending window, the sequence number of the last message in the first sending window, the sequence number of the first message in the first receiving window, the sequence number of the last message in the first receiving window, the bitmap of the first receiving window, or the sequence number of a message that the first slave access point did not send to the first STA. Thus, the second slave access point includes a second sending window and / or a second receiving window. The second slave access point can determine the third message to be sent belonging to the downlink service based on the sequence number of the first message in the first sending window, the sequence number of the last message in the first sending window, and / or the sequence number of a message that was not sent to the first STA, and use the second sending window to send the third message of the downlink service to the first STA. And / or,

[0197] The second access point can send the sequence number of the first message in the first receive window and / or the sequence number of the last message in the first receive window to the first STA. Based on the sequence number of the first message in the first receive window and / or the sequence number of the last message in the first receive window, the first STA determines the fourth message to be sent belonging to the uplink service and sends the fourth message of the uplink service to the second access point. The second access point uses the second receive window to receive the fourth message of the uplink service. And / or,

[0198] The second access point can send a bitmap of the first receive window to the first STA. Based on the bitmap of the first receive window, the first STA determines a second message that the first access point failed to receive, and sends the determined second message to the second access point. The second access point then uses the second receive window to receive the second message.

[0199] Optionally, the service context information includes key update information used to transmit the service, and the second access point uses the key update information to encrypt the multicast data and / or broadcast data to be sent to the first STA, and sends the encrypted multicast data and / or broadcast data to the first STA.

[0200] Optionally, the service context information includes at least one of the following: message sequence number, IP message identifier, SN context information, or OMI status information of the first STA. A downlink message is sent to the first STA based on the message sequence number, or an aggregation message is sent to the first STA based on the SN context information, or the channel bandwidth and number of flows are determined based on the OMI status information of the first STA.

[0201] In some embodiments, when the first STA moves to the coverage area of ​​the second slave access point, i.e. during the roaming of the first STA, the primary access point sends a service shutdown indication message to the first slave access point. The service shutdown indication message is used to instruct the first slave access point to shut down service interaction with the first STA.

[0202] The primary access point receives a service shutdown feedback message from the first secondary access point. This service shutdown feedback message is used to indicate whether the service interaction with the first STA has been successfully shut down.

[0203] Optionally, the service shutdown instruction message includes the identification information of the first STA.

[0204] Optionally, the service shutdown instruction message can also be used to instruct the first access point to report the context information of the service interaction with the first STA.

[0205] Optionally, the service shutdown feedback message indicates that the first access point has successfully shut down service interaction with the first STA.

[0206] Optionally, the service shutdown feedback message includes context information about the service interaction between the first access point and the first STA.

[0207] Optionally, the context information indicated by the service shutdown indication message or the context information included in the service shutdown feedback message may include one or more of the following: packet number (PN), sequence number (SN) context, message sequence number, or operating mode indication (OMI) status information of the first STA.

[0208] Optionally, the OMI status information of the first STA includes one or more of the following: receive spatial stream count, channel bandwidth, uplink multi-user transmission disabled, transmit spatial stream count, extended distance single-user transmission disabled, recommendation to re-perform downlink multi-user multiple-input multiple-output transmission channel probing, and uplink data multi-user transmission disabled.

[0209] In some embodiments, if service shutdown fails, the first slave access point will send a service shutdown failure message to the primary access point. If service shutdown succeeds, the first slave access point will send a service shutdown completion message to the primary access point. The service shutdown completion message and the service shutdown failure message can be collectively referred to as service shutdown feedback messages. The service shutdown feedback message indicates whether service shutdown was successful. If it indicates success, it can be called a service shutdown completion message; if it indicates failure, it can be called a service shutdown failure message.

[0210] As an example, the structure of a service closure completion message can be as shown in Table 5 below. The parameters in the table can be partially or fully carried as needed.

[0211] Table 5

[0212] In Table 5, Status = 0 corresponds to a service closure completion (or confirmation) message. Status = 1-255 corresponds to a service closure failure message.

[0213] After the first access point successfully shuts down the service, it obtains the parameters that need to be synchronized. The service shutdown completion message includes the parameters that need to be synchronized. The parameters that need to be synchronized include the context information of the service interaction between the first access point and the first STA, such as the sequence numbers of the aggregate frames to be transmitted between the first access point and the first STA, and the sequence numbers of each data packet in the block acknowledgment. For example, the context information that needs to be synchronized may include one or more of the following: PN number, PN context, IPID, or the OMI status information of the first STA. The OMI status information of the first STA may include one or more of the following: receiver number of spatial streams (Rx NSS), channel width (CW), uplink multi-user disable, transmit number of spatial streams and time streams (Tx NSTS), extended distance single-user disable (ER SU disable), recommendation to resound downlink multi-user multiple-input multiple-output transmission (DL MU-MIMO), and uplink data multi-user disable (UL MU Data disable).

[0214] As an example, the parameters (context information) that need to be synchronized can be found in Table 6. Some or all of the parameters in the table below can be carried as needed.

[0215] Table 6

[0216] In addition to the sequence number context parameters in the second row (number 2) of the table above, in one possible scenario, the sequence number context field may include one or more of the following parameters: the downlink sequence number of the traffic corresponding to each TID (referred to as each TID), the downlink window start number of each TID, the downlink window last number of each TID, the downlink window bitmap of each TID, the uplink window start number of each TID, the uplink window last number of each TID, and the uplink window bitmap of each TID. After these context parameters are passed to the target SFU, the target SFU can continue the traffic service of the STA, avoiding service interruption.

[0217] The information in sequence number 4 is optional. In some implementation scenarios, the key does not need to be updated, and the context information may include the fields in sequences 1-3.

[0218] Here, "key replay" indicates key reloading, and "rep replay counter" is a counter in the Extended Authentication Protocol over LAN (EAPOL) frame. The "Key replay counter__used" indicates the number of EAPOL-Key messages sent by the access point; this field increments by 1 for each EAPOL-Key message sent to prevent replay attacks. At the start of key negotiation, this field is 0 in the EAPOL-Key message sent by the AP (from the access point, such as the first or second access point). The client (STA, such as the first STA) receives the EAPOL-Key message and records this bit locally. When the client receives another EAPOL-Key message from the AP, this field must be greater than the locally recorded value; otherwise, the message is discarded and retransmitted. When the AP receives a message from the client, this field must match the locally stored value; otherwise, retransmission is required until a valid Key replay counter is received. If the maximum number of retransmissions is reached, the AP will delete the client.

[0219] As another example, the parameters (context information) that need to be synchronized can be found in Table 7. Some or all of the parameters in the table below can be carried as needed.

[0220] Table 7

[0221] Channel bandwidth indicates the channel bandwidth of Physical Layer Protocol Data Units (PPDUs) that the OM initiator supports transmitting or receiving (bandwidth is indicated uniformly for both transmission and reception). Received space-time stream count indicates the number of space-time streams of received PPDUs supported by the OM initiator; this value is less than or equal to its maximum supported space-time stream count. In other words, the received space-time stream count limits the number of space-time streams transmitted by the initiator when it is acting as the receiver of data transmission, and also limits the number of space-time streams transmitted by the sender on the other side; it cannot exceed the capacity of this received space-time stream count limit. Transmitted space-time stream count indicates the number of space-time streams of transmitted PPDUs supported by the OM initiator.

[0222] In other words, the number of space-time streams sent is a limitation imposed on the initiating end when it acts as the sender in the data transmission process. During data transmission, it cannot exceed the capacity limit set by the number of space-time streams sent.

[0223] As another example, the parameters (context information) that need to be synchronized can be seen in Table 8. Some or all of the parameters in the table below can be carried as needed.

[0224] Table 8

[0225] The core concept of Spatial Multiplexing Power Save (SM Power Save) lies in controlling antenna usage strategies. In scenarios requiring energy conservation, the first STA can adjust the number of operating antennas, such as switching from dual-stream to single-stream, or completely shutting down some antennas to reduce the energy consumption of wireless transmission. However, since the 802.11 protocol focuses more on the interaction between the first STA and the AP, the requirements for uplink transmission and downlink reception are different.

[0226] During uplink transmission, the first STA can independently decide how many antennas to use and indicate the number of spatial streams via a peamble. Downlink reception can be negotiated with the AP to avoid the station being unable to receive data due to the AP sending multiple streams. Therefore, the station can inform the AP of the status of its own antennas in advance to coordinate reception behavior.

[0227] SMPS enabled: In a WIFI network, before enabling SM Power Save, you can check the AP's beacon frame, such as the HT Capability field, to determine whether the network supports SMPS. Once the network supports it, the site will negotiate the working mode with the AP through the action frame.

[0228] SM Power Save has two operating modes: static mode and dynamic mode. Static mode is a simple on / off mode. Once enabled, the site will default to SM power saving mode, using single-stream reception by default. Full antenna operation will only resume when this mode is explicitly disabled. Static mode is similar to 802.11 OMI technology, but the functional scenarios and parameter settings differ.

[0229] Dynamic SM Power Save is more flexible. By default, the site maintains single-stream reception. When the AP needs multi-stream transmission, it triggers a request to send / clear to send (RTS / CTS) to temporarily activate all antennas to receive multi-stream data. During this process, the RTS and CTS may not require multi-stream transmission but rather single-stream acknowledgment, as the protocol does not explicitly require it. In dynamic mode, after receiving an RTS, the site triggers multi-stream reception via a single-stream RTS frame and acknowledges it with a single-stream CTS. After receiving data, the site provides feedback via a single-stream ACK, and then reverts to single-stream reception. This dynamic mode switching ensures high energy efficiency while maintaining data transmission accuracy.

[0230] In some embodiments, the communication system described above can be an FTTR system, also known as an FTTR network. The primary access point is the MFU in the FTTR network, and the secondary access points (first secondary access point and / or second secondary access point) are the SFUs in the FTTR network. Referring to Figure 7a, the WMCI management channel is a low-latency channel between the MFU and SFU in the FTTR network that implements functions such as WLAN control. It is used to carry WMCI messages and is carried through an independent optical module front-end module port-id (FEM Port-ID). The WMCC is the WMCI bearer channel. The management channels in the data link layer shown in Figure 7a include a dynamic link library (DLL) management channel, an embedded operations, administration and maintenance (OAM) management channel, a physical layer operations, administration and maintenance (PLOAM) management channel, an operations and maintenance control center (OMCC), and a central management communication control (WMCC).

[0231] In some embodiments, any of the above-described WMCI messages are encapsulated in an FEM frame for managing and controlling the WLAN functions of the SFU. The FTTR transceiver can identify the destination of the WMCI message through the FEM port ID in the FEM frame. See Table 9 below for the WMCI message structure.

[0232] Table 9

[0233] The 7th to Nth bytes of the WMCI message content may include service context information and / or connection information for the first connection. The Message type ID and / or parameter format are used to indicate what type of WMCI message it is, such as indicating whether the WMCI message is a first roaming message, second roaming message, third roaming message, fourth roaming message, roaming start message, roaming start confirmation message, roaming preprocessing indication, roaming preprocessing completion message, service shutdown indication message, service shutdown completion message, or service startup indication, etc.

[0234] Regarding the Message Type ID, it is an 8-bit field that indicates the type of message and defines the semantics of the message content. When the MFU receives an upstream message with a Message Type ID that is not supported, the MFU should ignore the message, including the Sequence Number field. When the SFU receives a message with a reserved or unsupported Message Type ID, it should ignore the message.

[0235] Optionally, the message content structure is as shown in Table 10, where Table 10 represents the collaborative roaming parameter configuration messages. Each collaborative roaming operation instruction corresponds to different configuration parameters, indicated by a mask. The roaming enable and disable messages contain sequence numbers 2-3, and the roaming parameter configuration messages contain sequence numbers 2-13. Roaming parameter configuration does not necessarily require configuring all messages; for example, message number 15 only needs to be configured when a new SFU comes online. The parameters in the table below can be partially or fully carried as needed.

[0236] Table 10

[0237] In some embodiments, different values ​​for the verification mode field or the verification model field have different meanings, as detailed below:

[0238] 0: Open system verification;

[0239] 1: Shared key verification;

[0240] 2: WPA Pre-Shared Key;

[0241] 3: WPA2 Pre-Shared Key;

[0242] 4: WAP / WPA2 Pre-Shared Key;

[0243] 5: WAP3 SAE;

[0244] 6: WAP2 / WAP3 PSK and SAE;

[0245] 7: WAP Enterprise;

[0246] 8: WPA2 Enterprise;

[0247] 9: WPA / WPA2-Enterprise.

[0248] In some embodiments, for the encryption mode field described above, different values ​​of the encryption model correspond to different meanings, as follows:

[0249] 0: WEP;

[0250] 1: TKIP;

[0251] 2: AES;

[0252] 3: TKIP & AES.

[0253] In Table 10 above, WPA stands for Wi-Fi Protected Access, WAP2 is WAP version 2, and WAP3 is WAP version 3. WPA Pre-Shared Key is abbreviated as WAP PSK, which stands for Wi-Fi Protected Access Pre-Shared Key. WAP / WPA2 Pre-Shared Key refers to the pre-shared key for WAP / WAP version 2.

[0254] WAP3 SAE stands for WAP3 Simultaneous Authentication of Equals, which is WAP3 peer-to-peer simultaneous authentication. WAP2 / WAP3 PSK and SAE refer to WAP / WAP version 2 pre-shared key and peer-to-peer simultaneous authentication. WAP Enterprise refers to WAP enterprises, WPA2 Enterprise refers to WAP version 2 enterprises, and WPA / WPA2-Enterprise refers to WAP / WAP version 2 enterprise.

[0255] WEP stands for Wired Equivalent Privacy; TKIP stands for Temporal Key Integrity Protocol; AES stands for Advanced Encryption Standard; RSSI stands for Received Signal Strength Indication; an RSSI LOW event is an event where the RSSI value is low.

[0256] For the sequence number (SeqNo), SeqNo is an 8-bit field containing a sequence number counter to ensure the robustness of the WMCI message channel. In the downlink direction, the SeqNo field is populated with the corresponding MFU sequence number counter value. The MFU maintains a separate sequence number counter for each SFU unicast and broadcast WMCI message stream. Each sequence number counter rolls from 255 to 1. A value of 0 is not used in the downlink direction.

[0257] In the uplink direction, when the uplink WMCI message is a response to a downlink message, the value of the SeqNo field is equal to the value of the SeqNo field in the downlink message. If the WMCI message is initiated by the SFU, then SeqNo = 0.

[0258] Regarding message length and processing requirement, the message length and priority field is a 2-byte field that represents the number of bytes in the message content and the message processing requirements.

[0259] X (the most significant bit of the third byte): This indicates the priority of processing this message. When X = 1, the message has a high priority; when X = 0, the message has a low priority.

[0260] LL LLLL LLLL: This field indicates the length of the message content. The value range is 0 to 1023.

[0261] O: Indicates the operation type of the current message.

[0262] In the downlink direction, when O=1, the message indicates that the operation type is a parameter request type, requesting the SFU to send the output indicated by the Message type ID field; when O=0, the message indicates that the message is a parameter configuration type message, and the parameter type configured in the message is indicated by the Message type ID field.

[0263] In the uplink direction, when O=1, the message is identified as an operation type of scheduling request, requesting the MFU to send the scheduling configuration indicated by the Message type ID field; when O=0, the message is identified as a parameter reporting message, with the parameter type of the message configuration indicated by the Message type ID field.

[0264] Regarding the message content, the format of the message content field is related to the specific message. The message content consists of two parts: a message mask and parameter content. The message mask is composed of a 16-bit mask, as shown in Table 11.

[0265] Table 11

[0266] Each message type can carry up to 16 parameters.

[0267] The message content should be filled in according to the order indicated by the parameter mask. For downlink Get or Request messages, the parameter mask represents the parameters that the MFU wants to retrieve.

[0268] Regarding the Message Verification (CRC) field, the CRC field is used to check whether the message has been corrupted during transmission. The value of this field is generated by the CRC algorithm.

[0269] Regarding the message exchange mechanism of FTTR networks, both MFU and SFU can proactively send WMCI messages or respond to messages sent by the other party.

[0270] Downlink messages are parameter request messages and configuration messages; uplink messages are parameter reporting messages, scheduling requests, and status alarm messages.

[0271] To maintain and ensure the normal operation of the WMCI channel, the MFU and SFU should periodically exchange messages. If the MFU or SFU does not receive a message from the other party within a certain period of time, the MFU or SFU can actively send a request message to ask for feedback. If feedback is received within a specific period of time, the WMCI channel can be considered to be working normally; otherwise, the WMCI channel can be judged to be faulty, and the SFU can reactivate the WMCI channel or exit the WMCI scheduling mode.

[0272] The format of the parameter request message is shown in Table 12 below.

[0273] Table 12

[0274] Parameter request messages are only for the parameter set requested by the Message type ID field in Table 12 for both uplink and downlink. The parameter template field identifies the parameters in the requested parameter set. The 7-N fields are invalid and can be determined by the MFU. After receiving the message, the SUF should return the corresponding parameters as instructed. If the parameters are invalid, the SFU should have all 0 values.

[0275] The format of the configuration message is shown in Table 13 below.

[0276] Table 13

[0277] The Message type ID field identifies the parameter set configured for this message, the parameter template field identifies the parameters in the parameter set, and the 7-N fields are filled in sequentially according to the valid parameter order.

[0278] The format of the parameter reporting message is shown in Table 14 below.

[0279] Table 14

[0280] The format of status alarm messages is shown in Table 15 below.

[0281] Table 15

[0282] In some embodiments, after enabling cooperative roaming on the primary access point (MFU) and at least one secondary access point (SFU), network information synchronization may also occur between the MFU and at least one secondary access point. For example, the MFU may obtain a multicast key GTK0 and distribute the multicast key GTK0 to each secondary access point and the STA communicating with each secondary access point. The MFU then periodically updates the multicast key and synchronizes the multicast key with at least one secondary access point. Optionally, the implementation process includes the following steps.

[0283] (11): The master access point instructs at least one slave access point in the communication system to disable the multicast key update function.

[0284] Optionally, the primary access point may instruct at least one secondary access point to disable the multicast key update function in a cooperative roaming enable message or other message.

[0285] For each slave access point, once the multicast key update function is disabled, it will not periodically update its own multicast key. In this way, the multicast keys of each device in the communication system (at least one slave access point and the STA communicating with each slave access point) can be updated by the master access point, as shown below.

[0286] (12): The primary access point updates the multicast key during the multicast key cycle (generating the first multicast key GTK1).

[0287] When the multicast key update cycle arrives, the primary access point generates the first multicast key GTK1.

[0288] Optionally, the primary access point generates the first multicast key GTK1 as follows: GTK1 = PRF(GMK + GNonce + Mac);

[0289] In this structure, GTK1 is the first multicast key, PRF is the pseudo-random function, Gnonce is a random number generated by the master access point, MAC is the BSSID of the master access point, and GMK is the group master key. Furthermore, the group master key GMK is generated by the master access point based on the master session key (MSK). The MSK is generated by the slave access point and synchronized to the master access point during the STA's connection to the slave access point.

[0290] (13): The primary access point sends a first multicast key synchronization message to the at least one secondary access point, the first multicast key synchronization message including an encrypted first multicast key.

[0291] The primary access point can use the key between itself and the secondary access points to encrypt the first multicast key.

[0292] Refer to Table 16-1 below. Table 16-1 shows the structure of the first multicast key synchronization message. GTK in sequence number 3 is the first multicast key GTK1 mentioned above. Some or all of the parameters in the table below can be carried as needed.

[0293] Table 16-1

[0294] For the first multicast key GTK1, as shown in Figure 7b, it includes GTK, a counter, and / or a random number.

[0295] In some embodiments, referring to Table 16-2, the first multicast key synchronization message may include one or more of the following parameters: first multicast key GTK1, length of the first multicast key (GTK_Len), integrity group transient key (IGTK), IGTK length (IGTK_Len), Gnonce, receive sequence counter (RSC) or key replay counter, etc.

[0296] Optionally, if the encryption mode used is WPA3 or 802.11w is enabled, the parameters such as the first multicast key GTK1, Gnonce, RSC, IGTK and / or key playback counter in the first multicast key synchronization message are encrypted parameters.

[0297] Table 16-2

[0298] (14): Receive the first multicast key synchronization message from the access point and update the local second multicast key to the first multicast key.

[0299] The access point can use the key between itself and the master access point to decrypt the first multicast key. Additionally, the second multicast key locally on the access point can be the multicast key received in the previous multicast key update cycle.

[0300] (15): The second multicast key synchronization message is sent from the access point to at least one STA, the second multicast key synchronization message including the encrypted first multicast key.

[0301] The access point can use the key between itself and the slave STA to encrypt the first multicast key.

[0302] In some embodiments, the second multicast key synchronization message includes some or all of the parameters in the first multicast key synchronization message. For example, both the first and second multicast key synchronization messages include a Gnonce. Both the first and second multicast key synchronization messages include an RSC. Both the first and second multicast key synchronization messages include a key playback counter.

[0303] (16): STA receives the second multicast key synchronization message and updates the local second multicast key to the first multicast key.

[0304] The STA can use the key between the STA and the access point to decrypt the first multicast key. Additionally, the STA's local second multicast key can be the multicast key received in the previous multicast key update cycle.

[0305] The access point then uses the first multicast key to send broadcast messages and / or multicast messages, etc.

[0306] In this embodiment, a first STA accesses a first slave access point and transmits services with the first slave access point. When the first STA moves to the coverage area of ​​a second slave access point, the primary access point sends an acquisition request message to the first slave access point, and the first slave access point sends an acquisition response message to the primary access point. This acquisition response message includes context information about the service. The primary access point then sends an update request message to the second slave access point. Because the update request message includes context information describing the services transmitted between the first STA and the first slave access point, the second slave access point can transmit the first STA's services based on this context information when the first slave access point stops transmitting the first STA's services. Thus, when the access point accessed by the first STA is switched from the first slave access point to the second slave access point, the transmission of the first STA's services can be resumed on the second slave access point, avoiding interruption of the first STA's services and achieving seamless roaming.

[0307] Referring to Figure 8, this application embodiment provides a communication method 800. The communication method 800 is applied to the communication system 100 shown in Figure 1 or Figure 2. In the communication method 800, a first STA accesses a first slave access point and transmits services with the first slave access point. When the first STA moves to the coverage area of ​​a second slave access point, the first slave access point actively sends service context information to a master access point. The master access point then sends service context information to the second slave access point, enabling the second slave access point to transmit the first STA's services based on the service context information. The communication method 800 includes the following process.

[0308] Step 801: Same as step 301 of method 300 shown in Figure 3, and will not be described in detail here.

[0309] Step 802: When the first STA moves to the coverage area of ​​the second slave access point, the first slave access point sends a first update request message to the master access point. The first update request message includes context information describing the services transmitted between the first STA and the first slave access point.

[0310] Within the coverage area of ​​the wireless LAN, the first STA may move into the coverage area of ​​the second slave access point, causing the signal quality between the second slave access point and the first STA to gradually increase, while the signal quality between the first slave access point and the first STA to gradually decrease. If the first STA moves into the coverage area of ​​the second slave access point and the signal quality between the second slave access point and the first STA is higher than a quality threshold, the first slave access point sends a first update request message to the master access point.

[0311] In some embodiments, if the first slave access point detects that the signal quality between the first slave access point and the first STA is lower than a quality threshold, the first slave access point sends a first update request message to the master access point.

[0312] In some embodiments, the first slave access point sends a first update request message to the primary access point via a second WMCI interface. Optionally, the first update request message is a WMCI message. Optionally, the first update request message is a first roaming message.

[0313] Step 803: The primary access point receives the first update request message and sends a second update request message to the second secondary access point. The second update request message includes the context information.

[0314] The destination address of the second update request message is different from the destination address of the first update request, and / or the destination port number of the second update request message is different from the destination port number of the first update request.

[0315] After receiving the first update request message, the primary access point sends roaming decision collection information to each of the secondary access points in the communication system. Each secondary access point receives the roaming decision collection information and, based on this information, sends roaming decision information to the primary access point. This roaming decision information includes the signal quality between the secondary access point and the first STA. The primary access point may receive roaming decision information from at least one secondary access point, thus determining the signal quality between at least one secondary access point and the first STA. The primary access point then selects the secondary access point with the best signal quality or one that exceeds a quality threshold with the first STA and sends a second update request message to the selected secondary access point.

[0316] In some embodiments, the second update request message may also include the identification information of the first STA.

[0317] In some embodiments, the primary access point receives a first update request message through a first WMCI interface, and sends a second update request message to a second secondary access point through the same first WMCI interface. The second update request message may be a type of WMCI message. The second update request message is a type of second roaming message.

[0318] Step 804: The second STA receives a second update request message from the access point and transmits the services of the first STA based on the context information included in the second update request message.

[0319] The detailed implementation process of transmitting the first STA's service based on the service context information from the access point is shown in step 305 of method 300 in Figure 3, and will not be described in detail here.

[0320] In this embodiment, a first STA accesses a first slave access point and transmits services with the first slave access point. When the first STA moves to the coverage area of ​​a second slave access point, the first slave access point sends a first update request message to the master access point, which includes service context information. The master access point then sends a second update request message to the second slave access point, which also includes service context information. This allows the second slave access point to transmit the first STA's services based on the service context information when the first slave access point stops transmitting the first STA's services. Thus, when the access point accessed by the first STA is switched from the first slave access point to the second slave access point, the transmission of the first STA's services can be resumed on the second slave access point, avoiding interruption of the first STA's services and achieving seamless roaming.

[0321] Referring to Figure 9, this application embodiment provides a communication method 900. The communication method 900 is applied to the communication system 100 shown in Figure 1 or Figure 2. In the communication method 900, a second STA accesses a primary access point and transmits services with the primary access point. When the second STA moves to the coverage area of ​​a secondary access point (the aforementioned first or second secondary access point), the primary access point sends service context information to the secondary access point, enabling the secondary access point to transmit the second STA's services based on the service context information. The communication method 900 includes the following process.

[0322] Step 901: The second STA accesses the main access point and transmits services with the main access point.

[0323] Step 902: When the second STA moves to the coverage area of ​​the access point, the primary access point obtains context information describing the services transmitted between the second STA and the primary access point.

[0324] Step 903: The primary access point sends an update request message to the secondary access point, which includes the context information of the service.

[0325] Step 904: Receive the update request message from the access point, and transmit the service of the second STA based on the service context information included in the update request message.

[0326] In step 901 above, the second STA accesses the main access point and transmits services with the main access point.

[0327] The second STA is located within the coverage area of ​​the primary access point, thus enabling the second STA to access the primary access point. Alternatively, in implementation, the second STA can access the primary access point through a process of authentication, association, and key negotiation.

[0328] Optionally, the second STA is located within the coverage area of ​​the main access point, and the signal quality between the second STA and the main access point is higher than the quality threshold, so that the second STA can access the main access point and then transmit services with the main access point.

[0329] Optionally, during the authentication, association, and key negotiation process, the second STA may negotiate with the primary access point the key information used for transmitting services, and / or negotiate with the primary access point the aggregation information used for transmitting services, etc.

[0330] Optionally, during the authentication, association, and key negotiation process, the second STA may send an association request message to the primary access point, send an authentication request message to the primary access point, and establish a first connection with the primary access point based on the key information and the request message (the association request message and / or authentication request message).

[0331] Optionally, the second STA may also send a reassociation request message to the primary access point.

[0332] In some embodiments, when a second STA accesses the primary access point, the primary access point can synchronize the connection information of the first connection with other access points in the communication system. Optionally, in implementation: the primary access point can send the connection information of the first connection to the secondary access point, the connection information of the first connection including one or more of the following: association request message, reassociation request message, authentication request message, key information, or aggregation information, etc. The secondary access point can save the connection information of the first connection upon receiving it.

[0333] Optionally, the primary access point sends a fourth roaming message to the secondary access point via the first WMCI interface. The fourth roaming message includes the connection information of the first connection. The secondary access point receives the fourth roaming message via the second WMCI interface and saves the connection information of the first connection.

[0334] Multiple pieces of information from the connection information of the first connection can be encapsulated in multiple fourth roaming messages, that is, the primary access point sends multiple fourth roaming messages to the secondary access point.

[0335] For example, see Table 17 below for the fourth roaming message used to encapsulate authentication request messages, association request messages, or reassociation request messages.

[0336] Table 17

[0337] For example, see the fourth roaming message used to encapsulate key messages, as shown in Table 18 below.

[0338] Table 18

[0339] For example, see Table 19 below for the fourth roaming message used to encapsulate the aggregation message.

[0340] Table 19

[0341] Optionally, the aggregation information in Table 19 may exclude frames but include aggregation parameters.

[0342] Multiple pieces of information from a fourth roaming message can be encapsulated within a single fourth roaming message; that is, a fourth roaming message includes multiple pieces of information from other fourth roaming messages. In this way, these multiple pieces of information can share the three fields: access point identification information, interface identification information, and second STA identification information.

[0343] The second STA can use the first connection to transmit services with the primary access point.

[0344] This service may include downlink traffic sent from the primary access point to the second STA, and the downlink traffic is a downlink service. And / or, this service may include uplink traffic received by the primary access point from the second STA, and the uplink traffic is an uplink service.

[0345] The primary access point includes a third sending window and / or a third receiving window. The third sending window is the window used by the primary access point to send downlink service messages to the second STA, and the third receiving window is the window used by the primary access point to receive uplink service messages from the second STA.

[0346] For the first message included in the aforementioned downlink service, the primary access point can send the first message to the second STA. The first message has a sequence number. The sequence number of the currently sent first message is obtained by adding the sequence number of the previous first message sent by the primary access point to the second STA. Both the previous first message and the currently sent first message belong to the downlink service.

[0347] Optionally, the sequence number of the currently sent first message can be obtained by adding 1 to the sequence number of the previous first message.

[0348] Optionally, the sequence number of the first message can be the SN of the first message, etc. For the 0th first message of the downlink service, the primary access point initializes the initial value of the SN of the 0th first message. For the nth first message of the downlink service, the SN of the nth first message is equal to the SN of the (n-1)th first message + P1, where P1 is an integer greater than or equal to 1 and n is an integer greater than or equal to 1.

[0349] Optionally, the first message may include multiple data units aggregated based on aggregation information, allowing multiple data units to be sent in a single first message, thus improving transmission efficiency. In implementation, the aggregation information includes the aggregation window size and / or aggregation strategy. The primary access point can aggregate multiple data units into a single first message based on the aggregation strategy, where the number of data units is less than or equal to the aggregation window size, and then send the first message to the second STA.

[0350] Referring to Figure 4, the primary access point (PA) uses a third transmission window to send the first downlink service message to the second STA. An example of sending the first downlink service message is given below. In this example, the PA initializes the SN of the 0th first downlink service message to 0, assuming P1 = 1. Thus, the SN of the 1st first message is 1, the SN of the 2nd first message is 2, and so on. Referring to Figure 4(a), the third transmission window includes multiple first downlink service messages (e.g., the third transmission window size is 4, including four first messages, namely first messages 0, 1, 2, and 3). The PA sends multiple first messages from the third transmission window to the second STA. Referring to Figure 4(b), after sending multiple first messages from the third transmission window, the PA moves the third transmission window to include multiple other first downlink service messages (e.g., the third transmission window includes first messages 4, 5, 6, and 7), and sends these multiple first messages from the third transmission window to the second STA. Repeating the above process, the PA can continuously send the first downlink service messages to the second STA.

[0351] Regarding the second message included in the aforementioned uplink service, the primary access point can receive the second message sent by the second STA. The second message has a sequence number. The sequence number of the second message currently sent by the second STA is obtained by incrementing the sequence number of the previous second message sent by the second STA to the primary access point. Both the previous second message and the currently sent second message belong to the uplink service.

[0352] Optionally, the sequence number of the currently sent second message can be obtained by adding 1 to the sequence number of the previous second message.

[0353] Optionally, the sequence number of the second message can be the SN of the second message, etc. For the 0th second message of the uplink service, the second STA initializes the initial value of the SN of the 0th second message. For the mth second message of the uplink service, the SN of the mth second message is equal to the SN of the (m-1)th second message + P2, where P2 is an integer greater than or equal to 1 and m is an integer greater than or equal to 1.

[0354] Optionally, the second message may include multiple data units aggregated based on the aggregation information, so that multiple data units can be sent through a single second message, thereby improving transmission efficiency.

[0355] Referring to Figure 5, the primary access point uses the third receive window to receive the second uplink service message sent by the second STA. The following is an example of receiving the second uplink service message. In this example, the second STA initializes the SN of the 0th second uplink service message to 0, assuming P2 = 1. Thus, the SN of the 1st second message is 1, the SN of the 2nd second message is 2, and so on. Referring to Figure 5(a), assuming the size of the third receive window is 4, the primary access point uses the third receive window to receive the four second uplink service messages, namely second messages 0, 1, 2, and 3, and sends the bitmap of the third receive window to the second STA.

[0356] This bitmap includes four bits corresponding one-to-one with the four second messages. For a second message successfully received using the third receive window, the bit corresponding to the successfully received second message in this bitmap is the first bit value. For a second message unsuccessfully received using the third receive window, the bit corresponding to the unsuccessfully received second message in this bitmap is the second bit value. Therefore, this bitmap is used to describe the reception status of the second messages included in the third receive window. Optionally, the first bit value is 1 and the second bit value is 0; or, the first bit value is 0 and the second bit value is 1. For a second message that is unsuccessfully received, the second STA needs to retransmit the second message, and the primary access point then receives the retransmitted second message.

[0357] Referring to Figure 5(b), the primary access point moves the third receiving window so that its starting position is equal to the SN+1 of the third second message. It then uses the third receiving window to receive four second messages, namely second messages 4, 5, 6, and 7, and sends the bitmap of the third receiving window to the second STA. By repeating this process, the primary access point can continuously receive second messages from the second STA for uplink services.

[0358] The second STA can move within the coverage area of ​​the wireless LAN. When the second STA moves within the coverage area of ​​at least one second access point, the second access point can transmit the services of the second STA through the following procedure.

[0359] Regarding step 902 above, when the second STA moves into the coverage area of ​​the access point, the primary access point obtains context information describing the services transmitted between the second STA and the primary access point.

[0360] The context information of the service includes one or more of the following: key update information used for transmitting the service, the sleep state of the second STA, the sequence number of the first packet in the third sending window, the sequence number of the last packet in the third sending window, the sequence number of the first packet in the third receiving window, the sequence number of the last packet in the third receiving window, the bitmap of the third receiving window, the sequence number of the packets that the primary access point did not send to the second STA, the packet sequence number, the identifier of the IP packet, or the OMI status information of the second STA, etc.

[0361] Optionally, the sequence number of a message that the primary access point does not send to the second STA may include the sequence number of the first second message that the primary access point does not send to the second STA.

[0362] Within the coverage area of ​​the wireless LAN, the second STA may move into the coverage area of ​​the secondary access point, causing the signal quality between the secondary access point and the second STA to gradually increase, while the signal quality between the primary access point and the second STA gradually decreases. When the second STA moves into the coverage area of ​​the secondary access point and the signal quality between the secondary access point and the second STA is higher than a quality threshold, the primary access point obtains the service context information.

[0363] In some embodiments, the second STA may move to the coverage area of ​​at least one secondary access point, and the signal quality between the second STA and the at least one secondary access point is higher than a quality threshold. For each secondary access point, if the secondary access point detects that the signal strength with the second STA is gradually increasing and that the signal strength is higher than the quality threshold, the secondary access point sends roaming decision information to the primary access point. The roaming decision information may include the signal quality between the secondary access point and the second STA, etc. The primary access point can then obtain the service context information.

[0364] In some embodiments, referring to Figure 10, the primary access point obtains service context information when it detects that the signal quality between the primary access point and the second STA is lower than a quality threshold.

[0365] The master access point also sends roaming decision collection information to each slave access point in the communication system. The slave access points receive the roaming decision collection information and, based on it, send roaming decision information to the master access point, which includes the signal quality between the slave access point and the second STA.

[0366] The primary access point may receive roaming decision information from at least one secondary access point, which allows it to determine the signal quality between at least one secondary access point and the second STA. The primary access point then selects the secondary access point with the best signal quality or one that exceeds a quality threshold with the second STA. Referring to Figure 10, the primary access point can send a roaming start message to the selected secondary access point.

[0367] After receiving the roaming start message from the access point, a roaming start confirmation message is sent to the primary access point.

[0368] After receiving the roaming start confirmation message from the secondary access point, the primary access point sends a roaming preprocessing instruction to the secondary access point.

[0369] Upon receiving a roaming preprocessing instruction from the access point, initiate the roaming preprocessing process. Two roaming preprocessing steps are possible:

[0370] The first type of roaming preprocessing is simulated aggregation. The simulated aggregation process is as follows: the access point establishes an aggregation with the second STA based on the aggregation information, then sends an aggregation frame to the second STA, or receives an aggregation frame from the second STA, and replies with a BA frame to the second STA. The BA frame is used to indicate successfully received frames and frames that were not successfully received.

[0371] The second type of roaming preprocessing involves establishing a second connection between the access point and the second STA, and then performing a simulated aggregation process.

[0372] After completing the roaming preprocessing, the access point sends a roaming preprocessing completion message to the primary access point. Upon receiving the roaming preprocessing completion message, the primary access point can perform the following steps.

[0373] In step 903 above, the primary access point sends an update request message to the secondary access point, which includes the context information of the service.

[0374] In some embodiments, the update request message may also include identification information of the second STA.

[0375] In some embodiments, the primary access point sends an update request message to the secondary access point through a first WMCI interface. The update request message may be a WMCI message and a second roaming message.

[0376] In some embodiments, referring to Figure 10, the primary access point shuts down the service of the second STA and sends a service activation indication to the secondary access point. The service activation indication message includes service context information and is an instance of an update request message.

[0377] In some embodiments, multiple pieces of information from the first roaming message can be encapsulated in an update request message. For example, see Table 20 below for an update request message used to encapsulate context information of a service.

[0378] Table 20

[0379] In step 904 above, the update request message is received from the access point, and the service of the second STA is transmitted based on the service context information included in the update request message.

[0380] In step 904, connection information of the first connection is obtained from the access point, a second connection is established between the second STA and the first STA based on the connection information of the first connection, and the services of the second STA are transmitted through the second connection based on the service context information.

[0381] The detailed implementation process of transmitting the services of the second STA from the access point based on the service context information is shown in step 305 of method 300 in Figure 3, and will not be described in detail here.

[0382] In this embodiment, the second STA accesses the primary access point and transmits services with it. When the second STA moves to the coverage area of ​​the secondary access point, the primary access point obtains the service context information and sends it to the secondary access point. Thus, when the primary access point shuts down the transmission of the second STA's services, the secondary access point can still transmit the second STA's services based on the service context information. Therefore, when the access point to which the second STA is connected is switched from the primary access point to the secondary access point, the transmission of the second STA's services can be resumed on the secondary access point, avoiding interruption of the second STA's services and achieving seamless roaming.

[0383] Referring to Figure 11, this application embodiment provides a communication device 1100. The device 1100 is located in a communication system, which further includes a first slave access point and a second slave access point. A station accesses the first slave access point, and the station is located within the coverage area of ​​the second slave access point. The device 1100 includes:

[0384] The receiving unit 1101 is used to receive a first roaming message, which includes context information of the service transmitted between the site and the first access point;

[0385] The sending unit 1102 is used to send a second roaming message to the second access point. The first roaming message carries the context information, which is used by the second access point to transmit the services of the site.

[0386] Optionally, the detailed implementation process of receiving unit 1101 receiving the first roaming message can be found in step 303 of method 300 shown in Figure 3 or the relevant content in step 803 of method 800 shown in Figure 8, and will not be described in detail here.

[0387] Optionally, the detailed implementation process of the sending unit 1102 sending the second roaming message to the second access point can be found in step 304 of method 300 shown in Figure 3 or step 803 of method 800 shown in Figure 8, and will not be described in detail here.

[0388] Optionally, the sending unit 1102 is further configured to send an acquisition request message to the first secondary access point when the site moves to the coverage area of ​​the second secondary access point, the acquisition request message being used to request the context information;

[0389] The receiving unit 1101 is used to receive a first acquisition response message sent from the access point, the acquisition response message including the context information.

[0390] Optionally, the detailed implementation process of the sending unit 1102 sending the acquisition request message to the first access point is described in step 302 of method 300 shown in Figure 3, and will not be described in detail here.

[0391] Optionally, the detailed implementation process of receiving unit 1101 receiving the first acquisition response message sent from the access point is described in step 304 of method 300 shown in Figure 3, and will not be described in detail here.

[0392] Optionally, the receiving unit 1101 is configured to receive an update request message sent by the first secondary access point when the site moves to the coverage area of ​​the second secondary access point, the update request message including the context information.

[0393] Optionally, the detailed implementation process of receiving unit 1101 receiving the first update request message sent from the access point is described in step 803 of method 800 shown in Figure 8, and will not be described in detail here.

[0394] Optionally, the context information in the first roaming message includes one or more of the following: key update information used by the transmission service, the station's sleep state, the sequence number of the first message in the sending window, the sequence number of the last message in the sending window, the sequence number of the first message in the receiving window, the sequence number of the last message in the receiving window, the bitmap of the receiving window, or the sequence number of the first message not sent from the access point to the station.

[0395] The service includes downlink service sent from the access point to the site and / or uplink service received from the site by the first access point. The sending window is the window used by the first access point to send downlink service messages to the site, the receiving window is the window used by the first access point to receive uplink service messages from the site, and the bitmap is used to describe the receiving status of the messages included in the receiving window.

[0396] Optionally, the sending unit 1102 is further configured to send a fourth roaming message to the second access point. The fourth roaming message includes connection information for establishing a connection between the site and the first access point, wherein the connection information establishes a connection between the second access point and the site.

[0397] Optionally, the detailed implementation process of the sending unit 1102 sending the fourth roaming message to the second access point can be found in step 301 of method 300 shown in Figure 3 or the relevant content in step 801 of method 800 shown in Figure 8, and will not be described in detail here.

[0398] Optionally, the connection information in the fourth roaming message includes one or more of the following: aggregation information used by the transmission service, key information used by the transmission service, a reassociation request message received from the site from the first access point, an association request message received from the site from the first access point, or an authentication request message received from the site from the first access point.

[0399] Optionally, the communication system includes a fiber-to-the-room (FTTR) system, wherein the device 1100 is the master FTTR device included in the FTTR system, and the first slave access point and the second slave access point are slave FTTR devices included in the FTTR system.

[0400] Optionally, the first roaming message is a service closure completion message, and the second roaming message is a service start indication.

[0401] Optionally, the context information includes at least one of the following: message sequence number, IP message identifier, and OMI status information of the site.

[0402] In this embodiment, since the site is connected to a first secondary access point and transmits services with that point, when the site moves to the coverage area of ​​a second secondary access point, the receiving unit can receive a first roaming message sent by the first secondary access point, and the sending unit can send a second roaming message to the second secondary access point. Since the first roaming message includes context information about the services transmitted between the site and the first secondary access point, and the second roaming message also includes this context information, when the access point to which the first STA is connected is switched from the first secondary access point to the second secondary access point, the transmission site's services can be resumed on the second secondary access point, avoiding interruption of the transmission site's services and achieving seamless roaming.

[0403] Referring to Figure 12, this application embodiment provides a schematic diagram of a device 1200. The device 1200 can be any of the access points provided in the above embodiments. For example, the device 1200 can be the main access point in the communication system 100 shown in Figure 1 or Figure 2, or the device 1200 can be the main access point in the method 400 shown in Figure 3, or the device 1200 can be the main access point in the method 800 shown in Figure 8. The device 1200 includes at least one processor 1201, internal connections 1202, a memory 1203, and at least one communication interface 1204.

[0404] The device 1200 is a hardware-structured device.

[0405] In some embodiments, the device 1200 can be used to implement the functional modules in the apparatus 1100 shown in FIG11. For example, those skilled in the art will realize that the receiving unit 1101 and the transmitting unit 1102 in the apparatus 1100 shown in FIG11 can be implemented through the at least one communication interface 1204. The device 1200 can also be used to implement the function of the main access point in any of the above embodiments.

[0406] The processor 1201 described above is, for example, a general-purpose central processing unit (CPU), a digital signal processor (DSP), a network processor (NP), a graphics processing unit (GPU), a neural network processing unit (NPU), a data processing unit (DPU), a microprocessor, or one or more integrated circuits for implementing the solutions of this application. For example, processor 1201 includes an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A PLD is, for example, a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL), or any combination thereof. It can implement or execute the various logic blocks, modules, and circuits described in conjunction with the disclosure of the embodiments of this application. The processor can also be a combination of functions that perform computing, such as a combination of one or more microprocessors, a combination of a DSP and a microprocessor, etc.

[0407] The aforementioned internal connection 1202 may include a pathway for transmitting information between the aforementioned components. The internal connection 1202 may be a single board or a bus, etc. The bus may be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of illustration, only one thick line is used in Figure 12, but this does not indicate that there is only one bus or one type of bus.

[0408] At least one communication interface 1204 described above uses any transceiver-like device for communicating with other devices or communication networks, such as Ethernet, wireless access networks, or wireless local area networks (WLANs). Communication interface 1204 may include wired communication interfaces and wireless communication interfaces. Specifically, communication interface 1204 may be an Ethernet interface, a Fast Ethernet (FE) interface, a Gigabit Ethernet (GE) interface, an Asynchronous Transfer Mode (ATM) interface, a WLAN interface, a cellular network communication interface, or a combination thereof. The Ethernet interface may be an optical interface, an electrical interface, or a combination thereof. In this embodiment, communication interface 1204 can be used by the device 1200 to communicate with other devices.

[0409] The aforementioned memory 1203 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto. The memory may exist independently and be connected to the processor via a bus. The memory 1203 may also be integrated with the processor 1201.

[0410] In a specific implementation, as one embodiment, processor 1201 may include one or more CPUs, such as CPU0 and CPU1 in FIG12. Each of these CPUs may be a single-core processor or a multi-core processor. Here, processor may refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0411] In a specific implementation, as one embodiment, the device 1200 may include multiple processors, such as processor 1201 and processor 1207 in FIG. 12. Each of these processors may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. Here, a processor may refer to one or more devices, circuits, and / or processing cores for processing data (e.g., computer program instructions).

[0412] Referring to Figure 13, this application embodiment provides a communication device 1300. The device 1300 is located in a communication system, which further includes a first slave access point and a second slave access point. A station accesses the first slave access point, and the station is located within the coverage area of ​​the second slave access point. The device 1300 includes:

[0413] Receiving unit 1301 is used to receive a third roaming message, the third roaming message including connection information for establishing a connection between the site and the first access point;

[0414] The sending unit 1302 is used to send a fourth roaming message to the second access point, the fourth roaming message including the connection information, the connection information being used by the second access point to establish a connection with the site.

[0415] Optionally, the connection information in the third roaming message includes one or more of the following: aggregation information used to transmit the service or key information used to transmit the service.

[0416] Optionally, the communication system includes a fiber-to-the-room (FTTR) system, the device 1300 is the master FTTR device included in the FTTR system, and the first slave access point and the second slave access point are slave FTTR devices included in the FTTR system.

[0417] Optionally, the connection information in the third roaming message includes one or more of the following: a reassociation request message received from the site by the first access point, an association request message received from the site by the first access point, or an authentication request message received from the site by the first access point.

[0418] Optionally, the third roaming message is an association request reporting message, and the fourth roaming message is an association request sending message.

[0419] Referring to Figure 14, this application embodiment provides a communication device 1400. The device 1400 is located in a communication system, which further includes a main access point and a first slave access point. A station is connected to the first slave access point, and the station is located within the coverage area of ​​the device 1400. The device 1400 includes:

[0420] The receiving unit 1401 is configured to receive a second roaming message sent by the primary access point, wherein the second roaming message includes context information of the service transmitted between the site and the first secondary access point;

[0421] Processing unit 1402 is used to transmit the services of the site based on the context information.

[0422] Optionally, the context information includes one or more of the following: key update information used to transmit the service, the dormant state of the site, the sequence number of the first message in the sending window, the sequence number of the last message in the sending window, the sequence number of the first message in the receiving window, the sequence number of the last message in the receiving window, the bitmap of the receiving window, or the sequence number of the first message not sent from the access point to the site.

[0423] The service includes downlink service sent from the first access point to the site and / or uplink service received from the site by the first access point. The sending window is the window used by the first access point to send the downlink service message to the site, and the receiving window is the window used by the first access point to receive the uplink service message from the site. The bitmap is used to describe the receiving status of the messages included in the receiving window.

[0424] Optionally, the context information includes at least one of the following: message sequence number, IP message identifier, sequence number (SN) context information, or the site's OMI status information.

[0425] Optionally, the processing unit 1402 is used for:

[0426] Send a downlink message to the station according to the message sequence number, or

[0427] The aggregated message is sent to the site based on the SN context information, or...

[0428] The channel bandwidth and number of streams are determined based on the OMI status information of the site.

[0429] Optionally, the processing unit 1402 is used for:

[0430] If the hibernation state is used to indicate that the station is in a sleep state, then the station is awakened; and / or,

[0431] Based on the sequence number of the first message in the sending window, the sequence number of the last message in the sending window, and / or the sequence number of the first message not sent from the access point to the site, the message to be sent belonging to the downlink service is determined; or,

[0432] Based on the sequence number of the first message in the receive window, the sequence number of the last message in the receive window, and the bitmap of the receive window, the station is instructed to determine the messages to be sent that belong to the uplink service; and / or,

[0433] The multicast data to be sent to the site is encrypted based on the key update information.

[0434] Referring to Figure 15, this application embodiment provides a communication device 1500. The device 1500 is located in a communication system. The communication system further includes a main access point and a first slave access point. A station is connected to the first slave access point, and the station is located within the coverage area of ​​the device 1500. The device 1500 includes:

[0435] The receiving unit 1501 is used to receive a fourth roaming message sent by the primary access point, wherein the fourth roaming message includes connection information for establishing a connection between the site and the first secondary access point;

[0436] Processing unit 1502 is used to transmit the services of the site based on the connection information.

[0437] Optionally, the connection information includes one or more of the following: a reassociation request message received from the site by the first access point, an association request message received from the site by the first access point, or an authentication request message received from the site by the first access point.

[0438] Optionally, the processing unit 1502 is used for:

[0439] A connection with the site is established based on the association request message, the reassociation request message, and the authentication request message. The connection is used to transmit the site's services.

[0440] This application also provides a computer program product including program instructions stored in a computer-readable storage medium. The processor of an access point reads the program instructions from the computer-readable storage medium and executes the program instructions, causing the access point to perform a portion of the process shown in FIG3, FIG8, or FIG9.

[0441] Those skilled in the art will recognize that the method steps and units described in the embodiments disclosed in this application can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the steps and components of each embodiment have been generally described in terms of functionality in the foregoing description. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0442] In the embodiments provided in this application, it should be understood that the disclosed system architecture, apparatus, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative. For instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be indirect coupling or communication connection through some interfaces, devices, or modules, or may be electrical, mechanical, or other forms of connection.

[0443] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of the embodiments of this application, depending on actual needs.

[0444] Furthermore, the modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules described above can be implemented in hardware or in software.

[0445] If the integrated module is implemented as a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, ROM, RAM, magnetic disks, or optical disks.

[0446] In this application, the terms "first" and "second," etc., are used to distinguish identical or similar items that have substantially the same function and purpose. It should be understood that there is no logical or temporal dependency between "first" and "second," nor does it limit the quantity or execution order. It should also be understood that although the following description uses the terms "first" and "second," etc., to describe various elements, these elements should not be limited by the terms. These terms are merely used to distinguish one element from another. For example, without departing from the scope of the various examples, a first access point can be referred to as a second access point, and similarly, a second access point can be referred to as a first access point. Both a first access point and a second access point can be access points, and in some cases, they can be separate and distinct access points.

[0447] The above description is merely an exemplary embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and such modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A communication method, characterized in that, The method is applied to the main access point of a communication system, which further includes a first slave access point and a second slave access point, wherein a site is connected to the first slave access point. The method includes: Receive a first roaming message, the first roaming message including context information of the service transmitted between the site and the first access point; A second roaming message is sent to the second access point, the second roaming message carrying the context information, the context information being used by the second access point to transmit the services of the site.

2. The method as described in claim 1, characterized in that, Receiving the first roaming message includes: When the site moves to the coverage area of ​​the second access point, an acquisition request message is sent to the first access point, the acquisition request message being used to request the context information; Receive the first retrieval response message sent from the access point, the retrieval response message including the context information.

3. The method as described in claim 1, characterized in that, Receiving the first roaming message includes: When the site moves to the coverage area of ​​the second access point, an update request message sent by the first access point is received, the update request message including the context information.

4. The method according to any one of claims 1-3, characterized in that, The context information in the first roaming message includes one or more of the following: key update information used to transmit the service, the dormant state of the site, the sequence number of the first message in the sending window, the sequence number of the last message in the sending window, the sequence number of the first message in the receiving window, the sequence number of the last message in the receiving window, the bitmap of the receiving window, or the sequence number of the first message that was not sent from the access point to the site. The service includes downlink service sent from the first access point to the site and / or uplink service received from the site by the first access point. The sending window is the window used by the first access point to send the downlink service message to the site, and the receiving window is the window used by the first access point to receive the uplink service message from the site. The bitmap is used to describe the receiving status of the messages included in the receiving window.

5. The method according to any one of claims 1-3, characterized in that, The communication system includes a fiber-to-the-room (FTTR) system, the primary access point is the primary FTTR device included in the FTTR system, and the first secondary access point and the second secondary access point are secondary FTTR devices included in the FTTR system.

6. The method according to any one of claims 1-5, characterized in that, The first roaming message is a service closure completion message, and the second roaming message is a service start indication.

7. The method according to any one of claims 1-6, characterized in that, The context information includes at least one of the following: message sequence number, IP message identifier, and OMI status information of the site.

8. The method according to any one of claims 1-7, characterized in that, The method further includes: Send a first multicast key synchronization message to the first slave access point and the second slave access point. The first multicast key synchronization message includes one or more of the following parameters: multicast key, length of the multicast key, integrity group temporary key IGTK, length of the IGTK, random number Gnonce, receive sequence counter RSC or key replay counter.

9. A communication method, characterized in that, The method is applied to the main access point of a communication system, which further includes a first slave access point and a second slave access point, wherein a site is connected to the first slave access point. The method includes: Receive a third roaming message, the third roaming message including connection information establishing a connection between the site and the first access point; A fourth roaming message is sent to the second access point, the fourth roaming message including the connection information, the connection information being used by the second access point to establish a connection with the site.

10. The method as described in claim 9, characterized in that, The connection information in the third roaming message includes one or more of the following: aggregation information used to transmit the service or key information used to transmit the service.

11. The method as described in claim 9 or 10, characterized in that, The communication system includes a fiber-to-the-room (FTTR) system, the primary access point is the primary FTTR device included in the FTTR system, and the first secondary access point and the second secondary access point are secondary FTTR devices included in the FTTR system.

12. The method according to any one of claims 9-11, characterized in that, The connection information in the third roaming message includes one or more of the following: a reassociation request message received from the site by the first access point, an association request message received from the site by the first access point, or an authentication request message received from the site by the first access point.

13. The method as described in any one of claims 12, characterized in that, The third roaming message is an association request reporting message, and the fourth roaming message is an association request sending message.

14. The method according to any one of claims 9-13, characterized in that, The method further includes: Send a first multicast key synchronization message to the first slave access point and the second slave access point. The first multicast key synchronization message includes one or more of the following parameters: multicast key, length of the multicast key, integrity group temporary key IGTK, length of the IGTK, random number Gnonce, receive sequence counter RSC or key replay counter.

15. A communication method, characterized in that, The method is applied to a second slave access point of a communication system, the communication system further including a master access point and a first slave access point, wherein a site accesses the first slave access point, and the method includes: Receive a second roaming message sent by the primary access point, the second roaming message including context information of the service transmitted between the site and the first secondary access point; The site's services are transmitted based on the context information.

16. The method as described in claim 15, characterized in that, The context information includes one or more of the following: key update information used to transmit the service, the dormant state of the site, the sequence number of the first message in the sending window, the sequence number of the last message in the sending window, the sequence number of the first message in the receiving window, the sequence number of the last message in the receiving window, the bitmap of the receiving window, or the sequence number of the first message that was not sent from the access point to the site. The service includes downlink service sent from the first access point to the site and / or uplink service received from the site by the first access point. The sending window is the window used by the first access point to send the downlink service message to the site, and the receiving window is the window used by the first access point to receive the uplink service message from the site. The bitmap is used to describe the receiving status of the messages included in the receiving window.

17. The method as described in claim 15, characterized in that, The context information includes at least one of the following: message sequence number, IP message identifier, sequence number (SN) context information, or the OMI status information of the site.

18. The method as described in claim 17, characterized in that, The service of transmitting the site based on the context information includes: Send a downlink message to the station according to the message sequence number; or... Send an aggregated message to the site based on the SN context information; or... The channel bandwidth and number of streams are determined based on the OMI status information of the site.

19. The method as described in claim 16, characterized in that, The service of transmitting the site based on the context information includes: If the hibernation state is used to indicate that the station is in a sleep state, then the station is awakened; and / or, Based on the sequence number of the first message in the sending window, the sequence number of the last message in the sending window, and / or the sequence number of the first message not sent from the access point to the site, the message to be sent belonging to the downlink service is determined; or, Based on the sequence number of the first message in the receive window, the sequence number of the last message in the receive window, and the bitmap of the receive window, the station is instructed to determine the messages to be sent that belong to the uplink service; and / or, The multicast data to be sent to the site is encrypted based on the key update information.

20. The method according to any one of claims 15-19, characterized in that, The method further includes: Receive a first multicast key synchronization message, which includes one or more of the following parameters: multicast key, length of the multicast key, integrity group temporary key IGTK, length of the IGTK, random number Gnonce, receive sequence counter RSC or key replay counter. Send a second multicast key synchronization message to the site, the second multicast key synchronization message including some or all of the parameters in the first multicast key synchronization message.

21. A communication method, characterized in that, The method is applied to a second slave access point of a communication system, the communication system further including a master access point and a first slave access point, wherein a site accesses the first slave access point, and the method includes: Receive a fourth roaming message sent by the primary access point, the fourth roaming message including connection information for establishing a connection between the site and the first secondary access point; The site's services are transmitted based on the connection information.

22. The method as described in claim 21, characterized in that, The connection information includes one or more of the following: a reassociation request message received from the site by the first access point, an association request message received from the site by the first access point, or an authentication request message received from the site by the first access point.

23. The method as described in claim 22, characterized in that, The service of transmitting the site based on the connection information includes: A connection with the site is established based on the association request message, the reassociation request message, and the authentication request message. The connection is used to transmit the site's services.

24. The method according to any one of claims 21-23, characterized in that, The method further includes: Receive a first multicast key synchronization message, which includes one or more of the following parameters: multicast key, length of the multicast key, integrity group temporary key IGTK, length of the IGTK, random number Gnonce, receive sequence counter RSC or key replay counter. Send a second multicast key synchronization message to the site, the second multicast key synchronization message including some or all of the parameters in the first multicast key synchronization message.

25. A main access point, characterized in that, The main access point includes a processor and a memory; The processor is configured to execute program instructions in the memory to perform the method as described in any one of claims 1 to 8 or any one of claims 9 to 14.

26. A method from an access point, characterized in that, The access point includes a processor and a memory; The processor is configured to execute program instructions in the memory to perform the method as described in any one of claims 15 to 20 or any one of claims 21 to 24.

27. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program or instructions are executed by a processor, they implement the method as described in any one of claims 1-8, any one of claims 9-14, any one of claims 15-20, or any one of claims 21-24.

28. A computer program product having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the method as described in any one of claims 1-8, any one of claims 9-14, any one of claims 15-20, or any one of claims 21-24.

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