Roaming signaling

Abstract

The invention relates to roaming signaling. Embodiments describe systems, methods, and apparatus for roaming operations in Wi-Fi. In some embodiments, a frame format for roaming operations includes a multi-link multi-device (MLMD) link addition request and an MLMD link addition response. A station (STA) may transmit an MLMD link addition request to a source access point (AP) multi-link device (MLD) to initiate a roaming operation to a target AP MLD. The source AP MLD may transmit an MLMD link addition response to the STA.

Description

Technical Field

[0001] This application relates in its entirety to wireless communication systems, including signaling and frames used for link addition requests and responses. Background Technology

[0002] Wireless communication technologies use various standards and protocols to send data between access points and wireless communication devices. Wireless communication system standards and protocols may include, for example, 3GPP Long Term Evolution (LTE) (e.g., 4G), 3GPP New Radio (NR) (e.g., 5G), and the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard for Wireless Local Area Networks (WLANs) (often referred to as Wi-Fi within the industry organization). ® ).

[0003] In the 802.11 standard for WLAN, an access point (AP) is used to create a wireless local area network (WLAN) or Wi-Fi. ® A network device. An access point (AP) can connect to a wired network (such as Ethernet) and provide wireless access to that network for other devices. A station is a device that can wirelessly connect to an AP to join a WLAN network. A station can be a laptop, smartphone, tablet, or any other device with a WLAN adapter.

[0004] APs and stations use Wi-Fi ® The protocols communicate with each other. Various protocols have been established to improve security on wireless communication networks. For example, simultaneous authentication by peer entities is the core authentication protocol of WPA3-Personal, and is used by all Wi-Fi networks. ® All Alliance Certified devices (including both access points (APs) and non-AP stations (STAs) must support this protocol. Attached Figure Description

[0005] To facilitate the identification of any particular element or action in the discussion, one or more of the most significant digits in the figure reference numerals refer to the figure number in which the element was first introduced.

[0006] Figure 1 An example signal flow diagram illustrating a two-step roaming operation according to some implementation schemes is shown.

[0007] Figure 2 An example of the action field format for a multi-link multi-device (MLMD) link reconfiguration request frame is shown according to some implementation schemes.

[0008] Figure 3 Example MLMD reconfiguration configuration fields are shown according to some implementation schemes.

[0009] Figure 4AExample UHR roaming block confirmation configuration parameters are shown, which may be included in the block confirmation configuration field of the request, according to some implementation schemes.

[0010] Figure 4B Example blocks confirming transport options are illustrated according to some implementation schemes.

[0011] Figure 5A Examples of link configuration parameters and TID configuration parameters that may be included in the configuration fields of a request, according to some implementation schemes, are shown.

[0012] Figure 5B Example TID options, which may be indicated in the option parameters according to some implementation schemes, are shown.

[0013] Figure 6 The example MLMD link reconfiguration response action field format is illustrated according to some implementation schemes.

[0014] Figure 7 Example block confirmation parameters are shown, which may be included in the parameter fields of the response from the source AP to the STA, according to some implementation schemes.

[0015] Figure 8 Example Flow Classification Service (SCS) parameters that may be included in the parameter fields of the response from the source AP to the STA, according to some implementation schemes.

[0016] Figure 9 An example two-step roaming frame exchange between a STA and a source AP is illustrated according to some implementation schemes.

[0017] Figure 10 An example one-step roaming frame exchange between a STA and a source AP is illustrated according to some implementation schemes.

[0018] Figure 11 An example is given of a method performed by the STA according to the implementation scheme described herein.

[0019] Figure 12 An example is given of a method performed by the AP MLD according to the implementation scheme described herein.

[0020] Figure 13 An example system for performing signaling between a wireless device and a network device according to an embodiment disclosed herein is illustrated. Detailed Implementation

[0021] Wireless communication technologies use various standards and protocols to send data between access points and wireless communication devices. One standard used for wireless communication is the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard for Wireless Local Area Networks (WLANs) (commonly referred to as Wi-Fi within the industry organization).® Wi-Fi ® This provides a convenient way to establish a network between devices. Devices (e.g., stations) can connect to Wi-Fi. ® The access point joins the network and connects wirelessly to the internet. (Wi-Fi) ® Security is crucial for protecting data and devices from unauthorized access.

[0022] Various implementations are described regarding Stations (STAs) and Access Points (APs). However, references to STAs and APs are provided for illustrative purposes only. The example implementations can be used with any electronic components capable of establishing a connection to a network and configured with hardware, software, and / or firmware for exchanging information and data with the network. Therefore, STAs and APs as described herein are used to represent any suitable electronic components.

[0023] In wireless networks, roaming refers to the process by which a STA moves from one access point (AP) to another within the same network, thus allowing uninterrupted connectivity. When a STA moves across different areas within the coverage area, it can switch to a new AP with a stronger signal.

[0024] In some implementations, roaming operations can utilize add-link signaling. Add-link signaling operations enable more seamless and efficient roaming in wireless networks. For example, the sequence may begin by sending an add-link message to the source AP's multi-link device (MLD). In some implementations, a two-step process can break down the routing switch operation to ensure minimal disruption.

[0025] Some implementations described in this paper define the signaling and frame formats used for roaming operations using Add Link signaling. Several features are described in these implementations, including sequence number handling, Block Acknowledgment (BA) sessions, and power management.

[0026] Figure 1 Example signal flow diagram 102 illustrates a two-step roaming operation according to some implementations. In some implementations, STA 104 can roam from a source AP (e.g., AP MLD1 106) to a target AP (e.g., AP MLD2 108) using a single-step operation involving a request from STA 104 and a response from the source AP. During the roaming process, the target AP processes 112 the new STA link addition and context. This processing may take time. If a single-step roaming operation is performed, the target AP's processing may be a blocking process, during which STA 104 cannot transmit or receive data. Therefore, the processing steps may introduce latency in a single-step operation.

[0027] The illustrated two-step roaming operation reduces the latency experienced by STA 104 by splitting the roaming operation to allow STA 104 to continue communicating with the original AP while the target AP processes the new STA link addition and context. In the illustrated implementation, AP MLD1 106 is the original AP, and AP MLD2 108 is the target AP. STA 104 roams from AP MLD1 106 to AP MLD2 108.

[0028] The first step of a two-step roaming operation can be initiating a link add request / response signaling (118) for switching. This does not yet switch the data path. As shown, STA 104 can send a link add request (114) to AP MLD1 106. During the link add process, a static context can be transferred to AP MLD2 108. For example, AP MLD1 106 can forward the link add request and static context (116) to AP MLD2 108. AP MLD2 108 can process the new STA link add request and static context (112). AP MLD2 108 can then send a link add response (122) to AP MLD1 106. This response can be sent before AP MLD2 108 completes processing the new STA link add request and context. AP MLD1 106 can then forward the link add response (124) to STA 104. During this exchange, data reception and transmission with the source AP can continue. As shown in the figure, uplink and downlink data 120 can continue between AP MLD1 106 and STA 104.

[0029] The second step of the two-step roaming operation may include STA 104 initiating a data path handover 126 using the second frame. Any dynamic context can be transmitted during this phase. During this (short) exchange, STA 104 may need to pause the uplink. As shown, STA 104 may send a route handover request 128 to AP MLD1 106. AP MLD1 106 may forward uplink buffer 130 to network 110. AP MLD1 106 may send a route handover request and dynamic context 132 to AP MLD2 108. AP MLD2 108 may send a route handover message 134 to network 110. AP MLD2 108 may send a roaming-ready message 136 to AP MLD1 106, and AP MLD1 106 may send a roaming-ready message 138 to STA 104. STA 104 and AP MLD2 108 can begin sending uplink / downlink data 140, and AP MLD1 106 can send buffered downlink data 142 to STA 104.

[0030] Figure 2An example of the action field format for a Multi-Link Multi-Device (MLMD) link reconfiguration request frame 202 according to some implementation schemes is shown. The MLMD link reconfiguration request frame 202 can provide a new Ultra-High Reliability (UHR) protected action frame that can be used for the MLMD link reconfiguration request. When compared to an EHT protected action frame link reconfiguration request, this frame may include additional fields.

[0031] MLMD Link Reconfiguration Request Frame 202 can be used to add a link to the target AP MLD. For example, Figure 1 STA 104 can transmit an MLMD link reconfiguration request frame 202 for link addition request 114. Some implementations can use timeout / removal of the link with the source AP.

[0032] In some implementations, variations of the same action frame (e.g., MLMD link reconfiguration request frame 202) can be used for link addition requests (e.g., Figure 1 Link addition request 114) and route switching operations (e.g., Figure 1 Both the link addition request (128) and the route switching request. Therefore, the STA can transmit an MLMD link reconfiguration request frame (202) for both the link addition request and the route switching request. The MLMD link reconfiguration request frame transmitted for the link addition request may have different configurations and / or content compared to the MLMD link reconfiguration request frame transmitted for the route switching request. For example, a link addition request may include reconfiguring multi-link elements, while a route switching request may not include reconfiguring multi-link elements.

[0033] As shown in the figure, the MLMD link reconfiguration request frame 202 may include a category field 204, a protected UHR action field 206, a session token field 208, a target AP MLD identifier field 210, a configuration field 212, and a reconfiguration multi-link element field 214. The category field 204 specifies the category of the requested action. The protected UHR action field 206 can be used in protection frames. The session token field 208 can be used as an identifier to associate requests and responses between the STA and the AP.

[0034] The Target AP MLD Identifier field 210 identifies the AP that the STA expects to roam. In some implementations, the Target AP MLD Identifier field 210 may include the AP MLD ID. The AP MLD ID is a value that is strictly local to the source AP MLD (e.g., received from a Reduced Neighbor Report (RNR)). In some implementations, the Target AP MLD Identifier field 210 may include the AP MLD address (e.g., received via a beacon / probe response).

[0035] Configuration field 212 provides roaming configuration. Details regarding the parameters of configuration field 212 are described in conjunction with the other accompanying figures in this document.

[0036] The reconfiguration multilink element field 214 may exist for each added link in a link addition operation. In some implementations, the reconfiguration multilink element field 214 may not exist in a route switching operation.

[0037] Figure 3 Example MLMD reconfiguration configuration field 302 is shown according to some implementation schemes. MLMD reconfiguration configuration field 302 is Figure 2 Example of configuration field 212 in the document, and it can be generated by... Figure 1 This is part of the Link Add Request 114 and Route Switch Request 128 transmitted by STA 104. MLMD reconfiguration configuration field 302 may include control subfield 304. Additionally, MLMD reconfiguration configuration field 302 may include one or more configurations for the roaming process (e.g., block acknowledgment configuration 306, link configuration 308, and service identifier (TID) configuration 310).

[0038] The MLMD reconfiguration configuration field 302 may include items that the STA may want to configure or modify during roaming. In some implementations, other parameters expected to remain unchanged may be expected to be transmitted between APs by default. For example, in some implementations, the STA may include configurations that have changed in the MLMD reconfiguration configuration field 302, but not those that have not changed. For configurations not included, the current AP MLD may assume that the configuration has not changed and transmit the configuration / context unchanged to the target AP.

[0039] The control subfield 304 may include an initiation route switching bit 312, a recovery bit 314, and several bits indicating the presence or absence of the configuration in the MLMD reconfiguration configuration field 302 (e.g., BA configuration preset bit 316, link configuration preset bit 318, and TID configuration preset bit 320).

[0040] The Initiate Route Switch bit 312 can be used to request a route switch. For example, in some implementations, the STA can set the Initiate Route Switch bit 312 to one to request a route switch. The STA can set the Initiate Route Switch bit 312 to one in the first request to indicate a single-step roaming. For a two-step roaming, the STA can set the Initiate Route Switch bit 312 to one in the first request (e.g., Figure 1 In the link addition request 114, the initiating route switch bit 312 is set to zero, and in the second request (e.g., Figure 1 In the route switching request (128), the route switching initiation bit is set to one.

[0041] The recovery bit 314 can be used to indicate that the STA has decided not to roam. For example, in some implementations, the STA can do so in a second phase (e.g., Figure 1 The route handover request 128 sets recovery bit 314 to one to signal to the STA that it does not intend to roam to the indicated target AP MLD. A use case for recovery bit 314 could be when the STA previously added a link but did not initiate a route handover and decides to cancel the roaming operation.

[0042] Additional bits in control subfield 304 can indicate the presence or absence of certain configurations in MLMD reconfiguration configuration field 302. For example, BA configuration preset bit 316 can indicate the presence or absence of block confirmation configuration 306. Link configuration preset bit 318 can indicate the presence or absence of link configuration 308. TID configuration preset bit 320 can indicate the presence or absence of TID configuration 310.

[0043] Figure 4A Examples of implementation schemes include those that may be included in the request (e.g., Figure 1 The configuration fields for (e.g., link addition request 114 or route switching request 128) Figure 3 The block confirmation configuration (e.g., MLMD reconfiguration configuration field 302) Figure 3 Example UHR roaming block confirmation configuration parameter 402 in the block confirmation configuration 306).

[0044] As shown in the figure, the block acknowledgment parameter set field format 404 may include a 16-bit format, where each segment has a specific bit allocation. Aggregated MAC Service Data Unit (A-MSDU) support 406 may be a bit indicating whether A-MSDU is supported at the target AP. Block acknowledgment policy 408 may be a bit specifying the acknowledgment policy used for the block acknowledgment session. TID 410 may be four bits, identifying the service type and priority level of the data stream for which the block acknowledgment session is being established. Buffer size 412 may be ten bits, specifying the maximum number of MPDUs that the receiver can buffer for this block acknowledgment session. A-MSDU support, block acknowledgment policy, buffer size, and timeout from the STA side are not expected to change. These parameters are automatically transmitted as part of the static context transfer between APs as long as the BA session persists.

[0045] When a STA roams as part of a context transport, the block acknowledgment session for the current AP may be expected to be operational at the target AP. In some implementations, the STA can use UHR roaming block acknowledgment configuration parameter 402 to modify the block acknowledgment session when roaming to the target AP.

[0046] The BA configuration shared by the STA in the roaming request may include one or more parameters shown in UHR roaming block acknowledgment configuration parameter 402. If the desired operation is non-default, zero or more block acknowledgment configuration parameters may be included (per block acknowledgment (BA) session). UHR roaming block acknowledgment configuration parameter 402 may include TID 414, initiator bit 416, SN reset bit 418, and transport option 420. TID 414 identifies the service type and priority level of the data flow that the block acknowledgment session is changing. Initiator bit 416 indicates whether the STA is the initiator or responder of the block acknowledgment setup. SN reset bit 418 can be used to reset the sequence number (SN), and transport option 420 can be used to indicate the desired options for transferring the block acknowledgment session from the current AP to the target AP.

[0047] A default block acknowledgment session transfer may involve transferring the SN to the target AP to allow the SN to continue. However, the STA can use the SN reset bit 418 to indicate an interest in resetting the SN to zero at the target AP. For example, the SN reset bit 418 can be set to zero to indicate no SN reset, and set to one to indicate an SN reset. If an SN reset is indicated, the SN value can be reset to zero at the target AP.

[0048] Figure 4B Example block acknowledgment transmission option 422 is illustrated according to some implementations. Transmission option 420 is set to option 0 to indicate that the STA expects to delete the block acknowledgment session. If the target AP supports the same size (or larger), transmission option 420 can be set to option 1 to transmit a window of the same size; otherwise, the AP will delete the block acknowledgment session at the target AP MLD. For option 2, if the target AP only supports a smaller size, the block acknowledgment window will be reduced to the maximum size supported by the target AP. In some implementations, additional transmission options may be included.

[0049] For the default configuration, SN reset bit 418 indicates no SN reset, and transmission option 420 can be set to transmission option 1. Note that the result of the requested operation and any potential changes at the target AP can be reported by the source AP in the response frame.

[0050] Figure 5A Examples of implementation schemes include those that may be included in the request (e.g., Figure 1 The configuration fields for (e.g., link addition request 114 or route switching request 128) Figure 3 Examples of link configuration parameter 502 and TID configuration parameter 504 in the MLMD reconfiguration configuration field 302. It's possible that an STA might expect certain parameters to be reconfigured at the link level rather than across the entire association. Link configuration parameter 502 can be used for link-level changes.

[0051] If a non-default operation is desired, the STA may include zero or more link configuration parameters 502. As shown, link configuration parameters 502 may include a link ID 506 and a power management (PM) status 508. The link ID 506 indicates which link the parameter applies to. The PM status 508 indicates the PM status of the added link on the target AP after a route switching response. The PM status 508 can be used to initially indicate which link the STA wants to receive downlink from the target AP MLD (MLD / Enhanced Multi-Link Single Radio (EMLSR) Roaming). For example, the STA may instruct one link to receive downlink from the target AP and use other links to receive buffered data from the source AP. In some implementations, the default behavior may be that all added links are initially in the PM status.

[0052] While the illustrated implementation includes only PM state 508 in link configuration parameter 502, additional items may be included. For example, optional items may include Operation Mode Indication (OMI) signaling. In some implementations, configuration parameters may include Target Wake-up Time (TWT), Unscheduled Automatic Power Saving Delivery (U-APSD), Wireless Network Management (WNM) sleep, etc. In some implementations, configuration parameters may include unicast group-addressed frame delivery.

[0053] In some implementations, TID configuration parameter 504 may include TID 510 to identify the service to which the change is applied. TID configuration parameter 504 may also include uplink / downlink bit 512 to indicate whether the change applies to the uplink or downlink. Option parameter 514 may indicate the options to be applied at the target AP.

[0054] Figure 5B Example TID options 516, which may be indicated in option parameter 514 according to some implementation schemes, are illustrated. There may be zero or more TID configuration parameters. These options instruct the source AP how to handle buffered data. As shown, options for buffered downlink data may include discarding the current and future frames at the source AP, transmitting (which is likely the default), transmitting with high priority, and transferring (e.g., transmitting the buffered data to the destination AP). Options for buffered uplink data may include discarding the buffer, forwarding all data to the distribution service (DS), forwarding to the first distribution port of the DS, and transferring. Note that some combinations of each TID configuration and block AC configuration may be invalid.

[0055] Figure 6An example MLMD link reconfiguration response 602 action field format is illustrated according to some implementation schemes. The MLMD link reconfiguration response 602 can provide a new UHR protected action frame that can be used for the MLMD link reconfiguration response. This frame may include additional fields when compared to an EHT protected action frame link reconfiguration response. The MLMD link reconfiguration response 602 can be used by an AP to transmit a response. For example, Figure 1 The AP MLD1 106 can transmit the MLMD link reconfiguration response 602 for either the link add response 124 or the roaming ready message 138.

[0056] As shown in the figure, the MLMD link reconfiguration request frame MLMD link reconfiguration response 602 may include a category field 604, a protected UHR action field 606, a session token field 608, an association identifier (AID) field 610, a target AP MLD identifier field 612, a count field 614, a reconfiguration status list field 616, a parameter field 618 (optionally), a group key field 620, and a basic multilink element field 622 (optionally).

[0057] The category field 604 specifies the category of the requested action. The protected UHR action field 606 can be used in a protection frame. The session token field 608 can be used as an identifier for requests and responses between the associated STA and AP. The AID field 610 can include the ID assigned by the AP to the associated STA. The AID can be assigned during association. During link reconfiguration, the AP MLD can transmit the AID in the response.

[0058] The Target AP MLD Identifier field 612 identifies the AP that the STA expects to roam. In some implementations, the Target AP MLD Identifier field 612 may include the AP MLD ID. The AP MLD ID is a value that is strictly local to the source AP MLD (e.g., received from the RNR). In some implementations, the Target AP MLD Identifier field 612 may include the AP MLD address (e.g., received via a beacon / probe response).

[0059] The count field 614 indicates the number of subfields or elements in the response frame, specifically within the reconfiguration status list field 616. The reconfiguration status list field 616 provides status updates for each requested reconfiguration item. Each entry in this list indicates whether a particular request (e.g., adding or removing a link, changing a frequency band, or adjusting power settings) was successful, partially applied, or failed.

[0060] Parameter field 618 may include roaming parameters. Details regarding roaming parameters are described with reference to other accompanying figures. When link reconfiguration involves changes affecting group security, group key data field 620 provides updated security information. Basic multilink element field 622 may include details regarding multilink configuration and AP capabilities. Basic multilink element field 622 may exist for link addition operations for each added link and may not exist in route switching operations.

[0061] In some implementations, parameter field 618 may include a block acknowledgment parameter. In some implementations, the block acknowledgment parameter in the response frame may include a single bit indicating whether all block acknowledgment sessions have been transmitted or no block acknowledgment sessions will be transmitted. In some such implementations, no other block acknowledgment parameters (or configurations) may be defined.

[0062] Figure 7 Examples of responses that may be included in the transmission from the source AP to the STA, according to some implementation schemes, are illustrated (e.g., Figure 1 The link adds a response 124 or a roaming ready message 138) parameter field (e.g., Figure 6 Example block acknowledgment parameter 702 in parameter field 618. There may be zero or more block acknowledgment parameters; these parameters may be included if changed, and omitted if not changed. Block acknowledgment parameter 702 may include initiator 704, TID 706, new buffer size 708, starting sequence number 710, A-MSDU support 712, and timeout value 714. Parameters such as the starting sequence number 710 may be specific to each TID 706.

[0063] Initiator 704 can indicate the initiator / receiver (uplink / downlink). TID 706 can include a service identifier value. New buffer size 708 can indicate the new buffer size at the target AP. For example, if the target AP has different capabilities than the source AP, new buffer size 708 can indicate the window size of the new buffer size at the target AP. If the BA session is deleted at the target, new buffer size 708 can be set to zero. A-MSDU support 712 and timeout value 714 can be set by the target AP (e.g., in an Add Block Acknowledgment (ADDBA) response).

[0064] The starting sequence number 710 indicates the starting sequence number used for downlink at the target AP. For uplink, the starting sequence can be reserved. The source AP may need gaps in allocating sequence numbers for potential downlink frames from the DS until the routing handover is complete. The starting sequence number assigned to the target AP can be shared with the STA, so that the STA does not bear the burden of downlink loss, and if outside the current window, the STA will not wait for downlink from the target AP until the window moves.

[0065] Figure 8 Examples of responses that may be included in the transmission from the source AP to the STA, according to some implementation schemes, are illustrated (e.g., Figure 1 The link adds a response 124 or a roaming ready message 138) parameter field (e.g., Figure 6 Example Stream Classification Service (SCS) parameter 802 in parameter field 618. SCS parameter 802 may include SCSID 804, service start time 806, and service start time LinkID 808. The parameter field may include zero or more SCS parameters. These parameters may be included if changed, and may be omitted if not changed.

[0066] SCS parameter 802 may include a Flow Classification Service Identifier (SCSID) 804. SCSID 804 can be an identifier used to uniquely distinguish different SCS sessions. The Service Start Time 806 value (and the associated Service Start Time LinkID 808) indicates the value for each SCS at the target AP. Service Start Time 806 indicates the start time of the SCS, and Service Start Time LinkID 808 specifies the specific link to which the service start time applies.

[0067] Figure 9 An example two-step roaming frame exchange 902 between STA 904 and source AP 906 according to some implementation schemes is illustrated. The illustrated roaming frame exchange 902 is a two-step link addition and route handover exchange. STA 904 can use roaming frame exchange 902 to roam from source AP 906 to target AP.

[0068] As shown in the figure, STA 904 can transmit an MLMD link add request 908 to the source AP 906. The MLMD link add request 908 may include the target AP MLD identifier, configuration, and reconfiguration of multi-link elements (as discussed in more detail with reference to the previous figures). In the illustrated implementation, the configuration of the MLMD link add request 908 includes a routing switching element set to zero and an uplink block acknowledgment configuration with SN reset. The routing switching element set to zero indicates that STA 904 does not yet want to perform a link switch. The UL block acknowledgment SN reset indicates that the uplink SN should be reset for the target AP.

[0069] The source AP 906 can communicate with the target AP and respond to STA 904 by transmitting an MLMD Link Add Response 910. The MLMD Link Add Response 910 may include the target AP MLD identifier, no parameters (indicating that the target AP has not changed), a reconfiguration status list indicating that all links have been successfully configured, and basic multilink elements.

[0070] When the STA is ready to roam to the target AP, it may transmit a second MLMD link add request 912. The second MLMD link add request 912 may include a configuration where routing switching is set to one to indicate a request to roam to the target AP. The source AP 906 may transmit a second MLMD link add response 914 including a downlink block acknowledgment SN and a group key. The STA 904 may then move to the target AP.

[0071] Figure 10 An example one-step roaming frame exchange 1002 between STA 1004 and source AP 1006 according to some implementation schemes is illustrated. The illustrated roaming frame exchange 1002 is a one-step link addition and route switching exchange. STA 1004 can use roaming frame exchange 1002 to roam from source AP 1006 to target AP.

[0072] In the illustrated implementation, a route switch is requested in the first request frame. For example, STA 1004 may transmit an MLMD link add request 1008 to the source AP 1006. The MLMD link add request 1008 may include a target AP MLD identifier, configuration, and reconfiguration of multi-link elements (as discussed in more detail with reference to the previous figures). In the illustrated implementation, the configuration of the MLMD link add request 1008 includes a route switching element set to one and a downlink buffer set as a transmission option. A route switch flag indicates that the route switch will occur in a single step, and the transmission downlink option indicates that the source AP should transmit downlink buffer data.

[0073] Source AP 1006 can perform this procedure with the target AP to establish a link. Source AP 1006 can send an MLMD Link Add Response 1010 to STA 1004. The MLMD Link Add Response 1010 may include the target AP MLD identifier, downlink block acknowledgment parameters (indicating a parameter change in the block acknowledgment session), a reconfiguration status list indicating that all links have been successfully configured, and basic multilink elements. STA 904 can then move to the target AP.

[0074] This document defines the frame format details for roaming operations in several implementations. Some implementations describe MLMD link-add requests and MLMD link-add responses. Some implementations describe using changes in signaling to support a two-step roaming process. Some implementations include configurations defined in the request frame and parameters defined in the response frame.

[0075] Figure 11A method 1100 performed by a STA according to an embodiment of this document is illustrated. The illustrated method 1100 includes initiating a roaming operation 1102 by transmitting an MLMD link add request to a source AP MLD, the MLMD link add request including a target AP MLD identifier and configuration fields for roaming configuration. Method 1100 also includes receiving an MLMD link add response 1104. Method 1100 further includes roaming from the source AP MLD to the target AP MLD 1106.

[0076] In some embodiments of method 1100, the configuration field includes a control subfield that includes an initiation route handover bit, a recovery bit, and one or more bits indicating the presence of the configuration in the configuration field. In some such embodiments, the roaming configuration in the MLMD link add request includes block acknowledgment configuration, link configuration, and TID configuration. In some such embodiments, the block acknowledgment configuration includes an SN reset bit and transport options, the SN reset bit indicating whether the SN should be reset to zero at the destination AP MLD, and the transport options indicating how the source AP MLD should handle buffered data. In some other such embodiments, the link configuration includes a link ID and a PM status indicator for the link ID. In some other such embodiments, the TID configuration includes an indication of how buffered data should be handled for each TID.

[0077] In some implementations of method 1100, the MLMD link addition response includes the target AP MLD identifier, AID, and parameter fields.

[0078] In some such implementations, the parameter fields include a block acknowledgment parameter, which has a new buffer size field indicating the new buffer size at the target AP MLD, an A-MSDU support indicator, a timeout value, and the start sequence number of the frame from the target AP MLD. In some other such implementations, the parameter fields include an SCS parameter, which includes a SCSID, a service start time, and a service start time link ID.

[0079] In some implementations, method 1100 further includes a transmission link switching request, which includes a second configuration field having a route switching initiation flag indicating to the AP MLD that a route switching should be performed, wherein the roaming operation is a two-step roaming operation, and the configuration field of the MLMD link addition request indicates that the STA does not want to perform a route switching at that time.

[0080] The embodiments contemplated herein include an apparatus comprising components for performing one or more elements of method 1100. This apparatus may be, for example, an STA (such as STA 1302, as described herein).

[0081] The embodiments contemplated herein include one or more non-transitory computer-readable media comprising instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of method 1100. The non-transitory computer-readable medium may be, for example, memory of an STA (such as memory 1306 of STA 1302, as described herein).

[0082] The embodiments contemplated herein include an apparatus comprising logic components, modules, or circuitry for performing one or more elements of method 1100. This apparatus may be, for example, an STA (such as STA 1302, as described herein).

[0083] The embodiments contemplated herein include an apparatus comprising: one or more processors and one or more computer-readable media including instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of method 1100. The apparatus may be, for example, an STA (such as STA 1302, as described herein).

[0084] The implementation scheme envisioned herein includes a signal as described in or associated with one or more elements of method 1100.

[0085] The embodiments contemplated herein include a computer program or computer program product comprising instructions, wherein execution of the program by a processor will cause the processor to perform one or more elements of method 1100. The processor may be a processor of an STA (such as processor 1304 of STA 1302, as described herein). These instructions may, for example, reside in the processor and / or in the memory of the STA (such as memory 1306 of STA 1302, as described herein).

[0086] Figure 12 A method 1200 performed by an AP MLD according to an embodiment of this document is illustrated. The illustrated method 1200 includes receiving, 1202, an MLMD link add request for a roaming operation initiated by a source AP MLD to a target AP MLD, the MLMD link add request including a target AP MLD identifier and configuration fields for roaming configuration. Method 1200 also includes transmitting, 1204, an MLMD link add response.

[0087] In some embodiments of method 1200, the configuration field includes a control subfield that includes an initiation route handover bit, a recovery bit, and one or more bits indicating the presence of the configuration in the configuration field. In some such embodiments, the roaming configuration in the MLMD link add request includes block acknowledgment configuration, link configuration, and TID configuration. In some such embodiments, the block acknowledgment configuration includes an SN reset bit and transport options, the SN reset bit indicating whether the SN should be reset to zero at the destination AP MLD, and the transport options indicating how the source AP MLD should handle buffered data. In some other such embodiments, the link configuration includes a link ID and a PM status indicator for the link ID. In some other such embodiments, the TID configuration includes an indication of how buffered data should be handled for each TID.

[0088] In some implementations of method 1200, the MLMD link add response includes a target AP MLD identifier, an AID, and parameter fields. In some such implementations, the parameter fields include a block acknowledgment parameter having a new buffer size field indicating the new buffer size at the target AP MLD, an A-MSDU support indicator, a timeout value, and the start sequence number of the frame from the target AP MLD. In some other such implementations, the parameter fields include an SCS parameter, which includes a SCSID, a service start time, and a service start time link ID.

[0089] In some implementations, method 1200 further includes receiving a link switching request, the link switching request including a second configuration field having a route switching initiation flag indicating to the AP MLD that a route switching should be performed, wherein the roaming operation is a two-step roaming operation, and the configuration field of the MLMD link add request indicates that the STA does not want to perform a route switching at that time.

[0090] The embodiments contemplated herein include an apparatus comprising components for performing one or more elements of method 1200. This apparatus may be, for example, an AP (such as AP 1318, as described herein).

[0091] The embodiments contemplated herein include one or more non-transitory computer-readable media comprising instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of method 1200. The non-transitory computer-readable medium may be, for example, the memory of an access point (such as memory 1322 of AP 1318, as described herein).

[0092] The embodiments contemplated herein include an apparatus comprising logic components, modules, or circuitry for performing one or more elements of method 1200. This apparatus may be, for example, an AP (such as AP 1318, as described herein).

[0093] The embodiments contemplated herein include an apparatus comprising: one or more processors and one or more computer-readable media including instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of method 1200. The apparatus may be, for example, an access point (such as AP 1318, as described herein).

[0094] The implementation scheme envisioned herein includes a signal as described in or associated with one or more elements of method 1200.

[0095] The embodiments contemplated herein include a computer program or computer program product comprising instructions, wherein execution of the program by a processing element will cause the processing element to perform one or more elements of method 1200. The processor may be the processor of an AP (such as processor 1320 of AP 1318, as described herein). These instructions may, for example, reside in the processor and / or in the memory of the AP (such as memory 1322 of AP 1318, as described herein).

[0096] Figure 13 A system 1300 for performing signaling 1334 between STA 1302 and AP 1318 according to an embodiment disclosed herein is illustrated. System 1300 may be part of a wireless communication system as described herein. STA 1302 may be, for example, a UE of a wireless communication system. AP 1318 may be, for example, an access point of a wireless communication system.

[0097] STA 1302 may include one or more processors 1304. Processor 1304 is executable instructions that cause various operations of STA 1302 to be performed as described herein. Processor 1304 may include one or more baseband processors, which may be implemented using, for example, a central processing unit (CPU), digital signal processor (DSP), application-specific integrated circuit (ASIC), controller, field-programmable gate array (FPGA) device, another hardware device, firmware device, or any combination thereof configured to perform the operations described herein.

[0098] STA 1302 may include memory 1306. Memory 1306 may be a non-transitory computer-readable storage medium that stores instructions 1308, which may include, for example, instructions executed by processor 1304. Instructions 1308 may also be referred to as program code or a computer program. Memory 1306 may also store data used by processor 1304 and results calculated by the processor.

[0099] STA 1302 may include one or more transceivers 1310, which may include radio frequency (RF) transmitter circuitry and / or receiver circuitry that uses antenna 1312 of STA 1302 to facilitate signaling (e.g., signaling 1334) to and / or from STA 1302 and other devices (e.g., AP 1318).

[0100] STA 1302 may include one or more antennas 1312 (e.g., one, two, four, or more antennas). In embodiments with multiple antennas 1312, STA 1302 can fully utilize the spatial diversity of such multiple antennas 1312 to transmit and / or receive multiple different data streams on the same time-frequency resource. This behavior can be referred to as, for example, multiple-input multiple-output (MIMO) behavior (referring to multiple antennas used at each of the transmitting and receiving devices to implement this aspect). MIMO transmission by STA 1302 can be achieved according to pre-decoding (or digital beamforming) applied at STA 1302, whereby the STA multiplexes data streams across antennas 1312 based on known or assumed channel characteristics, such that each data stream is received with appropriate signal strength relative to the other streams at a desired location in the spatial domain (e.g., the location of the receiver associated with that data stream). Some implementations may use a single-user MIMO (SU-MIMO) approach (where all data streams are directed to a single receiver) and / or a multi-user MIMO (MU-MIMO) approach (where individual data streams may be directed to individual (different) receivers at different locations in the airspace).

[0101] In some implementations with multiple antennas, STA 1302 can implement analog beamforming technology, whereby the phase of the signal transmitted by antenna 1312 is relatively adjusted, enabling (joint) transmission of the directional antenna 1312 (this is sometimes referred to as beam control).

[0102] STA 1302 may include one or more interfaces 1314. Interfaces 1314 can be used to provide input to or from the AP. For example, STA 1302 as a UE may include interfaces 1314, such as microphones, speakers, touchscreens, and buttons, to allow users of the UE to make inputs and / or outputs to the UE. Other interfaces of such UEs may consist of transmitters, receivers, and other circuitry that allow communication between the UE and other devices (e.g., in addition to the transceiver 1310 / antenna 1312 already described), and may be based on known protocols (e.g., Wi-Fi). ® ,Bluetooth ® (etc.) to perform the operation.

[0103] STA 1302 may include a roaming module 1316. The roaming module 1316 may be implemented via hardware, software, or a combination thereof. For example, the roaming module 1316 may be implemented as a processor, circuitry, and / or instructions 1308 stored in memory 1306 and executed by processor 1304. In some examples, the roaming module 1316 may be integrated within processor 1304 and / or transceiver 1310. For example, the roaming module 1316 may be implemented via a combination of software components (e.g., executed by a DSP or general-purpose processor) and hardware components (e.g., logic gates and circuitry) within processor 1304 or transceiver 1310.

[0104] The roaming module 1316 can be used in various aspects of this disclosure, for example, Figures 1 to 12 In all aspects. The roaming module 1316 is configured to authenticate AP 1318 and provide authentication credentials to AP 1318.

[0105] AP 1318 may include one or more processors 1320. Processor 1320 is executable instructions that cause AP 1318 to perform various operations as described herein. Processor 1320 may include one or more baseband processors, which may be implemented using, for example, a CPU, DSP, ASIC, controller, FPGA device, another hardware device, firmware device, or any combination thereof configured to perform the operations described herein.

[0106] AP 1318 may include memory 1322. Memory 1322 may be a non-transitory computer-readable storage medium that stores instructions 1324, which may include, for example, instructions executed by processor 1320. Instructions 1324 may also be referred to as program code or a computer program. Memory 1322 may also store data used by processor 1320 and results calculated by the processor.

[0107] AP 1318 may include one or more transceivers 1326, which may include RF transmitter circuitry and / or receiver circuitry that uses the antenna 1328 of AP 1318 to facilitate signaling (e.g., signaling 1334) to and / or from AP 1318 and other devices (e.g., STA 1302).

[0108] AP 1318 may include one or more antennas 1328 (e.g., one, two, four or more antennas). In embodiments with multiple antennas 1328, AP 1318 may perform MIMO, digital beamforming, analog beamforming, beam control, etc., as already described.

[0109] AP 1318 may include one or more interfaces 1330. Interface 1330 can be used to provide input to or from AP 1318. For example, AP 1318 as a base station may include interface 1330 consisting of transmitters, receivers and other circuitry (e.g., in addition to transceiver 1326 / antenna 1328 already described), which enables the base station to communicate with other equipment in the core network and / or enables the base station to communicate with external networks, computers, databases, etc., for the purpose of operating, managing and maintaining the base station or other equipment operable to the base station.

[0110] AP 1318 may include roaming module 1332. Roaming module 1332 may be implemented via hardware, software, or a combination thereof. For example, roaming module 1332 may be implemented as a processor, circuitry, and / or instructions 1324 stored in memory 1322 and executed by processor 1320. In some examples, roaming module 1332 may be integrated within processor 1320 and / or transceiver 1326. For example, roaming module 1332 may be implemented via a combination of software components (e.g., executed by a DSP or general-purpose processor) and hardware components (e.g., logic gates and circuitry) within processor 1320 or transceiver 1326.

[0111] The roaming module 1332 can be used in various aspects of this disclosure, for example, Figures 1 to 12 In all aspects. The roaming module 1332 is configured to authenticate STA 1302 and provide authentication credentials to STA 1302.

[0112] For one or more embodiments, at least one of the components set forth in one or more of the foregoing figures may be configured to perform one or more operations, techniques, processes, and / or methods as set forth herein. For example, a processor described herein in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples set forth herein. Similarly, circuitry associated with a STA or AP described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples shown herein.

[0113] Unless otherwise expressly stated, any of the embodiments described above may be combined with any other embodiment (or combination of embodiments). The foregoing description of one or more specific embodiments provides illustrative and descriptive information, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise forms disclosed. In light of the teachings above, modifications and variations are possible, or modifications and variations may be derived from practice with various embodiments.

[0114] Implementations and specific embodiments of the systems and methods described herein may include various operations embodied in machine-executable instructions to be executed by a computer system. The computer system may include one or more general-purpose or special-purpose computers (or other electronic devices). The computer system may include hardware components, including specific logical parts for performing the operations; or may include a combination of hardware, software, and / or firmware.

[0115] It should be recognized that the systems described herein include descriptions of specific implementations. These implementations may be combined into a single system, partially integrated into other systems, divided into multiple systems, or otherwise partitioned or combined. Furthermore, it is conceivable to use parameters, attributes, aspects, etc., of one implementation in one implementation. For clarity, these parameters, attributes, aspects, etc., are described only in one or more implementations, and it should be recognized that, unless expressly stated herein, these parameters, attributes, aspects, etc., may be combined with or substituted for parameters, attributes, aspects, etc., of another implementation.

[0116] As is widely recognized, the use of personally identifiable information should comply with privacy policies and practices that are generally accepted to meet or exceed industry or governmental requirements for protecting user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly explained to users.

[0117] Although the foregoing has been described in considerable detail for clarity, it will be apparent that certain changes and modifications can be made without departing from the principles of the invention. It should be noted that many alternative ways exist to implement both the processes and apparatus described herein. Therefore, embodiments of the invention should be considered illustrative rather than restrictive, and this specification is not limited to the details given herein, but can be modified within the scope and equivalents of the appended claims.

Claims

1. A method performed by a station (STA), the method comprising: Roaming is initiated by sending a Multi-Link Multi-Device (MLMD) link add request to the source access point (AP) multi-link device (MLD), the MLMD link add request including the target AP MLD identifier and configuration fields for roaming configuration; Receive MLMD link add response; as well as Roam from the source AP MLD to the target AP MLD.

2. The method according to claim 1, wherein the configuration field includes a control subfield, the control subfield including an initiation route switching bit, a recovery bit, and one or more bits for indicating the presence of configuration in the configuration field.

3. The method according to claim 2, wherein the roaming configuration in the MLMD link addition request includes block confirmation configuration, link configuration, and service identifier (TID) configuration.

4. The method of claim 3, wherein the block acknowledgment configuration includes a sequence number (SN) reset bit and a transmission option, the sequence number (SN) reset bit indicating whether the SN should be reset to zero at the target AP MLD, and the transmission option indicating how the source AP MLD should handle the buffered data.

5. The method of claim 3, wherein the link configuration includes a link identifier (ID) and a power management (PM) status indicator for the link ID.

6. The method of claim 3, wherein the TID configuration includes instructions on how buffered data should be handled for each TID.

7. The method of claim 1, wherein the MLMD link add response includes the target AP MLD identifier, the associated identifier (AID), and the parameter field.

8. The method of claim 7, wherein the parameter field includes a block acknowledgment parameter having a new buffer size field indicating a new buffer size at the target AP MLD, an aggregated MAC service data unit (A-MSDU) support indicator, a timeout value, and a start sequence number of the frame from the target AP MLD.

9. The method of claim 7, wherein the parameter field includes a Flow Classification Service (SCS) parameter, the Flow Classification Service (SCS) parameter including a Flow Classification Service Identifier (SCSID), a service start time, and a service start time link ID.

10. The method of claim 1, further comprising transmitting a link switching request, the link switching request including a second configuration field having an initiation route switching flag, the initiation route switching flag indicating to the AP MLD to perform a route switching. The roaming operation is a two-step roaming operation, and the configuration field of the MLMD link add request indicates that the STA does not want to perform a route switch at that time.

11. A method performed by an access point (AP) multilink device (MLD), the method comprising: Receive a multi-link multi-device (MLMD) link add request for a roaming operation initiated by a source access point (AP) multi-link device (MLD) to a target AP MLD, wherein the MLMD link add request includes a target AP MLD identifier and a configuration field for roaming configuration; as well as Add a response to the MLMD link.

12. The method of claim 11, wherein the configuration field includes a control subfield, the control subfield including an initiation route switching bit, a recovery bit, and one or more bits for indicating the presence of configuration in the configuration field.

13. The method of claim 12, wherein the roaming configuration in the MLMD link add request includes block confirmation configuration, link configuration, and service identifier (TID) configuration.

14. The method of claim 13, wherein the block confirmation configuration includes a sequence number (SN) reset bit and a transmission option, the sequence number (SN) reset bit indicating whether the SN should be reset to zero at the target AP MLD, and the transmission option indicating how the source AP MLD should handle the buffered data.

15. The method of claim 13, wherein the link configuration includes a link identifier (ID) and a power management (PM) status indicator for the link ID.

16. The method of claim 13, wherein the TID configuration includes instructions on how buffered data should be handled for each TID.

17. The method of claim 11, wherein the MLMD link add response includes the target AP MLD identifier, the association identifier (AID), and the parameter field.

18. The method of claim 17, wherein the parameter field includes a block acknowledgment parameter having a new buffer size field indicating a new buffer size at the target AP MLD, an aggregated MAC Service Data Unit (A-MSDU) support indicator, a timeout value, and a start sequence number of the frame from the target AP MLD.

19. The method of claim 17, wherein the parameter field includes a block acknowledgment parameter, the block acknowledgment parameter including bits indicating whether all block acknowledgment sessions have been transmitted or no block acknowledgment sessions will be transmitted.

20. The method of claim 17, wherein the parameter field includes a Flow Classification Service (SCS) parameter, the Flow Classification Service (SCS) parameter including a Flow Classification Service Identifier (SCSID), a service start time, and a service start time link ID.

21. The method of claim 11, further comprising receiving a link switching request, the link switching request including a second configuration field having an initiation route switching flag indicating to the AP MLD to perform a route switching, wherein the roaming operation is a two-step roaming operation, and the configuration field of the MLMD link add request indicates that the STA does not want to perform a route switching at that time.

22. An apparatus comprising components for performing the method according to any one of claims 1 to 21.

23. A computer-readable medium comprising instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform the method according to any one of claims 1 to 21.

24. An apparatus comprising a logic component, module, or circuit for performing the method according to any one of claims 1 to 21.

Images