Terminal device, base station device, and communication method

Abstract

Provided is a terminal device having a non-AP MLD, wherein: at least a first non-AP STA belongs to the non-AP MLD; at least a first AP belongs to a first AP MLD connected to the non-AP MLD; at least a second AP belongs to a second AP MLD not connected to the non-AP MLD; the terminal device includes a transmission unit that transmits a first frame, a reception unit that receives a second frame, and a processing unit; if the terminal device supports continuing to transmit data frames to the first AP until the second frame is received, upon transmitting the first frame, transmission of data frames to the first AP is not stopped until the second frame is received upon transmitting the first frame, and transmission of data frames to the second AP is started when the second frame is received; the first frame is a frame for executing SMD-based BSS transition; and the second frame is a response frame to the first frame.

Description

Terminal device, base station device, and communication method

[0001] The present invention relates to a terminal device, a base station device, and a communication method. This application claims priority to Japanese Patent Application No. 2024-193573, filed in Japan on November 5, 2024, the content of which is incorporated herein by reference.

[0002] The IEEE (The Institute of Electrical and Electronics Engineers Inc.) is considering accelerating wireless LAN (Local Area Network) communication and improving frequency utilization efficiency. Currently, the standardization of IEEE802.11bn has been started as a successor standard to IEEE802.11be.

[0003] IEEE802.11-23 / 1996r0, Po-Kai Huang (Intel), “Improve roaming between MLDs”, November 2023.

[0004] One aspect of the present invention provides a terminal device, a base station device, and a communication method capable of efficient communication.

[0005] (1) A first aspect of the present invention is a terminal device having a non-AP MLD, wherein the non-AP MLD has at least a first non-AP STA to it, a first AP MLD connected to the non-AP MLD has at least a first AP to it, and a second AP MLD not connected to the non-AP MLD has at least a second AP to it, and the terminal device includes a transmitting unit that transmits a first frame, a receiving unit that receives a second frame, and a processing unit, and when the terminal device transmits the first frame, if it supports continuing to transmit a Data frame to the first AP until it receives the second frame, when the terminal device transmits the first frame, it does not stop transmitting a Data frame to the first AP until it receives the second frame, and when it receives the second frame, it starts transmitting a Data frame to the second AP, and the first frame is a frame for executing an SMD-based BSS transition, and the second frame is a response frame to the first frame, the terminal device.

[0006] (2) A second aspect of the present invention is a base station device having a first AP MLD, wherein at least a first AP belongs to the first AP MLD, at least a first non-AP STA belongs to a non-AP MLD connected to the first AP MLD, and at least a second AP belongs to a second APMLD not connected to the non-AP MLD, and the base station device includes a receiving unit for receiving a first frame, a transmitting unit for transmitting a second frame, and a processing unit, wherein when the first non-AP STA transmits the first frame, it supports continuing to transmit a Data frame to the first AP until it receives the second frame, when the first frame is received, the first non-AP STA is not allowed to stop transmitting a Data frame to the first AP until it transmits the second frame, and when the second frame is transmitted, the first non-AP STA starts transmitting a Data frame to the second AP, and the first frame is SMD-based BSS A base station device, wherein the second frame is a frame for executing a transition, and the second frame is a response frame to the first frame.

[0007] (3) A third aspect of the present invention is a communication method wherein a non-AP MLD has at least a first non-AP STA to which it belongs, a first AP MLD connected to the non-AP MLD has at least a first AP to which it belongs, a second AP MLD not connected to the non-AP MLD has at least a second AP to which it belongs, and when the first non-AP STA transmits the first frame, it supports continuing to transmit a Data frame to the first AP until it receives the second frame, when the first non-AP STA transmits the first frame, it does not stop transmitting a Data frame to the first AP until it receives the second frame, and when it receives the second frame, it starts transmitting a Data frame to the second AP, the first frame is a frame for executing an SMD-based BSS transition, and the second frame is a response frame to the first frame.

[0008] This enables the realization of an efficient wireless communication system.

[0009] This is a diagram showing an example of a wireless LAN system according to one embodiment of this embodiment. This is a diagram showing an example of an OBSS according to one embodiment of this embodiment. This is a diagram showing an example of an STA configuration according to one embodiment of this embodiment. This is a diagram showing an example of an AP configuration according to one embodiment of this embodiment. This is a diagram showing an example of a MAC frame format according to one embodiment of this embodiment. This is a diagram showing an example of an A-MSDU according to one embodiment of this embodiment. This is a diagram showing an example of an A-MPDU according to one embodiment of this embodiment. This is a diagram showing an example of Fragmentation according to one embodiment of this embodiment. This is a diagram showing an example of a PPDU according to one embodiment of this embodiment. This is a diagram showing an example of a MAC data plane architecture for an MLD according to one embodiment of this embodiment. This is a diagram showing an example of a backoff procedure according to one embodiment of this embodiment. This is a diagram showing an example of a NAV according to one embodiment of this embodiment. This is a diagram showing an example of a UHR Link Reconfiguration procedure according to one embodiment of this embodiment.

[0010] Embodiments of the present invention will be described below.

[0011] "A, and / or B" may be a term that includes "A", "B", or "A and B".

[0012] The wireless LAN system in this embodiment comprises access points (APs) and stations (STAs). The network consisting of access points and stations is referred to as a BSS (Basic Service Set). The wireless LAN system may consist of one or more stations. If the wireless LAN system consists of two or more STAs, the wireless LAN system may also be referred to as a BSS.

[0013] An access point (AP) may also be called a base station device. A station (STA) may also be called a terminal device. A single base station device may have one or more APs. A single base station device may have one or more AP MLDs. A single base station device may have one or more Super MLDs. A single base station device may have one or more SuperAP MLDs. A single base station device may have one or more APs, one or more AP MLDs, and / or one or more SuperAP MLDs. A single terminal device may have one or more STAs. A single terminal device may have one or more non-AP STAs. A single terminal device may have one or more non-AP MLDs. A single terminal device may have one or more non-AP STAs, and / or one or more non-AP MLDs.

[0014] Figure 1 shows an example of a wireless LAN system according to one embodiment of this model. In Figure 1, the wireless LAN system comprises STA 103, STA 104, and AP 102. 101 may be referred to as BSS.

[0015] An STA may be a logical entity. This logical entity may be a logical entity that is a single addressable instance of the Medium Access Control (MAC) and physical layer interface to the Wireless Medium (WM). An STA may be a communication device over the Wireless Medium. An STA may also include an Access Point (AP) with base station functionality and / or a non-AP STA with terminal functionality. In other words, an STA may be an AP. An STA may also be a non-AP STA. An STA may also be both an AP and a non-AP STA. An STA may also be referred to as a terminal device.

[0016] The wireless medium may be the medium used to implement the transfer of Protocol Data Units (PDUs) between peer physical layer entities of a Wireless LAN. The wireless medium may be referred to as the medium. The medium may be referred to as Medium.

[0017] A channel may be an instance of a radio medium used to transmit PPDUs between two or more STAs.

[0018] An AP may include one STA and be an entity that provides access to distribution system services (DSS) via a wireless medium to associated STA(s). An AP may include an STA and a distribution system access function (DSAF). An AP may be referred to as an STA. In other words, an AP may be an STA.

[0019] A non-AP STA (non-access point station) may be an STA that is not included in an AP. For example, a non-AP STA may be an HT STA, a VHT STA, a HE STA, an EHT STA, or a UHR STA. A non-AP STA may be any STA other than those mentioned above. A non-AP STA may simply be referred to as an STA.

[0020] Distribution system services may be a set of services provided by the distribution system (DS). The distribution system access function may be a function within the AP that uses MAC services and distribution system services to provide access between the distribution system and the wireless medium. The distribution system may also be a system used to interconnect a set of BSSs and an integrated LAN to create an Extended Service Set (ESS).

[0021] A BSS may consist of a set of STAs that have successfully synchronized using JOIN service primitives and a set of STAs that uses a START primitive. For example, MLME-JOIN.confirm may be used as the JOIN service primitive. MLME-JOIN.confirm may be a primitive for confirming synchronization with the BSS. MLME-JOIN.request may be used as the JOIN service primitive. MLME-JOIN.request may be a primitive for requesting synchronization with the BSS. For example, MLME-START.request may be used as the START primitive. MLME-START.request may be a primitive for requesting a MAC entity to start a new BSS. A primitive may be an internal signal in an STA or AP. An internal signal here may be an internal signal used for information exchange between entities at different layers or different protocols, such as between an SME and an MLME, between an SME and a PLME, or between an MLME and a PLME.

[0022] An ESS is a set of one or more interconnected BSSs, which may appear as a single BSS in the Logical Link Control (LLC) layer of an STA associated with any of these BSSs. An ESS (Extended Service Set) may have a connection path via WM between one of the APs that are members of the ESS and a non-AP STA. An ESS may have overlapping communication areas (coverages) composed of multiple BSSs. The distances between the multiple BSSs in an ESS may be large, and the coverage covered by multiple BSSs may be arranged as a wider coverage. In other words, the communication area of ​​an ESS may be the same as or larger than the communication area of ​​a single BSS. The communication area composed of an ESS may be referred to as an ESA (Extended Service Area).

[0023] An OBSS (Overlapping Basic Service Set) may be a BSS that operates on the same channel as the STA's BSS, and within (partially or entirely) its BSA (Basic Service Area).

[0024] Figure 2 shows an example of OBSS according to one aspect of this embodiment. In Figure 2, 202 may be AP#1. 203 may be STA#1. 204 may be STA#2. 201 may be BSS#1 composed of 202, 203, and 204. 203 may be synchronized with 202. 204 may be synchronized with 202. 206 may be AP#2. 207 may be STA#3. 208 may be STA#4. 205 may be BSS#2 composed of 206, 207, and 208. 207 may be synchronized with 206. 208 may be synchronized with 206. 202 may not be synchronized with 207. 202 may not be synchronized with 208. 206 may not be synchronized with 203. 206 may not be synchronized with 204. 201 and 205 may be BSS operating on the same channel. 205 may be considered an OBSS to 201. 201 may be considered an OBSS to 205. For example, 202 may receive a frame transmitted by 207. 204 may receive a frame transmitted by 207. 207 may receive a frame transmitted by 202. 207 may receive a frame transmitted by 204. For example, 202 may determine that the channel is busy while 207 is transmitting. 204 may determine that the channel is busy while 207 is transmitting. 207 may determine that the channel is busy while 202 is transmitting. 207 may determine that the channel is busy while 204 is transmitting.

[0025] A BSA may be a region that includes members of a BSS. A BSA may also include members of other BSSs. For example, in Figure 2, 201 may be a BSA that includes 203, 204, and 207, where 207 may be a member of another BSS.

[0026] IBSS (Independent Basic Service Set) is a BSS that forms a self-contained network, and access to the DS is not available.

[0027] An addressable unit may be a station (STA). Physical and operational characteristics may be defined by modifiers placed before the term STA. For example, in the case of location or mobility, an addressable unit may be a fixed STA, a mobile STA, and a mobility STA. An STA is an addressable destination, but it does not (generally) have to be a fixed location. An STA may have several different characteristics, each of which may constitute its function. For example, a single addressable unit may simultaneously have the characteristics of a portable STA, a QoS STA, a dependent STA, and a hidden STA.

[0028] The architecture may consist of several components that interact to provide a WLAN that transparently supports the movement of STAs to higher layers. The BSS may be a fundamental component of the LAN. The range over which member STAs of the BSS can communicate may be considered the coverage area. The range of all possible directional transmissions by member STAs may be referred to as the BSA.

[0029] Physical limitations may determine the direct distance between STAs. An infrastructure BSS may be part of a network composed of multiple BSSs. The architectural component for interconnecting infrastructure BSSs may be a DS for non-General Link (non-GLK) operations. The DS and Extended Service Set (ESS) may be mechanisms for extending connectivity for non-GLK operations. GLK operations may involve using bridges to form an extended network. The radio medium and the DSM (Distribution System Medium) may be logically separated. Each logical medium may be used for different purposes by different components of the architecture. Recognizing that multiple media are logically different is important for understanding the flexibility of the architecture. The LAN architecture is specified independently of the physical characteristics of a particular implementation. The DS may enable support for mobile devices by providing logical services necessary for address-to-destination mapping and seamless integration of multiple BSSs. An AP is an entity with STA functionality and a DSAF (Distribution System Access Function), which may enable access to the DS via the radio medium for the associated STA. Data between the BSS and DS may travel via the DSAF within the AP. An AP may include an STA, and its STA address may be addressable on the radio medium. The address that the AP uses to communicate with the radio medium and the DSM does not necessarily have to be the same. Data sent from one of the STAs associated with the AP to the AP's STA address may always be received on an uncontrolled port and processed by a port access entity. If a controlled port is authorized, the frame may conceptually pass through the DS.

[0030] A DS Service Access Point (SAP) may be an interface between multiple DS SAP service users and a DS SAP service provider. DS SAP service users may be connected APs, meshgates, portals, and AP MLDs. A DS SAP service provider may be a DS.

[0031] DS SAP may perform some or all of the following actions: MAC service tuples are collections of MPDUs that may be delivered via DS between APs, mesh gates, ESS portals, and AP MLDs. Mapping updates may include updating the APs through which MAC service tuples delivered between STAs and DS. Mapping updates may include updating the mapping between the destination STA to which DS delivers MAC service tuples and the APs to which that STA connects. Mapping updates may include updating the mesh gates through which MAC service tuples delivered between STAs and DS. Mapping updates may include updating the mapping between the destination STA to which DS delivers MAC service tuples and the mesh gates to which that STA connects. Mapping updates may include updating the APMLDs through which MAC service tuples delivered between non-AP MLDs and DS. Mapping updates may involve updating the mapping between the non-AP MLDs to which DS delivers MAC service tuples and the AP MLDs to which those non-AP MLDs connect. The DS-STA-NOTIFY primitive may be a primitive used for mapping updates. The DS-STA-NOTIFY primitive may be generated in an AP, meshgate, or AP MLD. APs, meshgates, and AP MLDs may use the DS-STA-NOTIFY primitive to request a mapping update from DS SAP. For example, DS-STA-NOTIFY.request may be used as the DS-STA-NOTIFY primitive. Mapping updates may also be referred to as DS mapping update. a) Accept MSDUs from APs, meshgates, portals, and AP MLDs (as part of MAC service tuples).b) Distribute MSDUs to APs, meshgates, portals, or AP MLDs (as part of MAC service tuples). c) Accept mapping updates between STAs and APs from APs. d) Accept mapping updates between STAs and meshgates from meshgates. e) Accept mapping updates between non-AP MLDs and AP MLDs from AP MLDs.

[0032] When DS distributes MAC service tuples to AP, AP may decide when and how to distribute the MAC service tuples to AP's MAC via MAC SAP. When DS distributes MAC service tuples to mesh gate, mesh gate may decide when and how to distribute the MAC service tuples to mesh gate's MAC via MAC SAP. When DS distributes MAC service tuples to AP MLD through DSAF, AP MLD may decide when and how to distribute the MAC service tuples to AP MLD's MLD upper MAC sublayer via MAC SAP.

[0033] Wireless networks of any size and complexity may be constructed using DS and infrastructure BSS. This network may be referred to as an ESS (Extended Service Set). An ESS is a collection of infrastructure BSSs connected by the same SSID, which may be connected by DS. An ESS does not necessarily contain a DS. To the LLC layer, an ESS may look the same as an IBSS. STAs within an ESS can communicate, and mobile STA(s) may move transparently between BSSs to the LLC (within the same ESS). In an ESS, BSSs may partially overlap. This may be commonly used to position coverage within a physical range. In an ESS, BSSs may be physically separated. In an ESS, there may be no logical limit on the distance between BSSs. In an ESS, BSSs may be located in the same physical location. This may be done to provide redundancy. In an ESS, one or more IBSS(s) or ESS(s) may physically reside in the same location as one or more ESS(s).

[0034] Figure 3 shows an example of the device configuration of an STA according to one embodiment of this model. The STA may include an antenna unit SU1, an RF (Radio Frequency) unit SU2, a physical layer processing unit (PHY layer processing unit) SU3, a MAC layer processing unit SU4, and an upper layer packet processing unit SU5. The STA may also include a wireless transceiver unit SU6 and a frame processing unit SU7. The wireless transceiver unit SU6 may be configured to include the antenna unit SU1 and the RF unit SU2. The frame processing unit SU7 may be configured to include the physical layer processing unit SU3 and the MAC layer processing unit SU4. The RF unit SU2 receives wireless signals via the antenna unit SU1.

[0035] The signal received by the RF unit SU2 is converted into a baseband signal and sent to the physical layer processing unit SU3. The physical layer processing unit SU3 performs processing related to the physical layer function (PHY function) on the converted baseband signal. The signal that has undergone processing at the physical layer in the physical layer processing unit SU3 is sent to the MAC layer processing unit SU4. The MAC layer processing unit SU4 performs processing related to the MAC layer function (MAC function) on the baseband signal. The signal that has undergone processing at the MAC layer in the MAC layer processing unit SU4 is sent as an upper layer packet to the upper layer packet processing unit SU5. The upper layer packet processing unit SU5 performs processing related to the upper layer function on the upper layer packet extracted from the received signal.

[0036] The upper layer packet processing unit SU5 performs processing related to the functions of the upper layer when transmitting upper layer packets. The upper layer packet to be transmitted is sent from the upper layer packet processing unit SU5 to the MAC layer processing unit SU4. The MAC layer processing unit SU4 performs processing related to the functions of the MAC layer on the upper layer packet. The frame that has undergone MAC layer processing in the MAC layer processing unit SU4 (a frame generated by processing the upper layer packet) is sent to the physical layer processing unit SU3. The physical layer processing unit SU3 performs processing related to the functions of the physical layer on the frame that has undergone MAC layer processing. The frame sent from the physical layer processing unit SU3 to the RF unit SU2 is converted into an RF signal and transmitted as a wireless signal via the antenna unit SU1.

[0037] The processing of the physical layer processing unit SU3 may be controlled by a PLME (Physical Layer Management Entity), which is an entity that controls the physical layer. The processing of the MAC processing unit SU4 may be controlled by an MLME (MAC Layer Management Entity), which is an entity that controls the MAC layer. PLME and MLME provide their respective layer management service interfaces. PLME and MLME may also be controlled by an SME (Station Management Entity), which is an entity independent of the layer. PLME, MLME, and SME may be included in the frame processing unit SU7.

[0038] Figure 4 shows an example of the device configuration of an AP according to one aspect of this embodiment. The AP may have an antenna unit AU1, an RF unit AU2, a physical layer processing unit AU3, a MAC layer processing unit AU4, and a DSAF unit AU5. The DSAF unit AU5 may have a higher layer packet processing function. The AP may also have a wireless transceiver unit AU6 and a frame processing unit AU7. The wireless transceiver unit AU6 may be configured to include the antenna unit AU1 and the RF unit AU2. The frame processing unit AU7 may be configured to include the physical layer processing unit AU3 and the MAC layer processing unit AU4.

[0039] The signal received by the RF unit AU2 is converted into a baseband signal and sent to the physical layer processing unit AU3. The physical layer processing unit AU3 performs processing related to the physical layer functions on the converted baseband signal. The signal that has undergone processing at the physical layer in the physical layer processing unit AU3 is sent to the MAC layer processing unit AU4. The MAC layer processing unit AU4 performs processing related to the MAC layer functions on the baseband signal. The signal that has undergone processing at the MAC layer in the MAC layer processing unit AU4 is sent to the DSAF unit AU5 as an upper layer packet. The DSAF unit AU5 performs processing related to the upper layer functions on the upper layer packet extracted from the received signal. The DSAF unit AU5 may also provide the upper layer packet to the DS.

[0040] The DSAF unit AU5 may acquire upper-layer packets from the DS. When transmitting upper-layer packets, the DSAF unit AU5 performs processing related to the functions of the upper layer. The upper-layer packets to be transmitted from the DSAF unit AU5 are sent to the MAC layer processing unit AU4. The MAC layer processing unit AU4 performs processing related to the functions of the MAC layer on the upper-layer packets. The frame that has undergone MAC layer processing in the MAC layer processing unit AU4 (a frame generated by processing the upper-layer packets) is sent to the physical layer processing unit AU3. The physical layer processing unit AU3 performs processing related to the functions of the physical layer on the frame that has undergone MAC layer processing. The frame sent from the physical layer processing unit AU3 to the RF unit AU2 is converted into an RF signal and transmitted as a radio signal via the antenna unit AU1.

[0041] The processing of the physical layer processing unit AU3 may be controlled by PLME. The processing of the MAC processing unit AU4 may be controlled by MLME. Furthermore, PLME and MLME may be controlled by SME, which is an entity independent of the layer. PLME, MLME, and SME may be included in the frame processing unit AU7.

[0042] An MLD (Multi-Link Device) may also be a logical entity that supports multiple affiliated STAs (STAs) and can be operated using multiple affiliated STAs. An affiliated STA may be an STA that provides link-specific MLD lower MAC sublayers and physical layer (PHY) services within the MLD. In other words, an affiliated STA may be an STA belonging to an MLD. An MLD may have two STAs belonging to it. An MLD may have three or more STAs belonging to it. An affiliated STA may be either an AP or a non-AP STA. An AP MLD (Access Point Multi-Link Device) may be an MLD in which each of the STAs belonging to it is an AP. A non-AP MLD (non-Access Point Multi-Link Device) may be an MLD in which each of the STAs belonging to it is a non-AP STA. An MLO (Multi-Link Operation) may be an operation between two MLDs.

[0043] In MLD, the MAC layer may be divided into an MLD upper MAC sublayer and an MLD lower MAC entity. The MLD upper MAC sublayer may perform functions common to all links. The MLD lower MAC entity may be shared between the MLD and the APs or non-AP STAs belonging to that MLD. The MLD lower MAC entity may perform functions local to each link. Some functions may require joint processing by both the MLD upper MAC sublayer and the MLD lower MAC entity.

[0044] A Super MLD (Super Multi-Link Device) may be defined. A Super MLD may be a logical entity that supports multiple affiliated MLDs and can be operated using multiple affiliated MLDs. An affiliated MLD may be an MLD that provides MLD-specific MAC sublayers and / or physical layer (PHY) services within a Super MLD. In other words, an affiliated MLD may be an MLD belonging to a Super MLD. A Super MLD may have two MLDs belonging to it. A Super MLD may have three or more MLDs belonging to it. A Super MLD may be referred to by names other than SuperMLD. For example, a Super MLD may be referred to as Single Mobility Domain (SMD), Seamless Mobility Domain (SMD), Single Mobility Domain (SMD) MLD, Seamless Mobility Domain (SMD) MLD, non-colocated MLD, virtual MLD, or roming MLD, etc. An affiliated MLD may be referred to by names other than affiliated MLD. An MLD may include a Super MLD. In other words, an MLD may be a Super MLD. Furthermore, an MLD that is not a Super MLD may be called a Normal MLD. Each MLD belonging to a Super MLD may also be an AP MLD. Each MLD belonging to a Super MLD may also be a non-AP MLD. In addition to MLDs, STAs may belong to a Super MLD. In addition to MLDs, APs may belong to a Super MLD. A Super MLD may be an AP MLD. A Super MLD may be a non-AP MLD. A Super MLD that is an AP MLD may be called a Super AP MLD. A Super AP MLD may be called by a name other than Super AP MLD.For example, Super AP MLD may be referred to as Single Mobility Domain (SMD) AP MLD, Seamless Mobility Domain (SMD) AP MLD, non - colocated AP MLD, virtual AP MLD, or roaming AP MLD, etc.

[0045] The MAC layer of Super MLD does not necessarily need to be divided into two or more MAC sub - layers or MAC entities. The MAC layer of Super MLD may be referred to as Super MLD MAC entity, etc. The Super MLD MAC entity may be referred to by other names outside the Super MLD MAC entity. The Super MLD MAC entity may execute functions common to all MLDs. The Super MLD MAC entity may execute functions common to all MLDs belonging to the Super MLD. The upper - layer MLD MAC sub - layer may be shared between the Super MLD and the AP MLDs belonging to that Super MLD. The upper - layer MLD MAC sub - layer may execute functions local to each MLD. The upper - layer MLD MAC sub - layer may execute functions local to each MLD belonging to the Super MLD. Some functions may require joint processing by both the Super MLD MAC entity and the upper - layer MLD MAC sub - layer.

[0046] In Super MLD, the MAC layer may be divided into a Super MLD upper MAC sublayer and a Super MLD lower MAC entity. The Super MLD upper MAC sublayer may be referred to by a name other than the Super MLD upper MAC sublayer. The Super MLD lower MAC entity may be referred to by a name other than the Super MLD lower MAC entity. The Super MLD upper MAC sublayer may perform functions common to all MLDs. The Super MLD upper MAC sublayer may perform functions common to all MLDs belonging to Super MLD. The Super MLD lower MAC entity may be shared between Super MLD and the APMLDs belonging to Super MLD. The Super MLD lower MAC entity may perform functions local to each MLD. The Super MLD lower MAC entity may perform some or all of the functions performed by the MLD lower MAC entity. In addition to or instead of the above, a Super MLD lower MAC entity may perform some or all of the functions performed by the MLD upper MAC sublayer. A Super MLD lower MAC entity may also be an MLD lower MAC entity. Alternatively, a Super MLD lower MAC entity may be split into an MLD upper MAC sublayer and an MLD lower MAC entity. Some functions may require joint processing by both the Super MLD upper MAC sublayer and the Super MLD lower MAC entity.

[0047] The MLD upper MAC sublayer may be common to two or more AP MLDs. The MLD upper MAC sublayer common to two or more AP MLDs may be called the MLD common MAC sublayer, or the MLD common upper MAC sublayer, etc. The MLD common MAC sublayer may be referred to by names other than MLD common MAC sublayer. The MLD common MAC sublayer may perform functions common to all MLDs. The MLD common MAC sublayer may perform functions common to all MLDs belonging to the same Super MLD. Alternatively, the MAC layer of an AP MLD may be divided into the MLD common MAC sublayer, the MLD upper MAC sublayer, and the MLD lower MAC entities. Some functions may require joint processing of both the MLD common MAC sublayer and the MLD lower MAC entities. Some functions may require joint processing of both the MLD common MAC sublayer and the Super MLD lower MAC entities. Some functions may require joint processing of both the MLD common MAC sublayer and the MLD upper MAC sublayer. Some functions may require the collaborative processing of three or more MAC sublayers or MAC entities, such as the MLD common MAC sublayer, the MLD upper MAC sublayer, and the MLD lower MAC entities.

[0048] HT STA (High-Throughput STA) may provide PHY and MAC functions that can support throughput of 100 Mb / s or more measured at the MAC data service access point (SAP). The HT STA may be a QoS STA. The HT feature may be utilized in an HT STA associated with an HT AP (High-Throughput AP). A subset of the HT feature may be used between two HT STAs that are members of the same IBSS. Some PHY functions that distinguish an HT STA from a non-HT STA (non-HT STA) may be multiple-input multiple-output (MIMO) operation, spatial multiplexing (SM), space mapping (including transmit beamforming), space-time block coding (STBC), low-density parity-check (LDPC) coding, and antenna selection (ASEL). The PPDU formats permitted in an HT STA may be a non-HT format, an HT-mixed format, and an HT-greenfield format. In an HT STA, the PPDU may be transmitted with a 20 MHz bandwidth. In an HT STA, the PPDU may be transmitted with a 40 MHz bandwidth. The HT STA may have MAC functions including frame aggregation, some block ack features, power-saving multipole (PSMP) operation, reverse direction (RD), and a protection mechanism that supports coexistence with non-HT STAs.

[0049] A VHT STA (Very High-Throughput STA) may be an HT STA that supports VHT functions in addition to the functions supported by an HT STA. The main PHY functions of a VHT STA may support 40MHz and 80MHz channel widths. VHT single-user (SU) PPDUs may be supported as a main PHY function of a VHT STA. 160MHz and 80+80MHz channel widths may be supported as a main PHY function of a VHT STA. VHT multi-user (MU) PPDUs may be supported as a main PHY function of a VHT STA. The main PHY functions of a VHT STA do not necessarily have to be present in an HT STA. A-MPDU padding of VHT PPDUs may be supported as a main MAC function of a VHT STA. S-MPDU may be supported as a main MAC function of a VHT STA. Bandwidth indication response may be supported as a main MAC function of a VHT STA. The main MAC functions of a VHT STA do not necessarily have to be present in an HT STA. The VHT functionality may be used in VHT STAs associated with a VHT AP (Very High-Throughput AP). A subset of the VHT functionality may be used between two VHT STAs that are members of the same IBSS.

[0050] The operating channel width may also be the channel width that the STA can currently receive.

[0051] A High Efficiency (HE) STA may also be a VHT STA if operating in the 5GHz band. A 20MHz-only HE STA may not support 40MHz and 80MHz channel widths. Support for a 20MHz operating channel width may be mandatory for HE STAs. A 20MHz-only non-AP HE STA may be required to support 40MHz and 80MHz operating channel widths. Support for 160MHz and 80+80MHz operating channel widths may be optional for HE STAs. A HE STA may also be an HT STA. The main PHY features of an HE STA that are not present in HT STAs or VHT STAs may include support for DL ​​and UL OFDMA (Up Link Orthogonal Frequency Division Multiple Access). The main PHY features of an HE STA that are not present in HT STAs or VHT STAs may include support for DL ​​MU-MIMO (Down Link Multi User Multiple Input Multiple Output) with an HE AP supporting four or more spatial streams when MU-MIMO (Multi User Multiple Input Multiple Output) is performed across the entire PPDU bandwidth. The main PHY function of HE STA that is not present in HT STA or VHT STA may be support for DL ​​MU-MIMO reception in non-AP HE STA. The main MAC function of HE STA that is not present in HT STA or VHT STA may be support for the AP's OMI (Operating Mode Indication) responder and OMI initiator. The main MAC function of HE STA that is not present in HT STA or VHT STA may be support for the AP's individual TWT (Target Wake Time).One of the main MAC features of HE STA that is not present in HT STA or VHT STA may be support for two NAV operation in non-AP STA.

[0052] An EHT (Extreme High Throughput) STA may operate in a bandwidth between 1 GHz and 7.250 GHz. For example, an EHT STA may be an HE STA at 5 GHz and 6 GHz. For example, an EHT STA may be an HE STA at 2.4 GHz. An EHT STA may use an operation element for HT and / or VHT and / or HE STA. A key PHY function of an EHT STA that is not present in HT STA, VHT STA, or HE STA may be support for MRU (Multiple Resource Unit). A key PHY function of an EHT STA that is not present in HT STA, VHT STA, or HE STA may be support for any type of preamble puncturing in non-OFDMA, which is required for MRU (Multiple Resource Unit) support in non-OFDMA. A key MAC function of an EHT STA that is not present in HT STA, VHT STA, or HE STA may be support for MLO in the case of an EHT AP. The main MAC function of EHT STA that is not present in HT STA, VHT STA, or HE STA may, in the case of MLD, be support for the ML (Multi-Link) discovery procedure. The main MAC function of EHT STA that is not present in HT STA, VHT STA, or HE STA may, in the case of MLD, be support for the ML (re)setup procedure. The main MAC function of EHT STA that is not present in HT STA, VHT STA, or HE STA may, in the case of MLD, be support for the ML BlockAck procedure. The main MAC function of EHT STA that is not present in HT STA, VHT STA, or HE STA may, in the case of MLD, be support for MLD level sequence number spaces. The main MAC function of EHT STA that is not present in HT STA, VHT STA, or HE STA may, in the case of MLD, be support for MLD level packet number space.The main MAC function of EHT STA, which is not present in HT STA, VHT STA, or HE STA, may be support for ML reconfiguration procedures in the case of MLD.

[0053] A UHR (Ultra High Reliability) STA may operate in a bandwidth between 1 GHz and 7.250 GHz. For example, a UHR STA may be an EHT STA at 5 GHz and 6 GHz. For example, a UHR STA may be an HE STA at 5 GHz and 6 GHz. For example, a UHR STA may be a VHT STA at 5 GHz and 6 GHz. For example, a UHR STA may be an HE STA at 2.4 GHz. For example, a UHR STA may be an HT STA at 2.4 GHz. A UHR STA may support Super MLD. A UHR STA may support Seamless Roaming. A UHR STA may use operation elements for HT, and / or VHT, and / or HE STA, and / or UHR STA. That is, a UHR STA may be controlled by an HT operation element, and / or a VHT operation element, and / or an HE operation element, and / or an EHT operation element, and / or a UHR operation element.

[0054] APs and STAs within a BSS may transmit based on CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance). The CSMA / CA protocol may be a protocol designed to reduce the probability of collisions at the point in time when collisions between multiple STAs accessing the medium are most likely to occur.

[0055] An HT BSS may be a BSS in which the Beacon frame transmitted by the HT STA includes an HT Capabilities element. A VHT BSS may be a BSS in which the Beacon frame transmitted by the VHT STA includes a VHT Operation element. A HE BSS may be a BSS in which the Beacon frame transmitted by the HE STA includes an HE Operation element. An EHT BSS may be a BSS in which the Beacon frame transmitted by the HE STA includes an EHT Operation element. For example, an HT BSS may consist of an STA that supports the capabilities of the HT STA. For example, a VHT BSS may consist of an STA that supports the capabilities of the VHT STA. For example, a HE BSS may consist of an STA that supports the capabilities of the HE. For example, an EHT BSS may consist of an STA that supports the capabilities of the EHT. For example, a UHR BSS may consist of an STA that supports the capabilities of the UHR.

[0056] In this embodiment, STA may be, for example, HT STA, VHT STA, HE STA, EHT STA, or UHR STA. STA may also be any STA other than those described above.

[0057] APs and STAs may transmit frames of multiple frame types that share a common frame format. Frames may be defined at the physical layer, MAC layer, and Logical Link Control (LLC) layer, respectively.

[0058] A MAC frame may be a unit of data exchanged between MAC entities. A synonym for MAC frame may be MPDU. An MPDU (MAC Protocol Data Unit) may be a unit of data exchanged between two peer MAC entities using physical layer (PHY) data services. A synonym for MPDU may be MAC frame. An MSDU (MAC Service Data Unit) may be information delivered as a single unit between MAC service access points (SAPs). In an STA, a MAC frame may be processed by the MAC layer processing unit SU4. In an STA, a MAC frame may be processed by the frame processing unit SU7. In an AP, a MAC frame may be processed by the MAC layer processing unit AU4. In an AP, a MAC frame may be processed by the frame processing unit AU7.

[0059] A PHY frame may be a unit of data exchanged between PHY entities. A synonym for PHY frame may be PPDU. A PPDU (PHY Protocol Data Unit) may be a unit of data exchanged between two peer PHY entities using physical layer (PHY) data services. A synonym for PPDU may be PHY frame. In the STA, a PHY frame may be processed by the physical layer processing unit SU4. In the STA, a PHY frame may be processed by the frame processing unit SU7. In the AP, a PHY frame may be processed by the physical layer processing unit AU4. In the AP, a PHY frame may be processed by the frame processing unit AU7.

[0060] The MAC frame format may consist of a MAC header, a Frame body, and an FCS. The MAC frame format may also consist of a set of fields that occur in a fixed order in all frames.

[0061] The MAC header may consist of a Frame Control field, a Duration / ID field, an Address 1 field, an Address 2 field, an Address 3 field, a Sequence Control field, an Address 4 field, a QoS Control field, an HT Control field, etc. The MAC header may consist of all of the aforementioned fields. The MAC header may consist of some of the aforementioned fields.

[0062] Figure 5 shows an example of a MAC frame format according to one aspect of this embodiment. In Figure 5, the MAC frame format may consist of a MAC header, a Frame Body, and an FCS. In Figure 5, the MAC header may consist of a Frame Control field, a Duration field, an Address 1 field, an Address 2 field, an Address 3 field, a Sequence Control field, an Address 4 field, and a QoS Control field. The MAC frame format may also be an MPDU.

[0063] The MAC header's Frame Control field may consist of subfields such as Protocol Version, Type, Subtype, To DS, From DS, More Fragments, Retry, Power Management, More data, Protected Frame, +HTC, Control Frame Extension, Compressed SSID Present, ANO Present, BSS BW, Security, AP PM, etc. The MAC header's Frame Control field may consist of some of the aforementioned subfields. The MAC header's Frame Control field may consist of all of the aforementioned subfields. The MAC header's Frame Control field may consist of a specific combination of subfields depending on the frame type.

[0064] The frame type may be indicated in the Type subfield contained in the Frame Control field of the MAC header. Control frame, Management frame, and Data frame may be defined as frame types. The Type subfield may indicate any of these three. For example, the Type subfield may be a two-bit subfield. If the Type subfield is set to 00, the frame type may be a Management frame. If the Type subfield is set to 01, the frame type may be a Control frame. If the Type subfield is set to 10, the frame type may be a Data frame.

[0065] A Management frame may be a frame for managing the connection status between devices. A Control frame may be a frame for managing the communication status between devices. A Data frame may be a frame containing the actual data to be transmitted.

[0066] The Subtype subfield in the Frame Control field of the MAC header may indicate the frame's subtype. Possible subtypes of the frame include Association Request, Association Response, Reassociation Request, Reassociation Response, Probe Request, Probe Response, Beacon, ATIM, Disassociation, Authentication, Deauthentication, Action, Block Ack Request, Block Ack, PS-Poll, RTS, CTS, Ack, CF-End, Data, QoS Data, etc. Other subtypes may also be defined.

[0067] The frame subtype may be determined from the Type subfield and Subtype subfield contained in the Frame Control field of the MAC header. The Subtype subfield may be a 4-bit subfield. If the Type subfield is set to 00, the Type subfield may indicate a Management frame. If the Type subfield is set to 01, the Type subfield may indicate a Control frame. If the Type subfield is set to 10, the Type subfield may indicate a Data frame.

[0068] For example, if the Type subfield indicates Management frame and the Subtype subfield is set to 0000, the subtype may be Association Request. If the Type subfield indicates Management frame and the Subtype subfield is set to 0001, the subtype may be Association Response. If the Type subfield indicates Management frame and the Subtype subfield is set to 0010, the subtype may be Reassociation Request. If the Type subfield indicates Management frame and the Subtype subfield is set to 0011, the subtype may be Reassociation Response. If the Type subfield indicates Management frame and the Subtype subfield is set to 0100, the subtype may be Probe Request. If the Type subfield indicates Management frame and the Subtype subfield is set to 0101, the subtype may be Probe Response. If the Type subfield indicates Management frame and the Subtype subfield is set to 1000, the subtype may be Beacon.

[0069] A Beacon frame may contain information such as the Beacon's period and SSID. A Beacon frame may be a frame that is periodically sent to the STA in the BSS. An Association Response frame may contain information such as the Status code. An Association Response frame may be a frame sent in response to a received Association Request frame. A Reassociation Response frame may contain information such as the Status code. A Reassociation Response frame may be a frame sent in response to a received Reassociation Request frame. A Probe Response frame may contain information such as the Beacon's period and SSID. A Probe Response frame may be a frame sent in response to a received Probe Request frame.

[0070] For example, if the Type subfield indicates Control frame and the Subtype subfield is set to 1011, the subtype may be RTS. If the Type subfield indicates Control frame and the Subtype subfield is set to 1100, the subtype may be CTS. If the Type subfield indicates Control frame and the Subtype subfield is set to 1101, the subtype may be Ack.

[0071] For example, if the Type subfield indicates Data frame and the Subtype subfield is set to 0000, then subtype may be Data. If the Type subfield indicates Data frame and the Subtype subfield is set to 1000, then subtype may be QoS Data.

[0072] The Frame body field of a MAC frame format may consist of fields and elements defined for each subtype of management frame. Fields and elements are displayed in a specified relative order, and non-existent fields or elements may be skipped. If the STA encounters an element ID that it does not recognize in the frame body of a received management frame, it ignores that element and continues to parse the rest of the management frame body (if any) in search of additional elements with recognizable element IDs. In other words, the frame body of a management frame may contain one or more elements.

[0073] The element format of each element included in the Frame body may be defined in the Element ID field, Length field, Element ID Extension field, information field, etc. The Information field may contain information specific to the element. For example, if Element ID is 61, it may indicate an element for HT Operation. For example, if Element ID is 191, it may indicate an element for VHT Capabilities. For example, if Element ID is 192, it may indicate an element for VHT Operation. For example, if Element ID is 255, it may indicate an element for HE Capabilities. For example, if Element ID is 255, it may indicate an element for HE Operation.

[0074] The Capabilities element may contain information indicating the capabilities supported by STA. The Capabilities element may consist of multiple fields.

[0075] The HT Capabilities element may be defined by the Element ID field, Length field, HT Capability Information field, A-MPDU Parameters field, Supported MCS Set field, HT Extended Capabilities field, Transmit Beamforming Capabilities field, and ASEL Capabilities field. The HT Capability Information field may consist of the LDPC Coding Capability subfield, Supported Channel Width Set subfield, SM Power Save subfield, etc. The HT Extended Capabilities field may consist of the MCS Feedback subfield, +HTC-HT Support subfield, etc. The capabilities supported by the HT STA may be indicated by the HT Capabilities element. In other words, the HT Capabilities element may be a Capabilities element that indicates the capabilities supported by the HT STA.

[0076] An HT Capabilities element may be sent in a Management frame. An HT Capabilities element may be sent in a Control frame. An HT Capabilities element may be sent in a Data frame. For example, an HT Capabilities element may be sent in a Beacon frame. For example, an HT Capabilities element may be sent in an Association Request frame. For example, an HT Capabilities element may be sent in an Association Response frame. For example, an HT Capabilities element may be sent in a Reassociation Request frame. For example, an HT Capabilities element may be sent in a Reassociation Response frame. For example, an HT Capabilities element may be sent in a Probe Request frame. For example, an HT Capabilities element may be sent in a Probe Response frame.

[0077] A VHT Capabilities element may be defined by an Element ID field, a Length field, a VHT Capabilities Information field, and a Supported VHT-MCS and NSS Set field. The VHT Capabilities Information field may consist of subfields such as Maximum MPDU Length, Supported Channel Width Set, and Rx LDPC. The capabilities supported by VHT STA may be indicated by the VHT Capabilities element. In other words, a VHT Capabilities element may be a Capabilities element that indicates the capabilities supported by VHT STA.

[0078] A VHT Capabilities element may be sent in a Management frame. A VHT Capabilities element may be sent in a Control frame. A VHT Capabilities element may be sent in a Data frame. For example, a VHT Capabilities element may be sent in a Beacon frame. For example, a VHT Capabilities element may be sent in an Association Request frame. For example, a VHT Capabilities element may be sent in an Association Response frame. For example, a VHT Capabilities element may be sent in a Reassociation Request frame. For example, a VHT Capabilities element may be sent in a Reassociation Response frame. For example, a VHT Capabilities element may be sent in a Probe Request frame. For example, a VHT Capabilities element may be sent in a Probe Response frame.

[0079] The HE Capabilities element may be defined by the Element ID field, Length field, Element ID Extension field, HE MAC Capabilities Information field, HE PHY Capabilities Information field, Supported HE-MCS and NSS Set field, and PPE Thresholds field. The HE MAC Capabilities Information field may consist of subfields such as +HTCHE, TWT Requester, and TWT Responder. The HE PHY Capabilities Information field may consist of subfields such as Supported ChannelWidth Set, Punctured Preamble Rx, and Device Class. Capabilities supported by HE STA may be indicated by the HE Capabilities element. In other words, the HE Capabilities element may be a Capabilities element that indicates the capabilities supported by HE STA.

[0080] The HE Capabilities element may be sent in a Management frame. The HE Capabilities element may be sent in a Control frame. The HE Capabilities element may be sent in a Data frame. For example, the HE Capabilities element may be sent in a Beacon frame. For example, the HE Capabilities element may be sent in an Association Request frame. For example, the HE Capabilities element may be sent in an Association Response frame. For example, the HE Capabilities element may be sent in a Reassociation Request frame. For example, the HE Capabilities element may be sent in a Reassociation Response frame. For example, the HE Capabilities element may be sent in a Probe Request frame. For example, the HE Capabilities element may be sent in a Probe Response frame.

[0081] The EHT Capabilities element may be defined by the Element ID field, Length field, Element ID Extension field, EHT MAC Capabilities Information field, EHT PHY Capabilities Information field, Supported EHT-MCS And NSS Set field, and EHT PPE Thresholds field. The EHT MAC Capabilities Information field may consist of subfields such as EPCS Priority Access Support, EHT OM Control Support, TXS Mode 1 Support, and TXS Mode 2 Support. The EHT PHY Capabilities Information field may consist of subfields such as Support For 320 MHz In 6 GHz, Support For 242-tone RU In BW Wider Than 20 MHz, and Partial Bandwidth UL MU-MIMO. Capabilities supported by the EHT STA may be indicated by the EHT Capabilities element. In other words, the EHT Capabilities element may be a Capabilities element that indicates the capabilities supported by the EHT STA.

[0082] An EHT Capabilities element may be sent in a Management frame. An EHT Capabilities element may be sent in a Control frame. An EHT Capabilities element may be sent in a Data frame. For example, an EHT Capabilities element may be sent in a Beacon frame. For example, an EHT Capabilities element may be sent in an Association Request frame. For example, an EHT Capabilities element may be sent in an Association Response frame. For example, an EHT Capabilities element may be sent in a Reassociation Request frame. For example, an EHT Capabilities element may be sent in a Reassociation Response frame. For example, an EHT Capabilities element may be sent in a Probe Request frame. For example, an EHT Capabilities element may be sent in a Probe Response frame.

[0083] The UHR Capabilities element may be defined by some or all of the following fields: Element ID field, Length field, Element ID Extension field, UHR MAC Capabilities Information field, UHR PHY Capabilities Information field, Supported UHR-MCS And NSS Set field, UHR PPE Thresholds field, and / or other fields. The UHR MAC Capabilities Information field may consist of some or all of the following subfields: UHR Link ReconfigurationSupport subfield, UHR Link Reconfiguration Mode 2 Support subfield, etc. Capabilities supported by UHR STA may be indicated by the UHR Capabilities element. In other words, the UHR Capabilities element may be a Capabilities element that indicates the capabilities supported by UHR STA. The UHR Capabilities element may be referred to by something other than the UHR Capabilities element. Similarly, UHR MAC Capabilities Information may be referred to by something other than UHR MAC Capabilities Information.

[0084] A UHR Capabilities element may be sent in a Management frame. A UHR Capabilities element may be sent in a Control frame. A UHR Capabilities element may be sent in a Data frame. For example, a UHR Capabilities element may be sent in a Beacon frame. For example, a UHR Capabilities element may be sent in an Association Request frame. For example, a UHR Capabilities element may be sent in an Association Response frame. For example, a UHR Capabilities element may be sent in a Reassociation Request frame. For example, a UHR Capabilities element may be sent in a Reassociation Response frame. For example, a UHR Capabilities element may be sent in a Probe Request frame. For example, a UHR Capabilities element may be sent in a Probe Response frame.

[0085] The UHR Link Reconfiguration Support subfield may also be a subfield indicating support for UHR Link Reconfiguration. That is, the UHR Link Reconfiguration Support subfield may be a subfield indicating whether or not the UHR STA supports UHR Link Reconfiguration. The UHR Link Reconfiguration Support subfield may be set to a first value if the UHR STA supports UHR Link Reconfiguration Mode 1, as described below. For example, the UHR Link Reconfiguration Support subfield may be set to 1 if the UHR STA supports UHR Link Reconfiguration Mode 1. The UHR Link Reconfiguration Support subfield may be set to a second value different from the first value if the UHR STA supports UHR Link Reconfiguration Mode 2, as described below. For example, the UHR Link Reconfiguration Support subfield may be set to 2 if the UHR STA supports UHR Link Reconfiguration Mode 2. The UHR Link Reconfiguration Support subfield may be set to a third value different from the first and second values ​​if the UHR STA supports both UHR Link Reconfiguration Mode 1 and UHR Link Reconfiguration Mode 2, as described below. For example, the UHR Link ReconfigurationSupport subfield may be set to 3 if the UHR STA supports both UHR Link Reconfiguration Mode 1 and UHR Link Reconfiguration Mode 2.For example, the UHRLink Reconfiguration Support subfield may be set to 0 if the UHR STA does not support UHR Link Reconfiguration. The UHR Link Reconfiguration Support subfield may be named in a different way. "UHR STA" may be rephrased as "non-AP MLD" or "non-AP STA belonging to a non-AP MLD".

[0086] The UHR Link Reconfiguration Mode 2 Support subfield may also be a subfield indicating support for UHR Link Reconfiguration Mode 2, as described below. That is, the UHR Link Reconfiguration Mode 2 Support subfield may also be a subfield indicating whether or not the UHR STA supports UHR Link Reconfiguration Mode 2. For example, the UHR Link Reconfiguration Mode 2 Support subfield may be set to 1 if the UHR STA supports UHR Link Reconfiguration Mode 2. For example, the UHR Link Reconfiguration Mode 2 Support subfield may be set to 0 if the UHR STA does not support UHR Link Reconfiguration Mode 2. For example, both the UHR Link Reconfiguration Support subfield and the UHR Link Reconfiguration Mode 2 Support subfield may be set to 1 if the UHR STA supports both UHR Link Reconfiguration Mode 1 and UHR Link Reconfiguration Mode 2. "UHR STA" can also be rephrased as "non-AP MLD" or "non-AP STA belonging to non-AP MLD".

[0087] The UHR Link Reconfiguration Support subfield may be sent in the Management frame. The UHR Link Reconfiguration Support subfield may be sent in the Control frame. The UHR Link Reconfiguration Support subfield may be sent in the Data frame. For example, the UHR Link Reconfiguration Support subfield may be sent in the Beacon frame. For example, the UHR Link Reconfiguration Support subfield may be sent in the Association Request frame. For example, the UHR Link Reconfiguration Support subfield may be sent in the Association Response frame. For example, the UHR Link Reconfiguration Support subfield may be sent in the Reassociation Request frame. For example, the UHR Link Reconfiguration Support subfield may be sent in the Reassociation Response frame. For example, the UHR Link Reconfiguration Support subfield may be sent in the Probe Request frame. For example, the UHR Link Reconfiguration Support subfield may be sent in the Probe Response frame.

[0088] The UHR Link Reconfiguration Mode 2 Support subfield may be sent in a Management frame. The UHR Link Reconfiguration Mode 2 Support subfield may be sent in a Control frame. The UHR Link Reconfiguration Mode 2 Support subfield may be sent in a Data frame. For example, the UHR Link Reconfiguration Mode 2 Support subfield may be sent in a Beacon frame. For example, the UHR Link Reconfiguration Mode 2 Support subfield may be sent in an Association Request frame. For example, the UHR Link Reconfiguration Mode 2 Support subfield may be sent in an Association Response frame. For example, the UHR Link Reconfiguration Mode 2 Support subfield may be sent in a Reassociation Request frame. For example, the UHR Link Reconfiguration Mode 2 Support subfield may be sent in a Reassociation Response frame. For example, the UHR Link Reconfiguration Mode 2 Support subfield may be sent in a Probe Request frame. For example, the UHR Link Reconfiguration Mode2 Support subfield may be sent in the Probe Response frame.

[0089] UHR Link Reconfiguration Mode 1 may be a mode of UHR Link Reconfiguration in which a non-AP STA belonging to a non-AP MLD sends a frame (UHR Link ReconfigurationRequest Frame, described below) to request the addition of a link to a target AP MLD, stops sending data frames to APs belonging to the current AP MLD until it receives a response frame (UHR Link Reconfiguration Response Frame, described below) to the request to add a link to the target AP MLD, and starts sending data frames to APs belonging to the target AP MLD when it receives the response frame to the request to add a link to the target AP MLD. In other words, if a non-AP STA belonging to a non-AP MLD supports UHR Link Reconfiguration Mode 1, it may send a UHR Link Reconfiguration Request Frame, stop sending data frames to APs belonging to the current AP MLD until it receives a UHR Link Reconfiguration Response Frame, and start sending data frames to APs belonging to the target AP MLD when it receives the UHR Link Reconfiguration Response Frame.UHR Link Reconfiguration Mode 2 may be a mode of UHR Link Reconfiguration in which a non-AP STA belonging to a non-AP MLD sends a frame (UHR Link Reconfiguration Request Frame, described below) to request the addition of a link to a target AP MLD, and continues sending data frames to APs belonging to the current AP MLD until it receives a response frame (UHR Link Reconfiguration Response Frame, described below) to the request to add a link to the target AP MLD, and then starts sending data frames to APs belonging to the target AP MLD when it receives the response frame to the request to add a link to the target AP MLD. In other words, if a non-AP STA belonging to a non-AP MLD supports UHR Link Reconfiguration Mode 2, it may send a UHR Link Reconfiguration Request Frame, and continue sending data frames to APs belonging to the current AP MLD until it receives a UHR Link Reconfiguration Response Frame, and then start sending data frames to APs belonging to the target AP MLD when it receives the UHR Link Reconfiguration Response Frame. If a non-AP STA belonging to a non-AP MLD does not support UHR Link Reconfiguration Mode 2, it may stop sending data frames to APs belonging to the current AP MLD when sending a UHR Link Reconfiguration Request Frame until it receives a UHR Link Reconfiguration Response Frame, and then start sending data frames to APs belonging to the target AP MLD when it receives a UHR Link Reconfiguration Response Frame.AP MLDs and / or APs belonging to AP MLDs may support both UHR Link Reconfiguration Mode 1 and UHR Link Reconfiguration Mode 2. For example, AP MLDs and / or APs belonging to AP MLDs may set the UHR Link Reconfiguration Support subfield to 3. "Data frame" may be rephrased as "MSDU", "A-MSDU", or "PPDU", etc. "Without stopping the transmission of Data frames" may be rephrased as "Continue transmitting Data frames", "Persistently transmit Data frames", etc. "Non-AP STA belonging to a non-AP MLD" and "AP belonging to an AP MLD" may be rephrased as "non-AP MLD" and "AP MLD", respectively.

[0090] An Operation element may be information for controlling the operation of STA within BSS. An Operation element may consist of multiple fields.

[0091] An HT Operation element may be defined by the Element ID field, Length field, Primary Channel field, HT Operation information field, and Basic HT-MCS Set field. The Primary Channel field may indicate the channel number of the primary channel. The HT Operation information field may consist of fields such as Secondary Channel Offset field and STA Channel Width field. The Secondary Channel Offset field may indicate the offset of the secondary channel relative to the primary channel. If the Secondary Channel Offset field is set to 1, the secondary channel may be located above the primary channel. If the Secondary Channel Offset field is set to 3, the secondary channel may be located below the primary channel. If the Secondary Channel Offset field is set to 0, the secondary channel may not exist. The STA Channel Width field may define the channel width that the STA can use for transmission. The STA Channel Width field may be set to 0 for 20MHz. The STA Channel Width field may be set to 1 to allow the use of any channel within the supported channel width set. The operation of HT STA(s) in the BSS may be controlled by the HT Operation element. In other words, the HT Operation element may be an operation element that controls the operation of the HT STA within the BSS.

[0092] An HT operation element may be sent in a Management frame. An HT operation element may be sent in a Control frame. An HT operation element may be sent in a Data frame. For example, an HT operation element may be sent in a Beacon frame. For example, an HT operation element may be sent in an Association Response frame. For example, an HT operation element may be sent in a Reassociation Response frame. For example, an HT operation element may be sent in a Probe Response frame.

[0093] A VHT Operation element may be defined by an Element ID field, a Length field, a VHT Operation Information field, and a Basic VHT-MCS And NSS Set field. The VHT Operation Information field may consist of a Channel Width field, a Channel Center Frequency Segment 0 field, and a Channel Center Frequency Segment 1 field. The operation of VHT STA(s) within the BSS may be controlled by an HT Operation element and a VHT Operation element. In other words, a VHT Operation element may be an operation element that controls the operation of VHT STA within the BSS.

[0094] A VHT operation element may be sent in a Management frame. A VHT operation element may be sent in a Control frame. A VHT operation element may be sent in a Data frame. For example, a VHT operation element may be sent in a Beacon frame. For example, a VHT operation element may be sent in an Association Response frame. For example, a VHT operation element may be sent in a Reassociation Response frame. For example, a VHT operation element may be sent in a Probe Response frame.

[0095] The Channel Width field in the VHT Operation information field, along with the STA channel width field in the HT operation element, may define the BSS bandwidth. The Channel Width field may be set to 0 for a 20MHz or 40MHz BSS bandwidth. The Channel Width field may be set to 1 for an 80MHz, 160MHz, or 80+80MHz BSS bandwidth. The Channel Width field may be set to 2 for a 160MHz BSS bandwidth. The Channel Width field may be set to 3 for an 80+80MHz BSS bandwidth. Values ​​in the Channel Width field ranging from 4 to 255 may be reserved.

[0096] The Channel Center Frequency Segment 0 field within the VHT Operation information field may define the channelcenter frequency for VHT BSS of 20MHz, 40MHz, 80MHz, 160MHz, or 80+80MHz. For BSS bandwidths of 20MHz, 40MHz, or 80MHz, the Channel Center Frequency Segment 0 field may indicate the channel center frequency index for the 20MHz, 40MHz, or 80MHz channel on which the VHT BSS operates. For a 160MHz BSS bandwidth and a Channel Width subfield of 1, the Channel Center Frequency Segment 0 field may indicate the channel center frequency index for the 80MHz channel segment containing the primary channel. For a 160MHz BSS bandwidth and a Channel Width subfield of 2, the Channel Center Frequency Segment 0 field may indicate the channel center frequency index for the 160MHz channel on which the VHT BSS operates. The Channel Center Frequency Segment0 field may indicate the channel center frequency index of the primary 80MHz channel of the VHT BSS when the BSS bandwidth is 80 + 80MHz and the Channel Width subfield is 1 or 3.

[0097] The Channel Center Frequency Segment 1 field in the VHT Operation information field may define the channel center frequency for a 160MHz or 80+80MHz VHT BSS. The Channel Center Frequency Segment 1 field may be set to 0 for a BSS bandwidth of 20MHz, 40MHz, or 80MHz. The Channel Center Frequency Segment 1 field may indicate the channel center frequency index of the 160MHz channel on which the VHTBSS operates when the BSS bandwidth is 160MHz and the Channel Width subfield is 1. The Channel Center Frequency Segment 1 field may be set to 0 when the BSS bandwidth is 160MHz and the Channel Width subfield is 2. The Channel Center Frequency Segment 1 field may indicate the channel center frequency index of the Secondary 80MHz channel of the VHT BSS when the BSS bandwidth is 80+80MHz and the Channel Width subfield is 1 or 3.

[0098] The HE Operation element format may consist of fields such as Element ID, Length, ElementID Extension, HE Operation Parameter, BSS Color Information, Basic HE-MCS And NSS Set, VHT Operation Information, Max Co-Hosted BSSID Indicator, and 6GHz Operation Information. When operating in the 2.4GHz band, the HE STA in the HE BSS may be controlled by the HT Operation element and the HE Operation element. When operating in the 5GHz band, the HE STA in the HE BSS may be controlled by the HT Operation element, the VHT Operation element (if present), and the HE Operation element. When operating in the 6GHz band, the HE STA in the HE BSS may be controlled by the HE Operation element. In other words, the HE Operation element may be an operation element that controls the operation of the HE STA in the BSS.

[0099] HE operation elements may be sent in a Management frame. HE operation elements may be sent in a Control frame. HE operation elements may be sent in a Data frame. For example, HE operation elements may be sent in a Beacon frame. For example, HE operation elements may be sent in an Association Response frame. For example, HE operation elements may be sent in a Reassociation Response frame. For example, HE operation elements may be sent in a Probe Response frame.

[0100] The HE Operation Parameter field format of the HE Operation element format may consist of the Default PE Duration subfield, TWT Required subfield, TXOP Duration RTS Threshold subfield, VHT Operation Information Present subfield, Co-Hosted BSS subfield, ER SU Disabled subfield, 6GHz Operation Information Present subfield, Reserved subfield, etc. The VHT Operation Information Present subfield may be set to 1 to indicate that the VHT Operation Information field exists in the HE Operation element, and to 0 otherwise. The 6GHz Operation Information Present field may be set to 1 to indicate that the 6GHz Operation Information field exists, and to 0 otherwise.

[0101] The BSS Color Information field format of the HE Operation element format may consist of a BSS Color subfield, a Partial BSS Color subfield, a BSS Color Disabled subfield, and so on.

[0102] The 6GHz Operation Information field in the HE Operation element format may provide channel and bandwidth information related to 6GHz operation. The 6GHz Operation Information field format may consist of a Primary channel field, a Control field, a Channel Center Frequency Segment 0 field, a Channel Center Frequency Segment 1 field, a Minimum Rate field, etc. The Primary Channel field may indicate the channel number of the primary channel at 6GHz. The Channel Center Frequency Segment 0 field may indicate the channel center frequency index of a 20MHz, 40MHz, 80MHz, 160MHz, or 80+80MHz channel of the BSS operating at 6GHz. The Channel Center Frequency Segment 0 field may indicate the channel center frequency index of the primary 80MHz channel if the BSS channel width is 160MHz or 80+80MHz. The Channel Center Frequency Segment 1 field may indicate the channel center frequency index of a 160MHz channel of the BSS operating at 6GHz. The Channel Center Frequency Segment 1 field may indicate the channel center frequency index of the secondary 80MHz channel when the channel width is 80+80MHz. The Control field format within the 6GHz Operation Information field format may consist of the Channel Width field, Duplicate Beacon subfield, Regulatory Info subfield, Reserved subfield, etc.The Channel Width field indicates the BSS channel width and may be set to 0 for 20MHz, 1 for 40MHz, 2 for 80MHz, or 3 for 80+80MHz or 160MHz.

[0103] The EHT Operation element format may also be an Operation element for controlling an EHT STA operating in an EHT BSS. When operating in the 2.4GHz band, an EHT STA in an EHT BSS may be controlled by an HT Operation element, an HE Operation element, and an EHT Operation element. When operating in the 5GHz band, an EHT STA in an EHT BSS may be controlled by an HT Operation element, a VHT Operation element (if present), an HE Operation element, and an EHT Operation element. When operating in the 6GHz band, an EHT STA in an EHT BSS may be controlled by an HE Operation element and an EHT Operation element.

[0104] The EHT Operation element format may consist of the following fields: Element ID, Length, Element ID Extension, EHT Operation Parameter, Basic EHT-MCS And Nss Set, and EHT Operation Information. The EHT Operation Information field may consist of the Control subfield, CCFS0 subfield, CCFS1 subfield, and Disabled Subchannel Bitmap subfield. The Control subfield may include the Channel Width subfield. The Channel Width subfield may be a subfield for defining the EHT BSS bandwidth. The Channel Width subfield may define 0 for a 20MHz EHT BSS bandwidth. The Channel Width subfield may define 1 for a 40MHz EHT BSS bandwidth. The Channel Width subfield may define 2 for an 80MHz EHT BSS bandwidth. The Channel Width subfield may define 3 for a 160MHz EHT BSS bandwidth. The Channel Width subfield may define 4 for a 320MHz EHT BSS bandwidth. The CCFS0 subfield may define the center frequency of the primary 80MHz channel for 20MHz EHT BSS, 40MHz EHT BSS, 80MHz EHT BSS, 160MHz EHT BSS, or the primary 160MHz channel for 320MHz EHT BSS. The CCFS0 subfield may also indicate the channel center frequency index of the 20MHz channel, 40MHz channel, or 80MHz channel on which the EHT BSS operates, for a 20MHz BSS bandwidth, 40MHz BSS bandwidth, or 80MHz BSS bandwidth.The CCFS0 subfield may indicate the channel center frequency index of the primary 80MHz channel for a 160MHz BSS bandwidth. The CCFS0 subfield may indicate the channel center frequency index of the primary 160MHz channel for a 320MHz BSS bandwidth. The CCFS1 subfield may define the center frequency of a 160MHz EHT BSS or a 320MHz EHT BSS. The CCFS1 subfield may be set to 0 for a 20MHz BSS bandwidth, a 40MHz BSS bandwidth, or an 80MHz BSS bandwidth. The CCFS1 subfield may index the center frequency of a 160MHz channel for a 160MHz BSS bandwidth. The CCFS1 subfield may index the center frequency of a 320MHz channel for a 320MHz BSS bandwidth.

[0105] An A-MSDU (Aggregate MSDU) may be a sequence of A-MSDU subframes. Each A-MSDU subframe may consist of an A-MSDU subframe header, followed by the MSDU and padding of 0 to 3. In an A-MSDU subframe, the A-MSDU subframe header may include a DA field, an SA field, and a Length field. The DA and SA fields may contain values ​​passed in MA-UNITDATA.request and MAUNITDATA.indication primitives. The Length field may contain the length of the MSDU in octets (i.e., 8 bits).

[0106] Figure 6 shows an example of an A-MSDU according to one aspect of this embodiment. In Figure 6, the MAC frame format may consist of a MAC header, a Frame Body, and an FCS. Here, the MAC header may consist of a Frame Control field, a Duration field, an Address 1 field, an Address 2 field, an Address 3 field, a Sequence Control field, an Address 4 field, and a QoS Control field. The MAC frame format may also be an MPDU. The Frame Body may consist of n A-MSDU subframes. Each A-MSDU may consist of an A-MSDU subframe header, an MSDU, and Padding. The A-MSDU subframe header may consist of a DA field, an SA field, and a Length field.

[0107] An A-MPDU (Aggregate MPDU) may consist of a sequence of one or more A-MPDU subframes and a variable amount of EOFPadding. Each A-MPDU subframe may optionally consist of an MPDU followed by an MPDU delimiter. Each nonfinal A-MPDU subframe within an A-MPDU may have padding octets added to make the subframe length a multiple of four octets. The EOF Padding field may consist of an EOF Padding subframe field and an EOF Padding Octets field. The A-MPDU pre-EOF padding may refer to the contents of the A-MPDU without including the EOF Padding field. The MPDU delimiter may consist of an EOF field, a Reserved field, an MPDULength field, a CRC field, and a Delimiter Signature field.

[0108] Figure 7 shows an example of an A-MPDU according to one embodiment of this model. In Figure 7, the A-MPDU may consist of n A-MPDU subframe fields and an EOF Padding field. The n A-MPDU subframe fields may be referred to as A-MPDU pre-EOF padding. Each A-MPDU subframe field may consist of an MPDU delimiter field, an MPDU field, and a padding field. The MPDU delimiter field may consist of an EOF field, a Reserved field, an MPDU Length field, a CRC field, and a Delimiter Signature field. The EOF Padding field may consist of an EOF Padding subframe field and an EOF Padding Octets field.

[0109] The process of dividing an MSDU or MMPDU (MAC Management Protocol Data Unit) into smaller MAC-level frames, or MPDUs, may be called fragmentation. A MAC may fragment and reassemble an MSDU or MMPDU that is carried in individually addressed MPDUs.

[0110] Figure 8 shows an example of Fragmentation according to one aspect of this embodiment. In Figure 8, the MSDU may be fragmented into n parts. The MSDU is divided into n Frame Bodies, and each Frame Body may be assigned a MAC HDR (header) and a CRC (Cyclic Redundancy Check).

[0111] A PPDU may consist of a PHY preamble, a PHY header, a PSDU (PHY Service Data Unit), etc. A PPDU may be assigned L-STF, L-LTF, and L-SIG. A PPDU may be assigned HT-STF, HT-LTF, and HT-SIG. A PPDU may be assigned VHT-STF, VHT-LTF, VHT-SIG-A, and VHT-SIG-B. A PPDU may be assigned HE-STF, HE-LTF, HE-SIG-A, and HE-SIG-B. A PPDU may be assigned HT-STF, HT-LTF, and HT-SIG in addition to L-STF, L-LTF, and L-SIG. A PPDU may be assigned VHT-STF, VHT-LTF, VHT-SIG-A, and VHT-SIG-B in addition to L-STF, L-LTF, and L-SIG. In addition to L-STF, L-LTF, and L-SIG, PPDU may also be assigned HE-STF, HE-LTF, HE-SIG-A, and HE-SIG-B.

[0112] Figure 9 shows an example of a PPDU according to one aspect of this embodiment. In Figure 9, L-STF and L-LTF may be added to the PPDU in the PHY layer. In Figure 9, the PPDU may consist of PSDU, PHYpreamble, PHY header, Tail, and Padding. Here, the PSDU may be an A-MPDU in the MAC sublayer. The A-MPDU may consist of multiple MAC frame formats. Here, one MAC frame format may consist of a MAC header field, an A-MSDU field, and an FCS field.

[0113] Figure 10 shows an example of a MAC data plane architecture for an MLD according to one aspect of this embodiment. The MAC data plane architecture may refer to processing that involves the transmission of all or part of an MSDU. In the MLO, one or more links may be used for communication between AP MLDs and non-AP MLDs. During transmission, an MSDU from a MAC Service Access Point (SAP) may be forwarded to one or more MLD subordinate MAC entities and then to the corresponding PHY SAPs, after going through the processing on the left side of Figure 10, and then through TID-To-Link Mapping (TTLM) processing that forwards one or more MPDUs based on a Traffic Identifier (TID). During reception, MPDUs sent from different PHY SAPs may first pass through MLD subordinate MAC entities, then through merging processing, and then through the remaining processing on the right side of Figure 10, after which one or more MSDUs may be delivered to the LLC layer via MAC SAPs or to the DS via DSAFs.

[0114] The functions of the MLD upper MAC sublayer may include some or all of the following: - Authentication, association, and reassociation between AP MLD and non-AP MLD - Security associations such as PMKSA (Pairwise Master Key Security Association) and PTKSA (Pairwise Transient Key Security Association), and distribution of GTK (Group Temporal Key) / IGTK (Integrity Group Temporal Key) / BIGTK (Beacon Integrity Group Temporal Key) - Assignment of SN (Sequence Number) / PN (Packet Number) for frames encrypted by PTK (Pairwise Transient Key) for individually addressed frames - Assignment of SN for multiple MSDUs addressed to a group - Power-saving buffering of individually addressed frames (AP MLD only) - Encryption / decryption of individually addressed frames by PTK - Selection of MLD lower MAC entities for transmission - Merging of MPDUs received from two or more links - Each Block Packet sorting for sequential delivery within each Ack session; scoreboarding of Block Acks for individually addressed frames in cooperation with MLD lower MAC entities; exchange / instruction of MLD-level management information via MLD lower MAC entities; and selection of each STA's own EDCA (Enhanced Distributed Channel Access) parameters.

[0115] The functions of the MLD lower MAC entities may include some or all of the following: • Exchange / instruction of link-specific control information such as RTS / CTS, acknowledgements, and NDP (Null Data PPDU) • MAC address filtering for power save status and mode frame reception • Block Ack scoreboarding for individually addressed frames in cooperation with the MLD upper MAC sublayer.

[0116] The functionality of the Super MLD MAC entity may include some or all of the following. The functionality of the Super MLD upper MAC sublayer may include some or all of the following. The functionality of the MLD common MAC sublayer may include some or all of the following.- Operations performed by two MLDs belonging to the same Super MLD - Operations performed by two MLDs belonging to different Super MLDs - Operations performed by one MLD belonging to a Super MLD and one MLD not belonging to a Super MLD - Operations performed by a Super MLD and a Normal MLD - Operations performed by two Super MLDs - Operations performed by two AP MLDs - Seamless Roaming between AP MLDs and non-AP MLDs - Other operations between AP MLDs and non-AP MLDs - Security associations such as PMKSA and PTKSA, and distribution of GTK / IGTK / BIGTK - Assignment of SN / PN for frames encrypted by PTK for individually addressed frames - Assignment of SN for multiple MSDUs addressed to a group - Power-saving buffering for individually addressed frames - PTK encryption / decryption of individually addressed frames - Selection of Super MLD lower MAC entities for transmission - Selection of MLD lower MAC entities for transmission - Selection of MLD upper MAC sublayers for transmission - Merging of MPDUs received from two or more MLDs - Each Block Packet sorting for sequential delivery of packets for each Ack session; Block Ack scoreboarding for individually addressed frames in cooperation with Super MLD lower MAC entities; Block Ack scoreboarding for individually addressed frames in cooperation with MLD lower MAC entities; Block Ack scoreboarding for individually addressed frames in cooperation with MLD upper MAC sublayers; Exchange / instruction of MLD-level management information via Super MLD lower MAC entities; Exchange / instruction of MLD-level management information via MLD lower MAC entities; Exchange / instruction of MLD-level management information via MLD upper MAC sublayers; Selection of EDCA parameters for each MLD series; Selection of EDCA parameters for each AP MLD.

[0117] The functions of a Super MLD lower MAC entity may include some or all of the following: • Authentication, association, and re-association between AP MLD and non-AP MLD • Power-saving buffering of individually addressed frames (AP MLD only) • PTK encryption / decryption of individually addressed frames • Selection of MLD lower MAC entities for transmission • Merging of MPDUs received from two or more links • Packet reordering to ensure sequential delivery of packets for each Block Ack session • Block Ack scoreboarding for individually addressed frames in cooperation with MLD lower MAC entities • Exchange / instruction of MLD-level management information via MLD lower MAC entities • Selection of its own EDCA parameters for each series STA • Exchange / instruction of link-specific control information such as RTS / CTS, acknowledgements, and NDP (Null Data PPDU) • Power-saving status and mode • MAC address filtering for frame reception • Block Ack scoreboarding for individually addressed frames in cooperation with the Super MLD upper MAC sublayer

[0118] The time interval between frames may be referred to as IFS (Inter-Frame Space). The STA may use carrier sensing functionality at a specified time interval to determine if the medium is idle. In other words, the STA may perform carrier sensing over the IFS period to determine whether the medium is idle or not.

[0119] Multiple types of IFS may be defined. For example, IFS may include RIFS (Reduced Inter Frame Space), SIFS (Short Inter Frame Space), PIFS (Priority Inter Frame Space), DIFS (DCF Inter Frame Space), AIFS (Arbitration Inter Frame Space), EIFS (Extended Inter Frame Space), SBIFS (Short Beamforming Inter Frame Space), BRPIFS (Beam Refinement Inter Frame Space), MBIFS (Medium Beamforming Inter Frame Space), and LBIFS (Long Beamforming Inter Frame Space).

[0120] The time interval may differ depending on the type of IFS. For example, PIFS may have a longer time interval than SIFS. DIFS may also have a longer time interval than PIFS. The type of IFS may provide a priority level for access to the wireless medium. In other words, an IFS with a shorter time interval may be an IFS with a higher priority level for access to the wireless medium.

[0121] SIFS (Short Inter Frame Space) may be the time from the end of the last symbol or signal extension (if any) of the previous frame until the first symbol of the preamble of the next frame is seen on the radio medium.

[0122] Priority Inter Frame Space (PIFS) may be used to control access to media in order to obtain priority access. PIFS may also be used to perform Clear Channel Assessment (CCA) on secondary 20MHz, secondary 40MHz, and secondary 80MHz channels before transmission at 40MHz, 80MHz, and 160MHz.

[0123] Clear Channel Assessment (CCA) may determine the current usage status of a wireless medium. CCA may be a function at the physical layer for determining the current usage status of a wireless medium. CCA may also be referred to as the CCA function.

[0124] DIFS (DCF Inter Frame Space) may be used by an STA operating with DCF to transmit data frames (MPDUs) and management frames (MMPDUs). An STA using DCF may transmit after successfully receiving a frame, if the CS (Carrier Sense) mechanism determines that the medium is idle at a TxDIFS slot boundary, and the value of the STA's backoff counter is zero.

[0125] AIFS (Arbitration Inter Frame Space) may be used for QoS STAs that access media using EDCAF.

[0126] EIFS (Extended Inter Frame Space) may be used in DCF when the medium is immediately determined to be idle after receiving a frame with an incorrect FCS value.

[0127] The basic method of accessing MACs used by STAs may be DFC (Distributed Coordination Function). DCF may be a class of coordination function where the same coordination logic is always active in each STA within the BSS when the network is operational. DCF may be a type of CSMA / CA. DCF may be a function that needs to be implemented in all STAs.

[0128] To initiate a transmission, the STA detects the medium and determines whether another STA is currently transmitting. If the medium is not busy, the STA may proceed with the transmission. If the medium is determined to be busy, the STA postpones transmission until the current transmission is complete.

[0129] In the CSMA / CA distributed algorithm, there is a specified time gap between frame exchange sequences. This specified time gap between frame exchange sequences may be referred to as the IFS (Interval Free Time). Before attempting to transmit, the transmitting STA (Signal Agent) ensures that the medium is idle for a required period. This required period may be the specified time gap between frame exchange sequences. This required period may be referred to as the IFS.

[0130] The STA may initialize the backoff counter to a random backoff counter before attempting to transmit again after a delay or immediately after a successful transmission. The STA may decrement the backoff counter once per aSlotTime period while the medium is idle. aSlotTime may be the duration of the slot. The duration of the slot may be the duration of the slot that the MAC uses to define the IFS. Alternatively, aSlotTime may be a predetermined duration (e.g., a fixed duration in microseconds).

[0131] The basic media access protocol may be DCF. DCF enables automatic sharing of media between compatible PHYs through the use of CSMA / CA and a random backoff counter after the media becomes busy. All individually addressed traffic uses an immediate positive acknowledgment (Ack frame), and if an Ack frame is not received, the sender schedules a retransmission. Multiple STAs may be waiting for the media to become available, and collisions are most likely when the media goes from busy to idle. Therefore, a random backoff procedure is necessary to resolve media contention. An STA transmission may interfere with (collision with) another STA transmission even if the carrier sense function (CS function) indicates that the media is not busy. Interference may be identified when the expected response frame is not received.

[0132] An STA that wants to initiate the transfer of data frames or management frames using DCF may use a carrier sense mechanism to determine the busy / idle state of the medium. If the medium is busy, the STA waits without interruption for an IFS until the medium is determined to be idle. Here, the type of IFS may be EIFS if the transition to the last idle state was due to the detection of a frame that was not properly received on the medium. Otherwise, the type of IFS may be DIFS. After the medium is idle in DIFS or EIFS, the STA may generate a random backoff count for additional delay time before transmission. However, if the backoff counter already contains a non-zero value, the selection of a random number is not required. The backoff counter may be a pseudo-random integer obtained by subtracting a uniform variance between [0, CW]. CW may be an integer within the range of aCWmin and aCWmax values, which are characteristics of the PHY. CW may be greater than or equal to aCWmin and less than or equal to aCWmax. CW may be referred to as the Contention Window.

[0133] The contention window parameter may take the initial value of aCWmin. The contention window takes a series of values ​​each time an MPDU transmission attempt fails and any STA retry increases until the contention window reaches the value of aCWmax. Once the contention window reaches aCWmax, it maintains the value of aCWmax until the contention window is reset. If a data frame or management frame is successfully transmitted, the contention window may be reset to aCWmin. If the SSRC reaches dot11ShortRetryLimit, the contention window may be reset to aCWmin. The set of contention window values ​​may be in ascending order as integers obtained by powers of 2 minus 1, starting from the PHY-specific aCWmin value and continuing up to the PHY-specific aCWmax. For example, if aCWmin is 7 and aCWmax is 255, the set of contention window values ​​may be a set containing 7, 15, 31, 63, 127, and 255.

[0134] For example, in OFDM PHY characteristics, with a 20MHz channel spacing, aSlotTime may be 9μs. In OFDM PHY characteristics, with a 20MHz channel spacing, aCWmin may be 15. In OFDM PHY characteristics, with a 20MHz channel spacing, aCWmax may be 1023.

[0135] A QoS facility may include an additional coordinating function called HCF (Hybrid Coordination Function), which is only available in a QoS network configuration. HCF may be implemented in all QoS STAs. HCF is a coordinating function that combines aspects of competition-based and competition-free access methods to provide prioritized, parameterized QoS access to the radio medium for QoS STAs, and may continue to support non-QoS STAs for best-effort forwarding. HCF may include functionality provided by both EDCA (Enhanced Distributed Channel Access) and HCCA (HCF controlled channel access). HCF may use a competition-based channel access method called the EDCA mechanism for competition-based forwarding. HCF may use a controlled channel access method called the HCCA mechanism for competition-free forwarding.

[0136] HCCA (HCF Controlled Channel Access) may be a channel access mechanism used by a Hybrid Coordinator (HC) to coordinate the use of a non-contradiction-free medium by a QoS STA for individually addressed downlink, uplink, and direct-link transmissions.

[0137] The EDCA mechanism may use eight different User Priorities (UPs) to provide STAs with differentiated, distributed access to the wireless medium. UPs are values ​​associated with MAC Service Data Units (MSDUs) and may indicate how the MSDU should be handled. UPs may be assigned to MSDUs at higher layers of the MAC. UPs may take any value from 0 to 7. The EDCA mechanism may define four Access Categories (ACs) to support the delivery of traffic using STAs' UPs. ACs may be labels for a common set of EDCA parameters that QoS STAs use to compete for channels and transmit MSDUs with specific priorities. ACs may take any value from AC_BE, AC_BK, AC_VI, and AC_VO. AC_BE, AC_BK, AC_VI, and AC_VO may indicate access categories corresponding to best-effort, background, video, and voice, respectively.

[0138] A Quality of Service (QoS) facility may include extensions, channel access rules, frame formats, frame exchange sequences, and managed objects used to provide parameterized and prioritized QoS. A QoS STA may be an STA that implements the QoS function. A QoS AP may be an AP that supports the QoS function. A QoS BSS may be a BSS that provides the QoS function. An Infrastructure QoS BSS may include a QoS AP.

[0139] A QMF (QoS Management Frame) policy may be a policy that defines the AC of Management frames. A QMF service may be a service that determines the AC of the EDCA that sends Management frames according to the configured policy. A QMF STA may be an STA that implements the QMF service. A QMF AP may be an AP that implements the QMF service. A QMF MLD may be an MLD that implements the QMF service. A Non-QMF STA may be an STA that does not implement the QMF service. A Non-QMF AP may be an AP that does not implement the QMF service. A Non-QMF MLD may be an MLD that does not implement the QMF service. An IQMF (Individually addressed QoS Management Frame) may be an individually addressed Management Frame that is sent using the QMF service.

[0140] An Enhanced Distributed Channel Access Function (EDCA) is a logical function within a QoS STA that uses the EDCA to determine when a frame in a transmit queue with an associated AC is permitted to be transmitted over the radio medium. There may be one EDCFA per AC. The DCF and HCF may be defined to operate within the same BSS.

[0141] Each EDCAF may maintain a backoff counter measured in the backoff slot. When the backoff procedure is called, the backoff counter may be set to a randomly selected integer value in a uniform distribution from 0 to CW. AIFS may be defined as AIFSN × aSlotTime + aSIFSTime. For example, in OFDM PHY characteristics, for a 20MHz channel spacing, aSlotTime may be 9μs and aSIFTTime may be 16μs. AIFSN may differ for each AC. For example, if AC is AC_BK, AIFSN may be 7. If AC is AC_BE, AIFSN may be 3. If AC is AC_VI, AIFSN may be 2. If AC is AC_VO, AIFSN may be 2. CW may be in ascending order as a power of 2 minus 1 integer, starting from a PHY-specific CWmin value and continuing to a PHY-specific CWmax. CWmin and CWmax may differ for each AC. For example, if AC is AC_BK, CWmin may be aCWmin and CWmax may be aCWmax. If AC is AC_BE, CWmin may be aCWmin and CWmax may be aCWmax. If AC is AC_VI, CWmin may be {(aCWmin+1) / 2}-1 and CWmax may be aCWmin. If AC is AC_VO, CWmin may be {(aCWmin+1) / 4}-1 and CWmax may be {(aCWmin+1) / 2}-1. In OFDM PHY characteristics, with a 20MHz channel spacing, aCWmin may be 15. In OFDM PHY characteristics, with a 20MHz channel spacing, aCWmax may be 1023. The STA may decrement its backoff counter once per aSlotTime period while the medium is idle. Each time an MPDU transmission attempt fails and any STA retry increases, it takes a series of the following values.

[0142] In HCF, the basic unit of assigning transmission rights to a radio medium may be a TXOP. A TXOP (Transmission Opportunity) may be a time interval in which a particular QoS STA has the right to initiate a frame exchange sequence on the radio medium. A TXOP may be defined by its start time and maximum duration. A TXOP may be acquired through EDCA. That is, an STA may acquire a TXOP if it performs an EDCA.

[0143] Figure 11 is a diagram showing an example of a backoff procedure according to one aspect of this embodiment. In Figure 11, the horizontal axis may represent time. 1101 may be a transmission by STA#1. 1102 may be an IFS. 1103 may be a backoff counter. 1103 may also be called a contention window. 1104 may be a transmission by STA#2. In Figure 11, STA#2 may detect 1101 on the channel. While STA#2 is detecting 1101, it may determine that the channel is busy. That is, 1101 may be the period during which the channel is determined to be busy. STA#2 may perform carrier sense and determine whether the channel is busy or not. When the period of 1101 has ended and STA#2 determines that the channel is idle, it may perform carrier sense during the period of 1102. For example, 1102 may be a DIFS. 1102 may also be an AIFS. STA#2 may start 1103 if it is idle during the period 1102. 1103 decrements the backoff counter while the channel is idle. For example, six backoff counters may be generated in 1103. The backoff counter is decremented while the channel is idle, and when the backoff counter reaches 0, STA#2 may transmit (1104). Here, the backoff counter may be determined between 0 and CW. CW may be a value selected from a range of values ​​between aCWmin and aCWmax. The channel may be referred to as the radio medium.

[0144] The carrier sense mechanism may be a mechanism that combines the Network Allocation Vector (NAV) status with the physical carrier sense of the STA transmitter to determine whether the medium is busy or idle. The NAV may be maintained by each STA and may be an indicator of the period during which transmission to the wireless medium is not initiated by the STA, regardless of whether the STA's Clear Channel Assessment (CCA) function senses that the medium is busy.

[0145] The carrier sense mechanism in STA may be performed in the physical layer processing unit SU3 and / or the MAC layer processing unit SU3. The carrier sense mechanism in AP may be performed in the physical layer processing unit AU3 and / or the MAC layer processing unit AU3.

[0146] The NAV may be a counter that counts down to zero at a constant rate. The STA may indicate that the virtual carrier sense is idle if the NAV counter is zero. The STA may indicate that the virtual carrier sense is busy if the NAV counter is not zero. Physical and virtual carrier sense functions may be used to determine the state of the medium. If either the physical or virtual carrier sense function indicates busy, the medium may be considered busy. If both the physical and virtual carrier sense functions indicate idle, the medium may be considered idle. The virtual carrier sense may be referred to as the NAV. The NAV may be provided by all MACs. The NAV counter may be referred to as the NAV timer.

[0147] The physical carrier sense function in the STA may be controlled by the physical layer processing unit SU3. The virtual carrier sense function in the STA may be controlled by the MAC layer processing unit SU4. The physical carrier sense function in the AP may be controlled by the physical layer processing unit AU3. The virtual carrier sense function in the AP may be controlled by the MAC layer processing unit AU4. The NAV in the STA may be controlled by the MAC layer processing unit SU4. The NAV in the AP may be controlled by the MAC layer processing unit AU4.

[0148] The STA may set the NAV if the address field of a received frame is not its own address. The STA may update the NAV using the information from any valid Duration field in the PSDU when it receives at least one valid frame in the PSDU. The STA may update the NAV if the value indicated by the Duration field of a received frame is greater than the current NAV value. The STA does not update the NAV if the RA (address) of a received frame is equal to the STA's own MAC address.

[0149] An STA may maintain two NAVs. An AP may maintain two NAVs. The two NAVs may be an intra-BSS NAV and a basic NAV. The intra-BSS NAV may be updated by an intra-BSS PPDU. The basic NAV may be updated by an inter-BSS PPDU. The basic NAV may be updated by a PPDU that cannot be classified as an intra-BSS PPDU or an inter-BSS PPDU. An STA maintaining two NAVs may indicate that the medium is idle if the timers of both NAVs are 0. In other words, an STA maintaining two NAVs may indicate that the medium is idle if the timers of both the intra-BSS NAV and the basic NAV are 0. If at least one of the two NAV timers is not 0, the virtual CS indication may indicate that the medium is busy. In other words, if an STA or AP maintaining two NAVs has a timer that is not zero for at least one Intra-BSS NAV or basic NAV, the virtual CS indication may indicate that the medium is busy.

[0150] NAV may also be basic NAV. NAV may also be intra-BSS NAV. Basic NAV may also be NAV. Intra-BSS NAV may also be NAV. NAV may be called basic NAV. NAV may also be called intra-BSS NAV. Basic NAV may also be called NAV. Intra-BSS NAV may also be called NAV.

[0151] Carrier sense (CS) may be performed through both physical and virtual mechanisms. Carrier sense may also be referred to as a carrier sense function. Carrier sense may also be referred to as a carrier sense mechanism. A virtual carrier sense mechanism is implemented by distributing reservation information that notifies of the advance use of a medium. Exchanging RTS and CTS frames before the actual data frame may be one means of distributing medium reservation information. RTS and CTS frames may include a Duration field that defines the period during which the medium is reserved for transmitting the actual data frame and Ack frame. An STA that receives an RTS frame (sent by the originating STA) or a CTS frame (sent by the destination STA) processes the medium reservation. An STA can know that it is planning to transmit a data frame using the medium even if it does not receive from the originating STA. Medium reservation information may be distributed in the Duration / ID field of an individually addressed frame. The Duration / ID field may indicate the time (period) during which the medium is reserved. The Duration / ID field may indicate the time during which the medium is reserved, ending in the following Ack frame. In the case of fragment sequences, the Duration / ID field may indicate the time the medium is reserved until the end of the Ack frame following the next fragment. The RTS / CTS mechanism may also function when multiple BSSs using the same channel overlap. The medium reservation mechanism may also function across BSS boundaries.

[0152] The RTS (Request To Send) frame format may include a Frame Control field, a Duration field, an RA field, a TA field, and an FCS field. The Duration field of the RTS frame format may indicate the time (in microseconds) required to send the pending data or management frame, one CTS frame, one Ack frame, and three SIFS frames. The RA field of the RTS frame may be the address of the STA that is the intended direct recipient of the pending individually addressed frame. The TA field may be the address of the STA sending the RTS frame or the bandwidth signal TA of the STA sending the RTS frame.

[0153] The CTS (Clear To Send) frame format may include a Frame Control field, a Duration field, an RA field, and an FCS field. The Duration field of a CTS frame format sent in response to an RTS frame may be the Duration field of the immediately preceding RTS frame minus the time required to send the CTS frame and its corresponding SIFS. In other words, it may be the time required to send the pending data or management frame, one Ack frame, and two SIFS. If the CTS frame is the first frame in the exchange and the pending data or management frame requires an acknowledgment, the Duration field may be the time (in microseconds) required to send the pending data or management frame, two SIFS, and one Ack frame. If the CTS frame is the first frame in the exchange and the pending data or management frame does not require an immediate acknowledgment, the Duration field may be the time required to send the pending data or management frame and one SIFS. If the CTS frame is a response to an RTS frame, the RA field of the CTS frame may contain the address from the TA field of the RTS frame, and the individual / group bits may be set to 0. If the CTS frame is the first frame in a frame exchange, the RA field may contain the source MAC address.

[0154] Figure 12 shows an example of NAV according to one aspect of this embodiment. In Figure 12, the horizontal axis may represent time. For example, 1201 may be the timeline of AP#1's operation. 1202 may be the timeline of STA#1's operation. 1203 may be the timeline of AP#2's operation. 1204 may be the timeline of STA#2's operation. 1201, 1202, 1203, and 1204 may be timelines on the same channel. 1205 may be an RTS frame. 1206 may be the NAV period of AP#1. 1207 may be a CTS frame. 1208 may be the NAV period of STA#2. 1209 may be a Data frame. 1210 may be an AcK frame. 1211 may be an IFS. 1212 may be a contention window (backoff counter, backoff procedure). STA#1 may send 1205 to AP#2. Upon receiving 1205, AP#1 may set 1206 for the period indicated in the RTS Duration field. Upon receiving 1205, AP#2 may send 1207 to STA#1. Upon receiving 1207, STA#2 may set 1208 for the period indicated in the CTS Duration field. Upon receiving 1207, STA#1 may send 1209. Upon receiving 1209, AP#2 may send 1210 to STA#1. After 1206 is completed, AP#1 may start 1212 with 1211 if the channel is idle. After 1208 is completed, STA#2 may start 1212 with 1211 if the channel is idle. There may be an IFS between 1205 and 1207. AP#2 may transmit 1207 if the channel is idle during the IFS period before transmitting 1207. There may be an IFS period between 1207 and 1209. STA#1 may transmit 1209 if the channel is idle during the IFS period before transmitting 1209. There may be an IFS period between 1209 and 1210. AP#2 may transmit 1210 if the channel is idle during the IFS period before transmitting 1210.Here, for example, AP#1 may be 202 in Figure 2. For example, STA#1 may be 207 in Figure 2. For example, AP#2 may be 206 in Figure 2. For example, STA#2 may be 208 in Figure 2. 1201 may be a timeline of the operation of AP or STA. 1202 may be a timeline of the operation of AP or STA. 1203 may be a timeline of the operation of AP or STA. 1204 may be a timeline of the operation of AP or STA.

[0155] An STA or AP may perform a frame exchange. For example, a frame exchange may occur when an STA or AP sends an RTS and the STA or AP sends a CTS to the RTS. For example, a frame exchange may occur when an STA or AP sends a Trigger frame and the STA or AP sends a CTS to the Trigger frame. For example, a frame exchange may occur when an STA or AP sends an MU-RTS and the STA or AP sends a CTS to the MU-RTS. For example, a Trigger frame may be used by an AP to allocate a Resource Unit (RU) to an STA. A Trigger frame may be a frame containing at least a Common Info field and / or a User Info List field. The Common Info field may be a field for notifying multiple STAs of information common to them. The User Info List field may contain zero or more User Info fields. The User Info field may be a field for allocating RUs to each STA. For example, the User Info field may contain an RU allocation subfield.

[0156] A BSS transition may refer to a change in the association between two BSSs within the same ESS, performed by an STA. An association may refer to a service that establishes a mapping between an AP and an STA, enabling STA invocation by distribution system services (DSSs), or a service that establishes a mapping between an AP MLD and a non-AP MLD, enabling non-AP MLD invocation by a DSS. A disassociation service may refer to a service that removes an existing association. A reassociation service may refer to a service that transfers an association established between an AP and an STA from one AP to another (or the same AP). Authentication may refer to a service used to establish the identity of one STA as a member of a set of STAs authorized to connect to another STA, or to establish the identity of one MLD as a member of a set of MLDs authorized to connect to another MLD. A Robust Security Network Association (RSNA) may refer to the type of association used by a pair of STAs when the procedure for establishing authentication or association between them involves a 4-way handshake or the Fast BSS Transition (FT) protocol.A 4-way handshake may be defined as a pairwise key management protocol in which two parties verify that they mutually possess a Pairwise Master Key (PMK) and distribute a Group Temporal Key (GTK). The PMK may be a key derived from a key generated using the Extensible Authentication Protocol (EAP) method, or a key obtained directly from a pre-shared key (PSK). The GTK may be a temporary key used to protect information exchanged in a group-addressed Data Frame.

[0157] The primary purpose of a MAC sublayer may be to transfer MSDUs between MAC sublayer entities. The information necessary for the distribution system service to operate is provided by association services. Before the MSDU is processed by the distribution system service, the STA or MLD may be "associated".

[0158] A BSS transition may be defined for an STA or MLD. In a BSS transition, the movement of an STA from one BSS within a given ESS to another BSS within the same ESS may be defined. In a BSS transition, the movement of a non-AP MLD may be defined from one APMLD within a given ESS, where each non-AP STA belonging to a non-AP MLD is in one BSS, and different non-AP STAs belonging to a non-AP MLD are in different BSSs, to another AP MLD within the same ESS, where each non-AP STA belonging to a non-AP MLD is in another BSS, and different non-AP STAs belonging to a non-AP MLD are in different BSSs. In a BSS transition, a movement may be defined for a non-AP MLD to move from one AP MLD within one ESS to another BSS within the same ESS, where the MLD MAC address of the non-AP MLD is the same as the MAC address of the non-AP STA, and the non-AP STA belonging to the non-AP MLD is in one BSS, and different non-AP STAs belonging to the non-AP MLD are in different BSSs. In a BSS transition, a movement may be defined for a non-AP STA to move from one BSS within a certain ESS to an AP MLD within the same ESS, where the MLD MAC address of the non-AP STA is the same as the MLD MAC address of the non-AP MLD, and the non-AP STA belonging to the non-AP MLD is in another BSS, and different non-AP STAs belonging to the non-AP MLD are in different BSSs, and the MAC address of the non-AP STA is the same as the MLD MAC address of the non-AP MLD, and the non-AP STA becomes a non-AP MLD.

[0159] To deliver MSDUs within an ESS via a DS, the DS needs to know which AP or AP MLD within the ESS to deliver the MSDUs to. This information may be provided to the DS through the concept of association. Association is necessary, but not sufficient, to support BSS-transition mobility. Association may be one of the services of the DSS. A non-AP STA may first be associated with an AP before being permitted to deliver MSDUs via the AP. A non-AP MLD may first be associated with an AP MLD before being permitted to deliver MSDUs via the AP MLD. In the case of a non-GLK STA that does not belong to an MLD, the act of connecting with an AP may invoke an association service and provide the DS with a mapping from the STA to the AP. In the case of a non-AP MLD, the act of connecting with an AP MLD may invoke an association service and provide the DS with a mapping from the non-AP MLD to the AP MLD.

[0160] At any given moment, a non-AP STA may connect to one AP, and a non-AP MLD may connect to one AP MLD. Once association is complete between a non-AP STA and an AP, the non-AP STA may communicate by making full use of the DS. Similarly, once association is complete between a non-AP MLD and an AP MLD, the non-AP MLD may communicate by making full use of the DS. Association between a non-AP STA and an AP may always be initiated by the non-AP STA, not by the AP. Association between a non-AP MLD and an AP MLD may always be initiated by the non-AP MLD, not by the AP MLD.

[0161] An AP may connect to multiple non-AP STAs simultaneously. Similarly, an AP MLD may connect to multiple non-AP MLDs simultaneously.

[0162] A non-AP STA may learn which APs exist and what operational capabilities are available from each of those APs, and then initiate an association service to establish an association. Similarly, a non-AP MLD may learn which MLDs exist and what operational capabilities are available from each of those AP MLDs and the APs belonging to each AP MLD, and then initiate an association service to establish an association with the AP MLDs.

[0163] To support BSS-transition mobility, additional functionality is required, which may be provided by a reassociation service. Reassociation may also be one of the DSS services.

[0164] The Reassociation service may be started to move the current association of an AP and a non-AP STA from one AP to the same AP or a different AP. The Reassociation service may be started to move the current association of an AP MLD and a non-AP MLD from one AP MLD to the same AP MLD or a different AP MLD. The Reassociation service may be started to move the current association of an AP and a non-AP STA to an association of an AP MLD and a non-AP MLD where the MLD MAC address of the non-AP MLD is the same as the MAC address of the non-AP STA. The Reassociation service may be started to move the current association of an AP MLD and a non-AP MLD to an association of an AP and a non-AP STA where the MAC address of the non-AP STA is the same as the MLD MAC address of the non-AP MLD.

[0165] In ESS, the reassociation service may notify the DS of the current mapping between APs and non-AP STAs, or between AP MLDs and non-AP MLDs. Reassociation may also allow non-AP STAs or non-AP MLDs to modify the association attributes of an established association while remaining connected to the same AP or AP MLD, respectively. Reassociation may always be initiated by a non-AP STA or non-AP MLD.

[0166] The Authentication service may be used in both ESS and IBSS for all STAs to establish their identity with the STA they are communicating with. If a mutually acceptable level of authentication is not established between two STAs, association may not be established. An STA may authenticate with many other STAs simultaneously. If authentication continues until reassociation, it may affect the speed at which STAs reassociate between APs, potentially limiting the performance of BSS-transition mobility. By using preauthentication, the overhead of the authentication service may be removed from the time-critical reassociation process.

[0167] An STA (local STA) for which dot11OCBActivated is false may keep an enumerated state variable for each STA (remote STA) that requires direct communication via WM. An MLD (local MLD) may keep an enumerated state variable for each MLD (remote MLD) that requires direct communication between two MLDs via WM, from one STA belonging to the local MLD to another STA belonging to the remote MLD.

[0168] This state variable may represent the relationship between local STA and remote STA. This state variable may also represent the relationship between local MLD and remote MLD. The state variable may take any of the following values: ・State 1: Initial startup state of non-DMG STA performing authentication. Initial startup state of MLD performing authentication. Unauthenticated and unassociated. ・State 2: Authenticated but unassociated. ・State 3: Authenticated and associated. Pending RSNA Authentication. ・State 4: Authenticated and associated. RSNA established or not required.

[0169] When an MLME-REASSOCIATE.request primitive is received, non-AP STAs, non-AP MLDs, and non-PCPs (PBSS control point) STAs may perform reassociation with APs, AP MLDs, or PCPs using the following procedures, respectively: • If the STA or non-AP MLD is not connected within the same ESS, or if the new AP, AP MLD, or PCP is in State 1, the STA may issue an MLME-REASSOCIATE.confirm primitive to notify the SME that reassociation failed and terminate this process. • A non-AP STA may send a Reassociation Request frame to the new AP or PCP, or a non-AP STA belonging to a non-AP MLD may send a Reassociation Request frame containing a Basic Multi-Link element to an AP belonging to the new AP MLD. Unless otherwise specified, a non-AP STA belonging to a Non-AP MLD may start sending a Reassociation Request frame on the recommended link included in the MLME-REASSOCIATE.request primitive. The Reassociation Request frame may include the RSNE (Robust Security Network Element) contained in the MLME-ASSOCIATE.request primitive. If a Reassociation Response frame with a status code of SUCCESS is received, the state variable of the new AP, AP MLD, or PCP is set to State 4, or to State 3 if dot11RSNAActivated is true and the FT protocol is not used for the new AP, AP MLD, or PCP.Additionally, unless the old AP, AP MLD, or PCP is identical to the new AP, AP MLD, or PCP, the state variable of the old AP, AP MLD, or PCP may be set to State 2. The MLME may also issue the MLME-REASSOCIATE.confirm primitive to notify the SME that the reassociation was successful. If the MLME-REASSOCIATION.request primitive stores the MAC address of the new AP, AP MLD, or PCP in the CurrentAPAddress parameter (reassociation to the same AP, AP MLD, or PCP), the following states, agreements, and allocations may be deleted or reset to their initial values.1) All EDCAF (Enhanced Distributed Channel Access Function) state2) Any block ack agreements that are not GCR (GroupCast with Retries) agreements3) Sequence number4) Duplicate detection caches5) Anything queued for transmission6) Fragmentation and reassembly buffers7) Power management mode8) WNM (Wireless Network Management) sleep mode9) TDLS (Tunneled Direct-Link Setup) agreements10) TPKSAs (TDLS PeerKey Security Associations) established with any peers11) TSPECs (Traffic SPECification)12) DMG (Directional Multi-Gigabit) TSPECs13) GLK-GCR agreement14) MSCS (Mirrored Stream Classification Service)15) SCS (Stream Classification Service)16) TWT (Target Wake Time) - If the reassociation destination is the same AP and the existing association is not between MLDs, the following states, agreements, and allocations may not be affected by the reassociation procedure.1) Enablement / Deenablement 2) GDD (Geolocation Database Dependent) enablement 3) MMSLs (Multiple MAC Sublayers Links) 4) GCR agreements that are not GLK-GCR agreements 5) DMS (Directed Multicast Service) agreements 6) TFS (Traffic Filtering Service) agreements 7) FMS (Flexible Multicast Service) agreements 8) Triggered autonomous reporting agreements 9) FTM (Fine Timing Measurement) sessions 10) DMG SP (Service Period) and CBAP (Contention Based Access Period) allocations 11) PTP (Peer-To-Peer) TSPECs. • In the case of reassociation to a different AP, AP MLD, or PCP, or in the case of reassociation to an AP when the new AP address is the same as the value of the CurrentAPAddress parameter and the existing association is between MLDs, or when the new AP MLD address is the same as the value of the CurrentAPAddress parameter and the existing association is not between MLDs. For reassociations with MLD, all of the above states, agreements, and allocations may be deleted or reset to their initial values.

[0170] If an AP or PCP receives a Reassociation Request frame from an STA, or if an AP belonging to an AP MLD receives a Reassociation Request frame containing a Basic Multi-Link element from a non-AP STA belonging to a non-AP MLD, the following procedure may be used: The MLME may issue an MLME-REASSOCIATE.indication primitive to notify the SME of the reassociation request. The SME may issue an MLME-REASSOCIATE.response primitive to the STA or non-AP MLD identified by the PeerSTAAddress parameter of the MLME-REASSOCIATE.indication primitive. If the reassociation fails, the SME may indicate the specific reason for the failure of the reassociation in the ResultCode parameter. Upon receiving the MLME-REASSOCIATE.response primitive, the MLME may send a Reassociation Response frame. - If a Reassociation Response frame with a status code indicating SUCCESS is acknowledged by a non-AP STA belonging to an STA or non-AP MLD, the state of the STA or non-AP MLD may be set to State 4, or to State 3 if dot11RSNAActivated is true and the reassociation is not part of a fastBSS transition.- If the ResultCode of the MLME-REASSOCIATE.response primitive is SUCCESS and the CurrentAPAddress parameter of the MLME-REASSOCIATION.indication primitive is the MAC address of the AP or PCP (reassociation to the same AP or PCP), the AP or PCP will treat the agreements and allocations of the non-AP STA as described above. The AP or PCP may delete or reset to its default values ​​any items (states, agreements, and allocations described above) that the non-AP STA has requested to be deleted or reset to their default values. The AP or PCP does not have to change states, agreements, and allocations that are listed as unaffected by the reassociation procedure. - If the ResultCode of the MLME-REASSOCIATE.response primitive is SUCCESS and the CurrentAPAddress parameter of the MLME-REASSOCIATION.indication primitive is the MLD MAC address of the AP MLD (reassociation to the same AP MLD), the AP MLD will treat the agreements and allocations of the non-AP MLD as described above. The AP MLD may delete or reset to its initial value any items (states, agreements, and allocations described above) that the non-AP MLD has requested to be deleted or reset to their initial value. The AP MLD does not have to change states, agreements, and allocations that are listed as not being affected by the reassociation procedure.- If the ResultCode of MLME-REASSOCIATE.response primitive is SUCCESS and the CurrentAPAddress parameter of MLME-REASSOCIATION.indication is not the MAC address of its own AP or PCP, all states, agreements, and allocations of the connected STA (associating STA) described above may be deleted or reset to their initial values. - If the ResultCode of MLME-REASSOCIATE.response primitive is SUCCESS and the CurrentAPAddress parameter of MLME-REASSOCIATION.indication is not the MLD MAC address of its own AP MLD, all states, agreements, and allocations of the connected non-AP MLD (associating non-AP MLD) described above may be deleted or reset to their initial values.

[0171] Fast BSS transition may aim to reduce the time during which connectivity is lost between STA and DS, or between non-AP MLD and DS, during BSS transition. FT (Fast BSS Transition) protocols are part of a relations service and may only apply when an STA or MLD moves to an AP or AP MLD within the same mobility domain in the same ESS. A mobility domain is a set of BSSs within the same ESS and may support Fast BSS transitions between sets.

[0172] The FT protocol may require the exchange of information between an STA and an AP, or between a non-AP MLD and an AP MLD, during the initial association (or subsequent reassociation). The STA and non-AP MLD may be referred to as the FT Originator (FTO). The AP and AP MLD may be referred to as the FT Responder (FTR). The initial exchange may be referred to as the FT initial mobility domain association. Successive reassociations to FTRs within the same mobility domain may use the FT protocol.

[0173] Two FT protocols may be defined: the FT protocol and the FT resource request protocol. The FT protocol may be executed when an FTO moves to a target FTR and may not require a resource request before the move. The FT resource request protocol may be executed when an FTO requires a resource request before the move.

[0174] When an FTO travels to a target FTR using FT protocols, message exchange may be performed using one of two methods: Over-the-Air or Over-the-DS. Over-the-Air, the FTO may communicate directly with the target FTR using authentication by the FT authentication algorithm. Over-the-DS, the FTO may communicate with the target FTR via the current FTR. Over-the-DS, communication between the FTO and the target FTR may take place using FT Action frames between the FTO and the current FTR. Over-the-DS, communication between the current FTR and the target FTR may take place using an encapsulation method. Over-the-DS, the current FTR may convert between the two encapsulations.

[0175] Seamless Roaming may be a process in which a terminal device transitions from one base station device to another. A terminal device may support multiple different frequency bands. A terminal device may communicate with another base station device using a frequency band different from the frequency band used to communicate with one base station device. A terminal device may transition to another base station device using a different frequency band while still communicating with one base station device using a certain frequency band. A terminal device may be an STA. A terminal device may have a non-AP MLD built in. A terminal device may be a set of multiple STAs. A terminal device may have multiple non-AP MLDs built in. A base station device may be an AP. A base station device may have an AP MLD built in. A base station device may be a set of multiple APs. A base station device may have multiple APMLDs built in. A base station device may have a program that has Super MLD functionality built in. Both of the above two base station devices may have a program that implements Super MLD functionality by communicating between programs. Another communication device connected to the above two base station devices may have a program that has Super MLD functionality built in. A communication device incorporating a program with Super MLD functionality may maintain multiple base station devices, including the two base station devices mentioned above. For example, a communication device incorporating a program with Super MLD functionality and connected to the two base station devices may be maintained by sending signaling from the program with Super MLD functionality to the two base station devices so that the sequence numbers assigned by the two base station devices to the frames transmitted to the terminal device are consecutive. For example, a communication device incorporating a program with Super MLD functionality and connected to the two base station devices may be maintained by sending signaling from the program with Super MLD functionality to the two base station devices so that the packet numbers assigned by the two base station devices to the frames transmitted to the terminal device are consecutive.If both of the above two base station devices have built-in programs that have Super MLD functionality, the two base station devices may implement Super MLD functionality by communicating between their programs. For example, the two base station devices may maintain each other by sending signaling between their built-in programs so that the sequence numbers assigned to frames sent to terminal devices are consecutive. For example, the two base station devices may maintain each other by sending signaling between their built-in programs so that the packet numbers assigned to frames sent to terminal devices are consecutive. Seamless Roaming may be roaming in which a non-AP MLD roams from one AP MLD to another AP MLD, and the non-AP MLD remains in State 4 during and after roaming to the other AP MLD. Seamless Roaming may be referred to by names other than Seamless Roaming. For example, Seamless Roaming may also be referred to as MLD Roaming, SMD Roaming, UHR BSS Transition, UHR Link Reconfiguration, MLD-based mobility, SMD-based mobility, Super MLD-based mobility, MLD-based BSS transition, SMD-based BSS transition, Super MLD-based BSS transition, MLD-based fast BSS transition, etc. "Roaming" may also be referred to as "transition," "movement," etc. "Roaming" may be rephrased as "transition," "movement," etc. Roaming may include BSS transition. Roaming may include reassociation. Roaming may include reassociation service. Roaming may include Fast BSS transition. Roaming may include MLO. Super MLD may be used in roaming.In roaming, two or more AP MLDs belonging to a Super MLD may be used. "One AP MLD" may be referred to as "current AP MLD," etc. "Another AP MLD" may be referred to as "target AP MLD," etc.

[0176] APs and / or STAs may perform Seamless Roaming. AP MLDs and / or non-AP MLDs may perform Seamless Roaming. Super MLDs and / or non-AP MLDs may perform Seamless Roaming. Super AP MLDs and / or non-AP MLDs may perform Seamless Roaming. In Seamless Roaming, an STA belonging to an STA and / or non-AP MLD may send a frame to an AP belonging to an AP and / or AP MLD requesting roaming to the target AP MLD. An STA belonging to an STA and / or non-AP MLD may initiate the Seamless Roaming procedure by sending a frame to an AP belonging to an AP and / or AP MLD requesting roaming to the target AP MLD. For example, the “frame requesting roaming to the target AP MLD” may be a frame requesting the addition of a link to the target AP MLD. The “frame for requesting roaming to target AP MLD” may also be called a UHR Link Reconfiguration Request Frame, etc. The UHR Link Reconfiguration Request Frame may be used by a non-AP MLD to request the current AP MLD to add a link to the target AP MLD. The “frame for requesting roaming to target AP MLD” may also be a Reassociation Request frame. The “frame for requesting roaming to target AP MLD” may also be an FT Request frame, which is one of the FT Action frames.The “frame for requesting roaming to target AP MLD” may also be a Link Reconfiguration Request frame used in ML reconfiguration procedures. The “frame for requesting roaming to target AP MLD” may be a frame with a different name. In Seamless Roaming, APs and / or APs belonging to an AP MLD may send a frame to an STA and / or STA belonging to a non-AP MLD to respond to a request for roaming to target AP MLD. For example, the “frame for responding to a request for roaming to target AP MLD” may also be a response frame to a request for adding a link to target AP MLD. The “frame for responding to a request for roaming to target AP MLD” may also be called a UHR Link Reconfiguration Response Frame, etc. A UHR Link Reconfiguration Response Frame is sent by the current AP MLD in response to a UHR Link Reconfiguration Request Frame received from a non-AP MLD, and may accept or reject the request for adding a link to target AP MLD. The "frame for responding to a roaming request to the target AP MLD" may be a Reassociation Responseframe. The "frame for responding to a roaming request to the target AP MLD" may be an FT Response frame, which is one of the FT Action frames. The "frame for responding to a roaming request to the target AP MLD" may be a Link Reconfiguration Response frame used in ML reconfiguration procedures.The “frame for responding to a roaming request to the target AP MLD” may be a frame with a different name. “Non-AP STA belonging to a non-AP MLD” and “AP belonging to an AP MLD” may be replaced with “non-AP MLD” and “AP MLD,” respectively.

[0177] A non-AP STA belonging to a non-AP MLD may send a frame containing an information element that includes information related to Seamless Roaming. A non-AP STA belonging to a non-AP MLD may send a frame containing an information element that includes information related to Seamless Roaming when performing Seamless Roaming. A non-AP STA belonging to a non-AP MLD may send a frame containing an information element that includes information related to Seamless Roaming when sending a UHR Link Reconfiguration Request Frame, to indicate whether or not to stop sending Data Frames to APs belonging to the current AP MLD until a UHR Link Reconfiguration Response Frame is received. A non-AP STA belonging to a non-AP MLD does not need to include an information element that includes information related to Seamless Roaming in the frame it sends if it is not performing Seamless Roaming. For example, an information element that includes information related to Seamless Roaming may be called a UHR Link Reconfiguration element. For example, an information element containing information related to Seamless Roaming may be called a UHR Link Reconfiguration operation element. For example, an information element containing information related to Seamless Roaming may be called a UHR operation element. For example, an information element containing information related to Seamless Roaming may be called a UHR Multi-Link element. An information element containing information related to Seamless Roaming may be referred to in ways other than those mentioned above.For example, a frame containing an information element with information related to Seamless Roaming may be a frame for initiating the Seamless Roaming procedure. For example, a frame containing an information element with information related to Seamless Roaming may be a UHR Link Reconfiguration Request Frame. For example, a frame containing an information element with information related to Seamless Roaming may be an Association Request Frame. For example, a frame containing an information element with information related to Seamless Roaming may be a Reassociation Request Frame. For example, a frame containing an information element with information related to Seamless Roaming may be an FT Request Frame. For example, a frame containing an information element with information related to Seamless Roaming may be a Link Reconfiguration Request Frame. A frame containing an information element with information related to Seamless Roaming may be any other Management Frame.

[0178] A non-AP STA belonging to a non-AP MLD may decide whether to include an information element containing information related to Seamless Roaming in the frame it transmits, based on whether it supports UHR Link Reconfiguration. A non-AP STA belonging to a non-AP MLD may decide whether to include an information element containing information related to Seamless Roaming in the frame it transmits, based on whether the current AP MLD and / or the target AP MLD support UHR Link Reconfiguration. A non-AP STA belonging to a non-AP MLD may decide whether to include an information element containing information related to Seamless Roaming in the frame it transmits, based on whether it supports UHR Link Reconfiguration Mode 2. For example, if a non-AP STA belonging to a non-AP MLD supports UHR Link Reconfiguration Mode 2, it may include a UHR Link Reconfiguration element containing a field indicating UHR Link Reconfiguration Mode 2 in the frame it transmits to the AP belonging to the current AP MLD. For example, if a non-AP STA belonging to a non-AP MLD does not support UHR Link Reconfiguration Mode 2, it may include a UHR Link Reconfiguration element containing a field indicating UHR Link Reconfiguration Mode 1 in the frame it sends to the AP belonging to the current AP MLD.For example, if a non-AP STA belonging to a non-AP MLD supports UHR Link Reconfiguration Mode 2, it may include a UHR Link Reconfiguration element containing a UHR Link Reconfiguration Mode subfield set to 1 in the frame it sends to the AP belonging to the current AP MLD. For example, if a non-AP STA belonging to a non-AP MLD does not support UHR Link Reconfiguration Mode 2, it may include a UHR Link Reconfiguration element containing a UHR Link Reconfiguration Mode subfield set to 0 in the frame it sends to the AP belonging to the current AP MLD.

[0179] An Element ID may be set for the UHR Link Reconfiguration element. An Element ID may be set for the UHR Link Reconfiguration operation element. An Element ID may be set for the UHR operation element. An Element ID may be set for the UHR Multi-Link element. For example, the UHR Link Reconfiguration element may show information for UHR Link Reconfiguration. The UHR Link Reconfiguration element may consist of one or more fields. The UHR Link Reconfiguration element may include a field indicating the Element ID. The UHR Link Reconfiguration element may include a field indicating whether or not to stop sending Data Frames to APs belonging to the current AP MLD when a non-AP STA belonging to a non-AP MLD sends a UHR Link Reconfiguration Request Frame until it receives a UHR Link Reconfiguration Response Frame. The UHR Link Reconfiguration element may include a field indicating the mode of UHR Link Reconfiguration. Fields other than those mentioned above may be included in the UHR Link Reconfiguration element.For example, if a non-AP STA belonging to a non-AP MLD refrains from sending data frames to an AP belonging to the current AP MLD until it receives a UHR Link Reconfiguration Response Frame when sending a UHR Link Reconfiguration Request Frame, it may include a UHR Link Reconfiguration element containing a field indicating UHR Link Reconfiguration Mode 1 in the frame sent to the AP belonging to the current AP MLD. If a non-AP STA belonging to a non-AP MLD does not refrain from sending data frames to an AP belonging to the current AP MLD until it receives a UHR Link Reconfiguration Response Frame when sending a UHR Link Reconfiguration Request Frame, it may include a UHR Link Reconfiguration element containing a field indicating UHR Link Reconfiguration Mode 2 in the frame sent to the AP belonging to the current AP MLD. For example, the field containing the UHR Link Reconfiguration element that indicates the UHR Link Reconfiguration mode may be called the UHR Link Reconfiguration Mode subfield. The UHR Link Reconfiguration Mode subfield may also be a subfield indicating whether a non-AP STA belonging to a non-AP MLD will stop sending Data Frames to APs belonging to the current AP MLD until it receives a UHR Link Reconfiguration Response Frame when sending a UHR Link Reconfiguration Request Frame.For example, if a non-AP STA belonging to a non-AP MLD sends a UHR Link Reconfiguration Request Frame and stops sending Data Frames to APs belonging to the current AP MLD until it receives a UHR Link Reconfiguration Response Frame, the UHR Link Reconfiguration Mode subfield may be set to the first value (e.g., 0). For example, if a non-AP STA belonging to a non-AP MLD sends a UHR Link Reconfiguration Request Frame and does not stop sending Data Frames to APs belonging to the current AP MLD until it receives a UHR Link Reconfiguration Response Frame, the UHR Link Reconfiguration Mode subfield may be set to a second value different from the first value (e.g., 1). For example, if a non-AP STA belonging to a non-AP MLD decides to stop sending Data Frames to APs belonging to the current AP MLD until it receives a UHR Link Reconfiguration Response Frame when sending a UHR Link Reconfiguration Request Frame, it may include a UHR Link Reconfiguration element containing a UHR Link Reconfiguration Mode subfield set to 0 in the frame sent to the AP belonging to the current AP MLD.If a non-AP STA belonging to a non-AP MLD sends a UHR Link Reconfiguration Request Frame and does not stop sending Data Frames to APs belonging to the current AP MLD until it receives a UHR Link Reconfiguration Response Frame, it may include a UHR Link Reconfiguration element containing the UHR Link Reconfiguration Mode subfield, which is set to 1, in the frame it sends to the AP belonging to the current AP MLD.

[0180] For example, a UHR operation element may indicate information for controlling a UHR STA. For example, a UHR operation element may indicate information for UHR Link Reconfiguration. A UHR operation element may consist of one or more fields. A UHR operation element may include a field indicating an Element ID. A UHR operation element may include a field indicating whether the UHR operation element contains information related to UHR Link Reconfiguration. A UHR operation element may include a field indicating whether a non-AP STA belonging to a non-AP MLD will stop sending Data Frames to APs belonging to the current AP MLD until it receives a UHR Link Reconfiguration Response Frame when it sends a UHR Link Reconfiguration Request Frame. A UHR operation element may include a field indicating the mode of UHR Link Reconfiguration. If the UHR operation element indicates that it contains information related to UHR Link Reconfiguration, it may include a field indicating whether a non-AP STA belonging to a non-AP MLD should stop sending Data Frames to APs belonging to the current AP MLD when sending a UHR Link Reconfiguration Request Frame until it receives a UHR Link Reconfiguration Response Frame.A UHR operation element may include a field indicating the UHR Link Reconfiguration mode if it indicates that the UHR operation element contains information related to UHR Link Reconfiguration. Fields other than those mentioned above may be included in the UHR operation element. For example, if a non-AP STA belonging to a non-AP MLD sends a UHR Link Reconfiguration Request Frame and stops sending Data Frames to APs belonging to the current AP MLD until it receives a UHR Link Reconfiguration Response Frame, it may include a UHR operation element containing a field indicating UHR Link Reconfiguration Mode 1 in the frame sent to the AP belonging to the current AP MLD. If a non-AP STA belonging to a non-AP MLD sends a UHR Link Reconfiguration Request Frame and does not stop sending Data Frames to APs belonging to the current AP MLD until it receives a UHR Link Reconfiguration Response Frame, it may include a UHR operation element containing a field indicating UHR Link Reconfiguration Mode 2 in the frame sent to the AP belonging to the current AP MLD.

[0181] For example, a UHR Multi-Link element may indicate information for controlling the MLD to which a UHR STA belongs. For example, a UHR Multi-Link element may indicate information for UHR Link Reconfiguration. A UHR Multi-Link element may consist of one or more fields. A UHR Multi-Link element may include a field indicating an Element ID. A UHR Multi-Link element may include a field indicating whether the UHR Multi-Link element contains information related to UHR Link Reconfiguration. A UHR Multi-Link element may include a field indicating whether a non-AP STA belonging to a non-AP MLD sends a UHR Link Reconfiguration Request Frame and stops sending Data Frames to APs belonging to the current AP MLD until it receives a UHR Link Reconfiguration Response Frame. A UHR Multi-Link element may include a field indicating the mode of UHR Link Reconfiguration. If the UHR Multi-Link element indicates that it contains information related to UHR Link Reconfiguration, it may include a field indicating whether a non-AP STA belonging to a non-AP MLD should stop sending Data Frames to APs belonging to the current AP MLD when sending a UHR Link Reconfiguration Request Frame until it receives a UHR Link Reconfiguration Response Frame.A UHR Multi-Link element may include a field indicating the UHR Link Reconfiguration mode if it indicates that the UHR Multi-Link element contains information related to UHR Link Reconfiguration. Fields other than those mentioned above may be included in the UHR Multi-Link element. For example, if a non-AP STA belonging to a non-AP MLD sends a UHR Link Reconfiguration RequestFrame and stops sending Data Frames to APs belonging to the current AP MLD until it receives a UHR Link Reconfiguration Response Frame, it may include a UHR Multi-Link element containing a field indicating UHR Link Reconfiguration Mode 1 in the frame sent to the AP belonging to the current AP MLD. If a non-AP STA belonging to a non-AP MLD sends a UHR Link Reconfiguration RequestFrame and does not stop sending Data Frames to APs belonging to the current AP MLD until it receives a UHR Link Reconfiguration Response Frame, it may include a UHR Multi-Link element containing a field indicating UHR Link Reconfiguration Mode 2 in the frame sent to the AP belonging to the current AP MLD.

[0182] Information related to Seamless Roaming may include at least information indicating the UHR Link Reconfiguration mode. Information indicating the UHR Link Reconfiguration mode may also include information indicating whether a non-AP STA belonging to a non-AP MLD will stop sending Data frames to APs belonging to the current AP MLD when sending a UHR Link Reconfiguration Request Frame until it receives a UHR Link Reconfiguration Response Frame. Information related to Seamless Roaming may include at least the UHR Link Reconfiguration Mode subfield. A non-AP STA belonging to a non-AP MLD may send a frame containing information related to Seamless Roaming if it supports at least one of UHR Link Reconfiguration Mode 1 or UHR Link Reconfiguration Mode 2. If an AP belonging to the current AP MLD receives a frame from a non-AP STA belonging to a non-AP MLD that contains information related to Seamless Roaming, it may decide whether to forward the Data frame to an AP belonging to the target AP MLD based on the received information. For example, if an AP belonging to the current AP MLD receives a frame from a non-AP STA belonging to a non-AP MLD that contains information related to Seamless Roaming indicating UHR Link Reconfiguration Mode 1, it may decide not to forward the data frame to the AP belonging to the target AP MLD.For example, an AP belonging to the current AP MLD may decide to forward a data frame to the AP belonging to the target AP MLD if the frame received from a non-AP STA belonging to the non-AP MLD contains information related to Seamless Roaming indicating UHR Link ReconfigurationMode 2.

[0183] If an AP belonging to the current AP MLD decides to forward a Data frame to an AP belonging to the target AP MLD, it may forward the Data frame received from a non-AP STA belonging to a non-AP MLD to the AP belonging to the target AP MLD. For example, if an AP belonging to the current AP MLD receives a Data frame from a non-AP STA belonging to a non-AP MLD after a DS mapping update, it may forward that Data frame to the AP belonging to the target AP MLD until it sends a UHR Link Reconfiguration Response Frame. The AP belonging to the target AP MLD may deliver the Data frame forwarded from the AP belonging to the current AP MLD to the DS as MAC service tuples. If an AP belonging to the current AP MLD receives a Data frame from a non-AP STA belonging to a non-AP MLD after a DS mapping update, it does not have to forward that Data frame to the AP belonging to the target AP MLD after sending a UHR Link Reconfiguration Response Frame. If an AP belonging to the current AP MLD receives a Data Frame from a non-AP STA belonging to a non-AP MLD before a DS mapping update, it does not need to forward that Data Frame to an AP belonging to the target AP MLD. If an AP belonging to the current AP MLD receives a Data Frame from a non-AP STA belonging to a non-AP MLD before a DS mapping update, it may distribute that Data Frame to the DS as MAC service tuples.

[0184] In Seamless Roaming, while a non-AP MLD roams from the current AP MLD to the target AP MLD, the context associated with the non-AP MLD may be transferred from the current AP MLD to the target AP MLD. For example, in Seamless Roaming, the current AP MLD may begin transferring the context associated with the non-AP MLD to the target AP MLD when it receives a frame from an STA belonging to the non-AP MLD requesting roaming to the target AP MLD from an AP belonging to the current AP MLD. The "context associated with the non-AP MLD" may include the Sequence Number (SN). The "context associated with the non-AP MLD" may include the Packet Number (PN). The "context associated with the non-AP MLD" may include the Pairwise Transient Key (PTK). The "context associated with the non-AP MLD" may include the Pairwise Master Key (PMK). The "context associated with the non-AP MLD" may include information about the Stream Classification Service (SCS). The “context related to non-AP MLD” may include information regarding TWT (Target Wake Time). The “context related to non-AP MLD” may include Block Ack (BA) agreements. The “context related to non-AP MLD” may include other information related to non-AP MLD.

[0185] In Seamless Roaming, while a non-AP MLD roams from the current AP MLD to the target AP MLD, the current AP MLD may forward one or more frames to the target AP MLD. In Seamless Roaming, frames forwarded from the current AP MLD to the target AP MLD may include Data frames sent from APs belonging to the current AP MLD and / or the target AP MLD to STAs belonging to the non-AP MLD. In Seamless Roaming, frames forwarded from the current AP MLD to the target AP MLD may include individually addressed QoS Data frames. In Seamless Roaming, frames forwarded from the current AP MLD to the target AP MLD may include individually addressed Management frames. In Seamless Roaming, frames forwarded from the current AP MLD to the target AP MLD may include IQMFs. In Seamless Roaming, frames forwarded from the current AP MLD to the target AP MLD may include other types of frames.

[0186] Because MAC-level acknowledgments and retransmissions are built into the protocol, frames may be received multiple times. The procedures described in this document may attempt to filter out these duplicates. Filtering of duplicate frames may be facilitated by including the Sequence Control field (consisting of a sequence number and a fragment number) in Data, Management, and Extension frames, the TID subfield in the QoS Control field in QoS Data frames, the ACI (Access Category Index) subfield in the Sequence Number field in QMFs (QoS Management Frames), and the PTID (Peer Traffic Indication) / Subtype subfield in the FrameControl field in PV1 (Protocol Version 1) Data frames.

[0187] An STA may maintain one or more sequence number spaces used to determine the sequence number of a frame when it transmits a frame. An MLD may maintain one or more sequence number spaces used to determine the sequence number of a frame when an STA belonging to the MLD transmits an individually addressed QoS Data frame to an STA belonging to an associated MLD.

[0188] A Super MLD may maintain one or more sequence number spaces used to determine the sequence number of a frame when an AP belonging to an AP MLD belonging to the Super MLD sends an individually addressed QoS Data frame to a non-AP STA belonging to an associated non-AP MLD. An "individually addressed QoS Data frame" may be referred to as a "frame." An "individually addressed QoS Dataframe" may be rephrased as a "frame." The aforementioned "frame" may include individually addressed QoS Data frames and other types of frames.

[0189] AP MLD3 and AP MLD4 may hold one or more sequencenumber spaces used to determine the sequence number of a frame when an AP belonging to AP MLD3 or AP MLD4 sends an individually addressed QoS Data frame to a non-AP STA belonging to the connected non-APMLD5. AP MLD3 and AP MLD4 may belong to a Super MLD. The “individually addressed QoS Data frame” may be referred to as a “frame.” The “individually addressed QoS Data frame” may be rephrased as a “frame.” The “frame” described above may include individually addressed QoS Data frames and other types of frames.

[0190] If either MLD1 or MLD2 is a non-QMF MLD, MLD1 may maintain a single sequence number space used to determine the sequence number of a frame when it sends an individually addressed Management frame to an STA belonging to another STA belonging to MLD2 via an STA belonging to MLD1.

[0191] If any of the AP MLD3, AP MLD4, or non-AP MLD5 belonging to Super MLD is a non-QMF MLD, Super MLD may maintain a single sequence number space used to determine the sequence number of a frame when sending an individually addressed Management frame to a non-AP STA belonging to non-AP MLD5 via an AP belonging to AP MLD3 or AP MLD4. "AP MLD3 or AP MLD4" may be referred to as "AP MLD3 and AP MLD4", "AP MLD3", etc. "AP MLD3 or AP MLD4" may be rephrased as "AP MLD3 and AP MLD4", "AP MLD3", etc. "If any of the AP MLD3, AP MLD4, or non-AP MLD5 belonging to Super MLD is a non-QMF MLD" may be referred to as "If either Super MLD or non-AP MLD5 is a non-QMF MLD". The phrase “If any of AP MLD3 belonging to Super MLD, or AP MLD4 belonging to Super MLD, or non-AP MLD5 is a non-QMF MLD” may be rephrased as “If either Super MLD or non-AP MLD5 is a non-QMF MLD.” “Individually addressed Management frame” may be referred to as “frame.” “Individually addressed Management frame” may be rephrased as “frame.” The aforementioned “frame” may include individually addressed Management frames and other types of frames.

[0192] If either AP MLD3 or AP MLD4, or non-AP MLD5, is a non-QMF MLD, then AP MLD3 and AP MLD4 may maintain a single sequence number space used to determine the frame sequence number when sending individually addressed Management frames to non-AP STAs belonging to non-AP MLD5 via APs belonging to AP MLD3 or AP MLD4. "AP MLD3 or AP MLD4" may also be referred to as "AP MLD3 and AP MLD4", "AP MLD3", etc. "AP MLD3 or AP MLD4" may also be rephrased as "AP MLD3 and AP MLD4", "AP MLD3", etc. AP MLD3 and AP MLD4 may belong to a Super MLD. In this case, "if either AP MLD3 or AP MLD4, or non-AP MLD5, is a non-QMF MLD" may also be referred to as "if either Super MLD or non-AP MLD5, is a non-QMF MLD". The phrase “If AP MLD3 or AP MLD4 or non-AP MLD5 is a non-QMF MLD” may be rephrased as “If Super MLD or non-AP MLD5 is a non-QMF MLD.” “Individually addressed Management frame” may be referred to as “frame.” “Individually addressed Management frame” may be rephrased as “frame.” The aforementioned “frame” may include individually addressed Management frames and other types of frames.

[0193] A QMF MLD may maintain a single sequencenumber space for each AC, which is used to determine the sequence number of a frame when the MLD transmits an IQMF to an STA belonging to another QMF MLD via an STA belonging to the MLD.

[0194] If either AP MLD6 or AP MLD7 belonging to Super MLD is a QMF MLD, Super MLD may maintain a single sequence number space for each AC used to determine the sequence number of a frame when an AP MLD belonging to Super MLD transmits IQMF to a non-AP STA belonging to another QMF MLD via an AP belonging to that AP MLD. The phrase "if either AP MLD6 or AP MLD7 belonging to Super MLD is a QMF MLD" may also be referred to as "if the AP MLD belonging to Super MLD is a QMF MLD", "if Super MLD is a QMF MLD", etc. The phrase "if either AP MLD6 or AP MLD7 belonging to Super MLD is a QMF MLD" may also be rephrased as "if the AP MLD belonging to Super MLD is a QMF MLD", "if Super MLD is a QMF MLD", etc. "AP MLD belonging to Super MLD" and "the said AP MLD" may also be referred to as "QMF MLD belonging to Super MLD" and "the said QMF MLD," respectively. "AP MLD belonging to Super MLD" and "the said AP MLD" may also be rephrased as "QMF MLD belonging to Super MLD" and "the said QMF MLD," respectively. "IQMF" may also be referred to as "frame." "IQMF" may also be rephrased as "frame." The aforementioned "frame" may include IQMF and other types of frames.

[0195] If either AP MLD6 or AP MLD7 is a QMF MLD, AP MLD6 and AP MLD7 may maintain a single sequence number space for each AC used to determine the sequence number of a frame when the QMF MLD transmits an IQMF to a non-AP STA belonging to another QMF MLD via the AP belonging to that QMF MLD. AP MLD6 and AP MLD7 may belong to a Super MLD. The phrase "If either AP MLD6 or AP MLD7 is a QMF MLD" may also be referred to as "If the AP MLD is a QMF MLD", "If the Super MLD is a QMF MLD", etc. The phrase "If either AP MLD6 or AP MLD7 is a QMF MLD" may also be rephrased as "If the AP MLD is a QMF MLD", "If the Super MLD is a QMF MLD", etc. "IQMF" may also be referred to as "frame". The aforementioned “frames” may include IQMF and other types of frames.

[0196] If multiple sequence number spaces are supported, the appropriate sequence number space may be determined by information from the MAC control fields of the transmitted frame. Each sequence number space may be represented by a modulo 4096 counter that starts at 0 and increments by 1 for each MSDU, A-MSDU, or MMPDU transmitted using that sequence number space. If dot11MACPrivacyActivated is true, the counter in each sequence number space may be set to a modulo 4096 random number when the STA's MAC address changes. If a Super MLD holds a sequence number space, the Super MLD may sequentially assign sequence numbers to frames transmitted by APs belonging to AP MLDs belonging to the Super MLD. If AP MLD1 and AP MLD2 hold sequence number spaces, AP MLD1 and AP MLD2 may sequentially assign sequence numbers to frames transmitted by APs belonging to AP MLD1 or AP MLD2. If AP MLD1 and AP MLD2, which belong to Super MLD, maintain a sequence number space, AP MLD1 and AP MLD2 may sequentially assign sequence numbers to frames transmitted by APs belonging to AP MLD1 or AP MLD2.

[0197] MPDUs contained within the same MSDU or A-MSDU may have the same sequence number. Different MSDUs or A-MSDUs may (with a high probability) have different sequence numbers.

[0198] The transmitting STA may support applicable sequence number spaces. The MLD may support applicable sequence number spaces, with a status of "Mandatory".

[0199] Super MLD may support applicable sequence number spaces with a status of "Mandatory". AP MLD1 and AP MLD2 may support applicable sequence number spaces with a status of "Mandatory".

[0200] An STA belonging to an MLD may use the sequence number space identifier maintained by the MLD to determine the sequence number of an individually addressed QoS Data frame sent to an STA belonging to another MLD.

[0201] APs belonging to an AP MLD belonging to a Super MLD may use the sequence number space identifier held by the Super MLD to determine the sequence number of an individually addressed QoS Data frame sent to a non-AP STA belonging to a connected non-AP MLD (associated non-AP MLD). The “individually addressed QoS Data frame” may also be referred to as a “frame.” The “individually addressed QoS Data frame” may be rephrased as a “frame.” The aforementioned “frame” may include individually addressed QoS Data frames and other types of frames. The “sequence number space identifier held by the Super MLD” may be a different sequence number space identifier from the “sequence number space identifier held by the MLD.” The “sequence number space identifier held by the Super MLD” may be the same sequence number space identifier as the “sequence number space identifier held by the MLD.”

[0202] APs belonging to AP MLD3 or AP MLD4 may use the sequence number space identifiers held by AP MLD3 and AP MLD4 to determine the sequence number of an individually addressed QoS Data frame sent to a non-AP STA belonging to the connected non-AP MLD5. AP MLD3 and AP MLD4 may also belong to a Super MLD. The “individually addressed QoS Data frame” may be referred to as a “frame.” The “individually addressed QoS Data frame” may be rephrased as a “frame.” The aforementioned “frame” may include individually addressed QoS Data frames and other types of frames. The “sequence number space identifiers held by AP MLD3 and AP MLD4” may be different from the “sequence number space identifiers held by the MLD.” The “sequence number space identifiers held by AP MLD3 and AP MLD4” may be the same as the “sequence number space identifiers held by the MLD.”

[0203] If either MLD1 or MLD2 is a non-QMF MLD, the STA belonging to MLD1 may use the sequence number space identifier held by MLD1 to determine the sequence number of the individually addressed Management frame that is sent to the other STA belonging to MLD2.

[0204] If any of the AP MLD3, AP MLD4, or non-AP MLD5 belonging to Super MLD is a non-QMF MLD, the AP belonging to AP MLD3 or AP MLD4 may use the sequence number space identifier held by Super MLD to determine the sequence number of the individually addressed Management frame sent to the non-AP STA belonging to non-AP MLD5. "AP MLD3 or AP MLD4" may also be referred to as "AP MLD3 and AP MLD4", "AP MLD3", etc. "AP MLD3 or AP MLD4" may also be rephrased as "AP MLD3 and AP MLD4", "AP MLD3", etc. "If any of the AP MLD3, AP MLD4, or non-AP MLD5 belonging to Super MLD is a non-QMF MLD" may also be referred to as "If either Super MLD or non-AP MLD5 is a non-QMF MLD". The phrase “If any of AP MLD3 belonging to Super MLD, or AP MLD4 belonging to Super MLD, or non-AP MLD5 is a non-QMF MLD” may be rephrased as “If either Super MLD or non-AP MLD5 is a non-QMF MLD.” “Individually addressed Management frame” may be referred to as “frame.” “Individually addressed Management frame” may be rephrased as “frame.” The aforementioned “frame” may include individually addressed Management frames and other types of frames. “The sequence number space identifier held by Super MLD” may be a different sequence number space identifier from “the sequence number space identifier held by MLD1.”The "sequence number space identifier held by Super MLD" may be the same sequence number space identifier as the "sequence number space identifier held by MLD1".

[0205] If either AP MLD3 or AP MLD4, or non-AP MLD5, is a non-QMF MLD, the AP belonging to AP MLD3 or AP MLD4 may use the sequence number space identifier held by AP MLD3 and AP MLD4 to determine the sequence number of the individually addressed Management frame sent to the non-AP STA belonging to non-AP MLD5. "AP MLD3 or AP MLD4" may also be referred to as "AP MLD3 and AP MLD4", "AP MLD3", etc. "APMLD3 or AP MLD4" may also be rephrased as "AP MLD3 and AP MLD4", "AP MLD3", etc. AP MLD3 and AP MLD4 may also belong to a Super MLD. In this case, "if either AP MLD3 or AP MLD4, or non-AP MLD5, is a non-QMF MLD" may also be referred to as "if either SuperMLD, or non-AP MLD5, is a non-QMF MLD". The phrase “If APMLD3 or AP MLD4 or non-AP MLD5 is a non-QMF MLD” may be rephrased as “If Super MLD or non-AP MLD5 is a non-QMF MLD.” “Individually addressed Management frame” may be referred to as “frame.” “Individually addressed Management frame” may be rephrased as “frame.” The aforementioned “frame” may include individually addressed Management frames and other types of frames. The “sequence number space identifier held by AP MLD3 and AP MLD4” may be a different sequence number space identifier from the “sequence number space identifier held by MLD1.”The "sequence number space identifier held by AP MLD3 and AP MLD4" may be the same sequence number space identifier as the "sequence number space identifier held by MLD1".

[0206] An STA belonging to a QMF MLD may use the sequence number space identifier maintained by the QMF MLD to determine the sequence number of an IQMF that is sent to an STA belonging to another QMF MLD.

[0207] If either AP MLD6 or AP MLD7 belonging to Super MLD is a QMF MLD, the AP belonging to that QMF MLD may use the sequence number space identifier held by Super MLD to determine the sequence number of the IQMF that is sent to a non-AP STA belonging to another QMF MLD. The phrase "If either AP MLD6 or AP MLD7 belonging to Super MLD is a QMF MLD" may also be referred to as "If the AP MLD belonging to Super MLD is a QMF MLD", "If Super MLD is a QMF MLD", etc. The phrase "If either AP MLD6 or AP MLD7 belonging to Super MLD is a QMF MLD" may also be rephrased as "If the AP MLD belonging to Super MLD is a QMF MLD", "If Super MLD is a QMF MLD", etc. "IQMF" may also be referred to as "frame". The aforementioned “frames” may include IQMF and other types of frames. The “sequence number space identifier held by Super MLD” may be a different sequence number space identifier from the “sequence number space identifier held by QMF MLD.” The “sequence number space identifier held by Super MLD” may be the same sequence number space identifier as the “sequence number space identifier held by QMF MLD.”

[0208] If either AP MLD6 or AP MLD7 is a QMF MLD, the AP belonging to that QMF MLD may use the sequence number space identifier held by AP MLD6 and AP MLD7 to determine the sequence number of the IQMF transmitted to a non-AP STA belonging to the other QMF MLD. The phrase "If either AP MLD6 or AP MLD7 is a QMF MLD" may also be referred to as "If the AP MLD is a QMF MLD," "If the Super MLD is a QMF MLD," etc. The phrase "If either AP MLD6 or AP MLD7 is a QMF MLD" may also be rephrased as "If the AP MLD is a QMF MLD," "If the Super MLD is a QMF MLD," etc. "IQMF" may also be referred to as "frame." "IQMF" may also be rephrased as "frame." The above-mentioned "frame" may include IQMF and other types of frames. The "sequence number space identifier held by Super MLD" may be a different sequence number space identifier from the "sequence number space identifier held by AP MLD6 and AP MLD7". The "sequence number space identifier held by SuperMLD" may be the same sequence number space identifier as the "sequence number space identifier held by AP MLD6 and AP MLD7".

[0209] STA or MLD may maintain one or more duplicate detection caches. When a Data, Management, or Extension frame is received, the record of that frame may be inserted into the appropriate cache. The record may be identified by its sequence number and, optionally, by other information from the frame's MAC control fields. When a Data, Management, or Extension frame is received in which the Retry subfield of the Frame Control field is equal to 1, the appropriate cache may search for a matching frame, if any. In DMG (Directional Multi-Gigabit), when a group-addressed frame is received, the appropriate cache may search for a matching frame, if any, even if the Retry subfield in the Frame Control field is absent. If the search is successful, the frame may be considered a duplicate. Duplicate frames may be discarded. All non-AP STAs belonging to a non-AP MLD may, when receiving a frame from an AP belonging to an AP MLD belonging to a Super MLD, use the sequence number of that frame to detect duplicate frames sent from APs belonging to other AP MLDs belonging to the same Super MLD. All non-AP STAs belonging to a non-AP MLD may, when receiving a frame from an AP belonging to a certain APMLD, use the sequence number of that frame to detect duplicate frames sent from APs belonging to other AP MLDs.

[0210] A receiving STA may implement applicable receiver requirements, with a status of "Mandatory". An MLD may implement applicable receiver requirements, with a status of "Mandatory".

[0211] All STAs belonging to an MLD may use identifiers that identify duplicate detection caches held by the MLD to assist the MLD in discarding duplicate, individually addressed QoS Data frames belonging to TIDs without BA negotiation that are sent from STAs belonging to other MLDs.

[0212] All non-AP STAs belonging to a non-AP MLD may use identifiers that identify duplicate detection caches held by the non-AP MLD to assist the non-AP MLD in discarding duplicate, individually addressed QoS Data frames belonging to TIDs without BA negotiation, transmitted from APs belonging to AP MLDs belonging to Super MLDs. A “duplicate, individually addressed QoS Data frame belonging to a TID without BA negotiation” may be referred to as a “duplicate frame.” The “duplicate frame” described above may include duplicate, individually addressed QoS Data frames and other types of duplicate frames belonging to TIDs without BA negotiation.

[0213] All non-AP STAs belonging to non-AP MLD3 may use identifiers that identify duplicate detection caches held by non-AP MLDs to assist non-AP MLDs in discarding duplicate, individually addressed QoS Data frames belonging to TIDs without BA negotiation, transmitted from APs belonging to AP MLD4 or AP MLD5. AP MLD3 and AP MLD4 may belong to Super MLDs. The “duplicate, individually addressed QoS Data frame belonging to a TID without BA negotiation” may be referred to as a “duplicate frame.” The “duplicate frame” described above may include duplicate, individually addressed QoS Data frames and other types of duplicate frames belonging to TIDs without BA negotiation.

[0214] If either MLD1 or MLD2 is a non-QMF MLD, all STAs belonging to MLD1 may use identifiers that identify duplicate detection caches held by MLD1 to assist MLD1 in discarding duplicate, individually addressed Management frames sent from STAs belonging to the other MLD2.

[0215] If non-AP MLD3, or AP MLD4 belonging to Super MLD, or AP MLD5 belonging to Super MLD is a non-QMF MLD, all non-AP STAs belonging to non-AP MLD3 may use identifiers that identify duplicate detection caches held by non-AP MLD3 to assist non-AP MLD3 in discarding duplicate, individually addressed Management frames sent from APs belonging to AP MLD3 or AP MLD4. "AP MLD4 or AP MLD5" may also be referred to as "AP MLD4 and AP MLD5", "AP MLD4", etc. "AP MLD4 or AP MLD5" may also be rephrased as "AP MLD4 and AP MLD5", "AP MLD4", etc. The phrase “when either non-AP MLD3, or AP MLD4 belonging to Super MLD, or AP MLD5 belonging to Super MLD is a non-QMF MLD” may also be referred to as “when either non-AP MLD3, or Super MLD is a non-QMF MLD.” The phrase “when either non-AP MLD3, or AP MLD4 belonging to Super MLD, or AP MLD5 belonging to Super MLD is a non-QMF MLD” may also be rephrased as “when either non-AP MLD3, or Super MLD is a non-QMF MLD.” “Duplicate individually addressed Management frames” may also be referred to as “duplicate frames.” The “duplicate frames” described above may include duplicate individually addressed Management frames and other types of duplicate frames.

[0216] If non-AP MLD3, AP MLD4, or AP MLD5 is a non-QMF MLD, all non-AP STAs belonging to non-AP MLD3 may use identifiers that identify duplicate detection caches held by non-AP MLD3 to assist non-AP MLD3 in discarding duplicate, individually addressed Management frames sent from APs belonging to AP MLD3 or AP MLD4. "AP MLD4 or AP MLD5" may be referred to as "AP MLD4 and AP MLD5", "AP MLD4", etc. "AP MLD4 or AP MLD5" may be rephrased as "AP MLD4 and AP MLD5", "AP MLD4", etc. AP MLD4 and AP MLD5 may belong to a Super MLD. In this case, “when non-AP MLD3, AP MLD4, or AP MLD5 is a non-QMF MLD” may be rephrased as “when non-AP MLD3, or Super MLD is a non-QMF MLD.” “when non-AP MLD3, AP MLD4, or AP MLD5 is a non-QMF MLD” may be rephrased as “when non-AP MLD3, or Super MLD is a non-QMF MLD.” “Duplicate individually addressed Management frames” may be rephrased as “duplicate frames.” The “duplicate frames” described above may include duplicate individually addressed Management frames and other types of duplicate frames.

[0217] All STAs belonging to a QMF MLD may use identifiers that identify duplicate detection caches held by the QMF MLD to assist the QMF MLD in discarding duplicate IQMFs sent from STAs belonging to other QMF MLDs.

[0218] If either AP MLD6 or AP MLD7 belonging to Super MLD is a QMF MLD, all non-AP STAs belonging to the QMF MLD may use identifiers that identify duplicate detection caches held by the QMF MLD to assist the QMF MLD in discarding duplicate IQMFs transmitted from the AP MLD belonging to Super MLD through the AP belonging to that AP MLD. The phrase "If either AP MLD6 or AP MLD7 belonging to Super MLD is a QMF MLD" may also be referred to as "If the AP MLD belonging to Super MLD is a QMF MLD", "If the Super MLD is a QMF MLD", etc. The phrase "If either AP MLD6 or AP MLD7 belonging to Super MLD is a QMF MLD" may also be rephrased as "If the AP MLD belonging to Super MLD is a QMF MLD", "If the Super MLD is a QMF MLD", etc. "AP MLD belonging to Super MLD" and "the said AP MLD" may also be referred to as "QMF MLD belonging to Super MLD" and "the said QMF MLD," respectively. "AP MLD belonging to Super MLD" and "the said AP MLD" may also be rephrased as "QMF MLD belonging to Super MLD" and "the said QMF MLD," respectively. "Duplicate IQMF" may also be referred to as "duplicate frame." "Duplicate IQMF" may also be rephrased as "duplicate frame." The above-mentioned "duplicate frame" may include duplicate IQMF and other types of duplicate frames.

[0219] If either AP MLD6 or AP MLD7 is a QMF MLD, all non-AP STAs belonging to the QMF MLD may use identifiers that identify duplicate detection caches held by the QMF MLD to assist the QMF MLD in discarding duplicate IQMFs transmitted from other QMF MLDs through APs belonging to that QMF MLD. AP MLD6 and AP MLD7 may also belong to a Super MLD. "If either AP MLD6 or AP MLD7 is a QMF MLD" may be referred to as "if the AP MLD is a QMF MLD", "if the Super MLD is a QMF MLD", etc. "If either AP MLD6 or AP MLD7 is a QMF MLD" may be rephrased as "if the AP MLD is a QMF MLD", "if the Super MLD is a QMF MLD", etc. "Duplicate IQMF" may be referred to as "duplicate frame". "Duplicate IQMF" may be rephrased as "duplicate frame". The aforementioned “duplicate frames” may include duplicate IQMF and other types of duplicate frames.

[0220] An A-MSDU may contain only an MSDU of a single service class and may inherit that service class for the purposes of the following rules: For MSDUs or A-MSDUs belonging to the QoSAck service class when the receiver is a QoS STA, the QoS Data frame used to transmit these MSDUs or A-MSDUs may have an ack policy of Normal Ack, Implicit BAR, PSMP Ack, or Block Ack. For MSDUs or A-MSDUs belonging to the QoSNoAck service class when the receiver is a QoS STA, the QoS Data frame used to transmit these MSDUs or A-MSDUs may have an ack policy of No Ack.

[0221] Figure 13 shows an example of a UHR Link Reconfiguration procedure according to one aspect of this embodiment. 1301 may be a non-AP MLD. 1301 may be a non-AP STA belonging to a non-AP MLD. 1302 may be a current AP MLD. 1302 may be an AP belonging to a current AP MLD. 1303 may be a target AP MLD. 1303 may be an AP belonging to a target AP MLD. 1304 may be a DS. In Figure 13, the vertical axis may represent time. 1305 may be a timeline of the operation of 1301. 1306 may be a timeline of the operation of 1302. 1307 may be a timeline of the operation of 1303. 1308 may be a timeline of the operation of 1304. 1309 may be the transmission of a UHR Link Reconfiguration Request Frame to 1302. 1309 may receive a UHR Link Reconfiguration Request Frame from 1301. 1310 may update the AP MLD that MAC service tuples distributed between 1301 and 1304 pass through from 1302 to 1303. 1310 may generate a DS-STA-NOTIFY primitive by 1302. 1310 may generate a DS-STA-NOTIFY primitive by 1303. 1310 may perform a DS mapping update. 1311 may send a UHR Link Reconfiguration Response Frame to 1301. 1311 may receive a UHR Link Reconfiguration Response Frame from 1302. 1301 may send a frame to 1302 before 1309. 1302 may receive a frame from 1301 before 1309. If 1302 receives a frame from 1301 before 1309, it may deliver that frame to 1304 before 1310.If 1301 supports UHR Link Reconfiguration Mode 1, it does not need to send frames to 1302 after 1309. If 1301 supports UHR Link Reconfiguration Mode 1, it does not need to send frames to 1302 from 1309 until 1311. 1302 does not need to receive frames from 1301 after 1309. If 1301 supports UHR Link Reconfiguration Mode 2, it may send frames to 1302 after 1309. If 1301 supports UHR Link Reconfiguration Mode 2, it may send frames to 1302 from 1309 until 1311. 1302 may receive frames from 1301 after 1309. If 1302 receives a frame from 1301 after 1309, it may deliver that frame to 1304 before 1310. If 1302 receives a frame from 1301 after 1309, it may forward that frame to 1303 after 1310. If 1302 receives a frame from 1301 after 1309, it does not have to forward that frame to 1303 after 1311. If 1302 receives a frame from 1301 after 1309, it does not have to forward that frame to 1303 before 1310. If 1302 receives a frame from 1301 before 1309, it does not have to forward that frame to 1303. If 1303 receives a frame from 1302, it does not have to forward that frame to 1304. "After 1309" may also be referred to as "before 1311". If 1301 supports UHR Link Reconfiguration Mode 1, it may send a frame to 1303 after 1311. If 1301 supports UHR Link Reconfiguration Mode 1, it may start sending frames to 1303 at the same time as 1311.If 1301 supports UHR Link Reconfiguration Mode 2, it may send a frame to 1303 after 1311. If 1301 supports UHR Link Reconfiguration Mode 2, it may start sending frames to 1303 before 1311. 1303 may receive a frame from 1301 after 1311. If 1303 receives a frame from 1301 after 1311, it may deliver that frame to 1304. In Figure 13, the frames transmitted, received, forwarded, and / or delivered may be, for example, Data frames. In Figure 13, the frames transmitted, received, forwarded, and / or delivered may be, for example, MSDUs. In Figure 13, the frames transmitted, received, forwarded, and / or delivered may be, for example, A-MSDUs. In Figure 13, the frames transmitted, received, forwarded, and / or delivered may be, for example, MMPDUs. In Figure 13, the frames transmitted, received, forwarded, and / or delivered may be, for example, PPDUs. In Figure 13, the frames transmitted, received, forwarded, and / or delivered may be, for example, individually addressed QoS Data frames. In Figure 13, the frames transmitted, received, forwarded, and / or delivered may be, for example, individually addressed Management frames. In Figure 13, the frames transmitted, received, forwarded, and / or delivered may be, for example, IQMFs. In Figure 13, the frames transmitted, received, forwarded, and / or delivered may be, for example, other types of frames. "Frame" may be replaced with "MAC service tuples," etc.

[0222] The term "frame" may also be referred to as a "MAC frame." The term "frame" may be rephrased as "MAC frame." The term "frame" may include MSDU, A-MSDU, and / or MMPDU.

[0223] "Maintaining a sequence number space" may also mean maintaining it in order to determine the sequence number of a frame. For example, "maintaining a sequence number space" may include "starting a modulo 4096 counter from 0" or "incrementing a modulo 4096 counter by 1". "Maintaining a sequence number space" may also be called "maintaining the sequence number space". "Maintaining a sequence number space" may be rephrased as "maintaining the sequence number space". "Maintaining a sequence number space identifier" may also be called "maintaining the sequence number space identifier". "Maintaining a sequence number space identifier" may be rephrased as "maintaining the sequence number space identifier".

[0224] A Super MLD may maintain a 1-based 48-bit counter for sequentially assigning packet numbers (PNs) to frames transmitted by APs belonging to AP MLDs belonging to the Super MLD. AP MLD1 and AP MLD2 may maintain a 1-based 48-bit counter for sequentially assigning packet numbers to frames transmitted by APs belonging to AP MLD1 or AP MLD2. AP MLD1 and AP MLD2 belonging to the Super MLD may maintain a 1-based 48-bit counter for sequentially assigning packet numbers to frames transmitted by APs belonging to AP MLD1 or AP MLD2. All non-AP STAs belonging to a non-AP MLD may, upon receiving a frame from an AP belonging to an AP MLD belonging to the Super MLD, use the packet number of that frame to detect tampered frames transmitted from APs belonging to other AP MLDs belonging to the same Super MLD. All non-AP STAs belonging to a non-AP MLD may, upon receiving a frame from an AP belonging to a certain AP MLD, use the packet number of that frame to detect tampered frames transmitted from APs belonging to other AP MLDs. Packet numbers are not repeated for the same temporal key.

[0225] As described above, in embodiments of the present invention, when a non-AP STA belonging to a non-AP MLD sends a frame to request the addition of a link to a target AP MLD, it continues to send data frames to APs belonging to the current AP MLD until it receives a response frame to the request to add a link to the target AP MLD. In one aspect of this invention, a non-AP STA belonging to a non-AP MLD can send data frames to APs belonging to an AP MLD with low latency even during Seamless Roaming.

[0226] The programs that operate in the base station device and terminal device according to embodiments of the present invention may be programs that control the CPU (Central Processing Unit) and the like (programs that make the computer function) in order to realize the functions of the above embodiments according to embodiments of the present invention. The information handled by these devices is temporarily stored in RAM (Random Access Memory) during processing, and then stored in various ROMs such as Flash ROM (Read Only Memory) or HDD (Hard Disk Drive), and read, modified, and written by the CPU as needed.

[0227] Furthermore, the terminal device and some of the base station devices in the above-described embodiment may be implemented using a computer. In that case, the program for implementing this control function may be recorded on a computer-readable recording medium, and the program recorded on this recording medium may be loaded into a computer system and executed.

[0228] Furthermore, the term "computer system" as used herein refers to a computer system built into a terminal device or base station device, and includes hardware such as the operating system and peripheral devices. Also, "computer-readable recording media" refers to portable media such as flexible disks, magneto-optical disks, ROMs, and CD-ROMs, as well as storage devices such as hard disks built into computer systems.

[0229] Furthermore, "computer-readable recording media" may include those that dynamically hold programs for a short period of time, such as communication lines used when transmitting programs via networks such as the Internet or communication lines such as telephone lines, as well as those that hold programs for a certain period of time, such as volatile memory within a computer system that acts as a server or client in such cases. In addition, the above-mentioned program may be for the purpose of realizing some of the functions described above, and may also be a program that can realize the above-mentioned functions in combination with a program already recorded in the computer system.

[0230] The terminal device may consist of at least one processor and at least one memory containing computer program instructions (computer program). The memory and computer program instructions (computer program) may be configured to cause the terminal device to perform the operations and processing described in the above embodiment using the processor. The base station device may consist of at least one processor and at least one memory containing computer program instructions (computer program). The memory and computer program instructions (computer program) may be configured to cause the base station device to perform the operations and processing described in the above embodiment using the processor.

[0231] Furthermore, the base station equipment in the above-described embodiment can also be implemented as an assembly (device group) composed of multiple devices. Each device constituting the device group may have some or all of the functions or functional blocks of the base station equipment related to the above-described embodiment. The device group only needs to have a complete set of functions or functional blocks of the base station equipment. In addition, the terminal equipment related to the above-described embodiment can also communicate with the base station equipment as an assembly.

[0232] Furthermore, some or all of the terminal device and base station device in the above-described embodiments may be implemented as LSIs, which are typically integrated circuits, or as chipsets. Each functional block of the terminal device and base station device may be individually chipped, or some or all of them may be integrated into a single chip. In addition, the method of implementing the integrated circuit is not limited to LSIs; it may also be implemented using dedicated circuits or general-purpose processors. Moreover, if advances in semiconductor technology lead to the emergence of integrated circuit technologies that can replace LSIs, it is also possible to use integrated circuits based on those technologies.

[0233] Furthermore, although the above-described embodiment mentions a terminal device as an example of a communication device, the present invention is not limited to this and can also be applied to stationary or non-movable electronic devices installed indoors or outdoors, such as AV equipment, kitchen equipment, cleaning and washing machines, air conditioning equipment, office equipment, vending machines, and other household appliances, as well as terminal devices or communication devices.

[0234] While embodiments of this invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments, and design modifications and the like that do not depart from the gist of this invention are also included. Furthermore, various modifications are possible within the scope of the claims for one aspect of the present invention, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. In addition, configurations in which elements described in each of the above embodiments that produce similar effects are substituted for each other are also included.

[0235] One aspect of the present invention can be used, for example, in communication systems, communication equipment (e.g., mobile phone devices, base station devices, wireless LAN devices, or sensor devices), integrated circuits (e.g., communication chips), or programs.

[0236] 101, 201, 205 BSS 102, 202, 206 AP 103, 104, 203, 204, 207, 208 STA SU1, AU1 Antenna section SU2, AU2 RF section SU3, AU3 Physical layer processing section SU4, AU4 MAC layer processing section SU5 Upper layer packet processing section SU6, AU6 Wireless transceiver section SU7, AU7 Frame processing section AU5 DSAF section 1101, 1104 STA transmission 1102, 1211 IFS 1103, 1212 Backoff counter (concentration window) 1201, 1202, 1203, 1204 Timeline 1205 RTS frame 1206, 1208 NAV period 1207 CTS frame 1209 Data frame 1210 AcK frame

Claims

1. A terminal device having a non-AP MLD, wherein the non-AP MLD has at least a first non-AP STA, the first AP MLD connected to the non-AP MLD has at least a first AP, and the second AP MLD not connected to the non-AP MLD has at least a second AP, the terminal device includes a transmitting unit that transmits a first frame, a receiving unit that receives a second frame, and a processing unit, and when the terminal device transmits the first frame, it supports continuing to transmit a Data frame to the first AP until it receives the second frame, when the terminal device transmits the first frame, it does not stop transmitting a Data frame to the first AP until it receives the second frame, and when it receives the second frame, it starts transmitting a Data frame to the second AP, the first frame is a frame for executing an SMD-based BSS transition, and the second frame is a response frame to the first frame.

2. A base station device having a first AP MLD, wherein at least a first AP belongs to the first AP MLD, at least a first non-AP STA belongs to a non-AP MLD connected to the first AP MLD, at least a second AP belongs to a second AP MLD not connected to the non-AP MLD, the base station device includes a receiving unit for receiving a first frame, a transmitting unit for transmitting a second frame, and a processing unit, wherein when the first non-AP STA transmits the first frame, it supports continuing to transmit a Data frame to the first AP until it receives the second frame, when the first frame is received, the base station device does not allow the first non-AP STA to stop transmitting a Data frame to the first AP until it transmits the second frame, when the second frame is transmitted, the base station device instructs the first non-AP STA to start transmitting a Data frame to the second AP, the first frame is a frame for executing an SMD-based BSS transition, and the second frame is a response frame to the first frame.

3. A communication method comprising: a non-AP MLD to which at least a first non-AP STA belongs; a first AP MLD connected to the non-AP MLD to which at least a first AP belongs; a second AP MLD not connected to the non-AP MLD to which at least a second AP belongs; if the first non-AP STA supports continuing to transmit a Data frame to the first AP until it receives the second frame when transmitting the first frame, the first non-AP STA does not stop transmitting a Data frame to the first AP until it receives the second frame when transmitting the first frame, and when it receives the second frame, it starts transmitting a Data frame to the second AP; the first frame is a frame for executing an SMD-based BSS transition; and the second frame is a response frame to the first frame.

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