Multiple AP coordinated secondary channel access in WIFI systems

Abstract

Methods, devices and systems for multiple AP (MAP) coordinated secondary channel access (SCA) in WIFI systems are disclosed. The method, devices and systems may include MAP negotiation for SCA. The method, devices and systems may include MAP coordinated SCA procedure using trigger frames. The method, devices and systems may include MAP coordinated SCA procedure using unicast initial control frames.

Description

MULTIPLE AP COORDINATED SECONDARY CHANNEL ACCESS IN WIFI SYSTEMSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 554,003, Feb 15, 2024, the contents of which are incorporated herein by reference.BACKGROUND

[0002] Secondary channel access mechanisms allow an access point (AP) or non-AP STA(s) to transmit or receive frames on one or more secondary subchannels when the primary subchannel is busy or occupied observed or measured either at transmitter side or receiver side or both sides by an overlapping basic service set (OBSS) transmission.SUMMARY

[0003] Methods, devices and systems for multiple AP (MAP) coordinated secondary channel access (SCA) in WIFI systems are disclosed The method, devices and systems may include MAP negotiation for SCA. The method, devices and systems may include MAP coordinated SCA procedure using trigger frames. The method, devices and systems may include MAP coordinated SCA procedure using unicast initial control frames.BRIEF DESCRIPTION OF THE DRAWINGS

[0004] A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings, wherein like reference numerals in the figures indicate like elements, and wherein:

[0005] FIG. 1A is a system diagram illustrating an example communications system in which one or more disclosed embodiments may be implemented;

[0006] FIG. 1 B is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1 A according to an embodiment;

[0007] FIG. 1C is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG. 1A according to an embodiment;

[0008] FIG. 1 D is a system diagram illustrating a further example RAN and a further example CN that may be used within the communications system illustrated in FIG. 1 A according to an embodiment;

[0009] FIG. 2 illustrates an example of individual target wake time (TWT) operation;

[0010] FIG. 3 illustrates an exemplary procedure I of MAP coordinated secondary channel access; and

[0011] FIG. 4 illustrates an exemplary procedure II of MAP coordinated pre-emption for secondary channel access.DETAILED DESCRIPTION

[0012] Secondary channel access mechanisms allow an access point (AP) or non-AP STA(s) to transmit or receive frames on one or more secondary subchannels when the primary subchannel is busy or occupied observed or measured either at transmitter side or receiver side or both sides by an overlapping basic service set (OBSS) transmission.

[0013] Methods, devices and systems for multiple AP (MAP) coordinated secondary channel access (SCA) in WIFI systems are disclosed The method, devices and systems may include MAP negotiation for SCA. The method, devices and systems may include MAP coordinated SCA procedure using trigger frames. The method, devices and systems may include MAP coordinated SCA procedure using unicast initial control frames.

[0014] A system, device and method performed in a station (STA) associated with a basic service set (BSS) are disclosed. The method includes negotiating with at least one other STA assocaited with an overlapping BSS (OBSS) regarding accessing a primary channel that is overlapping between the BSS and OBSS, receiving a first message indicating that the at least one other STA acquired access to the primary channel, and broadcasting a second message that the STA is switching from the primary channel to a non-primary channel. The method may further include transmitting a frame on the non-primary channel. The method may further include overlapping between the BSS and OBSS comprising the primary channel being occupied by an OBSS transmission. The method may further include at least one of the STA and the at least one other STA being an access point (AP). The method may further include the first message being received from the at least one other STA. The method may further include the first message being sent from an AP. The method may further include the second message updating at least one of the at least one other STA and an AP to enable traffic for the STA to be delivered. The method may further include the switching to the non-primary channel being for a period of time. The method may further include the period of time being specified in at least one of the first message and the second message. The method may further include the first message being a trigger frame associated with the switching to the non-primary channel. The method may further include the first message being a unicast initial control frame associated with the switching to the non-primary channel. The method may further include the negotiating being initiated based on the STA supporting secondary channel access (SCA).

[0015] A station (STA) associated with a basic service set (BSS) is described. The STA includes a processor; and a transceiver operably coupled to the processor. The processor and transceiver are configured to negotiate with at least one other STA associated with an overlapping BSS (OBSS) regarding accessing a primary channel that is overlapping between the BSS and OBSS, receive a first message indicating that the at least one other STA acquired access to the primary channel, and broadcast a second message that the STA is switching from the primary channel to a non-primary channel. The processor and transceiver are further configured to transmit a frame on the non-primary channel. The STA may include at least one of the STA the at least one other STA being an AP. The STA may include the first message being received from the at least one other STA. The STA may include the first message being sent from an AP. The STA may include the second message updating at least one of the at least one other STA and an AP to enable traffic for the STA to be delivered.The STA may include the switching to the non-primary channel being for a period of time specified in at least one of the first message and the second message. The STA may include the negotiating being initiated based on the STA supporting SCA.

[0016] FIG. 1A is a diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique-word discrete Fourier transform Spread OFDM (ZT-UW-DFT-S-OFDM), unique word OFDM (UW-OFDM), resource block-filtered OFDM, filter bank multicarrier (FBMC), and the like.

[0017] As shown in FIG. 1A, the communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104, a core network (ON) 106, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a station (STA), may be configured to transmit and / or receive wireless signals and may include a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fl device, an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c and 102d may be interchangeably referred to as a UE.

[0018] The communications systems 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106, the Internet 110, and / or the other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a NodeB, an eNode B (eNB), a Home Node B, a Home eNode B, a next generation NodeB, such as a gNode B (gNB), a new radio (NR) NodeB, a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0019] The base station 114a may be part of the RAN 104, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, and the like. The base station 114a and / or the base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for a wireless service to a specific geographical area that may be relatively fixed or that may change over time. The cell may further be divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to transmit and / or receive signals in desired spatial directions.

[0020] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0021] More specifically, as noted above, the communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 104 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 116 using wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink (DL) Packet Access (HSDPA) and / or High-Speed Uplink (UL) Packet Access (HSUPA).

[0022] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0023] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR Radio Access , which may establish the air interface 116 using NR.

[0024] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for instance using dual connectivity (DC) principles. Thus, the air interface utilized by WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., an eNB and a gNB).

[0025] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi), IEEE 802.16 (i.e., Worldwide Interoperability for MicrowaveAccess (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.

[0026] The base station 114b in FIG. 1A may be a wireless router, Home Node B, Home eNode B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a roadway, and the like. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as I EEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR etc.) to establish a picocell or femtocell. As shown in FIG. 1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 via the CN 106.

[0027] The RAN 104 may be in communication with the CN 106, which may be any type of network configured to provide voice, data, applications, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not shown in FIG. 1A, it will be appreciated that the RAN 104 and / or the CN 106 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 or a different RAT. For example, in addition to being connected to the RAN 104, which may be utilizing a NR radio technology, the CN 106 may also be in communication with another RAN (not shown) employing a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0028] The CN 106 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or the other networks 112. The PSTN 108 may include circuit-switched telephone networks that provide plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP) and / or the internet protocol (IP) in the TCP / IP internet protocol suite. The networks 112 may include wired and / or wireless communications networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 or a different RAT.

[0029] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with differentwireless networks over different wireless links). For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0030] FIG. 1 B is a system diagram illustrating an example WTRU 102. As shown in FIG. 1 B, the WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138, among others. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0031] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), any other type of integrated circuit (IC), a state machine, and the like. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. While FIG. 1 B depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0032] The transmit / receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It will be appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals

[0033] Although the transmit / receive element 122 is depicted in FIG. 1 B as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0034] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit / receive element 122 and to demodulate the signals that are received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11 , for example.

[0035] The processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128 (e.g., a liquid crystal display (LCD) display unitor organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and / or the removable memory 132. The non-removable memory 130 may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0036] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control the power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickelcadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like.

[0037] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, the information from the GPS chipset 136, the WTRU 102 may receive location information over the air interface 116 from a base station (e.g., base stations 114a, 114b) and / or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by way of any suitable location-determination method while remaining consistent with an embodiment.

[0038] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photographs and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a Virtual Reality and / or Augmented Reality (VR / AR) device, an activity tracker, and the like. The peripherals 138 may include one or more sensors. The sensors may be one or more of a gyroscope, an accelerometer, a hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor, an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, a humidity sensor and the like.

[0039] The WTRU 102 may include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the UL (e.g., for transmission) and DL (e.g., for reception) may be concurrent and / or simultaneous. The full duplex radio may include an interference management unit to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WTRU 102 may include a half-duplex radiofor which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the UL (e.g., for transmission) or the DL (e.g., for reception)).

[0040] FIG. 1C is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0041] The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a.

[0042] Each of the eNode-Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, and the like. As shown in FIG. 1 C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0043] The CN 106 shown in FIG. 1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (PGW) 166. While the foregoing elements are depicted as part of the CN 106, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0044] The MME 162 may be connected to each of the eNode-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0045] The SG W 164 may be connected to each of the eNode Bs 160a, 160b, 160c in the RAN 104 via the S1 interface.The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring user planes during Inter-eNode B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like.

[0046] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0047] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 mayinclude, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers.

[0048] Although the WTRU is described in FIGS. 1A-1 D as a wireless terminal, it is contemplated that in certain representative embodiments that such a terminal may use (e.g., temporarily or permanently) wired communication interfaces with the communication network.

[0049] In representative embodiments, the other network 112 may be a WLAN.

[0050] A WLAN in Infrastructure Basic Service Set (BSS) mode may have an Access Point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have access or an interface to a Distribution System (DS) or another type of wired / wireless network that carries traffic in to and / or out of the BSS. Traffic to STAs that originates from outside the BSS may arrive through the AP and may be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS may be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. The traffic between STAs within a BSS may be considered and / or referred to as peer-to-peer traffic. The peer-to-peer traffic may be sent between (e.g., directly between) the source and destination STAs with a direct link setup (DLS). In certain representative embodiments, the DLS may use an 802.11e DLS or an 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and the STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may sometimes be referred to herein as an “ad-hoc” mode of communication.

[0051] When using the 802.11ac infrastructure mode of operation or a similar mode of operations, the AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., 20 MHz wide bandwidth) or a dynamically set width. The primary channel may be the operating channel of the BSS and may be used by the STAs to establish a connection with the AP. In certain representative embodiments, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) may be implemented, for example in 802.11 systems. For CSMA / CA, the STAs (e.g., every STA), including the AP, may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0052] High Throughput (HT) STAs may use a 40 MHz wide channel for communication, for example, via a combination of the primary 20 MHz channel with an adjacent or nonadjacent 20 MHz channel to form a 40 MHz wide channel.

[0053] Very High Throughput (VHT) STAs may support 20MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. The 40 MHz, and / or 80 MHz, channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining 8 contiguous 20 MHz channels, or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, the data, after channel encoding, may bepassed through a segment parser that may divide the data into two streams. Inverse Fast Fourier Transform (IFFT) processing, and time domain processing, may be done on each stream separately. The streams may be mapped on to the two 80 MHz channels, and the data may be transmitted by a transmitting STA. At the receiver of the receiving STA, the above described operation for the 80+80 configuration may be reversed, and the combined data may be sent to the Medium Access Control (MAC).

[0054] Sub 1 GHz modes of operation are supported by 802.11 af and 802.1 1ah. The channel operating bandwidths, and carriers, are reduced in 802.11 af and 802.11 ah relative to those used in 802.11 n, and 802.11 ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11 ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11 ah may support Meter Type Control / Machine-Type Communications (MTC), such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and / or limited bandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0055] WLAN systems, which may support multiple channels, and channel bandwidths, such as 802.11 n, 802.11 ac, 802.11 af, and 802.11 ah, include a channel which may be designated as the primary channel. The primary channel may have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA, from among all STAs in operating in a BSS, which supports the smallest bandwidth operating mode. In the example of 802.11 ah, the primary channel may be 1 MHz wide for STAs (e.g., MTC type devices) that support (e.g., only support) a 1 MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or Network Allocation Vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, due to a STA (which supports only a 1 MHz operating mode) transmitting to the AP, all available frequency bands may be considered busy even though a majority of the available frequency bands remains idle.

[0056] In the United States, the available frequency bands, which may be used by 802.11 ah, are from 902 MHz to 928 MHz. In Korea, the available frequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the available frequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.11 ah is 6 MHz to 26 MHz depending on the country code.

[0057] FIG. 1 D is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 may employ an NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0058] The RAN 104 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 104 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 108b may utilize beamforming totransmit signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum while the remaining component carriers may be on licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0059] The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using transmissions associated with a scalable numerology. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using subframe or transmission time intervals (TTIs) of various or scalable lengths (e.g., containing a varying number of OFDM symbols and / or lasting varying lengths of absolute time).

[0060] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c without also accessing other RANs (e.g., such as eNode-Bs 160a, 160b, 160c). In the standalone configuration, WTRUs 102a, 102b, 102c may utilize one or more of gNBs 180a, 180b, 180c as a mobility anchor point. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration WTRUs 102a, 102b, 102c may communicate with / connect to gNBs 180a, 180b, 180c while also communicating with / connecting to another RAN such as eNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In the non-standalone configuration, eNode-Bs 160a, 160b, 160c may serve as a mobility anchor for WTRUs 102a, 102b, 102c and gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for servicing WTRUs 102a, 102b, 102c.

[0061] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support of network slicing, DC, interworking between NR and E-UTRA, routing of user plane data towards User Plane Function (UPF) 184a, 184b, routing of control plane information towards Access and Mobility Management Function (AMF) 182a, 182b and the like. As shown in FIG. 1 D, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0062] The CN 106 shown in FIG. 1D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. While the foregoing elements are depicted as part of the CN 106, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0063] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 via anN2 interface and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticatingusers of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling of different protocol data unit (PDU) sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of non-access stratum (NAS) signaling, mobility management, and the like. Network slicing may be used by the AMF 182a, 182b in order to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for MTC access, and the like. The AMF 182a, 182b may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0064] The SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN 106 via an N11 interface. The SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN 106 via an N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating UE IP address, managing PDU sessions, controlling policy enforcement and QoS, providing DL data notifications, and the like. A PDU session type may be IP-based, non-IP based, Ethernet-based, and the like.

[0065] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multihomed PDU sessions, handling user plane QoS, buffering DL packets, providing mobility anchoring, and the like.

[0066] The CN 106 may facilitate communications with other networks. For example, the CN 106 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to a local DN 185a, 185b through the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0067] In view of FIGs. 1A-1 D, and the corresponding description of FIGs 1A-1 D, one or more, or all, of the functions described herein with regard to one or more of: WTRU 102a-d, Base Station 114a-b, eNode-B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-b, UPF 184a-b, SMF 183a-b, DN 185a-b, and / or any other device(s) described herein, may be performed by one or more emulation devices (not shown). The emulation devices may be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, the emulation devices may be used to test other devices and / or to simulate network and / or WTRU functions.

[0068] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and / or in an operator network environment. For example, the one or more emulation devices may perform the one or more, or all, functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. The one or more emulation devices may perform the one or more, or all, functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device may be directly coupled to another device for purposes of testing and / or performing testing using over-the-air wireless communications.

[0069] The one or more emulation devices may perform the one or more, including all, functions while not being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in a testing scenario in a testing laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network in order to implement testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and / or wireless communications via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0070] An overview of WLAN Systems is provided. A WLAN in Infrastructure Basic Service Set (BSS) mode has an Access Point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP typically has access or interface to a Distribution System (DS) or another type of wired / wireless network that carries traffic in and out of the BSS. Traffic to STAs that originates from outside the BSS arrives through the AP and is delivered to the STAs. Traffic originating from STAs to destinations outside the BSS is sent to the AP to be delivered to the respective destinations. Traffic between STAs within the BSS may also be sent through the AP where the source STA sends traffic to the AP and the AP delivers the traffic to the destination STA. Such traffic between STAs within a BSS is really peer-to-peer traffic. Such peer-to-peer traffic may also be sent directly between the source and destination STAs with a direct link setup (DLS) using an 802.11e DLS or an 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode has no AP, and / or STAs, communicating directly with each other. This mode of communication is referred to as an “ad-hoc” mode of communication. Using the 802.11 ac infrastructure mode of operation, the AP may transmit a beacon on a fixed channel, usually the primary channel. This channel may be 20 MHz wide, and is the operating channel of the BSS. This channel is also used by the STAs to establish a connection with the AP. The fundamental channel access mechanism in an 802.11 system is Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA). In this mode of operation, every STA, including the AP, may sense the occupancy or vacancy of the primary channel. If the channel is detected to be busy, the STA backs off. Hence only one STA may transmit at any given time in a given BSS.

[0071] In 802.11n, High Throughput (HT) STAs may also use a 40 MHz wide channel for communication. This is achieved by combining the primary 20 MHz channel, with an adjacent 20 MHz channel to form a 40 MHz wide contiguous channel.

[0072] In 802.11ac, Very High Throughput (VHT) STAs may support 20MHz, 40 MHz, 80 MHz, and 160 MHz wide channels. The 40 MHz, and 80 MHz, channels are formed by combining contiguous 20 MHz channels similar to 802.11ndescribed above. A160 MHz channel may be formed either by combining 8 contiguous 20 MHz channels, or by combining two non-contiguous 80 MHz channels, this may also be referred to as an 80+80 configuration. For the 80+80 configuration, at the transmitter, the data, after channel encoding, is passed through a segment parser that divides it into two streams. IFFT and time domain processing are done on each stream separately. The streams are then mapped on to the two channels, and the data is transmitted. At the receiver, this mechanism is reversed, and the combined data is sent to the MAC.

[0073] Sub 1 GHz modes of operation are supported by 802.11 af, and 802.11 ah. For these specifications the channel operating bandwidths, and carriers, are reduced relative to those used in 802.11n, and 802.1 1ac. 802.11 af supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11 ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. A possible use case for 802.11 ah is support for Meter Type Control (MTC) devices in a macro coverage area. MTC devices may have limited capabilities including only support for limited bandwidths, but also include a requirement for a very long battery life.

[0074] WLAN systems, which support multiple channels, and channel widths, such as 802.11 n, 802.11ac, 802.11 af, and 802.11ah, may include a channel which is designated as the primary channel. The primary channel may, but not necessarily, have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel is therefore limited by the STA, of all STAs in operating in a BSS, which supports the smallest bandwidth operating mode. In the example of 802.11 ah, the primary channel may be 1 MHz wide if there are STAs (e.g. MTC type devices) that only support a 1 MHz mode even if the AP, and other STAs in the BSS, may support a 2 MHz, 4 MHz, 8 MHz, 16 MHz, or other channel bandwidth operating modes. All carrier sensing, and NAV settings, depend on the status of the primary channel; i.e., if the primary channel is busy, for example, due to a STA supporting only a 1 MHz operating mode is transmitting to the AP, then the entire available frequency bands are considered busy even though majority of it stays idle and available.

[0075] In the United States, the available frequency bands which may be used by 802.11 ah are from 902 MHz to 928 MHz. In Korea it is from 917.5 MHz to 923.5 MHz; and in Japan, it is from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.11 ah is 6 MHz to 26 MHz depending on the country code.

[0076] Non-primary channel access (NPCA) is an operation which enable a STA to access a secondary channel while the primary channel is busy. If a STA switches to a secondary channel without additional assistance, the switch may not be synchronized, such as because of hidden node issues, for example. As described herein, multiple access points (APs) may negotiate to coordinate for NPCA for each other. An AP that acquired the channel may send a CMC request frame to its coordinated APs. The coordinated APs may determine if they should switch to the non-primary channel. If so, the coordinated APs (i.e., or the ones that switch to the non-primary channel) may respond with a CMC response frame and announce to their associated STAs that the BSS is moving to the non-primary channel, such as for a certain time, for example.

[0077] Subchannel Selective T ransmission (SST) may be used for Secondary Channel Access. Starting from 802.11 ax, an SST mechanism is defined to allow a STA to transmit and receive on a secondary channel. A HE SST non-AP STA and a HE SST AP may set up SST operation by negotiating a trigger enabled Target Wake Time (TWT) using individual TWT agreements. An example of individual TWT operation is shown in FIG. 2.

[0078] FIG. 2 illustrates an example of individual TWT operation 200. As illustrated in FIG. 2, there is an AP 210 with two STAs, STA1 220 and STA2 230. AP 210 receives a TWT response frame 215 and another TWT response frame 225. After the STAs 220, 230 doze a trigger-enabled TWT SP 240 occurs with AP 210. After an initiation of a basic trigger 235, each of the STAs 220, 230 utilize a PS-Poll 245, 255 respectively. A multi-STA block acknowledgement 265 is provided by AP 210. A download MU PPDU 275 is provided by AP 210. STA1 220 acknowledges the DL MU PPDU 275 with a block acknowledgement 285. STA2 230 acknowledges the DL MU PPDU 275 with a block acknowledgement 295.

[0079] The TWT Request frame and TWT Response frame 215, 225 may carry one or more TWT elements. The TWT element is shown in T able 1 .Table 1 : TWT element

[0080] The Control field of the TWT element defined in 802.11 be is shown in Table 2.Table 2: Control field in TWT element in 802.11be

[0081] The Broadcast subfield in the Negotiation Type subfield indicates whether the TWT element is for broadcast TWT or individual TWT. If the Broadcast field of the Negotiation Type subfield is 0 (the TWT element is for individual TWT), then only one Individual TWT parameter set is contained in the TWT element.

[0082] The Individual TWT Parameter Info field defined in 802.11 be is shown in Table 3. The TWT Channel subfield in the Individual TWT Parameter Set field indicates the subchannels the STA may need to be monitored.Table 3: Individual TWT Parameter Set field defined in 802.11 be

[0083] The SST operation allows a non-AP STA to operate on a secondary 20MHz subchannel or a secondary 80MHz subchannel in the negotiated TWT SP. The non-AP STA may be available at the TWT start time and may not access the medium in the subchannel using DCF or EDCAF. Instead, the channel access for non-AP STA during the SST operation is trigger based. Meaning that the AP grants uplink resources for the non-AP STAs to perform uplink transmission. A non- AP STA may include a Channel Switch Timing element in (Re)Association Request frames it transmits to an AP to indicate the time required by the STA to switch between different subchannels.

[0084] The IEEE 802.11 Ultra High Reliability (UHR) Study Group was formed in September 2022. UHR is considered as the next major revision to IEEE 802.11 standards following 802.11 be,. UHR is formed to explore the possibility to improve reliability, support low latency traffic and further increase peak throughput and improve efficiency of the IEEE 802.11 networks. Secondary channel access was discussed in 802.11 bn and UHR SG.

[0085] MAP Coordinated Secondary Channel Access (SCA) is discussed. Secondary channel access mechanisms allow an AP or non-AP STA(s) to transmit or receive frames on one or more secondary subchannels when the primary subchannel is busy or occupied observed or measured either at transmitter side or receiver side or both sides by an OBSS (overlapping basic service set) transmission. A challenge is the STAs may not be able to announce the primary channel to secondary channel switch if the primary channel is busy.

[0086] Multi-AP Coordinated Preemption for SCA (HL) may be used to provide MAP Coordinated SCA. Secondary channel access mechanism allows an AP or a non-AP STA to transmit or receive frames on one or more secondary subchannels when the primary subchannel is busy or occupied either at transmitter side or receiver side or both sides. The AP may define and announce one or more anchor channels which may be used as subchannels where the AP and non-AP STAs may perform channel access by using physical and / or virtual carrier sensing. The anchor channels may be used temporarily as the primary channel when the primary channel is busy. The STAs (e.g., AP and / or non-AP STAs) may start transmitting when the physical and / or virtual carrier sensing results determine the wireless media is idle.

[0087] Multiple APs (such as AP1 , AP2 and STA1 disclosed in FIGs. 3 and 4 herein below) which may form a MAP BSS may coordinate and may help each other for secondary channel access. A MAP BSS may contain multiple APs and STAs associated with the APs. A MAP BSS is an extended BSS which is controlled by the APs in the MAP BSS. APs in the MAP BSS may negotiate with each other on how to perform MAP coordinated secondary channel access. In the case that an AP’s (referred as a targeting AP) primary channel (e.g., primary 20MHz channel) is occupied by one or more APs in the same MAP BSS and the targeting AP’s secondary channels is idle, the targeting AP may switch to the idling secondary channel and announce its switch using methods disclosed below on its primary channel.

[0088] One or more MAP signaling RUs may be defined in each AP’s primary channel (e.g., primary 20MHz channel). The MAP signaling RU may be used for the targeting AP to announce time sensitive signaling, e.g., the targeting AP may switch to a secondary channel, the targeting AP may have low latency traffic etc., when the targeting AP’s primary channel is occupied. When other APs acquire a channel which includes the targeting AP’s primary channel, the other APs may transmit PPDUs which do not use the targeting AP’s MAP signaling RU so that the targeting AP has a chance to transmitthe information. If more than one AP in the MAP BSS have the same primary channel, in one method, their MAP signaling RU may be the same. Alternatively, if more than one AP in the MAP BSS have the same primary channel, each AP may have its unique MAP signaling RU.

[0089] APs which support MAP coordinated SCA may indicate its capability by setting MAP Coordinated SCA support subfield in its transmitted UHR Capabilities element or UHR MAP Capabilities element or other capabilities element.

[0090] MAP Negotiation and setup for SCA may be performed before the coordinated SCA. APs which are able to perform coordinated transmission (e.g. , coordinated SCA transmissions) may exchange frames to each other to set up the system operation parameters which may be used for the coordinated transmission. The exemplary parameters are:

[0091] Primary channels which is a field that may indicate the detailed primary channels used for the AP’s BSS. For example, primary 20MHz channel, primary 40MHz channel, primary 80MHz channel etc. In one example Channel Center Frequency Segments field defined in HTA / HT / HE / EHG Operation element may be carried to indicate the primary channels. Or the HT / VHT / HE / EHG Operation element may be carried to indicate the primary channels.

[0092] Anchor channels which is a field that may indicate the detailed anchor channels used for the AP’s BSS. For example, anchor 20MHz channel in second / third / fourth / fifth / sixth / seventh / eighth 40MHz channel, secondary / third / fourth 80MHz channel etc. In one example Channel Center Frequency of the anchor channel may be carried to indicate the anchor channels.

[0093] Anchor Channel Order which is a field that may indicate the order of anchor channels the AP may switch to when the primary channel is occupied.

[0094] BSS Color which is a field that may indicate the BSS Color used by the AP and / or the MAP BSS Color used for the coordinated transmission. The MAP BSS Color may be a value used to identify the extended BSS by the multiple APs.

[0095] MAP Signaling RU which is a field that may indicate the MAP signaling RU of the AP. The MAP signaling RU may be identified by the RU index and primary channel of the AP. A receiving STA may need to identify the primary channel of the AP and then use the RU index to locate the RU.

[0096] Primary / Secondary Channel Switch Time which is a field that may indicate the time needed for the AP to switch between primary channel and secondary channel.

[0097] NAV Duration Threshold which is a field that may indicate a duration threshold for other APs in the MAP BSS to initiate the MAP coordinated CSA procedure. Here we may refer the AP which transmits the NAV Duration Threshold as a targeting AP. When another AP acquires the WM and start a TXOP, it sets the Duration field based on the expectation of the time duration it may occupy the WM. If the TXOP duration is greater than the NAV Duration Threshold of the targeting AP, it may start the TXOP allowing the MAP coordinated CSA for the targeting AP. For example, it may preempt the MAP signaling RU(s) of other APs as shown in MAP Coordinated SCA procedure 1.

[0098] The abovementioned fields may be included in one or more elements which may be carried in a management frame or an action frame and exchanged between APs. The fields may be, alternatively, or additionally, included in one ormore control frames which may be exchanged between APs. The fields may be, alternatively, or additionally, included in MAC headers of data / management frames which may be exchanged between APs. MAP Coordinated SCA Procedure I.

[0099] FIG. 3 illustrates an exemplary procedure I of MAP coordinated secondary channel access 300. As illustrated in FIG. 3, there is an AP 310 with two STAs, STA1 320 and AP2 330 (as would be understood AP2 330 could be a STA2 such as an AP STA, for example). The BSS associated with AP1 310, and the BSS associated with AP2 330 have overlapping primary channel and a negotiation to conduct coordinated secondary channel access may occur. The results of the negotiation may be announced by AP 310 in its beacon, for example. As illustrated, AP 310 negotiates in a MAP negotiation 305 and receives information in MAP negotiation 315. An initial control frame (ICF) 325 occurs from AP 310. STA1 320 provides an initial control response (ICR) 335 and AP2 330 provides ICR 345. ICR 345 may be on the primary channel of AP2 330, for example and AP2 330 may announce a switch to a secondary channel using the ICR.

[0100] In this example, a trigger frame is utilized as an initial control frame for the MAP coordinated SCA. In the exemplary method illustrated in FIG. 3, once an AP (referred as a sharing AP or coordinating AP) acquires the wireless medium and start a TXOP, the AP may transmit an initial control frame (ICF) 325 at the beginning. ICF 325 may be addressed to multiple devices, such as STA1 320 and AP2 330, for example In one example, ICF 325 may be a variant of Trigger frame. ICF 325 may be transmitted to one or more intended STAs associated with AP 310 (e.g., 320 in the figure) and / or one or more APs (referred as shared APs or coordinated APs) (e.g., 330 in the figure) in the MAP BSS which has the overlapping primary channel as the sharing AP (or the shared AP's primary channel is utilized by the sharing AP in the TXOP).

[0101] For the intended non-AP STAs (e.g., STA1 320), ICF 325 may allocate resources for the non-AP STAs to respond, and / or request initial control response (ICR) frames 335 from the non-AP STAs 320 to indicate that they are clear to communicate.

[0102] For the shared APs in the MAP BSS, ICF 325 may allocate resources for the APs to respond. In one method, the allocated resources may in the primary channel of the shared AP, and / or request initial control response (ICR) frames 345 from the shared AP to announce that the primary channel is occupied, and the shared AP 310 may switch to one of its secondary channels.

[0103] On reception of ICR frame 335, 345 from a shared AP 310, its associated STA 320 and AP2 330 may follow the AP 310 switch to the secondary channel until the end of the TXOP.

[0104] FIG. 3 illustrates an exemplary procedure of MAP coordinated pre-emption for secondary channel access. In the example of FIG. 3, AP1 and AP2 belong to a MAP BSS. STA1 is associated with AP1 .

[0105] In one method, an AP (e.g., AP1 310, referred as the sharing AP) in the MAP BSS acquires the WM and start a TXOP. The sharing AP 310 may support SCA and / or MAP coordinate SCA. It may start the MAP coordinated SCA procedure if at least one AP (refer as shared AP) in its MAP BSS may meet one or more conditions including: the shared AP(s) in the MAP BSS may support SCA and / or MAP coordinated SCA; there are STAs associated with the shared AP(s)in the MAP BSS supporting SCA and willing to switch to secondary channel if needed, the operating channel of the upcoming TXOP may include shared AP's primary channel; the shared AP(s) in the MAP BSS which may have primary channel occupied and have one or more secondary channel idle, the upcoming TXOP duration may be longer than the value carried in the NAV Duration field set by shared AP in the MAP BSS; and the shared AP and sharing AP may have negotiated and agree to perform MAP coordinated SCA for each other.

[0106] The sharing AP may transmit an Initial Control frame (ICF), or control or management frame with another name, to one or more its associated STAs and / or one or more shared APs in the MAP BSS which may satisfy abovementioned conditions. The ICF may announce the detailed channel usage related information for the upcoming TXOP. The ICF may allocate resource units to the non-AP STAs and APs. Transmitting the ICF to non-AP STAs allows for checking if the intended non-AP STAs may be ready to transmit and receive in the TXOP. The intention of transmitting the ICF to the shared APs is to check if the shared APs may be ready to switch to their secondary channel, and meanwhile it may give the shared APs a chance to announce their channel switch to their associated or intended STAs.

[0107] In a method, the ICF may be a variant of Trigger frame. For example, the MU-RTS frame, BSRP frame, the NFRP frame, or a new variant of Trigger frame.

[0108] In a method, the ICF may be transmitted on the overlapping subchannels of the sharing AP and the shared AP (e.g., AP1 and AP2 in the example shown in FIG. 3. In a method, the ICF may be transmitted on each 20MHz subchannels acquired by the sharing AP. The ICF may be carried by a non-HT duplicate PPDU, non-HT PPDU, HE PPDU, EHT PPDU or EHT+ PPDU. Here the EHT+ PPDU means PPDU with PHY version later than EHT The ICF may carry:

[0109] Address fields that include the sharing AP’s MAC address / ID, the shared AP's MAC address / ID, the MAP BSS ID / MAC address, the intended receiving non-AP STAs’ ID / MAC addresses may be included in the ICF. In one method, the RA field of the ICF may be set to the broadcast address. The TA address of the ICF may indicate the sharing AP (e.g., AP1). The shared AP’s ID and intended non-AP STA's ID may be indicated using AID12 subfield in the User Info field assuming the ICF is reusing Trigger frame format.

[0110] TXOP duration may include a field to indicate the duration from the end of the ICF to the end of the TXOP the sharing AP may reserve. In a method, the Duration field in MAC header of the ICF is set to indicate the time from the end of the ICF to the end of the ICR frame. In this case, the ICF may not reserve long NAV and the sharing AP may transmit another frame xlFS time after the reception of the responding frames (e.g., ICR frames) and the sharing AP may set a new value in the Duration field to reserve the WM again. In this case, a TXOP Duration subfield may be included explicitly in the ICF frame to indicate the TXOP duration the sharing AP may plan to reserve. For example, the TXOP Duration field may be included in the Common Info field, or other fields to carry information to all the intended STAs (e.g., Special User Info field), of the ICF frame. In a method, the Duration field in MAC header of the ICF is set to indicate the time from the end of the ICF to the end of the upcoming TXOP. In this case the transmission between APs may reserve long NAV for the intended non-AP STAs. In this way, the Duration field in the MAC header of the ICF frame may serve as the TXOP Duration field.

[0111] TXOP Operating Band Width may include a field to indicate the upcoming TXOP operating band width. The receiving STAs (e.g., APs) may know the primary channel and channel center frequency (e.g., CCFS fields) of the sharing AP during the Beacon frame and / or AP-to-AP frame exchanges happened before. On reception of the TXOP operating band width, and together with the center frequency and primary channels of the sharing AP, the shared APs may know the channels to be occupied by the sharing AP, and thus the shared AP may know if its primary channel and / or secondary channels will be occupied. If ICF is using the Trigger frame format, the UL BW subfield in the Common Info field in the Trigger frame may indicate the TXOP Operating Band Width.

[0112] Punctured Subchannels may include a field to indicate the punctured channels (e.g., static puncturing and dynamic puncturing) in the upcoming TXOP. On reception of the punctured subchannel field, the shared APs may know the channels to be occupied by the sharing AP and channels not occupied by the sharing AP.

[0113] BSS Color may include a field to be used to indicate the MAP BSS Color. In one method, the APs which agree to perform MAP coordinated SCA may have a specific BSS Color. By setting the BSS Color to the MAP BSS Color, the receiving STAs (APs and non-AP STAs) may know the transmission may involve communications between multiple APs. In one method, the intended STAs including APs and non-AP STAs may use the BSS Color field carried here to set the BSS Color field in the TB PPDU which carries the ICR frames. If the ICF is carried by HE PPDU, EHT PPDU or EHT+ PPDU, the BSS Color contained in the SIG fields in the PPDU may be used to indicate the MAP BSS Color. If the ICF is carried by a PPDU where BSS Color is not included in the SIG fields, e.g., non-HT PPDU or non-HT duplicate PPDU, then the BSS Color field may be explicitly carried in the ICF. For example, if ICF is a Trigger frame, then the BSS Color field may be carried in the Common Info field or other fields to carry information to all the intended STAs (e.g., Special User Info field)

[0114] Resource Allocation may include a field for the sharing AP to use to assign resource units to the intended AP(s) and STA(s). In one method, the sharing AP may know the primary channel of the shared AP (e.g., by the AP-to-AP negotiation happened before the TXOP). The sharing AP may allocate at least one resource unit located in the shared AP’s primary channel to the shared AP. So that the shared AP may transmit its ICR frame on its primary channel and its associated STAs may notice the transmission.

[0115] On reception of the ICF, an intended non-AP STA may respond with an ICR frame using the allocated resource and following the instructions carried in the ICF. A shared AP may determine if it may want to switch to its secondary channel. The decision may be made based on one or more of the following: if the shared AP may have primary channel occupied and at least one secondary channel idle; if the upcoming TXOP is long enough, e.g., greater than the NAV Duration Threshold field it announced, and / or if the shared AP has traffic to transmit.

[0116] The shared AP may transmit an ICR frame (or control or management frame with another name) to the sharing AP and the shared AP's associated STAs. The ICR may indicate if the shared AP may switch to the secondary channel and how long it may stay on the secondary channel. It may also indicate the detailed channel usage related information forthe secondary channels. In a method, the ICR may be transmitted on the assigned resource unit indicated in the ICF. In a method, the ICR frame may be transmitted using trigger based (TB) PPDU.

[0117] Address fields may include the shared AP’s MAC address / ID, the sharing AP’s MAC address / ID, the MAP BSS ID / MAC address may be included in the ICR frame In a method, some addresses / IDs mentioned above may be included in the Address 1, Address 2, Address 3 and Address 4 fields in the current MAC frame. For example, the TA field may be set to the shared AP’s MAC address, and the RA field may be set to the sharing AP’s MAC address, the BSSID field may be set to the MAP BSS MAC address. In another example, the RA field may be set to the broadcast MAC address. In a method, the frame may be a broadcast / multicast frame transmitted to the shared AP’s associated STAs, the sharing AP and / or the other APs in the MAP BSS. In a method, the frame may be a broadcast / multicast frame transmitted to one or more STAs which are associated with the shared AP or the MAP BSS, the sharing AP and / or the other APs in the MAP BSS.

[0118] Secondary Channel Switch may be included a field to indicate the shared AP may switch to the secondary channel after the transmission of ICR frame.

[0119] Secondary Channel Duration may be included in a field to indicate the duration the shared AP may stay on the secondary channel. In a method, the shared AP may set the field to indicate it may stay on the secondary channel from the end of the ICR frame to the end of the TXOP the sharing AP may reserve. The shared AP may calculate a time duration using the value carried in the Duration field in the ICF minus the time used to transmit the ICR frame and use this value to set the Duration field in the MAC header of the ICR frame. If the Duration field in the MAC header of the ICF frame indicates the time duration from the end of the ICF frame to the end of the upcoming TXOP, this field may be used to implicitly indicate the time duration the shared AP may stay on the secondary channel. If the Duration field in the MAC header of the ICF indicates the time duration from the end of the ICF frame to the end of the ICR frame, the Secondary Channel Duration field may be used to explicitly indicate the time duration the shared AP may stay on the secondary channel.

[0120] Secondary TXOP Operating Band Width may be included in a field to indicate the expected TXOP operating band width on the secondary channel the shared AP may switch to. The receiving STAs (e.g., APs and non-AP STAs) may know the primary channel and channel center frequency (e.g., CCFS fields) of the shared AP during Beacon frame and / or the AP-to-AP frame exchanges happened before. On reception of the Secondary TXOP operating band width, and together with the center frequency and primary channels of the shared AP, the STAs (including APs and non-AP STAs) may know the channels to be occupied by the shared AP on the secondary channel (s).

[0121] Secondary Punctured Subchannels may be included in a field to indicate the punctured channels (e.g., static puncturing and dynamic puncturing) on the secondary channel the shared AP switch to.

[0122] AP Switch Delay may be included in a field to indicate the time needed for the shared AP to switch from primary channel to one or more of its secondary channels. In a method, the AP Switch Delay field may indicate a time from the end of the ICF to the beginning of the first transmission from the shared AP on the secondary channel. In a method, the value carried by the AP Switch Delay field may be greater than or equal to the time the shared AP needed to switch from theprimary channel to one or more of its secondary channels. It may be calculated as the maximum delay among the AP and its associated STAs or a group of its intended receiving STAs or a group of STAs.

[0123] In a method, the ICR frame transmitted by the shared AP may be carried by a TB PPDU. In 802.11 ax and 802.11 be, a TB PPDU is considered as a UL frame, and non-AP STAs may not need to continue detecting the entire MAC frame carried in the TB PPDU since they are not the intended receivers. In an example, a broadcast frame may be transmitted by an AP being carried in a TB PPDU, and thus procedures may be modified to allow a non-AP STA to detect a TB PPDU may be transmitted by an AP and / or notice a broadcast frame may be carried in the TB PPDU and thus the non-AP STA may stay detecting the entire TB PPDU. In a method, if a BSS Color field in a SIG field of the TB PPDU may indicate a special value or a MAP BSS Color, then the TB PPDU may be transmitted by an AP and / or may carry information for one or more non-AP STAs. In a method, the PPDU Type And Compression Mode field (or field with other name, or combination of several fields) in a SIG field of the TB PPDU may be set to a special value to indicate the TB PPDU may be transmitted by an AP and / or may carry information for one or more non-AP STAs.

[0124] In a method, one or more MAP Signaling RUs in a TB PPDU may be used to carry information for non-AP STAs. The AP may broadcast MAP Signaling RU indices in its Beacon frame or other broadcast frame so that the non-AP STAs may detect the information carried on the special RU(s) when some fields in a SIG field of the TB PPDU indicates the TB PPDU may be transmitted by an AP and / or may carry information for non-AP STAs. The sharing AP may need to allocate MAP Signaling RU(s) to the shared AP in the ICF.

[0125] In a method, the information bits carried by the MAP Signaling RU(s) in a TB PPDU may be modulated by a predefined / predetermined MCS so that the non-AP STAs may use the MCS to decode them. The AP may broadcast MCS for the MAP Signaling RU in its Beacon frame or other broadcast frame. The sharing AP and shard AP may exchange the MCS used for the MAP Signaling RU(s) when then negotiate to coordinate. The sharing AP may need to assign the MCS for the shared AP to transmit on the allocated MAP Signaling RU(s) in the ICF.

[0126] By detecting the ICR frame in the MAP Signaling RU in TB PPDU, the STAs associated with the shared AP (e.g., AP2) or STAs which may communicate with the shared AP may know the shared AP may switch to one or more secondary channels from the end of the ICR frame. The STAs may determine if they may want to switch to the secondary channel(s) based on following conditions: if the STA may have the secondary channel(s) idle or the STA may expect the secondary channel may not be occupied for a long time. Since the AP and non-AP STAs may see different interference levels due to different locations, the shared AP may be idle while the non-AP STAs may be busy on the secondary channels; if the upcoming TXOP is long enough, e.g., greater than a threshold the STA may have. The threshold may be related to the primary / secondary channel switch delay needed for the STA. If the primary / secondary channel switch delay for the STA is long, the threshold may be big; and / or if the STA has traffic to transmit. Or the STA knows the AP has buffered data to it.

[0127] The shared AP and its STAs may switch to the secondary channel(s) after the ICR frame. They may switch back to primary using one or more methods below: both the shared AP and STAs may switch back to the primary channel rightafter the TXOP; the shared AP may switch back to the primary channel right after the TXOP and the STAs may switch back in a later time; both the shared AP and STAs may switch back to the primary channel sometime after the TXOP; and the shared AP may switch back to the primary channel after the TXOP and the STAs may switch back in a later time.

[0128] The above-mentioned methods / procedures / signaling are illustrated using the ICF / ICR frame exchange between APs for SCA. The examples may be extended to general AP-to-AP frame exchanges to any purpose. For example, a TB PPDU may be allowed to be transmitted by an AP. If the TB PPDU transmitted by an AP needs to be detected by the non- AP STAs, the MAP Signaling RU, signaling in a SIG field, and the MCS for the MAP Signaling RU may be used.

[0129] MAP Coordinated SCA Procedure II may be used. Exemplary procedure II of MAP coordinated pre-emption for secondary channel access is illustrated in FIG. 4. FIG. 4 illustrates an exemplary procedure II of MAP coordinated preemption for secondary channel access 400. As illustrated in FIG. 4, there is two Aps, AP1 410 and AP2 430 with a single STA 420. APs 410, 430 have overlapping primary channel and a negotiation to conduct coordinated secondary channel access may occur. As illustrated, AP1 410 and AP2 430 negotiate in a MAP negotiation 405 and receive information in MAP negotiation 415. Coordinated MAP control frame exchanges (CMC Req) 425 between AP1 410 and AP2 430 may occur if the impending TXOP is long. A CMC Resp 435 may be provided between AP1 410 and AP2 430. CMC Resp 435 may be an announce frame for the transmitting AP to announce its switch to the secondary channel right after the CMC Resp transmission. An initial control frame (ICF) 445 occurs from AP1 410. STA1 420 provides an initial control response (ICR) 445. After the CMC exchange 425, 435 AP2 430 and its STAs switch to a secondary channel.

[0130] In this example, coordinated MAP control frames 425, 435 are exchanged at the beginning of the TXOP. In a method, an AP (e.g., AP1 410, referred also as the sharing AP) in the MAP BSS acquires the WM and start a TXOP. The sharing AP 410 may support SCA and / or MAP coordinate SCA. It may start the MAP coordinated SCA procedure if at least one AP 430 (referred also as the shared AP) in its MAP BSS may meet one or more conditions below: the shared AP(s) 430 in the MAP BSS may support SCA and / or MAP coordinated SCA; there are STAs associated with the shared AP(s) 430 in the MAP BSS supporting SCA and willing to switch to secondary channel if needed; the operating channel of the upcoming TXOP may include shared AP's 430 primary channel; the shared AP(s) 430 in the MAP BSS which may have primary channel occupied and have one or more secondary channel idle; the upcoming TXOP duration may be longer than the value carried in the NAV Duration field set by shared AP 430 in the MAP BSS; and the shared AP 430 and sharing AP 410 may have negotiated 405, 415 and agree to perform MAP coordinated SCA for each other.

[0131] The sharing AP 410 may transmit a Coordinated MAP Control Request (CMC Request) frame 425 (or control or management frame with another name) to one or more shared APs 430 in the MAP BSS which may satisfy abovementioned conditions. The CMC Request frame 425 may announce the detailed channel usage related information for the upcoming TXOP and may check if the shared APs 430 may want to switch to their secondary channels. In one method, the CMC Request frame 425 may be transmitted on the overlapping subchannels of the sharing AP 410 and the shared AP 430 (e.g., AP1 410 and AP2 430 in the example illustrated in FIG. 4). In a method, the CMC Request frame 425 may be transmitted on each 20MHz subchannels acquired by the sharing AP. The CMC Request frame 425 may be carriedby a non-HT duplicate PPDU, non-HT PPDU, HE PPDU, EHT PPDU or EHT+ PPDU. Here the EHT+ PPDU means PPDU with PHY version later than EHT (e.g., UHR PPDU). The CMC Request frame 425 may carry various fields.

[0132] Address fields for the sharing AP’s 410 MAC address / ID, the shared AP’s 430 MAC address / ID, the MAP BSS ID / MAC address may be included in the CMC Request frame 425. In one method, some addresses / IDs mentioned above may be included in the Address 1 , Address 2, Address 3 and Address 4 fields in the current MAC frame.

[0133] A TXOP Duration to indicate the duration from the end of the CMC Request frame 425 to the end of the TXOP the sharing AP 410 may reserve. In a method, the Duration field in MAC header of the CMC Request frame is set to indicate the time from the end of the CMC Request frame 425 to the end of the CMC Response frame 435. In this case the transmission between APs 410, 430 may not reserve long NAV for the non-AP STAs so that the non-AP STAs may response the ICE frame 445 transmitted after the end of the CMC Response frame 435. In this way, the TXOP Duration field may be carried in the CMC Request frame 425 to explicitly indicate the time duration the sharing AP 410 intended to use for the entire TXOP. In a method, the Duration field in MAC header of the CMC Request frame 425 to indicate the time from the end of the CMC Request frame 425 to the end of the upcoming TXOP. In this case the transmission between APs may reserve long NAV for the non-AP STAs. A new rule may be defined for the non-AP STAs to ignore the NAV set by its associated AP with a transmission between APs. For example, if a non-AP STA may have a NAV set by its associated AP, and later on within the NAV period (e.g., the NAV is not zero), it may receive an ICE frame, or Trigger frame addressed to it and request a response, the non-AP STA may be able to ignore the previous NAV and respond. In this way, the Duration field in the MAC header of the IGF frame 445 may serve as the TXOP Duration field.

[0134] TXOP Operating Band Width may be a field that indicates the upcoming TXOP operating band width. The receiving STAs (e.g., APs and non-AP STAs) may know the primary channel and channel center frequency (e.g., CCFS fields) of the sharing AP 410 during the AP-to-AP frame exchanges 405, 415 happened before. On reception of the TXOP operating band width, and together with the center frequency and primary channels of the sharing AP 410, the shared APs 430 may know the channels to be occupied by the sharing AP 410, and thus the shared AP 430 may know if its primary channel and / or secondary channels will be occupied.

[0135] Punctured Subchannels may indicate the punctured channels (e.g., static puncturing and / or dynamic puncturing) in the upcoming TXOP of the sharing AP. On reception of the punctured subchannel field, the shared APs 430 may know the channels to be occupied by the sharing AP 410 and channels not occupied by the sharing AP 410. In this way, with one method, the shared AP may be allowed to use the punctured subchannel (s) of the sharing AP if it is idle for the shared AP.

[0136] Buffered Traffic Indication may indicate which STAs may have buffered traffic at the shared AP 430. Or the field may indicate which STAs may be the potential intended STAs for the secondary channel transmissions at shared AP side In a method, the TIM element may be reused. In a method, a newly defined field / element / frame may be used to indicate the AIDs and buffered traffic information of the intended STAs.

[0137] On reception of the CMC Request frame, a shared AP 430 may determine if it may want to switch to it secondary channel. The decision may be made based on one or more of the following: if the shared AP 430 may have primary channel occupied and at least one secondary channel idle; if the upcoming TXOP is long enough, e.g., greater than the NAV Duration Threshold field it announced; and if the shared AP 430 has traffic to transmit.

[0138] On reception of the CMC Request frame, the shared AP 430 may transmit a CMC Response frame (or control or management frame with another name) to the sharing AP 410 and the shared AP’s 430 associated STAs. The CMC Request frame may indicate if the shared AP 430 may switch to the secondary channel and, if so, how long it may stay on the secondary channel. It may also indicate the detailed channel usage related information for the secondary channels. In a method, the CMC Response frame may be transmitted on the overlapping subchannels of the sharing AP 410 and the shared AP 430. In a method, the CMC Response frame may be transmitted on each 20MHz idle subchannels acquired by the sharing AP 410. In a method, the CMC Response frame may be transmitted on each 20MHz idle subchannels within the operating band of the shared AP 430. The CMC Response frame may be carried by a non-HT duplicate PPDU, non- HT PPDU, HE PPDU, EHT PPDU or EHT+ PPDU. Here the EHT+ PPDU means PPDU with PHY version later than EHT (e.g., UHR PPDU). The CMC Response frame may carry:

[0139] Address fields for the shared AP's MAC address / ID, the sharing AP's MAC address / ID, the MAP BSS ID / MAC address may be included in the CMC Request frame. In a method, some addresses / IDs mentioned above may be included in the Address 1, Address 2, Address 3 and Address 4 fields in the current MAC frame. In a method, the frame may be a broadcast / multicast frame transmitted to the shared AP’s 430 associated STAs, the sharing AP 410 and / or the other APs in the MAP BSS. In a method, the frame may be a broadcast / multicast frame transmitted to one or more STAs which are associated with the shared AP 430 or the MAP BSS, the sharing AP 410 and / or the other APs in the MAP BSS.

[0140] Secondary Channel Switch which may indicate the AP may switch to the secondary channel after the transmission of the CMC Response frame.

[0141] Secondary Channel Duration which may indicate the duration the AP may stay on the secondary channel. In one method, the shared AP 430 may set the field to indicate it may stay on the secondary channel from the end of the CMC Response frame to the end of the TXOP the sharing AP 410 may reserve. The shared AP 430 may calculate a time duration using the value carried in the Duration field in the CMC Request frame minus the time used to transmit the CMC Response frame and use this value to set the Duration field in the MAC header of the CMC Response frame. If the Duration field in the MAC header of the CMC Request frame indicates the time duration from the end of the CMC Request frame to the end of the upcoming TXOP, the Duration field in the MAC header may be used to implicitly indicate the time duration the shared AP 430 may stay on the secondary channel. If the Duration field in the MAC header of the CMC Request frame indicates the time duration from the end of the CMC Request frame to the end of the CMC Request frame, the Secondary Channel Duration field may be used to explicitly indicate the time duration the shared AP 430 may stay on the secondary channel.

[0142] Secondary TXOP Operating Band Width which may indicate the expected TXOP operating band width on the secondary channel the shared AP 430 may switch to. The receiving STAs (e.g., APs and non-AP STAs) may know the primary channel and channel center frequency (e.g., CCFS fields) of the shared AP 430 during Beacon frame and / or the AP-to-AP frame exchanges happened before. On reception of the Secondary TXOP operating band width, and together with the center frequency and primary channels of the shared AP 430, the STAs (including APs and non-AP STAs) may know the channels to be occupied by the shared AP 430 on the secondary channel(s).

[0143] Secondary Punctured Subchannels which may indicate the punctured channels (e.g., static puncturing and dynamic puncturing) when the shared AP 430 switch to the secondary channel.

[0144] AP Switch Delay which may indicate the time needed for the shared AP 430 to switch from primary channel to one or more of its secondary channels. In a method, the AP Switch Delay field may indicate a time from the end of the CMC Response frame to the beginning of the first transmission from the shared AP 430 on the secondary channel. The value carried by the AP Switch Delay field may be greater than or equal to the time the shared AP 430 needed to switch from the primary channel to one or more of its secondary channels. It may be calculated as the maximum delay among the AP and its associated STAs or a group of its intended receiving STAs or a group of STAs.

[0145] The STAs associated with the shared AP 430 (e.g., AP2 430) or STAs which may communicate with the shared AP 430 may know the shared AP 430 may switch to one or more secondary channels from the end of the CMC Response frame. The STAs may determine if they may want to switch to the secondary channel(s) based on following conditions: if the STA may have the secondary channel(s) idle or the STA may expect the secondary channel may not be occupied for a long time. Since the AP and non-AP STAs may see different interference levels due to different locations, the shared AP 430 may be idle while the non-AP STAs may be busy on the secondary channels; if the upcoming TXOP is long enough, e.g., greater than a threshold the STA may have. The threshold may be related to the primary / secondary channel switch delay needed for the STA. If the primary / secondary channel switch delay for the STA is long, the threshold may be big; and / or if the STA has traffic to transmit. Or the STA knows the AP has buffered data to it.

[0146] The shared AP 430 and its STAs may switch to the secondary channel(s) after the CMC Response frame. They may switch back to primary using one or more methods below: both the shared AP 430 and STAs may switch back to the primary channel right after the TXOP; the shared AP 430 may switch back to the primary channel right after the TXOP and the STAs may switch back in a later time; both the shared AP 430 and STAs may switch back to the primary channel sometime after the TXOP; and the shared AP 430 may switch back to the primary channel after the TXOP and the STAs may switch back in a later time.

[0147] The procedure may be extended to the case that more than one shared APs 430 may be involved. In this case, the CMC Request / Response frames may be exchanged between the sharing AP 410 and each shared AP sequentially before the sharing AP 410 starts its TXOP

[0148] Although features and elements are described above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with the other features and elements.In addition, the methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted over wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

CLAIMSWhat is Claimed:1 . A method performed in a station (STA) associated with a basic service set (BSS), the method comprising: negotiating with at least one other STA associated with an overlapping BSS (OBSS) regarding accessing a primary channel that is overlapping between the BSS and OBSS; receiving a first message indicating that the at least one other STA acquired access to the primary channel; and broadcasting a second message indicating that the STA is switching from the primary channel to a non-primary channel.

2. The method of claim 1 , further comprising transmitting a frame on the non-primary channel.

3. The method of claim 1 , wherein overlapping between the BSS and OBSS comprises the primary channel being occupied by an OBSS transmission.

4. The method of claim 1 , wherein at least one of the STA and the at least one other STA is an access point (AP).

5. The method of claim 1, wherein the first message is received from the at least one other STA.

6. The method of claim 1 , wherein the first message is sent from an AP.

7. The method of claim 1, wherein the second message updates at least one of the at least one other STA and an AP to enable traffic for the STA to be delivered.

8. The method of claim 1 , wherein the switching to the non-primary channel is for a period of time.

9. The method of claim 8, wherein the period of time is specified in at least one of the first message and the second message.

10. The method of claim 1 , wherein the first message is a trigger frame associated with the switching to the non-primary channel.

11. The method of claim 1 , wherein the first message is a unicast initial control frame associated with the switching to the non-primary channel.

12. The method of claim 1 , wherein the negotiating is initiated based on the STA supporting secondary channel access (SCA).

13. A station (STA) associated with a basic service set (BSS), the STA comprising: a processor; and a transceiver operably coupled to the processor, the processor and transceiver configured to: negotiate with at least one other STA associated with an overlapping BSS (OBSS) regarding accessing a primary channel that is overlapping between the BSS and OBSS; receive a first message indicating that the at least one other STA acquired access to the primary channel; and broadcast a second message that the STA is switching from the primary channel to a non-primary channel.

14. The STA of claim 13, wherein the processor and transceiver are further configured to transmit a frame on the non-primary channel.

15. The STA of claim 13, wherein at least one of the STA the at least one other STA is an AP.

16. The STA of claim 13, wherein the first message is received from the at least one other STA.

17. The STA of claim 13, wherein the first message is sent from an AP.

18. The STA of claim 13, wherein the second message updates at least one of the at least one other STA and an AP to enable traffic for the STA to be delivered.

19. The STA of claim 13, wherein the switching to the non-primary channel is for a period of time specified in at least one of the first message and the second message.

20. The STA of claim 13, wherein the negotiating is initiated based on the STA supporting SCA.

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