System, apparatus, and method for extending broadcast services in a wireless local area network

Abstract

Disclosed herein are apparatuses and methods for enhancing broadcast services in a wireless local area network (WLAN).Embodiments provide systems, apparatuses, and methods that ensure that a mobile transceiver station (STA) receiving a broadcast stream receives the stream in a continuous and seamless manner when the STA moves from an area covered by a first AP to an area covered by a second AP.Further embodiments provide systems, apparatuses, and methods in which an access point obtains channel sounding information from one or more sensor devices, including a transceiver station (STA), to provide enhanced broadcast channel condition services to STAs operating within the AP coverage area.

Description

Technical Field

[0001] (Cross-Reference to Related Applications) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 234,615 filed on August 18, 2021 and U.S. Provisional Patent Application No. 63 / 331,028 filed on April 14, 2022, the contents of which are incorporated herein by reference. Background Art

[0002] Wireless networks include mobile, portable, and fixed stations (STAs), whose functions and usage profiles are becoming increasingly diversified. For example, in an Internet of Things (IoT) environment, a wireless Internet access point (AP) may serve a large number of small sensor STAs with limited functions. Such sensor devices typically relay a relatively small amount of various sensed environmental parameters to a remote receiver via a wireless uplink to the AP. At the same time, the AP may also provide Internet access to STAs including wireless laptops, PDAs, mobile phones, and the like. These devices can be equipped with multiple transceivers configured for wireless communication in one or more radio frequency bands corresponding to one or more IEEE 802.11 standards, namely 900 MHz (802.11ah), 2.4 GHz (802.11b / g / n / ax), 3.6 GHz (802.11y), 4.9 GHz to 5 GHz (802.11j-WLAN), 5 GHz (802.11a / h / j / n / ac / ax), 5.9 GHz (802.11p), 6 GHz (802.11ax), and 60 GHz (802.11ad / ay).

[0003] An access point (AP) typically provides a wide range of services to wireless stas (STAs) operating within its broadcast range. For example, an AP can broadcast a stream of media content to laptops, PDAs, and smartphone STAs within its broadcast range. An AP can also broadcast channel status not only to STAs already associated with the AP, but also to STAs attempting to connect to the AP. Therefore, it is crucial that the AP understands the channel status of its broadcast. It is also important that the AP can support STAs receiving the broadcast stream when they move from an area covered by one AP to an area covered by a different AP. Thus, there is a need for APs to provide extended broadcast services to STAs operating in a wireless local area network (WLAN). [Overview of the Initiative]

[0004] This specification discloses apparatus and methods for extending broadcast services in wireless local area networks (WLANs). Embodiments provide systems, apparatus and methods for ensuring that a mobile transceiver (STA) receiving a broadcast stream receives the stream in a continuous and seamless manner as it moves from an area covered by a first AP to an area covered by a second AP. Further embodiments provide systems, apparatus and methods for an access point device to acquire channel sounding information from one or more sensor devices, including a transceiver station (STA), and to provide extended broadcast channel state services to an STA operating within an AP coverage area. [Brief explanation of the drawing]

[0005] A more detailed understanding can be obtained from the following description, which is given as an example in conjunction with the attached drawings, where similar reference numbers in the drawings indicate similar elements. [Figure 1A] This is a system diagram illustrating an exemplary communication system in which one or more disclosed embodiments may be implemented. [Figure 1B] This is a system diagram illustrating an exemplary wireless transmit / receive unit (WTRU) that may be used in a communication system illustrated in Figure 1A, according to one embodiment. [Figure 1C] This is a system diagram illustrating an exemplary radio access network (RAN) and an exemplary core network (CN) that may be used in a communication system illustrated in Figure 1A according to one embodiment. [Figure 1D] This is a system diagram illustrating a further exemplary RAN and a further exemplary CN that may be used in the communication system illustrated in Figure 1A according to one embodiment. [Figure 2A] An example of an enhanced broadcast service (EBCS) neighbor AP child element is illustrated. [Figure 2B] An example of an EBCS neighbor AP subfield is illustrated. [Figure 2C] This is a signal flow diagram of the procedure for using FILS discovery frames to transmit EBCS information. [Figure 3] This is a signal flow diagram of the coordinated interaction taken by the sensing initiator STA and sensing responder station STA to measure the channel. [Figure 4] This is a signal flow diagram of the coordinated interaction taken by a sensing initiator AP and a sensing responder STA to measure a channel in a multi-user (MU) scenario. [Figure 5] This is a signal flow diagram for channel sensing. [Figure 6] This is a signal flow diagram of an exemplary sensing measurement procedure using MU-RTS / CTS and RTS / CTS exchange. [Figure 7]This is a signal flow diagram of an exemplary sensing measurement procedure using MU-RTS / CTS and RTS / CTS exchange. [Modes for carrying out the invention]

[0006] Figure 1A illustrates an exemplary communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content such as voice, data, video, message transmission, and broadcast to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communication system 100 may use 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 filter OFDM, and filter bank multicarrier (FBMC).

[0007] As shown in Figure 1A, the communication system 100 may include radio transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a radio access network (RAN) 104, a core network (CN) 106, a public switched telephone network (PSTN) 108, the internet 110, and other networks 112, but it will be understood that the disclosed embodiments intend any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, and 102d may be any type of device configured to operate and / or communicate in a radio environment. For example, WTRU102a, 102b, 102c, and 102d, all of which may be referred to as stations (STAs), may be configured to transmit and / or receive radio signals, but may include user equipment (UEs), mobile stations, fixed or mobile subscriber units, subscriber-based units, pagers, mobile phones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, hotspots or Mi-Fi devices, Internet of Things (IoT) devices, watches or other wearables, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in the context of industrial and / or automated processing chains), consumer electronics devices, and devices operating on commercial and / or industrial wireless networks. Any of WTRU102a, 102b, 102c, and 102d may interchangeably be referred to as UEs.

[0008] The communication system 100 may also include base stations 114a and / or base stations 114b. Each of the base stations 114a and 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, and 102d to facilitate access to one or more communication networks such as CN 106, the Internet 110, and / or other networks 112. As an example, base stations 114a and 114b may be next-generation NodeBs such as base transceiver stations (BTS), NodeBs, eNode Bs (eNBs), Home Node Bs, Home eNode Bs, gNode Bs (gNBs), new radio (NR) NodeBs, site controllers, access points (APs), wireless routers, etc. Although base stations 114a and 114b are each depicted as single elements, it will be understood that base stations 114a and 114b may include any number of interconnected base stations and / or network elements.

[0009] Base station 114a may be part of RAN 104, which may also include other base stations such as a base station controller (BSC), a radio network controller (RNC), relay nodes, and / or network elements (not shown). Base station 114a and / or base station 114b may be configured to transmit and / or receive radio signals on one or more carrier frequencies which may be referred to as cells (not shown). These frequencies may be licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage of radio services to a particular geographic area which may be relatively fixed or change over time. A cell may be further divided into cell sectors. For example, a cell associated with base station 114a may be divided into three sectors. Thus, in one embodiment, base station 114a may include three transceivers, i.e., one transceiver per sector of the cell. In one embodiment, the base station 114a may use 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 a desired spatial direction.

[0010] Base stations 114a and 114b may communicate with one or more WTRUs 102a, 102b, 102c, and 102d via an air interface 116, which may be any suitable radio 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).

[0011] More specifically, as described above, the communication system 100 may be a multiple access system and may use one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, base stations 114a of RAN 104 and WTRU 102a, 102b, 102c may implement radio technologies such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA) and may establish an 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 Packet Access (HSDPA) and / or High-Speed ​​Uplink Packet Access (HSUPA).

[0012] In one embodiment, base stations 114a and WTRUs 102a, 102b, and 102c may implement radio technologies such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish an air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0013] In one embodiment, the base station 114a and WTRUs 102a, 102b, and 102c may implement radio technologies such as NR radio access, which may establish an air interface 116 using NR.

[0014] In one embodiment, base station 114a and WTRU 102a, 102b, 102c may implement multiple radio access technologies. For example, base station 114a and WTRU 102a, 102b, 102c may implement LTE radio access and NR radio access together, for example, using the dual connectivity (DC) principle. Thus, the air interface utilized by WTRU 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions transmitted to and from multiple types of base stations (e.g., eNB and gNB).

[0015] In other embodiments, base stations 114a and WTRUs 102a, 102b, and 102c may implement wireless technologies such as IEEE 802.11 (i.e., Wireless Fidelity, WiFi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access, WiMAX), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Provisional Standard 2000 (IS-2000), Provisional Standard 95 (IS-95), Provisional Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), and GSM EDGE (GERAN).

[0016] The base station 114b in Figure 1A may be, for example, a wireless router, home node B, home e-node B, or access point, and may utilize any suitable RAT to facilitate wireless connectivity in local areas such as offices, homes, vehicles, campuses, industrial facilities, aerial corridors (for use by drones), roads, etc. In one embodiment, the base station 114b and WTRU 102c, 102d may implement wireless technologies such as IEEE 802.11 to establish a wireless local area network (WLAN). In one embodiment, the base station 114b and WTRU 102c, 102d may implement wireless technologies such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, base stations 114b and WTRUs 102c, 102d may establish picocells or femtocells using cellular-based RATs (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.). As shown in Figure 1A, base station 114b may have a direct connection to the internet 110. Therefore, base station 114b may not need to access the internet 110 via CN 106.

[0017] RAN104 may communicate with CN106, 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 WTRU102a, 102b, 102c, and 102d. The data may have various quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, and mobility requirements. CN106 may provide call control, billing services, mobile location-based services, prepaid calls, internet connectivity, video distribution, etc., and / or high-level security functions such as user authentication. Although not shown in Figure 1A, it will be understood that RAN104 and / or CN106 may communicate directly or indirectly with other RANs using the same RAT or different RAT as RAN104. For example, in addition to being connected to RAN104 which may utilize NR radio technology, CN106 may also communicate with another RAN (not shown) using GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0018] CN106 may also function as a gateway for WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network that provides plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices, wherein said networks and devices use common communication protocols, such as transmission control protocol (TCP), user datagram protocol (UDP), and / or internet protocol (IP) of the TCP / IP internet protocol suite. The network 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, the network 112 may include another CN connected to one or more RANs, which may use the same RAT as the RAN 104 or a different RAT.

[0019] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication system 100 may include multi-mode functionality (e.g., the WTRUs 102a, 102b, 102c, 102d may include a plurality of transceivers for communicating with different wireless networks via different wireless links). For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with a base station 114a, which may use cellular-based radio technology, and a base station 114b, which may use IEEE 802 radio technology.

[0020] FIG. 1B is a system diagram illustrating an example WTRU 102. As shown in FIG. 1B, the WTRU 102 may include, among others, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, a non-removable memory 130, a removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138. It will be appreciated that the WTRU 102 may comprise any subcombination of the foregoing elements while remaining consistent with an embodiment.

[0021] 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, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), 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. Although FIG. 1B 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.

[0022] The transmit / receive element 122 may be configured to transmit signals to or receive signals from a base station (e.g., base station 114a) via 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 one embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive, for example, IR, UV, or visible light signals. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF signals and optical signals. It will be understood that the transmit / receive element 122 may be configured to transmit and / or receive any combination of radio signals.

[0023] Although the transmit / receive element 122 is depicted as a single element in Figure 1B, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may utilize 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 radio signals via the air interface 116.

[0024] The transceiver 120 may be configured to modulate the signal transmitted by the transmit / receive element 122 and demodulate the signal received by the transmit / receive element 122. As described above, the WTRU 102 may have multimode capabilities. Therefore, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0025] The processor 118 of the WTRU102 may be coupled to a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light-emitting diode (OLED) display unit) from which it can receive user-input data. 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 any type of suitable memory, such as non-removable memory 130 and / or removable memory 132, and store data in such memory. 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 memory not physically located on the WTRU 102, such as on a server or home computer (not shown), and store data in such memory.

[0026] The processor 118 may receive power from the power supply 134, but may be configured to distribute and / or control power to other components in the WTRU 102. The power supply 134 may be any suitable device for supplying power to the WTRU 102. For example, the power supply 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0027] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) about the current location of the WTRU 102. In addition to or instead of the information from the GPS chipset 136, the WTRU 102 may determine its location based on receiving location information from base stations (e.g., base stations 114a, 114b) via the air interface 116 and / or based on the timing of signals received from two or more nearby base stations. It will be understood that the WTRU 102 may acquire location information by any preferred location determination method while maintaining consistency with one embodiment.

[0028] The processor 118 may be further coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functions, and / or wired or wireless connectivity. For example, peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or videos), 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, etc. Peripherals 138 may include one or more sensors. The sensor may be one or more of the following: gyroscope, accelerometer, Hall effect sensor, magnetometer, orientation sensor, proximity sensor, temperature sensor, time sensor, geolocation sensor, altimeter, light sensor, touch sensor, barometer, gesture sensor, biometric sensor, humidity sensor, etc.

[0029] WTRU102 may include a full-duplex radio in which the transmission and reception of some or all of a signal (for example, associated with specific subframes of both UL (for example, for transmission) and DL (for example, for reception) may be simultaneous and / or together. The full-duplex radio may include an interference management unit for reducing and / or substantially eliminating self-interference either through hardware (e.g., chokes) or signal processing via a processor (e.g., via a separate processor (not shown) or processor 118). In one embodiment, WTRU102 may include a half-duplex radio for the transmission and reception of some or all of a signal (for example, associated with specific subframes of either UL (for example, for transmission) or DL ​​(for example, for reception)).

[0030] Figure 1C is a system diagram illustrating RAN104 and CN106 according to one embodiment. As described above, RAN104 can communicate with WTRU102a, 102b, and 102c via the air interface 116 using E-UTRA wireless technology. RAN104 can also communicate with CN106.

[0031] RAN104 may include e-nodes-B160a, 160b, and 160c, but it will be understood that RAN104 may include any number of e-nodes-B while maintaining consistency with one embodiment. Each of e-nodes-B160a, 160b, and 160c may include one or more transceivers for communicating with WTRU102a, 102b, and 102c via the air interface 116. In one embodiment, e-nodes-B160a, 160b, and 160c may implement MIMO technology. Thus, e-node-B160a may, for example, use multiple antennas to transmit radio signals to and / or receive radio signals from WTRU102a.

[0032] Each of the e-nodes B160a, 160b, and 160c may be associated with a specific cell (not shown) and may be configured to handle wireless resource management decisions, handover decisions, user scheduling, etc., in UL and / or DL. As shown in Figure 1C, the e-nodes B160a, 160b, and 160c may communicate with each other via the X2 interface.

[0033] The CN106 shown in Figure 1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (PGW) 166. Although these elements are depicted as part of CN106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0034] The MME162 can be connected to each of the e-nodes B162a, 162b, and 162c in RAN104 via the S1 interface and can function as a control node. For example, the MME162 may perform roles such as authenticating users of WTRU102a, 102b, and 102c, activating / deactivating bearers, and selecting gateways for specific services during the initial attachment of WTRU102a, 102b, and 102c. The MME162 may provide control plane functionality for switching between RAN104 and other RANs (not shown) employing other radio technologies such as GSM and / or WCDMA.

[0035] The SGW164 can be connected to each of the e-nodes B160a, 160b, and 160c in RAN104 via the S1 interface. The SGW164 can generally route and forward user data packets to and from WTRU102a, 102b, and 102c. The SGW164 can also perform other functions, such as anchoring the user plane during e-node B handovers, triggering paging when DL data is available to WTRU102a, 102b, and 102c, and managing and remembering the context of WTRU102a, 102b, and 102c.

[0036] SGW164 may be connected to PGW166, which may provide WTRU102a, 102b, and 102c with access to a packet-switched network such as the Internet 110 to facilitate communication between WTRU102a, 102b, and 102c and IP-enabled devices.

[0037] CN106 can facilitate communication with other networks. For example, CN106 can provide WTRU102a, 102b, and 102c with access to a circuit-switched network such as PSTN108 to facilitate communication between WTRU102a, 102b, and 102c and conventional terrestrial line communication devices. For example, CN106 may include or communicate with an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that acts as an interface between CN106 and PSTN108. In addition, CN106 may provide WTRU102a, 102b, and 102c with access to another network 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0038] Although the WTRU is described as a wireless terminal in Figures 1A to 1D, in certain representative embodiments, such a terminal is intended to be able to use a wired communication interface (e.g., temporary or permanent) with a communication network.

[0039] In a typical embodiment, the other network 112 may be a WLAN.

[0040] A WLAN in Basic Service Set (BSS) mode may have an Access Point (AP) of the BSS and one or more stations (STAs) associated with the AP. The AP may have access to or interfaces with a Distribution System (DS) or another type of wired / wireless network that carries traffic within and / or outside the BSS. Traffic originating outside the BSS to an STA may reach and be delivered to the STA via the AP. Traffic originating from an STA to a destination outside the BSS may be sent to the AP and then delivered to its respective destination. Traffic between STAs within the BSS may be sent, for example, via the AP; the source STA may send traffic to the AP, and the AP may deliver the traffic to the destination STA. Traffic between STAs within the BSS may be considered and / or referred to as inter-layer traffic. Inter-layer traffic may be sent between the source STA and the destination STA (for example, directly between them) in a direct link setup (DLS). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunneled DLS (TDLS). A WLAN using Independent BSS (IBSS) mode may not have APs, and STAs within or using IBSS (e.g., all STAs) may communicate directly with each other. The IBSS mode of communication may be referred to herein as “ad hoc” communication mode.

[0041] When using the 802.11ac infrastructure operating mode or a similar operating mode, an AP may transmit beacons on a fixed channel, such as the primary channel. The primary channel may be of a fixed width (e.g., a 20 MHz bandwidth) or a dynamically set width. The primary channel may be the operating channel of the BSS and may be used by the STA to establish a connection with the AP. In certain typical embodiments, a Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) scheme may be implemented, for example, in an 802.11 system. In the case of CSMA / CA, the STA, including the AP (e.g., all STAs), may sense the primary channel. If the primary channel is sensed / detected and / or determined to be operating by a particular STA, that particular STA may be backed off. A single STA (e.g., only one station) may transmit at any given time on a given BSS.

[0042] High-throughput (HT) STAs may use a 40 MHz wide channel for communication, which can be formed, for example, through a combination of a primary 20 MHz channel and adjacent or non-adjacent 20 MHz channels.

[0043] Very High Throughput (VHT) STAs may support channels with widths of 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz. The 40 MHz and / or 80 MHz channels mentioned above may be formed by combining multiple consecutive 20 MHz channels. A 160 MHz channel may be formed by combining eight consecutive 20 MHz channels, or by combining two non-consecutive 80 MHz channels, which may be referred to as an 80+80 configuration. In the 80+80 configuration, after channel coding, the data may pass through a segment parser that can split the data into two streams. Inverse Fast Fourier Transform (IFFT) processing and time-domain processing may be performed separately for each stream. The streams may be mapped to two 80 MHz channels, and the data may be transmitted by a transmitting STA. In the receiver of a receiving STA, the operation described above for the 80+80 configuration may be reversed, and the combined data may be transmitted to Medium Access Control (MAC).

[0044] Sub-1 GHz operating modes are supported by 802.11af and 802.11ah. Channel operating bandwidth and carrier are reduced in 802.11af and 802.11ah compared to those used in 802.11n and 802.11ac. 802.11af supports bandwidths of 5 MHz, 10 MHz, and 20 MHz in the TV White Space (TVWS) spectrum, while 802.11ah supports bandwidths of 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz using the non-TVWS spectrum. According to a typical embodiment, 802.11ah may support meter-type control / machine-type communications (MTC), such as MTC devices in a macro coverage area. MTC devices may have specific features, including support for specific and / or limited bandwidths (e.g., support only for those bandwidths). MTC devices may include batteries with a battery life exceeding a threshold (for example, to maintain a very long battery life).

[0045] A WLAN system capable of supporting multiple channels and channel bandwidths such as 802.11n, 802.11ac, 802.11af, and 802.11ah includes a channel that can be designated as the primary channel. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by an STA from among all STAs operating in a BSS that support the minimum bandwidth operating mode. In the 802.11ah example, the primary channel may be 1 MHz wide for an STA (e.g., an MTC type device) that supports (e.g., only) the 1 MHz mode, even if other STAs in the AP and 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 state of the primary channel. For example, if the primary channel is busy, an STA (which only supports 1MHz operating mode) sending to the AP may consider the entire available frequency band to be busy, even if most of the available frequency band is idle.

[0046] In the United States, the available frequency band that can be used by 802.11ah is 902MHz to 928MHz. In South Korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz, depending on the country code.

[0047] Figure 1D is a system diagram illustrating RAN104 and CN106 according to one embodiment. As described above, RAN104 can communicate with WTRU102a, 102b, and 102c via the air interface 116 using NR radio technology. RAN104 can also communicate with CN106.

[0048] RAN104 may include gNB180a, 180b, and 180c, but it will be understood that RAN104 may include any number of gNBs while maintaining consistency with one embodiment. Each of gNB180a, 180b, and 180c may include one or more transceivers for communicating with WTRU102a, 102b, and 102c via the air interface 116. In one embodiment, gNB180a, 180b, and 180c may implement MIMO technology. For example, gNB180a and 180b may use beamforming to transmit and / or receive signals to gNB180a, 180b, and 180c. Thus, gNB180a may, for example, use multiple antennas to transmit radio signals to and / or receive radio signals from WTRU102a. In one embodiment, gNB180a, 180b, and 180c may implement carrier aggregation technology. For example, gNB180a may transmit multiple component carriers to WTRU102a (not shown). A subset of these component carriers may be on the unauthorized spectrum, and the remaining component carriers may be on the authorized spectrum. In one embodiment, gNB180a, 180b, and 180c may implement coordinated multi-point (CoMP) technology. For example, WTRU102a may receive coordinated transmissions from gNB180a and gNB180b (and / or gNB180c).

[0049] WTRU102a, 102b, and 102c may communicate with gNB180a, 180b, and 180c using transmissions associated with an expandable numerology. For example, OFDM symbol intervals and / or OFDM subcarrier intervals may vary for different transmissions, different cells, and / or different portions of the radio transmission spectrum. WTRU102a, 102b, and 102c may communicate with gNB180a, 180b, and 180c using subframes or transmission time intervals (TTI) of varying or expandable lengths (e.g., including varying numbers of OFDM symbols and / or varying durations of absolute time).

[0050] gNB180a, 180b, and 180c can be configured to communicate with WTRU102a, 102b, and 102c in standalone and / or non-standalone configurations. In a standalone configuration, WTRU102a, 102b, and 102c can communicate with gNB180a, 180b, and 180c without accessing other RANs (e.g., e-node-B160a, 160b, and 160c). In a standalone configuration, WTRU102a, 102b, and 102c can utilize one or more of gNB180a, 180b, and 180c as mobility anchor points. In a standalone configuration, WTRU102a, 102b, and 102c can communicate with gNB180a, 180b, and 180c using signals in unlicensed bands. In a non-standalone configuration, WTRU102a, 102b, and 102c can communicate with and connect to gNB180a, 180b, and 180c, while also communicating with and connecting to other RANs such as e-nodes-B160a, 160b, and 160c. For example, WTRU102a, 102b, and 102c can implement DC principles to communicate substantially simultaneously with one or more gNB180a, 180b, and 180c and one or more e-nodes-B160a, 160b, and 160c. In a non-standalone configuration, e-nodes B160a, 160b, and 160c can function as mobility anchors for WTRU102a, 102b, and 102c, while gNB180a, 180b, and 180c can provide additional coverage and / or throughput to service WTRU102a, 102b, and 102c.

[0051] Each of the gNB180a, 180b, and 180c may be associated with a specific cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, user scheduling in UL and / or DL, support for network slices, interaction between DC, NR and E-UTRA, routing of user plane data to User Plane Functions (UPFs) 184a and 184b, routing of control plane information to Access and Mobility Management Functions (AMFs) 182a and 182b, and so on. As shown in Figure 1D, the gNB180a, 180b, and 180c may communicate with each other via the Xn interface.

[0052] The CN106 shown in Figure 1D may include at least one AMF182a, 182b, at least one UPF184a, 184b, at least one Session Management Function (SMF)183a, 183b, and optionally a Data Network (DN)185a, 185b. Although the aforementioned elements are depicted as part of CN106, it will be understood that any of these elements may be owned and / or operated by entities other than the CN operator.

[0053] AMF182a and 182b can be connected to one or more gNB180a, 180b, and 180c in RAN104 via the N2 interface and can function as control nodes. For example, AMF182a and 182b may play roles such as user authentication for WTRU102a, 102b, and 102c, support for network slicing (e.g., handling different protocol data unit (PDU) sessions with different requirements), selection of specific SMF183a and 183b, management of registration areas, termination of non-access stratum (NAS) signaling, and mobility management. Network slicing can be used by AMF182a and 182b to customize CN support for WTRU102a, 102b, and 102c based on the type of service utilizing WTRU102a, 102b, and 102c. For example, different network slices may be established for different use cases, such as services that rely on ultra-high reliability low latency (URLLC) access, services that rely on enhanced massive mobile broadband (eMBB) access, and services for MTC access. AMF182a, 182b may provide control plane functionality for switching between RAN104 and other RANs (not shown) using other radio technologies such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0054] SMF183a and 183b can be connected to AMF182a and 182b in CN106 via the N11 interface. SMF183a and 183b can also be connected to UPF184a and 184b in CN106 via the N4 interface. SMF183a and 183b can select and control UPF184a and 184b and configure the routing of traffic through UPF184a and 184b. SMF183a and 183b can perform other functions such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, and providing DL data notifications. PDU session types can be IP-based, non-IP-based, Ethernet-based, etc.

[0055] UPF184a and 184b may be connected via the N3 interface to one or more of the gNB180a, 180b, and 180c in RAN104, thereby providing WTRU102a, 102b, and 102c with access to packet-switched networks such as the Internet 110, and facilitating communication between WTRU102a, 102b, and 102c and IP-enabled devices. UPF184 and 184b may perform other functions such as packet routing and forwarding, enforcement of user plane policies, support for multi-homed PDU sessions, processing of user plane QoS, buffering of DL packets, and providing mobility anchoring.

[0056] CN106 can facilitate communication with other networks. For example, CN106 may include, or communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that functions as an interface between CN106 and PSTN108. In addition, CN106 may provide WTRU102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, WTRU102a, 102b, 102c may be connected to local DN185a, 185b via UPF184a, 184b through N3 interfaces to UPF184a, 184b and N6 interfaces between UPF184a, 184b and DN185a, 185b.

[0057] With regard to Figures 1A-1D and the corresponding descriptions in Figures 1A-1D, one or more of the functions described herein with respect to one or more of the WTRU102a-d, base stations 114a-b, eNode-B160a-c, MME162, SGW164, PGW166, gNB180a-c, AMF182a-b, UPF184a-b, SMF183a-b, DN185a-b, and / or any other devices described herein may be performed by one or more emulation devices (not shown). An emulation device may be one or more devices configured to emulate one or more of the functions described herein. For example, an emulation device may be used to test other devices and / or simulate network and / or WTRU functions.

[0058] Emulation devices may be designed to implement testing of one or more other devices in a laboratory and / or operator network environment. For example, one or more emulation devices may perform one or more or all functions while fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices in a communication network. One or more emulation devices may perform one or more or all functions while temporarily implemented / deployed as part of a wired and / or wireless communication network. Emulation devices may be directly coupled to another device for the purpose of testing and / or performing testing using over-the-air wireless communication.

[0059] One or more emulation devices may perform one or more functions when not implemented / deployed as part of a wired and / or wireless communication network. For example, emulation devices may be used in test laboratory test scenarios and / or in undeployed (e.g., test) wired and / or wireless communication networks to implement testing of one or more components. One or more emulation devices may be test equipment. Direct RF coupling and / or wireless communication via RF circuitry (e.g., which may include one or more antennas) may be used by emulation devices to transmit and / or receive data.

[0060] The Extended Broadcast Service (eBCS or EBCS) used herein is any broadcast service that extends the transmission and reception of broadcast data in an infrastructure BSS where there is an association between an AP (broadcast transmitter) and one or more STA clients (broadcast receivers), and also in situations where there is no association between the AP server and the AP clients.

[0061] The channel sensing used herein is a mechanism for detecting channel occupancy or predicting future traffic in a wireless network using a carrier-sensing multiple access / collision avoidance scheme (CSMA / CA). For example, virtual channel sensing technology uses a timer mechanism based on the duration of previous frame transmissions to predict future traffic on a channel. The network allocation vector (NAV) is used as a counter that counts down to 0. The maximum NAV duration is the transmission time required for one frame, and the time the channel is busy. At the start of frame transmission, the NAV value is set to its maximum value. A non-zero value indicates that the channel is busy and therefore STAs are not competing for wireless medium. When the NAV value decreases to 0, it indicates that the channel may be free and then STAs can compete for wireless medium.

[0062] The sensing procedure used herein is a series of steps or actions by which a wireless device performs channel sensing for the purpose of measuring some parameter of a channel.

[0063] As used herein, a sensing session is a temporary and coordinated exchange of signals or information between two or more devices for performing channel sensing. A sensing session may be further defined by the operating parameters associated with that sensing session. A sensing session may include one or more of the following processes: setup, measurement, reporting, and / or termination. Accordingly, an STA implementing sensing according to the disclosed embodiments is configured to perform one or more of the following sensing functions: setup, measurement, reporting, and / or termination.

[0064] The sensing initiator is the STA that initiates the sensing session.

[0065] A sensing responder is an STA that participates in a sensing session initiated by a sensing initiator.

[0066] The sensing transmitter is an STA that transmits a protocol packet data unit (PPDU) corresponding to a sensing measurement or sensing session.

[0067] The sensing receiver is an STA that receives the PPDU transmitted by the sensing transmitter and performs sensing measurement actions as part of the sensing session.

[0068] Under the above definition, an STA can play one or more roles in a sensing session. For example, in a given session, the first STA can function as both a sensing transmitter and a sensing receiver. In another session, the first STA can function as a sensing transmitter, and the second STA can function as a sensing transmitter. Not all STAs in a BSS participate in all sensing sessions. In some cases, no STA functions as either a sensing transmitter or a sensing receiver.

[0069] In some embodiments, an EBCS AP broadcasts a data stream downlink to non-AP STAs. In some embodiments, the AP provides broadcast services (i.e., data streams) to unassociated STAs as well as associated STAs. In some embodiments, a single AP provides broadcast services to up to 300 non-AP STAs. Non-AP STAs may be low-cost non-AP STAs that can only receive AP broadcast data streams and cannot send directly to APs.

[0070] The embodiments described herein can be found in a variety of applications. For example, an AP broadcasts a video stream to a STA within a sports stadium. In another exemplary application, an AP broadcasts a stream of safety information to a vehicle. In some embodiments, an AP broadcasts data provided via an uplink from a sensor to the AP. Other applications include broadcasting museum information, multilingual broadcasts, event producer information, and content broadcasts.

[0071] An AP can automatically provide EBCS data streams or provide specific EBCS traffic streams on a routine or schedule basis, depending on the broadcast schedule or configuration. For some data streams, STAs within the AP coverage area do not need to associate with the AP to receive broadcast data streams from the AP. For some data streams, STAs do not need to register with the AP or request it to the AP to receive broadcast data streams. Therefore, in scenarios where the AP is broadcasting data streams to STAs that it does not associate with and / or unregistered STAs, the AP may not have a record of all STAs that are receiving that broadcast data stream. In these examples, STAs do not need to request to receive EBCS data streams. In other examples, the AP provides one or more EBCS traffic streams only upon request or registration of one or more STAs.

[0072] In some cases, depending on the operator's configuration, one or more EBCS data streams may always be provided, with other EBCS data streams provided upon request from the STA. For EBCS data streams transmitted by the AP in response to a request or registration from the STA, mobility support may be required for STAs that are currently receiving the EBCS data stream and are expected to move outside the current AP's broadcast coverage range. This scenario raises the question of how to provide an efficient mechanism to ensure that the EBCS traffic stream can continue seamlessly when it leaves the coverage area of ​​the first AP and enters the coverage area of ​​the second AP.

[0073] An EBCS AP may provide a broadcast data stream to either an EBCS AP-associated STA or an EBCS AP-unassociated STA. Information about the EBCS broadcast service provided by the AP may be contained within an EBCS Information (Info) frame that can be broadcast by the AP. The discovery methods disclosed herein may be used by an STA to discover the EBCS service provided by the AP by efficiently discovering the timing of the EBCS Info frames.

[0074] In some embodiments, a WLAN sensing protocol (e.g., 802.11bf) may support sensing operations by a large number (e.g., thousands) of non-AP STAs with specific sensing capabilities, including legacy STAs (e.g., devices prior to 802.11bf). Sensing operations may include various sensing phases, including a setup phase, a measurement phase, a reporting phase, and / or a termination phase.

[0075] In one embodiment, a seamless transition of receiving an EBCS traffic stream is performed by the STA from a first AP to a second AP. The STA receives the EBCS traffic stream from the first AP. The STA is mobile and leaves the area covered by the first AP and enters the area covered by one or more second APs. The first AP, which is an EBCS AP, can provide information about other EBCS APs that provide the same EBCS data stream that one or more EBCS STAs are currently consuming, or information about one or more EBCS data streams that an EBCS AP is currently providing. The first AP may transmit at least one of the following: beacons, short beacons, probe responses, fast initial link setup (FILS) discovery frames and / or other management, control, or data frames, including an indication of one or more second APs that provide the same or similar EBCS data stream as that provided by the first AP.

[0076] In one embodiment, the first AP provides a representation of one or more second EBCS APs that provide similar or identical EBCS data streams within a Neighbor Report element, a Reduced Neighbor Report element, or a newly designed element. For example, an STA may send a request for a neighbor report to the first AP. The first AP sends a neighbor report or reduced neighbor report containing information about known candidate neighbor APs so that the first STA or other STAs can receive the same EBCS data stream provided by the first AP. This information may include whether the first STA needs to associate with one or more second APs in order to receive the same EBCS data stream from one or more second APs.

[0077] In one embodiment, the first AP provides a representation of one or more second EBCS APs that provide the same or similar EBCS data stream by assembling EBCS neighbor AP child elements, which may be contained within a neighbor report element, a reduced neighbor report element, a newly designed EBCS neighbor element, or other newly designed element. The EBCS neighbor AP child elements may then be sent to, for example, the STA.

[0078] Referring to Figure 2A, the EBCS neighbor AP child element 200 includes one or more of the following fields or subfields: a child element ID field 210, a length field 220, and a content ID indication field 230. The child element ID field 210 can be used to indicate that the child element is an EBCS neighbor AP child element. The child element ID field may contain several bits that encode a value indicating to the decoder that the child element is an EBCS neighbor AP child element. The length field 220 is used to indicate the length of the child element. The length field may contain several bits that encode a value indicating to the decoder that the length of the child element is. The content ID indication field 230 can be used to indicate one or more content identifiers associated with one or more EBCS data streams or content provided by the AP. This field may be a bitmap for indicating one or more content IDs of the EBCS data stream that the AP is currently broadcasting. This field can provide an explicit indication of each content ID associated with the EBCS traffic stream that the current AP is currently providing.

[0079] An EBCS neighbor AP child element may be contained within one or more elements, such as a neighbor report element or a reduced neighbor report element, and these elements may be used to indicate one or more neighbor APs, thereby allowing the display of AP IDs to be omitted within the EBCS neighbor AP child element.

[0080] In another embodiment, the first AP generates neighbor AP information. The first AP may generate a target beacon transmission time (TBTT) information subfield or a BSS parameters subfield and include it within a neighbor report element, a reduced neighbor report element, or a newly designed element. In any case, the first AP inserts one or more indicator bits and sets the bits to "true" or "false" (which may correspond to values ​​of 1 or 0, respectively, or vice versa) to indicate that the APs associated with the neighbor AP information field support one or more data streams or content supported by the first AP.

[0081] In another embodiment, one or more indicator bits may be set to "true" or "1" to indicate that the AP associated with the neighbor AP information supports one or more or all of the active EBCS data streams or content currently provided by the transmitting AP. In another embodiment, one or more indicator bits may be set to "true" or "1" to indicate that the AP associated with the neighbor AP information supports one or more or all of the EBCS data streams or content currently provided by the transmitting AP, or all EBCS data streams or content that require registration or request. Such indications may be contained within a reduced neighbor report element or any other element. In one embodiment, this indication is not set for any co-installed or co-hosted AP or any non-transmitting transmitting AP's Basic Service Set Identifier (BSSID).

[0082] Figure 2B illustrates an EBCS neighbor AP element 250. An EBCS neighbor AP element may include one or more of the following fields. Although shown in Figure 2B as including all fields, this is for illustrative purposes only, and any combination of the fields shown may exist within the EBCS neighbor AP element 250. Element ID 260 is used to indicate that the element is an EBCS neighbor AP element. Element ID 260 may include several bits to indicate to the decoder that the element is an EBCS neighbor AP element 250. Length 262 is used to indicate the length of the element. Length 262 may include several bits to encode a value to indicate the length of the EBCS neighbor AP element 250 to the decoder. AP ID 264 indicates the AP ID, such as the AP's MAC address, BSSID, or the MAC address of the AP MLD. AP ID 264 may include several bits to encode a value to indicate the aforementioned ID to the decoder. Operation class 266 and operation channel 268 indicate the AP's operation class and operation channel, respectively. The operation class 266 and operation channel 268 fields may contain several bits that encode values ​​to indicate the operation class and operation channel of the AP to the decoder, respectively. The content ID display 270 displays one or more content IDs associated with one or more EBCS data streams transmitted by the AP. This field may also be implemented as a bitmap showing one or more content IDs for the EBCS data streams provided by the current transmitting AP. Alternatively, this field may include an explicit display of each content ID. Alternatively, this field may be a bitmap indicating which EBCS traffic streams provided by the current AP are supported.

[0083] Note that any of the information described above may reside in or within a child element. Any one or more subfields or pieces of information provided therein may be contained within any existing or new element, child element, control, management, data frame, and / or PHY and MAC headers, or any combination thereof.

[0084] In some embodiments, the STA may receive a reduced neighbor report and decide to receive an EBCS stream from another AP discovered through the reduced neighbor report received within the beacon frame of the associated AP.

[0085] As described above, when an STA is consuming an EBCS traffic stream from a first AP, it may be desirable for the STA to continue consuming the EBCS traffic stream even when the STA moves to another AP. An EBCS AP / BSS transition procedure is required. In one embodiment, the EBCS AP / BSS transition procedure can be initiated by an EBCS AP broadcasting one or more EBCS data streams. The AP indicates available EBCS data streams in one or more frames, such as beacons, short beacons, EBCS Info frames, and / or FILS discovery frames. For example, the AP may periodically send EBCS Info frames, which may contain information about which EBCS traffic streams the AP is providing or transmitting. The EBCS AP may include information about one or more EBCS neighbor APs in one or more elements or frames, including but not limited to neighbor report elements or reduced neighbor report elements, or it may send new EBCS neighbor AP elements, frames, or other data structures. For example, an EBCS neighbor AP element may be included within a neighbor report element to indicate that the AP can provide all traffic streams currently provided by the sending AP, or all active EBCS traffic streams, or any other content, or that the AP can provide all or all active EBCS traffic streams and / or content currently provided by the first AP, regardless of whether the STA needs to register or request a second AP.

[0086] An STA that is not an EBCS AP may consume EBCS data streams or content that require the STA to register with an AP or to send a request via an EBCS content request frame. An STA that is not an EBCS AP may receive frames from an EBCS AP that is a transmitter of or capable of providing EBCS traffic streams or content that include one or more indicators of one or more EBCS neighbor APs. Such information may be contained within a neighbor report element, a reduced neighbor report element, or an EBCS neighbor AP element. An STA that is not an EBCS AP may use the information received regarding EBCS neighbor APs to register with one or more EBCS data streams or content provided by one or more indicated EBCS neighbor APs. An STA that is not an EBCS AP may use an EBCS traffic stream or content request ANQP element to register with one or more EBCS data streams or content provided by neighbor APs. Alternatively, an STA that is not an EBCS AP may use the information received from EBCS neighbor APs to request one or more EBCS data streams or content from one or more indicated EBCS neighbor APs, for example, using an EBCS traffic stream or content request frame.

[0087] If a registration request made using an EBCS traffic stream or content request ANQP element, or a registration request made using an EBCS request containing an EBCS traffic stream / content request frame, fails, the EBCS AP may respond with an ANQP element or EBCS traffic stream / content response frame in which the EBCS request status bit is set to a value indicating "failure". In some embodiments, the EBCS AP may include EBCS neighbor AP information in the response frame, such information may be included in a neighbor report element, a reduced neighbor report element, or an EBCS neighbor AP element, which can identify EBCS neighbor APs that provide the same EBCS traffic stream or content requested by the EBCS STA. An STA that is not an EBCS AP may use the received information about EBCS neighbor APs to register for one or more EBCS traffic streams or content that are being transmitted or provided by one or more indicated EBCS neighbor APs. To do so, an STA that is not an AP may use a frame containing an EBCS traffic stream or content request ANQP element, or an EBCS STA that is not an AP may use information received on an EBCS neighbor AP to request one or more EBCS traffic streams or content from one or more indicated EBCS neighbor APs using an EBCS traffic stream or content request frame.

[0088] To terminate one or more EBCS traffic streams or content, an EBCS AP may send one or more termination notification frames indicating that the AP is about to terminate the transmission of the EBCS traffic stream or content. In some embodiments, the EBCS AP includes EBCS neighbor AP information in the termination notification frame. For example, if the EBCS AP does not extend the transmission of the EBCS traffic stream or content (regardless of whether an STA that is not an EBCS AP requests an extension of the EBCS traffic stream), the EBCS AP sets the negotiation method field to "no negotiation". The EBCS neighbor AP information may be inserted within a neighbor report element, a reduced neighbor report element, or an EBCS neighbor AP element, and these elements may be included in the EBCS termination notification indicating that the EBCS neighbor AP will provide the same EBCS traffic stream or content that the sending EBCS AP is terminating. The STA that is not an EBCS AP then uses the information received regarding the EBCS neighbor AP to register for one or more EBCS traffic streams or content. This registration can be achieved using a frame that includes an EBCS traffic stream or content request ANQP element. Alternatively, an STA that is not an EBCS AP may use information received on an EBCS neighbor AP to request one or more EBCS traffic streams or content from one or more indicated EBCS neighbor APs. The requested EBCS traffic streams or content may be the same as or similar to the EBCS traffic streams or content currently consumed by the STA.

[0089] Exemplary techniques for efficient discovery of Extended Broadcast Services (EBCS) are described in the following embodiments. In one embodiment, a Fast Initial Link Setup (FILS) discovery frame can be used for the discovery of EBCS services and EBCS traffic streams. For example, referring to Figure 2C, the signal flow diagram 2500 shows a first EBCS AP 2510 transmitting an EBCS traffic stream 2540 to at least one EBCS STA 2520 that receives an EBCS traffic stream 2542. In one embodiment, a second EBCS AP 2530 transmits a FILS discovery frame 2544 that includes an indication that the second EBCS AP 2530 is an EBCS AP and / or that this AP provides EBCS broadcasting services. For example, a FILS discovery frame transmitted by an EBCS AP may include, but is not limited to, one or more EBCS-related fields such as an EBCS function indication, an EBCS Info frame transmit field, and / or an EBCS Info frame transmit (Tx) countdown field, which are described in detail below.

[0090] In some embodiments, the EBCS Info frame transmission field and / or the EBCS Info frame TX countdown field contained within the FILS discovery frame 2544 may be 1 or 2 bytes in length. The values ​​shown within the EBCS Info frame transmission field and / or the EBCS Info frame TX countdown field may be one or more units of any of the following: the number of target beacon transmission times (TBTT), the number of beacon intervals, the number of time units (e.g., TU), and / or duration (e.g., microseconds, milliseconds, or other time units). The EBCS Info frame transmission field and / or the EBCS Info frame TX countdown field help the EBCS STA 2520 receive subsequent EBCS Info frames by providing the EBCS STA 2520 with information regarding subsequent transmissions of EBCS Info frames by the second EBCS AP 2530.

[0091] In some embodiments, the FILS discovery frame 2544 may include an EBCS Info frame transmit field presence bit or an EBCS Info frame Tx countdown presence bit. An EBCS Info frame transmit field presence bit or an EBCS Info frame Tx countdown presence bit configured to encode a value of 1 indicates that the current FILS discovery frame carrying that bit may contain an EBCS Info frame transmit field and / or an EBCS Info frame Tx countdown field, respectively. Alternatively, a value encoded to 0 may indicate the same information.

[0092] In some embodiments, the FILS discovery frame 2544 transmitted by the EBCS AP2530 includes EBCS parameter elements. Table 1 shows the FILS discovery frame format including EBCS parameter elements.

[0093] [Table 1]

[0094] The EBCS parameter element may include an EBCS Info frame TX countdown field that can indicate the remaining time until the next transmission of an EBCS Info frame by the AP. The value indicated in the EBCS Info frame TX countdown field may be any one or more units of the following, as described above: the number of TBTTs, the number of beacon intervals, the number of time units (e.g., TUs), and / or the duration (e.g., microseconds, milliseconds, or other time units).

[0095] Still referring to Figure 2C, an EBCS-enabled EBCS AP, such as a second EBCS AP 2530 that transmits a FILS discovery frame 2544, may include EBCS parameter elements in the FILS discovery frame 2544 it transmits. In embodiments where an AP is not in a set of multiple BSSIDs and has enabled EBCS, this AP may include EBCS parameter elements in the FILS discovery frame it transmits. In embodiments where an AP in a set of multiple BSSIDs corresponding to a transmitted BSSID has enabled EBCS, the AP may include EBCS parameter elements in the FILS discovery frame it transmits.

[0096] In other embodiments, an AP or STA that transmits a FILS discovery frame and has a true value for dot11EBCSSupportActivated may include an EBCS parameter element in the FILS discovery frame it transmits. In other embodiments, an AP that is not in a set of multiple BSSIDs and has a true value for dot11EBCSSupportActivated may include an EBCS parameter element in the FILS discovery frame it transmits. An AP that is in a set of multiple BSSIDs, corresponds to a transmitted BSSID, and has a true value for dot11EBCSSupportActivated may include an EBCS parameter element in the FILS discovery frame it transmits. In any case, the transmitted FILS discovery frame includes an EBCS Info frame TX countdown field in the EBCS parameter element.

[0097] In another embodiment, an AP or STA that transmits a FILS discovery frame and has a true value for dot11EBCSSupportActivated and a dot11EBCSContentList length greater than 0 may include an EBCS parameter element in the FILS discovery frame it transmits. In one embodiment, an AP that is not in a set of multiple BSSIDs, has a true value for dot11EBCSSupportActivated, and a dot11EBCSContentList length greater than 0 may include an EBCS parameter element in the FILS discovery frame it transmits. An AP that is in a set of multiple BSSIDs, corresponds to a transmitted BSSID, has a true value for dot11EBCSSupportActivated, and a dot11EBCSContentList length greater than 0 may include an EBCS parameter element in the FILS discovery frame it transmits. In any case, the transmitted transmit FILS discovery frame includes an EBCS Info frame TX countdown field within the EBCS parameter element.

[0098] Still referring to Figure 2C, when EBCS STA2520 receives FILS discovery frame 2544 from second EBCS AP2530, using the information contained within FILS discovery frame 2544, in particular information contained within the EBCS parameter elements carried therein, such as the EBCS Info frame TX countdown field, EBCS STA2520 can receive EBCS Info frames 2548, 2550 transmitted by second EBCS AP2530. Using the information contained within EBCS Info frame 2550, EBCS STA2520 can then receive desired EBCS traffic streams 2552, 2554 transmitted by second EBCS AP2530. In this embodiment, the EBCS traffic stream 2554 transmitted by second EBCS AP2530 does not require EBCS STA2520 to be associated in order to receive the transmitted EBCS traffic stream 2554.

[0099] However, in some embodiments, the EBCS STA2520 must be associated with a second EBCS AP2530 to receive an EBCS traffic stream 2554. In this scenario, the EBCS STA2520 can request an EBCS data stream using the method described above. To facilitate this, an EBCS AP providing one or more EBCS traffic streams requiring association may include robust security network (RSN) information in the FILS Discovery (FD) RSN information subfield within the FILS Discovery Information field of the FILS Discovery frame. Thus, if the received FILS Discovery frame contains EBCS parameter elements, the EBCS STA2520 that received the FILS Discovery frame containing EBCS parameter elements can determine the beacon interval until the next EBCS Info frame 2550 is expected to be sent by the second EBCS AP2530.

[0100] EBCS STA2520, upon receiving a FILS discovery frame 2544 containing an EBCS parameter element with RSN information in the FILS discovery RSN information subfield, may use the RSN information to perform FILS authentication / association 2560 with a second EBCS AP2530 (for example, using the FILS authentication protocol). EBCS STA2520 does this if it determines that the second EBCS AP2530 provides one or more desired EBCS traffic streams requiring association. EBCS STA2520 may determine that the AP provides one or more desired EBCS traffic streams requiring association based on parameters such as SSID, short SSID, or through other means.

[0101] In other relevant embodiments, methods for extending broadcast services by performing channel sensing methods are described herein. APs typically broadcast beacon signals that carry information to STAs operating within their broadcast range. A wireless network can include a large number of STAs that are not APs, e.g., thousands. STAs that are not APs can include a wide variety of sensors operating in an Internet of Things (IoT) environment where sensors wirelessly transmit their sensed data to APs within their transmission range. Many of these sensors are suitable for sensing environmental phenomena useful for characterizing the channels on which STAs and APs operate. Embodiments of systems, apparatus, and methods disclosed and described herein provide an extended channel sounding beacon service that provides channel information based on data provided by one or more of these sensor devices, thereby improving the ability of STAs to broadcast accurate reports of channel conditions within their operating area.

[0102] In some embodiments, the method includes establishing at least one service period (SP) in which at least one channel sounding procedure is performed. For example, in some embodiments, the method includes establishing a first SP and performing one or more channel sounding setup actions within the first SP; then establishing a second SP and performing at least one channel measurement action within the second SP; then establishing a third SP and performing at least one channel measurement report action within the third SP; and then establishing a fourth SP and performing at least one channel sounding termination action within the fourth SP.

[0103] In some embodiments, the measurement action includes acquiring channel state information (CSI) associated with the channel. For example, a sensing initiator performs one or more actions to collect CSI or to collect changes in CSI in a particular sensing environment. These actions may include the initiator sending one or more trigger frames to a non-AP sensor STA to request uplink data from the non-AP sensor STA.

[0104] Figure 3 illustrates the signal flow of a sensing procedure 300 according to one embodiment. In this procedure, a sensing initiator AP310 communicates wirelessly with a first sensing responder STA320 and a second sensing responder STA330. The sensing initiator AP310 sends a request to transmit (RTS1) 342 to the first sensing responder STA320. In response to the RTS 342, the first sensing responder STA320 transmits a Physical Protocol Data Unit (PPDU) carrying a clear to send (CTS) 344 signal. The sensing initiator AP310 performs a channel measurement 346 while the sensing responder STA320 transmits the PPDU carrying the CTS 344. In some embodiments, the PPDU carrying the CTS 344 includes a training field used by the sensing initiator AP310 to measure the CSI. In some embodiments, the training field is used to measure the CSI at another receiver located near the sensing initiator AP310. This procedure is then repeated for a second sensing responder STA330 using another PPDU carrying another RTS348 and CTS350, so that the sensing initiator AP310 can measure channel 352.

[0105] Therefore, the embodiments use the RTS / CTS frame not for use in preparation for data transmission, but for measuring the channel in a novel way. Thus, the length of the RTS transmitted by the sensing initiator AP can be set to a very small value. In some embodiments, the first RTS may be long enough to cover the time of one RTS / CTS transmission, or the time of multiple RTS / CTS transmissions, during which one or more additional STAs perform actions to set the NAV so that interference is avoided during the measurement time. This is illustrated by the NAV timer 360 in Figure 3. The NAV timer 360 present in each sensing responder STA is updated upon reception of each received message. In some embodiments, the CTS and RTS are subsequently transmitted to set the length of all remaining RTS / CTS transmissions based on the remaining countdown time from the initial setting, so that they can be set in accordance with NAV settings from other devices. Note that the “other messages” block shown in Figure 3 may be used to signal additional actions such as termination sensing.

[0106] In some embodiments where the responding STA is an 802.11bf-compliant sensing device, a flag, such as a 1-bit indicator, is used, provided within the service field of the RTS data field. This bit indicates that this RTS is transmitted as part of a sensing procedure. Thus, the responding STA does not expect to subsequently receive data from the RTS transmitter, in this case the sensing initiator. In some embodiments, the sensing initiator and sensing responder are high-efficiency (HE) or extremely high-throughput (EHT) capable devices. In such embodiments, the channel measurement action may be performed using a MU-RTS / CTS mechanism where multi-user (MU) transmission is utilized. Figure 4 illustrates one embodiment of this method.

[0107] Referring to Figure 4, a signal flow 400 according to one embodiment includes a sensing initiator AP410 that is HE or EHT compliant and therefore MU compliant, a first sensing responder STA420 and a second sensing responder STA430 that are both HE and MU compliant, and a legacy third sensing responder STA440 that is neither HE nor MU compliant. Note that MU-compliant devices are described herein as HE or EHT compliant devices, but this is not an limitation. Any MU-compliant device conforming to a future standard is included in the embodiments described herein. The sensing initiator AP410 transmits a MU-RTS trigger 450 to the first sensing responder STA420 and the second sensing responder STA430, requesting the HE STA to transmit a CTS in MU coordinated transmission on the resource indicated in the MU-RTS trigger 450. The first sensing responder STA420 transmits a first PPDU452 carrying a CTS within the MU resource indicated by the MU-RTS trigger 450, while the second sensing responder STA transmits a second PPDU454 carrying a CTS. The training fields within the first and second CTS-carrying PPDUs (452 ​​and 454) are then used by the sensing initiator AP410 to perform a channel measurement 456. In some embodiments, as shown in Figure 4, both HE STAs and legacy STAs are present within the WLAN. Therefore, to measure the channel associated with the legacy STA, the sensing initiator AP410 uses a legacy RTS transmit 462 to request a PPDU460 carrying a CTS from a third legacy sensing responder STA440. In one embodiment, the legacy RTS transmission 462 and the PPDU 260 carrying the CTS from the third legacy sensing responder STA 440 occur on the same transmission opportunity as the other transmissions described. The MU-RTS trigger frame request and the method of setting NAV or length information within the RTS frame, the NAV timer in each STA, and the use of the “other messages” illustrated and described above with reference to Figure 3 may also be applied to the method shown in Figure 4.

[0108] In a further embodiment, a Target Wake Time (TWT) sensing method is described below. Referring to Figure 5, AP510 has two associated STAs, STA1 520 and STA2 530, and AP510 establishes a channel sensing session using the TWT procedure. First, AP510 notifies of its ability to perform TWT-based sensing within a TWT Service Period (SP) (not shown). The notification is made using one of the following: a beacon frame, a probe response frame, a (re)association response frame, or another appropriate type of management or control frame. Similarly, an STA that is not an AP or a sensing responder STA notifies of its ability to perform TWT-based sensing within the SP using one of the following: a probe request frame, a (re)association request frame, or another type of management or control frame (also not shown).

[0109] As shown in Figure 5, STA520, which is not an AP, can acquire TWT membership by negotiating with AP510, sending a TWT request frame 540 to AP510, and receiving a TWT response frame 542 from AP510. STA510, which is currently in TWT operation and is not an AP, enters an awakened state before transmitting a beacon frame 544 carrying a broadcast TWT IE546. STA520 determines the broadcast sensing TWT SP570 based on the information in the broadcast TWT IE546. In TWT IE550, the AP indicates the broadcast TWT start time, TWT wake duration, interval between broadcast TWT service periods, and support for trigger-based TWTs.

[0110] The broadcast TWT IE546 may also include setup information for scheduled sensing procedures. For example, in some embodiments, the information may include identification of sensing initiators and sensing responders, indication of sensing measurement types, e.g., CQI, CSI, SINR, path loss, time of arrival (TOA), angle of arrival (AOA), and angle of departure (AOD). The broadcast TWT IE546 may further indicate parameters of sensing procedures to be performed during the broadcast sensing TWT service period, e.g., multi-antenna configuration, channel bandwidth configuration, sensing measurement resolution, etc. The IE may further indicate the periodicity of the broadcast sensing TWT service period, as well as the TWT sensing channels, which may or may not include a primary channel.

[0111] Next, AP510 sends a trigger frame 548, which may be a basic trigger frame, to the STAs awake for each TWT. The STAs scheduled for the TWT (STA1 520 and STA2 530) respond with an indication of their awake status and readiness to participate in the sensing procedure. For example, STA1 520 and STA2 530 each send a QoS null frame 550 (or PS-Poll frame or NDP packet). In some embodiments, during the sounding exchange 580 stage of the sensing TWT SP 570, the AP and STA exchange frames, such as NDPA frames, NDP frames, NDP trigger frames, BFRP trigger frames, BF report frames, or any other frames suitable for a particular sensing procedure. A sensing broadcast TWT ID may be used in some embodiments to uniquely identify the sensing TWT SP. The STAs may return to a doze state after the scheduled TWT.

[0112] In some embodiments, the AP advertises TWT SP parameters and AP update information within a beacon frame. A non-AP STA sends a TWT response frame to negotiate the TWT SP parameters. In some embodiments, the AP terminates periodically occurring sensing TWT SPs by sending a broadcast TWT IE indicating the end of the sensing TWT.

[0113] In another embodiment, referring to Figure 6, a signal flow 600 similar to the procedure described above with reference to Figure 4 includes the sensing initiator AP610 transmitting an MU-RTS (trigger) frame 650 to invite STAs (i.e., a first MU-enabled sensing STA responder STA620, a second MU-enabled sensing responder STA630, and a legacy sensing responder STA640) that can transmit trigger-based (TB) PPDUs. The first MU-enabled sensing responder STA620 and the second MU-enabled sensing responder STA630 each transmit their respective PPDUs 652 and 654 that carry the CTS. The sensing initiator AP measures each channel (i.e., a first channel between sensing initiator AP610 and the first MU-enabled sensing responder STA620, a second channel between sensing initiator AP610 and the second MU-enabled sensing responder STA630, or an integrated channel between sensing initiator AP610 and MU-enabled sensing responders STA620 and STA630) using PDDUs 652 and 654 that carry the received CTS. Sensing initiator AP610 may then transmit one or more legacy RTS frames 658 to request at least one non-MU-enabled sensing responder STA640 to transmit a PPDU 660 that carries the CTS frame. Sensing initiator AP610 may perform channel measurements using the PPDU 660 that carries the CTS frame transmitted by at least one non-MU-enabled (i.e., legacy) sensing responder STA640. In some embodiments, the sensing initiator AP610 may send a MU-RTS trigger frame 650 with the duration field in the Media Access Control (MAC) header set to (N×2+1)×aSIFSTime+(N+1)×aCTSTime+N×aRTSTime, where aSIFSTime is the duration of the Short Interframe Space (SIFS), aCTSTime is the time to send a CTS frame, aRTSTime is the time to send an RTS frame, and N is the number of legacy RTS / CTS exchanges following the current MU-RTS / CTS exchange.The MU-RTS trigger frame 650 may be used to request one or more CTS frames from STAs (e.g., HE STA, EHT STA, and / or future generation STAs) that can interpret MU-RTS frames (i.e., 620, 630). STAs 620, 630 may respond by sending CTS frames 652, 654 on the resources allocated by the MU-RTS trigger frame 650, and STAs 620, 630 may set the duration field of CTS frames 652, 654 to N × 2 × aSIFSTime + N × aCTSTime + N × aRTSTime.

[0114] In another embodiment, referring to Figure 7, similar to the example described above with reference to Figure 6, the signal flow 700 includes PPDUs 754, 756 carrying CTS, transmitted by a first MU-enabled sensing responder STA 720 and a second MU-enabled sensing responder STA 730, and triggered by a sensing initiator AP 710 that transmits a MU-RTS trigger 752. Following the MU-RTS trigger 752 and CTS 754, 756 exchange, one or more legacy RTS / CTS exchanges 760 may follow within the same TXOP and / or different TXOPs. One or more legacy RTS / CTS exchanges 760 may be initiated by the sensing initiator AP 710 and may request a legacy STA 740, whether or not it can understand the MU-RTS frame, to transmit a PPDU 764 carrying a CTS frame. When CTS frame 764 is transmitted by sensing responder STA740, sensing initiator AP710 may measure channel 766. In each RTS frame 762, if there are M RTS / CTS exchanges following the current RTS / CTS exchange, the duration field in the MAC header may be set to (M × 2 + 1) × aSIFSTime + (M + 1) × aCTSTime + (M - 1) × aRTSTime.

[0115] In the embodiments described with reference to Figures 6 and 7, other STAs that are listening on the media and reading duration information from the MU-RTS frames, (legacy) RTS frames, and / or (legacy) CTS frames may set or update their NAV times, delay access to the media by the indicated duration, and save power.

[0116] In another embodiment, one or more MU-RTS / CTS exchanges may follow a MU-RTS / CTS exchange, and thereafter, one or more RTS / CTS exchanges may follow within the same TXOP and / or different TXOPs.

[0117] In the exemplary procedure described above, the sensing initiator (e.g., AP) may also, after initially initiating one or more legacy RTS / CTS exchanges, send one or more MU-RTS frames to request CTS frames from multiple STAs that can interpret the MU-RTS frames.

[0118] In other embodiments, the MU-RTS / CTS exchange may be replaced by a buffer status report poll (BSRP) / buffer status report (BSR) exchange, with reference to any of the procedures described above, so that the sensing initiator AP can measure the channel on non-overlapping subchannels within the channel when the BSR frame is transmitted by the sensing responder STA. In this embodiment, the duration field setting in the BSRP frame may be calculated as (N × 2 + 1) × aSIFSTime + N × aCTSTime + N × aRTSTime + aBSRTime, where aBSRTime is the time to transmit the BSR frame and N is the number of legacy RTS / CTS exchanges following the current BSRP / BSR exchange. Using the BSRP frame, one or more BSR frames may be requested from an STA (e.g., HE STA, EHT STA, and / or future generation STA) that can interpret the BSRP frame. HE / EHT / future generation STA may respond to a BSRP frame by sending a BSR frame on the resources allocated by the BSRP frame, and set the duration field of the CTS frame to N×2×aSIFSTime+N×aCTSTime+N×aRTSTime

[0119] Following a BSRP / BSR exchange, N (N≧0) RTS / CTS exchanges may follow within the same TXOP and / or different TXOPs. RTS / CTS exchanges may be initiated by a sensing initiator to request CTS frames transmitted by the STA, regardless of whether the MU-RTS frame is understood. The sensing initiator AP can measure the channel when the CTS frame is transmitted by the sensing responder STA. For each RTS frame, the duration field in the MAC header may be set to (M×2+1)×aSIFSTime+(M+1)×aCTSTime+(M-1)×aRTSTime, if there are M RTS / CTS exchanges following the current RTS / CTS exchange. In all the examples described herein, SIFS may be used as an example, but other interframe intervals or durations may be used instead of SIF.

[0120] In other embodiments, the MU-RTS frame (or sensing trigger frame) described in the embodiments above may include a new class of User Info fields or Sensing User Info fields. For example, the sensing user Info field may include a resource unit (RU) allocation for a sensing response STA that does not occupy the primary channel, which may be used by the sensing initiating AP to measure a particular RU or subchannel. The sensing MU-RTS or sensing trigger frame may include a User Info field that can be used to request a CTS frame from a legacy STA on a subchannel that occupies the primary channel, or a User Info field that requests a CTS or other sensing frame from an STA such as an 802.11bf STA (or future generation STA).

[0121] A legacy STA receiving a sensing MU-RTS frame or sensing trigger frame containing a new class in the user information field may respond with a (legacy) CTS frame on a subchannel occupying the primary channel, and an STA such as an 802.11bf STA receiving a sensing MU-RTS frame or sensing trigger frame containing a new class in the user information field may respond with a CTS frame or other type of sensing frame on a subchannel that does not occupy the primary channel, as indicated by the received sensing MU-RTS or sensing trigger frame.

[0122] In another embodiment, the new Sensing Report Poll frame may be an extended version of a trigger frame, such as a BFRP frame or an NFRP frame. The Sensing Report Poll frame may include a threshold field, for example, within the common information field or in other parts of the Sensing Report Poll frame. The Sensing Report Poll frame may assign one or more random access RUs within its frame body (for example, using one or more of the user information fields). If a channel measurement performed by a Sensing Responder STA exceeds the value indicated in the threshold field included in the received Sensing Report Poll frame, the Sensing Responder STA that performed the channel measurement may respond to the Sensing Report Poll frame by transmitting channel measurement information and / or CSI on one or more assigned random access RUs.

[0123] While the features and elements of the present invention are described in preferred embodiments in specific combinations, each feature or element can be used alone without other features and elements of the preferred embodiments, or in various combinations with or without other features and elements of the present invention. Although the solutions described herein conform to one or more 802.11-specific protocols, it is understood that the solutions described herein are not limited to implementation in 802.11 networks but are also suitable for implementation in other wireless systems. SIFS is used to illustrate various interframe spacings in the embodiments of the design and procedure, but all other interframe spacings, such as RIFS, AIFS, DIFS, or other permissible time intervals, may be applied to the same solutions.

[0124] While features and elements are described above in specific combinations, those skilled in the art will understand that each feature or element can be used alone or in any combination with other features and elements. In addition, the methods described herein can be implemented in computer programs, software, or firmware embedded in non-temporary computer-readable media for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted via wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, 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 associated with software can be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

1. It is a station (STA), A receiver configured to receive Fast Initial Link Setup (FILS) discovery frames from an access point (AP) to which the STA is not associated, wherein the FILS discovery frame includes an Extended Broadcast Services (EBCS) information frame transmission countdown field, A station (STA) is configured to receive EBCS information frames from APs that are not associated with the STA, based on the received EBCS information frame transmission countdown field.

2. The STA according to claim 1, wherein the EBCS information frame transmission countdown field indicates the number of target beacon transmission times (TBTT) until the next EBCS information frame is transmitted by the AP, to which the STA is not associated.

3. The STA according to claim 1, wherein the EBCS information frame transmission countdown field has a length of 2 bytes.

4. The STA according to claim 1, wherein the EBCS information frame transmission countdown field is included within the EBCS parameter element.

5. The STA according to claim 1, wherein the received EBCS information frame includes information about available EBCS traffic streams.

6. It is STA, The system further comprises a processor configured to select an available EBCS traffic stream based on the received EBCS information frame, The STA according to claim 1, wherein the receiver is configured to receive the selected EBCS traffic stream based on the received EBCS information frame.

7. The STA according to claim 1, wherein when the AP, which is not associated with the STA, is transmitting an EBCS traffic stream that requires association, the FILS discovery frame includes robust secure network (RSN) information.

8. The system further comprises a processor and a transmitter, wherein the processor is configured to select the EBCS traffic streams that require association. The STA according to claim 7, wherein the transmitter and the processor are configured to use the RSN information to perform FILS authentication with the AP to which the STA is not associated.

9. The STA according to claim 8, wherein the receiver is configured to receive the selected EBCS traffic streams that require association after the performance of the FILS authentication.

10. A method for use in a station (STA), Receiving a Fast Initial Link Setup (FILS) discovery frame from an access point (AP) that is not associated with the aforementioned STA, wherein the FILS discovery frame includes an Extended Broadcast Service (EBCS) information frame transmission countdown field. A method comprising receiving an EBCS information frame from an AP that is not associated with the STA, based on the received EBCS information frame transmission countdown field.

11. The method according to claim 10, wherein the EBCS information frame transmission countdown field indicates the number of target beacon transmission times (TBTT) until the next EBCS information frame is transmitted by the AP, which is not associated with the STA.

12. The method according to claim 10, wherein the EBCS information frame transmission countdown field has a length of 2 bytes.

13. The method according to claim 10, wherein the EBCS information frame transmission countdown field is included within the EBCS parameter element.

14. The method according to claim 10, wherein the received EBCS information frame includes information about available EBCS traffic streams.

15. Based on the received EBCS information frame, select an available EBCS traffic stream, The method according to claim 10, further comprising receiving the selected EBCS traffic stream based on the received EBCS information frame.

16. The method according to claim 10, wherein when the AP, which is not associated with the STA, is transmitting an EBCS traffic stream that requires association, the FILS discovery frame includes robust secure network (RSN) information.

17. Select the EBCS traffic streams that require association, The method according to claim 16, further comprising using the RSN information to perform FILS authentication with the AP which the STA is not associated with.

18. The method according to claim 17, further comprising receiving the selected EBCS traffic streams that require association after the performance of the FILS authentication.

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