Method for efficient rediscovery and medium access for wake-up radios - Patents.com

Abstract

To provide methods and apparatuses for rediscovery and medium access for wake-up radios.SOLUTION: A WTRU may receive, via a first transceiver, a frame that includes a WUR operation element having a first counter value. The WTRU may deactivate the first transceiver and activate a second transceiver, the first transceiver entering a doze state and the second transceiver being in an awake state. The WTRU may then receive, via the second transceiver in the awake state, a WUR frame that includes a second counter value indicating a plurality of basic server set (BSS) parameters associated with the first transceiver. On condition that the second counter value is different than the first counter value, the WTRU may activate the first transceiver to update the plurality of BSS parameters, the first transceiver entering an awake state.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a method and apparatus for efficient discovery, rediscovery and medium access for wake-up radios. [Background technology]

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 62 / 616,977, filed January 12, 2018, and U.S. Provisional Patent Application No. 62 / 691,799, filed June 29, 2018, the contents of which are incorporated herein by reference.

[0003] A wake-up radio (WUR) receiver may act as a companion radio to a primary connectivity radio (PCR) to receive a wake-up signal or wake-up packet. The wake-up signal or wake-up packet carries control information and may have an active receiver power consumption of less than 1 milliwatt (mW). Receiving the wake-up signal or wake-up packet by the WUR receiver may wake up the PCR from sleep. For example, a wake-up signal transmitted from an access point (AP) triggers a wireless transmit / receive unit (WTRU) equipped with a WUR receiver to wake up from sleep mode and begin receiving activity using the PCR. However, if the AP loses power or stores information about existing WTRUs, a WTRU previously associated with the AP may not be aware that the AP does not have existing WUR information for the WTRU. Furthermore, when a multicast wake-up signal is used to wake up several WTRUs, there may be congestion on the wireless medium as the woken-up WTRUs attempt to access the medium at approximately the same time. Therefore, a method and apparatus are needed that allows a WTRU to efficiently rediscover an AP and / or reliably access the medium for a WUR. Summary of the Invention [Means for solving the problem]

[0004] Methods and apparatuses for efficient (re)discovery and medium access for wake-up radio are described herein. For example, a wireless transmit / receive unit (WTRU) may receive a frame including a wake-up radio (WUR) operation element having a first counter value via a first transceiver. The received frame may be a WUR action frame, such as a beacon frame or a WUR mode setup frame. The WTRU may maintain a counter variable (or counter field) and update the value of the counter variable to the first counter value in the WUR operation element. After a negotiation procedure for WUR parameters with an access point (AP) is completed, the WTRU may deactivate the first transceiver and activate the second transceiver, thereby causing the first transceiver to enter a doze state and the second transceiver to enter an awake state to save power consumption of the WTRU. While the second transceiver is in the awake state, the WTRU may receive a WUR frame via the second transceiver including a second counter value indicating that an update to multiple BSS parameters related to a basic server set (BSS) of the first transceiver is available. The WUR frame may be a broadcast WUR wake-up frame. If the second counter value is different from the first counter value, the WTRU may activate the first transceiver in the doze state to update the multiple BSS parameters. The first transceiver may then enter the awake state and receive a beacon frame from the AP including the multiple BSS parameters. The first transceiver may be a primary connectivity radio (PCR), and the second transceiver may be a companion radio, a wake-up radio, or a receiver of the wake-up radio. [Brief explanation of the drawings]

[0005] A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings, in which like reference numerals indicate like elements and in which:

[0006] [Figure 1A] FIG. 1 is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented. [Figure 1B] 1B is a system diagram illustrating an exemplary wireless transmit / receive unit (WTRU) that may be used within the communication system shown in FIG. 1A, according to one embodiment. [Figure 1C] 1B is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communication system shown in FIG. 1A, according to one embodiment. [Figure 1D] FIG. 1B is a system diagram illustrating a further exemplary RAN and a further exemplary CN that may be used within the communication system shown in FIG. 1A, according to one embodiment. [Figure 2] FIG. 1 is a system diagram illustrating an example wake-up radio (WUR) system in which one or more disclosed embodiments may be implemented. [Figure 3] FIG. 1 illustrates an exemplary (re)discovery procedure using a basic service set (BSS) counter. [Figure 4] A diagram showing an example STA procedure using implicit multi-user available group indication. [Figure 5] FIG. 10 illustrates an exemplary STA procedure using explicit PCR operation indication. [Figure 6] 1 illustrates an example procedure for multi-STA wake-up and uplink (UL) multi-user (MU) medium access based on one or more group delays. [Figure 7] A diagram showing an example STA procedure using a WUR trigger frame. [Figure 8] FIG. 10 illustrates an example Group ID List subfield of a WUR Mode element. [Figure 9] FIG. 10 illustrates an example frame format for a WUR parameter control field indicating the presence of a group maximum PCR transition time. [Figure 10] FIG. 10 illustrates an example WUR parameter field of a WUR mode element. [Figure 11] FIG. 10 illustrates an exemplary Group Max PCR Transition Time subfield for Format 1. [Figure 12] FIG. 10 illustrates an exemplary Group Max PCR Transition Time subfield for Format 2. DETAILED DESCRIPTION OF THE INVENTION

[0007] 1A illustrates an example 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, messaging, broadcasts, etc., to multiple wireless users. The communication system 100 may enable the multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communication system 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique-word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block-filtered OFDM, filter bank multicarrier (FBMC), etc.

[0008] 1A, communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, RANs 104 / 113, CNs 106 / 115, public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, although it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a “station” and / or “STA,” may be configured to transmit and / or receive wireless signals and may include user equipment (UE), mobile stations, fixed or mobile subscriber units, subscription-based units, pagers, cellular 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 industrial and / or automated processing chain contexts), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be referred to interchangeably as a UE.

[0009] The communications system 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communications networks, such as the CN 106 / 115, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node B, an eNodeB, a Home Node B, a Home eNodeB, a gNB, an NR Node B, a site controller, an access point (AP), a wireless router, etc. While the base station 114a, 114b is shown as a single element, it will be appreciated that the base station 114a, 114b may include any number of interconnected base stations and / or network elements.

[0010] The base station 114a may be part of the RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and / or base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, sometimes referred to as a cell (not shown). These frequencies may be in the licensed spectrum, the unlicensed spectrum, or a combination of the licensed and unlicensed spectrum. A cell may provide coverage for wireless services in a particular geographic area, which may be relatively fixed or may change over time. A cell may be further divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In one embodiment, the base station 114a may employ multiple-input multiple-output (MIMO) technology and utilize multiple transceivers per sector of the cell. For example, beamforming may be used to transmit and / or receive signals in desired spatial directions.

[0011] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communications 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).

[0012] More specifically, as noted above, the communication system 100 may be a multiple-access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base stations 114a and WTRUs 102a, 102b, 102c in the RAN 104 / 113 may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 115 / 116 / 117 using Wideband CDMA (WCDMA). WCDMA may include communication protocols such as High Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High Speed ​​UL Packet Access (HSUPA).

[0013] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE Advanced (LTE-A) and / or LTE Advanced Pro (LTE-A Pro).

[0014] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as New Radio (NR) radio access, which may establish the air interface 116 using NR.

[0015] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may jointly implement LTE and NR radio access, for example, using a dual connectivity (DC) principle. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions sent to and from multiple types of base stations (e.g., eNBs and gNBs).

[0016] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement a wireless technology such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi)), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile Communications (GSM), Enhanced Data Rates for GSM Evolution (EDGE), GSM EDGE (GERAN), or the like.

[0017] 1A may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point and may utilize any suitable RAT to facilitate wireless connectivity in a local area, such as a workplace, a home, a vehicle, a premises, an industrial facility, an air corridor (e.g., for use by drones), a road, etc. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a picocell or femtocell. 1A, the base station 114b may have a direct connection to the Internet 110. Therefore, the base station 114b may not need to access the Internet 110 via the CN 106 / 115.

[0018] The RAN 104 / 113 may be in communication with the CN 106 / 115, which may be any type of network configured to provide voice, data, application, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have varying Quality of Service (QoS) requirements, such as different throughput, latency, error resilience, reliability, data throughput, mobility, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions such as user authentication. Although not shown in FIG. 1A , it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may be in direct or indirect communication with other RANs employing the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may utilize NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) that employs GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0019] The CN 106 / 115 may also serve as a gateway for the 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 that use common communication protocols such as Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and / or Internet Protocol (IP) in 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 that may employ the same RAT as the RAN 104 / 113 or a different RAT.

[0020] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with a base station 114a that may employ a cellular-based wireless technology and with a base station 114b that may employ an IEEE 802.2 wireless technology.

[0021] 1B is a system diagram illustrating an example WTRU 102. As shown in FIG. 1B, the WTRU 102 may include, among other things, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138. It will be appreciated that the WTRU 102 may include any sub-combination of the above elements while remaining consistent with an embodiment.

[0022] The processor 118 may be a general-purpose processor, a special-purpose processor, a conventional processor, a digital signal processor (DSP), multiple 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) circuit, other types of integrated circuits (ICs), a state machine, etc. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. While FIG. 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.

[0023] The transmit / receive element 122 may be configured to transmit signals to or receive signals from a base station (e.g., base station 114a) or an AP (access point) over the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In one embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It will be appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0024] 1B as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More particularly, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0025] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and demodulate signals received by the transmit / receive element 122. As mentioned above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate via multiple RATs, such as, for example, NR and IEEE 802.11.

[0026] Although it is not shown in FIG. 1B, the transceiver 120 may comprise a main transceiver (or primary connectivity radio) and a secondary transceiver (or wake-up radio transceiver) operably coupled to the processor 118 and the transmit / receive element 122.

[0027] The processor 118 of the WTRU 102 may be coupled to and may receive user input data from the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. Furthermore, the processor 118 may access information from and store data in any type of suitable memory, such as non-removable memory 130 and / or removable memory 132. The non-removable memory 130 may include random access memory (RAM), read-only memory (ROM), a hard disk, or other types of memory storage devices. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, etc. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or home computer (not shown).

[0028] The processor 118 may receive power from the power source 134 and may be configured to distribute and / or control power to other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel-metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0029] 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) regarding the current location of the WTRU 102. In addition to or in place of information from the GPS chipset 136, the WTRU 102 may receive location information from base stations (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by way of any suitable location determination method while remaining consistent with an embodiment.

[0030] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for 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 modulation (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. The peripherals 138 may include one or more sensors, which may be one or more of a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor, a geolocation sensor, an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0031] The WTRU 102 may include a full-duplex radio in which transmission and reception of some or all of the signals (associated with a particular subframe for both the UL (e.g., for transmission) and the downlink (e.g., for reception)) may be parallel and / or simultaneous. The full-duplex radio may include an interference management unit 139 to reduce or substantially eliminate self-interference through either hardware (e.g., chokes) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In one embodiment, the WTRU 102 may include a half-duplex radio for transmission and reception of some or all of the signals (associated with a particular subframe for either the UL (e.g., for transmission) or the downlink (e.g., for reception)).

[0032] 1C is a system diagram illustrating the RAN 104 and the CN 106, according to one embodiment. As noted above, the RAN 104 may employ E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0033] The RAN 104 may include eNodeBs 160a, 160b, 160c, although it will be appreciated that the RAN 104 may include any number of eNodeBs while remaining consistent with an embodiment. The eNodeBs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the eNodeBs 160a, 160b, 160c may implement MIMO technology. Thus, the eNodeB 160a, for example, may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0034] Each of the eNodeBs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, etc. As shown in FIG. 1C, the eNodeBs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0035] 1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. While each of the above elements is shown as part of the CN 106, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0036] The MME 162 may be connected to each of the eNodeBs 162a, 162b, 162c in the RAN 104 via an S1 interface and may act as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, activating / deactivating bearers, selecting a particular serving gateway during initial attach of the WTRUs 102a, 102b, 102c, etc. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies such as GSM and / or WCDMA.

[0037] The SGW 164 may be connected to each of the eNodeBs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to and from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions such as anchoring the user plane during handovers between eNodeBs, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing the context of the WTRUs 102a, 102b, 102c, etc.

[0038] The SGW 164 may be connected to a PGW 166 that may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0039] The CN 106 may facilitate communication with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communication between the WTRUs 102a, 102b, 102c and traditional fixed communication devices. For example, the CN 106 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 106 and the PSTN 108. Additionally, the CN 106 may provide the WTRUs 102a, 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.

[0040] Although the WTRU is illustrated in FIGS. 1A-1D as a wireless terminal, it is expected that in certain representative embodiments that such a terminal may use (e.g., temporarily or permanently), wired communications will interface with the communications network.

[0041] In a representative embodiment, the other network 112 may be a WLAN.

[0042] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have access to or interface with a distribution system (DS) or another type of wired / wireless network that carries traffic into and out of the BSS. Traffic to a STA originating from outside the BSS may arrive through the AP and be sent to the STA. Traffic originating from a STA to a destination outside the BSS may be sent to the AP for delivery to the respective destination. Traffic between STAs within a BSS may be sent through the AP, e.g., where a source STA may send traffic to the AP, and the AP may send traffic to the destination STA. Traffic between STAs within a BSS may be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic may be sent between (e.g., directly between) a source STA and a destination STA using direct link setup (DLS). In one exemplary embodiment, the DLS may use 802.11e DLS or 802.11z TDLS (tunneled DLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and STAs within or using the IBSS (e.g., all of the STAs) may communicate directly with each other. The IBSS communication mode may be referred to herein as an "ad hoc" communication mode.

[0043] When using the 802.11ac infrastructure operating mode or a similar operating mode, an AP may transmit beacons on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., a 20 MHz wide bandwidth) or a width dynamically set via signaling. The primary channel may be the operating channel of the BSS and may be used by STAs to establish a connection with the AP. In a representative embodiment, CSMA / CA (Carrier Sense Multiple Access / Collision Avoidance) may be implemented, for example, in an 802.11 system. In CSMA / CA, STAs (e.g., every STA), including the AP, may sense the primary channel. If the primary channel is sensed / detected by a particular STA and / or determined to be busy, the particular STA may turn off. One STA (e.g., only one station) may transmit at a given time in a given BSS.

[0044] A high-throughput (HT) STA may use a 40 MHz wide channel for communication, for example, via a combination of a primary 20 MHz channel with adjacent or non-adjacent 20 MHz channels to form a 40 MHz wide channel.

[0045] A very high throughput (VHT) STA may support 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. 40 MHz and / or 80 MHz channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining eight contiguous 20 MHz channels or by combining two non-contiguous 80 MHz channels, sometimes referred to as an 80+80 configuration. In the 80+80 configuration, after channel encoding, the data may be passed through a segment parser that may split the data into two streams. Inverse fast Fourier transform (IFFT) processing and time-domain processing may be performed separately on each stream. The streams may be mapped onto two 80 MHz channels, and the data may be transmitted by the transmitting STA. At the receiving STA receiver, the operations described above for the 80+80 configuration may be reversed, and the combined data may be sent to the media access control (MAC).

[0046] Sub-1 GHz operating modes are supported by 802.11af and 802.11ah. Channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah compared to those used in 802.11n and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, while 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to representative embodiments, 802.11ah may support meter-type control / machine-type communications, such as MTC devices, in macro coverage areas. MTC devices may have limited capabilities, including, for example, support for certain bandwidths and / or limited bandwidths (e.g., only support for ). MTC devices may include batteries with above-threshold battery life (e.g., to maintain very long battery life).

[0047] WLAN systems that can support multiple channels and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include a channel that can be designated as a primary channel. The primary channel can have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel can be set and / or limited by the STA that supports the smallest bandwidth operating mode among all STAs operating in the BSS. In an 802.11ah example, the primary channel can be 1 MHz wide for a STA (e.g., an MTC-type device) that supports (e.g., only supports) the 1 MHz mode, even if the AP and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or NAV (Network Allocation Vector) setting can depend on the status of the primary channel. For example, if the primary channel is busy for a STA (that only supports 1 MHz mode of operation), it may be considered busy to transmit the entire available frequency band to the AP, even though most of the frequency band may remain idle and be available for use.

[0048] In the United States, the available frequency bands that can be used by 802.11ah are 902 MHz to 928 MHz. In South Korea, the available frequency bands are 917.5 MHz to 923.5 MHz. In Japan, the available frequency bands are 916.5 MHz to 927.5 MHz. The total available bandwidth for 802.11ah is 6 MHz to 26 MHz depending on the country code.

[0049] 1D is a system diagram illustrating the RAN 113 and the CN 115, according to one embodiment. As mentioned above, the RAN 113 may employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0050] The RAN 113 may include gNBs 180a, 180b, and 180c, although it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, and 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, and 180c may implement MIMO technology. For example, the gNBs 180a, 180b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, and 180c. Thus, the gNB 180a may use multiple antennas to transmit wireless signals to and / or receive wireless signals from, for example, the WTRU 102a. In one embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on an unlicensed spectrum, while the remaining component carriers may be on a licensed spectrum. In one embodiment, the gNBs 180a, 180b, 180c may implement coordinated multipoint (CoMP) technology. For example, the WTRU 102a may receive coordinated transmissions from the gNBs 180a and 180b (and / or 180c).

[0051] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using scalable numerology-related transmissions. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or transmission time intervals (TTIs) of varying or scalable lengths (e.g., including various numbers of OFDM symbols and / or lasting for varying lengths of absolute time).

[0052] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c without accessing another RAN (e.g., eNodeBs 160a, 160b, 160c, etc.). In a standalone configuration, the WTRUs 102a, 102b, 102c may utilize one or more of the gNBs 180a, 180b, 180c as mobility anchor points. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in unlicensed bands. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate with / connect to a gNB 180a, 180b, 180c while also communicating with / connecting to another RAN, such as an eNodeB 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNodeBs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNodeBs 160a, 160b, 160c may act as mobility anchors for the WTRUs 102a, 102b, 102c, and the gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0053] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support for network slicing, dual connectivity, interconnection between NR and E-UTRA, routing of user plane data towards user plane functions (UPFs) 184a, 184b, routing of control plane information towards access and mobility management functions (AMFs) 182a, 182b, etc. As shown in FIG. 1D , the gNBs 180a, 180b, 180c may communicate with one another via an Xn interface.

[0054] 1D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. While each of the above elements is shown as part of the CN 115, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0055] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may act as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, supporting network slicing (e.g., handling different PDU sessions with different requirements), selecting a particular SMF 183a, 183b, managing registration areas, terminating NAS signaling, mobility management, etc. Network slicing may be used by the AMF 182a, 182b to customize the CN support of the WTRUs 102a, 102b, 102c based on the type of service being utilized by the WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases, such as services relying on highly reliable and low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services with machine-type communications (MTC) access, etc. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies, such as WiFi.

[0056] The SMFs 183a and 183b may be connected to the AMFs 182a and 182b in the CN 115 via an N11 interface. The SMFs 183a and 183b may also be connected to the UPFs 184a and 184b in the CN 115 via an N4 interface. The SMFs 183a and 183b may select and control the UPFs 184a and 184b and configure the routing of traffic through the UPFs 184a and 184b. The SMFs 183a and 183b may perform other functions such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, etc. The type of PDU session may be IP-based, non-IP-based, Ethernet-based, etc.

[0057] The UPFs 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks such as the Internet 110 to facilitate communication between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPFs 184, 184b may perform other functions such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, etc.

[0058] The CN 115 may facilitate communication with other networks. For example, the CN 115 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 115 and the PSTN 108. Additionally, the CN 115 may provide the WTRUs 102a, 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, the WTRUs 102a, 102b, 102c may be connected to the local data networks (DNs) 185a, 185b through the UPFs 184a, 184b via an N3 interface to the UPFs 184a, 184b and an N6 interface between the UPFs 184a, 184b and the DNs 185a, 185b.

[0059] 1A-1D and the corresponding description thereof, one or more or all of the functions described herein with respect to one or more of the WTRUs 102a-d, base stations 114a-b, eNodeBs 160a-c, MME 162, SGW 164, PGW 166, gNBs 180a-c, AMFs 182a-ab, UPFs 184a-b, SMFs 183a-b, DNs 185a-b, and / or any other devices described herein may be performed by one or more emulation devices (not shown). The emulation devices may be one or more devices configured to emulate one or more or all of the functions described herein. For example, the emulation devices may be used to test other devices and / or simulate network and / or WTRU functionality.

[0060] The emulation device may be designed to perform one or more tests of other devices in a lab environment and / or an 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 communications network to test other devices in the communications 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 communications network. The emulation device may be directly coupled to another device for purposes of performing tests and / or may perform testing using over-the-air wireless communications.

[0061] A WLAN in infrastructure basic service set (BSS) mode has an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. An AP may be interchangeable with a base station as described herein. A STA may also be interchangeable with a WTRU as described herein. An AP typically has access to or an interface with a distribution system (DS) or another type of wired / wireless network that carries traffic into and out of the BSS. Traffic to a STA originating from outside the BSS arrives through the AP and is sent to the STA. Traffic originating from a STA to a destination outside the BSS is sent to the AP to be sent to the respective destination. Traffic between STAs within a BSS may also be sent through the AP, where the source STA sends traffic to the AP and the AP sends traffic to the destination STA. The above traffic between STAs within a BSS may be considered peer-to-peer traffic. Furthermore, the above peer-to-peer traffic can be sent directly between the source and destination STAs using 802.11e Direct Link Setup (DLS) or DLS using 802.11z Tunneled DLS (TDLS). WLANs using Independent BSS (IBSS) mode do not have APs and / or STAs and communicate directly with each other. This communication mode is called an "ad hoc" communication mode.

[0062] Using the 802.11ac infrastructure mode of operation, an AP may transmit beacons on a fixed channel, usually the primary channel. This channel may be 20 MHz wide and may be the operating channel of the BSS. This channel may also be used by STAs to establish a connection with the AP. The basic channel access mechanism in 802.11 systems may be carrier sense multiple access with collision avoidance (CSMA / CA). In this mode of operation, every STA, including the AP, will sense the primary channel. If the channel is detected to be busy, the STA will turn itself off. Therefore, only one STA may transmit at a given time in a given BSS.

[0063] In 802.11n, high-throughput (HT) STAs may also use 40 MHz-wide channels for communication, which is accomplished by combining a primary 20 MHz channel with an adjacent 20 MHz channel to form a 40 MHz-wide contiguous channel.

[0064] In 802.11ac, very high throughput (VHT) STAs may support 20 MHz, 40 MHz, 80 MHz, and 160 MHz wide channels. 40 MHz and 80 MHz channels are formed by combining contiguous 20 MHz channels, similar to 802.11n described above. 160 MHz channels may be formed by combining eight contiguous 20 MHz channels or two non-contiguous 80 MHz channels, sometimes referred to as an 80+80 configuration. In the 80+80 configuration, after channel encoding, the data may be passed through a segment parser that splits it into two streams. IFFT and time-domain processing may be performed separately on each stream. The streams may then be mapped onto the two channels, and the data may be transmitted. At the receiver, this process is reversed, and the combined data may be sent to the MAC.

[0065] Sub-1 GHz operating modes may be supported by 802.11af and 802.11ah. In these specifications, channel operating bandwidths and carriers may be reduced compared to those used in 802.11n and 802.11ac. 802.11af may support 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, while 802.11ah may support 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. A possible use case for 802.11ah is the support of machine-type control (MTC) devices in macro coverage areas. MTC devices have limited capabilities, including limited bandwidth support, but may also have very long battery life requirements.

[0066] WLAN systems that support multiple channels and channel widths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include a channel designated as the primary channel. The primary channel may, but is not necessarily, equal to the largest common operating bandwidth supported by all STAs in the BSS. Thus, the bandwidth of the primary channel is limited by the STA supporting the smallest bandwidth operating mode among all STAs operating in the BSS. In the example of 802.11ah, even if the AP and other STAs in the BSS may support 2 MHz, 4 MHz, 8 MHz, 16 MHz, or other channel bandwidth operating modes, if there is an STA (e.g., an MTC-type device) that only supports 1 MHz mode, the primary channel may be 1 MHz wide. All carrier sensing and NAV setting depend on the status of the primary channel (i.e., if the primary channel is busy because, for example, a STA that only supports 1 MHz operating mode is transmitting to the AP, the entire available frequency band is considered busy even if most of it remains idle and available).

[0067] In the United States, the available frequency band that can be used by 802.11ah is 902MHz to 928MHz. In South Korea, it is 917.5MHz to 923.5MHz, and in Japan, it is 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz depending on the country code.

[0068] IEEE 802.11 High-Efficiency WLAN (HEW) can be modified to improve the quality of service experienced by all users across a variety of wireless users in many usage scenarios, including high-density scenarios in the 2.4 GHz and 5 GHz bands. New use cases that support high-density deployment of APs and STAs and associated radio resource management (RRM) techniques can be implemented using HEW.

[0069] HEW can be applied to emerging usage scenarios such as data distribution for stadium events, high user density scenarios such as train stations, or enterprise / retail environments, and can also address increased reliance on wireless services for video distribution and medical applications.

[0070] In some scenarios, measured traffic for various applications may have the potential for short packets, and there may be network applications that may also generate short packets. These scenarios may include, but are not limited to, virtual office, TPC ACK, video streaming ACK, device / controller (e.g., mouse, keyboard, game control, etc.), access (e.g., probe request / response), network selection (e.g., probe request and / or ANQP), and / or network management (e.g., control frames). 802.11ax may have multi-user (MU) features, including orthogonal frequency division multiple access (OFDMA) on the uplink (UL) and downlink (DL) and multi-user multiple-in multiple-out (MU-MIMO) on the UL and DL. Designing and defining mechanisms for multiplexing UL random access for different purposes may be described herein.

[0071] Wake-up radio (WUR) can be used in conjunction with PHY and MAC modifications to procedures to provide enhanced low-power operation of 802.11 devices. MAC and PHY modifications can enable WUR operation.

[0072] The WUR may operate in bands including 2.4 GHz, 5 GHz, and may extend to sub-1 GHz. A WUR device may operate as a companion radio to a primary connectivity radio used to transmit standard 802.11 or cellular packets. The WUR transmits packets carrying control information and may have an active receiver power consumption of less than 1 milliwatt (mW). Receiving a wake-up packet by the WUR may wake the primary connectivity radio from sleep. The WUR is expected to have a range at least equal to that of the primary connectivity radio operating on a payload bandwidth of at least 20 MHz. Both APs and non-AP STAs may have the WUR as a companion radio. Some use cases for the WUR include, but are not limited to, low-power operation for IoT devices, smartphones, quick message / incoming call notification scenarios, quick status query / reporting, configuration change scenarios, and / or quick emergency / critical event reporting scenarios. The terms access point (AP) and base station (BS) may be used interchangeably throughout this disclosure.

[0073] WUR STA / AP rediscovery may be associated with, for example, 802.11ba or cellular networks such as NR (New Radio) and may address issues associated with STA rediscovery by an AP after the AP is reset or replaced, and / or issues associated with STA rediscovery of an AP where the STA may wake up if it detects a WUR beacon for a certain period of time and is unable to communicate with the AP or discover other APs.

[0074] As used herein, the term primary connectivity radio (PCR) may refer to a main radio capable of transmitting and receiving one or more physical layer protocol data units (PPDUs) over various channels. The term wake-up radio (WUR) may refer to a companion radio to a PCR capable of transmitting or receiving one or more WUR PPDUs. As used herein, the terms wake-up radio, wake-up radio receiver, wake-up radio transceiver, wake-up wireless device, companion transceiver, companion receiver, companion radio, passive receiver, passive transceiver, zero energy (ZE) receiver, ZE transceiver, secondary transceiver, or any combination thereof, may be used interchangeably throughout this disclosure. The terms primary connectivity radio, primary connectivity transceiver, main receiver, main transceiver, main modem, primary transceiver, or any combination thereof may be used interchangeably throughout this disclosure. As used herein, the terms WUR (wake-up radio) packet, WUR signal, WUR frame, or any combination thereof may be used interchangeably throughout this disclosure.

[0075] FIG. 2 illustrates an example wake-up radio (WUR) system 200 in which one or more disclosed embodiments may be implemented. As shown in FIG. 2, WTRUs 202a, 202b (e.g., IoT devices) may include WUR transceivers 210, 220 operably coupled to primary connectivity radios (PCRs) 205, 215. The PCRs 205, 215 may be designed to transmit and receive large amounts of data, e.g., at Mb / s or even GB / s. The WUR transceivers 210, 220 may be designed to transmit and receive small amounts of data with extremely low power consumption (e.g., less than 1 mW). For example, as shown in FIG. 2, the WTRU 202a may turn off (or deactivate) its PCR 205 transceiver and turn on (or activate) the WUR transceiver 210 when the WTRU 202a is waiting for a WUR packet 216. While the PCR 205 is off (or in a doze / sleep state) and the WUR is on (or in an awake / active state), the WTRUs 202a, 202b may receive a wake-up radio (WUR) packet 216 from the AP 214 via the WUR 210, 220 to wake up or to know when to expect to receive a WUR packet 216 from the AP 214 to wake up. For example, upon receiving the WUR packet 216 at the WUR transceiver 220, the WTRU 202b may turn on the PCR 215 to further transmit or receive data to or from the AP 214.

[0076] When an existing AP is replaced with a new AP, it may be infeasible to manually reset all WUR transceivers (or WUR devices) associated with the existing AP, especially when STAs equipped with WUR transceivers are currently in WUR mode. If the WUR AP loses power, it may lose stored information about existing STAs, such as the STA's wake-up ID (WID), WUR schedule and duty cycle, etc. For previously associated STAs, these STAs may be in WUR mode and may be unaware that the WUR AP does not have existing WUR information.

[0077] One or more embodiments may provide a rediscovery procedure to ensure that the WUR AP and STAs can rediscover each other quickly and efficiently, and WUR scheduling and information may be reestablished as quickly as possible to conserve energy for STAs with WUR transceivers.

[0078] A WUR AP may be unexpectedly lost due to power loss, malfunction, damage, theft, or other reasons. In some cases, a WUR AP may return to normal operation but may have lost existing information, such as its associated STAs and WUR STAs, WUR parameters such as WID, WUR group ID (GID), WUR duty cycle, etc. In some other cases, a new AP may need to be brought in to replace the old AP, which may be unaware of the existing WUR schedule, duty cycle, or other parameters / information. WUR STAs associated with a lost WUR AP, particularly those in WUR mode, may be unaware of the loss of WUR parameters at the AP and may continue their scheduled WUR operation. A WUR STA may not monitor every WUR beacon, or may only monitor WUR beacons for a certain period, such as a scheduled duty cycle. These WUR STAs may need to be woken up, have a new association with the same or a new AP, and / or negotiate a new WUR schedule and parameters as described above.

[0079] In one embodiment for rediscovering a lost WUR AP, a passphrase or other piece of security-related information may be used to wake up the WUR STA. The WUR AP may be configured or pre-configured with one or more pieces of security information, such as a passphrase or passcode. Such a passphrase or passcode may be used for emergency recovery with the same or another AP using the same or different BSSID and / or SSID. Such emergency recovery may also be used as an encryption key or for other security purposes. The emergency recovery information may also be one or more combinations of a specific GID and / or security key or passphrase.

[0080] A WUR AP may include emergency recovery information in one or more frames, such as management frames, action frames, WUR frames, etc., sent to WUR STAs that are authenticated or associated with it. For example, the emergency recovery information may be included in a (re)association response, or in a WUR action frame, or in other types of frames, such as a beacon or short beacon.

[0081] Emergency recovery information may also be included as part of the WUR negotiation setup process and / or WUR mode suspend negotiation.

[0082] The emergency recovery information may be stored in a location in the AP, such as its hard disk, or in the cloud to ensure that it is not lost due to a power outage.

[0083] When a WUR AP is reset and resumes operation, it may include emergency recovery information in a wake-up frame (or WUR frame) targeted to one or more WUR STAs that may be in WUR mode. For example, the wake-up frame (or WUR frame) may be sent to a specific GID associated with a general wake-up or a WUR reset. The GID may be combined with one or more passphrases, encryption keys, or pieces of security information to indicate that it is associated with a general wake-up or a WUR reset (i.e., when all STAs must wake up to reestablish WUR mode negotiation, including one or more of the WUR channel / band, WUR rate, WUR duty cycle, etc.). The wake-up packet (WUP) may include or embed one or more pieces of security information, such as the BSSID, passcode, or SSID. The WUP may include a reason for the wake-up, such as "WUR reset" or "BSS-wide reset," which may indicate that the STA needs to wake up. The WUP may be sent or repeated across all available WUR channels, WUR bands, and for a periodicity that may be sufficient to wake up all WUR STAs currently in WUR mode.

[0084] The replacement WUR AP may use the same emergency recovery information known to the operator or recovered from the cloud or through other methods to wake up WUR STAs associated with the previous WUR AP.

[0085] An AP may indicate that it has restarted in one or more PCR (primary connectivity radio) frames, such as a beacon, short beacon, or broadcast WUR action frame. A PCR frame may refer to a frame transmitted or received over the PCR and may include a management frame or an action frame.

[0086] A WUR STA in WUR mode may wake up based on one or more conditions upon receiving a WUP (e.g., during the ON duration of its WUR duty cycle). One condition may be that the WUP is targeted to the WUR STA's WID. Another condition may be that the WUP is targeted to a GID with which the WUR STA is associated and the BSSID embedded in the WUP indicates the WUR STA's BSSID. Another condition may be that the security information in the WUP is verified to be authentic. Another condition may be that the WUP is targeted to a GID associated with a "general wakeup" or a "BSS-wide reset," or that the WUP is targeted to a multicast / broadcast group, which may include a reason for the wakeup being a "general wakeup" or a "BSS-wide reset." Yet another condition may be that the BSSID embedded in the WUP indicates the WUR STA's BSSID.

[0087] The WUR STAs may wake up and send UL packets to the AP on their PCRs according to the WUR procedure. The WUR AP may then send a disassociation frame. In one example, the WUR AP may send a broadcast disassociation frame to all STAs by, for example, invoking the disassociate.request primitive using the broadcast MAC address and the reason code for "STA reset." In another example, when a WUR STA wakes up for a "WUR reset" or "BSS-wide reset" reason, it may wake up and send a disassociation frame to the WUR AP. In yet another example, the WUR STA may disassociate from the AP after a timeout after waking up.

[0088] The replacement WUR AP may indicate in one or more PCR frames, for example, in a beacon, short beacon, broadcast WUR action frame, FILS discovery frame, etc., that it is a replacement AP for the previous AP.

[0089] A WUR STA may elect to (re)associate with a WUR AP and perform WUR negotiation to establish WUR parameters. The WUR STA may then request to enter WUR mode and turn off or deactivate its PCR.

[0090] After each reset, the AP may refresh emergency recovery information such as a new passphrase, a new passcode, a new GID, etc.

[0091] FIG. 3 shows an example procedure 300 for using a basic service set (BSS) counter that may be used in combination with any of the other embodiments described herein. In step 305, a WTRU or STA equipped with one or more transceivers may receive a frame including a first counter. The one or more transceivers may include a first transceiver for PCR and a second transceiver for WUR. The frame may be received via the first transceiver (i.e., PCR) and may be a management frame or an action frame as described above. Examples of management frames may include, but are not limited to, a beacon frame, an association request frame, an association response frame, a reassociation request frame, a reassociation response frame, a probe request frame, and a probe response frame. Examples of action frames may include, but are not limited to, a WUR mode setup frame, a WUR mode release frame, etc. The frame received via the first transceiver (i.e., PCR) may be a management frame, such as a beacon frame. The frame received via the first transceiver (i.e., PCR) may be an action frame, such as a WUR mode setup frame, or a WUR action frame.

[0092] Regardless of whether the WTRU is in a negotiation procedure, the received management frame and / or the received action frame (e.g., a beacon frame and / or a WUR mode setup frame) may include a WUR operation element in the frame as described above. The WUR operation element may include a set of parameters necessary to support WUR operation. For example, the WUR operation element may include a WUR parameter including a counter subfield. The counter subfield may include the first counter value of step 305. The first counter value may be a counter value of the current BSS (basic serve set) or a counter value of the updated BSS.

[0093] In step 307, the WTRU or STA that locally stores and maintains the counter variable may update the value of the counter variable to the value of the first counter in the WUR operation element, which may be the most recent counter value included in the WUR operation element in the beacon or WUR mode setup frame.

[0094] After the negotiation procedure is completed, the WTRU turns off (or deactivates) the first transceiver (i.e., PCR) and turns on (or activates) the second transceiver (i.e., WUR) in step 310 to save power. Note that the second transceiver may be turned on (or activated) after the first transceiver is turned off (or deactivated), or may be turned on (or activated) before the first transceiver is turned off (or deactivated). When the first transceiver is turned off, the first transceiver may enter a doze (or sleep) state. The first transceiver may be in a power save (PS) mode. The second transceiver may be in an active mode to receive a wake-up signal.

[0095] In particular, when the WTRU is in a WUR mode, the second transceiver of the WTRU may be in an awake state during a WUR duty cycle schedule agreed upon between the AP and the WTRU.

[0096] In step 315, the WTRU may monitor for a WUR frame or a WUR packet via the second transceiver in an awake state. In step 320, the WTRU may receive a WUR frame including a second counter value from the AP via the second transceiver in an awake state.

[0097] The WUR frame received in step 320 may be a WUR wake-up (i.e., type=1) frame. The WUR wake-up frame may include fields such as a TD control field. The TD control field may include a counter subfield. The counter subfield may include the second counter value of step 320. The second counter value may be a BSS counter value. The second counter value may indicate whether any significant updates have occurred to the BSS-related parameters of the AP or the first transceiver (or PCR). Alternatively or additionally, if the WUR wake-up frame is broadcast, the WUR wake-up frame may include a BSS update counter field that includes the second counter value of step 320. The second counter value in the BSS update counter field may indicate whether any significant updates have occurred to the BSS parameters (of the PCR) of the AP or the first transceiver associated with the AP.

[0098] The AP may maintain a BSS parameter update counter. The AP may, for example, increment or decrement the value of the BSS parameter update counter when a significant update occurs to any of the elements in the beacon frame. The AP may include the current value of the BSS parameter update counter (i.e., the second counter value) in the counter subfield of the TD control field in the transmitted broadcast / multicast / unicast WUR wake-up frame.

[0099] In step 325, the WTRU may determine whether the first counter value and the second counter value are different. If the first counter value and the second counter value are not different (i.e., are the same), the WTRU may determine that there is no significant update to the AP or BSS parameters associated with the AP. However, if the first counter value is different from the second counter value, the WTRU may determine that there is a significant update to the AP or BSS parameters associated with the AP.

[0100] If the WTRU determines that there is an important update to the AP or BSS parameters associated with the AP, the WTRU may wake up the first transceiver by activating it in step 330. The first transceiver may then enter an awake or active state to update the BSS parameters associated with the AP and / or to receive further information related to the update. For example, in step 335, the WTRU may receive a beacon frame (i.e., a PCR beacon) via the first transceiver to update the BSS parameters. The WTRU may also send a response frame to the AP using its first transceiver (i.e., the PCR component) after receiving a WUR wakeup frame with the address field set to the WID that identifies the WTRU.

[0101] In one embodiment for rediscovery, a BSS counter in a WUR frame or beacon may be used to wake up a WUR STA or WUR WTRU. A specific BSS counter value may be used to indicate that the WUR AP has been newly restarted. For example, such a BSS counter value may be all "0"s or all "1"s or a predefined value. Such a value may be used in any WUR frame as a result of changing the BSS settings. Such a value may also be included in a WUR action frame, such as a WUR response frame. Furthermore, a WUR action frame, such as a WUR response frame, may include a "current WUR BSS counter" value so that the WUR STA is aware of the current setting of the WUR beacon or the WUR BSS counter value used in the beacon when it enters WUR mode. The current BSS counter value may be derived from or based on another counter, such as an access point-connectivity services network (AP-CSN) counter, or other beacon- or BSS setting-related counters used in the BSS.

[0102] After rebooting, the WUR AP may set the value of the BSS counter value to a value indicating a new reboot, or may indicate "WUR reset" or "BSS-wide reset" (e.g., in a WUR beacon or broadcast / multicast / unicast WUR frame). In another example, the WUR AP may randomly set the BSS counter, and to ensure that all STAs will be woken up for the new BSS settings, the WUR AP may increment the BSS counter one or more times after its reboot without requiring that the BSS settings be updated.

[0103] The WUR AP may set a BSS counter using the BSS counter value in the WUR beacon to wake up all WUR STAs currently in WUR mode. Additionally or alternatively, a wake-up frame may be defined for WUR reset / BSS reset. The wake-up frame may indicate the BSS counter value. The WUR beacon and / or WUR reset frame may be embedded with the AP's BSSID. The WUR beacon or WUR frame may be sent or repeated across all available WUR channels, WUR bands, and for a period that may be sufficient to wake up all WUR STAs currently in WUR mode.

[0104] The AP may indicate that it has restarted in one or more PCR frames, such as a beacon, short beacon, broadcast WUR action frame, etc. The WUR AP may include a WUR BSS counter in the PCR frame.

[0105] A WUR STA in WUR mode may wake up based on one or more conditions, for example, upon receiving a wake-up frame or wake-up packet (WUP) for the duration of its WUR duty cycle. One such condition may be that the WUR beacon contains a different BSS counter value than the value included in the last WUR beacon it received, or a different value than the value indicated during the WUR negotiation process, or a different value derived from the existing counter when it entered WUR mode, or a value indicating an "AP restart" and / or a "BSS reset" and / or a "WUR reset." Another condition may be that the AP has been restarted and / or that the wake-up frame indicates a BSS / WUR reset. Another condition may be that the included security information is verified. Another condition may be that the embedded BSSID / SSID is the desired BSSID / SSID. The WUR STA may wake up and send a UL packet to the AP on their PCRs according to the WUR procedure. The WUR AP may then send a disassociation frame. In one example, the WUR AP may send a broadcast disassociation frame to all STAs by invoking the disassociate.request primitive using, for example, the broadcast MAC address and a reason code for "STA reset" or "BSS reset." In another example, when a WUR STA wakes up for a reason of "WUR reset" or "BSS-wide reset," which may be indicated by a specific BSS counter value or by the type of wake-up frame, the WUR STA may wake up and send a disassociation frame to the WUR AP. In yet another example, the WUR STA may disassociate from the AP after a timeout after waking up.

[0106] A WUR STA may choose to (re)associate with a WUR AP and then perform WUR negotiation to establish one or more WUR parameters, and the WUR STA may then request to enter WUR mode and turn off its PCR.

[0107] In one embodiment, an AP may perform one or more steps to indicate to a STA the current BSS counter value or the current BSS update counter value. The AP may indicate the current value of the counter subfield included in the most recent wake-up packet, such as the last broadcast wake-up packet, using an element in a beacon or WUR action frame transmitted using the AP's PCR. For example, such an element may be a WUR operation element, a WUR mode element, or a WUR capability element. Such an element may be included in a beacon frame, a short beacon frame, and / or a WUR mode setup frame. Additionally or alternatively, the current value of the counter subfield included in the most recent wake-up packet, such as the most recent broadcast wake-up packet, may be included directly in a beacon and / or a WUR action frame, such as a WUR mode setup frame, and / or other types of management, control, data, action, or extension frames. The AP may include a WUR operation element in a WUR action frame, such as a WUR mode setup frame, when the WUR operation element was recently updated (e.g., when the counter field was increased, the WUR operating channel was changed, the WUR beacon offset was changed, the WUR beacon period was changed, etc.).

[0108] Non-AP STAs and / or APs capable of WUR operation may maintain a counter variable. Additionally or alternatively, non-AP STAs and / or APs with dot11WUROptionImplemented set to true may maintain a counter variable or counter field. The STA may update the value of the counter variable or counter field to the most recent counter value received in a frame using its PCR component, such as a beacon, or received in a WUR action frame, such as a WUR mode setup frame. The most recent counter value may be included in a WUR operation element, a WUR mode element, or a WUR capability element, as described above.

[0109] A non-AP STA that receives a counter subfield of the TD control field in a WUR wake-up frame containing a value different from its counter variable (or counter field) may turn on its PCR component and follow the Traffic Indication Map (TIM) broadcast procedure to attempt to receive PCR beacon information subject to its PCR delay constraint.

[0110] In one example, a non-AP STA may turn off its PCR components immediately after it successfully receives PCR beacon information from its associated AP. In this example, the AP may consider the PCR components of a non-AP STA that has completed a successful WUR mode negotiation to be in doze mode from the time of transmission of a broadcast WUR packet containing an updated counter field in its TD control field (Tb) until the time the PCR transmission delay (PCR_delay) indicated by the non-AP STA expires. The PCR components of a non-AP STA that has completed a successful WUR mode negotiation may be in awake mode from the time (Tb+PCR_delay) until the first PCR beacon is transmitted. To ensure correct reception of the beacon, the AP may consider the PCR of the non-AP STA to be in awake mode for a predefined number of beacon intervals after Tb+PCR_delay. The AP may then consider the PCR components of a non-AP STA that has completed a successful WUR mode negotiation to be in doze mode.

[0111] In another example, a non-AP STA that receives a counter subfield of the TD control field in a WUR wake-up frame containing a value different from its counter variable or counter field may turn on its PCR component and follow the TIM broadcast procedure to attempt to receive PCR beacon information subject to its PCR delay constraint. The non-AP STA may perform a frame exchange with its AP using its PCR component to notify the AP that it is in an awake state after successfully receiving a PCR beacon from the AP. The non-AP STA may proceed to WUR mode or WUR suspended mode after successfully completing a WUR action frame exchange and receiving a PCR beacon from its AP.

[0112] A non-AP STA that receives a broadcast WUP from an AP, or that receives a broadcast WUP from its AP, or that receives a multicast WUP addressed to it (e.g., by including a GID with which the STA is associated) may turn on its PCR components. A non-AP STA that receives a broadcast WUP from its AP indicating that the STA should receive group-addressed data packets using its PCRs, or that receives a multicast WUP addressed to it indicating that the STA should receive group-addressed data packets using its PCRs (e.g., by including an ID of "0" in the WUP), may turn on its PCR components to receive group-addressed data packets using its PCRs.

[0113] In one example, a non-AP STA may turn off its PCR components immediately after it successfully receives a group-addressed data frame from its associated AP using its PCR. In this example, the AP may consider the PCR components of a non-AP STA with which it has completed a successful WUR mode negotiation to be in doze mode from the time of transmission of a broadcast WUR packet containing an updated counter field in its TD control field (Tb) until the time the PCR transmission delay (PCR_delay) indicated by the non-AP STA expires. The PCR components of a non-AP STA with which it has completed a successful WUR mode negotiation may be in awake mode from time (Tb+PCR_delay) until the first PCR beacon is transmitted. To ensure correct reception of the beacon, the AP may consider these PCRs of the non-STA to be in awake mode for a predefined number of beacon intervals after Tb+PCR_delay. The AP may then consider the PCR components of a non-AP STA with which it has completed a successful WUR mode negotiation to be in doze mode.

[0114] In another example, a non-AP STA that receives a broadcast WUP from its AP indicating that the STA should receive group-addressed data packets using its PCR, or receives a multicast WUP addressed to it indicating that the STA should receive group-addressed data packets using its PCR (e.g., by including an ID of "0"), may turn on its PCR components to receive group-addressed data packets using its PCR. The non-AP STA may use its PCR components to perform a frame exchange with its AP to notify the AP that it is in an awake state after successfully receiving a PCR beacon from the AP. The non-AP STA may proceed to WUR mode or WUR suspended mode after it successfully completes a WUR action frame exchange and receives a group-addressed frame from its AP.

[0115] In one embodiment for rediscovery of a lost WUR AP, a neighboring AP may be used as a recovery AP. A WUR AP may indicate one or more neighbor APs as backup APs for its WUR STAs. Such indication may be in any existing field, such as the Reduced Neighbor Report, or in a newly defined element, such as the WUR Operation element. For example, one or more bits in the Reduced Neighbor Report element or any other field or subfield may be used to indicate that a neighbor AP supports WUR service and / or is a backup AP for the current AP. Security information, a specific GID for WUR reset, a BSSID / SSID or other ID for the replacement AP, and / or a passphrase may be included in any PCR frame (e.g., a WUR Action frame or a WUR Response frame) that may be part of a WUR negotiation.

[0116] When a WUR AP is lost, for example, due to theft or damage, a replacement AP may be used to wake up existing WUR STAs in WUR mode. The replacement AP may send a wake-up packet to the WUR device associated with the lost AP using security information, its ID, or GID to wake up the WUR device and / or reset the WUR device.

[0117] A WUR STA may wake up after receiving a WUR packet based on one or more conditions. One such condition may be that the WUR packet is from a replacement AP for the WUR AP with which it is associated. Another condition may be that the WUR packet is targeted to the GID / broadcast ID to which the WUR STA belongs, or that the GID is associated with the loss of an existing AP. Another condition may be that an ID, such as the BSSID, SSID, or other type of ID, of the WUR AP may be included in the WUR packet.

[0118] A WUR STA may wake up and disassociate with its previous AP after a timeout after waking up.

[0119] The replacement AP may indicate in one or more of its PCR frames that it is a replacement AP for a lost AP and / or the ID of one or more replacement APs.

[0120] A WUR STA may choose to (re)associate with the replacement AP or with one of the replacement APs.

[0121] In one embodiment for rediscovery of a lost WUR AP when the lost WUR AP was a member of an 802.11 Extended Service Set (ESS), the AP may not exist independently because it is a member of the ESS. APs in an ESS may be components of an extended form of a network built with multiple BSSs (APs). The architectural component used to interconnect the BSSs (APs) is the Distribution System (DS). This added architectural component, the DS, may enable multiple types of recovery when an AP (BSS) is unexpectedly lost. This may be enabled by the AP informing the DS of the WUR STA's association, configuration, security, and any other information. This notification may be part of the WUR STA association process. The DS and / or the Distribution System Service (DSS) or a controller connected to the DS may then track WUR STA configuration values, security information, and expected behavior. The DS or attached controller is aware of the loss of the AP (BSS) and may then, based on the DS's knowledge of the ESS, send the information it has about the WUR STAs associated with the unexpectedly lost AP to one or more of the remaining APs in the ESS to provide replacement functionality for the lost AP. This may allow for restoration of WUR functionality without notification of the WUR STA or without the WUR STA having to re-establish a WUR service or schedule. This may be transparent restoration of WUR functionality for the WUR STA. The new WUR AP or APs may provide the WUR STA with the MAC address and configuration information of the new AP in a wake-up message, or upon waking up, the WUR STA may select a different BSS in the ESS to associate with, just as an associated STA in the ESS selects its associated BSS.

[0122] A similar type of transparent recovery may also be possible for a General Link (GLK) AP that has a WUR controller as part of its GLK network. Such a GLK AP may provide WUR services to both WUR GLK STAs and WUR non-GLK STAs. The associated WUR controller may have knowledge of WUR STA association parameters, just as a DS does, and may provide WUR services to each of the WUR STAs associated with the unexpectedly lost AP by using other GLK APs about which it has knowledge to provide WUR functionality.

[0123] In addition to transparent recovery, the DS and / or WUR controller may wake up WUR STAs associated with the unexpectedly lost AP and request them to associate with the currently active ESS AP or GLK AP to re-establish WUR services and scheduling. In partially transparent recovery, the associated WUR STA may have some of its WUR capabilities granted in a transparent manner and some of its WUR capabilities granted only after re-association.

[0124] Association of a WUR STA with an AP that is part of an ESS may require the AP to forward all WUR STA association information to the DS. Association of a WUR STA with a GLK AP that is part of a network that includes a WUR controller may require the GLK AP to forward all WUR STA association information to the WUR controller or another entity.

[0125] As part of this recovery process, there may be control signaling during the WUR transmission sent to the WUR STA. This signaling may include frequency band information, the MAC address of the new AP, the MAC addresses of several potential new APs, neighbor report information, AP beacon timing information, WUR beacon timing information, ESS information, BSS information, or any other information that may enable the WUR STA to remain associated with an ESS or a different BSS and / or continue to receive WUR service. Portions of the signaling may be sent in the WUR transmission, portions of the signaling may be sent using 802.11, or the WUR transmission may indicate that signaling must be performed over the 802.11 radio to configure / reconfigure the WUR STA's association or reassociation. The WUR transmission sent to the WUR STA may also request that the WUR STA take measurements or provide information about specific or available APs recognized by the STA.

[0126] In one embodiment for rediscovery of a lost WUR AP, the WUR AP may be "lost" because it has been replaced or upgraded by a new WUR AP and, therefore, its loss may be expected and planned. A specific BSS counter value may be used to indicate that the WUR AP is terminating its service (i.e., being lost). Such a BSS counter value may be all "0"s or all "1"s or a predefined value. Such a value may not be used to indicate a change in the normal BSS setting. Furthermore, the above value may also be included in a PCR frame, such as a management frame, action frame, WUR action frame, or WUR response frame. Furthermore, a WUR action frame, such as a WUR response frame, may include a "current WUR BSS counter value" value, so that the WUR STA is aware of the current setting of the WUR BSS counter value used in the WUR beacon when it enters WUR mode. The current BSS counter value may be derived from or based on another counter, such as the AP-CSN, or other beacon counters used in the BSS.

[0127] Before an existing WUR AP is replaced, it may set the value of the BSS counter to a value indicating "terminating service." In another example, the WUR AP may randomly set the value of the BSS counter, and to ensure that all STAs will be woken up for the new BSS configuration, the WUR AP may increment the BSS counter without requiring that the BSS configuration be updated.

[0128] The WUR AP may set a BSS counter using the BSS counter value in the WUR beacon to wake up all WUR STAs currently in WUR mode. Additionally or alternatively, a new wake-up frame may be defined for service termination. The new wake-up frame may indicate the BSS counter value. The WUR beacon and / or WUR termination wake-up frame may be embedded with the AP's BSSID. Such WUR beacons or WUR frames may be sent or repeated across all available WUR channels, WUR bands, and for a period that may be sufficient to wake up all WUR STAs currently in WUR mode.

[0129] An AP may indicate that it is terminating service in one or more primary connectivity radio (PCR) frames (e.g., management frames or action frames), such as a beacon, short beacon, and / or broadcast WUR action frame. A WUR AP may include a WUR BSS counter in a PCR frame. A WUR AP may include a replacement AP, for example, in a reduced neighbor report element. In one example, one or more bits may be used in a reduced neighbor report to indicate that it supports WUR operation.

[0130] A WUR STA in WUR mode may wake up based on one or more conditions upon receiving a WUR, such as during the on-duration of its WUR duty cycle. One such condition may be that the WUR beacon contains a value indicating an "AP is terminating service" with a different BSS counter value than the value contained in the last WUR beacon it received, or a different value indicated during the WUR negotiation process, or a different value derived from an existing counter when it entered WUR mode. Another condition may be that the wake-up frame indicates that the AP is terminating service, as indicated by its type and / or GID, address, or other indicator. Another condition may be that the included security information is verified. Another condition may be that the embedded BSSID / SSID is the desired BSSID / SSID.

[0131] The WUR STAs may wake up and send UL packets to the AP on their PCRs according to the WUR procedure. The WUR AP may then send a disassociation frame. In one example, the WUR AP may send a broadcast disassociation frame to all STAs by invoking the disassociate.request primitive, for example, using a broadcast MAC address and a reason code for "STA reset" or "BSS reset." In another example, a WUR STA may wake up and send a disassociation frame to the WUR AP when it wakes up for a "BSS end" or "AP service end" reason, which may be indicated by a specific BSS counter value or by the type of wake-up frame. In yet another example, the WUR STA may disassociate from the AP after a timeout after waking up.

[0132] The WUR STA may choose to (re)associate with the replacement AP and then perform WUR negotiation to establish WUR parameters, and the WUR STA may then request to enter WUR mode and turn off its PCR.

[0133] In one embodiment for rediscovery of a lost WUR AP, the loss of the AP may be expected and may be in an ESS or GLK network. In such an embodiment, the AP does not exist independently because it is a member of the ESS. APs in an ESS are components of an extended form of a network built with multiple BSSs (APs). The architectural component used to interconnect the BSSs (APs) is the Distribution System (DS). This added architectural component, the DS, may enable multiple types of recovery when an AP (BSS) is expected to be lost. This may be enabled by the AP informing the DS of WUR STA association, configuration, security, and / or any other information. This notification may be part of the WUR STA association process. The DS and / or DSS and / or a controller connected to the DS may then track WUR STA configuration values, security information, and expected behavior. Based on its knowledge of the ESS configuration and the AP expected to be lost, the DS or connected controller may determine how to transparently replace the AP expected to be lost or how to reconfigure the WUR STAs associated with the AP expected to be lost. This process may be done in a manner that is transparent to the WUR STAs, or by waking up the WUR STAs and having them reassociate with the selected AP, or by allowing the WUR STAs to select a new AP in the ESS to reassociate with. It may also be possible for the DS and / or DSS and / or a controller connected to the DS to wake the WUR STA and request that it associate with a new AP that may or may not be in the ESS.

[0134] A similar type of recovery can also be performed for a GLK AP that has a WUR controller as part of its GLK network. Such a GLK AP can provide WUR services to both WUR GLK STAs and WUR non-GLK STAs. The associated WUR controller will have knowledge of WUR STA association parameters, just as a controller connected to a DS and / or DSS and / or DS would. The associated WUR controller can provide WUR services to each WUR STA associated with the lost AP by using other GLK APs about which it has knowledge to provide WUR functionality.

[0135] In addition to transparent recovery, the DS and / or WUR controller may also wake up WUR STAs associated with the lost AP and cause them to associate with another active ESS AP or GLK AP to re-establish WUR services and scheduling. There may also be partially transparent recovery, causing the associated WUR STAs to provide some of their WUR functions in a transparent manner and some only after re-association.

[0136] Association of a WUR STA with an AP that is part of an ESS may require the AP to forward all WUR STA association information to the DS. Association of a WUR STA with a GLK AP that is part of a network that includes a WUR controller may require the GLK AP to forward all WUR STA association information to the WUR controller or another entity.

[0137] As part of this process, there may be control signaling during the WUR transmission sent to the WUR STA. This signaling may include frequency band information, the MAC address of the new AP, the MAC addresses of several potential new APs, neighbor report information, AP beacon timing information, WUR beacon timing information, ESS information, BSS information, and / or any other information that enables the WUR STA to remain associated with an ESS or a different BSS and / or continue to receive WUR service. Part of the signaling may be sent in the WUR transmission, part of the signaling may be sent using 802.11, or the WUR transmission may indicate that signaling should be performed using the 802.11 radio to configure / reconfigure the WUR STA's association or reassociation. The WUR transmission sent to the WUR STA may also request that the WUR STA take measurements or provide information about specific or available APs recognized by the STA.

[0138] Multiple WUR STAs (or multiple WUR WTRUs) may be divided into WUR wakeup groups using a WUR group ID so that they can be woken up using multicast wakeup packets. Multiple parameters may be associated with the multicast wakeup frame, such as data rate, wakeup channel / band, etc. Due to changing channel conditions, the data rate, wakeup channel / band, etc. may no longer be suitable for some members of a multi-STA WUR group. One or more embodiments may provide procedures that address how to manage multicast WUR STA groups and how to provide updated parameters to the WUR STA groups. These procedures may be initiated by the WUR AP or by the WUR STAs.

[0139] In one embodiment, the WUR AP may group one or more STAs into a WUR multicast group by assigning one or more GIDs to these STAs. Such grouping may be based on one or more of the STAs' capabilities, such as UL MU capability, OFDMA capability, UL MU-MIMO capability, maximum wake-up delay (or duration), minimum wake-up delay, remaining duration, remaining delay, group maximum (or minimum) PCR transition time, and / or one or more group delays. Grouping may also be based on the distance from the STA to the AP. A group of STAs located closer to the AP may be woken up using a WUR packet with a higher data rate. A group of STAs located farther from the AP may be woken up using a WUR packet with a lower data rate. The WUR data rate, channel / band, and duty cycle may be indicated to the STAs by the WUR AP as part of the WUR negotiation process (e.g., in a WUR response frame).

[0140] The AP may initiate a WUR multicast group management procedure if it determines that one or more STAs in a multicast WUR group have not been woken up by using one or more multicast WUPs.

[0141] The AP may send one or more lower data rate WUPs to one or more STAs. The AP may send a multicast WUP by setting the receiver ID in the multicast WUP to the GID to which the STA belongs or to the broadcast ID. The multicast WUP may contain multiple fields, with each field indicating information of one or more WUR STAs to be woken up. The AP may send one or more unicast WUPs to the STAs. The WUP may carry an indication that the purpose of the wakeup is for WUR multicast group management.

[0142] A WUR STA may wake up after receiving a multicast or unicast WUP containing an indication for itself. After waking up, the STA may indicate to the AP that it is in an awake state.

[0143] The WUR AP may request the WUR STA to enter WUR mode suspend to maintain the existing WUR parameters while renegotiating other WUR parameters (e.g., WUR data rate, wake-up channel, band, etc.). The WUR AP may indicate the parameters that need to be changed in a WUR mode suspend request, action frame, or WUR action frame. The WUR AP may assign one or more new GIDs to the STA along with a new duty cycle, sleep time, etc.

[0144] After multicast WUR group management and negotiation of WUR parameters, the WUR STA may request to enter WUR mode and may enter WUR mode after receiving a positive response from the WUR AP.

[0145] In one embodiment, the WUR AP may group one or more STAs into a WUR multicast group by assigning one or more GIDs to these STAs. Such grouping may be based on one or more of the STAs' capabilities, such as UL MU capability, OFDMA capability, UL MU-MIMO capability, minimum wake-up latency, etc. Grouping may also be based on the distance from the STA to the AP. A group of STAs located closer to the AP may be woken up using a WUR packet with a higher data rate. A group of STAs located farther from the AP may be woken up using a WUR packet with a lower data rate. The WUR data rate, channel / band, and / or duty cycle may be indicated to the STAs by the WUR AP as part of the WUR negotiation process (e.g., in a WUR response frame).

[0146] A WUR STA may initiate a WUR multicast group management procedure if it determines that the current WUR parameters are no longer suitable for it. Such a decision may be based on WUR beacon measurements or on a change in operating mode (e.g., enabling or disabling UL MUs, enabling MU-MIMO, or requesting a different duty cycle, longer / shorter awake time, etc.).

[0147] The WUR STA wakes up, and the STA may then indicate to the AP that it is in an awake state. The WUR STA may initiate a multicast WUR group management procedure by requesting to enter WUR mode suspend to maintain the existing WUR parameters while renegotiating other WUR parameters (e.g., WUR data rate, wake-up channel, band, etc.). The WUR STA may indicate the parameters that need to be changed in a WUR mode suspend request or WUR action frame. The WUR AP may assign one or more new GIDs to the STA along with a new duty cycle, sleep time, etc.

[0148] After multicast WUR group management and negotiation of WUR parameters, the WUR STA may request to enter WUR mode and may enter WUR mode after receiving a positive response from the WUR AP.

[0149] As described above, in wireless networks such as cellular or 802.11ba networks, multicast wake-up frames may be used to wake up several STAs. In particular, several wake-up frames may be used to reliably wake up multiple STAs. However, this may create inefficiencies in some cases because the wake-up timing for different STAs may differ, thereby causing UL MU capabilities to go unused. For example, there may be congestion in the medium when STAs are woken up at roughly similar times. One or more embodiments may address procedures for efficient multi-STA wake-up and subsequent UL medium access to ensure that multiple STAs can reliably wake up and efficiently transmit their uplink packets.

[0150] In one embodiment for MU capability-based WUR grouping and wake-up, an AP may group one or more STAs together for WUR operation. In one example example, the AP may group them based on STA capabilities, such as uplink (UL) or downlink (DL). For example, STAs that support UL MU triggered-based (TB) access (UMTA) transmissions may be grouped together as one group. STAs that support UMTA and / or UL OFDMA-based random access (UORA) transmissions may be grouped together as another group. STAs that support triggered uplink access (TUA) transmissions may be grouped together as another group. Legacy STAs that are not also capable of performing DL / UL multiple access may be grouped together as another group.

[0151] In one example, one or more WUR group IDs (GIDs) may be reserved for these groups of STAs. For example, the AP may assign the N1 WUR GID for the UMTA-available group, the N2 WUR GID for the UMTA / UORA-available group, and the N3 WUR GID for the legacy group. In another example, the AP may reserve all GIDs in a range for the UMTA-available group, all GIDs in a second range for the UMTA / UORA-available group, and all GIDs in a third range for the legacy group. The number of GIDs assigned for each group and / or GID range may be predetermined, predefined, or configurable. If the GID range may be configurable, the configuration may be announced by the AP in management frames, control frames, action frames, or other types of control / management / action frames, such as beacon frames and (re)association frames.

[0152] By assigning one of these GIDs, the STA may be aware that all of the users in the group may or may not have MU capability. Furthermore, when the STA is woken up by a WUR frame with a WUR GID, the STA may check the range of the GID and perform the corresponding channel access method based on the group capability. As used herein, the terms WUR GID and GID may be used interchangeably throughout this disclosure.

[0153] 4 shows an example STA procedure 400 using implicit MU available group indication, which may be used in combination with any of the other embodiments described herein. Before entering WUR mode, a STA may be assigned one or more WUR GIDs by the AP during the WUR negotiation / configuration procedure. While the STA is in WUR mode, the STA may receive a unicast / broadcast / multicast WUR frame with a WUR GID in step 405. The WUR frame with this WUR GID may wake up a group of WUR STAs. For example, if a GID is assigned to the STA in the group, the STA may switch to PCR in step 410. The STA may check the WUR GID in step 415.

[0154] If the WUR GID is within the range of a UMTA available WUR group in step 420, the STA may monitor the PCR channel and wait for a trigger frame to trigger a UL OFDMA or UL MU-MIMO transmission in step 425. The trigger frame may indicate that the STA that just switched from WUR to PCR may use the opportunity to transmit. The trigger frame may include this information for the dedicated STA. The STA may use the allocated resources to perform a UL OFDMA or UL MU-MIMO transmission.

[0155] If the WUR GID is within the range of a UMTA / UORA-enabled WUR group in step 430, the STA may monitor the PCR channel and wait for a trigger frame to trigger UL OFDMA / MU-MIMO transmission in step 435. The trigger frame may indicate that the STA that just switched from WUR to PCR may use the opportunity to transmit. The trigger frame may include information on resource allocation for dedicated STAs and / or randomly accessed uplink transmissions. The STA may perform UL OFDMA / MU-MIMO transmission using dedicated allocated resources. If the STA does not find a dedicated allocation, the trigger frame may have an allocation for UORA transmission (e.g., by setting the AID12 value to 0), where the STA may perform UL OFDMA based on the random access procedure and transmit on one or more assigned RUs. In one example, UMTA operation may be omitted for this group.

[0156] If the WUR GID is within the range of the legacy WUR group in step 440, the STA may monitor the PCR channel and perform an EDCA / CA channel access procedure to notify the AP that the STA is awake in step 445. The trigger frame described herein may allocate resources and request one or more TB PPDU transmissions. The trigger frame may also carry other information required by the responding STA to send the TB PPDU. The frame format for the trigger frame may include, but is not limited to, a frame control, duration, RA, TA, common information, one or more user information, padding, or FCS field.

[0157] In one embodiment, the grouping procedure may be based on MU capabilities. In the WUR frame, a PCR Operation Indication (POI) field may be included. This field may indicate whether UMTA operation, UORA operation, or legacy channel access may be expected. Figure 5 shows an example STA procedure 500 using explicit POI, which may be used in combination with any of the other embodiments described herein.

[0158] 5, a STA may be assigned one or more WUR GIDs by the AP during the WUR negotiation / configuration procedure. In step 505, the STA may receive a broadcast / multicast WUR frame with a WUR GID. If a GID is assigned to the STA, the STA may switch to PCR in step 510. In step 515, the STA may check the POI included in the WUR frame.

[0159] If the POI indicates that a UMTA transmission may be expected in step 520, the STA may monitor the PCR channel and wait for a trigger frame to trigger a UL OFDMA or UL MU-MIMO transmission in step 526. The trigger frame may indicate that this frame may be used to trigger the STA to switch from WUR to PCR. The trigger frame may include information dedicated to the STA. The STA may use the allocated resources to perform a UL OFDMA or UL MU-MIMO transmission.

[0160] If the POI indicates that a UMTA / UORA transmission may be expected in step 530, the STA may monitor the PCR channel and wait for a trigger frame to trigger an UL OFDMA / MU-MIMO transmission in step 535. The trigger frame may indicate that this frame may be used to trigger the STA to switch from WUR to PCR. The trigger frame may include information on resource allocation for dedicated STA and / or randomly accessed uplink transmissions. The STA may use the dedicated allocated resources to perform UL OFDMA / MU-MIMO transmissions.

[0161] If the STA did not find a dedicated allocation, the trigger frame may have an allocation for UORA transmission (e.g., by setting the AID12 value to 0), where the STA may perform UL OFDMA based random access procedure to transmit on one or more allocated RUs.

[0162] If in step 540 the POI indicates that legacy transmissions are expected, then in step 545 the STA may monitor the PCR channel and perform an EDCA / CA channel access procedure to notify the AP that the STA is awake.

[0163] As discussed herein, there may be a UMTA-available group and a UORA-available group. In an alternative or additional example, the two groups may be merged into an MU-available group. For example, STAs woken up by the MU-available group may need to monitor PCRs and wait for a trigger frame.

[0164] As discussed herein, it should be noted that there may be MU-available groups (including UMTA and UORA) that may need to wait for a trigger frame to perform MU UL access. In another example, MU-available STAs (including UMTA and UORA) may be enabled to monitor the medium for a fixed duration for a trigger frame. Once the duration expires and a trigger frame is not received, the STA may be enabled to perform conventional EDCA / CA channel access. The fixed duration may be referred to as the Maximum_Trigger_Waiting_Duration for MU-available STAs. The fixed duration may be predefined, predetermined, or configurable. In cases where the duration may be configurable, the configuration may be present in a beacon frame, a (re)association frame, or other type of control / management / action frame.

[0165] FIG. 6 shows an example procedure 600 for multi-STA wake-up and uplink (UL) multi-user (MU) medium access based on one or more group delays, which may be used in combination with any of the other embodiments described herein. As described above, multiple STAs may be grouped together and assigned a group ID (e.g., a WUR GID) by the AP based on the STAs' capabilities. After the WUR negotiation / configuration procedure is complete, the group of STAs may enter WUR mode based on their respective negotiated parameters. While the group of STAs is in WUR mode, each STA in the group may receive one or more unicast / broadcast / multicast WUR frames 605, 610, 615 that include a WUR GID that matches the STA's GID. For example, the first STA in the group may receive WUR frame 1 605, the second STA in the group may receive WUR frame 2 610, and the Nth STA in the group may receive WUR frame 3 615 to wake up. The WUR frames 605, 610, 615 may be identical and may be transmitted repeatedly to a group of STAs to ensure wake-up reliability.

[0166] The WUR frames 605, 610, 615 may include a remaining WUR duration 640, 645 (or remaining WUR delay) indicated by the AP to each STA in the group. For example, WUR frame 1 605 transmitted to the first STA in the group may include 10 ms as the remaining WUR duration 640, and WUR frame 2 610 transmitted to the second STA in the group may include 5 ms as the remaining WUR duration 645. WUR frame 3 615 transmitted to the Nth STA in the group may include 0 ms as the remaining WUR duration. After the STAs in the group receive WUR frames 605, 610, 615 including the remaining WUR durations 640, 645, the STAs may not wake up from WUR mode until the remaining durations 640, 645 expire. For example, the first STA in the group may wait 10 ms before turning on its PCR component. The second STA in the group may wait 5 ms until the second STA in the group turns on its PCR component. The Nth STA in the group does not have to wait because the received remaining WUR duration indicates 0 ms (i.e., no delay). By aligning the wake-up timing for each STA or turning on the PCR component of the STAs in the group at approximately the same time, the STAs, particularly the first and second STAs in the group, can conserve energy because they do not need to wake up (or turn on PCR) until the nth STA in the group is ready to wake up (or turn on PCR). As used herein, the terms remaining WUR duration, remaining WUR delay, remaining duration, remaining delay, or any combination thereof, may be used interchangeably throughout this disclosure.

[0167] After the STAs in a group turn on their PCR components, the STAs may start a timer to ensure receipt of a trigger frame. For example, the STAs may run a timer until the maximum group wake-up delay 650 (or maximum group wake-up duration) expires, unless the STA receives the trigger frame 620. For example, if the STA receives the trigger frame 620 when the timer has not expired (i.e., the timer is less than or equal to the maximum group wake-up delay 650), the STA may transmit UL packets such as UL packet STA 1 625, UL packet STA N-1 630, and UL packet STA N 635, as shown in FIG. 6. The maximum group wake-up delay 650 may be received from the AP during the negotiation / configuration procedure. As used herein, the terms maximum group wake-up delay, maximum group wake-up duration, maximum trigger wait delay, maximum trigger wait duration, group wake-up delay, group wake-up duration, or any combination thereof may be used interchangeably throughout this disclosure.

[0168] It should be noted that the remaining WUR durations 640, 645 and the maximum group wake-up delay 650 may form a single duration or delay for waking up the STA and receiving a trigger frame. The single duration or delay may be determined by the AP during the negotiation / configuration procedure or may be determined by the STA before or during WUR mode. For example, the STA may receive a WUR frame or PCR frame that includes one or more group delays determined by the STA or AP, activate one or more group delays for waking up, and receive a trigger frame for initiating UL MU media access. The one or more delays may be referred to interchangeably as a remaining delay, a remaining duration, a group maximum (or minimum) wake-up delay, a group maximum (or minimum) wake-up duration, etc.

[0169] A trigger frame may be used to trigger MU access for STAs switching from WUR to PCR. In some scenarios in WUR, a unicast / broadcast / multicast wake-up frame may not be able to wake up all STAs in a group, and multiple wake-up frames may be transmitted. Correspondingly, multiple trigger frames may be required in PCR to trigger a subset of awake STAs in the group. A field in the trigger frame may indicate that the trigger frame may be used to trigger STAs that have just entered PCR from WUR. For example, a trigger type field may be used to indicate a WUR trigger. This trigger frame may be referred to as a WUR trigger frame. A STA may perform a TB transmission in response to a WUR trigger. If the STA receives an acknowledgment for the TB transmission, the STA may not respond to a subsequently transmitted WUR trigger frame.

[0170] 7 shows an example STA procedure 700 using a WUR trigger frame, which may be used in combination with any of the other embodiments described herein. At step 705, the STA may receive a unicast / multicast / broadcast WUR frame through the WUR. The STA may be the intended receiver of the WUR frame. The WUR frame may explicitly or implicitly indicate that the STA may expect to receive a WUR trigger frame in the PCR. At step 710, the STA may switch to the PCR and wait for the trigger frame. At step 715, the STA may start or continue using a timer.

[0171] If the STA receives a WUR trigger frame in step 720 while the timer is less than or equal to Maximum_Trigger_Waiting_Duration, then the STA may perform a UMTA or UORA transmission in step 725 .

[0172] If the STA successfully receives the acknowledgment in step 730, the STA may stop monitoring for a WUR trigger frame in step 740. More specifically, the STA may not be triggered to perform a UORA later. The STA may also stop the timer.

[0173] If the STA does not successfully receive an acknowledgment in step 730, the STA may further wait until it receives a WUR trigger frame in step 740, provided the timer is less than or equal to Maximum_Trigger_Wating_Duration. If the timer expires (or is greater than Maximum_Trigger_Wating_Duration), the STA may perform normal PCR operations (e.g., EDCA / CA in step 745). Alternatively or additionally, if the STA does not successfully receive an acknowledgment, the STA may continue the timer and monitor for a WUR trigger frame (i.e., returning to steps 715 and / or 720).

[0174] If the STA does not receive a WUR trigger frame when the timer is less than or equal to Maximum_Trigger_Waiting_Duration in step 720, the STA may be enabled for EDMA / CA channel access in step 745. Alternatively, the STA may be triggered by a later-transmitted WUR trigger frame. The STA may stop the timer.

[0175] In another example, when multiple wake-up frames are used to wake up one or more WUR STAs, the wake-up frame may include the remaining number of wake-up frames, the remaining number of wake-up frames, and / or the remaining time for transmitting wake-up frames to the same group of STAs. Several wake-up frames may be used to ensure that all STAs in the group can be woken up. The remaining number or time for transmitting wake-up frames to the same group of STAs may be in units of the current wake-up frame or in units of high data rate wake-up frames. A sequence of such wake-up frames may use the same or different rates. A sequence of such wake-up frames may be transmitted consecutively using one legacy 20 MHz band header and WUR markup. The wake-up frames may also be transmitted through different channels. Additionally, a group maximum or minimum wake-up delay may be defined for the group and associated with a GID and may be indicated to the WUR STAs in the WUR negotiation process (e.g., in the WUR response frame). Such a group maximum or minimum wake-up delay determination may be made based on minimum wake-up delay information provided by the WUR STA to the AP in the capabilities exchange. The target time for transmitting a trigger frame for a group of STAs on a PCR may be expected at or near the end of the interval used to transmit the remaining WUR and the group's maximum or minimum wake-up delay.

[0176] In another example, a WUR AP may initially send a multicast WUP containing only a GID to every member of the group of STAs associated with that GID. The GID, address field, and / or any other fields in the multicast WUP may indicate that it is an initial or “whole set” multicast WUP transmission. All WUR STAs that receive the initial or “whole set” multicast WUP addressing to their associated GID may wake up and alert the AP that they are awake. If the WUR AP wishes to address only a subset of STAs in the multicast WUP, such as in a retransmission of the multicast WUP, or if the WUR AP wishes to wake up only a subset of STAs in a multicast WUR STA group, it may send a multicast WUP that may be addressed to a broadcast address and include a list of individual STA IDs (e.g., WIDs) that the AP wants to wake up. In another example, a WUR AP can send a multicast WUP addressed to a GID of a group of STAs and may include a list of individual STA IDs (e.g., WIDs) that the AP wants to wake up. The WUP may carry an indication in the address field or any other field that the multicast WUP is a retransmission and / or that it is for waking up a subset of STAs associated with the GID or broadcast address. When a WUR STA receives a WUP addressed to a broadcast address or its associated GID and detects an indication of "subset wakeup" or "multicast WUP retransmission," it may further decode the WUP to see if its individual ID (e.g., WID) is included in the multicast WUP. If its ID is included, the WUR STA may wake up and alert the AP that it is awake.Otherwise, the WUR STA may not wake up.

[0177] In one example, a group maximum wake-up delay or group maximum PCR transition time may be defined for a group associated with a group ID. This group maximum PCR transition time may be included in the WUR parameters field from the WUR AP, which may be part of the WUR mode element or any other element that may be included in a WUR action frame, such as a WUR mode setup frame sent from an AP to a non-AP STA.

[0178] 8 shows an example Group ID List subfield 800 of a WUR Mode element that may be used in combination with any of the other embodiments described herein. As shown in FIG. 8, the Group ID List subfield 800 may include, but is not limited to, a Group ID Bitmap Size 805, a Starting Group ID 810, a Group ID Bitmap 815, a Group 1 Max PCR Transition Time 820, and a Group N Max PCR Transition Time 825. If membership to N group IDs is indicated for a particular STA in the Group ID Bitmap subfield 815, the N subfields of the Group Max PCR Transition Time 820, 825 may be included in the same Group ID List subfield 800 or may be included in the same element, such as in a WUR Mode element, which may be included in a WUR action frame, such as a WUR Mode Setup frame with Response Status set to Accept in the same WUR Action Frame. The Group Max PCR Transition Time 820, 825 for a group identified by a Group ID, or GID, may be determined by the AP using all PCR transition times provided by all non-AP STAs in the same group.

[0179] 9 shows an example frame format 900 of a WUR parameter control field indicating the presence of a group max PCR transition time 910, which may be used in combination with any of the other embodiments described herein. As shown in FIG. 9, the WUR parameter control field in a WUR mode element may include a group ID list present 905, a group max PCR transition time present 910, and a reserved subfield 915. The group max PCR transition time may be provided by the AP to non-AP STAs. For example, the AP may include an indication of whether the group max PCR transition time is included using the WUR parameter control field in the WUR mode element.

[0180] The Group Max PCR Transition Time Present subfield 910 may be set to 1 if a Group Max PCR Transition Time subfield is present in the subsequent WUR parameter field. Otherwise, it may be set to 0. In one example, two or more bits may be used to indicate one or more formats for the Group Max PCR Transition Time subfield. For example, a value of "0" may indicate that a Group Max PCR Transition Time subfield is not present. A value of "1" may indicate that a Group Max PCR Transition Time subfield of format 1 is included in the subsequent WUR parameter field. A value of "n" may indicate that a Group Max PCR Transition Time subfield of format n is included in the subsequent WUR parameter field.

[0181] 10 shows an example WUR parameter field 1000 of a WUR mode element, which may be used in combination with any of the other embodiments described herein. As shown in FIG. 10, the WUR parameter field format from a WUR AP may include, but is not limited to, a WUR ID 1005, a WUR channel offset 1010, a reserved subfield 1015, a start time of a WUR duty cycle 1020, a group ID list 1025, and a group maximum PCR transition time subfield 1030. The group maximum PCR transition time subfield 1030 may be included directly in the WUR parameter field or as a subfield of the group ID list subfield.

[0182] The Group Max PCR Transition Time subfield 1030 may indicate the group maximum PCR transition time for one or more of the group IDs assigned to the STA. The Group Max PCR Transition Time subfield 1030 may be present if the Group Max PCR Transition Time Present subfield 1010 of the WUR Parameter Control field is set to 1.

[0183] FIG. 11 shows an exemplary group maximum PCR transition time subfield 1100 for format 1, which may be used in combination with any of the other embodiments described herein. As shown in FIG. 11, the group maximum PCR transition time subfield 1100 for format 1 may include a group ID bitmap 1105, a group 1 maximum PCR transition time 1110, and a group N maximum PCR transition time. The group ID bitmap 1105 may be the same size as the group ID bitmap in the group ID list. A "1" bit may indicate that the group maximum PCR transition time subfields 1110, 1115 are present following the group ID bitmap. The order of the group maximum PCR transition times 1110, 1115 for each group may follow the order of the "1" bits in the group ID bitmap subfield 1105.

[0184] In another example, the group ID bitmap 1105 may be named a group delay bitmap. The group delay bitmap may have the same size as the group ID bitmap in the Group ID List subfield and may indicate whether a maximum group PCR transition delay is provided for a group ID in the Max Group Delay List field. Bit position "n" in the group delay bitmap may correspond to bit position "n" in the group ID bitmap in the Group ID List subfield, and thus to a group ID equal to (SGID+n). A bit in the group delay bitmap cannot be set to 1 if the corresponding bit in the group ID bitmap in the Group ID List subfield is set to 0. A bit in the group delay bitmap may be set to 1 to indicate that a maximum group PCR transition delay is provided for the corresponding group ID in the Max Group Delay List field. The total number of bits set to 1 in the group delay bitmap field may indicate the number of Max Group PCR transition delay fields included in the Max Group Delay List subfield.

[0185] The Max Group Delay List subfield may include one or more Max Group PCR Transition fields, which may have multiple bits (e.g., 8 bits).

[0186] The nth Maximum Group PCR Transition Delay field may correspond to the nth bit set to 1 in the Group Delay Bitmap subfield and may indicate the maximum PCR transition delay among all STAs in the group associated with the Group ID corresponding to the nth bit set to 1 in the Group Delay Bitmap subfield. The encoding of the Maximum Group PCR Transition field may follow the encoding of the PCR Transition Delay subfield, as described in the WUR Capability element above.

[0187] FIG. 12 shows an exemplary group maximum PCR transition time subfield 1200 of format 2. As shown in FIG. 12, the group maximum PCR transition time subfield 1200 of format 2 may include a number of group maximum PCR transition time fields 1205, group ID 1 1210, a group maximum PCR transition time for group ID 1 1215, group ID N 1220, and a group maximum PCR transition time for group ID N 1225. This format 1200 may be used when there are group maximum PCR transition times for only a few group IDs. The group maximum PCR transition time field count 1205 may indicate the number of group IDs for which a group maximum PCR transition time is indicated. The group maximum PCR transition time field count 1205 may indicate a value less than or equal to the number of bits “1” included in the group ID bitmap subfield within the group ID list subfield. The group ID subfield may indicate the group ID for which a group maximum PCR transition time is indicated in the group N maximum PCR transition time field following the group ID field.

[0188] The WUR AP may be provided in the Max Group Delay subfield in the WUR Parameters field included in the WUR Mode element. The Max PCR Transition Delay for a group of STAs may be identified by a Group ID. The Max PCR Transition Delay may be defined as the maximum of the PCR Transition Delay values ​​in the WUR Capabilities element indicated by all WUR non-AP STAs that are not awake, have negotiated WUR power management services with the WUR AP, and are in WUR mode.

[0189] A non-AP STA with its WUROptionImplemented set to "true" may record the group maximum PCR transition times for all groups to which it is assigned. When it receives a wake-up frame for which it contains the group ID with which it is associated, it may first check the stored group maximum PCR transition times and determine the difference between its own PCR transition time and the group maximum PCR transition time.

[0190] In another example, a non-AP with its WUROptionImplemented set to "true" could calculate the difference between the group maximum PCR transition time and its own PCR transition time for all groups to which it is assigned and store the difference for each group associated with a GID. When it receives a wake-up frame containing a group ID associated with it, it could first check the stored time difference for the group associated with the GID. The non-AP STA could delay its PCR transition by an amount of time less than or equal to the difference between the group maximum PCR transition time for a particular GID and its own PCR transition time. Alternatively or additionally, it could immediately turn on its PCR components but not attempt to receive packets until a time less than or equal to the difference between the group maximum PCR transition time for a particular GID and its own PCR transition time has passed.

[0191] In another example, if a WUR non-AP STA receives a WUR wake-up frame from its associated WUR AP addressed to the group ID to which the STA is assigned, and if a maximum PCR transition delay for the group ID is indicated by the AP in the WUR mode element, the PCR component of the WUR non-AP STA may be in a doze state until the maximum PCR transition delay for the group ID expires.

[0192] While the embodiments described herein consider 802.11-specific protocols, it should be understood that the embodiments described herein are not limited to this scenario and are also applicable to other wireless systems, such as cellular networks, 4G networks, and 5G (or NR) networks. In the example designs and procedures, SIFS is used to indicate various inter-frame spacings, but all other inter-frame spacings, such as RIFS or other agreed-upon time intervals, may apply to the same solution.

[0193] Although features and elements have been described above in particular combinations, those skilled in the art will understand that each feature or element can be used alone or in any combination with the other features and elements. In addition, the methods described herein may be implemented in a computer program, software, or firmware embodied in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted over wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, 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 in conjunction with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer. [Explanation of symbols]

[0194] 100 Communication Systems 102a Receiver Unit (WTRU) 102b Receiver Unit (WTRU) 102c Receiver Unit (WTRU) 102d Receiver Unit (WTRU) 108 Public Switched Telephone Network (PSTN) 110 Internet 112 Network 114a base station 114b base station 116 Air Interface 118 processors 120 Walkie-Talkie 122 receiving element 124 microphones 126 keypad 128 Touchpad 130 Memory 132 Memory 134 Power supply 136 chipset 138 Peripherals 139 Interference Management Unit 162 Mobility Management Entity (MME) 164 Serving Gateway (SGW) 166 Gateway (or PGW) 182a Mobility Management Function (AMF) 182b Mobility Management Function (AMF) 183a Session Management Facility (SMF) 183b Session Management Facility (SMF) 184a User Plane Function (UPF) 184b User Plane Function (UPF) 185a Data Network (DN) 185b Data Network (DN)

Claims

1. 1. A method for use in a wireless station (STA), comprising: receiving, via the transceiver, a beacon frame or a wake-up-radio (WUR) action frame including a WUR operation element having a first counter value indicating a current value of a basic service set (BSS) parameter update counter; Entering a WUR mode, wherein the STA enters a doze state; receiving a WUR frame including a second counter value; determining, in response to the second counter value being equal to the first counter value, that an update to one or more BSS parameters associated with the BSS of the transceiver is not available; and In response to said determining, remaining in said WUR mode; exiting the WUR mode in response to expiration of a time period; transmitting an uplink frame to the wireless access point (AP) that transmitted the beacon frame or the WUR action frame; A method comprising:

2. 2. The method of claim 1, wherein the action frame is a WUR mode setup frame.

3. 10. The method of claim 1, further comprising activating a wireless radio transceiver in the doze state, the wireless radio transceiver being a companion radio.

4. 2. The method of claim 1, further comprising receiving the WUR frame including the second counter value via the transceiver while the transceiver is in a low power mode.

5. The method of claim 1 , wherein the WUR frame is a broadcast WUR wake-up frame.

6. The method of claim 1 , wherein the WUR frame includes an identifier of the STA.

7. The method of claim 1 , wherein the WUR frame includes identifiers of different STAs.

8. The method of claim 1 , wherein the WUR frame includes a wireless access point (AP) identifier.

9. A wireless station (STA), comprising: Walkie-talkies, and processor the processor configured to maintain a basic service set (BSS) parameter update counter associated with a BSS of the transceiver; the processor is configured to receive a first beacon frame or a wake-up-radio (WUR) action frame including a wake-up-radio (WUR) operation element having a first counter value indicating a current value of the BSS parameter update counter associated with the BSS associated with the transceiver; The processor: updating the BSS parameter update counter to the first counter value received in the WUR operation element; Entering WUR mode, the STA enters a doze state; receiving a WUR frame including a second counter value during the WUR mode; determining, in response to the second counter value being the same as the first counter value, that an update to one or more BSS parameters associated with the BSS of the transceiver is not available; in response to said determining, remaining in said WUR mode; exiting said WUR mode in response to expiration of a time period; Transmitting an uplink frame to the wireless access point (AP) that transmitted the beacon frame or the WUR action frame It is further configured as follows: STA characterized by:

10. The STA of claim 9 , wherein the action frame is a WUR mode setup frame.

11. The STA of claim 9 , further comprising a WUR transceiver that is activated when the STA is in the doze state.

12. 10. The STA of claim 9, wherein the processor is further configured to receive the WUR frame including the second counter value via a PCR transceiver while the transceiver is in a low power mode.

13. The STA of claim 9 , wherein the WUR frame is a broadcast WUR wake-up frame.

14. The STA of claim 9 , wherein the WUR frame includes an identifier of the STA.

15. The STA of claim 9 , wherein the WUR frame includes an identifier of a different STA.

16. The STA of claim 9 , wherein the WUR frame includes an identifier of a wireless access point (AP).

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