Flexible registration of ambient internet of things (IOT) device

Abstract

A wireless transmit / receive unit (WTRU) for flexible registration. The WTRU may send a first registration request message to a network node: receive a first registration accept message from the network node, wherein the first registration accept message indicates a periodic registration timer vaiue and a granted periodic registration eariy time value; and determine a first time period based on the periodic registration timer vaiue and a second time period based on the granted periodic registration early time value. On a condition that the first time period has elapsed, the second time period is pending, and the WTRU has enough energy available to perform a procedure with the network entity, the WTRU may send a second registration request message to the network node. The WTRU may receive a second registration accept message from the network node, wherein the second registration accept message indicates that the WTRU should enter a sieep mode.

Description

Flexible Registration of Ambient Internet of Things (IoT) Device CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No.63 / 444,320, filed February 9, 2023, the contents of which are hereby incorporated by reference herein. BACKGROUND

[0002] Mobile communications using wireless communication continue to evolve. A fifth generation of mobile communication radio access technology (RAT) may be referred to as 5G new radio (NR). A previous (legacy) generation of mobile communication RAT may be, for example, fourth generation (4G) long term evolution (LTE). SUMMARY

[0003] This disclosure describes systems, devices, and methods for providing ambient Internet of Things (IoT) device availability coordination. An ambient IoT device may be a wireless transmit / receive unit (WTRU). This disclosure also describes systems, devices, and methods for providing energy harvesting devices, which may include WTRUs.

[0004] An example wireless transmit / receive unit (WTRU) may include a processor configured to perform one or more actions. The WTRU may send a first registration request message to a network node. The network node may be associated with a network function. The WTRU may receive a first registration accept message from the network node. The first registration accept message may indicate a periodic registration timer value and a granted periodic registration early time value. The WTRU may determine a first time period based on the granted periodic registration early time value and a second time period based on the periodic registration timer value. On a condition that the first time period has elapsed, the second time period is pending, and the WTRU has sufficient energy available to perform a procedure with the network entity, the WTRU may send a second registration request message to the network node. The WTRU may receive a second registration accept message from the network node, wherein the second registration accept message indicates for the WTRU to enter a sleep mode.

[0005] The second registration request message may indicate that the second registration request message is an early periodic registration request. On a condition that the first time period and the second time period have elapsed and the WTRU has not sent the second registration request message, the WTRU may determine that the WTRU has been deregistered.

[0006] At least one of the first registration request message or the second registration request message may indicate that the WTRU supports the periodic registration timer value and the granted periodic registration early time value. The WTRU may be associated with a periodic registration time window value based on an anticipated period that the WTRU will be without power. The periodic registration timer value and the granted periodic registration early time value may be based on the periodic registration time window value.

[0007] The WTRU may be an ambient internet of things (IoT) device. The WTRU may determine that the WTRU has sufficient energy available to perform the procedure with the network node. The WTRU may determine that the WTRU has sufficient energy available to perform the procedure with the network node by determining an energy criterion; determining an amount of energy to be used for a task associated with the procedure; and determining that the amount of energy satisfies the energy criterion. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG.1A is a system diagram illustrating an example communications system in which one or more disclosed embodiments may be implemented.

[0009] FIG.1B is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communications system illustrated in FIG.1A according to an embodiment.

[0010] FIG.1C is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG.1A according to an embodiment.

[0011] FIG.1D is a system diagram illustrating a further example RAN and a further example CN that may be used within the communications system illustrated in FIG.1A according to an embodiment.

[0012] FIG.2 illustrates an example WTRU configuration technique (e.g., so that periodic registration timing is flexible).

[0013] FIG.3 illustrates an example technique for obtaining anticipated downlink data without listening for a page. EXAMPLE NETWORKS FOR IMPLEMENTATION OF THE EMBODIMENTS

[0014] FIG.1A is a diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communicationssystems 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), and the like.

[0015] As shown in FIG.1A, the communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a RAN 104 / 113, a CN 106 / 115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a “station” and / or a “STA”, may be configured to transmit and / or receive wireless signals and may include a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c and 102d may be interchangeably referred to as a UE.

[0016] The communications systems 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106 / 115, the Internet 110, and / or the other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a gNB, a NR NodeB, a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0017] 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 the base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to asa cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for a wireless service to a specific geographical area that may be relatively fixed or that may change over time. The cell may further be divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to transmit and / or receive signals in desired spatial directions.

[0018] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0019] More specifically, as noted above, the communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 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).

[0020] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0021] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR Radio Access , which may establish the air interface 116 using New Radio (NR).

[0022] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for instance using dual connectivity (DC) principles. Thus, the air interface utilized by WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., an eNB and a gNB).

[0023] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA20001X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.

[0024] The base station 114b in FIG.1A may be a wireless router, Home Node B, Home eNode B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a roadway, and the like. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as 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. As shown in FIG.1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 via the CN 106 / 115.

[0025] 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, applications, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106 / 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 that employ 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 be utilizing a NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) employing a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0026] 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 the other networks 112. The PSTN 108 may include circuit- switched telephone networks that provide plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use commoncommunication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP) and / or the internet protocol (IP) in the TCP / IP internet protocol suite. The networks 112 may include wired and / or wireless communications networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 113 or a different RAT.

[0027] 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 the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0028] FIG.1B is a system diagram illustrating an example WTRU 102. As shown in FIG.1B, the WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138, among others. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0029] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. While FIG.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.

[0030] The transmit / receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It willbe appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0031] Although the transmit / receive element 122 is depicted in FIG.1B as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0032] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit / receive element 122 and to demodulate the signals that are received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11, for example.

[0033] 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 organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and / or the removable memory 132. The non-removable memory 130 may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0034] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control the power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like.

[0035] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, the information from the GPS chipset 136, the WTRU 102 may receive location information over the air interface 116 from a base station (e.g., base stations 114a, 114b) and / or determine its location based on the timing of the signals being received from two or more nearby base stations. It willbe appreciated that the WTRU 102 may acquire location information by way of any suitable location- determination method while remaining consistent with an embodiment.

[0036] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photographs and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a Virtual Reality and / or Augmented Reality (VR / AR) device, an activity tracker, and the like. The peripherals 138 may include one or more sensors, the sensors may be one or more of a gyroscope, an accelerometer, a hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0037] The WTRU 102 may include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the UL (e.g., for transmission) and downlink (e.g., for reception) may be concurrent and / or simultaneous. The full duplex radio may include an interference management unit to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WRTU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the UL (e.g., for transmission) or the downlink (e.g., for reception)).

[0038] FIG.1C is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0039] The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a.

[0040] Each of the eNode-Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling ofusers in the UL and / or DL, and the like. As shown in FIG.1C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0041] The CN 106 shown in FIG.1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. While each of the foregoing elements are depicted as part of the CN 106, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0042] The MME 162 may be connected to each of the eNode-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0043] The SGW 164 may be connected to each of the eNode Bs 160a, 160b, 160c in the RAN 104 via the S1 interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring user planes during inter- eNode B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like.

[0044] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0045] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers.

[0046] Although the WTRU is described in FIGS.1A-1D as a wireless terminal, it is contemplated that in certain representative embodiments that such a terminal may use (e.g., temporarily or permanently) wired communication interfaces with the communication network.

[0047] In representative embodiments, the other network 112 may be a WLAN.

[0048] 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 an access or an interface to a Distribution System (DS) or another type of wired / wireless network that carries traffic in to and / or out of the BSS. Traffic to STAs that originates from outside the BSS may arrive through the AP and may be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS may be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. The traffic between STAs within a BSS may be considered and / or referred to as peer-to- peer traffic. The peer-to-peer traffic may be sent between (e.g., directly between) the source and destination STAs with a direct link setup (DLS). In certain representative embodiments, the DLS may use an 802.11e DLS or an 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and the STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may sometimes be referred to herein as an “ad- hoc” mode of communication.

[0049] When using the 802.11ac infrastructure mode of operation or a similar mode of operations, the AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling. The primary channel may be the operating channel of the BSS and may be used by the STAs to establish a connection with the AP. In certain representative embodiments, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) may be implemented, for example in in 802.11 systems. For CSMA / CA, the STAs (e.g., every STA), including the AP, may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0050] High Throughput (HT) STAs may use a 40 MHz wide channel for communication, for example, via a combination of the primary 20 MHz channel with an adjacent or nonadjacent 20 MHz channel to form a 40 MHz wide channel.

[0051] Very High Throughput (VHT) STAs may support 20MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. The 40 MHz, and / or 80 MHz, channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining 8 contiguous 20 MHz channels, or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, the data, after channel encoding, may be passed through a segment parser that may divide the data into two streams. Inverse Fast Fourier Transform (IFFT) processing, and time domain processing, may be done on each stream separately. The streams may be mapped on to the two 80 MHzchannels, and the data may be transmitted by a transmitting STA. At the receiver of the receiving STA, the above described operation for the 80+80 configuration may be reversed, and the combined data may be sent to the Medium Access Control (MAC).

[0052] Sub 1 GHz modes of operation are supported by 802.11af and 802.11ah. The channel operating bandwidths, and carriers, are reduced in 802.11af and 802.11ah relative 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, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non- TVWS spectrum. According to a representative embodiment, 802.11ah may support Meter Type Control / Machine-Type Communications, such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and / or limited bandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0053] WLAN systems, which may support multiple channels, and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include a channel which may be designated as the primary channel. The primary channel may have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA, from among all STAs in operating in a BSS, which supports the smallest bandwidth operating mode. In the example of 802.11ah, the primary channel may be 1 MHz wide for STAs (e.g., MTC type devices) that support (e.g., only support) a 1 MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or Network Allocation Vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, due to a STA (which supports only a 1 MHz operating mode), transmitting to the AP, the entire available frequency bands may be considered busy even though a majority of the frequency bands remains idle and may be available.

[0054] In the United States, the available frequency bands, which may be used by 802.11ah, are from 902 MHz to 928 MHz. In Korea, the available frequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the available frequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.11ah is 6 MHz to 26 MHz depending on the country code.

[0055] FIG.1D is a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment. As noted above, the RAN 113 may employ an 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.

[0056] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 108b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum while the remaining component carriers may be on licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0057] The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using transmissions associated with a scalable numerology. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using subframe or transmission time intervals (TTIs) of various or scalable lengths (e.g., containing varying number of OFDM symbols and / or lasting varying lengths of absolute time).

[0058] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c without also accessing other RANs (e.g., such as eNode-Bs 160a, 160b, 160c). In the standalone configuration, WTRUs 102a, 102b, 102c may utilize one or more of gNBs 180a, 180b, 180c as a mobility anchor point. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration WTRUs 102a, 102b, 102c may communicate with / connect to gNBs 180a, 180b, 180c while also communicating with / connecting to another RAN such as eNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In the non-standalone configuration, eNode-Bs 160a, 160b, 160c may serve as a mobility anchor for WTRUs 102a, 102b, 102c and gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for servicing WTRUs 102a, 102b, 102c.

[0059] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support of network slicing, dual connectivity, interworking between NR and E- UTRA, routing of user plane data towards User Plane Function (UPF) 184a, 184b, routing of control plane information towards Access and Mobility Management Function (AMF) 182a, 182b and the like. As shown in FIG.1D, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0060] The CN 115 shown in FIG.1D may include at least one AMF 182a, 182b, at least one UPF 184a,184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. While each of the foregoing elements are depicted 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.

[0061] 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 serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling of different PDU sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of NAS signaling, mobility management, and the like. Network slicing may be used by the AMF 182a, 182b in order to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for machine type communication (MTC) access, and / or the like. 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.

[0062] The SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN 115 via an N11 interface. The SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN 115 via an N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating UE IP address, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, and the like. A PDU session type may be IP-based, non-IP based, Ethernet- based, and the like.

[0063] The UPF 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 communications between the WTRUs 102a, 102b,102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, and the like.

[0064] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to a local Data Network (DN) 185a, 185b through the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0065] In view of Figures 1A-1D, and the corresponding description of Figures 1A-1D, one or more, or all, of the functions described herein with regard to one or more of: WTRU 102a-d, Base Station 114a-b, eNode-B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-b, UPF 184a-b, SMF 183a-b, DN 185a-b, and / or any other device(s) described herein, may be performed by one or more emulation devices (not shown). The emulation devices may be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, the emulation devices may be used to test other devices and / or to simulate network and / or WTRU functions.

[0066] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and / or in an operator network environment. For example, the one or more emulation devices may perform the one or more, or all, functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. The one or more emulation devices may perform the one or more, or all, functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device may be directly coupled to another device for purposes of testing and / or may performing testing using over-the-air wireless communications.

[0067] The one or more emulation devices may perform the one or more, including all, functions while not being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in a testing scenario in a testing laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network in order to implement testing of one or more components. The one or more emulation devices may be testing equipment. Direct RF coupling and / or wireless communications via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation devices to transmit and / or receive data.DETAILED DESCRIPTION

[0068] This disclosure describes systems, devices, and methods for providing ambient Internet of Things (IoT) device availability coordination. An ambient IoT device may be a wireless transmit / receive unit (WTRU) This disclosure also describes systems, devices, and methods for providing energy harvesting devices, which may WTRUs.

[0069] In an embodiment, a WTRU may be configured by the network so that the WTRU may detect when it may be allowed to perform a periodic registration (e.g., an early periodic registration). The WTRU may be configured with the information about a periodic registration (e.g., an early periodic registration) and may be allowed to perform periodic registration updates (e.g., early Periodic Registration Updates). This may be done, for example, to decrease the chance that a WTRU may not have enough energy to perform the Periodic Registration Update. As another example, this may be done to avoid unwanted implicit registrations.

[0070] In an embodiment, the WTRU may be configured by the network with information about anticipated downlink data so that the WTRU may enter a low state power (e.g., sleep or mobile initiated connection only (MICO) Mode where the WTRU may not need to listen for pages) until after an anticipated arrival time of downlink data. The WTRU may initiate a Service Request procedure without listening for a page and use the Service Request procedure to indicate to the network that the WTRU is ready and able to download the downlink data. By configuring the WTRU with information about anticipated downlink data, the WTRU may be enabled to sleep longer, and the chances that the WTRU may miss downlink data (e.g., because it slept too long, and the data was flushed from the network buffer) may be decreased.

[0071] Reference to a timer herein may refer to determination of a time or determination of a period of time. Reference to a timer expiration herein may refer to determining that the time has occurred or that the period of time has expired. Reference to a timer herein may refer to a time, a time period, tracking the time, tracking the period of time, etc.

[0072] The following abbreviations and acronyms are used here: AF Application Function AMF Access and Mobility Function CM Connection Management IoT Internet of Things MICO Mobile Initiated Connection Only MM Mobility Management NAS Non-Access StratumNEF Network Exposure Function RM Registration Management RRC Radio Resource Control SDM Subscriber Data Management SMF Session Management UDM User Data Management UDR User Data Repository UE User Equipment UPF User Plane Function WTRU Wireless Transmit Receive Unit

[0073] Feature(s) associated with wireless transmit / receive unit (WTRU) registration flexibility are provided herein.

[0074] Feature(s) associated with an ambient IoT device (e.g., WTRU) are provided herein. An example ambient IoT device may send a registration request to a network. The example ambient IoT device may receive a registration accept message from the network. The registration accept message may include a granted periodic registration early time value (e.g., a granted periodic registration EARLY TIME value) and a periodic registration timer value (e.g., a T3512 timer).

[0075] The example ambient IoT device may enter a CM-IDLE state. The example ambient IoT device may start one or more timers (e.g., two timers). An example timer (e.g., a first timer) may be configured based on the granted periodic registration early time value (e.g., the granted periodic registration EARLY TIME value). An example timer (e.g., a second timer) may be configured based on the periodic registration timer value (e.g., a T3512 timer).

[0076] The example ambient IoT device may determine to send a second registration request to the network. The determination may be made based on one or more conditions being met. For example, the example ambient IoT device may determine to send the second registration request if the following three conditions are met: the first timer has expired, the second timer has not expired (e.g., is ongoing or pending), and enough energy is available to perform a procedure with the network.

[0077] The example ambient IoT device may send the second registration request to the network. The second registration request may indicate that the registration request is an early periodic registration request.

[0078] The example ambient IoT device may receive a second registration accept message from the network. The second registration accept message may trigger the WTRU to enter the CM-IDLE state.

[0079] The registration request message(s) (e.g., the first and / or second registration request messages) may indicate to the network that the ambient IoT device supports a periodic registration window feature.

[0080] The registration request message(s) (e.g., the first and / or second registration request messages) may include a requested periodic registration time value and / or a requested periodic registration early time value (e.g., a requested periodic registration EARLY TIME value).

[0081] The WTRU may be in the CM-IDLE state when the first timer expires.

[0082] Feature(s) associated with WTRU anticipated downlink data are provided herein.

[0083] An example ambient IoT device (e.g., a WTRU) may send a registration request to the network.

[0084] The ambient IoT device may receive a registration accept message from the network. The registration accept message may include an anticipated downlink data time. The registration accept message may include a periodic registration timer (e.g., a T3512 timer).

[0085] The ambient IoT device may enter the CM-IDLE state.

[0086] The ambient IoT device may determine to send a service request to the network. The determination may be made based on one or more conditions being met. For example, the ambient IoT device may determine to send the service request if the current time is equal to or past the anticipated downlink data time and / or if enough energy is available to perform a procedure with the network.

[0087] The ambient IoT device may send the service request to the network. The service request may be sent to the network to retrieve buffered data that was anticipated.

[0088] The ambient IoT device may receive a service accept message from the network. The service accept message may indicate the status of the buffered data.

[0089] The registration request may indicate (e.g., to the network) that the ambient IoT device supports sending a service request to the network that is triggered by an anticipated downlink data timer.

[0090] The registration accept message may include a buffer expiration time. The WTRU may use the buffer expiration time to determine whether to send the service request message. The WTRU may determine to send the service request message if (e.g., only if) the current time is less than the buffer expiration time.

[0091] The registration accept message may include a reference identifier (ID) that represents or identifies a location in the network where the buffered data will be stored. The WTRU may include the reference ID in the service request to indicate to the network the buffer to which the service request relates.

[0092] The service accept message may indicate to the ambient IoT device (e.g., WTRU) that buffered data is available. The service accept message may indicate that the ambient IoT device may establish a user plane connection.

[0093] The service accept message may indicate to the ambient IoT device (e.g., WTRU) that the buffered data is no longer available in the buffer.

[0094] The service accept message may indicate to the ambient IoT device (e.g., WTRU) that the network never received the buffered data.

[0095] The service accept message may include information about the priority of the buffered data. For example, the network may determine the priority of the buffered data based on the identity of the data source, how much time remains until the data in the buffer is discarded (e.g., if the data is to be discarded soon, then the data may be considered higher in priority), or a combination thereof. The ambient IoT device may use the priority information to help determine how and whether to use stored energy to receive the data.

[0096] The service accept message may include information about the buffered data. For example, the network may indicate if the buffered data is to be delivered over the user plane or the control plane, the amount of buffered data, and / or the like. The ambient IoT device may use the information about the buffered data to determine how and / or whether to use stored energy to receive the data.

[0097] The service accept message may include information about the Quality of Service (QoS) requirements of a (e.g., any) response sent by the ambient IoT device for the buffered data. The ambient IoT device may use this information to help determine when, how, and / or whether to use stored energy to send a response (e.g., an acknowledgement) after receiving the buffered data.

[0098] Feature(s) associated with registration timers are provided herein.

[0099] A WTRU may initiate a registration procedure by sending a registration request (e.g., at the expiry of a periodic registration timer). The purpose of the registration procedure may be to let the network know that the WTRU is still active.

[0100] An access and mobility function (AMF) may send the periodic registration timer value to the WTRU based on local policies, subscription information, and / or information provided by the WTRU. The periodic registration timer value may be sent to the WTRU by the AMF in the registration accept message.

[0101] If a WTRU in a RM-REGISTERED state enters the CM-IDLE state, the WTRU may start a periodic registration timer (e.g., according to the periodic registration timer value received from the AMF). If the periodic registration timer expires, the WTRU may send a registration request to the AMF to inform the network that the WTRU is still active.

[0102] If a WTRU in the RM-REGISTERED state enters the CM-IDLE state, the AMF may start a mobile reachable timer (e.g., according to the periodic registration timer value sent to the WTRU). If the AMF receives a registration request from the WTRU before the mobile reachable timer expires, the AMF may stop the timer. If the timer expires before the WTRU sends a registration request to the AMF, the AMF may start a second timer. The second timer may be referred to as an implicit de-registration timer. If the implicit de-registration timer expires before the WTRU contacts the network, the AMF may (e.g., implicitly) de- register the WTRU. The implicit de-registration timer may give (e.g., may effectively give) the WTRU extra time to contact the network before the network implicitly de-registers the WTRU.

[0103] The WTRU may stop the periodic registration timer if (e.g., each time) the WTRU enters the CM- CONNECTED state. The WTRU may restart the timer if (e.g., each time) the WTRU re-enters the CM-IDLE state. If the WTRU does not stay in the CM-IDLE state for long periods of time, the WTRU may not perform or may rarely perform a registration update procedure. A system, such as a fifth generation (5G) system, may support a feature called “strictly periodic registration timer indication.” If the strictly periodic registration timer indication feature is activated, the AMF may send a strictly periodic registration timer indication to the WTRU in the registration accept message. The strictly periodic registration timer indication may cause the WTRU to refrain from stopping and / or restarting the periodic registration timer when the WTRU enters the CM-CONNECTED state. For example, the WTRU may keep the periodic registration timer running while in the CM-CONNECTED state and after returning to the CM-IDLE state. If the WTRU is in the CM-IDLE state when the timer expires, the WTRU may initiate a registration procedure. If the WTRU is in the CM- CONNECTED state when the timer expires, the WTRU may restart the periodic registration timer and may not initiate a registration procedure. The strictly periodic registration timer indication feature may allow the network to configure the WTRU to be reachable for downlink data at known times and in known time intervals.

[0104] The registration procedure may be a type of non-access stratum mobility management (NAS- MM) procedure.

[0105] The WTRU configuration update procedure may be used to send the periodic registration timer value and / or the strictly periodic registration timer indication to the WTRU.

[0106] The WTRU configuration update procedure may be a type of NAS-MM procedure.

[0107] Feature(s) associated with an extended connected time are provided herein.

[0108] If the network (e.g., the AMF) anticipates that downlink data will be (e.g., will soon need to be) sent to the WTRU, the AMF may keep the WTRU in the CM-CONNECTED state, and the RAN may keep the WTRU in the RRC-CONNECTED state for an extended connected time period (e.g., to ensure thedownlink data is delivered to the WTRU). The extended connected time value may indicate a minimum time for the RAN to keep the WTRU in the RRC-CONNECTED state (e.g., regardless of inactivity).

[0109] The AMF may send the extended connected time value to the RAN. For example, the AMF may send the extended connected time value to the RAN when the AMF sends a registration accept message or a service accept message to the WTRU.

[0110] Providing the extended connected time to the RAN may keep the WTRU in the RRC- CONNECTED state. If the WTRU were to enter the RRC-IDLE state, the WTRU may have to be paged before the downlink data can be sent, or the network may have to wait for the WTRU to come out of mobile initiated connection only (MICO) mode before the data can be sent.

[0111] The extended connected time may be determined by the AMF (e.g., based on local configuration or information that was sent to the AMF by a unified data manager (UDM)). The UDM may obtain information about the expected downlink data from an application function (AF).

[0112] Feature(s) associated with a service request are provided herein.

[0113] If the WTRU is in the CM-IDLE and RM-REGISTERED states, the WTRU may send a service request message to the network to transition to the CM-REGISTERED state and establish user plane resources. The WTRU may determine to send the service request message if the WTRU has uplink data to send. The WTRU may determine to send the service request message if the WTRU detects that the WTRU is being paged by the network.

[0114] The service request procedure may be a type of NAS-MM procedure.

[0115] Feature(s) associated with ambient IoT devices, which may be WTRUs, are provided herein.

[0116] An example ambient IoT device may be a WTRU and may have one or more of the following characteristics (e.g., capabilities): harvest energy from the environment; have no battery or long-term energy storage capabilities; have power available intermittently (e.g., only intermittently); have (e.g., only have) enough energy to communicate with the network at unpredictable times (e.g., because the time at which the device may harvest energy from the environment is unpredictable); may not be able to listen to the network for network-initiated indications (e.g., paging); and / or may be (e.g., may only be able to be) active for short periods of time.

[0117] If a WTRU is in the CM-IDLE state for too long of a time (e.g., without entering the CM- CONNECTED state to perform a registration procedure), the WTRU may be (e.g., implicitly) de-registered by the network. An ambient IoT device may not have sufficient power to perform the registration procedure when a periodic registration timer expires. The ambient IoT device may be (e.g., implicitly) de-registered by the network. De-registration (e.g., implicit de-registration) events may be costly to the ambient IoT deviceand the network because an initial registration and establishment (e.g., a new initial registration and establishment) of the ambient IoT device context may be required for the ambient IoT device to use the network again.

[0118] The network (e.g., AMF) may be configured with information so that the network may know time period(s) when downlink data for the WTRU is expected to arrive at the network. The strictly periodic registration timer indication may be used (e.g., by the 5G system) to configure the WTRU so that the WTRU will leave the CM-IDLE state at predictable times and perform a registration procedure with the network. The network may be able to trigger the delivery of the downlink data (e.g., once the registration procedure is complete). An ambient IoT device may not have sufficient power to perform the registration procedure when the periodic registration timer expires. The ambient IoT device may not wake up to receive the downlink data.

[0119] If the network (e.g., AMF) anticipates that downlink data will be (e.g., will soon need to be) sent to the WTRU, the AMF may keep the WTRU in the CM-CONNECTED state until the downlink data is available to be sent to the WTRU. The ambient IoT device may not have sufficient power available to stay in the RRC-CONNECTED state for an extended time. The ambient IoT device may run out of power while waiting for the downlink data to be delivered.

[0120] An example registration technique is provided herein. The registration technique may be optimized to decrease the risk that an ambient IoT device will miss a periodic registration update procedure and be (e.g., implicitly) de-registered. The registration technique may allow the network to maintain control over when the ambient IoT device performs periodic registration updates.

[0121] The registration technique may allow the network to inform the ambient IoT device (e.g., a WTRU) about anticipated downlink data (e.g., so that the WTRU may perform a service request without listening for a page from the network). The ambient IoT device may indicate to the network that the service request was triggered based on an anticipated downlink data notification (e.g., as opposed to an explicit page).

[0122] Feature(s) associated with downlink data optimization are provided herein.

[0123] Feature(s) associated with registration flexibility for ambient IoT devices are provided herein. An ambient IoT device may be a wireless transmit / receive unit (WTRU). An example wireless transmit / receive unit (WTRU) may include a processor configured to perform one or more actions. The WTRU may send a first registration request message to a network node. The network node may be associated with a network function. The WTRU may receive a first registration accept message from the network node. The first registration accept message may indicate a periodic registration timer value and a granted periodic registration early time value. The WTRU may determine a first time period based on the granted periodicregistration early time value and a second time period based on the periodic registration timer value. On a condition that the first time period has elapsed, the second time period is pending, and the WTRU has sufficient energy available to perform a procedure with the network entity, the WTRU may send a second registration request message to the network node. The WTRU may receive a second registration accept message from the network node, wherein the second registration accept message indicates for the WTRU to enter a sleep mode.

[0124] The second registration request message may indicate that the second registration request message is an early periodic registration request. On a condition that the first time period and the second time period have elapsed and the WTRU has not sent the second registration request message, the WTRU may determine that the WTRU has been deregistered.

[0125] At least one of the first registration request message or the second registration request message may indicate that the WTRU supports the periodic registration timer value and the granted periodic registration early time value. The WTRU may be associated with a periodic registration time window value based on an anticipated period that the WTRU will be without power. The periodic registration timer value and the granted periodic registration early time value may be based on the periodic registration time window value.

[0126] The WTRU may be an ambient internet of things (IoT) device. The WTRU may determine that the WTRU has sufficient energy available to perform the procedure with the network node. The WTRU may determine that the WTRU has sufficient energy available to perform the procedure with the network node by determining an energy criterion; determining an amount of energy to be used for a task associated with the procedure; and determining that the amount of energy satisfies the energy criterion.

[0127] A WTRU (e.g., also sometimes referred to herein as an ambient IoT device) may determine (e.g., choose) to perform a periodic registration update (e.g., before the periodic registration time expires). Performing the periodic registration early may lead to more registration messages over time (e.g., in terms of overall signaling). Performing the registration procedure early may decrease the chance that the ambient IoT device will miss a registration procedure (e.g., because the ambient IoT device does not have enough energy to perform the procedure when the timer expires).

[0128] It may be sub-optimal (e.g., from a system design perspective) to allow the ambient IoT device to arbitrarily perform the registration procedure early without parameters (e.g., allowing the WTRU to use an arbitrary amount of time). For example, an ambient IoT device may (e.g., by design) determine to perform the periodic registration procedure by an unnecessarily large amount of time (e.g., to avoid an unwanted implicit de-registration).

[0129] FIG.2 illustrates an example technique for the ambient IoT device to perform early registrations (e.g., while preventing the ambient IoT device from performing registrations that are unnecessarily early). The network may provide the WTRU with a timer value that indicates how early the WTRU is permitted to initiate a periodic registration procedure. The network may indicate how much time in advance of the periodic registration timer expiring the ambient IoT device is allowed to perform the periodic registration update procedure.

[0130] At 201, an AF may send information about the ambient IoT device type to the network. The information may be a time value representing how long the ambient IoT device can be expected to go without power. The device may be associated with a periodic registration time window value based on an anticipated period that the WTRU will be without power. For example, if the ambient IoT device harvests energy from vibrations on a road, and the road is unlikely to go more than four hours without accommodating traffic, then the value that the AF provides may be four hours. In this example, the AF may indicate that the ambient IoT device is unlikely to go more than four hours without power. This value may be referred to as the “recommended periodic registration TIME WINDOW value.” The periodic registration timer value and the granted periodic registration early time value may be based on the periodic registration time window value. The recommended periodic registration time window value (e.g., recommended periodic registration TIME WINDOW value) may be sent from the AF to the NEF, from the NEF to the UDM, and stored in the ambient IoT device’s subscription data in the unified data repository (UDR) by the UDM. The NEF may choose to send the recommended periodic registration time window value (e.g., recommended periodic registration TIME WINDOW value) to the UDR via the UDM (e.g., rather than directly to the UDR) so that the UDM may verify that the recommended periodic registration TIME WINDOW value is within an allowed range. For example, an Nnef_ParameterProvision procedure may be enhanced to allow the AF to provide the network the recommended periodic registration time window value (e.g., recommended periodic registration TIME WINDOW value).

[0131] At 202, the ambient IoT device may send a registration request to the network (e.g., to a network node associated with a network function, for example the AMF). The ambient IoT device may indicate that the registration request type is “initial registration” or “mobility registration,” for example. The ambient IoT device may indicate to the AMF (e.g., in the registration request) that the ambient IoT device supports a “periodic registration window” feature, a “requested periodic registration time value,” and / or a “requested periodic registration early time value” (e.g., a “requested periodic registration EARLY TIME value”).

[0132] At 203 (e.g., as part of the registration procedure), the AMF may use the Nudm_SDM_Get application programming interface (API) of the UDM to obtain subscription information for the ambient IoT device. The subscription information may include a “recommended periodic registration time value” and / ora “recommended periodic registration time window value” (e.g., a “recommended periodic registration TIME WINDOW value”).

[0133] At 204, the AMF may use the recommended periodic registration time value and the recommended periodic registration time window value (e.g., recommended periodic registration TIME WINDOW value) from the UDM, and / or the requested periodic registration time value and a requested periodic registration early time value (e.g., a requested periodic registration EARLY TIME value) from the WTRU, to determine a periodic registration timer (e.g., a T3512 timer) and a “granted periodic registration early time value” (e.g., a “granted periodic registration EARLY TIME value”). The AMF may send (e.g., to the ambient IoT device / WTRU), and the WTRU may receive, a registration accept message. The registration accept message may include the periodic registration timer value (e.g., a T3512 timer) and / or the granted periodic registration early timer value (e.g., the granted periodic registration EARLY TIME value).

[0134] At 205, the ambient IoT device may enter the CM-IDLE state and start one or more timers (e.g., two timers). The device may determine a first time period based on the granted periodic registration early time value and a second time period based on the periodic registration timer value. For example, the first time period may be based on the granted periodic registration early time value and the second time period may be based on the periodic registration timer value (e.g., a T3512 timer). At 205, the ambient IoT device may determine to perform another procedure. For example, at 205 the ambident IoT device may determine to send a (e.g., another) registration request message to the network node (e.g., may proceed to 206) if (e.g., on a condition that) the first timer / time period (e.g., based on the granted periodic registration early value) has expired, the second timer / time period (e.g., based on the periodic registration timer value) is ongoing / pending, and the WTRU determines that the WTRU has enough (e.g., sufficient) energy to perform a procedure with the network node (e.g., to perform the periodic registration procedure). The WTRU may determine that the WTRU has sufficient energy available to perform the procedure with the network node by determining an energy criterion; determining an amount of energy to be used for a task associated with the procedure; and determining that the amount of energy satisfies the energy criterion.

[0135] At 206, the ambient IoT device may send a registration request to the network (e.g., if the first time period has elapsed, the second time period is ongoing, and the WTRU has sufficient energy available to perform a procedure with the network node). If the second timer / time period (e.g., the T3512 timer) (and the first timer / time period) has / have expired / elapsed (e.g., and the WTRU has not sent the second registration request message), the ambient IoT device / WTRU may determine that the ambient IoT device / WTRU has been (e.g., implicitly or explicitly) de-registered and set the registration type of the registration request to “initial.” If the first timer (e.g., the T3512 timer) has not expired, the ambient IoTdevice may determine that the ambient IoT device has not yet been (e.g., implicitly or explicitly) de- registered. The registration request message may indicate that the registration request message is an early periodic registration request (e.g., the WTRU may set the registration type of the registration request to “periodic-early”) The registration request may include an indication that the ambient IoT device (e.g., WTRU) supports the periodic registration timer value and the granted periodic registration early time value (e.g., supports a periodic registration window feature, a requested periodic registration time value, and / or a requested periodic registration early time value).

[0136] At 207, the AMF may send (e.g., to the WTRU), and the WTRU may receive, a (e.g., another) registration accept message to the WTRU. The registration accept message may include the periodic registration timer (e.g., the T3512 timer) and / or the granted periodic registration early value. The registration accept message may indicate for the WTRU to enter a sleep mode (e.g., may trigger the WTRU to enter the CM-IDLE state). The ambient IoT device may restart the periodic registration timer (e.g., the T3512 timer) and the periodic registration early time value timer. At the network side, both timers may be restarted.

[0137] Feature(s) associated with wireless transmit / receive unit (WTRU) registration flexibility are provided herein.

[0138] Feature(s) associated with an ambient IoT device (e.g., WTRU) are provided herein. An example ambient IoT device may send a registration request to a network. The example ambient IoT device may receive a registration accept message from the network. The registration accept message may include a granted periodic registration early time value and a periodic registration timer (e.g., a T3512 timer).

[0139] The example ambient IoT device may enter a CM-IDLE state. The example ambient IoT device may start one or more timers (e.g., two timers). An example timer (e.g., a first timer) may be configured based on the granted periodic registration early time value. An example timer (e.g., a second timer) may be configured based on the periodic registration timer (e.g., a T3512 timer).

[0140] The example ambient IoT device may determine to send a second registration request to the network. The determination may be made based on one or more conditions being met. For example, the ambient IoT device may determine to send the second registration request if the following three conditions are met: the first timer has expired, the second timer has not expired, and sufficient (e.g., enough) energy is available to perform a procedure with the network.

[0141] The ambient IoT device may send the second registration request to the network. The second registration request may indicate that the registration request is an early periodic registration request.

[0142] The ambient IoT device may receive a second registration accept message from the network. The second registration accept message may indicate for the WTRU to enter a sleep mode (e.g., may trigger the WTRU to enter the CM-IDLE state).

[0143] The registration request message(s) (e.g., the first and / or second registration request messages) may indicate to the network that the ambient IoT device supports a periodic registration window feature.

[0144] The registration request message(s) (e.g., the first and / or second registration request messages) may include a requested periodic registration time value and / or a requested periodic registration early time value.

[0145] The WTRU may be in the CM-IDLE state when the first timer expires.

[0146] Feature(s) associated with anticipated downlink data for ambient IoT devices are provided herein. An example wireless transmit / receive unit (WTRU) may include a processor configured to perform one or more actions. The WTRU may send a registration request to a network node. The network node may be associated with a network function. The WTRU may receive a registration accept message from the network node. The registration accept message may include / indicate an anticipated downlink data time value. On a condition that a time value is equal to or after the anticipated downlink data time value and the WTRU has sufficient energy available to perform a procedure with the network node, the WTRU may send a service request message to the network node. The service request message may indicate that the WTRU is attempting to retrieve buffered data stored in a buffer. The WTRU may receive a service accept message from the network node. The service accept message may indicate a status of the buffered data.

[0147] The registration accept message may include a buffer expiration time value. The WTRU may send the service request message based on the time value and the buffer expiration time value. At least one of the registration accept message or the service request message may include a reference identifier that identifies a storage location of the buffered data.

[0148] The service accept message may indicate that: the buffered data is available and for the WTRU to establish a user plane connection; the buffered data is no longer available in the buffer; or the buffered data was not received by the network node. The service accept message may indicate information about a priority of the buffered data. The service accept message may indicate at least one of: a size of the buffered data, or whether the buffered data is to be delivered over a user plane or a control plane.

[0149] The WTRU may receive the buffered data. The WTRU may determine whether to send an acknowledgment message based on quality of service (QoS) information associated with sending the acknowledgment message. The service accept message may indicate the QoS information.

[0150] If a WTRU (e.g., also sometimes referred to herein as an ambient IoT device) performs a periodic registration procedure with the network, the AMF may keep the WTRU in the RRC-CONNECTED mode in anticipation of pending downlink data.

[0151] FIG.3 illustrates an example approach to handling the case in which downlink data is anticipated for an ambient IoT device. FIG.3 an example in which the network provides an anticipated downlink time to the WTRU in the registration accept message (e.g., and does not provide an extended wait time value to the RAN). The WTRU may be able to (e.g., immediately) enter the CM-IDLE state or dormant state and begin to save power. The ambient IoT device may wait until after the anticipated downlink time to contact the network and receive the downlink data. The downlink data may be buffered in the network in case the ambient IoT device waits (e.g., needs to wait) until after (e.g., long after) the anticipated downlink time to contact the network (e.g., to ensure that the ambient IoT device has enough energy stored to contact the network). If the anticipated downlink time has passed and the ambient IoT device has enough energy stored to contact the network, the ambient IoT device may send a service request message to the network. The service request message may indicate to the network that the purpose of the service request message is to download anticipated downlink data.

[0152] As shown in FIG.3, at 301, an AF may send information about the ambient IoT device type to the network. The information may include an anticipated communication time. The anticipated communication time value may be sent from the AF to the NEF, from the NEF to the UDM, and stored in the ambient IoT device’s subscription data in the UDR by the UDM. The NEF may choose to send the anticipated communication time value to the UDR via the UDM (e.g., rather than directly to the UDR) so that the UDM can verify that the anticipated communication time value is within an allowed range. For example, an Nnef_ParameterProvision procedure may be used to send expected WTRU behavior parameters to the network.

[0153] At 302, the ambient IoT device may send a registration request message to the network (e.g., to a network node associated with a network function). For example, the ambient IoT device may determine to send the registration request because a periodic registration timer expired. The registration request may include an indication to the network that the ambient IoT device supports sending a service request message to the network that is triggered by anticipated downlink data.

[0154] At 303 (e.g., as part of registration), the AMF may use the Nudm_SDM_Get API of the UDM to obtain subscription information for the ambient IoT device. The subscription information may include the anticipated downlink data time.

[0155] At 304, the AMF may send, to the WTRU, (e.g., and the WTRU may receive) a registration accept message. The registration accept message may include one or more of the following information.

[0156] The registration accept message may include an anticipated downlink data time value. By providing the anticipated downlink data time, the ambient IoT device may be able to (e.g., more quickly) return to a sleep (e.g., CM-IDLE) state, re-connect to the network, and download the data from a network buffer at a later time (e.g., after the anticipated downlink data time).

[0157] The registration accept message may include an indication that the WTRU may perform a service request any time after the anticipated downlink data time. The presence of the anticipated downlink data time in the registration accept message may serve as this indication.

[0158] The registration accept message may include a buffer expiration time value that indicates how long, or until what time, the network is willing to buffer the data. The ambient IoT device may use the buffer expiration information to determine if the ambient IoT device may attempt to retrieve the buffered data. For example, if the ambient IoT device has enough energy to communicate with the network, but the network has discarded the buffered data, the ambient IoT device may not continue to initiate the service request.

[0159] The registration accept message may include a reference identifier (ID) that identifies (e.g., represents) a storage location of the buffered data (e.g., the location where the network will store the buffered data). The reference ID may be a value that the network is able to resolve to an SMF ID, UPF ID, UDSF ID, or PDU session ID.

[0160] The registration accept message may include data for the ambient IoT device. For example, the network may send some (or all) of the data buffered for the ambient IoT device in the registration accept message.

[0161] If data is included in the registration accept message, the registration accept message may include an indication of whether more data remains in the buffer for the WTRU to receive. If the network indicates that there is no more data to receive, the ambient IoT device may be able to return to a sleep state (e.g., more quickly).

[0162] At 305, downlink data for the ambient IoT device may arrive at the network. The data may be buffered in the network (e.g., in an SMF or UPF).

[0163] At 306, the ambient IoT device may be in the CM-IDLE state (e.g., and may have been in the CM-IDLE state since receiving the registration accept message). The ambient IoT device may wait until the anticipated downlink data time. On a condition that a time value (e.g., a current time value) is equal to or after the anticipated downlink data time value and the WTRU has sufficient energy available to perform a procedure with the network node, the WTRU may send a service request message to the network node. For example, if the anticipated downlink data time is detected (e.g., the anticipated downlink data time has elapsed), the ambient IoT device may wait until the ambient IoT device determines that sufficient (e.g., enough) energy is available to perform a procedure with the network. If the ambient IoT device hassufficient (e.g., enough) energy to perform a procedure with the network, and the buffer expiration time has not elapsed (e.g., has not passed), the ambient IoT device may take further action (e.g., proceed to 307 and send a service request message to the network).

[0164] At 307, the ambient IoT device may send a service request message to the network. A service type information element in the service request message may indicate (e.g., to the network) that the WTRU is attempting to retrieve buffered data stored in a buffer (e.g., that the service request's purpose is to retrieve anticipated buffered data). The service request message may include one or more reference ID(s) (e.g., received at 304).

[0165] At 308, the ambient IoT device may receive a service accept message from the network node. The service accept message may indicate (e.g., to the ambient IoT device) a status of the buffered data. For example, the service accept message may indicate that the buffered data is available and / or that the ambient IoT device may establish a user plane connection or that an existing user plane connection has been activated. The service accept message may indicate to the ambient IoT device that the buffered data is no longer available in the buffer or was not (e.g., was never) received by the network (e.g., triggering the ambient IoT device to return to the CM-IDLE (or sleep) state).

[0166] At 309, the AMF may use the reference ID to determine where the data is buffered. The AMF may trigger delivery of the data from the buffer to the ambient IoT device.

[0167] At 310, the WTRU may receive the buffered data (e.g., the buffered downlink data).

[0168] The network may send the anticipated downlink data time, an indication that the WTRU may perform a service request any time after the anticipated downlink data time, a buffer expiration time, and / or a reference ID to the WTRU in a registration accept message. This information may be sent to the ambient IoT device in a WTRU configuration update command. If the ambient IoT device receives the information in a WTRU configuration update command, the actions described at 306 through 310 may be triggered. The network may determine to send the WTRU configuration update command to the ambient IoT device if the network is aware of anticipated downlink data and the WTRU is in the CM-CONNECTED state.

[0169] Feature(s) associated with WTRU anticipated downlink data are provided herein.

[0170] An example ambient IoT device (e.g., a WTRU) may send a registration request to the network.

[0171] The ambient IoT device may receive a registration accept message from the network. The registration accept message may include an anticipated downlink data time. The registration accept message may include a periodic registration timer (e.g., a T3512 timer).

[0172] The ambient IoT device may enter the CM-IDLE state.

[0173] The ambient IoT device may determine to send a service request to the network. The determination may be made based on one or more conditions being met. For example, the ambient IoT device may determine to send the service request if the current time is equal to or past the anticipated downlink data time and / or if enough energy is available to perform a procedure with the network.

[0174] The ambient IoT device may send the service request to the network. The service request may be sent to the network to retrieve buffered data that was anticipated.

[0175] The ambient IoT device may receive a service accept message from the network. The service accept message may indicate the status of the buffered data.

[0176] The registration request may indicate (e.g., to the network) that the ambient IoT device supports sending a service request to the network that is triggered by an anticipated downlink data timer.

[0177] The registration accept message may include a buffer expiration time. Sending the service request message may be based on the buffer expiration time value and / or the time value (e.g., current time). For example, the WTRU may use the buffer expiration time to determine whether to send the service request message. The WTRU may determine to send the service request message if (e.g., only if) the time value (e.g., the current time) is less than the buffer expiration time.

[0178] The registration accept message may include a reference identifier (ID) that represents or identifies a location in the network where the buffered data will be stored. The WTRU may include the reference ID in the service request to indicate to the network the buffer to which the service request relates.

[0179] The service accept message may indicate to the ambient IoT device (e.g., WTRU) that buffered data is available. The service accept message may indicate that the ambient IoT device may establish a user plane connection. The service accept message may indicate to the ambient IoT device (e.g., WTRU) that the buffered data is no longer available in the buffer. The service accept message may indicate to the ambient IoT device (e.g., WTRU) that the network never received the buffered data.

[0180] The service accept message may include information about the priority of the buffered data. For example, the network may determine the priority of the buffered data based on the identity of the data source, how much time remains until the data in the buffer is discarded (e.g., if the data is to be discarded soon, then the data may be considered higher in priority), or a combination thereof. The ambient IoT device may use the priority information to help determine how and whether to use stored energy to receive the data.

[0181] The service accept message may include information about the buffered data. For example, the network may indicate if the buffered data is to be delivered over the user plane or the control plane, a size (e.g., the amount) of the buffered data, and / or the like. The ambient IoT device may use the information about the buffered data to help determine how and whether to use stored energy to receive the data.

[0182] The service accept message may indicate Quality of Service (QoS) information (e.g., may include information about the QoS requirements) of a (e.g., any) response that the ambient IoT device may send for the buffered data. The ambient IoT device may determine whether to send an acknowledgment message based on the QoS information associated with sending the acknowledgment message. For example, the ambient IoT device may use this information to help determine when, how, and whether to use stored energy to send a response (e.g., an acknowledgement) after receiving the buffered data.

[0183] Although features and elements described herein are described in particular combinations, each feature or element may be used alone without the other features and elements of the preferred embodiments, or in various combinations with or without other features and elements.

[0184] Although the implementations described herein may consider 3GPP specific protocols, it is understood that the implementations described herein are not restricted to this scenario and may be applicable to other wireless systems. For example, although the solutions described herein consider LTE, LTE-A, New Radio (NR) or 5G specific protocols, it is understood that the solutions described herein are not restricted to this scenario and are applicable to other wireless systems as well.

[0185] The processes described herein may be implemented in a computer program, software, and / or firmware incorporated in a computer-readable medium for execution by a computer and / or processor. Examples of computer-readable media include, but are not limited to, electronic signals (transmitted over wired and / or wireless connections) and / or computer-readable storage media. Examples of computer- readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as, but not limited to, internal hard disks and removable disks, magneto-optical media, and / or optical media such as compact disc (CD)-ROM disks, and / or digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, terminal, base station, RNC, and / or any host computer.

Claims

What is Claimed:

1. A wireless transmit / receive unit (WTRU), the WTRU comprising: a processor configured to: send a first registration request message to a network node, wherein the network node is associated with a network function; receive a first registration accept message from the network node, wherein the first registration accept message indicates a periodic registration timer value and a granted periodic registration early time value; determine a first time period based on the granted periodic registration early time value and a second time period based on the periodic registration timer value; on a condition that the first time period has elapsed, the second time period is ongoing, and the WTRU has sufficient energy available to perform a procedure with the network node, send a second registration request message to the network node; and receive a second registration accept message from the network node, wherein the second registration accept message indicates for the WTRU to enter a sleep mode.

2. The WTRU of claim 1, wherein the second registration request message indicates that the second registration request message is an early periodic registration request.

3. The WTRU of claim 1, wherein the processor is further configured to, on a condition that the first time period and the second time period have elapsed and the WTRU has not sent the second registration request message, determine that the WTRU has been deregistered.

4. The WTRU of claim 1, wherein at least one of the first registration request message or the second registration request message indicates that the WTRU supports the periodic registration timer value and the granted periodic registration early time value.

5. The WTRU of claim 1, wherein the WTRU is associated with a periodic registration time window value based on an anticipated period that the WTRU will be without power, and wherein the periodic registration timer value and the granted periodic registration early time value are based on the periodic registration time window value.

6. The WTRU of claim 1, wherein the WTRU is an ambient internet of things (IoT) device.

7. The WTRU of claim 1, wherein the processor is further configured to determine that the WTRU has sufficient energy available to perform the procedure with the network node.

8. The WTRU of claim 7, wherein the processor being configured to determine that the WTRU has sufficient energy available to perform the procedure with the network node comprises the processor being configured to: determine an energy criterion; determine an amount of energy to be used for a task associated with the procedure; and determine that the amount of energy satisfies the energy criterion.

9. A method, performed by a wireless transmit / receive unit (WTRU), the method comprising: sending a first registration request message to a network node, wherein the network node is associated with a network function; receiving a first registration accept message from the network node, wherein the first registration accept message indicates a periodic registration timer value and a granted periodic registration early time value; determining a first time period based on the granted periodic registration early time value and a second time period based on the periodic registration timer value; on a condition that the first time period has elapsed, the second time period is ongoing, and the WTRU has sufficient energy available to perform a procedure with the network node, sending a second registration request message to the network node; and receiving a second registration accept message from the network node, wherein the second registration accept message indicates for the WTRU to enter a sleep mode.

10. The method of claim 9, wherein the second registration request message indicates that the second registration request message is an early periodic registration request.

11. The method of claim 9, wherein the method further comprises, on a condition that the first time period and the second time period have elapsed and the WTRU has not sent the second registration request message, determining that the WTRU has been deregistered.

12. The method of claim 9, wherein at least one of the first registration request message or the second registration request message indicates that the WTRU supports the periodic registration timer value and the granted periodic registration early time value.

13. The method of claim 9, wherein the WTRU is associated with a periodic registration time window value based on an anticipated period that the WTRU will be without power, and wherein the periodic registration timer value and the granted periodic registration early time value are based on the periodic registration time window value.

14. The method of claim 9, wherein the WTRU is an ambient internet of things (IoT) device.

15. The method of claim 9, wherein the method further comprises determining that the WTRU has sufficient energy available to perform the procedure with the network node.

16. The method of claim 15, wherein determining that the WTRU has sufficient energy available to perform the procedure with the network node comprises: determining an energy criterion; determining an amount of energy to be used for a task associated with the procedure; and determining that the amount of energy satisfies the energy criterion.

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