Method and apparatus for AIOT access with an intermediate node using small data transmission

Abstract

A WTRU receives a release message from a base station. The release message includes a list of ambient internet-of-things (AIoT) device identifiers (IDs). The WTRU also receives at least one AIoT message from at least one AIoT device. The at least one AIoT message includes a device ID of the at least one AIoT device. If the device ID received in the at least one AIoT message is in the list of AIoT device IDs received in the release message, the WTRU triggers a resume to connected mode and sends a transmission to the base station. If the device ID received in the at least one AIoT message is not in the list of AIoT device IDs received in the release message, the WTRU sends the transmission to the base station using UL SDT without triggering a resume to connected mode.

Description

METHOD AND APPARATUS FOR AIOT ACCESS WITH AN INTERMEDIATE NODE USING SMALL DATA TRANSMISSIONCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 572,674, filed April 1 , 2024, the contents of which are incorporated herein by reference.SUMMARY

[0002] A WTRU receives a release message from a base station. The release message includes a list of ambient internet-of-things (AloT) device identifiers (IDs). The WTRU also receives at least one AloT message from at least one AloT device. The at least one AloT message includes a device ID of the at least one AloT device. If the device ID received in the at least one AloT message is in the list of AloT device IDs received in the release message, the WTRU triggers a resume to connected mode and sends a transmission to the base station. If the device ID received in the at least one AloT message is not in the list of AloT device IDs received in the release message, the WTRU sends the transmission to the base station using UL SDT without triggering a resume to connected mode.BRIEF DESCRIPTION OF THE DRAWINGS

[0003] A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings, wherein like reference numerals in the figures indicate like elements, and wherein:

[0004] FIG. 1A is a system diagram illustrating an example communications system in which one or more disclosed embodiments may be implemented;

[0005] FIG. 1 B is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1A according to an embodiment;

[0006] 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;

[0007] FIG. 1 D is a system diagram illustrating a further example RAN and a further example CN that may be used within the communications system illustrated in FIG. 1A according to an embodiment;

[0008] FIG. 2 is a signal diagram of an example inventory procedure for radio frequency identification (RFID;

[0009] FIG. 3 is a system diagram of an example Topology 2 AIOT system;

[0010] FIG. 4 is a diagram of an example of topology 3 with use of an assisting node for downlink assistance;

[0011] FIG. 5 is a diagram of an example of topology 3 with use of an assisting node for uplink assistance;

[0012] FIG. 6 is a signal diagram of an example of a method of small data transmission (SDT)-based access to AloT via an intermediate node (WTRU); and

[0013] FIG. 7 is a flow diagram of an example method of small data transmission (SDT)-based access to AloT via an intermediate node (WTRU), such as illustrated in the signal diagram of FIG. 6DETAILED DESCRIPTION

[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 communications systems 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), singlecarrier FDMA (SC-FDMA), zero-tail unique-word discrete Fourier transform Spread OFDM (ZT-UW-DFT-S- OFDM), unique word OFDM (UW-OFDM), resource block-filtered OFDM, filter bank multicarrier (FBMC), and the like.

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

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

[0017] The base station 114a may be part of the RAN 104, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, and the like. The base station 114a and / or the base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for a wireless service to a specific geographical area that may be relatively fixed or that may change over time. The cell may further be divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to transmit and / or receive signals in desired spatial directions.

[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 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 116 using wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink (DL) Packet Access (HSDPA) and / or High-Speed Uplink (UL) Packet Access (HSUPA).

[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 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, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.

[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.

[0025] The RAN 104 may be in communication with the CN 106, which may be any type of network configured to provide voice, data, applications, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not shown in FIG. 1A, it will be appreciated that the RAN 104 and / or the CN 106 may be in direct or indirect communicationwith other RANs that employ the same RAT as the RAN 104 or a different RAT. For example, in addition to being connected to the RAN 104, which may be utilizing a NR radio technology, the CN 106 may also be in communication with another RAN (not shown) employing a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0026] The CN 106 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or the other networks 112. The PSTN 108 may include circuit-switched telephone networks that provide plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP) and / or the internet protocol (IP) in the TCP / IP internet protocol suite. The networks 112 may include wired and / or wireless communications networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 or a different RAT.

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

[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), 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, thetransmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It will be appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[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 will be appreciated thatthe 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, a humidity sensor and the like.

[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 DL (e.g., for reception) may be concurrent and / or simultaneous. The full duplex radio may include an interference management unit to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WTRU 102 may include a half-duplex 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 DL (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 of users in the UL and / or DL, and the like. As shown in FIG. 10, 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 (PGW) 166. While the foregoing elements are depicted as part of the CN 106, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

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

[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 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. The primary channel may be the operating channel of the BSS and may be used by the STAs to establish a connection with the AP. In certain representative embodiments, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) may be implemented, for example in 802.11 systems. For CSMA / CA, the STAs (e.g., every STA), including the AP, may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[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 noncontiguous 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 MHz channels, and the data may be transmitted by a transmitting STA. At the receiver of the receiving STA, the above described operation for the 80+80 configuration may be reversed, and the combined data may be sent to the Medium Access Control (MAC).

[0052] Sub 1 GHz modes of operation are supported by 802.11 af 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 (MTC), such as MTC devices in a macro coverage area. MTC devices may have certaincapabilities, 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 802.11 n, 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 ST As 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, all available frequency bands may be considered busy even though a majority of the available frequency bands remains idle.

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

[0055] FIG. 1D is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 may employ an NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0056] The RAN 104 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 104 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 108b may utilize beamforming 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 subcarrierspacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using subframe or transmission time intervals (TTIs) of various or scalable lengths (e.g., containing a varying number of OFDM symbols and / or lasting varying lengths of absolute time).

[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, DC, interworking between NR and E-UTRA, routing of user plane data towards User Plane Function (UPF) 184a, 184b, routing of control plane information towards Access and Mobility Management Function (AMF) 182a, 182b and the like. As shown in FIG. 1 D, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0060] The CN 106 shown in FIG. 1D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. While the foregoing elements are depicted as part of the CN 106, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0061] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 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 protocol data unit (PDU) sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of non-access stratum (NAS) signaling, mobility management, and the like. Network slicing may be used by the AMF 182a, 182b in order to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases such as services relying onultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for MTC access, and the like. The AMF 182a, 182b may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0062] The SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN 106 via an N11 interface. The SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN 106 via an N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating UE IP address, managing PDU sessions, controlling policy enforcement and QoS, providing DL data notifications, and the like. A PDU session type may be IP-based, non-IP based, Ethernet-based, and the like.

[0063] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 104 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering DL packets, providing mobility anchoring, and the like.

[0064] The CN 106 may facilitate communications with other networks. For example, the CN 106 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to a local DN 185a, 185b through the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

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

[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 temporarilyimplemented / deployed as part of a wired and / or wireless communication network. The emulation device may be directly coupled to another device for purposes of testing and / or performing testing using over-the-air wireless communications.

[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 test equipment. Direct RF coupling and / or wireless communications via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0068] In recent years, Internet-of-Things (loT) has attracted much attention in the wireless communication world. More “things” are expected to be interconnected for improving productivity efficiency and increasing comforts of life. Further reduction of size, complexity, and power consumption of loT devices can enable the deployment of tens or even hundreds of billions of loT devices for various applications and provide added value across the entire value chain. Due to this increased popularity of loT, 3GPP has agreed to a study item on ambient loT (AloT) in Release 19.

[0069] It is currently not possible to power all AloT devices by a battery that needs to be replaced or recharged manually, which leads to high maintenance cost, serious environmental issues, and even safety hazards for some use cases (e.g., wireless sensor in electric power and petroleum industry). For this reason, energy harvesting is one possible consideration for powering AloT devices. However, energy harvesters may have limited output power (typically from 1 pW to a few hundreds of piW) when used to power AloT devices due in large part to the limited size and complexity required by practical applications for batteryless devices with no energy storage capability or devices with limited energy storage that do not need to be replaced or recharged manually. Therefore, they may not work well as power supplies for cellular devices operating as AloT devices, which typically have peak power consumption higher than 10mW.

[0070] An example type of application is asset identification, which presently has to resort mainly to barcode and radio frequency identification (RFID) in most industries. The main advantage of these two technologies is the ultra-low complexity and small form factor of the TAGs. However, the limited reading range of a few meters usually requires either handheld scanning, which leads to labor intensive and time-consuming operations, or RFID portals / gates, which leads to costly deployments. Moreover, the lack of interference management results in severe interference between RFID readers and -capacity problems, especially in cases of dense deployment. It is difficult to support large-scale networks with seamless coverage for RFID.

[0071] FIG. 2 is a signal diagram 200 of an example inventory procedure for radio frequency identification (RFID). RFID is conventionally used for asset identification applications. In the example illustrated in FIG. 2, an interrogator 204 (also referred to as an RFID reader) may begin each inventory round by sending a querymessage 206 to energize all or a subset of the TAGs 202. Following the query message 206, a TAG 202 may select a random number from 0 to 2AQ-1 (210) and load its memory with that number. Q is a variable that can be configured by the network to define the number of time access occasions in an inventory procedure, whereby 2AQ gives the number of access occasions.

[0072] The interrogator 204 may then begin sending a series of query reps 210a, 210b, 210c, 210d. At each transmission of a QueryRep 210, the TAG 202 may decrement its counter until the counter reaches 0. When the counter reaches 0 (214), the TAG 202 may initiate a contention resolution procedure 216, which may include the TAG 202 transmitting its device ID in the uplink and waiting for confirmation of the device ID in the downlink. This may be done to address possible collision between multiple devices selecting the same random number. Fora device that has passed contention resolution, the interrogator 204 can send dedicated read / write commands 218 to which the TAG 202 responds. Dedicated read / write commands for specific TAGs are illustrated as 212a and 212b in FIG. 2.

[0073] FIG. 3 is a system diagram of an example Topology 2 AIOT system 300. In Topology 2, and as illustrated in FIG. 3, an AIOT device 306 may communicate bidirectionally with an intermediate node 304 between the AIOT device 306 and the base station 302. In this topology, the intermediate node 304 can be, for example, a relay, an IAB node, a WTRU, or a repeater that is capable of AIOT. The intermediate node 304 may transfer information between the base station 302 and the AIOT device 306. The intermediate node 304 may communicate with the base station 302 via a Uu interface 308 and may communicate with the AIOT device using an AIOT link 310.

[0074] FIG. 4 is system diagram of an example Topology 3 AIOT system 400 with downlink assistance. In Topology 3 AIOT with downlink assistance, and as illustrated in FIG. 4, an AIOT device 406 transmits data / signaling to a base station 402, and receives data / signaling from the assisting node 404. The base station 402 may communicate directly with the assisting node 404 via a Uu interface 408. In this topology, the assisting node 404 can be, for example, a relay, IAB, WTRU, or repeater, that is capable of AIOT.

[0075] FIG. 5 is a system diagram of an example Topology 3 AIOT system 500 with uplink assistance. In Topology 3 with uplink assistance, and as illustrated in FIG. 5, an AIOT device 506 receives data / signaling from a base station 502 and transmits data / signaling to the assisting node 504. The base station 502 may communicate directly with the assisting node 504 via a Uu interface 508. In this topology, the assisting node 504 can be, for example, a relay, IAB, WTRU, or repeater that is capable of AIOT.

[0076] 3GPP Releases 17 and 18 specify UE-to-Network (U2N) relays. These U2N relays have a topology similar to topology 2 for AloT, which is illustrated in FIG. 3 and described above. In such topology, a relay node may act as an intermediate node for extending the coverage between a base station and a remote WTRU. In relays, the interface between the intermediate node (or relay) and end device (or remote WTRU) is sidelink (SL) / PC5. On the other hand, for topology 2, the interface will be a new AloT interface that is the subject of discussions in 3GPP for Topology 1.

[0077] In 3GPP releases 17 and 18, a remote WTRU may initiate a PC5-RRC connection with a relay WTRU as soon as the remote WTRU is out of coverage and finds a suitable relay WTRU. The setup and configuration of the PC5-RRC connection may allow the remote WTRU to later access the network when it wants to. The relay WTRU may forward a SIB to a remote WTRU to which it has a PC5-RRC connection, so the remote WTRU will have the necessary system information (e.g., barring, timers) to access the cell via the relay WTRU. The relay WTRU may monitor paging on behalf of the remote WTRU and forward the paging to the remote WTRU when received.

[0078] A remote WTRU can initiate a Uu radio resource control (RRC) connection with the network, either as a result of receiving a page from the network or the arrival of UL data destined for the network, by having the relay transparently forward RRC signaling between the remote WTRU and the network. A relay WTRU in RRC_IDLE / RRC_INACTIVE may be configured with special triggers to move to RRC_CONNECTED when the remote WTRU wants to initiate an RRC_CONNECTION with the network. It may be assumed that any time the remote WTRU is in RRC_CONNECTED, the relay WTRU will be in RRC_CONNECTED.

[0079] The relay WTRU may rely on legacy SL transmission, such as Release 16 SL transmission, to avoid interference with other SL WTRUs, which may include other relay WTRUs. In mode 1 , downlink control information (DCI) may be used to allocate SL resources. In mode 2, sensing-based transmissions in a resource pool may be used for collision avoidance.

[0080] Small data transmission (SDT) is a procedure allowing data and / or signaling transmission while remaining in RRCJNACTIVE state, or, in other words, without transitioning to RRC_CONNECTED state. SDT may be enabled on a radio bearer basis and can be initiated either by the WTRU in case of Mobile Originated SDT (MO-SDT) or by the network in case of Mobile Terminated SDT (MT-SDT). MO-SDT may be initiated by the WTRU only if: less than or equal to a configured amount of UL data awaits transmission across all radio bearers for which SDT is enabled, the DL reference signal received power (RSRP) is above a configured threshold, and a valid SDT resource is available. MT-SDT may be initiated by the network with an indication to the WTRU in a paging message when DL data awaits transmission for radio bearers configured for SDT. Based on the indication, the WTRU may initiate the MT-SDT only if the DL RSRP is above a configured threshold. When MT-SDT is initiated by the WTRU, a resume cause indicating MT-SDT may be included in the RRCResumeRequest / RRCResumeRequestl. A maximum duration for performing the SDT procedure may be dictated by an SDT failure detection timer that is configured by the network. The network can enable MO-SDT, MT-SDT, or both in a cell.

[0081] The SDT procedure may be initiated by a transmission over a random access channel (RACH), configured via system information or over Type 1 configured grant (CG) resources, or configured via dedicated signaling in RRCRelease. The SDT resources can be configured on the initial bandwidth part (BWP) for both RACH and CG. RACH and CG resources for SDT can be configured on either or both of supplementary uplink (SUL) and non-SUL (NUL) carriers. The CG resources for SDT may only be valid within the primary cell (Pcell)of the WTRU when the RRCRelease with suspend indication is received. CG resources may be associated with one or multiple synchronization signal / physical broadcast channel (PBCH) blocks (SSBs). For RACH, the network can configure 2-step and / or 4-step random access (RA) resources for MO-SDT. When both 2-step and 4-step RA resources for MO-SDT are configured, the WTRU may select the RA type. If the MT-SDT procedure is initiated over RACH, only the RACH resources not configured for SDT can be used by the WTRU. CFRA is not supported for SDT over RACH.

[0082] Once initiated, the SDT procedure may either be: successfully completed after the WTRU is directed to RRCJDLE (via RRCRelease), directed to continue in RRCJNACTIVE (via RRCRelease or RRCReject), or directed to RRC_CONNECTED (via RRCResume or RRCSetup) or unsuccessfully completed upon cell reselection, expiry of the SDT failure detection timer, a MAC entity reaching a configured maximum physical RACH (PRACH) preamble transmission threshold, a radio link control (RLC) entity reaching a configured maximum retransmission threshold, integrity check failure while the SDT procedure is ongoing, or expiry of SDT-specific timing alignment timer or configuredGrantTimer while the SDT procedure is ongoing over CG and the WTRU has not received a response from the network after the initial physical uplink shared channel (PUSCH) transmission. Upon unsuccessful completion of the SDT procedure, the WTRU may transition to RRCJDLE.

[0083] In Topology 2, the WTRU can be assumed to be a relay with limited functionality or intelligence with respect to the inventory procedure. In this case, the inventory may be performed by the gNB and may rely on the intermediate node to relay the commands / data.

[0084] When the network directly queries the AloT devices, the inventory procedure for AloT can be similar to the RFID inventory procedure illustrated in FIG.2 and described above. RFID, however, has not defined an inventory procedure that could apply to topology 2 where an intermediate WTRU can perform / assist in the inventory procedure. Current U2N SL relay technology in Release 17 could be re-used to perform the inventory procedure whereby the gNB has the relay WTRU transparently forward query, response, read / write commands and data between the gNB and each AloT device.

[0085] Release 17 relay WTRUs may always be expected to be in RRC_CONNECTED. SDT is an option that could potentially be used to perform relaying while the relay WTRU is not in the RRC_CONNECTED state as it allows for transmission of a certain amount of data while the relay WTRU is in RRCJDLE state. It would be straightforward to adapt SDT for AloT. For example, MT-SDT may be used to receive commands or data from the network to be forwarded to the AloT device, and MO-SDT may be used to transmit ID or sensor data received from the device to the network. However, currently, the SDT procedure is limited to applications where data is terminated at, or originated from, the WTRU. For Topology 2, the data going over the Uu link may simply be forwarded to the intermediate WTRU, and neither may originate or terminate at this WTRU.

[0086] Embodiments described herein leverage UL and DL SDT to perform the inventory procedure in an efficient way for AloT applications. Such embodiments may resolve issues, such as how to allow the networkto issue targeted read / write commands to the AloT device via an intermediate node so that the intermediate node can remain in an RRCJNACTIVE state during the inventory and command / response procedure. For example, in some embodiments, a WTRU may determine whether to use UL SDT based on the WTRU ID received from an AloT device. Where UL SDT is used, the WTRU may also determine which type of UL SDT (CG-based or RACH-based) to use based on whether the WTRU is sending the ID of an AloT device or the response to a network initiated command.

[0087] A WTRU may receive a release message, such as from a network on a first interface, which may initiate a UL or DL SDT-based inventory procedure. The message may include, for example, a list of device IDs, one or more messages (e.g., a container that contains the contents of one or more messages) to be transmitted (e.g., on a second interface such as an AIOT interface), and / or a configuration indicating UL-SDT resources comprising one or more of UL-SDT configured grant (CG) resources and / or RACH-based SDT resources. The WTRU may initiate an inventory procedure by transmitting (e.g., on the AloT interface) one or more messages (e.g., RRC messages) using the contents of the received container (or the received one or more messages).

[0088] A WTRU may receive a PDU or transmission from the network, using DL-SDT or RRC_CONNECTED signaling. The transmission may include a command or a command container of a first type (e.g., first message of each occasion). For each such transmission received by the WTRU, the WTRU may transmit the command or command container, receive a device ID from a device, and determine whether to transmit the received device ID to the network using an UL-SDT CG resource. The WTRU may transmit the command or command container on the AloT interface to at least one device. The WTRU may receive the device ID from the device, for example via a RACH transmission. For one example, if the received device ID matches one of the device IDs in the list provided in the release message, the WTRU may transmit the device ID to the network using UL-SDT. For another example, if the received device ID does not match one of the device IDs in the list provided in the release message, the WTRU may transmit the device ID to the network using RRC_CONNECTED.

[0089] If the WTRU determines to transmit the received device ID using a UL-SDT CG resource, the WTRU may perform one or more of the following: transmitting the received device ID in a first (e.g., earliest) UL-SDT CG resource that occurs after receiving the device ID; transmitting a response command, which may be predefined and sent via the second interface, for example, using the received device ID; and / or following transmission of the device ID using the first interface (e.g., to the network). If the WTRU receives a DL message (e.g., from the NW) before a second UL-SDT CG resource (which occurs after the first UL-SDT CG resource) and the DL message includes a command (or command container) of a second type, the WTRU may perform one or more of the following: transmitting the command (or command container) of the second type (e.g., read / write command) over the second interface (e.g., to the AloT device) using the received device ID and / or transmitting the response to the network (e.g., via the first interface) using RACH-based SDT resources if a response to the command of the second type is received.

[0090] The terms device, AIOT WTRU, and TAG are used interchangeably herein to mean the AloT device that is being inventoried / queried by the reader. An AloT device may also refer to a device (e.g., loT device) that may be able to transmit / backscatter / receive data and / or control signals from RAN entities (e.g., gNB, WTRU, network etc.).

[0091] The term reader refers to the entity that queries the AloT device, either directly, or via an intermediate WTRU in Topology 2. The term reader in Topology 2 may also refer to the intermediate WTRU. As a result, the term reader may refer to a network node or a WTRU, depending on the context and / or the topology.

[0092] As used herein, reader, network, and intermediate WTRU may be used interchangeably to mean the reader. Further, as used herein, inventory may refer to the overall procedure of a reader triggering access by one or more devices using a sequence of messages (e.g., similar to a query followed by query rep in RFID). The inventory procedure may refer to a single round of attempts to have each device respond or attempt to respond with its access ID or perform a RACH procedure. The inventory procedure may also refer to a set of access occasions which may have 0 or at least 1 device respond within the access occasion. The inventory procedure may be performed similarly to a legacy RFID procedure. Although referred to herein as an inventory procedure, it may be termed differently in device requirements or specifications (e.g., query procedure, paging procedure, etc.). As used herein, query and / or query rep may refer to the messages / sequences, etc. transmitted (e.g., broadcasted) by the WTRU (e.g., reader) to request the devices to transmit a response (e.g., inventory response).

[0093] As used herein, occasion or inventory occasion may refer to the opportunity for device transmission that may be delimited by the transmission of a query rep message (or similar). A device may perform a transmission in an occasion by performing an AloT transmission in a defined time following the query rep associated with that transmission. Alternatively, an occasion may include both a time aspect and a frequency aspect. A device may determine an occasion as a transmission following a specific query rep and by transmitting on one of a number of frequencies (e.g., FDM). Wherever selection of an occasion is indicated, it can apply equivalently to selection of only a time component and / or selection of a frequency component.

[0094] Herein, depending on the embodiment, any reference to time can be associated with an absolute time measurement (e.g., seconds, slots, frames, etc.). Alternatively, it can refer to a number of executions of a procedure, which may be triggered by a reader (e.g., number of inventory procedures, number of accesses or RACH procedures, etc.). Alternatively, it can refer to a number of received or transmitted messages, such as of a specific type, or containing specific information.

[0095] The embodiments described herein are for a use case where the WTRU is the intermediate node in Topology 2 or Topology 3 of AloT. However, these concepts are equally applicable to the use case where the WTRU is a WTRU-to- Network relay. Concepts can be generalized to the use case where the WTRU transparently forwards information between the network and a remote WTRU using SDT on the Uu link.Topology 2 for AloT can be replaced with an architecture where a remote WTRU communicates with a network node via a WTRU-to-Network relay, where the communication between the relay WTRU and the remote WTRU is over sidelink, and the communication between the relay WTRU and the network is over the Uu link. When referencing properties of the AloT interface herein, it is intended that most properties can be extended to an SL interface. A property on the AloT interface mentioned herein (e.g., congestion) may have an equivalent or similar counterpart on the SL interface, and embodiments described herein are extendible to SL assuming such counterpart.

[0096] Some embodiments described herein are directed toward communication by a WTRU, which may be referred to herein as an intermediate WTRU, with an AloT device, while the WTRU is in RRC_IDLE / RRC_INACTIVE in order to make use of SDT on the Uu interface. However, the behaviors associated with the WTRU’s transmissions on the AloT interface may be applicable to an intermediate WTRU in any RRC state.

[0097] In legacy relaying, data may be transmitted transparently in an end-to-end fashion between the network and the remote WTRU. For AloT, however, the access procedure may need to be performed in a different fashion due to the simplicity of the protocol on the AloT interface. As a result, the intermediate WTRU may need to be able to receive control messages from the network that trigger a sequence of actions.

[0098] In some embodiments, a WTRU may receive a procedure configuration. The procedure configuration may be received in a DL RRC message or SIB. A WTRU may receive a procedure configuration in paging, such as in DCI, MAC CE, etc. Such procedure configuration may be, for example, a release message to inactive state (e.g., RRC release). A WTRU may further trigger one or more AloT transmissions upon reception of a message containing a procedure configuration. For example, a WTRU may trigger an AloT inventory procedure upon reception of an RRC reconfiguration message that contains an AloT-specific configuration. For example, a WTRU may trigger an AloT inventory procedure upon reception of a release message that contains an AloT-specific configuration.

[0099] In a procedure configuration, a WTRU may receive: configuration elements or conditions that control whether and / or when to use UL SDT to transmit data or when to initiate RRC resume; contents (partial or full) of messages to be transmitted on the AloT interface; and / or an indication of the type of message and / or a type of behavior on the AloT interface associated with each message (e.g., a command type). For example, a WTRU may receive, in a procedure configuration, a list of device IDs, information regarding a set of device types, and / or one or more partial or full information associated with the devices, which may or may not correspond to the use of UL SDT, as described herein. In another example, a WTRU may receive information regarding any of the thresholds, timers or similar parameters described herein. In yet another example, a WTRU may receive information regarding the time to be respected between successive transmissions over the AloT interface or the time between reception and the next transmission or vice versa. In another example, the WTRU may receive, in the procedure configuration, the contents of any messages to be transmitted on theAloT interface. This may include the full message. Alternatively, this may include part of the message, and the WTRU may include other elements (e.g., device ID) from other messages (e.g., received from the device). In another example, depending on the message type, the WTRU may determine whether to transmit the full message or add specific elements to the message. In yet another example, the procedure configuration may include information, such as indicating whether to include a device ID with the message or not, indicating whether to expect a response to the message and, if so, how long the WTRU should wait before performing a retransmission, and / or indicating a number of times the WTRU should repeat the same message (in some embodiments with a different device ID received from the AloT interface in another message).

[0100] In some embodiments, a WTRU may receive data that is mapped to a transmission on the AloT interface. For example, the WTRU may be configured with one or more DL logical channels (LCHs) that are mapped to transmissions on the AloT interface. Data received on the DL LCH for AloT may be organized to simplify relaying on the AloT interface. For example, they may be sent along with control PDUs that may provide the WTRU with instructions regarding the behavior on the AloT interface. For example, a MAC PDU received by the WTRU on the Uu interface may include data for the AloT LCH. Along with such MAC PDU, the WTRU may receive (e.g., in the same TB) a MAC CE with control information about the transmission of the accompanied data. By way of example, the MAC CE may include identifiers, which may direct to the WTRU to one or more of: transmit the data in the MAC PDU over the AloT interface by adding the last received device ID stored at the WTRU, transmit the data in the MAC PDU over the AloT interface by adding the device ID included in the same or another MAC CE, transmit the data in the MAC PDU over the AloT interface without a device ID, and / or transmit the data in the MAC PDU over the AIOT interface only when the WTRU receives a response to another AloT transmission. These MAC CEs can also indicate the command types described herein that may result in different SDT behavior at the WTRU when a response to those commands is sent by an AloT device

[0101] One configuration aspect related to the use of SDT may be the number of responses received before such responses are forwarded over Uu (e.g., using SDT). Although such configuration aspect is described here for SDT, it may also be applicable for transmission by a WTRU over Uu in RRC connected mode (i.e., forwarding data and / or triggering some UL transmission such as SR or BSR, etc.). By way of example, the UL transmission made by the WTRU in such scenario may be UL data (forwarded data from AloT device), an SR / BSR, a RACH transmission, or an RRC message. The WTRU may be configured to accumulate or buffer a number of responses / messages from AloT devices before transmitting the received messages to the network. Such configuration may be based on a period of time, a number of messages, a buffered data volume, a number of control messages (e.g., of a specific type), a time interval indicated by the CG occasion, a number of TAGs that have been successfully identified and / or a request from the network to the WTRU to transmit the received messages. Regarding configuration based on a period of time, for example, the network may configure a timer, and the WTRU may forward the received messages only when the timer expires. Alternatively, the network may configure the period of time in terms of start time instance and / or stop time instance, and the WTRU mayforward the received message when the stop time is reached. Regarding configuration based on a number of received messages, for example, the network may configure a maximum number of received messages, and the WTRU may forward the received messages only when the number of messages is received. Regarding configuration based on a buffered data volume, for example, a WTRU may be configured with a data volume and may trigger a UL transmission (e.g., the actual data, BSR, SR, control message, etc.) when the data received from one or more AloT devices reaches a threshold amount.

[0102] Regarding configuration based on a number of control messages, for example, the WTRU may be configured with a number of transmissions to be made on the AloT interface, which may be for a specific control message type in some embodiments. The WTRU may perform transmission on the UL only when the responses from each of the number of configured transmissions has been completed. The WTRU may further be configured with a timer associated with the expected time to wait for each AloT response to a given transmission, as described herein, and may assume the response has been sent if the timer expires. Regarding configuration based on a time interval dictated by the CG occasion, for example, the WTRU may determine the number of responses to buffer until UL transmission based on the timing of the CG occasion. For example, the WTRU may perform as many AloT transmissions and receive the corresponding responses until each CG occasion. The WTRU may transmit all responses on the same CG occasion. Regarding configuration based on a number of TAGs that have been successfully identified, for example, the network may configure a maximum / minimum number of devices, and the WTRU can forward the received messages only when the number of devices is identified.

[0103] In some embodiments, an intermediate WTRU may perform transactions with its device and with a network (e.g., in the context of Topology 2) while remaining in RRCJNACTIVE state. On Uu, transactions with the network may be performed using SDT. In some embodiments, a WTRU may determine whether to perform UL SDT or to trigger a resume procedure (i.e., non SDT) based on one ora combination of the following factors: detection of contention on the AloT interface, measurement of congestion on the AloT interface, number of AloT devices, device IDs, size of CG grant, measurements AloT interface, measurements on the Uu interface, device type or capabilities of one or more AloT devices, contents of a previous message received on the Uu interface, timing of a previous message received on the Uu interface, contents of the received message from the AloT interface, size of a message received on the AloT interface, buffer status on Uu, presence of other data to transmit in UL that is not AloT related, logical channel on Uu, measure of the time difference between received AloT messages, and / or measure of the last time a specific device responded.

[0104] In some embodiments, a WTRU may determine whether to request moving to RRC connected based on a detection of contention or collision on the AloT interface during the device RACH procedure. Specifically, the WTRU may initiate a RACH procedure in multiple devices, which may be associated with a specific inventory occasion. The WTRU may determine whether to perform UL SDT to trigger a legacy resume based on detection of contention or collision during the RACH procedure and / or based on whether the WTRU is able to resolve the WTRU ID or IDs of the devices that collided. For example, the WTRU may perform ULSDT if it does not detect any collision in the RACH procedure, or the WTRU may perform UL SDT if it detects collision in the RACH procedure from multiple devices. The WTRU may initiate a normal resume if it detects collision and is able to decode the device IDs of one, at least one, at least X (where X can be configured), and / or all the devices that transmitted RACH with their ID.

[0105] In some embodiments, a WTRU may determine whether to request moving to RRC connected or using UL SDT as a function of the measured congestion on the AloT interface. For example, congestion can be measured using RSSI measurements (e.g., similar to CBR), using a process of counting responses, and / or using a process of measuring how often a device is transmitting. For example, the WTRU may be configured with a threshold CBR level. If the CBR is below (or above) a threshold, the WTRU may use UL SDT. For example, the WTRU may be configured with a threshold percentage of time and / or frequency / channel occupancy of the AloT interface. If the percentage is below (or above) a threshold, the WTRU may use UL SDT. For another example, the WTRU may count the number of devices that respond to a command it transmits on the AloT interface (e.g., within a configured period of time, such as within a time frame delimited by the transmission of two specific AloT messages). The WTRU may be configured with a threshold value or device number. If the counted number of devices is below (or above) a threshold, the WTRU may use UL SDT.

[0106] In some embodiments, a WTRU may determine whether to request moving to RRC connected or using UL SDT as a function of the number of devices the WTRU is communicating with. The WTRU may determine the number of devices based on network signaling (e.g., provided in the DL message). Alternatively, the WTRU may determine the number of devices based on the number of responses. Alternatively, the number of devices may be implicitly indicated by the network in a DL message. For example, the WTRU may receive a number of devices in, for example, a DL RRC message, a DL AloT control message, or a SIB. The WTRU may use UL SDT upon reception of data from one or more of these devices if the number of devices is below (or above) a threshold. Alternatively, the WTRU may decide based on the number of AloT devices that responded in a period of time or in a specific sequencing of messages over the Uu interface or the AloT interface (e.g., an inventory period).

[0107] In some embodiments, a WTRU may determine whether to request moving to RRC connected or using UL SDT based on one or more inventoried or received AloT device IDs. For example, the WTRU may determine this by checking whether, for example, at least one device ID or subset of devices IDs received from the devices correspond to the set of configured device IDs. In some embodiments, the WTRU may receive a set of partial device IDs from the network. For example, the WTRU may receive the first N bits or digits and corresponding device IDs and may decide based on whether the first N bits or digits of the device ID or IDs received correspond to the indicated partial device IDs from the network.

[0108] In some embodiments, a WTRU may determine whether to request moving to RRC connected based on the size of the CG configured for SDT (in some embodiments, in relation to the received data and / or the amount of buffered data). For example, if the size of the data to be sent in UL, or the size of one or moremessages received from one ormore AloT device, is greater than the size of the CG resource (or some amount larger than the size of the CG resource), the WTRU may request a resume. Otherwise, it may use SDT. For another example, if the payload size (e.g., in bits) is larger than a configured amount, the WTRU may request a resume. Otherwise, it may use SDT.

[0109] In some embodiments, a WTRU may determine whether to request moving to RRC connected or trigger an SDT procedure based on the measurements on the AloT interface. Such measurements may consist of RSRP, RSSI, SINR, and / or received signal power. Such measurements may include measurements of the power of the backscatter! ng signal. The network may be capable of managing a bad AloT link if the intermediate WTRU is in RRC connected. For example, if the AloT measurements are below a threshold, the WTRU may trigger a resume procedure. Otherwise, the WTRU may use UL SDT.

[0110] In some embodiments, the WTRU may determine whether to request moving to RRC connected based on one or more channel conditions or measurements (e.g., L1 / L3 RSRP, RSRQ, SINR, etc.). A legacy condition of Uu RSRP can be reused as one condition. For example, the WTRU may use UL SDT if the Uu RSRP is above a threshold.

[0111] In some embodiments, a WTRU may determine whether to request moving to RRC connected or to trigger an SDT procedure based on the AloT device type, capability, etc. For example, the WTRU may determine the device type or the capabilities of a specific device based on a signaling exchange with that device. For example, the WTRU may determine the device type or device capabilities based on the received waveform, the carrier frequency used, or other determination from the properties of the physical layer signal. For one example, a WTRU may perform UL SDT following reception from an AloT device only when that device is of a certain type or capability. For another example, a WTRU may trigger a resume procedure when at least one device to which the WTRU is communicating is of a specific type.

[0112] In some embodiments, a WTRU may determine whether to request moving to RRC connected or use UL SDT based on information received in a previous message (e.g., a control message) on the Uu interface. This may include a specific command or command type. Alternatively, this may include an explicit indication in a DL message that indicates to move to RRC connected. For example, a WTRU may receive a command in a DL message. Following reception of the DL message with a specific command, reception of a message on the AloT interface may trigger UL SDT or a resume procedure, depending on the specific command. For example, the WTRU may be configured (or prespecified) with the set of commands that triggers UL SDT upon reception of a subsequent AloT message. For example, a WTRU may receive an indication in a DL message (e.g., trigger resume). Following reception of the message, the WTRU may trigger resume upon reception of an AloT message. Otherwise, the WTRU may use UL SDT upon reception of an AloT message.

[0113] A trigger to request connection or use UL SDT may occur upon reception of a specific message received on the AloT interface relative to the DL message. For example, a WTRU may receive a DL RRC message, a DL MAC CE, a DCI message, or any protocol control element that indicates to use UL SDT (ortrigger resume procedure) for the next message received on the AloT interface, the next N messages received on the AloT interface (where N may be indicated in the downlink or configured or specified), the next set of messages received in a configured time window, and / or one or more messages received on the AloT interface after the next (e.g., N) messages.

[0114] In some embodiments, a WTRU may determine whether to use UL SDT or trigger resume as a function of the time difference between a DL message received on the Uu interface and the reception of a message from the AloT device intended for UL transmission.

[0115] In some embodiments, a WTRU may trigger resume or use UL SDT as a function of the contents of the received message from the AloT interface. In one example, the WTRU may perform such determination based on the protocol, LCH, radio bearer, or equivalent used in the received message. For another example, the WTRU may request resume if it receives a PDU that contains an RRC message (e.g., PC5-RRC, RRC on AIOT interface, etc.). Otherwise, it may use UL SDT. In another example, the WTRU may perform such determination based on the presence or absence of a control element in the message. For example, the WTRU may request resume if it receives a PDU that contains a control element of a specific protocol layer (e.g., a MAC CE, an RLC status PDU, an adaptation layer control message, etc.). For example, the WTRU may request resume if it receives a particular type of RRC message or control element (e.g., a specific MAC CE, a specific PC5-RRC message, a specific type of status PDU, etc.). For example, the WTRU may request resume if it receives a PDU containing a specific element within the protocol header (e.g., a MAC header is received, the MAC header contains a specific control element, a specific flag is set in the MAC header, etc.). In yet another example, the WTRU may perform such determination based on reception of an explicit indication. In another example, the WTRU may request a resume if it receives an explicit indication from the AloT device to request a resume. In yet another example, the WTRU may perform such determination based on an indication of an error by the AloT device. For example, if the AloT device transmits an error message, the WTRU may trigger a resume procedure. In yet another example, the WTRU may receive information about the device that implicitly dictates such determination. For example, the WTRU may request a resume if the AloT device indicates some information about the direct link between the device and the network (in case such direct link exists) such as the presence of such a link, the characteristics of that link, the properties of that link (e.g., link quality) etc. These examples may also apply to using UL SDT based on the conditions rather than requesting a resume.

[0116] In some embodiments, a WTRU may determine whether to request moving to RRC connected based on the size or amount of data received on the AloT link, which may be in relation to other factors. For example, if the size of the data to be sent in UL, or the size of one or more messages received from one or more AloT devices, exceeds a threshold, the WTRU may request a resume. Otherwise, it may use UL SDT. For example, if the number of AloT messages received and / or buffered at the WTRU is larger than a threshold, the WTRU may request a resume. Otherwise, it may use UL SDT.

[0117] The buffer status may be considered for the decision of whether to initiate a resume procedure or use UL SDT. If the buffer status associated with a logical channel is below a threshold, the WTRU may use UL SDT. Otherwise, the WTRU may trigger a resume procedure.

[0118] In some embodiments, a WTRU may determine whether to request moving to RRC connected or using UL SDT as a function of the presence of other data that may be non-AloT related. For example, a WTRU may not be allowed to use UL SDT when it has both AloT data and non-AIOT data to send in the uplink at the same time. If the WTRU is using UL SDT for AloT data (or non AloT data) and new data arrives for transmission in the uplink of non AloT data (or AloT data), the WTRU may always trigger a resume procedure. For example, whether to request moving to connected may be a function of the data priority, DRB, LCH, or delay associated with the other non-AloT data.

[0119] The logical channel may be considered for the decision as in legacy. If the logical channel in which data is available for transmission is configured for UL SDT, the WTRU may perform UL SDT. Otherwise, the WTRU may trigger a resume procedure.

[0120] In some embodiments, a WTRU may determine whether to request moving to RRC connected or use UL SDT based on a function of the time difference between reception of messages at the AloT interface. The motivation of such technique would be to reduce the overhead of RRC messages included in UL due to frequent triggers of the resume procedure from the arrival of new data. For example, if the time difference between two consecutive received AloT messages is less than a threshold (e.g., for a period of time or over a number of consecutive time differences), the WTRU may request a resume. Otherwise, it may use UL SDT. For another example, the WTRU may trigger a first event if the time between two consecutive received AloT messages is smaller than a first threshold. Following the first event trigger, the WTRU may cancel the event if the time difference between consecutive subsequent messages is larger than a second threshold. On the other hand, while the event is triggered, if the event is not canceled for at least a period of time, or a number of consecutive messages, the WTRU may trigger request to resume. Otherwise, it may use UL SDT.

[0121] In some embodiments, a WTRU may determine whether to use UL SDT based on the time between responses associated with a specific device ID or the time since the last message was reported for a given device. For example, the WTRU may be configured with a threshold time. If the WTRU receives a response from a device with a particular ID, and the time since the last response from that ID is larger than the threshold, the WTRU may trigger a request to move to connected.

[0122] As mentioned above, combinations of the factors described above may also be used in the determination of whether to use UL SDT or request resume. Combinations of the above factors may include, but not be limited to: a condition associated with one factor AND a condition of another factor being satisfied; a condition associated with one factor OR a condition of another factor being satisfied; a condition associated with one factor being satisfied is used to determine whether a second condition associated with a second factor should be checked; a condition being satisfied when a value or variable (or function thereof) of one factor iscompared to a value or variable (or function thereof) of another factor (a function of a value / variable of one factor may use another function to calculate the condition); and / or a condition associated with factor that is defined with a threshold that is related to another factor, is satisfied.

[0123] In one example of a combination of conditions, the WTRU may determine whether to use UL SDT based on the time difference between the reception of different messages on the AloT interface, while taking data size of the messages into account. Specifically, the WTRU may first compute a total data size of two consecutive received messages. Based on the total data size, the WTRU may determine a corresponding threshold (e.g., RRC configuration may define a mapping between a range of data sizes to a particular time threshold). If the time difference between the two messages is below the computed threshold, the WTRU may trigger a resume procedure. In addition, conditions described below for determining whether to use CG SDT resources or RACH-based resources may also be used to determine whether to use UL SDT or not.

[0124] In the embodiments described above, using UL SDT may refer to the legacy trigger of using UL SDT to transmit data, which may include either: transmitting a resume request message along with data in the same TB using a CG configured for SDT, which may, in some embodiments, be followed by transmission of additional TBs (associated with the same new data trigger) in subsequent CG resources without a resume request message; or transmitting a resume request message using a RACH procedure, but using a specific partition of RACH resources that are dedicated to the use of SDT. On the other hand, requesting a resume procedure, triggering a resume procedure, requesting a move to connected, or initiating a transition to connected may all refer to the WTRU initiating a RACH procedure to then transmit the resume request message (without multiplexing data in the resume request), and doing so by using normal RACH resources.

[0125] In some embodiments, a WTRU may be configured with criteria to determine when CG-SDT resources are available and / or whether to use CG SDT or RACH-based SDT. Such criteria may be a function of any of the factors described above for selection between triggering resume procedure and using UL SDT.

[0126] In one example, the WTRU may determine whether to use CG-SDT resources or RACH-based resources based on the number of devices and / or responses received by the WTRU over the AloT interface. If the number of devices and / or responses is above a threshold, the WTRU may use RACH-based resources. Otherwise, it may use CG-SDT resources.

[0127] In another example, the WTRU may determine whether to use CG-SDT resources or RACH-based resources to send the response from an AloT device over the Uu interface based on the type of command received from the network and consequently sent to the device or devices by the WTRU prior to the response. If the WTRU receives a first command type from the network and triggers a transmission over that AloT interface containing the first command, the WTRU may use CG-SDT resources to send the received response over the Uu interface. Alternatively, for the second command type, it may use a RACH-based SDT resource. A command type, in this case, may be carried, for example, by an RRC message, a MAC CE, and / or a flag in the MAC header over the Uu interface.

[0128] In addition, the WTRU may use any or a combination of the following factors in the determination as to when CG-SDT resources are available and / or whether to use CG SDT or RACH-based SDT: the type of data received from the AloT device, the method used to transmit prior to the AloT response, the RRC state of the WTRU when it received the message to be relayed to the AloT device, the presence of a device ID on the message sent to the AloT device and / or the priority of data and / or Uu LCH.

[0129] In some embodiments, the WTRU may determine whether to use RACH-based SDT or CG SDT based on the type of data received from the AloT device. This may be differentiated by, for example, the type of message (e.g., data or control), the information in the message (e.g., ID or response to a read command), and / or whether the message is sent in a contention free fashion or with possibility of contention. For example, the WTRU may send the RACH information (e.g., the device ID) using a CG resource and may send the response to subsequent commands in a RACH-based resource.

[0130] In some embodiments, the WTRU may determine whether to use RACH-based SDT or CG SDT as a function of the way the WTRU received the message (e.g., command) from the network prior to reception of the response from the AloT device. For example, if the WTRU received a message using a dynamic grant from the network (e.g., in DL-SDT), when the message is then used to generate a transmission on the AloT interface, the response may be forwarded using RACH-based SDT. On the other hand, if the message was received in a SIB, or in dedicated RRC signaling while the WTRU was in RRC_CONNECTED state, the WTRU may send the response that was received over the AloT interface to the network using CG SDT resources.

[0131] Regarding the RRC state of the WTRU when it received the message to be relayed to the AloT device, the WTRU may consider the RRC state of the WTRU when it received the command message used to trigger the response. For example, if the WTRU was in RRC_CONNECTED, it would use CG SDT resources to forward the response to the network. Otherwise, it would use RACH based resources.

[0132] In some embodiments, the WTRU may determine whether to use RACH-based SDT or CG SDT to forward a response from the AloT device to the network based on whether the message to the AloT device that triggered the response contained a device ID. For example, if the message transmitted by the WTRU contained a device ID, the response may be forwarded using CG SDT. Otherwise, it may be forwarded using RACH-based SDT or vice versa.

[0133] In some embodiments, the WTRU may determine whether to use RACH-based SDT or CG SDT to forward the response from the AloT device based on the priority of the response and / or the UL LCH to which the response is mapped. For example, for a first priority or UL LCH, CG SDT may be used, and for a second priority or UL LCH, RACH-based SDT may be used.

[0134] A WTRU may be configured with a CG SDT TA timer, as per legacy. When using SDT for forwarding AloT data, the WTRU may be configured with different behavior upon expiry of such timer. In some scenarios, the WTRU may release the CG SDT resource upon expiry of the timer. Alternatively, the WTRU may beconfigured to initiate a RACH procedure, a resume procedure, or similar in order to acquire an updated TA while maintaining the resource.

[0135] In some embodiments, a WTRU may determine whether to release the CG SDT resource or perform a RACH procedure based on one or a combination of the following: the last message (or command type) transmitted by the WTRU over the AloT interface, the status of a second timer at the WTRU, a DL transmission from the network, the contents of the last AloT message received, and / or the number of messages transmitted by the WTRU on the AloT interface, which may be a specific type and may follow another message transmission of another type.

[0136] Regarding the WTRU determining whether to release the CG SDT resource or perform a RACH procedure based at least on the last message or command type transmitted by the WTRU of the AloT interface, the WTRU may release the CG SDT resource at TA timer expiry if the last message transmitted by the WTRU is of a predetermined type.

[0137] Regarding the WTRU determining whether to release the CG SDT resource or perform a RACH procedure based at least on the status of a second timer at the WTRU, for example, the WTRU may be configured with another second timer (e.g., the maximum duration of an inventory procedure or of an occasion of an inventory procedure) and may release the CG SDT resource only when the second timer is not running and the TA timer has expired

[0138] Regarding the WTRU determining whether to release the CG SDT resource or perform a RACH procedure based at least on a DL transmission from the network, for example, the WTRU may be configured, after a first network transmission, to transmit RACH following the TA timer until a second network transmission. Following the second network transmission, the WTRU may release CG SDT resources at the next expiry of the TA timer. The NW transmissions may be explicit control information sent by the network (e.g., in a DL RRC message or in a DL MAC CE), which in some embodiments may be sent using DL SDT. Alternatively, the network transmissions may be associated with different command types included with the AloT messages to be transmitted by the WTRU.

[0139] Regarding the WTRU determining whether to release the CG SDT resource or perform a RACH procedure based at least on the contents of the last AloT message received, for example, the WTRU may be configured to transmit RACH upon SDT TA expiry until the WTRU receives a transmission from an AIOT device. In some embodiments, the received transmission may include a specific or configured device ID and certain other contents (e.g., some flag in the MAC CE).

[0140] Regarding the WTRU determining whether to release the CG SDT resource or perform a RACH procedure based at least on the number of messages transmitted by the WTRU on the AloT interface, for example, the WTRU may be configured to perform RACH following SDT TA timer expiry starting from the reception from the network of a first command type, or the transmission by the WTRU of the command type. Alternatively, the WTRU may be configured to perform RACH following SDT TA timer expiry followingconfiguration of the CG SDT resources. The WTRU may continue to trigger the RACH procedure until it completes the transmission of X messages of the first type on the AloT interface or some time after the completion of the transmission of X messages of the first type on the AloT interface). In some embodiments, the X messages of the first type are to be transmitted following a message of a second type.

[0141] In some embodiments, a WTRU may select between multiple CGs or CG resources when transmitting data from AloT devices. Such selection may apply to intermediate WTRUs using SDT, but the same solutions may also be valid for an intermediate WTRU in RRC_CONNECTED. In some embodiments, a WTRU may select between CGs or CG resources based on device ID. For example, a WTRU may be configured with a CG for one or more device IDs and may transmit data associated with the one or more device IDs on that CG. In some embodiments, a WTRU may select between CGs or CG resources based on whether the traffic is related to data at the WTRU itself or data received from one or more AloT devices. For example, the WTRU may transmit all AloT traffic on a dedicated CG or CG resource.

[0142] In some embodiments, a WTRU may select between CGs or CG resources based on the command type (e.g., indicated or configured by the network), as described herein. For example, a WTRU may send the responses received from transmitting one AloT command in a first CG or CG resource and send the responses received from transmitting a second AloT command in a second CG or CG resource. In some embodiments, a WTRU may select between CGs or CG resources based on the size of message received from the device. For example, the WTRU may be configured with a range of message sizes in which to use a particular CG or CG resource.

[0143] In some embodiments, a WTRU may select between CG or CG resources based on device type or device capabilities. For example, transmissions from devices that support autonomous WTRU transmissions can be forwarded on one specific CG or CG resource. For example, transmissions from a device that support only backscattering can be forwarded, for example, on one specific CG or CG resource. In some embodiments, a WTRU may select between CG or CG resources based on an indication from the network (e.g., in a dynamic grant). The WTRU may receive an indication (e.g., in the DL message, which may contain the command) of the CG resource to use, or an indication to change the CG resource.

[0144] In some embodiments, a WTRU may be configured to send CG-uplink control information (UCI) (e.g., on PUCCH resources, using SR, using BSR, and / or using a RACH resource,) in any of the following cases: the WTRU sends a command of a specific type (as indicated by the network) and the WTRU does not receive any response within a configured period of time; a condition on the received (e.g., relative) power associated with the different devices is met; and / or the WTRU sends a command of a specific type (as indicated by the network), and the WTRU detects multiple transmissions from different AloT devices, such that: the WTRU is unable to decode at least one (or a configured number X) device ID and / or the WTRU is unable to decode all of the device IDs.

[0145] In some embodiments associated with transport block (TB) creation for transmission to the device, the WTRU may be configured with certain restrictions associated with creation of a TB and how to include data into a transport block. Such restrictions may include any of restrictions on the multiplexing of data with control or restrictions on the multiplexing of the number of SDUs received, such as by the MAC layer from upper layers.

[0146] Regarding restrictions on the multiplexing of data with control, for example, a WTRU may not be allowed to transmit control by itself. For example, control may only be included in a TB if the WTRU has data to send, and the control and data may be included in the same TB. For another example, a WTRU may only be allowed to transmit control of a specific type (or from a specific logical channel) with data of a specific type (or from a specific logical channel). For example, a TB can be composed of data of a first logical channel and a third logical channel only, or composed of data of a second logical channel and a fourth logical channel only, but cannot contain data from a first logical channel and a second logical channel together (or data from a third logical channel or fourth logical channel).

[0147] Regarding restrictions on the multiplexing of the number of SDUs received (e.g., received by the MAC layer from upper layers), for example, a WTRU may be allowed to include a maximum of X SDUs, where X may be any combination of: configured by the network (e.g., a maximum number explicitly configured); dependent on the type of device to which the WTRU is transmitting to (for example, device type 1 may have a first maximum number of SDUs allowed to be transmitted in a TB, and device type 2 may have a second number of SDUs allowed to be transmitted in a TB); and / or dependent on measurements of the WTRU made on the AloT interface (i.e., measurements of the device transmission). For example the number of SDUs may depend on measurements of the AloT interface such as RSRP or RSSI. For another example, the number of SDUs that can be included in a TB may depend on the control information (e.g., MAC CE or RRC message) that will be included in the TB. For example, if a first type of RRC message is included in a TB, the WTRU may be allowed to include only one data SDU, while in other cases, the WTRU may be allowed to include more than one SDU.

[0148] FIG. 6 is a signal diagram of an example of a method of small data transmission (SDT)-based access to AloT via an intermediate node (WTRU) 604. In the example illustrated in FIG. 6, an intermediate node (WTRU) 604 receives a release message 608 from a base station 602. The release message 608 may contain a configuration for an inventory procedure and a list of AloT device IDs, which configuration may allow the WTRU to transmit multiple AloT messages on the AloT interface, for example to AloT devices in the list. In some embodiments, the multiple AloT messages may be transmitted consecutively. The contents of the of these messages (illustrated as query 610 and query rep 612 in FIG. 6) may be defined in the release message. The query and query rep messages are similar to the query and query rep messages illustrated in FIG. 2 for an RFID procedure, and the query rep message 612 signifies the start of inventory round / inventory occasion and, in this case, the start of inventory occasion 650a.

[0149] In response to one of the messages from the WTRU 604 (e.g., the query 610 or a subsequent query rep, such as query rep 612), any AloT device that receives it, such as the AIOT device 606 in FIG. 6, may send an AloT message 614 to the WTRU 604 during a first inventory occasion 650a. The message 614 may include the ID of the transmitting AloT device 606 as well as some message content, such as a command. Upon reception of a message 614 during a first inventory occasion 650a, the WTRU 604 may initiate a process of checking for the conditions to trigger a resume to connected mode (616). If a condition associated with the received device ID in the transmission by an AloT device is met, such as by determining a device ID received from the AloT device is one of the IDs in the list received in the release message 608, the WTRU may trigger a resume procedure to enter RRC_CONNECTED. In the first inventory occasion 650a illustrated in FIG. 6, however, the condition is not met, and the WTRU 604 transmits the received AloT message 619 (including the ID) to a base 602 in the next CG SDT resource 618a.

[0150] The WTRU may further receive data from the DL, using DL SDT in some embodiments. In the example illustrated in FIG. 6, during the first inventory occasion 650a, the base station 602 sends a DL-SDT transmission 620 (before the next CG occasion). Upon reception of such DL transmission, the WTRU 604 may trigger a transmission to the AloT device 606 on the AloT link. The contents of the transmission may been previously configured by the network or included in the DL SDT transmission 620 itself. In the example illustrated in FIG. 6, the WTRU 604 sends a Read Command 622 to the AloT device 606 and, in response thereto, the WTRU 604 may receive data from the AloT device 606 intended for the base station 602. Reception of the DL SDT transmission 620 may trigger the WTRU 604 to provide any data received from the AloT device using RACH-based UL SDT transmission instead of transmission using the CG SDT resources. In the example illustrated in FIG. 6, the WTRU 604 uses RACH-based UL-SDT to send data 629 to the base station 602.

[0151] Prior to the to the next CG occasion 618b, the WTRU 604 may begin a second inventory occasion 650b by sending another query rep 628 to the AloT device 606. In some embodiments, the query rep transmission 628 may be initiated at some configured time prior to the next CG resource occasion 618b. For any specific query rep transmission, such as the query rep transmission 618b, failure of the any AloT device, such as the AloT device 606, to transmit may result in the WTRU sending a CG UCI, such as the UCI 632, to the base station 602, in the next CG occasion, such as the CG occasion 618b in FIG. 6.

[0152] During the inventory occasion 650b, the WTRU 604 may initiate a process of checking for the conditions to trigger a resume to connected mode (631). If a condition associated with the received device ID in the transmission by an AloT device is met, such as by determining a device ID received from the AloT device is one of the IDs in the list received in the release message 608, the WTRU may trigger a resume procedure to enter RRC_CONNECTED. In the second inventory occasion 650b illustrated in FIG. 6, the condition is met, and the WTRU 604 transmits the received UCI 632 (including the device ID) to a base 602 in the next CG SDT resource 618a. In this case, the WTRU 604 triggers a resume to RRC-CONNECTED prior to transmitting the UCI 632 to the base station 602.

[0153] FIG. 7 is a flow diagram 700 of an example method of small data transmission (SDT)-based access to AloT via an intermediate node (WTRU), such as illustrated in the signal diagram of FIG. 6. In the example illustrated in FIG. 7, a WTRU may receive a release message from a base station (702). In some embodiments, the release message is a release to an inactive state message, which may include a configuration for a small data transmission (SDT)-based inventory procedure, a list of ambient internet-of-things (AloT) device identifiers (IDs), and a first container including contents of one or more messages to be transmitted over a second interface. This release message may be received, by the WTRU, over the Uu interface. In some embodiments, the configuration may indicate UL-SDT resources, which may include one or more of UL-SDT CG resources and / or RACH-based SDT resources. The WTRU may initiate the inventory procedure (704) by transmitting, over an AloT interface, one or more messages using the contents of the container. These messages may, for example, be the query and / or query messages 610 and / or 612 of FIG. 6.

[0154] The WTRU may receive an AloT message from an AloT device (706). The AloT message may be received over the AloT interface of link. The AloT message may include an ID of transmitting AloT device. The AloT message may additionally include at least one command.

[0155] The WTRU may determine whether the device ID received in the AloT message is in the list of AloT device IDs received in the release message (708). In some embodiments, the WTRU may determine whether to use UL SDT based on the WTRU ID received from an AloT device, and, if UL SDT is used, the WTRU may determine which type of UL SDT (CG-based or RACH-based) to use based on whether the WTRU is sending the ID of an AloT device or the response of a network initiated command.

[0156] Based on the WTRU determining (708) that the device ID received in the at AloT message is in the list of AloT device IDs received in the release message, the WTRU may trigger a resume to connected mode (710) and transmit the command received in the AloT message to the base station (712). If the device ID in the AloT message is not on the list provided by the base station, the WTRU may transmit the device ID provided in the second message to the base station (714). While the embodiment illustrated in FIGs. 6 and 7 may imply that only one AloT device may respond to the intermediate node initiating an inventory procedure, any number of AloT devices may respond to the intermediate node during any inventory procedure or round.

[0157] More specifically, for example, for each PDU or transmission received (e.g., using DL-SDT and / or received from the network) that includes a command or command container of a first type (e.g., first message of each occasion), the WTRU may transmit the command or command container (e.g., on the AloT interface and / or to at least one device), receive a device ID from a device (e.g., via a RACH transmission), and determine whether to transmit the received device ID to the network using an UL-SDT CG resource. For example, if the received device ID matches one of the device IDs in the list provided in the release message, the WTRU may transmit the device ID to the network using an UL-SDT CG resource. Alternatively, for example, if the received device ID does not match one of the device IDs in the list provided in the release message, the WTRU may transmit the device ID to the network using an UL-SDT CG resource.

[0158] If the WTRU determines to transmit the received device ID using a UL-SDT CG resource, the WTRU may perform one or more of the following: transmitting the received device ID in a first (e.g., earliest) UL-SDT CG resource that occurs after receiving the device ID and transmitting a response command via the second interface using the received device ID. The transmitted response may be a predefined response in some embodiments. Following transmission of the device ID using the first interface (e.g., to the network), if the WTRU receives a DL message (e.g., from the network) before a second UL-SDT CG resource (which occurs after the first UL-SDT CG resource) and the DL message includes a command (or command container) of a second type, the WTRU may perform one or more of transmitting the command or command container of the second type (e.g., read / write command) over the second interface (e.g., to the AloT device) using the received device ID and / or, if a response to the command of the second type is received (e.g., via the second interface), transmitting the response to the network (e.g., via the first interface) using RACH-based SDT resources.

[0159] Although features and elements are described above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with the other features and elements. In addition, the methods described herein may be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted over wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magnetooptical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

CLAIMSWhat is Claimed:

1. A method, implemented in a wireless transmit / receive unit (WTRU), the method comprising: receiving, from a base station, a release message, wherein the release message comprises a list of ambient internet-of-things (AloT) device identifiers (IDs); receiving at least one AloT message from at least one AloT device, wherein the at least one AloT message comprises a device ID of the at least one AloT device; on a condition that the device ID received in the at least one AloT message is in the list of AloT device IDs received in the release message: triggering a resume to connected mode, and sending a transmission to the base station; and on a condition that the device ID received in the at least one AloT message is not in the list of AloT device IDs received in the release message, sending the transmission to the base station using UL SDT without triggering a resume to connected mode.

2. The method of claim 1 , wherein the release message further comprises: one or more messages for one or more AloT devices corresponding to the AloT device IDs in the list, and a configuration for an SDT-based inventory procedure, wherein the configuration comprises an indication of one or more UL SDT configured grant (CG) resources and random access channel (RACH)-based SDT resources.

3. The method of claim 2, further comprising initiating the SDT-based inventory procedure by transmitting the one or more messages to the one or more AloT devices.

4. The method of claim 3, wherein the at least one AloT message further comprises responses to at least some of the one or more messages, and wherein the transmission comprises the device IDs and the responses.

5. The method of claim 4, further comprising sending the device IDs to the base station using UL SDT and the UL SDT CG resources.

6. The method of claim 5, further comprising sending the device IDs to the base station in the first UL SDT CG resource after receiving the device ID.

7. The method of claim 5, further comprising sending the responses to the base station using UL SDT and the RACH-based SDT resources.

8. The method of claim 4, wherein the one or more messages comprise READ commands, and the responses comprise data for the base station.

9. The method of claim 1 , wherein the WTRU is a relay or an intermediate WTRU.

10. A wireless transmit / receive unit (WTRU) comprising: a processor; and a transceiver, wherein the processor and the transceiver are configured to receive, from a base station, a release message, wherein the release message comprises a list of ambient internet-of-things (AloT) device identifiers (IDs), wherein the processor and the transceiver are further configured to receive at least one AloT message from at least one AloT device, wherein the at least one AloT message comprises a device ID of the at least one AloT device, wherein the processor and the transceiver are further configured to, on a condition that the device ID received in the at least one AloT message is in the list of AloT device IDs received in the release message: trigger a resume to connected mode, and send a transmission to the base station, and wherein the processor and the transceiver are further configured to, on a condition that the device ID received in the at least one AloT message is not in the list of AloT device IDs received in the release message, send the transmission to the base station using UL SDT without triggering a resume to connected mode.

11. The WTRU of claim 10, wherein the release message further comprises: one or more messages for one or more AloT devices corresponding to the AloT device IDs in the list, and a configuration for an SDT-based inventory procedure, wherein the configuration comprises an indication of one or more UL SDT configured grant (CG) resources and random access channel (RACH)-based SDT resources.

12. The WTRU of claim 11 , wherein the processor and the transceiver are further configured to initiate the SDT-based inventory procedure by transmitting the one or more messages to the one or more AloT devices.

13. The WTRU of claim 12, wherein the at least one AloT message further comprises responses to at least some of the one or more messages, and wherein the transmission comprises the device IDs and the responses.

14. The WTRU of claim 13, wherein the processor and the transceiver are further configured to send the device IDs to the base station using UL SDT and the UL SDT CG resources.

15. The WTRU of claim 14, wherein the processor and the transceiver are further configured to send the device IDs to the base station in the first UL SDT CG resource after receiving the device ID.

16. The WTRU of claim 13, wherein the processor and the transceiver are further configured to send the responses to the base station using UL SDT and the RACH-based SDT resources.

17. The WTRU of claim 13, wherein the one or more messages comprise READ commands, and the responses comprise data for the base station.

18. The WTRU of claim 10, wherein the WTRU is a relay or an intermediate WTRU.

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