Methods and appartuses for mobility actions related to uplink traffic and radio signal levels in wireless communications

Abstract

Systems, methods, devices, and instrumentalities are described herein related to enhancements based on predictive traffic and radio conditions in wireless systems. A wireless transmit / receive unit (WTRU) may receive configuration information associated with an initiation of an action related to mobility. The configuration information may include trigger condition(s) associated with the initiation of the action related to mobility. In examples, the trigger condition(s) may include a predicted or current uplink (UL) buffer data threshold, a predicted or current radio signal level threshold. The WTRU may determine at least one of: a current or predicted radio signal level of a cell, or a current or predicted UL buffer data level. The WTRU may monitor the trigger condition(s). Based on the trigger condition(s) being satisfied, the WTRU may select the action related to mobility. The WTRU may perform the selected action related to mobility.

Description

METHODS AND APPARTUSES FOR MOBILITY ACTIONS RELATED TO UPLINK TRAFFIC AND RADIO SIGNAL LEVELS IN WIRELESS COMMUNICATIONSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of Provisional U.S. Patent Application No. 63 / 531 ,172, filed August 7, 2023, the disclosure of which is incorporated herein by reference in its entirety.BACKGROUND

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

[0003] Systems, methods, devices, and instrumentalities are described herein related to enhancements based on predictive traffic and radio conditions in wireless systems.

[0004] A wireless transmit / receive unit (WTRU) may receive configuration information associated with an initiation of an action related to mobility. In examples, configuration information may be received via a radio resource control (RRC) reconfiguration message. The configuration information may include at least one trigger condition associated with the initiation of the action related to mobility. In examples, the at least one trigger condition may include a predicted or current uplink (UL) buffer data threshold (e.g., buffer value(s) for a bearer or subset of bearer(s) associated with the predicted or current UL buffer data threshold, buffer value(s) for an application identification (ID) or subset of application I D(s) associated with the predicted or current UL buffer data threshold), a predicted or current radio signal level threshold.

[0005] The WTRU may determine at least one of: a current or predicted radio signal level of a cell, or a current or predicted UL buffer data level. The WTRU may monitor the at least one trigger condition. Based on the at least one trigger condition being satisfied, the WTRU may select the action related to mobility. Inexamples, based on the current or predicted UL buffer data level satisfying the current or predicted UL buffer data threshold (e.g., based on the predicted buffer value(s) associated with a bearer or subset of bearer(s) or predicted buffer value(s) associated with an application ID or subset of application I D(s) satisfying the current or predicted UL buffer data threshold), the WTRU may select the action related to mobility. In examples, based on the current or predicted radio signal level of a cell satisfying the current or predicted radio signal level threshold, the WTRU may select the action related to mobility. The WTRU may perform the selected action related to mobility.

[0006] In examples, the action related to mobility may be at least one of: an initiation of a randomaccess channel (RACH) procedure with a target cell, sending a channel state information (CSI) report of a neighbor cell, or an evaluation of a conditional reconfiguration. In examples, the action related to mobility may be an action related to L1 / L2 based triggered mobility (LTM). The action related to LTM may be at least one of: an early timing advance (TA) acquisition, switching off CSI reporting, switching on or updating a CSI reporting configuration, performance of an LTM cell switch, monitoring a physical downlink control channel (PDCCH) on a target cell, performance of buffer failure detection (BFD) or radio link monitoring (RLM) on the target cell, activation or deactivation of a secondary cell (SCell), an initiation of a buffer status report (BSR), or an initiation of a report that indicates a traffic data amount.BRIEF DESCRIPTION OF THE DRAWINGS

[0007] A more detailed understanding may be had from the detailed description below, given by way of example in conjunction with drawings appended hereto. Figures in such drawings, like the detailed description, are examples. As such, the Figures (FIGs.) and the detailed description are not to be considered limiting, and other equally effective examples are possible and likely. Furthermore, like reference numerals ("ref.") in the FIGs. indicate like elements, and wherein:

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

[0009] 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.

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

[0011] FIG. 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.

[0012] FIG. 2 illustrates an example of a measurement model.

[0013] FIG. 3 illustrates an example of Inter-cell L1 / 2 triggered mobility (LTM) using carrier aggregation(CA).

[0014] FIG. 4 illustrates an example of a current LTM signaling procedure.

[0015] FIG. 5 illustrates an example of an updated LTM baseline procedure.

[0016] FIG. 6 illustrates an example of a time series prediction for reference signal reference power(RSRP).DETAILED DESCRIPTION

[0017] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of embodiments and / or examples disclosed herein. However, it will be understood that such embodiments and examples may be practiced without some or all of the specific details set forth herein. In other instances, well-known methods, procedures, components and circuits have not been described in detail, so as not to obscure the following description. Further, embodiments and examples not specifically described herein may be practiced in lieu of, or in combination with, the embodiments and other examples described, disclosed or otherwise provided explicitly, implicitly and / or inherently (collectively "provided") herein. Although various embodiments are described and / or claimed herein in which an apparatus, system, device, etc. and / or any element thereof carries out an operation, process, algorithm, function, etc. and / or any portion thereof, it is to be understood that any embodiments described and / or claimed herein assume that any apparatus, system, device, etc. and / or any element thereof is configured to carry out any operation, process, algorithm, function, etc. and / or any portion thereof.

[0018] The methods, procedures, apparatuses and systems provided herein are well-suited for communications involving both wired and wireless networks. An overview of various types of wireless devices and infrastructure is provided with respect to FIGs. 1A-1 D, where various elements of the network may utilize, perform, be arranged in accordance with and / or be adapted and / or configured for the methods, apparatuses and systems provided herein.

[0019] 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 accesssystem that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique-word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block-filtered OFDM, filter bank multicarrier (FBMC), and the like.

[0020] As shown in FIG. 1 A, the communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a RAN 104 / 113, a ON 106 / 115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a “station” and / or a “ST A”, 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.

[0021] The communications systems 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106 / 115, the Internet 110, and / or the other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a gNB, a NR NodeB, a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will beappreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0022] The base station 114a may be part of the RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and / or the base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to 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.

[0023] 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).

[0024] More specifically, as noted above, the communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 115 / 116 / 117 using wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink (DL) Packet Access (HSDPA) and / or High-Speed UL Packet Access (HSUPA).

[0025] 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).

[0026] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR Radio Access, which may establish the air interface 116 using New Radio (NR).

[0027] 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., a eNB and a gNB).

[0028] 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.

[0029] The base station 114b in FIG. 1 A 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. 1 A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 via the CN 106 / 115.

[0030] The RAN 104 / 113 may be in communication with the CN 106 / 115, which may be any type of network configured to provide voice, data, applications, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like.The CN 106 / 115 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not shown in FIG. 1 A, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may be utilizing a NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) employing a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0031] The CN 106 / 115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or the other networks 112. The PSTN 108 may include circuit- switched telephone networks that provide plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use 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 / 113 or a different RAT.

[0032] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0033] FIG. 1 B is a system diagram illustrating an example WTRU 102. As shown in FIG. 1 B, the WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138, among others. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0034] 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 SpecificIntegrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. While FIG. 1 B depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0035] The transmit / receive element 122 may be configured to transmit signals to, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It will be appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0036] Although the transmit / receive element 122 is depicted in FIG. 1 B as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0037] 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.

[0038] 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 mayinclude 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).

[0039] 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.

[0040] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, the information from the GPS chipset 136, the WTRU 102 may receive location information over the air interface 116 from a base station (e.g., base stations 114a, 114b) and / or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by way of any suitable locationdetermination method while remaining consistent with an embodiment.

[0041] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photographs and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a Virtual Reality and / or Augmented Reality (VR / AR) device, an activity tracker, and the like. The peripherals 138 may include one or more sensors, the sensors may be one or more of a gyroscope, an accelerometer, a hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0042] The WTRU 102 may include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the UL (e.g., for transmission) and downlink (e.g., for reception) may be concurrent and / or simultaneous. The full duplex radio may include aninterference management unit to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WRTU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the uplink (UL) (e.g., for transmission) or the downlink (e.g., for reception)).

[0043] FIG. 1 C 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.

[0044] 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.

[0045] Each of the eNode-Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, and the like. As shown in FIG. 1 C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0046] The CN 106 shown in FIG. 1 C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. While each of the foregoing elements are depicted as part of the CN 106, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] In representative embodiments, the other network 112 may be a WLAN.

[0053] A WLAN in Infrastructure Basic Service Set (BSS) mode may have an Access Point (AP) for the BSS and one or more stations (ST As) associated with the AP. The AP may have an access or an interface to a Distribution System (DS) or another type of wired / wireless network that carries traffic in to and / or out of the BSS. Traffic to ST As that originates from outside the BSS may arrive through the AP and may be delivered to the ST As. 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 usean 802.11 e DLS or an 802.11 z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and the ST As (e.g. , all of the ST As) 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.

[0054] When using the 802.11 ac infrastructure mode of operation or a similar mode of operations, the AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling. The primary channel may be the operating channel of the BSS and may be used by the STAs to establish a connection with the AP. In certain representative embodiments, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) may be implemented, for example in in 802.11 systems. For CSMA / CA, the STAs (e.g., every STA), including the AP, may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0055] 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.

[0056] Very High Throughput (VHT) STAs may support 20MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. The 40 MHz, and / or 80 MHz, channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining 8 contiguous 20 MHz channels, or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, the data, after channel encoding, may be passed through a segment parser that may divide the data into two streams. Inverse Fast Fourier Transform (IFFT) processing, and time domain processing, may be done on each stream separately. The streams may be mapped on to the two 80 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).

[0057] Sub 1 GHz modes of operation are supported by 802.11 af and 802.11 ah. The channel operating bandwidths, and carriers, are reduced in 802.11 af and 802.11 ah relative to those used in 802.11 n, and 802.11 ac. 802.11 af supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11 ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11 ah may support Meter Type Control / Machine-Type Communications, such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and / or limited bandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0058] WLAN systems, which may support multiple channels, and channel bandwidths, such as 802.11 n, 802.11 ac, 802.11af, and 802.11 ah, include a channel which may be designated as the primary channel. The primary channel may have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a ST A, from among all STAs in operating in a BSS, which supports the smallest bandwidth operating mode. In the example of 802.11 ah, the primary channel may be 1 MHz wide for STAs (e.g., MTC type devices) that support (e.g., only support) a 1 MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or Network Allocation Vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, due to a STA (which supports only a 1 MHz operating mode), transmitting to the AP, the entire available frequency bands may be considered busy even though a majority of the frequency bands remains idle and may be available.

[0059] 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.

[0060] FIG. 1 D is a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment. As noted above, the RAN 113 may employ an NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0061] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 108b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a. In an embodiment, thegNBs 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).

[0062] The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using transmissions associated with a scalable numerology. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using subframe or transmission time intervals (TTIs) of various or scalable lengths (e.g, containing varying number of OFDM symbols and / or lasting varying lengths of absolute time).

[0063] 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.

[0064] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support of network slicing, dual connectivity, interworking between NR and E- UTRA, routing of user plane data towards User Plane Function (UPF) 184a, 184b, routing of control plane information towards Access and Mobility Management Function (AMF) 182a, 182b and the like. As shown in FIG. 1D, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0065] The CN 115 shown in FIG. 1 D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. While each of the foregoing elements are depicted as part of the CN 115, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0066] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling of different PDU sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of NAS signaling, mobility management, and the like. Network slicing may be used by the AMF 182a, 182b in order to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for machine type communication (MTC) access, and / or the like. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0067] The SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN 115 via an N11 interface. The SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN 115 via an N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating WTRU IP address, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, and the like. A PDU session type may be IP-based, non-IP based, Ethernet-based, and the like.

[0068] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet- switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, and the like.

[0069] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to a local Data Network (DN) 185a, 185b through the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0070] In view of Figures 1A-1D, and the corresponding description of Figures 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.

[0071] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and / or in an operator network environment. For example, the one or more emulation devices may perform the one or more, or all, functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. The one or more emulation devices may perform the one or more, or all, functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device may be directly coupled to another device for purposes of testing and / or may performing testing using over-the-air wireless communications.

[0072] 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.

[0073] Reference to a timer herein may refer to determination of a time or determination of a period of time. Reference to a timer expiration herein may refer to determining that the time has occurred or that the period of time has expired. Reference to a timer herein may refer to a time, a time period, tracking the time, tracking the period of time, etc.

[0074] Systems, methods, devices, and instrumentalities are described herein related to enhancements based on predictive traffic and radio conditions in wireless systems.

[0075] A wireless transmit / receive unit (WTRU) may receive configuration information associated with an initiation of an action related to mobility. In examples, configuration information may be received via a radio resource control (RRC) reconfiguration message. The configuration information may include at least one trigger condition associated with the initiation of the action related to mobility. In examples, the at least one trigger condition may include a predicted or current uplink (UL) buffer data threshold (e.g., buffer value(s) for a bearer or subset of bearer(s) associated with the predicted or current UL buffer data threshold, buffer value(s) for an application identification (ID) or subset of application I D(s) associated with the predicted or current UL buffer data threshold), a predicted or current radio signal level threshold.

[0076] The WTRU may determine at least one of: a current or predicted radio signal level of a cell, or a current or predicted UL buffer data level. The WTRU may monitor the at least one trigger condition. Based on the at least one trigger condition being satisfied, the WTRU may select the action related to mobility. In examples, based on the current or predicted UL buffer data level satisfying the current or predicted UL buffer data threshold (e.g., based on the predicted buffer value(s) associated with a bearer or subset of bearer(s) or predicted buffer value(s) associated with an application ID or subset of application I D(s) satisfying the current or predicted UL buffer data threshold), the WTRU may select the action related to mobility. In examples, based on the current or predicted radio signal level of a cell satisfying the current or predicted radio signal level threshold, the WTRU may select the action related to mobility. The WTRU may perform the selected action related to mobility.

[0077] In examples, the action related to mobility may be at least one of: an initiation of a randomaccess channel (RACH) procedure with a target cell, sending a channel state information (CSI) report of a neighbor cell, or an evaluation of a conditional reconfiguration. In examples, the action related to mobility may be an action related to L1 / L2 based inter-cell mobility (LTM). The action related to LTM may be at least one of: an early timing advance (TA) acquisition, switching off CSI reporting, switching on or updating a CSI reporting configuration, performance of an LTM cell switch, monitoring a physical downlink control channel (PDCCH) on a target cell, performance of buffer failure detection (BFD) or radio link monitoring (RLM) onthe target cell, activation or deactivation of a secondary cell (SCell), an initiation of a buffer status report (BSR), or an initiation of a report that indicates a traffic data amount.

[0078] A WTRU may be configured with triggering condition(s) (e.g., predicted / current radio condition(s), predicted / current buffer levels, an explicit indication from the network to perform neighbor cell preparation such as UL synch, etc.,) for sending an indication to the network regarding predicted UL buffer levels. The WTRU may monitor the triggering conditions. If the triggering conditions are fulfilled, the WTRU may send an indication to the network indicating (e.g., either explicit or implicit) one or more of current / predicted BSR. A WTRU may be configured with triggering condition(s) (e.g., predicted / current radio condition(s), predicted / current buffer levels, etc.) for initiating an action (e.g., UL synch to a neighbor cell, CSI / CQI reporting of neighbor cells, evaluation of a conditional reconfiguration criteria, etc.). The WTRU may monitor the triggering condition(s). If the triggering condition(s) are fulfilled, the WTRU may initiate the corresponding action. A WTRU may be configured with condition(s) for deferring a handover (HO) (e.g., a time window from the reception of the HO command or fulfillment of condition handover (CHO) condition(s), current / predicted UL buffer levels, current / predicted signal levels of source / target cell, etc.). The WTRU may defer the HO if (e.g., as long as) the condition(s) for deferring the HO are fulfilled and transmit data via the source. The WTRU may execute the HO and transmit data via the target if the condition(s) are not (e.g., when the conditions are no longer) fulfilled. The WTRU may determine the best target cell based on current UL buffer and grant at targets.

[0079] Examples describing measurements in the radio access network (RAN) and on mobility procedures in the RAN2, named L1 / L2 triggered mobility (LTM), are provided herein.

[0080] FIG. 2 illustrates an example of a measurement model. In RRC_CONNECTED, the WTRU may measure multiple beams (e.g., at least one) of a cell. The measurements results (e.g., power values) may be averaged to derive the cell quality. The WTRU may be configured to consider a subset of the detected beams. Filtering may take place at two different levels: at the physical layer to derive beam quality and (e.g., and then) at the RRC level to derive cell quality from multiple beams. Cell quality from beam measurements may be derived in the same way for the serving cell (s) and for the non-serving cell (s). Measurement reports may include the measurement results of the X best beams if the WTRU is configured to do so by the gNB.

[0081] FIG. 3 illustrates an example of Inter-cell L1 / 2 triggered mobility (LTM) using carrier aggregation (CA). In FIG. 3, the candidate cell group may be configured by an RRC and a dynamic switch of PCell and SCell may be achieved using L1 / 2 signaling.

[0082] Examples of inter-cell beam management may be used which can manage the beams in CA cases, but no cell change / add may be supported. Examples specifying mechanisms and procedures of L1 / L2 based inter-cell mobility for mobility latency reduction are provided herein.

[0083] To specify mechanism and procedures of L1 / L2 based inter-cell mobility for mobility latency reduction, configuration and maintenance for multiple candidate cells may allow fast application of configurations for candidate cells (e.g. , RAN2, RAN1). To specify mechanism and procedures of L1 / L2 based inter-cell mobility for mobility latency reduction, dynamic switch mechanisms among candidate serving cells (e.g., including SpCell and SCell) for the potential applicable scenarios based on L1 / L2 signaling (e.g., RAN2, RAN1) may be provided. To specify mechanism and procedures of L1 / L2 based inter-cell mobility for mobility latency reduction, L1 enhancements for inter-cell beam management, including L1 measurement and reporting, and beam indication (e.g, RAN1 , RAN2) may be provided (e.g, early RAN2 involvement may be necessary, including the possibility of further clarifying the interaction between this bullet with the previous bullet). To specify mechanism and procedures of L1 / L2 based intercell mobility for mobility latency reduction, examples of timing advance management (e.g, RAN1 , RAN2) may be provided. To specify mechanism and procedures of L1 / L2 based inter-cell mobility for mobility latency reduction, central unit-distributed unit (CU-DU) interface signaling to support L1 / L2 mobility (e.g, if needed, RAN3) may be provided.

[0084] The procedure of L1 / L2 based inter-cell mobility may be applicable to one or more of the following scenarios: standalone, CA and dual connectivity (DC) cases with serving cell changes within one cell group (CG); intra-DU cases and intra-CU inter-DU cases (e.g, applicable for standalone and CA: no new RAN interfaces are expected); both intra-frequency and inter-frequency; both FR1 and FR2; source and target cells that may be synchronized or non-synchronized; or if inter-CU cases are not included.

[0085] L1 / L2 based mobility and inter-cell beam management may address intra-DU and intra-frequency scenarios. The serving cell may remain unchanged (e.g, there is no possibility to change the serving cell using L1 / 2 based mobility). In FR2 deployments, CA may be used in order to exploit the available bandwidth (e.g, to aggregate multiple CCs in one band). These component carriers (CCs) may be transmitted with the same analog beam pair (e.g, gNB beam and WTRU beam). The WTRU may be configured with transmission configuration indicator (TCI) states (e.g, can have fairly large number such as 64) for reception of physical downlink control channel (PDCCH) and physical data shared channel (PDSCH). The TCI states (e.g, each TCI state) may include a reference signal (RS) or synchronization signal block (SSB) that the WTRU refers to for setting its beam. The SSB may be associated with a non-serving physical cell ID (PCI). Medium access control (MAC) signaling (TCI state indication for WTRU- specific PDCCH MAC CE) may activate the TCI state for a CORESET / PDCCH. Reception of PDCCH from a non-serving cell may be supported by a MAC CE indicating a TCI state associated to a non-serving PCI. MAC signaling (TCI States Acti vation / Deacti vation for WTRU-specific PDSCH) may activate a subset of (up to) 8 TCI states for PDSCH reception. Downlink control information (DCI) may indicate which of the 8 TCI states. A unified TCI state may (e.g., may also) be supported with a different updating mechanism (e.g., DCI-based), but without multi transmission / reception point (multi-TRP). A unified TCI state with multi-TRPs may (e.g., may also) be supported.

[0086] LTM may improve handover latency. With a conventional L3 handover or conditional handover, the WTRU may typically first send a measurement report using RRC signaling. In response to the measurement report, the network may provide a further measurement configuration and potentially a conditional handover configuration. With a conventional handover, the network may provide a configuration for a target cell (e.g., after the WTRU reports, using RRC signaling, that the cell meets a configured radio quality criteria). With conditional handover, in order to reduce the handover failure rate due to the delay in sending a measurement report then receiving an RRC reconfiguration the network provides, a target cell configuration as well as a measurement criteria (e.g., which may determine if the WTRU should trigger the CHO configuration) may be provided (e.g., in advance). Both conventional and conditional handover L3 examples may include some amount of delay due to the sending of measurement reports and receiving of target configurations (e.g., particularly in case of the conventional (non-conditional) handover).

[0087] LTM may allow for fast application of configurations for candidate cells, including dynamically switching between SCells and switching of the PCell (e.g., switching the roles between SCell and PCell) without performing RRC signaling. The inter-CU case may not be included, as this may require relocation of the packet data convergence protocol (PDCP) anchor. An RRC based approach may be provided at least to support inter-CU handover. With legacy L3 handover mechanisms, any currently active SCell (s) may be released before the WTRU completes the handover to a target cell in the coverage area of a new site. The currently active SCell(s) may (e.g., may only) be added back after successful handover, which may lead to throughput degradation during handover. L1 / 2 may enable CA operations to be enabled instantaneously when a serving cell changes.

[0088] FIG. 4 illustrates an example of a current LTM signaling procedure. FIG. 5 illustrates an example of an updated LTM baseline procedure (e.g., RAN2). The procedure may execute mobility procedures using resources from L1 and L2 and is named L1 / L2 Triggered Mobility (LTM). The basics of the updatedLTM procedure are depicted in FIG. 4. The updated LTM procedure may provide enhancements to relevant information from the baseline mechanism. The updated procedure works by activating mobility via L2 signaling, namely, via a MAC control element (CE). The WTRU may be configured with a set of target cells with L3 signaling (e.g., LTM preparation) and may (e.g., may then) perform HO based on L2 MAC CE signaling (e.g., LTM execution), which may be faster than L3 legacy mobility. In between the preparation and execution phases, there may be a synchronization phase (e.g., not shown herein).

[0089] As shown in FIG. 5, the procedure for the updated LTM is as follows. At 1, the WTRU may send a MeasurementReport message to the gNB. The gNB may decide to use LTM and initiate LTM candidate preparation. At 2, the gNB may transmit an RRCReconfiguration message to the WTRU including the configuration of one or multiple LTM candidate target cells. At 3, the WTRU may store the configuration of LTM candidate target cell (s) and transmit a RRCReconfigurationComplete message to the gNB. At 4, the WTRU may perform downlink (DL) synchronization and TA acquisition with candidate target cell(s) before receiving the LTM cell switch command. DL synchronization for candidate cell(s) before cell switch command may be supported (e.g., at least based on SSB). TA acquisition of candidate cell(s) before an LTM cell switch command may be supported (e.g., at least based on PDCCH ordered RACH, where the PDCCH order may only be triggered by source cell. At 5, the WTRU may perform L1 measurements on the configured LTM candidate target cell(s) and may transmit lower-layer measurement reports to the gNB (e.g., whether the lower-layer measurement reports are carried on L1 or MAC). At 6, the gNB may decide to execute LTM cell switch to a target cell and may transmit a MAC CE triggering LTM cell switch by including the candidate configuration index of the target cell. The WTRU may switch to the configuration of the LTM candidate target cell. At 7, the WTRU may perform a random-access procedure towards the target cell (e.g, if TA is not available). At 8, the WTRU may indicate successful completion of the LTM cell switch towards target cell (e.g, whether an uplink signal or message after the WTRU has switched to the target cell may be used to indicate successful completion of the LTM cell switch).

[0090] Examples of Conditional Handover (CHO) are provided herein. CHO may reduce the number of failure occurrences while a user is moving (e.g, if a handover between cells fails, or if a connection fails even before a handover (HO) is triggered). In CHO (e.g, instead of preparing one target cell as in the legacy HO case), multiple candidate target cells may be prepared in advance by the network. This may enable the HO command to be sent to the WTRU earlier than conventional when the radio conditions are still good (e.g, rather than when conditions start to degrade as in legacy HO).

[0091] If receiving the CHO command, the WTRU may store the command (e.g., instead of applying it immediately). The WTRU may (e.g., may only) apply the stored command if a condition configured in the WTRU is satisfied for one of the configured candidate target cells. The WTRU may execute (e.g., may then execute) the HO and connect to the target cell as in a legacy HO.

[0092] In the context of mobility robustness optimization (MRO), CHO and Dual Access Protocol Stack (DAPS) may be applied in an attempt to decrease the number of failed HOs (e.g., mainly for WTRUs in mobility). CHO may aim at this, while in DAPS, there may be continued Tx / Rx in the source cell (e.g., even after HO has been decided and not yet completed, in an attempt to reduce HO interruption time for URLLC).

[0093] In CHO, the RAN may give the WTRU a condition to monitor. This can be either an event CondEvent_A3 (current cell measurement below a threshold #1) or CondEvent_A5 (current cell measurement below a threshold #1 and candidate target cell measurement higher than a threshold #2). The WTRU may be able to monitor (e.g., also monitor): if conditions are better from other cells other than the ones informed by the RAN; if radio conditions are good enough and provide enough stability in other cells in the list provided by the RAN, but with less priority.

[0094] DAPS HO may be characterized by: continued transmission in the source cell after receiving the HO request; simultaneous reception of user data from a source and target cell; and uplink transmission of user data switched to a target cell at completion of a random access procedure at a target cell. To be able to transmit downlink user data from both the source and target cell, the network may forward duplicate user data between the source and target cells. The simultaneous reception of User Plane (UP) data on the WTRU from both source and target cell may be a significant burden on RAN elements (e.g., noticeably the gNBs). Efficient strategies for data forwarding may be challenging on the basis that (e.g., in many cases) it may be difficult to predict the next target cell for a WTRU in mobility.

[0095] Examples of Buffer Status Reporting (BSR) are provided herein. The Buffer Status reporting (BSR) procedure may be used to provide the serving gNB with information about UL data volume in the MAC entity. RRC may configure the one or more of following parameters to control the BSR: periodicBSR- Timer; retxBSR-Timer; logicalChannelSR-DelayTimerApplied; logicalChannelSR-DelayTimer; logicalChannelSR-Mask; logicalChannelGroup, logicalChannelGroupI AB-Ext; or sdt-LogicalChannelSR- DelayTimer. The logical channels (e.g., each logical channel) may be allocated to a logical channel gropu (LCG) using the logicalChannelGroup. The maximum number of LCGs may be eight except for lAB-MTs configured with logicalChan nelGroup I AB-Ext, for which the maximum number of LCGs may be 256. TheMAC entity may determine the amount of UL data available for a logical channel according to the data volume calculation procedures.

[0096] Buffer status reporting has several triggering mechanisms. The content of these reports is described below. The fields in the BSR MAC CE may be defined as LCG ID, LCGi, and buffer size.

[0097] For LCG ID, the logical channel group ID field may identify the group of logical channel(s) whose buffer status is being reported. The length of the field may be 3 bits for the case of short BSR and short truncated BSR formats. The length of the field may be 8 bits for the case of extended short BSR and extended short truncated BSR formats.

[0098] For LCGi, for the long BSR format, extended long BSR format, pre-emptive BSR format, and extended pre-emptive BSR format, this field may indicate the presence of the buffer size field for the logical channel group i. The LCGi field set to 1 may indicate that the buffer size field for the logical channel group i is reported. The LCGi field set to 0 may indicates that the buffer size field for the logical channel group i is not reported. For the long truncated BSR format and the extended long truncated BSR format, this field may indicate whether logical channel group i has data available. The LCGi field set to 1 may indicate that logical channel group i has data available. The LCGi field set to 0 may indicate that logical channel group i does not have data available.

[0099] For buffer size, the buffer size field may identify the total amount of data available according to the data volume calculation procedures across logical channels (e.g., all logical channels) of a logical channel group after the MAC packet data unit (PDU) has been built (e.g., after the logical channel prioritization procedure, which may reduce the value of the buffer size field to zero). The amount of data may be indicated in number of bytes. The size of the radio link control (RLC) headers and MAC subheaders may not be considered in the buffer size computation. The length of this field for the short BSR format and the short truncated BSR format may be 5 bits. The length of this field for the extended short BSR format and the extended short truncated BSR format may be 8 bits. The length of this field for the long BSR format, the long truncated BSR format, the extended long BSR format, and the extended long truncated format may be 8 bits. For the long BSR format, the long truncated BSR format, the extended long BSR format, and the extended long truncated format, the buffer size fields may be included in ascending order based on the LCGi. For the long truncated BSR format and the extended long truncated format, the number of buffer size fields included may be maximized, while not exceeding the number of padding bits. For the pre-emptive BSR format and the extended pre-emptive BSR format, the buffer size field may identify the total amount of the data expected to arrive at the IAB-MT of the node where the pre-emptive BSR / extendedpre-emptive BSR is triggered and may not include the volume of data currently available in the IAB-MT. Pre-emptive BSR format may be identical to the long BSR format. Extended pre-emptive BSR format may be identical to the extended long BSR format.

[0100] Legacy mobility procedures (HO, CHO, etc.,) may be based on radio related measurements (e.g., neighbor cell becomes better than serving cell by more than a certain threshold) collected by the network from WTRUs or measured and applied for reconfiguration in the context of CHO. The network may (e.g., may also) trigger handovers based on load considerations of serving and neighbor cells, but these aspects may be left to network implementation. Legacy approaches may be reactive and slow to react to fast changing conditions at the WTRU / network. If the WTRU or the network can predict data traffic and / or signal levels of serving / neighbor cells (e.g., based on AI / ML models), the network may not rely on reactive mechanisms. Mobility decisions may be made in advance, thereby reducing the risk of radio link failures, handover failures, sudden / frequent overloading, and ensuring the QoS requirements of bearers (e.g., those with strict latency requirements) are fulfilled. Examples of enhancing WTRU mobility mechanisms by using the prediction of UL traffic and radio conditions are provided herein.

[0101] Performing LTM or performing LTM procedures may refer to performing any / all of the procedures described in FIG. 4. Specifically, for early synchronization in DL and / or UL to one or more of the candidate cells, performing LTM or performing LTM procedures may refer to performing L1 measurements and reporting on one or more of the candidate cells and / or switching (e.g., performing handover) between candidate cells. In examples, performing LTM may mean that the WTRU moves / switches between multiple candidate cells during the procedure.

[0102] The one or more candidate cell sets may be groups of more than one RRC configuration corresponding to a handover configuration for one or more candidate SpCells and optionally SCells. This may be modelled or received as one or more complete RRC reconfiguration messages, one or more cell group configurations, or one or more cell configurations. Each of the candidate cell configurations may include a candidate configuration identifier, and each of the candidate cell groups may include a candidate cell group identifier. If the grouping is performed at RRC, the switching between different sets of candidate cells may include updating the serving cell indexes or candidate configuration indexes which are used in L1 and MAC signaling to refer to specific indexes (e.g., a MAC CE triggering the reconfiguration may include a candidate configuration index informing the WTRU which cell to perform the reconfiguration to).

[0103] The one or more candidate cell groups may be configured as a single list or group of candidate cell configurations at RRC. The grouping may occur at the early synchronization or LTM execution phaserather than the configuration phase. This means the candidate cell set may be considered as a single group in terms of an RRC configuration list or group, while the cells selected for performing early synchronization, L1 measurements, and LTM execution may depend on a further grouping into multiple subsets of the overall candidate cell list. The grouping itself may not be modelled at RRC using candidate configuration identifiers, but the grouping may be executed as part of the early synchronization or the LTM execution procedure.

[0104] If referring to an LTM candidate configuration, the LTM candidate configuration may apply to any type of preconfigured cell information. For example, a WTRU may be configured with one or more conditional reconfigurations such as a conditional handover (CHO), a conditional PSCell addition (CPA), or a conditional PSCell change (CPC), which may be valid before and / or after a cell change, or may be valid in certain cells.

[0105] An L1 measurement may include a measurement of RSRP, RSRQ, RSSI, etc. performed by a WTRU of a cell, beam, set of cells, or set of beams. Such L1 measurement may be similar to L3 measurements reported in radio resource management (RRM), with differences in the filtering, reference signals measured, reporting mechanisms, etc. Measurements may refer to L1 measurements for LTM. Examples herein may (e.g., may also) apply to RRM / L3 measurements, as well as other measurements (e.g., measurements of speed, location, height, traffic, etc.).

[0106] The WTRU experienced conditions may come from real measurements the WTRU performs over time. In mobility scenarios, a WTRU in mobility may read the current serving cell’s RSRP and report it to the network. If the WTRU is moving to an area approaching the serving cell’s edge, it may record that the RSRP values are decreasing. These values may be communicated to the network via measurement reports for the network to make a decision.

[0107] The WTRU or the network may be assumed to have a pre-trained AI / ML model that may be able to produce predictions of air-interface measurements (RSRP, RSRQ, SINR, etc.) of serving and / or neighbor cells (e.g., any cell). The predictions are a tool that may be used to anticipate the radio conditions the WTRU will experience, instead of waiting for the WTRU to report.

[0108] FIG. 6 illustrates an example of a time series prediction for RSRP. In this example, from the moment the network predictions are triggered, the WTRU may produce several prediction outputs over a future time span, with a certain granularity or time.

[0109] The predictions may (e.g., may also) be done for one point in time only and may extend over several times. In scenarios, prediction with time series output may be more beneficial than single value predictions as it may be difficult to match the prediction (e.g., a network configured event) with a single prediction point.

[0110] The granularity of the timestamp associated with a prediction may be an issue. If the WTRU or the network predict one or more future values, a timestamp may be associated with that prediction (e.g., a timestamp for t+1 , t+2, etc). The granularity of th at timestamp may depend on the AI / ML model in use and on other ML related settings. Terminology like predicted value, inferred value, future value, and others may refer to future predicted values that may or may not have an associated timestamp. If the future predicted values have an associated timestamp, the timestamp may be considered a small delta time interval within which the predicted value is considered to be accurate or valid, either completely or with a certain degree of confidence. In (e.g., all) WTRU-network exchanges, predictions may be represented by a tuple such as [“predicted value”; timestamp - delta; timestamp + delta].

[0111] A WTRU may be configured to predict future measurements based on current and / or historical measurements. In examples, the WTRU may be configured with a trained AI / ML model that may be able to produce predictions for radio interface radio signal levels. In examples, the AI / ML model at the WTRU may be implementation based. In examples, the WTRU may obtain the AI / ML model from the network. In examples, the AI / ML model may be configured to take as an input current and / or historical RSRP measurements. In examples, the AI / ML model may be configured to take inputs (e.g., additional inputs) such as WTRU location information, WTRU mobility, etc. In examples, the AI / ML model may be configured to produce single value predictions (e.g., RSRP at a future time instant t). In examples, the AI / ML model may be configured to predict a series of RSRP values corresponding to future time instances t+1 , t+2 so on up to t+t_fb. A model may be offline trained, or online, and may be exchanged in pre-configuration.

[0112] For a predicted value, either by the network or the WTRU, the predicted value itself may be associated and / or represented by a confidence or error value. The predicted value itself may (e.g., may also) be represented by an average, peak, minimum value, etc. along a small time window representing the validity of that prediction.

[0113] Examples here may provide increased mobility robustness and buffer flushing options before HO.

[0114] The gNB (e.g., a CU in case of CU / DU split architecture (e.g., RRC resides in CU)) may configure potential LTM candidates using RRC signaling. For example, the WTRU may receive the LTM candidateconfigurations using an RRC reconfiguration message, for example during the LTM preparation phase shown in FIG. 5. The WTRU may store the LTM candidate configurations to later apply if receiving an indication using L1 / 2 signaling (e.g. , MAC CE) to perform a cell switch, for example in the LTM execution phase shown in FIG. 5.

[0115] In examples, the configuration of potential LTM candidates may include candidate sets, such a first candidate set and a second candidate set. The first candidate set may be suitable for a first path (e.g., a WTRU turns left and takes a first road). The second candidate set may be suitable for a second path (e.g. a WTRU turns right and takes a second road).

[0116] In examples, some or all of the candidate set information may be broadcasted in system information. The WTRU may enable the pre-configuration of these broadcast configurations if receiving an indication in dedicated signaling (e.g., RRC reconfiguration), which may refer to the broadcast of one or more configurations (e.g., using an index or identifier)

[0117] In examples, the configuration may include all or a subset of the potential cells in a specific area (e.g., all cells belonging to the CU with which the WTRU is currently connected or cells within a particular geographical area). These cells may not yet have been detected or measured by the WTRU, but may be configured in advance. For example (e.g., after the initial configuration of LTM candidate configurations), the WTRU may receive an update to the configuration to modify, add, remove, or replace any part of the LTM candidate configurations.

[0118] In examples, the WTRU may receive an indication to enable or disable some or all of the LTM configurations. For example, if it is predicted that the WTRU mobility would be better handled using L3 (e.g., RRC measurement report, RRC reconfiguration, conditional reconfiguration), then LTM may be disabled. If it is predicted that LTM would better suit the WTRU mobility, then LTM may be enabled (e.g., a previously configured and disabled LTM configuration may be re-enabled). The configuration may be based on a prediction model internal to and determined by the network (e.g., gNB). This prediction may be based on what it (e.g., the network prediction model) determines to be the WTRU’s most likely paths.

[0119] Candidate cell configurations may include all or a part of the information necessary to complete a reconfiguration (e.g., handover) to the candidate cell, such as channel configurations (e.g. PRACH, DPCCH, DPSCH), CORESET, BWP, security parameters, L2 parameters (e.g., MAC, RLC, PDCP), radio bearer configurations, etc.

[0120] LTM trigger may refer to a condition or a set of conditions for performing LTM (e.g., a conditional handover trigger or measurement report trigger), which may either be configured or indicated by the network to the WTRU, or estimated / determined by the WTRU.

[0121] A trigger may be based on one or more of the following: time; radio quality measurement or predicted radio quality of one or more serving cells or target cells; position; an L3 measurement event; an L1 measurement event or condition; any predicted event; an explicit indication from the network; or a measured, predicted, or estimated throughput, error rate, buffer status, or QoS parameter.

[0122] The time may be an absolute or relative time measured time at the WTRU, a SFN, or a subframe number.

[0123] A radio quality measurement or predicted radio quality of one or more serving cells or target cells may refer to any cell and / or any beam or reference signal (e.g., RSRP (beam or cell), reference signal reference quality (RSRQ) (beam or cell), cri-RI-PMI-CQI, cri-RI-i1, cri-RI-i1-CQI, cri-RI-CQI, cri-RSRP, ssb- Index-RSRP, cri-RI-LI-PMI-CQI).

[0124] The position may be an area (e.g., defined by reference point and radius), a range of coordinates, or a distance threshold from a reference location.

[0125] The L3 measurement event may be an event A1 (serving becomes better than threshold), an event A2 (serving becomes worse than threshold), an event A3 (neighbor becomes offset better than SpCell), an event A4 (neighbor becomes better than threshold), an event A5 (SpCell becomes worse than thresholdl and neighbor becomes better than threshold2), an event A6 (neighbor becomes offset better than SCell); an event B1 (inter random access technology (RAT) neighbor becomes better than threshold), or an event B2 (PCell becomes worse than thresholdl and inter RAT neighbor becomes better than threshold2).

[0126] An L1 measurement event or condition may be any event defined which utilizes L1 beam measurements to evaluate whether a criteria or condition is met.

[0127] Any predicted event may be using any of the measurement quantities previously listed under measured or predicted CSI information.

[0128] The WTRU may enable CSI reporting based on an explicit indication (e.g., a MAC CE) received from the network (e.g., then the WTRU may execute an LTM cell switch if receiving a second MAC CE from the network).

[0129] The trigger may include one or more condition(s) under which the WTRU is allowed to perform any action related to mobility (e.g., any action related to LTM). In examples, the WTRU may perform one or more of the following procedures: early TA acquisition; switching off CSI reporting; switching on or updating the CSI reporting configuration; performing LTM cell switch; monitoring PDCCH on a target cell; performing BFR or RLM on a target cell; activating or deactivating certain SCells; initiating a BSR that indicates a traffic data amount, or initiating a report that indicates a traffic data amount (e.g., another traffic data amount).

[0130] For early TA acquisition, the WTRU may trigger a RACH to a target LTM cell. The WTRU may receive a TA value in a random-access response (RAR) (e.g., RAR may come from target cell, or via source cell). The WTRU may receive a TA value in a MAC CE triggering the cell switch. The WTRU may perform power ramping and preamble retransmission on the target if a RAR / MAC CE is not received.

[0131] For switching off CSI reporting, the WTRU may be allowed to, or may be required to, switch off CSI reporting in order to reduce reporting overhead in the uplink. The CSI reporting may be reduced rather than switched off (e.g., via a reduced number of cells or beams reported, or via a reduced frequency of reporting). The WTRU may resume CSI reporting if the condition is no longer met.

[0132] For switching on or updating the CSI reporting configuration, the WTRU may be required to perform and report CSI measurements on one or a subset of LTM candidate cells during the window.

[0133] For performing an LTM cell switch, conditions or criteria under which the WTRU is allowed to trigger LTM cell switch may be provided.

[0134] For monitoring PDCCH on a target cell, the WTRU may be configured to monitor on a target cell for a DCI scheduling PDSCH or indicating one or more actions on the target cell (e.g., to initiate the cell switch procedure).

[0135] For performing BFR or RLM on a target cell, the WTRU may be configured to monitor beam failure detection (BFD) resources on a target cell or perform radio link monitoring (RLM) on a target cell during the window.

[0136] For activating or deactivating certain SCells, the WTRU may be configured with one or more specific SCells which may be active or not active during the window.

[0137] For initiating a BSR or report indicating another traffic data amount: the WTRU may be configured as part of the LTM procedure to perform BSR; the WTRU may be configured to indicate a current or predicted MAC, RLC, or PDCP data amount; or the WTRU may be configured to indicate a current or predicted application data amount.

[0138] A WTRU may perform an action related to mobility based on triggering condition(s) related to current / predicted UL traffic and radio signal levels. The WTRU may receive configuration information (e.g., via an RRC reconfiguration message) with a set of different condition(s) to monitor that may serve as triggers if the condition(s) is determined to be met by the WTRU. If the at least one trigger condition(s) are satisfied, the WTRU may determine the action related to mobility to take (e.g., initiate RACH procedure with a target cell, start sending CSI reports of neighbor cells, start evaluation of a conditional reconfiguration, etc.,). The actions related to mobility performed by the WTRU may be the most adequate at any given point in time where a decision is made (e.g., so an action selection is important). There may be more than one action taken by the WTRU (e.g., depending on whether the criteria for that action is met). For example, the WTRU may start the evaluation of a conditional reconfiguration, and while the evaluation is ongoing, may send (e.g., a CSI report with) information pertaining to neighbor cells.

[0139] The criteria configured in the WTRU may be associated with different actions in multiple ways. In different solutions for initiating a RACH procedure towards a target cell, the WTRU may trigger this action based on any criteria given. The criteria may be combined (e.g., the WTRU may start the RACH procedure based on the criteria for current radio measurements and predicted UL buffer status values).

[0140] The criteria may have a timer or other form of validity condition associated with it. Different criteria associated with one or more actions may have different validities. For example, the WTRU may receive a configuration where the validity of one or more criteria for a certain action may expire. The WTRU may start the monitoring of a second criteria based on a second validity. The same may apply for a third, fourth, and so on criteria. The validities may or may not overlap. The WTRU (e.g., in some cases) may start the monitoring of a second criteria while the assessment of the first criteria is still valid. The validity may assume other forms other than time. In examples, the validity may be assessed as a timer. In examples, the validity may be assessed as an amount of UL data starting from (e.g., as indicated in a previous buffer status report) a range defined by a difference between a radio quantity from the moment the configuration is received until a certain delta from that quantity is detected. In examples, the validity may be assessed as an amount of DL data. In examples, the validity may be assessed as a change rate for throughput in the UL or DL, a distance, etc.

[0141] The WTRU may not be prevented from triggering multiple actions if their criteria are met. The WTRU may determine, based on the predicted radio conditions in relation to a candidate LTM target cell, to perform a sequence of actions (e.g., activate an SCell and update the CSI reporting configuration for that cell). The WTRU may start early TA acquisition for a target cell and based on predicted radio conditionsand UL buffer status, may de-activate a measurement configuration for a subset of the LTM candidate cells, switch off CSI reporting on the source cell, and / or may trigger a BSR reporting procedure. Based on predicted radio conditions for both source and candidate cells, the WTRU may determine the radio conditions are favorable for a seamless cell switch and may reduce CSI reporting contents to limit UL signaling overhead. Based on UL buffer predictions and current radio measurement assessment, the WTRU may switch on CSI reporting for one or more LTM candidate cells. Based one or more of: current CSI measurements on the source cell; current and / or predicted UL buffer levels; current and / or predicted radio quantities; or current and / or predicted CSI measurements, the WTRU may perform an LTM cell switch. The WTRU may start the monitoring of a PDCCH channel on one or more target cells, trigger a BSR, and / or update the CSI reporting for the source cell.

[0142] The WTRU may determine at least one of: current or predicted UL data traffic / current or predicted UL buffer data level(s); or current or predicted radio signal levels of cell(s) (e.g., serving and neighbor cells (e.g., based on an AI / ML model)).

[0143] The WTRU may monitor the criteria for reporting, which may include at least one trigger condition. If determining the fulfilment of a trigger condition(s), the WTRU may select an action related to mobility (e.g., initiate RACH procedure with a target cell, start sending CSI reports of neighbor cells, start evaluation of conditional reconfiguration, etc.). In examples, based on the current or predicted UL buffer data level satisfying the current or predicted UL buffer data threshold (e.g., based on the predicted buffer value(s) associated with a bearer or subset of bearer(s) or predicted buffer value(s) associated with an application ID or subset of application I D(s) satisfying the current or predicted UL buffer data threshold), the WTRU may select the action related to mobility. In examples, based on the current or predicted radio signal level of a cell satisfying the current or predicted radio signal level threshold, the WTRU may select the action related to mobility. The WTRU may perform the selected action related to mobility.

[0144] The WTRU may facilitate the preparation of target cells (e.g., for handover, for addition as secondary cells for carrier aggregation, for addition as a secondary cell group for dual connectivity, etc.,) in anticipation of increased UL traffic.

[0145] A WTRU may be configured with triggering conditions (e.g., predicted / current radio conditions, predicted / current buffer levels, etc.) for initiating an action (e.g., UL synch to a neighbor cell, CSI / CQI reporting of neighbor cells, evaluation of a conditional reconfiguration criteria, etc.). The WTRU may monitor the trigger condition(s). If the trigger condition(s) are fulfilled, the WTRU may initiate the corresponding action.

[0146] A WTRU may receive configuration information (e.g., via an RRC reconfiguration message) associated with initiating an action related to mobility (e.g., perform UL synchronization with a neighbor cell, start sending CSI / CQI reports related to a neighbor cell, etc.). The configuration information may include at least one trigger condition for initiating the action related to mobility. The at least one trigger condition may include one or more of the following: conditions related to current radio signal levels of serving and neighbor cells (e.g., absolute thresholds, relative thresholds, a current radio signal level threshold, etc.); conditions related to predicted radio signal levels of serving and neighbor cells (e.g., absolute thresholds, relative thresholds, a predicted radio signal level threshold, etc.); conditions related to current UL buffer levels (e.g., a current UL buffer data threshold, buffer value(s) for a specific or a subset of bearer(s) associated with the current UL buffer data threshold, buffer value(s) for a specific or a subset of application I D(s) associated with the current UL buffer data threshold, etc.); conditions related to predicted UL buffer levels (e.g., a predicted UL buffer data threshold, predicted buffer value(s) for a specific or a subset of bearer(s) associated with the predicted UL buffer data threshold, predicted buffer value(s) for a specific or a subset of application I D(s) associated with the predicted UL buffer data threshold, etc.); or conditions specific for the WTRU to determine the action to take (e.g., initiate RACH procedure with a target cell, start sending CSI reports of neighbor cell (s), start an evaluation of a conditional reconfiguration, etc.).

[0147] The WTRU may determine at least one of: current or predicted UL data traffic / current or predicted UL buffer data level (s); or current or predicted radio signal level (s) of cell (s) (e.g., of serving and neighbor cells (e.g., based on an AIML model)).

[0148] The WTRU may monitor the at least one trigger condition. If the at least one trigger condition is fulfilled, the WTRU may select an action related to mobility (e.g., initiate RACH procedure with a target cell, start sending CSI reports of neighbor cell(s), start evaluation of conditional reconfiguration, etc.) based on the fulfilled trigger condition(s). In examples, based on the current or predicted UL buffer data level satisfying the current or predicted UL buffer data threshold (e.g., based on the predicted buffer value(s) associated with a bearer or subset of bearer(s) or predicted buffer value(s) associated with an application ID or subset of application I D(s) satisfying the current or predicted UL buffer data threshold), the WTRU may select the action related to mobility. In examples, based on the current or predicted radio signal level of a cell satisfying the current or predicted radio signal level threshold, the WTRU may select the action related to mobility. The WTRU may perform the selected action related to mobility.

[0149] A WTRU may perform an action related to mobility based on trigger condition(s) related to current / predicted UL traffic and radio signal levels. The WTRU may facilitate the preparation of target cells(e.g., for handover, for addition as secondary cells for carrier aggregation, for addition as secondary cell group for dual connectivity, etc.,) in anticipation of increased UL traffic.

[0150] A WTRU may be configured with trigger condition(s) (e.g., predicted / current radio condition(s), predicted / current buffer levels, etc.) for initiating an action (e.g., UL synch to a neighbor cell, CSI / CQI reporting of neighbor cells, evaluation of a conditional reconfiguration criteria, etc.). The WTRU may monitor the trigger condition(s). If the trigger condition(s) are fulfilled, the WTRU may initiate the corresponding action.

[0151] A WTRU may receive configuration information for initiating an action related to mobility (e.g., perform UL synch with a neighbor cell, start sending CSI / CQI reports related to a neighbor cell, etc.). The configuration information may include trigger condition(s) for initiating the action. The trigger condition(s) may include one or more of the following: condition(s) related to current radio signal levels of serving and neighbor cells (e.g., absolute thresholds, relative thresholds, etc.); condition(s) related to predicted radio signal levels of serving and neighbor cells (e.g., absolute thresholds, relative thresholds, etc.); condition(s) related to current UL buffer levels (e.g., buffer values for a specific or a subset of bearers, for a specific or a subset application ID, etc.); condition(s) related to predicted UL buffer levels (e.g., predicted buffer values for a specific or a subset of bearers, for a specific or a subset application ID, etc.); or conditions specific for the WTRU to determine the action to take (e.g., initiate RACH procedure with a target cell, start sending CSI reports of neighbor cells, start evaluation of a conditional reconfiguration, etc.).

[0152] The WTRU may determine current or predicted UL data traffic, and / or current or predicted radio signal levels of serving and neighbor cells (e.g., based on an AI / ML model). The WTRU may monitor the trigger condition(s). If the trigger condition(s) are fulfilled, the WTRU may select an action (e.g., initiate RACH procedure with a target cell, start sending CSI reports of neighbor cells, start evaluation of conditional reconfiguration, etc.) based on the fulfilled trigger condition(s). The WTRU may perform the selected action.

[0153] Although features and elements described above are described in particular combinations, each feature or element may be used alone without the other features and elements of the preferred embodiments, or in various combinations with or without other features and elements.

[0154] Although the implementations described herein may consider 3GPP specific protocols, it is understood that the implementations described herein are not restricted to this scenario and may be applicable to other wireless systems. For example, although the solutions described herein consider LTE,LTE-A, New Radio (NR) or 5G specific protocols, it is understood that the solutions described herein are not restricted to this scenario and are applicable to other wireless systems as well.

[0155] The processes described above may be implemented in a computer program, software, and / or firmware incorporated in a computer-readable medium for execution by a computer and / or processor.Examples of computer-readable media include, but are not limited to, electronic signals (transmitted over wired and / or wireless connections) and / or computer-readable storage media. Examples of computer- readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as, but not limited to, internal hard disks and removable disks, magneto-optical media, and / or optical media such as compact disc (CD)-ROM disks, and / or digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, terminal, base station, RNC, and / or any host computer.

Claims

CLAIMSWhat is Claimed:1 . A wireless transmit / receive unit (WTRU), comprising: a processor configured to: receive configuration information associated with an initiation of an action related to mobility, wherein the configuration information comprises at least one trigger condition associated with the initiation of the action related to mobility, and wherein the at least one trigger condition includes a predicted uplink (UL) buffer data level threshold associated with a bearer or a subset application identification (ID); determine a predicted UL buffer data level associated with the bearer or the subset application ID; determine that the at least one trigger condition is satisfied, wherein the determination that the at least one trigger condition is satisfied is at least based on the predicted UL buffer data level satisfying the predicted UL buffer data level threshold; based on the at least one trigger condition being satisfied, select the action related to mobility; and perform the action related to mobility.

2. The WTRU of claim 1 , wherein the at least one trigger condition further includes a predicted radio signal level threshold, and wherein the processor is further configured to: determine a predicted radio signal level of a cell, wherein the determination that the at least one trigger condition is satisfied is further based on the predicted radio signal level of the cell satisfying the predicted radio signal level threshold.

3. The WTRU of claim 1 , wherein the at least one trigger condition further includes a current UL buffer data level threshold associated with the bearer or the subset application ID, and wherein the processor is further configured to: determine a current UL buffer data level associated with the bearer or the subset application ID, wherein the determination that the at least one trigger condition is satisfied is further based on the current UL buffer data level satisfying the current UL buffer data level threshold.

4. The WTRU of claim 1 , wherein the action related to mobility is at least one of: an initiation of a random-access channel (RACH) procedure with a target cell, sending a channel state information (CSI) report of a neighbor cell, or an evaluation of a conditional reconfiguration.

5. The WTRU of claim 1 , wherein the action related to mobility is an action related to L1 / L2 based inter-cell mobility (LTM), wherein the action related to LTM is at least one of: an early timing advance (TA) acquisition, switching off CSI reporting, switching on or updating a CSI reporting configuration, performance of an LTM cell switch, monitoring a physical downlink control channel (PDCCH) on a target cell, performance of buffer failure detection (BFD) or radio link monitoring (RLM) on the target cell, activation or deactivation of a secondary cell (SCell), an initiation of a buffer status report (BSR), or an initiation of a report that indicates a traffic data amount.

6. The WTRU of claim 1 , wherein the configuration information is received via a radio resource control (RRC) reconfiguration message.

7. A method associated with wireless transmit / receive unit (WTRU), the method comprising: receiving configuration information associated with an initiation of an action related to mobility, wherein the configuration information comprises at least one trigger condition associated with the initiation of the action related to mobility, and wherein the at least one trigger condition includes a predicted uplink (UL) buffer data level threshold associated with a bearer or a subset application identification (ID); determining a predicted UL buffer data level associated with the bearer or the subset application ID; determining that the at least one trigger condition is satisfied, wherein the determination that the at least one trigger condition is satisfied is at least based on the predicted UL buffer data level satisfying the predicted UL buffer data level threshold; based on the at least one trigger condition being satisfied, selecting the action related to mobility; and performing the action related to mobility.

8. The method of claim 7, wherein the at least one trigger condition further includes a predicted radio signal level threshold, further comprising:determining a predicted radio signal level of a cell, wherein the determination that the at least one trigger condition is satisfied is further based on the predicted radio signal level of the cell satisfying the predicted radio signal level threshold.

9. The method of claim 7, wherein the at least one trigger condition further includes a current UL buffer data level threshold associated with the bearer or the subset application ID, further comprising: determining a current UL buffer data level associated with the bearer or the subset application ID, wherein the determination that the at least one trigger condition is satisfied is further based on the current UL buffer data level satisfying the current UL buffer data level threshold.

10. The method of claim 7, wherein the action related to mobility is at least one of: an initiation of a random-access channel (RACH) procedure with a target cell, sending a channel state information (CSI) report of a neighbor cell, or an evaluation of a conditional reconfiguration.11 . The method of claim 7, wherein the action related to mobility is an action related to L1 / L2 based inter-cell mobility (LTM), wherein the action related to LTM is at least one of: an early timing advance (TA) acquisition, switching off CSI reporting, switching on or updating a CSI reporting configuration, performance of an LTM cell switch, monitoring a physical downlink control channel (PDCCH) on a target cell, performance of buffer failure detection (BFD) or radio link monitoring (RLM) on the target cell, activation or deactivation of a secondary cell (SCell), an initiation of a buffer status report (BSR), or an initiation of a report that indicates a traffic data amount.

12. The method of claim 7, wherein the configuration information is received via a radio resource control (RRC) reconfiguration message.

Images