Method, architecture, apparatus, and system for coexistence of layer 1 / layer 2 triggered mobility and layer 3 triggered mobility

Abstract

Methods, apparatus, systems, devices, and computer program products for L1 / L2 inter-cell mobility and / or measurement are provided. One method can include performing a measurement of signal quality of a serving cell, and, based on a first condition based on the signal quality of the serving cell, performing a measurement of signal quality of a Layer 1 / Layer 2 triggered mobility (LTM) candidate cell, performing evaluation of the measurement of the LTM candidate cell using a first measurement evaluation method, and / or reporting using a first reporting method. Based on a second condition based on the signal quality of the LTM candidate cell, performing a measurement of signal quality of a cell outside the set of LTM candidate cells, performing evaluation of the measurement of the cell outside the set of LTM candidate cells using a second measurement evaluation method, and / or reporting using a second reporting method.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 421,822, filed November 2, 2022, the contents of which are incorporated herein by reference in their entirety.

[0002] The present disclosure is generally directed to the fields of communications, software, and coding, including, for example, methods, architectures, devices, and systems related to Layer 1 (L1) / Layer 2 (L2) inter-cell mobility and / or measurements. Summary of the Invention

[0003] One embodiment may be directed to a wireless transmit / receive unit (WTRU) that may include circuitry including any one or more of a transmitter, a receiver, a processor, and / or a memory. The circuitry is configured to receive information indicating a set of layer 1 / layer 2 triggered mobility (LTM) candidate cells, a configuration of a first condition associated with signal quality of the serving cell, and / or a configuration of a second condition associated with signal quality of the LTM candidate cell. The circuitry is configured to perform measurements of the signal quality of the serving cell. Based on the first condition associated with the signal quality of the serving cell being satisfied, the circuitry is configured to perform any one or more of measurements of the signal quality of the LTM candidate cell, a first measurement evaluation method of the measurements (e.g., performing evaluation of the measurements of the LTM candidate cell using the first measurement evaluation method), and / or a first measurement reporting method (e.g., reporting the measurements using the first measurement reporting method). Based on a second condition associated with the signal quality of the LTM candidate cell being satisfied (e.g., when the first condition and the second condition are satisfied), the circuitry is configured to perform a measurement of the signal quality of a cell not in the set of LTM candidate cells, a second measurement evaluation method of the measurement (e.g., performing evaluation of the measurement of the non-LTM candidate cell using the second measurement evaluation method), and / or a second measurement reporting method (e.g., reporting the measurement of the non-LTM candidate cell using the second measurement reporting method). Conditional on the radio quality condition based on the second measurement evaluation method being satisfied, the circuitry is configured to transmit a measurement report using the second reporting method.

[0004] One embodiment may be directed to a method that may be implemented by a WTRU. The method may include receiving information indicating a set of Layer 1 / Layer 2 triggered mobility (LTM) candidate cells, a configuration of a first condition associated with signal quality of the serving cell, and / or a configuration of a second condition associated with signal quality of the LTM candidate cell. The method may include performing a measurement of the signal quality of the serving cell. Based on the first condition associated with the signal quality of the serving cell being met, the method may include performing any one or more of a measurement of the signal quality of the LTM candidate cell, a first measurement evaluation method of the measurement (e.g., performing evaluation of the measurement of the LTM candidate cell using the first measurement evaluation method), and / or a first measurement reporting method (e.g., reporting the measurement using the first measurement reporting method). Based on a second condition associated with the signal quality of the LTM candidate cell being satisfied (e.g., when the first condition and the second condition are satisfied), the method may include performing a measurement of the signal quality of a cell not in the set of LTM candidate cells, a second measurement evaluation method of the measurement (e.g., performing evaluation of the measurement of the non-LTM candidate cell using the second measurement evaluation method), and / or a second measurement reporting method (e.g., reporting the measurement of the non-LTM candidate cell using the second measurement reporting method). Conditional on the radio quality condition based on the second measurement evaluation method being satisfied, the method may include transmitting a measurement report using the second reporting method. [Brief explanation of the drawings]

[0005] A more detailed understanding will be had from the following detailed description, given by way of example in conjunction with the accompanying drawings, in which: Figures in these drawings, like the detailed description, are exemplary; therefore, the figures and detailed description are not limiting, and other examples which are equally effective are possible and likely. Furthermore, like reference numerals in the figures refer to like elements.

[0006] [Figure 1A] FIG. 1 is a system diagram illustrating an example communication system. [Figure 1B]1B is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communication system shown in FIG. 1A. [Figure 1C] 1B is a system diagram illustrating an exemplary radio access network (RAN) and an exemplary core network (CN) that may be used within the communications system illustrated in FIG. 1A, according to one embodiment. [Figure 1D] 1B is a system diagram illustrating a further exemplary RAN and a further exemplary CN that may be used within the communication system shown in FIG. 1A according to one embodiment. [Figure 2] FIG. 2 illustrates an example of a high-level measurement model, according to one embodiment. [Figure 3A] FIG. 1 illustrates an exemplary handover (HO) scenario in NR according to one embodiment. [Figure 3B] FIG. 1 illustrates an exemplary handover (HO) scenario in NR according to one embodiment. [Figure 4] FIG. 1 illustrates an example signaling diagram illustrating conditional HO (CHO), according to one embodiment. [Figure 5] FIG. 1 illustrates an example of Layer 1 / Layer 2 triggered mobility (LTM) operation, according to one embodiment. [Figure 6] FIG. 1 illustrates an exemplary flow diagram of a method according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the embodiments and / or examples disclosed herein. It will be understood, however, 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. Furthermore, embodiments and examples not specifically described herein may be practiced in place of, or in combination with, the embodiments and other examples described, disclosed, or explicitly, implicitly, and / or inherently provided (collectively "provided") herein. Although various embodiments are described and / or claimed herein in which apparatuses, systems, devices, etc. and / or any elements thereof perform operations, processes, algorithms, functions, etc. and / or any portions thereof, it should be understood that any embodiment described and / or claimed herein presupposes that any apparatus, system, device, etc. and / or any elements thereof are configured to perform any operations, processes, algorithms, functions, etc. and / or any portions thereof.

[0008] Exemplary Communication System

[0009] The methods, apparatus, and systems provided herein are well suited for communications involving both wired and wireless networks. With reference to Figures 1A-1D, an overview of various types of wireless devices and infrastructures is provided, and various elements of the networks may utilize, perform, be arranged, and / or adapted and / or configured in accordance with the methods, apparatus, and systems provided herein.

[0010] 1A is a system diagram illustrating an example communication system 100 in which one or more disclosed embodiments can be implemented. The communication system 100 may be a multiple-access system that provides content, such as voice, data, video, messaging, broadcasts, etc., to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content through sharing of system resources, including wireless bandwidth. For example, the communication system 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tailed (ZT) unique word (UW) discrete Fourier transform (DFT) spread OFDM (ZT UW DFT-s OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, filter bank multicarrier (FBMC), etc.

[0011] 1A, communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, and 102d, a radio access network (RAN) 104 / 113, a core network (CN) 106 / 115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, although it will be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of WTRUs 102a, 102b, 102c, and 102d may be any type of device configured to operate and / or communicate in a wireless environment. For example, WTRUs 102a, 102b, 102c, 102d, all of which may be referred to as “stations” and / or “STAs,” may be configured to transmit and / or receive wireless signals and may include (or be) user equipment (UE), mobile stations, fixed or mobile subscriber units, subscription-based units, pagers, cellular phones, personal digital assistants (PDAs), smartphones, laptops, notebooks, personal computers, wireless sensors, hotspot or Mi-Fi devices, IoT devices, watches or other wearables, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in the context of industrial and / or automated processing chains), consumer electronic devices, devices operating on commercial and / or industrial wireless networks, etc. WTRUs 102a, 102b, 102c, and 102d, or any other WTRUs mentioned or described herein, may all be referred to interchangeably as UEs.

[0012] The communications system 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communications networks, such as the CN 106 / 115, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be any of a Base Transceiver Station (BTS), a NodeB (NB), an eNodeB (eNB), a Home NodeB (HNB), a Home eNodeB (HeNB), a gNodeB (gNB), a NR NodeB (NR NB), a site controller, an access point (AP), a wireless router, etc. While the base stations 114a, 114b are each depicted as a single element, it will be understood that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0013] The base station 114a may be part of the RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and / or base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for wireless services in a particular geographic area, which may be relatively fixed or may change over time. A cell may be further divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In one embodiment, the base station 114a may employ multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each sector of the cell or for any sector of the cell. For example, beamforming may be used to transmit and / or receive signals in desired spatial directions.

[0014] 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).

[0015] More particularly, 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, etc. For example, the base stations 114a and WTRUs 102a, 102b, 102c in the RAN 104 / 113 may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 116 using Wideband CDMA (WCDMA). WCDMA may include communications protocols such as High Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink Packet Access (HSDPA) and / or High Speed ​​Uplink Packet Access (HSUPA).

[0016] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE Advanced (LTE-A) and / or LTE Advanced Pro (LTE-A Pro).

[0017] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as New Radio (NR) radio access, which may establish the air interface 116 using NR.

[0018] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may jointly implement LTE and NR radio access, e.g., using a dual connectivity (DC) principle. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions sent to and from multiple types of base stations (e.g., eNBs and gNBs).

[0019] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a wireless technology such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi)), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, 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), or the like.

[0020] 1A may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point and may utilize any suitable RAT to facilitate wireless connectivity in a local area, such as a workplace, a home, a vehicle, a premises, an industrial facility, an air corridor (e.g., for use by drones), a road, etc. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a small cell, a picocell, or a femtocell. 1A, the base station 114b may have a direct connection to the Internet 110. Therefore, the base station 114b may not need to access the Internet 110 via the CN 106 / 115.

[0021] The RAN 104 / 113 may be in communication with the CN 106 / 115, which may be any type of network configured to provide voice, data, application, and / or VoIP services to one or more of the WTRUs 102a, 102b, 102c, and 102d. The data may have various quality of service (QoS) requirements, such as different throughput, latency, error resilience, reliability, data throughput, and mobility requirements. The CN 106 / 115 may provide call control, billing services, mobile location services, prepaid calling, Internet connectivity, video distribution, and / or perform high-level security functions such as user authentication. Although not shown in FIG. 1A , it will be understood that the RAN 104 / 113 and / or the CN 106 / 115 may be in direct or indirect communication with other RANs employing the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may utilize NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) that employs GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0022] The CNs 106 / 115 may also serve as gateways for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network providing 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 TCP, UDP, and / or IP in the TCP / IP Internet protocol suite. The networks 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, the network 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RANs 104 / 113 or a different RAT.

[0023] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with a base station 114a, which may employ a cellular-based wireless technology, and with a base station 114b, which may employ an IEEE 802.2 wireless technology.

[0024] 1B is a system diagram illustrating an example of a WTRU 102. As shown in FIG. 1B, the WTRU 102 may include, among other things, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a GPS chipset 136, and / or other elements / peripherals 138. It will be understood that the WTRU 102 may include any subcombination of the foregoing elements while remaining consistent with an embodiment.

[0025] The processor 118 may be a general-purpose processor, a special-purpose processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) circuit, other types of integrated circuits (ICs), a state machine, etc. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. While FIG. 1B depicts the processor 118 and the transceiver 120 as separate components, it will be understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0026] The transmit / receive element 122 may be configured to transmit and receive signals to and from a base station (e.g., 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 one embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In one embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It will be understood that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0027] 1B depicts the transmit / receive element 122 as a single element, the WTRU 102 may include any number of transmit / receive elements 122. For example, 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.

[0028] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As mentioned above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate via multiple RATs, such as, for example, NR and IEEE 802.11.

[0029] The processor 118 of the WTRU 102 may be coupled to and may receive user input data from a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. Furthermore, the processor 118 may access information and store data in any type of suitable memory, such as non-removable memory 130 and / or removable memory 132. The non-removable memory 130 may include RAM, ROM, a hard disk, or any other type of memory storage device. The removable memory 132 may include a SIM card, a memory stick, a secure digital (SD) memory card, etc. In other embodiments, the processor 118 may access information and store data in memory that is not physically located on the WTRU 102, such as on a server or home computer (not shown).

[0030] The processor 118 may receive power from the power source 134 and may be configured to distribute and / or control the power to other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel-metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0031] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or instead of, information from the GPS chipset 136, the WTRU 102 may receive location information from base stations (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be appreciated that the WTRU 102 may obtain location information by way of any suitable location-determination method while remaining consistent with an embodiment.

[0032] The processor 118 may also be coupled to other elements / peripherals 138, which may include one or more software and / or hardware modules / units that provide additional features, functionality, and / or wired or wireless connectivity. For example, the elements / peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (e.g., for photos and / or videos), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, a Bluetooth module, a frequency modulation (FM) radio unit, a digital music player, a media player, a video game player module, an internet browser, a virtual reality and / or augmented reality (VR / AR) device, an activity tracker, etc. The elements / peripherals 138 may include one or more sensors. The sensor 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.

[0033] 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 a particular subframe for both the uplink (e.g., for transmission) and the downlink (e.g., for reception)) may be concurrent and / or simultaneous. The full-duplex radio may include an interference management unit 139 to reduce and / or substantially eliminate self-interference through either hardware (e.g., a choke) or signal processing via a processor (e.g., a separate processor (not shown) or the processor 118). In one embodiment, the WTRU 102 may include a half-duplex radio for transmission and reception of some or all of the signals (e.g., associated with a particular subframe for either the uplink (e.g., for transmission) or the downlink (e.g., for reception)).

[0034] 1C is a system diagram illustrating the RAN 104 and the CN 106, according to one embodiment. As noted above, the RAN 104 may employ E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0035] The RAN 104 may include eNode-Bs 160a, 160b, and 160c, although it will be understood that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, and 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 116. In one embodiment, the eNode-Bs 160a, 160b, and 160c may implement MIMO technology. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to and receive wireless signals from the WTRU 102a.

[0036] Each of the eNodeBs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the uplink (UL) and / or downlink (DL), etc. As shown in FIG. 1C, the eNodeBs 160a, 160b, 160c may communicate with each other via an X2 interface.

[0037] 1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (PGW) 166. While each of the above elements is shown as part of the CN 106, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0038] The MME 162 may be connected to each of the eNodeBs 160a, 160b, 160c in the RAN 104 via an S1 interface and may act as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, activating / deactivating bearers, selecting a particular serving gateway during initial attach of the WTRUs 102a, 102b, 102c, etc. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies such as GSM and / or WCDMA.

[0039] The SGW 164 may be connected to each of the eNodeBs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to and from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions such as anchoring the user plane during handovers between eNodeBs, triggering paging when DL data is available to the WTRUs 102a, 102b, 102c, and managing and storing the context of the WTRUs 102a, 102b, 102c.

[0040] The SGW 164 may be connected to a PGW 166 that may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0041] 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 fixed communication devices. For example, the CN 106 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 106 and the PSTN 108. Additionally, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0042] Although the WTRU is depicted in FIGS. 1A-1D as a wireless terminal, it is contemplated that in some representative embodiments such a terminal may use a wired communication interface with the communication network (e.g., temporarily or permanently).

[0043] In an exemplary embodiment, the other network 112 may be a WLAN.

[0044] A WLAN in infrastructure basic service set (BSS) mode has an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have access or an interface to a distribution system (DS) or another type of wired / wireless network that carries traffic to and / or from the BSS. Traffic to a STA originating from outside the BSS may arrive through the AP and be sent to the STA. Traffic originating from a STA to a destination outside the BSS may be sent to the AP and delivered to the respective destination. Traffic between STAs within a BSS may be sent through the AP; for example, a source STA may send traffic to the AP, which then delivers the traffic to the destination STA. Traffic between STAs within a BSS may be considered or referred to as peer-to-peer traffic. Peer-to-peer traffic may be sent (e.g., directly) between a source STA and a destination STA using direct link setup (DLS). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and STAs within or using the IBSS (e.g., all STAs) may communicate directly with each other. The IBSS communication mode is sometimes referred to herein as an "ad hoc" communication mode.

[0045] When using 802.11ac infrastructure mode operation or a similar mode of operation, an AP may transmit beacons on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., a wide 20 MHz bandwidth) or a width dynamically set via signaling. The primary channel may be the operating channel of the BSS and may be used by STAs to establish a connection with the AP. In certain representative embodiments, carrier sense multiple access with collision avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. With CSMA / CA, STAs (e.g., all STAs), including the AP, may sense the primary channel. If the primary channel is sensed / detected by a particular STA and / or determined to be busy, the particular STA may back off. One STA (e.g., only one station) may transmit on a given BSS at any time.

[0046] High-throughput (HT) STAs may use 40 MHz wide channels for communication, for example, by combining a primary 20 MHz channel with adjacent or non-adjacent 20 MHz channels to form the 40 MHz wide channel.

[0047] A Very High Throughput (VHT) STA can support channels of 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz width. A 40 MHz and / or 80 MHz channel can be formed by combining contiguous 20 MHz channels. A 160 MHz channel can be formed by combining eight contiguous 20 MHz channels or two non-contiguous 80 MHz channels, sometimes referred to as an 80+80 configuration. In the 80+80 configuration, the channel-encoded data passes through a segment parser, which splits the data into two streams. Inverse Fast Fourier Transform (IFFT) processing and time-domain processing can be performed separately on each stream. The streams are mapped to two 80 MHz channels, and the data is transmitted by the transmitting STA. At the receiver of the receiving STA, the above operations for the 80+80 configuration can be reversed, and the combined data can be transmitted to a medium access control (MAC) layer, entity, etc.

[0048] Sub-1 GHz operating modes are supported by 802.11af and 802.11ah. The channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah compared to those used in 802.11n and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, while 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to representative embodiments, 802.11ah can support meter-type control / machine-type communication (MTC), such as MTC devices in macro coverage areas. MTC devices may have limited functionality, including specific features, such as support for (e.g., only support for) specific and / or limited bandwidths. MTC devices may include batteries with above-threshold battery life (e.g., maintaining a very long battery life).

[0049] A WLAN system may support multiple channels and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, and the WLAN system includes a channel that may be designated as a primary channel. The bandwidth of the primary channel may be equal to the largest common operating bandwidth supported by all STAs in a BSS. The bandwidth of the primary channel may be configured and / or limited by the STA from among all STAs operating in the BSS that support the smallest bandwidth operating mode. In an 802.11ah example, the primary channel of a STA (e.g., an MTC-type device) that supports (e.g., only supports) 1 MHz mode may be 1 MHz wide, 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) configuration may depend on the status of the primary channel. For example, if the primary channel is busy because a STA (that only supports a 1 MHz mode of operation) is transmitting to the AP, the entire available frequency band may be considered busy, even though most of the frequency band may remain idle and available for use.

[0050] In the United States, the available frequency bands available for 802.11ah are 902MHz to 928MHz. In South Korea, the available frequency bands are 917.5MHz to 923.5MHz. In Japan, the available frequency bands are 916.5MHz to 927.5MHz. The total available bandwidth for 802.11ah is 6MHz to 26MHz depending on the country code.

[0051] 1D is a system diagram illustrating the RAN 113 and the CN 115, according to one embodiment. As noted above, the RAN 113 may employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0052] The RAN 113 may include gNBs 180a, 180b, and 180c, although it will be understood that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, and 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, and 180c may implement MIMO technology. For example, the gNBs 180a and 180b may transmit and / or receive signals to and from the WTRUs 102a, 102b, and 102c using beamforming. Thus, for example, the gNB 180a may transmit and / or receive wireless signals to and from the WTRU 102a using multiple antennas. In one embodiment, the gNBs 180a, 180b, and 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 the unlicensed spectrum, and the remaining component carriers may be on the licensed spectrum. In one embodiment, the gNBs 180a, 180b, and 180c may implement Coordinated Multi-Point (CoMP) technology. For example, the WTRU 102a may receive coordinated transmissions from the gNBs 180a and 180b (and / or 180c).

[0053] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with 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 the gNBs 180a, 180b, 180c using subframes or transmission time intervals (TTIs) of different or scalable lengths (e.g., including different numbers of OFDM symbols and / or different lengths of absolute time duration).

[0054] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c can communicate with the gNBs 180a, 180b, 180c without accessing another RAN (e.g., eNodeBs 160a, 160b, 160c, etc.). In a standalone configuration, the WTRUs 102a, 102b, 102c can utilize one or more gNBs 180a, 180b, 180c as mobility anchor points. In a standalone configuration, the WTRUs 102a, 102b, 102c can communicate with the gNBs 180a, 180b, 180c using signals in unlicensed bands. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate / connect with a gNB 180a, 180b, 180c while also communicating / connecting with another RAN, such as an eNode-B 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement a DC principle to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c at approximately the same time. In a non-standalone configuration, the eNode-Bs 160a, 160b, 160c may act as mobility anchors for the WTRUs 102a, 102b, 102c, and the gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0055] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support for network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data to User Plane Functions (UPFs) 184a, 184b, routing of control plane information to Access and Mobility Management Functions (AMFs) 182a, 182b, etc. As shown in FIG. 1D , the gNBs 180a, 180b, 180c may communicate with each other via an Xn interface.

[0056] 1D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and at least one Data Network (DN) 185a, 185b. While each of the above elements is shown as part of the CN 115, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0057] The AMF 182a, 182b may be connected to one or more gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may function as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, supporting network slicing (e.g., handling different protocol data unit (PDU) sessions with different requirements), selecting a particular SMF 183a, 183b, managing registration areas, terminating NAS signaling, mobility management, etc. Network slicing may be used by the AMF 182a, 182b to customize CN support for the WTRUs 102a, 102b, 102c based on the type of service being utilized by the WTRUs 102a, 102b, 102c. Different network slices may be established for different use cases, for example, services relying on Ultra-Reliable Low-Latency (URLLC) access, services relying on enhanced Massive Mobile Broadband (eMBB) access, services for MTC access, etc. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that use other radio technologies such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0058] The SMFs 183a and 183b may be connected to the AMFs 182a and 182b in the CN 115 via an N11 interface. The SMFs 183a and 183b may also be connected to the UPFs 184a and 184b in the CN 115 via an N4 interface. The SMFs 183a and 183b may select and control the UPFs 184a and 184b and configure the routing of traffic through the UPFs 184a and 184b. The SMFs 183a and 183b may perform other functions such as managing and assigning UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notification, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0059] The UPFs 184a, 184b may be connected to one or more gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which provides the WTRUs 102a, 102b, 102c with access to packet-switched networks such as the Internet 110 and facilitates communication between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPFs 184, 184b may perform other functions such as routing and forwarding packets, enforcing user plane policy, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing a mobility anchor, etc.

[0060] The CN 115 may facilitate communication with other networks. For example, the CN 115 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 115 and the PSTN 108. Additionally, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to local data networks (DNs) 185a, 185b through the UPFs 184a, 184b via an N3 interface to the UPFs 184a, 184b and an N6 interface between the UPFs 184a, 184b and the DNs 185a, 185b.

[0061] 1A-1D and the corresponding description thereof, one or more, or all, of the functions described herein with respect to one or more of the WTRUs 102a-d, base stations 114a-b, eNodeBs 160a-c, MME 162, SGW 164, PGW 166, gNBs 180a-c, AMFs 182a-b, UPFs 184a-b, SMFs 183a-b, DNs 185a-b, and / or other elements / devices described herein may be performed by one or more emulation elements / devices (not shown). An emulation device may be one or more devices configured to emulate one or more or all of the functions described herein. For example, the emulation device may be used to test other devices and / or to simulate network and / or WTRU functionality.

[0062] The emulation device can be designed to implement one or more tests of other devices in a lab environment and / or an operator network environment. For example, one or more emulation devices can be fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to perform one or more, or all, functions for testing other devices in the communication network. One or more emulation devices can be temporarily implemented / deployed as part of a wired and / or wireless communication network to perform one or more, or all, functions. The emulation device can be directly coupled to another device for testing purposes and / or can perform testing using wireless communication.

[0063] One or more emulation devices may also perform one or more functions (including all functions) without being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in test scenarios in a test lab and / or in test scenarios in non-deployed (e.g., test) wired and / or wireless communication networks to implement testing of one or more components. One or more emulation devices may be test equipment. Direct RF coupling and / or wireless communication via RF circuitry (which may, for example, include one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0064] Throughout the embodiments described herein, the terms "serving base station," "base station," "gNB," and collectively "gNB" may be used interchangeably to refer to any network element, such as a network element that functions as a serving base station. The embodiments described herein are not limited to gNBs and may also be applicable to any other type of base station.

[0065] In the RRC_CONNECTED state, the UE can measure multiple beams of (e.g., at least one) cell, and the measurement results (power values) can be averaged to derive cell quality. In doing so, the UE can be configured to consider a subset of detected beams. Filtering can be done at two different levels: at the physical layer to derive beam quality, and at the radio resource control (RRC) level to derive cell quality from multiple beams. Cell quality from beam measurements can be derived in the same way for serving and non-serving cells. The measurement report can include measurement results of the X best beams if the UE is configured to do so by the gNB.

[0066] FIG. 2 shows an example of a corresponding high-level measurement model according to one embodiment. As shown in the example of FIG. 2, at A, measurements (beam-specific samples) within the physical layer may be performed. Note that in this example, K beams are configured by the gNB for L3 mobility and correspond to measurements on SSB or CSI-RS resources detected by the UE at L1. In one example, an internal Layer 1 filtering of the input measured at point A may be performed. The specific filtering method may depend on the implementation. How measurements are actually performed at the physical layer by the implementation (input A and Layer 1 filtering) is not constrained by the standard. A 1 In

[0047] , measurements (i.e., beam-specific measurements) may be reported from Layer 1 to Layer 3 after Layer 1 filtering.

[0067] As shown in the example of Figure 2, beam-specific measurements can be aggregated to derive cell quality at 205. The behavior of beam aggregation / selection can be standardized, and the configuration of this module can be provided by RRC signaling. The reporting period at B is A. 1 At point B, measurements derived from beam-specific measurements (i.e., cell quality) may be reported to Layer 3 after beam aggregation / selection. As shown at 210, Layer 3 filtering (e.g., for cell quality) may be performed on the measurements provided at point B. The behavior of the Layer 3 filter may be standardized, and the configuration of the Layer 3 filter may be provided by RRC signaling. The filtering reporting period at C is equal to one measurement period at B. As shown at C, measurements may be performed after processing with the Layer 3 filter. The reporting rate may be the same as or substantially similar to the reporting rate at point B. This measurement may be used as input for one or more evaluations of reporting criteria.

[0068] In the example of FIG. 2, an evaluation of the reporting criteria can be performed at 215 to check whether an actual measurement report is required at point D. The evaluation can be done, for example, based on a flow of multiple measurements at reference point C in order to compare different measurements. In FIG. 2, this can be done for inputs C and C. 1 The UE may, for example, determine whether at least the new measurement results are at points C, C 1 The reporting criteria can be evaluated each time a measurement is reported at point A. The reporting criteria can be standardized and the configuration can be provided by RRC signaling (UE measurements). As shown in the example at D in Figure 2, the measurement report information (message) can be transmitted over the air interface. Then, L3 beam filtering is performed at point A. 1 The filtering reporting period in E may be performed on measurements provided in A (i.e., beam-specific measurements). The behavior of the beam filters may be standardized, and the configuration of the beam filters may be provided by RRC signaling. 1 At E, a post-beam filter measurement (i.e., a beam-specific measurement) may be performed. The reporting rate is 1 The reporting rate may be the same as or substantially similar to the reporting rate in (F). This measurement may be used as an input for selecting the X measurements to be reported. At 220, beam selection for beam reporting may be performed to select X measurements from the measurements provided at point E. The behavior of beam selection may be standardized, and the configuration of this module may be provided by RRC signaling. As shown at F, beam measurement information may be included in the measurement report (sent at) over the air interface.

[0069] Layer 1 filtering may introduce a level of measurement averaging. Exactly how and when the UE performs the necessary measurements is implementation specific, in that the output at B meets the performance requirements set out in 3GPP TS38.133. Layer 3 filtering of the cell quality and related parameters used is specified in TS38.331 and does not introduce any delay in sample availability between B and C. 1 is the input used in the event evaluation. The L3 beam filtering and related parameters used are specified in TS38.331 and do not introduce any delay in sample availability between E and F.

[0070] The measurement report may be characterized by one or more of the following: the measurement report includes the measurement ID of the associated measurement configuration that triggered the report; the cell and beam measurement quantities included in the measurement report are configured by the network; the number of non-serving cells reported may be limited by configuration by the network; cells belonging to an exclusion list configured by the network are not used for event evaluation and / or reporting; conversely, if an allowed list is configured by the network, only cells belonging to the allowed list are used for event evaluation and reporting; and / or the beam measurements included in the measurement report are configured by the network (beam identifier only, measurement results and beam identifier, and / or no beam report).

[0071] Intra-frequency neighbor (cell) measurements and inter-frequency neighbor (cell) measurements may be defined as follows: Synchronization Signal Block (SSB)-based intra-frequency measurement: if the center frequency of the SSB of the serving cell and the center frequency of the SSB of the neighboring cell are the same and the subcarrier spacing of the two SSBs is also the same, the measurement is defined as an SSB-based intra-frequency measurement; and / or · SSB-based inter-frequency measurement: If the center frequency of the SSB of the serving cell and the center frequency of the SSB of the neighboring cell are different, or if the subcarrier spacing of the two SSBs is different, the measurement is defined as an SSB-based inter-frequency measurement.

[0072] It should be noted that for SSB-based measurements, one measurement object corresponds to one SSB, and the UE considers different SSBs as different cells.

[0073] A Channel State Information Reference Signal (CSI-RS) based intra-frequency measurement may indicate a measurement that is defined as a CSI-RS based intra-frequency measurement if the following conditions are met:

[0074] The subcarrier spacing of the CSI-RS resources on the neighboring cell configured for measurement is the same as the subcarrier spacing (SCS) of the CSI-RS resources on the serving cell indicated for measurement; and

[0075] For 60 kHz subcarrier spacing, the cyclic prefix (CP) type of the CSI-RS resources on the neighboring cell configured for measurement is the same as the CP type of the CSI-RS resources on the serving cell indicated for measurement; and

[0076] The center frequency of the CSI-RS resource on the neighbor cell configured for measurement is the same as the center frequency of the CSI-RS resource on the serving cell indicated for measurement.

[0077] If a CSI-RS-based inter-frequency measurement is not a CSI-RS-based intra-frequency measurement, it may refer to a measurement defined as a CSI-RS-based inter-frequency measurement. Whether a measurement is non-gap-assisted or gap-assisted depends on the UE capability, the UE's active bandwidth portion (BWP), and the current operating frequency. For SSB-based inter-frequency measurements, if measurement gap requirement information is reported by the WTRU, measurement gap configuration may be provided according to the information. Otherwise, measurement gap configuration may be provided in the following cases (e.g., always): if the UE supports only per-UE measurement gaps and / or if the UE supports per-frequency range (FR) measurement gaps and any of the serving cells is within the same frequency range of the measurement object. For SSB-based intra-frequency measurements, if measurement gap requirement information is reported by the UE, measurement gap configuration may be provided according to the information. Otherwise, measurement gap configuration may be provided in the following cases (e.g., always): if any of the UE-configured BWPs other than the initial BWP does not include the frequency domain resource of the SSB associated with the initial DL BWP. In a non-gap-assisted scenario, the UE may be able to perform such measurements without a measurement gap. In a gap-assisted scenario, the UE may not be expected to be able to perform such measurements without a measurement gap.

[0078] Channel state information (CSI) can be used as an indicator from the UE to the network about how good (or bad) the channel is at any given time. CSI can be used by the gNB to make scheduling decisions such as modulation and coding scheme (MCS) selection and to assist beamforming. According to TS38.214, the time and frequency resources that the UE can use to report CSI are controlled by the gNB. CSI can include a channel quality indicator (CQI), a precoding matrix indicator (PMI), a CSI-RS resource indicator (CRI), a SS / PBCH block resource indicator (SSBRI), a layer indicator (LI), a rank indicator (RI), a L1 reference signal received power (RSRP), a L1 signal-to-interference-and-noise ratio (SINR), and / or a Capability[Set]Index.

[0079] For CQI, PMI, CRI, SSBRI, LI, RI, L1-RSRP, L1-SINR, and / or Capability[Set]Index, the UE can be configured by higher layers using N≧1 CSI-ReportConfig reporting settings, M≧1 CSI-ResourceConfig resource settings, and / or a list of one or two trigger states (e.g., specified by higher layer parameters CSI-AperiodicTriggerStateList and CSI-SemiPersistentOnPUSCH-TriggerStateList). Each trigger state in CSI-AperiodicTriggerStateList can include a list of associated CSI-ReportConfigs indicating resource set IDs for the channel and, optionally, for interference. Each trigger state in CSI-SemiPersistentOnPUSCH-TriggerStateList may include one associated CSI-ReportConfig.

[0080] Each reporting configuration CSI-ReportConfig is associated with a single downlink BWP specified in the associated CSI-ResourceConfig for channel measurements (e.g., indicated by the higher layer parameter BWP-Id) and can include parameters for one CSI reporting band, such as: codebook configuration including codebook subset restriction, time domain behavior, frequency granularity of CQI and PMI, measurement restriction configuration, and CSI-related quantities to be reported by the UE (e.g., Layer Indicator (LI), L1-RSRP, L1-SINR, CRI, SSBRI (SSB Resource Indicator), and Capability[Set]Index).

[0081] The time-domain behavior of CSI-ReportConfig is indicated by the higher layer parameter reportConfigType, which can be set to "aperiodic", "semiPersistentOnPUCCH", "semiPersistentOnPUSCH", or "periodic". For "periodic" and "semiPersistentOnPUCCH" / "semiPersistentOnPUSCH" CSI reporting, the configured periodicity and slot offset may be applied to the UL BWP value at which the CSI report is configured to be transmitted. The higher layer parameter reportQuantity can indicate the amount of CSI-related, L1-RSRP-related, L1-SINR-related, or Capability[Set]Index-related information to report. The reportFreqConfiguration can indicate the reporting granularity in the frequency domain, including the CSI reporting band and whether PMI / CQI reporting is wideband or subband. The timeRestrictionForChannelMeasurements parameter of CSI-ReportConfig can be configured to enable time-domain restrictions on channel measurements, and timeRestrictionForInterferenceMeasurements can be configured to enable time-domain restrictions on interference measurements. CSI-ReportConfig can include CodebookConfig, which can include configuration parameters for Type 1, Type 2, Extended Type 2 CSI, or further extended Type 2 port selection, including codebook subset restrictions, if applicable, as well as configuration for group-based reporting.

[0082] Each CSI resource configuration CSI-ResourceConfig may include a configuration of a list of S≧1 CSI resource sets (e.g., given by the higher layer parameter csi-RS-ResourceSetList), where the list may consist of references to either or both of NZP CSI-RS resource sets and SS / PBCH block sets, or the list may consist of references to CSI-IM resource sets. Each CSI resource configuration may be located in a DL BWP identified by the higher layer parameter BWP-id, and all CSI resource configurations linked to a CSI reporting configuration may have the same DL BWP.

[0083] The time-domain behavior of CSI-RS resources within a CSI resource configuration can be indicated by the higher layer parameter resourceType and can be configured as aperiodic, periodic, or semi-persistent. For periodic and semi-persistent CSI resource configurations, if the UE is configured with groupBasedBeamReporting-r17, the number of configured CSI resource sets is S = 2; otherwise, the number of configured CSI-RS resource sets is limited to S = 1. For periodic and semi-persistent CSI resource configurations, the configured periodicity and slot offset can be specified by the number of associated DL BWPs, specified by BWP-id. If a UE is configured with multiple CSI-ResourceConfigs containing the same NZP CSI-RS resource ID, the same time-domain behavior must be configured for each CSI-ResourceConfig. If a UE is configured with multiple CSI-ResourceConfigs containing the same CSI-IM resource ID, the same time-domain behavior may be configured for each CSI-ResourceConfig. All CSI resource configurations linked to a CSI reporting configuration may have the same time-domain behavior.

[0084] For one or more CSI resource configurations for channel and interference measurements, the following may be configured via higher layer signaling: CSI-IM resources for interference measurements as described in clause 5.2.2.4 of TS38.214, NZP CSI-RS resources for interference measurements as described in clause 5.2.2.3.1 of TS38.214, and / or NZP CSI-RS resources for channel measurements as described in clause 5.2.2.3.1 of TS38.214.

[0085] FIG. 3 illustrates an exemplary handover (HO) scenario in NR. In the example of FIG. 3, at 0, the UE context in the source gNB includes information about roaming and access restrictions provided at connection establishment or the last timing advance (TA) update. At 1, the source gNB configures the UE measurement procedure, and the UE reports according to the measurement configuration. At 2, the source gNB decides to hand over the UE based on the received measurements. At 3, the source gNB issues a handover request message to the target gNB and can pass a transparent RRC container with information necessary to prepare the handover on the target side. This information can include at least the target cell ID, KgNB*, the UE's C-RNTI at the source gNB, RRM configuration including the UE's inactivity time, basic AS configuration including antenna information and DL carrier frequency, current QoS flow to data radio bearer (DRB) mapping rule applied to the UE, SIB1 from the source gNB, UE capabilities for different RATs, PDU session-related information, and, if available, UE-reported measurement information including beam-related information.

[0086] As further shown in the example of FIG. 3, admission control can be performed by the target gNB at 4. If the UE can be admitted at 5, the target gNB can prepare a handover with L1 / L2 and send a HANDOVER REQUEST ACKNOWLEDGE to the source gNB, which can include a transparent container that is sent to the UE as an RRC message to perform the handover. At 6, the source gNB triggers a Uu handover by sending an RRC Reconfiguration message to the UE, which includes information necessary to access the target cell, i.e., at least a target cell ID, a new cell radio network temporary identifier (C-RNTI), and / or a target gNB security algorithm identifier for the selected security algorithm. This can include a set of dedicated RACH resources, an association between random access channel (RACH) resources and SSB, an association between RACH resources and a UE-specific CSI-RS configuration, common RACH resources, and system information of the target cell.

[0087] In the example of FIG. 3, at 7, the source gNB sends an SN STATUS TRANSFER message to the target gNB to convey the uplink Packet Data Convergence Protocol (PDCP) Sequence Number (SN) receiver status and downlink PDCP SN transmitter status of the DRBs to which PDCP status preservation applies (i.e., RLC AM). At 8, the UE synchronizes to the target cell and completes the RRC handover procedure by sending an RRCReconfigurationComplete message to the target gNB. At 9, the target gNB sends a PATH SWITCH REQUEST message to the AMF, triggering the 5GC to switch the DL data path to the target gNB and establish an NG-C interface instance to the target gNB. At 10, the 5GC switches the DL data path to the target gNB. The UPF sends one or more "End Marker" packets to the source gNB on the old path for each PDU session / tunnel, and then releases any U-plane / TNL resources towards the source gNB. At 11, the AMF acknowledges the path switch request message with a path switch request acknowledgment message. At 12, upon receiving the path switch request acknowledgment message from the AMF, the target gNB notifies the source gNB of the success of the handover by sending a UE CONTEXT RELEASE message. The source gNB can release radio and C-plane related resources associated with the UE context. Ongoing data transfer may continue.

[0088] Release 16 NR introduced the concepts of conditional handover (CHO) and conditional primary secondary serving cell (PSCell) addition / change (CPA / CPC, or collectively CPAC) with the primary objective of reducing the likelihood of radio link failure (RLF) and handover failure (HOF).

[0089] Legacy LTE or NR handovers are typically triggered by measurement reports, even though nothing prevents the network from sending an HO command to the UE without receiving a measurement report. For example, a UE can be configured with an A3 event that triggers a measurement report to be sent when the radio signal level / quality (e.g., RSRP, RSRQ) of a neighboring cell becomes better than the primary serving cell (PCell) or, in the case of dual connectivity (DC), the primary secondary serving cell (PSCell). The UE monitors the serving cell and neighboring cells and sends a measurement report when the condition is met. When such a report is received, the network (current serving node / cell) prepares an HO command (e.g., an RRC reconfiguration message with reconfigurationWithSync) and sends it to the UE, which executes it (e.g., immediately), connecting the UE to the target cell.

[0090] 4 shows an exemplary signaling diagram depicting CHO according to one example. At 405, a source node may send a CHO request to a potential target node. At 410, the potential target node may send a CHO request ACK to the source node (e.g., using RRCReconfiguration). At 415, the source node may send a CHO configuration (e.g., including CHO conditions, such as A3 / A5 events, and RRCReconfiguration) to the UE. At 420, the UE may monitor CHO conditions of candidate target cells, and if / when the conditions are met, the UE may perform HO at 425. At 430, the UE may send a CHO confirmation to the target node, which may perform path switching and UE context release, as shown at 435.

[0091] CHO differs from legacy handover in several ways. For example, in CHO, multiple handover targets are prepared (e.g., compared to only one target in the legacy case). Furthermore, in CHO, the UE does not immediately perform CHO as in legacy handover. Instead, the UE is configured with trigger conditions, which are a set of radio conditions, and the UE performs a handover towards one of the targets only if / when the trigger conditions are met.

[0092] Because the CHO command can be sent when radio conditions to the current serving cell are still favorable, two major failure points in legacy handover can be reduced: the risk of failing to send a measurement report (e.g., if the link quality to the current serving cell is below an acceptable level when the measurement report is triggered in a normal handover) and the risk of failing to receive a handover command (e.g., if the link quality to the current serving cell is below an acceptable level after the UE sends a measurement report but before receiving the HO command). The trigger conditions for CHO may be based on the radio qualities of the serving and neighboring cells, similar to the conditions used to trigger measurement reports in legacy NR / LTE. For example, a UE may be configured with CHO having a trigger condition such as A3 and an associated HO command. The UE monitors the current and serving cells, and when the A3 trigger condition is met, it executes the associated HO command instead of sending a measurement report and switches its connection to the target cell.

[0093] Another advantage of CHO is that it can prevent unnecessary re-establishment in the event of a radio link failure (RLF). For example, assume that a UE is configured with multiple CHO targets and experiences an RLF before the trigger condition for any of the targets is met. In conventional operation, an RRC re-establishment procedure would be required, resulting in significant disruption for the UE's bearers. However, with CHO, if the UE were to select a cell with which the CHO is associated after detecting an RLF (i.e., if the target cell is already prepared for it), the UE would directly execute an HO command associated with this target cell instead of continuing with the full re-establishment procedure.

[0094] Conditional PSCell Change (CPC) and Conditional PSCell Addition (CPA) are extensions of CHO in dual connectivity (DC) scenarios. A UE can be configured with trigger conditions for PSCell change or addition, and when the trigger conditions are met, the UE executes the associated PSCell change or PSCell addition command.

[0095] Currently, in Release 17, for carrier aggregation (CA), beams can be managed using inter-cell beam management, but cell change / addition is not currently supported. In Release 18, one of the objectives of the work item "Further NR Mobility Enhancements" is to specify mechanisms and procedures for L1 / L2-based inter-cell mobility for mobility latency reduction. This may include one or more of the following: configuration and maintenance of multiple candidate cells to enable rapid application of candidate cell configuration; dynamic switching mechanisms between candidate serving cells for potentially applicable scenarios based on L1 / L2 signaling; L1 enhancements for inter-cell beam management including L1 measurement / reporting and beam indication; timing advance management; and centralized unit (CU)-distributed unit (DU) interface signaling to support L1 / L2 mobility as needed. Note that L1 / L2-based inter-cell mobility can be applied, for example, in the following cases: - Standalone, CA and NR-DC cases with serving cell change within one CG. - Intra-DU case and intra-CU, inter-DU case (e.g. no new RAN interface is assumed, applicable to standalone and CA). - Both intra- and inter-frequency. - Both frequency range (FR) 1 and frequency range (FR) 2. The source and target cells may or may not be synchronized. -Inter-CU cases are not included.

[0096] L1 / L2-based mobility was originally introduced in Release 17, and inter-cell beam management in Release 17 targets intra-DU and / or intra-frequency scenarios. In this case, the serving cell remains unchanged (e.g., there is no possibility to change the serving cell using L1 / L2-based mobility). In FR2 deployments, CA may be used, for example, to aggregate multiple CCs within one band to exploit available bandwidth. These CCs are typically transmitted on the same analog beam pair (gNB beam and UE beam). UEs are configured with transmission configuration indicator (TCI) states (which can have a fairly large number, e.g., 64) for reception of the physical downlink control channel (PDCCH) and physical downlink shared channel (PDSCH). Each TCI state contains a reference signal (RS) or SSB that the UE references to configure its beam. In Release 17, SSBs may be associated with a non-serving physical cell ID (PCI). Medium Access Control (MAC) signaling ("TCI state indication for UE-specific PDCCH MAC CE") activates the TCI state for the CORESET / PDCCH. Reception of PDCCH from non-serving cells is supported by a MAC Control Element (CE) indicating the TCI state associated with the non-serving PCI. MAC signaling ("TCI States Activation / Deactivation for UE-specific PDSCH") activates a subset of (up to) eight TCI states for PDSCH reception. The DCI indicates one of the eight TCI states. Release 17 also supports a "unified TCI state" with a different update mechanism (DCI-based), but multi-TRP is not supported. Release 18 supports unified TCI state with multi-TRP.

[0097] The overall objective of inter-cell L1 / L2 triggered mobility (LTM) is to improve handover latency. In traditional L3 handover or conditional handover, the UE typically first sends a measurement report using RRC signaling. In response, the network can provide additional measurement configurations and possibly conditional handover configurations. In traditional handover, the UE reports using RRC signaling that the cell meets the configured radio quality criteria, and then the network provides the target cell configuration. In conditional handover, to reduce handover failure rates due to delays in sending measurement reports and receiving RRC reconfiguration, the network provides the target cell configuration and measurement criteria that determine when the UE should trigger CHO configuration in advance. However, both of these L3 methods can incur some delays due to the sending of measurement reports and receiving the target configuration, especially in the case of traditional (unconditional) handover.

[0098] In particular, the purpose of LTM is to enable rapid application of candidate cell configurations, including dynamic switching between SCells and PCell switching (e.g., switching roles between SCell and PCell) without performing RRC signaling. The inter-CU case is not included because it requires PDCP anchor relocation and has already been excluded from the work item. Therefore, an RRC-based approach is needed to support at least inter-CU handover.

[0099] Furthermore, with the legacy L3 handover mechanism, any currently active SCells are released before the UE completes the handover to the target cell within the coverage area of ​​the new site and can only be added after the handover is successful, which reduces throughput during the handover. Therefore, one of the goals of L1 / 2 is to enable CA operation immediately upon a serving cell change.

[0100] Figure 5 shows an example of an LTM operation according to one embodiment. As shown in the example of Figure 5, a candidate cell group can be configured by the RRC, and dynamic switching of the PCell and SCell is achieved using L1 / L2 signaling. More specifically, in the example of Figure 5, the RRC initially configures cells 1 to 4 as candidates and activates PCell 1 and SCell 2. Furthermore, as shown in Figure 5, dynamic SCell switching can be performed between Cell 2 and Cell 3, and dynamic switching from the PCell to Cell 1 and from the SCell to Cell 4 can be performed.

[0101] As mentioned above, the inter-CU case is not included because it requires PDCP anchor relocation and has already been excluded from the work item. Therefore, an RRC-based approach is preferred at least to support inter-CU handover. This means that if LTM is configured with measurement and measurement reporting mechanisms to support LTM, it must run in parallel with or coexist with RRC-based measurement and mobility.

[0102] For LTM, 3GPP expects that L1 measurements will be used at least to make cell switching decisions. Various solutions are being considered, including supporting the use of L1 measurements only and using L3 measurements to enable L1 measurements. For example, L3 measurements could be used to perform candidate cell detection / measurements, and when a candidate cell meets certain conditions, such as a radio quality threshold, L1 measurements could be configured or enabled and reported, allowing for faster measurement triggering and handover.

[0103] 3GPP also assumes that some L2 reconfiguration procedures may be avoided when performing LTM (i.e., cell change). Since LTM supports intra-DU cell changes, in these cases the UE may not need to perform a full MAC reset since the MAC resides in the DU part of the network. Therefore, if both cells belong to the same DU, MAC configuration and PDU storage in transmission / retransmission buffers may be maintained during the cell change. Similarly, in both intra-DU and inter-DU cases, only intra-CU cell changes are supported in LTM. In this case, RLC and PDU re-establishment may not be necessary because they reside in the CU part of the network. Therefore, if both cells belong to the same CU, configuration and PDU storage in transmission / retransmission buffers may be maintained during the cell change. Furthermore, since cell changes are limited to cells within the same CU, it is assumed that security key changes do not need to be performed in LTM. Reducing the amount of reconfiguration that needs to be performed, as well as other potential enhancements such as performing DL and / or UL synchronization before reconfiguration, will improve handover interruption times and improve mobility performance, at least for cell changes that occur within the same CU or same DU using LTM.

[0104] Due to the enhancements described above (i.e. faster measurement triggering, reduced handover delay, reduced handover interruptions, reduced RRC reconfiguration), when LTM is configured, it is appropriate for the UE to perform mobility within the set of configured LTM candidate cells for as long as possible and only perform inter-CU handovers (which have associated additional overhead in terms of reconfiguration effort, handover interruptions, etc.) when moving out of the coverage of the current CU or the current LTM candidate set.

[0105] Additionally, since L3 mobility is controlled by the CU while LTM may be under the control of the DU (e.g., in the case of intra-DU mobility), race conditions may occur, such as when the DU and CU each initiate a cell change / reconfiguration at approximately the same time. As an example, the CU may send an RCC reconfiguration to the UE, which may be sent using a Radio Link Control (RLC) PDU and a MAC PDU, and the DU may send a MAC CE to trigger a cell change while the RCC reconfiguration is being sent.

[0106] Thus, certain embodiments provide a solution on how to prioritize mobility within an LTM candidate set (e.g., within the same CU, using L1 / L2 triggered reconfiguration) over mobility outside the LTM candidate set (e.g., between CUs, using L3 triggered reconfiguration). Furthermore, exemplary embodiments can minimize conflicts between LTM and L3 mobility (L3M).

[0107] An embodiment may provide separate conditions for performing LTM measurements and for performing L3 intra- and inter-frequency measurements (on cells outside the LTM candidate set). The conditions for L3 measurements may take into account the radio quality of cells in the LTM candidate set.

[0108] For example, in certain embodiments, the UE may monitor the signal quality of the serving cell. If a radio quality condition based on measurements of the serving cell is met (e.g., if the PCell is below Threshold 1), the UE may perform one or more of the following: measurements on cells in the LTM candidate set, evaluation of measurements using a first measurement evaluation method (e.g., LTM-specific measurement events performed on cells in the set), and / or reporting using a first reporting method (e.g., reporting using MAC CE).

[0109] According to some embodiments, if certain radio quality conditions based on the signal quality of the serving cell and / or the LTM candidate cell are met, the UE may perform (e.g., enable) one or more of: measurements on cells outside the LTM candidate set; evaluation of measurements using a second measurement evaluation method (e.g., RRC measurement events); and / or reporting using a second reporting method (e.g., RRC measurement events).

[0110] In one embodiment, if a radio quality condition based on the second measurement evaluation method is met, a measurement report using the second reporting method may be triggered.

[0111] One embodiment may provide a measurement event that is triggered when a condition for the serving cell and a cell inside the LTM candidate set is met and a cell outside the LTM set is above a threshold (e.g., similar to Event A5, but using not only the SpCell but also other candidate cells). According to a particular embodiment, the UE may (e.g., be configured to) perform measurements on a set of cells in the LTM set, derive a first signal quality based on the measurements, and evaluate the signal quality based on the first condition. In one embodiment, the UE may (e.g., be configured to) perform measurements on cells outside the LTM set, derive a second signal quality, and evaluate the signal quality based on the second condition. A measurement report may be triggered when the first condition and the second condition are met (e.g., are met simultaneously).

[0112] FIG. 6 illustrates a flow diagram of a method according to an exemplary embodiment. According to a particular embodiment, the method of FIG. 6 may be performed by a UE or a WTRU. In the exemplary method of FIG. 6, at 605, the UE may receive configuration for LTM candidate cells. The configuration may include a list of cell IDs (e.g., PCI), a list of measurement resources (e.g., SSB or CSI-RS), and configuration to apply when the UE receives an indication indicating a cell change using MAC CE or DCI. The UE may also receive configuration for cells outside the candidate set, e.g., a neighbor cell list. In addition to the candidate and neighbor cell configurations, the UE may also receive at 605 configurations of (e.g., first) conditions based on the signal quality of the serving cell and (e.g., second) conditions based on the signal quality of the LTM candidate cells to be evaluated. The first condition may be, for example, a first measurement evaluation method using a (e.g., first) signal quality threshold (e.g., s-Measure) and a first reporting method used to trigger measurements of an LTM candidate cell when the signal quality of the serving cell measured at 610 falls below a configured threshold at 615. This may save UE power because measurements of the candidate cell may not be needed while the quality of the serving cell is relatively high. This first threshold is applied as a trigger for measurements of cells in the LTM candidate set. The first threshold may be used to trigger evaluation of an LTM candidate cell. For example, an LTM measurement event evaluation may be used to perform a measurement event configured to enable (e.g., L1) CSI reporting when (e.g., L3) event criteria are met. The first threshold may be used to trigger L1 CSI measurements used to determine an LTM cell change.

[0113] In addition to the (e.g., first) condition based on the signal quality of the serving cell, the UE may receive at 605 a configuration of a separate (e.g., second) condition based on the signal quality of the LTM candidate cells measured at 620, which is evaluated at 625. This second condition may be, for example, a (e.g., second) signal quality threshold (e.g., s-Measure) used to trigger measurements of cells outside the candidate set, and a second measurement evaluation method using a second reporting method at 630 when the signal quality of one (e.g., the serving cell) or more (e.g., all cells) of the LTM candidate cells falls below a threshold.

[0114] In one embodiment, the UE may perform an RRC measurement event evaluation using the second evaluation method at 635, for example, and transmit a measurement event using the second reporting method at 640 when the event is triggered based on measurements of a cell outside the LTM set.

[0115] According to certain embodiments, measurements and evaluations of cells outside the LTM set may be triggered when one or more of the following occur: a) PCell is below threshold 2 (threshold 2<threshold 1); b) the PCell signal drops below a certain threshold within a given time; c) all LTM candidate cells are below a certain threshold (the threshold can be the same for all candidate cells or each candidate cell has a threshold associated with it); d) the average signal level of all LTM candidate cells is below a certain threshold; e) the signal levels of all LTM candidate cells have decreased (e.g., decreased by a certain threshold within a given time); and / or f) Any of the above conditions is met for a minimum period (e.g., triggering time).

[0116] Certain exemplary embodiments may provide separate s-Measure thresholds for controlling measurements and evaluations of cells in the LTM candidate set and cells outside the LTM candidate set. In one embodiment, both the first and second thresholds may be compared to the quality of the serving cell (e.g., measurements of LTM candidate cells initiated when the PCell falls below threshold 1, and measurements of non-LTM candidate cells initiated when the PCell falls further below threshold 2). In this case, the first threshold may be set to a higher value than the second threshold. The first threshold may trigger measurements of cells in the LTM candidate set and may trigger evaluation of measurement events associated with the LTM candidate cells, such that the UE can send MAC CE measurement reports and receive MAC CEs that trigger a cell change. The second threshold may be used to trigger measurements of cells outside the LTM candidate set (e.g., in addition to measurements of cells in the LTM candidate set). The second threshold may be used to control when the UE starts evaluating measurement events associated with L3 mobility, so that the UE can send L3 measurement reports to the gNB and receive RRC reconfiguration in response, or may be used to control when the UE starts evaluating trigger conditions for CHO associated with cells that are not in the LTM candidate set.

[0117] In this example, both the first and second thresholds compare the signal quality of the serving cell to a threshold, but the first threshold provides (e.g., only provides) an indication of the quality of the serving cell, while the second threshold implies the quality of cells in the LTM set. This is because the first threshold allows measurements (and mobility) of cells in the LTM set, which will ensure that under normal conditions, the cell with the highest quality among the cells in the LTM set is configured as the serving cell. If the quality of the serving cell falls below the second threshold, this means that all cells in the LTM set are below this threshold, and therefore L3 mobility measurements need to be triggered so that the UE can be reconfigured (e.g., by RRC) to a cell outside the LTM set.

[0118] In one embodiment, the second threshold may be compared to the signal quality of multiple cells (e.g., the PCell and some or all of the cells in the LTM set). The UE may, for example, perform an average of the N best cells or N best beams (e.g., beams of multiple cells) to derive the signal quality of the LTM set. This LTM set quality may be compared to a threshold (e.g., similar to the s-Measure example above), and when this is met (e.g., when the quality of the LTM set is above the threshold), the UE may begin measuring cells outside the LTM candidate set or evaluating trigger conditions associated with cells outside the LTM candidate set. In another example, the averaging may also include the signal level of the current PCell.

[0119] In another example, the UE may enable L3 measurements on cells outside the LTM set when the number of LTM cells above a certain signal level threshold falls below a certain value. For example, if the number of cells is set to 3 and the threshold is set to a value X, there is no need to perform measurements on cells outside the LTM set if there are at least three LTM candidate cells whose measured signal quality exceeds threshold X. However, when the number of cells whose measured signal quality exceeds threshold X falls below 3, the UE may perform measurements on cells outside the LTM set in preparation for a potential L3 reconfiguration or conditional reconfiguration. In yet another example, the current PCell may also be considered as part of the number of cells compared to the signal level threshold (e.g., in the example above, this may mean that if two LTM candidate cells and a PCell exceed threshold X, no measurements are performed on non-LTM candidate cells).

[0120] In the example described above, separate conditions (e.g., s-Measure) can be used to control measurement timing for cells within the LTM set and cells outside the LTM set. In other examples, these conditions can alternatively or additionally be used to control measurement evaluation type.

[0121] In one embodiment, the UE may be configured with one or more measurement events associated with LTM, such as a measurement event triggered when a candidate cell exceeds a threshold. Such an event may be used, for example, to control when L1 CSI measurements are enabled on this candidate cell. In this example, the UE may also be configured with one or more measurement events or conditional reconfiguration used to perform L3 mobility. These may be one or more existing measurement events, such as, but not limited to, A3, A4, and A5. If a first condition is met, the UE may evaluate events associated with LTM using measurements performed on the LTM candidate cell. If a second condition is met, the UE may evaluate events associated with L3M using measurements performed on cells outside the LTM set and, in some examples, may additionally or alternatively consider measurements performed on cells within the LTM set.

[0122] In some embodiments, measurement events may be performed separately and may use different trigger conditions and potentially different reporting mechanisms. For example, LTM events may be reported using MAC CE, and L3M events may be reported using RRC measurement reports. These separate measurement events may be used, for example, to perform intra-CU mobility using LTM measurement events (within the LTM candidate set) and inter-CU mobility using L3M measurement events (outside the LTM candidate set).

[0123] According to one embodiment, if only the first condition is met, the UE may perform measurement and event evaluations associated with LTM but not with L3M. This avoids or minimizes a potential race condition where both LTM and L3M triggers are received simultaneously (meaning that the order in which the UE receives the commands may be unknown to the network, since they may be issued by different network nodes and transmitted using different parts of the protocol). In one solution, if the second condition is met, the UE may stop performing measurement event evaluations associated with LTM and perform measurement event evaluations associated with L3M. In other words, LTM event evaluation and reporting can be stopped when L3M evaluation and reporting begins, ensuring that only one mobility method is used at any given time, even if both mobility methods are configured in parallel at the UE. The UE effectively switches between LTM and L3M based on distinct conditions, using different measurement, measurement event, and reporting mechanisms according to the mobility method in use.

[0124] In other words, according to certain embodiments, the first threshold may control whether measurements need to be performed or whether the UE may choose not to perform measurements, while the second threshold may control the type of measurement evaluation and reporting performed by the UE. The UE may evaluate using a first set of measurement events (e.g., candidate cell evaluation) and report using a first reporting method (e.g., MAC CE) when the PCell measurements are above the second threshold, and may evaluate using a second set of measurement events (e.g., candidate cell and neighbor cell evaluation) and report using a second reporting method (e.g., RC measurement reporting) when the PCell measurements are below the second threshold.

[0125] In one embodiment, when the second condition is met (or when the UE detects that the second condition is no longer met), the UE can send an indication to the network. This indication may be sent, for example, using an RRC measurement report or may be carried within the UL MAC CE. This indication effectively informs the network which measurement rule and / or set of events (i.e., first or second) is being used by the UE, allowing the network to, for example, stop using LTM triggers for handover while the UE is performing L3 measurement evaluation. This is one way for the network to avoid, for example, issuing a MAC CE sent by the DU to trigger an intra-DU cell change while the CU is preparing an inter-CU cell change using L3. In this example, the UE can continue to perform both types of measurement evaluation and reporting, while the network can avoid using one or the other type of handover trigger.

[0126] In one embodiment, a third condition may be provided, such that, for example, a first condition is used to control when measurements, evaluations, and reporting are performed for cells in the LTM set, a second condition is used to control when measurements, evaluations, and reporting are performed for cells used to maintain the LTM set (e.g., to determine when to add / remove / replace LTM candidates from the set), and a third condition is used to control when measurements, evaluations, and reporting are performed to support L3M.

[0127] It should be noted that in other examples, more than two conditions may be provided to allow for measurements and evaluations associated with more than two objectives.

[0128] According to certain example embodiments, the UE may (e.g., may be configured to) perform measurements on a set of cells in the LTM set, derive a first signal quality based on the measurements, and evaluate the signal quality based on a first condition. The UE may (e.g., may be configured to) perform measurements on cells outside the LTM set, derive a second signal quality, and evaluate the signal quality based on a second condition. If the first condition and the second condition are met (e.g., met simultaneously), the UE may trigger (e.g., may be configured to trigger) a measurement report.

[0129] In one embodiment, a new type of measurement event trigger and / or conditional reconfiguration trigger may be provided, which may control the measurement event trigger using, for example, one of the above conditions.

[0130] According to one embodiment, the measured quality of the LTM set may be compared to a first condition, and measurements of cells outside the LTM set may be compared to a second condition. Taking the existing event A5 as an example, it may be triggered when the SpCell is below a threshold and a neighboring cell is above a threshold. As another example, event A3 may be triggered when the offset of a neighboring cell becomes better than the SpCell. One embodiment may be triggered when all cells in the LTM set are below a threshold (i.e., as described above in determining the s-Measure, only cells in the LTM set are considered) and a cell outside the LTM set (neighbor) is above a threshold, rather than the SpCell alone.

[0131] In some embodiments, cells in the LTM set may be averaged using, for example, any of the following approaches: (1) the SpCell is considered to have the same weight as the candidate cell. For example, the signal quality is derived using an equal-weighted average of the N best cells in the LTM set, which may include the SpCell; and / or (2) the SpCell may have a greater weight than other cells in the LTM set. For example, the average is calculated using any method of calculating a weighted average and assigning a greater weight to the SpCell than other cells.

[0132] In another embodiment, three conditions can also be used: for example, an event can be defined that is triggered when the SpCell is below a first threshold, the LTM candidate cell is below a second threshold, and the non-LTM (neighbor) cell is above a third threshold.

[0133] Alternatively, in one embodiment, a condition on the number of cells may be used, similar to that described above for s-Measure. For example, a measurement event may be triggered when fewer than three cells in the LTE set are above a first threshold and a cell outside the LTM set is above a second threshold.

[0134] In embodiments where a separate s-Measure is also used, the UE may perform measurements on both cells within the LTM set and cells outside the LTM set so that the results can be compared if the second condition is met.

[0135] One example embodiment may be directed to a method that may be performed by a WTRU. The method may include receiving information indicating a set of Layer 1 / Layer 2 triggered mobility (LTM) candidate cells, a configuration of a first condition associated with signal quality of the serving cell, and / or a configuration of a second condition associated with signal quality of the LTM candidate cell. The method may include performing measurements of the signal quality of the serving cell. Based on the first condition associated with the signal quality of the serving cell being met, the method may include performing any one or more of measurements of the signal quality of the LTM candidate cell, a first measurement evaluation method of the measurements (e.g., performing evaluation of the measurements of the LTM candidate cell using the first measurement evaluation method), and / or a first measurement reporting method (e.g., reporting the measurements using the first measurement reporting method). Based on a second condition associated with the signal quality of the LTM candidate cell being satisfied (e.g., when the first condition and the second condition are satisfied), the method may include performing a measurement of the signal quality of a cell not in the set of LTM candidate cells, a second measurement evaluation method of the measurement (e.g., performing evaluation of the measurement of the non-LTM candidate cell using the second measurement evaluation method), and / or a second measurement reporting method (e.g., reporting the measurement of the non-LTM candidate cell using the second measurement reporting method). Conditional on the radio quality condition based on the second measurement evaluation method being satisfied, the method may include transmitting a measurement report using the second reporting method.

[0136] In one embodiment, the first measurement evaluation method may be or may include Layer 1 (L1) measurement. In one embodiment, the first measurement reporting method may be or may include Channel State Information (CSI) reporting.

[0137] In one embodiment, the second measurement evaluation method may be or may include a Layer 3 (L3) measurement. In one embodiment, the second measurement reporting method may be or may include a Radio Resource Control (RRC) measurement report.

[0138] In one embodiment, the first condition is met if (e.g., conditionally below) the measured signal quality of the primary cell (PCell) is below a first threshold. In one embodiment, the second condition is met if one or more of the following conditions occur: the signal quality of all LTM candidate cells is below a second threshold, the average signal level of all LTM candidate cells is below a third threshold, and / or the signal level of all LTM candidate cells is decreasing.

[0139] While features and elements have been provided above in specific combinations, those skilled in the art will understand that each feature or element can be used alone or in any combination with other features and elements. The present disclosure is not limited to the specific embodiments described in this application, which are intended to be illustrative of various aspects. Many modifications and variations may be made without departing from the spirit and scope of the present disclosure, as will be apparent to those skilled in the art. No element, act, or instruction used in the description of the present application should be construed as critical or essential to the invention unless expressly defined as such. Functionally equivalent methods and apparatuses within the scope of the present disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing description. Such modifications and variations are intended to be encompassed by the appended claims. The present disclosure is limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It will be understood that the present disclosure is not limited to any particular method or system.

[0140] In some embodiments described herein, (e.g., configuration) information may be described as being received by the WTRU from the network, e.g., via system information or any type of protocol message. Although not explicitly mentioned throughout the embodiments described herein, the same (e.g., configuration) information may also be pre-configured in the WTRU (e.g., via any type of pre-configuration method, such as factory default), such that this (e.g., configuration) information may be used by the WTRU without receiving it from the network.

[0141] Any feature, variation, or embodiment described with respect to the methods is compatible with apparatus devices that include means for processing the disclosed methods, such as a processor configured to process the disclosed methods, a computer program product that includes program code instructions, and a device that includes a non-transitory computer-readable storage medium that stores program instructions.

[0142] The above-described embodiments are described with respect to the terminology and structure of infrared-enabled devices, i.e., infrared emitters and receivers, for ease of explanation. However, the embodiments described herein are not limited to these systems and are applicable to other systems that use other forms of electromagnetic waves or non-electromagnetic waves, such as sound waves.

[0143] It should also be understood that the terms used herein are for the purpose of describing particular embodiments only and are not limiting. As used herein, the terms “video” or “image” may refer to either a snapshot, a single image, and / or multiple images displayed on a time basis. As another example, when referred to herein, the terms “user equipment” and its abbreviation “UE,” “remote,” and / or “head-mounted display” and its abbreviation “HMD” may mean or include (i) a wireless transmit / receive unit (WTRU), (ii) any of several embodiments of a WTRU, (iii) a wireless-enabled and / or wired-enabled (e.g., tetherable) device configured with, among other things, some or all of the structure and functionality of a WTRU, (iv) a wireless-enabled and / or wired-enabled device configured with less than all of the structure and functionality of a WTRU, or (v) others. Details of an example WTRU that may be representative of any WTRU described herein are set forth herein with reference to FIGS. 1A-1D . As another example, various embodiments disclosed above and below are described as utilizing a head-mounted display. Those skilled in the art will understand that devices other than head-mounted displays are available and that some or all of the present disclosure and various embodiments may be modified accordingly without undue experimentation. Examples of such other devices include drones and other devices configured to stream information to provide an adaptive reality experience.

[0144] Additionally, the methods provided herein can be implemented in a computer program, software, or firmware embodied in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted over wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random-access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks and digital versatile disks (DVDs). A processor in combination with software can be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

[0145] The above-described methods, apparatus, and systems may be modified in various ways without departing from the scope of the present invention. In view of the wide variety of possible embodiments, it should be understood that the illustrated embodiments are merely examples and are not intended to limit the scope of the claims. For example, the embodiments provided herein include handheld devices that may include or be utilized with any suitable voltage source, such as a battery that provides any suitable voltage.

[0146] Furthermore, in the above embodiments, reference is made to processing platforms, computing systems, controllers, and other devices that include processors. These devices may include at least one central processing unit (CPU) and memory. In accordance with the practices of those skilled in the art of computer programming, references to symbolic representations of acts and operations or instructions may be performed by various CPUs and memories. Such acts and operations or instructions may be referred to as being "executed," "executed by a computer," or "executed by a CPU."

[0147] Those skilled in the art will appreciate that these acts and symbolically represented operations or instructions include the manipulation of electrical signals by a CPU. The electrical system represents data bits that may cause the resulting transformation or reduction of the electrical signals and the retention of the data bits in memory locations within a memory system, thereby reconfiguring or altering the operation of the CPU and other signal processing. The memory locations where the data bits are maintained are physical locations that have particular electrical, magnetic, optical, or organic properties that correspond to or represent the data bits. It should be understood that embodiments are not limited to the above platforms or CPUs, and that other platforms and CPUs may support the provided methods.

[0148] The data bits can be stored on computer-readable media, including magnetic disks, optical disks, and any other volatile (e.g., random access memory (RAM)) or non-volatile (e.g., read-only memory (ROM)) mass storage system readable by a CPU. The computer-readable media includes cooperative or interconnected computer-readable media, which may reside solely on a processing system or distributed among multiple interconnected processing systems, which may be local or remote to the processing system. It should be understood that embodiments are not limited to the above memories and may support other platforms and ways in which memory is provided.

[0149] In an example embodiment, any of the operations, processes, etc. described herein may be implemented as computer-readable instructions stored on a computer-readable medium that may be executed by a processor of a mobile unit, a network element, and / or other computing device.

[0150] There is little distinction between hardware and software implementations of aspects of a system. The use of hardware or software is typically (though not always, as the choice between hardware and software may be significant in certain situations) a design choice representing a trade-off between cost and efficiency. There are various means (e.g., hardware, software, and / or firmware) for implementing the processes and / or systems and / or other techniques described herein, and the preferred means may vary depending on the context in which the processes and / or systems and / or other techniques are deployed. For example, if an implementer determines that speed and accuracy are paramount, they may choose a primarily hardware and firmware implementation. If flexibility is paramount, they may choose a primarily software implementation. Alternatively, an implementer may choose a combination of hardware, software, and / or firmware.

[0151] The foregoing detailed description has set forth various embodiments of devices and / or processes via the use of block diagrams, flowcharts, and / or examples. To the extent that such block diagrams, flowcharts, and / or examples include one or more functions and / or operations, those skilled in the art will appreciate that each function and / or operation within such block diagrams, flowcharts, or examples can be individually and / or collectively implemented by a wide range of hardware, software, firmware, or substantially any combination thereof. In one embodiment, portions of the subject matter described herein may be implemented via Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), digital signal processors (DSPs), and / or other integrated formats. However, those skilled in the art will recognize that some aspects of the embodiments disclosed herein may equivalently be implemented, in whole or in part, as an integrated circuit, one or more computer programs executing on one or more computers (e.g., one or more programs executing on one or more computer systems), one or more programs executing on one or more processors (e.g., one or more programs executing on one or more microprocessors), firmware, or substantially any combination thereof. Those skilled in the art will also recognize that, in light of this disclosure, designing circuitry and / or creating software and / or firmware code is within the skill of those in the art. Furthermore, those skilled in the art will understand that the mechanisms of the subject matter described herein may be distributed as a program product in various forms, and that the exemplary embodiments of the subject matter described herein apply regardless of the particular type of signal-bearing medium used to actually achieve distribution. Examples of signal-bearing mediums include, but are not limited to, recordable media such as floppy disks, hard disk drives, CDs, DVDs, digital tape, computer memory, and transmission-type media such as digital and / or analog communications media (e.g., fiber optic cables, wave guides, wired communications links, wireless communications links, etc.).

[0152] Those skilled in the art will understand that it is common in the art to describe devices and / or processes in the manner described herein and then use engineering techniques to integrate such described devices and / or processes into a data processing system. That is, at least a portion of the devices and / or processes described herein can be integrated into a data processing system through a reasonable amount of experimentation. Those skilled in the art will understand that a typical data processing system may generally include one or more of the following: a system unit housing; a video display device; memory, such as volatile and non-volatile memory; a processor, such as a microprocessor and a digital signal processor; computational entities, such as an operating system, drivers, a graphical user interface, and application programs; one or more interaction devices, such as a touchpad or screen; and / or a control system, including feedback loops and control motors (e.g., feedback for sensing position and / or velocity, control motors for moving and / or adjusting parts and / or quantities). A typical data processing system can be implemented using suitable commercially available components, such as those typically found in data computing / communication systems and / or network computing / communication systems.

[0153] The subject matter described herein may depict different components contained within or connected to other different components. It should be understood that the architectures depicted are merely examples, and that many other architectures that achieve the same functionality may actually be implemented. Conceptually, any arrangement of components to achieve the same functionality is substantially "associated," and the desired functionality may be achieved. Thus, any two components combined herein to achieve a particular function may be considered to be "associated" with each other such that the desired functionality is achieved, regardless of the architecture or intervening components. Similarly, any two components so associated may also be considered to be "operably connected" or "operably coupled" to each other to achieve the desired functionality. Additionally, any two components that can be associated in this manner may also be considered to be "operably coupleable" to each other to achieve the desired functionality. Specific examples of what is operably coupleable include, but are not limited to, physically matable and / or physically interacting components, wirelessly interacting and / or wirelessly interacting components, and / or logically interacting and / or logically interacting components.

[0154] With respect to the use of substantially any plural and / or singular terms herein, those skilled in the art can convert from plural to singular and / or from singular to plural as appropriate to the context and / or application. Various singular / plural permutations may be explicitly set forth herein for clarity.

[0155] In general, those skilled in the art will understand that the terms used herein, and particularly the terms used in the appended claims (e.g., the body of the appended claims), are generally intended as “open” terms (e.g., the term “comprising” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “including” should be interpreted as “including but not limited to,” etc.). Furthermore, those skilled in the art will understand that when a specific number of claims is intended in an introduced claim recitation, such intention will be explicitly set forth in the claim; in the absence of such a recitation, no such intention exists. For example, when only one item is intended, the term “single” or similar terminology may be used. To aid in understanding, the appended claims and / or the description herein below may include the use of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be interpreted as meaning that the introduction of the indefinite article “a” or “an” into a claim recitation means that a particular claim including that introduced claim recitation is limited to embodiments including only one such recitation. This is also true when the same claim contains the introductory phrase "one or more" or "at least one" and an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should be interpreted to mean "at least one" or "one or more"). The same applies to the use of definite articles when introducing claim recitations. Moreover, even when a specific number of recitations of an introduced claim are explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g., the mere recitation of "two recitations," without any other modifier, means at least two recitations, or more than two recitations).Furthermore, when notation similar to "at least one of A, B, C, etc." is used, such an interpretation is generally intended in the sense that one of ordinary skill in the art would understand the notation (e.g., "a system having at least one of A, B, C" includes, but is not limited to, systems that include A only, B only, C only, A and B together, A and C together, B and C together, and / or A, B, C together, etc.). When notation similar to "at least one of A, B, C, etc." is used, such an interpretation is generally intended in the sense that one of ordinary skill in the art would understand the notation (e.g., "a system having at least one of A, B, C" includes, but is not limited to, systems that include A only, B only, C only, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). Furthermore, those skilled in the art will understand that, whether in the description, claims, or drawings, virtually any disjunctive word and / or phrase presenting two or more alternative terms contemplates the possibility of including one of the terms, either term, or both terms. For example, the phrase "A or B" is understood to include the possibilities of "A" or "B," or "A and B." Furthermore, as used herein, the term "any" followed by a list of multiple items and / or categories of multiple items is intended to include "any," "any combination," "any plurality," and / or "any combination of any plurality" of the items and / or categories of items, individually or in combination with other items and / or categories of items. Furthermore, as used herein, the term "set" is intended to include any number of items, including zero. Furthermore, as used herein, the term "number" is intended to include any number, including zero. And, as used herein, the term "multiple" is intended to be synonymous with "a plurality."

[0156] Additionally, when features or aspects of the disclosure are described in terms of a Markush group, those skilled in the art will understand that the disclosure is also described in terms of any individual member or subgroup of members of the Markush group.

[0157] As will be understood by those skilled in the art, all ranges disclosed herein encompass all possible subranges and combinations of subranges for all purposes, including providing a written description. Any recited range is readily recognizable as fully descriptive and allowing for division of the same range into at least one half, one third, one quarter, one fifth, one tenth, etc. As a non-limiting example, each range discussed herein can be readily subdivided into a lower third, middle third, upper third, etc. As will be understood by those skilled in the art, all expressions such as "up to," "at least," "greater than," "less than," etc., are inclusive of the recited values ​​and indicate ranges that can be subsequently subdivided into subranges as described above. Finally, as will be understood by those skilled in the art, ranges include individual values. For example, a group containing 1 to 3 cells indicates a group containing 1, 2, or 3 cells. Similarly, a group containing 1 to 5 cells indicates a group containing 1, 2, 3, 4, or 5 cells.

[0158] Furthermore, the claims should not be construed as limited to the order or elements provided unless specifically stated to that effect. Furthermore, the use of the phrase "means for" in a claim is intended to construe claims under 35 U.S.C. § 112, paragraph 6, or means-plus-function claim format; any claim that does not contain the phrase "means for" is not intended to construe claims under such format.

[0159] While various embodiments have been described in terms of communications systems, it is envisioned that these systems may be implemented in software on a microprocessor / general purpose computer (not shown). In particular embodiments, one or more functions of the various components may be implemented in software controlling the general purpose computer.

[0160] Moreover, while several exemplary embodiments have been illustrated and described herein, the invention is not intended to be limited to the details shown. Rather, various modifications and changes can be made in the details within the scope and range of equivalents of the claims and without departing from the spirit or scope of the invention.

Claims

1. 1. A wireless transmit / receive unit (WTRU), comprising: a circuit including a transmitter, a receiver, a processor, and a memory, the circuit comprising: Receiving information indicating (1) a set of Layer 1 / Layer 2 triggered mobility (LTM) candidate cells, (2) a configuration of a first condition based on a signal quality of a serving cell, and (3) a configuration of a second condition based on a signal quality of an LTM candidate cell; performing measurements of the signal quality of the serving cell; Based on the first condition being satisfied, (1) performing one or more of a first measurement of the signal quality of the LTM candidate cell, (2) a first measurement evaluation method for the first measurement, and (3) a first measurement reporting method; Based on the second condition being satisfied, performing (1) a second measurement of the signal quality of a cell not in the set of LTM candidate cells, (2) a second measurement evaluation method for the second measurement, and (3) a second measurement reporting method; transmitting a measurement report using the second measurement report method on the condition that a radio quality condition based on the second measurement evaluation method is satisfied; The WTRU is configured to perform the following:

2. The WTRU of claim 1 , wherein the first measurement evaluation method includes Layer 1 (L1) measurements.

3. The WTRU of claim 1 , wherein the first measurement reporting method comprises a channel state information (CSI) report.

4. The WTRU of claim 1 , wherein the second measurement evaluation method includes Layer 3 (L3) measurements.

5. The WTRU of claim 1 , wherein the second measurement reporting method comprises a radio resource control (RRC) measurement report.

6. The WTRU of claim 1 , wherein the first condition is met when a measured signal quality of a primary cell (PCell) falls below a first threshold.

7. The second condition is one or more of the following: The signal quality of all LTM candidate cells is below a second threshold; the average signal level of all LTM candidate cells is below a third threshold; and / or The signal levels of all LTM candidate cells are reduced; The WTRU of claim 1 , wherein the condition is satisfied when the following occurs:

8. 1. A method performed by a wireless transmit / receive unit (WTRU), comprising: Receiving information indicating (1) a set of Layer 1 / Layer 2 triggered mobility (LTM) candidate cells, (2) a configuration of a first condition based on a signal quality of a serving cell, and (3) a configuration of a second condition based on a signal quality of an LTM candidate cell; performing measurements of the signal quality of the serving cell; Based on the first condition being satisfied, (1) performing one or more of a first measurement of the signal quality of the LTM candidate cell, (2) a first measurement evaluation method for the first measurement, and (3) a first measurement reporting method; Based on the second condition being satisfied, performing (1) a second measurement of the signal quality of a cell not in the set of LTM candidate cells, (2) a second measurement evaluation method for the second measurement, and (3) a second measurement reporting method; transmitting a measurement report using the second measurement report method on the condition that a radio quality condition based on the second measurement evaluation method is satisfied; A method comprising:

9. The method of claim 8 , wherein the first measurement evaluation method comprises a layer 1 (L1) measurement.

10. 10. The method of claim 8, wherein the first measurement reporting method comprises a channel state information (CSI) report.

11. The method of claim 8 , wherein the second measurement evaluation method comprises a layer 3 (L3) measurement.

12. The method of any one of claims 8 to 11, wherein the second measurement reporting method comprises a radio resource control (RRC) measurement reporting.

13. 13. The method of claim 8, wherein the first condition is met when a measured signal quality of a primary cell (PCell) falls below a first threshold.

14. The second condition is one or more of the following: The signal quality of all LTM candidate cells is below a second threshold; the average signal level of all LTM candidate cells is below a third threshold; and / or The signal levels of all LTM candidate cells are reduced; 14. The method of claim 8, wherein the condition is satisfied when

15. 1. A wireless transmit / receive unit (WTRU), comprising: means for receiving information indicating (1) a set of Layer 1 / Layer 2 triggered mobility (LTM) candidate cells, (2) a configuration of a first condition based on signal quality of a serving cell, and (3) a configuration of a second condition based on signal quality of an LTM candidate cell; means for performing measurements of the signal quality of the serving cell; Based on the first condition being satisfied, means for performing one or more of: (1) a first measurement of the signal quality of the LTM candidate cell; (2) a first measurement evaluation method for the first measurement; and (3) a first measurement reporting method; means for performing, based on the second condition being satisfied, (1) a second measurement of the signal quality of a cell not in the set of LTM candidate cells, (2) a second measurement evaluation method for the second measurement, and (3) a second measurement reporting method; means for transmitting a measurement report using the second measurement report method on the condition that a radio quality condition based on the second measurement evaluation method is satisfied; A WTRU comprising:

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