METHOD AND APPARATUS FOR MOBILITY COEXISTENCE OF LAYER 1 / LAYER 2 Triggers AND LAYER 3 Triggers

Abstract

Methods, apparatus, systems, devices, and computer program products for L1 / L2 inter-cell mobility and / or measurements are provided. A method may include performing a measurement of signal quality of a serving cell; and performing 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 first condition according to signal quality of the serving cell being satisfied. Based on a second condition according to the signal quality of the LTM candidate cells being satisfied, measurement of the signal quality of cells other than the set of LTM candidate cells is performed, measurement of cells other than the set of LTM candidate cells is evaluated using a second measurement evaluation method, and / or reporting is performed using a second reporting method.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 421,822, filed on Nov. 2, 2022; the content of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure generally relates 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

[0004] One embodiment may relate to a wireless transmit / receive unit (WTRU) that may include circuitry that includes 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 the signal quality of a serving cell, and / or a configuration of a second condition associated with the signal quality of the LTM candidate cells. The circuitry is configured to perform 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 circuitry is configured to perform any one or more of the following: a measurement of the signal quality of the LTM candidate cells, a first measurement evaluation method of the measurement (e.g., evaluating the measurement of the LTM candidate cells 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 the second condition associated with the signal quality of the LTM candidate cells being met (e.g., when the first condition and the second condition are met), the circuitry is configured to perform: a measurement of the signal quality of cells not in the set of LTM candidate cells, a second measurement evaluation method of the measurement (e.g., evaluating the measurement of non - LTM candidate cells using the second measurement evaluation method), and / or a second measurement reporting method (e.g., reporting the measurement of non - LTM candidate cells using the second measurement reporting method). Under the condition of meeting the radio quality condition based on the second measurement evaluation method, the circuitry is configured to transmit a measurement report using the second reporting method.

[0005] One embodiment may relate 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 the signal quality of a serving cell, and / or a configuration of a second condition associated with the signal quality of an 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 satisfied, the method may include performing any one or more of the following: a measurement of the signal quality of an LTM candidate cell, a first measurement evaluation method of the measurement (e.g., evaluating the measurement of an 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 the second condition associated with the signal quality of an 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., evaluating the measurement of a non-LTM candidate cell using the second measurement evaluation method), and / or a second measurement reporting method (e.g., reporting the measurement of a non-LTM candidate cell using the second measurement reporting method). Under the condition of satisfying the radio quality condition based on the second measurement evaluation method, the method may include transmitting a measurement report using the second reporting method. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] A more detailed understanding may be obtained from the following detailed description given by way of example in conjunction with the accompanying drawings. The various figures in such drawings (as in the detailed description) are examples. Thus, the figures (FIGs.) and the detailed description should not be considered restrictive, and other equally valid examples are possible and likely. In addition, the same reference numerals (“ref.”) in the various figures indicate the same elements, and in which:

[0007] Figure 1A is a system diagram showing an example communication system;

[0008] Figure 1B is showing that it can be in Figure 1A A system diagram of an example wireless transmit / receive unit (WTRU) that can be used within the shown communication system;

[0009] Figure 1C is showing that it can be in Figure 1A A system diagram of an example radio access network (RAN) and an example core network (CN) that can be used within the shown communication system;

[0010] Figure 1D is showing that it can be in Figure 1ASystem diagram of a further exemplary RAN and a further exemplary CN used within the illustrated communication system;

[0011] Figure 2 An example of an advanced measurement model according to one embodiment is shown;

[0012] Figure 3 An example handover (HO) scenario in NR according to one embodiment is shown;

[0013] Figure 4 An example signaling diagram depicting conditional HO (CHO) according to one embodiment is shown;

[0014] Figure 5 An example of layer 1 / layer 2 triggered mobility (LTM) operation according to one embodiment is shown; and

[0015] Figure 6 An example flowchart of a method according to one embodiment is shown. Detailed Description

[0016] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments and / or examples disclosed herein. However, it will be understood that such embodiments and examples may be practiced without some or all of the specific details set forth herein. In other instances, well-known methods, procedures, components, and circuits have not been described in detail so as not to obscure the following description. Additionally, embodiments and examples not specifically described herein may be practiced in lieu of or in combination with the embodiments and other examples explicitly, implicitly, and / or inherently described, disclosed, or otherwise provided (collectively "provided") herein. Although various embodiments are described and / or claimed herein in which a device, system, apparatus, etc. and / or any of its elements perform an operation, process, algorithm, function, etc. and / or any part thereof, it should be understood that any embodiment described and / or claimed herein assumes that any device, system, apparatus, etc. and / or any of its elements is configured to perform any operation, process, algorithm, function, etc. and / or any part thereof.

[0017] Exemplary Communication System

[0018] The methods, apparatuses, and systems provided herein are well-suited for communication involving both wired and wireless networks. Referring to Figures 1A - 1D An overview of various types of wireless devices and infrastructure is provided, where various elements of the network can utilize, execute, be arranged according to, and / or be adapted for and / or be configured for the methods, apparatuses, and systems provided herein.

[0019] Figure 1AFIG. 0 is a system diagram showing an example communication system 100 in which one or more of the disclosed embodiments may be implemented. The communication system 100 may be a multi-access system that provides content such as voice, data, video, messaging, broadcasting, etc. to a plurality of wireless users. The communication system 100 may enable a plurality of wireless users to access such content by sharing system resources including wireless bandwidth. For example, the communication system 100 may employ one or more channel access methods such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single carrier FDMA (SC-FDMA), zero-tail (ZT) unique word (UW) discrete Fourier transform (DFT) spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, filter bank multicarrier (FBMC), etc.

[0020] As Figure 1A shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 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, but it should be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d (any of which may be referred to as a "station" and / or "STA") may be configured to transmit and / or receive wireless signals and may include (or be) a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular phone, a personal digital assistant (PDA), a smart phone, a laptop computer, a netbook, a personal computer, a wireless sensor, a hot spot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable device, a head-mounted display (HMD), a vehicle, a drone, a medical device and application (e.g., remote surgery), an industrial device and application (e.g., a robot and / or other wireless devices operating in an industrial and / or automation processing chain environment), a consumer electronic device, a device operating on a commercial and / or industrial wireless network, etc. Any one of the WTRUs 102a, 102b, 102c, and 102d or any other WTRU mentioned or described herein may be interchangeably referred to as a UE.

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

[0022] Base station 114a may be part of 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), a relay node, etc. 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 in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage of wireless services to a particular geographic area, which may be relatively fixed or may change over time. A cell may also be divided into cell sectors. For example, the cell associated with base station 114a may be divided into three sectors. Thus, in one embodiment, base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In one embodiment, base station 114a may employ multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each or any sector of the cell. For example, beamforming may be used to transmit and / or receive signals in a desired spatial direction.

[0023] Base stations 114a, 114b may communicate with one or more of WTRUs 102a, 102b, 102c, 102d via air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, millimeter wave, infrared (IR), ultraviolet (UV), visible light, etc.). Any suitable radio access technology (RAT) may be used to establish air interface 116.

[0024] More specifically, as described above, the communication system 100 can be a multi-access system and can employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base stations 114a and the WTRUs 102a, 102b, 102c in the RAN 104 / 113 can implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which can use Wideband CDMA (WCDMA) to establish the air interface 116. WCDMA can include communication protocols such as High Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA can include High Speed Downlink Packet Access (HSDPA) and / or High Speed Uplink Packet Access (HSUPA).

[0025] In one embodiment, the base stations 114a and the WTRUs 102a, 102b, 102c can implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which can use Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-A Pro to establish the air interface 116.

[0026] In one embodiment, the base stations 114a and the WTRUs 102a, 102b, 102c can implement a radio technology such as NR radio access, which can use New Radio (NR) to establish the air interface 116.

[0027] In an embodiment, the base stations 114a and the WTRUs 102a, 102b, 102c can implement multiple radio access technologies. For example, the base stations 114a and the WTRUs 102a, 102b, 102c can implement LTE radio access and NR radio access together, for example, using the Dual Connectivity (DC) principle. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c can be characterized by multiple types of radio access technologies and / or transmissions to / from multiple types of base stations (e.g., eNBs and gNBs).

[0028] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (Wi-Fi)), 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 Rate for GSM Evolution (EDGE), GSM EDGE (GERAN), etc.

[0029] For example, Figure 1A the base station 114b in may be a wireless router, a home Node B, a home eNode-B, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in a local area, such as a commercial venue, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for 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 one 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 any one of a small cell, a pico cell, or a femto cell. As Figure 1A shown, the base station 114b may have a direct connection to the Internet 110. Thus, it may not be required that the base station 114b access the Internet 110 via the CN 106 / 115.

[0030] The RAN 104 / 113 may communicate with the CN 106 / 115, and the CN 106 / 115 may be any type of network configured to provide voice, data, applications, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have different Quality of Service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, prepaid calls, Internet connectivity, video distribution, etc. and / or perform advanced security functions such as user authentication. Although in Figure 1ANot shown in the figure, but it should be understood that RAN104 / 113 and / or CN 106 / 115 can communicate directly or indirectly with other RANs that use the same RAT as RAN 104 / 113 or different RATs. For example, in addition to being connected to RAN 104 / 113 that may utilize NR radio technology, CN 106 / 115 can also communicate with another RAN (not shown) that uses any one of GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or Wi-Fi radio technology.

[0031] CN 106 / 115 can also be used as a gateway for WTRU 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 can include a circuit-switched telephone network that provides plain old telephone service (POTS). The Internet 110 can include a global system of interconnected computer networks and devices that use common communication protocols such as Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and / or Internet Protocol (IP) in the TCP / IP Internet protocol suite. The network 112 can include wired and / or wireless communication networks owned and / or operated by other service providers. For example, the network 112 can include another CN connected to one or more RANs, which can use the same RAT as RAN 104 / 114 or a different RAT.

[0032] Some or all of the WTRU 102a, 102b, 102c, 102d in the communication system 100 can include multimodal capabilities (e.g., the WTRU 102a, 102b, 102c, 102d can include multiple transceivers for communicating with different wireless networks via different wireless links). For example, Figure 1A the WTRU 102c shown in the figure can be configured to communicate with a base station 114a that can use cellular-based radio technology and with a base station 114b that can use IEEE802 radio technology.

[0033] Figure 1B is a system diagram showing an example WTRU 102. As Figure 1B shown, among other things, the WTRU 102 can include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, a non-removable memory 130, a removable memory 132, a power supply 134, a Global Positioning System (GPS) chipset 136, and / or other elements / peripherals 138. It should be understood that the WTRU 102 can include any sub-combination of the foregoing elements while remaining consistent with the embodiments.

[0034] The processor 118 can be a general-purpose processor, a dedicated 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, any other type of integrated circuit (IC), a state machine, etc. The processor 118 can perform signal encoding, data processing, power control, input / output processing, and / or any other functions that enable the WTRU 102 to operate in a wireless environment. The processor 118 can be coupled to the transceiver 120, and the transceiver 120 can be coupled to the transmit / receive element 122. Although Figure 1B the processor 118 and the transceiver 120 are depicted as separate components, it should be understood that the processor 118 and the transceiver 120 can be integrated together, such as in an electronic package or a chip.

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

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

[0037] The transceiver 120 can be configured to modulate the signals to be transmitted by the transmit / receive element 122 and demodulate the signals received by the transmit / receive element 122. As described above, the WTRU 102 can have multi-modal capabilities. Thus, the transceiver 120 can include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0038] The processor 118 of the WTRU 102 may be coupled to the speaker / microphone 124, keypad 126, and / or the display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit), and may receive user input data therefrom. The processor 118 may also output user data to the speaker / microphone 124, keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from and store data in any type of suitable memory, such as non-removable memory 130 and / or removable memory 132. The non-removable memory 130 may include random access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, etc. In other embodiments, the processor 118 may access information from and store data in a memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0039] The processor 118 may receive power from a power supply 134 and may be configured to distribute and / or control power to other components in the WTRU 102. The power supply 134 may be any suitable device for powering the WTRU 102. For example, the power supply 134 may include one or more dry cells (e.g., nickel cadmium (NiCd), nickel zinc (NiZn), nickel metal hydride (NiMH), lithium ion (Li-ion), etc.), a solar cell, a fuel cell, etc.

[0040] 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) about the current location of the WTRU 102. In addition to, or instead of, the information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) via an air interface 116, and / or may determine its location based on the timing of signals received from two or more nearby base stations. It should be understood that the WTRU 102 may obtain location information by any suitable location determination method while remaining consistent with the embodiments.

[0041] 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 connections. For example, the elements / peripherals 138 may include an accelerometer, an electronic 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, modules, a frequency modulation (FM) radio unit, a digital music player, a media player, an electronic 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, and the sensors may be one or more of a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geographical location sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, an attitude sensor, a biometric sensor, and / or a humidity sensor.

[0042] The WTRU 102 may include a full-duplex radio for which the transmission and reception of some or all 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 to reduce and / or substantially eliminate self-interference through hardware (e.g., a choke) or through signal processing by a processor (e.g., a separate processor (not shown) or by the processor 118). In one embodiment, the WTRU 102 may include a half-duplex radio for which the transmission and reception of some or all signals (e.g., associated with a particular subframe for the uplink (e.g., for transmission) or the downlink (e.g., for reception)).

[0043] Figure 1C is a system diagram showing the RAN 104 and the CN 106 according to an embodiment. As described above, the RAN 104 may communicate with the WTRU 102a, 102b, and 102c via the air interface 116 using E-UTRA radio technology. The RAN 104 may also communicate with the CN 106.

[0044] The RAN 104 may include eNode-Bs 160a, 160b, 160c, but it should be understood that the RAN 104 may include any number of eNode-Bs while remaining consistent with the embodiments. Each of the eNode-Bs 160a, 160b, 160c may include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c via the air interface 116. In one embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO technology. Thus, for example, the eNode-B 160a may use multiple antennas to transmit wireless signals to and receive wireless signals from the WTRU 102a.

[0045] Each of the eNode-Bs 160a, 160b, and 160c may be associated with a specific cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, user scheduling in the uplink (UL) and / or downlink (DL), etc. As Figure 1C shown, the eNode-Bs 160a, 160b, 160c may communicate with each other via the X2 interface.

[0046] Figure 1C The CN 106 shown in may include a Mobility Management Entity (MME) 162, a Serving Gateway (SGW) 164, and a Packet Data Network (PDN) Gateway (PGW) 166. Although each of the foregoing elements is described as part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0047] The MME 162 may be connected to each of the eNode-Bs 160a, 160b, 160c in the RAN 104 via the 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, bearer activation / deactivation, selecting a specific serving gateway during the initial attachment of the WTRUs 102a, 102b, 102c, etc. The MME 162 may provide control plane functions for handover between the RAN 104 and other RANs (not shown) employing other radio technologies such as GSM and / or WCDMA.

[0048] The SGW 164 can be connected to each of the eNode-Bs 160a, 160b, 160c in the RAN 104 via the S1 interface. The SGW 164 can generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 can perform other functions such as anchoring the user plane during handovers between eNode-Bs, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing the context of the WTRUs 102a, 102b, 102c, etc.

[0049] The SGW 164 can be connected to the PGW 166, which can provide the WTRUs 102a, 102b, 102c with access to a packet switched network such as the Internet 110 to facilitate communication between the WTRUs 102a, 102b, 102c and IP enabled devices.

[0050] The CN 106 can facilitate communication with other networks. For example, the CN 106 can provide the WTRUs 102a, 102b, 102c with access to a circuit switched network such as the PSTN 108 to facilitate communication between the WTRUs 102a, 102b, 102c and traditional landline communication devices. For example, the CN 106 can include an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 106 and the PSTN 108, or can communicate therewith. In addition, the CN 106 can provide the WTRUs 102a, 102b, 102c with access to other networks 112, which can include other wired and / or wireless networks owned and / or operated by other service providers.

[0051] Although the WTRU is described as a wireless terminal in Figures 1A - 1D it is contemplated that in some representative embodiments, such a terminal can use (e.g., temporarily or permanently) a wired communication interface to the communication network.

[0052] In a representative embodiment, another network 112 can be a WLAN.

[0053] Infrastructure Basic Service Set (BSS) mode WLANs can have an Access Point (AP) for the BSS and one or more Stations (STAs) associated with the AP. The AP can have access or an interface to a Distribution System (DS) or another type of wired / wireless network that conveys traffic to and / or from the BSS. Traffic destined for an STA from outside the BSS can reach the STA via the AP and can be delivered to the STA. Traffic from an STA to a destination outside the BSS can be sent to the AP to be delivered to the corresponding destination. For example, traffic between STAs within a BSS can be sent through the AP, where the source STA can send the traffic to the AP and the AP can deliver the traffic to the destination STA. Traffic between STAs within a BSS can be considered and / or referred to as peer traffic. Peer traffic can be sent between a source and destination STA (e.g., directly between them) using Direct Link Setup (DLS). In some representative embodiments, DLS can use 802.11e DLS or 802.11z Tunnel DLS (TDLS). WLANs using Independent BSS (IBSS) mode may not have an AP, and STAs within the IBSS or using the IBSS (e.g., all STAs) can communicate directly with each other. The IBSS communication mode is sometimes referred to here as the "ad-hoc" communication mode.

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

[0055] High Throughput (HT) STAs can communicate using 40 MHz wide channels, e.g., by combining the primary 20 MHz channel with an adjacent or non-adjacent 20 MHz channel to form a 40 MHz wide channel.

[0056] A very high throughput (VHT) STA can support 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. The 40 MHz and / or 80 MHz channels can be formed by combining contiguous 20 MHz channels. The 160 MHz channel can be formed by combining eight contiguous 20 MHz channels, or by combining two non - contiguous 80 MHz channels, which can be referred to as an 80 + 80 configuration. For the 80 + 80 configuration, after channel coding, the data can pass through a segment parser, which can divide the data into two streams. The inverse fast Fourier transform (IFFT) processing and time - domain processing can be performed separately on each stream. The streams can be mapped to two 80 MHz channels, and the data can be transmitted by the transmitting STA. At the receiver of the receiving STA, the operations of the above 80 + 80 configuration can be reversed, and the combined data can be sent to the media access control (MAC) layer, entity, etc.

[0057] 802.11af and 802.11ah support sub - 1GHz operation modes. The channel operation bandwidth 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, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non - TVWS spectrum. According to a representative embodiment, 802.11ah can support metering type control / machine type communication (MTC), such as MTC devices in a macro coverage area. The MTC devices can have certain capabilities, for example, limited capabilities, including supporting (e.g., only supporting) certain and / or limited bandwidths. The MTC devices can include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

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

[0059] In the United States, the available frequency band that 802.11ah can use is from 902MHz to 928MHz. In Korea, the available frequency band is from 917.5MHz to 923.5MHz. In Japan, the available frequency band is from 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz, depending on the country code.

[0060] Figure 1D It is a system diagram showing RAN 113 and CN 115 according to an embodiment. As described above, RAN 113 can communicate with WTRUs 102a, 102b, 102c via air interface 116 using NR radio technology. RAN 113 can also communicate with CN 115.

[0061] The RAN 113 may include gNBs 180a, 180b, 180c, but it should be understood that the RAN 113 may include any number of gNBs while remaining consistent with the embodiments. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c via the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, the gNBs 180a, 180b may utilize beamforming to transmit signals to and / or receive signals from the WTRUs 102a, 102b, 102c. Thus, for example, the gNB 180a may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a. In one embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers (not shown) to the WTRU 102a. A subset of these component carriers may be on unlicensed spectrum, while the remaining component carriers may be on licensed spectrum. In one embodiment, the gNBs 180a, 180b, 180c may implement coordinated multi-point (CoMP) technology. For example, the WTRU 102a may receive coordinated transmissions from the gNB 180a and the gNB 180b (and / or gNB 180c).

[0062] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with scalable numerology. For example, the OFDM symbol interval and / or the OFDM subcarrier interval may be different for different transmissions, different cells, and / or different portions of the radio transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or transmission time intervals (TTIs) of various or scalable lengths (e.g., including a variable number of OFDM symbols and / or an absolutely variable length in time).

[0063] gNB 180a, 180b, 180c can be configured to communicate with WTRUs 102a, 102b, 102c in a stand-alone configuration and / or a non-stand-alone configuration. In the stand-alone configuration, WTRUs 102a, 102b, 102c can communicate with gNB 180a, 180b, 180c without accessing other RANs (e.g., such as eNode-Bs 160a, 160b, 160c). In the stand-alone configuration, WTRUs 102a, 102b, 102c can utilize one or more of gNB 180a, 180b, 180c as a mobility anchor. In the stand-alone configuration, WTRUs 102a, 102b, 102c can communicate with gNB 180a, 180b, 180c using signals in an unlicensed band. In the non-stand-alone configuration, WTRUs 102a, 102b, 102c can communicate / connect with gNB 180a, 180b, 180c while also communicating / connecting with another RAN such as eNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b, 102c can implement the DC principle to communicate with one or more of gNB 180a, 180b, 180c and one or more of eNode-Bs 160a, 160b, 160c substantially simultaneously. In the non-stand-alone configuration, eNode-Bs 160a, 160b, 160c can act as the mobility anchor for WTRUs 102a, 102b, 102c, and gNB 180a, 180b, 180c can provide additional coverage and / or throughput for serving WTRUs 102a, 102b, 102c.

[0064] Each of gNB 180a, 180b, 180c can be associated with a specific cell (not shown) and can be configured to handle radio resource management decisions, handover decisions, user scheduling in UL and / or DL, network slice support, dual connectivity, interworking between NR and E-UTRA, routing user plane data to user plane functions (UPFs) 184a, 184b, routing control plane information to access and mobility management functions (AMFs) 182a, 182b, etc. As Figure 1D shown, gNB 180a, 180b, 180c can communicate with each other via the Xn interface.

[0065] Figure 1DThe illustrated CN 115 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. Although each of the foregoing elements is described as part of CN 115, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0066] The AMF 182a, 182b may be connected to one or more gNBs 180a, 180b, 180c in the RAN 113 via the N2 interface and may act as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRU 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 the registration area, terminating NAS signaling, mobility management, etc. The AMF 182a, 182b may use network slicing, e.g., to customize the CN support for the WTRU 102a, 102b, 102c based on the service type used by the WTRU 102a, 102b, 102c. For example, different network slices may be established for different use cases, such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for machine type communication (MTC) access, etc. The AMF 162 may provide control plane functions for handover between the RAN 113 and other RANs (not shown) employing other radio technologies such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as Wi-Fi.

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

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

[0069] The CN 115 can facilitate communication with other networks. For example, the CN 115 can include an IP gateway (such as an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 115 and the PSTN 108, or can communicate with the IP gateway. In addition, the CN 115 can provide access to other networks 112 to the WTRUs 102a, 102b, 102c, and the other networks 112 can include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c can be connected to a local data network (DN) 185a, 185b via the N3 interface to the UPFs 184a, 184b and the N6 interface between the UPFs 184a, 184b and the DNs 185a, 185b.

[0070] In view of Figures 1A - 1D and Figures 1A - 1D the corresponding descriptions, one or more or all of the functions described herein for any one of the following: WTRUs 102a-d, base stations 114a-b, eNode-Bs 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 any other element / devices (plural) described herein can be performed by one or more policy elements / devices (not shown). The emulation device can be one or more devices configured to emulate one or more or all of the functions described herein. For example, the emulation device can be used to test other devices and / or simulate network and / or WTRU functions.

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

[0072] One or more emulation devices can perform one or more functions, including all functions, without being implemented / deployed as part of a wired and / or wireless communication network. For example, emulation devices can be used to test test scenarios in a laboratory and / or non-deployed (e.g., test) wired and / or wireless communication networks in order to implement tests of one or more components. One or more emulation devices can be test devices. Emulation devices can transmit and / or receive data using direct RF coupling and / or wireless communication via an RF circuit (e.g., which can include one or more antennas).

[0073] Note that throughout the example embodiments described herein, the terms "serving base station", "base station", "gNB", collectively "gNB" can be used interchangeably to denote any network element, such as a network element acting as a serving base station. The embodiments described herein are not limited to gNBs and are applicable to any other type of base station.

[0074] In the RRC_CONNECTED state, the UE can measure multiple (at least one) beams of a cell, and the measurement results (power values) are averaged to derive the cell quality. In doing so, the UE is configured to consider a subset of the detected beams. Filtering can be performed at two different levels: deriving beam quality at the physical layer and deriving cell quality from multiple beams at the radio resource control (RRC) level. For the serving cell and non-serving cells, the cell quality from beam measurements can be derived in the same way. The measurement report can contain the measurement results of the X best beams if the gNB configures the UE to do so.

[0075] Figure 2 An example of a corresponding high-level measurement model according to one embodiment is shown. As Figure 2As shown in the example of , at point A, measurements within the physical layer (beam-specific samples) can be performed. Note that in this example, K beams correspond to measurements on SSB or CSI-RS resources configured by the gNB for L3 mobility and detected by the UE at L1. In one example, internal layer 1 filtering of the input measured at point A can be performed. The exact filtering method may depend on the implementation. How the measurements are actually performed in the physical layer through the implementation (input A and layer 1 filtering) is not constrained by this standard. At A 1 , after layer 1 filtering, the measurements (i.e., beam-specific measurements) can be reported by layer 1 to layer 3.

[0076] As Figure 2 shown in the example of , at 205, beam-specific measurements can be combined to derive cell quality. The behavior of beam combining / selection can be standardized, and the configuration of this module can be provided by RRC signaling. The reporting period at point B is equal to one measurement period at A 1 . At point B, after beam combining / selection, the measurements (i.e., cell quality) derived from beam-specific measurements can be reported to layer 3. As shown in 210, layer 3 filtering (e.g., for cell quality) can be performed on the measurements provided at point B. The behavior of the layer 3 filter can be standardized, and the configuration of the layer 3 filter can be provided by RRC signaling. The filtered reporting period at point C is equal to one measurement period at point B. As shown at point C, the measurements can be performed after processing in the layer 3 filter. The reporting rate can be the same as or substantially similar to the reporting rate at point B. This measurement can be used as an input for one or more evaluations of the reporting criteria.

[0077] At Figure 2 the example of , at 215, an evaluation of the reporting criteria can be performed to check whether a measurement report is actually necessary at point D. This evaluation can be based on more than one measurement stream at reference point C to, for example, compare different measurements. At Figure 2 this, this is shown by input C and C 1 . For example, at least each time a new measurement result is reported at points C, C 1 , the UE can evaluate the reporting criteria. The reporting criteria can be standardized, and the configuration can be provided by RRC signaling (UE measurements). As Figure 2 shown in the example at D in , the measurement report information (message) can be sent over the radio interface. Then, L3 beam filtering can be performed on the measurements provided at point A 1 (i.e., beam-specific measurements). The behavior of the beam filter can be standardized, and the configuration of the beam filter can be provided by RRC signaling. The filtered reporting period at point E is equal to A 1A measurement period at a certain location. At E, measurements after processing in the beam filter can be performed (i.e., beam-specific measurements). The reporting rate can be the same as or substantially similar to that at point A 1 . The measurement can be used as an input for selecting X measurements to be reported. At 220, beam selection for beam reporting can be performed to select X measurements from the measurements provided at point E. The behavior of beam selection can be standardized, and the configuration of this module can be provided via RRC signaling. As shown at F, beam measurement information can be included in the measurement report (sent) on the radio interface.

[0078] Layer 1 filtering introduces a certain degree of measurement averaging. How and when the UE precisely performs the required measurements depends on the implementation where the output at B meets the performance requirements set in 3GPP TS 38.133. Layer 3 filtering for cell quality and the relevant parameters used are specified in TS 38.331 and do not introduce any delay in the sample availability between B and C. C 1 is the input used in event evaluation. The L3 beam filtering and the relevant parameters used are specified in TS 38.331 and do not introduce any delay in the sample availability between E and F.

[0079] The measurement report can be characterized by one or more of the following: The measurement report includes the measurement identity 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 to be reported can be restricted by network configuration; Cells belonging to the exclusion list configured by the network are not used for event evaluation and reporting, and conversely, when the network configures an allowed list, 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 (only beam identifiers, measurement results and beam identifiers, or no beam report).

[0080] Intra-frequency adjacent (cell) measurements and inter-frequency adjacent (cell) measurements can be defined as follows:

[0081] ● Intra-frequency measurements based on Synchronization Signal Block (SSB): If the center frequency of the SSB of the serving cell and the center frequency of the SSB of the adjacent cell are the same, and the subcarrier spacing of the two SSBs is also the same, the measurement is defined as an intra-frequency measurement based on SSB; and / or

[0082] ● Inter-frequency measurements based on SSB: If the center frequency of the SSB of the serving cell and the center frequency of the SSB of the adjacent cell are different, or the subcarrier spacing of the two SSBs is different, the measurement is defined as an inter-frequency measurement based on SSB.

[0083] Note that for SSB-based measurements, one measurement object corresponds to one SSB, and the UE treats different SSBs as different cells.

[0084] Intra-frequency measurements based on the channel state information reference signal (CSI-RS) may refer to measurements defined as intra-frequency measurements based on CSI-RS, provided that:

[0085] the subcarrier spacing of the CSI-RS resources on the neighboring cells configured for measurement is the same as the subcarrier spacing (SCS) of the CSI-RS resources on the serving cell indicated for measurement; and

[0086] for a 60 kHz subcarrier spacing, the cyclic prefix (CP) type of the CSI-RS resources on the neighboring cells configured for measurement is the same as the CP type of the CSI-RS resources on the serving cell indicated for measurement; and

[0087] the center frequency of the CSI-RS resources on the neighboring cells configured for measurement is the same as the center frequency of the CSI-RS resources on the serving cell indicated for measurement.

[0088] If it is not an intra-frequency measurement based on CSI-RS, then the inter-frequency measurement based on CSI-RS may refer to measurements defined as inter-frequency measurements based on CSI-RS. Whether the measurement is non-gap-assisted or gap-assisted depends on the UE's capabilities, the UE's active bandwidth part (BWP), and the current operating frequency. For inter-frequency measurements based on SSB, if the UE reports measurement gap requirement information, the measurement gap configuration may be provided according to this information. Otherwise, the measurement gap configuration is provided in the following cases (e.g., always provided): if the UE only supports per-UE measurement gaps, and / or if the UE supports per-FR measurement gaps and any serving cell is within the same frequency range of the measurement object. For intra-frequency measurements based on SSB, if the UE reports measurement gap requirement information, the measurement gap configuration may be provided according to this information. Otherwise, the measurement gap configuration is provided in the following cases (e.g., always provided): except for the initial BWP, if any UE-configured BWP does not contain the frequency-domain resources of the SSB associated with the initial DL BWP. In a non-gap-assisted scenario, the UE may be able to perform such a measurement without a measurement gap. In a gap-assisted scenario, it cannot be assumed that the UE can perform such a measurement without a measurement gap.

[0089] Channel State Information (CSI) can be used as an indicator from the UE to the network indicating how good (or bad) the channel is at any point in time. The gNB can use CSI to make scheduling decisions, such as selecting a Modulation and Coding Scheme (MCS), and assist in beamforming. According to TS 38.214, the time and frequency resources that can be used by the UE to report CSI are controlled by the gNB. CSI can include Channel Quality Indicator (CQI), Precoding Matrix Indicator (PMI), CSI-RS Resource Indicator (CRI), SS / PBCH Block Resource Indicator (SSBRI), Layer Indicator (LI), Rank Indicator (RI), L1 Reference Signal Received Power (RSRP), L1 Signal-to-Interference-plus-Noise Ratio (SINR), and / or a capability [Set] index.

[0090] For CQI, PMI, CRI, SSBRI, LI, RI, L1-SINR, and / or a capability [Set] index, the UE can be configured by the higher layers with N≥1 CSI-ReportConfig reporting settings, M≥1 CSI-ResourceConfig resource settings, and one or two trigger state lists (e.g., given by the higher layer parameters CSI-AperiodicTriggerStateList and CSI-SemiPersistentOnPUSCH-TriggerStateList). Each trigger state in the CSI-AperiodicTriggerStateList can contain a list of associated CSI-ReportConfigs that indicate the resource set IDs for the channel and optionally for interference. Each trigger state in the CSI-SemiPersistentOnPUSCH-TriggerStateList can contain an associated CSI-ReportConfig.

[0091] Each reporting setting CSI-ReportConfig can be associated with a single downlink BWP (e.g., indicated by the higher layer parameter BWP-Id) given in the associated CSI-ResourceConfig for channel measurement, and contains parameters for a CSI reporting band: codebook configuration including codebook subset limitations, time-domain behavior, frequency granularity of CQI and PMI, measurement limitation configuration, and CSI-related quantities to be reported by the UE, such as layer indicator (LI), L1-RSRP, L1-SINR, CRI, and SSB resource indicator (SSBRI), and a capability [Set] index.

[0092] The time domain behavior of CSI-ReportConfig is indicated by the higher layer parameter reportConfigType and can be set to "aperiodic", "semiPersistentOnPUCCH", "semiPersistentOnPUSCH", or "periodic". For "periodic" and "semiPersistentOnPUCCH / semiPersistentOnPUSCH" CSI reports, the configured periodicity and slot offset are applied to the numerology of the UL BWP on which the CSI report is configured to be transmitted. The higher layer parameter reportQuantity indicates the CSI-related, L1-RSRP-related, L1-SINR-related, or capability [Set] index-related quantity to be reported. The reportFreqConfiguration indicates the reporting granularity in the frequency domain, including the CSI reporting band and whether the PMI / CQI reporting is wideband or subband. The timeRestrictionForChannelMeasurements parameter in CSI-ReportConfig can be configured to enable the time domain restriction for channel measurements, and the timeRestrictionForInterferenceMeasurements can be configured to enable the time domain restriction for interference measurements. CSI-ReportConfig can also contain CodebookConfig, which contains configuration parameters for type I, type II, enhanced type II-CSI, or further enhanced type II port selection, including codebook subset restrictions when applicable, and the configuration for group-based reporting.

[0093] Each CSI resource setting CSI-ResourceConfig contains the configuration of a list of S ≥ 1 CSI resource sets (given by the higher layer parameter csi-RS-ResourceSetList), where the list includes references to one or both of the NZP CSI-RS resource set and the SS / PBCH block set, or the list includes a reference to a CSI-IM resource set. Each CSI resource setting can be located in the DL BWP identified by the higher layer parameter BWP-id, and all CSI resource settings linked to a CSI report setting have the same DL BWP.

[0094] The time-domain behavior of CSI-RS resources within a CSI resource setting is indicated by the higher-layer parameter ResourceType and can be set to aperiodic, periodic, or semi-persistent. For periodic and semi-persistent CSI resource settings, when 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 restricted to S = 1. For periodic and semi-persistent CSI resource settings, the configured periodicity and slot offset are given in the numerology of its associated DL BWP, as given by BWP-id. When the UE is configured with multiple CSI-ResourceConfigs that include the same NZP CSI-RS resource ID, the same time-domain behavior should be configured for the CSI-ResourceConfigs. When the UE is configured with multiple CSI-ResourceConfigs that include the same CSI-IM resource ID, the same time-domain behavior can be configured for the CSI-ResourceConfigs. All CSI resource settings linked to a CSI reporting setting can have the same time-domain behavior.

[0095] The following can be configured via higher-layer signaling of one or more CSI resource settings for channel and interference measurements: CSI-IM resources for interference measurements as described in clause 5.2.2.4 of TS 38.214; NZP CSI-RS resources for interference measurements as described in clause 5.2.2.3.1 of TS 38.214; and / or NZP CSI-RS resources for channel measurements as described in clause 5.2.2.3.1 of TS 38.214.

[0096] Figure 3 An example handover (HO) scenario in NR is shown. In Figure 3In the example at 0, within the source gNB, the UE context contains information on roaming and access restrictions, which is provided during connection establishment or at 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 sends a handover request message to the target gNB, transmitting a transparent RRC container with the necessary information to prepare the handover on the target side. This information can include at least the target cell ID, KgNB*, the C-RNTI of the UE in the source gNB, the RRM configuration including the UE inactivity time, the basic AS configuration including antenna information and DL carrier frequency, the mapping rule of the current QoS flow applied to the UE to the Data Radio Bearer (DRB), SIB1 from the source gNB, the UE capabilities of different RATs, PDU session-related information, and can include the measurement information reported by the UE, including beam-related information (if available).

[0097] As Figure 3 Further shown in the example at 4, at 5, the admission control can be performed by the target gNB. At 6, if the UE can be admitted, the target gNB prepares the handover to L1 / L2 and sends a handover request confirmation to the source gNB, which includes a transparent container to be sent to the UE as an RRC message to perform the handover. At 7, the source gNB triggers the Uu handover by sending an RRCReconfiguration message to the UE, which contains the information required to access the target cell, such as: at least the target cell ID, the new Cell Radio Network Temporary Identifier (C-RNTI), and / or the target gNB security algorithm identifier for the selected security algorithm. It can also include the dedicated RACH resource set, the association between the Random Access Channel (RACH) resource and the SSB, the association between the RACH resource and the UE-specific CSI-RS configuration, the common RACH resource and the system information of the target cell, etc.

[0098] At Figure 3In the example of [description], at step 7, the source gNB sends an SN status transfer message to the target gNB to convey the PDCP sequence number (SN) receiver status of the DRBs (i.e., RLC AM) for which uplink packet data convergence protocol (PDCP) status retention is applicable and the downlink PDCP SN transmitter status. At step 8, the UE synchronizes with the target cell and completes the RRC handover process by sending an RRCReconfigurationComplete message to the target gNB. At step 9, the target gNB sends a path switch request message to the AMF to trigger the 5GC to switch the DL data path towards the target gNB and establish an NG-C interface instance towards the target gNB. At step 10, the 5GC switches the DL data path towards the target gNB. The UPF sends one or more "end marker" packets to the source gNB per PDU session / tunnel on the old path and can then release any U-plane / TNL resources to the source gNB. At step 11, the AMF acknowledges the path switch request message with a path switch request acknowledgment message. At step 12, when receiving the path switch request acknowledgment message from the AMF, the target gNB sends a UE context release to notify the source gNB that the handover was successful. The source gNB can then release the radio and C-plane related resources associated with the UE context. Any ongoing data forwarding can continue.

[0099] Rel-16 NR introduced the concepts of conditional handover (CHO) and conditional primary-secondary cell (PSCell) addition / change (CPA / CPC, or collectively CPAC), mainly aiming to reduce the likelihood of radio link failure (RLF) and handover failure (HOF).

[0100] Traditional LTE or NR handovers are usually triggered by measurement reports, but nothing prevents the network from sending a HO command to the UE even without receiving a measurement report. For example, the UE can be configured with an A3 event, which, in the case of dual connectivity (DC), triggers the sending of a measurement report when the radio signal level / quality (RSRP, RSRQ, etc.) of an adjacent cell becomes better than that of the primary serving cell (PCell) or the primary-secondary cell (PSCell). The UE monitors the serving cell and adjacent cells and sends a measurement report when the conditions are met. When receiving such a report, the network (the current serving node / cell) prepares a HO command (basically, an RRC reconfiguration message with reconfigurationWithSync) and sends it to the UE, and the UE executes (e.g., immediately) the command, resulting in the UE connecting to the target cell.

[0101] Figure 4Shows an example signaling diagram depicting CHO according to an example. At 405, the source node may send a CHO request to a potential target node. At 410, the potential target node may send a CHO request ACK (e.g., with RRCReconfiguration) to the source node. At 415, the source node may send a CHO configuration to the UE (e.g., including CHO conditions such as A3 / A5 events and RRCReconfiguration). At 420, the UE may monitor the CHO conditions of candidate target cells, and if / when the conditions are met, at 425, the UE may perform HO. At 430, the UE may send a CHO confirmation to the target node, and the target node may perform path switching and UE context release, as shown at 435.

[0102] CHO is different from traditional handover in some aspects. For example, in CHO, multiple handover targets are prepared (compared to only one target in the traditional case). Additionally, in CHO, the UE does not perform CHO immediately as in the case of traditional handover. Instead, the UE is configured with trigger conditions for a set of radio conditions, and the UE performs a handover to one of the targets only if / when the trigger conditions are met.

[0103] When the radio conditions for the current serving cell are still favorable, a CHO command can be sent, thus reducing two major failure points in traditional handover, namely, the risk of failing to send a measurement report (e.g., when a measurement report is triggered in normal handover and the link quality to the current serving cell drops below an acceptable level) and the risk of failing to receive a handover command (e.g., if after the UE has sent a measurement report but before it has received an HO command, the link quality to the current serving cell drops below an acceptable level). The trigger conditions for CHO can also be based on the radio quality of the serving cell and neighboring cells, as in the conditions used to trigger measurement reports in traditional NR / LTE. For example, the UE can be configured with a CHO having A3 class trigger conditions and an associated HO command. The UE monitors the current and serving cells, and when the A3 trigger condition is met, it will execute the associated HO command and switch its connection to the target cell instead of sending a measurement report.

[0104] Another benefit of CHO is to help prevent unnecessary reconstruction in the case of radio link failure (RLF). For example, assume that the UE is configured with multiple CHO targets and experiences RLF before the triggering conditions for any of the targets are met. Traditional operation would result in an RRC reconstruction process, which would cause a relatively long interruption time for the UE bearers. However, in the case of CHO, if the UE is in a cell for which it has a CHO associated with it after detecting RLF (i.e., the target cell is already prepared for it), the UE will directly execute the HO command associated with that target cell instead of proceeding with the full reconstruction process.

[0105] Conditional PSCell change (CPC) and conditional PSCell addition (CPA) are extensions of CHO but in the dual connectivity (DC) scenario. The UE can be configured with the triggering conditions for PSCell change or addition, and when the triggering conditions are met, the UE will execute the associated PSCell change or PSCell addition command.

[0106] Currently, in Rel 17, inter-cell beam management can be used to manage beams in the case of carrier aggregation (CA), but cell change / addition is not currently supported. In Rel 18, one of the goals of the work item "Further Enhance NR Mobility" is to specify mechanisms and procedures for L1 / L2-based inter-cell mobility to reduce mobility latency. This can include one or more of the following: configuration and maintenance of multiple candidate cells to allow for rapid application of the candidate cell configuration; a dynamic handover mechanism 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 when needed. Note that L1 / L2-based inter-cell mobility can apply to, for example, the following cases:

[0107] ● Standalone, CA, and NR-DC cases, serving cell change within a CG;

[0108] ● Intra-DU cases and inter-DU cases within the CU (e.g., applicable to standalone and CA, where no new RAN interfaces are expected);

[0109] ● Both intra-frequency and inter-frequency;

[0110] ● Both frequency range 1 (FR1) and frequency range 2 (FR2);

[0111] ● The source and target cells can be synchronous or asynchronous;

[0112] ● Excluding inter-CU cases.

[0113] L1 / L2-based mobility was initially introduced in Rel-17, and inter-cell beam management in Rel-17 addressed scenarios within the DU and within the frequency. In this case, the serving cell remains unchanged (i.e., it is not possible to use L1 / L2-based mobility to change the serving cell). In FR2 deployments, CA is typically used to utilize the available bandwidth, e.g., aggregating multiple CCs in one frequency band. These CCs typically use the same analog beam pair (gNB beam and UE beam) for transmission. The UE is configured with Transmission Configuration Indicator (TCI) states (which can be a fairly large number, e.g., 64) for receiving the Physical Downlink Control Channel (PDCCH) and the Physical Downlink Shared Channel (PDSCH). Each TCI state includes a Reference Signal (RS) or an SSB, and the UE refers to this reference signal or SSB to set its beam. For Rel-17, the SSB can be associated with a non-serving Physical Cell ID (PCI). Media Access Control (MAC) signaling ("TCI state indication for UE-specific PDCCH MAC CE") activates the TCI state for the CORESET / PDCCH. The MAC control element (CE) indicating the TCI state associated with a non-serving PCI enables receiving the PDCCH from a non-serving cell. MAC signaling ("TCI state activation / deactivation for UE-specific PDSCH") activates (up to) a subset of 8 TCI states for PDSCH reception. The DCI indicates which one of the eight TCI states. Rel-17 also supports "unified TCI states" with different update mechanisms (based on DCI), but without multi-TRP. Rel-18 will support unified TCI states with multi-TRP.

[0114] The overall objective of inter-cell L1 / L2-triggered mobility (LTM) is to improve handover latency; for a regular L3 handover or a conditional handover, the UE will typically first send a measurement report using RRC signaling. In response to this, the network can provide further measurement configurations and potential conditional handover configurations. For a regular handover, after the UE reports using RRC signaling that the cell meets the configured radio quality criteria, the network provides the configuration for the target cell. For a conditional handover, to reduce the handover failure rate due to the delay in sending the measurement report and then receiving the RRC reconfiguration, the network pre-provides the target cell configuration and the measurement criteria for determining when the UE should trigger the CHO configuration. However, due to sending the measurement report and receiving the target configuration, both of these L3 methods can suffer a certain amount of delay, especially in the case of a regular (unconditional) handover.

[0115] In particular, the aim of LTM is to allow for the rapid application of the configuration of candidate cells, including dynamic handovers between SCell and handovers of the PCell (e.g., switching of roles between SCell and PCell), without performing RRC signaling. The inter-CU case is excluded as this requires re-locating the PDCP anchor and has been excluded from the work item. Therefore, at least an RRC-based method is required to support inter-CU handover.

[0116] Furthermore, with traditional L3 handover mechanisms, any currently active SCell is released before the UE completes the handover to the target cell in the coverage area of the new site and can only be added back after a successful handover, which results in throughput degradation during handover. Therefore, one of the aims of L1 / 2 is to enable CA operation to be instantaneously enabled when the serving cell changes.

[0117] Figure 5 An example of LTM operation according to one embodiment is shown. As Figure 5 shown in the example, the candidate cell group can be configured by RRC, and the dynamic switching of the PCell and SCell is achieved using L1 / L2 signaling. More specifically, in Figure 5 the example, RRC can initially configure cells 1 - 4 as candidate cells and activate PCell1 and SCell2. Additionally, as Figure 5 shown, a dynamic SCell handover can be performed between Cell2 and Cell3, as well as dynamic handovers of the PCell to Cell1 and the SCell to Cell4.

[0118] As mentioned above, the inter-CU case is excluded as this requires re-locating the PDCP anchor and has been excluded from the work item. Therefore, an RRC-based method is at least desirable for supporting inter-CU handover. This means that when configuring LTM and the measurement and measurement reporting mechanisms to support LTM, it needs to run in parallel with or coexist with RRC-based measurements and mobility.

[0119] For LTM, it is assumed in 3GPP that L1 measurements will be used at least to make cell handover decisions. Various solutions are being considered, including using L1 measurements alone, and using L3 measurements to support enabling L1 measurements - for example, using L3 measurements to perform candidate cell detection / measurement, and once a candidate cell meets specific conditions (e.g., radio quality threshold), configuring or enabling L1 measurements and reporting to achieve faster measurement triggering and handover.

[0120] It is also assumed in 3GPP that when performing LTM (i.e., cell change), some L2 reconfiguration procedures can be avoided. Since LTM supports in-DU cell change, for these cases, the UE may not need to perform a full MAC reset because the MAC resides in the DU part of the network and thus when two cells belong to the same DU, the MAC configuration and the storage of PDUs in the transmission / retransmission buffers can be maintained during cell change. Similarly, for in-DU and inter-DU cases, where LTM will only support in-CU cell change - for this case, RLC and PDU reconstruction may not be necessary because they reside in the CU part of the network and thus when two cells belong to the same CU, the configuration and the storage of PDUs in the transmission / retransmission buffers can be maintained during cell change. Additionally, it is assumed that no change of security keys is required for LTM because the cell change is limited to cells within the same CU. 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, also improves the handover interruption time, allowing for improved mobility performance at least for cell changes occurring within the same CU or the same DU using LTM.

[0121] Due to the enhancements explained above (i.e., faster measurement triggering, reduced handover waiting time, reduced handover interruption, reduced RRC reconfiguration), when configuring LTM, it is better for the UE to perform mobility within the configured LTM candidate cell set for as long as possible and only perform an inter-CU handover when moving out of the coverage of the current CU or the current LTM candidate set (which has associated additional overhead in terms of reconfiguration effort, handover interruption, etc.).

[0122] Furthermore, since LTM may be under the control of the DU (e.g., for in-DU mobility) while L3 mobility is controlled by the CU, there may be cases of race conditions, e.g., the DU and the CU each initiating a cell change / reconfiguration at approximately the same time. As an example, the CU may transmit an RRC reconfiguration to the UE, which may be sent using radio link control (RLC) PDUs and MAC PDUs, and the DU may transmit a MAC CE to trigger a cell change while the RRC reconfiguration is being transmitted.

[0123] Therefore, some embodiments provide solutions on how to ensure that mobility within the LTM candidate set (e.g., within the same CU, using L1 / L2-triggered reconfiguration) is better than mobility outside the LTM candidate set (e.g., inter-CU, using L3-triggered reconfiguration). Additionally, example embodiments can minimize the conflict between LTM and L3 mobility (L3M).

[0124] One embodiment may provide separate conditions for performing LTM measurements (on cells outside the LTM candidate set) and for performing L3 intra-frequency and inter-frequency measurements. The conditions for the L3 measurements may take into account the radio quality of the cells within the LTM candidate set.

[0125] For example, in some embodiments, the UE may monitor the signal quality of the serving cell. When a radio quality condition based on serving cell measurements is met (e.g., the PCell is below threshold 1), the UE may perform one or more of the following: measure cells within the LTM candidate set, evaluate the measurements using a first measurement evaluation method (e.g., LTM-specific measurement events performed on cells within the set), and / or report using a first reporting method (e.g., report using a MAC CE).

[0126] According to some embodiments, when a specific radio quality condition based on the signal quality of the serving cell and / or LTM candidate cells is met, the UE may perform (e.g., enable) one or more of the following: measure cells outside the LTM candidate set, evaluate the measurements using a second measurement evaluation method (e.g., RRC measurement events), and / or report using a second reporting method (e.g., RRC measurement events).

[0127] In one embodiment, when a radio quality condition based on the second measurement evaluation method is met, a measurement report using the second reporting method may be triggered.

[0128] One embodiment may provide a measurement event that is triggered when the serving cell and the cells within the LTM candidate set meet a condition and the cells outside the set of cells are above a threshold (e.g., similar to event A5, but using not only the SpCell but also other candidate cells). According to certain embodiments, the UE may (e.g., may be configured to) perform measurements on a set of cells within the set of cells, derive a first signal quality based on the measurements, and evaluate the signal quality based on a first condition. In one embodiment, the UE may (e.g., may be configured to) perform measurements on cells outside the set of cells, derive a second signal quality, and evaluate the signal quality based on a second condition. When the first and second conditions are met (e.g., simultaneously), a measurement report may be triggered.

[0129] Figure 6 A flowchart of a method according to an example embodiment is shown. According to certain embodiments, Figure 6 the method may be implemented by a UE or a WTRU. In Figure 6In an example method, at 605, the UE may receive the configuration of the 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 may include the configuration to be applied when the UE receives an indication to change cells using MAC CE or DCI. The UE may also receive the configuration of cells outside the candidate set, such as a neighbor list. In addition to the candidate cell and neighboring cell configurations, at 605, the UE may also receive the configuration of a (e.g., first) condition based on the signal quality of the serving cell and the configuration of a (e.g., second) condition based on the signal quality of the LTM candidate cells to be evaluated. The first condition may be, for example, a (e.g., first) signal quality threshold (e.g., s-metric) that is used to trigger the measurement of the LTM candidate cells, and a first measurement evaluation method using the first reporting method when the signal quality of the serving cell measured at 610 is lower than the threshold configured in step 615. This allows the UE to save power because when the serving cell quality is relatively high, it may not be necessary to measure the candidate cells. The first threshold will be used as a trigger for cell measurements within the LTM candidate set. The first threshold may be used to trigger the evaluation of the LTM candidate cells. For example, it may be used to perform LTM measurement event evaluation, such as the measurement event being configured such that when the (e.g., L3) event criteria are met, this enables (e.g., L1) CSI reporting. The first threshold may be used to trigger L1 CSI measurements for LTM cell change decisions.

[0130] In addition to the (e.g., first) condition based on the signal quality of the serving cell, the UE may receive, at 605, the configuration of a separate (e.g., second) condition that is based on the signal quality of the LTM candidate cells to be evaluated at 620 and measured at 625. The second condition may be, for example, a (e.g., second) signal quality threshold (e.g., s-metric) that is used to trigger the measurement of cells outside the candidate set, and a second measurement evaluation method using the second reporting method in step 630 when the signal quality of one (e.g., serving) or more (e.g., all) LTM candidate cells is lower than the threshold.

[0131] In one embodiment, the UE may perform RRC measurement event evaluation using the second evaluation method, for example, in step 635, and use the second reporting method to send the measurement event at 640 when the event is triggered based on the measurement of cells outside the cell set.

[0132] According to certain embodiments, the measurement and evaluation of cells outside the cell set may be triggered when one or more of the following occur:

[0133] a) The PCell is below threshold 2 (threshold 2 < threshold 1);

[0134] b) The PCell signal drops by more than a certain threshold within a given time;

[0135] c) All LTM candidate cells are below a certain threshold (where the threshold can be the same for all candidate cells, or each candidate cell has a threshold associated with it);

[0136] d) The average signal level of all LTM candidate cells is below a certain threshold;

[0137] e) The signal levels of all LTM candidate cells are decreasing (e.g., dropping by a certain threshold within a given time); and / or

[0138] f) Any of the above conditions are met within a minimum time period (e.g., the trigger time).

[0139] Some example embodiments may provide separate s - metric thresholds for controlling the measurement and evaluation of cells inside and outside the LTM candidate set. In one embodiment, both a first and a second threshold may be compared with the serving cell quality (e.g., start measuring LTM candidate cells when the PCell drops below threshold 1, and start measuring non - LTM candidate cells when the PCell further drops 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 the measurement of cells within the LTM candidate set and may trigger the evaluation of measurement events associated with the LTM candidate cells, which may cause the UE to send a MAC CE measurement report and receive a MAC CE triggering a cell change. The second threshold may be used to trigger measurements outside the LTM candidate set (e.g., in addition to the measurement of cells within the LTM candidate set). The second threshold may be used to control when the UE starts evaluating measurement events associated with L3 mobility, which may cause the UE to send an L3 measurement report to the gNB and, in response, receive an RRC reconfiguration, or may be used to control when the UE starts evaluating the triggering conditions for CHOs associated with cells not in the LTM candidate set.

[0140] Although in this example both the first and second thresholds compare the signal quality of the serving cell with a threshold, the first threshold provides (e.g., only provides) an indication of the serving cell quality, while the second threshold implies the cell quality within the cell set. This is because the first threshold enables the measurement (and thus mobility) of cells within the cell set, which in turn will ensure that under normal conditions the cell with the best quality among those within the cell set is configured as the serving cell. When the serving cell quality is below the second threshold, this means that all cells within the cell set are below that threshold and thus should trigger L3 mobility measurements to ensure that the UE can be reconfigured (e.g., via RRC) to a cell outside the cell set.

[0141] In one embodiment, a second threshold may be compared with the signal quality of multiple cells (e.g., some or all of the PCell and the set of cells). For example, the UE may perform an average of the N best cells or the N best beams (e.g., beams on multiple cells) to derive the set of cell signal quality. Then, the set of cell quality may be compared with a threshold (e.g., similar to the s - metric example above), and when this is satisfied (e.g., when the set of cell quality is higher than the threshold), the UE may start measuring cells outside the LTM candidate set, or evaluate the triggering conditions associated with cells outside the LTM candidate set. In another example, the average may also include the signal level of the current PCell.

[0142] In another example, when the number of LTM cells with a signal level above a certain signal level threshold is below a certain value, the UE may enable L3 measurements on cells outside the set of cells. For example, if the number of cells is set to the value 3, and the threshold is set to the value X, then if the measured signal quality of at least 3 LTM candidate cells is higher than the threshold X, no measurements need to be performed on cells outside the set of cells. However, when the number of cells with a measured signal quality higher than the threshold X is less than 3, then the UE may perform measurements on cells outside the set of cells to prepare for potential L3 reconfiguration or conditional reconfiguration. In yet another example, the current PCell may also be considered as part of the number of cells to be compared with the signal level threshold (e.g., for the above example, this may mean that if 2 LTM candidate cells and the PCell are above the threshold X, no measurements are performed on non - LTM candidate cells).

[0143] In the examples discussed above, separate conditions (e.g., s - metric) may be used to control when measurements are performed on cells within and outside the set of cells. In other examples, these conditions may alternatively or additionally be used to control the measurement evaluation type.

[0144] 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 that candidate cell. In this example, the UE may also be configured with one or more measurement events or conditional reconfigurations for performing L3 mobility. These may be, but are not limited to, one or more existing measurement events, such as A3, A4, A5. When a first condition is satisfied, the UE may use the measurements performed on LTM candidate cells to evaluate events associated with LTM. When a second condition is satisfied, the UE uses the measurements performed on cells outside the set of cells to evaluate events associated with L3M, and in some examples, the measurements performed on cells within the set of cells may also be considered additionally or alternatively.

[0145] In some embodiments, the measurement events can be separate and can use different triggering conditions and potentially different reporting mechanisms. For example, LTM events can be reported using MAC CE, and L3M events can be reported using RRC measurement reports. These separate measurement events can be used, for example, to perform intra-CU mobility using the LTM measurement events (within the LTM candidate set), and inter-CU mobility using the L3M measurement events (outside the LTM candidate set).

[0146] According to one embodiment, when only the first condition is met, the UE can perform measurements and event evaluations associated with LTM and can refrain from performing measurements and event evaluations associated with L3M. This can avoid or minimize potential race conditions under which LTM and L3M triggers are received simultaneously (potentially issued by different network nodes and transmitted using different parts of the protocol, meaning the order in which the UE receives the commands may be unknown to the network). In one solution, when the second condition is met, the UE can stop performing measurement event evaluations associated with LTM and perform measurement event evaluations associated with L3M. In other words, when the evaluation and reporting of L3M begin, the evaluation and reporting of LTM events can stop, which ensures that only one mobility method is used at any point in time, even if both methods are configured in parallel in the UE. The UE effectively switches between LTM and L3M based on separate conditions, using different measurements, measurement events, and reporting mechanisms depending on the mobility method used.

[0147] In other words, according to certain embodiments, the first threshold can control whether measurements need to be performed or whether the UE can choose not to perform measurements, while the second threshold can control the type of measurement evaluations and reports performed by the UE. The UE can use a first set of measurement events for evaluation (e.g., evaluating candidate cells), and can report using a first reporting method (e.g., MAC CE) when the PCell measurement is above the second threshold, and can use a second set of measurement events for evaluation (e.g., evaluating candidate cells and neighboring cells), and can report using a second reporting method (e.g., RRC measurement report) when the PCell measurement is below the second threshold.

[0148] In one embodiment, when the second condition is met (or when the UE detects that the second condition is no longer met), the UE may send an indication to the network. For example, this may be transmitted using an RRC measurement report or may be conveyed in a UL MAC CE. This indication effectively notifies the network which set of measurement rules and / or events (i.e., the first set or the second set) is being used in the UE and allows the network to, for example, stop using LTM triggering for handover when the UE is performing L3 measurement evaluation. This is a way to avoid the network issuing, for example, a MAC CE sent by the DU to trigger an in-DU cell change when the CU is using L3 to prepare for an inter-CU cell change. In this example, the UE may continue to perform both types of measurement evaluation and reporting, while the network may avoid using one or the other type of handover trigger.

[0149] In one embodiment, a third condition may be provided. This may be used such that, for example, the first condition is used to control when to perform measurements, evaluations, and reports on cells within a cell set, the second condition is used to control when to perform measurements, evaluations, and reports for maintaining the cell set (e.g., determining when to add / remove / replace LTM candidates from the set), and the third condition is used to control when to perform measurements, evaluations, and reports to support L3M.

[0150] Note that in other examples, more than three conditions may be provided in order to enable measurements and evaluations associated with more than three purposes.

[0151] According to some example embodiments, the UE may (e.g., may be configured to) perform measurements on a cell set within a cell collection, derive a first signal quality based on the measurements, and evaluate the signal quality based on the first condition. The UE may (e.g., may be configured to) perform measurements on cells outside the cell set, derive a second signal quality, and evaluate the signal quality based on the second condition. When the first and second conditions are met (e.g., simultaneously), the UE may (e.g., may be configured to) trigger a measurement report.

[0152] In one embodiment, a new type of measurement event trigger and / or a conditional reconfiguration trigger may be provided, which may control the measurement event trigger using, for example, one of the conditions described above.

[0153] According to one embodiment, the measured set of cell qualities can be compared with a first condition, while the measurements of cells outside the set of cells can be compared with a second condition. Taking the existing event A5 as an example, this can be triggered when the SpCell is below a threshold and the neighboring cell is above the threshold. As another example, event A3 can be triggered when a neighbor becomes better offset than the SpCell. One embodiment can be triggered when all cells in the set of cells are below a threshold (i.e., when determining the s - metric, only the set of cell cells are considered as described above) and a cell outside the set of cells (neighbor) is above the threshold, rather than being triggered only on the SpCell.

[0154] In some embodiments, the cells within the set of cells can be averaged, for example, using any of the following methods: (1) The SpCell is considered to have the same weight as the candidate cells. For example, an equal - weighted average of the N best cells in the set of cells is used to derive the signal quality, and this set can include the SpCell; and / or (2) The SpCell can have a greater weight than other cells in the set of cells. For example, any method of calculating a weighted average is used and a greater weight is assigned to the SpCell than to other cells to calculate the average value.

[0155] Another embodiment can use three conditions. 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 (neighboring) cell is above a third threshold.

[0156] Alternatively, in one embodiment, conditions regarding multiple cells can be used, similar to those described above for the s - metric. For example, a measurement event can be triggered when fewer than 3 cells in the LTE set are above a first threshold and a cell outside the set of cells is above a second threshold.

[0157] In one embodiment, a separate s - metric is also used. When a second condition is met, the UE can perform measurements on cells within and outside the set of cells in order to be able to compare the results.

[0158] An example embodiment may relate 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 the signal quality of a serving cell, and / or a configuration of a second condition associated with the signal quality of the LTM candidate cells. 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 satisfied, the method may include performing any one or more of the following: a measurement of the signal quality of the LTM candidate cells, a first measurement evaluation method of the measurement (e.g., evaluating the measurement of the LTM candidate cells 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 the second condition associated with the signal quality of the LTM candidate cells being satisfied (e.g., when the first condition and the second condition are satisfied), the method may include performing the following operations: a measurement of the signal quality of cells not in the set of LTM candidate cells, a second measurement evaluation method of the measurement (e.g., evaluating the measurement of non-LTM candidate cells using the second measurement evaluation method), and / or a second measurement reporting method (e.g., reporting the measurement of non-LTM candidate cells using the second measurement reporting method). Under the condition of satisfying the radio quality condition based on the second measurement evaluation method, the method may include transmitting a measurement report using the second reporting method.

[0159] 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 a channel state information (CSI) report.

[0160] In one embodiment, the second measurement evaluation method may be or may include layer 3 (L3) measurement. In one embodiment, the second measurement reporting method may be or may include a radio resource control (RRC) measurement report.

[0161] In one embodiment, the first condition is satisfied when the measured signal quality of the primary cell (PCell) is below a first threshold (e.g., under this condition). In one embodiment, the second condition is satisfied when any one or more of the following occur (e.g., under this condition): 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.

[0162] Although features and elements are provided above in specific combinations, it will be understood by those skilled in the art that each feature or element can be used alone or in combination with other features and elements. The present disclosure is not limited to the specific embodiments described in this application, which are intended to illustrate various aspects. Without departing from the spirit and scope of the present invention, many modifications and changes may be made, as will be apparent to those skilled in the art. Any element, action or instruction used in the description of this application should not be interpreted as being critical or necessary to the present invention unless explicitly provided as such. According to the foregoing description, in addition to the methods and devices listed here, functionally equivalent methods and devices within the scope of the present disclosure are apparent to those skilled in the art. Such modifications and changes are intended to fall within the scope of the appended claims. The present disclosure is limited only by the terms of the appended claims and the full scope of equivalents to which these claims are assigned. It should be understood that the present disclosure is not limited to a specific method or system.

[0163] In some example embodiments described herein, (e.g., configuration) information may be described as being received by the WTRU from the network, for example, through system information or via any kind of protocol message. Although not explicitly mentioned throughout the embodiments described herein, the same (e.g., configuration) information may be pre-configured in the WTRU (e.g., via any kind of pre-configuration method, such as, for example, via factory settings) so that the (e.g., configuration) information may be used by the WTRU without being received from the network.

[0164] Any features, variants or embodiments described for the method are compatible with an apparatus including means for processing the disclosed method, such as an apparatus including a processor configured to process the disclosed method, a computer program product including program code instructions, and a non-transitory computer-readable storage medium storing the program instructions.

[0165] For simplicity, the foregoing embodiments are discussed with respect to terminology and structure of devices having infrared capabilities (i.e., infrared transmitters and receivers). However, the embodiments discussed are not limited to these systems, but can be applied to other systems using other forms of electromagnetic waves or non-electromagnetic waves (such as sound waves).

[0166] It should also be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the term "video" or the term "image" can refer to any one of a snapshot, a single image, and / or multiple images displayed on a time basis. As another example, when mentioned herein, the term "user equipment" and its abbreviation "UE", the term "remote", and / or the term "head-mounted display" and its abbreviation "HMD" can represent or include (i) a wireless transmit and / or receive unit (WTRU); (ii) any one of a plurality of embodiments of the WTRU; (iii) a device having wireless capabilities and / or wired capabilities (e.g., tetherable), which is particularly configured with some or all of the structures and functions of the WTRU; (iii) a device having wireless capabilities and / or wired capabilities that is configured with less than all of the structures and functions of the WTRU; or (iv) the like. Reference is made herein to Figures 1A - 1D Details of example WTRUs that may represent any WTRU described herein are provided. As another example, the various embodiments disclosed above and below are described as utilizing a head-mounted display. Those skilled in the art will recognize that devices other than a head-mounted display may be utilized and that the present disclosure and some or all of the various disclosed embodiments may be modified accordingly without undue experimentation. Examples of such other devices may include drones or other devices configured to stream information to provide an augmented reality experience.

[0167] In addition, the methods provided herein may be implemented in a computer program, software, or firmware that is contained in a computer-readable medium for execution by a computer or a processor. Examples of computer-readable media include electrical signals (transmitted via a wired or wireless connection) 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 memories, 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 associated with the software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

[0168] Variations of the methods, devices, and systems provided above are possible without departing from the scope of the present invention. Given the various embodiments that may be applied, it should be understood that the illustrated embodiments are merely examples and should not be considered as limiting the scope of the appended claims. For example, the embodiments provided herein include a handheld device that may include or be used with any suitable voltage source that provides any suitable voltage, such as a battery, etc.

[0169] In addition, in the embodiments provided above, processing platforms, computing systems, controllers, and other devices that include a processor were mentioned. These devices can include at least one central processing unit (“CPU”) and a memory. In accordance with the practice of those skilled in the art of computer programming, references to actions and operations or instructions in symbolic representation can be performed by various CPUs and memories. Such actions and operations or instructions can be referred to as being “executed,” “computer-executed,” or “CPU-executed.”

[0170] Those of ordinary skill in the art will understand that actions and operations or instructions in symbolic representation include the manipulation of electrical signals by a CPU. An electrical system represents data bits, which can cause a final conversion or reduction of the electrical signals and maintain the data bits in a memory location in a memory system, thereby reconfiguring or otherwise changing the operation of the CPU and other processing of the signals. The memory location that maintains the data bits is a physical location having a particular electrical, magnetic, optical, or organic property corresponding to or representing the data bits. It should be understood that the embodiments are not limited to the above platforms or CPUs, and other platforms and CPUs can support the provided methods.

[0171] Data bits can also be maintained on a computer-readable medium, 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 medium can include cooperative or interconnected computer-readable media that are specifically present on a processing system or distributed among multiple interconnected processing systems, which can be local or remote to the processing system. It should be understood that the embodiments are not limited to the above memories, and other platforms and memories can support the provided methods.

[0172] In an illustrative embodiment, any operation, process, etc. described herein can be implemented as computer-readable instructions stored on a computer-readable medium. The computer-readable instructions can be executed by a processor of a mobile unit, a network element, and / or any other computing device.

[0173] There is little difference between the hardware and software implementations of various aspects of the system. The use of hardware or software is generally (but not always, as in some cases the choice between hardware and software may become important) a design choice representing a cost - efficiency trade - off. There can be various means to implement the processes and / or systems and / or other technologies described herein (e.g., hardware, software, and / or firmware), and the preferred means can vary with the environment in which the process and / or system and / or other technology is deployed. For example, if an implementer determines that speed and accuracy are of utmost importance, the implementer may choose tools that are primarily hardware and / or firmware. If flexibility is of utmost importance, the implementer may choose a primarily software implementation. Alternatively, the implementer may choose some combination of hardware, software, and / or firmware.

[0174] The foregoing detailed description has set forth various embodiments of devices and / or processes by use of block diagrams, flowcharts, and / or examples. To the extent such block diagrams, flowcharts, and / or examples include one or more functions and / or operations, those skilled in the art will recognize that each function and / or operation in such block diagrams, flowcharts, or examples can be implemented, individually and / or jointly, by a variety of hardware, software, firmware, or virtually any combination thereof. In an embodiment, several portions of the subject matter described herein can be implemented by 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 can be equivalently implemented, in whole or in part, in an integrated circuit, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and, in accordance with the present disclosure, designing the circuitry and / or writing the code for the software and / or firmware would be well within the skill of those in the art. Additionally, those skilled in the art will understand that the mechanisms of the subject matter described herein can be distributed in various forms as a program product, and the illustrative embodiments of the subject matter described herein apply regardless of the specific type of signal - bearing medium used to actually effect the distribution. Examples of signal - bearing media include, but are not limited to, the following: recordable type media such as floppy disks, hard disk drives, CDs, DVDs, digital tapes, computer memories, etc., and transmission type media such as digital and / or analog communication media (e.g., fiber optic cables, waveguides, wired communication links, wireless communication links, etc.).

[0175] Those skilled in the art will recognize that in the art, it is common to describe devices and / or processes in the manner set forth herein and then integrate the devices and / or processes so described into a data processing system using engineering practices. 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 recognize that a typical data processing system can generally include one or more of the following: a system unit housing, a video display device, memories such as volatile and non-volatile memories, processors such as microprocessors and digital signal processors, computing entities such as operating systems, drivers, graphical user interfaces, and application programs, one or more interaction devices such as touchpads or screens, and / or a control system including feedback loops and control motors (e.g., feedback for sensing position and / or speed, control motors for moving and / or adjusting components and / or quantities). A typical data processing system can be implemented using any suitable commercially available components, such as those commonly found in data computing / communication and / or network computing / communication systems.

[0176] The subject matter described herein is sometimes shown including different components within or connected to different other components. It should be understood that such described architectures are merely examples, and in fact, many other architectures can be implemented that achieve the same functionality. In a conceptual sense, any arrangement of components that achieves the same functionality is effectively "associated" such that the desired functionality can be achieved. Thus, any two components that are combined to achieve a particular function can be considered "associated" with each other such that the desired function is achieved, regardless of the architecture or intermediate components. Similarly, any two components so associated can also be considered "operably connected" or "operably coupled" to each other to achieve the desired function, and any two components that can be so associated can also be considered "operably coupled" to each other to achieve the desired function. Specific examples of operable coupling include, but are not limited to, components that physically mate and / or physically interact and / or components that wirelessly interact and / or can wirelessly interact and / or components that logically interact and / or can logically interact.

[0177] Regarding the use of substantially any plural and / or singular terms herein, those skilled in the art can appropriately translate from plural to singular and / or from singular to plural depending on the context and / or application. For clarity, various singular / plural permutations may be set forth herein.

[0178] Those skilled in the art will understand that, generally, the terms used herein, particularly the terms used in the appended claims (e.g., the subject matter of the appended claims), are generally intended to be "open" terms (e.g., the term "comprising" should be interpreted as "comprising 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.). Those skilled in the art will further understand that if the intention is to introduce a specific number of recited claims, such intention will be expressly recited in the claims, and if there is no such recitation, there is no such intention. For example, in cases where only one item is intended, terms such as "single" or similar language may be used. To assist in understanding, the appended claims and / or the description herein may include the use of introductory phrases such as "at least one" and "one or more" to introduce the recited claims. However, the use of such phrases should not be construed as implying that the introduction of a recited claim by the indefinite article "a" or "an" limits any particular claim that includes such introduced recited claim to embodiments including only one such recitation, even when the same claim includes an introductory phrase such as "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 as meaning "at least one" or "one or more"). This also applies to the use of definite articles used to introduce recited claims. In addition, even if the specific number of introduced recited claims is expressly recited, those skilled in the art will recognize that such recitation should be interpreted as meaning at least the recited number (e.g., a simple recitation of "two recitations" without any other modifiers means at least two recitations, or two or more recitations). Further, in those cases where there are conventions similar to "at least one of A, B, and C, etc.", generally, such a construction is intended to enable those skilled in the art to understand the convention (e.g., "a system having at least one of A, B, and C" will include, but not be limited to, systems having A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). In those cases where there are conventions similar to "at least one of A, B, or C, etc.", generally, such a construction is intended to enable those skilled in the art to understand the convention (e.g., "a system having at least one of A, B, or C" will include, but not be limited to, systems having A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). Those skilled in the art will further understand that any disjunctive word and / or phrase that actually represents two or more alternative terms, whether in the specification, claims, or drawings, should be understood as contemplating the possibility of including one of the terms, either term, or both terms. For example, the phrase "A or B" will be understood to include the possibility of "A" or "B" or "A and B".In addition, as used herein, the term "any" followed by a list of multiple items and / or multiple categories of items is intended to include "any one", "any combination", "any plurality", and / or "any combination of a plurality" of the items and / or categories of items, either individually or in combination with other items and / or other categories of items. Further, as used herein, the term "set" is intended to include any number of items, including zero. Additionally, as used herein, the term "quantity" is intended to include any number, including zero. And the term "plurality" as used herein is intended to be synonymous with "a number of".

[0179] In addition, in cases where the present disclosure is described in terms of a Markush group, those skilled in the art will recognize that the present disclosure is also thereby described in terms of any single member or subgroup of members of the Markush group.

[0180] As will be understood by those skilled in the art, for any and all purposes, such as in providing a written description, all ranges disclosed herein also include any and all possible subranges and combinations of those subranges. Any recited range can be readily deemed to fully describe and enable the same range to be divided into at least equal halves, thirds, quarters, fifths, tenths, etc. By way of non-limiting example, each range discussed herein can be readily broken down into a lower third, middle third, upper third, etc. Those skilled in the art will also understand that all language such as "up to", "at least", "greater than", "less than", etc., includes the recited numbers and refers to ranges that can then be broken down into the subranges as described above. Finally, as will be understood by those skilled in the art, a range includes each individual member. Thus, for example, a group having 1 - 3 cells refers to a group having 1, 2, or 3 cells. Similarly, a group having 1 - 5 cells refers to a group having 1, 2, 3, 4, or 5 cells, and so on.

[0181] In addition, the claims should not be construed as limited to the order or elements provided, unless so stated. Further, the use of the term "means for" in any claim is intended to invoke 35 U.S.C.§112, or the means - plus - function claim format, and any claim without the term "means for" does not have such an intent.

[0182] Although the various embodiments have been described in terms of a communication system, it is contemplated that the system may be implemented in software on a microprocessor / general - purpose computer (not shown). In some embodiments, one or more functions of the various components may be implemented in software controlling the general - purpose computer.

[0183] In addition, although some example embodiments have been illustrated and described herein, the present invention is not intended to be limited to the details shown. On the contrary, various modifications and variations can be made in the details within the scope and field of equivalents of the claims and without departing from the spirit or scope of the present invention.

Claims

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

2. The WTRU according to claim 1, wherein the first measurement evaluation method includes layer 1 (L1) measurement.

3. The WTRU according to at least one of claims 1-2, wherein the first measurement reporting method includes a channel state information (CSI) report.

4. The WTRU according to at least one of claims 1-3, wherein the second measurement evaluation method includes layer 3 (L3) measurement.

5. The WTRU according to at least one of claims 1-4, wherein the second measurement reporting method includes a radio resource control (RRC) measurement report.

6. The WTRU according to at least one of claims 1-5, wherein the first condition is satisfied under the condition that the measured signal quality of the primary cell (PCell) is lower than a first threshold.

7. The WTRU according to at least one of claims 1-6, wherein the second condition is satisfied under any one or more of the following conditions: the signal quality of all LTM candidate cells is lower than a second threshold; the average signal level of all LTM candidate cells is lower than a third threshold; and / or the signal levels of all LTM candidate cells are decreasing.

8. A method implemented by a wireless transmit / receive unit (WTRU), the method 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 the signal quality of a serving cell, and (3) a configuration of a second condition based on the signal quality of the LTM candidate cells; performing a measurement of the signal quality of the serving cell; and based on satisfying the first condition, perform the following: perform any one or more of the following: (1) a first measurement of the signal quality of the LTM candidate cells, (2) a first measurement evaluation method of the first measurement, and (3) a first measurement reporting method; Based on the second condition being satisfied, perform: (1) a second measurement of the signal quality of cells 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; And Under the condition that the radio quality condition based on the second measurement evaluation method is satisfied, transmit a measurement report using the second reporting method.

9. The method according to claim 8, wherein the first measurement evaluation method includes layer 1 (L1) measurement.

10. The method according to at least one of claims 8 - 9, wherein the first measurement reporting method includes a channel state information (CSI) report.

11. The method according to at least one of claims 8 - 10, wherein the second measurement evaluation method includes layer 3 (L3) measurement.

12. The method according to at least one of claims 8 - 11, wherein the second measurement reporting method includes a radio resource control (RRC) measurement report.

13. The method according to at least one of claims 8 - 12, wherein the first condition is satisfied under the condition that the measured signal quality of the primary cell (PCell) is lower than a first threshold.

14. The method according to at least one of claims 8 - 13, wherein the second condition is satisfied under any one or more of the following occurring: The signal quality of all LTM candidate cells is lower than a second threshold; The average signal level of all LTM candidate cells is lower than a third threshold; and / or The signal levels of all LTM candidate cells are decreasing.

15. 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 the signal quality of a serving cell, and (3) a configuration of a second condition based on the signal quality of LTM candidate cells; Means for performing a measurement of the signal quality of a serving cell; and Based on the first condition being satisfied: Means for performing any one or more of the following: (1) a first measurement of the signal quality of LTM candidate cells, (2) a first measurement evaluation method for the first measurement, and (3) a first measurement reporting method; Based on the second condition being satisfied, means for performing: (1) a second measurement of the signal quality of cells 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; And Means for transmitting a measurement report using the second reporting method under the condition that the radio quality condition based on the second measurement evaluation method is satisfied.

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