Method for managing measurement configurations with L1 / L2-based mobility

Abstract

A wireless transmit / receive unit (WTRU) is configured with multiple conditional handover and / or measurement reporting configurations. The WTRU activates or deactivates one or more of the multiple configurations in response to various conditions, such as a change in primary cell (PCell), a combination of currently active secondary cells (SCells) within a configured set of candidate L1 / L2 transfer cells, or a specific change in the combination of currently active cells within a configured set of candidate L1 / L2 transfer cells. A conditional reconfiguration can be performed that updates the set of candidate L1 / L2 transfer cells. A list of mobility area indexes can be included in the configuration, such as including an associated set of conditions for activating a particular area or a set of configurations to activate when the index is activated.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of U.S. Provisional Patent Application No. 63 / 388,111, filed July 11, 2022, U.S. Provisional Patent Application No. 63 / 394,888, filed August 3, 2022, and U.S. Provisional Patent Application No. 63 / 465,115, filed May 9, 2023, the entire contents of which are incorporated herein by reference. [Background technology]

[0002] A wireless transmit / receive unit (WTRU) may be configured with multiple conditional handover (HO) and / or measurement reporting configurations. The WTRU may be configured to activate or deactivate various configurations based on one or more conditions. The work item (WI) on "Further NR Mobility Enhancements" in 3GPP Release 18 includes several objectives related to this background. Summary of the Invention

[0003] A wireless transmit / receive unit (WTRU) may comprise a processor configured to receive configuration information. For example, the configuration information may indicate a plurality of transfer candidate cells and a plurality of measurement configurations. The WTRU may activate a first measurement configuration of the plurality of measurement configurations based on a first cell being a current serving cell for the WTRU. The WTRU may be configured to determine that a second measurement configuration of the plurality of measurement configurations is to be deactivated based on the first cell being a current serving cell for the WTRU. The WTRU may receive Layer 1 or Layer 2 (L1 / L2) control signaling indicating that the WTRU will perform a transfer to a second cell. For example, the second cell may be one of the plurality of transfer candidate cells.

[0004] Upon moving to the second cell, the WTRU may determine which of the plurality of measurement configurations should be activated and which of the plurality of measurement configurations should not be activated based on the second cell becoming a new serving cell for the WTRU and the movement to the second cell causing activation of a third cell of the plurality of movement candidate cells as a secondary cell. For example, the second cell may be a primary cell. Further, it may be determined that the second measurement configuration should be activated. The WTRU may perform one or more measurements associated with the second measurement configuration. The WTRU may send a measurement report via the second cell based on the measurements associated with the second measurement configuration. The plurality of measurement configurations may include a channel state information (CSI) reporting configuration.

[0005] The L1 / L2 control signaling may include a medium access control (MAC) control element (CE). The WTRU may be configured to receive configuration information indicating multiple movement candidate cells independently of the multiple measurement configurations. The L1 / L2 control signaling may indicate a new special cell (SpCell) and an activated secondary cell (Scell). The WTRU may be configured to receive multiple measurement configurations associated with one or more special cell (SpCell) / secondary cell (SCell) combinations. The WTRU may be configured to determine which of the multiple measurement configurations should be activated and which of the multiple measurement configurations should not be activated based on the one or more SpCell / SCell combinations when performing a movement to the second cell.

[0006] The WTRU may be configured to determine which of a plurality of measurement configurations should be activated and which of a plurality of measurement configurations should not be activated when performing a movement to a second cell based on a combination of currently active secondary cells (SCells) among a plurality of movement candidate cells. [Brief explanation of the drawings]

[0007] [Figure 1A] FIG. 1 is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented. [Figure 1B] 1B is a system diagram illustrating an exemplary wireless transmit / receive unit (WTRU) that may be used within the communication system illustrated in FIG. 1A, according to one embodiment. [Figure 1C] 1A is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communication system illustrated in FIG. 1A, according to one embodiment. [Figure 1D] 1B is a system diagram illustrating a further exemplary RAN and a further exemplary CN that may be used within the communication system illustrated in FIG. 1A, according to one embodiment. [Figure 2] An example of a basic handover scenario in NR is shown. [Figure 3] 10 shows an example of conditional handover configuration and execution. [Figure 4] An example of L1 / L2 inter-cell mobility using carrier aggregation (CA) is shown. [Figure 5] An example of an L1 / L2 mobility area is shown. [Figure 6] 1 illustrates an example of dynamic activation of conditional handover (CHO) settings. [Figure 7] An example of CHO settings is shown below. [Figure 8]An example of activating CHO / CPAC settings, determined by the current SpCell, is shown. [Figure 9] 1 shows another example of an L1 / L2 mobility area. [Figure 10] 1 shows a flowchart of the measurement setup using L1 / L2-based movement. DETAILED DESCRIPTION OF THE INVENTION

[0008] 1A is a diagram illustrating an example communication system 100 in which one or more disclosed embodiments may be implemented. Communication system 100 may be a multiple-access system that provides content, such as voice, data, video, messaging, broadcasts, etc., to multiple wireless users. Communication system 100 may enable multiple wireless users to access such content through sharing of system resources, including wireless bandwidth. For example, the communication system 100 may employ one or more channel access methods such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique-word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, filter bank multicarrier (FBMC), etc.

[0009] 1A, communications system 100 may include WTRUs 102a, 102b, 102c, 102d, RANs 104 / 113, CNs 106 / 115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, although it will be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of WTRUs 102a, 102b, 102c, 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 user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a mobile phone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and application (e.g., remote surgery), an industrial device and application (e.g., robots and / or other wireless devices operating in the context of an industrial and / or automated processing chain), a consumer electronics device, a device operating in a commercial and / or industrial wireless network, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be referred to interchangeably as a WTRU.

[0010] The communications system 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communications networks, such as the CN 106 / 115, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node B, an eNodeB, a Home Node B, a Home eNodeB, a gNB, a New Radio (NR) Node B, a site controller, an access point (AP), a wireless router, etc. Although the base stations 114a, 114b are each depicted as a single element, it will be understood that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0011] The base station 114a may be part of the RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and / or base station 114b may be configured to transmit and / or receive radio signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide wireless service coverage for a particular geographic area, which may be relatively fixed or may change over time. A cell may be further divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In one embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers per sector of the cell, for example, using beamforming to transmit and / or receive signals in desired spatial directions.

[0012] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over the air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0013] More specifically, as noted above, the communications system 100 may be a multiple-access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base station 114 a and the WTRUs 102 a, 102 b, 102 c in the RAN 104 / 113 may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 115 / 116 / 117 using wideband CDMA (WCDMA). WCDMA may include communications protocols such as High-Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High-Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High-Speed ​​Uplink (UL) Packet Access (HSUPA).

[0014] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0015] In one embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR radio access, which may establish the air interface 116 using NR.

[0016] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may jointly implement LTE radio access and NR radio access, e.g., using the principle of dual connectivity (DC). Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions sent to and from multiple types of base stations (e.g., eNBs and gNBs).

[0017] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement a wireless technology 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 rates for GSM Evolution (EDGE), GSM EDGE (GERAN), or the like.

[0018] 1A may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point and may utilize any suitable RAT to facilitate wireless connectivity in a local area, such as, for example, a business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a road, etc. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may establish a picocell or a femtocell using a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.). As shown in FIG. 1A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not need to access the Internet 110 through the CN 106 / 115.

[0019] The RAN 104 / 113 may communicate with the CN 106 / 115, which may be any type of network configured to provide voice, data, application, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have various quality of service (QoS) requirements, such as different throughput, latency, error tolerance, reliability, data throughput, and mobility requirements. The CN 106 / 115 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, and / or perform high-level security functions such as user authentication. Although not shown in FIG. 1A , it will be understood that the RAN 104 / 113 and / or the CN 106 / 115 may communicate directly or indirectly with other RANs employing the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may utilize NR radio technology, the CN 106 / 115 may also communicate with another RAN (not shown) employing GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or Wi-Fi radio technology.

[0020] The CN 106 / 115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network providing plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices, which use common communication protocols such as the transmission control protocol (TCP), the user datagram protocol (UDP), and / or the internet protocol (IP) of the TCP / IP Internet protocol suite. The network 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, the network 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 113 or a different RAT.

[0021] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links.) For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with a base station 114a, which may employ a cellular-based wireless technology, and a base station 114b, which may employ an IEEE 802.2 wireless technology.

[0022] 1B is a system diagram illustrating an example WTRU 102. As shown in FIG. 1B, the WTRU 102 may include, among other things, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138. It will be understood that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0023] The processor 118 may be a general-purpose processor, a special-purpose processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. While FIG. 1B depicts the processor 118 and the transceiver 120 as separate components, it will be understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0024] The transmit / receive element 122 may be configured to transmit signals to or receive signals from a base station (e.g., base station 114a) over the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive, for example, IR signals, UV signals, or visible light signals. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF signals and light signals. It will be understood that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0025] 1B as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0026] The transceiver 120 may be configured to modulate signals transmitted by the transmit / receive element 122 and demodulate signals received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate via multiple RATs, such as, for example, NR and IEEE 802.11.

[0027] The processor 118 of the WTRU 102 may be coupled to and may receive user-entered data from a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. Additionally, 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 memory that is not physically located on the WTRU 102, such as on a server or home computer (not shown).

[0028] The processor 118 may receive power from the power source 134 and may be configured to distribute and / or control the power to other components in the WTRU 102. The power source 134 may be any suitable device for providing power to the WTRU 102. For example, the power source 134 may include one or more dry batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0029] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to or instead of information from the GPS chipset 136, the WTRU 102 may receive location information from base stations (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of received signals from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by way of any suitable location-determination method while remaining consistent with an embodiment.

[0030] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or videos), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, a Bluetooth module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an internet browser, a virtual reality and / or augmented reality (VR / AR) device, an activity tracker, etc. The peripheral device 138 may include one or more sensors, which may be one or more of a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, a direction sensor, a proximity sensor, a temperature sensor, a time sensor, a geolocation sensor, an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0031] The WTRU 102 may include a full-duplex radio where transmission and reception of some or all of the signals associated with a particular subframe (e.g., for both the UL (e.g., for transmission) and downlink (e.g., for reception)) may be parallel and / or simultaneous. The full-duplex radio may include an interference management unit 139 for reducing and or substantially eliminating self-interference either through hardware (e.g., a choke) or signal processing via a processor (e.g., via a separate processor (not shown) or processor 118). In one embodiment, the WTRU 102 may include a half-duplex radio for either transmission and reception of some or all of the signals (e.g., associated with a particular subframe for either the UL (e.g., for transmission) or downlink (e.g., for reception)).

[0032] 1C is a system diagram illustrating the RAN 104 and the CN 106, according to an embodiment. As noted above, the RAN 104 may employ E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also communicate with the CN 106.

[0033] The RAN 104 may include eNodeBs 160a, 160b, and 160c, although it will be understood that the RAN 104 may include any number of eNodeBs while remaining consistent with an embodiment. The eNodeBs 160a, 160b, and 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 116. In one embodiment, the eNodeBs 160a, 160b, and 160c may implement MIMO technology. Thus, the eNodeB 160a may, for example, use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0034] Each of the eNodeBs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, etc. As shown in FIG. 1C, the eNodeBs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0035] 1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. While each of the foregoing elements is depicted as part of the CN 106, it will be understood that any of these elements may be owned and / or operated by an organization other than the operator of the CN.

[0036] The MME 162 may be connected to each of the eNodeBs 162a, 162b, 162c in the RAN 104 via an S1 interface and may function as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, activating / deactivating bearers, selecting a particular serving gateway during initial attach of the WTRUs 102a, 102b, 102c, etc. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies such as GSM and / or WCDMA.

[0037] The SGW 164 may be connected to each of the eNodeBs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to and from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions such as anchoring the user plane during inter-eNodeB handovers, triggering paging when DL data is available to the WTRUs 102a, 102b, 102c, and managing and storing the context of the WTRUs 102a, 102b, 102c.

[0038] The SGW 164 may be connected to a PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0039] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional landline communications devices. For example, the CN 106 may include or communicate with an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. Additionally, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0040] Although the WTRU is illustrated in FIGS. 1A-1D as a wireless terminal, it is contemplated that in certain representative embodiments, such a terminal may use a wired communication interface (e.g., temporary or permanent) with the communication network.

[0041] In a representative embodiment, the other network 112 may be a WLAN. A WLAN in infrastructure Basic Service Set (BSS) mode may have an access point (AP) of the BSS and one or more stations (STAs) associated with the AP. The AP may have access to or interface with a Distribution System (DS) or another type of wired / wireless network that carries traffic into and / or out of the BSS. Traffic originating from outside the BSS to a STA may arrive through the AP and be delivered to the STA. Traffic originating from a STA to a destination outside the BSS may be sent to the AP to be delivered to the respective destination. Traffic between STAs within a BSS may be sent through the AP, for example, where a source STA may send traffic to the AP, and the AP may deliver the traffic to the destination STA. Traffic between STAs within a BSS may be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic may be sent between (e.g., directly between) a source STA and a destination STA using a direct link setup (DLS). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and STAs within or using the IBSS (e.g., all of the STAs) can communicate directly with each other. The IBSS mode of communication may be referred to herein as an "ad hoc" communication mode.

[0042] When using the 802.11ac infrastructure mode of operation or a similar mode of operation, an AP may transmit beacons on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., a 20 MHz wide bandwidth) or a width that is dynamically configured via signaling. The primary channel may be the operating channel of the BSS and may be used by STAs to establish a connection with the AP. In certain representative embodiments, for example, in an 802.11 system, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) may be implemented. With CSMA / CA, STAs (e.g., all STAs), including the AP, may sense the primary channel. If a particular STA senses / detects and / or determines that the primary channel is busy, the particular STA may back off. In a given BSS, only one STA (e.g., only one station) may transmit at any given time.

[0043] High Throughput (HT) STAs may use 40 MHz wide channels for communication, which may be formed, for example, through a combination of a primary 20 MHz channel and adjacent or non-adjacent 20 MHz channels.

[0044] A Very High Throughput (VHT) STA may support 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. A 40 MHz and / or 80 MHz channel may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining eight contiguous 20 MHz channels or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, after channel encoding, the data may pass through a segment parser that may separate the data into two streams. Inverse Fast Fourier Transform (IFFT) processing and time-domain processing may be performed separately on each stream. The streams may be mapped to two 80 MHz channels, and the data may be transmitted by the transmitting STA. At the receiver of the receiving STA, the operations described above for the 80+80 configuration may be reversed, and the combined data may be sent to Medium Access Control (MAC).

[0045] Sub-1 GHz operating modes are supported by 802.11af and 802.11ah. Channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah compared to those used in 802.11n and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, while 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to representative embodiments, 802.11ah may support meter-type control / machine-type communications, such as MTC devices, within a macro coverage area. MTC devices may have limited capabilities, including, for example, support for (e.g., only support for) specific and / or limited bandwidths. MTC devices may include batteries with above-threshold battery life (e.g., to maintain very long battery life).

[0046] WLAN systems that can support multiple channels and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include a channel that can be designated as a primary channel. 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 configured and / or limited by the STAs among all STAs operating in the BSS that support the minimum bandwidth operating mode. In an 802.11ah example, the primary channel can be 1 MHz wide for STAs (e.g., MTC-type devices) that support (e.g., only) 1 MHz mode, even if the AP and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or Network Allocation Vector (NAV) configuration can depend on the status of the primary channel. For example, if the primary channel is busy due to a STA (that only supports 1 MHz operating mode) transmitting to the AP, the entire available frequency band may be considered busy, even though most of the frequency band may remain idle and be available for use.

[0047] In the United States, the available frequency band that can be used by 802.11ah is 902MHz to 928MHz. In South Korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz, depending on country regulations.

[0048] 1D is a system diagram illustrating the RAN 113 and the CN 115, according to one embodiment. As noted above, the RAN 113 may employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also communicate with the CN 115.

[0049] The RAN 113 may include gNBs 180a, 180b, and 180c, although it will be understood that the RAN 113 may include any number of gNBs while remaining consistent with the embodiments. The gNBs 180a, 180b, and 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, and 180c may implement MIMO technology. For example, the gNBs 180a and 180b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, and 180c. Thus, the gNB 180a may transmit wireless signals to and / or receive wireless signals from the WTRU 102a using, for example, multiple antennas. In an embodiment, the gNBs 180a, 180b, and 180c may implement carrier aggregation (CA) technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum, while the remaining component carriers may be on licensed spectrum. In an embodiment, the gNBs 180a, 180b, and 180c may implement coordinated multi-point (CoMP) technology. For example, the WTRU 102a may receive coordinated transmissions from the gNBs 180a and 180b (and / or 180c).

[0050] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with scalable numerology. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or transmission time intervals (TTIs) of varying or scalable lengths (e.g., including varying numbers of OFDM symbols and / or varying lengths of absolute time).

[0051] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c without accessing another RAN (e.g., eNodeBs 160a, 160b, 160c, etc.). In a standalone configuration, the WTRUs 102a, 102b, 102c may utilize one or more of the gNBs 180a, 180b, 180c as mobility anchor points. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in unlicensed spectrum. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate / connect with a gNB 180a, 180b, 180c while also communicating / connecting with another RAN, such as an eNodeB 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement a dual connectivity (DC) principle to communicate with one or more gNBs 180a, 180b, 180c and one or more eNodeBs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNodeBs 160a, 160b, 160c may act as mobility anchors for the WTRUs 102a, 102b, 102c, and the gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0052] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support for network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data to User Plane Functions (UPFs) 184a, 184b, routing of control plane information to Access and Mobility Management Functions (AMFs) 182a, 182b, etc. As shown in FIG. 1D , the gNBs 180a, 180b, 180c may communicate with each other via an Xn interface.

[0053] 1D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. While each of the foregoing elements is depicted as part of the CN 115, it will be understood that any of these elements may be owned and / or operated by an organization other than the operator of the CN.

[0054] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may function as a control node. For example, the AMF 182a, 182b may be responsible for user authentication of the WTRUs 102a, 102b, 102c, supporting network slicing (e.g., handling different protocol data unit (PDU) sessions with different requirements), selecting a particular SMF 183a, 183b, managing registration areas, terminating NAS signaling, mobility management, etc. The network slicing may be used by the AMF 182a, 182b to customize the CN support for the WTRUs 102a, 102b, 102c based on the type of service utilizing the WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases, such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for machine type communication (MTC) access, etc. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies like Wi-Fi.

[0055] The SMFs 183a, 183b may be connected to the AMFs 182a, 182b in the CN 115 via an N11 interface. The SMFs 183a, 183b may also be connected to the UPFs 184a, 184b in the CN 115 via an N4 interface. The SMFs 183a, 183b may select and control the UPFs 184a, 184b and configure the routing of traffic through the UPFs 184a, 184b. The SMFs 183a, 183b may perform other functions such as managing and assigning IP addresses for WTRUs, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notification, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0056] The UPFs 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks such as the Internet 110 to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPFs 184, 184b may perform other functions such as routing and forwarding packets, enforcing user plane policy, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, etc.

[0057] The CN 115 may facilitate communication with other networks. For example, the CN 115 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 115 and the PSTN 108. Additionally, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to local data networks (DNs) 185a, 185b through the UPFs 184a, 184b via an N3 interface to the UPFs 184a, 184b and an N6 interface between the UPFs 184a, 184b and the DNs 185a, 185b.

[0058] 1A-1D and the corresponding description thereof, one or more or all of the functions described herein with respect to one or more of the WTRUs 102a-102d, base stations 114a-b, eNodeBs 160a-160c, MME 162, SGW 164, PGW 166, gNBs 180a-180c, AMFs 182a-ab, UPFs 184a-184b, SMFs 183a-183b, DNs 185a-185b, and / or any other devices described herein may be performed by one or more emulation devices (not shown). The emulation devices may be one or more devices configured to emulate one or more or all of the functions described herein. For example, the emulation devices may be used to test other devices and / or simulate network and / or WTRU functions.

[0059] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and / or an operator network environment. For example, one or more emulation devices may perform one or more or all functions while fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices in the communication network. One or more emulation devices may perform one or more or all functions while temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation devices may be directly coupled to another device for testing purposes and / or may use terrestrial wireless communication to perform the tests.

[0060] One or more emulation devices may perform one or more functions, inclusive, while not being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in a test lab and / or in a test scenario in an undeployed (e.g., test) wired and / or wireless communication network to implement testing of one or more components. One or more emulation devices may be test equipment. Direct RF coupled communication and / or wireless communication via RF circuitry (which may include, for example, one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0061] 2 illustrates, for example, a handover scenario in New Radio (NR). During initial handover preparation, a WTRU (e.g., within the cell coverage of a source gNB) may receive information regarding roaming, access restrictions, and / or other mobility control information from an AMF, for example, at connection establishment and / or the last timing advance (TA) update. The mobility control information may be provided to the WTRU, source gNB, and / or target gNB by the AMF. The source gNB may configure WTRU measurement procedures, and the WTRU may report to the source gNB according to the measurement configuration. The source gNB may decide to hand over the WTRU based on the received measurements.

[0062] The source gNB may then issue a handover request message to the target gNB by passing a transparent radio resource control (RRC) container with information to prepare the handover at the target side. The information may include at least one or more of the WTRU's target cell ID in the source gNB, the KgNB, the WTRU's C-RNTI (Radio Link Identifier), radio resource management (RRM) configuration including WTRU inactivity time, basic AS configuration including antenna information and DL carrier frequency, current QoS flow to data radio bearer (DRB) mapping rule applied to the WTRU, SIB1 from the source gNB, WTRU capabilities for different RATs, and PDU session-related information, or may further include WTRU-reported measurement information including beam-related information, if available.

[0063] Admission control may be performed by the target gNB. If the WTRU is admitted, the target gNB may prepare the handover at L1 / L2 and send a HANDOVER REQUEST ACKNOWLEDGE to the source gNB, which may include a transparent container that is sent as an RRC message to the WTRU to perform the handover. Once the HANDOVER REQUEST ACKNOWLEDGE is delivered, handover execution may begin so that the WTRU can detach from the old cell and synchronize to the new cell.

[0064] The source gNB may trigger a WTRU handover by sending an RRCReconfiguration message to the WTRU containing information for accessing the target cell, such as a target cell ID, a new C-RNTI, and / or a target gNB security algorithm identifier for the selected security algorithm. The RRCReconfiguration message may also include a set of dedicated random access channel (RACH) resources, an association between RACH resources and synchronization signal blocks (SSBs), an association between RACH resources and a WTRU-specific CSI reference signal (RS) configuration, common RACH resources, and system information of the target cell. In some applications, buffered data and new data are delivered from the UPF.

[0065] When detachment is initiated, the source gNB may send Early Transfer Status Transfer Data and SN STATUS TRANSFER messages to the target gNB to convey uplink PDCP SN receiver status and downlink PDCP SN transmitter status for DRBs where PDCP status preservation applies (e.g., for radio link control (RLC) AM). User data may be provided by the WTRU to the source gNB and then to the target gNB. The WTRU may synchronize to the target cell and complete the RRC handover procedure by sending an RRCReconfigurationComplete message to the target gNB.

[0066] In the handover completion part of the above scenario, an HO success signal may be sent from the target gNB to the source gNB. The source gNB may provide SN Status Transfer to the target gNB. The target gNB may send 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. The 5GC may switch the DL data path towards the target gNB. The UPF may send one or more "end marker" packets per PDU session / tunnel on the old route towards the source gNB and may then release any U-plane / TNL resources towards the source gNB. The AMF may acknowledge the PATH SWITCH REQUEST message with a PATH SWITCH REQUEST ACKNOWLEDGE message. Upon receiving the PATH SWITCH REQUEST ACKNOWLEDGE message from the AMF, the target gNB may send a WTRU CONTEXT RELEASE to inform the source gNB about the successful handover. The source gNB may then release the radio and C-plane related resources associated with the WTRU context. Any ongoing data transfer may continue.

[0067] NR Release 16 introduced the concepts of conditional handover (CHO) and conditional primary secondary serving cell (PSCell) addition / change (continuous packet addition (CPA) / continuous packet change (CPC), or collectively referred to as CPAC), which have the potential to reduce the likelihood of radio link failure (RLF) and handover failure (HOF).

[0068] A conventional LTE / NR handover can generally be triggered by a measurement report, even though there is nothing to prevent the network from sending a handover (HO) command to the WTRU without receiving a measurement report. For example, the WTRU can be configured with an A3 event (Neighbor becomes better than SpCell by an offset) that triggers a measurement report to be sent when the radio signal level / quality (reference signal received power (RSRP), reference signal received quality (RSRQ), etc.) of a neighboring cell becomes better than the primary serving cell (PCell), or in case of DC, the PSCell. The A3 event can be triggered when the neighboring cell becomes better than the special cell (SpCell) by more than an offset. The special cell can be the primary serving cell of either the Master Cell Group (MCG) or the Secondary Cell Group (SCG). The offset can be either positive or negative. The A3 event can generally be used for intra-frequency or inter-frequency handover procedures. When the A2 event is triggered, the WTRU may be configured with a measurement gap to measure an A3 event for inter-frequency object and inter-frequency handover. The A3 event may provide a handover triggering mechanism based on relative measurement results. For example, the handover triggering mechanism may be configured to trigger when the RSRP of a neighboring cell is stronger than the RSRP of the special cell.

[0069] The WTRU may monitor the serving cell and neighboring cells and may send measurement reports when conditions are met. When such reports are received by the network, the network (current serving node / cell) may prepare an HO command. This HO command may be an RRC reconfiguration message with reconfiguration With Sync sent to the WTRU, which the WTRU may execute, resulting in the WTRU connecting to the target cell.

[0070] In some examples, multiple handover targets are prepared. Furthermore, the WTRU may not immediately perform the CHO. The WTRU may be configured with a triggering condition, such as a set of radio conditions, and the WTRU may perform a handover towards one of the targets if the triggering condition is met.

[0071] The CHO command may be sent from the network when radio conditions for the current serving cell are still favorable, thereby reducing, among other things, the risk of failing to send a measurement report (e.g., when a measurement report is triggered within a normal handover when the link quality to the current serving cell falls below an acceptable level) and failing to receive a handover command (e.g., when the link quality to the current serving cell falls below an acceptable level after the WTRU has sent a measurement report but before receiving the HO command). The WTRU may send the CHO command when radio conditions for the current serving cell start to deteriorate (e.g., worsen).

[0072] 3 shows conditional handover configuration and execution. At 302, a source node may send a CHO request 302 to a potential target node. At 304, the potential target node may send a CHO request ACK containing an RRCReconfiguration to the source node. At 306, the WTRU may perform CHO configuration. The source node may send an RRCReconfiguration to the WTRU, which receives it. The triggering conditions for CHO may be based on the radio quality of the serving cell and neighboring cells, e.g., the conditions used in conventional LTE / NR to trigger measurement reports. Furthermore, the WTRU may be configured with a CHO with triggering conditions and associated HO commands of A1 (e.g., serving cell becomes better than a threshold), A2 (e.g., serving cell becomes worse than a threshold), A3 (e.g., neighbor becomes better than SpCell by an offset), A4 (e.g., neighbor becomes better than a threshold), A5 (e.g., SpCell becomes better than threshold 1 by an offset and neighbor becomes better than threshold 2), A6 (e.g., neighbor becomes better than SCell by an offset), B1 (e.g., inter-RAT neighbor becomes better than a threshold), and / or B2 (e.g., PCell becomes worse than threshold 1 and inter-RAT neighbor becomes better than threshold 2). The A5 event may be triggered when the special cell becomes worse than threshold 1 and the neighbor cell becomes better than threshold 2. The A5 event may be used for intra-frequency or inter-frequency handover procedures. After the A2 event is triggered, the WTRU may be configured with the A5 event for measurement gaps and inter-frequency handover. The A5 event may provide a handover triggering mechanism based on absolute measurement results. The A5 event may be used to trigger a time-critical handover when the current special cell becomes weak and needs to change to another cell that may not meet the criteria for an A3 event handover. At 308, the WTRU may monitor CHO conditions for the current cell, the serving cell, and / or the candidate target cells.At 310, if the A3 triggering condition is met, the WTRU may execute an associated HO command and switch its connection towards the target cell instead of sending a measurement report. At 312, the WTRU may send a CHO confirmation to the target node. At 314, a path switch may be performed by the target node, and a WTRU context release may be performed by the source node (e.g., see 10.-12. in FIG. 2).

[0073] CHO can help prevent unnecessary re-establishment in the event of a radio link failure. For example, a WTRU may be configured with multiple CHO targets, and the WTRU may experience RLF before the triggering conditions with any of the targets are met. Conventional operation would result in an RRC re-establishment procedure that would result in significant disruption to the WTRU's bearers. However, with CHO, if the WTRU, after detecting RLF, reaches a cell that has an associated CHO (e.g., the target cell is already prepared for it), the WTRU can execute an HO command associated with this target cell directly instead of continuing with the full re-establishment procedure.

[0074] The CPC and CPA may be extensions of the CHO in a DC scenario. In an embodiment, the WTRU may be configured with a triggering condition for PSCell modification or addition, and may execute an associated PSCell modification or PSCell addition command when the triggering condition is met.

[0075] In NR Release 17, movement between cells L1 / L2 can manage beams in the case of CA without supporting cell change / add. In Release 18, one of the intended objectives is to specify mechanisms and procedures for L1 / L2-based inter-cell movement for reducing movement delay. In an embodiment, mechanisms and procedures for L1 / L2-based inter-cell movement for reducing movement delay may be specified. Configuration and maintenance for multiple candidate cells may be specified to enable fast application of configuration for candidate cells [RAN2, RAN3]. A dynamic switching mechanism between candidate serving cells (including special cells (SpCells) and / or SCells) for potentially applicable scenarios based on L1 / L2 signaling [RAN2, RAN1] may also be provided. An SpCell may refer to a PCell of a Master Cell Group (MSG) and / or a PSCell of a Secondary Cell Group (SCG) depending on whether the MAC entity is associated with a Master Cell Group (MCG) or a Secondary Cell Group (SCG). The WTRU may be configured to receive multiple measurement configurations involving association with one or more special cell (SpCell) / secondary cell (SCell) combinations. L1 extensions may be provided for inter-cell beam management, including L1 measurement and reporting and beam direction [RAN1, RAN2]. Early RAN2 involvement may be used, including the possibility of further clarifying interactions with dynamic switching. Timing advance management [RAN1, RAN2] and CU-DU interface signaling (if necessary [RAN3]) to support L1 / L2 mobility may also be provided. FR2-specific enhancements may not be excluded. Furthermore, L1 / L2-based inter-cell mobility procedures are applicable to various scenarios, including standalone, CA and NR-DC with serving cell change within one configured grant or cell group (CG), intra-DU and inter-DU within CU (applicable to standalone and CA when no new RAN interface is expected), intra-frequency, inter-frequency, FR1, FR2, synchronous or asynchronous source and target cells, and not inter-CU.

[0076] L1 / L2-based mobility was initially launched in NR Release 17, and inter-cell beam management in Release 17 addresses intra-DU and intra-frequency scenarios. In this case, the serving cell remains unchanged (e.g., there is no possibility to change the serving cell using L1 / L2-based mobility). In FR2 deployments, CA is typically used to aggregate multiple CCs in one band, for example, to utilize available bandwidth. These CCs are typically transmitted on the same analog beam pair (gNB beam and WTRU beam). The WTRU may be configured with a fairly large number of TCI states (which may be 64, for example) for reception of the physical downlink control channel (PDCCH) and the physical downlink shared channel (PDSCH). Each TCI state may include an RS or SSB that the WTRU references to configure its beam. In Release 17, the SSB may be associated with a non-serving PCI. MAC signaling ("TCI state indication for WTRU-specific PDCCH MAC Control Element (CE)") can activate the TCI state for the core set / PDCCH. Reception of PDCCH from non-serving cells can be supported by the MAC CE indicating the TCI state associated with the non-serving PCI. MAC signaling ("TCI state activation / deactivation for WTRU-specific PDSCH") can activate a subset of (up to) eight TCI states for PDSCH reception. Downlink control information (DCI) can indicate any of the eight TCI states. Release 17 also supports a "unified TCI state" with a different update mechanism (DCI-based) but without multiple transmission / reception points (TRPs). Release 18 may support a unified TCI state with multiple TRPs.

[0077] In conventional level 3 (L3) handover, the handover may be conditional on the WTRU first sending a measurement report using RRC signaling. In response, the network may provide further measurement configuration and potentially CHO configuration. In CHO, the network provides target cell configuration after the WTRU reports using RRC signaling that the cell meets the configured radio quality criteria. In conditional handover, to reduce handover failure rates due to delays in sending measurement reports and then receiving RRC reconfiguration, the network may provide target cell configuration in advance, as well as measurement criteria that determine when the WTRU may trigger CHO configuration. These L3 methods may introduce some delays, especially in the case of conventional (unconditional) handover, due to the sending of measurement reports and receiving the target configuration.

[0078] In embodiments, L1 / L2 inter-cell mobility can be used to improve handover latency. Furthermore, L1 / L2-based inter-cell mobility may enable fast application of configurations for candidate cells, including dynamic inter-SCell and PCell switching (e.g., switching roles between SCell and PCell) without RRC signaling. The inter-CU case, which involves PDCP anchor relocation, is not included in Release 18 since it is already excluded from the WI. An RRC-based approach may be desirable, such as to support inter-CU handover. One of the goals of L1 / L2 should also be to allow CA operation to be activated instantly upon serving cell change.

[0079] FIG. 4 illustrates an example of an L1 / L2 inter-cell mobility operation using carrier aggregation (CA), whereby a candidate cell group is configured by RRC and dynamic PCell and SCell switching can be achieved using L1 / L2 signaling. A WTRU may be configured with cells 1-4 as candidate cells via RRC and activate PCell 1 and SCell 2. The WTRU may receive configuration information indicating multiple mobility candidate cells and multiple measurement configurations. The base station may perform L1 / L2 signaling for SCell activation / deactivation (intra-CU). A CHO (intra-CU or inter-CU) for PCell switching may be performed, and the L1 / L2 candidate "set" may be updated. The WTRU may activate a first measurement configuration of multiple measurement configurations based on the first cell being the current serving cell for the WTRU. The WTRU may also determine that a second measurement configuration of multiple measurement configurations is to be deactivated based on the first cell being the current serving cell for the WTRU.

[0080] As the WTRU moves from left to right, the WTRU may switch (e.g., dynamically switch) the Scell ​​between cell 2 and cell 3. The higher frequency and higher bandwidth of cell 3 and cell 4 may be factors in the decision (or condition) to switch to the target cell. The WTRU may receive Layer 1 or Layer 2 (L1 / L2) control signaling indicating that the WTRU will move to a second cell, which is one of multiple movement candidate cells. As the WTRU continues to move to the right, the WTRU may switch (e.g., dynamically switch) the PCell to cell 2 and switch (e.g., dynamically switch) the SCell to cell 4. When the WTRU moves to the second cell (e.g., the second cell becoming the primary cell), the WTRU may determine which of the multiple measurement configurations to activate and which of the multiple measurement configurations to not activate based on the fact that the second cell becomes the new serving cell for the WTRU and that the move to the second cell causes a third cell of the multiple movement candidate cells to be activated as a secondary cell. A second measurement configuration may also be determined to be activated. The WTRU may be configured to determine which of the multiple measurement configurations should be activated and which of the multiple measurement configurations should not be activated based on one or more SpCell / SCell combinations when performing a movement to a second cell (e.g., from PCell1 to PCell2). The WTRU may also be configured to determine which of the multiple measurement configurations should be activated and which of the multiple measurement configurations should not be activated based on a combination of currently active secondary cells (SCells) among multiple movement candidate cells when performing a movement to the second cell.

[0081] As described herein, Release 18 does not introduce support for inter-CU handover using L1 / L2 signaling. Therefore, to cover at least this case, conventional or conditional handover may be employed. To support any movement from any particular L1 / L2 mobility area to another, conventional or conditional handover may be employed.

[0082] 5 shows an example of an L1 / L2 mobility area 500. L1 / L2 inter-cell mobility may be deployed in a particular area. The network may define an area with a set of multiple candidate L1 / L2 mobility cells. Furthermore, the network may divide its deployment into multiple L1 / L2 mobility areas for other reasons, such as cell planning, or due to limitations on the maximum number of cell configurations that can be stored in a WTRU simultaneously. The network may define a neighboring area with multiple cells (e.g., cells that are not candidate L1 / L2 mobility cells).

[0083] Because L1 / L2 inter-cell mobility may be intended to cover a much larger geographic area without RRC reconfiguration signaling than traditional handover (e.g., a WTRU can move between two or more PCells without RRC reconfiguration), this may have ramifications with regard to the amount of RRC configuration used to enable a WTRU to move around an L1 / L2 mobility area to support out-of-area mobility. In traditional L3 mobility, the network may generally provide measurement and conditional handover configurations based on the PCell currently serving the WTRU and potential target cells in the vicinity of the serving PCell. When a PCell change occurs due to either handover or conditional handover, the measurement configurations may be updated by RRC signaling, and a new CHO configuration may potentially be provided.

[0084] If the serving cell can be dynamically switched using L1 / L2 signaling, but the measurement configuration and conditional handover configuration still have to be updated using RRC signaling, this may limit the effectiveness of the dynamic switching mechanism, as the delays employed to perform the RRC signaling may be significant.

[0085] In an embodiment, it may be possible to pre-configure many measurement and conditional handover configurations, for example, so that if the WTRU moves into the coverage of another CU, the WTRU may be equipped to perform measurements and handovers to cells outside its configured L1 / L2 mobility area. However, there may be a limit to the number of CHO configurations and measurement targets that can be configured in the WTRU simultaneously. This may be in part due to limiting the complexity of the WTRU (in terms of the number of parallel measurements and conditions to evaluate), but may also be designed to limit the amount of resources the network reserves for any given WTRU; in the case of conditional handover, the network may reserve resources on the target cell in anticipation of the WTRU meeting the conditions and performing CHO. If the network wants to configure many CHOs, this also implies that the number of resources (in potential target cells) that may have to be reserved in the network may become unacceptably large.

[0086] In Release 18, enhancements to CPAC targeted at the WIs identified above are planned. NR-DC mechanisms and procedures are specified, for example, by selective activation of cell groups for SCGs via L3 enhancements. Furthermore, it is planned to enable subsequent cell group changes after changing CGs without reconfiguration and restart of CPC / CPA (RAN2, RAN3, RAN4). To minimize the workload in RAN2, it is possible that a harmonized RRC modeling approach can be considered.

[0087] The intent of this Release 18WI objective appears to be to allow the CPC / CPA configuration to become active after the CPC / CPA is triggered. Currently, when a reconfiguration is triggered, the WTRU may release any currently configured CPA / CPC configuration and the network may set up a new CPA / CPC configuration. This may also apply to CHO. Release 18 is meant to address CPA / CPC but not CHO / MGC. However, it is expected that similar issues may exist for CHO.

[0088] A WTRU may be configured with a set of multiple candidate target cells that may be dynamically activated using L1 and / or L2 signaling, as shown in FIG. 4. A configuration within the set of possible options, e.g., an active PCell or PCell / SCell combination, may be associated with one or more measurement reporting configurations for conventional measurement reporting or for CHO. Some of these measurement / CHO configurations may be stored but not active until the associated cell configuration may be dynamically activated using L1 / L2 signaling. Similarly, for CHO, the network may not need to reserve resources on the target cell until it activates a particular cell combination (or combination of other parameters). This allows the WTRU to store the measurement and CHO configurations that it will use throughout the area of ​​potential L1 / L2 mobile cells and activate those configurations when the WTRU is in the appropriate area.

[0089] As generally described herein, "measurement" refers to a measurement object and associated reporting configuration as in conventional NR (e.g., when a reporting condition is met, a measurement report may be sent), unless otherwise specified. Furthermore, "CHO ​​configuration" generally refers to a measurement object and associated reporting configuration for CHO (e.g., when a reporting condition is met, an associated CHO may be performed), unless otherwise specified. However, some measurement objects may be associated with multiple reporting configurations (for conventional measurement report triggering or for CHO).

[0090] FIG. 6 illustrates an example of dynamic activation of a conditional handover (CHO) configuration 600. In the L1 / L2 example of FIG. 6, signaling for Scell ​​activation / deactivation (intra-CU), CHO for Pcell switch (e.g., intra-CU or inter-CU), and updating of the L1 / L2 candidate “set” may be performed. In this example, the network may provide four cell configurations. In this example, the set of candidate L1 / L2 movement cells (e.g., cells 1-4) may be configured by RRC signaling. For example, a WTRU may receive four cell configurations indicating cells 1-4 as movement candidate cells and measurement configurations. The WTRU may receive multiple measurement configurations (e.g., for cells 1-4) via RRC signaling. The WTRU may activate a first measurement configuration (e.g., cell 1 activated as a PCell and cell 2 activated as an SCell) of the multiple measurement configurations based on the first cell (e.g., cell 1) being the current serving cell for the WTRU. In some cases, "serving cell" may refer to a primary cell, and "serving cell" may refer to the primary cell and a secondary cell. In some cases, "serving cell" may refer to a secondary cell. In other cases, "serving cell" may be used to refer to a set of one or more cells consisting of the primary cell and all secondary cells. In some cases, "primary serving cell" may include the primary cell, and "secondary serving cell" may include the secondary cell. In FIG. 6, the WTRU is using cell 1 as its current serving cell.

[0091] The WTRU may be configured to determine that a second measurement configuration of the plurality of measurement configurations is deactivated based on the first cell being the current serving cell for the WTRU. For example, cell 6 may be deactivated based on cell 1 being the current serving cell. Deactivation of cell 6 may occur for many reasons. For example, the distance between cell 1 and cell 6 may be too large for cell 1 and cell 6 to be activated simultaneously. That is, it may not be very efficient for cell 1 to be the PCell and cell 6 to be the SCell, since cell 6 may not function as a good secondary cell due to its distance from cell 1. As an example, a secondary cell may include a cell operating on a primary or secondary frequency, which may be configured once an RRC connection is established and can be used to provide additional radio resources to the WTRU. It may be difficult to provide additional radio resources to a WTRU located too far from the cells.

[0092] In FIG. 6, L1 (e.g., activating DCI, integrated TCI state) or L2 (e.g., MAC CE) signaling can be used to dynamically switch the roles of these four pre-configured cells. A WTRU may receive Layer 1 or Layer 2 (L1 / L2) control signaling indicating that the WTRU will move to a second cell that is one of multiple movement candidate cells. A "cell" may refer to, for example, a PCell, an SCell, a movement candidate cell, an activated cell, a deactivated cell, a first cell, a second cell, a third cell, a fourth cell, a fifth cell, an nth cell, or any other cell. A moving WTRU may include a WTRU moving in a particular direction. A moving WTRU may include predictions, estimates, measurements, and / or calculations regarding the speed, direction, acceleration, and / or one or more locations for the WTRU. For example, if the WTRU is moving to the right, the WTRU, Layer 1, Layer 2, and / or Layer 3 may predict where the WTRU will be located after a given time and activate desirable measurement configurations and deactivate undesirable measurement configurations. The WTRU's location within the cell (e.g., the region of the cell in which the WTRU is located) may be used to determine which measurement configurations to activate and deactivate. For example, in FIG. 6, when the WTRU is at the leftmost side of cell 1, the measurement configuration associated with cell 4 may be deactivated because cell 4 is toward the rightmost side of cell 1. When the WTRU is in the center of cell 1, the measurement configuration associated with cell 3 may be activated because cell 3 is located directly above (e.g., adjacent to) the center of cell 1.

[0093] When the WTRU performs a movement to the second cell, which becomes the primary cell, the WTRU may determine which of the plurality of measurement configurations should be activated and which of the plurality of measurement configurations should not be activated based on the fact that the second cell becomes the new serving cell for the WTRU and that the movement to the second cell causes the activation of a third cell of the plurality of movement candidate cells as a secondary cell, where the second measurement configuration is determined to be activated. For example, in FIG. 6, the WTRU performs a movement from PCell1 to PCell2, which causes the activation of cell4 as a secondary cell (SCell4), which was previously cell2. Radio resource control (RRC) may be the highest layer in the access stratum (AS) control plane. The RRC may transfer non-access stratum (NAS) messages, which are located above the RRC layer. Additionally, in one embodiment, the network may provide one or more (two in this example) conditional handover configurations to the target cell. The WTRU may be configured to determine which of a plurality of measurement configurations should be activated and which of a plurality of measurement configurations should not be activated when performing a movement to a second cell based on a combination of currently active secondary cells (SCells) among a plurality of movement candidate cells.

[0094] In 3GPP standards up to Release 17, when multiple conditional handover configurations are provided, the WTRU stores them and evaluates the trigger conditions in parallel. In the proposed method, these CHO configurations may not be activated immediately after configuration (e.g., a flag included in the measurement / CHO configuration where the relevant configuration may be stored) but may be activated in one or more ways, such as using explicit L1 / L2 signaling to indicate that the CHO or measurement configuration is to be activated. Further examples of activation may include when a cell becomes a PCell, when a SCell (e.g., or set of SCells) is activated, when a SCell (e.g., or set of SCells) is deactivated, when a PCell / SCell combination is activated or deactivated, and upon a change of combination (e.g., a change from PCell1 to PCell2 may activate a configuration, but a change from PCell3 to PCell2 may not).

[0095] In embodiments, a similar mechanism may be employed to deactivate an active CHO or measurement configuration. Other mechanisms may be employed to release / delete an active or inactive CHO or measurement configuration.

[0096] Embodiments can be used, for example, in the case of an L3 handover. In embodiments, CHO or CPAC configuration may be provided but not activated until an SpCell and / or one or more SCells are active, regardless of whether an L1 / L2 triggered move is used. In embodiments, the WTRU may perform a CPC-based configuration on the active configuration for the current serving cell. In embodiments, the WTRU may activate and begin evaluating stored CPC configurations associated with, for example, the new serving cell. In embodiments, procedures related to cell changes activated or triggered using explicit L1 / L2 commands may also apply to L3 RRC reconfiguration or cell changes using CHO, CPC, or CPA. In some cases, the WTRU may determine that a second measurement configuration of a plurality of measurement configurations is to be deactivated based on the first cell being the current serving cell for the WTRU.

[0097] CHO configuration 1 may be provided with target cell 5 and a measurement event to trigger CHO, such as CondEvent A3 (e.g., neighbor becomes better than SpCell by an offset) or CondEvent A5 (e.g., SpCell becomes worse than threshold 1 and neighbor becomes better than threshold 2). The network may not know the direction in which the WTRU will move, and therefore the network may set up targets in multiple directions around the WTRU (e.g., left, right, forward, backward, up, down). Thus, although the WTRU will eventually move to the right in FIG. 6, cell 5 (located in the upper left) is the target cell. The WTRU may be configured to activate CHO configuration 1 based on cell 1 being the PCell. When the WTRU moves from left to right, the WTRU may switch (e.g., dynamically switch) the Scell ​​between cell 2 and cell 3. As the WTRU continues to move to the right, the WTRU may switch (eg, dynamically switch) the PCell from cell 1 to cell 2 and switch (eg, dynamically switch) the SCell from cell 2 to cell 4.

[0098] The WTRU may perform one or more measurements associated with a second measurement configuration. For example, in FIG. 6, CHO configuration 2 may be provided with target cell 6 and a measurement event for triggering CHO, similar to CHO configuration 1. CHO configuration 2 may also be activated based on cell 2 being the PCell (e.g., or alternatively, the combination of PCell 1 and SCell 4 activates CHO configuration 2). Rather than evaluating all of the configured CHOs in parallel, the WTRU may evaluate CHO according to the associated active cell combination. This may reduce processing overhead at the WTRU, as related measurements and evaluations may be made according to the WTRU's location within the L1 / L2 mobility area. This may also reduce resource usage in the network. The network may not need to reserve resources on all configured target CHO cells, but rather may reserve resources according to the activated CHO configuration; e.g., since the network controls the active cell combination used by the WTRU (e.g., using L1 / L2 signaling), the network may also control what the currently active CHO configuration in the target CHO cell and the WTRU is. The same or similar methods can also be used to control measurement objects and measurement reporting for conventional handover. The WTRU can send measurement reports via the second cell based on measurements associated with the second measurement configuration. For example, instead of or in addition to one or more CHO configurations, one or more measurement objects can be configured for measurement reporting and associated with one or more L1 / L2 controlled cell combinations. In addition, the carrier and / or cell (e.g., neighboring carrier and cell) currently being measured by the WTRU can be associated with the L1 / L2 controlled cell combination.

[0099] Activation of measurement configuration and / or conditional reconfiguration may be based on any "condition" that describes where the WTRU may be located within an L1 / L2 mobility area or within an area corresponding to a set of cells with pre-configured measurements or CHO / CPAC. The conditions may include which PCells and / or SCells are activated, and may include cases where there may be no active SCells and / or SCells may be deactivated for power saving reasons.

[0100] A "mobility area index" is introduced and may be configured in each instance of "X" and "Y" with at least one "mobility area index." In an embodiment, "X" may include anything that may be activated / deactivated as a function of the WTRU's location, such as the TCI state, non-serving PCIs (e.g., in "NumberOfAdditionalPCI"), PCell / SCell combinations, active bandwidth part (BWP), SCell activation state, measurement event trigger conditions being met, DL synchronization trigger to the candidate cell, PDCCH indication RA towards the candidate cell, and / or enabling radio link monitoring (RLM) or beam failure detection (BFD) of the target cell. In some examples, a non-serving PCI may be activated if the TCI state associated with the PCI is activated.

[0101] "Y" may include anything that supports measurement / mobility, such as configured measurement configuration, configured conditional reconfiguration and / or channel state information (CSI) reporting configuration, BFR configuration, and / or neighbor carrier / cell list. Configured measurement configuration may include L3 measurement object, L1 or L3 measurement event, CSI measurement configuration, and / or L1 or L3 measurement RS configuration (e.g., SSB or CSI-RS resource for current or neighbor cell). Configured measurement configuration may include PCI or logical ID, SMTC location, frequency location, and / or SCS.

[0102] Based on the above, it is contemplated that examples of possible behaviors may include, for example, that if "X" is activated, any "Y" with the same "Mobility Area Index" configured for X is also activated. In some examples, if there is no activated "X" with the same "Mobility Area Index," Y may be deactivated. In some examples, an explicit activation / deactivation or switching of the "Mobility Area Index" may occur, which may activate / deactivate the corresponding X and / or Y.

[0103] An example of a "mobility area index" may be one or more indexes or identifiers that associate "X" (e.g., anything that can be activated / deactivated as a function of the WTRU's location) with "Y" (e.g., anything that supports measurement / mobility). For example, a WTRU may be configured with one or more measurement configurations, each having an index. The WTRU may additionally be configured with one or more conditions (e.g., SpCell / SCell combinations) and / or a list of one or more indices that identify measurement configurations to enable when one or more conditions are met. Each configured condition may be associated with the same or a different subset of measurement configurations. In this way, the measurement configurations may not need to be repeated for all possible SpCell / SCell combinations, but each combination for which the measurement configuration is applicable (e.g., SpCell / SCell combinations configured as L1 / L2 mobility candidate configurations) may use an index or identifier to reference the measurement configuration (e.g., configured in a list or structure independent of the L1 / L2 mobility candidate configurations). Additionally, this allows a larger number of measurements to be configured (e.g., by RRC) than would be applicable to any given SpCell / SCell combination (e.g., activated or triggered by a MAC CE).

[0104] FIG. 7 illustrates an example of dynamic activation of a CHO configuration 700. In this example, a first set of L1 / L2 transfer candidate cells consists of cells 1, 2, 3, and 4, and a second set of L1 / L2 transfer candidate cells consists of cells 5, 6, 7, and 8. While one or more CHO configurations may be configured in 704, one configuration is shown for purposes of this example. The CHO configuration includes a target PCell configuration, but may also include target PCell and SCell configurations (e.g., PCell1 and SCell3). The CHO configuration may also include a target set of L1 / L2 transfer candidate cells, i.e., a set of L1 / L2 transfer candidate cells that can be dynamically controlled using L1 / L2 signaling after successful completion of CHO. In some cases, the L1 / L2 control signaling may include a medium access control (MAC) control element (CE). The L1 / L2 control signaling may indicate a new special cell (SpCell) and an activated secondary cell (Scell). RRC and NAS message functions may be used to exchange signaling between the WTRU and the gNB, and the CE may be a special MAC structure that carries special control information. The MAC CE may operate between the UE (MAC) and the gNB (MAC) for FAST signaling communication exchange without involving higher layers. The WTRU may activate a first measurement configuration (e.g., PCell1, SCell3) of the multiple measurement configurations based on the first cell being the current serving cell for the WTRU. The WTRU may also determine that a second measurement configuration (e.g., measurement configurations associated with cells 2, 4-8) of the multiple measurement configurations be deactivated based on the first cell being the current serving cell for the WTRU.

[0105] At 706, the CHO trigger may use one of the existing measurement events, such as event A3 or event A5. CHO may instead utilize one or more new measurement events. CHO evaluation may be triggered (or activated) when cell 5 becomes a SCell, implying that the WTRU may be reaching the boundary between cell 1 and cell 2 and should therefore begin evaluating the conditions for handover to target cell 2. In some examples, the CHO trigger itself may be the activation of a specific combination of cells (activation of SCell 5 in this example) or the activation of any condition related to a mobility area, as described above. At 708, CHO may be performed, and PCell 1 may dynamically switch to PCell 2, and SCell 5 may dynamically switch to SCell 6. As the WTRU continues to move to the right, dynamic switching may continue to occur to secondary cells (e.g., cell 7, then cell 8) and primary cells.

[0106] In an embodiment, the criteria for activating or deactivating a measurement or CHO configuration may be related to a specific transition rather than a static configuration. For example, a change of SCell from cell 3 to cell 5 may not trigger a configuration, but a change of SCell from cell 4 to cell 5 may activate it. Thus, activation takes into account the current cell configuration and the previous cell configuration. When the WTRU performs a movement to a second cell that becomes the primary cell, the WTRU may determine which of the multiple measurement configurations should be activated and which of the multiple measurement configurations should not be activated based on the fact that the second cell becomes the new serving cell for the WTRU and that the movement to the second cell causes the activation of a third cell of the multiple movement candidate cells as a secondary cell, and it is determined that the second measurement configuration is activated.

[0107] In an embodiment, the WTRU may send an indication to the network whenever the activation status of a CHO or measurement configuration changes (e.g., when the configuration is activated, when the configuration is deactivated, when the configuration is released). In some cases, the measurement configuration may include a channel state information (CSI) reporting configuration.

[0108] FIG. 8 shows an example diagram 800 of CHO / CPAC configuration activation depending on the current SpCell. As shown in FIG. 8, a WTRU may be configured with multiple CHO (e.g., or CPC) target cells based on one or more measurement events. Upon performing CHO (e.g., or CPC) toward a new SpCell, the WTRU may begin evaluating stored CHO (e.g., or CPC) configurations that may potentially apply to the same target cell or toward a different target cell. The WTRU may be configured to receive multiple measurement configurations associated with one or more special cell (SpCell) / secondary cell (SCell) combinations. The WTRU may be configured to determine which of the multiple measurement configurations should be activated and which of the multiple measurement configurations should not be activated when performing a movement to a second cell based on one or more SpCell / SCell combinations and / or based on a combination of currently active secondary cells (SCells) among multiple movement candidate cells.

[0109] The WTRU may be configured with conditional triggers for cells 1 to 2 and 1 to 3. The WTRU may also be configured with conditional triggers for cells 2 to 3 and cells 3 to 2. The WTRU may receive configuration information indicating multiple movement candidate cells and multiple measurement configurations. The WTRU may be configured by the network with two conditional triggers with a target of cell 2, e.g., a conditional trigger to be used while present on cell 1 and another conditional trigger to be used while present on cell 3. Similarly, the WTRU may be configured with two conditional triggers with a target of cell 3, e.g., a conditional trigger to be used while present on cell 1 and another conditional trigger to be used while present on cell 2.

[0110] The WTRU may be configured with a conditional trigger to move to cell 2 that has a different offset depending on whether the WTRU is currently on cell 1 or 3. Similarly, the conditional trigger to move to cell 3 may be configured by the network with a different offset depending on whether the WTRU is currently on cell 1 or cell 2.

[0111] The WTRU may trigger a reconfiguration to cell 2. The WTRU may activate evaluation of conditional triggers for moving from cell 2 to cell 3 and / or from cell 2 to cell 1. The WTRU may activate a first measurement configuration of the multiple measurement configurations based on the first cell being the current serving cell for the WTRU. The WTRU may determine that a second measurement configuration of the multiple measurement configurations is to be deactivated based on the first cell being the current serving cell for the WTRU.

[0112] The CHO or CPC configuration may be independent, for example, based on the current RRC signaling structure. In some examples, the conditional trigger configuration may be as follows:

[0113] [Table 1]

[0114] In the above embodiment, each CHO / CPAC setting is (preferably) provided with an event type and offset / threshold / hysteresis / time to trigger parameters as needed. When triggering one active CHO or CPAC to a new SpCell, the WTRU may activate new conditional trigger settings for the CHO, CPA, or CPC associated with the new SpCell.

[0115] It may be desirable to reuse the same conditional trigger configuration for multiple cells, providing parameters that may differ. Conditional triggers (for CHO, CPC, CPA) may be provided for a specific target cell, e.g., conditional event A3. All of the configuration may be the same for the target cell regardless of the current cell, except for the offset to be used. The WTRU may then receive the conditional trigger configuration for the specific cell and may further receive a list of offsets to use that depend on the current SpCell.

[0116] In some embodiments, the WTRU may set initial conditions for the measurement configuration applied using a first condition, along with details of how to further update the configuration using a second condition.

[0117] In some embodiments, the WTRU may determine a first configuration based on a first condition (e.g., a new SpCell / SCell combination) and then update the configuration based on a second condition (e.g., activation / deactivation status of the SCell). For example, the WTRU may be configured to perform an L1 / L2 triggered handover and apply a configuration using cell 1 as the PCell and cells 2 and / or 3 as SCells. Cells 2 and 3 may additionally be configured as L1 / L2 handover target cells (e.g., target SpCells provided in the L1 / L2 handover candidate configuration). The initial state of the SCells may be deactivated. Based on this, the WTRU may apply a first measurement configuration associated with measuring and / or reporting cells 2 and 3 based on the cells being the L1 / L2 handover target cells. The WTRU may subsequently receive an instruction to activate one or both of cells 2 and 3. The WTRU may then apply a measurement configuration associated with reporting the active SCells. For example, the WTRU may be configured with one type of measurement resource (e.g., SSB measurement resource configuration), and / or the WTRU may report using a first type of report (e.g., a CSI report including information specific to L1 / L2 handover preparation) to use when the cell is configured as an SCell but is not active. In some cases, the WTRU may receive Layer 1 or Layer 2 (L1 / L2) control signaling indicating that the WTRU will perform a movement to a second cell, which is one of a plurality of movement candidate cells. The WTRU may also determine which of a plurality of measurement configurations should be activated and which of a plurality of measurement configurations should not be activated based on the fact that, upon movement to the second cell (e.g., the second cell becoming the primary cell), the second cell becomes a new serving cell for the WTRU and that the movement to the second cell causes activation of a third cell of the plurality of movement candidate cells as a secondary cell. The WTRU may determine the second measurement configuration to be activated.

[0118] The WTRU may be configured with a second type of measurement resource (e.g., a CSI-RS measurement resource configuration) and / or the WTRU may be configured to report using a second type of report (e.g., a CSI report for reporting an active SCell) when the cell is an activated SCell. Thus, the WTRU may decide to apply the first type of measurement configuration and / or the first type of report based on the SpCell / SCell combination (e.g., an SpCell / SCell combination configured by RRC and then activated / triggered using L1 / L2 signaling such as MAC CE) when an L1 / L2 handover occurs. The WTRU may subsequently decide to apply the second type of report and / or the second type of report when the SCell activation status changes (e.g., when a second MAC CE is received that changes the activation / deactivation status of the configured SCell). Alternatively or additionally, the WTRU may use any of the previously listed conditions as the first and / or second condition (e.g., "X"). The first condition may be a condition that applies when performing a handover (e.g., an L1 / L2 triggered handover) using a specific condition (e.g., an SpCell / SCell combination as pre-configured by RRC and triggered by a MAC CE), and the second condition may be any subsequent configuration change (e.g., activation / deactivation of an SCell by the MAC CE). The WTRU may perform one or more measurements associated with the second measurement configuration and send a measurement report via the second cell based on the measurements associated with the second measurement configuration.

[0119] FIG. 9 shows an example of an L1 / L2 mobility area 900. A WTRU (represented by a solid black dot in the center of the mobility area) may be surrounded by L1 / L2 mobile candidate cells. The WTRU may be configured to receive configuration information indicating multiple mobile candidate cells independently of multiple measurement configurations. That is, L1, L2, and / or Layer 3 (L3) may send information related to mobile candidate cells separately from multiple measurement configurations. "Independent" may mean separate, in different locations, on different signals, and / or on the same signal but in different locations, sub-blocks, and / or portions of the signal. Another set of cells may have active measurements determined based on active lower-layer triggered mobility (LTM) candidates. The lower layers may include the physical layer (PHY) and medium access control (MAC) layers. LTM may enable serving cell changes via L1 / L2 signaling while maintaining upper layer configurations and / or minimizing changes to lower layer configurations. This may help reduce delay, overhead, and disruption time during handover. LTM can support both intra-distributed unit (DU) movement and inter-DU movement within a central unit (CU). During LTM, the user plane may continue with the target cell without reset when possible (e.g., within the DU) to avoid data loss and additional delays in data recovery. A group of cells may have configured measurements that are currently not in use (e.g., due to the WTRU's location, movement trajectory, direction and / or speed, proximity to the cells).

[0120] 10 shows a flowchart of an example procedure 1000 performed by a WTRU for measurement configuration with L1 / L2-based mobility. At 1002, the WTRU may receive configuration information for multiple L1 / L2 mobility candidate cells. The configuration information may indicate multiple mobility candidate cells and multiple measurement configurations. In some examples, the WTRU may be configured to receive multiple measurement configurations involving association with one or more special cell (SpCell) / secondary cell (SCell) combinations.

[0121] At 1004, the WTRU may receive from the network (e.g., independently of the L1 / L2 candidate cells) one or more measurement configurations and CSI reporting configurations and associations with one or more SpCell / SCell combinations. For example, the WTRU may receive a first measurement configuration based on a first cell being a current serving cell for the WTRU. The WTRU may activate a first measurement configuration of multiple measurement configurations based on the first cell being a current serving cell for the WTRU. The WTRU may be configured to determine that a second measurement configuration is deactivated based on the first cell being a current serving cell for the WTRU. In some examples, the measurement configuration includes a channel state information (CSI) reporting configuration.

[0122] At 1006, the WTRU may receive L1 / L2 control signaling indicating a new SpCell and an activated Scell, and the WTRU may apply the associated candidate cell configuration. The Layer 1 or Layer 2 (L1 / L2) control signaling may indicate that the WTRU will perform a move to at least a second cell, where the second cell is one of a plurality of move candidate cells (e.g., as indicated by the configuration information received at 1002). In some examples, the L1 / L2 control signaling may include (e.g., may be provided via) a medium access control (MAC) control element (CE). In some examples, the L1 / L2 control signaling may indicate a new special cell (SpCell) and an activated secondary cell (Scell).

[0123] At 1008, based on the SpCell / SCell combination, the WTRU may determine one or more measurement configurations and CSI reporting configurations to be used. For example, the WTRU may be configured to determine which of the plurality of measurement configurations to activate and which of the plurality of measurement configurations to not activate based on the fact that upon movement to a second cell (e.g., the second cell becoming the primary cell), the second cell becomes a new serving cell for the WTRU and the movement to the second cell causes activation of a third cell of the plurality of movement candidate cells as a secondary cell. The WTRU may determine the second measurement configuration to be activated.

[0124] At 1010, the WTRU may activate the determined one or more measurement configurations and CSI reporting configurations and send an indication to the network. For example, the WTRU may perform one or more measurements associated with the second measurement configuration and send at least one measurement report via the second cell based on the measurements associated with the second measurement configuration.

[0125] The processes and techniques described herein may be applied to other wireless technologies and to other services.

[0126] The WTRU may refer to a physical device identity or subscription-related identity, e.g., a user identity such as MSISDN, SIP URI, etc., and the WTRU may refer to application-based identity, e.g., a username that may be used per application.

[0127] The processes described above may be implemented in a computer program, software, and / or firmware embodied in a computer-readable medium for execution by a computer and / or processor. Examples of computer-readable media include, but are not limited to, electronic signals (transmitted via wired and / or wireless connections) and / or computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random-access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media such as, but not limited to, internal hard disks and removable disks, magneto-optical media, and / or optical media such as CD-ROM disks and / or digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, and / or any host computer.

Claims

1. 1. A wireless transmit / receive unit (WTRU), comprising: a processor, the processor comprising: receiving configuration information indicating a plurality of movement candidate cells and a plurality of measurement configurations; activating a first measurement configuration of the plurality of measurement configurations based on a first cell being a current serving cell for the WTRU, wherein the processor is configured to determine that a second measurement configuration of the plurality of measurement configurations is to be deactivated based on the first cell being a current serving cell for the WTRU; receiving Layer 1 or Layer 2 (L1 / L2) control signaling indicating that the WTRU will perform a transfer to a second cell, the second cell being one of the plurality of transfer candidate cells; determining which of the plurality of measurement configurations should be activated and which of the plurality of measurement configurations should not be activated based on the fact that upon movement to the second cell, which becomes a primary cell, the second cell becomes a new serving cell for the WTRU and the movement to the second cell causes activation of a third cell of the plurality of movement candidate cells as a secondary cell, wherein the determining step is to activate the second measurement configuration; performing one or more measurements associated with the second measurement configuration; and sending a measurement report via the second cell based on the measurements associated with the second measurement configuration.

2. The WTRU of claim 1 , wherein the plurality of measurement configurations includes a channel state information (CSI) reporting configuration.

3. The WTRU of claim 1 or 2, wherein the L1 / L2 control signaling includes a Medium Access Control (MAC) Control Element (CE).

4. The WTRU of any one of claims 1 to 3, wherein the processor is further configured to receive the configuration information indicating the plurality of movement candidate cells independently of the plurality of measurement configurations.

5. The WTRU of any one of claims 1 to 4, wherein the L1 / L2 control signaling indicates a new special cell (SpCell) and an activated secondary cell (SCell).

6. The WTRU of any one of claims 1 to 5, wherein the processor is further configured to receive the plurality of measurement configurations associated with one or more special cell (SpCell) / secondary cell (SCell) combinations.

7. 7. The WTRU of claim 6, wherein, when performing the movement to the second cell, the processor is configured to determine which of the plurality of measurement configurations should be activated and which of the plurality of measurement configurations should not be activated based on the one or more SpCell / SCell combinations.

8. The WTRU of any one of claims 1 to 7, wherein the processor is configured to determine which of the plurality of measurement configurations should be activated and which of the plurality of measurement configurations should not be activated based on a combination of currently active secondary cells (SCells) among the plurality of movement candidate cells when moving to the second cell.

9. The WTRU of any preceding claim, wherein the processor is configured with one or more dependencies between a set of location-dependent settings and a set of mobility capabilities.

10. 10. The WTRU of claim 9, wherein the activation of one location-dependent setting activates one associated mobility function, and the activation of one mobility function activates one associated location-dependent setting.

11. 1. A method implemented by a wireless transmit / receive unit (WTRU), the method comprising: receiving configuration information indicating a plurality of movement candidate cells and a plurality of measurement configurations; activating a first measurement configuration of the plurality of measurement configurations based on a first cell being a current serving cell for the WTRU, wherein a second measurement configuration of the plurality of measurement configurations is determined to be deactivated based on the first cell being a current serving cell for the WTRU; receiving Layer 1 or Layer 2 (L1 / L2) control signaling indicating that the WTRU will perform a transfer to a second cell, the second cell being one of the plurality of transfer candidate cells; determining which of the plurality of measurement configurations should be activated and which of the plurality of measurement configurations should not be activated based on the fact that upon movement to the second cell, which becomes a primary cell, the second cell becomes a new serving cell for the WTRU and the movement to the second cell causes activation of a third cell of the plurality of movement candidate cells as a secondary cell, wherein it is determined that the second measurement configuration is activated; performing one or more measurements associated with the second measurement configuration; and sending a measurement report via the second cell based on the measurements associated with the second measurement configuration.

12. The method of claim 11 , wherein the plurality of measurement configurations includes a channel state information (CSI) reporting configuration.

13. 13. The method of claim 11 or 12, wherein the L1 / L2 control signaling comprises a Medium Access Control (MAC) Control Element (CE).

14. The method of any one of claims 11 to 13, further comprising receiving the configuration information indicating the plurality of movement candidate cells independently of the plurality of measurement configurations.

15. The method according to any one of claims 11 to 14, wherein the L1 / L2 control signaling indicates a new special cell (SpCell) and an activated secondary cell (SCell).

16. The method of any one of claims 11 to 15, further comprising receiving the plurality of measurement configurations with association with one or more special cell (SpCell) / secondary cell (SCell) combinations.

17. 17. The method of claim 16, further comprising: determining, upon transition to the second cell, which of the plurality of measurement configurations should be activated and which of the plurality of measurement configurations should not be activated based on the one or more SpCell / SCell combinations.

18. 18. The method according to claim 11, further comprising: determining, when performing the movement to the second cell, which of the plurality of measurement configurations should be activated and which of the plurality of measurement configurations should not be activated based on a combination of currently active secondary cells (SCells) among the plurality of movement candidate cells.

19. The method of any one of claims 11 to 18, further comprising one or more dependencies between the set of location-dependent settings and the set of mobility features.

20. 20. The method of claim 19, wherein the activation of one of the location-dependent settings activates an associated movement function, and the activation of a movement function activates an associated location-dependent setting.

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