Method for managing measurement configuration with l1 / l2-based mobility

Abstract

A wireless transmit / receive unit (WTRU) is configured with multiple condition handover and / or measurement report configurations. The WTRU activates or deactivates one or more of a plurality of configurations in accordance with various conditions such as changes in a combination of a primary cell (PCell), a currently active secondary cell (SCell) in a set of configurations of candidate L1 / L2 mobility cells, or in accordance with a specific change in a combination of currently active cells in a set of configurations of candidate L1 / L2 mobility cells. Conditional reconfiguration for updating the set of candidate L1 / L2 mobility cells may be performed. A list of mobility region indices may be included in the configuration, such as including an associated set of conditions for activating a particular region or a set of configurations to be activated when the indices are activated.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 388,111 filed on July 11, 2022, U.S. Provisional Application No. 63 / 394,888 filed on August 3, 2022, and U.S. Provisional Application No. 63 / 465,115 filed on May 9, 2023, the entire contents of which are incorporated herein by reference. Background Art

[0003] A wireless transmit / receive unit (WTRU) may be configured with multiple conditional handover (HO) and / or measurement reporting configurations. The WTRU may be set to activate or deactivate various configurations based on one or more conditions. In 3GPP Release 18, the work item (WI) on "Further NR Mobility Enhancements" includes several objectives related to this context. Summary of the invention

[0004] A wireless transmit / receive unit (WTRU) may include a processor configured to receive configuration information. For example, the configuration information may indicate multiple mobility candidate cells and multiple measurement configurations. The WTRU may activate a first measurement configuration in the multiple measurement configurations based on the first cell being a current serving cell of the WTRU. The WTRU may be configured to determine that a second measurement configuration in the multiple measurement configurations is deactivated based on the first cell being the current serving cell of the WTRU. The WTRU may receive layer 1 or layer 2 (L1 / L2) control signaling indicating that the WTRU will perform mobility to a second cell. For example, the second cell may be a mobility candidate cell among the multiple mobility candidate cells.

[0005] The WTRU may determine which of the multiple measurement configurations will be activated and which of the multiple measurement configurations will not be activated when performing mobility to the second cell based on the second cell being a new serving cell for the WTRU and the mobility to the second cell resulting in activation of a third cell in the multiple mobility candidate cells as a secondary cell. For example, the second cell may be a primary cell. In addition, the second measurement configuration may be determined to be activated. The WTRU may perform one or more measurements associated with the second measurement configuration. The WTRU may transmit a measurement report via the second cell based on the measurement associated with the second measurement configuration. The multiple measurement configurations may include a channel state information (CSI) reporting configuration.

[0006] The L1 / L2 control signaling includes a medium access control (MAC) control element (CE). The WTRU may be configured to receive the configuration information indicating the multiple mobility 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 the multiple measurement configurations and associations with one or more special cell (SpCell) / secondary cell (SCell) combinations. The WTRU may be configured to determine which of the multiple measurement configurations will be activated and which of the multiple measurement configurations will not be activated when performing mobility to the second cell based on the one or more SpCell / SCell combinations.

[0007] The WTRU may be configured to determine which of the multiple measurement configurations to activate and which of the multiple measurement configurations to not activate when performing mobility to the second cell based on a combination of currently active secondary cells (SCells) in the multiple mobility candidate cells. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0009] Figure 1B is an example of a method that can be used according to an embodiment of the present invention. Figure 1A A system diagram of an example wireless transmit / receive unit (WTRU) for use within an illustrated communication system.

[0010] Figure 1C is an example of a method that can be used according to an embodiment of the present invention. Figure 1A System diagram of an example Radio Access Network (RAN) and an example Core Network (CN) for use within the illustrated communication system.

[0011] Figure 1D is an example of a method that can be used according to an embodiment of the present invention. Figure 1A System diagram of an additional example RAN and an additional example CN for use within the illustrated communication system.

[0012] Figure 2 An example of a basic handover scenario in NR is shown.

[0013] Figure 3 An example of conditional handover configuration and execution is shown.

[0014] Figure 4 An example of L1 / L2 inter-cell mobility using carrier aggregation (CA) is shown.

[0015] Figure 5An example of L1 / L2 mobility zones is shown.

[0016] Figure 6 An example of dynamic activation of a conditional handover (CHO) configuration is shown.

[0017] Figure 7 An example of dynamic activation of a CHO configuration is shown.

[0018] Figure 8 An example of activating CHO / CPAC configuration according to the current SpCell is shown.

[0019] Fig. 9 Another example of L1 / L2 mobility zones is shown.

[0020] Fig.10 A flow chart is shown for measurement configuration using L1 / L2 based mobility DETAILED DESCRIPTION

[0021] Figure 1A 1 is a diagram illustrating an example communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content such as voice, data, video, messaging, broadcast, etc. to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content through sharing of system resources (including wireless bandwidth). For example, the communication system 100 may employ one or more channel access methods such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single carrier FDMA (SC-FDMA), zero tail unique word DFT spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, and filter bank multi-carrier (FBMC), etc.

[0022] like Figure 1AAs shown, the communication system 100 may include WTRUs 102a, 102b, 102c, 102d, RAN 104 / 113, CN 106 / 115, a public switched telephone network (PSTN) 108, the Internet 110 and other networks 112, but it should be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d (any of which may be referred to as a “station” and / or “STA”) may be configured to send 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 cellular phone, a personal digital assistant (PDA), a smart phone, 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 device, a head-mounted display (HMD), a vehicle, a drone, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in an industrial and / or automated process chain environment), a consumer electronic device, a device operating on a commercial and / or industrial wireless network, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a WTRU.

[0023] The communication 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 that is configured to interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106 / 115, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node B, an eNode B, a Home Node B, a Home eNode B, a gNB, a New Radio (NR) Node B, a site controller, an access point (AP), a wireless router, and the like. Although the base stations 114a, 114b are each depicted as a single element, it should be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0024] Base station 114a may be part of RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as base station controllers (BSC), radio network controllers (RNC), relay nodes, etc. Base station 114a and / or base station 114b may be configured to send and / or receive wireless signals on one or more carrier frequencies (which may be referred to as cells (not shown)). These frequencies may be in a licensed spectrum, an unlicensed spectrum, or a combination of a licensed spectrum and an unlicensed spectrum. A cell may provide coverage of wireless services to a specific geographic area, which may be relatively fixed or may change over time. The cell may be further divided into cell sectors. For example, the cell associated with base station 114a may be divided into three sectors. Therefore, in one embodiment, base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In an embodiment, base station 114a may employ multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to send and / or receive signals in a desired spatial direction.

[0025] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0026] More specifically, as noted above, the communication system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, and SC-FDMA, among others. For example, the base station 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may use Wideband CDMA (WCDMA) to establish the air interface 115 / 116 / 117. WCDMA may include communication protocols such as High Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High Speed ​​Uplink (UL) Packet Access (HSUPA).

[0027] 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) that may establish the air interface 116 using Long Term Evolution (LTE) and / or Advanced LTE (LTE-A) and / or Advanced LTE Pro (LTE-APro).

[0028] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR radio access, which may establish the air interface 116 using NR.

[0029] 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 together implement LTE radio access and NR radio access, for example using the dual connectivity (DC) principle. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions transmitted to / from multiple types of base stations (e.g., eNBs and gNBs).

[0030] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (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), GSM Enhanced Data Rates for Evolution (EDGE), and GSM EDGE (GERAN).

[0031] Figure 1AThe base station 114b in the 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 local areas such as commercial locations, homes, vehicles, campuses, industrial facilities, sky corridors (e.g., for use by drones), and roads. 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 IEEE802.15) to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a picocell or a femtocell. As Figure 1A As shown, base station 114b may have a direct connection to Internet 110. Therefore, base station 114b may not need to access Internet 110 via CN 106 / 115.

[0032] The RAN 104 / 113 may be in communication with the CN 106 / 115, which may be any type of network configured to provide voice, data, applications and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have different quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not described in detail in the text and video, the CN 106 / 115 may be configured to provide voice, data, applications and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have different quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Figure 1A Although not shown in the figure, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may utilize NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) that employs GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or Wi-Fi radio technology.

[0033] The CN 106 / 115 may also act 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 that provides plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and / or the Internet Protocol (IP) in the TCP / IP Internet protocol suite. The networks 112 may include wired communication networks and / or wireless communication networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 113 or a different RAT.

[0034] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication 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 via different wireless links). Figure 1A The illustrated WTRU 102c may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0035] Figure 1B is a system diagram illustrating an exemplary WTRU 102. Figure 1B As shown, 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 appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0036] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors 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) and state machine, etc. The processor 118 may perform signal decoding, 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. Although Figure 1B The processor 118 and the transceiver 120 are depicted as separate components, but it is understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0037] The send / receive element 122 may be configured to send a signal to a base station (e.g., base station 114a) or receive a signal from a base station via an air interface 116. For example, in one embodiment, the send / receive element 122 may be an antenna configured to send and / or receive an RF signal. In an embodiment, the send / receive element 122 may be a transmitter / detector configured to send and / or receive, for example, an IR, UV, or visible light signal. In another embodiment, the send / receive element 122 may be configured to send and / or receive both an RF signal and an optical signal. It should be understood that the send / receive element 122 may be configured to send and / or receive any combination of wireless signals.

[0038] Although the transmit / receive element 122 Figure 1B 102 as a single element, but 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.

[0039] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. For example, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0040] The processor 118 of the WTRU 102 may be coupled to and may receive user input data from a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from and store data in any type of suitable memory, such as a non-removable memory 130 and / or a removable memory 132. The non-removable memory 130 may include a random access memory (RAM), a 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, and a secure digital (SD) memory card, among others. In other embodiments, the processor 118 may access information from and store data in a memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0041] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel cadmium (NiCd), nickel zinc (NiZn), nickel metal hydride (NiMH), lithium ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0042] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to or in lieu of the information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by any suitable location-determination method while remaining consistent with an embodiment.

[0043] The processor 118 may also be coupled to other peripherals 138, which may include one or more software modules 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 video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, module, FM radio unit, digital music player, media player, video game player module, Internet browser, virtual reality and / or augmented reality (VR / AR) device and activity tracker, etc. Peripheral device 138 may include one or more sensors, which may be one or more of the following: gyroscope, accelerometer, Hall effect sensor, magnetometer, orientation sensor, proximity sensor, temperature sensor, time sensor; geolocation sensor; altimeter, light sensor, touch sensor, magnetometer, barometer, gesture sensor, biometric sensor and / or humidity sensor.

[0044] The WTRU 102 may include a full-duplex radio component for which transmission and reception of some or all signals (e.g., associated with specific subframes for both UL (for transmission) and downlink (for reception)) may be concurrent and / or simultaneous. The full-duplex radio component may include an interference management unit 139 for reducing and / or substantially eliminating self-interference via signal processing performed by hardware (e.g., a choke) or via a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WTRU 102 may include a half-duplex radio component for which transmission and reception of some or all signals (e.g., associated with specific subframes for both UL (for transmission) or downlink (for reception)) may be concurrent and / or simultaneous.

[0045] Figure 1C 1 is a system diagram illustrating the RAN 104 and the CN 106 in accordance with an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0046] The RAN 104 may include evolved Node-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of evolved Node-Bs while remaining consistent with an embodiment. The evolved Node-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the evolved Node-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the evolved Node-B 160a, for example, may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0047] Each of the evolved Node Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, and scheduling of users in the UL and / or DL, among other things. Figure 1C As shown, the eNode-Bs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0048] Figure 1C The illustrated CN 106 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 being part of the CN 106, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0049] The MME 162 may be connected to each of the evolved Node-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, and selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c. 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.

[0050] The SGW 164 may be connected to each of the evolved Node-Bs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring the user plane during an inter-evolved Node-B handover, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, and managing and storing the context of the WTRUs 102a, 102b, 102c.

[0051] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0052] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may be in communication with, an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired networks and / or wireless networks owned and / or operated by other service providers.

[0053] Although the WTRU Figures 1A to 1D Although described as a wireless terminal, it is contemplated that in certain representative embodiments such a terminal may (eg, temporarily or permanently) employ a wired communications interface with a communications network.

[0054] In a representative embodiment, other networks 112 may be WLANs. A WLAN in an infrastructure basic service set (BSS) mode may have an access point (AP) for a BSS and one or more stations (STAs) associated with the AP. The AP may have access or an interface to a distribution system (DS) or another type of wired / wireless network that carries traffic to and / or carries traffic away from the BSS. Traffic originating from outside the BSS and going to the STA may be reached by the AP and may be delivered to the STA. Traffic originating from the STA and going to a target outside the BSS may be transmitted to the AP to be delivered to the corresponding target. Traffic between STAs within the BSS may be transmitted by the AP, for example, where the source STA may transmit traffic to the AP, and the AP may deliver traffic to the destination STA. Traffic between STAs within the BSS may be considered and / or referred to as point-to-point traffic. Point-to-point traffic may be transmitted between the source and destination STAs (e.g., directly between them) using a direct link setup (DLS). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z tunnel DLS (TDLS). A WLAN using an independent BSS (IBSS) mode may not have an AP, and STAs (eg, all STAs) within or using the IBSS may communicate directly with each other. The IBSS communication mode may sometimes be referred to herein as an "ad hoc" communication mode.

[0055] When using the 802.11ac infrastructure operating mode or a similar operating mode, the AP may send 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 dynamically set via signaling. The primary channel may be an operating channel of the BSS and may be used by the STA to establish a connection with the AP. In certain representative embodiments, carrier sense multiple access / collision avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. For CSMA / CA, a STA (e.g., each STA) (including the AP) may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0056] High throughput (HT) STAs may communicate using a 40 MHz wide channel (eg, via a combination of a primary 20 MHz channel and adjacent or non-adjacent 20 MHz channels) to form a 40 MHz wide channel.

[0057] Very high throughput (VHT) STA can support 20MHz, 40MHz, 80MHz and / or 160MHz wide channels. 40MHz channels and / or 80MHz channels can be formed by combining continuous 20MHz channels. 160MHz channels can be formed by combining 8 continuous 20MHz channels, or by combining two non-continuous 80MHz channels (this can be called 80+80 configuration). For 80+80 configuration, after channel coding, the data can pass through a segment parser that can divide the data into two streams. Each stream can be processed by inverse fast Fourier transform (IFFT) and time domain processing separately. These streams can be mapped to two 80MHz channels, and the data can be sent by the transmitter STA. At the receiver of the receiver STA, the above-mentioned operation for the 80+80 configuration can be reversed, and the combined data can be transmitted to the medium access control (MAC).

[0058] 802.11af and 802.11ah support operating modes below 1GHz. Channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah relative to those used in 802.11n and 802.11ac. 802.11af supports 5MHz, 10MHz, and 20MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1MHz, 2MHz, 4MHz, 8MHz, and 16MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support instrument type control / machine type communications, such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities, including support for (e.g., only support for) certain bandwidths and / or limited bandwidths. MTC devices may include batteries with battery life above a threshold (e.g., to maintain very long battery life).

[0059] WLAN systems that can support multiple channels and channel bandwidths (such as 802.11n, 802.11ac, 802.11af, and 802.11ah) include channels that can be designated as primary channels. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA (which supports the minimum bandwidth operating mode) from all STAs operating in the BSS. In the example of 802.11ah, for STAs (e.g., MTC-type devices) that support (e.g., only support) a 1MHz mode, the primary channel may be 1MHz wide, even if the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or network allocation vector (NAV) settings may depend on the state of the primary channel. If the primary channel is busy, for example, because a STA (supporting only a 1MHz operating mode) is sending to the AP, the entire available band may be considered busy even if most of the band remains idle and may be available.

[0060] In the United States, the available frequency band for 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 the country code.

[0061] Figure 1D 1 is a system diagram showing the RAN 113 and the CN 115 in accordance with an embodiment. As noted above, the RAN 113 may employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0062] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, the gNBs 180a, 180b may utilize beamforming to send signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a may, for example, use multiple antennas to send wireless signals to and / or receive wireless signals from the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation (CA) technology. For example, gNB 180a may transmit multiple component carriers to 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, gNBs 180a, 180b, 180c may implement coordinated multi-point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0063] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with parameter sets that may be scalable. For example, 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., containing varying numbers of OFDM symbols and / or varying absolute time lengths over time).

[0064] 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 while also not accessing other RANs (e.g., such as the eNodeBs 160a, 160b, 160c). In a standalone configuration, the WTRUs 102a, 102b, 102c may use 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 an unlicensed band. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate / connect with the gNBs 180a, 180b, 180c while also communicating / connecting with another RAN, such as the eNode-Bs 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement dual connectivity (DC) principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the evolved Node-Bs 160a, 160b, 160c may act as mobility anchors for the WTRUs 102a, 102b, 102c and the gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0065] Each of the gNBs 180a, 180b, 180c may be associated with a specific cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in UL and / or DL, support of network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards a user plane function (UPF) 184a, 184b, routing of control plane information towards an access and mobility management function (AMF) 182a, 182b, etc. Figure 1D As shown, gNBs 180a, 180b, and 180c may communicate with each other via an Xn interface.

[0066] Figure 1DThe CN 115 shown in FIG. 1 may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one session management function (SMF) 183a, 183b, and possible data networks (DNs) 185a, 185b. Although each of the aforementioned elements is depicted as part of the CN 115, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0067] 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 act as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRU 102a, 102b, 102c, supporting network slicing (e.g., handling different protocol data unit (PDU) sessions with different requirements), selecting a specific SMF 183a, 183b, management of registration areas, termination of NAS signaling and mobility management, etc. The AMF 182a, 182b may use network slicing to customize CN support for the WTRU 102a, 102b, 102c based on the type of services utilized by the WTRU 102a, 102b, 102c. For example, different network slices may be established for different use cases, such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced mobile broadband (eMBB) access, and / or 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-APro, or non-3GPP access technologies, such as Wi-Fi.

[0068] The SMF 183a, 183b may be connected to the AMF 182a, 182b in the CN 115 via the N11 interface. The SMF 183a, 183b may also be connected to the UPF 184a, 184b in the CN 115 via the N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure traffic routing through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions such as managing and allocating WTRU IP addresses, managing PDU sessions, controlling policy enforcement and QoS, and providing downlink data notifications. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0069] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via the N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, and providing mobility anchoring, etc.

[0070] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include or may communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired networks 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 via the UPF 184a, 184b via an N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0071] Given that Figures 1A to 1D as well as Figures 1A to 1D Corresponding to the description of the present invention, one or more or all of the functions described herein with reference to one or more of the following items may be performed by one or more simulation devices (not shown): WTRU102a to 102d, base station 114a to 114b, evolved Node B 160a to 160c, MME 162, SGW 164, PGW 166, gNB180a to 180c, AMF 182a to 182ab, UPF 184a to 184b, SMF 183a to 183b, DN 185a to 185b and / or any other device described herein. The simulation device may be one or more devices configured to mimic one or more or all of the functions described herein. For example, the simulation device can be used to test other devices and / or simulate network and / or WTRU functions.

[0072] The simulation device may be designed to implement one or more tests of other devices in a laboratory environment and / or in an operator network environment. For example, one or more simulation devices may perform one or more functions or all functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network in order to test other devices within the communication network. One or more simulation devices may perform one or more functions or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The simulation device may be directly coupled to another device for testing purposes and / or may use over-the-air wireless communications to perform testing.

[0073] One or more simulation devices can perform one or more (including all) functions without being implemented / deployed as part of a wired and / or wireless communication network. For example, the simulation device can be used in a test scenario in a test laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network to implement testing of one or more components. One or more simulation devices can be test equipment. Direct RF coupling and / or wireless communication via RF circuitry (e.g., which can include one or more antennas) can be used by the simulation device to send and / or receive data.

[0074] Figure 2 A handover scenario, for example in New Radio (NR), is depicted. In initial handover preparation, the WTRU (e.g., within the cell coverage of the source gNB) may receive information about roaming, access restrictions and / or other mobility control information from the AMF, for example, at connection establishment and / or at last timing advance (TA) update. The mobility control information may be provided by the (AMF) to the WTRU, the source gNB and / or the target gNB. The source gNB may configure the 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 measurement results.

[0075] 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 for preparing the handover on the target side. The information may include at least one or more of the following: target cell ID, KgNB, C-RNTI (radio link identifier) ​​of the WTRU in the source gNB, 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 rules applied to the WTRU, SIB1 from the source gNB, WTRU capabilities and PDU session related information for different RATs, or may also include measurement information reported by the WTRU including beam related information (if available).

[0076] Admission control may be performed by the target gNB. If the WTRU is admitted, the target gNB may utilize L1 / L2 to prepare for the handover and send a Handover Request Acknowledgement (HANDOVERREQUEST ACKNOWLEDGE) to the source gNB, which may include a transparent container to be transmitted as an RRC message to the WTRU to perform the handover. Once the HANDOVERREQUESTACKNOWLEDGE is delivered, the handover execution may begin so that the WTRU may detach from the old cell and synchronize to the new cell.

[0077] The source gNB may trigger the WTRU handover by transmitting an RRCReconfiguration message to the WTRU containing information for accessing the target cell, such as the target cell ID, the new C-RNTI, and / or the 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 WTRU-specific CSI reference signal (RS) configurations, common RACH resources, and system information of the target cell. In one application, buffered data and new data may be delivered from the UPF.

[0078] As the detach begins, the source gNB may transmit an Early Transfer State Transfer Data and SN Status Transfer (SNSTATUS TRANSFER) message to the target gNB to convey the uplink PDCP SN receiver state and downlink PDCP SN transmitter state for DRBs to which PDCP state preservation (e.g., for Radio Link Control (RLC) AM) is applied. 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 may complete the RRC handover procedure by transmitting an RRCReconfigurationComplete message to the target gNB.

[0079] In the handover completion portion of the scenario, a HO success signal may be transmitted from the target gNB to the source gNB. The source gNB may provide an SN state transfer to the target gNB. The target gNB may transmit 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 transmit one or more "end marker" packets to the source gNB on the old path for each PDU session / tunnel 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 REQUESTACKNOWLEDGE message. Upon receiving the PATH SWITCH REQUEST ACKNOWLEDGE message from the AMF, the target gNB may transmit a WTRUCONTEXT RELEASE to notify the source gNB of the handover success. The source gNB may then release the radio and C-plane related resources associated with the WTRU context. Any ongoing data forwarding may continue.

[0080] NR Release 16 introduces the concepts of Conditional Handover (CHO) and Conditional Primary and Secondary Serving Cell (PSCell) Addition / Change (Continuous Packet Addition (CPA) / Continuous Packet Change (CPC) or collectively referred to as CPAC), which has the potential to reduce the likelihood of Radio Link Failure (RLF) and Handover Failure (HOF).

[0081] Traditional LTE / NR handovers may typically be triggered by measurement reports, and there is nothing that prevents the network from transmitting a HO command to the WTRU even if no measurement report is received. For example, the WTRU may be configured with an A3 event (neighbor's offset becomes better than SpCell), which triggers the transmission of a measurement report when the radio signal level / quality (reference signal received power (RSRP), reference signal received quality (RSRQ), etc.) of the neighboring cell becomes better than the primary serving cell (PCell) or, in the case of DC, also better than the PSCell. The A3 event may be triggered when the neighboring cell becomes better than the special cell (SpCell) by an offset. The special cell may be the primary serving cell of a master cell group (MCG) or a secondary cell group (SCG). The offset may be positive or negative. The A3 event may typically be used for intra-frequency or inter-frequency handover processes. When the A2 event is triggered, the WTRU may be configured with measurement gaps for measuring inter-frequency objects and A3 events for inter-frequency handovers. The A3 event may provide a handover trigger mechanism based on relative measurement results. For example, the handover trigger mechanism may be configured to be triggered when the RSRP of the neighboring cell is stronger than the RSRP of the special cell.

[0082] The WTRU may monitor the serving cell and neighboring cells and may transmit measurement reports when conditions are met. When the network receives such reports, the network (current serving node / cell) may prepare a HO command. The HO command may be an RRC reconfiguration message with ReconfigurationWithSync, which is transmitted to the WTRU and the WTRU may execute the RRC reconfiguration message, resulting in the WTRU connecting to the target cell.

[0083] In some examples, multiple handover targets are prepared. In addition, the WTRU may not perform CHO immediately. The WTRU may be configured with trigger conditions (such as a set of radio conditions), and if the trigger conditions are met, the WTRU may perform a handover towards one of the targets.

[0084] The CHO command may be transmitted from the network when the radio conditions towards the current serving cell are still good, thereby reducing the risk of failure to transmit measurement reports (e.g., if the link quality to the current serving cell drops below an acceptable level when the measurement report is triggered in a normal handover) and failure to receive a handover command (e.g., if the link quality to the current serving cell drops below an acceptable level after the WTRU has transmitted a measurement report but before it receives a HO command), etc. The WTRU may transmit a CHO command when the radio conditions towards the current serving cell start to get worse (e.g., deteriorate).

[0085] Figure 3Conditional handover configuration and execution are shown. At 302, the source node may transmit a CHO request 302 to the potential target node. At 304, the potential target node may transmit a CHO request ACK including an RRCReconfiguration to the source node. At 306, the WTRU may implement the CHO configuration. The source node may transmit an RRCReconfiguration to the WTRU, which is received by the WTRU. The triggering conditions for CHO may be based on the radio quality of the serving cell and the neighboring cells, such as the conditions used to trigger measurement reports in traditional LTE / NR. In addition, the WTRU may be configured with a CHO having A1 (e.g., serving cell becomes better than a threshold), A2 (e.g., serving cell becomes worse than a threshold), A3 (e.g., neighbor's offset becomes better than SpCell), A4 (e.g., neighbor becomes better than a threshold), A5 (e.g., SpCell becomes worse than threshold 1 and neighbor becomes better than threshold 2), A6 (e.g., neighbor's offset becomes better than SCell), 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) trigger conditions and associated HO commands. 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 a measurement gap and an A5 event for inter-frequency handover. The A5 event may provide a handover trigger 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 it is necessary to change to another cell that may not meet the criteria for an A3 event handover. At 308, the WTRU may monitor the CHO conditions for the current cell, the serving cell, and / or the target cell candidates. At 310, when the A3 triggering condition is met, the WTRU may execute the associated HO command and switch its connection towards the target cell instead of transmitting a measurement report. At 312, the WTRU may transmit a CHO confirmation to the target node. And at 314, a path switch may be performed by the target node and a WTRU context release may be performed by the source node (see, e.g. Figure 2 10 to 12).

[0086] CHO may help prevent unnecessary reestablishment 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 for any of these targets are met. Conventional operation may result in an RRC reestablishment procedure that may also cause a significant interruption time to the WTRU's bearers. However, in the case of CHO, if the WTRU eventually enters a cell associated with its CHO (e.g., for which a target cell may have been prepared) after detecting an RLF, the WTRU may directly execute the HO command associated with that target cell instead of continuing with the full reestablishment procedure.

[0087] CPC and CPA may be extensions of CHO in DC scenarios.In an embodiment, the WTRU may be configured with trigger conditions for PSCell change or addition, and when the trigger conditions are met, the WTRU may execute the associated PSCell change or PSCell add command.

[0088] In NR Release 17, inter-cell L1 / L2 mobility can manage beams in CA situations without supporting cell changes / additions. In Release 18, one of the envisioned objectives is to specify mechanisms and procedures for L1 / L2-based inter-cell mobility to reduce mobility delays. In an implementation scheme, mechanisms and procedures for L1 / L2-based inter-cell mobility to reduce mobility delays may be specified. Configuration and maintenance for multiple candidate cells may be specified to allow rapid application of configurations for candidate cells [RAN2, RAN3]. A dynamic switching mechanism in 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. SpCell may refer to the PCell of an MSG and / or the PSCell of a secondary cell group (SCG), depending on whether the MAC entity is associated with a primary cell group (MCG) or an SCG. The WTRU may be configured to receive multiple measurement configurations and associations with one or more special cell (SpCell) / secondary cell (SCell) combinations. L1 enhancements may be provided for inter-cell beam management, including L1 measurements and reporting and beam indication [RAN1, RAN2]. RAN2 early involvement may be exploited, including further elaboration of the possibility of interaction with dynamic switching. Timing advance management [RAN1, RAN2] and CU-DU interface signaling may also be provided to support L1 / L2 mobility (if required, [RAN3]). FR2 specific enhancements may not be excluded. In addition, the L1 / L2 based inter-cell mobility procedures are applicable to various scenarios, such as standalone deployments where the serving cell is changed within a configured grant or cell group (CG), CA and NR-DC cases, intra-DU cases and intra-CU inter-DU cases (applicable to standalone deployments and CA when no new RAN interface is expected), intra-frequency, inter-frequency, FR1, FR2, source cell and target cell synchronous or asynchronous, and excluding inter-CU cases.

[0089] L1 / L2-based mobility initially started in NR Release 17, and inter-cell beam management in Release 17 addresses both intra-DU scenarios and intra-frequency scenarios. In this case, the serving cell remains unchanged (e.g., it is not possible to change the serving cell using L1 / L2-based mobility). In FR2 deployments, CA is typically used to take advantage of the available bandwidth, for example, to aggregate multiple CCs in one band. These CCs are typically transmitted with the same analog beam pair (gNB beam and WTRU beam). The WTRU may be configured with TCI states (which may have a considerable number, e.g., 64) for receiving 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 in order to set its beam. For 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)") may activate the TCI state for Coreset / PDCCH. Receipt of PDCCH from non-serving cells may be supported by a MAC CE indicating the TCI state associated with the non-serving PCI. MAC signaling ("TCI state activation / deactivation for WTRU-specific PDSCH") may activate a subset of (up to) 8 TCI states for PDSCH reception. Downlink control information (DCI) may indicate a specific TCI state among the 8 TCI states. Release 17 also supports "unified TCI states" with a different update mechanism (DCI-based) but without multiple transmit / receive points (TRPs). Release 18 may support unified TCI states with multiple TRPs.

[0090] For conventional Level 3 (L3), handover may be conditional on the WTRU first transmitting measurement reports using RRC signaling. In response, the network may provide additional measurement configurations and potentially CHO configurations. With CHO, the network provides the configuration for the target cell after the WTRU reports using RRC signaling that the cell meets the configured radio quality criteria. For conditional handover, in order to reduce the handover failure rate due to delays in transmitting measurement reports and then receiving RRC reconfiguration, the network may provide the target cell configuration in advance as well as the measurement criteria that determine when the WTRU can trigger the CHO configuration. These L3 methods may result in a certain amount of delay due to the transmission of measurement reports and the reception of the target configuration, especially in the case of conventional (non-conditional) handovers.

[0091] In an embodiment, L1 / L2 inter-cell mobility may be used to improve handover latency. In addition, L1 / L2-based inter-cell mobility may allow for rapid application of configurations for candidate cells, including dynamic switching between SCells and switching of PCells (e.g., switching roles between SCells and PCells), without performing RRC signaling. The inter-CU case is not included in Release 18 as this involves relocation of the PDCP anchor and has been excluded from the WI. An RRC-based approach may be desirable, such as to support inter-CU handovers. One of the purposes of L1 / L2 should also allow CA operations to be enabled immediately upon a serving cell change.

[0092] Figure 4 An example of L1 / L2 inter-cell mobility operation using carrier aggregation (CA) is shown, whereby a candidate cell group is configured by RRC and dynamic switching of PCell and SCell can be achieved using L1 / L2 signaling. The WTRU may be configured with cell 1 to cell 4 as candidate cells and activate PCell 1 and SCell 2 via RRC. 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). CHO for Pcell switching (intra-CU or inter-CU) may occur, and the "set" of L1 / L2 candidates 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 of the WTRU. The WTRU may also determine that a second measurement configuration of the multiple measurement configurations is deactivated based on the first cell being the current serving cell of the WTRU.

[0093] As the WTRU performs mobility from left to right, the WTRU may switch (e.g., dynamically switch) between cell 2 and cell 3. The higher frequency and higher bandwidth of cell 3 and cell 4 may be factors (or conditions) in determining switching to a target cell. The WTRU may receive layer 1 or layer 2 (L1 / L2) control signaling indicating that the WTRU will perform mobility to a second cell, which is one of the multiple mobility candidate cells. As the WTRU continues to perform mobility 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. The WTRU may determine which of the multiple measurement configurations will be activated and which of the multiple measurement configurations will not be activated when performing mobility to the second cell (e.g., the second cell is a primary cell) based on the second cell being a new serving cell for the WTRU and the mobility to the second cell resulting in activation of a third cell in the multiple mobility candidate cells as a secondary cell. The second measurement configuration may also be determined to be activated. The WTRU may be configured to determine which of the multiple measurement configurations will be activated and which of the multiple measurement configurations will not be activated when performing mobility to the second cell (e.g., PCell 1 to PCell 2) based on the one or more SpCell / SCell combinations. The WTRU may also be configured to determine which of the multiple measurement configurations will be activated and which of the multiple measurement configurations will not be activated when performing mobility to the second cell based on a combination of currently active secondary cells (SCells) in the multiple mobility candidate cells.

[0094] As discussed herein, Release 18 does not introduce support for inter-CU handover using L1 / L2 signaling. Therefore, regular or conditional handover may be employed to at least cover this case. Regular or conditional handover may be employed to support any mobility from any specific L1 / L2 mobility area to another mobility area.

[0095] Figure 5 An example of an L1 / L2 mobility area 500 is shown. L1 / L2 inter-cell mobility may be deployed in certain areas. The network may define an area with a set of multiple candidate L1 / L2 mobility cells. In addition, the network may divide the deployment of the network into multiple L1 / L2 mobility areas for other reasons (such as cell planning) or due to restrictions on the maximum number of cell configurations that can be stored in the WTRU at the same time. The network may define a contiguous area with multiple cells (e.g., cells that are not candidate L1 / L2 mobility cells).

[0096] Since L1 / L2 inter-cell mobility may be intended to cover a much larger geographic area than conventional handover without any RRC reconfiguration signaling (e.g., a WTRU may move between more than one PCell without RRC reconfiguration), this may have a knock-on effect in terms of the amount of RRC configuration used to enable the WTRU to move around the L1 / L2 mobility area in order to support mobility outside the area. With conventional L3 mobility, the network may typically provide measurement configurations and conditional handover configurations based on the PCell currently serving the WTRU and potential target cells that are neighbors of the serving PCell. If a PCell change occurs due to a handover or conditional handover, the measurement configuration may be updated through RRC signaling and potentially a new CHO configuration may be provided.

[0097] If L1 / L2 signaling can be used to dynamically switch serving cells, but RRC signaling is still used to update measurement configuration and conditional handover configuration, this may limit the effectiveness of the dynamic switching mechanism because the delay in performing the RRC signaling may be significant.

[0098] In an embodiment, it may be possible to pre-configure many measurement configurations and conditional handover configurations so that the WTRU can be equipped to perform measurements and handover to a cell outside of the configured L1 / L2 mobility area; for example, for the case where the WTRU moves into the coverage of another CU. However, there may be a limit to the number of CHO configurations and measurement objects that can be configured simultaneously in the WTRU. This may be partly due to limiting the complexity of the WTRU (in terms of the number of parallel measurements and evaluation conditions), but may also be designed to limit the amount of resources that the network reserves for any given WTRU - in the case of conditional handover, the network may reserve resources on the target cell in the expectation that the WTRU meets the conditions and performs a CHO. If the network expects to configure many CHOs, this also means that the number of resources that may have to be reserved in the network (in potential target cells) may become unacceptably large.

[0099] In Release 18, enhancements to the CPAC targeted in the WI identified above are envisioned. Mechanisms and procedures for NR-DC are specified, where cell groups (SCG as an example) are selectively activated via L3 enhancements. Furthermore, it is envisioned to allow subsequent cell group changes after changing CG without reconfiguration and re-initiating CPC / CPA (RAN2, RAN3, RAN4). Possibly, a coordinated RRC modeling approach may be considered to minimize the workload in RAN2.

[0100] The intent of Release 18 WI purpose seems to be to allow CPC / CPA configuration to be active after CPC / CPA has been triggered. Currently, when reconfiguration is triggered, the WTRU may release any currently configured CPA / CPC configuration and the network may establish a new CPA / CPC configuration. The same may be the case for CHO. Release 18 means that CPA / CPC is resolved but CHO / MGC is not. However, it is envisaged that similar issues may exist for CHO.

[0101] The WTRU may be configured with a set of multiple candidate target cells, which may be selected using Figure 4 The WTRU may be dynamically activated using the L1 and / or L2 signaling shown. Configurations within the possibility set (e.g., an active PCell or a PCell / SCell combination) may be associated with one or more measurement reporting configurations for traditional measurement reporting or for CHO. Some of these measurement / CHO configurations may be stored but not active until L1 / L2 signaling can be used to dynamically activate the associated cell configuration. Similarly, in the case of CHO, the network may not need to reserve resources on the target cell until the network activates a particular cell combination (or combination of other parameters). This allows the WTRU to store measurement and CHO configurations that it will use across an entire area of ​​potential L1 / L2 mobility cells, and activate those configurations when it is in the appropriate area.

[0102] As generally discussed herein, unless otherwise specified, "measurement" refers to a measurement object and an associated reporting configuration as in a legacy NR (e.g., when a reporting condition is met, a measurement report may be transmitted). Additionally, unless otherwise specified, a "CHO ​​configuration" generally refers to a measurement object and an associated reporting configuration for CHO (e.g., when a reporting condition is met, an associated CHO may be performed). However, certain measurement objects may be associated with multiple reporting configurations (whether for legacy measurement report triggering or for CHO).

[0103] Figure 6 An example of dynamic activation of a conditional handover (CHO) configuration 600 is shown. Figure 6In the example of L1 / L2 of the WTRU, signaling for Scell ​​activation / deactivation (intra-CU), CHO for Pcell switching (e.g., intra-CU or inter-CU), and updating the "set" of L1 / L2 candidates may be performed. In this example, the network may provide four cell configurations. In this example, a set of candidate L1 / L2 mobility cells (e.g., cell 1 to cell 4) may be configured through RRC signaling. For example, the WTRU may receive four cell configurations indicating cell 1 to cell 4 as multiple mobility candidate cells and multiple measurement configurations. The WTRU may receive multiple measurement configurations (e.g., for cell 1 to cell 4) via RRC signaling. The WTRU may activate a first measurement configuration of multiple measurement configurations based on the first cell (e.g., cell 1) being the current serving cell of the WTRU (e.g., cell 1 is activated as PCell and cell 2 is activated as SCell). In some cases, a "serving cell" may refer to a primary cell, and a "serving cell" may refer to a primary cell and a secondary cell. In some cases, a "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 including a primary cell and all secondary cells. In some cases, a "primary serving cell" may include a primary cell, and a "secondary serving cell" may include a secondary cell. Figure 6 In the example, the WTRU is using cell 1 as the current serving cell.

[0104] The WTRU may be configured to determine that the second measurement configuration in the multiple measurement configurations is deactivated based on the first cell being the current serving cell of the WTRU. For example, cell 6 may be deactivated based on cell 1 being the current serving cell. The deactivation of cell 6 may occur for many reasons. For example, the distance between cell 1 and cell 6 may be too large for activating cell 1 and cell 6 at the same time. That is, cell 1 as a PCell and cell 6 as a SCell may not be so efficient because cell 6 may not be able to act 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 frequency or a secondary frequency, which may be configured once an RRC connection is established, and which may be used to provide additional radio resources to the WTRU. It may be difficult to provide additional radio resources to a WTRU that is too far from a cell.

[0105] exist Figure 6In the present invention, L1 (e.g., DCI activates unified TCI state) or L2 (e.g., MACCE) signaling may be used to dynamically switch the roles of the four pre-configured cells. The WTRU may receive layer 1 or layer 2 (L1 / L2) control signaling indicating that the WTRU will perform mobility to a second cell, which is one of the multiple mobility candidate cells. For example, "cell" may refer to a PCell, an SCell, a mobility 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. The WTRU performing mobility may include the WTRU moving in a certain direction. The WTRU performing mobility may include predictions, estimates, measurements, and / or calculations regarding speed, direction, acceleration, and / or one or more locations related to 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 within a given amount of time, and activate required measurement configurations and deactivate unneeded measurement configurations. The location of the WTRU within the cell (e.g., the area of ​​the cell where the WTRU is located) may also be used to determine which measurement configurations are activated and deactivated. Figure 6 In the example, when the WTRU is located at the leftmost side of cell 1, the measurement configuration associated with cell 4 may be deactivated because cell 4 is towards the rightmost side of cell 1. When the WTRU is in the middle of cell 1, the measurement configuration associated with cell 3 may be activated because cell 3 is located just above (e.g., close to) the center of cell 1.

[0106] The WTRU may determine which measurement configurations of the plurality of measurement configurations to activate and which measurement configurations of the plurality of measurement configurations to not activate when performing mobility to the second cell based on the second cell being a new serving cell for the WTRU and the mobility to the second cell resulting in activation of a third cell of the plurality of mobility candidate cells as a secondary cell, the second cell being a primary cell, wherein the second measurement configuration is determined to be activated. Figure 6 In the example, the WTRU performs mobility from PCell 1 to PCell 2, which results in activating cell 4 as a secondary cell (SCell4), where the secondary cell was previously cell 2). Radio resource control (RRC) may be the highest layer in the control plane of the access stratum (AS). The RRC may transfer messages of the non-access stratum (NAS) located above the RRC layer. In addition, in an embodiment, the network may provide one or more (2 in this example) conditional handover configurations regarding the target cell. The WTRU may be configured to determine which of the multiple measurement configurations will be activated and which of the multiple measurement configurations will not be activated when performing mobility to the second cell based on a combination of currently active secondary cells (SCells) in the multiple mobility candidate cells.

[0107] As of Release 17 of the 3GPP standard, when multiple conditional handover configurations are provided, the WTRU stores these conditional handover configurations and evaluates the triggering conditions in parallel. Using the proposed method, these CHO configurations may not become active immediately upon configuration (e.g., a flag included in the measurement / CHO configuration that can store the relevant configuration) and may be activated in one or more ways (such as using explicit L1 / L2 signaling indicating activation of the CHO or measurement configuration). Additional activation examples may include when a cell becomes a PCell, when a SCell (e.g., or a set of SCells) is activated, when a SCell (e.g., or a set of SCells) is deactivated, when a PCell / SCell combination becomes active or is deactivated, and at certain changes in the combination (e.g., a change of Pcell1->PCell 2 activates the configuration, but a change of PCell 3->PCell 2 may not activate the configuration).

[0108] In an embodiment, 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.

[0109] For example, an implementation scheme may be used in the context of an L3 handover. In an implementation scheme, a CHO or CPAC configuration may be provided, but will not be activated until a SpCell and / or one or more Scells become active, regardless of whether L1 / L2 triggered mobility is used. In an implementation scheme, the WTRU may perform a CPC-based configuration on the active configuration of the current serving cell. In an implementation scheme, the WTRU may activate and begin evaluating a stored CPC configuration, which is associated with a new serving cell, for example. In an implementation scheme, the processes associated with cell changes activated or triggered using explicit L1 / L2 commands may also be applicable to cell changes using L3 RRC reconfiguration or CHO, CPC, or CPA. In some cases, the WTRU may determine that a second measurement configuration among the multiple measurement configurations is deactivated based on the first cell being the current serving cell of the WTRU.

[0110] The CHO configuration 1 may be provided with a target cell 5 and a measurement event for triggering CHO, such as CondEvent A3 (e.g., the offset of the neighbor becomes better than SpCell) or CondEvent A5 (e.g., SpCell becomes worse than Threshold 1 and the neighbor becomes better than Threshold 2). The network may not know in which direction the WTRU will move, so the network may establish targets in more directions around the WTRU (e.g., left, right, front, back, up, down). For this reason, although the WTRU may eventually move to Figure 6, but cell 5 (located on the upper left) is still the target cell. The WTRU may be configured to activate CHO configuration 1 based on cell 1 being the PCell. As the WTRU performs mobility from left to right, the WTRU may switch (e.g., dynamically switch) the Scells between cell 2 and cell 3. As the WTRU continues to move to the right, the WTRU may switch (e.g., dynamically switch) the PCell from cell 1 to cell 2 and switch (e.g., dynamically switch) the SCell from cell 2 to cell 4.

[0111] The WTRU may perform one or more measurements associated with the second measurement configuration. Figure 6 In the example, similar to CHO configuration 1, a target cell 6 and a measurement event for triggering CHO may be provided to CHO configuration 2. CHO configuration 2 may also be activated based on cell 2 being a PCell (e.g., or alternatively, a combination of PCell 1 and SCell 4 activates CHO configuration 2). The WTRU may evaluate CHO based on an associated combination of active cells, rather than evaluating all configured CHOs in parallel. This may reduce processing overhead in the WTRU, so that relevant measurements and evaluations may be performed based on the WTRU 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 may reserve resources based on the activated CHO configuration, for example, because the network may control the combination of active cells used by the WTRU (e.g., using L1 / L2 signaling), the network also controls the content of the target CHO cell and the currently active CHO configuration in the WTRU. The same or similar methods may also be used to control measurement objects and measurement reports for conventional handover. The WTRU may transmit a measurement report via a second cell based on the measurement associated with the second measurement configuration. For example, as an alternative or in addition to one or more CHO configurations, one or more measurement objects may be configured for measurement reporting and associated with one or more L1 / L2 controlled cell combinations. Additionally, carriers and / or cells (e.g., neighboring carriers and cells) currently measured by the WTRU may be associated with L1 / L2 controlled cell combinations.

[0112] The activation measurement configuration and / or conditional reconfiguration may be based on any "condition" that indicates that 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. These conditions may include which PCells and / or SCells are activated, and may include situations where there may be no active SCells and / or SCells may be deactivated for power saving reasons.

[0113] In each instance of "X" and "Y" having at least one "mobility area index", a "mobility area index" may be introduced and configured. In an embodiment, "X" may include anything that may be activated / deactivated based on the location of the WTRU, such as: TCI state, non-serving PCI (e.g., within "NumberOfAdditionalPCI"), PCell / SCell combination, active bandwidth part (BWP), SCell activation state, satisfaction of measurement event trigger conditions, DL synchronization trigger for candidate cells, RA of PDCCH command towards candidate cells, and / or enabling of radio link monitoring (RLM) or beam failure detection (BFD) for the target cell. In some examples, if the TCI state associated with a non-serving PCI is activated, the PCI may be activated.

[0114] "Y" may include anything that supports measurement / mobility, such as a configured measurement configuration, a configured conditional reconfiguration, and / or a channel state information (CSI) reporting configuration, a BFR configuration, and / or a neighbor carrier / cell list. The configured measurement configuration may include an L3 measurement object, an L1 or L3 measurement event, a CSI measurement configuration, and / or an L1 or L3 measurement RS configuration (e.g., an SSB or CSI-RS resource for the current or neighbor cell). The configured measurement configuration may include a PCI or logical ID, an SMTC location, a frequency location, and / or an SCS.

[0115] Based on the above, it is contemplated that examples of possible behaviors may include, for example, that if "X" is activated, then 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", then Y may be deactivated. In some examples, explicit activation / deactivation or switching of the "mobility area index" may occur, which may activate / deactivate the corresponding X and / or Y.

[0116] An example of a "mobility area index" may be one or more indices or identifiers that associate "X" (e.g., anything that can be activated / deactivated based on the location of the WTRU) with "Y" (e.g., anything that supports measurement / mobility). For example, the WTRU may be configured with one or more measurement configurations, each with an index. Additionally, the WTRU may 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 that are enabled when the one or more conditions are met. Each of the configured conditions may be associated with the same or a different subset of the measurement configurations. In this way, it may not be necessary to repeat the measurement configuration for every possible SpCell / SCell combination, but each of the combinations to which the measurement configuration applies (e.g., a SpCell / Scell ​​combination configured as an L1 / L2 mobility candidate configuration) 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 configuration). Additionally, this also allows configuring (eg, by RRC) more measurements than would be applicable to any given SpCell / SCell combination (eg, activated or triggered by a MAC CE).

[0117] Figure 7An example of dynamic activation of a CHO configuration 700 is shown. In this example, a first set of L1 / L2 mobility candidate cells consists of cell 1, cell 2, cell 3, cell 4, and a second set of L1 / L2 mobility candidate cells consists of cell 5, cell 6, cell 7, cell 8. At 704, one or more CHO configurations may be configured, but for the purpose of this illustration, one configuration is shown. The CHO configuration includes a target PCell configuration, but may also include a target PCell and SCell configuration (e.g., PCell 1 and SCell 3). The CHO configuration may also include a target set of L1 / L2 mobility candidate cells, that is, a set of L1 / L2 mobility candidate cells that may 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 upper layers. The WTRU may activate a first measurement configuration (e.g., PCell 1, SCell 3) of a plurality of measurement configurations based on the first cell being the current serving cell of the WTRU. The WTRU may also determine that a second measurement configuration of the plurality of measurement configurations is deactivated (e.g., measurement configurations associated with cell 2, cell 4 to cell 8) based on the first cell being the current serving cell of the WTRU.

[0118] At 706, the CHO trigger may use one of the existing measurement events such as event A3 or event A5. Alternatively, CHO may utilize one or more new measurement events. When cell 5 becomes an SCell, a CHO evaluation may be triggered (or activated), which means that the WTRU may have reached the boundary between cell 1 and cell 2 and should therefore begin evaluating the conditions for handover to the target cell 2. In some examples, the CHO trigger itself may be an activation of a specific combination of cells (in this example, activation of SCell 5) or an activation of any condition related to the mobility areas previously explained. At 708, CHO may be performed and PCell 1 may be dynamically switched to PCell 2, and SCell 5 may be dynamically switched to SCell 6. As the WTRU continues to perform mobility to the right, dynamic switching for secondary cells (e.g., cell 7 and then cell 8) and primary cells may continue to occur.

[0119] In an embodiment, the criteria for activating or deactivating a measurement or CHO configuration may be associated with a specific transition rather than a static configuration. For example, a change of SCell from cell 3 to cell 5 may not trigger a specific configuration, but a change of SCell from cell 4 to cell 5 may activate the specific configuration. Therefore, the activation takes into account the current cell configuration and the previous cell configuration. The WTRU may determine which of the multiple measurement configurations will be activated and which of the multiple measurement configurations will not be activated when performing mobility to the second cell based on the second cell being the new serving cell of the WTRU and the mobility to the second cell resulting in activation of a third cell among the multiple mobility candidate cells as a secondary cell, the second cell being the primary cell, wherein the second measurement configuration is determined to be activated.

[0120] In an embodiment, the WTRU may transmit an indication to the network whenever the activation state 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.

[0121] Figure 8 An example diagram 800 is shown based on the current SpCell activation CHO / CPAC configuration. Figure 8 As shown, based on one or more measurement events, the WTRU may be configured with multiple CHO (e.g., or CPC) target cells. When performing CHO (e.g., or CPC) toward a new SpCell, the WTRU may begin evaluating stored CHO (e.g., or CPC) configurations, which are potentially applicable to the same target cell or may be applicable to different target cells. The WTRU may be configured to receive multiple measurement configurations and associations with one or more special cell (SpCell) / secondary cell (SCell) combinations. The WTRU may be configured to determine which of the multiple measurement configurations will be activated and which of the multiple measurement configurations will not be activated when performing mobility to the second cell based on one or more SpCell / SCell combinations and / or based on a combination of currently active secondary cells (SCells) in the multiple mobility candidate cells.

[0122] The WTRU may be configured with conditional triggers for cell 1 to cell 2 and cell 1 to cell 3. The WTRU may also be configured with conditional triggers for cell 2 to cell 3 and cell 3 to cell 2. The WTRU may receive configuration information indicating a plurality of mobility candidate cells and a plurality of measurement configurations. The WTRU may be configured by the network with two conditional triggers targeting cell 2, such as, for example, one condition to be used when on cell 1 and the other condition to be used when on cell 3. Similarly, the WTRU may be configured with two conditional triggers targeting cell 3, such as, one condition to be used when on cell 1 and the other condition to be used when on cell 2.

[0123] The WTRU may be configured with a conditional trigger for moving to cell 2 with a different offset depending on whether the WTRU is currently on cell 1 or cell 3. Similarly, the conditional trigger for moving 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.

[0124] The WTRU may trigger a reconfiguration to cell 2. The WTRU may activate an evaluation of a conditional trigger for performing mobility from cell 2 to cell 3 and / or from cell 2 to cell 1. The WTRU may activate a first measurement configuration of a plurality of measurement configurations based on the first cell being a current serving cell for the WTRU. The WTRU may 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.

[0125] 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:

[0126]

[0127] In the above embodiments, each CHO / CPAC configuration is (preferably) provided with an event type and offset / threshold / hysteresis / time to appropriately trigger the parameters. In the event of triggering an active CHO or CPAC to a new SpCell, the WTRU may activate a new conditional trigger configuration for the CHO, CPA or CPC associated with the new SpCell.

[0128] It may be desirable to reuse the same conditional trigger configuration for multiple cells and provide possibly different parameters. A conditional trigger (for CHO, CPC, CPA), such as conditional event A3, may be provided for a specific target cell. All configurations may be the same for the target cell, regardless of the current cell, except for the offsets to be used. The WTRU may then receive the conditional trigger configuration for a specific cell and further receive a list of offsets to be used depending on the current SpCell.

[0129] In some embodiments, the WTRU may use the first condition to set the initial conditions for the applied measurement configuration and details on how to further update the configuration using the second condition.

[0130] In some embodiments, the WTRU may determine a first configuration based on a first condition (e.g., a new SpCell / SCell combination), and may subsequently update the configuration based on a second condition (e.g., SCell activation / deactivation state). 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 using cell 2 and / or cell 3 as the SCell. Additionally, cell 2 and cell 3 may 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 SCell may be deactivated. Based on this, the WTRU may apply a first measurement configuration associated with measurements and / or reporting of these cells based on cell 2 and cell 3 being L1 / L2 handover target cells. Subsequently, the WTRU may receive an indication for activating one or both of cell 2 and cell 3. The WTRU may then apply the measurement configuration associated with reporting the active SCell. For example, the WTRU may be configured with a type of measurement resource (e.g., an SSB measurement resource configuration) and / or the WTRU may be configured to perform reporting using a first type of report (e.g., a CSI report containing information prepared for L1 / L2 handover) for use when a 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 is to perform mobility to a second cell, the second cell being one of a plurality of mobility candidate cells. The WTRU may also determine which of the plurality of measurement configurations are to be activated and which of the plurality of measurement configurations are not to be activated when performing mobility to the second cell (e.g., the second cell is a primary cell) based on the second cell being a new serving cell for the WTRU and the mobility to the second cell resulting in activation of a third cell in the plurality of mobility candidate cells as a secondary cell. The WTRU may determine the second measurement configuration to be activated.

[0131] 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 perform reporting using a second type of report (e.g., a CSI report for reporting active SCells) when the cell is an activated SCell. Thus, when L1 / L2 handover occurs, the WTRU may determine to apply the first type of measurement configuration and / or the first type of report based on the SpCell / SCell combination (e.g., a SpCell / SCell combination configured by the RRC and then activated / triggered using L1 / L2 signaling such as a MAC CE). Subsequently, when the SCell activation state changes (e.g., when a second MAC CE is received that changes the activation / deactivation state of the configured SCell), the WTRU may determine to apply the second type of report and / or the second type of report. Alternatively or additionally, the WTRU may use any of the previously listed conditions (e.g., "X") as the first condition and / or the second condition. The first condition may be a condition that applies when a handover (e.g., an L1 / L2 triggered handover) is performed using a specific condition (e.g., an SpCell / SCell combination pre-configured by RRC and triggered by a MAC CE), and the second condition may be any subsequent configuration change (e.g., SCell activation / deactivation by a MAC CE). The WTRU may perform one or more measurements associated with a second measurement configuration and transmit a measurement report via a second cell based on the measurements associated with the second measurement configuration.

[0132] Fig. 9An example of an L1 / L2 mobility area 900 is shown. A WTRU (as represented by a solid black dot in the center of the mobility area) may be surrounded by L1 / L2 mobility candidate cells. The WTRU may be configured to receive configuration information indicating multiple mobility candidate cells independently of the multiple measurement configurations. That is, L1, L2 and / or Layer 3 (L3) may transmit information related to mobility candidate cells separately from the multiple measurement configurations. "Independent" may mean separate, at different locations, in different signals and / or in the same signal but in different locations, sub-blocks and / or parts 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 a physical layer (PHY) and a medium access control (MAC) layer. LTM may implement serving cell changes via L1 / L2 signaling while maintaining the configuration of the upper layers and / or minimizing changes to the lower layer configurations. This may help reduce latency, overhead and interruption time during handover. LTM may support both intra-distributed unit (DU) and intra-central unit (CU)-inter-DU mobility. During LTM, the user plane may continue with the target cell when possible (e.g., within a DU) when no reset is required to avoid data loss and additional delays to data recovery. A set of cells may have configured measurements that are not currently used (e.g., due to the WTRU's location, trajectory, direction and / or speed of movement, proximity to the cell).

[0133] Fig.10 A flow chart of an example process 1000 performed by a WTRU for measurement configuration using L1 / L2 based mobility is shown. At 1002, the WTRU may receive configuration information for a plurality of L1 / L2 mobility candidate cells. The configuration information may indicate a plurality of mobility candidate cells and a plurality of measurement configurations. In some examples, the WTRU may be configured to receive the plurality of measurement configurations and associations with one or more special cell (SpCell) / secondary cell (SCell) combinations.

[0134] At 1004, the WTRU may receive one or more measurement configurations and CSI reporting configurations and associations with one or more SpCell / SCell combinations from a network (e.g., independent of the L1 / L2 candidate cells). For example, the WTRU may receive a first measurement configuration based on the first cell being a current serving cell of the WTRU. The WTRU may activate the first measurement configuration of a plurality of measurement configurations based on the first cell being a current serving cell of 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 of the WTRU. In some examples, the measurement configuration includes a channel state information (CSI) reporting configuration.

[0135] 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. Layer 1 or Layer 2 (L1 / L2) control signaling may indicate that the WTRU will perform mobility to at least a second cell, where the second cell is one of a plurality of mobility candidate cells (e.g., as indicated by the configuration information received at 1002). In some examples, the L1 / L2 control signaling may include a medium access control (MAC) control element (CE) (e.g., or provided by 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).

[0136] At 1008, based on the SpCell / SCell combination, the WTRU may determine one or more measurement configurations and CSI reporting configurations to use. For example, the WTRU may be configured to determine which measurement configurations of the plurality of measurement configurations to be activated and which measurement configurations of the plurality of measurement configurations to not be activated when performing mobility to the second cell (e.g., the second cell is a primary cell) based on the second cell being a new serving cell for the WTRU and the mobility to the second cell resulting in activation of a third cell of the plurality of mobility candidate cells as a secondary cell. The WTRU may determine a second measurement configuration to activate.

[0137] The WTRU may activate the determined one or more measurement configurations and CSI reporting configurations and transmit an indication to the network at 1010. For example, the WTRU may perform one or more measurements associated with the second measurement configuration and transmit at least one measurement report via the second cell based on the measurements associated with the second measurement configuration.

[0138] The processes and means described herein may be applied in any combination, may be applied to other wireless technologies, and may be used for other services.

[0139] The WTRU may refer to an identity of a physical device, or to an identity of a user, such as a subscription-related identity, for example, an MSISDN, a SIP URI, etc. The WTRU may refer to an application-based identity, such as a user name that may be used for each application.

[0140] The processes described above may be implemented in a computer program, software, and / or firmware incorporated in a computer-readable medium for execution by a computer and / or processor. Examples of computer-readable media include, but are not limited to, electronic signals (sent 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, built-in 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 associated with the software may be used to implement a radio frequency transceiver for a WTRU, UE, terminal, base station, RNC, and / or any host computer.

Claims

1. A wireless transmit / receive unit (WTRU), the wireless transmit / receive unit (WTRU) comprising: A processor, the processor being configured to: receiving configuration information indicating a plurality of mobility 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 of 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 of the WTRU; receiving layer 1 or layer 2 (L1 / L2) control signaling indicating that the WTRU is to perform mobility to a second cell, the second cell being one of the plurality of mobility candidate cells; determining which of the plurality of measurement configurations are to be activated and which of the plurality of measurement configurations are not to be activated when performing mobility to the second cell based on the second cell being a new serving cell for the WTRU and the mobility to the second cell results in activation of a third cell of the plurality of mobility candidate cells as a secondary cell, the second cell being a primary cell, wherein the second measurement configuration is determined to be activated; performing one or more measurements associated with the second measurement configuration; as well as A measurement report is transmitted via the second cell based on the measurement associated with the second measurement configuration.

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

3. The WTRU of any one of claims 1 or 2, wherein the L1 / L2 control signaling comprises 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 mobility candidate cells independently of the plurality of measurement configurations.

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

7. A WTRU according to claim 6, wherein the processor is configured to determine which of the multiple measurement configurations will be activated and which of the multiple measurement configurations will not be activated when performing mobility to the second cell based on one or more SpCell / SCell combinations.

8. A WTRU according to any one of claims 1 to 7, wherein the processor is configured to determine which of the multiple measurement configurations will be activated and which of the multiple measurement configurations will not be activated when performing mobility to the second cell based on a combination of currently active secondary cells (SCells) in the multiple mobility candidate cells.

9. The WTRU according to any one of claims 1 to 8, wherein the processor is configured with one or more dependencies between a set of location-related configurations and a set of mobility functions.

10. The WTRU of claim 9, wherein activation of a location-dependent configuration activates an associated mobility function, and wherein activation of a mobility function activates an associated location-dependent configuration.

11. A method implemented by a wireless transmit / receive unit (WTRU), the method comprising: receiving configuration information indicating a plurality of mobility 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 of the WTRU, wherein a second measurement configuration of the plurality of measurement configurations is deactivated based on the first cell being the current serving cell of the WTRU; receiving layer 1 or layer 2 (L1 / L2) control signaling indicating that the WTRU is to perform mobility to a second cell, the second cell being one of the plurality of mobility candidate cells; determining which of the plurality of measurement configurations are to be activated and which of the plurality of measurement configurations are not to be activated when performing mobility to the second cell based on the second cell being a new serving cell for the WTRU and the mobility to the second cell results in activation of a third cell of the plurality of mobility candidate cells as a secondary cell, the second cell being a primary cell, wherein the second measurement configuration is determined to be activated; performing one or more measurements associated with the second measurement configuration; as well as A measurement report is transmitted via the second cell based on the measurement associated with the second measurement configuration.

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

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

14. The method according to any one of claims 11 to 13, further comprising: The configuration information indicating the plurality of mobility candidate cells is received 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 according to any one of claims 11 to 15, further comprising: The plurality of measurement configurations and associations with one or more special cell (SpCell) / secondary cell (SCell) combinations are received.

17. The method according to claim 16, further comprising: Based on the one or more SpCell / SCell combinations, determining which of the multiple measurement configurations are to be activated and which of the multiple measurement configurations are not to be activated when performing mobility to the second cell.

18. The method according to any one of claims 11 to 17, further comprising: Which of the multiple measurement configurations are to be activated and which of the multiple measurement configurations are not to be activated when performing mobility to the second cell is determined based on a combination of currently active secondary cells (SCells) in the multiple mobility candidate cells.

19. The method according to any one of claims 11 to 18, further comprising one or more dependencies between a set of location-related configurations and a set of mobility functions.

20. The method of claim 19, wherein activation of one of the location-dependent configurations activates an associated mobility functionality, and wherein activation of a mobility functionality activates an associated location-dependent configuration.

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