Methods, architectures, apparatus, and systems for race conditions and the use of Layer 1 / Layer 2 triggered mobility (LTM).

Abstract

Procedures, methods, architectures, apparatus, systems, devices, and computer programs for Layer 1 / Layer 2 triggered mobility (LTM). For example, a wireless transmit / receive unit (WTRU) may receive information indicating configuration information associated with the quality of the LTM (e.g., by implementing a method for doing so). The WTRU may receive information indicating a measurement event. The WTRU may determine the quality of a first LTM set based on measurements of a first set of beams from a first set of cells. The WTRU may, for example, send a measurement report associated with the measurement event and / or perform a conditional reconfiguration based on (1) the measurement event being met using the determined quality of the first LTM set and (2) the elapsed time since the last LTM cell switchover.

Description

[Technical Field]

[0001] This disclosure generally covers the areas of communications, software, and coding, including, for example, procedures for mobility, and more specifically, methods, architectures, apparatus, and systems covering LTM use. [Background technology]

[0002] Cross-reference of related applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 456,933, filed on April 4, 2023, which is incorporated herein by reference.

[0003] A wireless transmit / receive unit (WTRU) can be configured to use an LTM. When an LTM is configured, it would be desirable to provide procedures for the LTM to operate in parallel with or coexist with radio resource control (RRC) based measurement and mobility, along with measurement and measurement reporting mechanisms to support the LTM. [Overview of the project]

[0004] In an exemplary embodiment, the WTRU may receive information indicating configuration information associated with the quality of the LTM (for example, by implementing a method for doing so). The WTRU may receive information indicating measurement events. The WTRU may determine the quality of a first set of LTMs based on measurements of a first set of beams from a plurality of first cells. The WTRU may, for example, send a measurement report associated with the measurement event and / or perform a conditional reconfiguration based on (1) the measurement event being met using the determined quality of the first set of LTMs and (2) the elapsed time since the last LTM cell switchover.

[0005] For example, the WTRU may determine the quality of a second LTM set based on measurements of a second set of beams from a second set of cells. Measurement events can be met (for example, determined to be met) using the determined quality of the first LTM set and the determined quality of the second LTM set. For example, the WTRU may determine a first set of beams as a subset of (for example, the first) beams from the first set of cells, and / or a second set of beams as a subset of (for example, the second) beams from the second set of cells. For example, the WTRU may determine the quality of a serving cell or target cell outside of the first LTM set. Measurement events can be met (for example, determined to be met) using the determined quality of the first LTM set and the determined quality of the serving cell or target cell. For example, the WTRU may perform the last LTM switchover before the measurement event is met. For example, a measurement report may include information indicating the determined quality of the first LTM set, and / or a conditional reconstruction may include sending information indicating the determined quality of the first LTM set.

[0006] In some representative embodiments, virtual cell quality derivation and / or modified cell quality derivation can be performed. For example, beams from different cells with L1 / L2 triggered mobility (LTM) candidate sets can be used and / or considered to derive the virtual cell quality of the LTM candidate set.

[0007] In some representative embodiments, the WTRU may consist of an active LTM set and a target LTM set. Cell quality derivation and / or comparison may be performed as in the legacy procedure, for example, by using N L1 filtered beam measurements on a cell to derive an L3 filtered cell quality. At least one additional triggering condition may be achieved by a certain number of cells in the target and / or source candidate set (for example, let's assume it is achieved).

[0008] In some representative embodiments, the WTRU can use the LTM to switch from a first serving cell to a second serving cell. When switching, the WTRU may determine the L3 cell quality and evaluate the L3 event triggers based on measurement results applicable to the first and second serving cells, such as when the first and second serving cells are a single serving cell. For example, the WTRU may continue evaluating the serving cell quality and measurement event triggers (e.g., current) even after the cell change, using previous (one or more) serving cell measurements as if they were the current cell measurements.

[0009] In some typical embodiments, the WTRU may perform procedures to ensure that, after an L3 handover, radio resource control (RRC) reconfiguration completion signaling is successfully delivered to the gNB's central unit (CU), etc., and / or that L3 measurement event evaluation is completed (for example, while the time-to-trigger is running). For example, the WTRU may be prevented from sending L1 measurement reports and / or performing LTM, which may result in the loss of LTM handovers and L3 signaling triggered by the distributed unit (DU), and / or this may result in the CU detecting a handover failure or reconfiguration failure. For example, the WTRU may apply (e.g., temporary) restrictions to neighbor cell and / or candidate cell L1 reports, for example, by using a timer and / or waiting for an RLC acknowledgment of sending an RRC message (complete), while current cell beam reporting is still enabled to allow scheduling.

[0010] In some typical embodiments, the WTRU may include information indicating a PCell identifier / identification in the uplink (UL) RRC message. For example, the PCell ID may correspond to the PCell at the time the event (e.g., measurement event, RRC reconfiguration) was triggered. In the case of RRC reconfiguration, the RRC reconfiguration completion signaling may include information indicating whether RRC reconfiguration, L2 triggered reconfiguration, or both were performed.

[0011] In some representative embodiments, the WTRU may receive configuration information associated with determining the LTM quality. This configuration information may include (i) the minimum number of beams and / or cells to be used in determining the LTM quality, (ii) offset and / or scaling information, (iii) associations between one or more beams of a serving cell and one or more beams of other cells, and / or (iv) an indication for using the LTM quality as serving cell quality or as an offset to the serving cell quality. The WTRU may receive configuration information indicating an L1 or L3 (L1 / L3) measurement event associated with a triggering condition. The WTRU may perform a first measurement of one or more beams of a serving cell and one or more beams of other cells associated with the serving cell. The WTRU may use the first measurement and the configuration information associated with determining the LTM quality to determine a first LTM quality. Based on the fulfillment of triggering conditions and the elapsed minimum time period since the last LTM cell switchover, the WTRU may send a report containing information indicating the first LTM quality associated with the L1 / L3 measurement event.

[0012] In some representative embodiments, the WTRU may receive configuration information associated with determining Layer 1 or Layer 2 (L1 / L2) trigger mobility (LTM) quality. For example, the configuration information may include (i) the minimum number of beams and / or cells to be used in determining the LTM quality, (ii) offset and / or scaling information, (iii) associations between one or more beams of a target cell and one or more beams of other cells, and / or (iv) an indication for using the LTM quality as the target cell quality or as an offset to the target cell quality. The WTRU may receive configuration information indicating L1 or L3 (L1 / L3) measurement events associated with the triggering conditions. The WTRU may perform a first measurement with one or more beams of a target cell and one or more beams of other cells associated with the target cell. The WTRU may use the first measurement and the configuration information associated with determining the LTM quality to determine a first LTM quality. Based on the fulfillment of triggering conditions and the elapsed minimum time period since the last LTM cell switchover, WTRU102 may transmit a report containing information indicating the first LTM quality associated with the L1 / L3 measurement event.

[0013] In some representative embodiments, the WTRU may receive configuration information associated with determining Layer 1 or Layer 2 (L1 / L2) trigger mobility (LTM) quality. The configuration information may include (i) the minimum number of beams and / or cells to be used in determining the LTM quality, (ii) offset and / or scaling information, (iii) associations between one or more beams of a serving cell and one or more beams of other cells, and / or (iv) an indication for using the LTM quality as serving cell quality or as an offset to the serving cell quality. The WTRU 102 may receive configuration information indicating L1 or L3 (L1 / L3) measurement events associated with the triggering conditions. The WTRU may perform a first measurement with one or more beams of a serving cell and one or more beams of other cells associated with the serving cell. The WTRU may use the first measurement and the configuration information associated with determining the LTM quality to determine a first LTM quality. The WTRU may perform a conditional reconfiguration associated with the L1 / L3 measurement event based on whether the triggering conditions are met and whether the minimum time period since the last LTM cell switchover has elapsed.

[0014] In some representative embodiments, the WTRU may receive configuration information associated with determining Layer 1 or Layer 2 (L1 / L2) trigger mobility (LTM) quality. This configuration information may include (i) the minimum number of beams and / or cells to be used in determining the LTM quality, (ii) offset and / or scaling information, (iii) associations between one or more beams of a target cell and one or more beams of other cells, and / or (iv) an indication for using the LTM quality as the target cell quality or as an offset to the target cell quality. The WTRU may receive configuration information indicating L1 or L3 (L1 / L3) measurement events associated with the triggering conditions. The WTRU may perform a first measurement with one or more beams of a target cell and one or more beams of other cells associated with the target cell. The WTRU may use the first measurement and the configuration information associated with determining the LTM quality to determine a first LTM quality. The WTRU may perform a conditional reconfiguration associated with the L1 / L3 measurement event based on whether the triggering conditions are met and whether the minimum time period since the last LTM cell switchover has elapsed.

[0015] In some representative embodiments, the WTRU may receive configuration information associated with the active LTM set and the target LTM set. The WTRU may receive configuration information indicating measurement events associated with triggering conditions for serving cells and / or neighbor cells. The WTRU may determine some cells in the active LTM set and / or some cells in the target LTM set based on the elapsed time since the last LTM switchover. The WTRU may perform measurements on some cells in the active LTM set and some cells in the target LTM set. The WTRU may transmit measurement reports associated with measurement events based on whether the triggering conditions are met, using (1) the quality of the serving cell corrected by a first offset and / or (2) the quality of the neighbor cell corrected by a second offset.

[0016] In some representative embodiments, the WTRU may receive configuration information associated with the active LTM set and the target LTM set. The WTRU may receive configuration information indicating measurement events associated with triggering conditions for serving cells and / or neighbor cells. The WTRU may determine some cells in the active LTM set and / or some cells in the target LTM set based on the elapsed time since the last LTM switchover. The WTRU may perform measurements on some cells in the active LTM set and some cells in the target LTM set. The WTRU may perform a conditional reconfiguration based on whether the triggering conditions are met, using (1) the quality of the serving cell corrected by a first offset and / or (2) the quality of the neighbor cell corrected by a second offset.

[0017] In some representative embodiments, the WTRU may receive configuration information associated with determining cell quality using L3 filtering. The WTRU may receive configuration information indicating measurement events associated with using a time-to-trigger (TTT) period and an offset. The WTRU may determine that a measurement event is satisfied at the beginning of a first time period, based on a first triggering condition using the quality of a first serving cell and the quality of a neighbor cell, using L3 filtering. The WTRU may receive information indicating that the first serving cell is switched to a second serving cell using Layer 1 / Layer 2 trigger mobility (LTM) at the end of the first time period, and the first time period is shorter than the TTT period. The WTRU may determine that a measurement event is satisfied during the second time period, based on a second triggering condition, based on the quality of a second serving cell and the quality of a neighbor cell, using L3 filtering during the second time period, and the second time period follows the first time period, with the sum of the first and second time periods being greater than or equal to the TTT period. Based on the neighbor cell quality being greater than the measurement result plus offset of the second serving cell, the WTRU may submit a measurement report containing information indicating (i) the first and second serving cells, and / or (ii) either the first or second time period.

[0018] In some representative embodiments, the WTRU may receive an RRC reconfiguration message containing information indicating an LTM measurement pause and the time period associated with it (for example, the LTM pause). The WTRU may send an RRC reconfiguration complete message. The WTRU may receive an LTM switching command. The WTRU may send information indicating that the LTM switching command will not be executed based on the elapsed time since receiving the RRC reconfiguration message being less than the indicated time period. The WTRU may send an LTM measurement report based on the elapsed time since receiving the RRC reconfiguration message being greater than the indicated time period.

[0019] In some representative embodiments, a WTRU may receive an RRC reconfiguration message that includes information indicating an LTM measurement suspension and a time period (e.g., associated with the LTM suspension). The WTRU may transmit an RRC reconfiguration complete message. The WTRU may receive an LTM switch command. The WTRU may transmit information indicating that the LTM switch command is not to be executed based on the elapsed time from the transmission of the RRC reconfiguration complete message being less than the time period. The WTRU may transmit an LTM measurement report based on the elapsed time from the reception of the RRC reconfiguration message being greater than the indicated time period.

[0020] In some representative embodiments, a WTRU may receive an RRC reconfiguration message that includes information indicating an LTM measurement suspension and a time period (e.g., associated with the LTM suspension). The WTRU may transmit an RRC reconfiguration complete message. The WTRU may receive an LTM switch command. The WTRU may transmit information indicating that the LTM switch command is not to be executed based on the elapsed time from the reception of the RRC reconfiguration message being less than the time period. The WTRU may transmit an LTM measurement report based on the elapsed time from the transmission of the RRC reconfiguration complete message being greater than the indicated time period.

[0021] In some representative embodiments, a WTRU may receive an RRC reconfiguration message that includes information indicating an LTM measurement suspension and a time period (e.g., associated with the LTM suspension). The WTRU may transmit an RRC reconfiguration complete message. The WTRU may receive an LTM switch command. The WTRU may transmit information indicating that the LTM switch command is not to be executed based on the elapsed time from the transmission of the RRC reconfiguration complete message being less than the time period. The WTRU may transmit an LTM measurement report based on the elapsed time from the transmission of the RRC reconfiguration complete message being greater than the indicated time period.

[0022] In some representative embodiments, a WTRU may receive information indicating the configuration of L3 measurement events and / or reports. The WTRU may receive information indicating the LTM configuration. The WTRU may receive information indicating conditions for including primary cell (PCell) information in an L3 measurement report. The WTRU may perform measurements on a serving cell and candidate cells. The WTRU may send an L1 / L2 measurement report based on the measurements, where the L1 / L2 measurement report includes information indicating that (i) the measurement result of a candidate cell is higher than (ii) the measurement result of the serving cell plus an offset. After sending the L1 / L2 measurement report, the WTRU may start sending an L3 measurement report based on the triggering of an L3 measurement event. The L3 measurement report may include information indicating the identifier of the WTRU's PCell associated with the triggering of the L3 measurement event. The WTRU may receive an LTM cell switch command. The WTRU may reconfigure to another cell based on the LTM cell switch command. The WTRU may complete sending the L3 measurement report.

[0023] In some representative embodiments, a WTRU may receive an RRC reconfiguration message in a source cell (e.g., from the source cell). The WTRU may apply the RRC reconfiguration information included in the RRC reconfiguration message. The WTRU may send an RRC reconfiguration complete message including information indicating the identifier of the WTRU's PCell and information indicating that the RRC reconfiguration complete message is due to the RRC reconfiguration.

[0024] In some representative embodiments, a WTRU may receive an RRC reconfiguration message in a source cell (e.g., from the source cell). The WTRU may apply the RRC reconfiguration information included in the RRC reconfiguration message. The WTRU may receive an LTM cell switch command. The WTRU may reconfigure to another cell based on the LTM cell switch command. The WTRU may send an RRC reconfiguration complete message including information indicating the identifier of the WTRU's PCell and information indicating that the RRC reconfiguration complete message is due to the RRC reconfiguration and the LTM reconfiguration. [Brief explanation of the drawing]

[0025] A more detailed understanding can be obtained from the following detailed description, which is given as examples along with the drawings attached to this specification. The figures in such drawings, as well as the detailed description, are examples. Therefore, the figures and detailed description should not be considered limiting, and other equally valid examples may be possible. Furthermore, similar reference numbers in the figures indicate similar elements.

[0026] [Figure 1A] This is a system diagram illustrating an exemplary communication system. [Figure 1B] Figure 1A is a system diagram showing an exemplary wireless transmit / receive unit (WTRU) that can be used in the communication system shown. [Figure 1C] Figure 1A is a system diagram showing exemplary radio access networks (RANs) and exemplary core networks (CNs) that can be used within the communication system shown. [Figure 1D] Figure 1A is a system diagram showing further exemplary RAN and further exemplary CN that can be used within the communication system shown. [Figure 2] This is a block diagram showing an example of a measurement model. [Figure 3] This system diagram shows an example of LTM operation. [Figure 4] This is a step-by-step diagram showing the baseline procedure for LTM. [Figure 5] This is a system diagram showing examples of switching within a control unit (CU) and switching between CUs. [Figure 6] This is a system diagram showing an example of a virtual cell. [Figure 7] This is a procedure diagram illustrating an exemplary procedure for measuring and reporting virtual cell information. [Figure 8] This is a system diagram showing an example of a neighboring area and a candidate LTM area. [Figure 9]This is a procedure diagram illustrating an exemplary procedure for determining and evaluating the active LTM set. [Figure 10] This system diagram shows an example of L3 filtering and measurement evaluation. [Figure 11] This is a procedure diagram illustrating exemplary steps for L3 filtering and measurement event evaluation. [Figure 12] This is a procedure diagram illustrating exemplary steps for LTM measurement and execution pause after L3 reconstruction. [Figure 13] This is a step diagram illustrating an exemplary procedure in which the current PCell identification information is displayed in the triggered measurement report. [Figure 14] A step diagram illustrating a similar procedure for RRC reconstruction. [Figure 15] This is a procedure diagram showing a first exemplary LTM procedure according to several representative embodiments. [Figure 16] This is a procedure diagram showing a second exemplary LTM procedure according to several representative embodiments. [Figure 17] This is a procedure diagram showing a third exemplary LTM procedure according to several representative embodiments. [Figure 18] This is a procedure diagram showing a fourth exemplary LTM procedure according to several representative embodiments. [Figure 19] This is a procedure diagram showing a fifth exemplary LTM procedure according to several representative embodiments. [Figure 20] This is a procedure diagram illustrating an exemplary procedure for measurement reporting that uses the correlation between the serving cell beam and the beams of other cells. [Figure 21] This is a procedure diagram illustrating an exemplary procedure for measurement reporting that uses the correlation between the target cell beam and the beams of other cells. [Figure 22] This is a step diagram illustrating an exemplary procedure for conditional reconfiguration using the association between the serving cell beam and the beams of other cells. [Figure 23]This is a step diagram illustrating an exemplary procedure for conditional reconstruction using the association between the target cell beam and the beams of other cells. [Figure 24] This is a procedure diagram illustrating an exemplary procedure for measurement reporting using an active LTM set and a target LTM set. [Figure 25] This is a step diagram illustrating an exemplary procedure for conditional reconfiguration using an active LTM set and a target LTM set. [Figure 26] This is a step diagram illustrating an exemplary procedure for measurement reporting using a trigger time (TTT) period. [Figure 27] This is a procedure diagram illustrating exemplary steps for pausing LTM measurements and reporting the results. [Figure 28] This is a procedure diagram illustrating another exemplary procedure for pausing LTM measurements and reporting the measurements. [Figure 29] This is a step diagram illustrating yet another exemplary procedure for pausing LTM measurements and reporting the measurements. [Figure 30] This is a procedure diagram illustrating yet another exemplary procedure for pausing LTM measurements and reporting the measurements. [Figure 31] This is a procedure diagram illustrating exemplary steps for LTM switching and measurement reporting. [Figure 32] This is a procedure diagram illustrating exemplary steps for LTM switching and RRC signaling. [Figure 33] This is a step diagram illustrating another exemplary procedure for LTM switching and RRC signaling. [Modes for carrying out the invention]

[0027] The following detailed description includes numerous specific details to provide a complete understanding of the embodiments and / or examples disclosed herein. However, it will be understood that such embodiments and examples may be practiced without some or all of the specific details described herein. In other instances, well-known methods, procedures, components and circuits are not described in detail so as not to obscure the following description. Furthermore, embodiments and examples not specifically described herein may be practiced instead of, or in combination with, the embodiments and other examples expressly, implicitly, and / or essentially described, disclosed, or otherwise provided herein (collectively, “Provided”). Various embodiments are described and / or claimed herein, in which apparatus, systems, devices, etc., and / or any element thereof perform operations, processes, algorithms, functions, etc., and / or any part thereof, but it should be understood that any embodiment described and / or claimed herein assumes that any apparatus, systems, devices, etc., and / or any element thereof is configured to perform any operation, process, algorithm, function, etc., and / or any part thereof.

[0028] Exemplary communication system

[0029] The methods, apparatus, and systems provided herein are suitable for communications involving both wired and wireless networks. An overview of various types of wireless devices and infrastructure is provided with respect to Figures 1A to 1D, and various elements of a network can utilize, implement, and arrange according to the methods, apparatus, and systems provided herein, as well as adapt and / or configure for them.

[0030] Figure 1A is a system diagram showing an exemplary 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, and broadcast to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content through the 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), quadrature FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail (ZT) unique-word (UW) discrete Fourier transform (DFT) spread OFDM (ZT UW DTS-s OFDM), unique-word OFDM (UW-OFDM), resource block-filtered OFDM, and filter bank multicarrier (FBMC).

[0031] As shown in Figure 1A, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, radio access networks (RANs) 104 / 113, core networks (CNs) 106 / 115, public switched telephone networks (PSTNs) 108, the internet 110, and other networks 112, but it will be understood that the disclosed embodiments intend any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, and 102d may be any type of device configured to operate and / or communicate in a wireless environment. For example, WTRU102a, 102b, 102c, and 102d may all be referred to as “stations” and / or “STAs” and can be configured to transmit and / or receive wireless signals, and may include (or be) user equipment (UEs), mobile stations, fixed or mobile subscriber units, subscription-based units, pagers, cellular phones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, hotspots or Mi-Fi devices, Internet of Things (IoT) devices, watches or other wearables, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in an industrial and / or automated processing chain context), consumer electronics devices, and devices operating on commercial and / or industrial wireless networks. Any of WTRU102a, 102b, 102c, and 102d may interchangeably be referred to as UEs.

[0032] The communication system 100 may also include base stations 114a and / or base stations 114b. Each of the base stations 114a and 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, and 102d to facilitate access to one or more communication networks, such as CN 106 / 115, the Internet 110, and / or network 112. As an example, base stations 114a and 114b may be any of the following: base station transceiver station (BTS), node B (NB), e-node B (eNB), home node B (HNB), home e-node B (HeNB), g-node B (gNB), NR node B (NR NB), site controller, access point (AP), wireless router, etc. Although base stations 114a and 114b are shown as single elements, it will be understood that base stations 114a and 114b may include any number of interconnected base stations and / or network elements.

[0033] Base station 114a may be part of RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), and relay nodes. Base stations 114a and / or base stations 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be called cells (not shown). These frequencies may be licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for wireless service to a particular geographic area, which may be relatively fixed or may change over time. A cell may be further divided into cell sectors. For example, a cell associated with base station 114a may be divided into three sectors. Thus, in one embodiment, base station 114a may include three transceivers, i.e., one for each sector of the cell. In one embodiment, the base station 114a may employ multiple-input multiple-output (MIMO) technology, and thus multiple transceivers may be available for each sector of the cell or any sector. For example, beamforming may be used to transmit and / or receive signals in a desired spatial direction.

[0034] Base stations 114a and 114b can communicate with one or more WTRUs 102a, 102b, 102c, and 102d via an air interface 116, the air interface 116 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).

[0035] More specifically, as described above, the communication system 100 can be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, and SC-FDMA. For example, base stations 114a in RAN 104 / 113, and WTRU 102a, 102b, and 102c may implement radio technologies, such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish an air interface 116 using broadband CDMA (WCDMA). WCDMA may include communication protocols such as High Speed ​​Packet Access (HSPA) and / or Advanced HSPA (HSPA+). HSPA may include High Speed ​​Downlink Packet Access (HSDPA) and / or High Speed ​​Uplink Packet Access (HSUPA).

[0036] In one embodiment, base stations 114a and WTRUs 102a, 102b, 102c may implement radio technologies such as Advanced UMTS Terrestrial Radio Access (E-UTRA), which can establish an air interface 116 using Long-Term Evolution (LTE) and / or LTE Advanced (LTE-A) and / or LTE Advanced Pro (LTE-A Pro).

[0037] In one embodiment, base stations 114a and WTRUs 102a, 102b, and 102c may implement radio technologies, such as NR radio access, which can establish an air interface 116 using New Radio (NR).

[0038] In one embodiment, base stations 114a and WTRUs 102a, 102b, and 102c may implement multiple radio access technologies. For example, base stations 114a and WTRUs 102a, 102b, and 102c may implement LTE radio access and NR radio access together, for example, using the dual connectivity (DC) principle. Thus, the air interface utilized by WTRUs 102a, 102b, and 102c may be characterized by multiple types of radio access technologies and / or transmissions to and from multiple types of base stations (e.g., eNBs and gNBs).

[0039] In one embodiment, base stations 114a and WTRUs 102a, 102b, and 102c may implement wireless 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 Advanced High Speed ​​Data Rate (EDGE), and GSM EDGE (GERAN).

[0040] In Figure 1A, base station 114b can be, for example, a wireless router, home node B, home enode B, or access point, and can utilize any suitable RAT to facilitate wireless connectivity in localized areas such as offices, homes, vehicles, premises, industrial facilities, aerial corridors (for use by drones), and roads. In one embodiment, base station 114b and WTRU 102c, 102d may implement radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In one embodiment, base station 114b and WTRU 102c, 102d may implement radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In one embodiment, base station 114b and WTRU 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, etc.) to establish any small cell, picocell, or femtocell. As shown in Figure 1A, base station 114b may have a direct connection to the internet 110. Therefore, base station 114b may not be required to access the internet 110 via CN 106 / 115.

[0041] RAN104 / 113 may communicate with CN106 / 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 WTRU102a, 102b, 102c, and 102d. The data may have various quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, and mobility requirements. CN106 / 115 may provide call control, billing services, mobile location-based services, prepaid calling, internet connectivity, video distribution, etc., and / or implement high-level security functions, such as user authentication. Although not shown in Figure 1A, it will be understood that RAN104 / 113 and / or CN106 / 115 may communicate directly or indirectly with other RANs employing the same RAT as RAN104 / 113 or different RATs. For example, in addition to being connected to RAN104 / 113, which may utilize NR radio technology, CN106 / 115 may also communicate with another RAN (not shown) employing one of the following technologies: GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or Wi-Fi radio technology.

[0042] CN106 / 115 can also act as a gateway for WTRU102a, 102b, 102c, and 102d to access PSTN108, the Internet 110, and / or other networks 112. PSTN108 may include a circuit-switched telephone network providing plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices using common communication protocols such as TCP, User Datagram Protocol (UDP), and / or IP in the Transmit Control Protocol (TCP) / Internet Protocol (IP) suite. Network 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, network 112 may include another CN connected to one or more RANs, which may employ the same RAT as RAN104 / 114 or a different RAT.

[0043] Some or all of the WTRUs 102a, 102b, 102c, and 102d in the communication system 100 may include multimode capability (for example, WTRUs 102a, 102b, 102c, and 102d may include multiple transceivers for communicating with different wireless networks via different wireless links). For example, WTRU 102c shown in Figure 1A may be configured to communicate with a base station 114a that may employ cellular-based radio technology and can be configured to communicate with a base station 114b that may employ IEEE 802 radio technology.

[0044] Figure 1B is a system diagram showing an exemplary WTRU 102. As shown in Figure 1B, the WTRU 102 may include, in particular, 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 supply 134, a Global Positioning System (GPS) chipset 136, and / or other elements / peripherals 138. It will be understood that the WTRU 102 may include any partial combination of the above elements while remaining consistent with one embodiment.

[0045] The processor 118 may be a general-purpose processor, a dedicated processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) circuit, any other type of integrated circuit (IC), a state machine, etc. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 can be coupled to a transceiver 120, which can be coupled to a transmit / receive element 122. Although Figure 1B shows the processor 118 and the transceiver 120 as separate components, it will be understood that the processor 118 and the transceiver 120 can be incorporated together, for example, in an electronic package or chip.

[0046] The transmit / receive element 122 can be configured to transmit a signal to or receive a signal from a base station (e.g., base station 114a) via the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In one embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive, for example, IR, UV, or visible light signals. In one embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF signals and optical signals. It will be understood that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0047] Although the transmit / receive element 122 is shown as a single element in Figure 1B, the WTRU 102 may include any number of transmit / receive elements 122. For example, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals via the air interface 116.

[0048] The transceiver 120 may be configured to modulate the signal to be transmitted by the transmit / receive element 122 and to demodulate the signal to be received by the transmit / receive element 122. As described above, the WTRU 102 may have multimode capability. Therefore, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0049] The processor 118 of the WTRU102 can be coupled to a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (for example, a liquid crystal display (LCD) display unit or an organic light-emitting diode (OLED) display unit) and can receive user input data from them. The processor 118 can also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. Furthermore, the processor 118 can access information from any type of suitable memory, such as non-removable memory 130 and / or removable memory 132, and store data therein. Non-removable memory 130 may include random access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. Removable memory 132 may include a subscriber identification module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from memory not physically located on the WTRU 102, such as on a server or home computer (not shown), and store data therein.

[0050] The processor 118 can receive power from the power supply 134 and may be configured to distribute and / or control power to other components in the WTRU 102. The power supply 134 may be any suitable device for supplying power to the WTRU 102. For example, the power supply 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.), a solar cell, a fuel cell, etc.

[0051] The processor 118 can also be coupled to a GPS chipset 136, which can be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or instead of, the information from the GPS chipset 136, the WTRU 102 may receive location information from base stations (e.g., base stations 114a, 114b) via 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 understood that the WTRU 102 may acquire location information via any preferred location determination method while remaining consistent with one embodiment.

[0052] The processor 118 can further be coupled to other elements / peripherals 138, which may include one or more software and / or hardware modules / units that provide additional features, functionality and / or wired or wireless connectivity. For example, elements / peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for example, photos and / or videos), a Universal Serial Bus (USB) port, a vibration device, a television transceiver, a hands-free headset, a Bluetooth® module, a frequency modulation (FM) radio unit, a digital music player, a media player, a video game player module, an internet browser, a virtual reality and / or augmented reality (VR / AR) device, an activity tracker, and the like. The element / peripheral device 138 may include one or more sensors, the sensors being 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.

[0053] WTRU102 may include, for example, a full-duplex radio in which the transmission and reception of some or all of a signal may be parallel and / or simultaneous, associated with a specific subframe for both an uplink (e.g., for transmission) and a downlink (e.g., for reception). The full-duplex radio may include an interference management unit for reducing and / or substantially eliminating self-interference, either through hardware (e.g., chokes) or signal processing via a processor (e.g., a separate processor (not shown), or processor 118). In one embodiment, WTRU102 may include a half-duplex radio for the transmission and reception of some or all of a signal (e.g., associated with a specific subframe for either an uplink (e.g., for transmission) or a downlink (e.g., for reception).

[0054] Figure 1C is a system diagram showing RAN104 and CN106 according to one embodiment. As described above, RAN104 may employ E-UTRA radio technology to communicate with WTRU102a, 102b, and 102c via the air interface 116. RAN104 may also communicate with CN106.

[0055] RAN104 may include enodes B160a, 160b, and 160c, but it will be understood that RAN104 may include any number of enodes B while remaining consistent with one embodiment. Each of enodes B160a, 160b, and 160c may include one or more transceivers for communicating with WTRU102a, 102b, and 102c via the air interface 116. In one embodiment, enodes B160a, 160b, and 160c may implement MIMO technology. Thus, enode B160a may use multiple antennas to, for example, transmit a wireless signal to WTRU102a and receive a wireless signal from WTRU102a.

[0056] Each of the e-nodes B160a, 160b, and 160c can be associated with a specific cell (not shown) and can be configured to handle wireless resource management decisions, handover decisions, user scheduling on the uplink (UL) and / or downlink (DL), etc. As shown in Figure 1C, the e-nodes B160a, 160b, and 160c can communicate with each other via the X2 interface.

[0057] The CN106 shown in Figure 1C may include a Mobility Management Entity (MME) 162, a Serving Gateway (SGW) 164, and a Packet Data Network (PDN) Gateway (PGW) 166. Although each of the above elements is shown as part of CN106, it will be understood that any one of these elements may be owned and / or operated by an entity other than the CN operator.

[0058] The MME162 can be connected to each of the e-nodes B160a, 160b, and 160c in RAN104 via the S1 interface and can act as a control node. For example, the MME162 may be responsible for authenticating users of WTRU102a, 102b, and 102c, activating / deactivating bearers, and selecting a specific serving gateway during the initial attachment of WTRU102a, 102b, and 102c. The MME162 may also provide control plane functionality for switching between RAN104 and other RANs (not shown) employing other radio technologies such as GSM and / or WCDMA.

[0059] The SGW164 can be connected to each of the e-nodes B160a, 160b, and 160c in RAN104 via the S1 interface. The SGW164 can generally route and forward user data packets to and from WTRU102a, 102b, and 102c. The SGW164 may also perform other functions, such as anchoring the user plane during e-node B handovers, triggering paging when DL data is available for WTRU102a, 102b, and 102c, and managing and remembering the context of WTRU102a, 102b, and 102c.

[0060] SGW164 can be connected to PGW166, which can provide WTRU102a, 102b, and 102c with access to a packet-switched network such as the Internet 110 to facilitate communication between WTRU102a, 102b, and 102c and IP-enabled devices.

[0061] CN106 can facilitate communication with other networks. For example, CN106 can provide WTRU102a, 102b, and 102c with access to a circuit-switched network such as PSTN108 to facilitate communication between WTRU102a, 102b, and 102c and legacy landline communication devices. For example, CN106 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between CN106 and PSTN108. Furthermore, CN106 can provide WTRU102a, 102b, and 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0062] Although the WTRU is described as a wireless terminal in Figures 1A to 1D, in some representative embodiments, such a terminal is intended to be able to use a wired communication interface with a communication network (for example, temporarily or permanently).

[0063] In a typical embodiment, the other network 112 may be a WLAN.

[0064] A WLAN in Infrastructure Basic Service Set (BSS) mode may have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have access to or interfaces with a distributed system (DS) or another type of wired / wireless network that carries traffic in and / or out of the BSS. Traffic originating outside the BSS to the STA can arrive through the AP and be delivered to the STA. Traffic originating from the STA to destinations outside the BSS can be sent to the AP to be delivered to their respective destinations. Traffic between STAs within the BSS can be sent through the AP, for example, here, a source STA may send traffic to the AP, and the AP may deliver the traffic to the destination STA. Traffic between STAs within the BSS is considered and / or may be called peer-to-peer traffic. Peer-to-peer traffic can be sent between a source STA and a destination STA (for example, directly between them) by a Direct Link Setup (DLS). In some typical embodiments, the DLS may be an 802.11e DLS or an 802.11z Tunnel DLS (TDLS). A WLAN using Independent BSS (IBSS) mode may not have an AP, and STAs within or using IBSS (e.g., all STAs) may communicate directly with one another. The IBSS communication mode is sometimes referred to as the “ad-hoc” communication mode in this specification.

[0065] When using the 802.11ac infrastructure operating mode or a similar operating mode, an AP may transmit beacons on a fixed channel, such as the primary channel. The primary channel may have a fixed width (e.g., a 20 MHz bandwidth) or a dynamically set width via signaling. The primary channel may be the operating channel of the BSS and may be used by STAs to establish a connection with the AP. In some typical embodiments, Carrier sense multiple access with collision avoidance (CSMA / CA) may be implemented, for example, in an 802.11 system. In CSMA / CA, an STA, including the AP (e.g., any STA), may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, that STA may back off. A single STA (e.g., only one station) may transmit at any given time within a given BSS.

[0066] A high-throughput (HT) STA may use a 40MHz wide channel for communication, for example, via a combination of a primary 20MHz channel and adjacent or non-adjacent 20MHz channels to form a 40MHz wide channel.

[0067] Ultra-high throughput (VHT) STAs can support 20MHz, 40MHz, 80MHz, and / or 160MHz wide channels. 40MHz channels and / or 80MHz channels can be formed by combining consecutive 20MHz channels. 160MHz channels can be formed by combining eight consecutive 20MHz channels, or by combining two discontinuous 80MHz channels, sometimes referred to as an 80+80 configuration. In the 80+80 configuration, data may be passed through a segment parser that, after channel coding, can split the data into two streams. Inverse fast Fourier transform (IFFT) processing and time-domain processing can be performed separately for each stream. The streams can be mapped onto two 80MHz channels, and the data can be transmitted by a transmitting STA. At the receiver of a receiving STA, the operation described above for the 80+80 configuration can be reversed, and the combined data can be sent to a media access control (MAC) layer, entities, etc.

[0068] Sub-1GHz operating modes are supported by 802.11af and 802.11ah. Channel operating bandwidth and carrier are reduced in 802.11af and 802.11ah compared to those used in 802.11n and 802.11ac. 802.11af supports 5MHz, 10MHz, and 20MHz bandwidths in the TV white space (TVWS) spectrum, while 802.11ah supports 1MHz, 2MHz, 4MHz, 8MHz, and 16MHz bandwidths using the non-TVWS spectrum. According to a typical embodiment, 802.11ah may support meter-type control / machine-type communications (MTC), such as MTC devices in a macro coverage area. An MTC device may have some capabilities, including limited capabilities, such as support for some and / or limited bandwidths (e.g., support only for that). An MTC device may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0069] A WLAN system that can support multiple channels and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, includes a channel that can be designated as the primary channel. The primary channel may have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel can be set and / or limited by the STA that supports the minimum bandwidth operating mode from among all STAs operating in the BSS. In the 802.11ah example, the primary channel may be 1 MHz wide for an STA (e.g., an MTC type device) that supports (e.g., only) 1 MHz mode, even if the AP and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier detection and / or network allocation vector (NAV) settings may depend on the status of the primary channel. For example, if the primary channel is busy because an STA (which only supports 1MHz operating mode) is transmitting to the AP, the entire available frequency band may be considered busy, even though a large portion of the frequency band remains idle and could be available.

[0070] In the United States, the available frequency band that can be used by 802.11ah is from 902 MHz to 928 MHz. In South Korea, the available frequency band is from 917.5 MHz to 923.5 MHz. In Japan, the available frequency band is from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.11ah is from 6 MHz to 26 MHz, depending on the country code.

[0071] Figure 1D is a system diagram showing RAN113 and CN115 according to one embodiment. As described above, RAN113 may employ NR radio technology to communicate with WTRU102a, 102b, and 102c via the air interface 116. RAN113 may also communicate with CN115.

[0072] RAN113 may include gNB180a, 180b, and 180c, but it will be understood that RAN113 may include any number of gNBs while remaining consistent with one embodiment. Each of the gNB180a, 180b, and 180c may include one or more transceivers for communicating with WTRU102a, 102b, and 102c via the air interface 116. In one embodiment, the gNB180a, 180b, and 180c may implement MIMO technology. For example, the gNB180a and 180b may utilize beamforming to transmit signals to and / or receive signals from the WTRU102a, 102b, and 102c. Thus, the gNB180a may, for example, use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU102a. In one embodiment, gNB180a, 180b, and 180c may implement carrier aggregation technology. For example, gNB180a may transmit multiple component carriers to WTRU102a (not shown). A subset of these component carriers may be on the unlicensed spectrum, while the remaining component carriers may be on the licensed spectrum. In one embodiment, gNB180a, 180b, and 180c may implement coordinated multi-point (CoMP) technology. For example, WTRU102a may receive coordinated transmissions from gNB180a and gNB180b (and / or gNB180c).

[0073] WTRU102a, 102b, and 102c may communicate with gNB180a, 180b, and 180c using transmissions associated with scalable numerology. For example, OFDM symbol spacing and / or OFDM subcarrier spacing may differ for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. WTRU102a, 102b, and 102c may communicate with gNB180a, 180b, and 180c using subframes or transmit time intervals (TTIs) of varying or scalable lengths (including, for example, a varying number of OFDM symbols and / or a varying duration of absolute time).

[0074] gNB180a, 180b, and 180c can be configured to communicate with WTRU102a, 102b, and 102c in standalone and / or non-standalone configurations. In a standalone configuration, WTRU102a, 102b, and 102c can communicate with gNB180a, 180b, and 180c without accessing other RANs (such as e-nodes B160a, 160b, and 160c). In a standalone configuration, WTRU102a, 102b, and 102c can utilize one or more of gNB180a, 180b, and 180c as mobility anchor points. In a standalone configuration, WTRU102a, 102b, and 102c can communicate with gNB180a, 180b, and 180c using signals in the unlicensed band. In a non-standalone configuration, WTRU102a, 102b, and 102c can communicate with gNB180a, 180b, and 180c while also communicating with other RANs such as enodes B160a, 160b, and 160c. For example, WTRU102a, 102b, and 102c can implement DC principles to communicate substantially simultaneously with one or more gNB180a, 180b, and 180c, and one or more enodes B160a, 160b, and 160c. In a non-standalone configuration, enodes B160a, 160b, and 160c can act as mobility anchors for WTRU102a, 102b, and 102c, and gNB180a, 180b, and 180c can provide additional coverage and / or throughput to service WTRU102a, 102b, and 102c.

[0075] Each of the gNB180a, 180b, and 180c can be associated with a specific cell (not shown) and can be configured to handle wireless resource management decisions, handover decisions, user scheduling in UL and / or DL, support for network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data to user plane functions (UPF) 184a and 184b, routing of control plane information to access and mobility management functions (AMF) 182a and 182b, etc. As shown in Figure 1D, the gNB180a, 180b, and 180c can communicate with each other via the Xn interface.

[0076] The CN115 shown in Figure 1D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and at least one Data Network (DN) 185a, 185b. Although each of the above elements is shown as part of CN115, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0077] AMF182a and 182b can be connected to one or more of gNB180a, 180b, and 180c in RAN113 via the N2 interface and can act as control nodes. For example, AMF182a and 182b may be responsible for user authentication of WTRU102a, 102b, and 102c, support for network slicing (e.g., handling different protocol data unit (PDU) sessions with different requirements), selection of specific SMF183a and 183b, management of registration areas, termination of NAS signaling, mobility management, etc. Network slicing can be used by AMF182a and 182b to customize CN support for WTRU102a, 102b, and 102c based on the type of service being used by WTRU102a, 102b, and 102c. For example, different network slices can be established for different use cases, such as services relying on ultra-high reliability low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, and services for MTC access. The AMF162 may provide control plane functionality for switching between RAN113 and other RANs (not shown) employing other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies like Wi-Fi.

[0078] SMF183a and 183b can be connected to AMF182a and 182b in CN115 via the N11 interface. SMF183a and 183b can also be connected to UPF184a and 184b in CN115 via the N4 interface. SMF183a and 183b can select and control UPF184a and 184b and configure the routing of traffic through UPF184a and 184b. SMF183a and 183b may perform other functions, such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, and providing downlink data notifications. PDU session types can be IP-based, non-IP-based, Ethernet-based, etc.

[0079] UPF184a, 184b can be connected via the N3 interface to one or more of gNB180a, 180b, 180c in RAN113, which may provide WTRU102a, 102b, 102c with access to a packet-switched network such as the Internet 110 to facilitate communication between WTRU102a, 102b, 102c and IP-enabled devices. UPF184, 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.

[0080] CN115 can facilitate communication with other networks. For example, CN115 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between CN115 and PSTN108. Furthermore, CN115 may provide WTRU102a,102b,102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, WTRU102a,102b,102c can be connected to DN185a,185b through UPF184a,184b via an N3 interface to UPF184a,184b, and an N6 interface between UPF184a,184b and local data networks (DN)185a,185b.

[0081] In view of Figures 1A to 1D and their corresponding descriptions, one or more, or all, of the functions described herein with respect to any of the WTRU 102a to d, base stations 114a to b, e-nodes B160a to c, MME 162, SGW 164, PGW 166, gNB 180a to c, AMF 182a to b, UPF 184a to b, SMF 183a to b, DN 185a to b, and / or any other (one or more) elements / devices described herein can be implemented by one or more emulation elements / devices (not shown). An emulation device may be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, an emulation device may be used to test other devices and / or to simulate network and / or WTRU functions.

[0082] Emulation devices can be designed to implement one or more tests of other devices in a laboratory environment and / or a carrier network environment. For example, one or more emulation devices may perform one or more, or all, of the functions while fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices in a communication network. One or more emulation devices may perform one or more, or all, of the functions while temporarily implemented / deployed as part of a wired and / or wireless communication network. Emulation devices may be directly coupled to another device for testing purposes and / or tests may be performed using over-the-air wireless communication.

[0083] One or more emulation devices may perform one or more functions, including all of them, while not implemented / deployed as part of a wired and / or wireless communication network. For example, emulation devices may be used in test laboratory and / or non-deployed (e.g., test) wired and / or wireless communication network test scenarios to implement testing of one or more components. One or more emulation devices may be test equipment. Direct RF coupling and / or wireless communication via RF circuitry (e.g., including one or more antennas) may be used by emulation devices to transmit and / or receive data.

[0084] introduction

[0085] measurement

[0086] In RRC_CONNECTED, WTRU102 can measure one or more beams from a cell's multiple beams. WTRU102 can average the measurement results (e.g., power values) to derive (e.g., determine) the cell quality corresponding to the cell. For example, WTRU102 can be configured to consider a subset of the detected beams. Filtering can be performed at two different levels: at the physical layer to derive beam quality, and then at the RRC layer to derive cell quality from multiple beams. Cell quality from beam measurements can be derived in the same way for (one or more) serving cells and (one or more) non-serving cells. The measurement report may include measurement results for X best beams, such as when WTRU102 is configured to do so by gNB180.

[0087] Figure 2 is a block diagram showing an example of a measurement model. In A in Figure 2, WTRU102 may perform one or more measurements (e.g., beam-specific samples) within the physical layer. In L1 filtering block 202, WTRU102 may perform internal L1 filtering of the input measured in A. For example, filtering may vary depending on the implementation. Strict filtering may be implementation-dependent. Implementation-dependent measurements in the physical layer (e.g., input A and L1 filtering) may not be constrained by normalization.

[0088] A in Figure 2 1In this configuration, measurements (e.g., beam-specific measurements) can be reported from Layer 1 to Layer 3 after Layer 1 filtering. In Beam Consolidation / Selection block 204, WTRU 102 may consolidate beam-specific measurements to derive cell quality information for the corresponding cell. The behavior of beam consolidation / selection can be normalized. For example, RRC signaling may constitute parameters associated with beam consolidation / selection.

[0089] In Figure 2, at B, measurement information derived from beam-specific measurements (e.g., cell quality) can be reported to Layer 3 after beam consolidation / selection block 204. For example, the reporting period in B is A 1 It can correspond to (for example, be equal to) one measurement period in . In the layer 3 filtering block 206 for cell quality, WTRU 102 may perform filtering on the measurements provided in B. For example, the behavior of the layer 3 filter can be normalized. For example, RRC signaling may constitute the parameters associated with the layer 3 filtering.

[0090] In Figure 2, at C, post-processing measurements can be provided in the Layer 3 filtering block 206. These measurements can be used as input for one or more evaluations of reporting criteria. For example, the filtering reporting period in C may correspond to (e.g., be equal to) one measurement period in B. The filtering reporting rate in C may correspond to (e.g., be equal to) the rate in B. In the reporting criterion evaluation block 208, WTRU 102 may check whether actual measurement reporting is required. The evaluation may be based on two or more flows of measurements at reference point C (e.g., to compare different measurements). In Figure 2, this is input C and C 1As indicated by WTRU102, new measurement results are at least point C and / or C. 1 Each time a report is submitted, the reporting criteria may be evaluated (for example, they may be evaluated). The reporting criteria can be standardized. For example, RRC signaling may constitute the parameters associated with the evaluation of the reporting criteria.

[0091] In Figure 2, at point D, the WTRU102 can transmit measurement report information (for example, in a message) to a network, such as the gNB180, via the wireless interface.

[0092] In the L3 beam filtering block 210 in Figure 2, WTRU102 is located at point A 1 Filtering can be performed on the measurements provided (e.g., beam-specific measurements). For example, the behavior of the beam filter can be normalized. For example, RRC signaling can constitute parameters associated with the beam filter configuration.

[0093] In Figure 2, at E, post-processing measurements (e.g., beam-specific measurements) in the L3 beam filtering block 210 can be provided. For example, the measurements can be used as input for selecting X measurements to be reported. For example, if the filtering reporting period in E is A 1 It can correspond to one measurement period in (for example, equal to). The filtering reporting rate is point A 1 It may be equivalent to the reporting rate in [location].

[0094] In beam selection block 212 for beam reporting, WTRU102 may select X measurements from the measurements provided in E. The beam selection behavior can be normalized. For example, RRC signaling may constitute the parameters associated with beam selection.

[0095] In Figure 2, at point F, the WTRU can transmit beam measurement information (for example, in beam measurement reports) to a network such as the gNB180 via a wireless interface.

[0096] For example, Layer 1 filtering may introduce a certain level of measurement averaging (e.g., including). How and when WTRU102 strictly performs the requested measurements may be implementation-specific to the point at which the output in B achieves the implementation requirements specified in TS38.133. The Layer 3 filtering and related parameters for cell quality used are specified in TS38.331 and may not introduce any delay in sample availability between B and C. In Figure 2, C 1 This is the input used in event evaluation. The L3 beam filtering and related parameters used are specified in TS38.331 and may not introduce any delay in sample availability between E and F.

[0097] For example, a measurement report may include measurement identification information for the associated measurement configuration that triggered the report. A measurement report may include cell and / or beam measurements configured by the network. The number of non-serving cells to be reported can be limited through network configuration. Cells belonging to an exclusion list configured by the network may not be used in event evaluation and reporting. Cells belonging to an allow list can be configured by the network. For example, cells belonging to an allow list (e.g., only those) can be used in event evaluation and reporting. Beam measurements to be included in a measurement report can be configured by the network (e.g., beam identifier only, measurement result and beam identifier, or no beam report).

[0098] For example, in-frequency neighbor (e.g., cell) measurements and inter-frequency neighbor (e.g., cell) measurements may include synchronization signal block (SSB) based measurements and / or channel state information reference signal (CSI-RS) based in-frequency measurements. For example, an SSB-based in-frequency measurement may refer to an SSB-based in-frequency measurement where the center frequency of the serving cell's SSB is the same as the center frequency of the neighbor cell's SSB, and / or the subcarrier spacing of the two SSBs is the same. For example, an SSB-based inter-frequency measurement may refer to an SSB-based in-frequency measurement where the center frequency of the serving cell's SSB is different from the center frequency of the neighbor cell's SSB, and / or the subcarrier spacing of the two SSBs is different. In the case of SSB-based measurements, one measurement can correspond to one SSB, and WTRU102 considers different SSBs to be different cells.

[0099] For example, a CSI-RS-based in-frequency measurement may refer to a measurement where the subcarrier spacing (SCS) of the CSI-RS resource on the neighbor cell configured for the measurement is the same as the SCS of the CSI-RS resource on the serving cell indicated for the measurement. For example, in the case of a 60 kHz subcarrier spacing, the CP type of the CSI-RS resource on the neighbor cell configured for the measurement may be the same as the CP type of the CSI-RS resource on the serving cell indicated for the measurement. For example, a CSI-RS-based in-frequency measurement may refer to a measurement where the center frequency of the CSI-RS resource on the neighbor cell configured for the measurement is the same as the center frequency of the CSI-RS resource on the serving cell indicated for the measurement.

[0100] For example, CSI-RS-based inter-frequency measurements may refer to measurements other than CSI-RS-based intra-frequency measurements (e.g., measurements that use CSI-RS resources). For example, extended CP may (or may not) be supported for CSI-RS-based measurements.

[0101] For example, a measurement may be referred to as non-gap-assisted or gap-assisted, depending on the WTRU capability, the WTRU's active BWP, and / or (e.g., current) operating frequency. For SSB-based inter-frequency measurements where measurement gap requirement information is reported by WTRU102, the measurement gap configuration may be provided in accordance with that information. Otherwise, the measurement gap configuration may be provided in the following cases (e.g., at any time): the WTRU supports only per-WTRU measurement gaps, and / or the WTRU supports per-FR measurement gaps, and any of the serving cells are in the same frequency range under measurement. For SSB-based in-frequency measurements where measurement gap requirement information is reported by WTRU, the measurement gap configuration may be provided in accordance with that information. Otherwise, the measurement gap configuration may be provided in the following cases (e.g., at any time): any configured BWP (e.g., other than the initial BWP) does not include the frequency domain resources of the SSB associated with the initial DL BWP.

[0102] In a non-gap-supported example, WTRU102 may be capable of performing such measurements without a measurement gap (for example, it is assumed to be possible). In a gap-supported scenario, it may not be assumed that WTRU102 can perform such measurements without a measurement gap (for example, it cannot be assumed).

[0103] Inter-cell L1 / L2 trigger mobility (LTM)

[0104] Currently, 5G NR Release 17 (R17) allows the use of inter-cell beam management, which can manage beams in the case of carrier aggregation (CA), but does not support cell changes and / or additions. In 5G NR Release 18 (R18), one of the goals of work item "Further NR Mobility Enhancements" in RP-213565 is to specify mechanisms and procedures for L1 / L2-based inter-cell mobility for mobility latency reduction, as shown below. 1. Define mechanisms and procedures for L1 / L2-based inter-cell mobility to reduce mobility latency. • Configuration and maintenance for multiple candidate cells to enable rapid application of configurations for candidate cells [RAN2, RAN3] • Dynamic switching mechanism between candidate serving cells (including SpCell and SCell) for potential applicable scenarios based on L1 / L2 signaling [RAN2, RAN1] • L1 extensions for inter-cell beam management, including L1 measurement and reporting, and beam indication [RAN1, RAN2] - Note 1: Early RAN2 involvement is needed, which may further clarify the interaction between this black circle and the previous black circle. • Timing Advance Management [RAN1, RAN2] • CU-DU interface signaling [RAN3] to support L1 / L2 mobility, if necessary.

[0105] Note 2: FR2-specific extensions, if any, will not be excluded.

[0106] Note 3: The L1 / L2-based inter-cell mobility procedure is applicable to the following scenarios. □ Standalone, CA, and NR-DC with serving cell changes within a single CG □ Within a DU and between CUs (applicable for standalone and CA; no new RAN interface is expected) □Both within and between frequencies □ Both FR1 and FR2 □ Source cells and target cells can be synchronous or asynchronous. □This does not include cases between CUs.

[0107] L1 / L2-based mobility is initially initiated at R17, and inter-cell beam management at R17 addresses in-DU and in-frequency scenarios. In this case, the serving cell may remain unchanged (e.g., there is no possibility of changing the serving cell using L1 / 2-based mobility). In FR2 deployments, CAs are generally used to leverage available bandwidth, such as to aggregate multiple component carriers (CCs) within a single band. CCs are generally transmitted over the same analog beam pair (e.g., gNB beam and WTRU beam). WTRU102 can consist of TCI states for receiving PDCCH and PDSCH (e.g., 64 TCI states). Each TCI state may include an RS or SSB that WTRU102 references to set its beam. At R17, the SSB may be associated with a non-serving physical cell ID (PCI). MAC signaling (e.g., "TCI state indication for UE-specific PDCCH MAC CE") activates TCI states for Coreset / PDCCH. Reception of PDCCH from non-serving cells is supported by MAC CE indicating TCI states associated with non-serving PCI. MAC signaling (e.g., "TCI state activation / deactivation for UE-specific PDSCH") activates a subset of up to eight TCI states for PDSCH reception. DCI indicates one of the eight TCI states. R17 also supports "integrated TCI states" without multi-TRP, but with a different update mechanism (e.g., DCI-based). R18 is expected to support integrated TCI states with multi-TRP.

[0108] The overall goal of LTM is to improve handover latency. In legacy L3 handover (HO) or conditional handover (CHO), the WTRU102 can generally first send a measurement report using RRC signaling. In response, the network may provide further measurement configurations and potentially conditional handover configurations. In legacy L3 handover, the network provides configurations for the target cell after the WTRU102 reports using RRC signaling that the cell satisfies the configured radio quality criteria. In legacy conditional handover, to reduce the handover failure rate due to delays in sending the measurement report and then receiving the RRC reconfiguration, the network provides the target cell configuration in advance, as well as the metrics that determine when the WTRU102 should trigger the CHO configuration. However, both of these L3 handover methods suffer from some amount of delay due to sending the measurement report and receiving the target configuration, especially in the case of unconditional handover.

[0109] One of the goals of LTM is to enable rapid application of configurations for candidate cells, including dynamic switching between SCells and PCells (e.g., role switching between SCells and PCells), without performing RRC signaling. In the case of inter-central units (CUs), this is not included as it requires the relocation of PDCP anchors and is already excluded from the work items. Therefore, an RRC-based approach is required, at least to support inter-CU handovers.

[0110] Furthermore, in the legacy L3 handover mechanism, one or more currently active SCells are released before WTRU102 moves to complete the handover to the target cell in the coverage area of ​​the new site. Scells can only be added again after the handover is successful, which leads to reduced throughput during the handover. Therefore, one of the goals of L1 / 2 is to allow CA operation to be activated instantaneously when the serving cell changes.

[0111] Figure 3 is a system diagram showing an example of LTM operation. Candidate cell groups can be configured by RRC. Dynamic switching between PCell and SCell can be achieved by WTRU102 using L1 / 2 signaling.

[0112] In Figure 3, RRC signaling may configure WTRU102 using cells 1, 2, 3, and 4 as candidate cell groups. For example, cell 1 302 may be operating at 3.5 GHz, cell 2 304 at 2.1 GHz, cell 3 306 at 26 GHz, and / or cell 4 308 at 26 Hz. Cell 1 302 can be activated as a Pcell. Cell 2 304 can be activated as an Scell. WTRU102 may perform dynamic Scell ​​switching between cell 2 304, cell 3 306, and / or cell 4 308 (for example, during mobility). WTRU102 may perform dynamic Pcell switching between cell 1 302 and cell 2 304 (for example, during mobility).

[0113] In March 2023, RAN Working Group 2 (RAN2) approved a baseline procedure for LTM. Figure 4 is a procedure diagram showing the baseline procedure for LTM. At 402, WTRU102 may be in an RRC connection state with the network (e.g., gNB180). At 404 in Figure 4, WTRU102 may send a MeasurementReport message to gNB180. gNB180 may decide to use LTM and begin preparing (one or more) candidate cells.

[0114] In 406, gNB180 may prepare an LTM candidate cell configuration, and in 408, gNB180 may send an RRCReconfiguration message to WTRU102 containing the LTM candidate cell configuration of one or more candidate cells.

[0115] In 410, WTRU102 may store the LTM candidate cell configuration and send an RRCReconfigurationComplete message to the gNB.

[0116] In 412, WTRU102 may perform DL synchronization and / or timing advance (TA) capture with (one or more) candidate cells before receiving a cell switching command. For example, DL synchronization for (one or more) candidate cells prior to a cell switching command may be based on (for example, at least) SSB. For example, TA capture for (one or more) candidate cells prior to an LTM cell switching command may be based on (for example, at least) PDCCH ordered RACH, where the PDCCH order is triggered only by the source cell. In 414, WTRU102 may perform UL synchronization with (one or more) candidate cells before receiving a cell switching command.

[0117] In 416, WTRU102 can perform L1 measurements on the configured (one or more) candidate cells and transmit (e.g., report) lower layer measurements to the gNB. For example, lower layer measurement reports can be carried over L1 or MAC. For example, the order of DL synchronization, UL synchronization, and / or L1 measurement reports (e.g., 412, 414, 416 in Figure 4) can be changed and / or modified.

[0118] At 418, gNB180 may perform an LTM determination and, at 420, may decide to perform a cell switch to the target cell. At 420, gNB180 may transmit a MAC CE that triggers the cell switch. For example, gNB180 may include information indicating the candidate configuration index of the target cell. At 422, WTRU102 may switch to the configuration of the target cell. For example, gNB180 may provide information indicating one or more beams of the target cell.

[0119] In 424, WTRU102 may perform random access procedures toward the target cell, for example, when required by cell switching.

[0120] In 426, WTRU102 can indicate the successful completion of a cell switch to the target cell. For example, WTRU102 may send an uplink signal and / or message to indicate the successful completion of an LTM cell switch to the target cell.

[0121] For example, WTRU102 may perform steps 412 through 426 once or more times for subsequent LTM cell switching, based on the configuration provided in 408.

[0122] As mentioned above, in the case of inter-CU switching, this is not included because it requires the relocation of the PDCP anchor and is already excluded from the work items. Therefore, RRC-based methods can be provided to support inter-CU handovers, such as in the case of a DU / CU split architecture. For example, inter-CU handover procedures can be used in conjunction with LTM procedures for inter-CU, inter-DU, and / or inter-DU switching. For example, when LTM is configured, RRC-based measurement and mobility can be performed in parallel with the measurement and measurement reporting mechanisms to support LTM, along with the measurement and measurement reporting mechanisms to support LTM.

[0123] Figure 5 is a system diagram showing examples of intra-CU switching and inter-CU switching. Simply as an example, LTM can be used for mobility between cells 1 502, 3 504, and 4 506 belonging to the first CU, and LTM can be used for mobility between cells 2 508, 5 510, and 6 512 belonging to the second CU. L3 mobility can be used for mobility between cells belonging to the first DU and cells belonging to the second DU, for example, for a handover from cell 1 502 to cell 2 508 (e.g., measurement reporting and RRC reconstruction, and / or conditional reconstruction (CHO)).

[0124] For example, LTM may perform reconfiguration (handover) using L1 measurement reporting and MAC CE triggers. For example, L3 mobility may use L3 measurements and RRC triggers for reconfiguration. The latency of L1 measurement and MAC triggering can be expected to be significantly lower than that of L3 measurement and RRC triggering for several reasons. Firstly, measurement filtering performed at L1 can be performed over a shorter time scale than measurement filtering performed at L3, and measurement event evaluation at L1 can be expected to be performed over a shorter time scale than L3 measurement evaluation, which uses a relatively longer trigger time. Handover using L3 signaling is relatively expensive in terms of overhead, and service interruptions should only be performed when necessary, so L3 measurement evaluation can be performed using longer filtering and longer trigger times, and the trigger times and filtering are designed to reduce the possibility of ping-ponging between cells and ensure stable target cell measurements before performing a handover. L1 mobility implies lower overhead and service disruption costs due to the use of pre-configured cell configurations, faster handover execution times, avoidance of full MAC resets when performing in-DU handovers, and further enhancements such as performing UL and DL synchronization before performing cell changes. Therefore, measurements can be performed more quickly to improve latency and handover failure / radio link failure rates at the expense of higher ping-pong rates, which, as described, has less cost than in the case of L3 mobility. Thus, any changes in cell quality can be detected earlier in L1 than in L3.

[0125] Secondly, LTM may be under the control of the DU (e.g., the source DU in the case of inter-DU mobility), while L3 mobility (e.g., RRC) is controlled by the CU. RRC signaling between WTRU102 and CU may be slower compared to L1 / L2 signaling between WTRU102 and DU. RRC signaling can be transmitted through the DU using the L1 / 2 protocol layer, while MAC / L1 signaling can be received at the DU. RRC signaling may be more reliable than using L2 (e.g., L2 only) by using RRC acknowledgments (e.g., RRC Reconfiguration Complete), RLC AM (e.g., ARQ), and MAC (e.g., HARQ). Multiple levels of acknowledgments imply further latency and delay.

[0126] For these reasons, several potential race conditions exist when LTM is configured. Race conditions may refer to conditions that exist between different measurement types and reporting types, and / or between different handover trigger signaling mechanisms. The challenges include any of the following: (1) premature mobility outside the LTM area, (2) delayed and / or blocked mobility outside the LTM area, (3) a race condition in which WTRU102 receives signaling for both L3 mobility and L1 / 2 mobility, and / or (4) a race condition in which WTRU102 triggers an L3 measurement report and the L2 mobility procedure is performed before the successful delivery of the L3 report.

[0127] For premature mobility outside the LTM area, in some scenarios, an L3 measurement event may be triggered based on a comparison between the current serving cell and neighboring cells, even if a suitable configured LTM candidate exists.

[0128] For delayed or blocked mobility outside the LTM area, in some scenarios, frequent L2 trigger handovers can reset L3 measurement evaluations, thus preventing L3 measurement events from being triggered.

[0129] Furthermore, if WTRU102 receives signaling for L3 mobility that can be controlled by CU, as well as L1 and / or L2 mobility (for example, both) that can be controlled by DU, a race condition may exist.

[0130] Furthermore, if WTRU102 triggers an L3 measurement report, a race condition may exist. An L2 mobility procedure is executed before WTRU102 can successfully deliver the L3 report.

[0131] Overview

[0132] Abbreviations and acronyms

[0133] The following abbreviations and acronyms may be used herein.

[0134] ACK (Acknowledgment)

[0135] BLER Block Error Rate

[0136] BWP Bandwidth Part

[0137] CA Career Aggregation

[0138] CAP channel access priority

[0139] CAPC Channel Access Priority Class

[0140] CCA Clear Channel Assessment

[0141] CCE control channel element

[0142] CE control element

[0143] CG configuration grant or cell group

[0144] CHO Conditional Handover

[0145] CP cyclic prefix

[0146] CP-OFDM (based on cyclic prefixes) is a conventional OFDM.

[0147] CPA conditional PsCell addition

[0148] CPAC Conditional PsCell Addition / Modification

[0149] CPC Conditional PsCell Modification

[0150] CQI Channel Quality Indicator

[0151] CRC Cyclic Redundancy Check

[0152] CSI Channel Status Information

[0153] CW Contention Window

[0154] CWS Contention Window Size

[0155] CO channel occupancy

[0156] DAI Downlink Allocation Index

[0157] DC Dual Connectivity

[0158] DCI Downlink Control Information

[0159] DFI Downlink Feedback Information

[0160] DG Dynamic Grant

[0161] DL Downlink

[0162] DM-RS demodulation reference signal

[0163] DRB Data Wireless Bearer

[0164] eLAA Enhanced Licensed Assisted Access

[0165] FeLAA Further Extended License Assistance Access

[0166] HARQ Hybrid Automated Resend Request

[0167] LAA License Assistance Access

[0168] LBT Listen Before Talk

[0169] LTE, for example, Long-Term Evolution from 3GPP LTE R8 or later.

[0170] LTM L1 / 2 Trigger Mobility

[0171] NACK Negative ACK

[0172] MCG Mastercell Group

[0173] MAC Media Access Control

[0174] MCS Modulation and Coding Scheme

[0175] MIMO Multi-Input Multi-Output

[0176] NR new radio

[0177] OFDM (Orthogonal Frequency Division Multiplexing)

[0178] PCell Primary Cell

[0179] PCI physical cell identification information

[0180] PHY Physical Layer

[0181] PID (Process ID)

[0182] PO Paging Occasions

[0183] PRACH Physical Random Access Channel

[0184] PSCell Primary SCG Cell

[0185] PSS Primary Sync Signal

[0186] RA Random Access (or Procedure)

[0187] RACH Random Access Channel

[0188] RAR Random Access Response

[0189] RCU (Radio Access Network Central Unit)

[0190] RF Wireless Frontend

[0191] RLC Wireless Link Control

[0192] RLF wireless link failed

[0193] RLM Wireless Link Monitoring

[0194] RNTI (Radio Network Identifier)

[0195] RO RACH Occasion

[0196] RRC (Radio Resource Control)

[0197] RRM Wireless Resource Management

[0198] RS reference signal

[0199] RSRP Reference Signal Received Power

[0200] RSSI Received Signal Strength Indicator

[0201] SCell Secondary Cell

[0202] SCG Secondary Cell Group

[0203] SDU Service Data Unit

[0204] SpCell Special Cell

[0205] SRS Sounding Reference Signal

[0206] SS synchronization signal

[0207] SSS Secondary Synchronization Signal

[0208] SWG (Switching Gap in a Self-Contained Subframe)

[0209] SPS Semi-Persistent Scheduling

[0210] SUL Supplemental Uplink

[0211] TB transport block

[0212] TBS Transport Block Size

[0213] TRP Transmit / Receive Point

[0214] TSC Time-sensitive communication

[0215] TSN Time-Sensitive Networking

[0216] UL Uplink

[0217] URLLC: Ultra-high reliability and low latency communication

[0218] WBWP Wideband Part

[0219] WLAN (Wireless Local Area Network) and related technologies (IEEE 802.xx domain)

[0220] As used herein, the term SpCell may refer to either a PCell of the MCG and / or a PSCell of the SCG (depending, for example, whether the MAC entity is associated with the MCG or the SCG).

[0221] In some representative embodiments, the LTM virtual cell quality can be determined (e.g., derived) from multiple LTM candidate cells. For example, it may be possible to avoid premature mobility outside the LTM area, such as due to (e.g., transient) radio link quality issues in a serving cell while other candidate cells within the LTM area are acceptable. In other words, WTRU102 may perform procedures to determine whether it is worthwhile (e.g., efficient) to make an L3 switch to a cell outside the LTM (e.g., by using an L3 filter to compare an LTM set with cells outside that set) or to switch to a separate LTM set (e.g., by comparing LTM sets).

[0222] In some representative embodiments, the L3 cell quality may be determined for a virtual cell using beams from a subset or all of the cells in the LTM candidate set. Virtual cell quality derivation (e.g., procedure) may refer to a modified cell quality derivation, where beams from different cells in the LTM candidate set may be considered to derive the virtual cell quality of the LTM candidate set. The virtual cell quality of the source LTM candidate set may be used as the quality of the source cell or to determine an offset to apply to (e.g., on top of) the quality of the source cell. The virtual cell quality of the target LTM candidate set (e.g., a set of neighbor cells) may be used as the quality of the target cell or to determine an offset to apply to (e.g., on top of) the quality of the target cell. WTRU102 may use virtual cell quality to report measurement information, for example, under conditions such as the elapsed time period (e.g., maximum or minimum) since the (last) LTM cell switchover.

[0223] For example, WTRU102 might average across a first (e.g., larger) set of cells and / or beams immediately after a cell switch, and then use a second (e.g., smaller) set of cells and / or beams, such as only the source cell or the best candidate cell. This could ensure that WTRU102 can eventually switch to a better LTM set.

[0224] In a first exemplary embodiment, WTRU102 may receive information indicating the configuration associated with determining the quality of the LTM set (e.g., how it should be derived). The determined quality may consider beams on all or a subset of the cells in the LTM set. For example, the configuration may include information indicating the maximum / minimum number of cells to be included in the derivation, the maximum / minimum number of beams to be included in the derivation, the minimum quality of beams / cells to be included in the derivation (e.g., absolute / relative to serving cells, absolute / relative to the best cell), one or more averaging / filtering weights to be applied for the derivation, one or more offsets and / or scaling parameters to be applied to the derivation, a list of cells and / or beams that must be included in the derivation, a list of cells and / or beams that may not be included in the derivation, an association between each serving beam and a list of beams on other cells to be included in the virtual cell quality derivation, an indication for using the derived LTM set quality as the quality of the source and / or target cells, and / or an indication for using the derived LTM set quality as an offset to be applied (e.g., on top of) the quality of the source and / or target cells.

[0225] The WTRU102 may receive information indicating the configuration for L1 and / or L3 measurement events. For example, triggering conditions for an event may be based on a comparison between at least one LTM set quality (e.g., serving LTM set, target LTM set) and one or more of the following: another LTM set quality, individual cell quality (e.g., serving cell outside the LTM set, target cell outside the LTM set), cell quality threshold, maximum time since the last LTM cell switchover, and / or minimum time since the last LTM cell switchover.

[0226] WTRU102 can determine the cells and / or beams to be considered for LTM set quality derivation (for example, based on the above configuration for the serving LTM set and / or target LTM set).

[0227] WTRU102 can perform measurements and derive the LTM set quality of the source LTM set and / or target LTM set.

[0228] WTRU102 may use the derived LTM set quality as source and / or target cell quality (for example, based on the above configuration). WTRU102 may apply the derived LTM set quality to serving cell and / or target cell quality (for example, as offset, scaling factor, etc.) (for example, based on the above configuration).

[0229] WTRU102 may determine that one or more of the event triggering conditions have been met, such as the minimum time period elapsed since the last LTM cell switchover; send a measurement report associated with the event (including, for example, one or more derived LTM set qualities, details of the cells and / or beams used for their derivation, legacy cell and / or beam measurement results); perform an associated conditional reconfiguration (if configured); and / or send an indication regarding the performance of a conditional reconfiguration (including, for example, one or more derived LTM set qualities, details of the cells and / or beams used for their derivation, legacy cell and / or beam measurement results).

[0230] In some representative embodiments, LTM serving cell quality can be modified by taking into account LTM candidate cell quality. For example, when most cells in a candidate LTM area have low quality, or when the current LTM set has multiple active candidates, it may be possible to avoid premature mobility outside the LTM area. When switching from one LTM set to another (for example, between CUs), WTRU102 may (for example, should) verify that the target set has two or more candidates and / or that the source set does not have enough (e.g., configured or a predetermined number) active candidates.

[0231] In some representative embodiments, WTRU102 may consist of an active LTM set and a target LTM set. For example, cell quality derivation and / or comparison may be performed as a legacy procedure (e.g., using N L1 filtered beam measurements on a cell to derive L3 filtered cell quality) and may be modified with one or more additional triggering conditions that must be achieved by a certain number of cells in the target and / or source candidate set. The active LTM set may be determined as a set of configured LTM candidate cells in which WTRU102 maintains downlink synchronization, WTRU102 has a valid timing advance (e.g., UL synchronization), WTRU102 actively reports L1 CSI measurements, WTRU102 is configured to perform TRS tracking, and / or candidate cells that exceed a radio quality threshold. The target LTM set may be associated with a list of cell identification information, PCI, and / or SSB. WTRU102 may perform L1 and / or L3 measurements, as well as measurement reporting or CHO triggering evaluation. The active LTM set quality can be determined by applying a first offset to the measured serving cell quality of any additional LTM cells (e.g., each) determined to be in the active LTM set. The target LTM set quality can be determined by applying a second offset to the measured neighbor cell quality of any additional neighbor cells (e.g., each) in the target set, such as cells that satisfy a configured threshold.

[0232] For example, WTRU102 is a serving cell after applying one or more (e.g., a first) offsets that achieve an event condition (e.g., event A4 concerning the target cell) and a target cell after applying one or more (e.g., a second) offsets that achieve an event condition (e.g., event A3 comparing the source and target, event A5 comparing the source and target to different thresholds, etc.) and a certain number of candidates in the candidate set Measurement reports may be sent or CHOs associated with an event may be performed when any of the following are achieved: a cell satisfies a condition (e.g., a target cell satisfies events A3 / A4 / A5 and N cells in the target set satisfy the threshold); a target cell achieves an event condition after applying one or more offsets (e.g., a second one) and a certain number of cells in the source set satisfy a condition (e.g., a target cell satisfies events A3 / A4 / A5 and it is determined that N cells in the source set fall below the second threshold or fewer than N cells are in the LTM active set); and / or a certain number of target cells achieve an event condition (e.g., N target cells achieve events A3 / A4 / A5). The number of target cells and / or the number of cells in the LTM active set may depend on elapsed time, such as the time elapsed since the last LTM cell switchover (e.g., a first number if the elapsed time is below the threshold, and a second number otherwise).

[0233] In a second exemplary embodiment, WTRU102 may receive information indicating at least one configuration associated with (for example, to identify) an active LTM set and / or a target LTM set. For example, the configuration for an LTM set may include information indicating one of the following: a list of cell identification information, a list of PCIs, and / or a list of SSBs. The list may be associated with an active LTM set. The list may be associated with a target LTM set.

[0234] For example, WTRU102 may receive information indicating at least one configuration for L1 and / or L3 measurement events. For example, the triggering conditions for an event may be based on (one or more) criteria (e.g., an RSRP threshold) for determining additional suitable candidate cells (in addition to, for example, a target SpCell), the number of n additional candidates to consider in the criteria, and / or a timer value for determining whether to use the n additional candidates.

[0235] For example, WTRU102 may determine the number of additional candidates as its first value. WTRU may determine the first number of additional candidates (e.g., 0) based on elapsed time, such as when the time elapsed since the last LTM cell switchover falls below a configured threshold (e.g., a timer value), and otherwise determine a second value (e.g., n greater than 0).

[0236] For example, WTRU102 may perform measurements on active and target LTM sets. WTRU102 may determine which cells should be included in the active and target LTM sets based on any of the following: cells for which WTRU102 maintains downlink synchronization, cells for which WTRU102 has a valid timing advance (e.g., UL synchronization), cells for which WTRU102 is actively reporting L1 CSI beam measurements, cells for which WTRU102 is configured to perform TRS tracking, and / or cells that exceed the radio quality threshold.

[0237] For example, WTRU102 may determine (e.g., a first) offset to apply to any serving cell measurement based on the cells in the active and / or target LTM set. WTRU102 may also determine (e.g., a second) offset to apply to any neighbor cell measurement based on the cells in the target LTM set.

[0238] For example, WTRU102 may evaluate a measurement event based on serving cell measurements (e.g., after the first offset is applied) and / or neighbor cell measurements (e.g., after the second offset is applied). If the triggering conditions for an event are met, WTRU102 may either send a measurement report associated with the event (e.g., including information indicating the identification of any additional cells considered in the event and / or the main cell that triggers the event), and / or, if configured, perform the associated conditional reconfiguration, and / or send information indicating the execution of the conditional reconfiguration (e.g., including information indicating the identification of any additional cells considered in the event and / or the main cell that triggers the event).

[0239] In some representative embodiments, long-term measurement evaluations can be performed across multiple LTM serving cells. For example, a network might want to configure relatively long trigger time (TTT) values ​​for one or more L3 measurement events to prevent premature switching from an LTM set. Side effects may include WTRU102 switching frequently (e.g., more frequently than per TTT) between cells using LTMs, and / or L3 measurement events being triggered too late (or never triggered) because the serving cells of WTRU102 change within the TTT. Trigger conditions can be extended to allow all serving cells within the TTT to be considered, such as when a candidate cell is significantly better than the current serving cell.

[0240] For example, when WTRU102 switches from the first serving cell to the second serving cell using LTM, WTRU102 can derive L3 cell quality and evaluate L3 event triggers based on measurement results applicable to the first and second serving cells (as if the serving cell were a single serving cell). WTRU102 may continue evaluating the serving cell quality and measurement event triggers (e.g., current) after the cell change. After the cell change, WTRU102 may use (e.g., continue) previous (one or more) serving cell measurements as if they were current cell measurements. WTRU102 may trigger a measurement report if at least one condition is met for the current serving cell over the TTT duration (e.g., evaluated using the first and second serving cells). WTRU102 can perform the above under the condition that the measurement result for the candidate cell exceeds the threshold; otherwise, WTRU102 may be triggered (for example, only if the condition is met over TTT for the current serving cell). For example, the L3 filtered result for the second serving cell may be based on the L3 filtered result for the first serving cell at the time of cell switching.

[0241] In a third exemplary embodiment, the WTRU may receive information indicating a configuration associated with determining the serving cell quality (e.g., how it should be derived) using L3 filtering, which takes L1 RSRP, RSRQ, and / or SINR samples from any cell that was a Pcell within the filtering window. For example, the configuration may include information indicating at least one of the filter coefficients, RS type, and / or RS index.

[0242] For example, WTRU102 may receive information indicating the configuration for L1 and / or L3 measurement events. The configuration may include information indicating that the evaluation over TTT (e.g., period, duration, interval) is performed using the measurement results of any cell that was a serving cell while TTT was running (e.g., during TTT), and / or thresholds for neighbor cell measurement results.

[0243] For example, WTRU102 may determine that the conditions for an event are satisfied for a first serving cell and a neighbor cell over a first time period. The first time period may be shorter than (e.g., shorter than) the TTT.

[0244] For example, WTRU102 may receive information indicating that it will use LTM to switch from the first serving cell to the second serving cell at the end of the first time period (or before).

[0245] For example, WTRU102 may determine that the conditions for an event are met for a second serving cell and a neighbor cell over a second time period. The sum of the first and second time periods may be equal to or greater than the TTT. Under the condition that the neighbor cell result exceeds the second serving cell result plus a threshold, WTRU102 may trigger the transmission of a measurement report containing information indicating the first serving cell and / or the second serving cell, as well as the first and / or second time periods.

[0246] In some representative embodiments, a timer prohibition for LTM measurement reporting after an L3 handover procedure may be applied. For example, a timer for L1 reporting may be prohibited after an L3 cell switchover to (e.g., temporarily) limit reporting. The exemplary prohibitions described herein may address race conditions in which an LTM handover occurs before L3 signaling (e.g., RRC reconfiguration completion transmission using RLC AM) is completed, even though the L3 handover is completed. This may occur for L3 handovers involving an LTM set during target configuration, and also during initial LTM setup (e.g., an LTM cell switchover occurs before the delivery of RRC reconfiguration completion corresponding to the LTM setup is completed).

[0247] To ensure that RRC reconfiguration completion signaling is successfully delivered (e.g., to the CU) after an L3 handover, WTRU102 may be prevented from sending L1 measurement reports and / or performing LTM, which may result in a DU-triggered LTM handover and loss of L3 signaling, leading the CU to detect a handover failure or reconfiguration failure. For example, a temporary restriction on neighbor cell and / or candidate cell L1 reporting (e.g., while current cell beam reporting is still enabled to allow scheduling) may be by using a timer or waiting for an RLC acknowledgment of sending an RRC message (e.g., complete). For example, WTRU102 may be prevented from performing LTM while the TTT period has not elapsed (e.g., while the TTT is running).

[0248] In a fourth exemplary embodiment, the WTRU102 may receive an RRC reconfiguration message containing information indicating the LTM measurement pause and / or associated timer value.

[0249] For example, WTRU102 can perform RRC reconfiguration and (if already operational) stop reporting LTM L1 measurements for neighbor cells. WTRU102 can send an RRC reconfiguration complete message.

[0250] For example, under the condition that the amount of time elapsed since the reception of the RRC reconstruction is less than the indicated time amount (e.g., timer value), and WTRU102 receives the LTM cell switching command, WTRU102 may send an indication (e.g., via MAC CE) that the cell switching will not be performed. If the LTM cell switching is received before the timer expires (e.g., the elapsed time is less than the indicated time), WTRU102 may not execute the LTM cell switching command and may respond with a failure indication.

[0251] For example, under the condition that the amount of time elapsed since the transmission of the RRC reconfiguration complete message or successful acknowledgment is less than the indicated time amount (e.g., timer value), and WTRU102 receives an LTM cell switching command, WTRU102 may send an indication (e.g., via MAC CE) that the cell switching will not be performed. If the LTM cell switching is received before the timer expires (e.g., the elapsed time is less than the indicated time), WTRU102 may not execute the LTM cell switching command and may respond with a failure indication.

[0252] For example, when a time period corresponding to the indicated timer value has elapsed since the receipt of the RRC reconstruction message, WTRU102 may start (or restart) reporting the LTM L1 measurement for the candidate cell.

[0253] For example, WTRU102 may start (or restart) reporting the LTM L1 measurement for the candidate cell after a time period corresponding to the indicated timer value has elapsed since the RRC reconstruction completion message was sent.

[0254] In some typical embodiments, the WTRU may provide the network with an identification of the PCell in use when an RRC message is generated while the LTM is in use. In the case of UL, a race condition can be addressed where an L3 measurement report is triggered, but an LTM handover occurs before the RRC message is sent. The L3 measurement report may be sent to the wrong cell (e.g., not the cell on which the event was configured). If the same measurement configuration (e.g., ID) is configured on the target cell, there may be ambiguity as to which cell the event was triggered. In the case of DL, the RRC reconfiguration message is sent by the CU, but the DU is performing the LTM, and a race condition can be addressed. If the RRC message does not contain configuration specific to the old cell group served by the first DU (e.g., DU#1), the CU can safely retransmit the RRC message to WTRU102 via the second DU (e.g., DU#2). A challenge may arise if the content of the RRC message has an expired configuration associated with the old serving cell group on the first DU. If an RRC message is retransmitted to WTRU102 via a second DU, WTRU102 may fail to apply the expired RRC configuration because it refers to the old serving cell group and WTRU102 connects to the new serving cell group. This can trigger a connection re-establishment by WTRU102. If an RRC message is not retransmitted to WTRU102 via a second DU, any new RRC message from the same SRB must use a new PDCP sequence number (SN) commanded for replay protection using the same AS security context. This can create a PDCP SN gap. Since the default value for the t-Reordering timer for SRB1 is infinity, the t-Reordering timer may never expire, and the SRB's PDCP SDU may not be deliverable to the upper layer.

[0255] In some representative embodiments, information indicating the PCell ID may be included in the UL RRC message corresponding to the PCell when the corresponding event (e.g., measurement event, RRC reconfiguration) is triggered. For example, an RRC reconfiguration may be triggered, and the RRC reconfiguration complete message may include information indicating whether an RRC reconfiguration and / or L2 triggered reconfiguration occurred.

[0256] In a fifth exemplary embodiment, WTRU102 may receive information indicating an L3 measurement event and / or reporting configuration. WTRU102 may receive information indicating an LTM configuration. WTRU102 may receive information indicating the configuration of conditions for including the current PCell information in the L3 measurement report (e.g., any candidate cell in the most recent L1 and / or L2 report that is higher than the measurement result of the serving cell with or without an added offset). WTRU102 may perform a measurement evaluation on the current cell and send an L1 and / or L2 measurement report. WTRU102 may decide to trigger the transmission of an L3 measurement report based on the L3 measurement configuration. If the L1 and / or L2 measurement report indicates that the measurement result of the candidate cell is higher than the measurement result of the serving cell (e.g., its plus offset), WTRU102 may send an L3 measurement report containing information indicating the current PCell. WTRU102 may receive an LTM cell switching command and complete the RRC transmission on the new cell.

[0257] In a sixth exemplary embodiment, WTRU102 may receive an RRC reconfiguration message in the source cell. WTRU102 may apply the RRC reconfiguration and send an RRC reconfiguration complete message (for example, before LTM). The RRC reconfiguration complete message may include information indicating that the RRC reconfiguration completion is due to applying the RRC reconfiguration (for example, only) and information indicating the source cell (for example, PCI).

[0258] In a seventh exemplary embodiment, the WTRU 102 may receive an RRC reconfiguration message in a source cell. The WTRU 102 may apply the RRC reconfiguration. The WTRU 102 may receive (or determine) an LTM trigger and reconfigure for a new cell. The WTRU 102 may transmit an RRC reconfiguration complete message that includes information indicating that the RRC reconfiguration completion is due to applying the RRC reconfiguration and the LTM reconfiguration, and information indicating the source cell (e.g., PCI).

[0259] For example, an LTM-only reconfiguration may cause the WTRU 102 to transmit an RRC reconfiguration complete message that does not include any indication (e.g., PCI of the source cell). As another example, the RRC reconfiguration complete message may include information indicating that the message is due to applying only the LTM reconfiguration.

[0260] Common terms

[0261] As used herein, performing LTM or performing an LTM procedure may refer to performing any or all of the steps described in FIG. 4. For example, the WTRU 102 may perform L1 measurements, report on one or more of the candidate cells, switch between the candidate cells (e.g., perform a handover), and perform LTM including early synchronization in DL and / or UL to one or more of the candidate cells. As another example, the WTRU 102 may perform an LTM that refers to the WTRU 102 moving between multiple candidate cells during a procedure and / or switching between them.

[0262] As used herein, a candidate cell set may refer to a group of RRC configurations corresponding to HO configurations for one or more candidate SpCells and / or SCells. One or more candidate cell sets may be groups of two or more RRC configurations corresponding to HO configurations for one or more candidate SpCells and / or SCells. For example, a candidate cell set may include and / or be used interchangeably with one or more complete RRC reconfiguration messages, one or more cell group configurations, and / or one or more cell configurations. A candidate cell configuration may include a candidate configuration identifier, and / or a candidate cell group may include a candidate cell group identifier. For example, grouping of candidate cells may be performed using RRC signaling. Switching between different sets of candidate cells may include updating a serving cell index or a candidate configuration index used in L1 and MAC signaling to reference a specific index. As an example, a MAC CE that triggers a reconfiguration may include a candidate configuration index that informs WTRU102 which cells should be reconfigured.

[0263] In some representative embodiments, one or more candidate cell groups can be configured as a single list or group of candidate cell configurations using the RRC. Grouping may occur in the early sync (sync) or LTM execution phase (e.g., rather than the configuration phase). While a set of candidate cells can be considered a single group with respect to the RRC configuration list or group, the cells selected for performing the early sync, L1 measurement, and LTM execution may rely on further grouping into multiple subsets of the entire candidate cell list. In other words, grouping itself may not be modeled in the RRC using candidate configuration identifiers, but grouping can be performed as part of the early sync or LTM execution procedure.

[0264] The LTM candidate configuration used herein may refer to any type of pre-configured cell information. For example, the WTRU 102 can be configured with one or more conditional reconfigurations, such as conditional handover (CHO), conditional PSCell addition (CPA), and / or conditional PSCell change (CPC), which are valid before and / or after cell change or are valid in some cells.

[0265] Common principles and observations

[0266] L1 measurements

[0267] The L1 measurements used herein may refer to the measurement of any one of RSRP, RSRQ, RSSI, and / or similar values. The L1 measurements can be performed by the WTRU 102 for any one of a cell, a beam, a set of cells, and / or a set of beams. The L1 measurements can be similar to the L3 measurements reported in RRM, but with differences in filtering, the reference signals measured, and the reporting mechanism.

[0268] Without limitation, in some representative examples, including the context of 3GPP specifications, the L1 measurements may refer to the measurements associated with points A and A in FIG. 2. 1 There may be.

[0269] L3 measurements

[0270] As used herein, the L3 measurement may refer to a measurement after processing in the L3 filter. In some representative examples, including, but not limited to, the 3GPP standard context, the L3 measurement may refer to the measurement at point B in Figure 2 (e.g., a cell quality measurement derived from beam-specific measurements reported to Layer 3 after beam consolidation / selection) or the measurement at point C in Figure 2 (e.g., a measurement after processing in the Layer 3 filter). For example, the reporting rate at C may be approximately the same as (e.g., equivalent to) the reporting rate at point B. The L3 measurement can be used as input for one or more evaluations of reporting criteria.

[0271] General measurement

[0272] As used herein, L1 measurement may refer to L1 measurement for LTM, and L3 measurement may refer to measurement performed in RRC using specified L3 filtering and cell quality derivation. Several representative embodiments can be applied to L1 measurement and / or RRM / L3 measurement, as well as other measurements (e.g., measurements of speed, location, height, traffic, etc.) or alternative processing (e.g., different types of filtering or different types of averaging) or different measured quantities (e.g., RSRP, RSRQ, RSSI, CSI, etc.).

[0273] Measurement event

[0274] As used herein, measurement events may refer to occurrences in which a measurement satisfies specific conditions. Several representative embodiments may include the use of measurement events described in 3GPP TS38.331 Section 5.5.4, including, as will be familiar to those skilled in the art, event A1 (serving is better than the threshold), event A2 (serving is worse than the threshold), event A3 (neighbor has a better offset than SpCell), event A4 (neighbor is better than the threshold), event A5 (SpCell is worse than threshold 1 and neighbor is better than threshold 2), and so on. Measurement events described herein include, but are not limited to, the above events.

[0275] Common advantages

[0276] In some representative embodiments, multiple types of mobility, measurement, and reporting can coexist. For example, WTRU102 may implement L1 / 2 triggered mobility procedures and L3 triggered mobility procedures. Due to the nature of the procedures, race conditions may exist due to different measurement timings, different signaling latencies, different network nodes controlling the mobility, and / or different protocol layers handling processing in WTRU102 and in the network. Accordingly, the embodiments disclosed herein may enable interaction between different mobility types and / or provide measures to mitigate or eliminate potential problems that may arise due to race conditions between procedures.

[0277] LTM and measurement configuration

[0278] In some representative embodiments, the LTM configuration may include configurations for RRC pre-configuration for multiple serving cells and / or L1 measurements (e.g., CSI reporting, L1 event triggers) for use with the LTM. For example, WTRU102 may consist of L3 measurements for measurement reporting and / or conditional reconstruction (CHO).

[0279] In some representative embodiments, WTRU102 may consist of associations between L1 and L3 measurements. For example, WTRU102 may consist of information indicating which of the L1 measurement results may influence the L3 measurement results. For example, in some cases, a specific measurement target, measurement identification information, and / or conditional reconstruction may be used with a specific CSI measurement report and / or resource configuration.

[0280] ability

[0281] In some representative embodiments, the WTRU102 may report capability information (e.g., WTRU-specific capability) about specific features, such as LTM support, support for specific measurement derivation methods, and / or the maximum number of beams, cells, and / or carriers that can be measured using any specific measurement method. For example, capability information may include performance indications, such as the number of RF receivers, maximum bandwidth, processing capacity, and / or timing information. LTM and / or measurement capability may be reported per band or per band combination.

[0282] LTM virtual cell quality derived from beams from multiple LTM candidate cells

[0283] In some representative embodiments, the WTRU102 may avoid premature mobility outside the LTM area, such as when there is a temporary radio link quality issue in the serving cell while other candidate cells within the LTM area are acceptable. For example, the WTRU102 may determine whether it is worthwhile to perform an L3 switch to a cell outside the LTM area or to perform a switch to a separate LTM set (e.g., by comparing LTM sets), such as by using an L3 filter to compare an LTM set with cells outside that set.

[0284] In some representative embodiments, the L3 cell quality can be determined (e.g., derived) for a “virtual cell.” The L3 cell quality for a virtual cell may utilize beams from a subset or all of the cells in the LTM candidate set. For example, a virtual cell quality derivation may refer to a modified cell quality derivation, such as when beams from different cells in the LTM candidate set can be considered to derive the virtual cell quality of the LTM candidate set. For example, the virtual cell quality of a source LTM candidate set may be used as the quality of the source cell or to determine an offset to apply (e.g., on top of the quality of the source cell). For example, the virtual cell quality of a target LTM candidate set may be used as the quality of the target cell or to determine an offset to apply (e.g., on top of the quality of the target cell). For example, WTRU102 may use virtual cell quality to report measurement information under conditions such as the maximum time period elapsed since the last LTM cell switchover, or the minimum time period elapsed since the last LTM cell switchover. In some typical embodiments, WTRU102 may perform filtering (e.g., averaging) over a larger set of cells and / or beams during a first time period after cell switching, and then during a second time period (e.g., after the first time period) use a smaller set of cells and / or beams (e.g., only source cells or best candidate cells) to ensure that WTRU102 can eventually switch to a better LTM set.

[0285] In some representative embodiments, the WTRU 102 may receive information indicating a configuration associated with determining the quality of a set of LTMs (e.g., how it should be derived). The determined quality may consider beams on all or a subset of cells within the set of LTMs. For example, the configuration may include the maximum / minimum number of cells to include during derivation, the maximum / minimum number of beams to include during derivation, the minimum quality of the beams / cells to include during derivation (e.g., absolute / relative to the serving cell, absolute / relative to the best cell), one or more averaging / filtering weights to apply for the derivation, one or more offset and / or scaling parameters to apply for the derivation, a list of cells and / or beams that must be included during derivation, a list of cells and / or beams that may not be included during derivation, an association of each serving beam with a list of beams on other cells to include during virtual cell quality derivation, an indication for using the derived LTM set quality as the quality of the source and / or target cell, and / or an indication for using the derived LTM set quality as an offset to apply to the quality of the source and / or target cell (e.g., thereon), and may include information indicating any of the foregoing.

[0286] The WTRU 102 may receive information indicating a configuration for L1 and / or L3 measurement events. For example, the triggering conditions for the events may be based on a comparison of at least one LTM set quality (e.g., serving LTM set, target LTM set) with one or more of another LTM set quality, an individual cell quality (e.g., serving cell outside the LTM set, target cell outside the LTM set), a cell quality threshold, a maximum time from the last LTM cell switch, and / or a minimum time from the last LTM cell switch.

[0287] WTRU102 can determine the cells and / or beams to be considered for LTM set quality derivation (for example, based on the above configuration for the serving LTM set and / or target LTM set).

[0288] WTRU102 can perform measurements and derive the LTM set quality of the source LTM set and / or target LTM set.

[0289] WTRU102 may use the derived LTM set quality as source and / or target cell quality (for example, based on the above configuration). WTRU102 may apply the derived LTM set quality to serving cell and / or target cell quality (for example, as offset, scaling factor, etc.) (for example, based on the above configuration).

[0290] WTRU102 may determine that one or more of the event triggering conditions have been met, such as the minimum time period elapsed since the last LTM cell switchover; send a measurement report associated with the event (including, for example, one or more derived LTM set qualities, details of the cells and / or beams used for their derivation, legacy cell and / or beam measurement results); perform an associated conditional reconfiguration (if configured); and / or send an indication regarding the performance of a conditional reconfiguration (including, for example, one or more derived LTM set qualities, details of the cells and / or beams used for their derivation, legacy cell and / or beam measurement results).

[0291] Figure 6 is a system diagram showing an example of a virtual cell 602. For example, virtual cell and / or virtual cell quality can be used interchangeably with LTM set quality. For example, WTRU102 may consist of two or more candidate LTM cells, such as cell 1 (e.g., PCI1) 604 and cell 2 (e.g., PCI2) 606. For each candidate LTM cell, WTRU102 may consist of one or more beams (e.g., SSB or CSI-RS resources) 608 for performing measurements using them. WTRU102 may be configured to perform cell quality derivation based on beam consolidation and L3 filtering performed on L1 beam measurements performed on one or more beams 608 of the same cell (e.g., having the same PCI). In L3 handover, this can be advantageous because cell quality can take into account multiple beams on the same cell, and therefore allows WTRU102 to evaluate measurement events and report them to the gNB, thereby allowing the gNB to make a determination as to whether a handover from one cell to another should be performed. In the case of LTMs, WTRU102 can be configured with multiple candidate cells and can be configured to maintain uplink and / or downlink synchronization with multiple candidate cells and can be triggered to perform handovers from one cell to another, such as without completely resetting the MAC. These enhancements allow for significantly improved latency for switching cells with less overhead, and it can be anticipated that performing cell switching between cells within a configured LTM set (e.g., belonging to the same DU or the same CU / gNB) may be preferable to changing CUs and / or gNBs. This improved mobility between cells configured as LTM candidate cells allows the cells belonging to this configured set to be considered as a group or set. In some locations, such as near the boundary between two configured LTM candidates, WTRU102 may be capable of measuring multiple beams from multiple cells.For example, WTRU102 may be capable of measuring six good beams (e.g., three beams 608 from cell 1 604 and three beams 608 from cell 2 606, as in Figure 6). When evaluating the L3 measurement conditions to compare LTM set quality to either another cell or another LTM set, it may be preferable to consider all six beams together. In one example, a cell outside the configured LTM set may have an individual cell quality (e.g., based on the number of beams from that cell) that is higher than the individual cell quality of cell 1 604 or cell 2 606. When the LTM set quality considers all six good beams from both cell 1 604 and cell 2 606 that WTRU102 can switch, the overall quality of this virtual cell 602 may be better than that of a cell outside the LTM candidate set. LTM set quality can be derived based on two or more cells to determine whether it is better to remain in the current LTM configuration using L1 / 2-based mobility procedures, or whether an L3 reconfiguration should be performed on a cell or LTM set outside of the current LTM configuration.

[0292] As used herein, the terms virtual cell and LTM set quality may be used interchangeably and may refer to the radio quality of a set of cells derived from the individual beam measurement quality of beams from two or more cells in the set. For example, a virtual cell may refer to a cell quality derivation, such as an RSRP similar to that defined in 3GPP TS38.331, section 5.5.3.3, based on individual beam measurements (e.g., L1 RSRP) from multiple cells (rather than deriving cell measurement results by measuring one or more beams associated with each cell configured by the network, as specified in 3GPP TS38.331, section 5.5.3.1).

[0293] Figure 7 is a step diagram illustrating an exemplary procedure for measuring and reporting virtual cell information. At 702 in Figure 7, WTRU102 may receive information indicating the configuration associated with the LTM candidate set. The configuration may include information on how the quality of the LTM candidate set should be derived, and that quality may consider beams on all or a subset of cells in the candidate set. For example, configuration information may include the maximum and / or minimum number of cells to be included in the derivation, the maximum and / or minimum number of beams to be included in the derivation, the maximum and / or minimum number of beams per cell to be included in the derivation, or the exact number of beams to be included in the derivation, the minimum quality of beams and / or cells to be included in the derivation (e.g., absolute / relative with respect to serving cells, absolute / relative with respect to the best cell), the averaging and / or filtering weights to be applied to perform the derivation, the offsets and / or scaling to be applied to the quality derivation, a list of cells and / or beams that may (and must) be included in the derivation, a list of cells / beams that may not be included in the derivation, an association between any (e.g., each) serving beam and a list of beams on other cells to be included in the virtual cell quality derivation, and / or an indication of whether the derived LTM set quality should be used as the quality of the source or target cell, and / or as an offset to be applied to (e.g., on top of) the quality of the source or target cell.

[0294] For example, WTRU102 can consist of the maximum number of cells in an LTM set to be considered in the LTM set quality derivation. As an example, WTRU102 can be configured to include beams from N or fewer cells in the cell quality. WTRU102 can select N cells that have beams with the highest L1 measurement (e.g., RSRP). For example, WTRU102 can consist of the minimum number of cells. For example, WTRU102 can use a standard or normal cell quality derivation (e.g., it shall use one) if beams from fewer than N cells satisfy a minimum quality threshold (e.g., absThreshSS-BlocksConsolidation). For example, WTRU102 can consist of the exact number of cells to be included in the derivation.

[0295] For example, WTRU102 can consist of the maximum number of beams in an LTM set to be considered in the LTM set quality derivation. As an example, WTRU102 can be configured to include N or fewer beams during cell quality derivation (e.g., using nrofSS-BlocksToAverage). For example, WTRU102 can consist of the minimum number of beams. As an example, WTRU102 may use a standard or normal cell quality derivation (e.g., it shall use one) if fewer than N beams satisfy one or more criteria such as a minimum quality threshold (e.g., absThreshSS-BlocksConsolidation). As another example, WTRU102 can consist of the exact number of beams to be included during the derivation.

[0296] For example, WTRU102 can consist of the maximum and / or minimum number of beams per cell to be included in the derivation. For example, WTRU102 can consist of the exact number of beams to be included in the derivation.

[0297] For example, WTRU102 can consist of the minimum quality of beams and / or cells that should be included during the derivation (e.g., absolute / relative to serving cells, absolute / relative to the best cells). As an example, WTRU102 can consist of an absolute threshold (e.g., absThreshSS-BlocksConsolidation). As an example, WTRU102 can consist of a relative threshold, such as a threshold that allows a beam or cell to be included within XdB of a serving cell (PCell), or within XdB of the best cell or best beam.

[0298] For example, WTRU102 can be configured to derive each cell measurement based on the SS / PBCH block as a linear power-scale average of the highest beam measurement value exceeding absThreshSS-BlocksConsolidation, for instance, when the total number of averaged beams does not exceed nrofSS-BlocksToAverage (for example, it is assumed that it does not). Alternatively, WTRU102 can be composed of weights to be applied to each beam measurement. When averaging is performed, the beam with the highest beam measurement can carry the largest weight, while other beams may have smaller weights.

[0299] For example, LTM set quality can be derived by including an offset for the best beam measurement. For instance, the best beam might have an RSRP of X dBm. The offset can be added to the beam measurement for each additional beam that satisfies one or more criteria (e.g., a minimum threshold). As another example, the best beam measurement may use a scaling factor according to the number of other beams that satisfy one or more criteria.

[0300] For example, WTRU102 may consist of a list of cells and / or beams that may (for example, must) be included in the derivation. For example, WTRU102 may consist of a list of cells and / or beams that may not (for example, are not to be included) in the derivation. In one example, WTRU102 may consist of one or more specific cells and / or beams to be included in or excluded from the LTM set quality derivation.

[0301] For example, WTRU102 may consist of a list of cells and / or beams for each of the Pcells and / or best beams to be used in the derivation. For example, for a given current Pcell, or for any given serving beam, or for any best beam, WTRU102 may have a list of other beams to be measured and included in the LTM set derivation.

[0302] For example, WTRU102 may consist of an indication of a method for deriving LTM set quality. As an example, the indication may consist of WTRU102 indicating whether LTM set quality should be derived based on beam averaging from multiple cells, or whether LTM set quality should be derived based on adding an offset to the cell quality derivation as described herein.

[0303] For example, WTRU102 may consist of a list of cells and / or beams that can be dynamically updated by gNB. For example, gNB may construct the list of cells and / or beams using one or more of the techniques described herein. WTRU102 can then be provided with indications of a subset of cells and / or beams (e.g., control signaling in MAC CE). In one example, the cells and / or beams may be determined from the cells and / or beams used for L1 measurements (e.g., the same set of cells / beams may be used).

[0304] In Figure 7, at 704, WTRU102 can receive information indicating a configuration for an L1 or L3 measurement event, where the triggering conditions for the event may be based on a comparison between at least one LTM set quality (e.g., serving LTM candidate set, target LTM candidate set) and one or more of another LTM set quality, individual cell quality, cell quality threshold, maximum time since last LTM cell switchover, and / or minimum time since last LTM cell switchover.

[0305] For example, WTRU102 may compare the serving LTM set and / or the current LTM set with a potential target set. The current set may include cells and / or beams in which WTRU102 is already configured (e.g., LTM candidate configurations), and the target set may be a list of cells and / or measurement resources that indicate that the cells and / or measurement resources form a set. For example, WTRU102 may be configured to evaluate normal measurement events (e.g., as specified in 3GPP TS38.331 section 5.5.4). The derived LTM set quality of the current and target can be used as the measurement result of the serving cell (e.g., Ms) and the measurement result of the neighbor cell (e.g., Mn). For example, the current LTM set quality can be used as the measurement result of the serving cell. For example, the target LTM set quality can be used as the measurement result of the neighbor cell.

[0306] For example, WTRU102 can consist of individual cell quality (e.g., serving cells outside the LTM set, target cells outside the LTM set). As an example, WTRU102 can be configured to evaluate a normal measurement event (e.g., event A3, where the neighbor has a better offset than the SpCell, as specified in 3GPP TS38.331 section 5.5.4). The LTM set quality can be used as the measurement result for the serving cell (e.g., Ms), and the conventional cell quality of the neighbor cell can be used as the measurement result for the neighbor cell (e.g., Mn).

[0307] For example, WTRU102 can consist of a cell quality threshold. WTRU102 can compare the current LTM set quality or target LTM set quality to an absolute threshold. As an example, WTRU102 can consist of measurement events (e.g., event A1, serving is better than the threshold, or event A2, serving is worse than the threshold), and the derived LTM set quality can be used as the measurement result for the serving cell (e.g., Ms). As an example, WTRU102 can consist of measurement events (e.g., event A4, neighbor is better than the threshold), and the derived LTM set quality can be used as the measurement result for the neighbor cell (e.g., Mn). As an example, WTRU102 may consist of measurement events (e.g., event A5, where SpCell is worse than threshold 1 and neighbor is better than threshold 2), where the derived LTM set quality of the current and target can be used as the derived measurement result of the serving cell (e.g., Ms) and the derived measurement result of the neighbor cell (e.g., Mn).

[0308] For example, WTRU102 can be configured to consist of the maximum time period since the last LTM cell switchover. As an example, WTRU102 can be configured to perform an assessment using LTM set quality up to the maximum time period since the last LTM cell switchover. This can be used to configure WTRU102 to use LTM set quality when the SpCell changes frequently due to LTM (for example, because WTRU102 is mobile), and to use serving cell quality when WTRU102 is stationary.

[0309] For example, WTRU102 can be configured to use the LTM set quality only after a specific time has elapsed since the last LTM cell switchover (e.g., only thereafter). This can be used, for example, to configure WTRU102 to use the LTM set quality only after it has had enough time to begin performing early synchronization of target candidate cells after an LTM cell switchover.

[0310] In Figure 7, at 706, WTRU102 may determine the cells and / or beams to be considered for LTM set quality derivation based on the above configuration (for example, for the serving LTM set and / or target LTM set). Using the configurations received in 1. and / or 2., WTRU102 may select which cells to consider in LTM set derivation. For example, the selection may depend on the current SpCell and / or Pcell, an explicit list of cells and / or beams, and / or the current measurement configuration (for example, the CSI resource configuration).

[0311] In Figure 7, at 708, WTRU102 can perform measurements and derive the LTM set quality of the source LTM set and / or target LTM set. For example, WTRU102 can perform measurements based on the above configuration according to any configured RRM and / or CSI resources (e.g., SSB, CSI-RS). Based on the L1 beam measurements (for example, in cell measurements, the network can be configured with any of RSRP, RSRQ, SINR, RSCP, and / or EcN0 as trigger quantities), WTRU102 can select which of the measured beams should be included in the LTM set quality derive. For example, WTRU102 can perform a selection of any of the following: the best N beams, the best L beams per cell, a particular best beam and / or up to N best beams configured to be included for a cell, any particular beam (e.g., regardless of their quality), any beam above a certain absolute threshold, or any beam within a relative threshold (e.g., compared to the best beam or SpCell).

[0312] Based on the beams selected by WTRU102 to include during LTM set quality derivation, WTRU102 may derive quality values. For example, the LTM set metric may be based on one or more SS / PBCH blocks as a linear power-scale average of the highest beam metric values ​​above a threshold (e.g., absThreshSS-BlocksConsolidation). For example, the total number of averaged beams may not exceed a threshold (e.g., nrofSS-BlocksToAverage) (e.g., it is assumed not to exceed it). Exemplary beam metric values ​​are described in 3GPP TS38.215.

[0313] For example, WTRU102 may use, but is not limited to, any of the averaging methods or parameters described in the configuration of 702 in Figure 7.

[0314] In Figure 7, at 710, WTRU102 may use the derived LTM set quality as the source and / or target cell quality, depending on its configuration. For example, WTRU102 may add the derived LTM set quality on top of the serving cell quality and / or target cell quality.

[0315] For example, for any of the measurement events described in 3GPP TS38.331 Section 5.5.4, WTRU102 may use the current LTM set quality instead of the serving cell quality (e.g., Ms).

[0316] For example, for any of the measurement events described in 3GPP TS38.331 Section 5.5.4, WTRU102 may use target LTM set quality instead of neighbor cell quality (e.g., Mn).

[0317] For example, WTRU102 may use any of the various types of comparisons or evaluations to compare the derived current LTM set quality and / or target LTM set quality with another LTM set quality and / or cell quality.

[0318] In Figure 7, at 712, WTRU102 can determine whether the triggering conditions for the evaluated event are met.

[0319] In Figure 7, at 714, WTRU102 can determine whether a minimum time period (e.g., T1) has elapsed since the last LTM cell switchover.

[0320] In Figure 7, at 716, when the triggering conditions for the evaluated event are met, and a minimum time period (e.g., T1) has elapsed since the last LTM cell switchover, and / or a maximum time period (e.g., T2) has not elapsed since the last LTM cell switchover, WTRU102 may perform one of the following actions. For example, if WTRU102 consists of an RRC measurement event, subject, or report, WTRU102 may transmit a measurement report associated with the event. As an example, WTRU102 may include information (e.g., in the measurement report) indicating either the derived LTM set quality, details of the specific cell and / or beam used for the derivation (e.g., beam ID and / or cell ID), and / or the conventional cell and / or beam measurement results for the LTM set and / or neighbor cell. For example, WTRU102 may perform an associated conditional reconfiguration if configured. As an example, in or in a reconfiguration completion message, WTRU102 may include information indicating that a conditional reconfiguration has been performed, which may include the derived LTM set quality, details of the specific cell and / or beam used for its derivation (e.g., beam ID and / or cell ID), and / or conventional cell and / or beam measurement results for the LTM set and / or neighbor cell.

[0321] In some representative embodiments, LTM cell quality can be reported (e.g., to the serving cell) using L1 signaling (e.g., PUCCH and / or PUSCH). For example, WTRU102 reporting can be periodic or aperiodic (e.g., triggered by the serving cell).

[0322] LTM serving cell quality corrected using LTM candidate cell quality

[0323] When some (e.g., most) of the cells in a candidate LTM area have insufficient quality, or when the current LTM set has multiple active candidates, the LTM serving cell quality may be corrected based on the LTM candidate cell quality to avoid premature mobility outside the LTM area. When switching from one LTM set to another (e.g., between CUs), WTRU102 may (e.g., should) verify that the target set has more than a single candidate and that the source set does not have enough active candidates.

[0324] In some representative embodiments, WTRU102 may consist of an active LTM set and a target LTM set. For example, cell quality derivation and / or comparison may be performed as a legacy procedure (e.g., using N L1 filtered beam measurements on a cell to derive L3 filtered cell quality) and may be modified with one or more additional triggering conditions that must be achieved by a certain number of cells in the target and / or source candidate set. The active LTM set may be determined as a set of configured LTM candidate cells and / or candidate cells that exceed a radio quality threshold, where one of the following is achieved: WTRU102 maintains downlink synchronization, WTRU102 has a valid timing advance (e.g., UL synchronization), WTRU102 is actively reporting L1 CSI measurements, or WTRU102 is configured to perform TRS tracking. The target LTM set may be associated with a list of cell identification information, PCI, and / or SSB. WTRU102 may perform L1 and / or L3 measurements, as well as measurement reporting or CHO triggering evaluation. The active LTM set quality can be determined by applying a first offset to the measured serving cell quality of any additional LTM cells (e.g., each) determined to be in the active LTM set. The target LTM set quality can be determined by applying a second offset to the measured neighbor cell quality of any additional neighbor cells (e.g., each) in the target set, such as cells that satisfy a configured threshold.

[0325] For example, WTRU102 is a serving cell after applying one or more (e.g., first) offsets that achieve an event condition (e.g., event A4 concerning the target cell) and a target cell after applying one or more (e.g., second) offsets that achieve an event condition (e.g., event A3 comparing the source and target, event A5 comparing the source and target to different thresholds, etc.) and is in the candidate set Measurement reports may be sent or CHOs associated with events may be executed when any of the following are achieved: a certain number of cells satisfy a condition (e.g., a second condition) (e.g., a target cell satisfies events A3 / A4 / A5 and N cells in the target set satisfy a threshold); a target cell achieves an event condition after applying one or more offsets (e.g., a second condition) and a certain number of cells in the source set satisfy a condition (e.g., a target cell satisfies events A3 / A4 / A5 and it is determined that N cells in the source set fall below the second threshold or fewer than N cells are in the LTM active set); and / or a certain number of target cells achieve an event condition (e.g., N target cells achieve events A3 / A4 / A5). The number of target cells and / or the number of cells in the LTM active set may depend on elapsed time, such as the time elapsed since the last LTM cell switch (e.g., a first number if the elapsed time is below the threshold, otherwise a second number).

[0326] In some representative embodiments, WTRU102 may receive information indicating at least one configuration associated with (for example, to identify) an active LTM set and / or a target LTM set. For example, the configuration for an LTM set may include information indicating one of the following: a list of cell identification information, a list of PCIs, and / or a list of SSBs. The list may be associated with the active LTM set. The list may be associated with the target LTM set.

[0327] For example, WTRU102 may receive information indicating at least one configuration for L1 and / or L3 measurement events. For example, the triggering conditions for an event may be based on (one or more) criteria (e.g., an RSRP threshold) for determining additional suitable candidate cells (in addition to, for example, a target SpCell), the number of n additional candidates to consider in the criteria, and / or a timer value for determining whether to use the n additional candidates.

[0328] For example, WTRU102 may determine the number of additional candidates as its first value. WTRU may determine the first number of additional candidates (e.g., 0) based on elapsed time, such as when the time elapsed since the last LTM cell switchover falls below a configured threshold (e.g., a timer value), and otherwise determine a second value (e.g., n greater than 0).

[0329] For example, WTRU102 may perform measurements on active and target LTM sets. WTRU102 may determine which cells should be included in the active and target LTM sets based on any of the following: cells for which WTRU102 maintains downlink synchronization, cells for which WTRU102 has a valid timing advance (e.g., UL synchronization), cells for which WTRU102 is actively reporting L1 CSI beam measurements, cells for which WTRU102 is configured to perform TRS tracking, and / or cells that exceed the radio quality threshold.

[0330] For example, WTRU102 may determine (e.g., a first) offset to apply to any serving cell measurement based on the cells in the active and / or target LTM set. WTRU102 may also determine (e.g., a second) offset to apply to any neighbor cell measurement based on the cells in the target LTM set.

[0331] For example, WTRU102 may evaluate a measurement event based on serving cell measurements (e.g., after the first offset is applied) and / or neighbor cell measurements (e.g., after the second offset is applied). If the triggering conditions for an event are met, WTRU102 may either send a measurement report associated with the event (e.g., including information indicating the identification of any additional cells considered in the event and / or the main cell that triggers the event), and / or, if configured, perform the associated conditional reconfiguration, and / or send information indicating the execution of the conditional reconfiguration (e.g., including information indicating the identification of any additional cells considered in the event and / or the main cell that triggers the event).

[0332] Figure 8 is a system diagram showing an example of a neighboring area 802 and a candidate LTM area 804. In Figure 8, two areas of a cell are shown. One area may be a neighboring area 802, and the other area may be a candidate LTM area 804 with a set of LTM candidate cells 806. For example, the two areas may be associated with two CUs. WTRU102 may consist of a set of LTM candidate cells 806 in one of the areas (e.g., a CU). In Figure 8, WTRU102 is connected to one SpCell / PCell and is further configured to perform additional procedures relating to two additional target LTM candidate cells 808 (e.g., neighbor cells from a neighboring area). In some examples, WTRU102 may perform L1 CSI measurements on these two additional target cells, as well as / or maintain downlink and / or uplink synchronization. The two additional target candidate cells 808 are now “ready” for WTRU102 to perform the LTM procedure toward them (e.g., WTRU102 may receive a MAC CE that triggers a fast reconfiguration / handover to one of these cells), so these cells can also be considered to contribute to the overall serving cell quality at L3 when compared to cells outside the configured LTM candidate set 804. WTRU102 can derive the active LTM set quality based on measurements of cells within the active LTM set (e.g., any cells with measurements above a threshold, any cells for which WTRU102 has a valid TA, any cells for which WTRU102 maintains DL synchronization, and / or any cells for which WTRU102 is actively reporting CSI information). For example, the active LTM candidate set 804 may include a subset of cells that are configured candidate LTM cells 808. It may be desirable to perform LTM over L3 mobility whenever possible, as the overhead and latency associated with LTM handover are improved compared to L3 handover.Therefore, by considering the active LTM candidate cell 808 in the L3 cell quality, the perceived cell quality of the active LTM set can be improved compared to considering only the current PCell. Using the increased quality derived by considering the additional cell, the L3 measurement event evaluation can compare the active LTM set quality to one or more potential target cells. The target cells can use conventional cell quality derivations (e.g., LTM set quality is compared to neighbor cell quality). In some examples, the quality of the target cell can use LTM set quality. The target LTM set can be determined, for example, using cell identification information or a list of PCIs, and WTRU102 can include a cell in the target LTM set if its respective cell quality and / or beam quality measurements exceed a configured threshold. For example, the target LTM set may include a subset of cells from neighboring areas of multiple cells. In this way, WTRU102 can derive target LTM set quality based on multiple potential LTM candidate cells that have not yet been considered as such. WTRU102 then performs a comparison between the current (e.g., active) LTM set and the potential (e.g., target) LTM set, and may send an metric report or perform a CHO if the target set is deemed to be of higher quality than the current set (e.g., only then). Subsequently, an L3 reconfiguration from the current set to the target set may be performed, which may involve changes to the gNB / CU and require an L2 reset, security reinitialization, configuration of a new set of LTM candidate cells, etc. Since an L3 reconfiguration implies more overhead and longer latency, it may be performed only if the evaluated quality of the target set is better than the current set (e.g., only then).

[0333] Figure 9 is a procedure diagram illustrating an exemplary procedure for determining and measuring the active LTM set. At 902 in Figure 9, WTRU102 may receive information indicating a configuration for identifying the active LTM set and / or the target LTM set. For example, the configuration may include any of the following: a list of cells and / or beams that must be included in the derivation; a list of cells and / or beams that may not be included in the derivation; one or more radio quality thresholds to be used in the derivation; an indication of one or more criteria to be used; the maximum and / or minimum number of cells to be included in the derivation; an offset and / or scaling to be applied to the quality derivation; an association between each serving beam and a list of beams on other cells that should be included in the virtual cell quality derivation; an indication for using the derived LTM set quality as the quality of the source or target cell; and / or an indication for using the derived LTM set quality as an offset to be applied to (for example, on) the quality of the source or target cell.

[0334] For example, WTRU102 may consist of one or more specific cells and / or beams (e.g., sets thereof) to be included in and / or excluded from the LTM set quality derivation. For example, WTRU102 may consist of one of the following: a list of cell identification information to consider, a list of PCI to consider, a list of SSB and / or CSI-RS to consider, and / or a list of LTM candidate cell identification information to consider.

[0335] For example, WTRU102 can consist of one or more radio quality thresholds to be used, such as a minimum quality threshold for beams and / or cells that should be included during derivation. Thresholds can be absolute or relative to serving cells and / or absolute or relative to the best cell. As an example, WTRU102 can consist of an absolute threshold (e.g., absThreshSS-BlocksConsolidation). As another example, thresholds can be relative thresholds, such as a threshold that allows beams and / or cells to be included within XdB of serving cells (PCells) and / or within XdB of the best cell and / or best beam.

[0336] For example, WTRU102 may consist of indications for the criteria to use, such as using a cell with measurements that exceed the wireless quality threshold, using a cell in the evaluation if WTRU102 maintains DL and / or UL sync (e.g., has a valid TA), and / or using a cell in the evaluation if it is currently actively sending CSI reports for that cell.

[0337] For example, WTRU102 can consist of the maximum and / or minimum number of cells to be included in the derivation. As an example, WTRU102 can consist of the maximum number of cells in an LTM set to be considered in the LTM set quality derivation. For example, WTRU102 can be configured to include beams from N or fewer cells in the cell quality derivation. WTRU102 may select N cells that have beams with the highest L1 measurement (e.g., RSRP). As another example, WTRU102 can consist of the minimum number of cells, for example, if WTRU102 intends to use the normal (or conventional) cell quality derivation if beams from fewer than N cells satisfy one or more criteria such as a minimum quality threshold (e.g., absThreshSS-BlocksConsolidation).

[0338] For example, WTRU102 may consist of one or more offsets and / or scaling factors to be applied to the quality derivation. For example, LTM set quality may be derived by including an offset for the best beam measurement. For example, the best beam may have an RSRP of X dBm, and for each further beam that satisfies one or more criteria (e.g., a minimum threshold), an offset may be added to the beam measurement. As another example, the best beam measurement may use a scaling factor according to the number of other beams that satisfy one or more criteria.

[0339] For example, WTRU102 may consist of an association between each serving beam and a list of beams on other cells that should be included during virtual cell quality derivation. As an example, WTRU102 may have a list of cells and / or beams for each Pcell and / or best beam to be used during derivation. For example, for any given current Pcell, or for any given serving beam, and / or for any best beam, WTRU102 may have a list of other beams to be measured and included during LTM set derivation.

[0340] For example, WTRU102 may consist of an indication of whether the derived LTM set quality should be used as the quality of the source or target cell, or as an offset to be applied to (for example, on top of) the quality of the source / target cell. As an example, an indication of the method of LTM set quality derivation may be provided. The indication may consist of WTRU102 regarding whether the LTM set quality derivation should be performed based on beam averaging from multiple cells, as described above, or whether the LTM set quality should be derived based on adding an offset to the cell quality derivation.

[0341] In Figure 9, at 904, WTRU102 may receive information indicating a configuration for an L1 or L3 measurement event. The triggering conditions for the event may be at least in part based on one or more criteria (e.g., an RSRP threshold) for determining additional suitable candidate cells, such as in addition to the target SpCell. For example, the configuration may include either the number of additional cells to consider (e.g., n) and / or a timer value (e.g., time period or duration) for determining whether to use (e.g., n) additional cells or another value (e.g., 0).

[0342] The triggering conditions for a measurement event can be at least partially based on a comparison between at least one LTM set quality (e.g., serving LTM candidate set, target LTM candidate set) and one or more of the following: another LTM set quality, individual cell quality, cell quality threshold, maximum time since the last LTM cell switchover, and / or minimum time since the last LTM cell switchover.

[0343] For example, LTM set quality can be compared to the quality of another LTM set. As an example, WTRU102 may compare a serving LTM set and / or the current LTM set to a potential target set. The current set may include cells and / or beams in which WTRU102 has already been configured (e.g., LTM candidate configurations), and / or the target set may be a list of cells and / or measurement resources that indicate that the cells and / or measurement resources form a set. As an example, WTRU102 may be configured to evaluate normal (or conventional) measurement events (e.g., as specified in 3GPP TS38.331 section 5.5.4). The measurement results of the serving cell (e.g., Ms) and the neighbor cell (e.g., Mn) may be the derived LTM set quality for the current and target.

[0344] For example, LTM set quality can be compared to individual cell quality (e.g., serving cells outside the LTM set, target cells outside the LTM set). As an example, WTRU102 can be configured to evaluate a normal (or conventional) measurement event (e.g., event A3, where the neighbor has a better offset than the SpCell, as specified in 3GPP TS38.331 section 5.5.4). The measurement result for the serving cell (e.g., Ms) may be the LTM set quality, and the measurement result for the neighbor cell (e.g., Mn) may be the normal (or conventional) cell quality of the neighbor cell.

[0345] For example, LTM set quality can be compared to one or more cell quality thresholds. As an example, WTRU102 may compare the current LTM set quality or target LTM set quality to an absolute threshold. For example, WTRU102 may consist of measurement events such as event A1 (serving is better than the threshold), event A2 (serving is worse than the threshold), and the derived LTM set quality can be used as the measurement result (e.g., Ms) of the serving cell. As another example, WTRU102 may consist of measurement events such as event A4 (neighbor is better than the threshold), and the derived LTM set quality can be used as the measurement result (e.g., Mn) of the neighbor cell. As another example, WTRU102 can consist of measurement events, such as event A5 (SpCell becomes worse than threshold 1 and neighbor becomes better than threshold 2), and the derived LTM set quality of the current and target can be used as the derived measurement result of the serving cell (e.g., Ms) and the derived measurement result of the neighbor cell (e.g., Mn). For example, the current LTM set quality can be used as the measurement result of the serving cell. For example, the target LTM set quality can be used as the measurement result of the neighbor cell.

[0346] For example, LTM set quality can be compared using the maximum time since the last LTM cell switchover. As an example, WTRU102 can be configured to perform evaluations based on LTM set quality up to the maximum time since the last LTM cell switchover (e.g., before the maximum time has elapsed). This can be used to configure WTRU102 to use LTM set quality when SpCells change frequently due to LTM (e.g., because WTRU102 is mobile), and to use serving cell quality when WTRU102 is stationary.

[0347] For example, LTM set quality can be compared using the minimum time since the last LTM cell switchover. As an example, WTRU102 can be configured to perform an evaluation based on LTM set quality only after a certain amount of time has elapsed since the last LTM cell switchover (e.g., only thereafter). This can be used to configure WTRU102 to use LTM set quality only after it has had time to begin performing early synchronization of target candidate cells after an LTM cell switchover (e.g., only thereafter).

[0348] In Figure 9, at 906, WTRU102 may determine the number of additional candidates to use in the LTM set quality derivation. For example, WTRU102 may determine the number of additional candidates as a first value (e.g., 0) when the elapsed time since the last LTM cell switchover is below a threshold (e.g., a timer value configured in Figure 9, at 904), and as a second value (e.g., n configured in Figure 9, at 904) otherwise. As another example, WTRU102 may use the elapsed time since the last LTM candidate set switchover (e.g., when a PCell changes from a cell in LTM set x to a cell in LTM set y). As yet another example, WTRU102 may determine the number of additional candidates from a set of several values. In some representative embodiments, WTRU102 may use multiple elapsed time values, serving cell quality, and / or one or more other criteria to select the number of additional candidates.

[0349] In Figure 9, at 908, WTRU102 may perform measurements on the active and / or target LTM set (for example, based on the configurations received in 902 and 904 in Figure 9, and based on the decision in 906 in Figure 9). For example, WTRU102 may determine which cells to include in the active and / or target LTM set based on any of the following: measured cells in which WTRU102 maintains downlink synchronization, measured cells in which WTRU102 has a valid timing advance (e.g., UL synchronization), measured cells in which WTRU102 is actively reporting L1 CSI beam measurements, measured cells in which WTRU102 is configured to perform TRS tracking, measured cells that exceed a radio quality threshold, and / or the best N cells (cells with the highest measured radio quality up to the maximum number).

[0350] In some representative embodiments, WTRU102 may derive LTM set quality only for the active LTM set, or WTRU102 may use a normal (or conventional) cell quality derivation for neighbor cells. In some representative embodiments, LTM set quality may be determined for both the active LTM set and the target LTM set (for example, each separately).

[0351] In Figure 9, at 910, WTRU102 may determine a first offset to apply to serving cell measurement based on the cells in the active LTM set. WTRU102 may also determine a second offset to apply to neighbor cell measurement based on the cells in the target LTM set (if evaluated).

[0352] In some representative embodiments, the first and / or second offsets can be applied in 908 in Figure 9 after a certain number of cells (e.g., n) satisfy one or more criteria (e.g., only in that case). In some representative embodiments, the amount of offset to be applied for LTM set derivation can be based on the number of cells that satisfy one or more criteria (e.g., can be selected accordingly). For example, an offset of X dB can be added for one cell, an offset of 2*X dB can be added for two cells, and so on. In some representative embodiments, an average cell quality value can be used. For example, the linear average of all cells that satisfy one or more criteria up to a maximum number N can be used as the LTM set quality. For example, the offset to be applied can be based on the number of additional cells determined in 906 (e.g., can be selected accordingly).

[0353] In Figure 9, at 912, WTRU102 may evaluate a measurement event based on serving cell measurements (e.g., after the first offset is applied) and neighbor cell measurements (e.g., after the second offset is applied). For example, WTRU102 may, based on its configuration, use the derived LTM set quality as the source / target cell quality, or apply the derived LTM set quality to (e.g., on top of) the serving / target cell quality. For example, for any of the measurement events described in 3GPP TS38.331 Section 5.5.4, WTRU102 may use the current LTM set quality instead of the serving cell quality (e.g., Ms). For example, for any of the measurement events described in 3GPP TS38.331 Section 5.5.4, WTRU102 may use the target LTM set quality instead of the neighbor cell quality (e.g., Mn). For example, WTRU102 may use any type of comparison or evaluation to compare the derived current LTM set quality and / or target LTM set quality with another LTM set quality and / or cell quality.

[0354] In Figure 9, at 914, when the triggering conditions for the evaluated event are met (for example, under the conditions that the minimum time period has elapsed since the last LTM cell switchover and the maximum time period has not elapsed since the last LTM cell switchover), WTRU102 may either send a measurement report associated with the event and / or (for example, if configured) perform the associated conditional reconfiguration.

[0355] In some representative embodiments, if WTRU102 consists of an RRC measurement event, subject, and / or report, WTRU102 may transmit a measurement report associated with the event. For example, the measurement report may include information indicating the derived LTM set quality, details of the specific cell and / or beam used for the derivation (e.g., beam ID or cell ID), normal (or conventional) cell and / or beam measurement results for the LTM set and / or neighbor cell, and / or the derived LTM set quality.

[0356] In some representative embodiments, WTRU102 may perform associated conditional reconfiguration (for example, if configured). For example, WTRU102 may transmit information indicating the execution of conditional reconfiguration (for example, in a reconfiguration completion message or in a subsequent message). The transmitted information may include any of the following: derived LTM set quality, details of the specific cell and / or beam used for derivation (e.g., beam ID or cell ID), normal (or conventional) cell and / or beam measurement results for the LTM set and / or neighbor cell, and / or derived LTM set quality.

[0357] Long-term measurement evaluation across multiple LTM serving cells

[0358] In some typical embodiments, the network may want to configure a relatively long TTT value for L3 measurement events to prevent premature switching from the LTM set. A side effect is that WTRU102 may switch between cells frequently (e.g., more frequently than per TTT) using the LTM, and because the serving cell changes within the TTT, the L3 measurement event may be triggered too late (or never triggered at all). To address this, the trigger condition can be extended to allow consideration of serving cells (e.g., all) within the TTT, such as when a candidate cell is far better than the current serving cell.

[0359] For example, when WTRU102 switches from the first serving cell to the second serving cell using LTM, WTRU102 can derive L3 cell quality and evaluate L3 event triggers based on measurement results applicable to the first and second serving cells (as if the serving cell were a single serving cell). WTRU102 may continue evaluating the serving cell quality and measurement event triggers (e.g., current) after the cell change. After the cell change, WTRU102 may use (e.g., continue) previous (one or more) serving cell measurements as if they were current cell measurements. WTRU102 may trigger a measurement report if at least one condition is met for the current serving cell over the TTT duration (e.g., evaluated using the first and second serving cells). WTRU102 can perform the above under the condition that the measurement result for the candidate cell exceeds the threshold; otherwise, WTRU102 may be triggered (for example, only if the condition is met over TTT for the current serving cell). For example, the L3 filtered result for the second serving cell may be based on the L3 filtered result for the first serving cell at the time of cell switching.

[0360] In some representative embodiments, the WTRU may receive information indicating the configuration associated with determining the serving cell quality (e.g., how it should be derived) using L3 filtering, which takes L1 RSRP, RSRQ, and / or SINR samples from any cell that was a Pcell within the filtering window. For example, the configuration may include information indicating at least one of the filter coefficients, RS type, and / or RS index.

[0361] For example, WTRU102 may receive information indicating the configuration for L1 and / or L3 measurement events. The configuration may include information indicating that the evaluation over TTT (e.g., period, duration, interval) is performed using the measurement results of any cell that was a serving cell while TTT was running (e.g., during TTT), and / or thresholds for neighbor cell measurement results.

[0362] For example, WTRU102 may determine that the conditions for an event are satisfied for a first serving cell and a neighbor cell over a first time period. The first time period may be shorter than (e.g., shorter than) the TTT.

[0363] For example, WTRU102 may receive information indicating that it will use LTM to switch from the first serving cell to the second serving cell at the end of the first time period (or before).

[0364] For example, WTRU102 may determine that the conditions for an event are met for a second serving cell and a neighbor cell over a second time period. The sum of the first and second time periods may be equal to or greater than the TTT. Under the condition that the neighbor cell result exceeds the second serving cell result plus a threshold, WTRU102 may trigger the transmission of a measurement report containing information indicating the first serving cell and / or the second serving cell, as well as the first and / or second time periods.

[0365] Figure 10 is a system diagram illustrating an example of L3 filtering and measurement evaluation. In Figure 10, it is assumed that WTRU102 performs LTM using cells 1 1002 and 2 1004 while evaluating L3 measurement events by comparing a serving cell (e.g., cell 1, then cell 2) with a neighbor cell (e.g., cell 3 1006).

[0366] For example, conventional cell quality derivation may involve using L1 RSRP measurements provided for each beam from L1, performing beam consolidation (e.g., selecting the best N beams from the cell), and applying filters to average the measured samples over time. However, when LTM is used to switch serving cells, this type of reconfiguration can occur relatively frequently, and therefore, serving cell quality derivation may not be completed in some cases due to lack of time.

[0367] In some representative embodiments, L3 filtering of serving cell quality may not be limited to a single serving cell when the LTM is configured. For example, the filtering window may include RSRP results from any previous serving cells within the filtering window. In Figure 10, the serving cell changes from cell 1 1002 to cell 2 1004, and the cell quality derivation continues during and after the cell switch from cell 1 1002 to cell 2 1004. WTRU 102 may derive serving cell quality by using samples from both cell 1 1002 and cell 2 1004 as inputs to the filter.

[0368] According to 3GPP TS38.331, the measurement filter (for example, baseline) can be performed by WTRU102 as follows (for example, it is assumed that it will be performed): 1> In Section 5.8.10, as necessary, for each cell measurement, each beam measurement, each sidelink measurement, each CLI measurement performed by the UE in accordance with 5.5.3.1, and each candidate L2 U2N Relay UE measurement in accordance with 5.5.3.4: 2> Before using the measurement results for evaluation of reporting criteria or for measurement reporting, filter them using the following formula. F n =(1-a)*F n-1 +a*M n Here, M nThis is the last measurement result received from the physical layer, F n This is an updated and filtered measurement result used for evaluating reporting standards or for measurement reporting. F n-1 This is the old filtered measurement result, where when the first measurement result from the physical layer is received, F0 is set to M1, and in MeasObjectNR, a=1 / 2 (ki / 4) And here, k i is the filterCoefficient for the corresponding metric of the i-th QuantityConfigNR in quantityConfigNR-List, where i is represented by quantityConfigIndex in MeasObjectNR, and for other metrics, a = 1 / 2 (k / 4) Here, k is the filterCoefficient for the corresponding quantifier received by quantityConfig, and in UTRA-FDD, a = 1 / 2 (k / 4) Here, k is the filterCoefficient for the corresponding metric received by quantityConfigUTRA-FDD in QuantityConfig. 2> Observe that the filter coefficient k assumes a sample rate equal to Xms, and adapt the filter so that the filter's time characteristics are preserved at different input rates. The value of X corresponds to a single-frequency L1 measurement period as defined in TS38.133

[14] assuming non-DRX operation, and is frequency range dependent.

[0369] Note 1: If k is set to 0, Layer 3 filtering is not applicable.

[0370] Note 2: Filtering is performed in the same area used for evaluating reporting criteria or for measurement reporting, i.e., logarithmic filtering for logarithmic measurements.

[0371] Note 3: The filter input rate is implementation-dependent to meet the implementation requirements set out in TS38.133

[14] . For further details regarding physical layer measurements, see TS38.133.

[0372] Note 4: In CLI-RSSI measurements, whether or not filtering should be reset when BWP switching occurs depends on the UE implementation.

[0373] In some representative embodiments, a previously filtered measurement result (e.g., Fn-1) can be saved after an LTM cell switchover so that an updated filtered measurement result (e.g., Fn) is based on the previous serving cell result (e.g., Fn-1) and the current serving cell measurement result (e.g., Mn).

[0374] In measurement event evaluation, conditions may need to be met for the duration of the TTT. If frequent cell changes occur due to LTM, any measurement event that uses serving cell measurement results as part of the trigger condition may not be triggered because the serving cell measurement is not evaluated for a sufficiently long time.

[0375] In some representative embodiments, an L3 measurement event (for example, using serving cell measurements configured when LTM is also configured) can use previous and current cell measurement results as triggering conditions (for example, let us use them), and TTT can continue operating after cell switching. If the serving cell measurement (for example, previous or current) satisfies one or more criteria during the duration of TTT, the event can be triggered (for example, let us use them).

[0376] Figure 11 is a step diagram illustrating an exemplary procedure for L3 filtering and measurement event evaluation. In some typical embodiments, WTRU 102 may receive information indicating a configuration for how serving cell quality should be derived using L3 filtering, which takes L1 samples (e.g., RSRP, RSRQ, and / or SINR) from any cell that was a Pcell (e.g., a UE) within the filtering window, as shown in 1102 in Figure 11. For example, the configuration may include information indicating any of the filter coefficients, RS type, and / or RS index.

[0377] In some representative embodiments, WTRU 102 may receive information indicating a configuration that limits the cell quality derivation method to certain cells and / or groups of cells. For example, the use of the cell quality derivation method may be associated with a specific measurement event and / or object being measured. As an example, the configuration in 1102 may be received as part of a measurement event and / or conditional trigger configuration to be applied to that measurement evaluation. As another example, WTRU 102 may receive a configuration (e.g., a single one) that is applicable to any (e.g., all) of the configured measurements.

[0378] In Figure 11, at 1104, WTRU 102 may receive information indicating a configuration for an L1 or L3 measurement event. The configuration may include information indicating that an evaluation across TTT can (or should be) performed using the measurement results of any cell that was the serving cell during TTT. In some representative embodiments, the configuration for evaluation of measurement events across cells may be independent of the configuration for L3 filtering across cells. For example, these features may be independent or configured together.

[0379] For example, WTRU102 can be configured to perform measurement event evaluations by continuing TTT after a cell switch (for example, when performed using LTM), and to consider serving cell quality measurements from both the previous and current cells for one or more event criteria. In some typical embodiments, WTRU102 may receive information indicating a configuration that shows which cells should be included when performing evaluations across cells using TTT. For example, WTRU102 can continue evaluations across cells 1 and 2, but not across cells 2 and 3. In some typical embodiments, a single measurement event configuration may comprise a list of cells to which this event applies. For example, a measurement event can be configured to apply while in a set of cells (e.g., cells 1, 2, and 3), and if any LTM cell switch is performed between the set of cells, any current event criterion evaluation can be continued and applied by WTRU102 as if the set of cells were a single serving cell.

[0380] For example, the measurement event may take into account at least the serving cell quality. For example, the measurement event may take into account the neighbor cell quality (for example, it may also take into account that). In some typical embodiments, the measurement result of a serving cell (e.g., Ms) can be derived using filtering across multiple cells, according to the configuration in 1102 in Figure 11.

[0381] In some representative embodiments, WTRU102 can be configured to evaluate conventional measurement events comparing the serving cell and the neighbor cell (e.g., event A3, where the neighbor has a better offset than the SpCell, as specified in 3GPP TS38.331 section 5.5.4). The serving cell measurement result (e.g., Ms) can be derived by including previous cell measurement results during the filtering calculation. In some representative embodiments, neighbor cell measurement and evaluation can continue (e.g., can continue) when the serving cell changes due to LTM.

[0382] In some representative embodiments, WTRU102 may consist of measurement events such as event A1 (serving is better than the threshold) and / or event A2 (serving is worse than the threshold), which compare the serving cell to a threshold. For example, the measurement result of a serving cell (e.g., Ms) may be derived by including previous cell measurement results during the filtering calculation.

[0383] In some representative embodiments, WTRU102 may consist of measurement events, such as event A5, which compares the serving cell and neighbor cell to thresholds (SpCell is worse than threshold 1 and neighbor is better than threshold 2). For example, the serving cell measurement result (e.g., Ms) may be derived by including previous cell measurement results during the filtering calculation. For example, neighbor cell measurement and evaluation may continue (e.g., may continue) when the serving cell changes due to LTM.

[0384] In Figure 11, at 1106, WTRU 102 may determine that the conditions for an event are satisfied for a first serving cell and a neighbor cell over a first time period (for example, the first time period is shorter than the TTT). WTRU 102 may then initiate the TTT period. In some representative embodiments, a measurement event may evaluate both the serving cell and one or more neighbor cells (for example, event A3, the neighbor has a better offset than the SpCell). In some representative embodiments, a measurement event may evaluate only the serving cell (for example, event A1, the serving cell is better than the threshold). For example, this condition may continue to be satisfied for a first time period shorter than the TTT configured for the event.

[0385] In Figure 11, at 1108, at the end of the first time period, WTRU102 may receive information indicating an LTM trigger (e.g., a MAC CE indicating a new SpCell). WTRU102 may perform a reconfiguration on the indicated SpCell. The LTM trigger may occur (e.g., should occur) before the TTT has elapsed.

[0386] In Figure 11, at 1110, WTRU 102 is configured to continue evaluating the measurement event after a cell change from the first cell to the second cell, so that WTRU 102 can determine that the conditions for the event (e.g., the same conditions as in 1106) are satisfied over a second time period for the second serving cell and neighbor cell. For example, the sum of the first and second time periods is equal to or greater than the TTT. That is, while the TTT is running (e.g., during the TTT period), the measurement event conditions are satisfied for the first time period within the TTT using the first serving cell and for the second time period within the TTT using the second serving cell, which satisfies one or more criteria for triggering the event, since the conditions are satisfied by serving cells that are not necessarily the same serving cell for the duration of the TTT.

[0387] As another example, while the TTT is running when an LTM cell switching command is received, WTRU102 may reset the TTT timer or reset the TTT and start it with a different value (for example, a higher offset than the previous value). While the timer is running (for example, within the reset TTT period), WTRU102 may continue evaluating the event using the measurements from the new serving cell.

[0388] In Figure 11, at 1112, WTRU102 may trigger the transmission of a measurement report containing information indicating (e.g., identifying) the first and second serving cells and / or time periods, based on the condition that the neighbor cell's result exceeds the second serving cell's result plus a threshold. For example, WTRU102 may indicate all the serving cells that triggered the event. For example, WTRU102 may indicate the time each serving cell satisfied the condition. For example, WTRU102 may include filtered measurement results calculated based on two or more serving cells. For example, WTRU102 may include conventional measurement results for each of the cells that satisfy the condition.

[0389] Prohibition timer for LTM measurement reporting after L3 handover procedure

[0390] In some typical embodiments, the timer for L1 reporting can be disabled after an L3 cell switchover to restrict reporting (for example, temporarily).

[0391] The exemplary prohibitions described herein may address race conditions in which an LTM handover occurs before L3 signaling (e.g., RRC reconfiguration completion transmission using RLC AM) is completed, even though an L3 handover is completed. This can occur for L3 handovers involving LTM sets during target configuration, and can also occur during initial LTM setup (e.g., an LTM cell switchover occurs before the delivery of RRC reconfiguration completion corresponding to the LTM setup is completed).

[0392] To ensure that RRC reconfiguration completion signaling is successfully delivered (e.g., to the CU) after an L3 handover, WTRU102 may be prevented from sending L1 measurement reports and / or performing LTM, which may result in a DU-triggered LTM handover and loss of L3 signaling, leading the CU to detect a handover failure or reconfiguration failure. For example, a temporary restriction on neighbor cell and / or candidate cell L1 reporting (e.g., while current cell beam reporting is still enabled to allow scheduling) may be implemented by using a timer or by waiting for an RLC acknowledgment to send an RRC message (e.g., complete).

[0393] In some typical embodiments, the WTRU102 may receive an RRC reconstruction message containing information indicating the LTM measurement pause and / or associated timer value.

[0394] For example, WTRU102 can perform RRC reconfiguration and (if already operational) stop reporting LTM L1 measurements for neighbor cells. WTRU102 can send an RRC reconfiguration complete message.

[0395] For example, under the condition that the amount of time elapsed since the reception of the RRC reconstruction is less than the indicated time amount (e.g., timer value), and WTRU102 receives the LTM cell switching command, WTRU102 may send an indication (e.g., via MAC CE) that the cell switching will not be performed. If the LTM cell switching is received before the timer expires (e.g., the elapsed time is less than the indicated time), WTRU102 may not execute the LTM cell switching command and may respond with a failure indication.

[0396] For example, under the condition that the amount of time elapsed since the transmission of the RRC reconfiguration complete message or successful acknowledgment is less than the indicated time amount (e.g., timer value), and WTRU102 receives an LTM cell switching command, WTRU102 may send an indication (e.g., via MAC CE) that the cell switching will not be performed. If the LTM cell switching is received before the timer expires (e.g., the elapsed time is less than the indicated time), WTRU102 may not execute the LTM cell switching command and may respond with a failure indication.

[0397] For example, under the conditions that TTT is running for a configured RRC measurement event (e.g., started because the conditions were met but not yet expired) and WTRU102 receives an LTM cell switching command, WTRU102 may send information (e.g., via MAC CE) indicating that cell switching will not be performed. If an LTM cell switching is received while TTT is running for a configured RRC measurement event, WTRU102 may not execute the LTM cell switching command and may respond with a failure indication. For example, TTT running may refer to the time period corresponding to the TTT value not having elapsed. For example, TTT expired may refer to the time period corresponding to the TTT value having elapsed.

[0398] For example, when a time period corresponding to the indicated timer value has elapsed since the receipt of the RRC reconstruction message, WTRU102 may start (or restart) reporting the LTM L1 measurement for the candidate cell.

[0399] For example, WTRU102 may start (or restart) LTM L1 measurement reporting for candidate cells when a time period corresponding to the indicated timer value has elapsed since the sending of the RRC reconstruction completion message or successful acknowledgment.

[0400] For example, under conditions where the TTT is running for a configured RRC measurement event (e.g., started because the conditions were met but not yet expired), the UE may stop or pause LTM L1 measurement reporting for the candidate cell, and when the TTT has expired (e.g., a measurement event has been triggered) or stopped (e.g., the measurement event criteria are no longer met and therefore no event is triggered), the WTRU102 may start (or resume) LTM L1 measurement reporting for the candidate cell.

[0401] Figure 12 is a step diagram illustrating an exemplary procedure for pausing LTM measurement and execution after L3 reconfiguration (e.g., handover). In 1202 in Figure 12, WTRU 102 may receive an RRC reconfiguration message containing information indicating that LTM measurement and execution are to be paused. For example, a timer value may be indicated in the RRC reconfiguration. For example, a timer value may be derived (based on, for example, the number of LTM candidate cells and / or whether the RRC reconfiguration is performing several steps such as security reinitialization or L2 reset). For example, a fixed timer may be predetermined and / or provided as a standardized value (e.g., in 5G NR). In some representative embodiments, the indication pauses only LTM measurement and / or measurement reporting. In some representative embodiments, only LTM execution is paused. In some representative embodiments, both measurement and measurement reporting and execution are paused.

[0402] In some representative embodiments, the RRC reconfiguration may include information indicating one or more LTM candidate cell configurations. For example, an LTM candidate cell may have been previously configured (e.g., by an earlier RRC reconfiguration) and may be effective after a new RRC reconfiguration is applied. As an example, the RRC reconfiguration may indicate that a reconfiguration is performed using a stored LTM configuration (e.g., applying an LTM reconfiguration as indicated by the RRC). In some representative embodiments, the RRC reconfiguration may update a previously configured LTM candidate configuration. In some representative embodiments, the RRC reconfiguration may indicate a serving cell configuration, and may indicate a new SpCell, a new SCell, a change in the MCG and / or SCG, or any combination thereof.

[0403] In some representative embodiments, RRC reconfiguration can represent a handover of LTM cells from one set to another, such as when WTRU102 needs to be reconfigured from one CU to another.

[0404] In Figure 12, at 1204, WTRU 102 may apply the received RRC reconfiguration and (if operational) stop any LTM-based measurement reporting. LTM-based measurement reporting may refer to reporting of any LTM candidate cell using L1 measurement events, L1 CSI reports, and / or L3 reports. For example, WTRU 102 may start a timer (e.g., to determine the duration) equal to a value indicated in the RRC reconfiguration. For example, WTRU 102 may start a timer (e.g., to determine the duration) equal to a derived or implied value. In some typical embodiments, the timer may be started upon receipt of the RRC reconfiguration message. In some typical embodiments, the timer may be started upon transmission of the RRC reconfiguration complete message. In some typical embodiments, the timer may be started upon receipt of the RLC acknowledgment corresponding to the successful delivery of the RRC reconfiguration complete message.

[0405] In some representative embodiments, the first type of L1 CSI reporting may be suspended, while the second type of L1 CSI reporting may not. For example, periodic L1 CSI reporting may be suspended, while aperiodic L1 CSI reporting may not.

[0406] In Figure 12, at 1206, WTRU 102 may encode and transmit an RRC reconfiguration complete message. When LTM operation is paused, WTRU 102 may perform transmissions, including any necessary MAC, RLC, and / or PDCP retransmissions, without causing cell changes due to LTM. Thus, the message can be delivered on the cell where it is expected to be according to RRC reconfiguration, avoiding potential error conditions that may be caused by separately controlled mobility procedures (e.g., LTM controlled by DU and RRC controlled by CU).

[0407] In Figure 12, at 1208 and 1210, if a MAC CE (e.g., a MAC CE with an indication to perform an LTM cell switchover) is received and the timer is still running (e.g., the elapsed time since the reception of the RRC reconfiguration is less than the indicated timer value, or the elapsed time since the transmission of the RRC reconfiguration completion or successful acknowledgment is less than the indicated timer value), WTRU 102 may not apply the indicated MAC CE. For example, WTRU 102 may not perform an LTM reconfiguration for the indicated candidate configuration ID. In some typical embodiments, WTRU 102 may transmit a failure indication, such as by using a MAC CE or by using an RRC reconfiguration failure message. In some typical embodiments, WTRU 102 may include cause or reason information indicating that the failure is due to the LTM pause timer running. If the timer is no longer running (for example, the elapsed time since the reception of the RRC reconstruction is greater than or equal to the indicated timer value, or the elapsed time since the transmission of the RRC reconstruction completion or successful acknowledgment is greater than or equal to the indicated timer value), WTRU102 may perform LTM according to the received indication (for example, perform a cell switch to the indicated candidate configuration, or initiate measurement, synchronization, or any procedure applicable to LTM).

[0408] In some representative embodiments, priority quantities can be defined (e.g., high priority and / or low priority). For example, priority can be indicated by an index (e.g., 1 means high priority and 0 means low priority). The priority index may define whether an L1 / 2 (LTM) cell switch or an L3 handover has a higher priority. Priority can be configured and / or indicated. For example, priority can be indicated in a MAC CE. In some representative embodiments, if a MAC CE indicating a cell switch is received and the priority indicates that an L1 / 2 cell switch has a higher priority, WTRU102 may perform the L1 / 2 switch. In some representative embodiments, if a MAC CE indicating a cell switch is received and the priority indicates that an L3 cell switch has a higher priority, WTRU102 may abort the L1 / 2 switch when an L3 handover is pending (e.g., an RRC reconfiguration message is received).

[0409] In Figure 12, at points 1212 and 1214, when the timer expires (for example, when the elapsed time since the reception of the RRC reconstruction is greater than or equal to the indicated timer value), the WTRU102 may resume the L1 measurement or other measurements related to the LTM and may execute any commands received from the DU (for example, MAC CE), etc.

[0410] PCell identification when RRC messages are generated while using LTM

[0411] In some typical embodiments, the identification of the PCell in use when an RRC message is generated while an LTM is in use. In the case of UL, a race condition can be addressed where an L3 measurement report is triggered, but an LTM handover occurs before the RRC message is sent. The L3 measurement report may be sent to the wrong cell (e.g., not the cell on which the event was configured). If the same measurement configuration (e.g., ID) is configured on the target cell, there may be ambiguity as to which cell the event was triggered. In the case of DL, the RRC reconfiguration message is sent by the CU, but the DU is performing the LTM, and a race condition can be addressed. If the RRC message does not contain configuration specific to the old cell group served by the first DU (e.g., DU#1), the CU can safely retransmit the RRC message to WTRU102 via the second DU (e.g., DU#2). Issues may arise if the content of the RRC message has an expired configuration associated with the old serving cell group on the first DU. If an RRC message is retransmitted to WTRU102 via a second DU, WTRU102 may fail to apply the expired RRC configuration because it refers to the old serving cell group and WTRU102 connects to the new serving cell group. This can trigger a connection re-establishment by WTRU102. If an RRC message is not retransmitted to WTRU102 via a second DU, any new RRC message from the same SRB must use a new PDCP sequence number (SN) commanded for replay protection using the same AS security context. This can create a PDCP SN gap. Since the default value for the t-Reordering timer for SRB1 is infinity, the t-Reordering timer may never expire, and the SRB's PDCP SDU may not be deliverable to the upper layer.

[0412] In some representative embodiments, information indicating a cell identifier (e.g., PCell ID) may be included in the UL RRC message corresponding to the PCell when the corresponding event (e.g., measurement event, RRC reconfiguration) is triggered. For example, an RRC reconfiguration may be triggered, and the RRC reconfiguration complete message may include information indicating whether an RRC reconfiguration and / or L2 triggered reconfiguration occurred.

[0413] In a typical embodiment, WTRU102 may receive information indicating an L3 measurement event and / or reporting configuration. WTRU102 may receive information indicating an LTM configuration. WTRU102 may receive information indicating the configuration of conditions for including the current PCell information in the L3 measurement report (e.g., any candidate cell in the latest L1 and / or L2 report that is higher than the measurement result of the serving cell with or without an added offset). WTRU102 may perform a measurement evaluation on the current cell and send an L1 and / or L2 measurement report. WTRU102 may decide to trigger the transmission of an L3 measurement report based on the L3 measurement configuration. If the L1 and / or L2 measurement report indicates that the measurement result of the candidate cell is higher than the measurement result of the serving cell (e.g., its plus offset), WTRU102 may send an L3 measurement report containing information indicating the current PCell. WTRU102 may receive an LTM cell switching command and complete the RRC transmission on the new cell.

[0414] In a typical embodiment, WTRU102 may receive an RRC reconfiguration message in the source cell. WTRU102 may apply the RRC reconfiguration and send an RRC reconfiguration complete message (for example, before LTM). The RRC reconfiguration complete message may include information indicating that the RRC reconfiguration is complete due to applying the RRC reconfiguration (for example, only) and information indicating the source cell (for example, PCI).

[0415] In a typical embodiment, WTRU102 may receive an RRC reconfiguration message in the source cell. WTRU102 may apply the RRC reconfiguration. WTRU102 may receive (or determine) an LTM trigger and reconfigure the new cell. WTRU102 may send an RRC reconfiguration completion message that includes information indicating that the RRC reconfiguration is complete due to the application of RRC and LTM reconfiguration, and information indicating the source cell (e.g., PCI).

[0416] For example, LTM-only reconfiguration can cause WTRU102 to send an RRC reconfiguration completion message that does not include any indication (e.g., PCI of the source cell). As another example, the RRC reconfiguration completion message may include information indicating that the message is due to the application of LTM reconfiguration only.

[0417] For any transmitted RRC message, WTRU102 may include a cell ID to indicate which cell WTRU102 was in when the RRC message transmission was triggered. The cell ID can be a PCI, a serving cell ID, a candidate cell ID, or any value that can identify a cell. The identifier resolves a challenge introduced by L1 / 2 triggered RRC reconfiguration, as cells may change after being triggered by a DU, and the CU may not be aware of this. The cell identifier in the uplink RRC message received by the CU resolves any ambiguity.

[0418] In some cases, the cell identifier may correspond to the cell that triggered the measurement event (e.g., RRC measurement report).

[0419] In some cases, the cell identifier may correspond to the cell that received a mobility command (e.g., a MAC CE indicating RRC reconfiguration or LTM execution).

[0420] Figure 13 is a step diagram illustrating an exemplary procedure in which the current PCell identification information is shown in the triggered measurement report. At 1302 in Figure 13, WTRU 102 may determine that a measurement event has been triggered. WTRU 102 may generate an RRC measurement report. The generated RRC measurement report may include information indicating the cell identifier of the current PCell. For example, the RRC measurement report may include a field indicating the current PCell ID and / or the PCell from which the measurement event was triggered. At 1304, WTRU 102 may perform LTM. To transmit the RRC measurement report (e.g., submit it to a lower layer for transmission), the RRC measurement report may be physically transmitted on any cell at 1304 or 1306 in Figure 13 (e.g., if a MAC CE is received before the transmission is successfully completed).

[0421] In some representative embodiments, additional indications may be provided in the RRC Reconfiguration Complete message. For example, a MAC CE that triggers LTM may be received after RRC Reconfiguration is received. The MAC CE that triggers LTM may be received before RRC Reconfiguration Complete is sent (for example, while WTRU102 is still processing and applying RRC Reconfiguration).

[0422] The MAC CE can be received after the RRC reconfiguration complete message has been submitted to the lower layer for transmission (for example, WTRU102 may have the RRC reconfiguration complete message in the RLC or HARQ buffer for transmission / retransmission). In some LTM cell changes (e.g., within a DU), the MAC and RLC are not reset, so the RRC reconfiguration complete message may be sent to a different cell than the one indicated in the RRC reconfiguration. If the RRC message does not contain configuration information specific to the old cell group served by DU1, the CU can safely retransmit the RRC message to WTRU102 via DU2.

[0423] A problem can arise where the content of an RRC message contains expired configuration information associated with an old serving cell group on DU1. For example, if an RRC message is retransmitted to WTRU102 via DU2, WTRU102 may fail to apply the expired RRC configuration because it refers to the old serving cell group, and WTRU102 connects to the new serving cell group. This can trigger a connection re-establishment by the UE. For example, if an RRC message is not retransmitted to WTRU102 via DU2, a new RRC message from the same SRB would have to use a new PDCP sequence number commanded for replay protection using the same AS security context. This creates a PDCP SN gap. Since the default value for the t-Reordering timer for SRB1 is infinity, the t-Reordering timer may never expire, and the SRB's PDCP SDU may no longer be delivered to the upper layer.

[0424] In some representative embodiments, WTRU102 may include information (e.g., during measurement reporting) indicating that the RRC reconfiguration completion message is a response to an RRC reconfiguration (e.g., rather than a MAC CE indicating an LTM). In some representative embodiments, WTRU102 may include information indicating that the RRC reconfiguration completion message was sent before any LTM trigger was received. In some representative embodiments, WTRU102 indicates that the RRC reconfiguration completion is a response to an RRC reconfiguration, in addition to the reconfiguration indicated by the MAC CE. In some representative embodiments, WTRU102 may include information indicating the received RRC reconfiguration (e.g., a message ID, a counter value, and / or a security token corresponding to the received RRC reconfiguration).

[0425] Figure 14 is a step diagram illustrating an exemplary procedure for RRC reconfiguration. For example, an RRC reconfiguration completion flag may be used in the case of RRC reconfiguration while LTM is being performed. At 1402 in Figure 14, WTRU102 may receive an RRC reconfiguration message. At 1404, WTRU102 may apply this reconfiguration and set a value (e.g., a flag in the RRC reconfiguration completion message) to indicate that the RRC reconfiguration has been applied. For example, WTRU102 may indicate the primary cell (e.g., the PCell ID on which the RRC reconfiguration was received) (e.g., as an additional) in the RRC reconfiguration completion message. At 1406, WTRU102 may receive a MAC CE indicating an LTM cell switchover (e.g., before the RRC reconfiguration completion message is submitted to the lower layer for transmission). WTRU102 may perform LTM at 1408. For example, WTRU102 may set a value (e.g., an additional) in the RRC reconfiguration completion message to indicate that LTM was performed as an additional. In some representative embodiments, WTRU102 may include the LTM candidate cell ID (for example, as a value in 1410) in the RRC Reconstruction Complete message. After the RRC has sent the measurement report (e.g., submitted to a lower layer for transmission), the RRC Reconstruction Complete message may be physically transmitted on any cell in 1412 (e.g., if a MAC CE is received before the transmission is successfully completed).

[0426] Figure 15 is a procedure diagram illustrating exemplary procedures according to several representative embodiments. In Figure 15, WTRU102 may, at 1502, receive information indicating configuration information associated with the quality of the LTM (for example, by implementing a method for doing so). WTRU102 may, at 1504, receive information indicating a measurement event. WTRU102 may, at 1506, determine the quality of a first LTM set based on measurements of a first set of beams from a first plurality of cells. WTRU102 may, at 1508, for example, send a measurement report associated with the measurement event and / or perform a conditional reconfiguration based on (1) the measurement event being met using the determined quality of the first LTM set and (2) the elapsed time since the last LTM cell switchover.

[0427] In some representative embodiments, WTRU102 may receive (for example, by implementing a method for doing so) information indicating configuration information associated with the quality of the LTM. WTRU102 may receive information indicating measurement events. WTRU102 may determine the quality of a first set of LTMs based on measurements of a first set of beams from a first set of cells. WTRU102 may, for example, send a measurement report associated with a measurement event and / or perform a conditional reconfiguration based on (1) the measurement event being met using the determined quality of the first set of LTMs and (2) the elapsed time since the last LTM cell switchover.

[0428] For example, WTRU102 may determine the quality of a second LTM set based on measurements of a second set of beams from a second set of cells. A measurement event can be satisfied (or determined to be satisfied) using the determined quality of the first LTM set and the determined quality of the second LTM set.

[0429] For example, WTRU102 may determine a first set of beams as a subset of (e.g., first) beams from a first set of cells, and / or determine a second set of beams as a subset of (e.g., second) beams from a second set of cells.

[0430] For example, WTRU102 may determine the quality of a serving cell or target cell outside of the first LTM set. A measurement event can be met (for example, determined to be met) using the determined quality of the first LTM set and the determined quality of the serving cell or target cell.

[0431] For example, WTRU102 may perform the final LTM switchover before the measurement event is met.

[0432] For example, a measurement report may include information indicating the determined quality of the first LTM set, and / or a conditional reconstruction may include sending information indicating the determined quality of the first LTM set.

[0433] In some representative embodiments, WTRU102 may receive information indicating configuration information for the active LTM set and the target LTM set (e.g., by implementing a method for doing so). WTRU102 may receive information indicating measurement events associated with serving cells (e.g., associated with the active LTM set) and / or neighbor cells (e.g., associated with the target LTM set). WTRU102 may determine the number of cells based on the elapsed time since the last LTM switchover (e.g., since it was performed). WTRU102 may perform measurements on some cells in the active LTM set and some cells in the target LTM set. WTRU102 may send measurement reports associated with measurement events and / or perform conditional reconfiguration based on the measurement events being met, using (1) measurements of serving cells modified by a first offset and / or (2) measurements of neighbor cells modified by a second offset. For example, the first offset may be based on (e.g., determined using) measurements of the active LTM set. For example, the second offset can be based on measurements of the target LTM set (for example, it can be determined using those measurements).

[0434] For example, WTRU102 may determine the number of additional cells as a first value based on whether the elapsed time since the last LTM switchover is less than a threshold, or as a second value based on whether the elapsed time since the last LTM switchover is greater than a threshold.

[0435] For example, WTRU102 may select the number of cells in the active LTM set based on one or more (e.g., a first) criteria and / or select the number of cells in the target LTM set based on one or more (e.g., a second) criteria. For example, the one or more first criteria and the second criteria may be the same (or different).

[0436] For example, a measurement report may include information indicating the number of determined cells and / or (e.g., a specific) cell associated with triggering a measurement event, and / or a conditional reconfiguration may include sending information indicating the number of determined cells and / or (e.g., a specific) cell associated with triggering a measurement event.

[0437] For example, WTRU102 may determine a first offset based on measurements of an active LTM set that meets one or more (e.g., a first) criteria, and / or a second offset based on measurements of a target LTM set that meets one or more (e.g., a second) criteria. For example, one or more first criteria and a second criterion may be the same (or different).

[0438] For example, the last LTM switchover (performed by, for example, WTRU102) could be the last LTM candidate cell switchover.

[0439] In some representative embodiments, WTRU102 may receive information indicating configuration information associated with serving cell quality using L3 filtering (for example, by implementing a method for doing so). WTRU102 may receive information indicating measurement events associated with using the TTT period and offset (and / or scaling factor, and / or threshold). WTRU102 may determine that a measurement event is satisfied for a first serving cell and / or neighbor cell during a first time period. The first time period may be shorter than the TTT period (for example, shorter). WTRU102 may receive information indicating that a switch from the first serving cell to the second serving cell is made using LTM at the end of the first time period. WTRU102 may determine that a measurement event is satisfied for the second serving cell and / or neighbor cell during a second time period. The sum of the first and second time periods may be longer than or equal to the TTT period (for example, longer than or equal to). WTRU102 may send a measurement report containing information indicating the first serving cell, the second serving cell, and / or the first and second time periods, based on (1) the measurement result of the neighbor cell being greater than (2) the measurement result of the second serving cell plus an offset (or otherwise corrected by the offset). As an alternative example, the measurement result of the second serving cell may be corrected by a scaling factor. As an alternative example, the measurement report may be sent based on (1) the difference between the measurement result of the neighbor cell and the measurement result of the second serving cell being greater than (2) a threshold. In some embodiments, any combination of an offset, a scaling factor, and / or a threshold may be used.

[0440] For example, WTRU102 may use any of the L1, L2, and / or L3 measurements to determine that a measurement event is satisfied for a first serving cell and / or neighbor cell during a first time period.

[0441] For example, WTRU102 may determine that a measurement event is satisfied during a second time period for a first serving cell and / or a neighbor cell that uses L3 filtering.

[0442] For example, WTRU102 may determine that information indicating a switch from the first serving cell to the second serving cell can be received at MAC CE.

[0443] For example, WTRU102 may determine that configuration information associated with serving cell quality using L3 filtering may include information indicating one or more filter coefficients for L3 filtering and / or one or more reference signals for L3 filtering.

[0444] For example, configuration information associated with serving cell quality using L3 filtering may include information indicating one or more types of Layer 1 measurements to be used for L3 filtering.

[0445] In some representative embodiments, WTRU102 may receive information indicating an RRC reconfiguration message, which includes information indicating an LTM pause and time period (for example, by implementing a method for doing so). WTRU102 may send an RRC reconfiguration complete message (for example, by performing an RRC reconfiguration). WTRU102 may receive an LTM switchover command. Based on the fact that the elapsed time since receiving the RRC reconfiguration message is less than the time period, or that the elapsed time since sending the RRC reconfiguration complete message is less than the time period, WTRU102 may send information indicating that the LTM switchover command will not be executed.

[0446] For example, WTRU102 may stop reporting LTM Layer 1 based on receiving an LTM pause.

[0447] For example, information indicating that an LTM switchover command was not executed could be a failure indication.

[0448] For example, information indicating that the LTM switching command will not be executed can be sent via MAC CE.

[0449] For example, WTRU102 may initiate LTM Layer 1 reporting after the elapsed time since receiving the RRC reconfiguration message has exceeded or equaled the above time period.

[0450] For example, WTRU102 may initiate LTM Layer 1 reporting after the elapsed time since the RRC reconstruction complete message was sent has exceeded or equaled the above time period.

[0451] In some representative embodiments, WTRU102 may receive information indicating the configuration of L3 measurement events and / or reports (for example, by implementing a method for doing so). WTRU102 may receive information indicating the LTM configuration. WTRU102 may receive information indicating the conditions for including PCell information in the L3 measurement report. WTRU102 may perform measurements on the serving cell and candidate cell. WTRU102 may send an L1 / 2 measurement report based on the measurements. The L1 / 2 measurement report may include information indicating that the measurement result of the candidate cell is higher than the measurement result of the serving cell corrected by the offset (for example, that plus the offset). After sending the L1 / 2 measurement report, WTRU102 may initiate sending an L3 measurement report based on the triggering of an L3 measurement event. The L3 measurement report may include information indicating the identifier of the PCell of WTRU102 associated with the triggering of the L3 measurement event. WTRU102 may receive an LTM cell switching command. WTRU102 can be reconfigured for another cell based on an LTM cell switching command. WTRU102 can then complete the transmission of the L3 measurement report (for example, after reconfiguring for another cell).

[0452] In some representative embodiments, WTRU102 may receive an RRC reconfiguration message in the source cell (for example, while connected to the source cell). WTRU102 may apply the RRC reconfiguration information contained in the RRC reconfiguration message. WTRU102 may send an RRC reconfiguration complete message that includes information indicating the identifier of the PCell of WTRU102 and information indicating that the RRC reconfiguration complete message is due solely to RRC reconfiguration.

[0453] In some representative embodiments, WTRU102 may receive an RRC reconfiguration message in a source cell (for example, while connected to a source cell). WTRU102 may apply the RRC reconfiguration information contained in the RRC reconfiguration message. WTRU102 may receive an LTM cell switching command. WTRU102 may reconfigure to another cell based on the LTM cell switching command. WTRU102 may send an RRC reconfiguration completion message that includes information indicating the identifier of the PCell of WTRU102 and information indicating that the RRC reconfiguration completion message is due to RRC reconfiguration and LTM reconfiguration.

[0454] For example, an LTM cell switching command may be included in MAC CE.

[0455] For example, an RRC reconstruction complete message includes one of the following: a message identifier, a counter value, and / or a security token associated with the RRC reconstruction message.

[0456] Figure 16 is a step diagram showing a second exemplary LTM procedure according to several representative embodiments. In Figure 16, WTRU 102 may receive information (e.g., implement a method for doing so) indicating configuration information for the active LTM set and the target LTM set at 1602. WTRU 102 may receive information (e.g., implement a method for doing so) indicating measurement events associated with the serving cell (e.g., associated with the active LTM set) and / or associated with the neighbor cell (e.g., associated with the target LTM set) at 1604. WTRU 102 may determine the number of cells (e.g., based on the elapsed time since the last LTM switchover, e.g., since it was performed) at 1606. WTRU 102 may perform measurements (e.g., on some cells in the active LTM set and some cells in the target LTM set) at 1608. WTRU102 may, at 1610, send a measurement report associated with a measurement event and / or perform a conditional reconfiguration based on whether the measurement event is met, using (1) a measurement of a serving cell modified by a first offset and / or (2) a measurement of a neighbor cell modified by a second offset. For example, the first offset may be based on (for example, determined using) a measurement of the active LTM set. For example, the second offset may be based on (for example, determined using) a measurement of the target LTM set.

[0457] Figure 17 is a step diagram showing a third exemplary LTM procedure according to several representative embodiments. In Figure 17, WTRU 102 may receive information at 1702 indicating configuration information associated with serving cell quality using L3 filtering. WTRU 102 may receive information at 1704 indicating measurement events associated with using the TTT period and offset (and / or scaling factor, and / or threshold). WTRU 102 may determine at 1706 that the measurement events are satisfied for the first serving cell and / or neighbor cell during a first time period. The first time period may be smaller than the TTT period (e.g., smaller). WTRU 102 may receive information at 1708 indicating that LTM is used to switch from the first serving cell to the second serving cell at the end of the first time period. WTRU 102 may determine at 1710 that the measurement events are satisfied for the second serving cell and / or neighbor cell during a second time period. The sum of the first time period and the second time period may be greater than or equal to the TTT period (for example, greater than or equal to it). WTRU102 may, at 1712, send a measurement report containing information indicating the first serving cell, the second serving cell, and / or the first and second time periods, based on the fact that (1) the measurement result of the neighbor cell is greater than (2) the measurement result of the second serving cell plus the offset (or otherwise corrected by the offset).

[0458] Figure 18 is a step diagram showing a fourth exemplary LTM procedure according to several representative embodiments. In Figure 18, the WTRU may, at 1802, receive information indicating an RRC reconfiguration message containing information indicating an LTM pause and time period (for example, by implementing a method for doing so). The WTRU may, at 1804, send an RRC reconfiguration complete message (for example, by performing an RRC reconfiguration). The WTRU may, at 1806, receive an LTM switchover command. The WTRU may, at 1808, send information indicating that the LTM switchover command will not be executed, based on the fact that the elapsed time since receiving the RRC reconfiguration message is less than the time period, or that the elapsed time since sending the RRC reconfiguration complete message is less than the time period.

[0459] Figure 19 is a step diagram showing a fifth exemplary LTM procedure according to several representative embodiments. In Figure 19, WTRU102 may receive information indicating the configuration of an L3 measurement event and / or report at 1902. At 1904, WTRU102 may receive information indicating the LTM configuration. At 1906, WTRU102 may receive information indicating the conditions for including primary cell (PCell) information in the L3 measurement report. At 1908, WTRU102 may perform measurements on the serving cell and candidate cell. At 1910, WTRU102 may send an L1 / L2 measurement report based on the measurements. The L1 / L2 measurement report may include information indicating that the measurement result of the candidate cell is higher than the measurement result of the serving cell plus offset. At 1912, after sending the L1 / L2 measurement report, WTRU102 may initiate sending an L3 measurement report based on the triggering of an L3 measurement event. The L3 measurement report may include information indicating the identifier of the WTRU's PCell associated with the triggering of the L3 measurement event. At 1914, WTRU102 may receive an LTM cell switching command. At 1916, WTRU102 may reconfigure to another cell based on the LTM cell switching command. At 1918, WTRU102 may complete the transmission of the Layer 3 measurement report.

[0460] Figure 20 is a procedure diagram illustrating an exemplary procedure for measurement reporting using associations between serving cell beams and beams in other cells. In Figure 20, WTRU102 may receive configuration information associated with determining LTM quality in 2002. The configuration information may include (i) the minimum number of beams and / or cells to be used in determining LTM quality, (ii) offset and / or scaling information, (iii) associations between one or more beams of the serving cell and one or more beams of other cells, and / or (iv) an indication for using LTM quality as serving cell quality or as an offset to serving cell quality. In 2004, WTRU102 may receive configuration information indicating an L1 or L3 (L1 / L3) measurement event associated with a triggering condition. In 2006, WTRU102 may perform a first measurement with one or more beams of the serving cell and one or more beams of other cells associated with the serving cell. In 2008, WTRU102 may determine the first LTM quality using configuration information associated with the first measurement and determining the LTM quality. In 2010, WTRU may send a report containing information indicating the first LTM quality associated with the L1 / L3 measurement event, based on the fulfillment of triggering conditions and the elapsed minimum time period since the last LTM cell switchover.

[0461] In some representative embodiments, WTRU102 may perform a second measurement of one or more beams of a target cell and one or more beams of other cells associated with the target cell. WTRU102 may use the second measurement to determine a second LTM quality.

[0462] In some representative embodiments, the WTRU102 may determine that the triggering condition is met based on a comparison of (i) a first LTM quality and (ii) a second LTM quality.

[0463] In some representative embodiments, WTRU102 may determine that the triggering condition is met based on a comparison of (i) the serving cell quality offset and / or scaled using the first LTM quality with (ii) the second LTM quality.

[0464] In some representative embodiments, the WTRU102 may determine the serving cell quality using a first measurement of one or more beams of the serving cell.

[0465] In some representative embodiments, the WTRU102 may perform a second measurement of one or more beams of the target cell. The WTRU102 may use the second measurement to determine the quality of the target cell.

[0466] In some representative embodiments, WTRU102 may determine that the triggering condition is met based on a comparison of (i) the first LTM quality and (ii) the target cell quality.

[0467] In some representative embodiments, WTRU102 may determine that the triggering condition is met based on a comparison between (i) the serving cell quality offset and / or scaled using the first LTM quality and (ii) the target cell quality.

[0468] In some representative embodiments, the WTRU102 may determine the serving cell quality using a first measurement of one or more beams of the serving cell.

[0469] In some representative embodiments, the WTRU102 may send the report to the serving cell or to one of the other cells associated with one or more beams of the serving cell.

[0470] In some representative embodiments, WTRU102 may perform LTM cell switching to a target cell based on the fulfillment of triggering conditions. For example, a report may be sent to the target cell.

[0471] In some representative embodiments, WTRU102 may perform conditional reconfiguration based on the fulfillment of triggering conditions. For example, a report may be sent to the target cell.

[0472] Figure 21 is a procedure diagram illustrating an exemplary procedure for conditional reconstruction using associations between serving cell beams and beams of other cells. In Figure 21, WTRU102 may receive configuration information associated with determining Layer 1 or Layer 2 (L1 / L2) trigger mobility (LTM) quality in 2102. For example, the configuration information may include (i) the minimum number of beams and / or cells to be used in determining the LTM quality, (ii) offset and / or scaling information, (iii) associations between one or more beams of the target cell and one or more beams of other cells, and / or (iv) an indication for using the LTM quality as the target cell quality or as an offset to the target cell quality. In 2104, WTRU102 may receive configuration information indicating L1 or L3 (L1 / L3) measurement events associated with the triggering conditions. In 2106, WTRU102 may perform a first measurement of one or more beams of the target cell and one or more beams of other cells associated with the target cell. In 2108, WTRU102 may determine a first LTM quality using a first measurement and configuration information associated with determining the LTM quality. In 2110, WTRU102 may send a report containing information indicating the first LTM quality associated with an L1 / L3 measurement event, based on the fulfillment of triggering conditions and the elapsed minimum time period since the last LTM cell switchover.

[0473] In some representative embodiments, WTRU102 may perform a second measurement of one or more beams of a serving cell and one or more beams of other cells associated with the serving cell. WTRU102 may use the second measurement to determine a second LTM quality.

[0474] In some representative embodiments, the WTRU102 may determine that the triggering condition is met based on a comparison of (i) a first LTM quality and (ii) a second LTM quality.

[0475] In some representative embodiments, WTRU102 may determine that the triggering condition is met based on a comparison of (i) the target cell quality offset and / or scaled using the first LTM quality with (ii) the second LTM quality.

[0476] In some representative embodiments, the WTRU102 may determine the target cell quality using a first measurement of one or more beams of the target cell.

[0477] In some representative embodiments, the WTRU102 may perform a second measurement of one or more beams of the serving cell. The WTRU102 may use the second measurement to determine the serving cell quality.

[0478] In some representative embodiments, the WTRU102 may determine that the triggering condition is met based on a comparison of (i) the first LTM quality and (ii) the serving cell quality.

[0479] In some representative embodiments, the WTRU102 may determine that the triggering condition is met based on a comparison between (i) the target cell quality offset and / or scaled using the first LTM quality and (ii) the serving cell quality.

[0480] In some representative embodiments, the WTRU102 may send the report to the serving cell or to one of the other cells associated with one or more beams of the serving cell.

[0481] In some representative embodiments, WTRU102 may perform an LTM cell switch to the target cell based on the fulfillment of triggering conditions. WTRU102 may send a report to the target cell.

[0482] Figure 22 is a procedure diagram illustrating an exemplary procedure for conditional reconstruction using associations between a target cell beam and beams in other cells. In Figure 22, WTRU102 may receive configuration information associated with determining Layer 1 or Layer 2 (L1 / L2) trigger mobility (LTM) quality in 2202. The configuration information may include (i) the minimum number of beams and / or cells to be used in determining the LTM quality, (ii) offset and / or scaling information, (iii) associations between one or more beams in the serving cell and one or more beams in other cells, and / or (iv) an indication for using the LTM quality as the serving cell quality or as an offset to the serving cell quality. In 2204, WTRU102 may receive configuration information indicating L1 or L3 (L1 / L3) measurement events associated with the triggering conditions. In 2206, WTRU102 may perform a first measurement with one or more beams in the serving cell and one or more beams in other cells associated with the serving cell. In 2208, WTRU102 may determine the first LTM quality using the first measurement and configuration information associated with determining the LTM quality. In 2210, WTRU102 may perform a conditional reconfiguration associated with the L1 / L3 measurement event based on the fulfillment of triggering conditions and the elapsed minimum time period since the last LTM cell switchover.

[0483] In some representative embodiments, WTRU102 may perform a second measurement of one or more beams of a target cell and one or more beams of other cells associated with the target cell. WTRU102 may use the second measurement to determine a second LTM quality.

[0484] In some representative embodiments, the WTRU102 may determine that the triggering condition is met based on a comparison of (i) a first LTM quality and (ii) a second LTM quality.

[0485] In some representative embodiments, WTRU102 may determine that the triggering condition is met based on a comparison of (i) the serving cell quality offset and / or scaled using the first LTM quality with (ii) the second LTM quality.

[0486] In some representative embodiments, the WTRU102 may determine the serving cell quality using a first measurement of one or more beams of the serving cell.

[0487] In some representative embodiments, the WTRU102 may perform a second measurement of one or more beams of the target cell. The WTRU102 may use the second measurement to determine the quality of the target cell.

[0488] In some representative embodiments, WTRU102 may determine that the triggering condition is met based on a comparison of (i) the first LTM quality and (ii) the target cell quality.

[0489] In some representative embodiments, WTRU102 may determine that the triggering condition is met based on a comparison between (i) the serving cell quality offset and / or scaled using the first LTM quality and (ii) the target cell quality.

[0490] In some representative embodiments, the WTRU102 may determine the serving cell quality using a first measurement of one or more beams of the serving cell.

[0491] In some representative embodiments, WTRU102 may send a report containing information indicating a first LTM quality after conditional reconfiguration. For example, WTRU102 may send the report to the serving cell or to one of the other cells associated with one or more beams of the serving cell.

[0492] Figure 23 is a procedure diagram illustrating an exemplary procedure for conditional reconstruction using associations between a target cell beam and beams of other cells. In Figure 23, WTRU102 may receive configuration information in 2302 associated with determining Layer 1 or Layer 2 (L1 / L2) trigger mobility (LTM) quality. The configuration information may include (i) the minimum number of beams and / or cells to be used in determining the LTM quality, (ii) offset and / or scaling information, (iii) associations between one or more beams of the target cell and one or more beams of other cells, and / or (iv) an indication for using the LTM quality as the target cell quality or as an offset to the target cell quality. In 2304, WTRU102 may receive configuration information indicating L1 or L3 (L1 / L3) measurement events associated with the triggering conditions. In 2306, WTRU102 may perform a first measurement of one or more beams of the target cell and one or more beams of other cells associated with the target cell. In 2308, WTRU102 may determine the first LTM quality using the first measurement and configuration information associated with determining the LTM quality. In 2310, WTRU102 may perform a conditional reconfiguration associated with the L1 / L3 measurement event based on the fulfillment of triggering conditions and the elapsed minimum time period since the last LTM cell switchover.

[0493] In some representative embodiments, WTRU102 may perform a second measurement of one or more beams of a serving cell and one or more beams of other cells associated with the serving cell. WTRU102 may use the second measurement to determine a second LTM quality.

[0494] In some representative embodiments, the WTRU102 may determine that the triggering condition is met based on a comparison of (i) a first LTM quality and (ii) a second LTM quality.

[0495] In some representative embodiments, WTRU102 may determine that the triggering condition is met based on a comparison of (i) the target cell quality offset and / or scaled using the first LTM quality with (ii) the second LTM quality.

[0496] In some representative embodiments, the WTRU102 may determine the target cell quality using a first measurement of one or more beams of the target cell.

[0497] In some representative embodiments, the WTRU102 may perform a second measurement of one or more beams of the serving cell. The WTRU102 may use the second measurement to determine the serving cell quality.

[0498] In some representative embodiments, the WTRU102 may determine that the triggering condition is met based on a comparison of (i) the first LTM quality and (ii) the serving cell quality.

[0499] In some representative embodiments, the WTRU102 may determine that the triggering condition is met based on a comparison between (i) the target cell quality offset and / or scaled using the first LTM quality and (ii) the serving cell quality.

[0500] In some representative embodiments, WTRU102 may send a report containing information indicating a first LTM quality after conditional reconfiguration. For example, the report may be sent to the serving cell or to one of the other cells associated with one or more beams of the serving cell.

[0501] Figure 24 is a step diagram illustrating an exemplary procedure for measurement reporting using an active LTM set and a target LTM set. In Figure 24, WTRU102 may receive configuration information associated with the active LTM set and the target LTM set in 2402. In 2404, WTRU102 may receive configuration information indicating measurement events associated with triggering conditions for serving cells and / or neighbor cells. In 2406, WTRU102 may determine some cells in the active LTM set and / or some cells in the target LTM set based on the elapsed time since the last LTM switchover. In 2408, WTRU102 may perform measurements on some cells in the active LTM set and some cells in the target LTM set. In 2410, WTRU102 may send a measurement report associated with the measurement event based on whether the triggering conditions are met, using (1) the quality of the serving cell corrected by a first offset and / or (2) the quality of the neighbor cell corrected by a second offset.

[0502] In some representative embodiments, the WTRU102 may determine the number of additional cells as a first value based on the elapsed time since the last LTM switchover being less than a threshold, or as a second value based on the elapsed time since the last LTM switchover being greater than a threshold.

[0503] In some representative embodiments, the WTRU102 may determine the number of cells in the active LTM set and / or the number of cells in the target LTM set based on one or more criteria.

[0504] In some representative embodiments, one or more criteria used to determine the number of cells in an active LTM set may include any of the following: (i) a cell in an active LTM set whose WTRU has downlink synchronization; (ii) a cell in an active LTM set whose WTRU has uplink synchronization; (iii) a cell in an active LTM set whose WTRU is configured to report channel status information; (iv) a cell in an active LTM set whose WTRU is configured to perform trace reference signal (TRS) tracking; and / or (v) a cell in an active LTM set whose measured radio quality exceeds a threshold.

[0505] In some representative embodiments, the WTRU102 may determine a first offset based on the number of cells in the active LTM set and / or a second offset based on the number of cells in the target LTM set that satisfy a threshold.

[0506] In some representative embodiments, the WTRU102 may determine a first offset based on measurements of the active LTM set and / or a second offset based on measurements of the target LTM set.

[0507] In some representative embodiments, the measurement report may include information indicating the determined number of cells and / or the cells associated with triggering the measurement event.

[0508] In some representative embodiments, the WTRU102 may determine a first offset based on measurements of an active LTM set that meets one or more criteria, and / or a second offset based on measurements of a target LTM set that meets one or more criteria.

[0509] In some representative embodiments, WTRU102 may determine that the triggering condition is met based on a first condition that compares the quality of the serving cell with the quality of the neighbor cell.

[0510] In some representative embodiments, WTRU102 may determine that the triggering condition is met based on a second condition that compares the quality of the neighbor cell modified by the second offset with a threshold.

[0511] In some representative embodiments, the WTRU102 may determine that the triggering condition is met based on a second condition comparing the quality of the serving cell with a first threshold, and a third condition comparing the quality of the neighbor cell, modified by a second offset, with the second threshold.

[0512] In some representative embodiments, the WTRU 102 may determine that the triggering condition is met based on a second condition comparing the quality of neighbor cells modified by a second offset with a first threshold, and a third condition comparing the number of cells in the target LTM set that satisfy the second threshold with a third threshold.

[0513] In some representative embodiments, the WTRU102 may determine that the triggering condition is met based on a second condition comparing the quality of neighbor cells modified by a second offset with a first threshold, and a third condition comparing the number of cells in the active LTM set with the second threshold.

[0514] In some representative embodiments, the WTRU102 may determine that a triggering condition is met based on a first condition that compares the quality of each cell in the target LTM set with a first threshold, and a second condition that compares the number of cells that satisfy the first condition with a second threshold.

[0515] Figure 25 is a step diagram illustrating an exemplary procedure for conditional reconfiguration using an active LTM set and a target LTM set. In Figure 25, WTRU102 may receive configuration information associated with the active LTM set and the target LTM set in 2502. In 2504, WTRU102 may receive configuration information indicating measurement events associated with triggering conditions for serving cells and / or neighbor cells. In 2506, WTRU102 may determine some cells in the active LTM set and / or some cells in the target LTM set based on the elapsed time since the last LTM switchover. In 2508, WTRU102 may perform measurements on some cells in the active LTM set and some cells in the target LTM set. In 2510, WTRU102 may perform conditional reconfiguration based on the meeting of triggering conditions, using (1) the quality of the serving cell corrected by a first offset and / or (2) the quality of the neighbor cell corrected by a second offset.

[0516] In some representative embodiments, the WTRU102 may determine the number of additional cells as a first value based on the elapsed time since the last LTM switchover being less than a threshold, or as a second value based on the elapsed time since the last LTM switchover being greater than a threshold.

[0517] In some representative embodiments, the WTRU102 may determine the number of cells in the active LTM set and / or the number of cells in the target LTM set based on one or more criteria.

[0518] In some representative embodiments, one or more criteria used to determine the number of cells in an active LTM set may include any of the following: (i) a cell in an active LTM set whose WTRU has downlink synchronization; (ii) a cell in an active LTM set whose WTRU has uplink synchronization; (iii) a cell in an active LTM set whose WTRU is configured to report channel status information; (iv) a cell in an active LTM set whose WTRU is configured to perform trace reference signal (TRS) tracking; and / or (v) a cell in an active LTM set whose measured radio quality exceeds a threshold.

[0519] In some representative embodiments, the WTRU102 may determine a first offset based on the number of cells in the active LTM set and / or a second offset based on the number of cells in the target LTM set that satisfy a threshold.

[0520] In some representative embodiments, the WTRU102 may determine a first offset based on measurements of the active LTM set and / or a second offset based on measurements of the target LTM set.

[0521] In some representative embodiments, the WTRU102 may send a measurement report associated with the conditional reconstruction, which includes information indicating the number of cells determined and / or the cells associated with triggering the measurement event.

[0522] In some representative embodiments, the WTRU102 may determine a first offset based on measurements of an active LTM set that meets one or more criteria, and / or a second offset based on measurements of a target LTM set that meets one or more criteria.

[0523] In some representative embodiments, WTRU102 may determine that the triggering condition is met based on a first condition that compares the quality of the serving cell with the quality of the neighbor cell.

[0524] In some representative embodiments, WTRU102 may determine that the triggering condition is met based on a second condition that compares the quality of the neighbor cell modified by the second offset with a threshold.

[0525] In some representative embodiments, the WTRU102 may determine that the triggering condition is met based on a second condition comparing the quality of the serving cell with a first threshold, and a third condition comparing the quality of the neighbor cell, modified by a second offset, with the second threshold.

[0526] In some representative embodiments, the WTRU 102 may determine that the triggering condition is met based on a second condition comparing the quality of neighbor cells modified by a second offset with a first threshold, and a third condition comparing the number of cells in the target LTM set that satisfy the second threshold with a third threshold.

[0527] In some representative embodiments, the WTRU102 may determine that the triggering condition is met based on a second condition comparing the quality of neighbor cells modified by a second offset with a first threshold, and a third condition comparing the number of cells in the active LTM set with the second threshold.

[0528] In some representative embodiments, the WTRU102 may determine that a triggering condition is met based on a first condition that compares the quality of each cell in the target LTM set with a first threshold, and a second condition that compares the number of cells that satisfy the first condition with a second threshold.

[0529] Figure 26 is a step diagram illustrating an exemplary procedure for measurement reporting using a Trigger Time (TTT) period. In Figure 26, WTRU102 may receive configuration information associated with determining cell quality using L3 filtering in 2602. In 2604, WTRU102 may receive configuration information indicating a measurement event associated with using a Trigger Time (TTT) period and an offset. In 2606, WTRU102 may determine that a measurement event is satisfied at the start of a first time period based on a first triggering condition using the quality of a first serving cell and the quality of a neighbor cell using L3 filtering. In 2608, WTRU102 may receive information indicating that a switch from the first serving cell to a second serving cell is made using Layer 1 / Layer 2 Trigger Mobility (LTM) at the end of the first time period, where the first time period is shorter than the TTT period. In 2610, WTRU102 may determine that a measurement event is satisfied during the second time period based on the second triggering condition, based on the quality of the second serving cell and the neighbor cell during the second time period using L3 filtering, the second time period follows the first time period, and the sum of the first and second time periods is greater than or equal to the TTT period. In 2612, WTRU102 may send a measurement report containing information indicating (i) the first and second serving cells, and / or (ii) either the first or second time period, based on the neighbor cell quality being greater than the measurement result plus offset of the second serving cell.

[0530] In some representative embodiments, WTRU102 may perform a switch from the first serving cell to the second serving cell at the end of the first time period.

[0531] In some representative embodiments, the second time period may begin with the switch to the second serving cell.

[0532] In some representative embodiments, the WTRU102 may determine a first set of L1 measurements of one or more reference signals from a first serving cell. The WTRU102 may use L3 filtering of the first set of L1 measurements to determine the quality of the first serving cell.

[0533] In some representative embodiments, the WTRU102 may determine a second plurality of layer (L1) measurements of one or more reference signals from a second serving cell. The WTRU102 may use the second plurality of L1 measurements and L3 filtering of the first plurality of L1 measurements to determine the quality of the second serving cell.

[0534] In some representative embodiments, the measurement report may include information indicating the determined quality of the second serving cell.

[0535] In some representative embodiments, the WTRU102 may determine a third or more L1 measurements of one or more reference signals from neighbor cells. The WTRU102 may use the third or more L1 measurements to determine the quality of the neighbor cell.

[0536] In some representative embodiments, the WTRU102 may determine the quality of neighbor cells using L3 filtering of a third set of L1 measurements.

[0537] In some representative embodiments, configuration information associated with serving cell quality using L3 filtering may include information indicating one or more filter coefficients, one or more reference signal types, and / or one or more reference signal indices. WTRU102 may perform each L1 measurement based on the reference signal type and / or reference signal index, and / or perform L3 filtering based on the filter coefficients.

[0538] In some representative embodiments, information indicating that the LTM is used to switch the first serving cell to the second serving cell is included in the MAC CE.

[0539] In some representative embodiments, the measurement report may include information indicating the quality of the second serving cell and / or the quality of the first serving cell.

[0540] In some representative embodiments, the WTRU102 may perform L3 filtering for any of the following: reference signal received power (RSRP) measurement, reference signal received quality (RSRQ) measurement, or signal-to-interference plus noise ratio (SINR) measurement.

[0541] Figure 27 is a procedure diagram illustrating an exemplary procedure for LTM measurement pause and measurement reporting. In Figure 27, WTRU102 may receive an RRC reconfiguration message at 2702 that includes information indicating the LTM measurement pause and the time period associated with it (for example, the LTM pause). At 2704, WTRU102 may send an RRC reconfiguration complete message. At 2706, WTRU102 may receive an LTM switch command. At 2708, WTRU102 may send information indicating that the LTM switch command will not be executed, based on the elapsed time since receiving the RRC reconfiguration message being less than the indicated time period. At 2710, WTRU102 may send an LTM measurement report, based on the elapsed time since receiving the RRC reconfiguration message being greater than the indicated time period.

[0542] In some representative embodiments, WTRU102 may suspend LTM measurement reporting based on the indicated LTM pause while the elapsed time since the reception of the RRC reconstruction message is less than the indicated time period.

[0543] In some typical embodiments, information indicating that the LTM switching command will not be executed may be a failure indication.

[0544] In some typical embodiments, information indicating that the LTM switching command will not be executed is sent to the MAC CE.

[0545] In some representative embodiments, WTRU102 may send an LTM measurement report before receiving an RRC reconstruction message.

[0546] Figure 28 is a step diagram illustrating another exemplary procedure for LTM measurement pause and measurement reporting. In Figure 28, WTRU102 may receive an RRC reconfiguration message at 2802 that includes information indicating the LTM measurement pause and the time period associated with it (for example, the LTM pause). At 2804, WTRU102 may send an RRC reconfiguration complete message. At 2806, WTRU102 may receive an LTM switchover command. At 2808, WTRU102 may send information indicating that the LTM switchover command will not be executed, based on the fact that the elapsed time since the RRC reconfiguration complete message was sent is less than the time period indicated above. At 2810, WTRU102 may send an LTM measurement report, based on the fact that the elapsed time since the RRC reconfiguration message was received is greater than the indicated time period.

[0547] In some representative embodiments, WTRU102 may suspend LTM measurement reporting based on the indicated LTM pause while the elapsed time since the reception of the RRC reconstruction message is less than the indicated time period.

[0548] In some typical embodiments, information indicating that the LTM switching command will not be executed may be a failure indication.

[0549] In some typical embodiments, information indicating that the LTM switching command will not be executed is sent to the MAC CE.

[0550] In some representative embodiments, WTRU102 may send an LTM measurement report before receiving an RRC reconstruction message.

[0551] Figure 29 is a step diagram illustrating yet another exemplary procedure for LTM measurement pause and measurement reporting. In Figure 29, WTRU102 may receive an RRC reconfiguration message at 2902 that includes information indicating the LTM measurement pause and the time period associated with it (for example, the LTM pause). At 2904, WTRU102 may send an RRC reconfiguration complete message. At 2906, WTRU102 may receive an LTM switch command. At 2908, WTRU102 may send information indicating that the LTM switch command will not be executed, based on the fact that the elapsed time since receiving the RRC reconfiguration message is less than the indicated time period. At 2910, WTRU102 may send an LTM measurement report, based on the fact that the elapsed time since sending the RRC reconfiguration complete message is greater than the indicated time period.

[0552] In some representative embodiments, WTRU102 may suspend LTM measurement reporting based on the indicated LTM pause while the elapsed time since the RRC reconstruction complete message was sent is less than the indicated time period.

[0553] In some typical embodiments, information indicating that the LTM switching command will not be executed may be a failure indication.

[0554] In some typical embodiments, information indicating that the LTM switching command will not be executed is sent to the MAC CE.

[0555] In some representative embodiments, WTRU102 may send an LTM measurement report before receiving an RRC reconstruction message.

[0556] Figure 30 is a procedure diagram showing yet another exemplary procedure for LTM measurement pause and measurement reporting. In Figure 30, WTRU102 may receive an RRC reconfiguration message in 3002 that includes information indicating the LTM measurement pause and the time period associated with the LTM pause. In 3004, WTRU102 may send an RRC reconfiguration complete message. In 3006, WTRU102 may receive an LTM switch command. In 3008, WTRU102 may send information indicating that the LTM switch command will not be executed, based on the elapsed time since the RRC reconfiguration complete message was sent being less than the time period. In 3010, WTRU102 may send an LTM measurement report, based on the elapsed time since the RRC reconfiguration complete message was sent being greater than the indicated time period.

[0557] In some representative embodiments, WTRU102 may suspend LTM measurement reporting based on the indicated LTM pause while the elapsed time since the RRC reconstruction complete message was sent is less than the indicated time period.

[0558] In some typical embodiments, information indicating that the LTM switching command will not be executed may be a failure indication.

[0559] In some typical embodiments, information indicating that the LTM switching command will not be executed is sent to the MAC CE.

[0560] In some representative embodiments, WTRU102 may send an LTM measurement report before receiving an RRC reconstruction message.

[0561] Figure 31 is a procedure diagram illustrating exemplary procedures for LTM switching and measurement reporting. In Figure 31, WTRU102 may receive information in 3102 indicating the configuration of an L3 measurement event and / or report. In 3104, WTRU102 may receive information indicating the LTM configuration. In 3106, WTRU102 may receive information indicating the conditions for including primary cell (PCell) information in the L3 measurement report. In 3108, WTRU102 may perform measurements on the serving cell and candidate cell. In 3110, WTRU102 may send an L1 / L2 measurement report based on the measurements, which includes information indicating that (i) the measurement result of the candidate cell is higher than (ii) the measurement result of the serving cell plus offset. In 3112, after sending the L1 / L2 measurement report, WTRU102 may initiate sending an L3 measurement report based on the triggering of an L3 measurement event. The L3 measurement report may include information indicating the identifier of the PCell of the WTRU associated with the triggering of the L3 measurement event. In 3114, WTRU102 may receive an LTM cell switching command. In 3116, WTRU102 may reconfigure to another cell based on the LTM cell switching command. In 3118, WTRU102 may complete the transmission of the L3 measurement report.

[0562] In some representative embodiments, the conditions may be that (i) the measurement result of the candidate cell is higher than (ii) the measurement result of the serving cell plus offset.

[0563] In some typical embodiments, the LTM cell switching command may be received after the start of transmission of the L3 measurement report.

[0564] In some typical embodiments, the LTM cell switching command may be received before the completion of the transmission of the L3 measurement report.

[0565] In some typical embodiments, the transmission of the L3 measurement report can be completed after reconfiguration for other cells.

[0566] Figure 32 is a step diagram illustrating exemplary procedures for LTM switching and RRC signaling. In Figure 32, WTRU102 may receive an RRC reconfiguration message in the source cell (for example, from the source cell) in 3202. In 3204, WTRU102 may apply the RRC reconfiguration information contained in the RRC reconfiguration message. In 3206, WTRU102 may send an RRC reconfiguration complete message, which includes information indicating the identifier of the WTRU's PCell and information indicating that the RRC reconfiguration complete message is due to RRC reconfiguration.

[0567] In some representative embodiments, the RRC reconstruction completion message may include information indicating that the RRC reconstruction completion message is due solely to RRC reconstruction.

[0568] In some typical embodiments, the identifier of the PCell in the WTRU may be the physical cell identifier (PCI).

[0569] Figure 33 is a step diagram showing another exemplary procedure for LTM switching and RRC signaling. In Figure 33, WTRU102 may receive an RRC reconfiguration message in a source cell (e.g., from a source cell) in 3302. In 3304, WTRU102 may apply the RRC reconfiguration information contained in the RRC reconfiguration message. In 3306, WTRU102 may receive an LTM cell switching command. In 3308, WTRU102 may reconfigure to another cell based on the LTM cell switching command. In 3310, WTRU102 may send an RRC reconfiguration complete message, which includes information indicating the identifier of the WTRU's PCell and information indicating that the RRC reconfiguration complete message is due to RRC reconfiguration and LTM reconfiguration.

[0570] In some representative embodiments, the LTM cell switching command may be included in the MAC CE.

[0571] In some representative embodiments, the RRC reconstruction complete message may include a message identifier, a counter value, and / or a security token associated with the RRC reconstruction message.

[0572] In some representative embodiments, WTRU102 may be configured to include (for example, by implementing a method that includes) receiving information indicating configuration information associated with the quality of the LTM. WTRU102 may receive information indicating a measurement event. WTRU102 may determine the quality of a first LTM set based on measurements of a first set of beams from a first plurality of cells. WTRU102 may send a measurement report associated with a measurement event and / or perform a conditional reconfiguration based on (1) the measurement event being met using the determined quality of the first LTM set and (2) the elapsed time since the last LTM cell switchover.

[0573] For example, WTRU102 may determine the quality of a second LTM set based on measurements of a second set of beams from a second set of cells. A measurement event can be determined to be met using the determined quality of the first LTM set and the determined quality of the second LTM set.

[0574] For example, WTRU102 may determine a first set of beams as a subset of multiple beams from a first set of multiple cells, and / or determine a second set of beams as a subset of multiple beams from a second set of multiple cells.

[0575] For example, WTRU102 may determine the quality of a serving cell or target cell outside of the first LTM set. WTRU102 may determine that a measurement event is met using the determined quality of the first LTM set and the determined quality of the serving cell or target cell.

[0576] For example, WTRU102 may perform the final LTM switchover before the measurement event is met.

[0577] For example, WTRU102 may send a measurement report containing information indicating the determined quality of the first LTM set, and / or conditional reconstruction may include sending information indicating the determined quality of the first LTM set.

[0578] In some representative embodiments, WTRU102 can be configured to include (for example, by implementing a method that includes) receiving information indicating configuration information for the active LTM set and the target LTM set. WTRU102 may receive information indicating measurement events associated with serving cells and / or neighbor cells. WTRU102 may determine the number of cells based on the elapsed time since the last LTM switchover. WTRU102 may perform measurements on some cells in the active LTM set and some cells in the target LTM set. WTRU102 may send measurement reports associated with measurement events and / or perform conditional reconfiguration based on the fulfillment of measurement events, using (1) measurements of serving cells modified by a first offset and / or (2) measurements of neighbor cells modified by a second offset. The first offset may be based on measurements of the active LTM set and / or the second offset may be based on measurements of the target LTM set.

[0579] For example, WTRU102 may determine the number of additional cells as a first value based on whether the elapsed time since the last LTM switchover is less than a threshold, or as a second value based on whether the elapsed time since the last LTM switchover is greater than a threshold.

[0580] For example, WTRU102 may select the number of cells in the active LTM set and / or the number of cells in the target LTM set based on one or more criteria.

[0581] For example, WTRU102 may send a measurement report containing the number of determined cells and / or information indicating the cells associated with triggering a measurement event, and / or the implementation of a conditional reconfiguration may include sending the number of determined cells and / or information indicating the cells associated with triggering a measurement event.

[0582] For example, WTRU102 may determine a first offset based on measurements of an active LTM set that meets one or more criteria, and / or a second offset based on measurements of a target LTM set that meets one or more criteria.

[0583] For example, the last LTM switch could be the last LTM candidate cell switch.

[0584] In some representative embodiments, WTRU102 may be configured to receive information indicating a configuration associated with serving cell quality using L3 filtering (for example, by implementing a method that includes this). WTRU102 may receive information indicating a measurement event associated with the use of a trigger time (TTT) period and an offset. WTRU102 may determine that a measurement event is satisfied for a first serving cell and / or neighbor cell during a first time period. The first time period is shorter than the TTT period. WTRU102 may receive information indicating a switch from the first serving cell to the second serving cell using LTM at the end of the first time period. WTRU102 may determine that a measurement event is satisfied for the second serving cell and / or neighbor cell during a second time period. The sum of the first and second time periods is longer than or equal to the TTT period. Based on the fact that the neighbor cell measurement result is greater than the second serving cell measurement result plus offset, WTRU102 may send a measurement report that includes information indicating the first serving cell, the second serving cell, and / or the first and second time periods.

[0585] For example, WTRU102 may determine that a measurement event is satisfied during a first time period for a first serving cell and / or a neighbor cell that uses Layer 3 filtering.

[0586] For example, WTRU102 may determine that a measurement event is satisfied during a second time period for a first serving cell and / or a neighbor cell that uses Layer 3 filtering.

[0587] For example, information indicating a switch from the first serving cell to the second serving cell is received by MAC CE.

[0588] For example, a configuration associated with serving cell quality using L3 filtering may include information indicating one or more filter coefficients for L3 filtering and / or one or more reference signals for L3 filtering.

[0589] For example, a configuration associated with serving cell quality using L3 filtering may include information indicating one or more types of L1 measurements to be used for L3 filtering.

[0590] In some representative embodiments, WTRU102 may be configured to receive information indicating an RRC reconfiguration message, which includes information indicating an LTM pause and time period. WTRU102 may send an RRC reconfiguration complete message. WTRU102 may then receive an LTM switchover command. WTRU102 may then send information indicating that the LTM switchover command will not be executed, based on the fact that the elapsed time since receiving the RRC reconfiguration message is less than the time period, or that the elapsed time since sending the RRC reconfiguration complete message is less than the time period.

[0591] For example, WTRU102 may stop reporting LTM L1 based on receiving an LTM pause.

[0592] For example, information indicating that an LTM switchover command was not executed could be a failure indication.

[0593] For example, information indicating that the LTM switching command will not be executed is sent via MAC CE.

[0594] For example, WTRU102 may initiate LTM L1 reporting after the elapsed time since receiving the RRC reconfiguration message has exceeded or equaled the above time period.

[0595] For example, WTRU102 may initiate LTM L1 reporting after the elapsed time since the RRC reconstruction complete message was sent has exceeded or equaled the above time period.

[0596] In some representative embodiments, WTRU102 may be configured to include (for example, by implementing a method to include) receiving information indicating the configuration of L3 measurement events and / or reports. WTRU102 may receive information indicating the LTM configuration. WTRU102 may receive information indicating the conditions for including primary cell (PCell) information in the L3 measurement report. WTRU102 may perform measurements on the serving cell and candidate cell. WTRU102 may send an L1 / L2 measurement report based on the measurements. The L1 / L2 measurement report includes information indicating that the measurement result for the candidate cell is higher than the measurement result plus offset for the serving cell. After sending the L1 / L2 measurement report, WTRU102 may initiate sending an L3 measurement report based on the triggering of an L3 measurement event. The L3 measurement report includes information indicating the identifier of the PCell of WTRU102 associated with the triggering of the L3 measurement event. WTRU102 may receive an LTM cell switching command. WTRU102 can be reconfigured for another cell based on an LTM cell switching command. WTRU102 can then (for example, then) complete the transmission of the L3 measurement report.

[0597] In some representative embodiments, WTRU102 can be configured to include receiving an RRC reconfiguration message in the source cell (for example, by implementing a method that includes this). WTRU102 may apply the RRC reconfiguration information contained in the RRC reconfiguration message. WTRU102 may send an RRC reconfiguration complete message that includes information indicating the identifier of the WTRU's PCell and information indicating that the RRC reconfiguration complete message is due solely to RRC reconfiguration.

[0598] In some representative embodiments, WTRU102 can be configured to include (for example, implement a method for) receiving an RRC reconfiguration message in a source cell (for example, from a source cell). WTRU102 may apply RRC reconfiguration information contained in the RRC reconfiguration message. WTRU102 may receive an LTM cell switching command. WTRU102 may reconfigure to another cell based on the LTM cell switching command. WTRU102 may send an RRC reconfiguration completion message that includes information indicating the identifier of the WTRU's PCell and information indicating that the RRC reconfiguration completion message is due to RRC reconfiguration and LTM reconfiguration.

[0599] For example, an LTM cell switching command may be included in MAC CE.

[0600] For example, an RRC reconstruction complete message may include one of the following: a message identifier, a counter value, and / or a security token associated with the RRC reconstruction message.

[0601] conclusion

[0602] While features and elements are described above in specific combinations, those skilled in the art will understand that each feature or element can be used alone or in any combination with other features and elements. This disclosure should not be limited to the specific embodiments described herein, which are intended as illustrative examples of various aspects. As will be apparent to those skilled in the art, many modifications and variations can be made without departing from its spirit and scope. Elements, actions, or commands used in the description of this application should not be construed as important or essential to the invention unless so expressly given. In addition to those enumerated herein, functionally equivalent methods and apparatus within the scope of this disclosure will be apparent to those skilled in the art from the above description. Such modifications and variations are intended to fall within the scope of the appended claims. This disclosure should be limited only by the terminology of the appended claims, together with the entire scope of equivalents to which such claims are granted. It should be understood that this disclosure is not limited to any particular method or system.

[0603] For simplicity, the embodiments described above will be explained in terms of the terminology and structure of wireless communication-enabled devices (e.g., radio emitters and receivers). However, the embodiments described are not limited to these systems and can be applied to other systems using other forms of electromagnetic waves or non-electromagnetic waves such as sound waves.

[0604] Furthermore, it should be understood that the terms used herein are intended solely to describe specific embodiments and are not intended to limit them. As used herein, the terms “video” or “image” may mean any snapshot, a single image, and / or multiple images displayed over a period of time. As another example, when referred to herein, the terms “user equipment” and its abbreviation “UE,” the term “remote,” and / or the term “head-mounted display” or its abbreviation “HMD” may mean or include (i) a wireless transmit and / or receive unit (WTRU), (ii) any of several embodiments of a WTRU, (iii) a wireless-enabled and / or wired (e.g., tetherable) device configured using some or all of the structure and functionality of a WTRU, (iv) a wireless-enabled and / or wired device configured using less structure and functionality than all of a WTRU, or (v) similar. Details of exemplary WTRUs that can represent any WTRU enumerated herein are provided herein with respect to Figures 1A to 1D. As another example, the various embodiments disclosed above and below in this specification are described as utilizing a head-mounted display. Those skilled in the art will recognize that devices other than head-mounted displays may be used, and that some or all of the present disclosure and the various embodiments disclosed may be modified as appropriate without excessive experimentation. Examples of such other devices may include drones or other devices configured to stream information for providing an adapted reality experience.

[0605] Furthermore, the methods provided herein may be implemented in computer programs, software, or firmware embedded in computer-readable media for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted via wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks and digital multi-purpose disks (DVDs). A software-related processor may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

[0606] Modifications of the methods, apparatus, and systems provided above are possible without departing from the scope of the present invention. In view of the wide variety of embodiments to which it may be applied, it should be understood that the exemplary embodiments are merely examples and should not be taken as limiting the scope of the following claims. For example, embodiments provided herein include a handheld device that includes, or can be used with, any suitable voltage source, such as a battery, which provides any suitable voltage.

[0607] Furthermore, the embodiments provided above refer to other devices, including processing platforms, computing systems, controllers, and processors. These devices may include at least one central processing unit ("CPU") and memory. In accordance with the conventions of those skilled in computer programming, references to acts and symbolic representations of actions or instructions can be performed by various CPUs and memories. Such acts and actions or instructions may be referred to as "executed," "computer-executed," or "CPU-executed."

[0608] Those skilled in the art will understand that actions and symbolically represented operations or instructions involve the manipulation of electrical signals by the CPU. The electrical system represents data bits, causing the resulting transformation or reduction of electrical signals and the preservation of data bits in memory locations within the memory system, thereby reconfiguring or altering the CPU's operation and other processing of signals. The memory locations where data bits are preserved are physical locations having specific electrical, magnetic, optical, or organic properties corresponding to or representing the data bits. It should be understood that the embodiments are not limited to the platforms or CPUs described above, and other platforms and CPUs may support the methods provided.

[0609] Data bits may also be maintained on computer-readable media, including magnetic disks, optical disks, and any other volatile (e.g., random access memory (RAM)) or non-volatile (e.g., read-only memory (ROM)) mass storage systems readable by the CPU. The computer-readable media may include collaborative or interconnected computer-readable media distributed among multiple interconnected processing systems, which may reside exclusively on a processing system or be local or remote to a processing system. It should be understood that embodiments are not limited to the memory described above, and other platforms and memories may support the methods provided.

[0610] In exemplary embodiments, any of the operations, processes, etc., described herein may be implemented as computer-readable instructions stored on a computer-readable medium. These computer-readable instructions can be executed by a processor in a mobile unit, a network element, and / or any other computing device.

[0611] There is little distinction left between hardware and software implementations of a system configuration. The use of hardware or software is generally (but not always) a design selection representing a cost-effectiveness trade-off, in that in certain contexts the choice between hardware and software can be important. There can be various means (e.g., hardware, software, and / or firmware) by which the processes and / or systems and / or other technologies described herein can achieve their objectives, and the preferred means may differ depending on the context in which the processes and / or systems and / or other technologies are deployed. For example, if the implementer determines that speed and accuracy are paramount, the implementer may choose primarily hardware and / or firmware means. If flexibility is paramount, the implementer may choose primarily software implementation. Alternatively, the implementer may choose any combination of hardware, software, and / or firmware.

[0612] The detailed description above illustrates various embodiments of devices and / or processes through the use of block diagrams, flowcharts, and / or examples. Those skilled in the art will understand that, insofar as such block diagrams, flowcharts, and / or examples include one or more functions and / or operations, each function and / or operation within such block diagrams, flowcharts, or examples can be implemented individually and / or collectively by a wide range of hardware, software, firmware, or virtually any combination thereof. In one embodiment, several parts of the subject matter described herein may be implemented via application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), digital signal processors (DSPs), and / or other integrated formats. However, a person skilled in the art will recognize that some aspects of the embodiments disclosed herein can be equivalently implemented in an integrated circuit, either as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or virtually any combination thereof, and that designing circuits and / or writing code for software and / or firmware is well within the skill of a person skilled in the art in light of this disclosure. Furthermore, a person skilled in the art will understand that mechanisms of the subject matter described herein can be distributed as various forms of program products, and that exemplary embodiments of the subject matter described herein are applicable regardless of the particular type of signal-carrying medium used to actually carry out the distribution.Examples of signal-carrying media include, but are not limited to, recordable media such as floppy disks, hard disk drives, CDs, DVDs, digital tapes, and computer memory, as well as transmission media such as digital and / or analog communication media (e.g., fiber optic cables, waveguides, wired communication links, wireless communication links, etc.).

[0613] Those skilled in the art will recognize that it is common in the art to describe devices and / or processes in the manner described herein and then, using engineering conventions, to integrate such described devices and / or processes into data processing systems. That is, at least a portion of the devices and / or processes described herein can be integrated into data processing systems through a reasonable amount of experimentation. Those skilled in the art will recognize that a typical data processing system may generally include one or more of the following: a system unit housing, a video display device, memory such as volatile and non-volatile memory, a processor such as a microprocessor and a digital signal processor, computing entities such as an operating system, drivers, a graphical user interface, and application programs, one or more interaction devices such as a touchpad or screen, and / or control systems including feedback loops and control motors (e.g., feedback for sensing position and / or velocity, control motors for moving and / or adjusting components and / or quantities). A typical data processing system may be implemented using any suitable commercially available components, such as those typically found in data computing / communication and / or network computing / communication systems.

[0614] The subject matter described herein may include different components contained within or connected to other different components. Such shown architectures are merely examples, and it should be understood that in practice, many other architectures can be implemented to achieve the same functionality. Conceptually, any configuration of components to achieve the same functionality is effectively “associated” in such a way that the desired functionality can be achieved. Thus, any two components combined herein to achieve a particular functionality, whether architectural or intermediate components, can be considered “associated” with each other in such a way that the desired functionality can be achieved. Similarly, any two such associated components can also be considered “operably connected” or “operably coupled” with each other to achieve the desired functionality, and any two components that can be associated in such a way can also be considered “operably coupled” with each other to achieve the desired functionality. Specific examples of operably coupled components include, but are not limited to, physically matable and / or physically interacting components, as well as / or wirelessly interactable and / or wirelessly interacting components, as well as / or logically interacting and / or logically interactable components.

[0615] With regard to substantially any use of plural and / or singular terms herein, those skilled in the art can translate from plural to singular and / or singular to plural as appropriate to the context and / or use. Various singular / plural substitutions can be expressly described herein for clarity.

[0616] In general, it will be understood by those skilled in the art that the terms used herein, in particular in the appended claims (e.g., the text of the appended claims), are generally intended to be “open” terms (for example, “including” should be interpreted as “including but not limited to,” “having” should be interpreted as “having at least,” and “includes” should be interpreted as “includes but is not limited to,” etc.). It will further be understood by those skilled in the art that if a specific number of claims to be introduced is intended, such intention will be explicitly stated in that claim, and if such statement is not made, such intention does not exist. For example, if only one item is intended, the term “single” or similar wording may be used. For the sake of understanding, the following appended claims and / or description herein may include the use of the introductory phrases “at least one” and “one or more” to introduce the description of a claim. However, the use of such a phrase should not be interpreted as implying that the introduction of the claim by the indefinite article "a" or "an" limits any particular claim containing such introduced claim to embodiments containing only one such claim (for example, "a" and / or "an" should be interpreted as meaning "at least one" or "one or more"). The same applies to the use of the definite article used to introduce the claim. Furthermore, even if the specific number of claims being introduced is explicitly stated, a person skilled in the art will recognize that such a statement should be interpreted as meaning at least the number stated (for example, the mere statement "two statements" without other modifiers means at least two statements, or two or more statements).Furthermore, in cases where a convention similar to "at least one of A, B, and C" is used, such configurations are generally intended to be understood by those skilled in the art (for example, "a system having at least one of A, B, and C" is not limited to systems having only A, only B, only C, A and B together, A and C together, B and C together, and / or systems having A, B and C together). It will be further understood by those skilled in the art that virtually all disjunctive words and / or phrases presenting two or more alternative terms should be understood, whether in the specification, claims, or drawings, as intended to include the possibility of including one of those terms, either of those terms, or both of those terms. For example, the phrase “A or B” will be understood to include the possibility of “A” or “B” or “A and B.” Furthermore, the term “any of” as used herein, followed by an enumeration of multiple items and / or multiple categories of items, is intended to include “any of,” “any combination of,” “any multiple,” and / or “any combination of multiple,” of the categories of items and / or items, individually or in combination with other categories of items and / or items. Furthermore, the term “set” as used herein is intended to include any number of items, including zero. Furthermore, the term “number” as used herein is intended to include any number, including zero. Also, the term “multiple” as used herein is intended to be synonymous with “a plurality.”

[0617] Furthermore, if any feature or aspect of this disclosure is described in relation to the Markush Group, a person skilled in the art will recognize that this disclosure also describes any individual member or subgroup of a member of the Markush Group.

[0618] For all purposes, including providing explanations, as will be understood by those skilled in the art, all scopes disclosed herein also encompass all possible subscopes and combinations thereof. Any enumerated scope can be readily recognized as one that fully explains and enables that the same scope can be broken down into at least two, one-third, one-quarter, one-fifth, one-tenth, etc. As a non-limiting example, each scope described herein can be readily broken down into a lower third, a middle third, an upper third, etc. Also, as will be understood by those skilled in the art, all words such as “at most,” “at least,” “greater than,” and “less than” include the number stated and refer to scopes that can later be broken down into subscopes, as described above. Finally, as will be understood by those skilled in the art, a scope includes each individual member. Thus, for example, a group having one to three cells refers to a group having one, two, or three cells. Similarly, a group having one to five cells refers to a group having one, two, three, four, or five cells, and so on.

[0619] Furthermore, claims should not be interpreted as being limited to a given order or element unless stated to that effect. In addition, the use of the term “means for” in any claim is intended to implement § 112, paragraph 6 of the U.S. Patent Act, or the means-plus-function claim format, and any claim without the term “means for” is not intended to do so.

Claims

1. Processor, memory, transceiver and A wireless transmit / receive unit (WTRU) comprising the processor, the memory, and the transceiver, Receiving configuration information associated with determining Layer 1 or Layer 2 (L1 / L2) trigger mobility (LTM) quality, wherein the configuration information includes (i) the minimum number of beams and / or cells to be used in determining the LTM quality, (ii) offset and / or scaling information, (iii) associations between one or more beams of a serving cell and one or more beams of other cells, and / or (iv) an indication for using the LTM quality as serving cell quality or as an offset to the serving cell quality. Receiving configuration information indicating an L1 or L3 (L1 / L3) measurement event associated with the triggering condition, Perform a first measurement of one or more beams of the serving cell and one or more beams of the other cells associated with the serving cell. Determining the first LTM quality using the configuration information associated with the first measurement and determining the LTM quality, Based on the fulfillment of the triggering conditions and the elapsed time since the last LTM cell switchover, a report is sent that includes information indicating the first LTM quality associated with the L1 / L3 measurement event. A wireless transmitter / receiver unit (WTRU) configured to perform the following actions.

2. The processor, the memory, and the transceiver are, Perform a second measurement of one or more beams of a target cell and one or more beams of other cells associated with the target cell, The second LTM quality is determined using the second measurement described above. A WTRU according to claim 1, configured to perform the following.

3. The WTRU according to claim 2, wherein the processor, the memory, and the transceiver are configured to determine that the triggering condition is met based on a comparison of (i) the first LTM quality and (ii) the second LTM quality.

4. The WTRU according to claim 2, wherein the processor, the memory, and the transceiver are configured to determine that the triggering condition is met based on a comparison of (i) the serving cell quality offset and / or scaled using the first LTM quality and (ii) the second LTM quality.

5. The WTRU according to claim 4, wherein the serving cell quality is determined using the first measurement of one or more beams of the serving cell.

6. The processor, the memory, and the transceiver are, Perform a second measurement on one or more beams of the target cell, The second measurement described above is used to determine the quality of the target cell. A WTRU according to claim 1, configured to perform the following.

7. The WTRU according to claim 6, wherein the processor, the memory, and the transceiver are configured to determine that the triggering condition is met based on a comparison of (i) the first LTM quality and (ii) the target cell quality.

8. The WTRU according to claim 6, wherein the processor, the memory, and the transceiver are configured to determine that the triggering condition is met based on a comparison of (i) a serving cell quality offset and / or scaled using the first LTM quality and (ii) the target cell quality.

9. The WTRU according to claim 4, wherein the serving cell quality is determined using the first measurement of one or more beams of the serving cell.

10. The WTRU according to any one of claims 1 to 9, wherein the report is sent to the serving cell or to one of the other cells associated with the one or more beams of the serving cell.

11. The processor, the memory, and the transceiver are configured to perform LTM cell switching to the target cell based on the fulfillment of the triggering condition. The report is a WTRU according to any one of claims 2 to 10, which is sent to the target cell.

12. The processor, the memory, and the transceiver are configured to perform conditional reconfiguration based on the fulfillment of the triggering condition. The report is a WTRU according to any one of claims 2 to 10, which is sent to the target cell.

13. Processor, memory, transceiver and A wireless transmit / receive unit (WTRU) comprising the processor, the memory, and the transceiver, Receiving configuration information associated with determining Layer 1 or Layer 2 (L1 / L2) trigger mobility (LTM) quality, wherein the configuration information includes (i) the minimum number of beams and / or cells to be used in determining the LTM quality, (ii) offset and / or scaling information, (iii) associations between one or more beams of a target cell and one or more beams of other cells, and / or (iv) an indication for using the LTM quality as a target cell quality or as an offset to the target cell quality. Receiving configuration information indicating an L1 or L3 (L1 / L3) measurement event associated with the triggering condition, Perform a first measurement of the one or more beams of the target cell and the one or more beams of the other cells associated with the target cell, Determining the first LTM quality using the configuration information associated with the first measurement and determining the LTM quality, Based on the fulfillment of the triggering conditions and the elapsed time since the last LTM cell switchover, a report is sent that includes information indicating the first LTM quality associated with the L1 / L3 measurement event. A wireless transmitter / receiver unit (WTRU) configured to perform the following actions.

14. The processor, the memory, and the transceiver are, Perform a second measurement on one or more beams of a serving cell and one or more beams of other cells associated with the serving cell, The second LTM quality is determined using the second measurement described above. The WTRU according to claim 13, configured to perform the following.

15. The WTRU according to claim 14, wherein the processor, the memory, and the transceiver are configured to determine that the triggering condition is met based on a comparison of (i) the first LTM quality and (ii) the second LTM quality.

16. The WTRU according to claim 14, wherein the processor, the memory, and the transceiver are configured to determine that the triggering condition is met based on a comparison of (i) a target cell quality offset and / or scaled using the first LTM quality and (ii) the second LTM quality.

17. The WTRU according to claim 16, wherein the target cell quality is determined using the first measurement of one or more beams of the target cell.

18. The processor, the memory, and the transceiver are, Perform a second measurement on one or more beams of the serving cell, Determining the serving cell quality using the second measurement described above The WTRU according to claim 14, configured to perform the following.

19. The WTRU according to claim 14, wherein the processor, the memory, and the transceiver are configured to determine that the triggering condition is met based on a comparison of (i) the first LTM quality and (ii) the serving cell quality.

20. The WTRU according to claim 14, wherein the processor, the memory, and the transceiver are configured to determine that the triggering condition is met based on a comparison of (i) the target cell quality offset and / or scaled using the first LTM quality and (ii) the serving cell quality.

21. The WTRU according to any one of claims 14 to 20, wherein the report is sent to the serving cell or to one of the other cells associated with the one or more beams of the serving cell.

22. The processor, the memory, and the transceiver are configured to perform LTM cell switching to the target cell based on the fulfillment of the triggering condition. The report is a WTRU according to any one of claims 14 to 20, which is sent to the target cell.

23. A method implemented by a wireless transmitter / receiver unit (WTRU), wherein the method is A step of receiving configuration information associated with determining Layer 1 or Layer 2 (L1 / L2) trigger mobility (LTM) quality, wherein the configuration information includes (i) the minimum number of beams and / or cells to be used in determining the LTM quality, (ii) offset and / or scaling information, (iii) associations between one or more beams of a serving cell and one or more beams of other cells, and / or (iv) an indication for using the LTM quality as serving cell quality or as an offset to the serving cell quality. The steps include receiving configuration information indicating an L1 or L3 (L1 / L3) measurement event associated with a triggering condition, The steps include performing a first measurement of one or more beams of the serving cell and one or more beams of other cells associated with the serving cell, A step of determining a first LTM quality using the first measurement and the configuration information associated with determining the LTM quality, A step of sending a report, which includes information indicating the first LTM quality associated with the L1 / L3 measurement event, based on the fulfillment of the triggering conditions and the elapsed time period since the last LTM cell switchover. Methods that include...

24. A step of performing a second measurement of one or more beams of a target cell and one or more beams of other cells associated with the target cell, The steps include determining a second LTM quality using the second measurement described above, and The method according to claim 23, further comprising:

25. The method of claim 24, further comprising the step of determining that the triggering condition is met based on a comparison of the first LTM quality and (ii) the second LTM quality.

26. The method of claim 24, further comprising the step of determining that the triggering condition is met based on a comparison of (i) the serving cell quality offset and / or scaled using the first LTM quality and (ii) the second LTM quality.

27. The method according to claim 26, wherein the serving cell quality is determined using the first measurement of one or more beams of the serving cell.

28. A step of performing a second measurement on one or more beams of a target cell, The steps include determining the target cell quality using the second measurement described above, and The method according to claim 23, further comprising:

29. The method of claim 28, further comprising the step of determining that the triggering condition is met based on a comparison of (i) the first LTM quality and (ii) the target cell quality.

30. The method of claim 28, further comprising the step of determining that the triggering condition is met based on a comparison of (i) a serving cell quality offset and / or scaled using the first LTM quality and (ii) the target cell quality.

31. The method according to claim 26, wherein the serving cell quality is determined using the first measurement of one or more beams of the serving cell.

32. The method according to any one of claims 23 to 31, wherein the report is sent to the serving cell or to one of the other cells associated with the one or more beams of the serving cell.

33. The step further includes performing an LTM cell switch to the target cell based on the fulfillment of the triggering condition, The method according to any one of claims 24 to 32, wherein the report is sent to the target cell.

34. The step further includes performing a conditional reconfiguration based on the satisfaction of the triggering conditions, The method according to any one of claims 24 to 32, wherein the report is sent to the target cell.

35. A method implemented by a wireless transmitter / receiver unit (WTRU), wherein the method is A step of receiving configuration information associated with determining Layer 1 or Layer 2 (L1 / L2) trigger mobility (LTM) quality, wherein the configuration information includes (i) the minimum number of beams and / or cells to be used in determining the LTM quality, (ii) offset and / or scaling information, (iii) associations between one or more beams of a target cell and one or more beams of other cells, and / or (iv) an indication for using the LTM quality as a target cell quality or as an offset to the target cell quality. The steps include receiving configuration information indicating an L1 or L3 (L1 / L3) measurement event associated with a triggering condition, A step of performing a first measurement of one or more beams of the target cell and one or more beams of other cells associated with the target cell, A step of determining a first LTM quality using the first measurement and the configuration information associated with determining the LTM quality, A step of sending a report, which includes information indicating the first LTM quality associated with the L1 / L3 measurement event, based on the fulfillment of the triggering conditions and the elapsed time period since the last LTM cell switchover. Methods that include...

36. The steps include performing a second measurement of one or more beams of a serving cell and one or more beams of other cells associated with the serving cell, The steps include determining a second LTM quality using the second measurement described above, and The method according to claim 35, further comprising:

37. The method according to claim 36, further comprising the step of determining that the triggering condition is met based on a comparison of the first LTM quality and (ii) the second LTM quality.

38. The method of claim 36, further comprising the step of determining that the triggering condition is met based on a comparison of (i) a target cell quality offset and / or scaled using the first LTM quality and (ii) the second LTM quality.

39. The method according to claim 38, wherein the target cell quality is determined using the first measurement of one or more beams of the target cell.

40. The steps include performing a second measurement on one or more beams of the serving cell, The steps include determining the serving cell quality using the second measurement described above, and The method according to claim 36, further comprising:

41. The method according to claim 36, further comprising the step of determining that the triggering condition is met based on a comparison of the first LTM quality and (ii) the serving cell quality.

42. The method of claim 36, further comprising the step of determining that the triggering condition is met based on a comparison of (i) the target cell quality offset and / or scaled using the first LTM quality and (ii) the serving cell quality.

43. The method according to any one of claims 36 to 42, wherein the report is sent to the serving cell or to one of the other cells associated with the one or more beams of the serving cell.

44. The step further includes performing an LTM cell switch to the target cell based on the fulfillment of the triggering condition, The method according to any one of claims 36 to 42, wherein the report is sent to the target cell.

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