Adaptive measurements for L1 / L2 mobility

Abstract

A device, such as a wireless transmit / receive unit, may receive first candidate cell information and / or second candidate cell information. The first candidate cell information may indicate a first candidate cell and / or a first synchronization configuration, and the second candidate cell information may indicate a second candidate cell and / or a second synchronization configuration. The WTRU may receive a first measurement configuration and / or a second measurement configuration. The WTRU may select a measurement configuration associated with the first candidate cell based on the first synchronization configuration indicating whether the first candidate cell is associated with a random access channel (RACH) procedure or no RACH procedure. The WTRU may perform a measurement on the first candidate cell based on the selected measurement configuration. The WTRU may transmit a measurement report indicating measurements of the first candidate cell.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 410,960 filed on September 28, 2022 and U.S. Provisional Application Serial No. 63 / 421,745 filed on November 2, 2022, the contents of which are incorporated herein by reference. Background Art

[0003] In wireless communication systems such as new radio (NR) systems, devices such as wireless transmit / receive units (WTRUs) may undergo a handover procedure from a source cell to a target cell. Layer 3 (L3) measurements may be used to determine the feasibility of handover to the target cell. Layer 1 (L1) measurements and / or Layer 2 (L2) measurements may be used to determine handover feasibility, but may suffer from adverse effects compared to L3 measurements. Systems, methods, and / or means are described herein for using L1 / L2 measurements to reduce mobility without such adverse effects. Summary of the invention

[0004] Systems, methods, and means for selecting a measurement configuration for a candidate cell are described herein. A device such as a wireless transmit / receive unit (WTRU) may select a measurement configuration for a candidate cell. For example, a WTRU may select a measurement configuration for a candidate L1 cell and / or a L2 candidate cell based on an uplink (UL) synchronization state to the cell.

[0005] In an example, the WTRU may receive candidate cell information. For example, the WTRU may receive first candidate cell information and second candidate cell information. The candidate cell information may indicate a candidate cell and / or a synchronization configuration. In an example, the first candidate cell information may indicate a first candidate cell and / or a first synchronization configuration. In an example, the second candidate cell information may indicate a second candidate cell and / or a second synchronization configuration.

[0006] In an example, the WTRU may receive a measurement configuration. For example, the WTRU may receive a first measurement configuration and a second measurement configuration. The WTRU may select a measurement configuration based on one or more of: a synchronization configuration (such as a UL synchronization configuration), a type of resources available for transmission, a last received timing information associated with a candidate cell (such as a timing advance), or a duration for which UL data is buffered at the WTRU. The measurement configuration may be or may include one or more of a filter coefficient or a time to trigger (TTT).

[0007] In an example, the WTRU may select a measurement configuration associated with a first candidate cell and / or a second candidate cell. For example, the WTRU may select a measurement configuration associated with the first candidate cell based on a first synchronization configuration indicating whether the first candidate cell is associated with a random access channel (RACH) process or a no-RACH process. If the first candidate cell is associated with a RACH process, the WTRU may select the first measurement configuration. The determination that the first candidate cell is associated with the RACH process may be based on a first synchronization configuration indicating that the first candidate cell is unsynchronized. If the first candidate cell is associated with a no-RACH process, the WTRU may select a second measurement configuration. The determination that the first candidate cell is associated with a no-RACH process may be based on the first synchronization configuration indicating that the first candidate cell is synchronized.

[0008] In an example, the WTRU may select a measurement configuration based on the type of resources available for transmission. For example, the WTRU may determine whether the resources available for transmission are associated with a medium access control (MAC) reset. Based on a determination that the resources available for transmission are associated with a MAC reset, the WTRU may select a first measurement configuration. Based on a determination that the resources available for transmission are not associated with a MAC reset, the WTRU may select a second measurement configuration. The resources available for transmission associated with a MAC reset may be associated with an ultra-reliable low latency (URLLC) type service. The resources available for transmission not associated with a MAC reset may be associated with an enhanced massive mobile broadband (eMBB) type service.

[0009] In an example, the WTRU may select a measurement configuration based on the last time the timing information (e.g., timing advance) associated with the candidate cell was received. Based on the first synchronization configuration, the WTRU may determine the time when the timing information associated with the first candidate cell has been received. For example, the WTRU may determine the time that has passed since the timing information associated with the first candidate cell has been received. Based on the second synchronization configuration, the WTRU may determine the time when the timing information (e.g., timing advance) associated with the second candidate cell has been received. For example, the WTRU may determine the time that has passed since the timing information associated with the second candidate cell has been received. The WTRU may determine whether the time that has passed since the timing information was received is above a threshold level or below a threshold level. If the WTRU determines that the time that has passed since the timing information was received is above a threshold level, then the WTRU may select the first measurement configuration. If the WTRU determines that the time when the timing information was last received is below a threshold level, then the WTRU may select the second measurement configuration.

[0010] In an example, the WTRU may select a measurement configuration based on the amount of UL data that has been buffered at the WTRU. For example, the WTRU may determine whether the amount of uplink (UL) data that has been buffered and / or the amount of time since the UL data has been buffered at the WTRU exceeds a threshold level. If the WTRU determines that the amount of UL data that has been buffered at the WTRU exceeds the threshold level, then the WTRU may select a first measurement configuration. If the WTRU determines that the amount of UL data that has been buffered at the WTRU is below (e.g., does not exceed) the threshold level, then the WTRU may select a second measurement configuration. In an example, the WTRU may determine that the amount of time that the UL data has been buffered exceeds a threshold level. If the WTRU may determine that the amount of time that the UL data has been buffered exceeds the threshold level, then the WTRU may select the first measurement configuration. If the WTRU may determine that the amount of time that the UL data has been buffered is below the threshold level, then the WTRU may select the second measurement configuration.

[0011] The WTRU may perform measurements on the first candidate cell based on the selected measurement configuration based on one or more of: synchronization configuration (such as UL synchronization configuration), type of resources available for transmission, last time timing information associated with the candidate cell was received, and / or amount of UL data / amount of time since UL data has been buffered at the WTRU as described herein. The WTRU may send a measurement report. The measurement report may indicate measurements on the first candidate cell.

[0012] In an example, the WTRU may select a measurement configuration associated with a second candidate cell. As described herein, the WTRU may perform measurements (e.g., second measurements) of the second candidate cell based on the selected measurement configuration based on one or more of: a synchronization configuration (such as a UL synchronization configuration), a type of resources available for transmission, a last received timing information associated with the candidate cell, and / or an amount of UL data buffered at the WTRU. The WTRU may send a measurement report, such as a second measurement report. For example, the second measurement report may indicate measurements of the second candidate cell.

[0013] In a communication system (such as a communication network), an example WTRU may apply one or more measurement parameters (filter coefficients, time to trigger (TTT), etc.) to measure layer 1 (L1) quality of a cell based on a downlink (DL) / UL synchronization state to the cell. Such a WTRU may receive one or more of: a first set of measurement parameters (e.g., filter coefficients, TTT, etc.) associated with a cell to which the WTRU is neither UL synchronized nor DL ​​synchronized; a second set of measurement parameters associated with a cell to which the WTRU is DL synchronized but not UL synchronized; or a third set of measurement parameters to be applied to a cell to which the WTRU is both UL and DL synchronized.

[0014] In an example, based on one or more of a set of measurement parameters, the WTRU may determine, for a particular neighbor cell that is an L1 / Layer 2 (L2) mobility target, whether to maintain DL synchronization with the cell based on the Layer 3 (L3) reference signal received power (RSRP) of the cell and the number of supported synchronization cells.

[0015] In an example, based on one or more of the sets of measurement parameters, the WTRU may determine whether the WTRU is UL synchronized to a cell based on whether the cell has the same UL timing as the serving cell. Based on whether the cell is DL / UL synchronized, the WTRU may apply the associated measurement parameters in the case of measuring the cell. If the measurement of the cell triggers the generation of a measurement report, then any such WTRU may send a measurement report to the network.

[0016] In an example, an example WTRU may apply one or more measurement parameters based on an indication of the priority of data available for transmission in a buffer associated with the WTRU. If high priority data is available for transmission, such a WTRU may receive a first set of measurement parameters to be applied to a neighboring cell, and / or if high priority data is not available for transmission, such a WTRU may receive a second set of measurement parameters to be applied to a neighboring cell. Such a WTRU may receive a priority threshold indicating whether the data is high priority. If high priority data is available in a buffer associated with the WTRU, the WTRU may apply a first set of measurement parameters to measure the L1 / L2 candidates. If no high priority data is available in a buffer associated with the WTRU, the WTRU may apply a second set of measurement parameters to measure the L1 / L2 candidates. If the measurement of the cell triggers the generation of a measurement report, the WTRU may send the measurement report to the network.

[0017] The WTRU may be configured with different measurement parameters for use on different cells, and the measurement parameters to be used may be selected based on one or more of: whether the cell being measured is a SCell; a message from the network (e.g., a MAC control element (CE) or downlink control information (DCI)); whether the target cell is configured with a protocol layer reset (e.g., a MAC / radio link control (RLC) reset); whether the target cell is associated with a RACH-based procedure or a RACH-free procedure; or based on the results of measurements (e.g., different measurements, such as different measurement types, measurements of different cells or sets of cells, etc.). In an example, using different measurement parameters (e.g., filter coefficients) on different cells may be or may include using one or more parameters specific to a given cell for a given cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1Ais a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented.

[0019] Figure 1B is a diagram illustrating that according to an embodiment, Figure 1A A system diagram of an example wireless transmit / receive unit (WTRU) for use within a communication system is illustrated in FIG.

[0020] Figure 1C is a diagram illustrating that according to an embodiment, Figure 1A System diagram of an example radio access network (RAN) and an example core network (CN) for use within a communication system is shown.

[0021] Figure 1D is a diagram illustrating that according to an embodiment, Figure 1A System diagram of another example RAN and another example CN used within the communication system shown.

[0022] Figure 2 is a message flow diagram illustrating an example handover procedure in New Radio (NR).

[0023] Figure 3 is a process diagram illustrating example L1 / 2 inter-cell mobility operations.

[0024] Figure 4 An example flow diagram is illustrated in which a WTRU selects a measurement configuration for a cell and performs measurements on the cell based on the selected measurement configuration. Specific embodiments

[0025] Figure 1A 1 is a diagram illustrating an example communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content such as voice, data, video, messaging, broadcast, etc. to multiple wireless users. The communication system 100 may enable multiple wireless users to access such content by sharing system resources (including wireless bandwidth). For example, the communication system 100 may employ one or more channel access methods such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single carrier FDMA (SC-FDMA), zero tail unique word DFT-spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block filtered OFDM, and filter bank multi-carrier (FBMC), etc.

[0026] like Figure 1AAs shown, the communication system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, RAN 104 / 113, CN 106 / 115, public switched telephone network (PSTN) 108, Internet 110, and other networks 112, but it should be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. For example, the WTRUs 102a, 102b, 102c, 102d (any of which may be referred to as a "station" and / or "STA") may be configured to send and / or receive wireless signals and may include user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular phone, a personal digital assistant (PDA), a smart phone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (IoT) device, a watch or other wearable device, a head-mounted display (HMD), a vehicle, a drone, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in an industrial and / or automated process chain environment), a consumer electronic device, a device operating on a commercial and / or industrial wireless network, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0027] The communication system 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to facilitate access to one or more communication networks (e.g., the CN 106 / 115, the Internet 110, and / or other networks 112) of the WTRUs 102a, 102b, 102c, 102d through at least one wireless interface. For example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node B, an eNode B, a Home Node B, a Home eNode B, a gNB, an NR Node B, a site controller, an access point (AP), a wireless router, and the like. Although each of the base stations 114a, 114b is depicted as a single component, it should be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network components.

[0028] The base station 114a may be part of the RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), a relay node, etc. The base station 114a and / or the base station 114b may be configured to send and / or receive wireless signals on one or more carrier frequencies, which may be referred to as cells (not shown). These frequencies may be in a licensed spectrum, an unlicensed spectrum, or a combination of a licensed spectrum and an unlicensed spectrum. A cell may provide coverage for wireless services to a specific geographic area, which may be relatively fixed or may change over time. The cell may be further divided into cell sectors. For example, a cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, that is, each transceiver corresponds to a sector of the cell. In an embodiment, the base station 114a may use multiple-input multiple-output (MIMO) technology, and may use multiple transceivers for each sector of the cell. For example, beamforming may be used to transmit and / or receive signals in a desired spatial direction.

[0029] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio (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).

[0030] More specifically, as described above, the communication system 100 may be a multiple access system and may employ one or more channel access schemes such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base station 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may use Wideband CDMA (WCDMA) to establish the air interface 116. WCDMA may include communication protocols such as High Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High Speed ​​UL Packet Access (HSUPA).

[0031] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology that may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro), such as Evolved UMTS Terrestrial Radio Access (E-UTRA).

[0032] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology that may use new radio (NR) to establish the air interface 116, such as NR radio access.

[0033] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for example using the dual connectivity (DC) principle. Thus, the air interface used by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions transmitted to / from multiple types of base stations (e.g., eNBs and gNBs).

[0034] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi)), IEEE 802.16 (Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), GSM Enhanced Data rates for Evolution (EDGE), GSM EDGE (GERAN), and the like.

[0035] For example, Figure 1AThe base station 114b in the example may be a wireless router, a Home NodeB, a Home eNodeB, or an access point, and may use any appropriate RAT to facilitate wireless connectivity in a local area, such as a business location, a residence, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a road, and the like. In one embodiment, the base station 114b and the WTRUs 102c, 102d may establish a wireless local area network (WLAN) by implementing a radio technology such as IEEE 802.11. In an embodiment, the base station 114b and the WTRUs 102c, 102d may establish a wireless personal area network (WPAN) by implementing a radio technology such as IEEE 802.15. In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may establish a picocell or a femtocell by using a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.). Figure 1A As shown, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 via the CN 106 / 115.

[0036] The RAN 104 / 113 may be in communication with the CN 106 / 115, which may be any type of network configured to provide voice, data, applications, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have different quality of service (QoS) requirements, such as different throughput requirements, delay requirements, fault tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location-based services, pre-paid calls, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although in Figure 1A Although not shown, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may be in direct or indirect communication with other RANs that employ the same RAT or a different RAT as the RAN 104 / 113. For example, in addition to being connected to the RAN 104 / 113, which may employ NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) employing GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0037] The CN 106 / 115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network that provides plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the TCP / IP Internet protocol suite, such as the Transmission Control Protocol (TCP), the User Datagram Protocol (UDP), and / or the Internet Protocol (IP). The networks 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 113 or a different RAT.

[0038] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communication system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks via different wireless links). Figure 1A The illustrated WTRU 102c may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0039] Figure 1B is a system diagram illustrating an example WTRU 102. Figure 1B As shown, the WTRU 102 may include, among other things, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keyboard 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0040] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), any other type of integrated circuit (IC), a state machine, etc. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. Although Figure 1B The processor 118 and the transceiver 120 are depicted as separate components, but it will be appreciated that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0041] The transmit / receive element 122 may be configured to send or receive signals to or from a base station (e.g., base station 114a) via an air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to send and / or receive RF signals. In an embodiment, the transmit / receive element 122 may be a transmitter / detector configured to send and / or receive, for example, IR, UV, or visible light signals. In yet another embodiment, the transmit / receive element 122 may be configured to send and / or receive both RF and optical signals. It should be understood that the transmit / receive element 122 may be configured to send and / or receive any combination of wireless signals.

[0042] Although the transmit / receive element 122 is Figure 1B 116, but the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0043] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As described above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11.

[0044] The processor 118 of the WTRU 102 may be coupled to a speaker / microphone 124, a keyboard 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit), and may receive user input data from these components. The processor 118 may also output user data to the speaker / microphone 124, the keyboard 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from and store data in any type of suitable memory, such as a non-removable memory 130 and / or a removable memory 132. The non-removable memory 130 may include a random access memory (RAM), a read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from and store data in memories that are not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0045] The processor 118 may receive power from the power source 134, and may be configured to distribute and / or control power for use by other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel-metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0046] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to or in lieu of the information from the GPS chipset 136, the WTRU 102 may receive location information from a base station (e.g., base stations 114a, 114b) over the air interface 116 and / or determine its location based on the timing of signals received from two or more nearby base stations. It should be appreciated that the WTRU 102 may acquire location information via any suitable location-determination method while remaining consistent with an embodiment.

[0047] The processor 118 may also be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an electronic compass, a satellite transceiver, a digital camera (for photos and / or videos), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, a Bluetooth® module, a frequency modulation (FM) radio unit, a digital music player, a media player, a video game console module, an Internet browser, a virtual reality and / or augmented reality (VR / AR) device, an activity tracker, etc. The peripherals 138 may include one or more sensors, which may be one or more of the following: a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0048] The WTRU 102 may include a full-duplex radio for transmission and reception of some or all signals (e.g., signals associated with specific subframes for UL (e.g., for transmission) and downlink (e.g., for reception)) which may be concurrent and / or simultaneous. The full-duplex radio may include an interference management unit to reduce and / or substantially eliminate self-interference via hardware (e.g., choke) or via signal processing by a processor (e.g., a separate processor (not shown) or via the processor 118). In one embodiment, the WTRU 102 may include a half-duplex radio for transmission and reception of some or all signals (e.g., signals associated with specific subframes for UL (e.g., for transmission) or downlink (e.g., for reception)).

[0049] Figure 1C 1 is a system diagram illustrating the RAN 104 and the CN 106 in accordance with an embodiment. As described above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0050] The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO technology. Thus, for example, the eNode-B 160a may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0051] Each of the eNodeBs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, user scheduling in UL and / or DL, etc. Figure 1C As shown, the eNode-Bs 160a, 160b, 160c may communicate with one another via an X2 interface.

[0052] Figure 1C The illustrated CN 106 may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. While each of the foregoing elements is depicted as part of the CN 106, it should be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0053] The MME 162 may be connected to each of the eNode-Bs 160a, 160b, 160c in the RAN 104 via an S1 interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0054] The SGW 164 may be connected to each of the eNode-Bs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring the user plane during inter-eNode-B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing the context of the WTRUs 102a, 102b, 102c, and the like.

[0055] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0056] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0057] Although the WTRU Figures 1A-1D Although described as a wireless terminal, it is contemplated that in certain representative embodiments such a terminal may use (eg, temporarily or permanently) a wired communication interface with a communication network.

[0058] In a representative embodiment, other network 112 may be a WLAN.

[0059] A WLAN adopting an infrastructure basic service set (BSS) mode may have an access point (AP) for a BSS and one or more stations (STAs) associated with the AP. The AP may have access or an interface to a distribution system (DS) or another type of wired / wireless network that sends traffic into and / or out of the BSS. Traffic originating from outside the BSS to a STA may arrive through the AP and may be delivered to the STA. Traffic originating from a STA to a destination outside the BSS may be sent to the AP to be delivered to the corresponding destination. Traffic between STAs within a BSS may be sent through the AP, for example, where a source STA may transmit traffic to the AP, and the AP may deliver traffic to the destination STA. Traffic between STAs within a BSS may be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic may be sent between a source STA and a destination STA (e.g., directly between a source STA and a destination STA) using direct link establishment (DLS). In certain representative embodiments, the DLS may use 802.11 eDLS or 802.11 z tunnel DLS (TDLS). A WLAN using an independent BSS (IBSS) mode may not have an AP, and STAs (eg, all STAs) within or using the IBSS may communicate directly with each other. The IBSS communication mode may sometimes be referred to herein as an "ad-hoc" communication mode.

[0060] When using the 802.11 ac infrastructure mode of operation or a similar mode of operation, the AP may send beacons on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., a 20 MHz wide bandwidth) or a width dynamically set via signaling. The primary channel may be an operating channel of the BSS and may be used by STAs to establish a connection with the AP. In certain representative embodiments, carrier sense multiple access with collision avoidance (CSMA / CA) may be implemented, such as in an 802.11 system. For CSMA / CA, a STA (e.g., each STA) (including the AP) may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0061] A high throughput (HT) STA may communicate using a 40 MHz wide channel, for example, by combining a 20 MHz wide primary channel with an adjacent or non-adjacent 20 MHz wide channel to form the 40 MHz wide channel.

[0062] Very High Throughput (VHT) STA can support 20MHz, 40MHz, 80MHz and / or 160MHz wide channels. 40MHz and / or 80MHz channels can be formed by combining consecutive 20MHz channels. A 160MHz channel can be formed by combining 8 consecutive 20MHz channels or by combining two non-contiguous 80MHz channels, which can be referred to as an 80+80 configuration. For the 80+80 configuration, the data after channel coding can pass through a segment parser that can divide the data into two streams. Inverse Fast Fourier Transform (IFFT) processing and time domain processing can be performed on each stream separately. The stream can be mapped onto two 80MHz channels, and the data can be sent by the transmitting STA. At the receiver of the receiving STA, the above operations for the 80+80 configuration can be reversed, and the combined data can be transmitted to the medium access control (MAC).

[0063] Sub-1 GHz operation modes are supported by 802.11af and 802.11ah. The channel operation bandwidth and carrier in 802.11af and 802.11ah are reduced relative to the channel operation bandwidth and carrier used in 802.11n and 802.11ac. 802.11af supports 5MHz, 10MHz and 20MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1MHz, 2MHz, 4MHz, 8MHz and 16MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support meter type control / machine type communication, such as MTC devices in macro coverage areas. MTC devices may have certain capabilities, such as limited capabilities including support for (e.g., only support for) certain and / or limited bandwidths. MTC devices may include batteries with battery life above a threshold (e.g., to maintain very long battery life).

[0064] WLAN systems that can support multiple channels and channel bandwidths (such as 802.11n, 802.11ac, 802.11af, and 802.11ah) include channels that can be designated as primary channels. The primary channel may have a bandwidth equal to the maximum common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by the STA, which is from all STAs operating in the BSS that support the minimum bandwidth operating mode. In the example of 802.11ah, for STAs (e.g., MTC type devices) that support (e.g., only support) 1MHz mode, the primary channel may be 1MHz wide, even if the AP and other STAs in the BSS support 2MHz, 4MHz, 8MHz, 16MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or network allocation vector (NAV) settings may depend on the state of the primary channel. If the primary channel is busy, for example, because a STA (which only supports the 1MHz operating mode) sends to the AP, the entire available band may be considered busy even if most of the band remains idle and may be available.

[0065] In the United States, the available frequency band that 802.11 ah can use is from 902MHz to 928MHz. 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. Depending on the country code, the total bandwidth available for 802.11 ah is 6MHz to 26MHz.

[0066] Figure 1D 1 is a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment. As described above, the RAN 113 may employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0067] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, the gNBs 180a, 180b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, for example, the gNB 180a may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation techniques. For example, the gNB 180a may transmit multiple component carriers (not shown) to the WTRU 102a. A subset of these component carriers may be on an unlicensed spectrum, while the remaining component carriers may be on a licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c may implement coordinated multi-point (CoMP) techniques. For example, the WTRU 102a may receive coordinated transmissions from the gNB 180a and gNB 180b (and / or gNB 180c).

[0068] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with scalable numerologies. For example, OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or Transmission Time Intervals (TTIs) of various or scalable lengths (e.g., containing different numbers of OFDM symbols and / or lasting different lengths of absolute time) .

[0069] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c without accessing other RANs (e.g., such as the eNode-Bs 160a, 160b, 160c). In a standalone configuration, the WTRUs 102a, 102b, 102c may utilize one or more of the gNBs 180a, 180b, 180c as mobility anchors. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate / connect with the gNBs 180a, 180b, 180c while also communicating / connecting with another RAN, such as an eNode-B 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement the DC principle to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNode-Bs 160a, 160b, 160c may serve as mobility anchors for the WTRUs 102a, 102b, 102c, and the gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0070] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, user scheduling in UL and / or DL, support network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data to a user plane function (UPF) 184a, 184b, routing of control plane information to an access and mobility management function (AMF) 182a, 182b, and the like. Figure 1D As shown, gNBs 180a, 180b, and 180c may communicate with each other via an Xn interface.

[0071] Figure 1DThe illustrated CN 115 may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one session management function (SMF) 183a, 183b, and may include a data network (DN) 185a, 185b. Although each of the foregoing elements is depicted as part of the CN 115, it should be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0072] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via the N2 interface and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRU 102a, 102b, 102c, supporting network slicing (e.g., handling different PDU sessions with different requirements), selecting a specific SMF 183a, 183b, managing registration areas, termination of NAS signaling, mobility management, etc. The AMF 182a, 182b may use network slicing in order to customize CN support for the WTRU 102a, 102b, 102c based on the type of service used by the WTRU 102a, 102b, 102c. For example, different network slices may be established for different use cases, such as services that rely on ultra-reliable low latency (URLLC) access, services that rely on enhanced massive mobile broadband (eMBB) access, services for machine type communication (MTC) access, etc. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-APro, and / or non-3GPP access technologies such as WiFi.

[0073] The SMF 183a, 183b may be connected to the AMF 182a, 182b in the CN 115 via the N11 interface. The SMF 183a, 183b may also be connected to the UPF 184a, 184b in the CN 115 via the N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b, and configure the routing of services through the UPF 184a, 184b. The SMF 183a, 183b may perform other functions, such as managing and allocating UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notification, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0074] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184a, 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, providing mobility anchoring, and the like.

[0075] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) serving as an interface between the CN 115 and the PSTN 108 or may communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) serving as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to a local data network (DN) 185a, 185b through the UPF 184a, 184b via an N3 interface to the UPF 184a, 184b, and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0076] In view of Figures 1A-1D and about Figures 1A-1D As described herein, one or more or all of the functions described herein for one or more of the following may be performed by one or more simulation devices (not shown): WTRU 102a-d, base station 114a-b, eNodeB 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-b, UPF 184a-b, SMF 183a-b, DN 185a-b, and / or any (multiple) other devices described herein. The simulation device may be one or more devices configured to simulate one or more or all of the functions described herein. For example, the simulation device may be used to test other devices and / or simulate network and / or WTRU functions.

[0077] The simulation device can be designed to implement one or more tests of other devices in a laboratory environment and / or an operator network environment. For example, one or more simulation devices can perform one or more or all functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices within the communication network. One or more simulation devices can perform one or more or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. For testing purposes, the simulation device can be directly coupled to another device, and / or can use over-the-air wireless communication to perform testing.

[0078] One or more emulated devices can perform one or more functions, including all functions, while not being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulated devices can be used in a test lab and / or in a test scenario in a non-deployed (e.g., testing) wired and / or wireless communication network to implement testing of one or more components. One or more emulated devices can be test devices. The emulated devices can send and / or receive data using direct RF coupling and / or wireless communication via RF circuits (e.g., which can include one or more antennas).

[0079] In a communication system such as a communication network, an example device such as an example wireless transmit / receive unit (WTRU) may apply one or more measurement parameters for measuring layer 1 (L1) quality of a cell based on a downlink (DL) synchronization state and / or an uplink (UL) synchronization state to the cell. For example, the one or more measurement parameters may be or may include a filter coefficient, a time to trigger (TTT), etc. Such a WTRU may receive one or more of: a first set of measurement parameters (e.g., filter coefficients, TTT, etc.) associated with one or more cells to which the WTRU is neither UL synchronized nor DL ​​synchronized; a second set of measurement parameters (e.g., filter coefficients, TTT, etc.) associated with one or more cells to which the WTRU is DL synchronized but not UL synchronized; or a third set of measurement parameters (e.g., filter coefficients, TTT, etc.) to be applied to one or more cells to which the WTRU is both UL synchronized and DL synchronized.

[0080] In an example, based on one or more of the sets of measurement parameters, the WTRU may determine whether to maintain DL synchronization with a cell for a neighboring cell (e.g., a specific neighboring cell) that is a L1 / L2 mobility target. For example, the WTRU may determine whether to maintain DL synchronization with a cell based on the L3 reference signal received power (RSRP) of the cell and / or the number of supported synchronization cells.

[0081] In an example, based on one or more of the measurement parameter sets, the WTRU may determine whether the WTRU is UL synchronized to a cell based on whether the cell has the same UL timing as a serving cell. Based on whether the cell is DL / UL synchronized, the WTRU may apply associated measurement parameters in the case of measuring the cell. If the measurement of the cell triggers the generation of a measurement report, the WTRU may send the measurement report to the network, such as a base station.

[0082] In some examples, the WTRU may apply one or more measurement parameters (e.g., filter coefficients, TTT, etc.) based on an indication of the priority of data available for transmission in the WTRU's buffer. In an example, if high priority data is available for transmission, the WTRU may receive a first set of measurement parameters (e.g., filter coefficients, TTT, etc.) to be applied to one or more neighboring cells. In an example, if high priority data is not available for transmission, the WTRU may receive a second set of measurement parameters (e.g., filter coefficients, TTT, etc.) to be applied to one or more neighboring cells. The WTRU may receive a priority threshold indication. For example, the priority threshold indication may indicate whether the data is high priority. If high priority data is available in the WTRU's buffer, the WTRU may apply the first set of measurement parameters to measure the L1 / L2 candidates. If no high priority data is available in the WTRU's buffer, the WTRU may apply the second set of measurement parameters to measure the L1 / L2 candidates. If the measurement of the cell triggers the generation of a measurement report, the WTRU may send the measurement report to the network, such as a base station.

[0083] Reference Figure 2 , provides an example handover procedure in New Radio (NR). Figure 2 As illustrated, the WTRU context within the source base station (e.g., source gNB) may include information about roaming and / or access restrictions that may be provided at connection establishment and / or timing advance (TA) update. This information may be provided by an access and mobility management function (AMF).

[0084] Continue to refer Figure 2, the source gNB may configure one or more WTRU measurement procedures, and the WTRU may report in accordance with the measurement configuration. The source gNB may decide to hand over the WTRU. For example, the source gNB may decide to hand over the WTRU based on the received measurements. The source gNB may send a handover request message to the target gNB. For example, the source gNB may transmit a handover request message to the target gNB, the handover request message conveying a transparent radio resource control (RRC) container with information about preparing the handover on the target side. Such information may include at least one or more of the following: the target cell ID KgNB*, the cell radio network temporary identifier (C-RNTI) of the WTRU in the source gNB, the resource management entity (RRM) configuration including the WTRU inactivity time, the basic AS configuration including antenna information and downlink (DL) carrier frequency, the current QoS flow to data radio bearer (DRB) mapping rules applied to the WTRU, the system information block 1 (SIB1) from the source gNB, one or more WTRU capabilities for different radio access technologies (RATs), protocol data unit (PDU) session related information, and / or in some examples, the measurement information reported by the WTRU also includes beam related information (e.g., if available).

[0085] Continue to refer Figure 2 , the admission control procedure may be performed by the target gNB. If the WTRU may be admitted, the target gNB may prepare for the handover with L1 / L2 and send a handover request acknowledgement indication to the source gNB. The indication may include a transparent container to be sent as an RRC message to the WTRU to perform the handover.

[0086] Continue to refer Figure 2 , the source gNB may trigger a WTRU handover by sending an RRCReconfiguration message to the WTRU. The RRC message may include information associated with accessing the target cell: at least one or more of the target cell ID, the new C-RNTI, the target gNB, and / or a security algorithm identifier for the selected security algorithm. The RRC message may include information associated with a set of dedicated random access channel (RACH) resources, an indication of an association between RACH resources and synchronization signal blocks (SSBs), an indication of an association between RACH resources and WTRU-specific (multiple) CSI-RS configurations, an indication of common RACH resources, system information of the target cell, etc.

[0087] Continue to refer Figure 2, the source gNB may transmit an SN STATUS TRANSFER message to the target gNB. The target gNB may pass the uplink Packet Data Convergence Protocol (PDCP) Sequence Number (SN) receiver status and / or downlink PDCP SN transmitter status of the DRBs for which the PDCP status preservation is applicable (e.g., for Radio Link Control (RLC) Acknowledged Mode (AM)). The WTRU may synchronize to the target cell and indicate the completion of the handover procedure by sending an RRCReconfigurationComplete message to the target gNB.

[0088] Continue to refer Figure 2 , the target gNB may send a PATH SWITCH REQUEST indication to the AMF to trigger the 5G core network (5GC) to switch the DL data path to the target gNB and / or establish a next generation control plane (NG-C) interface instance with the target gNB. The 5GC may switch the DL data path to the target gNB. The user plane function (UPF) may transmit one or more end marker packets on the previous path to the source gNB per PDU session and / or tunnel, and may release one or more user plane (U-plane) resources and / or transport network layer (TNL) resources to the source gNB.

[0089] Continue to refer Figure 2 , the AMF may acknowledge the PATH SWITCH REQUEST indication using a PATH SWITCH REQUEST ACKNOWLEDGE message. In response to the PATH SWITCH REQUEST ACKNOWLEDGE message from the AMF, the target gNB may send a WTRU CONTEXT RELEASE message to notify the source gNB of the success of the handover. The source gNB may release the radio and / or control plane (C-plane) related resources associated with the WTRU context. Data forwarding (e.g., ongoing data forwarding) may continue.

[0090] exist Figure 2 In the example handover process shown above, the WTRU may be provided with a set of one or more measurement parameters associated with performing L3 measurements of neighbor / serving cells. The measurement parameters may include filter coefficients, TTT, etc. If L3 measurements are performed, the WTRU may apply the set of one or more parameters to one or more serving / neighboring cells.

[0091] Example handover procedures for conditional handover (CHO) and conditional PSCell addition / change (CPA / CPC) may be discussed. In CHO, an example WTRU may be configured (via, for example, an RRC reconfiguration message) with a handover target (e.g., a target cell configuration) and / or associated conditions regarding cell measurement events (e.g., events A3 / A5 and corresponding cells). After being configured by receiving a CHO command, such a WTRU may initiate monitoring of the associated conditions. In response to detecting that the conditions are met, the WTRU may trigger a handover (e.g., a reconfiguration) to an associated cell with a given configuration. For CPC and CPA, the WTRU may trigger a PSCell change or PSCell addition associated with a stored PSCell configuration. For example, for CPC and CPA, the WTRU may trigger a PSCell change or PSCell addition associated with a stored PSCell configuration upon detecting that the associated conditions defined by the measurement event are met.

[0092] L1 / L2 based mobility may be described herein. In an example L1 / L2 mobility scenario, the serving cell may remain unchanged (e.g., there is no possibility of changing the serving cell using L1 / 2 based mobility). For example, in a frequency range 2 (FR2) deployment, carrier aggregation (CA) may be used to utilize the available bandwidth, for example, for multiple CCs in an aggregated frequency band. Such CCs may be transmitted with an analog beam pair (e.g., a common analog beam pair, such as a gNB beam and a WTRU beam). In an example, the WTRU may be configured with a transmission configuration indicator (TCI) state (e.g., 64 states) for receiving physical downlink control channel (PDCCH) transmissions and physical downlink shared channel (PDSCH). The TCI state may contain a reference signal (RS) or SSB that the WTRU references for setting its beam. The SSB may be associated with a non-serving PCI. MAC signaling (e.g., a TCI state indication of a UE-specific PDCCH MAC CE) may be used to activate the TCI state of the CORESET / PDCCH. Reception of PDCCH transmissions from non-serving cells may be supported by a MAC CE indicating a TCI state associated with a non-serving physical layer cell ID (PCI). MAC signaling (e.g., TCI state activation / deactivation for WTRU-specific PDSCH) may be used to activate a subset of TCI states (e.g., up to 8 TCI states) for PDSCH reception. Downlink control information (DCI) may be used to indicate which TCI states (e.g., 8 TCI states) in a subset of TCI states are activated or deactivated. Some examples may support unified TCI states with different update mechanisms (DCI-based) but without multiple transmit and receive points (TRPs). Some examples may support unified TCI states with multiple TRPs.

[0093] In the L1 / L2 example, one or more mechanisms may be provided for reducing handover delay (e.g., improving handover delay). In an example L3 handover or conditional handover (CHO), the WTRU may use RRC signaling to indicate a measurement report. In response to the measurement report, a network such as a base station may provide a measurement configuration and / or a conditional handover configuration. In the case of a handover, the network may provide a configuration about the target cell after the WTRU reports, for example, using RRC signaling, that the cell meets the configured radio quality criteria. The network may provide (e.g., pre-provide) the WTRU, the target cell configuration, and / or the measurement criteria associated with the WTRU triggering the CHO configuration. The target cell configuration and / or the measurement criteria may be provided to reduce the handover failure rate due to delays in sending measurement reports and receiving RRC reconfigurations. The handover and CHO L3 mobility mechanism may cause delays (e.g., in the case of an L3 handover (such as a traditional L3 handover and / or a non-traditional L3 handover)) due to sending measurement reports and receiving target configurations.

[0094] L1 / L2 mobility may allow application (eg, fast application) of configuration for candidate cells, for example, by dynamically switching between SCells and by switching PCells (eg, by switching roles between SCells and PCells) without performing RRC signaling.

[0095] refer to Figure 3 , Figure 3 An example L1 / L2 inter-cell mobility operation is illustrated. Figure 3 As shown, a higher layer signaling (eg, RRC signaling) may be used to configure the candidate cell group, and dynamic switching of the PCell and the SCell may be implemented by using L1 / L2 signaling. Figure 3 As illustrated in , RRC may trigger (e.g., initial trigger) to configure cells 1-4 as candidates and activate cell 1 as PCell 1 and cell 2 as SCell 2. SCell configurations may be dynamically switched, for example, between cell 2 and cell 3. PCell configurations may be dynamically switched, for example, between cell 1 and cell 2. In the illustrated example, dynamic PCell switching may be associated with dynamic SCell switching, for example, dynamically switching PCell 1 to PCell 2 and dynamically switching SCell to SCell 4.

[0096] One or more delay components associated with L1 / L2 mobility may be described herein. L1 / L2 mobility may be used to achieve faster mobility, for example, by reducing one or more delay components associated with mobility. The delay components may include reconfiguration delay, DL synchronization delay, UL synchronization delay, and / or measurement delay.

[0097] RRC reconfiguration (e.g., including RRC reconfiguration associated with the reception of a handover command) may incur some latency at the example WTRU. For example, the WTRU may have to at least decode the RRC message. The WTRU may need to apply parameters and / or configurations associated with the RRC message. Applying the parameters and / or configurations may incur (e.g., require) some interruptions. In the L1 / L2 mobility example, such a configuration may be provided to the WTRU prior to mobility, and delays associated with the decoding of the RRC message may be avoided. In addition, in some L1 / L2 mobility examples, the mobility target cell configuration may be similar to the example current serving cell configuration. In the example, intra-distributed unit (intra-DU) mobility may include change parameters within the example SpCellConfig. In the example, inter-distributed unit (inter-DU) mobility may include change parameters within the example CellGroupConfig.

[0098] For example, if the WTRU detects a mobility trigger, the example WTRU may acquire DL timing associated with the target cell. DL timing acquisition may include acquiring SSB / beam timing associated with the target cell so that the WTRU can decode the PDCCH / PDSCH associated with the target cell.

[0099] Example A WTRU may receive a mobility trigger. Based on the mobility trigger, the WTRU may obtain the UL timing associated with the target cell in order to send a mobility complete message (e.g., a complete message in an L3 handover). The WTRU may perform a RACH procedure to send the mobility complete message. In an example, if the target cell is UL synchronized and the WTRU has UL resources available for transmission on the target cell, the WTRU may skip performing the RACH procedure.

[0100] In an example, L3 measurements may require filtering and applying TTT before generating a measurement report. In an example, L1 measurements may be utilized and may be sent with less or no filtering. Using L1 measurements may allow the network to determine a better cell more quickly than using L3 measurements. In an example where the target cell is temporarily or occasionally in a good state, applying L1 measurements without filtering may result in ping ponging (e.g., the WTRU may perform a handover to the target cell and then return to the source cell after the target cell condition deteriorates).

[0101] L1 measurement(s) (eg, instead of L3 measurements) may be used for mobility by identifying alternative cell(s) / beam(s). For example, the WTRU may use L1 measurements to move to an alternative cell and / or alternative beam, eg, to achieve higher throughput.

[0102] If a HO command is received when the serving cell has acceptable quality, then a radio link failure (RLF) due to degradation of the serving cell quality (e.g., rapid degradation) can be avoided. However, some handovers may result in a ping-pong effect. For example, if the target cell is acceptable for a time interval (e.g., a short time interval), and a subsequent HO is performed back to the original source cell, then a ping-pong effect may occur. The ping-pong effect may result in interruption in some cases. For example, if inter-DU mobility is performed, a MAC reset may be performed. A MAC reset may result in loss of data, such as stored in a MAC buffer. Data loss (e.g., loss of data stored in a MAC buffer) may result in retransmission of data. In certain types of mobility (e.g., intra-DU), a MAC reset may not be performed with less average.

[0103] In some examples, the target cell may be acceptable. For example, the target cell may be acceptable for a short period of time (e.g., only for a short period of time). If the target cell is acceptable only for a short period of time, then a subsequent handover to the source cell may be required. In some examples, this ping-pong effect may result in service interruption. For example, if inter-DU mobility is performed, a MAC reset may result in data loss from the MAC buffer, and a retransmission of the lost data may need to be performed. In other examples where a MAC reset is not required (e.g., intra-DU), mobility may benefit from measurements involving less averaging.

[0104] L1 measurements without ping-pong effects may be configured and / or used.

[0105] In an example, the measurement parameters and / or measurement configuration may refer to one or more coefficients or a set of coefficients for filtering for a measurement (e.g., an L1 measurement, an L3 measurement, etc.). The set of coefficients may be used in filtering. The set of coefficients may include actual values ​​of the filter coefficients and / or biases, offsets, factors, or the like for selecting a set of filter coefficients instead of another set of filter coefficients. For example, the actual values ​​of the filter coefficients and / or biases, offsets, factors, etc. may be used to calculate a set of filter coefficients relative to another set of filter coefficients.

[0106] In an example, measurement parameters and / or measurement configurations may refer to one or more specific beams to be averaged and / or considered when deriving cell measurements. Such measurement parameters may include the number of beams to be averaged (e.g., nrofSS-BlocksToAverage as configured in the example of RRC signaling). Such parameters may include thresholds or other rules for determining whether to consider a beam (e.g., abstThreshss-BlocksConsolidation).

[0107] In an example, a measurement parameter and / or measurement configuration may refer to one or more time to trigger (TTT) parameters associated with a duration during which one or more event conditions associated with a measurement report or CHO configuration remain valid. Such a measurement parameter may include a specific value of the TTT associated with one or more configured measurement events and / or may include a bias, offset, factor, or the like applicable to a configured (e.g., baseline) value of the TTT.

[0108] In an example, the measurement parameters and / or measurement configurations may refer to one or more offsets associated with one or more Ax type events. For example, such measurement parameters may include a first offset to be applied to a measurement value of a cell associated with an event and / or a second offset to be applied to a measurement value of a cell associated with another event. In an example, the application of such an offset may include determining whether to apply a bias to a baseline offset.

[0109] In an example, the measurement parameters and / or measurement configuration may refer to one or more sampling rates (e.g., percentages) of measurements (or measurement reports) associated with transmission to the network. In some examples, the WTRU may be configured to transmit a subset of measurements to the network (e.g., a base station). For example, the WTRU may be configured to transmit one measurement out of every X measurements to be reported, where X may depend on the factors described herein.

[0110] In an example, measurement parameters and / or measurement configuration may refer to one or more periodicities associated with one or more reference signals used in determining cell measurements.

[0111] In an example, the measurement parameters and / or measurement configuration may refer to one or more averaging periods over which measurements of reference signals associated with cell measurements are performed.

[0112] In an example, the measurement parameters and / or measurement configuration may refer to one or more measurement types. For example, such parameters may include a set of L1 filter coefficients associated with measurements made at L1 and / or a set of L3 filter coefficients associated with measurements made at L3. In an example, as part of the measurement, the WTRU may determine whether to perform L1 measurements and / or L3 measurements. In an example, the WTRU may determine whether to perform the measurement using a first reference signal or a second reference signal.

[0113] In an example, measurement parameters and / or measurement configuration may refer to specific reference signals, CSI measurement resources, SSB measurement resources, etc. that may be indicated to the WTRU (eg, as part of a measurement configuration).

[0114] In an example, measurement parameters and / or measurement configuration may refer to reporting criteria, such as whether to perform periodic or event-triggered reporting, the periodicity of reporting, or events or event configurations (e.g., A3 vs. A5, etc.) applied when measuring and / or reporting one or more target cells.

[0115] It should be understood that in various examples, measurement parameters may refer to any one or more of the above meanings, and / or to other meanings not listed. Further, the WTRU may be configured to have one or more of the measurement parameter sets. The measurement parameter sets described herein may be associated with one or more cells.

[0116] In an example measurement configuration, for a given measurement object (e.g., a frequency to be measured), the WTRU may be configured with a set of measurement parameters (e.g., a single set of measurement parameters). As described herein, the measurement parameters may be or may include filter coefficients, TTT, etc. Such measurement parameters may be applied to the serving cell and the candidate cells (e.g., each candidate cell) for L3 measurements.

[0117] In various examples, a set of measurement parameters may be referred to as a measurement configuration.

[0118] In an example, the WTRU may be configured to have measurements (e.g., L1 and / or L3). The measurement parameters to be applied may vary between one or more cells to be measured. For example, the WTRU may apply a first set of parameters when measuring a first neighboring cell, and may apply a second set of parameters when measuring a second neighboring cell. Based on the application of the first set of parameters or the second set of parameters, the WTRU may send a measurement report to the network (e.g., a base station). In some examples, the WTRU may send a measurement report to the network, where such measurements meet one or more configured criteria.

[0119] In various embodiments, the WTRU may determine the measurement parameters to be applied based on any one or a combination of the following factors or mechanisms: cell-specific configuration; configuration of the target cell (e.g., possibly with respect to the serving cell configuration); area / cell group specific configuration; downlink synchronization status; uplink synchronization status; whether the cell being measured is an SCell; in messages from the network, such as MAC CE and / or DCI; whether the target cell SIC is configured with the rest of the protocol layers (e.g., MAC / RLC reset); whether the target cell is associated with a RACH-based process or a RACH-free process; and / or based on the results of measurements (e.g., possibly different measurements).

[0120] For example, the WTRU may determine the measurement parameters to be applied based on the cell-specific configuration. The WTRU may receive a configuration of an L1 / L2 mobility candidate cell. Such a configuration may include measurement parameters (e.g., filter coefficients, TTT, etc.) to be used in performing measurements of the candidate cell. For example, the WTRU may receive a cell-specific configuration (e.g., L1 / L2 mobility candidate) for a neighboring cell from a serving cell. In an example, the WTRU may perform neighboring cell measurements for the neighboring cell using the measurement parameters configured for the neighboring cell as long as the WTRU remains on the serving cell.

[0121] For example, the WTRU may determine the measurement parameters to apply based on the configuration of the target cell associated with the serving cell configuration. In an example, the WTRU may determine whether to apply a first set of measurement parameters or a second set of measurement parameters for the target cell based on attributes associated with the target cell configuration (and in some other examples, compare those measurements with measurements of the serving cell).

[0122] For example, the WTRU may determine explicitly (eg, using a configured DU ID or cell / cell group configuration ID) or implicitly whether the serving cell and the target cell belong to the same distributed unit (DU) or to different DUs.

[0123] In an example, the WTRU may be configured by the serving cell to have two measurement configurations. The WTRU may determine which measurement configuration to apply when measuring a target neighboring cell based on the presence and / or absence of an IE in the target cell configuration. For example, if the target cell configuration is provided using the SpCellConfig IE, the WTRU may apply a first measurement configuration when measuring the target cell. If the target cell configuration is provided using the CellGroupConfig IE, the WTRU may apply a second measurement configuration when measuring the target cell.

[0124] In an example, multiple subsequent reconfigurations may be performed without receiving a full cell configuration. If multiple subsequent reconfigurations are performed without receiving a full cell configuration, the WTRU may configure two measurement configurations and may determine which measurement configuration to apply based on the difference in the target cell configuration compared to the source cell configuration. For example, if the target cell configuration includes the same RLC / MAC parameters as the source cell configuration, or the WTRU is not required to reconfigure these parameters, then the WTRU may use the first measurement configuration; otherwise, the WTRU may use the second measurement configuration.

[0125] In an example, the WTRU may determine whether to use a first measurement configuration or a second measurement configuration based on a cell ID of a target cell (e.g., a PCI) compared to a cell ID of a source cell. In an example, there may be a relationship between the cell IDs of the source cell and the target cell. For example, the WTRU may determine which measurement configuration to apply based on the target and source cell IDs being within a specific range. For another example, the WTRU may determine which measurement configuration to apply based on whether the target cell ID and the source cell ID are modulos of each other. In more examples, the WTRU may determine which measurement configuration to apply based on other cell ID relationships that may exist. The WTRU may also be configured with a set of cells for which the WTRU may use the first configuration and a set of another cells for which the WTRU may use the second configuration.

[0126] For example, the WTRU may determine the measurement parameters to be applied based on an area-specific configuration and / or a cell group-specific configuration. In an example, the WTRU may be configured to have a cell group and / or a cell area. The configured cell group and / or the configured cell area may be similar to the RAN area configuration. The WTRU may determine the applicable measurement configuration based on the cell group and / or the cell area. For example, the WTRU may determine the applicable measurement configuration from two or more configured measurement parameter sets based on the cell group and / or the cell area. In an example, for a target cell belonging to a cell group different from the cell group to which the serving cell belongs, the WTRU may use a first configuration. In an example, for a cell within the same cell group to which the serving cell belongs, the WTRU may use a second configuration.

[0127] In an example, a cell-specific configuration of one or more parameters (e.g., certain parameters) of a candidate cell (Cell) may be associated (e.g., explicitly associated) with a corresponding serving cell (e.g., PCell). For a candidate cell, a WTRU may be provided with a configuration. In an example, the configuration may be and / or may include {{TTT1, filter coefficient 1}, PCell = cell 1 or cell 2}, {{TTT2, filter coefficient 2}, PCell = cell 3 or cell 4}, and the like. Such an example configuration may indicate that the WTRU applies a first set of parameters when the PCell is set to cell 1 or cell 2, and applies a second set of parameters when the PCell is set to cell 3 or cell 4, and the like. In an example, the configuration may be and / or may include the following: {{TTT1, filter coefficient 1}, if the WTRU is configured with cell 1 or cell 2 as a serving cell}, {{TTT2, filter coefficient 2}, if the WTRU has cell 2 or cell 2 as a serving cell}, and the like. Such an example configuration may instruct the WTRU to apply a first set of parameters if the WTRU is configured with cell 1 or cell 2 as a serving cell (e.g., PCell, SCell, PSCell, etc.), and to apply a second set of parameters if the PCell is configured with cell 3 or cell 4 as a serving cell, etc. In such examples, cell 1 / cell 2 / cell 3 / cell 4 may be identified by one or more cell identifiers (such as a serving cell index, PCI, etc.).

[0128] In an example, one or more other groups may be configured based on one or more characteristics of a cell. For example, one or more other groups may be configured based on one or more characteristics of a cell rather than an explicit ID as discussed herein. As described herein, rules may be used. For example, as described herein, if the WTRU is configured with a PCell and / or SCell with certain frequencies, or is within a certain frequency range, bandwidth range, capability, parameter set, etc., then one or more parameters may be applied to measurements of neighboring cells.

[0129] The WTRU may determine the measurement parameters to be applied based on the downlink synchronization state. In an example, the WTRU may determine whether to use a first measurement configuration or a second measurement configuration based on the downlink synchronization state of the target cell at the time of measurement. The determination of the downlink synchronization state of the target cell at the time of measurement may be whether the WTRU has acquired the timing of the SSB / beam, whether the WTRU monitors the PDCCH on the target cell, etc. In an example, if the WTRU is downlink synchronized to a L1 / L2 mobility candidate, then the WTRU may use the first configuration. In an example, if the WTRU is not downlink synchronized to a L1 / L2 mobility candidate, then the WTRU may use the second configuration.

[0130] In an example, the WTRU may autonomously determine one or more target cells on which to maintain downlink synchronization. For example, the WTRU may rank one or more configured L1 / L2 mobility targets by cell quality, beam quality, number of beams, etc., and the WTRU may determine the best N cells on which to maintain downlink synchronization. In an example, the value of N may be configured. In an example, the value of N may be based on (e.g., dependent on) the capabilities of the WTRU. For example, the WTRU may use a first set of measurement parameters for one or more target cells on which the WTRU maintains downlink synchronization, and may use a second set of measurement parameters to measure one or more target cells on which the WTRU does not maintain downlink synchronization. In an example, the WTRU may use one or more configured measurement parameters and / or default measurement parameters to perform measurements on one or more potential target cells, for example, in order to rank one or more potential target cells to determine one or more cells on which to maintain synchronization.

[0131] In an example, the WTRU may receive a set of target cells on which to maintain synchronization. In an example, the WTRU may receive an indication to add and / or remove cells from the set of target cells. The WTRU may receive the indication via a MAC CE, via a DCI, etc. In an example, based on the set of target cells, the WTRU may use a first measurement configuration to perform measurements of target cells on which the WTRU maintains DL synchronization. In an example, based on the set of target cells, the WTRU may use a second measurement configuration to perform measurements of target cells on which the WTRU does not maintain DL synchronization.

[0132] The WTRU may determine the measurement parameters to be applied based on the uplink synchronization state. In an example, the WTRU may determine whether to use a first measurement configuration or a second measurement configuration to measure the target cell based on the UL synchronization state of the target cell. In an example, for a target cell to which the WTRU is uplink synchronized, the WTRU may measure the target cell with a first measurement configuration. In an example, for a target cell to which the WTRU is not uplink synchronized, the WTRU may measure the target cell with a second measurement configuration. Such an example WTRU may determine whether the WTRU is UL synchronized to the target cell based on determining one or more of the following: whether the target cell configuration includes an indication (such as an explicit indication) indicating whether the WTRU performs RACH-free mobility to the target cell; whether the target cell is configured as part of the same timing advance group as the serving cell; whether the WTRU is provided with RACH resources for the target cell; whether the WTRU maintains UL synchronization with the target cell; and / or the time when the WTRU last received timing information (e.g., timing advance) associated with the target cell from the serving cell (such as the time elapsed after the WTRU received the timing information).

[0133] The WTRU may determine one or more measurement parameters to be applied based on whether the measured cell is an SCell. For example, the WTRU may determine whether to use the first measurement configuration or the second measurement configuration to measure the target cell based on whether the target cell is an SCell when performing the measurement. After the target cell has become an SCell via L1 / L2 mobile cell exchange, the WTRU may change from one measurement configuration to another measurement configuration for the target cell (e.g., a potential L1 / L2 target cell). In the example, if the WTRU determines that the target cell is an SCell (e.g., when performing the measurement), then the WTRU may use the first measurement configuration. In the example, if the WTRU determines that the target cell is not an SCell (e.g., when performing the measurement), then the WTRU may use the second measurement configuration.

[0134] The WTRU may determine one or more measurement parameters to be applied based on a message from the network. The message may be sent from the network using a MAC CE, a DCI, etc. The WTRU may receive an indication of one of a plurality of measurement configurations (e.g., TTT, filter coefficients, etc. described herein). For example, the WTRU may receive the indication via an RRC message. For example, after receiving the indication, the WTRU may change from using a first measurement configuration to using a second measurement configuration after receiving an L1 / L2 message (e.g., a MAC CE or a DCI). For example, the WTRU may be configured with a plurality of measurement configurations in the RRC. The measurement configuration (e.g., each measurement configuration) may have an associated index. The WTRU may receive a message, such as a MAC CE message. The message may be configured to enable a configuration, disable a configuration, or switch from one configuration to another. In an example, a message such as a MAC CE message may indicate an index of one of the configurations.

[0135] The WTRU may determine one or more measurement parameters to be applied based on whether the target cell is configured with a reset of a protocol layer (e.g., a MAC reset and / or an RLC reset). The WTRU may receive a configuration for a candidate target cell. The configuration may include an indication of whether to reset or reestablish a protocol layer during a cell exchange. For example, the WTRU may receive a flag, such as a reset MAC flag and / or a remaining RLC flag, etc., wherein the flag is used to indicate whether to reset a specific protocol layer with each target cell configuration when L1 / L2 moves to the target cell. For example, the WTRU may receive a flag associated with the target cell and / or the source cell. Based on the received flag, the WTRU may apply a first measurement configuration or a second measurement configuration during the measurement of the target cell. In an example, if the WTRU receives a flag indicating that a specific protocol layer is reset at L1 / L2 mobility to the target cell, then the WTRU may apply a first measurement configuration. In an example, if the WTRU receives a flag indicating that a specific protocol layer is maintained (e.g., not reset) at L1 / L2 mobility to the target cell, then the WTRU may apply a second measurement configuration.

[0136] Figure 4 An example flow chart is illustrated in which a WTRU selects a measurement configuration for a cell and performs measurements on the cell based on the selected measurement configuration. For example, the WTRU may determine one or more measurement parameters to be applied based on whether the cell (such as a target cell) is associated with a RACH-based procedure or a RACH-free procedure. As described herein, the WTRU may receive candidate cell information. For example, the WTRU may receive first candidate cell information and second candidate cell information. The candidate cell information may indicate a candidate cell and / or a synchronization configuration. For example, the first candidate cell information may indicate a first candidate cell and / or a first synchronization configuration, and the second candidate cell information may indicate a second candidate cell and / or a second synchronization configuration.

[0137] like Figure 4As illustrated, the WTRU may receive a measurement configuration. For example, the WTRU may receive a first measurement configuration and / or a second measurement configuration. The WTRU may select a measurement configuration, such as a first measurement configuration or a second measurement configuration. For example, the WTRU may select a measurement configuration associated with the first candidate cell based on a first synchronization configuration indicating whether the first candidate cell is associated with a RACH process or associated with a no-RACH process. In the example, if the first candidate cell uses a RACH process and / or is associated with a RACH process, then the WTRU may select the first measurement configuration. The determination that the first candidate cell uses a RACH procedure and / or is associated with a RACH procedure may be based on a first synchronization configuration indicating that the first candidate cell is unsynchronized. In the example, if the first candidate cell uses a no-RACH process and / or is associated with a no-RACH process, then the WTRU may select a second measurement configuration. The determination that the first candidate cell uses a no-RACH process and / or is associated with a no-RACH process may be based on a first synchronization configuration indicating that the first candidate cell is synchronized.

[0138] In an example, the WTRU may select a measurement configuration associated with a second candidate cell based on a second synchronization configuration indicating whether the second candidate cell is associated with a RACH process or associated with a no-RACH process. In an example, if the second candidate cell uses a RACH process and / or is associated with a RACH process, the WTRU may select the first measurement configuration. The determination that the second candidate cell uses a RACH process and / or is associated with a RACH process may be based on a second synchronization configuration indicating that the second candidate cell is not synchronized. In an example, if the second candidate cell uses a no-RACH process and / or is associated with a no-RACH process, the WTRU may select the second measurement configuration. The determination that the second candidate cell uses a no-RACH process and / or is associated with a no-RACH process may be based on a second synchronization configuration indicating that the second candidate cell is synchronized.

[0139] like Figure 4 As illustrated, the WTRU may perform measurements (eg, first measurements) on a first candidate cell based on the selected measurement configuration. The WTRU may send a measurement report, eg, the first measurement report. For example, the first measurement report may indicate measurements of the first candidate cell.

[0140] In an example, the WTRU may perform a measurement (eg, a second measurement) of a second candidate cell based on the selected measurement configuration. The WTRU may send a measurement report, such as the second measurement report. For example, the second measurement report may indicate the measurement of the second candidate cell.

[0141] As described here and Figure 4As illustrated, the WTRU may determine whether to perform measurements according to a first configuration or a second configuration based on whether the WTRU is configured with a RACH procedure (e.g., a RACH-based procedure) or a non-RACH procedure. Whether the WTRU performs a RACH-based non-RACH cell switch procedure may be configured to the WTRU (e.g., configured per source and target cell pairing, such as described herein). For example, if the WTRU is configured with a RACH-based cell switch to a target cell, then the WTRU may perform measurements of the target cell in accordance with a first measurement configuration. If the target cell is configured with a non-RACH procedure, then the WTRU may perform measurements of the target cell in accordance with a second cell configuration.

[0142] The WTRU may determine one or more measurement parameters to apply based on the results of the measurements (e.g., different measurements). For example, the WTRU may determine the measurement configuration associated with the first measurement based on the measurement results associated with the second measurement (e.g., both measurements are associated with the same target cell or each measurement is associated with a different target cell). For example, the WTRU may be configured with a configuration (e.g., a different configuration) for performing an L1 measurement of the target cell. The WTRU may select the configuration to apply based on the value of another measurement (e.g., an L3 measurement) (e.g., a measurement of the same or a different cell). For example, if the L3 measurement of a cell (e.g., a target cell or a source cell) exceeds a threshold, the WTRU may use the first measurement configuration, and if the L3 measurement is within the threshold, the WTRU may use the second measurement configuration. The second measurement may be of a different type (e.g., L1 RSRP instead of L3 RSRP), a different reference signal, etc. In an example, the second measurement may be of the same type, or the reference signal and measurement configuration used for the second measurement may be based on a configuration (such as a default configuration configured in the RRC). In an example, the second measurement may correspond to the same cell (eg, the target cell in question) or a different cell (eg, the source cell), whereby the target may be a valid L1 / L2 mobility target.

[0143] In an example, the WTRU may be configured with one or more measurement parameters to be used based on previous mobility results. In an example, the WTRU may determine one or more measurement parameters to be used based on previous mobility results and / or historical data associated with L1 / L2 or L3 handovers. For example, the WTRU may determine and / or measure one or more of the following: the number of L1 / L2 or L3 handovers; the rate at which the WTRU performs L1 / L2 or L3 handovers; the time since the last mobility event; whether the cell switch follows an RRC reconfiguration or a subsequent L1 / L2 cell switch; whether the cell was a previous target of a cell switch; a measurement of the rate of ping-pong effects, such as a measurement of the rate at which a wireless transmit / receive unit performs a certain number of mobility events, or a measurement of the frequency at which a wireless transmit / receive unit performs mobility leaving and returning to a certain cell; and / or measurements that may be performed over a configured time span and / or duration.

[0144] In an example, the WTRU may select a measurement configuration (e.g., a first measurement configuration or a second measurement configuration) based on the last time the timing information (e.g., timing advance) associated with the candidate cell was received. For example, the WTRU may select the first measurement configuration based on the time that has passed since the timing information associated with the first candidate cell was received. In an example, the WTRU may receive the timing information, for example, using a synchronization configuration. The timing information may be or may include a timing advance for a transmission (e.g., a UL transmission) to a cell (e.g., a first candidate cell). In an example, the WTRU may determine the time that has passed since the timing information was received. Based on the time that has passed since the timing information was received, the WTRU may determine the last time the timing information associated with the first candidate cell was received. As described herein, the timing information (e.g., timing advance) may be received using a synchronization configuration (e.g., a first synchronization configuration). For example, based on the first synchronization configuration, the WTRU may determine the time that has passed since the timing information associated with the first candidate cell has been received. For example, the WTRU may determine the last time the timing information associated with the first candidate cell has been received based on the first synchronization configuration. The WTRU may determine whether the time that has passed since the timing information has been received is above a threshold level or below a threshold level. If the WTRU determines that the time elapsed since the timing information was received is above a threshold level, then the WTRU may select a first measurement configuration. If the WTRU determines that the time elapsed since the timing information was received is below a threshold level, then the WTRU may select a second measurement configuration. In an example, the threshold level may be preconfigured. In an example, the threshold level may be received from a base station. As described herein, based on the time elapsed since the timing information associated with the candidate cell was received (e.g., the last time the timing information associated with the candidate cell was received), the WTRU may perform measurements on the first candidate cell based on the selected measurement configuration. The WTRU may send a measurement report. The measurement report may indicate the measurements of the first candidate cell.

[0145] In an example, the WTRU may select a second measurement configuration based on the last time the timing information (e.g., timing advance) associated with the candidate cell was received. For example, the WTRU may select the second measurement configuration based on the time elapsed since the timing information associated with the second candidate cell was received. In an example, the WTRU may receive the timing information, for example, using a synchronization configuration. The timing information may be or may include a timing advance for a transmission (such as an UL transmission) to a cell (e.g., a second candidate cell). In an example, the WTRU may determine the time elapsed since the timing information was received. Based on the time elapsed since the timing information was received, the WTRU may determine the last time the timing information associated with the second candidate cell was received. As described herein, the timing information (e.g., timing advance) may be received using a synchronization configuration (e.g., a second synchronization configuration). For example, based on the second synchronization configuration, the WTRU may determine the time elapsed since the timing information associated with the second candidate cell has been received. For example, the WTRU may determine the last time the timing information associated with the second candidate cell has been received based on the second synchronization configuration. The WTRU may determine whether the time elapsed since the timing information has been received is above a threshold level or below a threshold level. If the WTRU determines that the time elapsed since the timing information was received is above a threshold level, then the WTRU may select a first measurement configuration. If the WTRU determines that the time elapsed since the timing information was received is below a threshold level, then the WTRU may select a second measurement configuration. In an example, the threshold level may be preconfigured. In an example, the threshold level may be received from a base station. As described herein, based on the time elapsed since the timing information associated with the candidate cell was received (e.g., the last time the timing information associated with the candidate cell was received), the WTRU may perform measurements on the first candidate cell based on the selected measurement configuration. The WTRU may send a measurement report. The measurement report may indicate measurements on the second candidate cell.

[0146] In an example associated with determining whether a cell switch is after an RRC reconfiguration or after a subsequent L1 / L2 cell switch, one or more of the following may apply. For example, the WTRU may measure one or more target cells using a first measurement configuration after an RRC reconfiguration and / or after L3 mobility. The WTRU may measure one or more target cells using a second measurement configuration after one or more L1 / L2 mobility / cell switches after the last reconfiguration / L3 switch. The WTRU may apply a configuration (e.g., a different measurement configuration) based on the number of L1 / L2 cell switches (e.g., subsequent L1 / L2 cell switches) that occurred since the last reconfiguration.

[0147] In an example associated with determining whether a cell was a previous target of a cell switch (e.g., it may have been since the last reconfiguration was performed and / or it may be associated with the cell), one or more of the following may apply. For example, if the target cell was not previously the PCell or SCell of the WTRU (e.g., since the last L3 reconfiguration or L3 handover), then the WTRU may use a first measurement configuration to measure the target cell. If the target cell was previously a PCell or SCell (e.g., at least once in a period since the last L3 reconfiguration / HO), then the WTRU may use a second measurement configuration to measure the target cell. The WTRU may use a configuration based on the number of subsequent L1 / L2 cell switches performed since the last L3 reconfiguration / handover (e.g., a different measurement configuration).

[0148] As an illustration, the WTRU may change from using a first set of measurement parameters to using a second set of measurement parameters after an event associated with the rate at which the WTRU performs mobility to / from a cell over a period of time (e.g., associated with a ping-pong rate). If the measured ping-pong rate exceeds a configured threshold, the WTRU may maintain the second set of measurement parameters.

[0149] As an illustration, the WTRU may be configured to change from using a first set of measurement parameters to using a second set of measurement parameters after an L1 / L2 handover or an L3 handover. The WTRU may be configured to use the second set of measurement parameters until a timer expires after the last mobility event (e.g., within a configured amount of time).

[0150] For example, the WTRU may be configured with a baseline measurement configuration and may scale the parameters of the configuration according to one or more mobility-related events described herein. For example, if the measurement result of the ping-pong effect rate on a cell exceeds a configured threshold, the WTRU may amplify the TTT associated with the measurement event (e.g., for a specific target cell) by a scaling factor. In an example, such a rate may be measured over a configured time span.

[0151] In an example, a WTRU may be configured with one or more measurement parameters based on UL and / or DL ​​data. For example, the WTRU may determine the measurement parameters to be used to measure one or more L1 / L2 mobility targets based on properties of data to be sent on the WTRU (such as configured bearers) or properties of data available for transmission on the WTRU (such as activated bearers, UL buffer status, etc.). In an example, as described herein, the WTRU may select a measurement configuration (e.g., a first measurement configuration and / or a second measurement configuration) based on the type of resources available for transmission. For example, the WTRU may determine whether the resources available for transmission are associated with an ultra-reliable low latency (URLLC) type service (e.g., associated with a medium access control (MAC) reset) or an enhanced massive mobile broadband (eMBB) type service (e.g., not associated with a MAC reset). Based on a determination that the resources available for transmission are associated with a URLLC type service (e.g., associated with a MAC reset), the WTRU may select a first measurement configuration. Based on a determination that the resources available for transmission are associated with an eMBB type service (e.g., not associated with a MAC reset), the WTRU may select a second measurement configuration.

[0152] In an example, the WTRU may determine whether the resources available for transmission are associated with a MAC reset. If the resources available for transmission are associated with a MAC reset, then the WTRU may select a first measurement configuration. If the resources available for transmission are not associated with a MAC reset, then the WTRU may select a second measurement configuration.

[0153] Based on the type of resources available for transmission as described herein, the WTRU may perform measurements of the first candidate cell and / or the second candidate cell based on the selected measurement configuration. The WTRU may send a measurement report. For example, the measurement report may indicate measurements of the first candidate cell and / or measurements of the second candidate cell.

[0154] In the example of a WTRU associated with eMBB-like traffic, aggressive L1 / L2 mobility may be advantageous, for example, where latency of a particular packet is not critical but achieving a large overall throughput is important. In an example, for eMBB and / or eMBB-like traffic, more frequent ping-pong effects may be acceptable. In an example, for a WTRU associated with URLLC type traffic, L1 / L2 mobility may prioritize avoiding ping-pong effects (e.g., for situations where mobility may result in disruptions such as MAC resets).

[0155] In an example, the WTRU may determine one or more measurement parameters (e.g., one or more measurement configurations) to be used for one or more L1 / L2 mobility targets based on the buffered UL data and / or one or more conditions associated with the buffered UL data. This determination may be further based on whether the buffered UL data belongs to one or more bearers and / or LCHs. In an example, if the amount of data buffered at the WTRU (e.g., data associated with a configured or scheduled LCH) exceeds a threshold, then the WTRU may use a first set of measurement parameters. In an example, if the amount of data buffered at the WTRU (e.g., data associated with a configured or scheduled LCH) is below a threshold, then the WTRU may use a second set of measurement parameters. As an illustration, the WTRU may use a first set of measurement parameters if the WTRU has data available for transmission (e.g., buffered) associated with a configured or scheduled LCH, or a period of time after the WTRU has at least some data available for transmission associated with a configured or scheduled LCH. In an example, if the WTRU has no data available for transmission (e.g., buffered) associated with a configured or scheduled LCH, or for a period of time after the WTRU has no data available for transmission associated with a configured or scheduled LCH, the WTRU may use a second set of measurement parameters. In an example, the WTRU may determine a time since the WTRU last had data available for transmission. If the WTRU determines that the time since the WTRU last had data available for transmission exceeds a threshold level (such as a threshold time period), the WTRU may select / use a first set of measurement parameters (e.g., a first measurement configuration). If the WTRU determines that the time since the WTRU last had data available for transmission is less than a threshold level (such as a threshold time period), the WTRU may select and / or use a second set of measurement parameters (e.g., a second measurement configuration).

[0156] In an example, as described herein, the WTRU may select a measurement configuration (e.g., a first measurement configuration or a second measurement configuration) based on the amount of UL data buffered at the WTRU. For example, the WTRU may determine whether the amount of UL data buffered at the WTRU exceeds a threshold level. In an example, the threshold level may be preconfigured. In an example, the threshold level may be received from a base station. If the WTRU determines that the amount of UL data buffered at the WTRU exceeds the threshold level, the WTRU may select the first measurement configuration. If the WTRU determines that the amount of UL data buffered at the WTRU is lower than (e.g., does not exceed) the threshold level, the WTRU may select the second measurement configuration. Based on the amount of UL data buffered at the WTRU as described herein, the WTRU may perform measurements on the first candidate cell and / or the second candidate cell based on the selected measurement configuration. The WTRU may send a measurement report. The measurement report may indicate measurements on the first candidate cell and / or the second candidate cell.

[0157] In an example, the WTRU may determine one or more measurement parameters for one or more mobility targets based on one or more attributes associated with DL scheduling data. The one or more attributes associated with the DL scheduling data may include a priority of the DL data. In an example, after scheduling high priority data, the WTRU may perform one or more measurements using a first set of measurement parameters. In an example, by not following the scheduling of the high priority data, the WTRU may change from using the first set of parameters to using the second set of parameters. The one or more attributes associated with the DL scheduling data may include an amount of DL data. In an example, if the amount of DL data (e.g., associated with one or more bearers) received within a period of time exceeds a threshold, the WTRU may use a first set of measurement parameters. In an example, if the amount of DL data (e.g., associated with one or more bearers) received within a period of time is below (e.g., does not exceed) a threshold, the WTRU may use a second set of measurement parameters. The one or more attributes associated with the DL scheduling data may include a time elapsed between scheduled data receptions, and in some examples, may also be associated with a priority. For example, an event associated with a priority or an amount of DL data may further depend on the time between such events. In an example, if the time between receiving high priority data exceeds a threshold, the WTRU may use a configured set of measurement parameters (such as a first set of measurement parameters). In an example, if the time between receiving high priority data is below (eg, does not exceed) a threshold, the WTRU may use a configured set of measurement parameters (eg, a different configured set of measurement parameters), such as a second set of measurement parameters.

[0158] In an example, the WTRU may use one or more parameters for serving cell measurements corresponding to the selected neighbor cell parameters. In an example, during evaluation of a measurement event (e.g., an L1 or L3 event that may trigger a measurement report or an event that may initiate some conditional mobility operation at the WTRU), the WTRU may use the measurement configuration associated with the serving cell as the measurement configuration of the neighbor cell associated with the event.

[0159] The WTRU may perform an evaluation of a measurement event (e.g., an L1 or L3 event, which may trigger a measurement report or may initiate a conditional mobility operation at the WTRU). The WTRU may use a set of parameters to measure a serving cell. The set of parameters used to measure the serving cell may be the same set of parameters used for the neighboring cells associated with the event. In an example, the WTRU may be configured with a set of parameters (e.g., filtering parameters) that may be based on a target for the A3 event while evaluating an event similar to A3. In an example, when evaluating an A3 event, the serving cell measurements may be evaluated using filtering parameters that are similar to the filtering parameters used for measurements of the cell that is compared with the serving cell for the event. For example, the same parameters (e.g., filter coefficients, number of coefficients, etc.) may be used for the target cell of the event as for the serving cell for the same event. The relationship between the target parameters to be used and the source parameters may be configured by the network.

[0160] Although the above features and elements are described in particular combinations, each feature or element may be used alone without the other features and elements of the preferred embodiments, or in various combinations with or without the other features and elements.

[0161] Although the implementation described herein may consider 3GPP specific protocols, it should be understood that the implementation described herein is not limited to this scenario and may be applicable to other wireless systems. For example, although the solution described herein considers LTE, LTE-A, New Radio (NR) or 5G specific protocols, it should be understood that the solution described herein is not limited to this scenario and may also be applicable to other wireless systems.

[0162] The above process may be implemented in a computer program, software, and / or firmware incorporated into a computer-readable medium for execution by a computer and / or processor. Examples of computer-readable media include, but are not limited to, electronic signals (sent via wired and / or wireless connections) and / or computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, read-only memory (ROM), random access memory (RAM), registers, buffer memory, semiconductor storage devices, magnetic media (such as, but not limited to, internal hard disks and removable disks), magneto-optical media, and / or optical media (e.g., compact disk (CD)-ROM disks and / or digital versatile disks (DVDs)). A processor associated with the software may be used to implement a radio transceiver used in a WTRU, terminal, base station, RNC, and / or any host computer.

Claims

1. A wireless transmit / receive unit (WTRU), comprising: The processor is configured as: receiving first candidate cell information and second candidate cell information, wherein the first candidate cell information indicates a first candidate cell and a first synchronization configuration, and wherein the second candidate cell information indicates a second candidate cell and a second synchronization configuration; receiving a first measurement configuration and a second measurement configuration; selecting a measurement configuration associated with the first candidate cell, wherein the selection of the measurement configuration is based on the first synchronization configuration indicating whether the first candidate cell is associated with a random access channel (RACH) procedure or a RACH-free procedure, and wherein the measurement configuration is the first measurement configuration or the second measurement configuration; performing measurement of the first candidate cell based on the selected measurement configuration; and Sending a measurement report, wherein the measurement report indicates the measurement of the first candidate cell.

2. The WTRU of claim 1 , wherein if the first candidate cell is associated with the RACH procedure, then the selected measurement configuration is the first measurement configuration, and wherein if the first candidate cell is associated with the no-RACH procedure, then the selected measurement configuration is the second measurement configuration.

3. The WTRU of claim 2, wherein: The determination that the first candidate cell is associated with the RACH procedure is based on the first synchronization configuration indicating that the first candidate cell is out of synchronization; as well as The determination that the first candidate cell is associated with the RACH-free procedure is based on the first synchronization configuration indicating that the first candidate cell is synchronized.

4. The WTRU of claim 1 , wherein the processor is further configured to: determining whether resources available for transmission are associated with a medium access control (MAC) reset; in, based on a determination that the resources available for the sending are associated with the MAC reset, the selected measurement configuration is the first measurement configuration; as well as Therein, based on a determination that the resources available for the sending are not associated with the MAC reset, the selected measurement configuration is the second measurement configuration.

5. The WTRU of claim 4, wherein the resources available for the transmission associated with the MAC reset are associated with an ultra-reliable low latency (URLLC) type service, and the resources available for the transmission associated with the MAC reset are associated with an enhanced massive mobile broadband (eMBB) type service.

6. The WTRU of claim 1 , wherein the processor is further configured to: determining, based on the first synchronization configuration, a time that has elapsed since timing information associated with the first candidate cell has been received; in, the selected measurement configuration being the first measurement configuration based on a determination that the time elapsed since receiving the timing information is above a threshold level; as well as wherein the selected measurement configuration is the second measurement configuration based on a determination that the time elapsed since the receipt of the timing information is below the threshold level.

7. The WTRU of claim 1 , wherein the processor is further configured to: determining whether uplink (UL) data buffered at the WTRU exceeds a threshold level; wherein the selected measurement configuration is the first measurement configuration based on a determination that the UL data buffered at the WTRU exceeds the threshold level; and Wherein the selected measurement configuration is the second measurement configuration based on a determination that the UL data that has been buffered at the WTRU is below the threshold level.

8. The WTRU of claim 1 , wherein the measurement is a first measurement and the measurement report is a first measurement report, and wherein the processor is configured to: A measurement configuration associated with the second candidate cell is selected, wherein: The selection of the measurement configuration is based on the second synchronization configuration indicating whether the second candidate cell is associated with a RACH procedure or a no-RACH procedure, and wherein the measurement configuration is the first measurement configuration or the second measurement configuration; performing a second measurement on a second candidate cell based on the selected measurement configuration; and A second measurement report is sent, wherein the second measurement report indicates the second measurement of the second candidate cell.

9. A method comprising: receiving first candidate cell information and second candidate cell information, wherein the first candidate cell information indicates a first candidate cell and a first synchronization configuration, and wherein the second candidate cell information indicates a second candidate cell and a second synchronization configuration; receiving a first measurement configuration and a second measurement configuration; selecting a measurement configuration associated with the first candidate cell, wherein the selection of the measurement configuration is based on the first synchronization configuration indicating whether the first candidate cell is associated with a random access channel (RACH) procedure or a RACH-free procedure, and wherein the measurement configuration is the first measurement configuration or the second measurement configuration; performing measurement of the first candidate cell based on the selected measurement configuration; and Sending a measurement report, wherein the measurement report indicates the measurement of the first candidate cell.

10. The method according to claim 9, wherein: If the first candidate cell is associated with the RACH procedure, then the selected measurement configuration is the first measurement configuration, and wherein, if the first candidate cell is associated with the no-RACH procedure, then the selected measurement configuration is the second measurement configuration, and wherein, The determination that the first candidate cell is associated with the RACH procedure is based on the first synchronization configuration indicating that the first candidate cell is out of synchronization; and The determination that the first candidate cell is associated with the RACH-free procedure is based on the first synchronization configuration indicating that the first candidate cell is synchronized.

11. The method according to claim 9, wherein: The method comprises: determining whether resources available for transmission are associated with a medium access control (MAC) reset; wherein, based on a determination that the resources available for the sending are associated with the MAC reset, the selected measurement configuration is the first measurement configuration; and Therein, based on a determination that the resources available for the sending are not associated with the MAC reset, the selected measurement configuration is the second measurement configuration.

12. The method according to claim 9, wherein: The method comprises: determining, based on the first synchronization configuration, a time that has elapsed since timing information associated with the first candidate cell has been received; wherein the selected measurement configuration is a first measurement configuration based on a determination that the time elapsed since the timing information was received is above a threshold level; and wherein the selected measurement configuration is the second measurement configuration based on a determination that the time elapsed since the receipt of the timing information is below the threshold level.

13. The method according to claim 9, wherein: The method comprises: determining whether buffered uplink (UL) data exceeds a threshold level; wherein, based on a determination that the buffered UL data exceeds a threshold level, the selected measurement configuration is a first measurement configuration; and Wherein, based on a determination that the buffered UL data is below the threshold level, the selected measurement configuration is the second measurement configuration.

14. The method according to claim 9, wherein: The measurement is a first measurement, the measurement report is a first measurement report, and wherein the method further comprises: selecting a measurement configuration associated with the second candidate cell, wherein the selection of the measurement configuration is based on the second synchronization configuration indicating whether the second candidate cell is associated with a RACH procedure or a no-RACH procedure, and wherein the measurement configuration is the first measurement configuration or the second measurement configuration; performing a second measurement on a second candidate cell based on the selected measurement configuration; and Send a second measurement report, wherein the second measurement report indicates the second measurement of the second candidate cell.

15. The method according to claim 9, wherein: The measurement configuration includes one or more of a filter coefficient or a trigger time TTT.

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