Method for UE cell handover preparation

Abstract

An apparatus configured to: determine to include L3 measurements in an L1 measurement report, where the L1 measurement report is configured to be used for lower layer triggered mobility cell handover preparation; and including the L3 measurement in the L1 measurement report. An apparatus configured to: determine that L3 measurements are to be included in an L1 measurement report, where the L1 measurement report is configured to be used for lower layer triggered mobility cell handover preparation; receiving an L1 measurement report, wherein the L1 measurement report comprises an L3 measurement; and determining whether to perform a lower layer triggered mobility cell handover based at least in part on the L3 measurement.

Description

Technical Field

[0001] The exemplary and non-limiting embodiments relate generally to Lower Layer Triggered Mobility (LTM), and more particularly to measurements upon which LTM cell handover commands are based. Background Art

[0002] In LTM, known L1 measurements or L3 measurements are included in the L1 measurement report. Summary of the Invention

[0003] The following summary is intended to be illustrative only and is not intended to limit the scope of the claims.

[0004] According to one aspect, an apparatus includes: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: determine to include L3 measurements in an L1 measurement report, wherein the L1 measurement report is configured to be used for mobility cell handover preparation triggered by a lower layer; and include the L3 measurements in the L1 measurement report.

[0005] According to one aspect, a method includes: determining, by a user equipment, to include L3 measurements in an L1 measurement report, wherein the L1 measurement report is configured to be used for lower layer triggered mobility cell handover preparation; and including the L3 measurements in the L1 measurement report.

[0006] According to one aspect, an apparatus includes means for: determining to include L3 measurements in an L1 measurement report, wherein the L1 measurement report is configured to be used for lower layer triggered mobility cell handover preparation; and including the L3 measurements in the L1 measurement report.

[0007] According to one aspect, a non-transitory computer-readable medium includes program instructions stored thereon for performing at least the following: determining to include L3 measurements in an L1 measurement report, wherein the L1 measurement report is configured to be used for lower layer triggered mobility cell handover preparation; and including the L3 measurements in the L1 measurement report.

[0008] According to one aspect, an apparatus includes: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: determine that L3 measurements are to be included in an L1 measurement report, wherein the L1 measurement report is configured to be used for lower layer triggered mobility cell handover preparation; receive the L1 measurement report, wherein the L1 measurement report includes L3 measurements; and determine whether to perform lower layer triggered mobility cell handover based at least in part on the L3 measurements.

[0009] According to one aspect, a method includes: determining, with a base station, that L3 measurements are to be included in an L1 measurement report, wherein the L1 measurement report is configured to be used for lower layer triggered mobility cell handover preparation; receiving the L1 measurement report, wherein the L1 measurement report includes L3 measurements; and determining whether to perform a lower layer triggered mobility cell handover based at least in part on the L3 measurements.

[0010] According to one aspect, an apparatus includes means for: determining that L3 measurements are to be included in an L1 measurement report, wherein the L1 measurement report is configured to be used for lower layer triggered mobility cell handover preparation; receiving the L1 measurement report, wherein the L1 measurement report includes L3 measurements; and determining whether to perform lower layer triggered mobility cell handover based at least in part on the L3 measurements.

[0011] According to one aspect, a non-transitory computer-readable medium includes program instructions stored thereon for performing at least the following: determining that L3 measurements are to be included in an L1 measurement report, wherein the L1 measurement report is configured to be used for lower layer triggered mobility cell handover preparation; receiving the L1 measurement report, wherein the L1 measurement report includes L3 measurements; and determining whether to perform lower layer triggered mobility cell handover based at least in part on the L3 measurements.

[0012] According to some aspects, the subject matter of the independent claims is provided. Some further aspects are defined in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The foregoing aspects and other features are explained in the following description taken in conjunction with the accompanying drawings, in which:

[0014] Figure 1 is a block diagram of one possible and non-limiting example system in which example embodiments may be practiced;

[0015] Figure 2 is a flow chart showing the steps as described herein;

[0016] Figure 3 is a flow chart showing the steps as described herein;

[0017] Figure 4 is a flow chart showing the steps as described herein;

[0018] Figure 5 is a diagram illustrating features as described herein;

[0019] Figure 6 is a flow chart showing the steps as described herein;

[0020] Figure 7 is a flow chart showing the steps as described herein;

[0021] Figure 8 is a flowchart showing the steps as described herein; and

[0022] Figure 9 is a flow chart showing the steps as described herein. DETAILED DESCRIPTION

[0023] The following abbreviations that may be found in the specification and / or drawings are defined as follows:

[0024] 3GPP Third Generation Partnership Project

[0025] 5G fifth generation

[0026] 5GC 5G core network

[0027] AMF Access and Mobility Management Function

[0028] BWP Bandwidth Part

[0029] Carrier Aggregation (CA)

[0030] CFRA Contention-free random access

[0031] CP Cyclic Prefix

[0032] cRAN Cloud Radio Access Network

[0033] CSI Channel State Information

[0034] CSI-RS Channel State Information Reference Signal

[0035] CU Central Unit

[0036] DAPS Dual Active Protocol Stack

[0037] DC Dual Connectivity

[0038] DL Downlink

[0039] DRB Data Radio Bearer

[0040] DRX Discontinuous Reception

[0041] DU Distributed Unit

[0042] Enhancements to Early Measurement Reporting in eEMR Version 18 and Beyond eMBB Enhanced Mobile Broadband

[0043] eNB (or eNodeB) Evolved Node B (e.g., LTE base station)

[0044] EN-DC E-UTRA-NR dual connectivity

[0045] en-gNB or Eng-gNB node, which provides NR user plane and control plane protocol termination to the UE and acts as a secondary node in EN-DC

[0046] E-UTRA Evolved Universal Terrestrial Radio Access, also known as LTE radio access technology

[0047] FFS needs further research

[0048] FR1 Frequency Range 1

[0049] FR1 / FR2 Frequency range 1 / 2

[0050] FR2 Frequency Range 2

[0051] gNB (or gNodeB) is a base station for 5G / NR, which provides NR user plane and control plane protocol termination to the UE and is connected to the 5GC via the NG interface.

[0052] I / F interface

[0053] L1 Layer 1 (physical layer)

[0054] L1 / L2 / L3 Layer 1 / 2 / 3

[0055] L3 Layer 3 (Network Layer)

[0056] LTE Long Term Evolution

[0057] LTM L1 / L2 triggered mobility

[0058] MAC Media Access Control

[0059] MAC-CE Media Access Control Element

[0060] MME Mobility Management Entity

[0061] Multi-RX UE capable of performing RX / TX on multiple cells. May be DAPS or different from DAPS

[0062] ng or NG new generation

[0063] ng-eNB or NG-eNB Next Generation eNB

[0064] NR New Radio, the new 5G radio access technology

[0065] N / W or NW network

[0066] O-RAN Open Radio Access Network

[0067] PCell Primary Cell

[0068] PDCCH Physical Downlink Control Channel

[0069] PDCP Packet Data Convergence Protocol

[0070] PHY Physical Layer

[0071] PRACH Physical Random Access Channel

[0072] Primary cell, primary and secondary cells of PSCell SCG

[0073] PUCCH Physical Uplink Control Channel

[0074] PUSCH Physical Uplink Shared Channel

[0075] RA Random Access

[0076] RAR Random Access Response

[0077] RACH Random Access Channel

[0078] RAN Radio Access Network

[0079] RF

[0080] RLC Radio Link Control (a sublayer of Layer 2 in the RAN)

[0081] RRC Radio Resource Control

[0082] RRH Remote Radio Head

[0083] RS reference signal

[0084] RSRP Reference Signal / Symbol Received Power

[0085] RTD Receive Timing Difference

[0086] RU Radio Unit

[0087] Rx Receiver

[0088] SCell secondary cell

[0089] SCG Sub-Cell Group

[0090] SDAP Service Data Adaptation Protocol

[0091] SGW Service Gateway

[0092] SIB System Information Block

[0093] SMF session management functions

[0094] SN Secondary Node

[0095] SSB Synchronous Signal Block

[0096] TA Timing Advance

[0097] TCI Transmission Configuration Indicator

[0098] Tx Transmitter

[0099] UE User Equipment (e.g., wireless, typically mobile)

[0100] UL Uplink

[0101] UPF User Plane Function

[0102] URLLC Ultra-Reliable and Low-Latency Communications

[0103] VNR Virtualized Network Function

[0104] Go to Figure 1 , which shows a block diagram of one possible and non-limiting example in which the examples may be practiced. A user equipment (UE) 110, a radio access network (RAN) node 170 and (multiple) network elements 190 are shown. Figure 1In the example of FIG, a user equipment (UE) 110 wirelessly communicates with a wireless network 100. A UE is a wireless device that can access the wireless network 100. The UE 110 includes one or more processors 120, one or more memories 125, and one or more transceivers 130 interconnected by one or more buses 127. Each of the one or more transceivers 130 includes a receiver Rx 132 and a transmitter Tx 133. The one or more buses 127 can be address, data, or control buses and can include any interconnection mechanism, such as a series of wires on a motherboard or integrated circuit, optical fiber, or other optical communication device. "Circuitry" can include dedicated hardware or hardware associated with software executable thereon. The one or more transceivers 130 are connected to one or more antennas 128. The one or more memories 125 include computer program code 123. The UE 110 includes a module 140, which includes one or both of the parts 140-1 and / or 140-2 and can be implemented in a variety of ways. Module 140 may be implemented in hardware as module 140-1, such as as part of one or more processors 120. Module 140-1 may also be implemented as an integrated circuit or through other hardware (such as a programmable gate array). In another example, module 140 may be implemented as module 140-2, which is implemented as computer program code 123 and executed by one or more processors 120. For example, one or more memories 125 and computer program code 123 may be configured to, together with one or more processors 120, cause user equipment 110 to perform one or more operations described herein. UE 110 communicates with RAN node 170 via wireless link 111.

[0105] In this example, RAN node 170 is a base station that provides access to wireless network 100 by wireless devices, such as UE 110. RAN node 170 may be, for example, a base station for 5G (also known as New Radio (NR)). In 5G, RAN node 170 may be an NG-RAN node, defined as a gNB or ng-eNB. A gNB is a node that provides NR user plane and control plane protocol termination to the UE and is connected to the 5GC (such as, for example, network element(s) 190) via an NG interface. An ng-eNB is a node that provides E-UTRA user plane and control plane protocol termination to the UE and is connected to the 5GC via an NG interface. An NG-RAN node may include multiple gNBs, which may also include a central unit (CU) (gNB-CU) 196 and distributed unit(s) (gNB-DU), with DU 195 shown. Note that a DU may include or be coupled to and control a radio unit (RU). The gNB-CU is a logical node that hosts the RRC, SDAP, and PDCP protocols for a gNB or the RRC and PDCP protocols for an en-gNB, and controls the operation of one or more gNB-DUs. The gNB-CU terminates the F1 interface with the gNB-DU. The F1 interface is shown as reference numeral 198, although reference numeral 198 also illustrates links between remote and centralized elements of the RAN node 170, such as the link between gNB-CU 196 and gNB-DU 195. The gNB-DU is a logical node that hosts the RLC, MAC, and PHY layers of a gNB or en-gNB, and its operation is partially controlled by the gNB-CU. A gNB-CU supports one or more cells. A cell is supported by only one gNB-DU. The gNB-DU terminates the F1 interface 198 with the gNB-CU. It should be noted that the DU 195 is considered to include the transceiver 160, e.g., as part of the RU, but some examples in this regard may have the transceiver 160 as part of a separate RU, e.g., under the control of and connected to the DU 195. The RAN node 170 may also be an eNB (evolved NodeB) base station for LTE (Long Term Evolution), or any other suitable base station, access point, access node, or node.

[0106] The RAN node 170 includes one or more processors 152, one or more memories 155, one or more network interfaces (N / WI / F) 161, and one or more transceivers 160 interconnected via one or more buses 157. Each of the one or more transceivers 160 includes a receiver Rx 162 and a transmitter Tx 163. The one or more transceivers 160 are connected to one or more antennas 158. The one or more memories 155 include computer program code 153. The CU 196 may include the processor(s) 152, the memory 155, and the network interface 161. It should be noted that the DU 195 may also include its own memory and processor(s) and / or other hardware, but these are not shown.

[0107] RAN node 170 includes module 150, which includes one or both of portions 150-1 and / or 150-2. Module 150 can be implemented in a variety of ways. Module 150 can be implemented in hardware as module 150-1, such as as part of one or more processors 152. Module 150-1 can also be implemented as an integrated circuit or through other hardware, such as a programmable gate array. In another example, module 150 can be implemented as module 150-2, which is implemented as computer program code 153 and executed by one or more processors 152. For example, one or more memories 155 and computer program code 153 are configured to, together with one or more processors 152, cause RAN node 170 to perform one or more operations described herein. It should be noted that the functionality of module 150 can be distributed, such as distributed between DU 195 and CU 196, or implemented solely in DU 195.

[0108] One or more network interfaces 161 communicate over a network, such as via links 176 and 131. Two or more gNBs 170 may communicate using, for example, link 176. Link 176 may be wired or wireless or both, and may implement, for example, an Xn interface for 5G, an X2 interface for LTE, or other suitable interfaces for other standards.

[0109] The one or more buses 157 may be address, data, or control buses and may include any interconnection mechanism, such as a series of wires on a motherboard or integrated circuit, optical fiber or other optical communication equipment, a wireless channel, etc. For example, the one or more transceivers 160 may be implemented as a remote radio head (RRH) 195 for LTE or a distributed unit (DU) 195 for a gNB implementation for 5G, where other elements of the RAN node 170 may be physically located at a different location than the RRH / DU, and the one or more buses 157 may be implemented in part, for example, as fiber optic cables or other suitable network connections to connect the other elements of the RAN node 170 (e.g., central unit (CU), gNB-CU) to the RRH / DU 195. Reference numeral 198 also indicates those suitable network link(s).

[0110] It should be noted that the description herein indicates that a "cell" performs functions, but it should be clear that the devices that form the cells will perform these functions. A cell constitutes part of a base station. That is, there can be multiple cells for each base station. For example, there can be three cells for a single carrier frequency and associated bandwidth, each cell covering one-third of a 360-degree area, so that the coverage area of ​​a single base station covers an approximately elliptical or circular area. In addition, each cell can correspond to a single carrier, and a base station can use multiple carriers. Therefore, if there are three 120-degree cells per carrier and there are two carriers, then the base station has a total of 6 cells.

[0111] The wireless network 100 may include one or more network elements 190, which may include core network functions and provide connectivity to another network, such as a telephone network and / or a data communications network (e.g., the Internet), via one or more links 181. Such core network functions for 5G may include access and mobility management function(s) (AMF(s)) and / or user plane function(s) (UPF(s)) and / or session management function(s) (SMF(s)). Such core network functions for LTE may include MME (Mobility Management Entity) / SGW (Serving Gateway) functions. These are merely illustrative functions that may be supported by the network element(s) 190, and it should be noted that both 5G and LTE functions may be supported simultaneously. The RAN node 170 is coupled to the network element 190 via a link 131. The link 131 may be implemented, for example, as an NG interface for 5G, an S1 interface for LTE, or other suitable interfaces for other standards. Network element 190 includes one or more processors 175, one or more memories 171, and one or more network interfaces (N / WI / F) 180, which are interconnected via one or more buses 185. One or more memories 171 include computer program code 173. One or more memories 171 and computer program code 173 are configured to, together with one or more processors 175, cause network element 190 to perform one or more operations.

[0112] Wireless network 100 can implement network virtualization, which is the process of combining hardware and software network resources and network functions into a single, software-based managed entity (virtual network). Network virtualization involves platform virtualization, often combined with resource virtualization. Network virtualization is categorized as external virtualization, which combines many networks or parts of networks into a single virtual unit, and internal virtualization, which provides network-like functionality as software containers on a single system. For example, a network can be deployed in a telecom cloud, with virtualized network functions (VNFs) running on, for example, data center servers. For example, network core functions and / or radio access networks (e.g., CloudRAN, O-RAN, edge cloud) can be virtualized. It should be noted that the virtualized entities resulting from network virtualization are still implemented to some extent using hardware (such as processors 152 or 175 and memories 155 and 171), and such virtualized entities produce technical effects.

[0113] It should also be noted that the operations of the example embodiments of the present disclosure may be performed by multiple cooperating devices (eg, cRAN).

[0114] Computer-readable memories 125, 155, and 171 may be of any type suitable for the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. Computer-readable memories 125, 155, and 171 may be components for performing storage functions. Processors 120, 152, and 175 may be of any type suitable for the local technical environment and, by way of non-limiting example, may include one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. Processors 120, 152, and 175 may be components for performing functions, such as controlling UE 110, RAN node 170, and other functions described herein.

[0115] In general, various example embodiments of user device 110 may include, but are not limited to, cellular telephones, such as smart phones with wireless communication capabilities, tablet computers, personal digital assistants (PDAs), portable computers with wireless communication capabilities, image capture devices with wireless communication capabilities (such as digital cameras), gaming devices with wireless communication capabilities, music storage and playback devices with wireless communication capabilities, Internet devices that allow wireless Internet access and browsing, tablet computers with wireless communication capabilities, and portable units or terminals incorporating combinations of these functions.

[0116] Having thus introduced a suitable but non-limiting technical context for the practice of example embodiments of the present disclosure, the example embodiments will now be described in more detail.

[0117] Features as described herein may generally relate to L1 / L2 triggered mobility (LTM). LTM is a cell handover procedure in which the serving cell of a UE (primary cell (PCell) or primary secondary cell (PSCell)) is switched by the network by sending an LTM cell handover command. LTM cell handover decisions may be based on L1 measurements performed and reported by the UE, as configured in an LTM candidate cell configuration provided by the network for one or more LTM candidate cells. An LTM candidate cell may be any neighboring cell or one of the serving cells of the UE's current serving cell (e.g., a secondary cell (SCell)).

[0118] Before cell switching, the network may optionally activate (multiple) transmission configuration indication (TCI) states for one or more candidate cells, and the UE will track the timing of (multiple) activated TCI states. The UE may also perform early uplink (UL) synchronization before cell switching. For early UL synchronization, the network may instruct the UE to send a random access preamble to the candidate cell via a physical downlink control channel (PDCCH) command so that the network can estimate the timing advance (TA) of the candidate cell in advance. This can be done before cell switching. If these procedures are performed before cell switching, the UE can skip the time tracking associated with TCI state activation and the random access (RA) procedure during cell switching. This can result in a shorter interruption time during cell switching.

[0119] An example of the LTM procedure is provided in the following table based on the change request for TS 38.300 executed by RAN2. Figure 2 is shown in the signaling diagram in .

[0120] During the LTM preparation phase 205, at 210, the UE may be in RRC_CONNECTED mode. At 215, the UE may send a measurement report (e.g., a MeasurementReport message) to the gNB. At 220, the gNB may perform LTM candidate preparation. In other words, the gNB may decide to configure LTM and initiate candidate cell preparation. At 225, the gNB may send an RRC reconfiguration message (e.g., LTM candidate configuration) to the UE. The RRCReconfiguration message may include the LTM candidate cell configuration for one or more candidate cells, which the UE may store. At 230, the UE may send an RRC reconfiguration complete message (e.g., an RRCReconfigurationComplete message) to the gNB.

[0121] During the early synchronization phase 235, at 240, the UE and gNB may perform DL synchronization with the candidate cell (e.g., before receiving a cell handover command). DL synchronization of the candidate cell prior to the cell handover command may be supported based on at least synchronization signal blocks (SSBs). The UE may perform early TA acquisition with the candidate cell(s) requested by the network prior to receiving the cell handover command. This may be accomplished via a contention-free random access (CFRA) triggered by a PDCCH command from the source cell, after which the UE may send a preamble to the indicated candidate cell. To minimize data interruption from the source cell to the candidate cell(s) due to CFRA, the UE may not receive a random access response (RAR) for TA value acquisition purposes, and the TA value of the candidate cell may be indicated in the cell handover command. The UE may not maintain a TA timer for the candidate cell and may rely on network implementation to ensure TA validity. At 245, the UE and gNB may perform UL synchronization with the candidate cell.

[0122] During the LTM execution phase 250, at 255, the UE may perform L1 measurements on the configured candidate cell(s) and may send a lower layer measurement report (e.g., an L1 measurement report) to the gNB. L1 measurements may be performed whenever the RRC reconfiguration at 225 applies. At 260, the gNB may make an LTM decision. The gNB may decide to perform a cell handover to the target cell. At 265, the gNB may send a cell handover command (e.g., a Media Access Control (MAC) Element (CE)) to the UE. The MAC CE may trigger the cell handover by including a candidate configuration index for the target cell. The UE may switch to the target cell and apply the configuration indicated by the candidate configuration index. At 270, the UE may detach from the source cell and apply the target configuration(s). At 275, if the UE does not have a valid TA for the target cell, the UE and gNB may perform a random access channel (RACH) procedure, e.g., toward the target cell.

[0123] During the LTM completion phase 280, at 285, the UE and the gNB may perform LTM completion. The UE may complete the LTM cell handover procedure by, for example, sending an RRCReconfigurationComplete message to the target cell. If the UE performed the RA procedure at 275, the UE may consider the LTM execution to have been successfully completed when the random access procedure successfully completes. For LTM without RACH, the UE may consider the LTM execution to have been successfully completed when the UE determines that the network has successfully received its first UL data. The UE may determine successful reception of its first UL data by receiving a PDCCH addressed to the UE's C-RNTI in the target cell, which may schedule new transmissions following the first UL data.

[0124] It can be assumed that the RRCReconfigurationComplete message is always sent each time LTM is executed.

[0125] The early synchronization phase 235, the LTM execution phase 250, and the LTM completion phase 280 may be performed multiple times using the LTM candidate cell configuration(s) provided at 225 for subsequent LTM cell handovers.

[0126] Regarding U-plane processing, in LTM, the UE can perform a MAC reset. Whether the UE performs radio link control (RLC) re-establishment and packet data convergence protocol (PDCP) data recovery during cell handover can be explicitly controlled by the network through RRC signaling. The PDCP data recovery procedure can be applied to RLC AM data radio bearers (DRBs) for distributed unit (DU) LTM cell handover.

[0127] For UE processing, the following (non-exhaustive) can be assumed to be performed after receiving a cell handover command: MAC / RLC reset (when configured); radio frequency (RF) retuning (e.g., required for inter-frequency); and / or baseband retuning.

[0128] TCI state activation can be performed before cell handover using a separate MAC-CE. If not performed before cell handover, TCI state activation (and related time tracking) can be based on the cell handover command and completed during the cell handover. Therefore, the cell handover command only indicates or also activates the target TCI state. Figure 3 The example process shown in is based on a RAN2 run change request for 38.300. Figure 3 The early TCI activation (steps 340, 350) in Figure 2 Between steps 255 and 265.

[0129] At 310, the UE may be in RRC_CONNECTED mode and / or CM-CONNECTEC mode. At 320, the gNB (cell A) may send an RRCReconfiguration message to the UE, which may include a list of TCI states for cell B. The gNB to which cell A belongs may provide the UE with a TA acquisition configuration within the RRCReconfiguration message. The TA acquisition configuration may include all RRC configuration information required to send a random access preamble to cell B so that the gNB to which cell B belongs can calculate the TA value to be used by the UE (e.g., in the event of an LTM cell handover procedure being performed to cell B). The TA acquisition configuration may include information for one or more cells for which the TA acquisition procedure may be performed by the UE. At 330, the UE may send an RRCReconfigurationComplete message to the gNB (cell A). At 340, the gNB (cell A) may send an Early TCI State Activation MAC CE to the UE, which may indicate the TCI state(s) of cell B. For example, the gNB to which cell A belongs may send a PDCCH command message to the UE to initiate a TA acquisition procedure with cell B. The PDCCH command message may include information required to send a random access preamble to cell B. At 350, the UE may activate the TCI state(s) for cell B. The UE may send a random access preamble to cell B so that the gNB to which cell B belongs can estimate the TA value to be used by the UE (e.g., if an LTM cell handover procedure to cell B is triggered). If no TA is acquired, the gNB to which cell A belongs may indicate a retransmission of the preamble for TA acquisition. At 360, the gNB (cell A) may send the TCI state to the UE, e.g., in a cell handover command indicating cell B as the target cell. For example, the gNB to which cell A belongs provides the TA value calculated by the gNB to which cell B belongs during the TA acquisition procedure (e.g., in an LTM cell handover command MAC CE that initiates a cell handover procedure to cell B).

[0130] Early TA acquisition based on PDCCH command can be as follows Figure 4 is performed as shown in . Early TA acquisition can be placed in Figure 2 245 of them.

[0131] At 410, the gNB to which cell A belongs may provide a TA acquisition configuration to the UE within an RRCReconfiguration message. The TA acquisition configuration may include all RRC configuration information required to send a random access preamble to cell B so that the gNB to which cell B belongs can calculate a TA value to be used by the UE, such as when an LTM cell handover procedure to cell B is performed. The TA acquisition configuration may include information for one or more cells for which the TA acquisition procedure may be performed by the UE.

[0132] At 420, the UE may reply with an RRCReconfigurationComplete message.

[0133] At 430, the gNB to which cell A belongs may send a PDCCH command message to the UE to initiate a TA acquisition procedure with cell B. The PDCCH command message may include information required to send a random access preamble to cell B.

[0134] At 440, the UE may send a random access preamble to cell B so that the gNB to which cell B belongs can estimate the TA value to be used by the UE, for example, if an LTM cell handover procedure to cell B is triggered. In the event that no TA is acquired, the gNB to which cell A belongs may instruct retransmission of the preamble for TA acquisition.

[0135] At 450, the gNB to which cell A belongs may provide the TA value calculated by the gNB to which cell B belongs during the TA acquisition process, for example in the LTM cell handover command MAC CE initiating the cell handover process to cell B.

[0136] The features described herein generally relate to LTM measurements. A UE may be configured to perform L1 measurements on candidate cells for LTM handover purposes. Candidate cells may be the current serving cell and / or neighboring cells. When a UE receives an LTM candidate cell configuration from the network, the UE may also be expected to be configured to perform L3 measurements on these cells in addition to the LTM L1 measurements. L3 measurements may have begun before the LTM candidate cell configuration was sent, and the UE may be assumed to continue these measurements concurrently with the LTM L1 measurements.

[0137] LTM cell handover decisions are made based on L1 measurements as defined by RAN1, but Rel-18 RAN4 has discussed the option of performing LTM handover based on L3 measurements reported in the L1 measurement report [see, for example, Way Forward R4-2314453, RAN4 meeting #108]. This is because, for example, the UE may have restrictions on the number of neighboring cells for which the UE may be able to perform L1 measurements. Therefore, the UE may only be able to perform L1 measurements on a subset of the configured candidate cells, which may limit the candidate cell selection to these cells.

[0138] L1 measurement reports can be sent to distributed units (DUs) in the network, while L3 measurement reports can be sent to central units (CUs) in the network. LTM cell handover decisions can be made by DU entities in the network. Therefore, in order to be able to use any reported L3 measurements for LTM target cell selection by the DU, RAN4 has proposed that the UE can include L3 measurements in the L1 report. This can enable the L3 measurements to be reported to the DU, so that the DU can perform target cell selection based on the L3 measurements.

[0139] Now refer to Figure 5 , shows an example of a DU and CU in a NR,RAN architecture. The 5GC (505) can be connected to the NG-RAN (515) via an NG interface (510, 530). The NG-RAN (515) can include multiple gNBs (520, 535), which can be connected via an Xn-C interface (525). The gNB (535) can include a gNB-CU (540) and one or more gNB-DUs (550) connected via (multiple) F1 interfaces (545). The latest protocol for L3 measurements in L1 measurement reports is as follows:

[0140] “…2.2 Sub-topic 2-2 Whether to use L3 measurement results in L1 measurement reports Question 2-2-1: Whether to use the final L3 measurement results for L1 measurement reports

[0141] <Protocol>: Introducing optional UE support to use L3 measurement results for intra-frequency and inter-frequency L1 measurement reporting.

[0142] Note: If all details and CR in RAN4#109 are not finalized, this solution will be removed from the WI scope. If there is an impact on RAN1 / 2, this solution will be removed from the WI scope.

[0143] Option 1:

[0144] UE capabilities

[0145] UE capability is introduced to use L3 measurement results for intra-frequency and inter-frequency L1 measurement reporting.

[0146] If the number of cells to be measured exceeds the L1-based LTM measurement capability, the UE is allowed to perform L3 measurements and report them in the L1 reporting format.

[0147] A UE supporting L3 measurements in the L1 measurement format capability shall also support the baseline L1 measurement capability.

[0148] Measurement Report

[0149] UE reporting based on L1 measurement configuration.

[0150] Measurement report mapping: Since L3 measurements in L1 measurement reports are supported, no changes are required to Table 10.1.6.1-1.

[0151] At least in the 18th edition, L3 and L1 measurements are not included in the same report Require

[0152] Follow L3 measurement requirements where applicable

[0153] RAN4 discusses accuracy requirements during the performance section.

[0154] For UEs capable of reporting L3 measurements in L1 reports, the number of frequency layers to be measured for neighboring cells follows the same requirements as for L3 measurements.

[0155] As a baseline: Same frequency in clause 9.2, different frequency in clause 9.3

[0156] The TCI state activation is based on the L3 measurements reported in the L1 measurement report.

[0157] In FR1, if the L1-RSRP measurement period is 160 ms, the UE does not need additional SSBs to meet the transmission timing requirement for PRACH on neighboring cells.

[0158] For FR2, the UE may need additional SSBs to meet the transmission timing requirements for PRACH on neighboring cells.

[0159] Similar to the baseline framework, the L1 measurement format derived from the L3 measurement results is reported in the UCI. The same number of M and L applies. RAN4 will specify RRM requirements for the following cases

[0160] RTD between cells of less than and greater than CP scenarios are supported.

[0161] The Rx SNR (ie, side conditions) is lower than -3dB but higher than -6dB.

[0162] FFS for cell handover delay component.

[0163] For FR1 and FR2, whether the UE needs additional SSBs for acquisition timing (if TCI state has been activated) is FFS.

[0164] Known and unknown cells are supported..."

[0165] Considering the above, the UE can report each LTM candidate cell to the network:

[0166] -L1 measurement results in L1 measurement report (reported to DU)

[0167] -L3 measurement results in L1 measurement reports (reported to DU, not yet standardized)

[0168] -L3 measurement results in L3 measurement report (reported to CU)

[0169] One benefit of using L3 measurements instead of or in addition to L1 measurements in candidate cell evaluation is that it enables faster cell handover after the UE receives the LTM candidate cell configuration. Rather than waiting for the UE to perform L1 measurements, the network can instruct the UE to perform cell handover based on L3 measurements, which the UE may have already performed for the candidate cell when the LTM candidate cell configuration arrives, and the UE can be expected to continue performing LTM L1 measurements. The UE may also be able to perform L3 measurements on more (e.g., a greater number) of LTM candidate cells than it is able to perform L1 measurements on.

[0170] L3 measurements can be assumed to be performed using coarse beams, while L1 measurements can be performed using fine beams. Therefore, if LTM cell handover is based on L1 measurements, beam refinement can be performed by the UE and the network before the cell handover. When L3 measurements are to be used, the UE can continue to perform beam refinement after the cell handover or in some cases during the cell handover. If the network needs to wait for the UE to perform beam refinement before continuing data transmission, this may cause longer interruptions in UE data transmission / reception at the time of cell handover. On the other hand, the network can make (sometimes faster) decisions about cell handover without requiring the UE to perform energy-consuming L1 measurements.

[0171] To prepare for LTM cell handover, the UE may be configured by the network to perform LTM (L1) measurements on one or more LTM candidate cells. Performing (L1) measurements consumes UE power and may cause interruption of the (multiple) serving cell procedures running simultaneously with the measurements.

[0172] Additionally, if the UE is measuring multiple candidate cells and cannot measure them simultaneously, the measurement delay may be assumed to be scaled, eg, by the number of candidate cells to be measured, which may in turn result in a longer measurement time.

[0173] The LTM process may also involve early TCI state activation and early TA acquisition via PDCCH commands. This may help to shorten the actual cell handover delay, but may require the UE to perform time tracking and induce RA procedures in (multiple) candidate cells before cell handover.

[0174] Taking into account all aspects of the UE's preparation for LTM cell handover, the actual cell handover delay / interruption caused by cell handover may be shorter than the current L3HO handover delay / interruption. However, the preparation period with energy consumption (L1) measurements and (multiple) additional interruptions may be expensive for the UE, especially if many candidate cells are considered before the cell handover decision.

[0175] When the UE supports L3 measurement reporting in L1 measurement reporting, this option may result in lighter UE measurements and, in some cases, faster reporting (i.e., shorter reporting delay), so the UE can prepare for cell handover sooner. However, in this case, the LTM cell handover delay may be longer. In some cases, this is preferred, but in other cases it may be preferred to fully utilize the LTM functionality by making cell handover decisions based on L1 measurements. Using L1 measurements in L1 measurement reporting may cause a longer reporting delay, so the UE may take longer to prepare for LTM cell handover. However, the actual LTM cell handover delay may be shorter.

[0176] In an example embodiment, the delay of LTM cell switching can be adjusted depending on whether the UE / network requests L1 or L3 reporting. A technical effect of example embodiments of the present disclosure may be that if radio conditions require a quick departure from the serving cell to avoid link issues, there may be a time benefit. In other scenarios (e.g., good serving cell conditions), the time delay for performing L1 measurements may not be a factor of concern.

[0177] When a UE has the capability to report both L1 and L3 measurements in an L1 measurement report, there is a lack of a mechanism for the UE to understand which measurements to perform and report.

[0178] In an example embodiment, a UE request and network indication for L3 measurement reporting in L1 measurement reporting may be introduced for LTM cell handover preparation purposes. Following the request / indication, the UE may perform and report L3 measurements in the L1 measurement report instead of performing L1 measurements on all or a subset of LTM candidate cells (which may be considered a default), and the network may make LTM cell handover decisions based on the reported L3 measurements instead of the L1 measurements.

[0179] UE request and network indication may be implemented independently, or they may coexist in the network.

[0180] It can be noted that a UE may or may not support the LTM functionality. The LTM functionality can be divided into multiple sub-functions (e.g., whether the UE has the ability to report L3 measurements in an L1 report). If a UE supports LTM and supports reporting L3 measurements in an L1 measurement report (e.g., in addition to including L1 measurements in an L1 report), such a UE may not always be able to perform L1 measurements. This may depend on the current UE conditions (which may be constantly changing).

[0181] When the L3 measurement reporting in the L1 report is based on a UE request, the network may accept or reject the request, and the UE may act accordingly. Additionally or alternatively, when the L3 measurement reporting in the L1 report is based on a UE request, the request may be considered an indication, and the UE may start reporting L3 measurements for LTM candidate cells in the L1 report without network confirmation / acknowledgement (i.e., based at least in part on a determination by the UE to include the L3 measurements in the L1 measurement report).

[0182] When the L3 measurement report in the L1 report is based on a network request, the UE may start reporting the L3 measurements for the LTM candidate cells in the L1 report based on the indication.

[0183] For UE request or network indication, the UE or network may provide additional information regarding which candidate cells to request / indicate.

[0184] In an example embodiment, the UE behavior of L3 measurement reporting in L1 measurement reporting may be implicit based on UE capabilities and / or the content of the LTM measurement configuration, and may not require additional signaling.

[0185] In an example embodiment, a UE may request an L3 measurement report in an L1 report. When the UE identifies a need or benefit for a faster / lighter LTM cell handover, the UE may request the L3 measurement report in an L1 report to prepare for the LTM cell handover by indicating this to the network. This request may be part of an existing message or a new message. For example, the UE may send such a request when the UE is moving very quickly and / or when the UE notices that the radio link begins to degrade before the network becomes visible, or if the UE is unable to perform L1 measurements on an LTM candidate cell (e.g., due to receive timing difference (RTD) limitations (RTD > CP)). In an example embodiment, the UE may request an L3 measurement report in an L1 report based at least in part on the UE's capabilities for performing L1 measurements, actual channel conditions at the UE, and / or other UE algorithms. The UE's capabilities for performing L1 measurements may include the ability to perform L1 measurements on a target gNB, e.g., at a given point in time or during a given time period. Even if the UE generally has the capability to perform L1 measurements, it may be unable to perform L1 measurements at a certain time due to channel conditions, UE implementation, reception time differences between the serving cell and neighboring cells, and / or other reasons. For example, some UEs may be able to support L1 measurements of neighboring cells, but the conditions under which the measurement results may be assumed to be useful on the network side may not be clear and / or may be unknown.

[0186] The UE request may be followed by an acknowledgement from the network, or the request may be regarded as an indication to the network that the UE will not or cannot perform L1 measurements, but instead perform L3 measurements and report the results in the L1 measurement report of the LTM candidate cell.

[0187] In addition to the request, the UE may also list candidate cells that are ready or good for L3 in LTM cell handover based on L1 reports. These cells may be, for example, cells for which the UE has prepared recent L3 measurement results, or cells for which the UE may currently be measuring (i.e., at the time of preparation / transmission of the UE request). In one option, candidate cells suitable for L3 in LTM based on L1 reports may be indicated together with the UE request. In another option, after the network has accepted the UE's request for L3 preparation for LTM cell handover based on L1 reports, the UE may send information about suitable candidate cells based on a separate network request.

[0188] If the UE no longer considers that L3 preparation based on L1 reporting is needed (for example, the UE may stop moving, or the radio link quality may improve, or the UE may now be able to perform L1 measurements), the UE may cancel the L1-based L3 preparation by another indication and continue with basic L1 measurements based on LTM measurement behavior. Additionally or alternatively, if the mobility of the device is below a threshold, the UE may determine that it is no longer necessary / beneficial to report the L3 measurements in the L1 measurement report. Additionally or alternatively, if the radio link quality has improved by a predetermined amount, or the radio link quality is above a threshold level, the UE may determine that it is no longer necessary / beneficial to report the L3 measurements in the L1 measurement report. Additionally or alternatively, if the receive timing difference between the source cell and the measurement candidate cell is less than or equal to the cyclic prefix, the UE may determine that it is no longer necessary / beneficial to report the L3 measurements in the L1 measurement report.

[0189] In an example embodiment, the network may choose to prioritize rapidly initiated cell handovers (and with longer cell handover delays) rather than prioritizing longer LTM cell handover preparations over shorter cell handover delays.

[0190] In an example embodiment, there may be a network indication of an L3 measurement report in the L1 report. The network may request the UE to perform L3 measurements and report L3 measurements in the L1 report in: (1) LTM candidate cell configuration, reference or incremental configuration; or (2) an existing or new message separated after the UE has received the LTM candidate cell configuration but before the LTM cell handover command.

[0191] The indication may be that one or more LTM candidate cells may be considered, and the network may indicate these candidate cells in the request.

[0192] L3 measurement reporting in L1 reporting indicated by the network can be considered as an exception to the basic LTM cell handover procedure, where LTM cell handover decisions are based on L1 measurements. Alternatively, L3 based on L1 and basic preparation for LTM cell handover can be equal options, and the network can always indicate one of them to the UE.

[0193] The network may also use another indication to cancel L1-based L3 preparation if it is no longer considered necessary, in which case the UE may continue measurements based on the basic UE measurement behavior in LTM (i.e. start performing and reporting L1 measurements).

[0194] In an example embodiment, UE behavior in LTM cell handover preparation based on L3 measurements in L1 reports may be defined. Depending on the UE measurement state at the time of the LTM cell handover request based on L3 in L1 or the network indication for LTM cell handover preparation based on L3 in L1, the UE may: (1) not start / continue L1 measurements on LTM candidate cells, but only perform L3 measurements and report the results in the L1 measurement report; or (2) if the network or UE has indicated that preparation based on L3 in L1 reports is only applicable to a subset of LTM candidate cells (i.e., suitable candidates for preparation based on L3 in L1), measure and report the results for these cells in the next possible reporting instance(s).

[0195] In an example embodiment, the UE may request LTM cell handover preparation based on L3 in L1 (e.g. Figure 6 ), and / or NW may indicate LTM cell handover preparation based on L3 in L1 (e.g. Figure 7 ).

[0196] Now refer to Figure 6 , shows an example in which the UE requests LTM cell handover preparation based on L3 in L1.

[0197] During the preparation phase (605), the UE may be in RRC_CONNECTED mode (610). At 615, the UE may perform and report L3 measurements. At 620, the source gNB may perform LTM candidate preparation. At 625, the network may send an LTM candidate cell configuration for one or more LTM candidate cells to the UE. Note that if the UE does not support one or more features, the network may be aware of the UE's limitations and take these limitations into account when configuring the UE. At 630, the UE may send an RRC reconfiguration complete message to the source gNB. Optionally, the UE may adopt the configuration provided by the source gNB based at least in part on whether it supports including L1 and / or L3 measurements in the L1 measurement report and / or based on whether the provided configuration appears beneficial (e.g., based on an evaluation / criteria). Optionally, if the UE disagrees with the configuration provided by the source gNB, the UE may request a modification or adjustment of the LTM configuration (e.g., utilizing a different / adjusted L1 and / or L3 measurement configuration for the L1 measurement report).

[0198] Although Figure 6 Not shown, but the UE may optionally send a UE capability message to the NW, which may include an indication of whether the UE supports including L3 measurements in L1 measurement reports. The UE and NW may coordinate whether L1 or L3 measurements can or should be performed and reported.

[0199] Optionally, the source gNB may receive normal L3 measurements in an L3 measurement report from the UE (e.g., 615) and may determine whether to configure LTM, e.g., based on the L1 measurements included in the L1 measurement report or the L3 measurements included in the L1 measurement report. The source gNB may determine how to configure LTM based on criteria (e.g., benefits / disadvantages of various configurations regarding L1 measurement reporting) and / or the capabilities of the UE.

[0200] During the LTM execution phase (635), at 640, the UE may request LTM cell handover preparation based on L3 in L1 reports after receiving the LTM candidate cell configuration. The UE may start measurements independently of the request and report L3 measurements in the L1 measurement report, or the network may accept the request with an acknowledgment, as at 645. The UE may also indicate in this request LTM candidate cells that are good candidates for L3 in L1 preparation preparation (e.g., cells for which the UE has already performed L3 measurements). Optionally, the UE request (640) may be sent as an L2 message. For the source gNB, the CU may enable the DU to change the LTM configuration (e.g., accept / reject the UE request (640)). Optionally, the UE may send a UE request (640) to the DU (e.g., if the message is a MAC message), and the DU may accept the request and expect the UE to send L3 measurements for the LTM cells in the L1 report instead of L1 measurements. Alternatively, the UE may send a UE request (640) as an L3 message to the CU of the source gNB, and the CU may reconfigure the UE and accept or reject the request (e.g., if RRC messaging is used). In this example, the CU may need to inform the DU of the UE request, as the DU may make LTM decisions and receive L1 report(s). These examples are not limiting; the UE request (640) may be sent in one or a combination of these ways, or in a different way.

[0201] At 645, the source gNB may optionally send an acknowledgment (acceptance) of the UE's request for LTM cell handover at L3 based on the L1 report. UE preparation may begin with this acknowledgment or independently of the UE request. At 650, based on the request / network acknowledgment, the UE may skip L1 measurements and only measure and report L3 measurements (all or a subset based on cell detectability and UE / network indications) in the L1 measurement report for the LTM candidate cell. At 655, the UE may report the L3 measurements in the L1 measurement report. At 660, the network may make an LTM decision based on the L3 measurements. At 665, the network may send an LTM cell handover command based on the cell handover decision made based on the L3 measurements. At 670, the UE may detach from the source gNB and apply the target gNB configuration(s).

[0202] During the LTM completion phase (675), at 680, a RACH procedure (ie, if the procedure is not RACH-less) may optionally be performed.

[0203] Now refer to Figure 7 , shows an example of a network indication of LTM cell handover preparation based on L3 in L1 reporting.

[0204] During the preparation phase (705), at 710, the UE may be in RRC_CONNECTED mode. At 715, the UE may perform and report L3 measurements. At 720, the source gNB may perform LTM candidate preparation. At 725, the network may send an LTM candidate cell configuration for one or more LTM candidate cells to the UE. In option 1, the network may include an indication / request for L3 measurement reporting in the L1 measurement report sent to the UE, for example, in the LTM candidate cell configuration. This request may be common to the entire configuration (i.e., the UE may prepare the cells it has measured or is currently measuring or the cells it may measure and report on); this option may be the fastest. Additionally or alternatively, the request may also consider a subset of cells in the candidate cell configuration (i.e., the UE may measure and report on this subset of cells (one or more) for LTM cell handover based on L3 in L1). At 730, the UE may send an RRC reconfiguration complete message to the source gNB.

[0205] During the LTM execution phase (735), at 740 in Option 2, the network may, after sending the LTM candidate cell configuration, alternatively indicate / request an LTM cell handover based on the L3 measurements in the L1 measurement report to the UE in a separate message. At 745, based on the request / network confirmation, the UE may skip the L1 measurements and only measure and report the L3 measurements in the L1 measurement report for the LTM candidate cells (e.g., all or a subset of candidate cells based on cell detectability and network indication). At 750, the UE may report the L3 measurements in the L1 measurement report. At 755, the network may make an LTM decision based on the L3 measurements. At 760, the network may send an LTM cell handover command based on the cell handover decision made based on the L3 measurements. At 765, the UE may detach from the source gNB and apply the target gNB configuration(s).

[0206] During the LTM completion phase (770), at 775, a RACH procedure may be optionally performed (ie, if not RACH-free).

[0207] In example embodiments, particularly in Release 18, the reporting behavior of L3 based on L1 can be implicit. In this case, the signaling can be based on a combination of UE capabilities and UE requirements. In example embodiments, the UE can indicate support for L3 measurements in the L1 reporting capability to the network.

[0208] In an example embodiment, when the UE has indicated this capability and when LTM has been configured and the L3 and L1 measurement configurations match on the underlay measurement resources, the UE may always send L3 measurement results in the L1 measurement report.

[0209] In an example embodiment, when the UE has indicated this capability, and when the UE is configured with L3 measurements and L1 reporting is configured in the LTM candidate cell configuration but the L1 measurement object is not included in the LTM candidate cell configuration, the UE may be required to send L3 measurements in the L1 measurement report.

[0210] In an example embodiment, when the UE has indicated this capability, the UE may always report the L3 measurements it has performed only in the first X≥1 configured(s) L1 measurement reporting instances after receiving the LTM candidate cell configuration, and may continue to measure and report L1 measurements according to the LTM candidate cell configuration thereafter.

[0211] Figure 8 Potential steps of an example method 800 are shown. The example method 800 may include: determining to include L3 measurements in an L1 measurement report, wherein the L1 measurement report is configured to be used for lower layer triggered mobility cell handover preparation, 810; and including the L3 measurements in the L1 measurement report, 820. The example method 800 may be performed, for example, by a UE.

[0212] Figure 9 Potential steps of an example method 900 are shown. Example method 900 may include: determining 910 that L3 measurements are to be included in an L1 measurement report, wherein the L1 measurement report is configured to be used for lower layer triggered mobility cell handover preparation; receiving 920 the L1 measurement report, wherein the L1 measurement report includes the L3 measurements; and determining 930 whether to perform a lower layer triggered mobility cell handover based at least in part on the L3 measurements. Example method 900 may be performed, for example, using a base station, a network node, an eNB, a gNB, or the like.

[0213] According to an example embodiment, an apparatus may include: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: determine to include L3 measurements in an L1 measurement report, wherein the L1 measurement report may be configured to be used for mobility cell handover preparation triggered by a lower layer; and include the L3 measurements in the L1 measurement report.

[0214] The example apparatus may be further configured to send a request to the source base station to include the L3 measurements in the L1 measurement report, wherein the request may be based at least in part on determining to include the L3 measurements in the L1 measurement report.

[0215] The request may include at least an indication of at least one candidate cell associated with the L3 measurement.

[0216] The example apparatus may be further configured to receive, from the source base station, an acknowledgment of the request to include the L3 measurements in the L1 measurement report.

[0217] The example apparatus may be further configured to, in response to the confirmation, send an indication of at least one candidate cell associated with the L3 measurement.

[0218] The L3 measurements may be included in the L1 measurement report based at least in part on the received confirmation.

[0219] The L3 measurements may be included in the L1 measurement report based at least in part on determining to include the L3 measurements in the L1 measurement report.

[0220] The example apparatus may be further configured to receive an indication from the source base station to include the L3 measurements in the L1 measurement report.

[0221] The L3 measurements may be included in the L1 measurement report based at least in part on the received indication.

[0222] The example apparatus may also be configured to send an indication to the source base station to cancel inclusion of the L3 measurement in the L1 measurement report.

[0223] The example apparatus may also be configured to determine to no longer include L3 measurements in the L1 measurement report based at least in part on at least one of: determining that the apparatus has stopped moving, determining that the movement of the apparatus is below a threshold, determining that the radio link quality has improved, determining that the apparatus is capable of performing L1 measurements, or determining that a receive timing difference between the source cell and the measured candidate cell is less than or equal to a cyclic prefix.

[0224] The example apparatus may be further configured to: receive an indication from the source base station to cancel including the L3 measurements in the L1 measurement report; and include the L1 measurements in the L1 measurement report based at least in part on the indication to cancel.

[0225] The example apparatus may be further configured to send an indication to the source base station that the apparatus supports including L3 measurements in the L1 measurement report.

[0226] Determining to include the L3 measurements in the L1 measurement report may include determining that one or more L3 measurement configurations and one or more L1 measurement configurations match at least one measurement resource.

[0227] Determining to include the L3 measurements in the L1 measurement report may include the example apparatus being further configured to determine that no L1 measurement objects are included in a lower layer triggered mobility cell handover configuration.

[0228] Determining to include the L3 measurements in the L1 measurement report may include the example apparatus being further configured to: determine to include a preconfigured number of L3 measurements in the L1 measurement report; and include at least one L1 measurement in the L1 measurement report.

[0229] According to one aspect, an example method may be provided, including: determining, with a user equipment, to include L3 measurements in an L1 measurement report, wherein the L1 measurement report may be configured to be used for lower layer triggered mobility cell handover preparation; and including the L3 measurements in the L1 measurement report.

[0230] The example method may also include sending a request to the source base station to include the L3 measurements in the L1 measurement report, where the request may be based at least in part on determining to include the L3 measurements in the L1 measurement report.

[0231] The request may include at least an indication of at least one candidate cell associated with the L3 measurement.

[0232] The example method may also include receiving, from the source base station, an acknowledgement of the request to include the L3 measurements in the L1 measurement report.

[0233] The example method may also include, in response to the confirmation, sending an indication of at least one candidate cell associated with the L3 measurement.

[0234] The L3 measurements may be included in the L1 measurement report based at least in part on the received confirmation.

[0235] The L3 measurements may be included in the L1 measurement report based at least in part on determining to include the L3 measurements in the L1 measurement report.

[0236] The example method may also include receiving an indication from the source base station to include the L3 measurements in the L1 measurement report.

[0237] The L3 measurements may be included in the L1 measurement report based at least in part on the received indication.

[0238] The example method may also include sending an indication to the source base station to cancel including the L3 measurement in the L1 measurement report.

[0239] The example method may also include determining to no longer include the L3 measurements in the L1 measurement report based at least in part on at least one of: determining that the device has stopped moving, determining that the movement of the device is below a threshold, determining that the radio link quality has improved, determining that the device is capable of performing L1 measurements, or determining that a receive timing difference between the source cell and the measured candidate cell is less than or equal to a cyclic prefix.

[0240] The example method may also include receiving an indication from the source base station to cancel including the L3 measurement in the L1 measurement report; and including the L1 measurement in the L1 measurement report based at least in part on the indication to cancel.

[0241] The example method may also include sending an indication to the source base station that the apparatus supports including the L3 measurements in the L1 measurement report.

[0242] Determining to include the L3 measurements in the L1 measurement report may include determining that one or more L3 measurement configurations and one or more L1 measurement configurations match at least one measurement resource.

[0243] Determining to include the L3 measurements in the L1 measurement report may include the example apparatus being further configured to determine that no L1 measurement objects are included in a lower layer triggered mobility cell handover configuration.

[0244] Determining to include the L3 measurements in the L1 measurement report may include the example apparatus being further configured to: determine to include a preconfigured number of L3 measurements in the L1 measurement report; and include at least one L1 measurement in the L1 measurement report.

[0245] According to an example embodiment, an apparatus may include: a circuit system configured to perform the following items: determine to include L3 measurements in an L1 measurement report, wherein the L1 measurement report may be configured to be used for mobility cell handover preparation triggered by a lower layer; and a circuit system configured to perform: include the L3 measurements in the L1 measurement report.

[0246] According to an example embodiment, an apparatus may include: a processing circuit system; a memory circuit system including computer program code, the memory circuit system and the computer program code being configured to, together with the processing circuit system, enable the apparatus to: determine to include L3 measurements in an L1 measurement report, wherein the L1 measurement report may be configured to be used for lower layer triggered mobility cell handover preparation; and include the L3 measurements in the L1 measurement report.

[0247] As used in this application, the term "circuitry" or "component" may refer to one or more or all of the following: (a) a hardware circuit implementation only (such as an implementation using only analog and / or digital circuitry); and (b) a combination of hardware circuitry and software, such as, as applicable: (i) a combination of analog and / or digital hardware circuitry with software / firmware and (ii) any portion of hardware processor(s) (including digital signal processor(s)) with software, software, and memory(s) that work together to enable a device (such as a mobile phone or server) to perform various functions; and (c) hardware circuitry and / or processor(s), such as microprocessor(s) or portion(s) of microprocessor(s) that requires software (e.g., firmware) to operate, but where software is not required for operation, the software may not be present. This definition of circuitry applies to all uses of the term in this application, including in any claims. As a further example, as used in this application, the term circuitry also encompasses an implementation of only hardware circuitry or a processor(s) or a portion of a hardware circuitry or processor and its(or their) accompanying software and / or firmware. For example, the term circuitry would also encompass, if applicable to a particular claim element, a baseband integrated circuit or a processor integrated circuit for a mobile device or a similar integrated circuit in a server, cellular network device, or other computing or networking device.

[0248] According to an example embodiment, an apparatus may include means for: determining to include L3 measurements in an L1 measurement report, wherein the L1 measurement report may be configured to be used for lower layer triggered mobility cell handover preparation; and including the L3 measurements in the L1 measurement report.

[0249] The component may be further configured to send a request to the source base station to include the L3 measurements in the L1 measurement report, wherein the request may be based at least in part on determining to include the L3 measurements in the L1 measurement report.

[0250] The request may include at least an indication of at least one candidate cell associated with the L3 measurement.

[0251] The component may be further configured to receive, from the source base station, an acknowledgement of the request to include the L3 measurements in the L1 measurement report.

[0252] The component may be further configured to, in response to the confirmation, send an indication of at least one candidate cell associated with the L3 measurement.

[0253] The L3 measurements may be included in the L1 measurement report based at least in part on the received confirmation.

[0254] The L3 measurements may be included in the L1 measurement report based at least in part on determining to include the L3 measurements in the L1 measurement report.

[0255] The component may also be configured to receive an indication from the source base station to include the L3 measurement in the L1 measurement report.

[0256] The L3 measurements may be included in the L1 measurement report based at least in part on the received indication.

[0257] The component may also be configured to: send an indication to the source base station for canceling the inclusion of the L3 measurement in the L1 measurement report.

[0258] The component may also be configured to determine not to include the L3 measurements in the L1 measurement report based at least in part on at least one of: determining that the apparatus has stopped moving, determining that the apparatus's movement is below a threshold, determining that the radio link quality has improved, determining that the apparatus is capable of performing L1 measurements, or determining that a receive timing difference between the source cell and the measured candidate cell is less than or equal to a cyclic prefix.

[0259] The component may be further configured to: receive an indication from the source base station to cancel including the L3 measurement in the L1 measurement report; and include the L1 measurement in the L1 measurement report based at least in part on the indication to cancel.

[0260] The component may also be configured to: send an indication to the source base station that the apparatus supports including L3 measurements in the L1 measurement report.

[0261] The means configured to determine to include the L3 measurements in the L1 measurement report may include means configured to determine that one or more L3 measurement configurations and one or more L1 measurement configurations match the at least one measurement resource.

[0262] The means configured to determine to include the L3 measurements in the L1 measurement report may include means configured to determine that no L1 measurement objects are included in the lower layer triggered mobility cell handover configuration.

[0263] The means configured to determine to include the L3 measurements in the L1 measurement report may include means configured to: determine to include a preconfigured number of L3 measurements in the L1 measurement report; and include at least one L1 measurement in the L1 measurement report.

[0264] A processor, memory, and / or example algorithms (which may be encoded as instructions, programs, or code) may be provided as example means for providing or causing the performance of operations.

[0265] According to an example embodiment, a non-transitory computer-readable medium includes instructions stored thereon that, when executed with at least one processor, cause the at least one processor to: determine to include L3 measurements in an L1 measurement report, wherein the L1 measurement report can be configured to be used for lower layer triggered mobility cell handover preparation; and include the L3 measurements in the L1 measurement report.

[0266] According to an example embodiment, a non-transitory computer-readable medium includes program instructions stored thereon for performing at least the following: determining to include L3 measurements in an L1 measurement report, wherein the L1 measurement report can be configured to be used for lower layer triggered mobility cell handover preparation; and including the L3 measurements in the L1 measurement report.

[0267] According to another example embodiment, a non-transitory program storage device readable by a machine may be provided, tangibly embodying instructions executable by the machine for performing operations including: determining to include L3 measurements in an L1 measurement report, wherein the L1 measurement report may be configured to be used for lower layer triggered mobility cell handover preparation; and including the L3 measurements in the L1 measurement report.

[0268] According to another example embodiment, a non-transitory computer-readable medium includes instructions that, when executed by an apparatus, cause the apparatus to at least perform the following: determine to include L3 measurements in an L1 measurement report, wherein the L1 measurement report can be configured to be used for lower layer triggered mobility cell handover preparation; and include the L3 measurements in the L1 measurement report.

[0269] A computer-implemented system comprises: at least one processor and at least one non-transitory memory, the at least one non-transitory memory storing instructions that, when executed by the at least one processor, cause the system to at least: determine to include L3 measurements in an L1 measurement report, wherein the L1 measurement report can be configured to be used for lower layer triggered mobility cell handover preparation; and include the L3 measurements in the L1 measurement report.

[0270] A computer-implemented system includes: means for determining to include L3 measurements in an L1 measurement report, wherein the L1 measurement report can be configured to be used for lower layer triggered mobility cell handover preparation; and means for including the L3 measurements in the L1 measurement report.

[0271] According to an example embodiment, an apparatus may include: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: determine that L3 measurements are to be included in an L1 measurement report, wherein the L1 measurement report may be configured to be used for lower layer triggered mobility cell handover preparation; receive the L1 measurement report, wherein the L1 measurement report may include L3 measurements; and determine whether to perform lower layer triggered mobility cell handover based at least in part on the L3 measurements.

[0272] Determining that the L3 measurements are to be included in the L1 measurement report may include the example apparatus being further configured to: receive a request from a user equipment to include the L3 measurements in the L1 measurement report; and determining, based at least in part on the request, that the L3 measurements are to be included in the L1 measurement report.

[0273] The request may include at least an indication of at least one candidate cell associated with the L3 measurement.

[0274] The example apparatus may be further configured to send an acknowledgment of the request to the user equipment.

[0275] The example apparatus may be further configured to, in response to the confirmation, receive an indication of at least one candidate cell associated with the L3 measurement.

[0276] The example apparatus may be further configured to send an indication to the user equipment to include the L3 measurements in the L1 measurement report.

[0277] The indication may be sent via at least one of: a radio resource control reconfiguration message, a lower layer triggered mobility candidate cell configuration, or a message sent after a lower layer triggered mobility candidate cell configuration has been sent.

[0278] The indication may include at least an indication of at least one candidate cell associated with the L3 measurement.

[0279] The example apparatus may be further configured to receive an indication from the user equipment to cancel inclusion of the L3 measurements in the L1 measurement report.

[0280] The example apparatus may be further configured to send an indication to the user equipment to cancel inclusion of the L3 measurements in the L1 measurement report.

[0281] According to one aspect, an example method may be provided, comprising: determining, with a base station, that L3 measurements are to be included in an L1 measurement report, wherein the L1 measurement report may be configured to be used for lower layer triggered mobility cell handover preparation; receiving the L1 measurement report, wherein the L1 measurement report may include L3 measurements; and determining whether to perform a lower layer triggered mobility cell handover based at least in part on the L3 measurements.

[0282] Determining that the L3 measurements are to be included in the L1 measurement report may include the example apparatus being further configured to: receive a request from a user equipment to include the L3 measurements in the L1 measurement report; and determining to include the L3 measurements in the L1 measurement report based at least in part on the request.

[0283] The request may include at least an indication of at least one candidate cell associated with the L3 measurement.

[0284] The example method may also include sending a confirmation of the request to the user equipment.

[0285] The example method may also include, in response to the confirmation, receiving an indication of at least one candidate cell associated with the L3 measurement.

[0286] The example method may also include sending an indication to the user equipment to include the L3 measurements in the L1 measurement report.

[0287] The indication may be sent via at least one of: a radio resource control reconfiguration message, a lower layer triggered mobility candidate cell configuration, or a message sent after a lower layer triggered mobility candidate cell configuration has been sent.

[0288] The indication may include at least an indication of at least one candidate cell associated with the L3 measurement.

[0289] The example method may also include receiving an indication from the user equipment to cancel inclusion of the L3 measurements in the L1 measurement report.

[0290] The example method may also include sending an indication to the user equipment to cancel inclusion of the L3 measurements in the L1 measurement report.

[0291] According to an example embodiment, an apparatus may include: a circuit system configured to perform the following items: determine that L3 measurements are to be included in an L1 measurement report, wherein the L1 measurement report may be configured to be used for lower layer triggered mobility cell handover preparation; a circuit system configured to perform: receive the L1 measurement report, wherein the L1 measurement report may include L3 measurements; and a circuit system configured to perform: determine whether to perform a lower layer triggered mobility cell handover based at least in part on the L3 measurements.

[0292] According to an example embodiment, an apparatus may include: a processing circuit system; a memory circuit system including computer program code, the memory circuit system and the computer program code being configured to, together with the processing circuit system, enable the apparatus to: determine that L3 measurements are to be included in an L1 measurement report, wherein the L1 measurement report may be configured to be used for lower layer triggered mobility cell handover preparation; receive the L1 measurement report, wherein the L1 measurement report may include L3 measurements; and determine whether to perform a lower layer triggered mobility cell handover based at least in part on the L3 measurements.

[0293] According to an example embodiment, an apparatus may include means for determining that L3 measurements are to be included in an L1 measurement report, wherein the L1 measurement report may be configured to be used for lower layer triggered mobility cell handover preparation; receiving the L1 measurement report, wherein the L1 measurement report may include L3 measurements; and determining whether to perform lower layer triggered mobility cell handover based at least in part on the L3 measurements.

[0294] The means for determining that L3 measurements are to be included in the L1 measurement report may include means configured to: receive a request from the user equipment to include the L3 measurements in the L1 measurement report; and determine, based at least in part on the request, that the L3 measurements are to be included in the L1 measurement report.

[0295] The request may include at least an indication of at least one candidate cell associated with the L3 measurement.

[0296] The component may also be configured to send an acknowledgment of the request to the user equipment.

[0297] The component may be further configured to receive, in response to the confirmation, an indication of at least one candidate cell associated with the L3 measurement.

[0298] The component may also be configured to send an indication to the user equipment to include the L3 measurement in the L1 measurement report.

[0299] The indication may be sent via at least one of: a radio resource control reconfiguration message, a lower layer triggered mobility candidate cell configuration, or a message sent after a lower layer triggered mobility candidate cell configuration has been sent.

[0300] The indication may include at least an indication of at least one candidate cell associated with the L3 measurement.

[0301] The component may also be configured to receive an indication from the user equipment for canceling the inclusion of the L3 measurement in the L1 measurement report.

[0302] The component may also be configured to send an indication to the user equipment for canceling the inclusion of the L3 measurement in the L1 measurement report.

[0303] According to an example embodiment, a non-transitory computer-readable medium includes instructions stored thereon that, when executed with at least one processor, cause the at least one processor to: determine that L3 measurements are to be included in an L1 measurement report, wherein the L1 measurement report can be configured to be used for lower layer triggered mobility cell handover preparation; receive the L1 measurement report, wherein the L1 measurement report can include L3 measurements; and determine whether to perform a lower layer triggered mobility cell handover based at least in part on the L3 measurements.

[0304] According to an example embodiment, a non-transitory computer-readable medium includes program instructions stored thereon for performing at least the following: determining that L3 measurements are to be included in an L1 measurement report, wherein the L1 measurement report can be configured to be used for lower layer triggered mobility cell handover preparation; receiving the L1 measurement report, wherein the L1 measurement report can include L3 measurements; and determining whether to perform a lower layer triggered mobility cell handover based at least in part on the L3 measurements.

[0305] According to another example embodiment, a non-transitory program storage device readable by a machine may be provided, tangibly embodying instructions executable by the machine for performing operations including: determining that L3 measurements are to be included in an L1 measurement report, wherein the L1 measurement report may be configured to be used for lower layer triggered mobility cell handover preparation; receiving the L1 measurement report, wherein the L1 measurement report may include L3 measurements; and determining whether to perform lower layer triggered mobility cell handover based at least in part on the L3 measurements.

[0306] According to another example embodiment, a non-transitory computer-readable medium includes instructions that, when executed by an apparatus, cause the apparatus to perform at least the following: determine that L3 measurements are to be included in an L1 measurement report, wherein the L1 measurement report can be configured to be used for lower layer triggered mobility cell handover preparation; receive the L1 measurement report, wherein the L1 measurement report can include L3 measurements; and determine whether to perform lower layer triggered mobility cell handover based at least in part on the L3 measurements.

[0307] A computer-implemented system includes: at least one processor and at least one non-volatile memory, the at least one non-volatile memory storing instructions that, when executed by the at least one processor, cause the system to at least perform the following: determine that L3 measurements are to be included in an L1 measurement report, wherein the L1 measurement report can be configured to be used for lower layer triggered mobility cell handover preparation; receive the L1 measurement report, wherein the L1 measurement report can include L3 measurements; and determine whether to perform lower layer triggered mobility cell handover based at least in part on the L3 measurements.

[0308] A computer-implemented system comprising: means for determining that L3 measurements are to be included in an L1 measurement report, wherein the L1 measurement report can be configured to be used for lower layer triggered mobility cell handover preparation; means for causing receipt of the L1 measurement report, wherein the L1 measurement report can include L3 measurements; and means for determining whether to perform a lower layer triggered mobility cell handover based at least in part on the L3 measurements.

[0309] The term "non-transitory" as used herein is a limitation of the medium itself (ie, tangible, as opposed to a signal), not a limitation of data storage persistence (eg, RAM vs. ROM).

[0310] It should be understood that the foregoing description is illustrative only. Various alternatives and modifications may be devised by those skilled in the art. For example, the features described in the dependent claims may be combined with one another in any suitable combination(s). In addition, features from the different embodiments described above may be selectively combined to form new embodiments. Therefore, this specification is intended to encompass all such alternatives, modifications, and variations that fall within the scope of the appended claims.

Claims

1. A device for communication, comprising: at least one processor; as well as at least one non-transitory memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: determining to include L3 measurements in an L1 measurement report, wherein the L1 measurement report is configured to be used for lower layer triggered mobility cell handover preparation; and The L3 measurements are included in the L1 measurement report.

2. The apparatus of claim 1 , wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus to at least: A request is sent to a source base station to include the L3 measurements in the L1 measurement report, wherein the request is based at least in part on a determination to include the L3 measurements in the L1 measurement report.

3. The apparatus according to claim 2, wherein the request comprises at least: An indication of at least one candidate cell associated with the L3 measurement.

4. The apparatus of claim 2 or 3, wherein the at least one memory stores instructions which, when executed by the at least one processor, cause the apparatus to: An acknowledgement of the request to include the L3 measurements in the L1 measurement report is received from the source base station.

5. The apparatus of claim 4, wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus to: In response to the confirmation, an indication of at least one candidate cell associated with the L3 measurement is sent.

6. The apparatus of claim 4 or 5, wherein the L3 measurements are included in the L1 measurement report based at least in part on the received acknowledgement.

7. The apparatus of claim 2 or 3, wherein the L3 measurements are included in the L1 measurement report based at least in part on determining to include the L3 measurements in the L1 measurement report.

8. The apparatus of any one of claims 1 to 5, wherein the at least one memory stores instructions which, when executed by the at least one processor, cause the apparatus to: An indication is received from a source base station to include the L3 measurement in the L1 measurement report.

9. The apparatus of claim 8, wherein the L3 measurements are included in the L1 measurement report based at least in part on the received indication.

10. The apparatus according to any one of claims 1 to 9, wherein the at least one memory stores instructions which, when executed by the at least one processor, cause the apparatus to: An indication for canceling including the L3 measurement in the L1 measurement report is sent to the source base station.

11. The apparatus of claim 10, wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus to: The determination to no longer include the L3 measurement in the L1 measurement report is based at least in part on at least one of: confirming that the device has stopped moving, determining that movement of the device is below a threshold, determining that the radio link quality has been improved, Determine that the device is capable of performing L1 measurements, or It is determined that a reception timing difference between the source cell and the measured candidate cell is less than or equal to a cyclic prefix.

12. The apparatus of any one of claims 1 to 9, wherein the at least one memory stores instructions which, when executed by the at least one processor, cause the apparatus to: receiving, from a source base station, an indication for cancelling the inclusion of the L3 measurement in the L1 measurement report; and Based at least in part on the indication to cancel, the L1 measurement is included in the L1 measurement report.

13. The apparatus of claim 1 , wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus to: An indication is sent to a source base station that the apparatus supports including the L3 measurement in the L1 measurement report.

14. The apparatus of claim 13, wherein determining to include the L3 measurement in the L1 measurement report comprises: It is determined that one or more L3 measurement configurations and one or more L1 measurement configurations match at least one measurement resource.

15. The apparatus of claim 13, wherein determining to include the L3 measurement in the L1 measurement report comprises: The at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus to: It is determined that no L1 measurement object is included in the lower layer triggered mobility cell handover configuration.

16. The apparatus of claim 13, wherein determining to include the L3 measurement in the L1 measurement report comprises: The at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus to: determining to include a preconfigured number of L3 measurements in the L1 measurement report; and At least one L1 measurement is included in the L1 measurement report.

17. An apparatus for communication, comprising: at least one processor; as well as at least one non-transitory memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least: determining that L3 measurements are to be included in the L1 measurement report, wherein the L1 measurement report is configured to be used for lower layer triggered mobility cell handover preparation; receiving the L1 measurement report, wherein the L1 measurement report includes the L3 measurement; as well as A determination is made whether to perform a lower layer triggered mobility cell handover based at least in part on the L3 measurement.

18. The apparatus of claim 17, wherein determining that the L3 measurements are to be included in the L1 measurement report comprises: The at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus to: receiving, from the user equipment, a request to include the L3 measurement in the L1 measurement report; as well as Based at least in part on the request, it is determined that the L3 measurements are to be included in the L1 measurement report.

19. The apparatus according to claim 18, wherein the request comprises at least: An indication of at least one candidate cell associated with the L3 measurement.

20. The apparatus of claim 18 or 19, wherein the at least one memory stores instructions which, when executed by the at least one processor, cause the apparatus to: A confirmation of the request is sent to the user equipment.

21. The apparatus of claim 20, wherein the at least one memory stores instructions that, when executed by the at least one processor, cause the apparatus to: In response to the confirmation, an indication of at least one candidate cell associated with the L3 measurement is received.

22. The apparatus of any one of claims 17 to 21, wherein the at least one memory stores instructions which, when executed by the at least one processor, cause the apparatus to: An indication is sent to the user equipment to include the L3 measurement in the L1 measurement report.

23. The apparatus of claim 22, wherein the indication is sent via at least one of: Radio Resource Control Reconfiguration Message, Mobility candidate cell configuration triggered by lower layers, or Message sent after lower layer triggering mobility candidate cell configuration has been sent.

24. The apparatus according to claim 22 or 23, wherein the indication comprises at least: An indication of at least one candidate cell associated with the L3 measurement.

25. The apparatus of any one of claims 17 to 24, wherein the at least one memory stores instructions which, when executed by the at least one processor, cause the apparatus to: An indication is received from the user equipment to cancel including the L3 measurement in the L1 measurement report.

26. The apparatus of any one of claims 13 to 18, wherein the at least one memory stores instructions which, when executed by at least one processor, cause the apparatus to: An indication is sent to the user equipment for canceling the inclusion of the L3 measurement in the L1 measurement report.

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