Timing advance management for layer 1 / layer 2 triggered mobility

Abstract

The present application relates to devices and components including apparatuses, systems, and methods for providing sounding reference signal-based uplink timing management for two timing advances.

Description

TECHNICAL FIELD

[0001] This application relates to the wireless arts, and particularly to timing advance management for Layer 1 (LI) / Layer 2 (L2) triggered mobility (LTM) in wireless systems. BACKGROUND

[0002] Third Generation Partnership Project (3GPP) networks provide multiple cells that can serve user equipment (UEs). Each of the cells can have a corresponding base station that serves UEs within the cell. As a UE moves through an area served by the network, the UE can move into and out of different cells provided by the network. As the UE moves between cells, the UE can perform procedures to establish connections with the corresponding cells of the base stations in which the UE is located. BRIEF DESCRIPTION OF DRAWINGS

[0003] Figure 1 An example user equipment (UE) based timing compensation method is illustrated in accordance with some embodiments.

[0004] Figure 2 An example non-serving cell sounding reference signal resource set (N-SRS-RESET) activation / deactivation for candidate cell arrangement is illustrated in accordance with some embodiments.

[0005] Figure 3 An example enhanced downlink control information (DCI) format 2_3 for providing transmit power control (TPC) for candidate cells is illustrated in accordance with some embodiments.

[0006] Figure 4 An example spatial relation arrangement is illustrated in accordance with some embodiments.

[0007] Figure 5 An example medium access control (MAC) control element (CE) format is illustrated in accordance with some embodiments.

[0008] Figure 6 An example process of operating a UE is illustrated in accordance with some embodiments.

[0009] Figure 7 An example process of operating a UE is illustrated in accordance with some embodiments.

[0010] Figure 8 An example process of operating a base station is illustrated in accordance with some embodiments.

[0011] Figure 9 An example process of operating a UE is illustrated in accordance with some embodiments.

[0012] Figure 10An example process of operating a UE according to some embodiments is illustrated.

[0013] Figure 11 An example process of operating a base station according to some embodiments is illustrated.

[0014] Figure 12 An example beamforming circuit according to some embodiments is illustrated.

[0015] Figure 13 An example UE according to some embodiments is illustrated.

[0016] Figure 14 An example next generation NodeB (gNB) according to some embodiments is illustrated. DETAILED DESCRIPTION

[0017] The following detailed description references the drawings, wherein like numerals indicate the same or similar elements. In the following description, for the purposes of explanation and not limitation, specific details are set forth, such as particular structures, architectures, interfaces, techniques, and so on in order to provide a thorough understanding of the various aspects of various embodiments. However, it will be apparent to those skilled in the art having the benefit of the present disclosure that the various aspects of various embodiments can be practiced in other examples that depart from these specific details. In some instances, descriptions of well-known devices, circuits, and methods are omitted so as not to obscure the description of the various embodiments with unnecessary detail. For the purposes of the present document, the phrase “A or B” means (A), (B), or (A and B); and the phrase “based on A” means “based at least in part on A,” e.g., it can be “based on A only,” or it can be “based on A and B.”

[0018] The following is a glossary of terms that can be used throughout this disclosure.

[0019] As used herein, the term "circuitry" refers to, is part of, or includes: hardware components such as an electronic circuit, a logic circuit, a processor (shared, dedicated, or group) or memory (shared, dedicated, or group), an Application Specific Integrated Circuit (ASIC), a field-programmable device (FPD) (e.g., a field-programmable gate array (FPGA), a programmable logic device (PLD), a complex PLD (CPLD), a high-capacity PLD (HCPLD), a structured ASIC, or a programmable system-on-a-chip (SoC)), a digital signal processor (DSP), etc., that are configured to provide the described functionality. In some embodiments, circuitry can execute one or more software or firmware programs to provide at least some of the described functionality. The term "circuitry" can also refer to the combination of one or more hardware elements (or a combination of circuits used in electrical or electronic systems) with the program code that the hardware elements are used to execute. In these embodiments, the combination of hardware elements and program code can be referred to as a "circuit."

[0020] As used herein, the term "processor circuitry" refers to, is part of, or includes circuitry capable of sequentially and automatically processing a series of arithmetic or logical operations or recording, storing, or transmitting digital data. The term "processor circuitry" can refer to an application processor, a baseband processor, a central processing unit (CPU), a graphics processing unit, a single-core processor, a dual-core processor, a triple-core processor, a quad-core processor, or any other device capable of executing or otherwise operating computer-executable instructions such as program code, software modules, and / or functional processes.

[0021] As used herein, the term "interface circuitry" refers to, is part of, or includes circuitry that enables the exchange of information between two or more components or devices. The term "interface circuitry" can refer to one or more hardware interfaces such as a bus, an I / O interface, a peripheral component interface, or a network interface card, among others.

[0022] As used herein, the term "user equipment" or "UE" refers to a device with radio communication capabilities and can describe a remote user of network resources in a communication network. Furthermore, the terms "user equipment" or "UE" can be considered synonymous, and can be referred to as a client, mobile, mobile device, mobile terminal, user terminal, mobile unit, mobile station, mobile user, subscriber, user, remote station, access agent, user agent, receiver, radio equipment, reconfigurable radio equipment, reconfigurable mobile device, etc. Furthermore, the terms "user equipment" or "UE" can include any type of wireless / wired device or any computing device including a wireless communication interface.

[0023] As used herein, the term “computer system” refers to any type of interconnected electronic devices, computer devices, or components thereof. Additionally, the term “computer system” or “system” can refer to various components of a computer that are communicatively coupled to each other. Further, the term “computer system” or “system” can refer to multiple computer devices or multiple computing systems that are communicatively coupled to each other and configured to share computing resources or networking resources.

[0024] As used herein, the term “resource” refers to a physical or virtual device, a physical or virtual component within a computing environment, or a physical or virtual component within a particular device, such as a computer device, a mechanical device, memory space, processor / CPU time, processor / CPU usage, processor and accelerator load, hardware time or usage, power, input / output operations, ports or network sockets, channel / link allocation, throughput, memory usage, storage, network, database and application, units of work, and the like. A “hardware resource” can refer to computing, storage, or network resources provided by a physical hardware element. A “virtualized resource” can refer to computing, storage, or network resources provided by a virtualization infrastructure to an application, device, system, and the like. The term “network resource” or “communication resource” can refer to resources that a computer device / system is able to access via a communication network. The term “system resource” can refer to any kind of shared entity that provides a service and can include computing resources or network resources. A system resource can be viewed as a set of coherent functionalities, network data objects, or services that are accessible through a server, where such system resources reside on a single host or multiple hosts and are clearly identifiable.

[0025] As used herein, the term “channel” refers to any tangible or intangible transmission medium that is used to convey or transfer data or data signals. The term “channel” can be synonymous with or equivalent to “communication channel,” “data communication channel,” “transmission channel,” “data transmission channel,” “access channel,” “data access channel,” “link,” “data link,” “carrier wave,” “radio frequency carrier wave,” or any other similar term denoting a pathway or medium through which data is conveyed. Additionally, as used herein, the term “link” refers to a connection made between two devices for transmitting and receiving information.

[0026] As used herein, the terms “instantiate,” “instantiation,” and the like refer to the creation of an instance. An “instance” refers to a concrete occurrence of an object, which can occur, for example, during execution of program code.

[0027] The term “connect” can mean that two or more elements have an established signaling relationship with each other over a communication channel, link, interface, or reference point at a common communication protocol layer.

[0028] As used herein, the term “network element” refers to physical or virtualized equipment or infrastructure used to provide wired or wireless communication network services. The term “network element” can be considered synonymous, and be referred to as, networked computers, networked hardware, network equipment, network nodes, virtualized network functions, etc.

[0029] The term “information element” refers to a structural element containing one or more fields. The term “field” refers to individual content of an information element, or a data element containing content. An information element can include one or more additional information elements.

[0030] New mobile services requiring low latency and high reliability performance (e.g., ultra-reliable low-latency communications (URLLC)) are emerging. While the fifth generation (5G) standards have been designed to address these services from the beginning, the evolution of 5G New Radio (NR) needs to continuously enhance mobility robustness performance for these challenging scenarios.

[0031] In the Radio Access Network (RAN) plenary 94-e meeting, a work item “NR mobility enhancements” was approved with the following objectives: Layer 1 (L1) enhancements for inter-cell beam management, including L1 measurements and reporting; and beam indication.

[0032] In the past RAN Working Group 1 (RAN1) meetings, several new issues related to timing advance (TA) management associated with candidate cells in the L1 / Layer 2 (L2) triggered mobility (LTM) procedure were identified, and methods to address these issues are needed.

[0033] For the first issue, one candidate method to obtain the TA of a non-serving cell is to trigger sounding reference signal (SRS) transmission, and the TA is calculated by the network based on the received SRS. So far, SRS transmission is limited to the serving cell and active uplink (UL) bandwidth part (BWP). There is a need to address how to implement SRS-based UL timing acquisition for the LTM procedure. The approaches described throughout this disclosure can provide SRS-based UL timing acquisition for the LTM procedure.

[0034] For the second issue, in general, the user equipment (UE) performing the measurements has better knowledge of when to trigger a cell handover compared to the network, enabling minimization of latency. On the other hand, UE-initiated random access channel (RACH) procedures need to avoid potential physical random access channel (PRACH) collisions, handover failures, and minimize system overhead. The approaches described throughout this disclosure can provide UE-initiated RACH procedures that avoid potential PRACH collisions and reduce the chance of handover failures while minimizing the amount of system overhead used for the UE-initiated RACH procedures.

[0035] SRS-based uplink timing management for two TAs According to certain aspects of this disclosure, various methods can be considered to trigger aperiodic SRS transmissions toward a target cell and derive the TA value from the network. For example, aperiodic SRS transmissions from a UE toward a target cell can be triggered. The UE can transmit SRS transmissions to the base station operating the target cell. The UE can derive the TA value based on the transmissions provided to the UE by the network.

[0036] Different options can be considered for the UL transmission timing of the SRS towards the target cell. A first option may include using downlink (DL) timing obtained from the DL reference signal (RS) used for L1 channel state information (CSI) measurement in the latest timeslot. For example, the UE can determine or has already determined the DL timing based on the DL RS used for L1 CSI measurement in the most recently received timeslot. The UE can then use the determined DL timing for the UL transmission timing of the SRS towards the first cell. Specifically, the UE can transmit the SRS towards the base station operating the first cell based on the determined DL timing.

[0037] The second option can include "UE-based" TA offset compensation. In the first step, refer to Figure 1 Offset value First, at the UE, the DL reception timing is based on the serving cell. and the DL reception timing of the target candidate cell Export, as follows: .

[0038] For example, Figure 1 An example of a UE-based timing compensation method representation 100 according to some implementation schemes is illustrated. The UE-based timing compensation method representation 100 can illustrate a method for implementing two TAs using UE-based timing compensation for SRS transmission.

[0039] The UE-based timing compensation method representation 100 may include an example system arrangement 102. System arrangement 102 may exemplify an arrangement of elements for which two timing interaction methods (TAs) can be enabled. For example, a first TA can be enabled for the serving cell, and a second TA can be enabled for the target cell.

[0040] System deployment 102 may include serving cell 104. Serving cell 104 may include base stations (such as gNB 1400) providing services to serving cell 104. Figure 14 Serving cell 104 may have a first service area 106. The base station of serving cell 104 may provide services to UEs located within the first service area 106.

[0041] The system arrangement 102 can include a target cell 108. The target cell 108 can include a base station, such as the gNB 1400, that provides service for the target cell 108. The target cell 108 can have a second service area 110. The base station of the target cell 108 can provide service to UEs located within the second service area 110.

[0042] The system arrangement 102 can include a UE 112. The UE 112 can include one or more of the features of the UE 1300 Figure 13 In the illustrated embodiment, the UE 112 can be located within both the first service area 106 of the serving cell 104 and the second service area 110 of the target cell 108. Further, in the illustrated embodiment, the UE 112 can have an established connection with the serving cell 104 such that the serving cell 104 is providing service to the UE 112. For the described method, the UE 112 can be triggered to send an aperiodic SRS transmission toward the target cell 108 and can derive a TA for the target cell 108.

[0043] The serving cell 104 can send a first DL transmission 114 to the UE 112. The UE 112 can determine a first DL reception timing of the serving cell 104 based on the first DL transmission 114, where the first DL reception timing can be referred to as The target cell 108 can send a second DL transmission 116 to the UE 112. The UE 112 can determine a second DL reception timing of the target cell 108 based on the second DL transmission 116.

[0044] The UE 112 can send an SRS transmission 118 to the target cell 108. As described further throughout this disclosure, the UE 112 can be triggered to send the SRS transmission 118 to the target cell 108. In a first option, the UE 112 can use a DL timing obtained from a DL RS used for L1 CSI measurement for the timing of the transmission of the SRS transmission 118. Specifically, the UE 112 can send the SRS transmission 118 at a time according to the determined DL timing.

[0045] In a second option, the UE 112 can determine a TA for the SRS transmission 118 utilizing the determined first DL reception timing of the serving cell 104 and the determined second DL reception timing of the target cell 108. The UE-based timing compensation method representation 100 includes a timing chart 120 that illustrates the determination of the timing for the SRS transmission 118 according to the second option.

[0046] The timing chart 120 indicates transmissions 122 for the serving cell 104 and transmissions 124 for the target cell 108. Further, the transmissions 122 for the serving cell 104 are split into a first portion of transmissions 126 received by the UE 112 from the serving cell 104 and a second portion of transmissions 128 transmitted by the UE 112 to the serving cell 104. The transmissions 124 for the target cell 108 are split into a third portion of transmissions 130 received by the UE 112 from the target cell 108 and a fourth portion of transmissions 132 transmitted by the UE 112 to the target cell 108.

[0047] In the illustrated embodiment of the timing chart 120, the UE 112 can receive a first SSB 134 from the serving cell 104. The UE 112 can determine a DL reception timing of the serving cell 104 based on the reception of the first SSB 134. The UE 112 can receive a second SSB 136 from the target cell 108. The UE 112 can determine a DL reception timing of the target cell 108 based on the reception of the second SSB 136. The UE 112 can determine an offset value D 138 between the determined DL reception timing of the serving cell 104 and the determined DL reception timing of the target cell 108. In some embodiments, the DL reception timing of the serving cell 104 can be obtained from a DL RS for L1 CSI measurement of the serving cell 104 and the DL reception timing of the target cell 108 can be obtained from a DL RS for L1 CSI measurement of the target cell 108.

[0048] In some designs, the window can be configured by higher layer (e.g., RRC signaling or system information block (SIB) message) which starts from the last symbol of the measured RS resource. During the window, the offset value D is considered valid for this candidate cell. The UE can stop storing / maintaining the offset value D after the window to minimize the memory cost. To save the signaling overhead, the default value can be hard-coded in the specification. Alternatively, no default value is introduced and the absence of this window configuration means that the offset value D is stored once obtained. to store the offset value D.

[0049] ​​For example, a window for storing the offset value Δ138. The window can define an amount of time to store the offset value Δ138. The length and / or initiation point of the window can be configured by higher layers, such as via RRC signaling or SIB messages. The UE 112 can be configured to initiate the window at the last symbol of the measured RS resource. For example, the UE 112 can initiate the window starting from the last symbol of the measured RS resource. The UE 112 can maintain the determined offset value Δ138 for the duration of the window, where the UE 112 can remove (e.g., stop storing / maintaining) the determined offset value Δ138 at the window cutoff.

[0050] In a second step, upon receiving the SRS trigger towards the target non-serving cell, the UE adjusts the UL timing for SRS transmission to the uplink timing of the serving cell based on the derived offset value , as follows: For example, the UE 112 can determine the UL timing for the SRS transmission 118 based on the determined offset value Δ138. The UE 112 can determine a first UL timing 140 (indicated as in the illustrated embodiment) for the serving cell 104, where the first UL timing 140 would result in receiving a message (such as a physical uplink shared channel (PUSCH) message 142 in the illustrated embodiment) at a time 144 in the illustrated embodiment. The time 144 can be indicated in the SRS trigger and / or configured to the UE 112. The UE 112 can determine that the SRS transmission 118 will be transmitted at a second UL timing 146 (indicated as in the illustrated embodiment), which is the offset value Δ138 before the first UL timing 140. Thus, the UE 112 can determine that the SRS transmission 118 will be transmitted at the second UL timing 146, which can be the TA for the target cell 108. Thus, the UE 112 can determine a first TA for the serving cell 104 and a second TA for the target cell 108.

[0051] According to certain aspects of the present disclosure, a set of new fields can be introduced for a set of SRS resources associated with a candidate non-serving cell. For the configuration of a set of SRS resources associated with a non-serving cell, two options can be considered, referred to as “N-SRS resource set” (N-SRS-RESET). In some instances, the N-SRS-RESET can refer to a non-serving cell sounding reference signal resource set. One or more resources for SRS transmission can be configured within the N-SRS-RESET.

[0052] In the first option, N-SRS-RESET for candidate cells (which can include target cells in some instances) can be configured as part of the serving cell configuration. For the first option, a new IE “Physical Cell ID” or “Additional PCI index” can be provided to identify the target candidate cell. In some designs, several information elements (IEs) are needed to provide N-SRS-RESET. Specifically, the center frequency of SSB and ssb-PositionsInBurst IE, Point A IE of the target cell (which is used to derive the SRS resource location in frequency domain), subcarrier spacing (SCS) IE, and / or sequence frame number (SFN) offset, and The halfFrameIndex value IE can provide N-SRS-RESET. To reduce the signaling overhead, in the absence of any of these IEs, the UE can assume the same as the IEs of the serving cell.

[0053] In the second option, N-SRS-RESET for candidate cells is configured as part of the associated “non-serving cell” configuration. For the second option, various signal designs can be considered to manage N-SRS-RESET associated with different candidate cells. In a first alternative of the second option, a new medium access control (MAC)-control element (CE) can be introduced to activate / deactivate periodic N-SRS-RESET and aperiodic N-SRS-RESET. If the UE is deactivated, the UE can skip the periodic N-SRS-RESET or triggered aperiodic N-SRS-RESET. In a second alternative of the second option, for aperiodic N-SRS-RESET, a new MAC-CE can be introduced to map N-SRS-RESET to SRS request codepoints faster. The MAC-CE of the second option can be used to map N-SRS-RESET to corresponding codepoints of SRS request field of DCI format.

[0054] Figure 2 An example N-SRS-RESET activation / deactivation for candidate cell arrangement 200 is illustrated in accordance with some embodiments. For example, the N-SRS-RESET activation / deactivation for candidate cell arrangement 200 can illustrate faster N-SRS-RESET activation / deactivation for candidate cells in accordance with the second alternative of the second option. Referring to Figure 2 During UE movement, the network can update the activated N-SRS-RESET from <1, 2, 9> for candidate cell <6, 3, 7> to <3, 8, 2> associated with candidate cell <1, 2, 3>, for example, based on beam reporting for candidate cells.

[0055] For example, the arrangement 200 can include a UE 202. The UE 202 can include one or more of the features of the UE 1300 Figure 13 ) described above. The UE 202 can be located within a fourth cell 204. The fourth cell 204 can be performing service to the UE 202.

[0056] The arrangement 200 can include one or more non-serving cells surrounding the serving cell. In the illustrated embodiment, the arrangement 200 includes a first cell 206, a second cell 208, a third cell 210, a fifth cell 212, a sixth cell 214, and a seventh cell 216 operating as non-serving cells in the illustrated embodiment.

[0057] The UE 202 can be configured with an identifier (ID) of the N-SRS-RESETs mapped to each of the activated non-serving cells. The UE 202 can be configured with the N-SRS-RESET to the identifier of the activated non-serving cells via a MAC-CE. In the illustrated embodiment, the first cell 206, the second cell 208, the third cell 210, the fifth cell 212, the sixth cell 214, and the seventh cell 216 can be activated non-serving cells. In the illustrated embodiment, the ID of the N-SRS-RESETs mapped to the cells are indicated by the numbers in the rectangles illustrated at the edges of the cells. Specifically, in the illustrated embodiment, the first cell 206 is assigned a third N-SRS-RESET ID 218, the second cell 208 is assigned an eighth N-SRS-RESET ID 220, the third cell 210 is assigned a second N-SRS-RESET ID 222, the fifth cell is assigned a fourth N-SRS-RESET ID 224, the sixth cell 214 is assigned a first N-SRS-RESET ID 226, and the seventh cell 216 is assigned a ninth N-SRS-RESET ID 228.

[0058] In the illustrated implementation, UE 202 may be moving, as illustrated by arrow 230. As UE 202 moves in the illustrated implementation, UE 202 may begin near third cell 210, sixth cell 214, and seventh cell 216. The network may assign the active N-SRS-RESET as a second N-SRS-RESET ID 222 corresponding to third cell 210, a first N-SRS-RESET ID 226 corresponding to sixth cell 214, and a ninth N-SRS-RESET ID 228 corresponding to seventh cell 216, based on the starting position of UE 202. UE 202 may move to a position close to first cell 206, second cell 208, and third cell 210. The network may update the active N-SRS-RESET based on beam reports from candidate cells. For the illustrated implementation, when the UE is moved to a location close to the first cell 206, the second cell 208, and the third cell 210, the network can update the active N-SRS-RESET based on beam reports to the third N-SRS-RESET ID 218 corresponding to the first cell 206, the eighth N-SRS-RESET ID 220 corresponding to the second cell 208, and the second N-SRS-RESET ID 222 corresponding to the third cell 210.

[0059] The power control fields of N-SRS-RESET associated with a given target cell can be described as follows. Open-loop power control parameters may include separate P0 and path loss compensation factor (α) values. In some designs, if no IE is provided, the configuration of the serving cell can be assumed. For example, in the absence of an IE associated with open-loop power control, the P0 and α values ​​may be pre-configured or determined based on pre-configured values ​​and factors associated with the target cell. In some implementations, the configuration of N-SRS-RESET may include P0 parameters and path loss compensation factor (α) for the target cell.

[0060] For Path Loss Reference Signal (RS), the SSB index or Channel State Information (CSI)-Reference Signal (RS) of the target cell can be provided by RRC signaling as part of the N-SRS-RESET configuration. For SSB-based Path Loss (PL)-RS, the SSB transmit power can be provided by the network for each candidate cell via the ss-Physical Broadcast Channel (PBCH)-BlockPower IE. For example, a base station (such as the base station of the UE's serving cell) can send an ss-PBCH-BlockPower IE to the UE, which is provided for candidate cells (such as those for the deployment of 200 ( Figure 2Each of the candidate cells described provides an SSB transmit power. To minimize overhead, a default value can be hardcoded in the specification (e.g., same as the SSB transmit power of the current serving cell). For example, the UE can be configured with a default value of the SSB transmit power that can be utilized without receiving the ss-PBCH-BlockPower IE.

[0061] For closed loop (CL) power control parameters, since there is no physical uplink shared channel (PUSCH) transmission for this non-serving cell, the UE can expect to be configured with “separate CL”. Alternatively, “separate CL” can be assumed by default for N-SRS-RESET without the need for explicit configuration. In some designs, the existing downlink control information (DCI) format 2_3 can be enhanced to provide transmit power control (TPC)-commands for the candidate cells for LTM operation. In a first implementation, an “additional physical cell identifier (PCI) index” field can be introduced and provided for each TPC command in DCI format 2_3.

[0062] Figure 3 An example enhanced DCI format 2_3 300 for providing TPC for candidate cells is illustrated in accordance with some embodiments. For example, the DCI format 2_3 300 illustrates an example DCI format 2_3 that provides TPC commands for candidate cells for LTM operation as described throughout this disclosure.

[0063] The enhanced DCI format 2_3 300 can include a number of blocks. For example, in the illustrated embodiment, the DCI 2_3 300 includes a first block 302, a second block 304, a third block 306, and an Nth block 308. The enhanced DCI format 2_3 300 can also include a cyclic redundancy check (CRC) block 310. The CRC block 310 can be located at the end of the enhanced DCI format 2_3 300.

[0064] One or more of the blocks can include a TPC command. For example, in the illustrated embodiment, the third block 306 can include a TPC command 312. Any of the blocks that include a TPC command can also include an additional PCI index. For example, in the illustrated embodiment, the third block 306 includes an additional PCI index 314 based on the third block 306 including the TPC command 312. The additional PCI index 314 can indicate a candidate cell that is to receive and / or process the TPC command 312.

[0065] According to certain aspects of the present disclosure, the following alternatives can be considered for determining the spatial relation for N-SRS-resource set transmission.

[0066] In a first alternative, the spatial relation can be explicitly configured using “SRS-SpatialRelationlnfo” for each N-SRS resource in N-SRS-RESET to be associated with the SSB index of the candidate cell. This alternative can allow SSB-specific N-SRS-RESET configuration to minimize the overhead. For example, the network can configure separate N-SRS-RESET for beams transmitted by the base station.

[0067] In a second alternative, the SSB with the largest measured L1-RSRP in the latest CSI report associated with the candidate cell with N-SRS-RESET configuration can be used for the spatial relation. This alternative is for UE-selected SRS transmission.

[0068] Figure 4 An example spatial relation arrangement 400 is illustrated in accordance with some embodiments. According to some embodiments, the spatial relation arrangement 400 can provide spatial relation information for a set of SRS resources configured for a non-serving cell. Figure 4 An example is provided to depict the first and second alternatives with the following assumptions. Three beams, i.e., beam #0 / #1 / #2, are operated by a candidate non-serving cell.

[0069] For example, the spatial relation arrangement 400 can include a serving cell 402 and a non-serving cell 404. The serving cell 402 can be operated by a first base station, and the non-serving cell 404 can be operated by a second base station. The first base station and the second base station can include one or more of the features of the gNB 1400 ( Figure 14 ) described above. The serving cell 402 can have a first service area 406, and the non-serving cell 404 can have a second service area 408.

[0070] The spatial relation arrangement 400 can include a UE 410. The UE 410 can include one or more of the features of the UE 1300 ( Figure 13 ) described above. In the illustrated embodiment, the UE 410 can be located within the first service area 406 of the serving cell 402 and the second service area 408 of the non-serving cell 404. The serving cell 402 can be providing service to the UE 410. In the illustrated embodiment, the UE 410 can be moving away from the serving cell 402 and toward the non-serving cell 404, as indicated by the arrow 412.

[0071] The non-serving cell 404 can transmit one or more beams. For example, in the illustrated embodiment, the non-serving cell 404 is illustrated as transmitting three beams. Specifically, in the illustrated embodiment, the non-serving cell 404 is shown as transmitting a first beam 414, a second beam 416, and a third beam 418 toward the UE 410.

[0072] With the first alternative, the network can configure separate sets of N-SRS-resources #1 / #2 for beams with SSB#1 and SSB#2, respectively. However, no set of N-SRS-resources is configured for beams with SSB#0. For example, the non-serving cell 404 can configure the first beam 414 without a set of N-SRS-resources and SSB#0, the second beam 416 with a first set of N-SRS-resources and SSB#1, and the third beam 418 with a second set of N-SRS-resources and SSB#2. The network can obtain the UL TA associated with the second beam 416 transmitting SSB#1 with the set of N-SRS-resources #1 transmission. For example, in the illustrated embodiment, the UL TA for the non-serving cell 404 can be determined based on the second beam 416.

[0073] For the second alternative, assuming the same set of N-SRS-resources is configured for the non-serving cell and the L1 -reference signal received power (RSRP) associated with SSB#2 is the largest, when the aperiodic SRS is triggered and the UE selects the resources, the UE can select the set of N-SRS-resources #2. For example, the UE 410 can determine the L1 -RSRP for SSBs for each of the first beam 414, the second beam 416, and the third beam 418. The UE 410 can determine that SSB#2 transmitted via the third beam 418 presents the largest L1 -RSRP for SSBs. Based on the UE 410 determining that SSB#2 presents the largest L1 -RSRP, when the SRS is triggered, the UE can select the set of N-SRS-resources #2 associated with transmitting the SRS to the non-serving cell.

[0074] According to certain aspects of the present disclosure, various signaling methods can be considered to trigger the set of SRS resources transmission toward the candidate non-serving cell. For the first alternative, the trigger for the set of SRS resources transmission can include adding a “physical cell ID” or an “additional PCI index” of the candidate cell for the set of SRS resources associated with the cell. For example, the base station can transmit a transmission to the UE to trigger the set of SRS resources transmission including the physical cell ID or the additional PCI index of the candidate cell.

[0075] For the second alternative, an "additional PCI index" can be added to the DCI format 0_1 in the UE-specific search space (USS) to indicate the candidate cell to which the same DCI format's SRS request field is applied. For example, the base station can transmit a transmission in the USS with DCI format 0_1 to indicate the candidate cell to which the same DCI format's SRS request field has been applied.

[0076] For the third alternative, a new MAC-CE can be introduced to associate the codepoint of the "aperiodicSRS-ResourceTrigger" field and the N-SRS resource set for the candidate cell faster. The new MAC-CE is identified by a MAC subheader with a dedicated logical channel identifier (LCID). The new MAC-CE can consist of several fields. The first field can be AperiodicSRS-ResourceTrigger. The AperiodicSRS-ResourceTrigger can include up to 2 bits indicating the associated codepoint of the DCI format's "SRS request" field. The second field can include the SRS resource set ID and the associated non-serving cell ID, including the "physical cell ID" or "additional PCI index" of the candidate cell.

[0077] Figure 5 An example MAC-CE format 500 is illustrated according to some embodiments. The MAC-CE format 500 can illustrate a MAC-CE based aperiodic SRS trigger update for N-SRS-RESET towards a candidate cell according to some embodiments. The MAC-CE format 500 can include an example MAC-CE format based on the third alternative, assuming a single SRS resource ID of the candidate cell is associated with the trigger state codepoint.

[0078] MAC-CE format 500 may include one or more octets for associating a code point in the aperiodicSRS-ResourceTrigger field with an N-SRS resource set for the candidate cell. MAC-CE format 500 may include an aperiodicSRS-ResourceTrigger field 502 to indicate that MAC-CE will trigger an aperiodic SRS to the candidate cell. MAC-CE format 500 may also include one or more additional PCI index and SRS resource set ID pairs for associating the aperiodicSRS-ResourceTrigger field with the N-SRS resource set. For example, MAC-CE format 500 may include a first additional PCI index 504 and a first SRS resource set ID 506 paired within a second octet 508 of MAC-CE format 500. The paired first additional PCI index 504 and first SRS resource set ID 506 may indicate that the first SRS resource set ID 506 will be associated with a trigger status code point associated with the first additional PCI index 504. In other implementations, the physical cell ID can replace the additional PCI index in the pair.

[0079] UE-initiated RACH for LTM procedure According to certain aspects of this disclosure, a UE can initiate a RACH procedure to trigger an LTM procedure and obtain a TA for the target cell when certain conditions are met. In a first alternative, the conditions for initiating a RACH procedure to trigger an LTM procedure may include the candidate cell becoming a better offset than the current serving cell, where the offset value is provided by RRC signaling. For example, a UE (such as UE 1300) Figure 13 It can be determined that there are candidate cells (such as those related to the arrangement of 200). Figure 2 The first offset value associated with the candidate cell described in the description. Furthermore, the UE can determine the first offset value associated with the serving cell (such as serving cell 104). Figure 1 ) and / or service cell 402 ( Figure 4 The UE can compare the first offset value and the second offset value and determine that the first offset value associated with the candidate cell is better than the second offset value associated with the serving cell (e.g., it is a smaller offset value). The UE can determine whether to trigger the RACH procedure based on the fact that the first offset value associated with the candidate cell is better than the second offset value associated with the serving cell.

[0080] In some embodiments, the UE can determine that one or more conditions are satisfied to initiate a RACH procedure to trigger a LTM procedure and obtain a TA for a target cell. In some embodiments, the one or more conditions can include determining that a measurement result of the target cell is better than a measurement result of a serving cell. In addition, the one or more conditions can include a difference between the measurement result of the target cell and the measurement result of the serving cell being equal to or greater than an offset value. In some embodiments, the offset value can be determined based on RRC signaling.

[0081] In a second alternative, the conditions for initiating a RACH procedure to trigger a LTM procedure can include using two thresholds to determine when to initiate a RACH procedure. For example, two thresholds (e.g., a first threshold and a second threshold ) can be configured by RRC signaling. If a measured result of a serving cell becomes worse than the first threshold and at least one measured result associated with a non-serving cell becomes better than the second threshold , a RACH procedure is triggered. For example, a base station can configure a UE with a first threshold and a second threshold via RRC signaling. The base station can configure the UE with the thresholds via RRC signaling. The UE can determine a measured result of a serving cell and at least one measured result associated with a non-serving cell. In some embodiments, the measured results can include a first offset value associated with the serving cell and a second offset value associated with the non-serving cell. The UE can determine whether the measured result of the serving cell is worse than the first threshold (e.g., has a larger first offset value) and the at least one measured result associated with the non-serving cell is better than the second threshold (e.g., has a smaller second offset value). The UE can determine that a RACH procedure will be triggered based on the measured result of the serving cell being worse than the first threshold and the at least one measured result associated with the non-serving cell being better than the second threshold .

[0082] In some embodiments, enabling UE-initiated PRACH for LTM can be controlled by the network by introducing a configurable parameter as part of the LTM configuration for a given candidate cell. For example, a base station can send a configurable parameter to a UE as part of the LTM configuration for a candidate cell. The configurable parameter can indicate whether UE-initiated PRACH for LTM is enabled for the candidate cell.

[0083] Further, to distinguish the PRACH transmission of LTM from the PRACH transmission of initial access procedure, dedicated PRACH resources can be configured for each candidate SSB of a candidate cell via RRC signaling. The RRC signaling can include the following IEs: PRACH resource configuration of candidate cell, SSB-perRACH-Occasion, and / or one or more pairs of <SSB, dedicated RACH resource index>. For example, the base station can configure the UE with dedicated PRACH resources for each candidate SSB of a candidate cell. The base station can configure the UE via RRC signaling. The RRC signaling can include PRACH resource configuration of candidate cell IE, SSB-perRACH-Occasion IE, and / or one or more pairs of SSB and dedicated RACH resource index IEs.

[0084] Figure 6 An example process 600 that operates a UE in accordance with some embodiments is illustrated. The UE can include one or more of the features of the UE 112 Figure 1 , the UE 202 Figure 2 , the UE 410 Figure 4 , and / or the UE 1300 Figure 13 . The process 600 can provide for transmission of SRS transmission to a target cell.

[0085] The process 600 can include determining, at 602, an UL transmission timing for SRS transmission. For example, the UE can determine an UL transmission timing for SRS transmission to a base station of a target cell. The UE can be served by a base station of a serving cell.

[0086] In some embodiments, determining the UL transmission timing can include determining a DL timing obtained from a DL RS for L1 CSI measurement. Further, in some embodiments, determining the UL transmission timing for SRS transmission can include determining an offset value based on a DL reception timing obtained from a DL RS for L1 CSI measurement of the serving cell and a DL reception timing obtained from a DL RS for L1 CSI measurement of the target cell.

[0087] In some embodiments, the UE can initiate a window starting from a last symbol of a measured RS resource. The UE maintains the determined offset value for a duration of the window. Further, the UE can remove the offset value after the window terminates.

[0088] In some embodiments, the UE can be configured with N-SRS-RESETs associated with the target cell. In some embodiments, the N-SRS-RESETs can be configured as part of the serving cell configuration. The N-SRS-RESETs can include a physical cell ID or an additional PCI index that identifies the target cell. In some embodiments, the N-SRS-RESETs can indicate a center frequency of SSBs and a ssb-PositionsInBurst field, a point A of the target cell to be used to derive SRS resource locations in the frequency domain, a SCS or a SFN offset and a halfFrameIndex value.

[0089] In some embodiments, the N-SRS-RESETs can be configured as part of the non-serving cell configuration. The N-SRS-RESETs can be activated / deactivated by a MAC-CE. Further, in some embodiments, the MAC-CE can be used to map the N-SRS-RESETs with corresponding codepoints of the SRS request field of the DCI format. In some embodiments, the configuration of the N-SRS-RESETs can include P0 and a path loss compensation factor (a) for the target cell.

[0090] In some embodiments, the UE can also receive SSB indices of the target cell or CSI-RSs for the N-SRS-RESETs via RRC signaling. Further, the UE can receive SSB transmission power for the target cell via a ss-PBCH-BlockPower IE. In some embodiments, the UE can receive TPC commands for the target cell of the LTM within a DCI format 2 3 transmission.

[0091] In some embodiments, the UE can also determine spatial relations for the N-SRS-RESET transmissions based on SRS-SpatialRelationlnfo for each N-SRS resource in the N-SRS-RESETs. Further, the UE can determine an SSB with a maximum measured Ll-RSRP for a latest CSI report associated with the target cell.

[0092] The process 600 can include transmitting, at 604, SRS transmissions to a base station of the target cell. Specifically, the UE can transmit the SRS transmissions to the base station of the target cell in accordance with the determined UL transmission timing for the SRS. In some embodiments, one or more resources for the SRS transmissions can be configured within the N-SRS-RESETs associated with the target cell. In some embodiments, transmitting the SRS transmissions can include transmitting the SRS transmissions based on the determined offset value and the UL transmission timing of the serving cell.

[0093] In some embodiments, the SRS transmission can be triggered based on a physical cell ID of the target cell or an additional PCI index for a set of SRS resources for the target cell. Further, in some examples, the SRS transmission can be triggered based on an additional PCI index included in DCI format 0 1 in the USS. In some embodiments, the SRS transmission can be triggered based on a MAC-CE to associate a codepoint of an aperiodicSRS-ResourceTrigger field with the N-SRS-RESET for the target cell.

[0094] Although Figure 6 It is possible to dispute the order of the operations of process 600, but it should be understood that in other embodiments, the operations can be performed in a different order and / or one or more of the operations can be performed concurrently. Further, it should be understood that in other embodiments, one or more of the operations of process 600 can be omitted and / or one or more additional operations can be added to process 600.

[0095] Figure 7 An example process 700 that operates a UE is illustrated in accordance with some embodiments. The UE can include one or more of the features of UE 112 ( Figure 1 ), UE 202 ( Figure 2 ), UE 410 ( Figure 4 ), and / or UE 1300 ( Figure 13 ). Process 700 can provide for SRS transmission to a target cell.

[0096] Process 700 can include receiving a configuration for an N-SRS-RESET for a target cell, at 702. In particular, the UE can receive a configuration for an N-RESET for a target cell. The UE can be served by a serving cell.

[0097] Process 700 can include configuring the N-SRS-RESET, at 704. In particular, the UE can configure the N-SRS-RESET according to the received configuration.

[0098] In some embodiments, the N-SRS-RESET can be configured as part of a serving cell configuration. Further, in some embodiments, the N-SRS-RESET can include a physical cell ID or an additional PCI index that identifies the target cell. In some embodiments, the N-SRS-RESET can indicate a center frequency of SSBs and a ssb-PositionsInBurst field, a point A of the target cell to be used to derive SRS resource locations in the frequency domain, a SCS, and / or a SFN offset and a halfFrameIndex value.

[0099] In some embodiments, the N-SRS-RESET can be configured as part of a non- serving cell configuration. Further, in some embodiments, the N-SRS-RESET can be activated / deactivated by a MAC-CE. In some embodiments, the MAC-CE can be used to map the N-SRS-RESET with a corresponding codepoint of the SRS request field of the DCI format.

[0100] In some embodiments, the configuration of the N-SRS-RESET can include a P0 parameter and a path loss compensation factor (a) for the target cell.

[0101] In some embodiments, the UE can also receive an SSB index of the target cell or a CSI-RS for the N-SRS-RESET via RRC signaling. Further, in some embodiments, the UE can receive an SSB transmission power for the target cell via a ss-PBCH-BlockPower IE. In some embodiments, the UE can also receive a TPC command for the target cell of the LTM within a DCI format 2_3 transmission.

[0102] The process 700 can include determining an UL transmission timing for the SRS transmission at 706. Specifically, the UE can determine an UL transmission timing for the SRS transmission to the base station of the target cell.

[0103] In some embodiments, determining the UL transmission timing can include determining a DL timing obtained from a DL RS for L1 CSI measurement. Further, determining the UL transmission timing can include determining an offset value based on a DL reception timing obtained from a DL RS for L1 CSI measurement of the serving cell and a DL reception timing obtained from a DL RS for L1 CSI measurement of the target cell.

[0104] In some embodiments, the UE can also initiate a window starting from a last symbol of the measured RS resource. The UE can also maintain the determined offset value for a duration of the window. Further, the UE can remove the offset value after the window terminates.

[0105] In some embodiments, the UE can also determine a spatial relation for the N-SRS-RESET transmission based on a SRS-SpatialRelationInfo for each N-SRS resource in the N-SRS-RESET. Further, in some embodiments, the UE can determine an SSB with a maximum measured L1-RSRP for a latest CSI report associated with the target cell.

[0106] The process 700 can include transmitting, at 708, the SRS transmission to the base station of the target cell. Specifically, the UE can transmit the SRS transmission to the base station of the target cell according to the determined UL transmission timing for the SRS transmission.

[0107] In some embodiments, transmitting the SRS transmission can include transmitting the SRS transmission according to the determined UL transmission timing. Further, transmitting the SRS transmission can include transmitting the SRS transmission based on the determined offset value and the UL transmission timing of the serving cell.

[0108] In some embodiments, the SRS transmission can be triggered based on a physical cell ID of the target cell or an additional PCI index for a set of SRS resources for the target cell. Further, in some embodiments, the SRS transmission can be triggered based on an additional PCI index included in DCI format 0 1 in the USS. In some embodiments, the SRS transmission is triggered based on a MAC-CE to associate a codepoint of an aperiodicSRS-ResourceTrigger field to the N-SRS-RESET for the target cell.

[0109] Although Figure 7 It is likely that the order of the operations implied by the process 700 can be disputed, but it will be understood that, in other embodiments, the operations can be performed in a different order and / or one or more of the operations can be performed simultaneously. Further, it will be understood that, in other embodiments, one or more of the operations of the process 700 can be omitted and / or one or more additional operations can be added to the process 700.

[0110] Figure 8 An example process 800 of operating a base station is illustrated in accordance with some embodiments. The base station can include one or more of the features of the gNB 1400 Figure 14 The process 800 can provide operations related to SRS transmissions for LTM that are to be performed.

[0111] The process 800 can include generating, at 802, a configuration transmission having a configuration for the N-SRS-RESET. Specifically, the base station can generate a configuration transmission having a configuration for the N-SRS-RESET. The N-SRS-RESET can define resources for transmission of the SRS transmission. In some embodiments, the configuration of the N-SRS-RESET can include a P0 parameter and a path loss compensation factor (a) for the target cell.

[0112] The process 800 can include transmitting, at 804, the configuration transmission to the UE. Specifically, the base station can transmit the configuration transmission to the UE. The UE will determine resources for transmitting the SRS to the target cell.

[0113] In some embodiments, the configuration transmission can be transmitted as part of a serving cell configuration. In some embodiments, the N-SRS-RESET can include a physical cell ID IE or an additional PCI index IE that identifies a target cell for transmission of SRS by the UE. In some embodiments, the N-SRS-RESET can include a center frequency and ssb-PositionsInBurst IE of an SSB, a point A of a target cell IE (point A of the target cell IE for deriving SRS resource location in frequency domain), and / or a SFN offset and halfFrameIndex value IE.

[0114] In some embodiments, the configuration transmission can be transmitted as part of a non-serving cell configuration. In some embodiments, the N-SRS-RESET can be activated / deactivated by a MAC-CE. In some embodiments, the MAC-CE can be used to map the N-SRS-RESET with a codepoint of a SRS request field of a DCI format.

[0115] In some embodiments, the base station can also transmit a DL RS to the UE. The DL RS can be used to determine a DL timing. The SRS can be transmitted by the UE based on the determined DL timing.

[0116] In some embodiments, the base station can be a first base station, where the first base station is associated with a first cell. The first base station can transmit a first SSB to the UE. The UE can determine an offset value for timing of transmission of SRS based on reception of the first SSB received from the first base station and a second SSB received from a second base station associated with a second cell. In some of these embodiments, the base station can also configure a window for the UE via RRC signaling or a SIB, where the UE can maintain the offset value for a duration of the window and remove the offset value based on expiration of the window.

[0117] In some embodiments, the base station can also transmit a SSB transmission power for the target cell via a ss-PBCH-BlockPower IE. Further, in some embodiments, the base station can transmit a TPC command for the target cell for LTM within a DCI format 2 3 transmission. In some embodiments, the base station can transmit a SRS-SpatialRelationInfo for each N-SRS resource in the N-SRS-RESET to indicate a spatial relation for the N-SRS-RESET.

[0118] The process 800 can include providing a SRS trigger to the UE, at 806. Specifically, the base station can provide a SRS trigger to the UE to trigger transmission of SRS by the UE.

[0119] In some embodiments, the SRS trigger can include a physical cell ID or an additional PCI index for the target cell of the N-SRS-RESET. Further, in some embodiments, the SRS trigger can include an additional PCI index in DCI format 0 1 in the USS. In some embodiments, the SRS trigger can include a MAC-CE to associate a codepoint of an aperiodicSRS-ResourceTrigger field with the N-SRS-RESET for the target cell.

[0120] Although Figure 8 It is possible to imply an order of the operations of process 800 controversially, it should be understood that in other embodiments, the operations can be performed in a different order and / or one or more of the operations can be performed simultaneously. Further, it should be understood that in other embodiments, one or more of the operations of process 800 can be omitted and / or one or more additional operations can be added to process 800.

[0121] Figure 9 An example process 900 of operating a UE is illustrated in accordance with some embodiments. The UE can include one or more of the features of UE 112 ( Figure 1 ), UE 202 ( Figure 2 ), UE 410 ( Figure 4 ), and / or UE 1300 ( Figure 13 ). Process 900 can provide a UE-initiated RACH for an LTM procedure.

[0122] Process 900 can include determining that one or more conditions are satisfied to trigger an LTM procedure, at 902. Specifically, the UE can determine that one or more conditions are satisfied to trigger an LTM procedure.

[0123] In some embodiments, determining that the one or more conditions are satisfied can include determining that a measurement result of a target cell is better than a measurement result of a serving cell and that a difference between the measurement result of the target cell and the measurement result of the serving cell is equal to or greater than an offset value. Further, in some embodiments, the offset value can be determined based on RRC signaling.

[0124] In some embodiments, the UE can also receive an indication of a first threshold and a second threshold. In some of these embodiments, determining that the one or more conditions are satisfied can include determining that a measured result of the serving cell is worse than the first threshold and determining that at least one measured result of the target cell is better than the second threshold. In some embodiments, the indication of the first threshold and the second threshold can be received via RRC signaling.

[0125] In some embodiments, the UE can also receive an LTM configuration for the target cell, and determine that UE-initiated PRACH for LTM is enabled based on a configurable parameter of the LTM configuration. In some embodiments, the LTM configuration can include dedicated PRACH resources for each SSB of the target cell. In some embodiments, the dedicated PRACH resources for each SSB of the target cell can be configured via RRC signaling. Further, in some embodiments, the RRC signaling can include a PRACH resource configuration IE, a SSB-perRACH-Occasion IE, and / or a SSB and dedicated RACH resource index IE pair of the target cell.

[0126] The process 900 can include initiating a RACH procedure to trigger a LTM procedure at 904. Specifically, the UE can initiate the RACH procedure to trigger the LTM procedure based on one or more conditions being satisfied.

[0127] The process 900 can include obtaining a TA for the target cell at 906. Specifically, the UE can obtain the TA for the target cell based on one or more conditions being satisfied.

[0128] Although Figure 9 It is possible to contest the order of the operations of the process 900, it should be understood that in other embodiments, the operations can be performed in a different order and / or one or more of the operations can be performed concurrently. Further, it should be understood that in other embodiments, one or more of the operations of the process 900 can be omitted and / or one or more additional operations can be added to the process 900.

[0129] Figure 10 An example process 1000 of operating a UE is illustrated in accordance with some embodiments. The UE can include one or more of the features of the UE 112 ( Figure 1 ), the UE 202 ( Figure 2 ), the UE 410 ( Figure 4 ), and / or the UE 1300 ( Figure 13 ). The process 1000 can provide UE-initiated RACH for a LTM procedure.

[0130] The process 1000 can include determining that UE-initiated PRACH for LTM is enabled at 1002. Specifically, the UE can determine that UE-initiated PRACH for LTM is enabled.

[0131] In embodiments, the UE can also obtain a TA for a target cell associated with the LTM procedure. Further, in some embodiments, the UE can receive a configurable parameter as part of the LTM configuration for the target cell associated with the LTM. The configurable parameter can indicate that UE-initiated PRACH for LTM is enabled.

[0132] In some embodiments, the UE can also configure PRACH resources for each candidate SSB of the target cell associated with the LTM procedure. In some embodiments, the PRACH resources for each candidate SSB can be configured via RRC signaling. In some embodiments, the RRC signaling can include a PRACH resource configuration IE of the target cell, an SSB-perRACH-Occasion IE, and / or an SSB and dedicated RACH resource index IE pair.

[0133] The process 1000 can include determining that the LTM procedure is to be triggered, at 1004. Specifically, the UE can determine that the LTM procedure is to be triggered based on one or more conditions being satisfied.

[0134] In some embodiments, the one or more conditions can include a measurement result of a target cell associated with the LTM procedure being better than a measurement result of a serving cell associated with the LTM procedure, and a difference between the measurement result of the target cell and the measurement result of the serving cell being equal to or greater than an offset value. In some embodiments, the offset value can be provided by RRC signaling.

[0135] In some embodiments, the one or more conditions can include the measurement result of the serving cell associated with the LTM procedure being worse than a first threshold value, and at least one measurement result associated with the target cell associated with the LTM procedure being better than a second threshold value. Further, in some embodiments, the UE can receive the first threshold value and the second threshold value via RRC signaling.

[0136] The process 1006 can include initiating a RACH procedure to trigger the LTM procedure, at 1006. Specifically, the UE can initiate the RACH procedure to trigger the LTM procedure based on determining that the LTM procedure is to be triggered.

[0137] Although Figure 10 While the order of operations implied by the process 1000 can be controversial, it will be appreciated that, in other embodiments, the operations can be performed in a different order and / or one or more of the operations can be performed concurrently. Further, it will be appreciated that, in other embodiments, one or more of the operations of the process 1000 can be omitted and / or one or more additional operations can be added to the process 1000.

[0138] Figure 11An example process 1100 of operating a base station is illustrated in accordance with some embodiments. The base station can include one or more of the features of the gNB 1400 ( Figure 14 ). The process 1100 can provide for a UE-initiated RACH for LTM procedures.

[0139] The process 1100 can include determining one or more values associated with one or more conditions for a UE to determine whether to initiate a RACH procedure at 1102. Specifically, the base station can determine one or more values associated with one or more conditions for a UE to determine whether to initiate a RACH procedure to trigger an LTM procedure.

[0140] In some embodiments, the one or more values can include a measurement associated with a target cell associated with the LTM procedure and a measurement associated with a serving cell associated with the LTM procedure, and an offset value for determining whether to initiate the RACH procedure based on the measurement associated with the target cell and the measurement associated with the serving cell. In some embodiments, the one or more conditions can include the measurement associated with the target cell being better than the measurement associated with the serving cell, and a difference between the measurement of the target cell and the measurement of the serving cell being equal to or greater than the offset value.

[0141] In some embodiments, the one or more values can include a first threshold value associated with the serving cell associated with the LTM procedure and a second threshold value associated with the target cell associated with the LTM procedure. Further, in some embodiments, the one or more conditions can include the serving cell having a measured result worse than the first threshold value and at least one measured result associated with the target cell being better than the second threshold value.

[0142] The process 1100 can include providing the one or more values to the UE at 1104. Specifically, the base station can provide the one or more values to the UE for determining whether to initiate the RACH procedure. In some embodiments, the one or more values can be provided to the UE via RRC signaling.

[0143] In some embodiments, the base station can also provide a configurable parameter to the UE as part of an LTM configuration for the target cell associated with the LTM procedure. The configurable parameter can be used to indicate whether UE-initiated PRACH for LTM is enabled.

[0144] In some embodiments, the base station can also configure a dedicated PRACH resource for each candidate SSB of the target cell associated with the LTM procedure. Further, in some embodiments, the dedicated PRACH resource for each candidate SSB can be configured via RRC signaling. In some embodiments, the RRC signaling can include a PRACH resource configuration IE, an SSB-perRACH-Occasion IE, and / or an SSB and dedicated RACH resource index IE pair of the target cell.

[0145] The process 1100 can include facilitating execution of the LTM procedure at 1106. Specifically, the base station can facilitate execution of the LTM procedure based on initiation of the RACH procedure by the UE.

[0146] Although Figure 11 It is contemplated that the order of operations implied by the process 1100 can be disputed, but it will be appreciated that, in other embodiments, the operations can be performed in a different order and / or one or more of the operations can be performed concurrently. Moreover, it will be appreciated that, in other embodiments, one or more of the operations of the process 1100 can be omitted and / or one or more additional operations can be added to the process 1100.

[0147] Figure 12 An example beamforming circuit 1200 is illustrated in accordance with some embodiments. The beamforming circuit 1200 can include a first antenna panel (panel 1 1204) and a second antenna panel (panel 2 1208). Each antenna panel can include a plurality of antenna elements. Other embodiments can include other numbers of antenna panels.

[0148] A digital beamforming (BF) component 1228 can receive an input baseband (BB) signal from, for example, a baseband processor such as, for example, the baseband processor 1304A of FIG. 13. Figure 13 The digital BF component 1228 can rely on complex weights to precode the BB signal and provide a beamformed BB signal to parallel radio frequency (RF) chains 1220 / 1224.

[0149] Each RF chain 1220 / 1224 can include a digital-to-analog converter that converts the BB signal into the analog domain, a mixer that mixes the baseband signal to an RF signal, and a power amplifier that amplifies the RF signal for transmission.

[0150] The RF signal can be provided to an analog BF component 1212 / 1216, which can additionally impose beamforming by providing a phase shift in the analog domain. The RF signal can then be provided to an antenna panel 1204 / 1208 for transmission.

[0151] In some embodiments, beamforming can be done in the digital domain only or in the analog domain only, instead of the hybrid beamforming shown here.

[0152] In various embodiments, control circuitry, which can reside in a baseband processor, can provide BF weights to the analog / digital BF components to provide transmit beams at respective antenna panels. These BF weights can be determined by the control circuitry to provide directional provisioning of a serving cell as described herein. In some embodiments, the BF components and antenna panels can operate together to provide a dynamic phased array capable of directing beams in a desired direction.

[0153] Figure 13 An example of an example UE 1300 is illustrated in accordance with some embodiments. The UE 1300 can be any mobile or non-mobile computing device, such as, for example, a mobile phone, a computer, a tablet, an industrial wireless sensor (e.g., a microphone, a carbon dioxide sensor, a pressure sensor, a humidity sensor, a thermometer, a motion sensor, an accelerometer, a laser scanner, a fluid level sensor, an inventory sensor, a voltage / current meter, an actuator, etc.), a video surveillance / monitoring device (e.g., a camera, a video camera, etc.), a wearable device (e.g., a smart watch), a loose IoT device. In some embodiments, the UE 1300 can be a RedCap UE or a NR-Light UE.

[0154] The UE 1300 can include a processor 1304, RF interface circuitry 1308, memory / storage 1312, user interface 1316, sensors 1320, drive circuitry 1322, power management integrated circuit (PMIC) 1324, antenna structure 1326, and battery 1328. The components of the UE 1300 can be implemented as integrated circuits (ICs), parts of integrated circuits, discrete electronic devices or other modules, logic components, hardware, software, firmware, or a combination thereof. Figure 13 The block diagram of FIG. 13 is intended to show a high-level view of some of the components of the UE 1300. However, some of the components shown can be omitted in some embodiments, additional components can be present, and different arrangements of the components shown can occur in other embodiments.

[0155] The components of the UE 1300 can be coupled through one or more interconnects 1332, which can represent any type of interface, input / output, bus (local, system, or expansion), transmission line, trace, optical connection, etc. that allows various circuit components (on common or different chips or chip sets) to interact with one another.

[0156] The processor 1304 can include processor circuitry such as, for example, baseband processor circuitry (BB) 1304A, central processor unit circuitry (CPU) 1304B, and graphics processor unit circuitry (GPU) 1304C. The processor 1304 can include any type of circuitry or processor circuitry that executes or otherwise operates computer-executable instructions, such as program code, software modules, or functional processes from memory / storage 1312, to cause the UE 1300 to perform operations as described herein.

[0157] In some embodiments, the baseband processor circuitry 1304A can access a communication protocol stack 1336 in the memory / storage 1312 to communicate over a 3GPP-compatible network. Generally, the baseband processor circuitry 1304A can access the communication protocol stack to perform user plane functions at the PHY layer, MAC layer, RLC layer, PDCP layer, SDAP layer, and PDU layer, and control plane functions at the PHY layer, MAC layer, RLC layer, PDCP layer, RRC layer, and non-access stratum layer. In some embodiments, PHY layer operations can additionally / alternatively be performed by components of the RF interface circuitry 1308.

[0158] The baseband processor circuitry 1304A can generate or process baseband signals or waveforms that carry information that is used for communications via the 3GPP-compatible network. In some embodiments, waveforms for NR can be based on cyclic prefix OFDM (CP-OFDM) in the uplink or downlink, and discrete Fourier transform spread OFDM (DFT-S-OFDM) in the uplink.

[0159] The memory / storage 1312 can include one or more non-transitory computer-readable media including instructions (e.g., the communication protocol stack 1336) executable by one or more of the processors 1304 to cause the UE 1300 to perform various operations described herein. The memory / storage 1312 includes any type of volatile or non-volatile memory that can be distributed throughout the UE 1300. In some embodiments, some of the memory / storage 1312 can reside on the processor 1304 itself (e.g., L1 cache and L2 cache) while other memory / storage 1312 is external to the processor 1304 but accessible thereby via a memory interface. The memory / storage 1312 can include any suitable volatile or non-volatile memory, such as, for example, dynamic random access memory (DRAM), static random access memory (SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, solid-state memory, or any other type of memory device technology.

[0160] RF interface circuitry 1308 can include transceiver circuitry and radio frequency front module (RFEM) that allow UE 1300 to communicate with other devices over a radio access network. RF interface circuitry 1308 can include various elements arranged in transmit or receive paths. These elements can include, for example, switches, mixers, amplifiers, filters, synthesizer circuitry, control circuitry, etc.

[0161] In the receive path, the RFEM can receive a radiated signal from the air interface via antenna structure 1326 and continue to filter and amplify (with a low noise amplifier) the signal. The signal can be provided to a receiver of the transceiver that down-converts the RF signal to a baseband signal that is provided to a baseband processor of the processor 1304.

[0162] In the transmit path, a transmitter of the transceiver up-converts baseband signals received from the baseband processor and provides RF signals to the RFEM. The RFEM can amplify the signal through a power amplifier before the RF signal is radiated across the air interface via antenna 1326.

[0163] In various embodiments, RF interface circuitry 1308 can be configured to transmit / receive signals in a manner compatible with NR access technology.

[0164] Antenna 1326 can include antenna elements to convert electrical signals to radio waves to travel through the air and to convert received radio waves to electrical signals. These antenna elements can be arranged in one or more antenna panels. Antenna 1326 can have antenna panels that are omnidirectional, directional, or a combination thereof, to enable beamforming and multiple-input multiple-output communication. Antenna 1326 can include microstrip antennas, patch antennas, phased array antennas, printed antennas fabricated on a surface of one or more printed circuit boards, etc. Antenna 1326 can have one or more panels designed for a particular frequency band including bands in FR1 or FR2.

[0165] In some embodiments, UE 1300 can include beamforming circuitry 1200 (e.g., beamforming circuitry 1200 of FIG. 12) that can be used to communicate with UE 1300. In some embodiments, components of UE 1300 and beamforming circuitry can be shared. For example, antenna 1326 of the UE can include panel 1 1204 and panel 2 1208 of beamforming circuitry 1200. Figure 12

[0166] ​The user interface circuitry 1316 includes various input / output (I / O) devices that allow a user to interact with the UE 1300. User interface 1316 includes input device circuitry and output device circuitry. Input device circuitry includes any physical or virtual means for entering or providing input to the UE 1300. This includes, inter alia, one or more physical or virtual buttons (e.g., a reset button), a physical keyboard, keypad, mouse, touchpad, touchscreen, microphone, scanner, headset, or any other suitable device for entering data into the UE 1300. Output device circuitry includes any physical or virtual means for displaying information, or for otherwise conveying information (such as sensor readings, actuator positions, or other like information). Output device circuitry can include any number or combination of audio or visual display, including one or more simple visual outputs / indicators (such as binary status indicators (e.g., light emitting diodes (LEDs)) and multi-character visual outputs, or more complex outputs such as display devices or touchscreens (e.g., liquid crystal displays (LCD), LED displays, quantum dot displays, projectors, etc.), where the output of characters, graphics, multimedia objects, and the like are generated or produced from the operation of the UE 1300.

[0167] The sensors 1320 can include devices, modules, or subsystems whose purpose is to detect events or changes in its environment and send the information (sensor data) about the detected events to some other a device, module, subsystem, etc. Examples of such sensors include, inter alia, inertia measurement units including accelerometers, gyroscopes, or magnetometers; microelectromechanical systems or nanoelectromechanical systems including 3-axis accelerometers, 3-axis gyroscopes, or magnetometers; level sensors; flow sensors; temperature sensors (e.g., thermistors); pressure sensors; barometric sensors; gravimeters; altimeters; image capture devices (e.g., cameras or lensless apertures); light detection and ranging sensors; proximity sensors (e.g., infrared radiation detectors, etc.); depth sensors; ambient light sensors; ultrasonic transceivers; microphones or other like audio capture devices; and the like.

[0168] The drive circuitry 1322 can include software and hardware elements that operate to control particular devices embedded in, or attached to, or otherwise interfaced with the UE 1300. The drive circuitry 1322 can include individual drivers that allow other components to interact with or control various input / output (I / O) devices that can be present within, or connected to, the UE 1300. For example, the drive circuitry 1322 can include a display driver to control and allow access to a display device, a touchscreen driver to control and allow access to a touchscreen interface, sensor drivers to obtain sensor readings from the sensor circuitry 1320 and control and allow access to the sensor circuitry 1320, drivers to obtain actuator positions of electromechanical components or to control and allow access to electromechanical components, a camera driver to control and allow access to an embedded image capture device, and an audio driver to control and allow access to one or more audio devices.

[0169] The PMIC 1324 can manage power provided to the various components of the UE 1300. In particular, with respect to the processor 1304, the PMIC 1324 can control the power source selection, voltage scaling, battery charging, or DC-to-DC conversion.

[0170] In some embodiments, the PMIC 1324 can control, or otherwise be part of, various power saving mechanisms of the UE 1300. For example, if the platform UE is in an RRC_Connected state, in which it is still connected to a RAN node as it expects to receive traffic shortly, then the platform UE can transition into a state known as Discontinuous Reception (DRX) in which it powers down for brief intervals of time. During that time, the UE 1300 can power down, and thus save power, for intervals of time. If there is no data traffic activity for some period of time, the UE 1300 can transition off to an RRC Idle state, where it disconnects from the network and does not perform operations such as channel quality feedback, handover, etc. The UE 1300 in the RRC Idle state awakens periodically to listen to the network for messages, at which point it powers up enough to listen for a small duration. The UE 1300 can transition back into the RRC Connected state to receive data when there is incoming traffic. Additionally, the UE 1300 can transition into a state known as

[0171] The battery 1328 can power the UE 1300, although in some examples the UE 1300 can be mounted deployed in a fixed location, and can have a power supply coupled to an electrical grid. The battery 1328 can be a lithium ion battery, a metal-air battery, such as a zinc-air battery, an aluminum-air battery, a lithium-air battery, and the like. In some implementations, such as in vehicle-based applications, the battery 1328 can be a typical lead-acid automotive battery.

[0172] Figure 14 An example gNB 1400 according to some embodiments is illustrated. The gNB 1400 can include a processor 1404, RF interface circuitry 1408, core network (CN) interface circuitry 1412, memory / storage circuitry 1416, and antenna structure 1426.

[0173] The components of the gNB 1400 can be coupled with various other components over one or more interconnects 1428.

[0174] The processor 1404, RF interface circuitry 1408, memory / storage circuitry 1416 (including communication protocol stack 1410), antenna structure 1426, and interconnects 1428 can be similar to those described with respect to Figure 13 Like-named components have been described with respect to other figures.

[0175] The CN interface circuitry 1412 can provide connectivity to a core network (e.g., a 5thGeneration Core Network (5GC) using a 5GC-compatible network interface protocol such as carrier Ethernet protocols or some other suitable protocol). Network connectivity can be provided to / from the gNB 1400 via fiber or wireless backhaul. The CN interface circuitry 1412 can include one or more specialized processors or FPGAs for communicating using one or more of the aforementioned protocols. In some implementations, the CN interface circuitry 1412 can include multiple controllers for providing connectivity to other networks using the same or different protocols.

[0176] It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled in a way to minimize risk of unauthorized or unintended access or use of the data and to minimize the detriment to users in the event of breaches of security. Further, users should be informed about how their data is being used and about fact that they can at any time elect not to provide personally identifiable information data or that they can withdraw permission to collect such data about them.

[0177] For one or more embodiments, at least one of the components set forth in one or more of the preceding figures can be configured to perform one or more operations, techniques, processes, or methods set forth in the following embodiment section. For example, the baseband circuitry described above in connection with one or more of the preceding figures can be configured to operate in accordance with one or more of the following embodiments. For another example, circuitry associated with a UE, base station, network element, etc. described above in connection with one or more of the preceding figures can be configured to operate in accordance with one or more of the embodiments set forth in the following embodiment section.

[0178] Embodiments In the following sections, additional example embodiments are provided.

[0179] Embodiment 1 can include a method of operating a user equipment (UE), the method comprising: determining an uplink (UL) transmission timing for a sounding reference signal (SRS) transmission to a base station of a target cell, the UE being served by a base station of a serving cell; and transmitting the SRS transmission to the base station of the target cell in accordance with the determined UL transmission timing for the SRS transmission.

[0180] Embodiment 2 can include the method of embodiment 1, wherein determining the UL transmission timing comprises: determining a downlink (DL) timing obtained from a DL reference signal (RS) for layer 1 (LI) channel state information (CSI) measurement; and transmitting the SRS transmission comprises transmitting the SRS transmission in accordance with the determined DL timing.

[0181] Embodiment 3 can include the method of embodiment 1, wherein determining the UL transmission timing for the SRS transmission comprises: determining an offset value based on a DL reception timing obtained from a downlink (DL) reference signal (RS) for layer 1 (LI) channel state information (CSI) measurement of the serving cell and a DL reception of the target cell; and transmitting the SRS transmission comprises transmitting the SRS transmission based on the offset value.

[0182] Embodiment 4 can include the method of embodiment 3, further comprising: initiating a window starting from a last symbol of a measured reference signal (RS) resource; maintaining the determined offset value for a duration of the window; and removing the offset value after the window terminates.

[0183] Example 5 can include the method of Example 1, further comprising configuring a non-serving cell SRS resource set (N-SRS-RESET) associated with the target cell, wherein one or more resources for SRS transmission are configured within the N-SRS-RESET.

[0184] Example 6 can include the method of Example 5, wherein the N-SRS-RESET is configured as part of a serving cell configuration.

[0185] Example 7 can include the method of Example 6, wherein the N-SRS-RESET includes a physical cell identifier (ID) or an additional physical cell ID (PCI) index that identifies the target cell.

[0186] Example 8 can include the method of Example 6, wherein the N-SRS-RESET indicates a center frequency and ssb-PositionsInBurst field of a synchronization signal block (SSB), a point A of the target cell to be used to derive SRS resource locations in frequency domain, a subcarrier spacing (SCS), or a system frame number (SFN) offset and halfFrameIndex value.

[0187] Example 9 can include the method of Example 5, wherein the N-SRS-RESET is configured as part of a non-serving cell configuration.

[0188] Example 10 can include the method of Example 9, wherein the N-SRS-RESET is activated / deactivated by a medium access control (MAC)-control element (CE).

[0189] Example 11 can include the method of Example 9, wherein a medium access control (MAC)-control element (CE) is used to map the N-SRS-RESET to a corresponding codepoint of a SRS request field of a downlink control information (DCI) format.

[0190] Example 12 can include the method of Example 5, wherein the configuration of the N-SRS-RESET includes a P0 parameter and a path loss compensation factor (a) for the target cell.

[0191] Example 13 can include the method of Example 5, further comprising receiving a synchronization signal block (SSB) index of the target cell or a channel state information (CSI)-reference signal (RS) for the N-SRS-RESET via radio resource control (RRC) signaling.

[0192] Example 14 can include the method of example 5, further comprising receiving a synchronization signal block (SSB) transmit power for the target cell via a ss-PBCH-BlockPower information element (IE).

[0193] Example 15 can include the method of example 5, further comprising receiving a transmit power control (TPC) command for the target cell for layer 1 (L1) / layer 2 (L2) triggered mobility (LTM) within a downlink control information (DCI) format 2_3 transmission.

[0194] Example 16 can include the method of example 5, further comprising determining a spatial relation for N-SRS-RESET transmission based on SRS-SpatialRelationlnfo for each N-SRS resource in the N-SRS-RESET.

[0195] Example 17 can include the method of example 5, further comprising determining a synchronization signal block (SSB) with a largest measured layer 1 (L1)-reference signal received power (RSRP) for a latest channel state information (CSI) report associated with the target cell.

[0196] Example 18 can include the method of example 1, wherein the SRS transmission is triggered based on a physical cell identifier (ID) or an additional physical cell ID (PCI) index of the target cell for a set of SRS resources for the target cell.

[0197] Example 19 can include the method of example 1, wherein the SRS transmission is triggered based on an additional physical cell identifier (PCI) index included in a downlink control information (DCI) format 0_1 in a UE-specific search space (USS).

[0198] Example 20 can include the method of example 1, wherein the SRS transmission is triggered based on a medium access control (MAC)-control element (CE) to associate a codepoint of an aperiodicSRS-ResourceTrigger field with a set of non-serving cell SRS resources (N-SRS-RESET) for the target cell.

[0199] Example 21 can include a method of operating a user equipment (UE), the method comprising: receiving a configuration for the N-SRS-RESET for the target cell, the UE being served by a serving cell; configuring the N-SRS-RESET according to the received configuration; determining an uplink (UL) transmission timing for a sounding reference signal (SRS) transmission to a base station of the target cell; and transmitting the SRS transmission to the base station of the target cell according to the determined UL transmission timing for the SRS transmission.

[0200] Example 22 can include the method of example 21, wherein determining the UL transmission timing comprises: determining a downlink (DL) timing obtained from a DL reference signal (RS) for layer 1 (L1) channel state information (CSI) measurement; and transmitting the SRS transmission comprises transmitting the SRS transmission according to the determined UL transmission timing.

[0201] Example 23 can include the method of example 21, wherein determining the UL transmission timing comprises: determining an offset value based on a DL reception timing obtained from a downlink (DL) reference signal (RS) for layer 1 (L1) channel state information (CSI) measurement of the serving cell and a DL reception timing obtained from a DL RS for L1 CSI measurement of the target cell; and transmitting the SRS transmission comprises transmitting the SRS transmission based on the determined offset value and an UL transmission of the serving cell.

[0202] Example 24 can include the method of example 23, further comprising: initiating a window starting from a last symbol of a measured reference signal (RS) resource; maintaining the determined offset value for a duration of the window; and removing the offset value after the window expires.

[0203] Example 25 can include the method of example 21, wherein the N-SRS-RESET is configured as part of a serving cell configuration.

[0204] Example 26 can include the method of example 25, wherein the N-SRS-RESET comprises a physical cell identifier (ID) or an additional physical cell ID (PCI) index identifying the target cell.

[0205] Example 27 can include the method of Example 25, wherein the N-SRS-RESET indicates a center frequency of a synchronization signal block (SSB) and a ssb-PositionsInBurst field, a Point-A of the target cell to be used for deriving SRS resource locations in frequency domain, a subcarrier spacing (SCS), or a system frame number (SFN) offset and a halfFrameIndex value.

[0206] Example 28 can include the method of Example 21, wherein the N-SRS-RESET is configured as part of a non-serving cell configuration.

[0207] Example 29 can include the method of Example 28, wherein the N-SRS-RESET is activated / deactivated by a medium access control (MAC)-control element (CE).

[0208] Example 30 can include the method of Example 28, wherein a medium access control (MAC)-control element (CE) is used to map the N-SRS-RESET to a corresponding codepoint of a SRS request field of a downlink control information (DCI) format.

[0209] Example 31 can include the method of Example 21, wherein the configuration of the N-SRS-RESET includes a P0 parameter and a pathloss compensation factor (a) for the target cell.

[0210] Example 32 can include the method of Example 21, further comprising receiving a synchronization signal block (SSB) index of the target cell or a channel state information (CSI)-reference signal (RS) for the N-SRS-RESET via radio resource control (RRC) signaling.

[0211] Example 33 can include the method of Example 21, further comprising receiving a synchronization signal block (SSB) transmission power for the target cell via a ss-PBCH-BlockPower information element (IE).

[0212] Example 34 can include the method of Example 21, further comprising receiving a transmission power control (TPC) command for the target cell for layer 1 (L1) / layer 2 (L2) triggered mobility (LTM) within a downlink control information (DCI) format 2_3 transmission.

[0213] Example 35 can include the method of Example 21, further comprising determining a spatial relation for N-SRS-RESET transmissions based on SRS-SpatialRelationlnfo for each N-SRS resource in the N-SRS-RESET.

[0214] Example 36 can include the method of Example 21, further comprising determining a synchronization signal block (SSB) with a largest measured layer 1 (L1)-reference signal received power (RSRP) for a latest channel state information (CSI) report associated with the target cell.

[0215] Example 37 can include the method of Example 21, wherein the SRS transmission is triggered based on a physical cell identifier (ID) or an additional physical cell ID (PCI) index of the target cell for a set of SRS resources for the target cell.

[0216] Example 38 can include the method of Example 21, wherein the SRS transmission is triggered based on an additional physical cell identifier (PCI) index included in a downlink control information (DCI) format 0 1 in a UE-specific search space (USS).

[0217] Example 39 can include the method of Example 21, wherein the SRS transmission is triggered based on a medium access control (MAC)-control element (CE) to associate a codepoint of an aperiodicSRS-ResourceTrigger field with a non-serving cell SRS resource set (N-SRS-RESET) for the target cell.

[0218] Example 40 can include a method of operating a base station, the method comprising: generating a configuration transmission having a configuration for a non-serving cell sounding reference signal resource set (N-SRS-RESET), the N-SRS-RESET defining resources for transmission of sounding reference signal (SRS) transmissions; transmitting the configuration transmission to a user equipment (UE), the UE determining resources for transmission of SRS to a target cell; and providing an SRS trigger to the UE to trigger transmission of the SRS by the UE.

[0219] Example 41 can include the method of Example 40, further comprising transmitting a downlink (DL) reference signal (RS) to the UE, the DL RS to be used to determine a DL timing, wherein the SRS is to be transmitted by the UE based on the determined DL timing.

[0220] Example 42 can include the method of Example 40, wherein the base station is a first base station, wherein the first base station is associated with a first cell, and wherein the method further comprises transmitting a first synchronization signal block (SSB) to the UE, and wherein the UE is to determine an offset value for timing of the transmission of the SRS based on reception of the first SSB received from the first base station and a second SSB received from a second base station associated with a second cell.

[0221] Example 43 can include the method of Example 42, further comprising configuring a window for the UE via radio resource control (RRC) signaling or a system information block (SIB), wherein the UE is to maintain the offset value for a duration of the window and remove the offset value based on termination of the window.

[0222] Example 44 can include the method of Example 40, wherein the configuration transmission is transmitted as part of a serving cell configuration.

[0223] Example 45 can include the method of Example 44, wherein the N-SRS-RESET includes a physical cell identifier information element or an additional physical cell ID (PCI) index information element that identifies the target cell for the transmission of the SRS by the UE.

[0224] Example 46 can include the method of Example 44, wherein the N-SRS-RESET includes a center frequency and ssb-PositionsInBurst information element (IE) of a synchronization signal block (SSB), a point A of the target cell IE, a point A of the target cell IE for deriving SRS resource locations in the frequency domain, or a sequence frame number (SFN) offset and halfFrameIndex value IE.

[0225] Example 47 can include the method of Example 40, wherein the configuration transmission is transmitted as part of a non-serving cell configuration.

[0226] Example 48 can include the method of Example 47, wherein the N-SRS-RESET is activated / deactivated by a medium access control (MAC)-control element (CE).

[0227] Example 49 can include the method of Example 47, wherein a medium access control (MAC)-control element (CE) is used to map the N-SRS-RESET to a codepoint of a SRS request field of a downlink control information (DCI) format.

[0228] Example 50 can include the method of Example 40, wherein the configuration of the N-SRS-RESET includes a P0 parameter and a path loss compensation factor (a) for the target cell.

[0229] Example 51 can include the method of Example 40, further comprising: transmitting a synchronization signal block (SSB) index of the target cell or a channel state information (CSI)-reference signal (RS) for the N-SRS-RESET via radio resource control (RRC) signaling.

[0230] Example 52 can include the method of Example 40, further comprising: transmitting a synchronization signal block (SSB) transmission power for the target cell via a ss-PBCH-BlockPower information element (IE).

[0231] Example 53 can include the method of Example 40, further comprising: transmitting a transmission power control (TPC) command for the target cell for layer 1 (L1) / layer 2 (L2) triggered mobility (LTM) within a downlink control information (DCI) format 2_3 transmission.

[0232] Example 54 can include the method of Example 40, further comprising: transmitting an SRS-SpatialRelationInfo for each N-SRS resource in the N-SRS-RESET to indicate a spatial relation for the N-SRS-RESET.

[0233] Example 55 can include the method of Example 40, wherein the SRS trigger includes a physical cell identifier (ID) or an additional physical cell ID (PCI) index for the target cell of the N-SRS-RESET.

[0234] Example 56 can include the method of Example 40, wherein the SRS trigger includes an additional physical cell identifier (PCI) index in a downlink control information (DCI) format 0_1 in a UE-specific search space (USS).

[0235] Example 57 can include the method of Example 40, wherein the SRS trigger includes a medium access control (MAC)-control element (CE) to associate a codepoint of an aperiodicSRS-ResourceTrigger field with a non-serving cell SRS resource set (N-SRS-RESET) for the target cell.

[0236] Example 58 can include a method of operating a user equipment (UE), the method comprising: determining that one or more conditions are satisfied to trigger a layer 1 (L1) / layer 2 (L2) triggered mobility (LTM) procedure; initiating a random access channel (RACH) procedure to trigger the LTM procedure based on the one or more conditions being satisfied; and obtaining a timing advance for a target cell based on the one or more conditions being satisfied.

[0237] Example 59 can include the method of Example 58, wherein determining that the one or more conditions are satisfied comprises determining that a measurement result of the target cell is better than a measurement result of a serving cell, and a difference of the measurement result of the target cell and the measurement result of the serving cell is equal to or greater than an offset value.

[0238] Example 60 can include the method of Example 59, wherein the offset value is determined based on radio resource control (RRC) signaling.

[0239] Example 61 can include the method of Example 58, further comprising: receiving an indication of a first threshold and a second threshold, wherein determining that the one or more conditions are satisfied comprises determining that a measured result of a serving cell is worse than the first threshold, and determining that at least one measured result of the target cell is better than the second threshold.

[0240] Example 62 can include the method of Example 61, wherein the indication of the first threshold and the second threshold is received via RRC signaling.

[0241] Example 63 can include the method of Example 58, further comprising: receiving an LTM configuration for the target cell, and determining that a UE-initiated physical random access channel (PRACH) for LTM is enabled based on a configurable parameter of the LTM configuration.

[0242] Example 64 can include the method of Example 63, wherein the LTM configuration comprises a dedicated PRACH resource for each synchronization signal block (SSB) of the target cell.

[0243] Example 65 can include the method of Example 64, wherein the dedicated PRACH resource for each SSB of the target cell is configured via radio resource control (RRC) signaling.

[0244] Example 66 can include the method of Example 65, wherein the RRC signaling comprises a PRACH resource configuration information element (IE), an SSB-perRACH-Occasion IE, or a pair of SSB and dedicated RACH resource index IE of the target cell.

[0245] Example 67 can include a method of operating a user equipment (UE), the method comprising: determining that a UE-initiated physical random access channel (PRACH) for LTM is enabled; determining that a LTM procedure will be triggered based on the one or more conditions being satisfied; and initiating a random access channel (RACH) procedure to trigger the LTM procedure based on the determination that the LTM procedure will be triggered.

[0246] Example 68 can include the method of Example 67, further comprising: obtaining a timing advance (TA) for a target cell associated with the LTM procedure.

[0247] Example 69 can include the method of Example 67, wherein the one or more conditions comprise a measurement result of a target cell associated with the LTM procedure being better than a measurement result of a serving cell associated with the LTM procedure, and a difference of the measurement result of the target cell and the measurement result of the serving cell being equal to or greater than an offset value.

[0248] Example 70 can include the method of Example 69, wherein the offset value is provided by radio resource control (RRC) signaling.

[0249] Example 71 can include the method of Example 67, wherein the one or more conditions comprise a measured result of a serving cell associated with the LTM procedure being worse than a first threshold value, and at least one measured result associated with a target cell associated with the LTM procedure being better than a second threshold value.

[0250] Example 72 can include the method of Example 71, further comprising: receiving the first threshold value and the second threshold value via radio resource control (RRC) signaling.

[0251] Example 73 can include the method of Example 67, further comprising: receiving a configurable parameter as part of an LTM configuration for a target cell associated with the LTM procedure, the configurable parameter indicating that the UE-initiated PRACH for LTM is enabled.

[0252] Example 74 can include the method of Example 67, further comprising: configuring PRACH resources for each candidate synchronization signal block (SSB) of a target cell associated with the LTM procedure.

[0253] Example 75 can include the method of Example 74, wherein the PRACH resources for each candidate SSB are configured via radio resource control (RRC) signaling.

[0254] Example 76 can include a method as described in example 75, wherein the RRC signaling comprises a PRACH resource configuration information element (IE), an SSB-perRACH-Occasion IE, or an SSB and dedicated RACH resource index IE pair of the target cell.

[0255] Example 77 can include a method of operating a base station, comprising: determining one or more values associated with one or more conditions for a user equipment (UE) to determine whether to initiate a random access channel (RACH) procedure to trigger a layer 1 (L1) / layer 2 (L2) triggered mobility (LTM) procedure; providing the one or more values to the UE for determining whether to initiate the RACH procedure; and facilitating performance of the LTM procedure based on initiation of the RACH procedure by the UE.

[0256] Example 78 can include the method of example 77, wherein the one or more values are provided to the UE via radio resource control (RRC) signaling.

[0257] Example 79 can include the method of example 77, wherein the one or more values comprise a measurement associated with a target cell associated with the LTM procedure and a measurement associated with a serving cell associated with the LTM procedure, and an offset value for determining whether to initiate a RACH procedure based on the measurement associated with the target cell and the measurement associated with the serving cell.

[0258] Example 80 can include the method of example 79, wherein the one or more conditions comprise the measurement associated with the target cell being better than the measurement associated with the serving cell, and a difference in the measurement of the target cell and the measurement of the serving cell being equal to or greater than the offset value.

[0259] Example 81 can include the method of example 77, wherein the one or more values comprise a first threshold associated with a serving cell associated with the LTM procedure and a second threshold associated with a target cell associated with the LTM procedure.

[0260] Example 82 can include the method of example 81, wherein the one or more conditions comprise a measured result of the serving cell being worse than the first threshold, and at least one measured result associated with the target cell being better than the second threshold.

[0261] Example 83 can include the method of example 77, further comprising providing a configurable parameter to the UE as part of an LTM configuration for a target cell associated with the LTM procedure, the configurable parameter indicating whether UE-initiated physical random access channel (PRACH) for LTM is enabled.

[0262] Example 84 can include the method of example 77, further comprising configuring dedicated physical random access channel (PRACH) resources for each candidate synchronization signal block (SSB) of a target cell associated with the LTM procedure.

[0263] Example 85 can include the method of example 84, wherein the dedicated PRACH resources for each candidate SSB are configured via radio resource control (RRC) signaling.

[0264] Example 86 can include the method of example 85, wherein the RRC signaling comprises a PRACH resource configuration information element (IE), an SSB-perRACH-Occasion IE, or a pair of SSB and dedicated RACH resource index IE of the target cell.

[0265] Example 87 can include an apparatus comprising means for performing one or more elements of a method described in or related to any of examples 1-86, or any other method or process described herein.

[0266] Example 88 can include one or more non-transitory computer-readable media comprising instructions to cause an electronic device, upon execution of the instructions by one or more processors of the electronic device, to perform one or more elements of a method described in or related to any of examples 1-86, or any other method or process described herein.

[0267] Example 89 can include an apparatus comprising logic, modules, or circuitry to perform one or more elements of a method described in or related to any of examples 1-86, or any other method or process described herein.

[0268] Example 90 can include a method, technique, or process as described in or related to any of examples 1-86, or portions or combinations of elements thereof.

[0269] Example 91 can include an apparatus comprising: one or more processors; and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform the method, techniques, or process as described in or related to any of Examples 1-86, or portions thereof.

[0270] Example 92 can include a signal as described in or related to any of Examples 1-86, or portions thereof.

[0271] Example 93 can include a datagram, information element, packet, frame, segment, PDU, or message, or portions thereof, as described in or related to any of Examples 1-86, or portions thereof.

[0272] Example 94 can include a signal encoded with data as described in or related to any of Examples 1-86, or portions thereof.

[0273] Example 95 can include a signal encoded with a datagram, IE, packet, frame, segment, PDU, or message, or portions thereof, as described in or related to any of Examples 1-86, or portions thereof.

[0274] Example 96 can include an electromagnetic signal carrying computer-readable instructions, wherein execution of the computer-readable instructions by one or more processors is to cause the one or more processors to perform a method, technique, or process as described in or related to any of Examples 1-86, or portions thereof.

[0275] Example 97 can include a computer program comprising instructions, wherein execution of the program by a processing element is to cause the processing element to perform a method, technique, or process as described in or related to any of Examples 1-86, or portions thereof.

[0276] Example 98 can include a signal in a wireless network as shown and described herein.

[0277] Example 99 can include a method of communicating in a wireless network as shown and described herein.

[0278] Example 100 can include a system for providing wireless communication as shown and described herein.

[0279] Example 101 can include an apparatus for providing wireless communication as shown and described herein.

[0280] Unless otherwise expressly stated, any of the embodiments described above can be combined with any other embodiment (or combinations of embodiments) described above. The foregoing description of one or more implementations provides functionality and / or technical advantages, but that does not mean that every implementation provides the recited functionality and / or technical advantages. Other implementations can be directed to other variations and modifications that fall within the scope of the implementations. Variations and modifications can be made to the foregoing implementations, and the implementations can take many different forms, including processes, apparatuses, systems, devices, articles of manufacture, and / or computer-readable storage devices.

[0281] While the above implementations have been described with a certain degree of particularity, the description is not intended to limit the scope of the implementations. Persons of ordinary skill in the art will appreciate that many variations and modifications can be made to the foregoing implementations, and other implementations will be apparent to those of ordinary skill in the art from this disclosure. The scope of the implementations is defined by the following claims.

Claims

1. One or more computer-readable media having instructions that, when executed by one or more processors, cause a user equipment (UE) to: determine an uplink (UL) transmission timing for a sounding reference signal (SRS) transmission to a base station of a target cell, the UE being served by a base station of a serving cell; and transmit the SRS transmission to the base station of the target cell in accordance with the determined UL transmission timing for the SRS transmission.

2. The one or more computer-readable media of claim 1, wherein the one or more computer-readable media are to: determine the UL transmission timing comprises determining a downlink (DL) timing obtained from a DL reference signal (RS) for layer 1 (LI) channel state information (CSI) measurement; and transmit the SRS transmission comprises transmitting the SRS transmission in accordance with the determined DL timing.

3. The one or more computer-readable media of claim 1, wherein the one or more computer-readable media are to: determining the UL transmission timing for the SRS transmission comprises: determine an offset value based on a DL reception timing obtained from a downlink (DL) reference signal (RS) for layer 1 (LI) channel state information (CSI) measurement of the serving cell and a DL reception timing obtained from a DL RS for LI CSI measurement of the target cell; and transmit the SRS transmission comprises transmitting the SRS transmission based on the determined offset value and an UL transmission of the serving cell.

4. The one or more computer-readable media of claim 1, wherein the instructions, when executed by the one or more processors, further cause the UE to: configure a non-serving cell SRS resource set (N-SRS-RESET) associated with the target cell, wherein one or more resources for SRS transmission are configured within the N-SRS-RESET.

5. The one or more computer-readable media of claim 4, wherein the N-SRS-RESET is configured as part of a serving cell configuration.

6. The one or more computer-readable media of claim 5, wherein the N-SRS-RESET includes a physical cell identifier (ID) or an additional physical cell ID (PCI) index that identifies the target cell.

7. The one or more computer-readable media of claim 4, wherein the N-SRS-RESET is configured as part of a non-serving cell configuration.

8. The one or more computer-readable media of claim 7, wherein the N-SRS-RESET is activated / deactivated by a medium access control (MAC)-control element (CE).

9. The one or more computer-readable media of claim 7, wherein a medium access control (MAC)-control element (CE) is used to map the N-SRS-RESET to a corresponding codepoint of a SRS request field of a downlink control information (DCI) format.

10. A user equipment (UE) comprising: a memory to store a non-serving cell sounding reference signal resource set (N-SRS-RESET) for a target cell; and one or more processors coupled to the memory, the one or more processors to: receive a configuration for the N-SRS-RESET for the target cell, the UE served by a serving cell; configure the N-SRS-RESET according to the received configuration; determine an uplink (UL) transmission timing for a sounding reference signal (SRS) transmission to a base station of the target cell; and transmit the SRS transmission to the base station of the target cell according to the determined UL transmission timing for the SRS transmission.

11. The UE of claim 10, wherein the UE is to: determine the UL transmission timing includes determining a downlink (DL) timing obtained from a DL reference signal (RS) for layer 1 (Ll) channel state information (CSI) measurement; and transmit the SRS transmission includes transmitting the SRS transmission according to the determined UL transmission timing.

12. The UE of claim 10, wherein the UE is to: determining the UL transmission timing comprises: determine an offset value based on a DL reception timing obtained from a downlink (DL) reference signal (RS) for layer 1 (Ll) channel state information (CSI) measurement of the serving cell and a DL reception timing obtained from a DL RS for Ll CSI measurement of the target cell; and transmit the SRS transmission includes transmitting the SRS transmission based on the determined offset value and a UL transmission of the serving cell.

13. The UE of claim 12, wherein the one or more processors are further to: initiate a window starting from a last symbol of a measured reference signal (RS) resource; maintain the determined offset value for a duration of the window; and remove the offset value after the window terminates.

14. The UE of claim 10, wherein the configuration of the N-SRS-RESET includes a P0 parameter and a path loss compensation factor (a) for the target cell.

15. The UE of claim 10, wherein the one or more processors are further to: receive a synchronization signal block (SSB) index of the target cell or a channel state information (CSI)-reference signal (RS) for the N-SRS-RESET via radio resource control (RRC) signaling.

16. The UE of claim 10, wherein the one or more processors are further to: receive a synchronization signal block (SSB) transmission power for the target cell via a ss-PBCH-BlockPower information element (IE).

17. The UE of claim 10, wherein the one or more processors are further to: receive a transmit power control (TPC) command for the target cell for layer 1 (Ll) / layer 2 (L2) triggered mobility (LTM) within a downlink control information (DCI) format 2_3 transmission.

18. A method of operating a base station, comprising: generating a configuration transmission having a configuration for a non-serving cell sounding reference signal resource set (N-SRS-RESET), the N-SRS-RESET defining resources for transmission of sounding reference signal (SRS) transmissions; transmitting the configuration transmission to a user equipment (UE), the UE determining resources for transmission of SRS to a target cell; and providing an SRS trigger to the UE to trigger transmission of the SRS by the UE.

19. The method of claim 18, further comprising: transmitting a downlink (DL) reference signal (RS) to the UE, the DL RS to be used to determine a DL timing, wherein the SRS is to be transmitted by the UE based on the determined DL timing.

20. The method of claim 18, wherein the base station is a first base station, wherein the first base station is associated with a first cell, and wherein the method further comprises transmitting a first synchronization signal block (SSB) to the UE, and wherein the UE is to determine an offset value for timing for transmission of the SRS based on reception of the first SSB received from the first base station and a second SSB received from a second base station associated with a second cell.

21. The method of claim 18, further comprising: transmitting a transmit power control (TPC) command for the target cell for layer 1 (L1) / layer 2 (L2) triggered mobility (LTM) within a downlink control information (DCI) format 2_3 transmission.

22. The method of claim 18, further comprising: transmitting an SRS-SpatialRelationlnfo for each N-SRS resource in the N-SRS- RESET to indicate a spatial relation for the N-SRS-RESET.

23. The method of claim 18, wherein the SRS trigger comprises a physical cell identifier (ID) or an additional physical cell ID (PCI) index for the target cell for the N-SRS- RESET.

24. The method of claim 18, wherein the SRS trigger comprises an additional physical cell identifier (PCI) index in a downlink control information (DCI) format 0_1 in a UE-specific search space (USS).

25. The method of claim 18, wherein the SRS trigger comprises a medium access control (MAC)-control element (CE) to associate a codepoint of an aperiodicSRS-ResourceTrigger field with a non-serving cell SRS resource set (N-SRS-RESET) for the target cell.

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