Cell Switching Commands for Layer 1 / Layer 2 Triggered Mobility in Wireless Communications

Abstract

The system and method are for determining a transmission configuration indicator (TCI) state of a target cell, the TCI state being specified in a medium access control (MAC) control element (CE) that identifies the target cell and a cell group (CG) of the target cell, the target cell being a candidate cell for switching in an L1 / L2 triggered mobility (LTM) scenario; activating a configured TCI state for the target cell in the target CG based on the determined TCI state indicator of the MAC-CE; and receiving a PDSCH or PDCCH transmission from the target cell of the target CG based on the activated TCI state.

Description

[Background technology]

[0001] Wireless communication networks provide integrated communications platforms and telecommunications services to wireless user devices. Exemplary telecommunications services include telephony, data (e.g., voice, audio, and / or video data), messaging, Internet access, and / or other services. Wireless communication networks have radio access nodes that exchange wireless signals with wireless user devices using radio network protocols, such as those described in various telecommunications standards promulgated by the 3rd Generation Partnership Project (3GPP). Exemplary wireless communication networks include code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal frequency division multiple access (OFDMA) networks, long term evolution (LTE), and fifth generation new radio (5G NR). Wireless communication networks facilitate mobile broadband services using technologies such as OFDM, multiple input multiple output (MIMO), advanced channel coding, massive MIMO, beamforming, and / or other features. Summary of the Invention

[0002] The devices, systems, and methods described herein are configured for mobility enhancements for wireless devices, such as user equipment (UE), in wireless networks. Specifically, the methods described herein include a cell handover command (e.g., a cell switch command) that includes specific fields (described in detail below) for managing cell switching during mobility scenarios. The command includes an enhanced Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM) procedure for improving Layer 3 inter-cell mobility.

[0003] The L1 extensions of the systems and processes described herein are configured to provide several advantages, which are further described below. The LTM procedure is configured to indicate beam information association with a target cell without requiring configuration of all potential target TCI states. The process described herein is configured to overcome the shortcomings of Rel-17 ICBM, which relies on configuration of all potential target TCI states for the serving cell and target cells (non-serving cells). Potential target cells include neighbor cells to the serving cell. Generally, Rel-17 ICBM does not consider mobility usage scenarios. In some mobility usage scenarios, a UE is configured with a large number of TCI states for candidate cell measurements, which can significantly affect the TCI state for the current intra-frequency serving cell. The LTM procedure described herein can overcome the limited number of available TCI states (e.g., 64). This is overcome because the LTM procedure does not configure all potential target TCI states. The LTM procedure described herein enables mobility scenarios because it does not require using the TCI states for all neighboring cells (non-serving cells) or substantially reducing the number of TCI states available for the serving cell. The LTM procedure also enables mobility scenarios under Rel-18 where multiple target or neighboring cells are selected as candidates without substantially reducing the available TCI states for the active serving cell.

[0004] Systems and processes are configured to avoid or reduce latency caused after handover by LTM procedures. The systems and processes for LTM procedures described herein reduce downlink (DL) synchronization and beam refinement latency for the physical data shared channel (PDSCH) by introducing aperiodic signals triggered by the LTM procedure, ensuring that DL T / F synchronization and beam refinement occur with minimal latency and therefore minimal impact on DL synchronization.

[0005] According to one aspect of the present disclosure, a process includes receiving a Medium Access Control (MAC) Control Element (CE) that specifies a Transmission Configuration Indicator (TCI) state for a target cell, the MAC CE further identifying the target cell and a Cell Group (CG) of the target cell, the target cell being a candidate cell for switching in an L1 / L2 Triggered Mobility (LTM) scenario. The process includes activating a configured TCI state for the target cell in the target CG based on the specified TCI state of the MAC CE. The process includes receiving a PDSCH or PDCCH transmission from the target cell of the target CG based on the activated TCI state.

[0006] In some implementations, the MAC CE includes a bitmap that specifies, for each bit of the bitmap, activation of a TCI state having a TCI state identifier value that corresponds to the index of that bit in the bitmap, and the activation includes mapping the activated TCI state having the TCI state identifier value to a codepoint of a TCI field in downlink control information (DCI).

[0007] In some implementations, the MAC CE includes a bandwidth portion identifier that indicates the downlink bandwidth portion of the target cell to which the MAC CE is applicable.

[0008] In some implementations, the MAC CE is used to support activating one or more TCI states for a target cell when at least two candidate cell groups are configured for an LTM scenario, with each candidate cell group comprising up to 32 deactivated candidate target cells.

[0009] In some implementations, the MAC CE is used to support activating one or more TCI states for a target cell when at least four candidate cell groups are configured for the LTM procedure, each candidate cell group comprising up to 16 deactivated candidate target cells.

[0010] In some implementations, the MAC CE comprises a CORESET ID field that indicates a CORESET identifier value for the default BWP for the target cell.

[0011] In some implementations, the MAC CE comprises a TCI State ID field, where the TCI State ID is configured by radio resource control (RRC) signaling for the target cell.

[0012] In some implementations, the TCI State ID field is 7 bits.

[0013] In some implementations, the spatial configuration for PUCCH / PUSCH transmission from the UE matches the spatial configuration for PDCCH reception at the UE during the lowest CORESET of the first active BWP during L1 / L2 triggered mobility (LTM) operation.

[0014] In some implementations, the MAC CE comprises a spatial relationship information (SRI) field that specifies spatial relationship information regarding PUCCH resources for transmission by the UE.

[0015] In some implementations, the MAC CE comprises a BWP ID field indicating the BWP to which the MAC-CE applies, and a TCI state identifier field indicating the TCI state associated with a given codepoint in the TCI field and applicable for the indicated BWP, the TCI identifier field being associated with a DL or UL field indicating whether the TCI state is associated with a downlink TCI state or an uplink TCI state.

[0016] In some implementations, the MAC CE comprises a P field that indicates whether a given codepoint is associated with a single TCI state or multiple TCI states.

[0017] In some implementations, the process includes triggering a cell switch based on a cell switch command (CSC), the cell switch command comprising a cell group identifier field indicating a cell group and a target SpCell identifier field indicating a target SpCell in the cell group.

[0018] In some implementations, the CSC further includes a bitmap field indicating activation or deactivation of each cell in the cell group. In some implementations, the CSC includes a BWP ID field indicating the identity of at least one bandwidth portion to be applied to the target SpCell indicated for LTM operation.

[0019] In some implementations, the first active downlink BWP and the first active uplink BWP configured by RRC signaling during the preparation phase for LTM operation are used during and after LTM operation for communication with the target cell.

[0020] In some implementations, the CSC further includes a beam information field that applies for the SpCells in the identified cell group.

[0021] In some implementations, the beam information field indicates a TCI state from one or more activated TCI states associated with the target cell.

[0022] In some implementations, the beam information field indicates an RS index from one or more reference signals (RS) used for target cell measurements and reporting.

[0023] In some implementations, the CSC further includes a timing advance field that includes a timing advance (TA) value or a time advance group (TAG) value.

[0024] In some implementations, the process includes providing a set of contention-free random access (CFRA) configurations to a UE via RRC signaling on an SpCell in each cell group as part of a cell group configuration. In some implementations, the process includes providing a CFRA configuration index for the SpCell of the cell group to the UE in a CSC. In some implementations, the process includes triggering a CFRA procedure based on the CFRA configuration associated with the indicated CFRA configuration index to obtain a timing advance value during LTM operation.

[0025] In a general aspect, the process includes providing a UE with one or more tracking reference signal TRS resource set bursts for a cell or for SpCells in a candidate cell group only, and triggering aperiodic TRS burst transmissions based on a TRS request field in a cell switch command (CSC) signal.

[0026] In some implementations, the TRS request field includes a non-zero value indicating a TRS ID that specifies the TRS resource burst transmission to be triggered.

[0027] In some implementations, the gaps between bursts of a TRS resource set are configured by separate radio resource control parameters in units of slots.

[0028] In some implementations, the triggering offset between the slot of the CSC signal and the slot in which the TRS resource set burst is transmitted is configured by the RRC based on the UE capability report.

[0029] In some implementations, one or more non-transitory computer-readable media contain instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform one or more elements of a process described in or related to any of the preceding implementations, or any other method or process described herein.

[0030] In some implementations, an apparatus includes logic, modules, or circuitry for performing one or more elements of the method described or associated with any of the preceding implementations, or any other method or process described herein.

[0031] In some implementations, an apparatus includes one or more processors and one or more computer-readable media containing instructions that, when executed by the one or more processors, cause the one or more processors to perform a method, technique, or process described in or related to any of the preceding implementations, or portions thereof.

[0032] In some implementations, the signals are used as described or related to any of the preceding implementations, or parts or portions thereof.

[0033] In some implementations, a datagram, information element, packet, frame, segment, PDU, or message is used as described or in connection with any of the above implementations, or any part or portion thereof, or as described in this disclosure.

[0034] In some implementations, the signal is encoded with data as described or associated with any of the preceding implementations, or portions thereof, or as described in this disclosure.

[0035] In some implementations, the signal is encoded in a datagram, IE, packet, frame, segment, PDU, or message as described or associated with any of the preceding implementations, or any part or portions thereof, or as described in this disclosure.

[0036] In some embodiments, the electromagnetic signals carry computer-readable instructions, and execution of the computer-readable instructions by one or more processors causes the one or more processors to perform a method, technique, or process described in or related to any of the preceding implementations or portions thereof.

[0037] In some implementations, a computer program includes instructions, and execution of the program by a processing element causes the processing element to perform a method, technique, or process described in or related to any of the above implementations, or portions thereof. The operations or actions performed by the instructions executed by the processing element may include the methods of any of the above implementations.

[0038] In some implementations, a system provides wireless communication as shown and described herein. The operations or actions performed by the system may include any of the methods of the aforementioned implementations.

[0039] In some implementations, a device provides wireless communication as shown and described herein. The operations or actions performed by the device can include the methods of any of the implementations described above.

[0040] The foregoing implementations can be implemented using a computer-implemented method, a non-transitory computer-readable medium storing computer-readable instructions for performing the computer-implemented method, and a computer system including a computer memory interoperably coupled to a hardware processor configured to perform the computer-implemented method or the instructions stored on the non-transitory computer-readable medium.

[0041] The details of one or more embodiments of these systems and methods are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of these systems and methods will be apparent from the description and drawings, and from the claims. [Brief explanation of the drawings]

[0042] [Figure 1] 1 illustrates a wireless network according to some implementations.

[0043] [Figure 2] 1 illustrates an exemplary medium access control (MAC) control element (CE) that controls cell activation or cell deactivation for an LTM switching procedure.

[0044] [Figure 3A] 10 shows an example MAC CE for TCI state for PDCCH for a deactivated target cell.

[0045] [Figure 3B] 10 shows an exemplary MAC CE for TCI state for PUCCH or PUSCH for a deactivated target cell.

[0046] [Figure 4] 1 illustrates an exemplary MAC CE for an LTM switching procedure for activation or deactivation of a target cell.

[0047] [Figure 5] 10 shows exemplary fields for a cell switch command (CSC).

[0048] [Figure 6] 1 shows a flowchart of an exemplary method, according to some implementations.

[0049] [Figure 7] 1 shows a flowchart of an exemplary method, according to some implementations.

[0050] [Figure 8] 1 illustrates a user equipment (UE) according to some implementations.

[0051] [Figure 9] 1 illustrates an access node according to some implementations. DETAILED DESCRIPTION OF THE INVENTION

[0052] The devices, systems, and methods described herein are configured for mobility enhancements for wireless devices, such as user equipment (UE), in wireless networks. Specifically, the methods described herein include a cell handover command (e.g., a cell switch command) that includes specific fields (described in detail below) for managing cell switching during mobility scenarios. The command includes an enhanced Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM) procedure for improving Layer 3 inter-cell mobility.

[0053] Systems and processes are configured to facilitate the use of mobile services that rely on low latency and high reliability performance. For example, these include Ultra-Reliable Low Latency Communications (URLLC) use cases. While 5G standards were designed to address these services from the outset, the evolution of 5G New Radio (NR) enhances mobility robustness performance for URLLC scenarios. The processes described herein include such enhancements. For example, the processes and systems are configured for Layer 1 (L1) enhancements for inter-cell beam management, including L1 measurements and reporting, and beam direction. The processes are based on the Rel-17 Inter-Cell Beam Management (ICBM) Channel State Information (CSI) measurement process used as a baseline. Use cases for LTM include Frequency Range 2 (FR2) communications, where there is directional communication between a base station (e.g., a node or gNB) and a user equipment (UE) performing an LTM procedure. For example, such communications include specifying / selecting a specific beam for a target cell.

[0054] The system and process are configured to indicate the transmission configuration indicator (TCI) state of a target cell in an LTM procedure. The TCI state is dynamically transmitted in a downlink control information (DCI) message, which includes configurations such as quasi-co-location (QCL) relationships between downlink (DL) reference signals (RSs) in one channel state information reference signal (CSI-RS) set and physical data shared channel (PDSCH) demodulation reference signal (DMRS) ports. A UE can be configured using a list of up to "M" TCI state configurations in the higher layer (RRC Re Config) parameter PDSCH-Config to decode a PDSCH according to a detected PDCCH with DCI intended for the UE and a given serving cell. M depends on the UE capability maxNumberActiveTCI-PerBWP. Each TCI state includes parameters for configuring the QCL relationship between one or two downlink reference signals and a DM-RS port of a PDSCH, a DM-RS port of a PDCCH, or a CSI-RS port of a CSI-RS resource. The quasi-co-location (QCL) relationship is configured by higher layer (e.g., RRC reconfiguration) parameters as qcl-Type 1 for the first DL RS and qcl-Type 2 for the second DL RS. Up to two qcl-types can be configured per TCI state.

[0055] The L1 extensions of the systems and processes described herein are configured to provide several advantages. The LTM procedure is configured to indicate beam information association with a target cell without requiring configuration of all potential target TCI states. The processes described herein are configured to overcome the shortcomings of Rel-17 ICBM, which relies on configuration of all potential target TCI states for the serving cell and target cells (non-serving cells). Potential target cells include neighbor cells to the serving cell. Generally, Rel-17 ICBM does not consider mobility usage scenarios. In some mobility usage scenarios, a UE is configured with a large number of TCI states for candidate cell measurements, which can significantly affect the TCI state for the current intra-frequency serving cell. The LTM procedure described herein can overcome the limited number of available TCI states (e.g., 64). This is overcome because the LTM procedure does not configure all potential target TCI states. The LTM procedure described herein enables mobility scenarios because it does not require using the TCI states for all neighboring cells (non-serving cells) or substantially reducing the number of TCI states available for the serving cell. The LTM procedure also enables mobility scenarios under Rel-18 where multiple target or neighboring cells are selected as candidates without substantially reducing the available TCI states for the active serving cell.

[0056] The system and process specify the capabilities and corresponding information fields indicated by the cell switch command. These fields allow the LTM procedure to use fewer TCI state identifiers, as explained earlier, and to reduce the latency for cell switching, as explained later. These fields, described below, contain L1 / L2 information used for cell handover.

[0057] Systems and processes are configured to avoid or reduce latency introduced after a handover due to an LTM procedure. The latency would be introduced due to periodic synchronization signal block (SSB) measurements on the target cell to achieve time or frequency (T / F) synchronization requirements after the LTM procedure. For example, one or more SSBs are transmitted periodically every 20 ms, introducing a delay (e.g., 20 ms due to the SSB periodicity) caused by waiting for the next available SSB to perform T / F synchronization after the LTM operation. The systems and processes for the LTM procedure described herein reduce downlink (DL) synchronization and beam refinement latency for the physical data shared channel (PDSCH) by introducing aperiodic signals triggered by the LTM procedure to ensure that DL T / F synchronization and beam refinement occur with minimal latency and therefore minimal impact on DL synchronization. As an example, assuming that the aperiodic signal can be triggered by an LTM procedure signal, the latency can be reduced to 2 ms or 3 ms, which is a significant reduction compared to the 20 ms latency in current systems.

[0058] 1 illustrates a wireless network 100 according to some implementations. The wireless network 100 includes a UE 102 and a base station 104 connected via one or more channels 106A, 106B over an air interface 108. The UE 102 and the base station 104 communicate using a system that supports control for managing access of the UE 102 to the network via the base station 104.

[0059] In some implementations, wireless network 100 may be a non-standalone (NSA) network incorporating Long Term Evolution (LTE) and Fifth Generation (5G) New Radio (NR) communication standards as defined by the 3rd Generation Partnership Project (3GPP) technical specifications. For example, wireless network 100 may be an Evolved Universal Terrestrial Radio Access (E-UTRA)-NR Dual Connectivity (EN-DC) network or an NR-EUTRA Dual Connectivity (NE-DC) network. However, wireless network 100 may also be a standalone (SA) network incorporating only 5G NR. Additionally, other types of communication standards are possible, including future 3GPP systems (e.g., sixth-generation (6G)) systems, Institute of Electrical and Electronics Engineers (IEEE) 802.11 technologies (e.g., IEEE 802.11a, IEEE 802.11b, IEEE 802.11g, IEEE 802.11-2007, IEEE 802.11n, IEEE 802.11-2012, IEEE 802.11ac, or other current or future-developed IEEE 802.11 technologies), IEEE 802.16 protocols (e.g., WMAN, WiMAX, etc.), etc. Although aspects may be described herein using terminology generally associated with 5G NR, aspects of the present disclosure may apply to other systems, such as systems subsequent to 3G, 4G, and / or 5G (e.g., 6G).

[0060] In wireless network 100, UE 102 and any other UEs in the system may be, for example, laptop computers, smartphones, tablet computers, machine-type devices such as smart meters or dedicated devices for healthcare, intelligent transportation systems, or any other wireless devices with or without a user interface. In network 100, base stations 104 provide UE 102 with network connectivity to a wider network (not shown). This UE 102 connectivity is provided over an air interface 108 within a base station service area provided by base station 104. In some implementations, such a wider network may be a wide area network operated by a cellular network provider or may be the Internet. Each base station service area associated with a base station 104 is supported by an antenna integrated with the base station 104. The service area is divided into multiple sectors associated with specific antennas. Such sectors may be physically associated with fixed antennas or may be assigned to a physical area using tunable antennas or antenna settings that can be adjusted in a beamforming process used to direct signals to specific sectors.

[0061] The UE 102 includes a control circuit 110 coupled to a transmit circuit 112 and a receive circuit 114. The transmit circuit 112 and the receive circuit 114 may each be coupled to one or more antennas. The control circuit 110 may include various combinations of application-specific and baseband circuitry. The transmit circuit 112 and the receive circuit 114 may be adapted to transmit and receive data, respectively, and may include radio frequency (RF) circuitry or front-end module (FEM) circuitry.

[0062] In various implementations, aspects of the transmit circuitry 112, the receive circuitry 114, and the control circuitry 110 may be integrated in various ways to implement the operations described herein. The control circuitry 110 may be adapted or configured to perform various operations, such as those described elsewhere in this disclosure related to a UE. For example, the control circuitry 110 may determine a transmission configuration indicator (TCI) state of a target cell, the TCI state specified in a medium access control (MAC) control element (CE) that identifies the target cell and a cell group of the target cell, the target cell being a candidate cell for switching in a high mobility scenario. The control circuitry may be configured to activate the TCI state of the target cell based on the determined TCI state indicator of the MAC CE.

[0063] The transmit circuitry 112 may perform various operations described herein. For example, the transmit circuitry 112 may transmit control switching commands. Furthermore, the transmit circuitry 112 may transmit multiple multiplexed uplink physical channels. The multiple uplink physical channels may be multiplexed by time division multiplexing (TDM) or frequency division multiplexing (FDM) with carrier aggregation. The transmit circuitry 112 may be configured to receive block data from the control circuitry 110 for transmission over the air interface 108.

[0064] The receive circuitry 114 may perform various operations described herein. For example, the receive circuitry 114 may receive a PDSCH or PDCCH transmission from a target cell based on an activated TCI state. Furthermore, the receive circuitry 114 may receive multiple multiplexed downlink physical channels from the air interface 108 and relay the physical channels to the control circuitry 110. The multiple downlink physical channels may be multiplexed using TDM or FDM with carrier aggregation. The transmit circuitry 112 and the receive circuitry 114 may transmit and receive both control data and content data (e.g., messages, images, videos, etc.) structured within data blocks carried by the physical channels.

[0065] 1 also shows a base station 104. In implementations, the base station 104 may be an NG Radio Access Network (RAN) or 5G RAN, an E-UTRAN, a non-terrestrial cell, or a legacy RAN such as UTRAN or GERAN. As used herein, terms such as "NG RAN" may refer to a base station 104 operating in an NR or 5G wireless network 100, and terms such as "E-UTRAN" may refer to a base station 104 operating in an LTE or 4G wireless network 100. The UE 102 utilizes connections (or channels) 106A, 106B, each of which includes a physical communication interface or layer.

[0066] The base station 104 circuitry may include control circuitry 116 coupled to transmit circuitry 118 and receive circuitry 120. The transmit circuitry 118 and receive circuitry 120 may each be coupled to one or more antennas that may be used to enable communication over the air interface 108. The transmit circuitry 118 and receive circuitry 120 may be adapted to transmit and receive data, respectively, to any UE connected to the base station 104. The transmit circuitry 118 may transmit a downlink physical channel that includes multiple downlink subframes. The receive circuitry 120 may receive multiple uplink physical channels from various UEs, including the UE 102.

[0067] In FIG. 1 , one or more channels 106A, 106B are depicted as air interfaces enabling communicative coupling and may conform to a cellular communication protocol such as a GSM protocol, a CDMA network protocol, a UMTS protocol, a 3GPP LTE protocol, an Advanced Long Term Evolution (LTE-A) protocol, an LTE-based access to unlicensed spectrum (LTE-U), a 5G protocol, an NR protocol, an NR-based access to unlicensed spectrum (NR-U) protocol, and / or any of the other communication protocols described herein. In implementations, the UE 102 may directly exchange communication data over the ProSe interface. The ProSe interface may alternatively be referred to as a sidelink (SL) interface and may include one or more logical channels, including, but not limited to, a physical sidelink control channel (PSCCH), a physical sidelink downlink discovery channel (PSDCH), and a physical sidelink broadcast channel (PSBCH).

[0068] 2 shows an example MAC CE 200 configured to control cell activation or cell deactivation for an LTM switching procedure. Specifically, the MAC CE is configured for TCI state indication of a target cell for an LTM procedure. The MAC CE 200 includes a cell group identifier field 202 (also referred to as CG ID) field. The MAC CE 200 includes a cell identifier field 204. The MAC CE 200 includes a bandwidth portion (BWP) identifier field 206. The MAC CE 200 is associated with multiple octaves 1 through N, each of which is associated with a state T0 through T1. ((N-2)×8+7) Includes TCI state values ​​such as

[0069] The MAC CE 200 is used with the LTM process to indicate the TCI state of candidate cells for L1 / L2 triggered mobility. For processes using MAC CE, the UE is configured with a list of TCI states in each DL BWP of each candidate cell. The UE may be configured during the preparation phase for the LTM process.

[0070] Once the UE is configured, there are different options for indicating the TCI state of the target cell. The first option includes LTM, which is supported based on the Rel-15 TCI framework. In the Rel-15 framework, the activation / deactivation of the TCI state is performed for each physical channel / signal using different MAC-CE formats. For example, two different MAC-CE formats are specified and used to independently activate the TCI states associated with the PDSCH and PDCCH channels. In this example, separate TCI states are configured and activated for PDCCH and PDSCH reception. The MAC CE 200 is introduced to activate or deactivate each of the TCI states for the PDSCH channels on the candidate cell group, which may be specified by the cell group identifier field 202.

[0071] For the LTM process of the PDSCH channel, an additional field is added to the MAC CE 200. The CG ID field 202 indicates the identity of the CG to which the MAC CE 200 is applicable. The Cell ID field 204 indicates the identity of a cell within a cell group. The CG ID field 202 and the Cell ID field 204 indicate the target cell for which the TCI status value is configured. For example, there may be several cell groups that do not include a serving cell, and each of these cell groups includes one or more cells. The CG ID field 202 points to the target cell group, and the Cell ID points to the target cell within the selected cell group.

[0072] The BWP ID field 206 indicates the DL BWP that the MAC CE 200 can apply to a selected target cell of a selected target cell group. In some implementations, the BWP ID field 206 is not included, and a default BWP is predefined for each of the candidate cells. For example, the first active BWP configured by radio resource control (RRC) may be designated as the one to be used for LTM operation.

[0073] Each of the TCI state fields in the octave has the value T i The TCI state value is marked by the TCI state ID T i is set to "1" to indicate that the TCI state corresponding to is activated and is mapped to a code point in the Downlink Control Information (DCI) TCI field. In general, the MAC CE 200 can have a variable size depending on the number of TCI states configured. The size of the MAC CE is determined by the number of octaves N. Note that the value of each TCI state is set to "1" or "0".

[0074] MAC CE 200 is one exemplary TCI state activation / deactivation MAC CE for LTM based on the Rel-15 framework. MAC CE 200 is configured to support up to two candidate CGs configured for LTM. Each CG may consist of up to 32 deactivated cells. To support more than two cell groups, the number of cells per candidate cell group may be reduced from 32 to 16. Accordingly, the cell group ID field 202 is increased from 1 bit to 2 bits. The cell ID field 204 is correspondingly reduced from 5 bits to 4 bits to accommodate the larger CG ID field 202. TCI state values ​​are pre-configured for each target cell. During inter-mobility operation, the target cell ID is used to select a valid set of TCI state values.

[0075] FIG. 3A shows an example MAC CE 300 for TCI states for a PDCCH for a deactivated target cell. The MAC CE is configured for use within the RE1-15 TCI framework. The MAC CE 300 includes a cell group identifier field 302, a cell identifier field 304, and a CORESET identifier field 306. The CG ID field 302 indicates the identity of the CG to which the MAC CE 300 is applicable. The CG identifier field 302 may be one bit as shown, or may be extended to multiple bits as described with respect to FIG. 2 for the MAC CE 200. The cell ID field 304 indicates the identity of a cell in the cell group identified in the CG ID field 302. The CG ID field 302 and the cell ID field 304 indicate the target cell for which the TCI state value is configured. For example, there may be several cell groups that do not include a serving cell, and each of these cell groups includes one or more cells. The CG ID field 302 points to the target cell group, and the cell ID points to the target cell within the selected cell group.

[0076] The CORESET identifier field 306 indicates the CORESET ID in the default BWP (e.g., the first active BWP) of the indicated cell. The CORESET ID can be a virtual ID. The virtual ID is defined by indexing the CORESET within the BWP of the indicated candidate cell. The CORESET ID consists of two bits, as shown in Figure 3A. Field R 308 is a "reserved" bit field and is not used in this release. The TCI state ID field 310 indicates the TCI state ID configured by RRC signaling for the target cell.

[0077] 3B shows an example MAC CE 320 for TCI states for PUCCH or PUSCH for a deactivated target cell. The MAC CE 320 is configured for use within the RE1-15 TCI framework. The MAC CE 320 includes a cell group identifier field 302, a cell identifier field 322, and a spatial relationship information identifier field 334. The MAC CE 350 explicitly indicates SRI data and is used in addition to the MAC CEs 200, 300.

[0078] The CG ID field 322 indicates the identity of the CG to which the MAC CE 320 is applicable. The CG identifier field 322 may be one bit as shown, or may be extended to multiple bits as described with respect to FIG. 2 for the MAC CE 200. The cell ID field 324 indicates the identity of a cell in the cell group identified in the CG ID field 322. The CG ID field 324 and the cell ID field 322 indicate the target cell for which the TCI status value is configured. For example, there may be several cell groups that do not include a serving cell, and each of these cell groups includes one or more cells. The CG ID field 322 points to the target cell group, and the cell ID points to the target cell within the selected cell group.

[0079] The spatial relationship information identifier (SRI) field 334 indicates the SRI identification information for the PUCCH / PUSCH on the target cell. The indicated SRI ID applies commonly to both PUCCH and PUSCH transmissions on a default BWP (e.g., the first uplink BWP). If the MAC CE 320 is not selected for use (e.g., MAC CE 200 or 300 is selected), the spatial configuration for PUCCH / PUSCH transmission from the UE is set to the same as the spatial configuration for PDCCH reception by the UE in the lowest CORESET of the first active BWP during LTM operation. This occurs until the UE receives PUCCH spatial relationship information (SRI) provided by the network after the LTM procedure. In these scenarios, UL / DL beam reciprocity is assumed, such that the UL beam used for transmission is assumed to be the same as the DL beam selected by the UE. In this case, the UL SRI does not need to be indicated.

[0080] FIG. 4 shows an exemplary MAC CE 400 for an LTM switching procedure for activation or deactivation of a target cell. For Rel-17, a unified TCI framework is used. For one direction (e.g., DL TCI state), a single TCI state applies to all DL channels, such as PDSCH and PDCCH. This is to simplify TCI indication. The following fields may be provided in an extended activation / deactivation MAC CE 400 for a target cell: CG ID field 402 indicates the identity of the cell group to which MAC CE 400 applies. CG identifier field 402 may be one bit as shown, or may be extended to multiple bits as described with respect to FIG. 2 for MAC CE 200. Cell ID field 404 indicates a cell ID within the cell group. DL BWP identifier field 406 or UL BWP identifier field 410 indicates the DL BWP or UL BWP ID to which MAC CE 400 applies. i Field 408 indicates whether each TCI codepoint has multiple TCI states or a single TCI state.i The field is 1 bit. The D / U field 412 a-n indicates whether the TCI state ID in the same octet is for a joint / downlink TCI state or an uplink TCI state. The TCI state ID field 414 a-n indicates the Nth bit of the TCI field. th indicates the TCI state ID associated with the codepoint. The MAC CE 400 may be variable size depending on the number of D / U fields 412n and the number of TCI state ID fields 414n, similar to the MAC CE 200. In some implementations, the number N of activated TCI states for deactivated candidate cells in the LTM may be reported as part of the UE capability signaling.

[0081] FIG. 5 shows example fields 502, 504, 506, 508, 510, 512, and 514 for a cell switch command (CSC) 500. Various information can be transmitted in the cell switch command (CSC) 500. The CSC command can include a new MAC CE or DCI format. In the following example, a MAC CE is described, but this can alternatively use a DCI format. The CG identifier field 502 indicates the identity of the cell group for which the LTM procedure is triggered and applied. The target SpCell identifier field 504 indicates the target SpCell ID in the cell group indicated in field 502. In some implementations, one SpCell is pre-configured for each cell group during the LTM preparation phase and before triggering the LTM operation. The target cell identifier field can be omitted from the CSC command 500. The RRC-configured SpCell in the target cell group becomes the SpCell once the LTM operation is complete.

[0082] The CSC command 500 includes an SCell activation / deactivation bitmap field 506. The bitmap field 506 indicates the activation or deactivation of cells in the indicated cell group 502. The BWP identifier field 508 is configured according to one of the following options: In a first option, the BWO ID field 508 indicates the identity of the BWP to be applied to the indicated target SpCell ID in field 504 for LTM operation. In a second option, the field 508 indicates multiple BWP IDs to be included, each BWP ID being associated with one activated cell. In a third option, the first active DL BWP and the first active UL BWP are configured by RRC signaling during the preparation phase to be applied for LTM operation. In this example, the BWP ID field 508 is omitted from the CSC command 500. In a fourth option, RRC signaling is introduced to indicate the presence of the BWP ID in the CSC command 500, which provides network flexibility between signaling overhead and LTM operation flexibility.

[0083] The CSC command 500 includes a beam indication (BI) field 510. For the beam indication field 510, there are several different options available regarding the number of BI fields. In the first option, one BI field applies to an SpCell in a candidate cell group. In the second option, multiple BI fields are applied, each BI applying to a cell in the cell group specified by field 502.

[0084] In general, various approaches can be considered to indicate beam information for a target cell to be applied after LTM operation. In a first option, one TCI field can be included in the CSC command 500 signal to indicate one TCI state from multiple TCI states activated by MAC-CE or one SRI value, as described above. In a second option, a reference signal (RS) can be indicated. The RS is in a set of reference signals used for L1 measurement reporting (including SSB or CSI-RS) as part of the LTM operation. The RS is used as a QCL source for both DL reception and UL transmission. In a third option, a contention-free random access (CFRA) configuration index is included in the CSC command 500 signal. The CSC command 500 includes an SSB index. The indicated SSB is used as a QCL source RS for both DL reception and UL transmission.

[0085] The CSC includes a Timing Advance (TA) indication field 512. There are several options for the timing advance indication. In the first option, the TA value or TAG index is directly included in the CSC command 500, as shown in FIG. 5. In the second option, a CFRA-based procedure is used to obtain the TA value during the LTM procedure. The CFRA-based procedure includes the following steps: First, during the LTM preparation phase, the UE is provided with a set of CFRA configurations by RRC signaling on the SpCell in each CG as part of the CG configuration. Second, the CFRA configuration index on the SpCell of the indicated cell group is included in the CSC command or a separate MAC-CE to trigger the CFRA procedure and obtain the TA value. In some implementations, the CFRA can be a PRACH transmission triggered on a deactivated SCell or a deactivated non-serving cell for TA acquisition purposes.

[0086] In a third option, the TA value is derived based on the TCI state or CG ID indicated by the CSC command. In some implementations, each UL TCI state or SRI is associated with a TAG by RRC signaling. The UE may then derive the TA value based on the UL TCI state indicated by the BI field. In some implementations, a TAG is assigned for each candidate cell group. Based on the indicated cell group ID, the UE derives the corresponding TA value.

[0087] In a fourth option, the presence of the TA field 512 in the CSC command 500 is configured by RRC signaling. If not present, the RRC signaling indicates one of a set of predefined candidate values, including a value of TA=0 or a value that is the same TA value as the current intra-frequency serving cell.

[0088] In a fifth option, based on the UE capabilities, the network allows UE-based TA calculation for the target CG based on the receive (Rx) timing difference between the serving cell and the target cell. Correspondingly, an indicator is included in the CSC command 500 signaling to indicate whether to use UE-derived TA for the LTM procedure. The maximum number of TAGs per frequency layer is reported as part of the UE capabilities report.

[0089] In some implementations, the CSC command 500 includes a tracking reference signal (TRS) field 514. The TRS field is used to configure aperiodic TRS triggering for the LTM procedure. In this example, to enable fast T / F improvement after LTM operation, one or more sets of aperiodic tracking RSs (TRSs) are configured for candidate cells in a cell group and are triggered by the CSC command 500 signal to assist with automatic gain control (AGC) settings and time / frequency synchronization. This process includes two steps. In the first step, the UE is provided with one or more TRS resource set bursts for each cell, or only for SpCells in the candidate cell group. Generally, each TRS resource set includes N TRS bursts, where N is configured by RRC signaling. The gap between bursts of the TRS resource set is configured in a separate RRC parameter in units of slots. In some implementations, a default value is predetermined and used when the gap field is not present. The QCL source is explicitly configured with reference to the SSB or periodic CSI-RS configured in the target cell. Each TRS resource set burst configuration is identified by a TRS-ID.

[0090] In a second step, one TRS request field 514 is included in the CSC command 500 signal. The TRS request field 514 triggers aperiodic TRS burst transmission for the target cell in the cell group. If the TRS-ID field in the CSC command 500 signal is set to a non-zero value, the corresponding TRS addressed by the TRS-ID is triggered. The triggering offset between the slot of the CSC command 500 signal and the slot in which the TRS resource set is transmitted is configured by the RRC based on the UE capability report. To minimize signaling overhead, the TRS triggered by the CSC signal is restricted to be within the first active BWP of the cell SCell to be activated in the target cell group. In some implementations, the application time for the CSC signal application is defined relative to the HARQ-ACK feedback of the CSC signal. In some implementations, different TRS values ​​are defined for different subcarrier spacing (SCS) values. For example, two slots may be defined for a 15 kilohertz (kHz) SCS. On the other hand, due to the smaller slot duration compared to the 15 kHz SCS, a larger value, for example four slots, may be defined for the 30 kHz SCS.

[0091] 6 illustrates a flowchart of an example method 600 according to some implementations. For clarity of presentation, the following description generally describes method V100 in the context of other figures in this description. For example, method 600 may be performed by UE 100 of FIG. 1. It will be understood that method 600 may be performed, for example, by any suitable system, environment, software, hardware, or combination of system, environment, software, and hardware, as appropriate. In some implementations, various steps of method 600 may be performed in parallel, in combination, in a loop, or in any order.

[0092] The method 600 includes receiving 602 a medium access control (MAC) control element (CE) specifying a transmission configuration indicator (TCI) state of a target cell, where the MAC CE further identifies the target cell and a cell group (CG) of the target cell, where the target cell is a candidate cell for switching in an L1 / L2 triggered mobility (LTM) scenario. The method 600 includes activating 604 a configured TCI state for the target cell in the target CG based on the designated TCI state of the MAC CE. The method 600 includes receiving 606 a PDSCH or PDCCH transmission from the target cell of the target CG based on the activated TCI state. In some implementations, the MAC CE includes a bitmap that specifies, for each bit of the bitmap, activation of a TCI state with a TCI state identifier value corresponding to an index of the bitmap, and the activation includes mapping the activated TCI state with the TCI state identifier value to a codepoint of a TCI field in downlink control information (DCI). In some implementations, the MAC CE includes a bandwidth portion identifier that indicates the downlink bandwidth portion of the target cell to which the MAC CE is applicable. In some implementations, the MAC CE is used to support activating one or more TCI states for the target cell when at least two candidate cell groups are configured for an LTM scenario, each candidate cell group comprising up to 32 deactivated candidate target cells. In some implementations, the MAC CE is used to support activating one or more TCI states for the target cell when at least four candidate cell groups are configured for an LTM procedure, each candidate cell group comprising up to 16 deactivated candidate target cells.

[0093] In some implementations, the MAC CE comprises a CORESET ID field that indicates a CORESET identifier value for the default BWP for the target cell. In some implementations, the MAC CE comprises a TCI State ID field, where the TCI State ID is configured by Radio Resource Control (RRC) signaling for the target cell. In some implementations, the TCI State ID field is 7 bits.

[0094] In some implementations, the spatial configuration for PUCCH / PUSCH transmission from the UE matches the spatial configuration for PDCCH reception at the UE in the lowest CORESET of the first active BWP during L1 / L2 triggered mobility (LTM) operation. In some implementations, the MAC CE comprises a Spatial Relationship Information (SRI) field that specifies spatial relationship information regarding PUCCH resources for transmission by the UE. In some implementations, the MAC CE comprises a BWP ID field that indicates the BWP to which the MAC-CE applies, and a TCI State Identifier field that indicates the TCI state associated with a given codepoint in the TCI field and applied for the indicated BWP, the TCI Identifier field being associated with a DL or UL field that indicates whether the TCI state is associated with a downlink TCI state or an uplink TCI state. In some implementations, the MAC CE comprises a P field that indicates whether a given codepoint is associated with a single TCI state or multiple TCI states.

[0095] In some implementations, the process 600 includes triggering a cell switch based on a cell switch command (CSC), where the cell switch command comprises a cell group identifier field indicating a cell group and a target SpCell identifier field indicating a target SpCell in the cell group. In some implementations, the CSC further comprises a bitmap field indicating activation or deactivation of each cell in the cell group and a BWP ID field indicating identification of at least one bandwidth portion to be applied to the target SpCell indicated for LTM operation. In some implementations, a first active downlink BWP and a first active uplink BWP configured by RRC signaling during a preparation phase for LTM operation are used for communication with the target cell during and after the LTM operation.

[0096] In some implementations, the CSC further comprises a beam information field that applies to SpCells in the identified cell group. In some implementations, the beam information field indicates a TCI state from one or more activated TCI states associated with the target cell. In some implementations, the beam information field indicates an RS index from one or more reference signals (RSs) used for target cell measurements and reporting.

[0097] In some implementations, the CSC further comprises a timing advance field including a timing advance (TA) value or a time advance group (TAG) value. In some implementations, process 600 includes providing a set of contention-free random access (CFRA) configurations to the UE via RRC signaling on an SpCell in each cell group as part of a cell group configuration. Process 600 includes providing a CFRA configuration index for the SpCell of the cell group to the UE in the CSC. Process 600 includes triggering a CFRA procedure based on the CFRA configuration associated with the indicated CFRA configuration index to obtain the timing advance value during LTM operation.

[0098] 7 illustrates a flowchart of an example method 700 according to some implementations. For clarity of presentation, the following description generally describes method 700 in the context of other figures in this description. For example, method 700 may be performed by UE 100 of FIG. 1. It will be understood that method 700 may be performed, for example, by any suitable system, environment, software, hardware, or combination of system, environment, software, and hardware, as appropriate. In some implementations, various steps of method 700 may be performed in parallel, in combination, in a loop, or in any order.

[0099] The method 700 includes providing a set of contention-free random access (CFRA) configurations to a UE via RRC signaling on an SpCell in each cell group as part of cell group configuration (702). The method 700 also includes providing, by the UE in a CSC, a CFRA configuration index for the SpCell of the cell group (704), where the CFRA configuration index is configured to trigger a CFRA procedure to obtain a timing advance value. In some implementations, the TRS request field includes a non-zero value indicating a TRS ID that specifies a triggered TRS resource burst transmission. In some implementations, the gap between bursts of the TRS resource set is configured by a separate radio resource control parameter in units of slots. In some implementations, the triggering offset between the slot of the CSC signal and the slot in which the TRS resource set burst is transmitted is configured by the RRC based on a UE capability report.

[0100] 8 illustrates a UE 800 according to some implementations. The UE 800 may be similar to and substantially interchangeable with the UE 102 of FIG.

[0101] The UE 800 may be any mobile or non-mobile computing device, such as a mobile phone, a computer, a tablet, an industrial wireless sensor (e.g., a microphone, a pressure sensor, a thermometer, a motion sensor, an accelerometer, an inventory sensor, a voltage / current meter, etc.), a video device (e.g., a camera, a video camera, etc.), a wearable device (e.g., a smart watch), a relaxed-IoT device, etc.

[0102] The UE 800 may include a processor 802, an RF interface circuit 804, a memory / storage 806, a user interface 808, a sensor 810, a driver circuit 812, a power management integrated circuit (PMIC) 814, an antenna structure 816, and a battery 818. The components of the UE 800 may be implemented as an integrated circuit (IC), portions thereof, discrete electronic devices or other modules, logic, hardware, software, firmware, or a combination thereof. The block diagram of FIG. 8 is intended to provide a schematic view of some of the components of the UE 800. However, some of the components shown may be omitted, additional components may be present, and different arrangements of the components shown may occur in other embodiments.

[0103] The components of the UE 800 may be coupled to various other components via one or more interconnects 820, which may represent any type of interface, input / output, bus (local, system, or expansion), transmission line, trace, optical connection, etc. that may allow various circuit components (on a common or different chips or chipsets) to interact with one another.

[0104] The processor 802 may include processor circuitry such as, for example, a baseband processor circuit (BB) 822A, a central processor unit (CPU) 822B, and a graphics processor unit (GPU) 822C. The processor 802 may 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 806 to cause the UE 800 to perform the operations described herein.

[0105] In some implementations, the baseband processor circuit 822A may access a communications protocol stack 824 in the memory / storage 806 to communicate over a 3GPP-compliant network. Generally, the baseband processor circuit 822A may access the communications protocol stack to perform control plane functions at the physical (PHY) layer, medium access control (MAC) layer, radio link control (RLC) layer, packet data convergence protocol (PDCP) layer, service data adaptation protocol (SDAP) layer, and PDU layer, and user plane functions at the PHY layer, MAC layer, RLC layer, PDCP layer, RRC layer, and non-access layer. In some implementations, PHY layer operations may additionally / alternatively be performed by components of the RF interface circuit 804. The baseband processor circuit 822A may generate or process baseband signals or waveforms that carry information within a 3GPP-compliant network. In some implementations, waveforms for NR may be based on cyclic prefix orthogonal frequency division multiplexing (OFDM) "CP-OFDM" in the uplink or downlink and discrete Fourier transform spread OFDM "DFT-S-OFDM" in the uplink.

[0106] The memory / storage 806 may include one or more non-transitory computer-readable media (e.g., communication protocol stack 824) that include instructions that may be executed by one or more of the processors 802 to cause the UE 800 to perform various operations described herein. The memory / storage 806 includes any type of volatile or non-volatile memory that may be distributed throughout the UE 800. In some implementations, some of the memory / storage 806 may be located within the processor 802 itself (e.g., L1 and L2 caches), while other memory / storage 806 is external to the processor 802 but accessible via a memory interface. Memory / storage 806 may include any suitable volatile or non-volatile memory, such as, but not limited to, 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.

[0107] The RF interface circuitry 804 may include transceiver circuitry and a radio frequency front module (RFEM) that enable the UE 800 to communicate with other devices over a radio access network. The RF interface circuitry 804 may include various elements disposed in the transmit or receive paths. These elements may include, for example, switches, mixers, amplifiers, filters, combiner circuits, control circuits, etc.

[0108] In the receive path, the RFEM may receive a radiated signal from the air interface via the antenna structure 816 and proceed to filter and amplify the signal (using a low noise amplifier). The signal may be provided to a receiver in the transceiver, which downconverts the RF signal to a baseband signal, which is provided to a baseband processor in the processor 802.

[0109] In the transmit path, the transmitter of the transceiver upconverts baseband signals received from the baseband processor and provides an RF signal to the RFEM, which may amplify the RF signal through a power amplifier before the signal is radiated over the air interface via the antenna 816. In various implementations, the RF interface circuitry 804 may be configured to transmit and receive signals in a manner that is compliant with NR access technologies.

[0110] The antenna 816 may include antenna elements that convert electrical signals into radio waves that travel through the air and convert received radio waves into electrical signals. The antenna elements may be arranged in one or more antenna panels. The antenna 816 may have antenna panels that are omnidirectional, directional, or a combination thereof to enable beamforming and multiple-input, multiple-output communications. The antenna 816 may include microstrip antennas, printed antennas fabricated on the surface of one or more printed circuit boards, patch antennas, phased array antennas, etc. The antenna 816 may have one or more panels designed for a specific frequency band, including bands in FR1 or FR2.

[0111] The user interface 808 includes various input / output (I / O) devices designed to enable user interaction with the UE 800. The user interface 808 includes input device circuitry and output device circuitry. The input device circuitry includes any physical or virtual means for accepting input, including, among other things, one or more physical or virtual buttons (e.g., a reset button), a physical keyboard, a keypad, a mouse, a touchpad, a touchscreen, a microphone, a scanner, a headset, etc. The output device circuitry includes any physical or virtual means for displaying or otherwise communicating information, such as sensor readings, actuator position(s), or other similar information. The output device circuitry may include, among other things, any number or combination of audio or visual displays, including one or more simple visual outputs / indicators (e.g., binary status indicators such as light-emitting diodes "LEDs" and multi-character visual outputs), or more complex outputs such as display devices or touchscreens (e.g., liquid crystal displays "LCDs," LED displays, quantum dot displays, projectors, etc.), where output, such as text, graphics, multimedia objects, etc., is generated or created from the operation of the UE 800.

[0112] The sensors 810 may include devices, modules, or subsystems designed to detect events or changes in their environment and transmit information about the detected events (sensor data) to some other device, module, subsystem, etc. Examples of such sensors include, among others, inertial measurement units including accelerometers, gyroscopes, or magnetometers, microelectromechanical or nanoelectromechanical systems including 3-axis accelerometers, 3-axis gyroscopes, or magnetometers, level sensors, temperature sensors (e.g., thermistors), pressure sensors, image capture devices (e.g., cameras or lensless apertures), light detection and ranging sensors; proximity sensors (e.g., infrared detectors, etc.); depth sensors; ambient light sensors; ultrasonic transceivers; microphones or other similar audio capture devices; and the like.

[0113] The driver circuit 812 may include software and hardware elements that operate to control particular devices embedded in, attached to, or otherwise communicatively coupled to the UE 800. The driver circuit 812 may include individual drivers that enable other components to interact with or control various input / output (I / O) devices that may be present in or connected to the UE 800. For example, the driver circuit 812 may include a display driver that controls and enables access to a display device, a touchscreen driver that controls and enables access to a touchscreen interface, a sensor driver that obtains sensor readings of the sensor circuit 810 and controls and enables access to the sensor circuit 810, a driver that obtains actuator positions of or controls and enables access to electromechanical components, a camera driver that controls and enables access to an embedded image capture device, and an audio driver that controls and enables access to one or more audio devices.

[0114] The PMIC 814 may manage the power supplied to various components of the UE 800. In particular, with respect to the processor 802, the PMIC 814 may control power source selection, voltage scaling, battery charging, or DC-DC conversion.

[0115] In some implementations, the PMIC 814 may control or otherwise be a part of various power saving mechanisms of the UE 800. The battery 818 may power the UE 800, although in some examples, the UE 800 may be mounted and deployed at a fixed location and may have a power source coupled to a power grid. The battery 818 may be a lithium-ion battery, a metal-air battery such as a zinc-air battery, an aluminum-air battery, a lithium-air battery, or the like. In some implementations, such as in vehicle-based applications, the battery 818 may be a typical automotive lead-acid battery.

[0116] 9 illustrates an access node 900 (e.g., a base station or a gNB) according to some implementations. The access node 900 may be similar to, and substantially interchangeable with, the base station 104. The access node 900 may include a processor 902, RF interface circuitry 904, a core network (CN) interface circuitry 906, memory / storage circuitry 908, and an antenna structure 910.

[0117] The components of the access node 900 may be coupled to various other components via one or more interconnects 912. The processor 902, RF interface circuitry 904, memory / storage circuitry 908 (including communication protocol stack 914), antenna structure 910, and interconnects 912 may be similar to the like-named elements shown and described with respect to Figure 8. For example, the processor 902 may include processor circuits such as a baseband processor circuit (BB) 916A, a central processing unit circuit (CPU) 916B, and a graphics processing unit circuit (GPU) 916C.

[0118] The CN interface circuitry 906 may provide connectivity to a core network, e.g., a 5th Generation Core network (5GC), using a 5GC-compliant network interface protocol, such as a Carrier Ethernet protocol or some other suitable protocol. Network connectivity may be provided to / from the access node 900 via optical fiber or wireless backhaul. The CN interface circuitry 906 may include one or more dedicated processors or FPGAs for communicating using one or more of the aforementioned protocols. In some implementations, the CN interface circuitry 906 may include multiple controllers to provide connectivity to other networks using the same or different protocols.

[0119] As used herein, terms such as “access node,” “access point,” and the like may describe equipment that provides wireless baseband functionality for data and / or voice connectivity between a network and one or more users. These access nodes may be referred to as BSs, gNBs, RAN nodes, eNBs, NodeBs, RSUs, TRxPs, TRPs, and the like, and may include terrestrial stations (e.g., terrestrial access points) or satellite stations that provide coverage within a geographic area (e.g., a cell). As used herein, terms such as “NG RAN node” may refer to an access node 900 operating in an NR or 5G system (e.g., gNB), and terms such as “E-UTRAN node” may refer to an access node 900 operating in an LTE or 4G system (e.g., eNB). According to various implementations, access node 900 may be implemented as one or more of dedicated physical devices, such as a macrocell base station, and / or a low power (LP) base station for providing a femtocell, picocell, or other similar cell having a smaller coverage area, lower user capacity, or higher bandwidth compared to a macrocell.

[0120] In some implementations, all or a portion of the access node 900 may be implemented as one or more software entities running on a server computer as part of a virtual network, which may be referred to as a CRAN and / or a virtual baseband unit pool (vBBUP). In a V2X scenario, the access node 900 may be or operate as a “roadside unit.” The term “roadside unit” or “RSU” may refer to any transportation infrastructure entity used for V2X communications. The RSU may be implemented in or by an appropriate RAN node or a stationary (or relatively stationary) UE; an RSU implemented in or by a UE may be referred to as a “UE-type RSU,” an RSU implemented in or by an eNB may be referred to as an “eNB-type RSU,” an RSU implemented in or by a gNB may be referred to as a “gNB-type RSU,” etc.

[0121] In the description herein, for convenience, various components may be described as performing a task or tasks. Such descriptions should be construed to include the phrase "configured to." It is expressly intended that a description of a component being configured to perform one or more tasks does not invoke 35 U.S.C. 112(f) interpretation with respect to that component.

[0122] For one or more embodiments, at least one of the components depicted in one or more of the foregoing figures may be configured to perform one or more operations, techniques, processes, or methods as described in the example section below. For example, the baseband circuitry described above in connection with one or more of the foregoing figures may be configured to operate according to one or more of the examples described below. As another example, circuitry associated with a UE, a base station, a network element, etc., as described above in connection with one or more of the foregoing figures, may be configured to operate according to one or more of the examples described below in the example section.

[0123] Any of the above examples may be combined with any other example (or combination of examples) unless otherwise stated. The foregoing description of one or more implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of various embodiments.

[0124] Although the above embodiments have been described in considerable detail, numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated, and it is intended that the following claims be interpreted to embrace all such variations and modifications.

[0125] It is understood that use of personally identifiable information should comply with generally recognized privacy policies and practices that meet or exceed industry or government requirements for maintaining user privacy. In particular, personally identifiable information data should be managed and handled in a manner that minimizes the risk of unintended or unauthorized access or use, and the nature of permitted uses should be clearly indicated to users.

Claims

1. receiving a Medium Access Control (MAC) Control Element (CE) specifying a Transmission Configuration Indicator (TCI) state for a target cell, the MAC CE further identifying the target cell and a Cell Group (CG) of the target cell, the target cell being a candidate cell for switching in an L1 / L2 Triggered Mobility (LTM) scenario; activating a configured TCI state for the target cell in the target CG based on the specified TCI state of the MAC-CE; receiving a PDSCH or PDCCH transmission from the target cell of the target CG based on the activated TCI state; A method comprising:

2. 2. The method of claim 1, wherein the MAC CE includes a bitmap that, for each bit of the bitmap, specifies activation of the TCI state with a TCI state identifier value that corresponds to the index of that bit in the bitmap, and the activation includes mapping the activated TCI state using the TCI state identifier value to a codepoint of a TCI field in downlink control information (DCI).

3. The method of claim 1 , wherein the MAC CE comprises a bandwidth portion identifier indicating a downlink bandwidth portion of the target cell to which the MAC CE is applicable.

4. 2. The method of claim 1, wherein the MAC CE is used to support activating one or more TCI states for a target cell when at least two candidate cell groups are configured for an LTM scenario, and each candidate cell group comprises up to 32 deactivated candidate target cells.

5. 2. The method of claim 1, wherein the MAC CE is used to support activating one or more TCI states for a target cell when at least four candidate cell groups are configured for an LTM procedure, each candidate cell group comprising up to 16 deactivated candidate target cells.

6. The method of claim 1 , wherein the MAC CE includes a CORESET ID field indicating a CORESET identifier value for a default BWP for the target cell.

7. 7. The method of claim 6, wherein the MAC CE includes a TCI State ID field, and the TCI State ID is configured by Radio Resource Control (RRC) signaling to the target cell.

8. 8. The method of claim 7, wherein the TCI State ID field is 7 bits.

9. 2. The method of claim 1, wherein during L1 / L2 triggered mobility (LTM) operation, a spatial configuration for PUCCH / PUSCH transmission from a UE matches a spatial configuration for PDCCH reception at the UE in the lowest CORESET of a first active BWP.

10. 2. The method of claim 1, wherein the MAC CE comprises a spatial relationship information (SRI) field that specifies spatial relationship information about PUCCH resources for transmission by a UE.

11. The MAC CE is A BWP ID field indicating the BWP to which the MAC-CE is applied; 2. The method of claim 1, comprising: a TCI state identifier field associated with a given codepoint of a TCI field and indicating a TCI state that applies to the indicated BWP, the TCI identifier field being associated with a DL field or a UL field that indicates whether the TCI state is associated with a downlink TCI state or an uplink TCI state.

12. 12. The method of claim 11, wherein the MAC CE comprises a P field that indicates whether the given codepoint is associated with a single TCI state or multiple TCI states.

13. triggering a cell switch based on a Cell Switch Command (CSC), the Cell Switch Command comprising a Cell Group Identifier field indicating a cell group and a Target SpCell Identifier field indicating the target SpCell within the cell group; The method of claim 1 further comprising:

14. The CSC a bitmap field indicating the activation or deactivation of each cell in the cell group; The method of claim 13 , further comprising: a BWP ID field indicating an identity of at least one bandwidth portion to be applied to the target SpCell designated for LTM operation.

15. 14. The method of claim 13, wherein a first active downlink BWP and a first active uplink BWP configured by RRC signaling during a preparation phase for LTM operation are used for communication with the target cell during and after LTM operation.

16. The method of claim 13 , wherein the CSC further comprises a beam information field that applies to the SpCells in the identified cell group.

17. The method of claim 16 , wherein the beam information field indicates a TCI state from one or more activated TCI states associated with the target cell.

18. 17. The method of claim 16, wherein the beam information field indicates a reference signal (RS) index from one or more RSs used for target cell measurement and reporting.

19. 14. The method of claim 13, wherein the CSC further comprises a timing advance field containing a timing advance (TA) value or a time advance group (TAG) value.

20. providing a set of contention-free random access (CFRA) configurations to the UE by RRC signaling on the SpCell in each cell group as part of the cell group configuration; providing a CFRA configuration index for an SpCell of the cell group to the UE via a CSC; triggering a CFRA procedure based on the CFRA configuration associated with the indicated CFRA configuration index to obtain a timing advance value during the LTM operation; The method of claim 1 further comprising:

21. providing the UE with one or more tracking reference signal (TRS) resource set bursts for only cells or SpCells in the candidate cell group; triggering aperiodic TRS burst transmission based on a TRS request field in a cell switch command (CSC) signal; A method comprising:

22. 20. The method of claim 19, wherein the TRS request field includes a non-zero value indicating a TRS ID that specifies the TRS resource burst transmission to be triggered.

23. 20. The method of claim 19, wherein the gaps between bursts of the TRS resource set are configured by separate radio resource control parameters in units of slots.

24. 20. The method of claim 19, wherein a triggering offset between the slot of the CSC signal and the slot in which the TRS resource set burst is transmitted is configured by RRC based on a UE capability report.

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