Method and apparatus for sidelink operation

Abstract

User equipment (UE) includes one or more non-transitory computer-readable media containing computer-executable instructions and at least one processor coupled to the one or more non-transitory computer-readable media, the at least one processor being configured to receive an indicator indicating that frequency shifting is performed on one or more carrier frequencies when Long Term Evolution (LTE) Vehicle-to-Everything (V2X) sidelink (SL) communication is shared with New Radio (NR) SL communication on one or more carrier frequencies; and when frequency shifting is performed when one or more NR SL packet carrier frequencies are transmitted on the first SL frequency carrier, if the indicator is associated with a first SL frequency carrier selected by the UE for NR SL packet transmission.

Description

[0001] Cross-references to related applications

[0002] This disclosure claims the benefit and priority of U.S. Provisional Patent Application Serial No. 62 / 910564 (hereinafter referred to as "'564 Provisional Case"), filed on October 4, 2019, entitled "Sidelink Configuration on Multiple Carriers". The disclosure of '564 Provisional Case is hereby incorporated herein by reference in its entirety. Technical Field

[0003] This disclosure relates to wireless communication, and more specifically, to methods and apparatus for side-link (SL) operation in wireless communication networks. Background Technology

[0004] With the massive growth in the number of connected devices and the rapid increase in user / network traffic, various efforts have been made to improve different aspects of wireless communication in cellular wireless communication systems, such as fifth-generation (5G) new radio (NR), by increasing data rates, latency, reliability and mobility.

[0005] 5G NR systems are designed to provide flexibility and configurability to optimize network services and types to adapt to various use cases, such as vehicle-to-vehicle (V2V), vehicle-to-person (V2P), and vehicle-to-everything (V2X) communications.

[0006] However, as the demand for radio access continues to increase, there is a need for further improvements in this field. Summary of the Invention

[0007] This disclosure relates to methods and apparatus for SL operations.

[0008] According to a first aspect of this disclosure, user equipment (UE) includes one or more non-transitory computer-readable media containing computer-executable instructions and at least one processor coupled to the one or more non-transitory computer-readable media. The at least one processor is configured to execute the computer-executable instructions to receive an indicator indicating frequency shifting on one or more carrier frequencies when Long-Term Evolution (LTE) Vehicle to Everything (V2X) sidelink (SL) communication is shared with New Radio (NR) SL communication on one or more carrier frequencies; and when the indicator is associated with a first SL frequency carrier selected by the UE for NR SL packet transmission, frequency shifting is performed when one or more NR SL packet carrier frequencies are transmitted on the first SL frequency carrier.

[0009] In an implementation of the first aspect, the indicator is received in one of the following ways: SL pre-configuration; SL configuration from the serving cell via the Uu interface; and SL configuration from another UE via the PC5 air interface through Radio Resource Control (RRC) signaling.

[0010] In an embodiment of the first aspect, the at least one processor is further configured to execute the computer-executable instructions to: when receiving one or more NR SL packets on the second SL frequency carrier, if the second SL frequency carrier selected by the UE is used for NR SL packet transmission associated with the indicator, implement frequency shift.

[0011] In another embodiment of the first aspect, the at least one processor is further configured to execute the computer-executable instructions to: when the indicator is associated with the selected first SL frequency carrier, and when transmitting a synchronization-reference (Sync-Ref) UE synchronized with the Radio Access Network (RAN) as an NR SL synchronization reference on the selected carrier frequency, perform frequency shifting on the selected carrier frequency.

[0012] In another embodiment of the first aspect, the RAN is an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) or a New Radio-RAN (NR-RAN).

[0013] In another embodiment of the first aspect, the at least one processor is further configured to execute the computer-executable instructions to: when the UE is configured to implement Global Navigation Satellite System (GNSS) synchronization priority rules on the selected carrier frequency and is configured to consider a synchronization-reference (Sync-Ref) UE directly synchronized with the Radio Access Network (RAN) as a candidate for synchronization reference for the NR SL communication, in the case of the one or more carrier frequencies selected in association with the indicator, perform frequency shifting on the selected carrier frequency.

[0014] In another embodiment of the first aspect, the at least one processor is further configured to execute the computer-executable instructions to: when the UE is configured to implement Global Navigation Satellite System (GNSS) synchronization priority rules on the selected carrier frequency and is configured to use a synchronization reference Sync-Ref UE indirectly synchronized with the Radio Access Network (RAN) as a candidate synchronization reference for the NR SL communication, in the case of the one or more carrier frequencies associated with the indicator, perform frequency shifting on the selected carrier frequency.

[0015] In another embodiment of the first aspect, the at least one processor is further configured to execute the computer-executable instructions to: when a burst of NR SL synchronization signal as a synchronization-reference (Sync-Ref) UE is transmitted on the selected carrier frequency, in the case that one of the one or more carrier frequencies is associated with the indicator, perform a frequency shift on the selected carrier frequency.

[0016] In another embodiment of the first aspect, the indicator includes radio access technology (RAT) shared bits associated with a carrier frequency in the NR SL frequency carrier configuration.

[0017] In another embodiment of the first aspect, the at least one processor is further configured to execute the calculator execution instructions to: if the RAT shared bit is set to true, when one of the one or more carrier frequencies is associated with the indicator, perform a frequency shift on the selected carrier frequency during NR SL reception.

[0018] According to the currently disclosed second aspect, a wireless communication method performed by a UE is provided. The method includes a reception indicator indicating that frequency shifting is performed on one or more carrier frequencies when Long-Term Evolution (LTE) Vehicle to Everything (V2X) sidelink (SL) communication is shared with New Radio (NR) SL communication on one or more carrier frequencies; and when the indication is associated with a first SL frequency carrier selected by the UE for NR SL packet transmission, frequency shifting is performed when one or more NR SL packet carrier frequencies are transmitted on the first SL frequency carrier.

[0019] In the second aspect of the implementation, the indicator is received in one of the following ways: SL pre-configuration; SL configuration from the serving cell via the Uu interface; and SL configuration from another UE via the PC5 air interface through Radio Resource Control (RRC) signaling.

[0020] In another embodiment of the second aspect, the method further includes: when one or more NR SL packets are received on the second SL frequency carrier, if the second SL frequency carrier selected by the UE is used for NR SL packet transmission associated with the indicator, frequency shifting is performed.

[0021] In another embodiment of the second aspect, the method further includes: when the indicator is associated with the selected first SL frequency carrier, performing a frequency shift on the selected carrier frequency while transmitting a synchronization reference (Sync-Ref) UE synchronized with the radio access network (RAN) as an NR SL synchronization reference on the selected carrier frequency.

[0022] In another embodiment of the second aspect, the RAN is an evolved universal terrestrial radio access network (E-UTRAN) or a new radio RAN (NR-RAN).

[0023] In another embodiment of the second aspect, the method further includes: when the UE is configured to implement Global Navigation Satellite System (GNSS) synchronization priority rules on the selected carrier frequency and is configured to use a synchronization reference (Sync-Ref) UE directly synchronized with the Radio Access Network (RAN) as a candidate for synchronization reference for the NR SL communication, in the case that one of the one or more carrier frequencies is associated with the indicator, the method further includes: implementing frequency shift on the selected carrier frequency.

[0024] In another embodiment of the second aspect, the method further includes: when the UE is configured to implement Global Navigation Satellite System (GNSS) synchronization priority rules on the selected carrier frequency and is configured to use a synchronization reference (Sync-Ref) UE indirectly synchronized with the Radio Access Network (RAN) as a candidate for synchronization reference for the NR SL communication, in the case that one of the one or more carrier frequencies is associated with the indicator, frequency shifting is performed on the selected carrier frequency.

[0025] In another embodiment of the second aspect, the method further includes: when a selected one of the one or more carrier frequencies is associated with the indicator, performing a frequency shift on the selected carrier frequency when an NR SL synchronization signal burst of a Sync-Ref UE is transmitted on the selected carrier frequency.

[0026] In another embodiment of the second aspect, the indicator includes radio access technology (RAT) shared bits associated with a carrier frequency in the NR SL frequency carrier configuration.

[0027] In another embodiment of the second aspect, the method further includes: if the RAT shared bit is set to true, when one of the one or more carrier frequencies is associated with the indicator, performing a frequency shift on the selected carrier frequency during NRSL reception. Attached Figure Description

[0028] The exemplary disclosures are best understood when read in conjunction with the accompanying drawings. The various features are not drawn to scale, and their dimensions may be increased or decreased at will for clarity of discussion.

[0029] Figure 1 This is a diagram illustrating V2X SL operation according to an exemplary embodiment of the present disclosure.

[0030] Figure 2 This is a flowchart of a method for V2X SL operation performed by a UE according to an exemplary embodiment of this disclosure.

[0031] Figure 3 This is a flowchart of a method for V2X SL operation performed by a UE according to an exemplary embodiment of this disclosure.

[0032] Figure 4 This is a flowchart of a method for NR SL operation performed by a base station according to an exemplary embodiment of the present disclosure.

[0033] Figure 5 This is a signal flow diagram between a base station and one or more UEs according to an exemplary embodiment of this disclosure.

[0034] Figure 6 This is a block diagram of a node for wireless communication shown according to various aspects of this disclosure. Detailed Implementation

[0035] The following description contains specific information relating to exemplary embodiments in this disclosure. The accompanying drawings and detailed descriptions are illustrative of exemplary embodiments. However, this disclosure is not limited to these exemplary embodiments. Other variations and embodiments of this disclosure will readily occur to those skilled in the art.

[0036] Unless otherwise indicated, similar or corresponding elements in the accompanying drawings may be indicated by similar or corresponding reference numerals. Furthermore, figures and illustrations are generally not drawn to scale and are not intended to correspond to actual relative dimensions.

[0037] For consistency and ease of understanding, similar features are identified by the same reference numerals in the exemplary figures (although not shown in some examples). However, features in different embodiments may differ in other respects and should therefore not be narrowly limited to what is shown in the figures.

[0038] The phrases “in one implementation” or “in some implementations” can refer to one or more of the same or different implementations, respectively. The term “coupled” is defined as a connection, directly or indirectly, via an intermediate component, and is not necessarily limited to a physical connection. The term “comprising” means “including, but not necessarily limited to” and specifically indicates an open inclusion or membership in said combination, group, series, or equivalent. The expressions “at least one of A, B, and C” or “at least one of the following”: A, B, and C refer to “only A, or only B, or only C, or any combination of A, B, and C.”

[0039] The terms "system" and "network" are used interchangeably. The term "and / or" is used only to describe the relationship between related objects, and indicates that three relationships can exist, such that A and / or B can indicate that A exists alone, A and B exist simultaneously, or B exists alone. The character " / " usually indicates that the related objects are in an "OR" relationship.

[0040] For the purpose of explanation rather than limitation, specific details (such as functional entities, technologies, protocols, and standards) are elaborated to provide an understanding of the technologies described. In other examples, detailed descriptions of well-known methods, technologies, systems, and architectures are omitted to avoid unnecessary detail from obscuring the description.

[0041] Those skilled in the art will recognize that any one or more network functions or algorithms described can be implemented by hardware, software, or a combination of software and hardware. The described functions may correspond to modules that can be software, hardware, firmware, or any combination thereof.

[0042] Software implementations may include computer-executable instructions stored on a computer-readable medium (such as memory or other types of storage devices). One or more microprocessors or general-purpose computers with communication processing capabilities are programmable with corresponding executable instructions and implement one or more described network functions or algorithms.

[0043] Microprocessors or general-purpose computers may be formed from application-specific integrated circuits (ASICs), programmable logic arrays, and / or using one or more digital signal processors (DSPs). Although some of the disclosed embodiments are directed to software installed and executed on computer hardware, alternative embodiments as firmware or hardware or a combination of hardware and software are also fully within the scope of this disclosure. Computer-readable media include, but are not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash memory, compact disc (CD) read-only memory (CDROM), magnetic tape cassettes, magnetic tape, disk storage devices, or any other equivalent medium capable of storing computer-readable instructions.

[0044] Radio communication network architectures (e.g., long term evolution (LTE) systems, LTE-Advanced (LTE-A) systems, LTE-A Pro systems, or New Radio (NR) systems) typically include at least one base station (BS), at least one user equipment (UE), and one or more optional network elements providing connectivity to the network. The UE communicates with the network (e.g., core network (CN), evolved packet core (EPC) network, evolved universal terrestrial radio access network (E-UTRAN), next-generation core (NGC), 5G CN (5GC), or the Internet) through a RAN established by one or more BSs.

[0045] The UE may include, but is not limited to, a mobile station, mobile terminal or device, or a user communication radio terminal. For example, the UE may be a portable wireless device, including but not limited to: a mobile phone, tablet computer, wearable device, sensor, or personal digital assistant (PDA) with wireless communication capabilities. The UE is configured to receive signals through the air interface and transmit signals to one or more cells in the RAN.

[0046] The BS can be configured to provide communication services based on at least one of the following radio access technologies (RATs): Worldwide Interoperability for Microwave Access (WiMAX), Global System for Mobile Communication (GSM, commonly referred to as 2G), GSM Enhanced Data Rate for GSM Evolution (EDGE) RAN (GERAN), General Packet Radio Service (GRPS), UMTS based on Wideband-code Division Multiple Access (W-CDMA) (commonly referred to as 3G), High-speed Packet Access (HSPA), LTE, LTE-A, Evolved LTE (eLTE) connected to 5GC, New Radio (NR, commonly referred to as 5G), and / or LTE-A Pro. However, the scope of this disclosure should not be limited to these protocols.

[0047] A BS may include, but is not limited to, a node B (NB) in UMTS, an evolved node B (eNB) in LTE-A, a radio network controller (RNC) in UMTS, a BS controller (BSC) in GSM / GERAN, an ng-eNB in ​​an Evolved Universal Terrestrial Radio Access (E-UTRA) BS connected to 5GC, a next-generation node B (gNB) in 5G-RAN, or any other device capable of controlling radio communications and managing radio resources within the cell. A BS may serve one or more UEs via a radio interface to the network.

[0048] The BS is operable to provide radio coverage to a specific geographic area using multiple cells forming the RAN. The BS supports cell operation. Each cell is operable to provide service to at least one UE within the cell's radio coverage area.

[0049] Each cell (typically referred to as the serving cell) provides services to one or more UEs within the cell's radio coverage area (e.g., each cell schedules DL resources and optional UL resources to at least one UE within the cell's radio coverage area for DL ​​and optional UL packet transmissions). The BS can communicate with one or more UEs in the radio communication system via multiple cells.

[0050] Cells can be allocated SL resources to support proximity service (ProSe) or vehicle-to-everything (V2X) services. Each cell can have coverage areas that overlap with other cells.

[0051] As mentioned earlier, NR's frame structure supports flexible configuration to adapt to various next-generation (e.g., 5G) communication requirements, such as Enhanced Mobile Broadband (eMBB), Massive Machine Type Communication (mMTC), and Ultra-Reliable and Low-Latency Communication (URLLC), while simultaneously achieving high reliability, high data rates, and low latency requirements. Orthogonal Frequency-Division Multiplexing (OFDM) technology from the 3GPP (3rd Generation Partnership Project) can be used as the baseline for NR waveforms. Scalable OFDM parameter sets, such as adaptive subcarrier spacing, channel bandwidth, and cyclic prefix (CP), can also be used.

[0052] NR offers two coding schemes: Low-Density Parity-Check (LDPC) codes and polar codes. The coding scheme can be adaptively configured based on channel conditions and / or the service application.

[0053] When the transmission time interval (TTI) of a single NR frame includes DL transmission data, protection period, and UL transmission data, the corresponding portions of the DL transmission data, protection period, and UL transmission data can be configured dynamically based on the NR network. SL resources can also be provided in the NR frame to support ProSe or V2X services.

[0054] The following provides illustrative examples of some selected terms used in this disclosure.

[0055] Primary Cell (PCell): For dual connectivity (DC) operations, the PCell is a master cell group (MCG) cell that operates on the primary frequency, where the UE performs the initial connection establishment procedure or initiates the connection re-establishment procedure.

[0056] Primary SCG Cell (PSCell): For DC operations, PSCell is a secondary cell group (SCG) cell where the UE performs random access when performing reconfiguration using the Sync procedure.

[0057] Special Cell: For DC operation, the term Special Cell (SpCell) refers to the PCell of the MCG or the PSCell of the SCG; otherwise, the term Special Cell refers to the PCell.

[0058] Secondary cell: For UEs configured with carrier aggregation (CA), a cell that provides additional radio resources on top of a special cell.

[0059] Serving Cell: For UEs in RRC_CONNECTED without CA / DC configured, there is only one serving cell, which can be referred to as the primary cell. For UEs in RRC_CONNECTED with CA / DC configured, the term "serving cell" can be used to refer to a cell group that includes the SpCell and all secondary cells.

[0060] Listen Before Talk (LBT) is a feature available in Wi-Fi that allows coexistence with other Wi-Fi nodes. LBT is a mechanism by which a device applies clear channel assessment (CCA) before using a channel. The 3rd Generation Partnership Project (3GPP) has chosen to specify a conservative LBT scheme similar to that used by Wi-Fi nodes to ensure coexistence between Licensed Assisted Access (LAA) and Wi-Fi. LAA uses carrier aggregation in the DL (Dedicated Linear Alignment) to combine LTE in unlicensed spectrum (e.g., 5 GHz) with LTE in licensed bands. In NR (Radio Frequency), LBT is also required before any transmission when operating on unlicensed spectrum.

[0061] For example, 3 rdAs described in 3GPP TR38.885, a UE can be configured with a set of synchronization priority rules based on GNSS (Global Navigation Satellite System) or a set of synchronization priority rules based on gNB (Next Generation Node B) / eNB (Evolved Node B) to select a synchronization source on one (or more) sidechain frequency carriers, as shown in Table 1.

[0062] It should be noted that the synchronization rules in the proposed application can be applied to NR sidechain synchronization (e.g., NR SL synchronization rules) and / or LTE V2X SL synchronization (e.g., LTE V2X SL synchronization rules).

[0063] Table 1: NR SL Synchronization Source Priority Rules

[0064]

[0065] Therefore, at a given carrier frequency, the UE can attempt to identify the target synchronization source (e.g., the target NR SL synchronization source) from the highest priority (e.g., P0) to the lowest priority (e.g., P6). In this disclosure, the GNSS-based synchronization rules in Table 1 are also referred to as "1GNSS-based synchronization rules".

[0066] According to the embodiments of this application, for further enhancement, the GNSS-based synchronization rules can be further configured to include sub-priorities to further consider the impact of the RAN (Radio Access Network) on the SL synchronization process. For example, the UE can configure a set of GNSS-based synchronization and gNB / eNB-based synchronization priority rules to select a synchronization source (e.g., an NR-SL synchronization source), as shown in Table 2.

[0067] Table 2: Enhanced Synchronization Rules Based on NR SL GNSS

[0068]

[0069]

[0070] Therefore, at a given carrier frequency, the UE may attempt to identify target synchronization sources from the highest priority (e.g., P0') to the lowest priority (e.g., P6').

[0071] As shown in Table 2, P3' (gNB / eNB), P4' (all UEs directly synchronized to the gNB / eNB), and P5' (all UEs indirectly synchronized to the gNB / eNB) can be further enabled or disabled on the UE side. Table 2 shows the GNSS-based synchronization rules with P3', P4', and P5' enabled. In this disclosure, the GNSS-based synchronization rules in Table 2 are also referred to as "GNSS-based Type 2 Synchronization Rules".

[0072] The embodiments disclosed herein include how to configure Type 1 and Type 2 GNSS-based synchronization rules to the UE.

[0073] refer to Figure 1 , Figure 1 This is a diagram illustrating V2X SL operation according to an exemplary embodiment of this disclosure. Figure 1 In this configuration, at least two UEs (e.g., UE1 and UE2) can be configured in an Access Stratum (AS)-layer / Non-Access Stratum (NAS) unicast group to implement NR-SL (also referred to as NR-V2X in some applications) and / or LTE-V2X services based on configured NR and / or LTE-SL configurations (e.g., NR-SL configuration and LTE V2X configuration). It should be noted that in some implementations, LTE V2X services may include LTE V2X communication via the LTE Uu interface (e.g., packet switching in the downlink / uplink direction between the UE and the serving radio access network) and / or LTE V2X SL packet switching via the LTE PC5 interface (e.g., LTE V2X SL communication and / or LTE V2X SL discovery between UEs). Therefore, in some implementations, LTE V2X configuration may include configuration for LTE V2X communication via the LTE Uu interface and / or configuration for LTE V2X SL communication / LTE V2X SL discovery via the LTE PC5 interface (e.g., LTE V2X SL configuration). It should also be noted that in some implementations, NR SL service may include NR SL packet exchange via the NR PC5 interface (e.g., NR SL communication and / or NR SL discovery between UEs). Therefore, in some implementations, NR SL configuration may include configuration for NR SL communication and / or NR SL discovery. In addition, NR SL communication may include NR SL transmission (e.g., a UE transmitting NR SL packets and / or SL NR control messages (e.g., SL control information (SCI) and / or PC5RRC signaling) and / or NR SL synchronization signals (NR SL synchronization burst sets) to nearby UEs in the same NR SL unicast / multicast / broadcast group) and / or NR SL reception (e.g., a UE receiving NR-SL packets and / or NR-SL control messages (e.g., SCI or PC5RRC signaling) and / or NR SL synchronization signals (NR SL synchronization burst sets) to nearby UEs in the same NR SL unicast / multicast / broadcast group).

[0074] In various embodiments disclosed herein, the serving cell (e.g., Figure 1In an NR cell, multiple SLCCs and associated RATs (or associated RANs) can be configured in the corresponding SLCC. According to an exemplary embodiment disclosed herein, refer to... Figure 1 At least two UEs (e.g., UE1 and UE2) can be configured in an (AS layer / NAS layer) multicast group to implement NR-SL (also known as NR-V2X in some applications) and / or LTE-V2X services based on the configured NR and / or LTE-SL configuration. In various embodiments disclosed herein, the serving cell (e.g., Figure 1 In an NR cell, multiple SLCCs and associated RATs (or associated RANs) can be configured in the corresponding SLCC. According to an exemplary embodiment disclosed herein, refer to... Figure 1 At least two UEs (e.g., UE1 and UE2) can be configured in an (AS layer / NAS layer) broadcast group to implement NR-SL (also known as NR-V2X in some applications) and / or LTE-V2X services based on the configured NR and / or LTE-SL configuration. In various embodiments disclosed herein, the serving cell (e.g., Figure 1 In a unicast / multicast / broadcast group, multiple SLCCs and associated RATs (or associated RANs) can be configured within the corresponding SLCC. It should be noted that in some implementations, a UE in a unicast / multicast / broadcast group can be served by one or more cells, which can be served by one or more RATs (e.g., New Radio, E-UTRA). In some other implementations, one or more UEs in a unicast / multicast / broadcast group can be outside the coverage area of ​​the cellular network (e.g., the UE cannot find at least one cell with a downlink reference signaling quality (e.g., DL-RSRP) higher than a predefined threshold). Furthermore, an out-of-coverage UE can communicate with other UEs in the same unicast / multicast / broadcast group based on SL pre-configuration or configuration obtained from neighboring UEs. A UE can join one or more unicast / multicast / broadcast groups.

[0075] ProSe (Proximity Service) unicast groups (or SL unicast groups in the AS-layer) can communicate with the serving RAN (i.e., the NR RAN connected to the 5GC (5G core) within, partially within, or beyond the coverage area. Figure 1 As shown. In another embodiment, the ProSe unicast group (or the SL unicast group in the AS-layer) can be within, partially within, or outside the coverage area of ​​the serving RAN, which is an E-UTRAN (Evolved Universal Terrestrial Radio Access Network) connected to the EPC (Evolved Packet Core).

[0076] UEs within the coverage area can receive NR or LTE SL configurations (e.g., based on LTE SL configuration according to 3GPP TS 36.331.V15.5.0 or NR SL configuration according to 3GPP TS 38.885.V16.0.0) via broadcast messages (e.g., via broadcast or receiving system information during SI on-demand processes) or dedicated control signaling (e.g., by receiving RRC signaling in the LTE or NR Uu interface, such as RRC (connection) (re)establishment messages, RRC (connection) release messages with / without suspended configuration, RRC (connection) reconfiguration messages with / without mobility control information V2X, or RRC (connection) reconfiguration messages with / without reconfiguration synchronization messages). When the serving RAN instructs the UE to perform a (intra-frame RAT / inter-frame RAT) handover procedure from its serving cell (e.g., secondary cell group change, etc.), a reconfiguration message with reconfiguration synchronization / mobility control information V2X messages can be transmitted.

[0077] UEs outside or partially covered by RAN can receive NR or LTE SL configurations from other UEs (e.g., via PC5RRC message exchange through the NRPC5 interface, via SL MIBs broadcast by neighboring UEs, or via other dedicated control signaling transmitted via physical sidelink control channels, physical sidelink shared channels, or physical sidelink feedback channels). Furthermore, when a UE is not within RAN coverage and has not received LTE or NR SL configurations from neighboring UEs, the UE can apply SL pre-configurations, which can be installed in the USIM (UMTS Subscriber Identity Module) or the UE's memory module. In some implementations, the UE can store NR SL configurations and / or LTE V2X SL configurations (in any combination) as SL pre-configurations stored on the UE side.

[0078] To implement NR SL synchronization in SL component carriers (CCs) (or frequency carriers), the UE can obtain the SL synchronization rules using the methods described above. Within an SL unicast group, the UE can act as a group leader or administrator to manage SL resources and SL configurations within the SL unicast group, for example, by transmitting PC5RRC messages to other UEs within the SL unicast group. Note that the transmission of PC5RRC messages is not restricted by the SL group leader / administrator. For example, any member UE in an SL group can also exchange PC5RRC messages with other member UEs.

[0079] Note that the above description also applies to SL multicast group and SL broadcast scenarios. For example, an SL multicast group / SL broadcast scenario can include two or more UEs in an SL group. Furthermore, one or more group leaders / managers and at least two group members can be configured in an SL multicast group.

[0080] According to various embodiments disclosed herein, SL carrier aggregation (CA) is also considered. For example, to support NR-SL service (or LTE-V2X service), both UE1 and UE2 are configured with N (N≥1) component carriers (e.g., CC#1 to CC#N). However, it is worth noting that different RATs (in the Uu interface) can be deployed on different SL CCs (each with a carrier frequency). For example, NR-RAN is deployed in CC#1, and the NR cell in CC#1 can provide NR SL configuration via broadcast system information or dedicated control signaling. Conversely, E-UTRAN is deployed in CC#2, and the LTE cell in CC#2 can also provide NR SL configuration via broadcast system information or dedicated control signaling. Therefore, it is clear that a UE may need to identify the RAT associated with each SL CC. Furthermore, different NR SL synchronization rules can be configured for each SL CC separately (e.g., as shown in Tables 1 and 2).

[0081] Various implementations of this disclosure are further discussed below. In some implementations, two UEs can exchange SL control signaling using PC5RRC messages. For example, UE#1 can act as the "(ProSe) group leader" (or SL group leader in the AS layer) in an SL unicast group, which may include UE#1 and UE#2. Therefore, in this disclosure, signaling exchange can also include PC5RRC messages in the NR PC5 interface. Furthermore, the implementations of this disclosure do not exclude PC5RRC message exchange supported by the LTE PC5 interface in its enhanced version. It should also be noted that the implementations of this disclosure are not limited to NR-SL services or LTE-V2X services. That is, the implementations of this disclosure are also applicable to other services implemented through SL operations on the LTE PC5 interface and / or NR PC5 interface.

[0082] In explicit signaling methods, the serving cell (e.g., Figure 1 (NR cells in the table). Multiple SL CCs and associated RATs (also referred to as associated RANs in some implementations) can be configured in the corresponding SL CC. In Table 3, one SL CC can be configured with one associated RAT because both NR-RAN and E-UTRAN can be configured with one or more NR SL configurations to support NR-SL services. It should be noted that Table 3 can also be applied to LTE-V2X services.

[0083] Table 3: SL CC and associated RAT(RAN) to support NR-SL services

[0084] SL CC Associated RAT(RAN) to support NR-SL services CC#1 LTE CC#2 NR CC#3 NA CC#i NR … …… CC#N LTE

[0085] As shown in Table 3, an SL CC can be associated with either an LTE or NR RAT. The UE can perform cell (re)selection based on the associated RAT. In some implementations, an SL CC may not be associated with either an LTE or NR RAT (e.g., there is no associated RAT in CC#3). In some implementations, NR-RAN (which may include public or non-public networks) and E-UTRAN can be deployed and share a CC. Therefore, the UE can still attempt to scan for LTE and / or NR cells on CC#3. In some implementations, "NA" in the associated RAT means that neither LTE RAN nor NR RAN will be deployed in CC#3. In some implementations, only a RAT different from the RAT of the serving cell (or camped cell) can be further indicated. For example, when an NR cell is configuring an SL CC using its associated RAT, the NR RAT can be considered the default setting in the SL configuration. Furthermore, if an SL CC is associated with an NR RAT, no specific indicator is provided to the SL CC. Conversely, when an SL CC is associated with an LTE network, the serving NR cell can further provide explicit indicators such as "LTE," "E-UTRA," or "E-UTRAN." Similar rules can be applied to LTE cells. For example, when an LTE cell is configured using its associated RAT, the LTE RAT can be considered the default setting in the configuration, so if an SL CC is associated with an LTE RAT, no specific indicator will be provided to it. Conversely, when an SL CC is associated with an NR network, the serving LTE cell (or the LTE-camped cell) can further provide explicit indicators such as "NR" or "New Radio."

[0086] It should be noted that the UE can receive the associations shown in Table 3 via SL pre-configuration (stored in the USIM or the UE's memory module), system information broadcast by the serving (or selected) NR / LTE cell, and dedicated control signaling (e.g., RRC messages transmitted by the NR / LTE cell) from the serving cell or control signaling (e.g., PC5RRC messages) transmitted by another UE.

[0087] It should also be noted that, through explicit signaling, each SL CC can be associated with an ARFCN (Absolute Radio Channel Number) or an NR-ARFCN (New Radio ARFCN) to indicate the SL CC's location in the frequency domain. Furthermore, for CCs associated with the NR RAT, the associated set of parameters (e.g., cyclic prefix length or subcarrier spacing) can be further indicated. In some cases, only the NR-ARFCN and subcarrier spacing can be configured for the UE. The implementations disclosed herein provide helpful information to improve the efficiency of UEs when performing cell (re)selection on relevant NR frequencies.

[0088] In Table 3-1, an SL CC can be configured with an associated standalone or non-standalone NR RAN to support NR-SL services. It should be noted that Table 3-1 can also be applied to LTE-V2X services.

[0089] Table 3-1: SL CC and associated independent / non-independent RAT(RAN) to support NR-SL services

[0090] SL CC Associated RAT (RAN) to support V2X services CC#1 LTE CC#2 NR (e.g., independent NR RAN) CC#3 NA CC#i NR (e.g., non-independent NR RAN) … …… CC#N LTE

[0091] It should also be noted that in some implementations, the SL CC configuration may include a non-standalone (NSA) NR-RAN (e.g., CC#i in Table 3-1) and a standalone NR-RAN (e.g., CC#2 in Table 3-1). The NSA NR cell may also broadcast NR-SL and / or LTE-V2X configurations via system information. Therefore, the UE can also implement NR-SL / LTE-V2X services based on the configuration provided by the NR NSA cell. In other words, cell (re)selection for V2X services on this non-service frequency can still be applied, and it may not affect the cell (re)selection process implemented in the Uu interface. In some implementations, there is no further indication of whether the NSA NR-RAN or SA NR-RAN is deployed on a specific component carrier (as shown in Table 3). In some implementations, further indication (e.g., NSA NR RAN or SA NR RAN, as shown in Table 3-1) may be provided when the RAN / UE indicates the supported SL CC and the supported NR RAT. In some implementations, the configuration only further indicates "NSA NR" without any additional indicators for the SL CC associated with the NR standalone network. In other words, SA NR RAN can be the default setting if no additional indicators are provided for the associated SL CC, and vice versa. In some implementations, when the UE performs a frequency prioritization process during the cell (re)selection process in the NR / LTE Uu interface, the UE can store the mapping configuration in Table 3 or Table 3-1 as supporting information. In some implementations, when the UE gives higher priority to the CC during the cell (re)selection process for determining the camping cell in the Uu interface, the UE may not prioritize the CC, where only the NSA NR RAN is deployed on the relevant frequency carrier. Furthermore, in some implementations, when the UE gives higher priority to the CC during the cell (re)selection process based on whether a specific V2X service is supported on the relevant SL CC, the UE may not prioritize the CC associated with the LTE RAT.

[0092] For NR UEs connected to an NR serving cell (e.g., in an NR RRC connection state), the UE can indicate to its serving cell via UE Assistance Information that it supports the LTE-Uu / LTE-PC5 interface (or whether the UE can include the eNB as a target in the NR SL synchronization rule). For RRC-connected UEs, the serving cell can configure the SL component and associated RAT based on the RAT supported by the UE. In other words, for UEs that only support the NR Uu / PC5 interface, it is not expected to configure the SL CC associated only with the LTE Uu or LTE PC5 interface. In some implementations, another bit (e.g., in the UECapabilityInformation or UEAssistanceInformation transmitted by the UE to the serving cell) can be used by the UE to report whether it supports the NR-PC5 interface (and / or the LTE-PC5 interface) or whether the UE can include the gNB / eNB as a target in the NR SL synchronization rule.

[0093] In some implementations, the serving base station (the serving cell that configures and maintains the UE) can obtain UE capabilities from signaling of other (NR / E-UTRA) base stations or from the core network via a backhaul connection. The UEAssistanceInformation element can also be applied to the NR Uu / NR PC5 interface when an LTE cell is configuring the associated RAT with the configured SLCC.

[0094] In some implementations, the SL CC can be shared by multiple operators (e.g., unlicensed Intelligent Transport System (ITS) bands), thus different network deployments can be applied to the SL CC. For example, the SL CCs and associated RATs in Table 3 (or Table 3-1) can be PLMN-specific configurations or mappings. Therefore, in some implementations, the RAN or UE can transmit mapping information with associated PLMN identifiers (as shown in Table 3 / Table 3-1). The PLMN identifier is a unique identifier consisting of (at least) a Mobile Country Code (MCC) and a Mobile Network Code (MNC). In the RAN, cells can be shared by different PLMNs. Therefore, a cell can broadcast a PLMN identifier (-ies) to indicate the PLMN supported by the cell. On the UE side, a UE can subscribe to NR-SL / LTE-V2X services with its registered telecom operator, and the operator can deploy at least one PLMN to support the subscribed UE. Therefore, a UE can access the RAN and perform SL operations based on a given configuration associated with a registered PLMN (e.g., a PLMN or an equivalent HPLMN). To enable a UE to implement NR-SL / LTE-V2X services based on the SL configuration of its registered PLMN, the RAN can transmit mapping information (e.g., PLMN-specific mappings associated with multiple PLMNs) to the UE (which has registered with different PLMNs). The RAN can transmit mapping information for multiple PLMNs via broadcast system information or via dedicated RRC signaling (as shown in Table 3 or Table 3-1). In the PC5 interface, the UE can transmit mapping information for multiple PLMNs via broadcast MIB-SL (Master Information Block Sidechain) or via (broadcast / multicast / unicast) PC5RRC messages.

[0095] It should also be noted that the PLMN in this disclosure may also cover non-public network (NPN) scenarios. In some implementations, an NPN scenario may be a stand-alone non-public network (SNPN) (e.g., the RAN is operated by an NPN operator and does not depend on network functions provided by the PLMN). In some implementations, an NPN scenario may be a public network integrated NPN (PNI-NPN) (e.g., a non-public RAN deployed with the support of a PLMN). A UE may identify an SNPN based on the PLMN ID and / or Network ID (NID) broadcast in the SIB1 of a cell supporting the SNPN. A PNI-NPN may be identified by the PLMN ID and / or Cell Access Group (CAG) ID broadcast in the SIB1 of a cell supporting the PNI-NPN.

[0096] In some implementations, each associated PLMN in the mapping information may be represented by a "PLMN index". The "PLMN index" is determined based on the PLMN sequence shown in the PLMN identifier list, which may be broadcast by the cell in system information (e.g., SIB1).

[0097] As shown in Table 4, the PLMN identifier list is provided in the system information. Furthermore, PLMN ID#a is the first PLMN shown in the PLMN identifier list, and PLMN ID#b is the second PLMN shown in the PLMN identifier list. To reduce signaling overhead, for example, the PLMN indicated by PLMN ID#a can be further associated with a PLMN index with a value of 0, and the PLMN indicated by PLMN ID#b can be further associated with a PLMN index with a value of 1. Therefore, mapping information can be associated with PLMN indices accordingly. On the UE side, the UE can interpret and / or determine which PLMN is associated with the configured mapping configuration by receiving the PLMN identifier list from the system information. The mapping rules between PLMN identifiers and PLMN indices can be pre-specified in the technical specifications or stored in the UE. Therefore, the PLMN index mapping provided in Table 4 can also be used to configure PLMN-specific mapping information between the SL CC and the associated RAT (Table 3 / Table 3-1).

[0098] Table 4: PLMN Index Configuration and Related PLMN Identifiers

[0099] PLMN identifier list (in SIB1) PLMN Index PLMN ID#a 0 PLMN ID#b 1 PLMN ID#c 2 …… … PLMN ID#N N-1

[0100] In some implementations, as shown in Table 5-1, the UE can configure one or more SL CCs (or frequency carriers) with associated NR SL synchronization rules (which include at least Type 1 / Type 2 GNSS synchronization rules and gNB / eNB-based synchronization).

[0101] Table 5-1: SL CC and related NR SL synchronization rules

[0102] SL CC Synchronization rules CC#1 Category 1 GNSS Synchronization Rules CC#2 Category 2 GNSS Synchronization Rules CC#i Synchronization rules based on gNB / eNB … …… CC#N Category 2 GNSS Synchronization Rules

[0103] In some implementations, two indicators can be provided to configure NR SL synchronization rules, as shown in Table 5-2.

[0104] Table 5-2: Two indicators or a bitmap for indicating the NR SL synchronization rules associated with each configured SL CC.

[0105]

[0106] The IE "Synchronization Rule" can be designed to indicate either "GNSS-based Synchronization Rule" or "gNB / eNB-based Synchronization Rule". Then, another indicator, "gNB / eNB Enable Bit", can be further provided to indicate either Type 1 GNSS-based Synchronization Rule (gNB / eNB bit is "disabled") or Type 2 GNSS-based Synchronization Rule (gNB / eNB bit is "enabled"). Furthermore, a bitmap can be provided accordingly in Table 5-2. The first bit in the bitmap indicates the synchronization rule based on GNSS (e.g., by configuring "0" (or "false") in the first bit) or the synchronization rule based on gNB / eNB (e.g., by configuring "1" (or "true") in the first bit). Then, the second bit in the bitmap indicates whether P3 / P4 / P5 is disabled (e.g., by configuring "0" (or "false") in the second bit) or enabled (e.g., by configuring "1" (or "true" / "enabled") if the first bit is set to "0" (or "false" / "disabled"). Furthermore, the values ​​(1, 0) in this bitmap can be reserved for other uses. In some other implementations, the bitmap and values ​​"0" and "1" shown in Table 5-2 can be replaced by options {GNSS-based, gNB / eNB}, enumerations (e.g., "enabled", "disabled"), and Boolean values ​​(e.g., "true", "false") in the ASN.1 signal design.

[0107] In some implementations, a set of default GNSS-based synchronization rules can be pre-specified (e.g., pre-defined in the 3GPP specification) or pre-configured. For example, Type 1 (or Type 2) GNSS-based synchronization rules can be pre-specified as the default GNSS-based synchronization rules in the 3GPP specification. Then, in the explicit signaling approach, the serving RAN may only need to further indicate the SL CC associated with the Type 2 GNSS-based synchronization rule. For example, in the 3GPP specification, Type 1 GNSS-based synchronization rules can be the default GNSS-based synchronization rules. The serving RAN can then further transmit an indicator to the UE to configure the UE to take the RAN (e.g., N-RAN, E-UTRAN) into account in the synchronization source decision (e.g., when the Type 2 GNSS-based synchronization rule is configured to the UE).

[0108] Table 5-3: An indicator used to indicate the NR SL synchronization rule associated with each configured SL CC by configuring a default setting in the GNSS-based synchronization rule.

[0109] SL CC NR SL Synchronization Rules gNB / eNB bits CC#1 Based on GNSS Enable CC#2 Based on GNSS NA Based on gNB / eNB NA CC#N Based on GNSS Enable

[0110] In some implementations, the UE can receive, via SL pre-configuration (e.g., stored in the USIM or the UE's memory module), the associated broadcast system information from the serving cell (or selected) NR / LTE cell, dedicated control signaling from the serving cell (e.g., RRC connection reconfiguration message delivery or other types of RRC signaling from the NR or LTE cell), or dedicated control signaling transmitted by another UE (e.g., PC5RRC messages).

[0111] In some implementations, the indications provided in Tables 5-1, 5-2, and 5-3 may be PLMN-specific, and the (NR / LTE) cell or UE may transmit mapping information with the associated PLMN identifier (based on the associations provided in Tables 5-1, 5-2, and 5-3). Furthermore, the (NR / LTE) cell or UE may transmit NR SL synchronization rules associated with different PLMN identifiers. In some implementations, the PLMN index-related configuration (as shown in Table 4) may not be limited to the mapping information shown in Tables 3 / 3-1, but may also cover the associated NR SL synchronization rules described in this disclosure. Therefore, the RAN / UE may also transmit PLMN-specific synchronization rules via broadcast messages or dedicated control signaling.

[0112] It should be noted that in some implementations, NR SL synchronization rules can be UE-specific. For example, only one set of rules (Type 1 or Type 2 GNSS-based synchronization rules or gNB / eNB-based synchronization rules) can be configured for the UE, and the configured NR SL synchronization rules can typically be applied to all configured SL CCs of a UE. In other words, the UE can apply only one set of NR SL synchronization rules to all configured SL CCs during the SL synchronization process. Furthermore, different NR-SL synchronization rules can be provided based on the UE type (e.g., NRUE or LTE UE). For example, an NR UE represents a UE served by an NR cell using the (NR)Uu interface, and an LTE UE represents a UE served by an LTE cell using the (LTE)Uu interface. Additionally, the serving NR cell and the serving LTE cell can configure NR SL / LTE V2X SL synchronization rules for the NR UE and the LTE UE, respectively. In some implementations, an LTE cell can configure a set of commonly used SL synchronization rules (e.g., Type 1 or Type 2 GNSS-based synchronization rules or gNB / eNB-based synchronization rules) to all LTE UEs to implement NR-SL services on one or more SL CCs. In some implementations, an NR cell can configure a set of generally used SL synchronization rules (Type 1 / Type 2 GNSS-based synchronization rules or gNB / eNB-based synchronization rules) to all NR UEs to implement NR-SL services on one or more SL CCs.

[0113] In some implementations, the associated synchronization rules can be valid within one or more validity areas. For example, the configurations in Table 5-3 can be transmitted via broadcast system information. Furthermore, the configured SL synchronization rules are valid within a systeminformationareaID. Therefore, after a UE changes to a serving cell through a cell (re)selection or handover procedure, the UE can apply the synchronization rules when the serving cell broadcasts the same systeminformationareaID in the system information. In some implementations, the systeminformationareaID can generally be applied to all broadcast system information. In some other implementations, a V2X_systeminformationareaID can be specified to define the validity area of ​​the NR-SL configuration or LTE-V2X configuration broadcast in the system information. In some implementations, the validity area associated with the synchronization rules can be specified by other methods, including a list of cell identifiers (e.g., a list of physical cell identifiers or a cellidentity unique to each cell in a PLMN), a list of RAN notification areas, a tracking area, a area-based method (e.g., using the area configuration in the LTE-V2X service as a reference), or through assistance information from other RATs (e.g., Wi-Fi, Bluetooth, GNSS, NR positioning).

[0114] In some implementations, the UE may further indicate to the serving cell whether it supports Type 2 GNSS-based synchronization rules (e.g., an information element indicating true or false regarding whether Type 2 GNSS-based synchronization rules are supported). The UE may provide this information to the serving cell in information elements such as UEcapabilityinformation (through a UE capability query procedure initiated by the serving cell) or UEAssistanceInformation.

[0115] In some implementations, a UE that does not support the Type 2 GNSS-based synchronization rule may revert to the Type 1 GNSS-based synchronization rule, for example, when the UE is configured with the Type 2 GNSS-based synchronization rule but is unable to implement the Type 2 GNSS-based synchronization rule due to its (hardware / software) capabilities.

[0116] In some implementations, the enabling and disabling of P3 / P4 / P5 in the GNSS-based synchronization rules can be handled separately and independently. Table 6 shows a bit diagram, where each bit is associated with the enabling / disabling conditions of {P3, P4, P5}, which can be configured to the UE (e.g., based on the signaling methods provided in this disclosure).

[0117] Table 6: Bitmap indicating whether {P3, P4, P5} are enabled and disabled respectively.

[0118] priority Enable / Disable Bit P3 gNB / eNB 1 (Enabled) P4 UE directly synchronizes to gNB / eNB 0 (Disabled) P5 UE indirectly synchronizes to gNB / eNB 0 (Disabled)

[0119] In Table 6, a bit is set to 1 (meaning the relevant priority is enabled, as in P3 in Table 6) or 0 (meaning the relevant priority is disabled, as in P4 and P5 in Table 6). In some implementations, the UE can be configured with a set of GNSS-based synchronization rules with a bitmap. Therefore, a new set of synchronization rules, different from the Type 1 / Type 2 GNSS-based synchronization rules, can be configured for a UE on (at least) one relevant SL-CC. Based on the configuration shown in Table 6, the relevant UE is able to find the gNB / eNB as the target for SL synchronization. However, the UE may not assign different priorities to Sync-Ref UEs based on their synchronization source. For example, there may be no further distinction between a Sync-Ref UE that is directly / indirectly synchronized with a gNB / eNB and a Sync-Ref UE that is synchronized with another Sync-Ref UE.

[0120] In some implementations, synchronization rules (e.g., in Tables 1 and 2) may be associated only with the SLCC associated with the NR RAT. In some implementations, synchronization rules may be associated with the SLCC associated with both the LTE RAT and the NR RAT. In some additional implementations, synchronization rules may be associated with all configured SLCCs, regardless of the associated RAT. Furthermore, for a configured SLCC, the associated RAT and associated synchronization rules may be provided jointly or independently.

[0121] Case 2: Implicit Methods

[0122] In the implicit method, the UE can determine whether to apply Type 1 or Type 2 GNSS-based synchronization rules based on some pre-specified or (pre-)configured trigger events. Table 7 shows the implicit method by which the UE determines the associated SL synchronization rules based on various trigger events.

[0123] Table 7: Implicit Methods for Implementing SL Synchronization Rules Based on Triggering Events

[0124]

[0125]

[0126]

[0127] refer to Figure 2 , Figure 2This is a flowchart of a method 200 performed by a UE for V2X SL operation according to an exemplary embodiment of this disclosure.

[0128] In action 202, the UE may receive an indicator indicating that it shares LTE-V2X service with NR SL service on at least one of one or more carrier frequencies. The indicator may be received via SL pre-configuration (e.g., pre-stored in the UE), SL configuration from the serving cell (e.g., via the Uu interface), and / or SL configuration from another UE (e.g., via RRC signaling through the PC5 air interface).

[0129] In action 204, the UE can select one or more carrier frequencies for NR SL communication.

[0130] In action 206, when an indicator is associated with one of one or more carrier frequencies, and the UE is configured to implement GNSS synchronization priority rules on the selected carrier frequency and configured to consider a Sync-Ref UE synchronized with the RAN as a synchronization reference candidate for SL, the UE can implement a frequency shift (e.g., a 7.5 kHz frequency shift) on the selected carrier frequency. In one implementation, the Sync-Ref UE can be directly synchronized with the RAN (e.g., NR RAN or E-UTRAN) as a synchronization reference candidate for SL communication. In another implementation, the Sync-Ref UE can be indirectly synchronized with the RAN (e.g., through another Sync-Ref UE) as a candidate for NR SL / LTE V2X SL synchronization reference for SL communication.

[0131] In action 208, when a UE receives one or more NR SL packets from a neighboring UE, it may perform a frequency shift (e.g., a 7.5 kHz frequency shift) on one of the selected carrier frequencies when the UE is associated with an indicator in one of the one or more carrier frequencies.

[0132] In action 210, when an indicator is associated with one of one or more carrier frequencies, the UE may implement a frequency shift (e.g., a 7.5 kHz frequency shift) on the selected carrier frequency while transmitting an NR SL synchronization signal burst group as a Sync-Ref UE (e.g., an NR-Sync-Ref UE based on the NR sidechain protocol) on the selected carrier frequency.

[0133] It should be noted that details of SL CC and related NR SL synchronization rules, as well as RAT and instructions for SL operation, are available as described in Cases 1 and 2 above.

[0134] refer to Figure 3 , Figure 3 This is a flowchart of a method 300 performed by a UE for V2X SL operation according to an exemplary embodiment of the present disclosure.

[0135] In action 312, the UE may receive an indicator (e.g., within an NR-SL configuration) that indicates that the LTE-V2X service is shared with the NR-SL service on at least one of one or more carrier frequencies.

[0136] In action 314, the UE can determine whether the indicator includes RAT shared bits associated with a carrier frequency in the SL frequency carrier configuration.

[0137] In one implementation, the SL frequency carrier configuration can be received via SL pre-configuration (e.g., pre-stored in the UE), SL configuration from the serving cell (e.g., via the NR / e-UTRA Uu interface), and / or SL configuration from another UE (e.g., via PC5 RRC signaling through the PC5 air interface). In one implementation, it can be... Figure 2 Action 314 is executed after action 202 in method 200 shown.

[0138] In action 316, when an indicator is associated with one of the one or more carrier frequencies, and the RAT shared bit is set to true, the UE can implement a frequency shift (e.g., a 7.5 kHz frequency shift) on one of the one or more carrier frequencies. In one implementation, action 316 may include... Figure 2 At least one of actions 206, 208 and 210 in the method 200 shown.

[0139] It should be noted that the details of SL CC and related synchronization rules, as well as the RAT and instructions for SL operations, can conform to the descriptions in cases 1 and 2 above.

[0140] Figure 4 This is a flowchart of a method for performing NR SL operations by a base station according to an exemplary embodiment of this disclosure. In action 410, the base station may configure an indicator that indicates LTE-V2X service and NR SL service are shared. In action 412, the base station may transmit the indicator to one or more UEs on at least one of one or more carrier frequencies. In one embodiment, the indicator is transmitted to the UE in an SL frequency carrier configuration. In one embodiment, the base station may further configure an indicator that indicates whether a frequency shift (e.g., a 7.5 kHz frequency shift) is applied in the SL frequency carrier configuration. In another embodiment, the base station may configure the UE to apply a frequency shift (e.g., a 7.5 kHz frequency shift) in the associated SL frequency carrier (configuration) by reusing the indicator that is shared between LTE-V2X service and NR SL service.

[0141] Figure 5 This is a signal flow diagram between a base station and one or more UEs according to an exemplary embodiment of this disclosure. As shown in FIG500, in action 522, the base station may transmit NR SL configuration (and / or LTE V2X SL configuration) to a UE (e.g., UE#1). In action 524, UE#1 may transmit the NR SL configuration (and / or LTE V2X SL configuration) received from the base station to another UE (e.g., UE#2).

[0142] In some implementations, the base station can directly transmit NR SL configuration (and / or LTE V2X SL configuration) to the UE via UE-specific control signaling (e.g., RRC signaling via the NR Uu interface or LTE Uu interface) or broadcast system information (e.g., NR SIB or E-UTRA SIB).

[0143] The NR SL configuration includes control parameters for the UE to implement NR SL operations (or NR SL services) in the access stratum (and / or non-access stratum) layer, and the LTE V2X SL configuration includes control parameters for the UE to implement LTE V2X services in the access stratum (and / or non-access stratum) layer.

[0144] In some other implementations, a UE (e.g., UE#1) can transmit an NR sidelink configuration (and / or LTE V2X SL configuration) to another UE (e.g., UE#2) via UE-specific control signaling (e.g., PC5RRC signaling). It should be noted that in some implementations, UE#1 can directly relay an NR SL configuration / LTE V2X SL configuration obtained from the cellular network to UE#2 (e.g., based on a request from UE#2 and / or a base station). In some additional implementations, UE#1 can autonomously (e.g., by referring to (partially) an NR SL / LTE V2X SL configuration obtained from the cellular network) generate an NR SL / LTE V2X SL configuration for UE#2. Also note that the base station can belong to either the serving RAN or a non-serving RAN of UE#1 (e.g., a base station that the UE has detected when implementing NR sidelink / LTE V2X SL service on a non-serving frequency).

[0145] Figure 6 This illustrates a node 600 for wireless communication according to this disclosure. (Example) Figure 6As shown, node 600 may include a transceiver 620, a processor 628, a memory 634, one or more presentation components 638, and at least one antenna 636. Node 600 may also include a radio frequency (RF) spectrum module, a BS communication module, a network communication module and a system communication management module, input / output (I / O) ports, I / O components, and a power supply (not shown in the diagram). Figure 6 (As shown).

[0146] Each of these components can communicate with each other directly or indirectly via one or more buses 640. Node 600 can perform actions such as... Figures 1 to 5 The various UEs or BSs with disclosed functions are shown.

[0147] Transceiver 620 includes a transmitter 622 (with transmitting circuitry) and a receiver 624 (with receiving circuitry), and can be configured to transmit and / or receive time and / or frequency resource allocation information. Transceiver 620 can be configured to transmit in different types of subframes and time slots, including but not limited to available, unavailable, and flexibly available subframe and time slot formats. Transceiver 620 can be configured to receive data and control channels.

[0148] Node 600 may include a variety of computer-readable media. Computer-readable media may be any media that can be accessed by node 600, and includes both volatile and non-volatile media, removable and non-removable media.

[0149] Computer-readable media can include computer storage media and communication media. Computer storage media include both volatile and non-volatile media, as well as removable and non-removable media, implemented in any way or by any technology for storing information such as computer-readable instructions, data structures, program modules, or data.

[0150] Computer storage media include RAM, ROM, EEPROM, flash memory or other memory technologies, Compact Disc Read-Only Memory (CD-ROM), Digital Versatile Disc (DVD) or other optical disc storage devices, cartridges, magnetic tapes, disk storage devices, or other magnetic storage devices. Computer storage media do not include transmitted data signals. Communication media typically embody computer-readable instructions, data structures, program modules, or other data in modulated data signals (such as carrier waves or other transmission mechanisms) and include any information delivery medium.

[0151] The term "modulated data signal" means a signal having one or more characteristics set or altered in a manner that encodes information in the signal. Communication media include wired media (such as wired networks or direct wired connections) and wireless media (such as acoustic, RF, infrared, and other wireless media). Combinations of any of the disclosed media should also be included within the scope of computer-readable media.

[0152] Memory 634 may include computer storage media in the form of volatile and / or non-volatile memory. Memory 634 may be removable, non-removable, or a combination thereof. Memory includes solid-state memory, hard disk drives, and optical disk drives. Figure 6 As shown, memory 634 may store computer-readable, computer-executable instructions 632 (e.g., software code) configured to cause processor 628 to perform various disclosed functions, for example, referencing Figures 1 to 5 Alternatively, instruction 632 cannot be executed directly by processor 628, but instruction 632 can be configured to cause node 600 (e.g., when compiled and executed) to perform various disclosed functions.

[0153] Processor 628 may include intelligent hardware devices (e.g., a central processing unit (CPU), a microcontroller, an application-specific integrated circuit (ASIC), etc.). Processor 628 may include memory. Processor 628 can process data 630 and instructions 632 received from memory 634, as well as information received via transceiver 620, a baseband communication module, and / or a network communication module. Processor 628 can also process information to be sent to transceiver 620 for transmission via antenna 636 to the network communication module for transmission to the core network.

[0154] One or more presentation components 638 present data to a person or other device. Presentation component 638 includes a display device, a speaker, a printing component, and a vibrating component.

[0155] In some embodiments disclosed herein, when multiple SL CCs are configured to support (NR / LTE) SL operations between UEs, the configuration of NR SL / LTE V2X SL synchronization rules is used.

[0156] In some embodiments disclosed herein, information regarding the SL CC associated with NR and / or LTE RAT is indicated to the UE (e.g., via the Uu interface).

[0157] In some embodiments disclosed herein, the association between the SL CC and the associated RAT can be PLMN-specific.

[0158] In some embodiments disclosed herein, an SLCC with relevant NR SL / LTE V2X SL synchronization rules is indicated.

[0159] In some embodiments disclosed herein, the association between the SL CC and the NR SL / LTE V2X SL synchronization rules can be PLMN-specific.

[0160] In some embodiments disclosed herein, the association between SL CC and NR SL / LTE V2X SL synchronization rules can be valid within a defined validity region.

[0161] In some embodiments disclosed herein, the above-mentioned instructions and / or association rules may be specified in advance in the technical specifications or predefined in the USIM or memory module in the UE, so that the UE can interpret and apply the above-mentioned instructions and / or association rules.

[0162] In view of this disclosure, it will be apparent that various techniques can be used to implement those concepts without departing from the scope of the concepts disclosed herein. Furthermore, although these concepts have been described with specific reference to certain embodiments, those skilled in the art will recognize that changes in form and detail can be made without departing from the scope of these concepts. Therefore, this disclosure should be considered illustrative rather than restrictive in all respects. It should also be understood that this disclosure is not limited to the specific embodiments described, but many rearrangements, modifications, and substitutions are possible without departing from the scope of this disclosure.

Claims

1. A user equipment (UE) for sidelink SL operation, the UE comprising: One or more non-transitory computer-readable media, the one or more non-transitory computer-readable media containing computer-executable instructions; as well as At least one processor, coupled to the one or more non-transitory computer-readable media, the at least one processor being configured to execute the computer-executable instructions to: A receive indicator indicating that when Long Term Evolution (LTE) V2X SL communication is shared with New Radio (NR) SL communication on one or more carrier frequencies, a frequency shift shall be performed on said one or more carrier frequencies; and When the first SL frequency carrier selected by the UE is used for NR SL packet transmission and is associated with the indicator, frequency shift is implemented when one or more NR SL packet carrier frequencies are transmitted on the first SL frequency carrier.

2. The UE as described in claim 1, characterized in that, The indicator is received in one of the following ways: SL pre-configuration; SL configuration from the serving cell via the Uu interface; and SL configuration from another UE via the PC5 air interface through Radio Resource Control (RRC) signaling.

3. The UE as described in claim 1, characterized in that, The at least one processor is further configured to execute the computer-executable instructions to: When the second SL frequency carrier selected by the UE is used for NR SL packet transmission and is associated with the indicator, frequency shift is implemented when one or more NR SL packets are received on the second SL frequency carrier.

4. The UE as described in claim 1, characterized in that, The at least one processor is further configured to execute the computer-executable instructions to: When the selected first SL frequency carrier is associated with the indicator, frequency shift is performed on the selected carrier frequency when transmitting a synchronization reference Sync-Ref UE synchronized with the radio access network RAN ​​as the NR SL synchronization reference on the selected carrier frequency.

5. The UE as described in claim 4, characterized in that, The RAN is either Evolved Universal Terrestrial Radio Access Network (E-UTRAN) or New Radio RAN (NR-RAN).

6. The UE as described in claim 4, characterized in that, The at least one processor is further configured to execute the computer-executable instructions to: When the UE is configured to implement the GNSS synchronization priority rule on the selected carrier frequency and is configured to use the synchronization reference Sync-Ref UE, which is directly synchronized with the Radio Access Network (RAN), as a candidate synchronization reference for the NR SL communication, frequency shifting is implemented on the selected carrier frequency.

7. The UE as described in claim 1, characterized in that, The at least one processor is further configured to execute the computer-executable instructions to: When the UE is configured to implement the GNSS synchronization priority rule on the selected carrier frequency and is configured to use the synchronization reference Sync-Ref UE, which is indirectly synchronized with the Radio Access Network (RAN), as a candidate synchronization reference for the NR SL communication, frequency shifting is implemented on the selected carrier frequency.

8. The UE as described in claim 1, characterized in that, The at least one processor is further configured to execute the computer-executable instructions to: When a selected one of the one or more carrier frequencies is associated with the indicator, a frequency shift is performed on the selected carrier frequency when an NR SL synchronization signal burst configured as a synchronization reference Sync-Ref UE is transmitted on the selected carrier frequency.

9. The UE as described in claim 1, characterized in that, The indicator includes Radio Access Technology (RAT) shared bits associated with a carrier frequency in the NR SL frequency carrier configuration.

10. The UE as described in claim 9, characterized in that, The at least one processor is further configured to execute the calculator execution instructions to: When one of the one or more carrier frequencies is associated with the indicator, if the RAT shared bit is set to true, a frequency shift is performed on the selected carrier frequency during NR SL reception.

11. A method for sidelink SL operation performed by a user equipment (UE), the method comprising: A receive indicator indicating that when Long Term Evolution (LTE) V2X SL communication is shared with New Radio (NR) SL communication on one or more carrier frequencies, a frequency shift shall be performed on said one or more carrier frequencies; and When the first SL frequency carrier selected by the UE is used for NR SL packet transmission and is associated with the indicator, frequency shift is implemented when one or more NR SL packet carrier frequencies are transmitted on the first SL frequency carrier.

12. The method as described in claim 11, characterized in that, The indicator is received in one of the following ways: SL pre-configuration; SL configuration from the serving cell via the Uu interface; and SL configuration from another UE via the PC5 air interface through Radio Resource Control (RRC) signaling.

13. The method of claim 11, further comprising: When the second SL frequency carrier selected by the UE is used for NR SL packet transmission and is associated with the indicator, frequency shift is implemented when one or more NR SL packets are received on the second SL frequency carrier.

14. The method of claim 11, further comprising: When the selected first SL frequency carrier is associated with the indicator, frequency shift is performed on the selected carrier frequency when transmitting a synchronization reference Sync-Ref UE synchronized with the radio access network RAN ​​as the NR SL synchronization reference on the selected carrier frequency.

15. The method as described in claim 11, characterized in that, RAN stands for Evolved Universal Terrestrial Radio Access Network (E-UTRAN) or New Radio RAN (NR-RAN).

16. The method of claim 11, further comprising: When the UE is configured to implement the GNSS synchronization priority rule on the selected carrier frequency and is configured to use the synchronization reference Sync-Ref UE, which is directly synchronized with the Radio Access Network (RAN), as a candidate synchronization reference for the NR SL communication, frequency shifting is implemented on the selected carrier frequency.

17. The method of claim 11, further comprising: When the UE is configured to implement the GNSS synchronization priority rule on the selected carrier frequency and is configured to use the synchronization reference Sync-Ref UE, which is indirectly synchronized with the Radio Access Network (RAN), as a candidate synchronization reference for the NR SL communication, frequency shifting is implemented on the selected carrier frequency.

18. The method of claim 11, wherein the method further comprises: When a selected one of the one or more carrier frequencies is associated with the indicator, a frequency shift is performed on the selected carrier frequency when an NR SL synchronization signal burst configured as a synchronization reference Sync-Ref UE is transmitted on the selected carrier frequency.

19. The method as described in claim 11, characterized in that, The indicator includes Radio Access Technology (RAT) shared bits associated with a carrier frequency in the NR SL frequency carrier configuration.

20. The method of claim 19, further comprising: When one of the one or more carrier frequencies is associated with the indicator, if the RAT shared bit is set to true, a frequency shift is performed on the selected carrier frequency during NR SL reception.

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