Methods and apparatus for sidelink carrier aggregation enhancements

Abstract

A user equipment (UE) includes one or more non-transitory computer-readable media having computer-executable instructions embodied thereupon 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, by a serving cell of a first radio access technology (RAT), a sidelink (SL) resource configuration of a second RAT; determine first validity area information associated with the first RAT and second validity area information associated with the second RAT, the first and second validity area information being associated with different frequency carriers; and identify, based on the first and second validity area information, a validity area of the SL resource configuration.

Description

[0001] Cross-references to related applications

[0002] This disclosure claims the benefit and priority of provisional U.S. patent application Serial No. 62 / 931,401, filed November 6, 2019, entitled “SL Carrier Aggregation Enhancement” (hereinafter referred to as “'401 Provisional Case”). The disclosure of '401 Provisional Case is hereby incorporated herein by reference in its entirety for all purposes. Technical Field

[0003] This disclosure relates to wireless communication, and more specifically, to methods and apparatus for sidelink (SL) carrier aggregation enhancement 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 different use cases, such as vehicle-to-vehicle (V2V), vehicle-to-pedestrian (V2P), and vehicle-to-everything (V2X) communications.

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

[0007] This disclosure relates to methods and apparatus for enhancing SL carrier aggregation in wireless communication networks.

[0008] According to a first aspect of the present disclosure, a user equipment (UE) includes one or more non-transitory computer-readable media having computer-executable instructions embodied thereon 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, by a serving cell of a first radio access technology (RAT), a sidelink resource configuration of a second RAT; determine first validity area information associated with the first RAT and second validity area information associated with the second RAT, the first and second validity area information being associated with different frequency carriers; and identify, based on the first and second validity area information, a validity area of the sidelink resource configuration.

[0009] In an implementation form of the first aspect, the at least one processor is further configured to execute the computer-executable instructions to access, after the validity area is identified as valid, sidelink resources associated with the validity area.

[0010] In a further implementation form of the first aspect, the first validity area information is associated with a first public land mobile network identity, PLMN identity, or a first non-public network identity, NPN identity, in a list of PLMN identities or a list of NPN identities, respectively, which are broadcast by the serving cell.

[0011] In yet another implementation form of the first aspect, the second validity area information is associated with at least one of one or more SL transmission resource pools, one or more SL reception resource pools, one or more (type 1 / type 2) sidelink configured grants, and one or more SL exceptional transmission resource pools.

[0012] In yet another implementation form of the first aspect, the first RAT is a 5th generation new radio (5G NR) RAT.

[0013] In yet another implementation form of the first aspect, the NR sidelink communication is considered as part of (or associated with) the 5G NR RAT.

[0014] In yet another implementation form of the first aspect, the NR sidelink communication is implemented based on the 5G NR RAT.

[0015] In yet another implementation form of the first aspect, the second RAT is an evolved universal terrestrial radio access (E-UTRA) RAT.

[0016] In yet another embodiment of the first aspect, the sidelink resource configuration of the second RAT is for Long Term Evolution (LTE) Vehicle-to-Everything (V2X) sidelink communication associated with an Evolved Universal Terrestrial Radio Access (E-UTRA) RAT.

[0017] In yet another embodiment of the first aspect, V2X sidelink communication and sidelink communication / discovery are considered as part of (or associated with) an E-UTRA RAT.

[0018] In yet another embodiment of the first aspect, V2X sidelink communication and sidelink communication / discovery are implemented based on an E-UTRA RAT.

[0019] In yet another embodiment of the first aspect, sidelink resource configuration of a second RAT (e.g., V2X sidelink communication) is received through system information broadcast by a serving cell of a first RAT.

[0020] In yet another embodiment of the first aspect, sidelink resource configuration of a first RAT (e.g., NR sidelink communication) is received through system information broadcast by a serving cell of a second RAT.

[0021] In yet another embodiment of the first aspect, the valid area of the sidelink resource configuration consists of at least one systemInformationAreaID broadcast by the serving cell of the first RAT.

[0022] In yet another embodiment of the first aspect, when the systemInformationAreaID is absent or the sidelink resource configuration is not indicated by the systemInformationAreaID broadcast by the serving cell, a first valid area of the first RAT consists of a cell identity of the serving cell of the first RAT.

[0023] In yet another embodiment of the first aspect, the sidelink resource configuration associated with the valid area is invalidated by the UE after the UE moves out of a first valid area associated with the first valid area information and / or a second valid area associated with the second valid area information.

[0024] According to a second aspect of the disclosure, a communication method performed by a UE is provided. The method comprises: receiving, by a serving cell of a first radio access technology (RAT), a sidelink resource configuration of a second RAT; determining first validity area information associated with the first RAT and second validity area information associated with the second RAT, the first and second validity area information being associated with different frequency carriers; and identifying, based on the first and second validity area information, a validity area of the sidelink resource configuration.

[0025] In an implementation form of the second aspect, the method further comprises that after the validity area is identified as valid, the UE can access the SL resources associated with the validity area.

[0026] In another implementation form of the second aspect, the first validity area information is associated with a first public land mobile network identity (PLMN identity) in a list of PLMN identities or a first PLMN identity in a list of non-public network identities (NPN identities), wherein the list of PLMN identities and the list of NPN identities are broadcasted by the serving cell.

[0027] In yet another implementation form of the second aspect, after a cell (re)selection procedure triggered by a UE mobility event, the UE can further check the first validity area information by checking whether the first PLMN identity (or the first NPN identity) of the serving cell has changed. Furthermore, when the UE is checking the validity of the first validity area information and the UE is not in standalone non-public network (SNPN) access mode, the UE can check the first PLMN identity (in the list of PLMN identities broadcasted by the serving cell). On the other hand, when the UE is checking the validity of the first validity area information and the UE is in SNPN access mode, the UE can check the first NPN identity (in the list of NPN identities broadcasted by the serving cell).

[0028] In yet another implementation form of the second aspect, the second validity area information is associated with at least one of one or more SL transmission resource pools, one or more SL reception resource pools, one or more SL exceptional transmission resource pools, and one or more (type 1 / type 2) sidelink configured grants.

[0029] In yet another implementation form of the second aspect, the first RAT is a 5th generation new radio (5G NR) RAT.

[0030] In yet another implementation form of the second aspect, the second RAT is an evolved universal terrestrial radio access (E-UTRA) RAT.

[0031] In a further implementation form of the second aspect, the sidelink resource configuration of the second RAT (e.g., V2X sidelink resource configuration associated with the E-UTRA RAT) is received through system information broadcast by a serving cell (e.g., NR cell) of the first RAT.

[0032] In a further implementation form of the second aspect, the valid area of the sidelink resource configuration consists of at least one systemInformationAreaID broadcast by the serving cell of the first RAT.

[0033] In a further implementation form of the second aspect, when the systemInformationAreaID is absent or the sidelink resource configuration is not indicated by the systemInformationAreaID broadcast by the serving cell, a first valid area of the first RAT consists of a cell identity of the serving cell of the first RAT.

[0034] In a further implementation form of the second aspect, the sidelink resource configuration associated with the valid area is invalidated by the UE after the UE moves out of a first valid area associated with the first valid area information or a second valid area associated with the second valid area information. BRIEF DESCRIPTION OF DRAWINGS

[0035] Various aspects of the disclosure can be best understood from the following detailed description taken in conjunction with the accompanying drawings. Various features are not drawn to scale. The sizes of various features can be increased or reduced for the sake of clarity. Figure One

[0036] Figure 1 is a diagram illustrating LTE / NR (V2X) SL operation according to an example embodiment of the present disclosure.

[0037] Figure 2A and Figure 2B is a diagram illustrating carrier aggregation for (LTE) V2X SL communication / NR SL communication according to an example embodiment of the present disclosure.

[0038] Figure 3 is a flowchart 300 of a method for NR SL operation performed by a UE according to an example embodiment of the present disclosure.

[0039] Figure 4 is a diagram illustrating a UE performing SL synchronization and SL cell (re)selection procedure under fallback mechanism to cross-carrier valid area configuration according to an example embodiment of the present disclosure. ​

[0040] Figure 5 Range-based SL resource association according to example embodiments of the present disclosure is shown.

[0041] Figure 6 is a block diagram illustrating a node for wireless communication according to various aspects of the present disclosure. DETAILED DESCRIPTION

[0042] The following description contains specific information pertaining to implementations in the present disclosure. The drawings and their accompanying descriptions should be understood to be in no way limiting of the implementation(s). The present disclosure is susceptible to alterations and modifications, which are specifically intended to be encompassed by the present disclosure.

[0043] Unless otherwise noted, like or similar elements throughout the figures can be referred to with like or similar reference numerals. Also, the figures and illustrations can not be to scale, and are generally intended for use in explaining principles of operation.

[0044] For consistency and ease of understanding, like reference numbers are used to designate like features across the figures (although some figures can not show all of the features). Features in different implementations can also be different in other respects as well. No single feature, material, or implementation is critical or essential to all implementations.

[0045] The phrase “in one implementation,” or “in some implementations,” can each refer to one or more of the same or different implementations. The term “coupled” is defined as connected, whether directly or indirectly through intervening components, and is not necessarily limited to a physical or mechanical connection. The term “includes” means “includes, but is not limited to”; it specifically indicates that under this description, an open-ended inclusion is intended such that other items, materials, acts, events or components not specifically recited are also contemplated. The expression “at least one of A, B and C” or “at least one of the following items: A, B and C” means “A or B or C or any combination of these items.”

[0046] The terms “system” and “network” can be used interchangeably. The term “and / or” is used to describe an association relationship of associated objects, and means that there can be three relationships, that is, A and / or B can represent A alone, A and B simultaneously, or B alone. The character “ / ” generally represents an “or” relationship between associated objects.

[0047] For the purpose of explanation and not limitation, specific details are set forth, such as functional entities, techniques, protocols, and standards, to provide an understanding of the disclosed technology. In other examples, detailed descriptions of well-known methods, techniques, systems, architectures, and the like are omitted so as not to obscure the description with unnecessary detail.

[0048] Those skilled in the art will immediately recognize that any of the network functions or algorithms disclosed can be implemented by hardware, software, or a combination of software and hardware. The functions described can correspond to modules, which can be software, hardware, firmware, or any combination thereof.

[0049] Software implementations can include computer-executable instructions stored on computer-readable media such as memory or other type of storage devices. One or more microprocessors or general purpose computers with communication processing capabilities can be programmed with the corresponding executable instructions and perform the disclosed network functions or algorithms.

[0050] These microprocessors or general purpose computers can include Application Specific Integrated Circuitry (ASIC), programmable logic arrays, and / or use one or more Digital Signal Processors (DSP). While several implementations are directed to software installed and executed on computer hardware, alternative implementations implemented as firmware or hardware or a combination of hardware and software are well within the scope of the present 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 Read-Only Memory (CD-ROM), tape, magnetic disk storage or any other equivalent storage medium in which computer readable instructions can be stored.

[0051] A radio communication network architecture such as a Long Term Evolution (LTE) system, an LTE-Advanced (LTE-A) system, an LTE-Advanced Pro system, or a 5G NR radio access network (RAN) generally includes at least one base station (BS), at least one UE, and one or more optional network elements providing connectivity to a network such as a core network (CN), an evolved packet core (EPC) network, an evolved universal terrestrial radio access network (E-UTRAN), a 5G core (5GC), or the Internet.

[0052] A UE can include, but is not limited to, a mobile station, a mobile terminal or device, a user communication radio terminal. The UE can be a portable radio equipment such as, but not limited to, a mobile phone, a tablet computer, a wearable device, a sensor, a vehicle, or a personal digital assistant (PDA) with wireless communication capabilities. The UE is configured to receive signals over an air interface and to transmit signals to one or more cells in a RAN.

[0053] The BS can be configured to provide communication services according to at least one of the following radio access technologies (RATs): Worldwide Interoperability for Microwave Access (WiMAX), Global System for Mobile Communications (GSM) often referred to as 2G, GSM EDGE Radio Access Network (GERAN) for Enhanced Data rates for GSM Evolution (EDGE), General Packet Radio Service (GPRS), Universal Mobile Telecommunication System (UMTS) often referred to as 3G based on Basic Wideband-Code Division Multiple Access (W-CDMA), High-Speed Packet Access (HSPA), LTE, LTE-A, evolved LTE (eLTE, i.e., LTE connected to 5GC), NR (often referred to as 5G), and / or LTE-A Pro. However, the scope of the present disclosure is not limited to these protocols.

[0054] The BS can include, but is not limited to, a Node B (NB) in UMTS, an evolved Node B (eNB) in LTE or 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 a 5G-RAN, and any other apparatus that can control radio communication and manage radio resources within a cell. The BS can serve one or more UEs through a radio interface.

[0055] The BS can operate to provide wireless radio coverage to a specific geographic area using a plurality of cells forming a RAN. The BS supports operation of the cells. Each cell can operate to provide service to at least one UE within its radio coverage.

[0056] Each cell (often referred to as a serving cell) provides service to serve one or more UEs within its radio coverage such that each cell schedules DL and optional Uplink (UL) resources to at least one UE within its radio coverage for DL and optional UL packet transmissions. A BS can communicate with one or more UEs in a wireless communication system through multiple cells.

[0057] A cell can allocate SL resources for supporting Proximity Service (ProSe), sidelink services (e.g., (LTE) sidelink communication service and / or (LTE) sidelink discovery service), or Vehicle-to-Everything (V2X) services (e.g., NR sidelink communication and / or (LTE) V2X sidelink communication). Each cell can have an overlapping coverage area with other cells.

[0058] As previously mentioned, the frame structure for NR supports flexible configurations for accommodating 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 meeting high reliability, high data rate, and low latency demands. Orthogonal Frequency Division Multiplexing (OFDM) technology as in the 3rd Generation Partnership Project (3GPP) can be used as a baseline for the NR waveform. Scalable OFDM numerology, such as adaptive subcarrier spacing, channel bandwidth, and cyclic prefix (CP) can also be used.

[0059] Two coding schemes are considered for NR, specifically, Low-Density Parity-Check (LDPC) codes and Polar codes. Coding scheme adaptation can be configured based on channel conditions and / or service applications.

[0060] When a transmission time interval (TTI) of a single NR frame includes DL transmission data, a guard period, and UL transmission data, each part of the DL transmission data, the guard period, and the UL transmission data can be configured based on the network dynamics of NR. SL resources can also be provided in the NR frame to support ProSe services or V2X services.

[0061] The following gives an exemplary description of some selected terms used in the present disclosure.

[0062] Primary Cell (PCell): For Dual Connectivity (DC) operation or Carrier Aggregation (CA) operation, the PCell is the master cell group (MCG) cell operating on the primary frequency in which the UE performs the initial connection establishment procedure or initiates the connection re-establishment procedure.

[0063] Primary SCG Cell (PSCell): For DC operation, the PSCell is the secondary cell group (SCG) cell in which the UE performs random access when performing reconfiguration with sync procedure.

[0064] Special Cell: For DC operation, the term Special Cell (SpCell) refers to either the PCell of the MCG or the PSCell of the SCG, otherwise (e.g., for CA operation), the term Special Cell refers to the PCell.

[0065] Secondary Cell: For a UE configured with Carrier Aggregation (CA), a cell that provides additional radio resources on top of a particular cell.

[0066] Serving Cell: For a UE in RRC_CONNECTED that is not configured with CA / DC, there is only one serving cell, which can be referred to as the primary cell. For a UE in RRC_CONNECTED that is configured with CA / DC, the term "serving cells" can be used to denote the set of cells including the SpCell(s) and all secondary cells.

[0067] Listen Before Talk (LBT) is a feature available in Wi-Fi that allows coexistence with other Wi-Fi nodes. LBT is a mechanism where a device applies a clear channel assessment (CCA) before using a channel. The Third Generation Partnership Project (3GPP) chose to specify a conservative LBT scheme similar to the one used by Wi-Fi nodes to ensure coexistence of Licensed Assisted Access (LAA) with Wi-Fi. LAA uses carrier aggregation in the DL to combine LTE in the licensed band with LTE in the unlicensed spectrum (e.g., 5 GHz). In NR, LBT can also be required before any transmission when operating on unlicensed spectrum.

[0068] In this disclosure, different embodiments focus on the functionality of NR cell supporting SL operation under SL carrier aggregation. In this disclosure, both frequency range 1 (FR1) and frequency range 2 (FR2) can be considered to support (NR-V2X) SL operation. A UE can need additional power to support SL operations such as SL synchronization, sidelink resource (pool) configuration, and SL (re)selection across multiple SL component carriers (serving / non-serving). To reduce the power consumption of the UE supporting these SL operations, various embodiments of this disclosure provide, in addition to this, cross-carrier valid area configuration in SL resource configuration as discussed in Embodiment 1 of this disclosure. Also, various embodiments of this disclosure provide, in addition to this, fallback mechanisms when there is no cross-carrier valid area configuration as discussed in Embodiment 2 of this disclosure.

[0069] In various embodiments of this disclosure, to maintain channel quality (e.g., beam management) in FR2, range-based SL resource association is provided to enable SL logical channel (LCH) to be associated with different combinations of SL component carriers (thus as SL resource configuration on these configured SL components) based on the distance (e.g., physical distance) between UEs (e.g., transmitting (Tx) / receiving (Rx) UEs) as discussed in Embodiment 2 of this disclosure.

[0070] In the SL carrier aggregation scenario, in some embodiments of the disclosure, NR non-standalone (NSA) cells can not support LTE / NR SL operation. In addition, the UE can not attempt to decode system information (e.g., SIB1) broadcast by the NR NSA cell to obtain system information on SL resource configuration for LTE V2X sidelink (communication) service and NR V2X service / NR sidelink (communication) service (e.g., the NSA cell is not a suitable cell for the UE, and if the UE is in a limited service state, the UE cannot access V2X service). In some embodiments of the disclosure, some component carriers can be deployed with NR NSA cells. As a result, the UE can select to camp on the NR NSA cell. For example, the UE can be in a 'camp on any cell' state, and the camped NSA cell is an 'acceptable cell' for the UE. However, these NSA cells can still support NR / LTE SL operation, and these NSA cells can still broadcast one or more SL configurations to the UE in system information. The UE can be in a limited service state and be able to access (public safety) V2X service or public safety related SL service. Embodiment 3 of the disclosure describes how the NR NSA cell supports NR / LTE SL operation.

[0071] In addition, with the introduction of FR2 for SL carrier aggregation, embodiments of the disclosure provide assistance information on how component carriers in FR1 can convey channel quality or packet delivery status. As described below, Embodiment 4 of the disclosure provides support for 'FR2 assistance information exchange' on FR1. In the disclosure, the range of FR1 can be designated to SL component carriers in a lower frequency range (e.g., less than 7 GHz), and the range of FR2 can be designated to SL component carriers in a higher frequency range (e.g., more than 7 GHz). Embodiments of the disclosure can be applied to SL unicast group scenarios, SL multicast / groupcast group scenarios, and SL broadcast scenarios. In addition, embodiments of the disclosure can be applicable to public-safety V2X services, non-public safety (e.g., commercial) V2X services, and (public-safety / non-public-safety) SL communication / discovery services.

[0072] Embodiment 5 of the disclosure provides stored valid areas and SL resource configurations across service frequencies and non-service frequencies, while cell (re)selection can be implemented on service frequencies and non-service frequencies.

[0073] Embodiment 1: Cross-carrier valid area configuration

[0074] Referring to Figure 1 , Figure 1 is a diagram 100 illustrating V2X SL operation according to an exemplary embodiment of the disclosure. In Figure 1In some embodiments, 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) services and / or LTE-V2X (sidelink) services based on configured NR and / or LTE SL configurations (e.g., NR SL configurations and LTE V2X configurations). It should be noted that, in some embodiments, LTE V2X services can include LTE V2X communication over LTE Uu interface (e.g., packet exchange over downlink / uplink direction between a UE and a serving radio access network) and / or LTE V2X SL packet exchange over LTE PC5 interface (e.g., LTE V2X SL communication and / or LTE V2X SL discovery between UEs). Thus, in some embodiments, LTE V2X configurations can include configurations for LTE V2X communication over LTE Uu interface and / or LTE V2X SL communication / LTE V2X SL discovery over LTE PC5 interface (e.g., LTE V2X SL configurations). It should also be noted that, in some embodiments, NR SL services can include NR SL packet exchange over NR PC5 interface (e.g., NR SL communication and / or NR SL discovery between UEs). Thus, in some embodiments, NR SL configurations can include configurations for NR SL communication and / or NR SL discovery. Further, NR SL communication can include NR SL transmission (e.g., one UE transmitting NR SL packets and / or SL NR control messages (e.g., SL control information (SCI) and / or SL NR control messages (RRC signaling and / or SL hybrid automatic repeat request (HARQ) acknowledgement / negative acknowledgement messages)) and / or NR SL synchronization signals (NR SL synchronization burst set) to proximate UEs in the same NR SL unicast / multicast (groupcast) / broadcast group, and / or NR SL reception (e.g., one UE receiving NR SL packets and / or NR SL control messages (e.g., SCI or PC5 RRC signaling) and / or NR SL synchronization signals (NR SL synchronization burst set) from proximate UEs in the same NR SL unicast / multicast (groupcast) / broadcast group).

[0075] In various embodiments of the disclosure, a serving cell (e.g., an NR cell in Figure 1 may configure multiple SL CCs and associated RATs (or associated RANs) in the corresponding SL CCs. According to exemplary embodiments of the disclosure, reference is made to Figure 1, at least two UEs (e.g., UE1 and UE2) can be configured in an (Access Stratum (AS)-layer / Non-Access Stratum (NAS)) multicast group to enable NR-SL (also referred to as NR-V2X (sidelink) in some applications) services and / or LTE-V2X (sidelink) services based on the configured NR and / or LTE SL configuration. In various embodiments of the disclosure, the serving cell (e.g., NR cell in Figure 1 , the NR cell in Figure 1 , at least two UEs (e.g., UE1 and UE2) can be configured in an (Access Stratum (AS)-layer / Non-Access Stratum (NAS)) multicast group to enable NR-SL (also referred to as NR-V2X (sidelink) in some applications) services and / or LTE-V2X (sidelink) services based on the configured NR and / or LTE SL configuration. In various embodiments of the disclosure, the serving cell (e.g., NR cell in Figure 1 , the NR cell in

[0076] ProSe (Proximity Services) unicast group (or SL unicast group in AS layer) can be in-coverage, partial-coverage, or out-of-coverage of a serving RAN (i.e., NR RAN connected to 5GC (5G Core) and / or EPC (Evolved Packet Core) as shown in Figure 1 ProSe unicast group (or SL unicast group in AS layer) can be in-coverage, partial-coverage, or out-of-coverage of a serving RAN (i.e., E-UTRAN (Evolved Universal Terrestrial Radio Access Network) connected to EPC (Evolved Packet Core) and / or 5GC (5G Core)).

[0077] In Figure 1 , a (NR) gNB in an NR-RAN (or an LTE eNB in an E-UTRAN) can provide physical resources to support NR-V2X SL operation and / or LTE-V2X SL operation. An interface between UE1 and UE2 supporting NR-V2X SL operation is referred to as an NR PC5 interface. For example, the NR PC5 interface can be configured by a serving RAN (e.g., an NR-RAN or an E-UTRAN), or by a pre-configuration that can be stored in a memory module or a USIM (UMTS Subscriber Identity Module) of a UE, to support NR V2X services. An interface between vehicles supporting LTE-V2X SL operation is referred to as an LTE PC5 interface. The LTE PC5 interface can be configured by a serving RAN (e.g., an NR-RAN or an E-UTRAN), or by a pre-configuration that can be stored in a memory module or a USIM (UMTS Subscriber Identity Module) of a UE, to support LTE V2X services. In some embodiments, a serving NR cell is a PCell (primary cell) for a UE. In some embodiments, a serving NR cell can be a PSCell (primary SCell) for a UE while the UE is configured with additional secondary nodes based on NR dual connectivity (or multi-connectivity) configuration. Further, the serving PSCell can transmit SL resource configurations directly to the UE through a configured radio bearer (e.g., SRB3). It should be noted that, in embodiments of the disclosure, the serving RAN is not limited to an NR RAN. For example, the serving RAN can be an E-UTRAN. Further, embodiments of the disclosure can cover both intra-RAT SL resource configuration (e.g., an NR cell can provide NR SL resource configuration and a LTE cell can provide LTE (V2X) SL resource configuration) and inter-RAT SL resource configuration (e.g., an NR cell can provide LTE SL resource configuration and a LTE cell can provide NR SL resource configuration).

[0078] Referring to Figure 2A and Figure 2B , Figure 2A and Figure 2B are diagrams illustrating V2X SL carrier aggregation according to example embodiments of the disclosure. As shown in diagram 200A in Figure 2A , one or more UEs (e.g., UE1 and UE2) can be served by a serving cell (cell #1) via an SL component carrier (e.g., CC #1). As shown in diagram 200B in Figure 2BAs shown in diagram 200B, cell #1 is deployed in CC#1, which is in FR1. As also shown in diagram 200B, there are several cells (cell #A, cell #B, and cell #C) deployed in another SL component carrier (e.g., CC#2). In one example, CC#2 is in FR2. Both CC#1 and CC#2 support (NR / LTE) SL operation. In addition, CC#2 can have paired DL frequency carriers (e.g., also in FR2) in cell #A, cell #B, cell #C in the (LTE / NR) Uu interface. It should be noted that CC#1 / CC#2 can or can not be a secondary frequency carrier to the UE when the UE(s) is configured with carrier aggregation in the (LTE / NR) Uu interface. In addition, in some further embodiments, CC#1 / CC#2 can or can not be the serving frequency carrier to the UE when the UE(s) performs SL operation with a non-serving cell operating on a non-serving frequency carrier.

[0079] In this disclosure, cell #1 can configure the UE(s) (e.g., UE1 and UE2) with an indication of the SL resource configuration of CC#2 with cross-carrier valid area configuration. In addition, the UE(s) can not need to perform SL synchronization and SL cell (re)selection on the associated SL frequency carrier of CC#2. In the involved frequency carriers, the UE(s) can not be configured with special cell(s) and secondary cell(s). In other words, for the UE, the involved CC#2 is neither a primary frequency carrier nor a secondary frequency carrier. In some embodiments, the serving cell (e.g., cell #1 in FIG. 2) can transmit timing adjustment instructions (e.g., timing advance instructions) to the UE to adjust their transmission timing based on the instructions from the serving cell.

[0080] In contrast, in LTE V2X protocol, the SL resources among multiple SL carriers can be configured by v2x-InterFreqInfoList (e.g., by broadcast system information or by dedicated RRC signaling over the Uu interface). It should be noted that in some embodiments, the UE(s) can need to implement SL synchronization and SL cell (re)selection on the relevant frequency (or on the paired DL frequency carrier for transmitting V2X SL communication) while the relevant frequency carrier is not the serving frequency of the UE. In some other embodiments, the UE(s) can be optionally configured with SyncFreqList, which specifies a list of candidate SL synchronization carrier frequencies for V2X SL communication on these non-serving frequency carriers. The additional SL synchronization can require additional power consumption of the UE.

[0081] In embodiments of this disclosure, as shown in diagram 200B,Figure 2A As shown, cell #1 can transmit the SL resource configuration (as well as the cross-carrier validity area configuration) related to CC #2 to the UE through control signaling (e.g., through broadcast system information or (UE-specific) dedicated RRC signaling). In addition, the associated validity area can consist of the cell(s) in CC #1, and cell #1 can also be located in the given validity area. In some embodiments, the validity area can consist of one or more cell identities, physical cell identities, systemInformationAreaIDs, RAN notification area codes, or tracking area codes, etc. The cell(s) in CC #1 can also transmit assistance information (e.g., cell identities, physical cell identities, systemInformationAreaIDs, RAN notification area codes, tracking area codes, and / or area IDs that the cell(s) belong to) to the UE to identify the scope of the validity area.

[0082] Based on the associated validity area configuration, the UE can directly transmit SL packets on CC #2 without the need to implement SL synchronization or SL cell (re)selection on CC #2 (or the DL frequency carrier associated with CC #2). The UE can transmit SL packets on CC #2 based on the timing reference obtained by the UE from CC #1. In addition, the UE can not need to use the DL frequency carrier associated with CC #2 in the LTE / NR Uu interface (which can also be the operating DL frequency carrier of cell #A, cell #B, and / or cell #C) as the timing reference when the UE transmits SL packets on CC #2. In some further embodiments, the UE can still implement sidelink synchronization and / or (non-serving) cell (re)selection on CC #2. However, the UE can only need to check whether the selected cell on CC #2 is located on the sidelink resource validity area based on the pre-stored validity area information related to CC #2 (e.g., the UE can receive the MIB and / or system information block type 1 (SIB1) of the selected cell after the cell (re)selection procedure (e.g., for cell identity reception and / or system information area ID reception that can be broadcast by the selected cell in the MIB / SIB1). Then, the UE can check the validity of the stored sidelink resource configuration based on the received cell identity / system information area ID broadcast by the selected cell and the stored validity area information associated with the stored sidelink resource configuration. However, the UE can not need to listen to other system information or broadcast control signaling broadcast by the selected cell for sidelink resource configuration reception when the stored sidelink resource configuration is still valid.

[0083] In some embodiments, cell #1 (e.g., an NR cell) can support both a normal uplink (NUL) carrier and at least one supplementary uplink (SUL) carrier. Further, cell #1 can provide SL resource configurations in both the NUL carrier and the SUL carrier. For example, at least one SL bandwidth part (BWP) configuration is associated with the NUL carrier, and at least one SL BWP configuration is associated with the SUL carrier. Accordingly, the UE(s) can transmit SL packets by accessing SL resources on the NUL carrier and / or the SUL carrier. In some embodiments, the UE(s) can transmit SL packets on both the NUL carrier and the SUL carrier simultaneously. In some embodiments, the UE(s) can select SL resource(s) only on the NUL carrier or the SUL carrier (e.g., depending on whether the NUL or the SUL is used in the UL direction).

[0084] In some embodiments, the UE can need to transmit the UE's SL carrier aggregation capability to the serving cell.

[0085] As shown in FIG. 1, the UE can transmit the UE's SL carrier aggregation capability to the serving cell. The UE can transmit the UE's SL carrier aggregation capability to the serving cell through a UE capability enquiry message (e.g., a UE capability enquiry message in an RRC connection request message, an RRC connection resume message, or an RRC connection reconfiguration message). The UE can transmit the UE's SL carrier aggregation capability to the serving cell through a UE capability enquiry message (e.g., a UE capability enquiry message in an RRC connection request message, an RRC connection resume message, or an RRC connection reconfiguration message). The UE can transmit the UE's SL carrier aggregation capability to the serving cell through a UE capability enquiry message (e.g., a UE capability enquiry message in an RRC connection request message, an RRC connection resume message, or an RRC connection reconfiguration message). Figure 2B As shown in FIG. 1, the effective area configuration in FR2 can be associated with cell #1 in FR1. Embodiments of the present disclosure can improve the UE's power consumption because the UE does not need to perform SL synchronization and SL cell (re)selection in FR2.

[0086] As described above, the SL synchronization on CC #1 can be performed with a global navigation satellite system (GNSS), a base station (eNB or gNB), or a neighboring UE (LTE UE or NR UE). Further, in some embodiments, the UE can be in an NR-RRC idle state, an NR-RRC deactivated state, an LTE-RRC idle state, or an LTE-RRC deactivated state. In some embodiments of the present disclosure, the UE can receive the above-mentioned configurations through system information. In some embodiments of the present disclosure, the UE can receive the above-mentioned configurations when the UE is in an NR-RRC connected state or an LTE-RRC connected state. In some embodiments of the present disclosure, the UE can receive the above-mentioned configurations through (UE-specific) dedicated RRC signaling. In some embodiments of the present disclosure, the UE can receive the above-mentioned configurations through dedicated RRC signaling (e.g., an RRC connection resume message, an RRC release message with a suspend configuration) when the UE is in an NR-RRC deactivated state or an LTE-RRC deactivated state.

[0087] As shown in FIG. 1, the effective area configuration in FR2 can be associated with cell #1 in FR1. Embodiments of the present disclosure can improve the UE's power consumption because the UE does not need to perform SL synchronization and SL cell (re)selection in FR2. Figure 2AAs shown, the UE (e.g., UE1 and / or UE2) is camping on cell #1 (located on FR1) in CC#1. The UE can be in NR-RRC deactivated state / NR-RRC idle state / NR-RRC connected state.

[0088] In some embodiments, the SL resource configuration on FR1 (e.g., CC#1) and FR2 (e.g., CC#2) can be configured with one associated validity area. At the UE side, the UE (e.g., UE1 and / or UE2) can be aware that the SL resource configuration on CC#2 is valid within the coverage of the configured validity area associated with the cell (e.g., cell #1) in CC#1. In addition, the UE (e.g., UE1 and / or UE2) can not need to perform SL synchronization or SL cell (re)selection in CC#2 when the UE is accessing the configured SL resource (e.g., when the UE is transmitting SL packets on the configured SL resource). In some further embodiments, the UE can still implement sidelink synchronization and / or (non-serving) cell (re)selection on CC#2. However, the UE can only need to check whether the selected cell on CC#2 is located in the sidelink resource validity area based on the pre-stored validity area information related to CC#2. In other words, the UE can not need to monitor other DL control signaling for sidelink resource configuration transmitted by the selected cell on CC#2.

[0089] In some embodiments, the configured SL resource can include dynamic SL grant, Type 1 SL configured grant, Type 2 SL configured grant, SL resource pool, and SL exceptional pool in the designated SL component carrier (e.g., CC#2) in Figure 2B In addition, it should be noted that the serving cell (e.g., cell #1) can transmit the configuration of Type 1 SL configured grant to the UE (e.g., UE1 and / or UE2) through broadcast message (e.g., system information) or dedicated control signaling (e.g., (UE-specific) RRC signaling). At the UE side, the configuration of Type 1 SL configured grant is valid to the UE (e.g., UE1 and / or UE2) after the UE successfully decodes the configuration from the serving cell. Therefore, the UE (e.g., UE1 and / or UE2) can transmit SL packets by accessing the configured Type 1 SL configured grant.

[0090] A serving cell (e.g., cell #1) can transmit part of the configuration of a type 2 SL configured grant (e.g., a periodicity in time domain for type 2 SL configured grant) to a UE (e.g., UE1 and / or UE2) through a broadcast message (e.g., system information) or dedicated control signaling (e.g., RRC signaling). The serving cell can then configure other parts of the type 2 SL configured grant (e.g., locations of SL resource blocks, such as sub-channels and symbols in frequency and time domain, respectively) by transmitting other dedicated control signaling to the UE (e.g., downlink control information scrambled by the C-RNTI of the UE or a medium access control control element (MAC CE)). Thus, after receiving the DCI from the serving cell (e.g., cell #1 in CC #1), the configured type 2 SL configured grant is activated to the UE, and thus the UE can transmit SL packets on the configured type 2 SL configured grant. On the other hand, for an activated SL configured grant, the serving cell can transmit another DCI to deactivate the SL configured grant. After receiving the deactivation message, the UE can stop accessing the configured type 2 SL configured grant and release the stored configuration received by the UE through the activation DCI message. In other words, the configuration received through RRC signaling can still be kept by the UE so that the next time the serving cell can configure other SL resources in another activation DCI to activate one type 2 SL configured grant.

[0091] The SL resource pool configuration or SL exceptional resource pool configuration can be provided to a UE (e.g., UE1 and / or UE2) so that the UE can autonomously select a SL grant with / without (e.g., through random selection) sensing or through a partial sensing mechanism.

[0092] The SL resource configuration can be associated with (at least) one SL bandwidth part (SL-BWP) configuration in one SL component carrier. Each SL bandwidth part configuration can include a numerology (e.g., length of cyclic prefix, subcarrier spacing, etc.) to operate the SL component carrier.

[0093] It should be noted that, in various embodiments of the present disclosure, the RRC signaling can cover RRC signaling in (LTE / NR) Uu interface, such as RRC (Connection) (Re)Establishment message, RRC (Connection) Setup message, RRC (Connection) Resume message, RRC (Connection) Release message with / without suspend configuration, RRC (Connection) Reconfiguration message with / without mobilitycontrolinfoV2X, or RRC (Connection) Reconfiguration message with / without reconfigurationwithsync message, etc. Furthermore, when the serving RAN is instructing the UE to implement a (intra-RAT / inter-RAT) handover procedure, secondary cell group change, etc., the reconfigurationwithsync / mobilitycontrolinfoV2X message can be conveyed.

[0094] It should be noted that the above-mentioned configurations can also be applicable during an intra-RAT (e.g., from a source LTE cell to a target LTE cell or from a source NR cell to a target NR cell) handover procedure, an inter-RAT (e.g., from a source LTE / NR cell to a target NR / LTE cell, respectively) handover procedure, an inter-system handover procedure in LTE protocol, a conditional handover procedure, and a Dual Active Protocol Stack (DAPS) handover procedure. In some further embodiments, the above-mentioned configurations can also be applicable during an MCG change / SCG change procedure. In addition, during the handover procedure, the serving cell can apply an incremental signaling method to reconfigure the SL resource configuration (e.g., the SL resource configuration of CC#2 in the present disclosure). For example, in order to provide a new SL resource (pool) configuration, the serving cell can transmit a SL_Resource_(Pool)_ToAddList to transmit the new SL resource (pool) configuration to the UE. Then, the UE can store the new SL resource (pool) configuration together with the stored SL resource (pool) configuration. In addition, all the stored SL resource (pool) configurations can be further associated with a SL resource (pool) index. Thus, the serving cell can instruct the UE to release one SL resource (pool) configuration by indicating the associated SL resource (pool) index in another SL_Resource_(Pool)_ToRemoveList. The SL_Resource_(Pool)_ToAddList and the SL_Resource_(Pool)_ToRemoveList can be included in the E reconfigurationwithsync (in NR protocol) / mobilitycontrolinfoV2X (in LTE protocol) when the serving cell is transmitting the RRC connection reconfiguration message to initiate the handover procedure. It should be noted that the above-mentioned mechanisms and signaling can also be applicable to the conditional handover procedure. It should be noted that the sidelink resource pool configuration can include a regular sidelink resource pool configuration and / or an exceptional sidelink resource pool configuration. It should be noted that the incremental signaling method can be applicable to the (Type1 / Type2) sidelink configured grant configuration.

[0095] In some embodiments, the UE can start accessing the configured SL resource (pool) after the handover procedure is successfully completed. In some embodiments, the UE can access the configured SL resource (pool) during the handover procedure. In some further embodiments, the UE can access the configured SL resource (pool) during the conditional handover procedure.

[0096] In some embodiments, the UE can obtain the timing advance command or timing offset value (or assistance information for the UE to adjust the timing when the UE transmits / receives the SL packet) in terms of symbol, microsecond, etc. for the SL packet transmission on FR2 by receiving the timing reference or timing advance command from the serving cell (e.g., cell #A) on FR1.

[0097] Table 1 shows the valid zone configuration of the SL resource in CC#1 in FR1 (e.g., Figure 2A or CC#2 in FR2 (e.g., Figure 2A .

[0098] Table 1: Cross-carrier valid zone configuration

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105] Figure 3 FIG. 3 is a flowchart 300 of a method for NR SL operation performed by a UE according to an example embodiment of the present disclosure.

[0106] In act 302, the UE can receive a SL resource configuration of a second radio access technology (RAT) (e.g., E-UTRA) by a serving cell of a first (e.g., 5G NR) RAT.

[0107] In act 304, the UE can determine first valid zone information associated with the first RAT and second valid zone information associated with the second RAT, the first and second valid zone information being associated with different frequency carriers.

[0108] In act 306, the UE can identify a valid zone of the SL resource configuration based on the first and second valid zone information.

[0109] In act 308, the UE can access the SL resource associated with the valid zone after the valid zone is identified as valid.

[0110] Embodiment 2: fallback mechanism for cross-carrier valid zone configuration

[0111] Referring to Figure 4 ,Figure 4 A diagram illustrates the UE performing SL synchronization and SL cell (re)selection processes under a backoff mechanism configured to cross-carrier effective areas, according to an exemplary embodiment of this disclosure.

[0112] In this implementation, after the UE moves out of the valid area to another valid area (e.g., valid area #2), the cross-carrier SL resource configuration associated with the valid area (e.g., valid area #1) can be invalidated by the UE.

[0113] In some implementations, after the UE moves out of the valid area associated with the stored SL resource configuration, the UE can release the invalid cross-carrier SL resource configuration.

[0114] In some implementations, the UE may begin performing the SL synchronization and SL cell (re)selection process in FR2 when one or more of the following backoff conditions are met:

[0115] Condition 1: In FR2, the UE may not have other SL resource configurations or valid areas configured (e.g., but CC#2 still supports SL in areas outside of valid area #1). In this case, the UE can initiate SL synchronization and SL cell (re)selection in SL CC#2 by itself.

[0116] Condition 2: Under some other conditions, the UE may be configured with another valid area #2 in FR1, but the UE may temporarily fail to find a suitable cell (e.g., when the UE moves to a coverage hole). In this case, the UE can perform SL synchronization and SL cell (re)selection in SLCC #2 by itself.

[0117] Condition 3: The serving cell in FR1 does not provide a valid area in FR1. Instead, the serving cell in FR1 can use a valid area indicated in FR2 (e.g., Figure 4 The effective area #2 in FR2 is used to configure SL resource configuration. For example, effective area #2 can consist of cells operating in CC #2. In some other implementations, effective area #2 consists of cellidentity / PCI / RANAC / tracking area code / SysteminformationareaID broadcast by cells in FR2. In this case, the UE can perform SL synchronization and SL cell (re)selection in SL CC #2 by itself.

[0118] It is important to note that after the SL cell (re)selection process, the UE can begin listening to system information broadcast by the selected (non-serving) cell for sidelink resource configuration reception (on CC#2).

[0119] Referring to Figure 5 , Figure 5 Range-based SL resource association according to example embodiments of the present disclosure is shown. In this embodiment, each SL LCH can have one or more associated SL carriers. One or more range-based SL resource configurations can be configured to the UE. For example, SL-resource configuration #1 and SL-resource configuration #2 can be provided to the UE based on a threshold of distance R1 (e.g., in meters).

[0120] In one example, a UE (e.g., UE#2 in FIG. 1) can apply SL-resource configuration #1 to utilize a paired UE (e.g., UE#1 in FIG. 1) to transmit SL packets when the physical distance between the Tx UE / Rx UE is less than R1. Figure 2A Figure 2A In another example, a UE (e.g., UE#2 in FIG. 1) can apply SL-resource configuration #2 to utilize a paired UE (e.g., UE#1 in FIG. 1) to transmit SL packets when the physical distance between the Tx UE / Rx UE is greater than R1.

[0121] For example, the value of R1 can reach several hundred meters.

[0122] In another example, a UE (e.g., UE#2 in FIG. 1) can apply SL-resource configuration #2 to utilize a paired UE (e.g., UE#1 in FIG. 1) to transmit SL packets when the physical distance between the Tx UE / Rx UE is greater than R1. Figure 2A Figure 2A In some embodiments, a UE (e.g., UE#2 in FIG. 1) can estimate the physical distance to another UE (e.g., UE#1 in FIG. 1) by receiving SL control information (SCI) transmitted by the (Tx) UE (e.g., by decoding the location information (such as zone ID or GNSS location information) of the Tx UE), for example, based on the first SCI and / or the second SCI received during the two-stage SCI transmission procedure. In some other embodiments, the UE can estimate the physical distance to another UE through other radio access technologies, such as NR positioning techniques or GNSS information exchange.

[0123] In another example, a UE (e.g., UE#2 in FIG. 1) can apply SL-resource configuration #2 to utilize a paired UE (e.g., UE#1 in FIG. 1) to transmit SL packets when the physical distance between the Tx UE / Rx UE is greater than R1. Figure 2A Figure 2A In another example, a UE (e.g., UE#2 in FIG. 1) can apply SL-resource configuration #2 to utilize a paired UE (e.g., UE#1 in FIG. 1) to transmit SL packets when the physical distance between the Tx UE / Rx UE is greater than R1.

[0124] ​​​It should be noted that SL packet delivery can become more critical when UE#1 and UE#2 are close to each other. In addition, channel impact (e.g., path loss) on different SL CCs can also need to be considered. Therefore, for one SL LCH, association with different SL CCs (and thus SL resource configurations, such as Type1 / Type2 SL configured grant, SL dynamic grant, resource pool, exceptional resource pool associated with SL CC) can help to maintain the QoS (Quality of Service) of SL packet delivery. As shown in Table 2, SL logical channel #1 can be associated with CC#1 (in FR1) in SL-resource configuration #2, because path loss impact in FR1 is less than path loss impact in FR2. Then, SL logical channel #1 can be associated with CC#2 (e.g., in FR2) in SL-resource configuration #2 when the physical distance between TxUE / RxUE is less than R1. In addition, in some other implementations, one SL LCH can be associated with more than one SL component carrier. As shown in Table 2, SL logical channel #2 can be associated with {CC#1} in SL-resource configuration #2, and the same SL logical channel #2 can be associated with {CC#1, CC#2, CC#3} in SL-resource configuration #2, and thus the UE can implement SL multiplexing to SL grant (based on received SL resource configuration in one SL CC, such as Type1 / Type2 SL configured grant, SL dynamic grant, resource pool, resource pool with zone configuration, exceptional resource pool associated with SL CC) based on the range-based association of SL LCH and SL CC. Also, it should be noted that in some implementations, the operating SL CC for SL HARQ or SL automatic repeat reQuest (ARQ) packet retransmission or SL packet repetition can be decided while the UE is preparing to transmit the first SL packet. Therefore, when the UE implements SL HARQ / ARQ packet retransmission and SL packet repetition for the same SL packet after the UE transmits the first SL packet, the UE can not change the operating SL CC. In some implementations, each time when the UE is preparing to transmit one or more SL packets (whether the SL packet is the first transmission, (SL-HARQ) retransmission, or repetition), the UE can independently decide the operating SL CC for each SL packet delivery (based on the configured rules).

[0125] Table 2: Range-based SL resource association

[0126]

[0127] In some embodiments, a default SL resource association (e.g., SL-resource configuration #1) can be indicated to UEs in an SL-group (e.g., unicast group or groupcast group). Thereby, if location information is (temporarily) not available at the Tx UE side, the Tx UE can apply the default SL resource association to transmit SL packets. In some embodiments, the default SL resource association can be obtained by SL pre-configuration or by a broadcast message (e.g., system information (SI)) or by an on-demand procedure of SI obtained by the Tx UE from the serving RAN.

[0128] Embodiment 3: NR non-standalone cell broadcast SL configuration

[0129] An NR non-standalone cell (NR-NSA cell) can also broadcast system information to support NR (public safety) V2X services / LTE V2X services or public safety SL communication services. In some embodiments, an NR-NSA cell can not broadcast a tracking area code (TAC) when the NR-NSA cell is broadcasting system information, and thus a UE can identify whether a cell is an NSA cell by checking the TAC. Further, when the UE is performing cell (re)selection (e.g., cell (re)selection in the (LTE / NR) Uu interface), the UE can consider an NR-NSA cell as a non-suitable cell. However, it can still be possible for the UE to select one NR-NSA cell as a cell for providing SL communication during (serving / non-serving) cell (re)selection. Thus, an NSA cell can become a serving cell for the UE, and the involved SL CC is also a serving frequency for the UE. At this stage, for the UE, the NR-NSA cell can be an ‘acceptable cell’, and after the (serving / non-serving) cell (re)selection procedure, the UE can select to camp on the NR-NSA cell (thus, the UE can also move to the ‘camped on any cell’ state). The UE can remain in the ‘restricted service state’. However, even in the ‘restricted service state’, when the UE camps on the NR-NSA cell, the UE can still be able to access several (restricted) LTE / NR V2X services through NR / LTE SL. Further, when the UE is in the ‘restricted service state’, one UE can still be able to exchange PC5 RRC signaling with a plurality of UEs in the vicinity (thus, the PC5 RRC signaling exchange can not be affected if one of the plurality of UEs moves to the ‘camped on any cell state’). Thus, an NR-NSA cell can broadcast NR / LTE SL configuration, which can include SL resource pool configuration, SL exceptional pool configuration, and SL synchronization configuration, to support SL operation for NR / LTE V2X services. Further, when the UE camps on the NR-NSA cell (or when the UE selects the NR-NSA cell), the UE can consider that it is in coverage. It should be noted that in some embodiments, an NSA cell can broadcast SL transmission resource pool configuration (e.g., v2x-CommTxPoolNormalCommon or p2x-CommTxPoolNormalCommon or discovery resource pool based on 3GPP TS 36.331.f.6.0) associated with the camping frequency in the broadcast system information. Further, when the NSA cell broadcasts SL information for V2X services, the UE can not initiate RRC connection with the NSA cell, but the NSA cell does not transmit SL transmission resource pool configuration that the UE needs (e.g., for V2X services, P2X services, or for discovery services) in the broadcast system information.In some embodiments, the UE can not expect that the NSA cell will broadcast SL resource configuration in case that the UE is not camped on the frequency carrier where the SL transmission resource pool configuration (e.g., v2x-delCommTxPoolNormalCommon or p2x-CommTxPoolNormalCommon) is transmitted.

[0130] In some embodiments, the NSA cell can operate on a non-serving frequency, and can also include the NSA cell when the UE is implementing cell selection and reselection for SL operation (by taking the cell selection and reselection for SL mechanism in 3GPP TS 36.304.15.6.0 as a baseline). Also, the NSA cell can also transmit SL resource configuration (with or without SL resource configuration associated with other SL CCs) associated with the involved SL frequency carrier, based on which the UE can transmit and / or receive SL packets on the involved SL CCs based on the received SL resource configuration and based on the timing information (e.g., DL timing) obtained from the NSA cell.

[0131] Embodiment 4: FR2 assistance information transmission by FR1

[0132] In embodiment 4, further association between SL CC on FR1 (e.g., CC#1) and SL CC on FR2 (e.g., CC#2) can be configured. For example, the UE can be configured to transmit FR2 assistance information for SL operation on FR2 by SL CC#1. In some embodiments, the UE can transmit the FR2 assistance information to the serving cell in FR1 (e.g., CC#1 in Figure 2A ) by LTE / NR Uu interface. In some embodiments, the UE can transmit the FR2 assistance information to the neighboring UE (e.g., SL group leader in SL multicast ( / multicast) group, such as UE#1 in Figure 2A ) by LTE / NR PC5 interface. In some embodiments, the FR2 assistance information can be transmitted to the serving cell (by (LTE / NR) Uu interface) or the paired UE (by PC5 RRC signaling (LTE / NR) PC5 interface) by transmitting SL-measurement report.

[0133] Table 3: FR2 assistance information

[0134]

[0135]

[0136]

[0137]

[0138]

[0139] In some embodiments, a UE can be configured with an event-based SL measurement object to provide SL-measurement reporting after a SL radio link failure event (or SL physical layer problem) occurs. The present disclosure introduces an additional timer T312_SL, where T312_SL can be configured to a UE configured with a SL measurement object. Also, in the present disclosure, a SL measurement object can include a SL-measurement reporting for a serving cell (e.g., a special cell such as a UE’s PCell and PSCell), a SL-measurement reporting for a paired UE in a SL unicast group, or other UEs. It is thus clear that a SL-measurement reporting corresponding to one SL-measObject can be transmitted over a (LTE / NR) Uu interface or a (LTE / NR) PC5 interface based on the target of the associated SL-measObject.

[0140] In some embodiments, a UE needs to report its support of T312_SL to a serving RAN during a SL-radio link failure (RLF) event. In an example, an information element ‘Timer312_SL = support’ can be explicitly indicated by a UE to a serving cell in a UE (NR / LTE) capability information. It should be noted that a SL-measurement reporting initiated when T312_SL starts counting / running can override a SL-measurement reporting for a LTE PC5 interface (e.g., CBR reporting over a LTE SL resource pool) and / or a NR PC5 interface (CBR reporting over a NR SL resource pool). In some embodiments, the ‘Timer312_SL = support’ IE can only be applied to a SL-measurement reporting for a LTE PC5 interface or a NR PC5 interface. In some embodiments, the ‘Timer312_SL = support’ IE can be applied to a SL-measurement reporting for both a LTE PC5 interface or a NR PC5 interface. Further, at a UE side, a UE can not support Timer312_SL in a default setting. Thus, if a UE does not support a SL-measurement reporting initiated after T312_SL starts counting, the UE does not need to indicate Timer312_SL not support.

[0141] Table 4: SL-measurement object with T312_SL

[0142]

[0143]

[0144]

[0145] In some embodiments, the start and stop / expiration conditions of T312_SL can be tightly coupled with those of T310_SL, which are summarized in Table 5.

[0146] Table 5: T310_SL Counting and Expiration

[0147]

[0148] Then, the start and stop / expiration conditions of T312_SL are summarized in Table 6.

[0149] Table 6: T312_SL Start and Stop / Expiration Conditions

[0150]

[0151]

[0152] In some embodiments of the present disclosure, a UE can be configured with a SL measurement object to provide SL measurement reports to other UEs over the (LTE / NR) PC5 interface. In some embodiments, the SL measurement object can be event-triggered, as shown in Table 7A (event V1a) and Table 7B (event V2a), respectively. For example, in some embodiments, the UE can trigger a SL-measurement report (e.g., a CBR report) when inequality V1-1 is satisfied. Similarly, the UE can stop transmitting CBR reports when inequality V1-2 as defined in Table 7A above is satisfied. Conversely, in some embodiments, the triggering event V2a can also trigger a SL-measurement report, as defined in Table 7B below. It should also be noted that the events V1a / V2a in Table 7B can be associated with LTE (V2X) SL or NR (V2X) SL. Furthermore, the UE can also be configured with events V1a / V2a associated with LTE SL and / or NR SL. In some embodiments, different parameters can be configured for LTE SL and NR SL in one UE.

[0153] In some embodiments, a UE can be configured with a SL measurement object to provide SL reports to the serving RAN over the (LTE / NR) Uu interface, as shown in Table 7C / Table 7D. In some embodiments, the SL measurement object can be event-triggered, as shown in Table 7C (event V1) and Table 7D (event V2), respectively.

[0154] Table 7A: CBR Reporting over NR / LTE PC5 Interface (Event V1a)

[0155]

[0156]

[0157] Table 7B: CBR reporting over NR / LTE PC5 interface (event V2a)

[0158]

[0159] Table 7C: CBR reporting over NR / LTE Uu interface (event V1)

[0160]

[0161]

[0162] Table 7D: CBR reporting over NR / LTE Uu interface (event V2)

[0163]

[0164]

[0165] The UE can obtain the configuration parameters in Tables 7A-7D through SL pre-configuration, dedicated control signaling (e.g., RRC signaling in (LTE / NR) Uu interface) / broadcast control signaling (e.g., system information or SI on-demand procedure) from the serving cell, or dedicated control signaling (e.g., PC5 RRC signaling) / broadcast control signaling (e.g., MIB-SL signaling) in the PC5 interface. Moreover, in some embodiments, the UE can also be enabled to transmit SL measurement reports (e.g., CBR reports) to the serving cell through (type 1 / type 2) UL configured grant or through (2-step / 4-step) random access procedure when the UE stays in RRC inactive state.

[0166] Embodiment 5: Optimization for cell (re)selection for SL

[0167] In this embodiment, when V2X services are supported on these frequencies, a UE can need to perform (LTE / NR) V2X SL communication / discovery services on one or more serving frequencies (e.g., the UE has serving cells on frequency carriers in the (LTE / NR) Uu interface, which can be camping cells, primary cells (e.g., on a primary frequency), secondary cells (e.g., on a secondary frequency), or primary secondary cells (e.g., on a primary frequency) in the (LTE / NR) Uu interface) and / or on one or more non-serving frequencies (e.g., the UE does not have serving cells on frequency carriers in the (LTE / NR) Uu interface, and thus, the UE can have selected cells on non-serving frequencies after a cell selection / reselection procedure to enable (NR / LTE) V2X (sidelink) services on the non-serving frequencies). In this embodiment, the UE can check and record the valid area configurations on the serving cells of the serving frequencies and the selected cells of the non-serving frequencies.

[0168] In some embodiments, cells in different frequencies (e.g., CC#1 and CC#2, which can provide serving frequencies and non-serving frequencies for a UE, respectively) can share the same SL resource configuration and valid area configuration. For example, the valid area for SL resource configuration can consist of cells operating on different frequencies (which can include serving frequencies and non-serving frequencies). In some embodiments, the valid area for SL resource configuration can consist of systemInformationAreaID / RAN notification area code or tracking area code. Then, cells on different frequencies can also share the same systemInformationAreaID / RAN notification area code or tracking area code. Thus, in this embodiment, a UE can record the SL resource configuration and associated valid area that the UE obtains from cells on serving frequencies and non-serving frequencies (e.g., cells in CC#1 and CC#2, respectively). For example, when the UE enables (NR / LTE) V2X (sidelink) services on CC#1, the UE can apply the SL resource configuration (which can cover SL resources on CC#1 and CC#2) and valid area configuration (which covers cells in CC#1 and CC#2) obtained from cells on non-serving frequencies. Furthermore, if the valid area is represented by systemInformationAreaID, and the SL resource configuration is broadcasted in system information (or system information is deliverable through SI on-demand procedure), the UE can apply the stored SL resource configuration associated with systemInformationAreaID without reading the rest of system information about the SL resource configuration (or the UE can not initiate a random access procedure to request system information to obtain the SL resource configuration) regardless of whether the cell (re)selection is enabled on serving frequencies or non-serving frequencies.

[0169] It should be noted that the stored valid area and associated SL resource configuration can apply to the fallback mechanism described in Embodiment 2 above. In the fallback embodiment, when the UE camps on or selects a cell (at one relevant frequency, e.g., CC#1) that does not belong to the stored valid area, the UE can still keep the stored SL resource configuration and valid area configuration. The stored valid area and SL resource configuration can still apply to the cell operating on other SL frequencies (e.g., CC#2). In some embodiments, if none of the serving cells (serving frequencies) / selected cells (non-serving frequencies) on all frequencies (on which the UE is performing SL operation) belong to the stored valid area, the UE can release or remove one stored valid area and associated SL resource configuration. In some embodiments, a timer can be further configured with the valid area configuration. After the UE finds that none of the serving cells (serving frequencies) and selected cells (non-serving frequencies) on all frequencies (on which the UE is performing SL operation) belong to the valid area, the timer (≥ 0) can be triggered. Then, the UE can release the stored valid area (and associated SL resource configuration) after the timer expires. In some further embodiments, the decision of when to release / remove the invalid SL resource configuration depends on the specific UE implementation.

[0170] Figure 6 is a block diagram illustrating a node 600 for wireless communication, in accordance with the present disclosure. As shown, the node 600 can include a transceiver 620, a processor 628, a memory 634, one or more presentation components 638, and at least one antenna 636. The node 600 can also include a radio frequency (RF) spectrum band module, a base station communication module, a network communication module, a system communication management module, an input / output (I / O) port, an I / O component, or a power source (not shown in FIG. 6). Figure 6 Figure 6 Each component can communicate, directly or indirectly, with one another over the one or more buses 640. The node 600 can be a UE or a BS that performs various functions disclosed with reference to the present disclosure.

[0171] Each component can communicate, directly or indirectly, with one another over the one or more buses 640. The node 600 can be a UE or a BS that performs various functions disclosed with reference to the present disclosure. Figures 1 to 5

[0172] ​​The transceiver 620, with transmitter 622 (e.g., transmitting / transmission circuitry) and receiver 624 (e.g., receiving / reception circuitry), can be configured to transmit and / or receive time and / or frequency resource partitioning information. The transceiver 620 can be configured to transmit in different types of subframes and slots, including but not limited to usable, unusable, and flexibly usable subframe and slot formats. The transceiver 620 can be configured to receive data and control channels.

[0173] The node 600 can include a variety of computer readable media. Computer readable media can be any available media that can be accessed by the node 600 and includes both volatile and nonvolatile media, removable and non-removable media.

[0174] Computer readable media can include computer storage media and communication media. Computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data.

[0175] Computer storage media includes RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices. Computer storage media does not include a propagated data signal. Communication media can typically be embodied in a modulated data signal, such as a carrier wave or other transport mechanism, and includes any information delivery media.

[0176] The term "modulated data signal" means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. Communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared, and other wireless media. Combinations of the any of the above can also be included within the scope of computer readable media.

[0177] The memory 634 can include computer storage media in the form of volatile and / or nonvolatile memory. The memory 634 can be removable, non-removable, or a combination thereof. For example, the memory can include solid state memory, hard drives, optical drives, etc. As Figure 6As shown, the memory 634 can store computer-readable, computer-executable instructions 632 (e.g., software code) configured to, when executed, cause the processor 628 (e.g., processing circuitry) to perform various functions disclosed herein, e.g., with reference to Figures 1 to 5 Alternatively, the instructions 632 can not be directly executable by the processor 628 but are configured to cause the node 600 (e.g., when compiled and executed) to perform various functions disclosed herein.

[0178] The processor 628 (e.g., having processing circuitry) can include an intelligent hardware device, e.g., a central processing unit (CPU), a microcontroller, an ASIC, etc. The processor 628 can include memory. The processor 628 can process data 630 and instructions 632 received from the memory 634, as well as information transmitted and received by the transceiver 620, baseband communication module, and / or network communication module. The processor 628 can also process information to be sent to the transceiver 620 for transmission through the antenna 636, to the network communication module for transmission to a core network.

[0179] The one or more presentation components 638 can present data indications to a human or other machine. Examples of presentation components 638 can include a display device, a speaker, a printing component, and a vibrating component, etc.

[0180] In some embodiments of the disclosure, configuration for NR SL / LTE V2X SL synchronization rules is utilized when multiple SL CCs are configured to support (NR / LTE) (V2X) SL operation between UEs.

[0181] In some embodiments of the disclosure, information about SL CCs associated with NR (e.g., for NR sidelink communication) and / or LTE RAT (e.g., for (LTE) V2X sidelink communication) is indicated to the UE (e.g., over a Uu interface).

[0182] In some embodiments of the disclosure, the association between a SL CC and an associated RAT can be network-specific (e.g., PLMN-specific or NPN-specific).

[0183] In some embodiments of the disclosure, a SL CC with associated NR SL / LTE V2X SL synchronization rules is indicated.

[0184] In some embodiments of the disclosure, the association between a SL CC and NR SL / LTE V2X SL synchronization rules can be PLMN-specific / NPN-specific.

[0185] In some embodiments of the disclosure, the association between SL CC and NR SL / LTE V2X SL synchronization rules can be valid within a defined valid area.

[0186] In some embodiments of the disclosure, the above-mentioned indication and / or association rules can be pre-specified in technical specifications or pre-defined in a USIM or a memory module in the UE, so that the UE can interpret and apply the above-mentioned indication and / or association rules.

[0187] In view of the present disclosure, it is apparent that the concepts can be implemented using various techniques without departing from the scope of the concepts in the present disclosure. Furthermore, although the concepts have been disclosed by specific reference to certain embodiments, it is apparent that modifications and changes can be made without departing from the scope of the concepts. Accordingly, the disclosed embodiments are to be considered illustrative and not restrictive. It is also to be understood that the disclosure is not limited to the particular embodiments disclosed, but the many rearrangements, modifications and substitutions that are possible without departing from the scope of the present disclosure.

Claims

1. A user equipment (UE), characterized in that, include: One or more non-transitory computer-readable media having computer-executable instructions contained thereon; as well as At least one processor, coupled to the one or more non-transitory computer-readable media, and configured to execute the computer-executable instructions to: The sidelink SL resource configuration of the second RAT is received through the serving cell of the first radio access technology RAT. Determine the first valid region information associated with the first RAT and the second valid region information associated with the second RAT; Based on the first valid region information and the second valid region information, the valid region for the SL resource configuration is identified, wherein... The first valid area information is associated with a first PLMNidentity in the Public Land Mobile Network Identifier (PLMNidentity) list or a first NPNidentity in the Non-Public Network Identifier (NPNidentity) list, wherein the PLMNidentity list and the NPNidentity list are broadcast by the serving cell.

2. 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: After the valid region is identified as valid, the SL resource associated with the valid region is accessed.

3. The UE as described in claim 1, characterized in that, The second valid area information is associated with at least one of one or more SL transport resource pools, one or more SL receive resource pools, and one or more SL exception transport resource pools.

4. The UE as described in claim 1, characterized in that, The first RAT is the 5th generation new radio 5G NR RAT.

5. The UE as described in claim 1, characterized in that, The SL resource configuration of the second RAT is for Long Term Evolution LTE Vehicle-to-Everything (V2X) SL communication associated with the Evolved Universal Terrestrial Radio Access (E-UTRA) RAT.

6. The UE as described in claim 1, characterized in that, The SL resource configuration of the second RAT is received through system information broadcast by the serving cell of the first RAT.

7. The UE as described in claim 1, characterized in that, The effective region of the SL resource configuration is defined by at least one system information region identifier broadcast by the serving cell of the first RAT. systemInformationAreaID composition.

8. The UE as described in claim 7, characterized in that, When the SL resource configuration is not broadcast by the serving cell systemInformationAreaID The system information indicated or broadcast by the serving cell does not contain the [information / information]. systemInformationAreaID At that time, the first effective area of ​​the first RAT consists of the cell identifier of the serving cell of the first RAT.

9. The UE as described in claim 1, characterized in that, After the UE moves out of the first valid region associated with the first valid region information or the second valid region associated with the second valid region information, the SL resource configuration associated with the valid region is invalidated by the UE.

10. A method performed by a user equipment (UE), the method comprising: The sidelink SL resource configuration of the second RAT is received through the serving cell of the first radio access technology RAT. Determine the first valid region information associated with the first RAT and the second valid region information associated with the second RAT; and Based on the first valid region information and the second valid region information, the valid region for the SL resource configuration is identified, wherein... The first valid area information is associated with a first PLMNidentity in the Public Land Mobile Network Identifier (PLMNidentity) list or a first NPNidentity in the Non-Public Network Identifier (NPNidentity) list, wherein the PLMNidentity list and the NPNidentity list are broadcast by the serving cell.

11. The method of claim 10, further comprising: After the valid region is identified as valid, the SL resource associated with the valid region is accessed.

12. The method as described in claim 10, characterized in that, The second valid area information is associated with at least one of one or more SL transport resource pools, one or more SL receive resource pools, and one or more SL exception transport resource pools.

13. The method as described in claim 10, characterized in that, The first RAT is the 5th generation new radio 5G NR RAT.

14. The method as described in claim 10, characterized in that, The SL resource configuration of the second RAT is for Long Term Evolution LTE Vehicle-to-Everything (V2X) SL communication associated with the Evolved Universal Terrestrial Radio Access (E-UTRA) RAT.

15. The method as described in claim 10, characterized in that, The SL resource configuration of the second RAT is received through system information broadcast by the serving cell of the first RAT.

16. The method as described in claim 10, characterized in that, The effective region of the SL resource configuration is defined by at least one system information region identifier broadcast by the serving cell of the first RAT. systemInformationAreaID composition.

17. The method as described in claim 16, characterized in that, When the SL resource configuration is not broadcast by the serving cell systemInformationAreaID The system information indicated or broadcast by the serving cell does not contain the [information / information]. systemInformationAreaID At that time, the first effective area of ​​the first RAT consists of the cell identifier of the serving cell of the first RAT.

18. The method as described in claim 10, characterized in that, After the UE moves out of the first valid region associated with the first valid region information or the second valid region associated with the second valid region information, the SL resource configuration associated with the valid region is invalidated by the UE.

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