Sidelink carrier aggregation for wireless communication networks

Abstract

Systems, methods, processors, and circuitry are provided for configuring sidelink (SL) communications for carrier aggregation (CA). In some aspects, a baseband processor is configured to perform operations including: receiving, at a user equipment (UE) from a peer UE, an indication of whether the peer UE supports SL CA; and generating an SL reconfiguration message for the peer UE based on the peer UE supporting the SL CA, the SL reconfiguration message configuring an SL data radio bearer (SL-DRB) to carry data from the UE to the peer UE.

Description

[0001] Citation of relevant applications

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 518,770, filed August 10, 2023, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] This disclosure relates to side-link (SL) technology for wireless communication networks. Background Technology

[0004] Wireless communication networks and services are becoming increasingly dynamic, complex, and ubiquitous. For example, wireless communication networks can be developed to enable fifth-generation (5G) or new radio (NR) technologies, sixth-generation (6G) technologies, and so on. Such technologies can include solutions for enabling user equipment (UEs) and network devices (such as base stations) to communicate with each other. Features of such networks and devices can include SL communication, which is direct communication between two UEs. Attached Figure Description

[0005] This disclosure will be readily understood and implemented through detailed description and accompanying drawings. The same reference numerals may designate the same features and structural elements. The drawings and corresponding descriptions are provided as non-limiting examples of aspects, embodiments, etc., of this disclosure, and references to “a” or “an” aspect, embodiment, etc., may not necessarily refer to the same aspect, embodiment, etc., and may mean at least one, one, or more, etc.

[0006] Figure 1 This is a diagram illustrating example wireless networks according to various aspects of this disclosure.

[0007] Figure 2 This is a message flow diagram illustrating various aspects of this disclosure for supporting SL communication between a transmitting UE (TX UE) and a receiving UE (RX UE) for transmitting messages between them.

[0008] Figure 3 This is another message flow diagram illustrating various aspects of this disclosure for supporting SL communication between the TX UE and the RX UE.

[0009] Figure 4 The layer of a TX UE according to various aspects of this disclosure is illustrated, which operates to configure a single component carrier (CC) of the SL signal radio bearer (SRB) for communication with the RX UE.

[0010] Figure 5The following illustrates a layer of a TX UE according to various aspects of this disclosure, which operates to configure multiple CCs of the SL-SRB for communication with the RX UE's SL.

[0011] Figure 6 This is a flowchart of an example method for declaring a radio link failure (RLF) during SL communication, based on an overview of various aspects of this disclosure.

[0012] Figure 7 This is a flowchart of another example method for declaring an RLF during SL communication, based on an overview of various aspects of this disclosure.

[0013] Figure 8A and Figure 8B This is a flowchart illustrating yet another example method for declaring an RLF during SL communication, based on an overview of the various aspects described.

[0014] Figure 9 This is a flowchart illustrating yet another example method for declaring an RLF during SL communication, based on an overview of various aspects of this disclosure.

[0015] Figure 10 This is a flowchart of an example method for determining whether to declare an RLF for an RX UE, based on an overview of various aspects of this disclosure and using a threshold number of carriers.

[0016] Figure 11 These are illustrations of examples of components of a device according to various aspects of this disclosure. Detailed Implementation

[0017] The following detailed description refers to the accompanying drawings. The same reference numerals in different drawings may identify the same or similar features, elements, operations, etc. Additionally, this disclosure is not limited to the following description, as other specific embodiments and structural or logical changes may be made without departing from the scope of this disclosure.

[0018] Communication in a wireless network can include downlink (DL) communication from a radio access network (RAN) node to a user equipment (UE), uplink (UL) communication from a UE to a RAN node, and sidelink (SL) communication between two peer UEs without RAN node guidance. One use case for SL communication between UEs is vehicle-to-everything (V2X) communication, through which vehicles can communicate with other vehicles and other communication elements (e.g., to facilitate autonomous transportation, enhance transportation safety, etc.). The interface that facilitates such SL communication between UEs is often referred to as PC5.

[0019] In the ongoing 3GPP (3rd Generation Partnership Project) standardization work, efforts have been made to support 5G or New Radio (NR) SL CA operations based on 4G or LTE SL carrier aggregation (CA) operations. Typically, such work assumes that only aspects of the LTE SL CA design (e.g., those related to SL carrier selection and reselection, synchronization of aggregated carriers, transmit power division for simultaneous SL transmissions, and packet repetition) will be reused for NR sidelink CA operations.

[0020] Typically, CA operations involve the concurrent use of multiple CCs to provide greater transmission bandwidth and / or enhanced reliability via packet repetition. For example, in LTE, DL CA operations involve using a single primary CC (PCC) and one or more secondary CCs (SCCs). The PCC can carry both data and control signaling, while each SCC carries only data. However, LTE SL operations exhibit characteristics that make the PCC / SCC design employed in DL CA operations inconvenient. These characteristics include, for example, the absence of Radio Resource Control (RRC) connectivity in the PC5 interface, the lack of SL unicast operations, the lack of Hybrid Automatic Repeat Request (HARQ) feedback, and the service identifier-to-carrier mapping provided by upper layers (e.g., the V2X layer) and not configured in the Access Layer (AS) layer.

[0021] Furthermore, while 3GPP Systems Side Working Group 2 (SA2) has utilized the use of LTE SL operations in the V2X layer to provide a mapping from V2X service identifiers associated with multiple CCs to Layer 2 (L2) destination addresses, the RAN Working Group (WG) assumes that NR SL operations use a single CC.

[0022] As discussed in more detail below, some aspects of this disclosure facilitate NR sidelink unicast transmission using carrier aggregation by mapping service IDs to multiple CCs at higher layers (e.g., V2X layer) without relying on PCC / SCC differentiation. In some aspects, the transmitting UE may employ multiple CCs for SL unicast transmission to the receiving UE for one or more SL data radio bearers (SL-DRBs) and / or SL signal radio bearers (one or more selective SL-SRBs, such as SL-SRB3) to improve the performance and / or reliability of the SL connection. For example, the transmitting UE may request and receive SL capability information from the receiving UE, where such information includes whether the receiving UE supports SL CA. In response, the transmitting UE may configure the receiving UE using one or more CCs for subsequent transmissions to the receiving UE (e.g., on one or more SL-DRBs and / or SL-SRB3).

[0023] Furthermore, in some aspects of this disclosure, the lower layer of the transmitting UE can handle at least some aspects of Radio Link Detection (RLM) and associated Radio Link Failure (RLF) processing (e.g., based on HARQ feedback from the receiving UE and / or RLC retransmission to the receiving UE). In some aspects, RLM and RLF processing can be performed independently on some or all carriers of SL-DRB and / or SL-SRB3, or on a per-destination (e.g., per receiving UE) basis. Moreover, in some aspects, as part of the RLM / RLF process, the transmitting UE can reconfigure carriers used for CA and / or duplicates (e.g., in response to the detection of errors on one or more CCs), thereby further enhancing the performance and / or reliability of the SL connection in an efficient manner without necessarily involving the upper layer of the transmitting UE.

[0024] Figure 1 Example network 100 is an example network according to one or more specific implementations described herein. Example network 100 may include UE 110-1, UE 110-2, etc. (collectively referred to as "UE 110" and individually referred to as "UE 110"), radio access network (RAN) 120, core network (CN) 130, application server 140 and external network 150.

[0025] The systems and devices of Example Network 100 may operate according to one or more communication standards, such as 2G, 3G, 4G (e.g., LTE), and / or 5G (e.g., NR) communication standards of the 3rd Generation Partnership Project (3GPP). Additionally or alternatively, one or more of the systems and devices of Example Network 100 may operate according to other communication standards and protocols discussed herein, including future versions or generations of 3GPP standards (e.g., 6G, 7G, etc.), Institute of Electrical and Electronics Engineers (IEEE) standards (e.g., Wireless Metropolitan Area Network (WMAN), Global Microwave Access Interoperability (WiMAX), etc.), and more.

[0026] As shown in the figure, UE 110 may include a smartphone (e.g., a handheld touchscreen mobile computing device capable of connecting to one or more wireless communication networks). Additionally or alternatively, UE 110 may include other types of mobile or non-mobile computing devices capable of wireless communication, such as personal data assistants (PDAs), pagers, laptops, desktop computers, cordless phones, smartwatches, etc. In some implementations, UE 110 may include an Internet of Things (IoT) device (or IoT UE), which may include a network access layer designed to utilize low-power IoT applications with short UE connections. Additionally or alternatively, the IoT UE may utilize one or more types of technologies such as machine-to-machine (M2M) communication or machine-type communication (MTC) (e.g., to exchange data with an MTC server or other device via a Public Land Mobile Network (PLMN), Proximity Services (ProSe) or Device-to-Device (D2D) communication, sensor networks, IoT networks, etc. Depending on the scenario, the M2M or MTC exchange of data can be machine-initiated, and the IoT network can include IoT UEs (which may include uniquely identifiable embedded computing devices within the internet infrastructure) interconnected with transient connections. In some scenarios, IoT UEs can execute background applications (e.g., keeping track of activity messages, status updates, etc.) to facilitate connectivity within the IoT network.

[0027] Connections may include M2M, MTC, D2D, SL, etc. Connections may involve the PC5 interface. In some implementations, UE 110 can be configured to discover each other, negotiate radio resources with each other, and establish connections with each other without the intervention or communication of RAN node 122 or another type of network node. In some implementations, discovery, authentication, resource negotiation, registration, etc., may involve communication with RAN node 122 or another type of network node.

[0028] UE 110 can communicate with each other using one or more radio (e.g., sidelink (SL)) connections 112. As described herein, UE 110-1 can communicate with RAN node 122 to request SL resources. RAN node 122 can respond to this request by providing UE 110 with a Dynamic Grant (DG) or Configuration Grant (CG) regarding the SL resources. The DG may involve granting based on a grant request from UE 110. The CG may involve granting resources without a grant request and may be based on the type of service offered (e.g., a service with strict timing or latency requirements). UE 110 can perform an Empty Channel Assessment (CCA) procedure based on the DG or CG, select SL resources based on the CCA procedure and the DG or CG, and communicate with another (e.g., a peer) UE 110 based on the SL resources. UE 110 can communicate with RAN node 122 using licensed frequency bands and with another UE 110 using unlicensed frequency bands. In some examples, one UE 110 (e.g., UE 110-1) can be a transmitting UE (TX UE), while another UE (e.g., UE 110-2) can be a receiving UE (RX UE).

[0029] UE 110 can communicate with and establish connections (e.g., communicatively coupled) with RAN 120, which may involve one or more radio channels 114-1 and 114-2, each of which may include a physical communication interface / layer.

[0030] The PC5 Quality of Service (QoS) Identifier (PQI) can be determined and used to indicate the QoS associated with sidelinks at unlicensed frequency band (SL-U) communications (e.g., channels, data streams, etc.). Similarly, Layer 1 (L1) priority values ​​can be determined and used to indicate the priority of SL-U transmissions, SL-U channels, SL-U data, etc. PQI and / or L1 priority values ​​are mapped to Channel Access Priority Class (CAPC) values, and PQI, L1 priority, and / or CAPC can indicate SL Channel Occupancy Time (COT) sharing, Maximum COT (MCOT), timing intervals for COT sharing, Listen-After-Talk (LBT) configuration, traffic, and channel priority, etc.

[0031] As shown in the figure, UE 110 can also or alternatively connect to access point (AP) 116 via connection interface 118, which may include an air interface enabling UE 110 to communicatively couple with AP 116. AP 116 may include a wireless local area network (WLAN), a WLAN node, a WLAN termination point, etc. Connection interface 118 may include a local wireless connection, such as a connection consistent with any IEEE 702.11 protocol, and AP 116 may include a wireless fidelity router or other AP. Although in Figure 1 It is not explicitly described, but AP 116 can connect to another network (e.g., the Internet) without needing to connect to RAN 120 or CN 130.

[0032] RAN 120 may include one or more RAN nodes 122-1 and 122-2 (collectively referred to as RAN node 122, and individually referred to as RAN node 122) that enable the establishment of channels 114-1 and 114-2 between UE 110 and RAN 120. RAN node 122 may include a network access point configured to provide radio baseband functionality for data and / or voice connectivity between the user and the network based on one or more communication technologies described herein (e.g., 2G, 3G, 4G, 5G, WiFi, etc.). Thus, as an example, a RAN node may be an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) node B (e.g., enhanced node B, eNodeB, eNB, 4G base station, etc.), a next-generation base station (e.g., 5G base station, NR base station, next-generation eNB (gNB), etc.). RAN node 122 may include roadside units (RSUs), transmit / receive points (TRxPs or TRPs), and one or more other types of ground stations (e.g., ground access points). In some scenarios, RAN node 122 may be dedicated physical equipment such as macro cell base stations and / or low-power (LP) base stations for providing smaller coverage areas, smaller user capacity, or higher bandwidth compared to macro cells, such as femtocells, picocells, etc. Additionally or alternatively, one or more RAN nodes in RAN node 122 may be next-generation eNBs (gNBs) that can provide E-UTRA user plane and control plane protocol terminals 126, 128 to UE 110 and can be connected to the 5G core network (5GC) 130 via NG interface 124.

[0033] Any RAN node in RAN 122 may terminate the air interface protocol and may be the first point of UE 110. In some implementations, any RAN node in RAN 122 may perform various logical functions of RAN 120, including but not limited to Radio Network Controller (RNC) functions such as radio bearer management, uplink and downlink dynamic radio resource management, data packet scheduling, and mobility management. UE 110 may be configured to communicate with each other or with any node in RAN 122 on a multi-carrier communication channel using Orthogonal Frequency Division Multiplexing (OFDM) communication signals according to various communication technologies, such as, but not limited to, Orthogonal Frequency Division Multiple Access (OFDMA) communication technology (e.g., for downlink communication) or Single Carrier Frequency Division Multiple Access (SC-FDMA) communication technology (e.g., for uplink and ProSe or sidelink (SL) communication), but the scope of such implementations is not limited in this respect. OFDM signals may include multiple orthogonal subcarriers.

[0034] In some implementations, the downlink resource grid can be used for downlink transmissions from any RAN node in RAN node 122 to UE 110, and uplink transmissions can utilize similar techniques. This grid can be a time-frequency grid (e.g., a resource grid or time-frequency resource grid), representing the physical resources of the downlink in each time slot. Such time-frequency representations are common practice for OFDM systems, making radio resource allocation intuitive. Each column and row of the resource grid corresponds to an OFDM symbol and an OFDM subcarrier, respectively. The duration of the resource grid in the time domain corresponds to a time slot in a radio frame. The smallest time-frequency unit in the resource grid is represented as a resource element (RE). Each resource grid includes resource blocks (RBs), which describe the mapping of certain physical channels to resource elements. Each RB can include a set of REs; in the frequency domain, this represents the minimum amount of resources currently available for allocation. Several different physical downlink channels exist that are transmitted using such RBs.

[0035] RAN nodes 122 can be configured to communicate with each other via interface 123. In a specific implementation where the system is an LTE system, interface 123 can be an X2 interface. In an NR system, interface 123 can be an Xn interface. An X2 interface can be defined between two or more RAN nodes 122 (e.g., two or more eNBs / gNBs or combinations thereof) connected to the Evolved Packet Core (EPC) or CN 130, or between two eNBs connected to the EPC.

[0036] CN 130 may include a plurality of network elements 132 configured to provide various data and telecommunications services to customers / subscribers (e.g., users of UE 110) connected to CN 130 via RAN 120. In some implementations, CN 130 may include an EPC, a 5G CN, and / or one or more additional or alternative types of CN. Components of CN 130 may be implemented in a physical node or in separate physical nodes, including components for reading and executing instructions from machine-readable or computer-readable media (e.g., non-transitory machine-readable storage media).

[0037] As shown in the figure, CN 130, application server 140 and external network 150 can be connected to each other via interfaces 134, 136 and 138, which may include IP network interfaces.

[0038] Figure 2 Examples of various aspects of this disclosure are provided for supporting SL communication (e.g., via...) between a transmitting UE (TX UE, such as UE 110-1) and a receiving UE (RX UE, such as UE 110-2). Figure 1 The message flow diagram for message transmission 200 of SL connection 112 is shown below. Figure 2 As illustrated, the TX UE can receive capability message 202 from the RX UE, which indicates to the TX UE that the RX UE supports SL carrier aggregation (CA). In response to capability message 202, the TX UE can send SL reconfiguration message 204 to the RX UE. In some aspects, SL reconfiguration message 204 can configure the SL data radio bearer (SL-DRB) for packet repetition or SL CA using multiple SL component carriers (CCs) to carry data from the TX UE to the RX UE. In some aspects of this disclosure, capability message 202 and SL reconfiguration message 204 can be carried on the SL signal radio bearer (SRB) (e.g., SL-SRB3), as described in more detail below.

[0039] Figure 3 This is another message flow diagram illustrating, according to various aspects of this disclosure, message transmission 300 for supporting SL communication between a TX UE (e.g., UE 110-1) and an RX UE (e.g., UE 110-2). Figure 3 As described, the TX UE and RX UE determine which one or more CCs to use to perform the message delivery operation to be followed.

[0040] Before exchanging messages between the TX UE and RX UE (e.g., to establish an SL connection between the TX UE and RX UE), the TX UE and RX UE may first perform a first CC selection 302, during which one or more CCs are selected to carry the initial communication between them to establish the SL connection (e.g., ...). Figure 1 SL connection 112). In some aspects, the first CC selection 302 can occur in the communication system (e.g., Figure 1 The upper layer (e.g., V2X layer) of the network 100. For example, the upper layer (e.g., V2X) of both TX UE and RX UE can be accessed through RAN 120 and CN 130 (e.g., ... Figure 1 (Example) communicates with application server 140 (e.g., V2X application server) to perform the first CC selection 302.

[0041] Figure 4 Examples of various aspects of a TX UE according to this disclosure are illustrated, which operates to configure a single component carrier (CC) of the SL signal radio bearer (SL-SRB) for SL communication with the RX UE. While in Figure 4 In China (and as described below) Figure 5 The middle section depicts the (top) V2X layer 410 and the Media Access Control (MAC) layer 420, but other layers (such as the Physical (PHY) layer) may also exist, but are not explicitly shown.

[0042] At V2X layer 410, service identifier (e.g., V2X service identifier) ​​to destination address mapping 412 and service identifier to frequency mapping 414 (e.g., carrier determination for SL-SRB0, SL-SRB1, SL-SRB2, and initial SL-SRB3) can be performed. In some aspects, destination address mapping 412 can map V2X service identifiers to Layer 2 (L2) identifier pairs (e.g., a source L2 identifier associated with a TX UE and a destination L2 identifier associated with an RX UE). Furthermore, in relation to... Figure 4 In the associated aspects, the service identifier is mapped to a single frequency f1 associated with a single CC, thereby preventing packet duplication using SL-SRB0, SL-SRB1, or SL-SRB2. Both destination address mapping 412 and frequency mapping 414 can be passed to the MAC layer 420, which can then perform MAC scheduling 422 to transmit messages on a single CC associated with a single frequency f1 (e.g., as described below). Figure 3 Messages 304-314, 318, and 320 associated with SL-SRB0, SL-SRB1, SL-SRB2, and the initial SL-SRB3.

[0043] In some aspects, the assignment of a single frequency f1 can occur in several ways. In some examples, V2X layer 410 may newly identify a single frequency f1. In other examples, the V2X layer may alternatively reuse the anchor carrier previously used for SL synchronization signal (SLSS) transmission. In still other examples, V2X layer 410 may introduce a new anchor carrier (e.g., different from the anchor carrier used for SLSS), which can be obtained from the TX UE. Figure 1 The System Information Block (SIB) received by RAN 120 is specified. In an additional example, the V2X layer can reuse the frequencies specified in the Information Element (IE) SL-ConfigCommonNR->sl-FreqInfoList-r16 provided in the SIB, where the limit for the number of single carriers / lists is equal to one (e.g., for possible backward compatibility with 3GPP Rel-16 / 17). In other aspects, other procedures are possible to determine a single frequency f1.

[0044] In other aspects of this disclosure, Figure 5 An example of a TX UE layer is illustrated, which operates to configure multiple CCs for SL-SRBs used for SL communication with the RX UE. At V2X layer 410, service identifier (e.g., V2X service identifier) ​​to destination address mapping 412 and service identifier to frequency mapping 414 (e.g., carrier determination for SL-SRB0, SL-SRB1, SL-SRB2, and initial SL-SRB3) can be performed. This is in conjunction with the above. Figure 3 As mentioned, in some aspects, destination address mapping 412 can map V2X service identifiers to Layer 2 (L2) identifier pairs (e.g., a source L2 identifier associated with a TX UE and a destination L2 identifier associated with an RX UE). In relation to Figure 5 In the associated aspects, service identifiers are mapped to multiple frequencies f1, f2, and f3. More specifically, in a particular aspect, frequency f1 is mapped for both SL-SRB0 and SL-SRB1, and frequencies f2 and f3 are mapped for SL-SRB2 (e.g., to facilitate packet repetition on both frequencies f2 and f3). Both destination address mapping 412 and frequency mapping 414 can be passed to MAC layer 420, which can then perform MAC scheduling 422 to transmit messages on multiple CCs associated with frequencies f1, f2, and f3 according to their association with SL-SRB0, SL-SRB1, and SL-SRB2 (e.g., as described below). Figure 3 Messages 304-314, 318 and 320).

[0045] Additionally, in other aspects, the initial use of SL-SRB3 (e.g., for switching with RX UE) Figure 3 Messages 312, 314, 318, and 320 can be carried on any of one or more frequencies f1, f2, and f3. In some aspects, SL-SRB3 may use the same mapping as one of SL-SRB0, SL-SRB1, or SL-SRB2 (e.g., a single-frequency mapping without repetition, or a multi-frequency mapping with repetition). In other aspects, SL-SRB3 may employ a single-frequency or multi-frequency mapping different from any of SL-SRB0, SL-SRB1, and SL-SRB2.

[0046] Return to Figure 3 Following the first CC selection 302 for SL-SRB0, SL-SRB1, and SL-SRB2, and the initial selection for SL-SRB3, a series of messages 304-310 can be exchanged between the TX UE and the RX UE (e.g., to establish an SL communication connection between them). In some aspects, messages 304-310 may be PC5 (LTE-V2X) signaling protocol stack (PC5-S) messages used for control plane signaling via the PC5 interface to establish, maintain, and / or release a secure direct SL connection between the TX UE and the RX UE. Additionally, in some aspects, messages 304-310 may include: a Direct Communication Request (DCR) message 304 on SL-SRB0; a Direct Security Mode Command message 306 on SL-SRB1; a Direct Security Mode Complete message 308 also on SL-SRB1; and a Direct Communication Accept (DCA) message 310 on SL-SRB2. In other aspects, the exchange of other messages may be employed to create an SL connection between the TX UE and the RX UE.

[0047] After the SL connection is established, the TX UE can begin the process of selecting one or more CCs for sending data over the SL connection. In some aspects, the TX UE can send an SL capability query message 312, which requests one or more capabilities of the RX UE, including whether the RX UE supports the use of SL CA when receiving data from the TX UE on multiple CCs. In response to the SL capability query message 312, the RX UE can send an SL capability information message 314, which includes at least an indication of whether the RX UE supports the use of SL CA. In some aspects, the SL capability query message 312 and the SL capability information message 314 can be PC5-RRC messages that provide RRC-like functionality between the TX UE and the RX UE, and can include one or more information elements (IEs). In such aspects, the SL capability query message 312 can be a CapabilityEnquirySidelink message, and the SL capability information message 314 can be a CapabilityInformationSidelink message.

[0048] Based on whether the RX UE supports the use of SL CA, the TX UE can perform a second CC selection 316 to select one or more CCs for subsequent signaling transmission on SL-SRB3 and / or for data transmission on one or more SL data radio bearers (SL-DRBs). In some aspects, in response to an SL capability information message 314 indicating that the RX UE does not support SL CA, the TX UE can select a single carrier (e.g., one of the same one or more carriers previously used for SL-SRB0, SL-SRB1, SL-SRB2 and / or SL-SRB3) for carrying subsequent signals on SL-SRB3 and / or SL-DRB.

[0049] Conversely, if the RX UE supports the use of SL CA, the TX UE can be configured with SL-SRB3 and / or one or more SL-DRBs having multiple CCs, where each of the SL-SRB3 and one or more SL-DRBs is associated with a set of CCs (e.g., as provided in advance by the V2X layer). In some aspects, the second CC selection 316 of multiple CCs can be based on the Channel Busy Ratio (CBR) associated with the CCs available for selection. Additionally, in some aspects, the CBR can be evaluated relative to the ProSe per-packet priority (PPPP) associated with the SL message to be transmitted.

[0050] In some aspects, the TX UE can send an SL reconfiguration message 318 (e.g., a PC5-RRC message, such as an RRCReconfigurationSidelink message) on SL-SRB3, which informs the RX UE which CCs will carry SL-SRB3 and one or more SL-DRBs. Figure 3 For example, the TX UE configures SL-SRB3 using a first CC set 322 with repetition, SL-DRB1 using a second CC set 324 with repetition, and SL-DRB2 using a second CC set 324 with CA. In some aspects, the TX UE may configure SL-SRB3 and / or one or more SL-DRBs for packet repetition based on whether the ProSe per-packet reliability (PPPR) associated with packets carried on the corresponding radio bearer exceeds a predefined or configured PPPR threshold. In some aspects, SL-SRB3 may be configured using a single CC or multiple CC sets for repetition. Moreover, in some aspects, the TX UE may individually configure more or fewer SL-DRBs with different or identical CC sets, and may individually configure each CC set for CA or repetition. Moreover, in some aspects, the TX UE may configure all available CCs for CA of one or more SL-DRBs, or may select a subset of available CCs for CA of one or more SL-DRBs, to reduce power consumption at the TX UE and / or RX UE.

[0051] In some aspects, in response to receiving an SL reconfiguration message 318, the RX UE may send an SL reconfiguration completion message 320 (e.g., a PC5-RRC message, such as an RRCReconfigurationCompleteSidelink message) on SL-SRB3, thereby confirming the configuration of SL-SRB3 and one or more SL-DRBs specified in the SL reconfiguration message 318. In response to the SL reconfiguration completion message 320, the TX UE may consider the multi-CC configuration in the SL reconfiguration message 318 as active, and transmit signals on SL-SRB3 and data on one or more SL-DRBs using the selected CC sets 322 and 324, as described above. Additionally, in some aspects, the TX UE may report to the network (e.g., by reporting to the base station to which the TX UE is connected, such as...) Figure 1(The RAN node 122) transmits at least some of the duplicate / CA configurations negotiated with the RX UE (e.g., the target or destination L2 identifier associated with the RX UE, the indication of the SL-SRB3 and / or SL-DRB identifier, the CC set 322 and / or 324 of the configuration associated with the identifier, and the indication of whether duplicate or CA is associated with each carrier set 322 and / or 324) (e.g., via RRC sidelink UE information (SUI) messages).

[0052] Therefore, as discussed above with respect to various aspects of this disclosure, the TX UE and RX UE can communicate directly using SL unicast CA without reference to the primary CC or secondary CC.

[0053] After the TX UE is configured with a CC for subsequent SL-SRB3 and one or more SL-DRBs, the TX UE may perform radio link monitoring (RLM) on various CCs used to determine whether to declare a radio link failure (RLF) to the upper layer of the TX UE (e.g., V2X layer), which may cause the CC to be reconfigured (e.g., via SL-SRB3) or other events. Figures 6 to 10 This is a flowchart of various example methods for declaring an RLF, based on an overview of various aspects of this disclosure.

[0054] For example, Figure 6 This is a flowchart of an example method 600 for declaring an RLF during SL communication, based on various aspects of this disclosure. In method 600, at operation 602, the TX UE can independently perform RLM for each SL-SRB3 CC and each SL-DRB CC. In some aspects, the TX UE can perform RLM by monitoring for each CC whether the number of consecutive HARQ discontinuous transmissions (DTX) events occurring when no HARQ is received at the TX UE exceeds a first threshold. Such tracking can occur at the PHY and / or MAC level of the TX UE. Moreover, in some aspects, the TX UE can monitor whether the number of retransmissions to the RX UE at the Radio Link Control (RLC) layer for each CC (e.g., for any Serving Data Unit (SDU) segment) exceeds a second threshold.

[0055] At operation 604, the TX UE can determine whether a CC of SL-SRB3 and / or one or more SL-DRBs has failed. In some aspects, the TX UE can monitor the number of HARQ DTX events and RLC retransmissions for each used CC, and determine that the CC has failed if the number of any one or two HARQ DTX events and RLC retransmissions for any single CC has exceeded its associated threshold.

[0056] At operation 606, the TX UE may declare an RLF to its upper layer (e.g., V2X layer) for each failed CC, as determined by the TX UE in operation 604. In some aspects, the upper layer may respond to an RLF for a CC by performing a "keep-alive" check for one or more failed CCs. In some aspects, upon receiving an RLF for a CC, the upper layer may start a timer and, if the associated CC continues to fail, attempt to reconfigure the CC connected to the RX UE's sidelink.

[0057] Additionally, at operation 608, TX UE (when in contact with the base station (e.g., Figure 1 In the case of the RAN node 122's RRC_CONNECTED state, fault information regarding the declared RLF of one or more CCs can be reported to the base station via an RRC message. In some aspects, such an RRC message may indicate one or more of the following: the destination L2 identifier associated with the faulty CC; an identifier for each faulty CC for which an RLF has been declared; and / or an indication of whether an RLF has been declared due to the number of consecutive HARQ DTX events for the CC exceeding a first threshold and / or due to the number of RLC retransmissions exceeding a second threshold.

[0058] Figure 7 This is a flowchart of another example method 700 for declaring an RLF during SL communication, based on an overview of various aspects of this disclosure. In some aspects, the TX UE specifically performs an RLM for each CC of SL-SRB3, rather than as combined above. Figure 6 Method 600 discusses performing RLM on each CC of both SL-SRB3 and one or more SL-DRBs. In some aspects, when focusing on the SL-SRB3 CC using method 700, the TX UE can reconfigure the CCs of one or more SL-DRBs based on reports from the RX UE regarding the SL Reference Signal Received Power (SL-RSRP) or CBR (e.g., by reconfiguring CCs, such as adding and / or releasing various CCs, or changing whether a particular set of CCs is configured for CA or packet repeating).

[0059] In method 700, at operation 702, the TX UE can independently perform RLM for each SL-SRB3 CC. In some aspects, to perform RLM, the TX UE can monitor for each SL-SRB3 CC whether the number of consecutive HARQ DTX events and / or the number of RLC retransmissions to the RX UE exceed the corresponding thresholds, as described above. Figure 6 The operation discussed in 602.

[0060] At operation 704, if the number of consecutive HARQ DTX events and / or the number of RLC retransmissions to the RXUE associated with the SL-SRB3 CC exceeds its corresponding threshold, the TX UE detects a failure of the CC. Therefore, at operation 706, the TX UE can declare an RLF for each failed SL-SRB3 CC to its upper layer (e.g., the V2X layer). In some aspects, the upper layer can respond to the RLF of the SL-SRB3 CC by performing a "keep-alive" check for the failed CC, as described above. Figure 6 As described in operation 606. Additionally, at operation 708, if in an RRC_CONNECTED state with the base station, the TX UE can report fault information to the base station regarding one or more declared RLFs of SL-SRB3 CCs. In some aspects, the types of information that can be reported are as described above regarding... Figure 6 The operation described in 608.

[0061] Furthermore, at operation 710, the TX UE can determine whether all SL-SRB3 CCs have failed due to the RLM performed in operation 702. If the TX UE determines that all SL-SRB3 CCs have been committed, then at operation 712, the TX UE can initiate a carrier reconfiguration procedure (e.g., PC5-RRC reconfiguration, such as via...). Figure 3 (RRCReconfigurationSidelink message 318). In some aspects, the TX UE may employ a carrier reconfiguration procedure to remove the faulty SL-SRB3 CC and add or reconfigure one or more other CCs for SL-SRB3.

[0062] Figure 8A and Figure 8B This is a flowchart of yet another example method 800 for declaring an RLF during SL communication, based on an overview of the various aspects described. Similar to... Figure 6 In method 600, RLM is performed on each CC for SL-SRB3 and one or more SL-DRBs. However, in method 800, the RLM declared for SL-SRB3 CC can be processed differently than the RLM declared for CCs associated with one or more SL-DRBs.

[0063] In method 800, at operation 802, the TX UE can independently perform RLM for each SL-SRB3 CC and each SL-DRBCC (e.g., by monitoring for each CC whether the number of consecutive HARQ DTX events for each CC and / or the number of RLC retransmissions to the RX UE exceed a second threshold), as described above. Figure 6 The operation discussed in 602.

[0064] At operation 804, the TX UE can determine whether the CC of SL-SRB3 and / or one or more SL-DRBs has failed. In some aspects, as described above... Figure 6 As described in Operation 604, the TX UE can monitor the number of HARQ DTX events and RLC retransmissions for each used CC, and determine that the CC has failed if either or both of the number of HARQ DTX events and RLC retransmissions for any single CC have exceeded their associated thresholds.

[0065] At operation 806, the TX UE can declare an RLF to its upper layer (e.g., the V2X layer) for each failed CC, as determined by the TX UE in operation 804. In some aspects, the upper layer can respond to the RLF for a CC by performing a "keep-alive" check for one or more failed CCs (e.g., as described above). Figure 6 (As discussed in Operation 606).

[0066] Additionally, at operation 808, the TX UE (in the case of being in the RRC_CONNECTED state with the gNB) can report fault information to the gNB regarding one or more declared RLFs (e.g., as mentioned above regarding...). Figure 6 Operation 608 is described.

[0067] At operation 810, the TX UE can determine whether all SL-SRB3 carriers have failed (e.g., as described above in conjunction with...). Figure 7 (As described in operation 710). If the TX UE has determined that all SL-SRB3 CCs have failed, then at operation 812, the TX UE can initiate a carrier reconfiguration procedure for the SL-SRB3 CCs (e.g., as described above in conjunction with...). Figure 7 (As discussed in operation 712). Additionally, at operation 814, the TX UE can determine whether any of the previously detected faulty CCs is associated with one or more SL-DRBs. If so, at operation 816, the TX UE can initiate a carrier reconfiguration procedure (e.g., PC5-RRC reconfiguration, such as via...). Figure 3(RRCReconfigurationSidelink message 318). In some aspects, the TX UE may employ a carrier reconfiguration procedure to remove one or more faulty SL-DRB CCs and add or reconfigure one or more other CCs for one or more SL-DRBs.

[0068] Figure 9 This is a flowchart of yet another example method 900 for declaring an RLF during SL communication, based on an overview of various aspects of this disclosure. Method 900 can declare an RLF for an RX UE, compared to methods 600, 700, and 800, which associate the declared RLF with a corresponding CC.

[0069] In method 900, at operation 902, the TX UE can independently perform RLM for each SL-SRB3 CC. In some aspects, as combined with the above... Figure 7 As described in operation 702, the TX UE can perform RLM by monitoring whether the number of consecutive HARQ DTX events for each SL-SRB3 CC exceeds a first threshold and / or whether the number of RLC retransmissions to the RX UE for each SL-SRB3 CC exceeds a second threshold.

[0070] At operation 904, the TX UE can determine whether the number of faulty SL-SRB3 CCs detected by the TX UE is greater than or equal to a third threshold (e.g., the value of X). For example, Figure 10 This is a flowchart of an example method 1000 for determining whether to declare an RLF for an RX UE using a threshold number of carriers, based on various aspects of this disclosure. In some aspects, the TX UE may execute method 1000 for operation 904.

[0071] In method 1000, at operation 1002, the TX UE can determine whether the number of SL-SRB3 CCs corresponding to its consecutive HARQ DTX events that exceeds a first threshold (THRESHOLD_1) is greater than a third threshold (X). If so, at operation 1006, the TX UE can determine that an RLF has occurred for the RX UE. Conversely, if at operation 1004, the TX UE determines that the number of SL-SRB3 CCs corresponding to its consecutive HARQ DTX events that exceeds a first threshold (THRESHOLD_1) is greater than X, then the TX UE can determine whether the number of SL-SRB3 CCs corresponding to its corresponding RLC retransmissions that exceeds a second threshold (THRESHOLD_2) is greater than X. If so, at operation 1006, the TX UE can determine that an RLF has occurred for the RX UE. Otherwise, at operation 1008, the TX UE can determine that an RLF has not yet occurred for the RX UE.

[0072] In some respects, the value of X can be an integer ranging from one to the total number of CCs associated with SL-SRB3. When X is one, a failure of a single CC associated with SL-SRB3 may cause an RLF (Restricted Level Failure) to be declared for the RX UE. When X equals the total number of CCs associated with SL-SRB3, failures of all such CCs may occur before the TX UE declares an RLF for the RX UE.

[0073] Return to Figure 9 At operation 904, if the number of detected faulty SL-SRB3 CCs is greater than or equal to X, then at operation 906, UE TX can declare an RLF for RX UE to its upper layer (e.g., V2X layer). In some aspects, TX UE can respond to an RLF for RX UE by performing a "keep-alive" check on all CCs (e.g., all SL-SRB3 CCs and all CCs of one or more SL-DRBs). In some aspects, upon receiving an RLF for RX UE, if the RLF condition for RX UE persists, the upper layer can start a timer and attempt to reconfigure the CCs connected to the SL of RX UE.

[0074] Additionally, at operation 908, the TX UE (in the case of being in the RRC_CONNECTED state with the base station) can report fault information about the claimed RLF of the RX UE to the base station, such as via an RRC message. In some aspects, such an RRC message may indicate one or more of the following: the destination L2 identifier associated with the RX UE that has failed; the identifier of each CC of SL-SRB3 and one or more SL-DRBs; the number of consecutive HARQ DTX events for each CC; and / or the number of RLC retransmissions for each CC.

[0075] As can be seen from the foregoing disclosure, various aspects of this disclosure provide a mechanism by which a UE can participate in SL unicast CA within an NR without the designation of a PCC and associated SCC, thereby providing CA performance and packet duplication reliability without the need for infrastructure differentiation associated with the PCC / SCC. A solution is also provided for RLM performed by a TX UE and for declaring RLF associated with SL communication between the TX UE and the RX UE.

[0076] The above are several flowcharts outlining example methods and message exchanges. In this specification and the appended claims, the term "determine" is used broadly when describing method steps or functions, referring to entities such as parameters, variables, etc. For example, "determine" is interpreted to cover, for example, communication that receives and parses encoded entities or entity values. "Determine" should be interpreted to cover accessing and reading stored entities or memory (e.g., lookup tables, registers, device memory, remote memory, etc.) for entity values. "Determine" should be interpreted to cover calculating or deriving the value of an entity or entity based on other quantities or entities. "Determine" should be interpreted to cover any manner of inferring or identifying the value of an entity or entity.

[0077] As used herein, when referring to an entity or the value of an entity, the term "identifier" will be interpreted broadly to cover any manner in which an entity or the value of an entity is determined. For example, the term "identifier" is interpreted to cover, for example, communication that receives and parses encoded entities or the values ​​of entities. The term "identifier" should be interpreted to cover accessing and reading storage entities or memory used for the values ​​of entities (e.g., device queues, lookup tables, registers, device memory, remote memory, etc.).

[0078] As used herein, when referring to an entity or the value of an entity, the term “encoding” will be interpreted broadly to encompass any means or techniques used to generate a sequence of data or signals that communicate an entity to another component.

[0079] As used herein, when referring to an entity or entity value, the term "selection" will be broadly interpreted to encompass any manner of determining an entity or entity value from a plurality of or a series of possible selections. For example, the term "selection" is interpreted to encompass accessing and reading storage entities or memory used for entity values ​​(e.g., lookup tables, registers, device memory, remote memory, etc.) and returning an entity or entity value from those stored. The term "selection" is interpreted to apply one or more constraints or rules to a set of input parameters to determine an appropriate entity or entity value. The term "selection" is interpreted broadly to encompass any manner of selecting an entity based on one or more parameters or conditions.

[0080] As used herein, the term “derive” is interpreted broadly when used with reference to an entity or the value of an entity. “Derivation” should be interpreted to encompass accessing and reading memory (e.g., lookup tables, registers, device memory, remote memory, etc.) that stores some initial or underlying values, and performing processing and / or logical / mathematical operations on one or more values ​​to generate a derived entity or value for an entity. The term “derive” should be interpreted to encompass calculating or measuring the value of an entity or entity based on other quantities or entities. The term “derive” should be interpreted to encompass any manner in which the value of an entity or entity is inferred or identified.

[0081] As used herein, when referring to an entity (e.g., a parameter or setting) or the value of an entity, the term "indicator" will be interpreted broadly to cover any manner in which an entity or the value of an entity is explicitly or implicitly conveyed. For example, bits within a transmitted message may be used to explicitly encode the value of an indicator, or may encode an index or other indicator mapped to the value of an indicator through prior configuration. The absence of a field within a message may implicitly indicate a value of an entity based on prior configuration.

[0082] Example

[0083] Example 1 is an apparatus for a user equipment (UE), the apparatus including a memory and a processor, the processor being coupled to the memory and configured to, when executing instructions stored in the memory, cause the UE to: receive, via an RF transceiver, an indication from a peer UE as to whether the peer UE supports side-link (SL) carrier aggregation (CA); and, based on the peer UE supporting SL CA, send, via the RF transceiver, an SL reconfiguration message to the peer UE, the SL reconfiguration message configuring an SL data radio bearer (SL-DRB) to carry data from the UE to the peer UE.

[0084] Example 2 includes the subject matter as described in Example 1, including or omitting optional elements, wherein the SL reconfiguration message configures the SL-DRB for grouped repetition or for SL CA.

[0085] Example 3 includes the subject matter as described in Example 1, including or omitting optional elements, wherein the SL reconfiguration message utilizes a first plurality of SL component carriers to configure the SL-DRB to carry the data from the UE to the peer UE.

[0086] Example 4 includes the subject matter according to Example 3, including or omitting optional elements, wherein the processor is further configured to cause the UE to: select the first plurality of SL component carriers from a plurality of permitted SL component carriers for transmission to the peer UE.

[0087] Example 5 includes the subject matter according to Example 3, including or omitting optional elements, wherein the processor is further configured to cause the UE to: send a first message via the RF transceiver to the peer UE inquiring about at least one capability of the peer UE, wherein the indication of whether the peer UE supports SL CA is included in a second message from the peer UE in response to the first message.

[0088] Example 6 includes the subject matter according to Example 5, including or omitting optional elements, wherein the processor is further configured to cause the UE to send a third message to the base station indicating at least some information included in the second message.

[0089] Example 7 includes the subject matter according to Example 5, including or omitting optional elements, wherein at least one of the first message, the second message, or the SL reconfiguration message is transmitted on SL Signal Radio Bearer (SRB) 3 (SL-SRB3).

[0090] Example 8 includes the subject matter according to Example 5, including or omitting optional elements, wherein the processor is further configured to cause the UE to: exchange multiple signaling messages with the peer UE via the RF transceiver on SL Signal Radio Bearer (SRB) 0 (SL-SRB0), SL-SRB1 and SL-SRB2 prior to the first message, in order to establish a connection between the UE and the peer UE.

[0091] Example 9 includes the subject matter described in Example 8, including or omitting optional elements, wherein the processor is further configured to cause the UE to: reuse the SL-ConfigCommonNR->sl-FreqInfoList-r16 information element (IE) in a System Information Block (SIB) with a single carrier limitation to determine a single SL component carrier; map the SL-SRB0, the SL-SRB1, and the SL-SRB2 to the single SL component carrier in the upper layer of the UE; and map the Vehicle-to-Everything (V2X) service identifier to the Layer 2 (L2) destination address of the peer UE in the upper layer of the UE.

[0092] Example 10 includes the subject matter according to Example 8, including or omitting optional elements, wherein the processor is further configured to cause the UE to: map at least one of the SL-SRB0, the SL-SRB1, or the SL-SRB2 to more than one corresponding SL component carrier in the upper layer of the UE; and map a vehicle-to-everything (V2X) service identifier to the Layer 2 (L2) destination address of the peer UE in the upper layer of the UE.

[0093] Example 11 includes the subject matter according to Example 10, including or omitting optional elements, wherein each of the SL-SRB0, the SL-SRB1, or the SL-SRB2 is mapped to the more than one corresponding SL component carrier.

[0094] Example 12 includes the subject matter according to Example 3, including or omitting optional elements, wherein the processor is further configured to cause the UE to: perform radio link monitoring (RLM) on at least one of the first plurality of SL component carriers, wherein the RLM is based on at least one of: the number of retransmissions to the peer UE at the radio link control (RLC) layer associated with each of the first plurality of SL component carriers; or the number of consecutive hybrid automatic repeat request (HARQ) discontinuous transmission (DTX) events associated with each of the first plurality of SL component carriers.

[0095] Example 13 includes the subject matter described in Example 3, including or omitting optional elements, wherein the processor is further configured to cause the UE to: independently perform radio link monitoring (RLM) for each of the first plurality of SL component carriers; and declare a radio link failure (RLF) of the first SL component carrier based on the RLM detecting a failure of the first SL component carrier among the first plurality of SL component carriers.

[0096] Example 14 includes the subject matter according to Example 3, including or omitting optional elements, wherein: the SL reconfiguration message further configures the SL signal radio bearer 3 (SL-SRB3) for packet repetition using a second plurality of SL component carriers; and the processor is configured to: independently perform RLM for each of the first plurality of SL component carriers and each of the second plurality of SL component carriers; and declare an RLF for the first SL component carrier based on the RLM detecting a fault in the first plurality of SL component carriers or the first SL component carrier among the second plurality of SL component carriers.

[0097] Example 15 includes the subject matter according to Example 3, including or omitting optional elements, wherein: the SL reconfiguration message further configures the SL signal radio bearer 3 (SL-SRB3) for packet repetition using a second plurality of SL component carriers; and the processor is configured to cause the UE to: independently perform RLM for each of the second plurality of SL component carriers; and declare an RLF for the first SL component carrier based on the RLM detecting a fault in the first SL component carrier among the second plurality of SL component carriers.

[0098] Example 16 includes the subject matter described in Example 15, including or omitting optional elements, wherein the processor is further configured to cause the UE to: determine whether the RLM has detected a fault in all SL component carriers of the second plurality of SL component carriers; and, based on the determination that the RLM has detected a fault in all SL component carriers of the second plurality of SL component carriers, reconfigure one or more SL component carriers of the second plurality of SL component carriers.

[0099] Example 17 includes the subject matter described in Example 16, including or omitting optional elements, wherein the processor is configured to cause the UE to: determine whether the RLM detects a fault in a second SL component carrier among the first plurality of SL component carriers; and, based on the determination that the RLM detects a fault in the second SL component carrier among the first plurality of SL component carriers, reconfigure one or more SL component carriers among the first plurality of SL component carriers.

[0100] Example 18 includes the subject matter described in Example 16, including or omitting optional elements, wherein the processor is configured to cause the UE to: receive a reception report from the peer UE via the RF transceiver regarding the first plurality of SL component carriers; and, based on the reception report, reconfigure one or more SL component carriers among the first plurality of SL component carriers.

[0101] Example 19 includes the subject matter according to Example 3, including or omitting optional elements, wherein: the SL reconfiguration message further configures the SL signal radio bearer 3 (SL-SRB3) for packet repetition using a second plurality of SL component carriers; and the processor is configured to cause the UE to: independently perform radio link monitoring (RLM) for each of the second plurality of SL component carriers; and declare a radio link failure (RLF) for the peer UE based on the RLM detecting a failure of at least a first number of SL component carriers among the second plurality of SL component carriers.

[0102] Example 20 includes the subject matter described in Example 19, including or omitting optional elements, wherein the first quantity is one.

[0103] Example 21 includes the subject matter described in Example 19, including or omitting optional elements, wherein the first quantity is the total number of the second plurality of SL component carriers.

[0104] Example 22 is a method for a user equipment (UE), the method comprising: receiving from a peer UE an indication of whether the peer UE supports sidelink (SL) carrier aggregation (CA); and, based on the peer UE supporting SL CA, sending an SL reconfiguration message to the peer UE, the SL reconfiguration message configuring an SL data radio bearer (SL-DRB) to carry data from the UE to the peer UE.

[0105] Example 23 includes the subject matter described in Example 22, including or omitting optional elements, wherein the SL reconfiguration message configures the SL-DRB for grouped repetition or for SL CA.

[0106] Example 24 includes the subject matter described in Example 22, including or omitting optional elements, wherein the SL reconfiguration message utilizes a first plurality of SL component carriers to configure the SL-DRB to carry the data from the UE to the peer UE.

[0107] Example 25 includes the subject matter described in Example 24, including or omitting optional elements, and the method further includes: selecting the first plurality of SL component carriers from a plurality of permitted SL component carriers for transmission to the peer UE.

[0108] Example 26 includes the subject matter described in Example 24, including or omitting optional elements, and the method further includes: sending a first message to the peer UE querying the peer UE for at least one capability of the peer UE, wherein the indication of whether the peer UE supports SL CA is included in a second message from the peer UE in response to the first message.

[0109] Example 27 includes the subject matter described in Example 26, including or omitting optional elements, and the method further includes: sending a third message to the base station indicating at least some information included in the second message.

[0110] Example 28 includes the subject matter described in Example 26, including or omitting optional elements, wherein at least one of the first message, the second message, or the SL reconfiguration message is transmitted on the SL signal radio bearer (SRB) 3 (SL-SRB3).

[0111] Example 29 includes the subject matter described in Example 26, including or omitting optional elements, and the method further includes: prior to the first message, exchanging multiple signaling messages with the peer UE on SL signal radio bearers (SRB) 0 (SL-SRB0), SL-SRB1, and SL-SRB2 to establish a connection between the UE and the peer UE.

[0112] Example 30 includes the subject matter described in Example 29, including or omitting optional elements, and the method further includes: reusing the SL-ConfigCommonNR->sl-FreqInfoList-r16 information element (IE) in a System Information Block (SIB) with a single carrier limitation to determine a single SL component carrier; mapping the SL-SRB0, the SL-SRB1, and the SL-SRB2 to the single SL component carrier in the upper layer of the UE; and mapping the service identifier to the Layer 2 (L2) destination address of the peer UE in the upper layer of the UE.

[0113] Example 31 includes the subject matter described in Example 29, including or omitting optional elements, and the method further includes: mapping at least one of the SL-SRB0, the SL-SRB1, or the SL-SRB2 to more than one corresponding SL component carrier in the upper layer of the UE; and mapping the service identifier to the layer 2 (L2) destination address of the peer UE in the upper layer of the UE.

[0114] Example 32 includes the subject matter described in Example 31, including or omitting optional elements, wherein each of the SL-SRB0, the SL-SRB1, or the SL-SRB2 is mapped to the more than one corresponding SL component carrier.

[0115] Example 33 includes the subject matter described in Example 24, including or omitting optional elements, and the method further includes: performing radio link monitoring (RLM) on at least one of the first plurality of SL component carriers, wherein the RLM is based on at least one of: the number of retransmissions to the peer UE at the radio link control (RLC) layer associated with each of the first plurality of SL component carriers; or the number of consecutive hybrid automatic repeat request (HARQ) discontinuous transmission (DTX) events associated with each of the first plurality of SL component carriers.

[0116] Example 34 includes the subject matter described in Example 24, including or omitting optional elements, wherein the method further includes: independently performing radio link monitoring (RLM) on each of the first plurality of SL component carriers; and declaring a radio link fault (RLF) on the first SL component carrier based on the RLM detecting a fault on the first SL component carrier among the first plurality of SL component carriers.

[0117] Example 35 includes the subject matter according to Example 24, including or omitting optional elements, wherein: the SL reconfiguration message further configures the SL signal radio bearer 3 (SL-SRB3) for packet repetition using a second plurality of SL component carriers; and the method further includes: independently performing RLM for each of the first plurality of SL component carriers and each of the second plurality of SL component carriers; and declaring an RLF for the first SL component carrier based on the RLM detecting a fault in the first plurality of SL component carriers or the first SL component carrier among the second plurality of SL component carriers.

[0118] Example 36 includes the subject matter according to Example 24, including or omitting optional elements, wherein: the SL reconfiguration message further configures the SL signal radio bearer 3 (SL-SRB3) for packet repetition using a second plurality of SL component carriers; and the method further includes: independently performing an RLM for each of the second plurality of SL component carriers; and declaring an RLF for the first SL component carrier based on the RLM detecting a fault in the first SL component carrier among the second plurality of SL component carriers.

[0119] Example 37 includes the subject matter described in Example 36, including or omitting optional elements, and the method further includes: determining whether the RLM detects a fault in all SL component carriers of the second plurality of SL component carriers; and reconfiguring one or more SL component carriers of the second plurality of SL component carriers based on the determination that the RLM detects a fault in all SL component carriers of the second plurality of SL component carriers.

[0120] Example 38 includes the subject matter described in Example 37, including or omitting optional elements, and the method further includes: determining whether the RLM detects a fault in a second SL component carrier among the first plurality of SL component carriers; and reconfiguring one or more SL component carriers among the first plurality of SL component carriers based on the determination that the RLM detects a fault in the second SL component carrier among the first plurality of SL component carriers.

[0121] Example 39 includes the subject matter described in Example 37, including or omitting optional elements, and the method further includes: receiving a reception report from the peer UE regarding the first plurality of SL component carriers; and reconfiguring one or more SL component carriers among the first plurality of SL component carriers based on the reception report.

[0122] Example 40 includes the subject matter described in Example 24, including or omitting optional elements, wherein: the SL reconfiguration message further configures the SL signal radio bearer 3 (SL-SRB3) for packet repetition using a second plurality of SL component carriers; and the method further includes: independently performing radio link monitoring (RLM) for each of the second plurality of SL component carriers; and declaring a radio link failure (RLF) for the peer UE based on the RLM detecting a failure of at least a first number of SL component carriers among the second plurality of SL component carriers.

[0123] Example 41 includes the subject matter according to Example 40, including or omitting optional elements, wherein the first quantity is one.

[0124] Example 42 includes the subject matter described in Example 40, including or omitting optional elements, wherein the first quantity is the total number of the second plurality of SL component carriers.

[0125] Example 43 is a user equipment (UE) including a radio frequency (RF) transceiver and a baseband processor, the baseband processor being configured to, upon executing instructions stored in memory, cause the UE to: select at least one first sidelink (SL) component carrier; exchange multiple signaling messages with a peer UE via the RF transceiver on SL signal radio bearers (SRBs) 0 (SL-SRB0), SL-SRB1, and SL-SRB2 on the at least one first SL component carrier to establish a connection between the UE and the peer UE; send a capability query message to the peer UE via the RF transceiver on the at least one first SL component carrier to query whether the peer UE supports SL carrier aggregation (CA); in response to the capability query message, receive a capability information message from the peer UE via the RF transceiver on the at least one first SL component carrier, the capability information message including an indication of whether the peer UE supports SL CA; and, based on the peer UE supporting SL... CA, via the RF transceiver, transmits an SL reconfiguration message to the peer UE on at least one first SL component carrier to configure at least one SL data radio bearer (SL-DRB) for packet repeating or SL CA using the first plurality of SL component carriers; and transmits data to the peer UE via the RF transceiver using the first plurality of SL component carriers on at least one SL-DRB.

[0126] Example 44 includes the subject matter according to Example 43, including or omitting optional elements, wherein: the at least one first SL component carrier includes a second plurality of SL component carriers; and at least one of SL-SRB0, SL-SRB1, or SL-SRB2 is configured to perform group repetition using the second plurality of SL component carriers.

[0127] Example 45 includes the subject matter according to Example 43, including or omitting optional elements, wherein: the at least one SL-DRB comprises a plurality of SL-DRBs; and each of the plurality of SL-DRBs is individually configured for grouped repetition or for SL CA.

[0128] Example 46 includes the subject matter described in Example 43, including or omitting optional elements, wherein the first plurality of SL component carriers refers to a subset of a plurality of possible SL component carriers assigned to the UE.

[0129] Example 47 includes the subject matter described in Example 43, including or omitting optional elements, wherein the capability query message, the capability information message, and the SL reconfiguration message are exchanged on SL-DRB3.

[0130] Example 48 includes the subject matter described in Example 47, including or omitting optional elements, wherein the SL-DRB3 is configured to perform grouped repetition using a third plurality of SL component carriers.

[0131] Example 49 is a computer program product including program instructions that, when executed by a computer, implement the subject matter according to any one of Examples 20 to 38, including or omitting optional elements.

[0132] Figure 11 This is an illustration of examples of components of a wireless communication device according to one or more embodiments described herein. In some embodiments, device 1100 may include at least application circuitry 1102, baseband circuitry 1104, RF circuitry 1106, front-end module (FEM) circuitry 1108, one or more antennas 1110, and power management circuitry (PMC) 1112 coupled together as shown. Components of the illustrated device 1100 may be included in a UE or RAN node. In some embodiments, device 1100 may include fewer components (e.g., the RAN node may not utilize application circuitry 1102, but instead include a processor / controller to process IP data received from the CN or Evolved Packet Core (EPC)). In some embodiments, device 1100 may include additional components such as, for example, memory / storage devices, displays, cameras, sensors (including one or more temperature sensors, such as a single temperature sensor, multiple temperature sensors at different locations in device 1100, etc.), or input / output (I / O) interfaces. In other implementations, the components described below may be included in more than one device (e.g., the circuitry may be included separately in more than one device for a cloud-RAN (C-RAN) implementation).

[0133] Application circuitry 1102 may include one or more application processors. For example, application circuitry 1102 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor may include any combination of general-purpose processors and special-purpose processors (e.g., graphics processors, application processors, etc.). The processor may be coupled to or may include such memory / storage device and may be configured to execute instructions stored in the memory / storage device to enable various applications or operating systems to run on device 1100. In some specific implementations, the processor of application circuitry 1102 may process IP data packets received from the EPC.

[0134] Baseband circuit 1104 may include circuitry, such as, but not limited to, one or more single-core or multi-core processors. Baseband circuit 1104 may include one or more baseband processors or control logic components to process baseband signals received from the receive signal path of RF circuit 1106 and generate baseband signals for the transmit signal path of RF circuit 1106. Baseband circuit 1104 may interact with application circuitry 1102 to generate and process baseband signals and control the operation of RF circuit 1106. For example, in some implementations, baseband circuit 1104 may include a 3G baseband processor 1104A, a 4G baseband processor 1104B, a 5G baseband processor 1104C, or other existing, under development, or future generations (e.g., 5G, 6G, etc.) baseband processor 1104D.

[0135] The baseband circuitry 1104 (e.g., one or more of baseband processors 1104A-1104D) can handle various radio control functions that can communicate with one or more radio networks via RF circuitry 1106. In other embodiments, some or all of the functionality of the baseband processors 1104A-1104D may be included in a module (e.g., a set of executable instructions) stored in memory 1104G or other machine-readable or computer-readable medium (e.g., a non-transitory machine-readable or computer-readable storage medium) and executed via a central processing unit (CPU) 1104E or another type of processor (e.g., a reduced instruction set computing (RISC) processor, a complex instruction set computing (CISC) processor, a graphics processing unit (GPU), a digital signal processor (DSP) such as a baseband processor, an application-specific integrated circuit (ASIC), a radio frequency integrated circuit (RFIC), another processor, or any suitable combination thereof).

[0136] Radio control functions may include, but are not limited to, signal modulation / demodulation, encoding / decoding, and radio frequency shifting. In some implementations, the modulation / demodulation circuitry of baseband circuit 1104 may include Fast Fourier Transform (FFT), precoding, or constellation mapping / demapping functionality. In some implementations, the encoding / decoding circuitry of baseband circuit 1104 may include convolution, tail-biting convolution, turbo, Viterbi, or low-density parity-check (LDPC) encoder / decoder functionality. Specific implementations of the modulation / demodulation and encoder / decoder functions are not limited to these examples and may include other suitable functions in other respects.

[0137] In some embodiments, the baseband circuit 1104 may include one or more audio digital signal processors (DSPs) 1104F. The audio DSP 1104F may include elements for compression / decompression and echo cancellation, and in other embodiments may include other suitable processing elements. In some embodiments, components of the baseband circuit 1104 may be suitably combined in a single chip, a single chipset, or disposed on the same circuit board. In some embodiments, some or all of the components of the baseband circuit 1104 and the application circuit 1102 may be implemented together, for example, on a system-on-a-chip (SoC).

[0138] In some implementations, baseband circuit 1104 can provide communication compatible with one or more radio technologies. For example, in some implementations, baseband circuit 1104 can support communication with NG-RAN, E-UTRAN, or other wireless metropolitan area networks (WMAN), wireless local area networks (WLAN), wireless personal area networks (WPAN), etc. Implementations in which baseband circuit 1104 is configured to support radio communication with more than one wireless protocol can be referred to as multimode baseband circuits.

[0139] RF circuit 1106 may embody an RF transceiver that uses modulated electromagnetic radiation to communicate with a wireless network via a non-solid medium. In various implementations, RF circuit 1106 may include switches, filters, amplifiers, etc., to facilitate communication with the wireless network. RF circuit 1106 may include a receive signal path that includes circuitry for down-converting the RF signal received from FEM circuit 1108 and providing a baseband signal to baseband circuit 1104. RF circuit 1106 may also include a transmit signal path that includes circuitry for up-converting the baseband signal provided by baseband circuit 1104 and providing an RF output signal to FEM circuit 1108 for transmission.

[0140] In some specific implementations, the received signal path of RF circuit 1106 may include mixer circuit 1106A, amplifier circuit 1106B, and filter circuit 1106C. RF circuit 1106 may also include synthesizer circuit 1106D for synthesizing frequencies used by mixer circuit 1106A for both the received signal path and the transmitted signal path.

[0141] RF circuit 1106 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuits, and baseband circuit 1104 may include a digital baseband interface for communicating with RF circuit 1106.

[0142] The synthesizer circuit 1106D of the RF circuit 1106 may include a frequency divider, a delay-locked loop (DLL), a multiplexer, and a phase accumulator.

[0143] FEM circuit 1108 may include a receive signal path, which may include circuitry configured to operate on RF signals received from one or more antennas 1110, amplify the received signals, and provide an amplified version of the received signals to RF circuit 1106 for further processing. FEM circuit 1108 may also include a transmit signal path, which may include circuitry configured to amplify the signal provided by RF circuit 1106 for transmission via one or more of the one or more antennas 1110. In various specific implementations, amplification via the transmit signal path and / or receive signal path may be performed only in RF circuit 1106, only in FEM circuit 1108, or in both RF circuit 1106 and FEM circuit 1108.

[0144] In some implementations, FEM circuit 1108 may include a TX / RX switch to switch between transmit mode operation and receive mode operation. The FEM circuit may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuit may include an LNA to amplify the received RF signal and provide the amplified received RF signal as an output (e.g., to RF circuit 1106). The transmit signal path of FEM circuit 1108 may include: a power amplifier (PA) for amplifying (e.g., provided by RF circuit 1106) the input RF signal; and one or more filters for generating an RF signal for subsequent transmission (e.g., through one or more antennas in one or more antennas 1110).

[0145] The processor of application circuit 1102 and the processor of baseband circuit 1104 can be used to execute elements of one or more instances of the protocol stack. For example, the processor of baseband circuit 1104 can be used alone or in combination to perform layer 3, layer 2, or layer 1 functionality, and the processor of baseband circuit 1104 can utilize data received from these layers (e.g., packet data) and further perform layer 4 functionality (e.g., transmitting communication protocol (TCP) and user datagram protocol (UDP) layers). As mentioned herein, layer 3 may include the Radio Resource Control (RRC) layer, which will be described in further detail below. As mentioned herein, layer 2 may include the Media Access Control (MAC) layer, the Radio Link Control (RLC) layer, and the PDCP layer, which will be described in further detail below. As mentioned herein, layer 1 may include the physical (PHY) layer of the UE / RAN node.

[0146] In some implementations, the PMC 1112 can manage the power supplied to the baseband circuitry 1104. Specifically, the PMC 1112 can control power selection, voltage scaling, battery charging, or DC-DC conversion. The PMC 1112 is typically included when the device 1100 can be powered by a battery, for example, when the device is included in a UE. The PMC 1112 can improve power conversion efficiency while providing the desired implementation size and thermal characteristics.

[0147] Although Figure 11 PMC 1112 is shown coupled only to baseband circuit 1104; however, in other specific implementations, PMC 1112 may be additionally or alternatively coupled to other components such as, but not limited to, application circuit 1102, RF circuit 1106, or FEM circuit 1108, and perform similar power management operations for these other components.

[0148] In some implementations, PMC 1112 can control or otherwise become part of various power-saving mechanisms of device 1100. For example, if device 1100 is in the RRC_CONNECTED state, in which the device is still connected to the RAN node because it expects to receive traffic soon, after a period of inactivity, the device can enter a state known as Discontinuous Receive (DRX) mode. During this state, device 1100 can be powered down for short intervals, thereby saving power.

[0149] If there is no data traffic activity for an extended period, device 1100 can transition to the RRC_IDLE state, in which the device disconnects from the network and does not perform operations such as channel quality feedback or handover. Device 1100 enters a very low power state and performs paging, during which the device periodically wakes up again to listen to the network and then powers off again. Device 1100 may not receive data in this state; to receive data, the device can transition back to the RRC_CONNECTED state.

[0150] Baseband circuit 1104 or one or more baseband processors or control logic of baseband circuit 1104 can be independently configured as follows: Figure 1 The UE 110 or RAN node 122 performs signaling and operations in accordance with the meaning described in this disclosure.

[0151] Examples in this document may include subjects such as methods, components for performing actions or blocks of methods, including at least one machine-readable medium containing executable instructions that, when executed by a machine (e.g., a processor with memory, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), etc.), cause the machine to perform actions of a method, apparatus, or system of concurrent communication using various communication technologies according to the specific implementation and examples described.

[0152] In this regard, although the subject matter of this disclosure has been described in conjunction with various examples, embodiments, aspects, and corresponding drawings, it should be understood where applicable that other similar aspects may be used or modifications and additions may be made to the disclosed subject matter to perform the same, similar, alternative, or substitute functions without departing from the disclosed subject matter. Therefore, the disclosed subject matter should not be limited to any single example, embodiment, or aspect described herein, but should be interpreted in accordance with the breadth and scope of the appended claims.

[0153] In particular, regarding the various functions performed by the aforementioned components or structures (assemblies, devices, circuits, systems, etc.), unless otherwise stated, the terminology used to describe such components (including references to "part") is intended to correspond to any component or structure that performs the specified functions of the described component (e.g., functionally equivalent), even if it is not structurally equivalent to the disclosed structure that performs the functions in the exemplary embodiments illustrated herein. Furthermore, although certain features have been disclosed with respect to only one of several embodiments, it may be desirable and advantageous for any given application to combine such features with one or more other features of other embodiments.

[0154] As used herein, the term “or” is intended to mean inclusive “or” rather than exclusive “or.” That is, unless otherwise stated or clearly apparent from the context, “X adopts A or B” is intended to mean any natural inclusive arrangement of natural inclusive arrangements. That is, if X adopts A; X adopts B; or X adopts both A and B, then “X adopts A or B” is satisfied in any of the foregoing cases. Additionally, the articles “a” and “an” used in this application and the appended claims should generally be interpreted as meaning “one or more” unless otherwise stated or clearly apparent from the context to refer to the singular form. Furthermore, to the extent that the terms “comprising,” “including,” “having,” “having,” “with,” or variations thereof are used in the embodiment or claims, such terms are intended to be included in a manner similar to the term “including.” Additionally, in the case of discussing one or more numbered items (e.g., “first X,” “second X,” etc.), generally, the one or more numbered items may be different or they may be the same, but in some cases, the context may indicate that they are different or that they are the same.

[0155] As is widely recognized, the use of personally identifiable information should comply with privacy policies and measures that are generally accepted to meet or exceed industry or governmental requirements for protecting user privacy. In particular, personally identifiable information data should be managed and disposed of to minimize the risk of unintentional or unauthorized access or use, and users should be clearly informed of the nature of authorized use.

Claims

1. A baseband processor configured to perform operations including: At the user equipment (UE), receive from the peer UE an indication of whether the peer UE supports sidelink (SL) carrier aggregation (CA); and Based on the peer UE's support for SL CA, an SL reconfiguration message is generated for the peer UE. The SL reconfiguration message configures the SL data radio bearer (SL-DRB) to carry data from the UE to the peer UE.

2. The baseband processor according to claim 1, wherein the operation further includes: A first message is generated for the peer UE to inquire about at least one capability of the peer UE, wherein the indication of whether the peer UE supports SL CA is included in a second message from the peer UE in response to the first message.

3. The baseband processor of claim 2, wherein at least one of the first message, the second message, or the SL reconfiguration message comprises a PC5-Radio Resource Control (PC5-RRC) message.

4. The baseband processor of claim 2, wherein at least one of the first message, the second message, or the SL reconfiguration message is transmitted on the SL signal radio bearer (SRB) 3 (SL-SRB3).

5. The baseband processor of claim 1, wherein the SL reconfiguration message configures the SL-DRB for packet repetition or for SL CA.

6. The baseband processor of claim 1, wherein the SL reconfiguration message utilizes a first plurality of SL component carriers to configure the SL-DRB to carry the data from the UE to the peer UE.

7. The baseband processor according to claim 6, wherein the operation further comprises: Radio link monitoring (RLM) is triggered for at least one of the first plurality of SL component carriers, wherein the RLM is based on at least one of the following: The number of retransmissions to the peer UE at the Radio Link Control (RLC) layer associated with each of the at least one of the first plurality of SL component carriers; or The number of consecutive Hybrid Automatic Repeat Request (HARQ) discontinuous transmission (DTX) events associated with each of the at least one of the first plurality of SL component carriers.

8. The baseband processor according to claim 6, wherein the operation further comprises: This triggers independent radio link monitoring (RLM) for each of the first plurality of SL component carriers. as well as Based on the RLM's detection of a fault in the first SL component carrier among the first plurality of SL component carriers, a radio link fault (RLF) is declared for the first SL component carrier.

9. The baseband processor according to claim 6, wherein: The SL reconfiguration message also configures SL signal radio bearer 3 (SL-SRB3) for packet repetition using a second plurality of SL component carriers; and The operation also includes: This causes independent radio link monitoring (RLM) for each of the first plurality of SL component carriers and each of the second plurality of SL component carriers; and Based on the RLM detecting a fault in the first SL component carrier among the first plurality of SL component carriers or the second plurality of SL component carriers, an RLF of the first SL component carrier is declared.

10. The baseband processor according to claim 6, wherein: The SL reconfiguration message also configures SL signal radio bearer 3 (SL-SRB3) for packet repetition using a second plurality of SL component carriers; and The operation also includes: This causes independent radio link monitoring (RLM) for each of the second plurality of SL component carriers; and Based on the RLM detecting a fault in the first SL component carrier among the second plurality of SL component carriers, an RLF of the first SL component carrier is declared.

11. The baseband processor of claim 10, wherein the operation further comprises: Determine whether the RLM detects a fault in all SL component carriers of the second plurality of SL component carriers; as well as Based on the determination of faults in all SL component carriers detected by the RLM in the second plurality of SL component carriers, one or more SL component carriers in the second plurality of SL component carriers are reconfigured.

12. The baseband processor of claim 11, wherein the operation further comprises: Determine whether the RLM has detected a fault in the second SL component carrier among the first plurality of SL component carriers; as well as Based on the determination by the RLM that a fault has been detected in the second SL component carrier among the first plurality of SL component carriers, one or more SL component carriers among the first plurality of SL component carriers are reconfigured.

13. The baseband processor of claim 11, wherein the operation further comprises: Receive a reception report from the peer UE regarding the first plurality of SL component carriers; as well as Based on the received report, one or more SL component carriers among the first plurality of SL component carriers are reconfigured.

14. The baseband processor according to claim 6, wherein: The SL reconfiguration message also configures SL signal radio bearer 3 (SL-SRB3) for packet repetition using a second plurality of SL component carriers; and The operation also includes: This causes independent radio link monitoring (RLM) for each of the second plurality of SL component carriers; and Based on the RLM detecting a fault in at least a first number of SL component carriers among the second plurality of SL component carriers, a radio link fault (RLF) is declared for the peer UE.

15. The baseband processor of claim 14, wherein the first quantity is one.

16. The baseband processor of claim 14, wherein the first quantity is the total number of the second plurality of SL component carriers.

17. A method for user equipment (UE), the method comprising: Receive an indication from the peer UE as to whether the peer UE supports side-link (SL) carrier aggregation (CA); as well as Based on the fact that the peer UE supports SL CA, an SL reconfiguration message is sent to the peer UE. The SL reconfiguration message configures the SL data radio bearer (SL-DRB) to carry data from the UE to the peer UE.

18. The method of claim 17, wherein the SL reconfiguration message configures the SL-DRB for group repetition or for SL CA.

19. The method of claim 17, wherein the SL reconfiguration message utilizes a first plurality of SL component carriers to configure the SL-DRB to carry the data from the UE to the peer UE.

20. The method according to claim 19, further comprising: The first plurality of SL component carriers are selected from a plurality of allowed SL component carriers for transmission to the peer UE.

21. The method according to claim 17, further comprising: A first message is sent to the peer UE to inquire about at least one capability of the peer UE, wherein the indication of whether the peer UE supports SL CA is included in a second message from the peer UE in response to the first message.

22. The method of claim 21, wherein at least one of the first message, the second message, or the SL reconfiguration message is transmitted on the SL signal radio bearer (SRB) 3 (SL-SRB3).

23. The method of claim 21, wherein at least one of the first message, the second message, or the SL reconfiguration message comprises a PC5-Radio Resource Control (PC5-RRC) message.

24. A user equipment (UE), the user equipment (UE) comprising: Radio frequency (RF) transceivers; and At least one processor, coupled to the RF transceiver, and configured to cause the UE to perform operations when instructions stored in memory are executed, the operations including: The RF transceiver receives an indication from the peer UE regarding whether the peer UE supports sidelink (SL) carrier aggregation (CA). as well as Based on the fact that the peer UE supports SL CA, an SL reconfiguration message is sent to the peer UE via the RF transceiver. The SL reconfiguration message configures the SL data radio bearer (SL-DRB) to carry data from the UE to the peer UE.

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