Beam failure recovery for sidelink carrier aggregation

Abstract

Aspects of the present disclosure generally relate to wireless communications. In some aspects, a user equipment (UE) may transmit reference signals on a primary sidelink carrier and on one or more secondary sidelink carriers using carrier aggregation. In some embodiments, the UE may receive a medium access control control element (MAC CE) indicating a beam failure on the primary sidelink carrier, the one or more secondary sidelink carriers, or both. The UE may transmit an aperiodic reference signal on the primary sidelink carrier in response to receiving the MAC CE. Numerous other aspects are described.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims priority to U.S. Patent Application No. 17 / 823,888, filed on August 31, 2022, entitled “BEAM FAILURE RECOVERY FOR SIDELINK CARRIER AGGREGATION” and assigned to the assignee of this application. The disclosure of the prior application is considered a part of this patent application and is incorporated by reference into this patent application. Technical Field

[0003] Aspects of the present disclosure relate generally to wireless communications, and to techniques and apparatus for beam failure recovery for sidelink carrier aggregation. Background Art

[0004] Wireless communication systems are widely deployed to provide a variety of telecommunication services, such as telephony, video, data, messaging, and broadcasting. Typical wireless communication systems may employ multiple access technologies that can support communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, time division synchronous code division multiple access (TD-SCDMA) systems, and long term evolution (LTE). LTE / LTE-Advanced is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by the Third Generation Partnership Project (3GPP).

[0005] A wireless network may include one or more network nodes that support communications for wireless communication devices, such as user equipment (UE) or multiple UEs. A UE may communicate with a network node via downlink communications and uplink communications. A "downlink" (or "DL") refers to a communication link from a network node to a UE, and an "uplink" (or "UL") refers to a communication link from a UE to a network node. Some wireless networks may support device-to-device communications, such as via a local link (e.g., a side link (SL), a wireless local area network (WLAN) link, and / or a wireless personal area network (WPAN) link, etc.).

[0006] The above-mentioned multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different UEs to communicate at a city, country, region and / or global level. New Radio (NR) (which may be referred to as 5G) is a set of enhancements to the LTE mobile standard promulgated by 3GPP. NR is designed to better support mobile broadband Internet access by: improving spectrum efficiency; reducing costs; improving services; utilizing new spectrum; and using orthogonal frequency division multiplexing (OFDM) (CP-OFDM) with cyclic prefix (CP) on the downlink, CP-OFDM and / or single carrier frequency division multiplexing (SC-FDM) (also known as discrete Fourier transform spread OFDM (DFT-s-OFDM)) on the uplink to better integrate with other open standards; and supporting beamforming, multiple input multiple output (MIMO) antenna technology and carrier aggregation. As the demand for mobile broadband access continues to increase, further improvements in LTE, NR and other radio access technologies remain useful. Summary of the invention

[0007] Some aspects described herein relate to a method of performing wireless communications by a user equipment (UE). The method may include sending a reference signal on a primary side link carrier and on one or more secondary side link carriers using carrier aggregation. The method may include receiving a medium access control control element (MAC CE) indicating a beam failure on the primary side link carrier, one or more secondary side link carriers, or both. The method may include sending a non-periodic reference signal on the primary side link carrier in response to receiving the MAC CE.

[0008] Some aspects described herein relate to a method of wireless communication performed by a UE. The method may include sending reference signals on a primary link carrier and on one or more secondary link carriers using carrier aggregation. The method may include receiving a first MAC CE indicating a failure of a beam on a secondary link carrier in one or more secondary link carriers. The method may include sending one or more non-periodic reference signals on other secondary link carriers in response to receiving the first MAC CE. The method may include receiving a message indicating one or more feasible beams of other secondary link carriers. The method may include sending a beam switching message on the primary link carrier via a second MAC CE based at least in part on the one or more feasible beams.

[0009] Some aspects described herein relate to a method of wireless communication performed by a UE. The method may include receiving a reference signal on a primary sidelink carrier and on one or more secondary sidelink carriers using carrier aggregation. The method may include detecting a beam failure based at least in part on a measurement of the reference signal. The method may include sending a first non-periodic MAC CE indicating a failure of one or more beams on the primary sidelink carrier or one or more of the one or more secondary sidelink carriers.

[0010] Some aspects described herein relate to a UE for wireless communication. The UE may include a memory, a transceiver, and one or more processors coupled to the transceiver and the memory. The one or more processors may be configured to: use carrier aggregation, send reference signals on a primary side link carrier and on one or more secondary side link carriers via the transceiver. The one or more processors may be configured to receive a MAC CE via the transceiver, the MAC CE indicating a beam failure on the primary side link carrier, one or more secondary side link carriers, or both. The one or more processors may be configured to: send a non-periodic reference signal on the primary side link carrier via the transceiver and in response to receiving the MAC CE.

[0011] Some aspects described herein relate to a UE for wireless communication. The UE may include a memory, a transceiver, and one or more processors coupled to the transceiver and the memory. The one or more processors may be configured to use carrier aggregation to send reference signals on a primary side link carrier and on one or more secondary side link carriers via a transceiver. The one or more processors may be configured to receive a first MAC CE via a transceiver, the first MAC CE indicating a failure of a beam on a secondary side link carrier in one or more secondary side link carriers. The one or more processors may be configured to send one or more non-periodic reference signals on other secondary side link carriers in one or more secondary side link carriers via a transceiver and in response to receiving the first MAC CE. The one or more processors may be configured to receive a message indicating one or more feasible beams of other secondary side link carriers via a transceiver. The one or more processors may be configured to send a beam switching message using a second MAC CE on the primary side link carrier via a transceiver, based at least in part on one or more feasible beams.

[0012] Some aspects described herein relate to a UE for wireless communication. The UE may include a memory, a transceiver, and one or more processors coupled to the transceiver and the memory. The one or more processors may be configured to: use carrier aggregation, receive reference signals on a primary side link carrier and on one or more secondary side link carriers via the transceiver. The one or more processors may be configured to: detect beam failure based at least in part on measurements of the reference signals. The one or more processors may be configured to send a first non-periodic MAC CE via the transceiver, the first non-periodic MAC CE indicating a failure of one or more beams on the primary side link carrier or one or more of the one or more secondary side link carriers.

[0013] Some aspects described herein relate to a non-transitory computer-readable medium storing an instruction set for wireless communication by a UE. The instruction set, when executed by one or more processors of the UE, may cause the UE to: send a reference signal on a primary side link carrier and on one or more secondary side link carriers using carrier aggregation. The instruction set, when executed by one or more processors of the UE, may cause the UE to: receive a MAC CE indicating a beam failure on the primary side link carrier, one or more secondary side link carriers, or both. The instruction set, when executed by one or more processors of the UE, may cause the UE to: send a non-periodic reference signal on the primary side link carrier in response to receiving the MAC CE.

[0014] Some aspects described herein relate to a non-transitory computer-readable medium storing an instruction set for wireless communication performed by a UE. The instruction set, when executed by one or more processors of the UE, may cause the UE to: use carrier aggregation to send reference signals on a primary side link carrier and on one or more secondary side link carriers. The instruction set, when executed by one or more processors of the UE, may cause the UE to: receive a first MAC CE indicating a failure of a beam on a secondary side link carrier in one or more secondary side link carriers. The instruction set, when executed by one or more processors of the UE, may cause the UE to: in response to receiving the first MAC CE, send one or more non-periodic reference signals on other secondary side link carriers in the one or more secondary side link carriers. The instruction set, when executed by one or more processors of the UE, may cause the UE to: receive a message indicating one or more feasible beams of other secondary side link carriers. The instruction set, when executed by one or more processors of the UE, may cause the UE to: send a beam switching message on the primary side link carrier via a second MAC CE based at least in part on the one or more feasible beams.

[0015] Some aspects described herein relate to a non-transitory computer-readable medium storing an instruction set for wireless communication by a UE. The instruction set, when executed by one or more processors of the UE, may cause the UE to: receive a reference signal on a primary side link carrier and on one or more secondary side link carriers using carrier aggregation. The instruction set, when executed by one or more processors of the UE, may cause the UE to: detect a beam failure based at least in part on a measurement of the reference signal. The instruction set, when executed by one or more processors of the UE, may cause the UE to: send a first non-periodic MAC CE indicating a failure of one or more beams on the primary side link carrier or one or more of the one or more secondary side link carriers.

[0016] Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include: a component for sending a reference signal on a primary sidelink carrier and on one or more secondary sidelink carriers using carrier aggregation. The apparatus may include: a component for receiving a MAC CE indicating a beam failure on the primary sidelink carrier, one or more secondary sidelink carriers, or both. The apparatus may include: a component for sending a non-periodic reference signal on the primary sidelink carrier in response to receiving the MAC CE.

[0017] Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include: a component for sending reference signals on a primary link carrier and on one or more secondary link carriers using carrier aggregation. The apparatus may include: a component for receiving a first MAC CE, the first MAC CE indicating a failure of a beam on a secondary link carrier in one or more secondary link carriers. The apparatus may include: a component for sending one or more non-periodic reference signals on other secondary link carriers in one or more secondary link carriers in response to receiving the first MAC CE. The apparatus may include: a component for receiving a message indicating one or more feasible beams of other secondary link carriers. The apparatus may include: a component for sending a beam switching message on the primary link carrier via a second MAC CE based at least in part on the one or more feasible beams.

[0018] Some aspects described herein relate to an apparatus for wireless communication. The apparatus may include: a component for receiving a reference signal on a primary sidelink carrier and on one or more secondary sidelink carriers using carrier aggregation. The apparatus may include: a component for detecting a beam failure based at least in part on a measurement of the reference signal. The apparatus may include: a component for sending a first non-periodic MAC CE indicating a failure of one or more beams on the primary sidelink carrier or one or more of the one or more secondary sidelink carriers.

[0019] Aspects collectively include methods, apparatus, systems, computer program products, non-transitory computer-readable media, user equipment, base stations, network entities, network nodes, wireless communication devices and / or processing systems as fully described herein with reference to the drawings and description and as illustrated in the drawings and description.

[0020] The features and technical advantages of examples according to the present disclosure have been outlined quite extensively above so that the following specific embodiments may be better understood. Additional features and advantages will be described below. The disclosed concepts and specific examples may be easily used as a basis for modifying or designing other structures for achieving the same purpose of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. The characteristics of the concepts disclosed herein, both in terms of their organization and method of operation, and the associated advantages will be better understood by considering the following description in conjunction with the accompanying drawings. Each of the figures in the accompanying drawings is provided for the purpose of illustration and description and not as a definition of limitations to the claims.

[0021] Although various aspects are described in the present disclosure by illustrating some examples, it will be understood by those skilled in the art that such aspects can be implemented in many different arrangements and scenarios. The technology described herein can be implemented using different platform types, devices, systems, shapes, sizes and / or packaging arrangements. For example, some aspects can be implemented via integrated chip implementations or other devices based on non-module components (e.g., end-user devices, vehicles, communication equipment, computing equipment, industrial equipment, retail / shopping equipment, medical equipment and / or artificial intelligence devices). Various aspects can be implemented in chip-level components, modular components, non-modular components, non-chip-level components, device-level components and / or system-level components. The equipment incorporating the various aspects and features described may include additional components and features for implementing and practicing the various aspects claimed and described. For example, the transmission and reception of wireless signals may include one or more components for analog and digital purposes (e.g., hardware components, including antennas, radio frequency (RF) chains, power amplifiers, modulators, buffers, processors, interleavers, adders and / or summers). The various aspects described herein are intended to be practiced in various devices, components, systems, distributed arrangements and / or end-user devices of various sizes, shapes and configurations. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to fully understand the above-mentioned features of the present disclosure, a more specific description of the invention briefly summarized above can be obtained by referring to various aspects (some of which are illustrated in the accompanying drawings). However, it should be noted that the accompanying drawings only illustrate certain typical aspects of the present disclosure and are therefore not to be considered as limiting the scope thereof, as the specification may admit of other equally effective aspects. The same reference numerals in different drawings may identify the same or similar elements.

[0023] Figure 1 is a diagram illustrating an example of a wireless network according to the present disclosure.

[0024] Figure 2 is a diagram illustrating an example of communication between a network node and a user equipment (UE) in a wireless network according to the present disclosure.

[0025] Figure 3 is a diagram illustrating an example of side link communication according to the present disclosure.

[0026] Figure 4 is a diagram illustrating an example of side link communication and access link communication according to the present disclosure.

[0027] Figure 5 is a diagram illustrating an example of a channel state information reference signal beam management process according to the present disclosure.

[0028] Figure 6 is a diagram illustrating an example of sidelink carrier aggregation according to the present disclosure.

[0029] Figure 7 is a diagram illustrating an example of beam failure detection for a side link according to the present disclosure.

[0030] Figure 8 is a diagram illustrating a first scenario associated with sidelink beam failure recovery (BFR) according to the present disclosure.

[0031] Fig. 9 is a diagram illustrating an example associated with a second scenario of sidelink BFR according to the present disclosure.

[0032] Fig.10 is a diagram illustrating an example associated with a third scenario of sidelink BFR according to the present disclosure.

[0033] Fig.11 is a diagram illustrating an example process performed, for example, by a UE according to the present disclosure.

[0034] Fig.12 is a diagram illustrating an example process performed, for example, by a UE according to the present disclosure.

[0035] Fig.13 is a diagram illustrating an example process performed, for example, by a UE according to the present disclosure.

[0036] Fig.14 is a diagram of an example apparatus for wireless communications according to the present disclosure. DETAILED DESCRIPTION

[0037] The various aspects of the present disclosure are described more fully below with reference to the accompanying drawings. However, the present disclosure can be embodied in many different forms, and should not be interpreted as being limited to any specific structure or function presented throughout the present disclosure. On the contrary, these aspects are provided so that the present disclosure will be thorough and complete, and the scope of the present disclosure will be fully conveyed to those skilled in the art. It should be understood by those skilled in the art that the scope of the present disclosure is intended to cover any aspect of the disclosure disclosed herein, whether it is implemented independently or in combination with any other aspect of the disclosure. For example, any number of aspects set forth herein may be used to implement a device or practice method. In addition, the scope of the present disclosure is intended to cover such a device or method that is practiced using other structures, functions, or structures and functions in addition to or different from the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of the claims.

[0038] Several aspects of telecommunication systems will now be presented with reference to various devices and techniques. These devices and techniques will be described in the following detailed description and illustrated in the accompanying drawings by various blocks, modules, components, circuits, steps, processes, algorithms, etc. (collectively referred to as "elements"). These elements can be implemented using hardware, software, or a combination thereof. Whether these elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0039] Although various aspects may be described herein using terms generally associated with 5G or new radio (NR) radio access technology (RAT), various aspects of the present disclosure may be applicable to other RATs, such as 3G RAT, 4G RAT and / or RATs beyond 5G (e.g., 6G).

[0040] Figure 11 is a diagram illustrating an example of a wireless network 100 according to the present disclosure. The wireless network 100 may be a 5G (e.g., NR) network and / or a 4G (e.g., Long Term Evolution (LTE)) network, or may include elements of a 5G (e.g., NR) network and / or elements of a 4G (e.g., Long Term Evolution (LTE)) network, etc. The wireless network 100 may include one or more network nodes 110 (shown as network node 110a, network node 110b, network node 110c, and network node 110d), user equipment (UE) 120 or multiple UEs 120 (shown as UE 120a, UE 120b, UE 120c, UE 120d, and UE 120e), and / or other entities. The network node 110 is a network node that communicates with the UE 120. As shown in the figure, the network node 110 may include one or more network nodes. For example, the network node 110 may be a converged network node, which means that the converged network node is configured to utilize a radio protocol stack that is physically or logically integrated within a single radio access network (RAN) node (e.g., within a single device or unit). For another example, the network node 110 may be a decomposed network node (sometimes referred to as a decomposed base station), which means that the network node 110 is configured to utilize a protocol stack that is physically or logically distributed between two or more nodes (such as one or more central units (CUs), one or more distributed units (DUs), or one or more radio units (RUs)).

[0041] In some examples, the network node 110 is or includes a network node (such as an RU) that communicates with the UE 120 via a radio access link. In some examples, the network node 110 is or includes a network node (such as a DU) that communicates with other network nodes 110 via a fronthaul link or a midhaul link. In some examples, the network node 110 is or includes a network node (such as a CU) that communicates with other network nodes 110 via a midhaul link or communicates with the core network via a backhaul link. In some examples, the network node 110 (such as an aggregated network node 110 or a decomposed network node 110) may include multiple network nodes, such as one or more RUs, one or more CUs, and / or one or more DUs. The network node 110 may include, for example, an NR base station, an LTE base station, a Node B, an eNB (e.g., in 4G), a gNB (e.g., in 5G), an access point, a transmit receive point (TRP), a DU, a RU, a CU, a mobility element of a network, a core network node, a network element, a network equipment, a RAN node, or a combination thereof. In some examples, network nodes 110 may be interconnected to each other or to one or more other network nodes 110 in wireless network 100 via various types of fronthaul, midhaul, and / or backhaul interfaces (such as direct physical connections, air interfaces, or virtual networks) using any suitable transport network.

[0042] In some examples, the network node 110 may provide communication coverage for a particular geographic area. In the Third Generation Partnership Project (3GPP), the term "cell" may refer to the coverage area of ​​the network node 110 and / or the network node subsystem serving the coverage area, depending on the context in which the term is used. The network node 110 may provide communication coverage for a macro cell, a pico cell, a femto cell, and / or another type of cell. A macro cell may cover a relatively large geographic area (e.g., a radius of several kilometers) and may allow unrestricted access by a UE 120 with a service subscription. A pico cell may cover a relatively small geographic area and may allow unrestricted access by a UE 120 with a service subscription. A femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by a UE 120 associated with the femto cell (e.g., a UE 120 in a closed subscriber group (CSG)). A network node 110 for a macro cell may be referred to as a macro network node. A network node 110 for a pico cell may be referred to as a pico network node. The network node 110 for a femto cell may be referred to as a femto network node or a home network node. Figure 1 In the example shown in , network node 110a may be a macro network node for macro cell 102a, network node 110b may be a pico network node for pico cell 102b, and network node 110c may be a femto network node for femto cell 102c. A network node may support one or more (e.g., three) cells. In some examples, a cell may not necessarily be stationary, and the geographic area of ​​a cell may move depending on the location of a mobile network node 110 (e.g., a mobile network node).

[0043] In some aspects, the term "base station" or "network node" may refer to a converged base station, a decomposed base station, an integrated access and backhaul (IAB) node, a relay node, or one or more components thereof. For example, in some aspects, a "base station" or "network node" may refer to a CU, a DU, a RU, a near real-time (near RT) RAN intelligent controller (RIC), or a non-real-time (non-RT) RIC, or a combination thereof. In some aspects, the term "base station" or "network node" may refer to a device configured to perform one or more functions (such as those described herein in conjunction with the network node 110). In some aspects, the term "base station" or "network node" may refer to a plurality of devices configured to perform one or more functions. For example, in some distributed systems, each of a number of different devices (which may be located in the same geographic location or in different geographic locations) may be configured to perform at least a portion of a function, or to repeat the execution of at least a portion of the function, and the term "base station" or "network node" may refer to any one or more of these different devices. In some aspects, the term "base station" or "network node" may refer to one or more virtual base stations or one or more virtual base station functions. For example, in some aspects, two or more base station functions may be instantiated on a single device. In some aspects, the term "base station" or "network node" may refer to one of the base station functions but not another base station function. In this way, a single device may include more than one base station.

[0044] The wireless network 100 may include one or more relay stations. A relay station is a network node that can receive transmissions of data from an upstream node (e.g., a network node 110 or a UE 120) and transmit transmissions of data to a downstream node (e.g., a UE 120 or a network node 110). A relay station may be a UE 120 that is capable of relaying transmissions for other UEs 120. Figure 1 In the example shown in , a network node 110d (e.g., a relay network node) may communicate with a network node 110a (e.g., a macro network node) and a UE 120d to facilitate communication between the network node 110a and the UE 120d. A network node 110 that relays communications may be referred to as a relay station, a relay base station, a relay network node, a relay node, a relay, etc.

[0045] The wireless network 100 may be a heterogeneous network that includes different types of network nodes 110, such as macro network nodes, pico network nodes, femto network nodes, relay network nodes, etc. These different types of network nodes 110 may have different transmit power levels, different coverage areas, and / or different impacts on interference in the wireless network 100. For example, a macro network node may have a high transmit power level (e.g., 5 watts to 40 watts), while a pico network node, a femto network node, and a relay network node may have a lower transmit power level (e.g., 0.1 watt to 2 watts).

[0046] The network controller 130 may be coupled to or in communication with a set of network nodes 110 and may provide coordination and control for the network nodes 110. The network controller 130 may communicate with the network nodes 110 via a backhaul communication link or a midhaul communication link. The network nodes 110 may also communicate directly with each other or indirectly via a wireless backhaul communication link or a wired backhaul communication link. In some aspects, the network controller 130 may be or may include a CU or a core network device.

[0047] UE 120 can be distributed throughout the wireless network 100, and each UE 120 can be stationary or mobile. UE 120 can include, for example, an access terminal, a terminal, a mobile station and / or a subscriber unit. UE 120 can be a cellular phone (e.g., a smart phone), a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet computer, a camera, a gaming device, a netbook, a smartbook, an ultrabook, a medical device, a biometric device, a wearable device (e.g., a smart watch, smart clothing, smart glasses, a smart wristband, smart jewelry (e.g., a smart ring or a smart bracelet)), an entertainment device (e.g., a music device, a video device and / or a satellite radio), a vehicle component or sensor, a smart meter / sensor, an industrial manufacturing equipment, a global positioning system device, a UE function of a network node and / or any other suitable device configured to communicate via a wireless or wired medium.

[0048] Some UEs 120 may be considered as machine type communication (MTC) or evolved or enhanced machine type communication (eMTC) UEs. MTC UEs and / or eMTC UEs may include, for example, robots, drones, remote devices, sensors, meters, monitors, and / or location tags, which may communicate with a network node, another device (e.g., a remote device), or some other entity. Some UEs 120 may be considered as Internet of Things (IoT) devices, and / or may be implemented as NB-IoT (narrowband IoT) devices. Some UEs 120 may be considered as customer premises equipment. UE 120 may be included inside a housing that houses components of UE 120, such as a processor component and / or a memory component. In some examples, a processor component and a memory component may be coupled together. For example, a processor component (e.g., one or more processors) and a memory component (e.g., a memory) may be operably coupled, communicatively coupled, electronically coupled, and / or electrically coupled.

[0049] In general, any number of wireless networks 100 may be deployed in a given geographic area. Each wireless network 100 may support a specific RAT and may operate on one or more frequencies. RAT may be referred to as a radio technology, air interface, etc. Frequency may be referred to as a carrier, frequency channel, etc. Each frequency may support a single RAT in a given geographic area to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks may be deployed.

[0050] In some examples, two or more UEs 120 (e.g., shown as UE 120a and UE 120e) may communicate directly using one or more sidelink channels (e.g., without using network node 110 as an intermediary to communicate with each other). For example, UE 120 may communicate using peer-to-peer (P2P) communication, device-to-device (D2D) communication, vehicle-to-everything (V2X) protocols (e.g., which may include vehicle-to-vehicle (V2V) protocols, vehicle-to-infrastructure (V2I) protocols, or vehicle-to-pedestrian (V2P) protocols), and / or mesh networks. In such examples, UE 120 may perform scheduling operations, resource selection operations, and / or other operations described elsewhere herein as being performed by network node 110.

[0051] The devices of the wireless network 100 may communicate using an electromagnetic spectrum, which may be subdivided into various categories, bands, channels, etc., according to frequency or wavelength. For example, the devices of the wireless network 100 may communicate using one or more operating bands. In 5G NR, two initial operating bands have been identified as frequency ranges designated FR1 (410 MHz-7.125 GHz) and FR2 (24.25 GHz-52.6 GHz). It should be understood that although portions of FR1 are greater than 6 GHz, FR1 is often (interchangeably) referred to as the "below 6 GHz" band in various documents and articles. A similar naming problem sometimes occurs with respect to FR2, which is often (interchangeably) referred to as the "millimeter wave" band in documents and articles, although it is different from the extremely high frequency (EHF) band (30 GHz-300 GHz) identified as the "millimeter wave" band by the International Telecommunication Union (ITU).

[0052] Frequencies between FR1 and FR2 are generally referred to as mid-band frequencies. Recent 5G NR research has identified the operating bands for these mid-band frequencies as frequency range designation FR3 (7.125GHz-24.25GHz). The bands falling within FR3 can inherit FR1 characteristics and / or FR2 characteristics, so the features of FR1 and / or FR2 can be effectively extended to mid-band frequencies. In addition, higher frequency bands are currently being explored to extend 5G NR operations to more than 52.6GHz. For example, three higher operating bands have been identified as frequency range designations FR4a or FR4-1 (52.6GHz-71GHz), FR4 (52.6GHz-114.25GHz) and FR5 (114.25GHz-300GHz). Each of these higher frequency bands falls within the EHF band.

[0053] Considering the above examples, unless otherwise specifically stated, it should be understood that if the term "below 6 GHz" or the like is used herein, the term may broadly refer to frequencies that may be lower than 6 GHz, may be within FR1, or may include mid-band frequencies. In addition, unless otherwise specifically stated, it should be understood that if the term "millimeter wave" or the like is used herein, the term may broadly refer to frequencies that may include mid-band frequencies, may be within FR2, FR4, FR4-a or FR4-1, and / or FR5, or may be within the EHF band. It is contemplated that the frequencies included in these operating bands (e.g., FR1, FR2, FR3, FR4, FR4-a, FR4-1, and / or FR5) may be modified, and the techniques described herein are applicable to those modified frequency ranges.

[0054] In some aspects, the UE 120 may include a communication manager 140. As described in more detail elsewhere herein, the communication manager 140 may use carrier aggregation to send reference signals on a primary sidelink carrier and on one or more secondary sidelink carriers. The communication manager 140 may receive a medium access control control element (MAC CE) indicating a beam failure on the primary sidelink carrier, one or more secondary sidelink carriers, or both. The communication manager 140 may send a non-periodic reference signal on the primary sidelink carrier in response to receiving the MAC CE.

[0055] In some aspects, the communication manager 140 may use carrier aggregation to send reference signals on the primary side link carrier and on one or more secondary side link carriers. The communication manager 140 may receive a first MAC CE indicating a failure of a beam on a secondary side link carrier among the one or more secondary side link carriers. The communication manager 140 may send one or more non-periodic reference signals on other secondary side link carriers among the one or more secondary side link carriers in response to receiving the first MAC CE. The communication manager 140 may receive a message indicating one or more feasible beams of the other secondary side link carriers, and send a beam switching message on the primary side link carrier via a second MAC CE based at least in part on the one or more feasible beams.

[0056] In some aspects, the communication manager 140 may receive a reference signal on a primary sidelink carrier and on one or more secondary sidelink carriers using carrier aggregation. The communication manager 140 may detect a beam failure based at least in part on a measurement of the reference signal and send a first non-periodic MAC CE indicating a failure of one or more beams on the primary sidelink carrier or one or more of the one or more secondary sidelink carriers. Additionally or alternatively, the communication manager 140 may perform one or more other operations described herein.

[0057] As indicated above, Figure 1 are provided as examples. Other examples can be found in the Figure 1 The content described is different.

[0058] Figure 2 2 is a diagram illustrating an example 200 of a network node 110 communicating with a UE 120 in a wireless network 100 according to the present disclosure. The network node 110 may be equipped with a set of antennas 234a to 234t, such as T antennas (T≥1). The UE 120 may be equipped with a set of antennas 252a to 252r, such as R antennas (R≥1). The network node 110 of example 200 includes one or more radio frequency components, such as an antenna 234 and a modem 254. In some examples, the network node 110 may include an interface, a communication component, or another component that facilitates communication with the UE 120 or another network node. Some network nodes 110 may not include a radio frequency component that facilitates direct communication with the UE 120, such as one or more CUs or one or more DUs.

[0059] At network node 110, transmit processor 220 may receive data intended for UE 120 (or a set of UEs 120) from data source 212. Transmit processor 220 may select one or more modulation and coding schemes (MCS) for UE 120 based at least in part on one or more channel quality indicators (CQIs) received from UE 120. Network node 110 may process (e.g., encode and modulate) the data for UE 120 based at least in part on the MCS selected for UE 120, and may provide data symbols for UE 120. Transmit processor 220 may process system information (e.g., for semi-static resource allocation information (SRPI)) and control information (e.g., CQI requests, grants, and / or upper layer signaling), and provide overhead symbols and control symbols. The transmit processor 220 may generate reference symbols for reference signals (e.g., cell-specific reference signals (CRS) or demodulation reference signals (DMRS)) and synchronization signals (e.g., primary synchronization signals (PSS) or secondary synchronization signals (SSS)). The transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on ​​data symbols, control symbols, overhead symbols, and / or reference symbols, where applicable, and may provide a set of output symbol streams (e.g., T output symbol streams) to a corresponding set of modems 232 (e.g., T modems) (shown as modems 232a to 232t). For example, each output symbol stream may be provided to a modulator component (shown as MOD) of the modem 232. Each modem 232 may process a corresponding output symbol stream (e.g., for OFDM) using a corresponding modulator component to obtain an output sample stream. Each modem 232 may also process (e.g., convert to analog, amplify, filter, and / or upconvert) the output sample stream using a corresponding modulator component to obtain a downlink signal. The modems 232a through 232t may transmit a set of downlink signals (eg, T downlink signals) via a corresponding set of antennas 234 (eg, T antennas) (shown as antennas 234a through 234t).

[0060] At the UE 120, a set of antennas 252 (shown as antennas 252a to 252r) may receive downlink signals from the network node 110 and / or other network nodes 110 and may provide a set of received signals (e.g., R received signals) to a set of modems 254 (e.g., R modems) (shown as modems 254a to 254r). For example, each received signal may be provided to a demodulator component (shown as DEMOD) of the modem 254. Each modem 254 may use a corresponding demodulator component to condition (e.g., filter, amplify, downconvert, and / or digitize) the received signal to obtain input samples. Each modem 254 may use a demodulator component to further process the input samples (e.g., for OFDM) to obtain received symbols. A MIMO detector 256 may obtain received symbols from the modem 254, may perform MIMO detection on the received symbols where applicable, and may provide detected symbols. The receive processor 258 may process (e.g., demodulate and decode) the detected symbols, may provide decoded data for the UE 120 to the data sink 260, and may provide decoded control information and system information to the controller / processor 280. The term "controller / processor" may refer to one or more controllers, one or more processors, or a combination thereof. The channel processor may determine a reference signal received power (RSRP) parameter, a received signal strength indicator (RSSI) parameter, a reference signal received quality (RSRQ) parameter, and / or a CQI parameter, among other things. In some examples, one or more components of the UE 120 may be included in the housing 284.

[0061] The network controller 130 may include a communication unit 294, a controller / processor 290, and a memory 292. The network controller 130 may include, for example, one or more devices in a core network. The network controller 130 may communicate with the network node 110 via the communication unit 294.

[0062] One or more antennas (e.g., antennas 234a to 234t and / or antennas 252a to 252r) may include or be included within one or more antenna panels, one or more antenna groups, one or more sets of antenna elements, and / or one or more antenna arrays, etc. Antenna panels, antenna groups, sets of antenna elements, and / or antenna arrays may include one or more antenna elements (in a single housing or multiple housings), sets of coplanar antenna elements, sets of non-coplanar antenna elements, and / or may be coupled to one or more transmit and / or receive components (such as, Figure 2 One or more antenna elements of one or more components in.

[0063] On the uplink, at the UE 120, the transmit processor 264 may receive and process data from the data source 262 and control information from the controller / processor 280 (e.g., for reports including RSRP, RSSI, RSRQ, and / or CQI). The transmit processor 264 may generate reference symbols for one or more reference signals. The symbols from the transmit processor 264 may be pre-decoded by the TX MIMO processor 266, where applicable, further processed by the modem 254 (e.g., for DFT-s-OFDM or CP-OFDM), and sent to the network node 110. In some examples, the modem 254 of the UE 120 may include a modulator and a demodulator. In some examples, the UE 120 includes a transceiver. The transceiver may include any combination of an antenna 252, a modem 254, a MIMO detector 256, a receive processor 258, a transmit processor 264, and / or a TX MIMO processor 266. The transceiver may be used by a processor (eg, controller / processor 280) and memory 282 to perform the functions described herein (eg, with reference to Figures 3 to 14 ) any aspects of any of the methods described herein.

[0064] At the network node 110, uplink signals from the UE 120 and / or other UEs may be received by the antenna 234, processed by the modem 232 (e.g., a demodulator component (shown as DEMOD) of the modem 232), detected by the MIMO detector 236 (where applicable), and further processed by the receive processor 238 to obtain decoded data and control information transmitted by the UE 120. The receive processor 238 may provide the decoded data to the data sink 239 and the decoded control information to the controller / processor 240. The network node 110 may include a communication unit 244 and may communicate with the network controller 130 via the communication unit 244. The network node 110 may include a scheduler 246 to schedule one or more UEs 120 for downlink communication and / or uplink communication. In some examples, the modem 232 of the network node 110 may include a modulator and a demodulator. In some examples, the network node 110 includes a transceiver. The transceiver may include any combination of antenna 234, modem 232, MIMO detector 236, receive processor 238, transmit processor 220, and / or TX MIMO processor 230. The transceiver may be used by a processor (e.g., controller / processor 240) and memory 242 to perform operations described herein (e.g., with reference to Figures 3 to 14 ) any aspects of any of the methods described herein.

[0065] The controller / processor 280 of the UE 120 and / or Figure 2Any other component in the UE 120 may perform one or more techniques associated with beam failure recovery for sidelink carrier aggregation, as described in more detail elsewhere herein. For example, the controller / processor 280 and / or Figure 2 Any other component of the Fig.11 Process 1100, Fig.12 The process 1200 Fig.13 1300 and / or operations of other processes as described herein. Memory 282 may store data and program codes for UE 120. In some examples, memory 282 may include a non-transitory computer-readable medium storing one or more instructions (e.g., code and / or program code) for wireless communication. For example, the one or more instructions, when executed by one or more processors of UE 120 (e.g., directly executed, or executed after compilation, conversion, and / or interpretation), may cause the one or more processors or UE 120 to perform or direct, for example, Fig.11 Process 1100, Fig.12 The process 1200 Fig.13 The process 1300 and / or operations of other processes as described herein. In some examples, executing instructions may include running instructions, converting instructions, compiling instructions, and / or interpreting instructions, etc.

[0066] In some aspects, the UE 120 includes components for sending reference signals on a primary sidelink carrier and on one or more secondary sidelink carriers using carrier aggregation (e.g., using the controller / processor 280, the transmit processor 264, the TX MIMO processor 266, the modem 254, the antenna 252, the memory 282, etc.); components for receiving a MAC CE indicating a beam failure on the primary sidelink carrier, one or more secondary sidelink carriers, or both (e.g., using the antenna 252, the modem 254, the MIMO detector 256, the receive processor 258, the controller / processor 280, the memory 282, etc.); and / or components for sending a non-periodic reference signal on the primary sidelink carrier in response to receiving the MAC CE (e.g., using the controller / processor 280, the transmit processor 264, the TX MIMO processor 266, the modem 254, the antenna 252, the memory 282, etc.).

[0067] In some aspects, the UE 120 includes a component for sending a reference signal on a primary sidelink carrier and on one or more secondary sidelink carriers using carrier aggregation (e.g., using the controller / processor 280, the transmit processor 264, the TX MIMO processor 266, the modem 254, the antenna 252, the memory 282, etc.); a component for receiving a first MAC CE indicating a failure of a beam on a secondary sidelink carrier in the one or more secondary sidelink carriers (e.g., using the antenna 252, the modem 254, the MIMO detector 256, the receive processor 258, the controller / processor 280, the memory 282, etc.); a component for sending one or more non-periodic reference signals on other secondary sidelink carriers in response to receiving the first MAC CE (e.g., using the controller / processor 280, the transmit processor 264, the TX MIMO processor 266, the modem 254, the antenna 252, the memory 282, etc.); and a component for sending one or more non-periodic reference signals on other secondary sidelink carriers in the one or more secondary sidelink carriers in response to receiving the first MAC CE (e.g., using the controller / processor 280, the transmit processor 264, the TX MIMO processor 266, the modem 254, the antenna 252, the memory 282, etc.). MIMO processor 266, modem 254, antenna 252, memory 282, etc.); a component for receiving a message indicating one or more feasible beams of other auxiliary side link carriers (e.g., using antenna 252, modem 254, MIMO detector 256, receive processor 258, controller / processor 280, memory 282, etc.); and / or a component for sending a beam switching message on the primary side link carrier via a second MAC CE based at least in part on the one or more feasible beams (e.g., using controller / processor 280, transmit processor 264, TX MIMO processor 266, modem 254, antenna 252, memory 282, etc.).

[0068] In some aspects, the UE 120 includes: a component for receiving a reference signal on a primary side link carrier and on one or more secondary side link carriers using carrier aggregation; a component for detecting a beam failure based at least in part on a measurement of the reference signal (e.g., using the antenna 252, the modem 254, the MIMO detector 256, the receive processor 258, the controller / processor 280, the memory 282, etc.); and / or a component for sending a first non-periodic MAC CE indicating a failure of one or more beams on the primary side link carrier or one or more of the one or more secondary side link carriers (e.g., using the controller / processor 280, the transmit processor 264, the TX MIMO processor 266, the modem 254, the antenna 252, the memory 282, etc.).

[0069] Although Figure 2The blocks in the 2000 and 2010 are illustrated as distinct components, but the functionality described above for these blocks may be implemented in a single hardware, software, or combined component or in various combinations of components. For example, the functionality described for the transmit processor 264, the receive processor 258, and / or the TX MIMO processor 266 may be performed by or under the control of the controller / processor 280.

[0070] As indicated above, Figure 2 are provided as examples. Other examples can be found in the Figure 2 The content described is different.

[0071] The deployment of a communication system (such as a 5G NR system) can be arranged with various components or components in a variety of ways. In a 5G NR system or network, a network node, a network entity, a mobility element of a network, a RAN node, a core network node, a network element, a base station or network equipment can be implemented in an aggregated or decomposed architecture. For example, a base station (such as a node B (NB), an evolved NB (eNB), an NR BS, a 5G NB, an access point (AP), a TRP or a cell, etc.) or one or more units (or one or more components) that perform base station functionality can be implemented as an aggregated base station (also called an independent base station or a monolithic base station) or a decomposed base station. A "network entity" or a "network node" may refer to a decomposed base station or one or more units of a decomposed base station (such as one or more CUs, one or more DUs, one or more RUs, or a combination thereof).

[0072] An aggregated base station (e.g., an aggregated network node) may be configured to utilize a radio protocol stack physically or logically integrated within a single RAN node (e.g., within a single device or unit). A decomposed base station (e.g., a decomposed network node) may be configured to utilize a protocol stack physically or logically distributed between two or more units (such as one or more CUs, one or more DUs, or one or more RUs). In some examples, a CU may be implemented within a network node, and one or more DUs may be co-located with the CU, or alternatively, may be geographically or virtually distributed across one or more other network nodes. A DU may be implemented to communicate with one or more RUs. Each of a CU, a DU, and a RU may also be implemented as a virtual unit, such as a virtual central unit (VCU), a virtual distributed unit (VDU), or a virtual radio unit (VRU), and the like.

[0073] Base station type operations or network designs may take into account the aggregated nature of base station functionality. For example, a decomposed base station may be utilized in an IAB network, an open radio access network (O-RAN (such as a network configuration initiated by the O-RAN Alliance)), or a virtualized radio access network (vRAN, also known as a cloud radio access network (C-RAN)) to facilitate the scaling of a communication system by separating base station functionality into one or more units that can be deployed separately. A decomposed base station may include functionality implemented across two or more units at various physical locations, as well as functionality implemented virtually for at least one unit, which may enable flexibility in network design. Individual units of a decomposed base station may be configured for wired or wireless communication with at least one other unit of the decomposed base station.

[0074] Figure 3 is a diagram illustrating an example 300 of sidelink communications according to the present disclosure.

[0075] like Figure 3 As shown, the first UE 305-1 can communicate with the second UE 305-2 (and one or more other UEs 305) via one or more side link channels 310. UEs 305-1 and 305-2 can communicate using one or more side link channels 310 for P2P communication, D2D communication, V2X communication (e.g., which may include V2V communication, V2I communication and / or V2P communication) and / or mesh networks. In some aspects, UE 305 (e.g., UE 305-1 and / or UE 305-2) may correspond to one or more other UEs described elsewhere herein, such as UE 120. In some aspects, one or more side link channels 310 may use a PC5 interface and / or may operate in a high frequency band (e.g., a 5.9 GHz band). Additionally or alternatively, UE 305 may use global navigation satellite system (GNSS) timing to synchronize the timing of a transmit time interval (TTI) (e.g., a frame, subframe, time slot, or symbol).

[0076] like Figure 3As further shown, the one or more sidelink channels 310 may include a physical sidelink control channel (PSCCH) 315, a physical sidelink shared channel (PSSCH) 320, and / or a physical sidelink feedback channel (PSFCH) 325. The PSCCH 315 may be used to communicate control information, similar to a physical downlink control channel (PDCCH) and / or a physical uplink control channel (PUCCH) used for cellular communication with the network node 110 via an access link or access channel. The PSSCH 320 may be used to communicate data, similar to a physical downlink shared channel (PDSCH) and / or a physical uplink shared channel (PUSCH) used for cellular communication with the network node 110 via an access link or access channel. For example, the PSCCH 315 may carry sidelink control information (SCI) 330, which may indicate various control information for sidelink communication, such as one or more resources (e.g., time resources, frequency resources, and / or space resources), wherein a transport block (TB) 335 may be carried on the PSSCH 320. The TB 335 may include data. The PSFCH 325 may be used to communicate sidelink feedback 340, such as hybrid automatic repeat request (HARQ) feedback (eg, acknowledgement or negative acknowledgement (ACK / NACK) information), transmit power control (TPC), and / or scheduling request (SR).

[0077] Although shown on PSCCH 315, in some aspects, SCI 330 may include multiple communications in different levels, such as a first level SCI (SCI-1) and a second level SCI (SCI-2). SCI-1 may be sent on PSCCH 315. SCI-2 may be sent on PSSCH 320. SCI-1 may include, for example, an indication of one or more resources (e.g., time resources, frequency resources, and / or space resources) on PSSCH 320, information for decoding sidelink communications on PSSCH, quality of service (QoS) priority value, resource reservation period, PSSCH DMRS mode, SCI format for SCI-2, beta offset for SCI-2, number of PSSCH DMRS ports, and / or MCS. SCI-2 may include information associated with data transmission on PSSCH 320, such as HARQ process ID, new data indicator (NDI), source identifier, destination identifier, and / or channel state information (CSI) report trigger.

[0078] In some aspects, one or more sidelink channels 310 may use a resource pool. For example, a scheduling assignment (e.g., included in SCI 330) may be sent in a subchannel across time using specific resource blocks (RBs). In some aspects, data transmissions associated with a scheduling assignment (e.g., on PSSCH 320) may occupy adjacent RBs in the same subframe as the scheduling assignment (e.g., using frequency division multiplexing). In some aspects, the scheduling assignment and the associated data transmission are not sent on adjacent RBs.

[0079] In some aspects, the UE 305 may operate using a sidelink transmission mode (e.g., Mode 1) in which resource selection and / or scheduling is performed by a network node 110 (e.g., a base station, CU, or DU). For example, the UE 305 may receive a grant for sidelink channel access and / or scheduling from the network node 110 (e.g., directly or via one or more network nodes) (e.g., in downlink control information (DCI) or in a radio resource control (RRC) message, such as a grant for configuration). In some aspects, the UE 305 may operate using a transmission mode (e.g., Mode 2) in which resource selection and / or scheduling is performed by the UE 305 (e.g., instead of the network node 110). In some aspects, the UE 305 may perform resource selection and / or scheduling by sensing channel availability for transmission. For example, UE 305 may measure RSSI parameters associated with various side link channels (e.g., sidelink-RSSI (S-RSSI) parameters), may measure RSRP parameters associated with various side link channels (e.g., PSSCH-RSRP parameters), and / or may measure RSRQ parameters associated with various side link channels (e.g., PSSCH-RSRQ parameters), and may select a channel for sending side link communications based at least in part on the measurement results.

[0080] Additionally or alternatively, the UE 305 may perform resource selection and / or scheduling using the SCI 330 received in the PSCCH 315, which may indicate occupied resources and / or channel parameters. Additionally or alternatively, the UE 305 may perform resource selection and / or scheduling by determining a channel busy rate (CBR) associated with each sidelink channel, which may be used for rate control (e.g., by indicating a maximum number of resource blocks that the UE 305 may use for a particular set of subframes).

[0081] In a transmission mode in which resource selection and / or scheduling is performed by the UE 305, the UE 305 may generate a sidelink grant and may transmit the grant in the SCI 330. The sidelink grant may indicate, for example, one or more parameters (e.g., transmission parameters) to be used for an upcoming sidelink transmission, such as one or more resource blocks (e.g., for TB 335) to be used for an upcoming sidelink transmission on the PSSCH 320, one or more subframes to be used for an upcoming sidelink transmission, and / or an MCS to be used for an upcoming sidelink transmission. In some aspects, the UE 305 may generate a sidelink grant that indicates one or more parameters (such as the periodicity of the sidelink transmission) for semi-persistent scheduling (SPS). Additionally or alternatively, the UE 305 may generate a sidelink grant for event-driven scheduling (such as for an on-demand sidelink message).

[0082] As indicated above, Figure 3 are provided as examples. Other examples can be found in the Figure 3 Described differently.

[0083] Figure 4 is a diagram illustrating an example 400 of side link communications and access link communications according to the present disclosure.

[0084] like Figure 4 As shown, the transmitter (Tx) / receiver (Rx) UE 405 and the Rx / Tx UE 410 can communicate with each other via a side link, as described above in conjunction with Figure 4 As further shown, in some sidelink modes, the network node 110 may communicate with the Tx / Rx UE 405 (e.g., directly or via one or more network nodes), such as via a first access link. Additionally or alternatively, in some sidelink modes, the network node 110 may communicate with the Rx / Tx UE 410 (e.g., directly or via one or more network nodes), such as via a first access link. The Tx / Rx UE 405 and / or the Rx / Tx UE 410 may correspond to one or more UEs described elsewhere herein, such as Figure 1 120. Thus, a direct link between UEs 120 (e.g., via a PC5 interface) may be referred to as a side link, and a direct link between network node 110 and UE 120 (e.g., via a Uu interface) may be referred to as an access link. Side link communications may be sent via a side link, and access link communications may be sent via an access link. Access link communications may be downlink communications (from network node 110 to UE 120) or uplink communications (from UE 120 to network node 110).

[0085] UE 120 may use carrier aggregation for sidelink channels. Carrier aggregation is a technique that enables two or more component carriers (CCs, sometimes referred to as carriers) to be combined (e.g., combined into a single channel) for a single UE 120 to enhance data capacity. Carriers in the same or different frequency bands may be combined. Additionally or alternatively, contiguous or non-contiguous carriers may be combined. Network node 110 may configure carrier aggregation for UE 120, such as in an RRC message, a DCI, and / or another signaling message.

[0086] In some aspects, carrier aggregation may be configured in an intra-band contiguous mode, where the aggregated carriers are contiguous with each other and in the same frequency band. In some aspects, carrier aggregation may be configured in an intra-band discontiguous mode, where the aggregated carriers are discontiguous with each other and in the same frequency band. In some aspects, carrier aggregation may be configured in an inter-band discontiguous mode, where the aggregated carriers are discontiguous with each other and in different frequency bands.

[0087] In carrier aggregation, UE 120 may be configured with a primary carrier or primary cell (PCell) and one or more secondary carriers or secondary cells (SCells). In some aspects, the primary carrier may carry control information (e.g., DCI and / or scheduling information) for scheduling data communications on one or more secondary carriers, which may be referred to as cross-carrier scheduling. In some aspects, a carrier (e.g., a primary carrier or a secondary carrier) may carry control information for scheduling data communications on the carrier, which may be referred to as self-carrier scheduling or carrier self-scheduling. In some aspects, carrier aggregation may include multiple secondary carriers (without a primary carrier). Some carrier aggregation configurations may provide CC activation and deactivation, cross-carrier grants (grants for one carrier are provided on another carrier), beam indications, and / or multi-bit feedback.

[0088] As indicated above, Figure 4 are provided as examples. Other examples can be found in the Figure 4 Described differently.

[0089] Figure 5 5 are diagrams illustrating examples 500, 510, and 520 of a CSI reference signal (CSI-RS) beam management process according to the present disclosure. Figure 5 As shown, examples 500, 510, and 520 include UE 120 communicating with network node 110 in a wireless network (e.g., wireless network 100). Figure 5The devices shown are provided as examples, and the wireless network may support communication and beam management between other devices (e.g., between UE 120 and network node 110 or TRP, between mobile terminal node and control node, between IAB child node and IAB parent node, and / or between scheduled node and scheduling node). In some aspects, UE 120 and network node 110 may be in a connected state (e.g., RRC connected state).

[0090] like Figure 5 As shown in , example 500 may include a network node 110 (e.g., one or more network node devices such as RU, DU and / or CU, etc.) and a UE 120 communicating to perform beam management using CSI-RS. Example 500 depicts a first beam management process (e.g., P1 CSI-RS beam management). The first beam management process may be referred to as a beam selection process, an initial beam acquisition process, a beam scanning process, a cell search process, and / or a beam search process. Figure 5 As shown in example 500, CSI-RS may be configured to be sent from network node 110 to UE 120. CSI-RS may be configured to be periodic (e.g., using RRC signaling), semi-persistent (e.g., using MAC CE signaling), and / or aperiodic (e.g., using DCI).

[0091] The first beam management process may include the network node 110 performing beam scanning on multiple transmit (Tx) beams. The network node 110 may use each transmit beam used for beam management to transmit a CSI-RS. In order to enable the UE 120 to perform receive (Rx) beam scanning, the network node may use the transmit beam to transmit each CSI-RS multiple times (e.g., with repetitions) within the same RS resource set, so that the UE 120 can sweep the receive beam in multiple transmit instances. For example, if the network node 110 has a set of N transmit beams and the UE 120 has a set of M receive beams, the CSI-RS may be transmitted M times on each of the N transmit beams, so that the UE 120 can receive M instances of the CSI-RS per transmit beam. In other words, for each transmit beam of the network node 110, the UE 120 may perform beam scanning on the receive beam of the UE 120. Thus, the first beam management process may enable UE 120 to measure CSI-RS on different transmit beams using different receive beams to support selection of a network node 110 transmit beam / UE 120 receive beam pair. UE 120 may report the measurements to network node 110 to enable network node 110 to select one or more beam pairs for communication between network node 110 and UE 120. Although example 500 has been described in conjunction with CSI-RS, the first beam management process may also use synchronization signal blocks (SSBs) to perform beam management in a similar manner as described above.

[0092] like Figure 5 As shown, example 510 may include network node 110 and UE 120 communicating to perform beam management using CSI-RS. Example 510 depicts a second beam management procedure (e.g., P2 CSI-RS beam management). The second beam management procedure may be referred to as a beam refinement procedure, a network node beam refinement procedure, a TRP beam refinement procedure, and / or a transmit beam refinement procedure. Figure 5As shown in example 510, the CSI-RS may be configured to be transmitted from the network node 110 to the UE 120. The CSI-RS may be configured to be non-periodic (e.g., using DCI). The second beam management process may include the network node 110 performing beam scanning on one or more transmit beams. The one or more transmit beams may be a subset of all transmit beams associated with the network node 110 (e.g., determined at least in part based on measurements reported by the UE 120 in conjunction with the first beam management process). The network node 110 may transmit the CSI-RS using each of the one or more transmit beams used for beam management. The UE 120 may measure each CSI-RS using a single (e.g., identical) receive beam (e.g., determined at least in part based on measurements performed in conjunction with the first beam management process). The second beam management process may enable the network node 110 to select the best transmit beam based at least in part on measurements of the CSI-RS reported by the UE 120 (e.g., measured by the UE 120 using a single receive beam).

[0093] like Figure 5 As shown, example 520 depicts a third beam management process (e.g., P3 CSI-RS beam management). The third beam management process may be referred to as a beam refinement process, a UE beam refinement process, and / or a receive beam refinement process. Figure 5 As shown in example 520, one or more CSI-RS may be configured to be sent from the network node 110 to the UE 120. The CSI-RS may be configured to be non-periodic (e.g., using DCI). The third beam management process may include the network node 110 sending the one or more CSI-RS using a single transmit beam (e.g., determined at least in part based on measurements reported by the UE 120 in conjunction with the first beam management process and / or the second beam management process). In order to enable the UE 120 to perform receive beam scanning, the network node may use the transmit beam to send the CSI-RS multiple times (e.g., with repetitions) within the same RS resource set, so that the UE 120 can sweep across one or more receive beams in multiple transmission instances. The one or more receive beams may be a subset of all receive beams associated with the UE 120 (e.g., determined at least in part based on measurements performed in conjunction with the first beam management process and / or the second beam management process). The third beam management process may enable the network node 110 and / or the UE 120 to select the best receive beam based at least in part on reported measurements received from the UE 120 (e.g., the reported measurements are measurements of the CSI-RS of the transmit beam using the one or more receive beams).

[0094] In some examples, a beam may fail during sidelink communications between a transmitting UE and a receiving UE. Beam Failure Detection (BFD) may include detecting a specified number of beam failure instances (e.g., insufficient sidelink reference signal strength, excessive interference) during a duration (using a beam failure timer). The receiving UE may send a beam failure indication (BFI) on a sidelink channel. This may be a request for beam failure recovery (BFR). BFR may include sending a random access channel (RACH) preamble using the same beam or another beam.

[0095] As indicated above, Figure 5 is provided as an example of a beam management process. Other examples of beam management processes can be found in Figure 5 For example, UE 120 and network node 110 may perform the third beam management procedure before performing the second beam management procedure, and / or UE 120 and network node 110 may perform a similar beam management procedure to select a UE transmit beam.

[0096] Figure 6 6 is a diagram illustrating example 600 of sidelink carrier aggregation according to the present disclosure. Example 600 shows UE 610 (e.g., UE 120) and UE 620 (e.g., UE 120) that can communicate with each other on a sidelink channel. A PC5-RRC connection or link can be established between UE 610 and UE 620 in each direction.

[0097] Example 600 shows UE 610 and UE 620 using carrier aggregation in two directions. For example, a primary CC (PCC) and a secondary CC (SCC) may be configured by direction (e.g., by UE, by sidelink channel) from UE 610 to UE 620 (in pipe 622) and from UE 620 to UE 610 (in pipe 624). The PCC may be on a different frequency than the SCC in each pipe. Radio link management (RLM) and radio link failure (RLF) may be declared on the PCC by direction. BFR on the PCC may use a RACH procedure, and each RACH procedure may be performed on the PCC by direction. If UE 610 is a transmitting UE, UE 610 may broadcast SSBs on the PCC. UE 610 may send periodic, semi-periodic, or aperiodic SSBs based on power constraints and interference mitigation criteria. BFR on the SCC may use measurement-based beam changing.

[0098] If the sidelink PCC is configured per UE, one CC is configured as the PCC for all sidelinks that the UE establishes or participates in. To establish a new sidelink to a new UE, there may be an indication from the network or a negotiation between UEs to ensure that the configured PCC can still act as the PCC for the new sidelink. The negotiation may be done directly between the UE and the new UE.

[0099] If the sidelink PCC is configured per sidelink, a specific CC is designated as the PCC for the sidelink. This can be done by negotiation or by an indication from the network. The CC designated as the PCC may be different for different sidelinks. The PCC used for the unicast sidelink may be different from the PCC used for the multicast sidelink. For the purpose of establishing the PCC, the multicast sidelink may be considered as multiple unicasts. The UE may agree on the CC to be used as the PCC. Each UE may have a different set of CCs other than the PCC, and may index its CCs differently, as long as they agree on a common index or reference when the PCC must be referenced.

[0100] If the sidelink PCC is configured per sidelink according to direction, each sidelink may have two sidelink PCCs, one for the forward direction and one for the reverse direction. That is, there may be one PCC from UE 610 to UE 620 (a forward PCC for UE 610 and a reverse PCC for UE 620) and another PCC for UE 620 to UE 610 (a forward PCC for UE 620 and a reverse PCC for UE 610). Note that for sidelink discontinuous reception (DRX), there is an agreement to configure UE 610 to UE 620 DRX and UE 620 to UE 610, respectively. This has no analogy in Uu because there is no separate DRX or discontinuous transmission (DTX) for downlink or uplink. In one example, the PCC may be configured with a BFD reference signal (RS) or BFD-RS. For bidirectional BFR, the BFD reference signal from UE 610 to UE 620 may be on the sidelink PCC from UE 610 to UE 620, and the BFD reference signal from UE 620 to UE 610 may be on the sidelink PCC from UE 620 to UE 610. In another example, the PCC may be a PCC that carries feedback on the PSFCH. Thus, the UE 610 to UE 620 sidelink PCC may carry all feedback on the PSFCH from UE 620 to UE 610, and the UE 620 to UE 610 sidelink PCC may carry all feedback on the PSFCH from UE 610 to UE 620.

[0101] The PCC can be part of the PCell and the SCC can be part of the SCell. SCells can be added and removed, activated and deactivated, but changes in the PCell are considered handovers and require a handover procedure. Currently, RLM is only performed on the PCell, and therefore RLF is only declared on the PCell, even when the UE is measuring on the SCell. The PCell and PUCCH-SCell are the only two cells that can carry PUCCH communications. RACH resources are only on the PCell. Sleep is only applicable to the SCell and not to the PCell of the Master Cell Group (MCG).

[0102] As indicated above, Figure 6 are provided as examples. Other examples can be found in the Figure 6 The content described is different.

[0103] Figure 7 7 is a diagram illustrating an example 700 of BFD for a sidelink according to the present disclosure. Example 700 shows a pipe 702 in the direction of UE 610 to UE 620 and a pipe 704 in the direction of UE 620 to UE 610. Pipe 702 includes a PCC with a BFD-RS set of BFD-RS, a first SCC with a BFD-RS set, and up to the nth SCC with a BFD-RS set. In the opposite direction, pipe 704 includes a PCC with a BFD-RS set of BFD-RS, a first SCC with a BFD-RS set, and up to the nth SCC with a BFD-RS set. Each BFD-RS set may be independent of another BFD-RS set.

[0104] According to various aspects described herein, a receiving UE (e.g., UE 620, MAC entity) may perform BFR for a PCC or SCC in different side links and / or in different directions. UE 620 may perform measurements on a BFD-RS set for a PCC and / or a BFD-RS set for a corresponding SCC. If all beams of a configured BFD-RS set for a CC have measurement results below a specified threshold (e.g., minimum RSRP, minimum signal-to-noise ratio (SNR), minimum RSSI), UE 620 may increment a beam failure instance counter associated with the CC (initially set to 0). If the counter reaches a count threshold (e.g., a maximum count), a beam failure is declared. If the beam failure time expires before the beam is successful, a beam failure is declared.

[0105] A UE (e.g., UE 610, UE 620) may perform BFR for different scenarios. In a first scenario, if a beam failure is detected for a PCC and all SCCs, the UE may initiate BFR (e.g., a RACH procedure on the PCC). In a second scenario, if a beam failure is detected on the PCC (and possibly on the SCC) but at least one SCC is available, the UE may initiate signaling through the SCC for beam change. For example, the UE may send an aperiodic reference signal on the PCC and a message to measure the aperiodic reference signal on the SCC. The reference signal may be aperiodic, rather than at a periodic time instance, to reduce latency compared to an existing BFR mechanism involving a periodic reference signal. In a third scenario, if a beam failure is detected on the SCC, the UE may trigger BFR for the serving cell. In this way, BFR may be performed per CC and per direction for faster beam recovery. Thus, the UE may reduce latency involved in BFD and BFR.

[0106] As indicated above, Figure 7 are provided as examples. Other examples can be found in the Figure 7 The content described is different.

[0107] Figure 8 is a diagram illustrating an example 800 associated with a first scenario of sidelink BFR according to the present disclosure.

[0108] Example 800 shows a first scenario when there is a beam failure on the PCC and all SCCs. Example 800 includes two SCCs (SCC1 and SCC2) in the direction from UE 610 to UE 620. As shown by reference numeral 805, UE 610 may send a BFD-RS set on the PCC, on SCC1, and on SCC2. A PCC may be associated with a serving cell.

[0109] As shown by reference numeral 810, UE 620 as a receiving UE may detect beam failure on PCC and SCC (all SCCs). No SCC is available. As shown by reference numeral 815, UE 620 may send a message (e.g., MAC CE) indicating beam failure on PCC and SCC (all SCCs). UE 620 may send MAC CE on SCC.

[0110] The UE 610 receiving the MAC CE may deactivate the SCC, as shown by reference numeral 820. The UE 610 may start a BFR recovery procedure. As shown by reference numeral 825, the UE 610 may send a BFR-RS on the PCC. The BFR-RS may be aperiodic or before a scheduled periodic instance for the BFR-RS. In response, the UE 620 may initiate a RACH procedure. As shown by reference numeral 830, the UE 620 may send a RACH preamble. The UE 610 may start a BFR timer and monitor the PSCCH for a random access response (RAR) using a sidelink radio network temporary identifier (RNTI). As shown by reference numeral 835, the UE 610 may send a RACH success message. If the BFR is successfully completed, the UE 610 may send a RACH success message (e.g., RACH msg4). If the RACH procedure is not completed before the BFR timer expires, RLF is declared and the UE 610 may send an RLF message, as indicated by reference numeral 840 .

[0111] By initiating a RACH procedure when the PCC and all SCCs have beam failure, the UE enables BFR to be performed quickly, which reduces latency.

[0112] As indicated above, Figure 8 are provided as examples. Other examples can be found in the Figure 8 Described differently.

[0113] Fig. 9 is a diagram illustrating an example 900 associated with a second scenario of sidelink BFR according to the present disclosure.

[0114] Example 900 illustrates a second scenario when there is a beam failure on the PCC but SCC1 and / or SCC2 are still available. As shown by reference numeral 905, UE 610 may send a BFD-RS set on the PCC, on SCC1, and on SCC2. As shown by reference numeral 910, UE 620 may detect a beam failure on the PCC (and possibly on SCC1). SCC2 is still available. As shown by reference numeral 915, UE 620 may send a message (e.g., MAC CE) indicating beam failure on the PCC and SCC1. UE 620 may send a MAC CE on the SCC.

[0115] UE 610 may start a BFR recovery process. As shown in reference numeral 920, UE 610 may send an aperiodic BFD-RS on the PCC. As shown in reference numeral 925, UE 610 may send a message to measure an aperiodic BFD-RS for faster BFR. As shown in reference numeral 930, UE 620 may perform PCC beam reselection to reselect to another beam in the beam set for PCC. UE 620 may measure an aperiodic BFD-RS on the PCC.

[0116] In some aspects, the UE 620 may utilize the PCC to perform a RACH process. If the RACH process is unsuccessful, a SCC to PCC cell change may be triggered, where the SCC may become a new PCC, subject to the availability of a suitable SCC. The UE 620 may measure the BFD-RS on one or more SCCs (e.g., available SCC2). As shown in reference numeral 935, the UE 620 may send one or more measurement results. As shown in reference numeral 940, the UE 610 may send a handover message (e.g., via MAC CE, SCI2) based at least in part on the one or more measurement results. The handover message may indicate that the PCC will be switched to SCC2 (SCC2 becomes the PCC). The previous PCC may become a possible SCC. As a later part of the PCC beam reselection, the UE 620 may reselect to SCC2 or another SCC based at least in part on the handover message. The handover message may be a message for switching the serving cell to the new PCC.

[0117] In some aspects, if the PCC beam reselection is unsuccessful, the UE 620 may perform a RACH procedure. This may include sending a RACH preamble, as shown by reference numeral 945. For a faster BFR RACH procedure, the UE 610 may send an aperiodic BFD-RS. The UE 610 may send a RAR. Beam refinement may be performed after the RACH. Faster BFR reduces latency. If the RACH is unsuccessful, an RLF may be declared on the PC5-RRC link.

[0118] In some aspects, as shown by reference numeral 950, UE 620 may perform an SCC to PCC cell change procedure. For example, if RACH is unsuccessful and the SCC is in good radio conditions, the cell of the SCC may become the primary cell. That is, the SCC may become the new PCC. If the cell change is unsuccessful, RLF may be declared on the PC5-RRC link.

[0119] As indicated above, Fig. 9 are provided as examples. Other examples can be found in the Fig. 9 Described differently.

[0120] Fig.10is a diagram illustrating an example 1000 associated with a third scenario of sidelink BFR according to the present disclosure.

[0121] Example 1000 illustrates a third scenario when there is a beam failure on an SCC, such as on SCC1. As indicated by reference numeral 1005, UE 610 may send a BFD-RS set on the PCC, on SCC1, and on SCC2. As indicated by reference numeral 1010, UE 620 may detect a beam failure on SCC1. SCC2 is still available. As indicated by reference numeral 1015, UE 620 may send a message (e.g., a MAC CE) indicating a beam failure on SCC1. UE 620 may send a MAC CE on the PCC or another SCC.

[0122] UE 610 may start a BFR recovery process. As shown in reference numeral 1020, UE 610 may send an aperiodic BFD-RS on SCC1. UE 610 may send a message on PCC to measure the aperiodic BFD-RS on SCC1. UE 610 may also send a trigger to indicate BFD-RS resources on MAC. UE 620 may measure the aperiodic BFD-RS.

[0123] As shown by reference numeral 1025, UE 620 may send an indication of one or more feasible beams on the PCC or other SCCs (e.g., on SCC2) or on any CC without beam failure. As shown by reference numeral 1030, UE 610 may send a switching message (e.g., via MAC CE, SCC2) based at least in part on one or more measurement results. The switching message may indicate that UE 620 will switch to a feasible beam for SCC1 or for SCC2. As shown by reference numeral 1035, UE 620 may switch to a feasible beam.

[0124] As indicated above, Fig.10 are provided as examples. Other examples can be found in the Fig.10 Described differently.

[0125] Fig.11 1 is a diagram illustrating an example process 1100 performed, for example, by a UE according to the present disclosure. Example process 1100 is an example in which a UE (eg, UE 120, UE 610) performs operations associated with BFR for sidelink carrier aggregation.

[0126] like Fig.11 As shown, in some aspects, process 1100 may include: using carrier aggregation to send a reference signal on a primary sidelink carrier and on one or more secondary sidelink carriers (block 1110). For example, a UE (e.g., using Fig.14The communication manager 1408 and / or the transmitting component 1404 depicted in FIG. 1404 may use carrier aggregation to transmit a reference signal on a primary side link carrier and on one or more secondary side link carriers, as described above, for example, with reference to Figure 6 , Figure 7 , Figure 8 and / or Fig. 9 as described.

[0127] like Fig.11 As further shown, in some aspects, process 1100 may include receiving a MAC CE indicating a beam failure on a primary sidelink carrier, one or more secondary sidelink carriers, or both (block 1120). Fig.14 The communication manager 1408 and / or receiving component 1402 depicted in FIG. 1 may receive a MAC CE indicating a beam failure on a primary side link carrier, one or more secondary side link carriers, or both, as described above, for example with reference to FIG. Figure 6 , Figure 7 , Figure 8 and / or Fig. 9 as described.

[0128] like Fig.11 As further shown, in some aspects, process 1100 may include, in response to receiving the MAC CE, sending an aperiodic reference signal on the primary sidelink carrier (block 1130). For example, a UE (e.g., using Fig.14 The communication manager 1408 and / or the transmitting component 1404 depicted in FIG. 1404 may transmit a non-periodic reference signal on the primary sidelink carrier in response to receiving the MAC CE, as described above, for example, with reference to Figure 6 , Figure 7 , Figure 8 and / or Fig. 9 as described.

[0129] Process 1100 may include additional aspects, such as any single aspect or any combination of aspects described below and / or in conjunction with one or more other processes described elsewhere herein.

[0130] In a first aspect, a MAC CE indicates a beam failure on a primary sidelink carrier and one or more secondary sidelink carriers.

[0131] In a second aspect, alone or in combination with the first aspect, sending reference signals comprises sending a first set of reference signals on a primary sidelink carrier and sending a respective set of reference signals on each of one or more secondary sidelink carriers.

[0132] In a third aspect, alone or in combination with one or more of the first and second aspects, receiving the MAC CE includes receiving the MAC CE on a secondary sidelink carrier of the one or more secondary sidelink carriers.

[0133] In a fourth aspect, alone or in combination with one or more of the first to third aspects, the beam failure recovery procedure is a RACH procedure, and wherein the method further comprises receiving a RACH preamble on a primary sidelink carrier.

[0134] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, the process 1100 includes: deactivating one or more secondary sidelink carriers before receiving a RACH preamble.

[0135] In a sixth aspect, alone or in combination with one or more of the first to fifth aspects, the primary sidelink carrier is associated with a serving cell.

[0136] In a seventh aspect, alone or in combination with one or more of the first to sixth aspects, the beam failure comprises a failure of all beams on a primary sidelink carrier and one or more secondary sidelink carriers.

[0137] In an eighth aspect, alone or in combination with one or more of the first to seventh aspects, the MACCE indicates a beam failure on a primary sidelink carrier.

[0138] In a ninth aspect, either alone or in combination with one or more of the first to eighth aspects, the process 1100 includes sending a message for measuring a non-periodic reference signal on a secondary link carrier of one or more secondary link carriers.

[0139] In the tenth aspect, alone or in combination with one or more aspects of the first to ninth aspects, process 1100 includes: receiving a non-periodic message indicating a measurement result of a non-periodic reference signal; and sending a switching message for switching a serving cell from a primary side link carrier to a secondary side link carrier among one or more secondary side link carriers based at least in part on the measurement result.

[0140] although Fig.11 Example blocks of process 1100 are shown, but in some aspects, process 1100 may include Fig.11 Additional blocks, fewer blocks, different blocks, or blocks arranged in a different manner than those depicted in the process 1100. Additionally or alternatively, two or more blocks of the blocks of process 1100 may be performed in parallel.

[0141] Fig.121 is a diagram illustrating an example process 1200 performed, for example, by a UE according to the present disclosure. Example process 1200 is an example in which a UE (eg, UE 120, UE 610) performs operations associated with BFR for sidelink carrier aggregation.

[0142] like Fig.12 As shown, in some aspects, process 1200 may include: using carrier aggregation to send a reference signal on a primary sidelink carrier and on one or more secondary sidelink carriers (block 1210). For example, a UE (e.g., using Fig.14 The communication manager 1408 and / or the transmitting component 1404 depicted in FIG. 1404 may use carrier aggregation to transmit a reference signal on a primary side link carrier and on one or more secondary side link carriers, as described above, for example, with reference to Figure 6 , Figure 7 and / or Fig.10 As described.

[0143] like Fig.12 As further shown, in some aspects, process 1200 may include receiving a first MAC CE indicating a failure of a beam on a secondary link carrier of one or more secondary link carriers (block 1220). Fig.14 The communication manager 1408 and / or receiving component 1402 depicted in FIG. 1 may receive a first MAC CE indicating a failure of a beam on a secondary link carrier in one or more secondary link carriers, as described above, for example with reference to Figure 6 , Figure 7 and / or Fig.10 As described.

[0144] like Fig.12 As further shown, in some aspects, process 1200 may include, in response to receiving the first MAC CE, sending one or more non-periodic reference signals on other secondary link carriers of the one or more secondary link carriers (block 1230). Fig.14 The communication manager 1408 and / or the transmitting component 1404 depicted in FIG. 1 may transmit one or more non-periodic reference signals on other secondary link carriers of the one or more secondary link carriers in response to receiving the first MAC CE, as described above, for example, with reference to Figure 6 , Figure 7 and / or Fig.10 As described.

[0145] like Fig.12 As further shown, in some aspects, process 1200 may include receiving a message indicating one or more feasible beams of other secondary link carriers (block 1240). Fig.14The communication manager 1408 and / or receiving component 1402 depicted in FIG. 1404 may receive a message indicating one or more feasible beams of other auxiliary side link carriers, such as described above with reference to FIG. Figure 6 , Figure 7 and / or Fig.10 As described.

[0146] like Fig.12 As further shown, in some aspects, process 1200 may include sending a beam switching message on a primary sidelink carrier via a second MAC CE based at least in part on one or more feasible beams (block 1250). Fig.14 The communication manager 1408 and / or the sending component 1404 depicted in FIG. 1 may send a beam switching message on the primary sidelink carrier via a second MAC CE based at least in part on one or more feasible beams, as described above, for example, with reference to Figure 6 , Figure 7 and / or Fig.10 As described.

[0147] Process 1200 may include additional aspects, such as any single aspect or any combination of aspects described below and / or in conjunction with one or more other processes described elsewhere herein.

[0148] In a first aspect, sending reference signals includes sending a first set of reference signals on a primary sidelink carrier and sending a respective set of reference signals on each of one or more secondary sidelink carriers.

[0149] In a second aspect, alone or in combination with the first aspect, process 1200 includes sending a message on a primary sidelink carrier to measure one or more aperiodic reference signals.

[0150] although Fig.12 Example blocks of process 1200 are shown, but in some aspects, process 1200 may include Fig.12 Additional blocks, fewer blocks, different blocks, or blocks arranged in a different manner than those depicted in the process 1200. Additionally or alternatively, two or more blocks of the blocks of process 1200 may be performed in parallel.

[0151] Fig.13 1 is a diagram illustrating an example process 1300 performed, for example, by a UE according to the present disclosure. Example process 1300 is an example in which a UE (eg, UE 120, UE 620) performs operations associated with BFR for sidelink carrier aggregation.

[0152] like Fig.13As shown, in some aspects, process 1300 may include receiving a reference signal on a primary sidelink carrier and on one or more secondary sidelink carriers using carrier aggregation (block 1310). Fig.14 The communication manager 1408 and / or receiving component 1402 depicted in FIG. 1404 may use carrier aggregation to receive a reference signal on a primary side link carrier and on one or more secondary side link carriers, as described above, for example, with reference to Figure 6 , Figure 7 , Figure 8 , Fig. 9 and / or Fig.10 As described.

[0153] like Fig.13 As further shown, in some aspects, process 1300 may include detecting beam failure based at least in part on measurements of reference signals (block 1320). Fig.14 The communication manager 1408 and / or BFD component 1412 depicted in FIG. 1 may detect beam failures based at least in part on measurements of reference signals, as described above, for example, with reference to FIG. Figure 6 , Figure 7 , Figure 8 , Fig. 9 and / or Fig.10 As described.

[0154] like Fig.13 As further shown, in some aspects, process 1300 may include sending a first non-periodic MAC CE indicating a failure of one or more beams on the primary sidelink carrier or one or more of the one or more secondary sidelink carriers (block 1330). For example, a UE (e.g., using Fig.14 The communication manager 1408 and / or the sending component 1404 depicted in FIG. 1 may send a first non-periodic MAC CE indicating a failure of one or more beams on the primary sidelink carrier or one or more of the one or more secondary sidelink carriers, as described above, for example, with reference to Figure 6 , Figure 7 , Figure 8 , Fig. 9 and / or Fig.10 As described.

[0155] Process 1300 may include additional aspects, such as any single aspect or any combination of aspects described below and / or in conjunction with one or more other processes described elsewhere herein.

[0156] In a first aspect, the beam failure is on a primary sidelink carrier and one or more secondary sidelink carriers.

[0157] In a second aspect, alone or in combination with the first aspect, process 1300 includes: receiving a non-periodic reference signal for a BFR process; and performing the BFR process for a primary sidelink carrier, wherein the BFR process is a RACH process, and wherein process 1300 includes: sending a RACH preamble code on the primary sidelink carrier.

[0158] In a third aspect, alone or in combination with one or more of the first and second aspects, sending the first non-periodic MAC CE includes: sending the first non-periodic MAC CE on a secondary sidelink carrier of the one or more secondary sidelink carriers.

[0159] In a fourth aspect, either alone or in combination with one or more of the first to third aspects, detecting a beam failure comprises detecting a beam failure based at least in part on the expiration of a beam failure count timer, or detecting a beam failure based at least in part on a beam failure counter reaching a beam failure threshold for all beams.

[0160] In a fifth aspect, alone or in combination with one or more of the first to fourth aspects, receiving reference signals includes: receiving a first set of reference signals on a primary side link carrier and receiving a set of reference signals on each of one or more secondary side link carriers.

[0161] In a sixth aspect, alone or in combination with one or more of the first to fifth aspects, the beam failure is on a secondary side link carrier of the one or more secondary side link carriers.

[0162] In a seventh aspect, either alone or in combination with one or more of aspects 1 to 6, process 1300 includes: receiving a non-periodic reference signal on a secondary link carrier; receiving a message for measuring the non-periodic reference signal on a primary carrier; measuring the non-periodic reference signal; and sending the measurement result in a second non-periodic MAC CE on the secondary link carrier.

[0163] In an eighth aspect, alone or in combination with one or more of aspects 1 to 7, process 1300 includes: receiving a switching message for switching a service cell; and switching the service cell from a beam of a primary side link carrier to a beam of a secondary side link carrier among one or more secondary side link carriers.

[0164] In a ninth aspect, either alone or in combination with one or more of aspects 1 to 8, process 1300 comprises sending a random access channel preamble on a primary side link carrier based at least in part on one or more of measurement results, unsuccessful beam reselection on the primary side link carrier, or unsuccessful switching of a serving cell.

[0165] In the tenth aspect, alone or in combination with one or more aspects of the first to ninth aspects, process 1300 includes: receiving a message for measuring one or more non-periodic reference signals on a primary side link carrier; receiving one or more non-periodic reference signals on one or more other secondary side link carriers; selecting one or more feasible beams of one or more other secondary side link carriers based at least in part on measuring the one or more non-periodic reference signals; sending a message indicating one or more feasible beams on a secondary side link carrier among the one or more other secondary side link carriers; receiving a beam switching message via a MAC CE on the primary side link carrier; and switching to a feasible beam of a secondary side link carrier among the one or more other secondary side link carriers.

[0166] although Fig.13 Example blocks of process 1300 are shown, but in some aspects, process 1300 may include Fig.13 Additional blocks, fewer blocks, different blocks, or blocks arranged in a different manner than those depicted in the process 1300. Additionally or alternatively, two or more blocks of the blocks of process 1300 may be performed in parallel.

[0167] Fig.14 1400 is a diagram of an example apparatus 1400 for wireless communication according to the present disclosure. Apparatus 1400 may be a UE (e.g., UE 120, UE 610, UE 620), or a UE may include apparatus 1400. In some aspects, apparatus 1400 includes a receiving component 1402 and a transmitting component 1404, which may communicate with each other (e.g., via one or more buses and / or one or more other components). As shown, apparatus 1400 may communicate with another apparatus 1406 (such as a UE, a base station, or another wireless communication device) using receiving component 1402 and transmitting component 1404. As further shown, apparatus 1400 may include a communication manager 1408. Communication manager 1408 may control and / or otherwise manage one or more operations of receiving component 1402 and / or transmitting component 1404. In some aspects, communication manager 1408 may include a communication manager 1408 in conjunction with Figure 2 One or more antennas, modems, controllers / processors, memories, or combinations thereof of the UE described herein. The communication manager 1408 may be or be similar to Figure 1 and Figure 21408. For example, in some aspects, the communication manager 1408 can be configured to perform one or more of the functions described as being performed by the communication manager 140. In some aspects, the communication manager 1408 can include a receiving component 1402 and / or a sending component 1404. The communication manager 1408 can include one or more of a carrier component 1410, a BFD component 1412, and / or a BFR component 1414, among others.

[0168] In some aspects, the apparatus 1400 may be configured to perform Figures 1 to 10 Additionally or alternatively, the apparatus 1400 may be configured to perform one or more processes described herein, such as Fig.11 Process 1100, Fig.12 The process 1200 Fig.13 In some aspects, the apparatus 1400 and / or Fig.14 One or more of the components shown in the figure may include a combination of Figure 2 Additionally or alternatively, Fig.14 One or more of the components shown may be combined with Figure 2 Additionally or alternatively, one or more components in the component set may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or codes stored in a non-transitory computer-readable medium and may be executed by a controller or processor to perform the function or operation of the component.

[0169] The receiving component 1402 may receive communications, such as reference signals, control information, data communications, or combinations thereof, from the device 1406. The receiving component 1402 may provide the received communications to one or more other components of the device 1400. In some aspects, the receiving component 1402 may perform signal processing (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, demapping, equalization, interference cancellation, or decoding, etc.) on the received communications and may provide the processed signals to one or more other components of the device 1400. In some aspects, the receiving component 1402 may include combining Figure 2 One or more antennas, modems, demodulators, MIMO detectors, receive processors, controllers / processors, memories, or combinations thereof of a described UE.

[0170] The transmitting component 1404 may transmit communications, such as reference signals, control information, data communications, or combinations thereof, to the device 1406. In some aspects, one or more other components of the device 1400 may generate communications and may provide the generated communications to the transmitting component 1404 for transmission to the device 1406. In some aspects, the transmitting component 1404 may perform signal processing (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, etc.) on the generated communications and may transmit the processed signals to the device 1406. In some aspects, the transmitting component 1404 may include combining Figure 2 One or more antennas, modems, modulators, transmit MIMO processors, transmit processors, controllers / processors, memories, or combinations thereof of the described UE. In some aspects, the transmit component 1404 can be co-located with the receive component 1402 in a transceiver.

[0171] In some aspects as a transmitting UE, the transmitting component 1404 can use carrier aggregation to transmit a reference signal on a primary side link carrier and on one or more secondary side link carriers. The receiving component 1402 can receive a MAC CE indicating a beam failure on the primary side link carrier, one or more secondary side link carriers, or both. The transmitting component 1404 can transmit an aperiodic reference signal on the primary side link carrier in response to receiving the MAC CE.

[0172] The carrier component 1410 may deactivate one or more secondary link carriers prior to receiving the RACH preamble. The transmitting component 1404 may transmit a message for measuring the aperiodic reference signal on a secondary link carrier of the one or more secondary link carriers. The receiving component 1402 may receive an aperiodic message indicating a measurement result of the aperiodic reference signal.

[0173] The sending component 1404 can send a switching message to switch the serving cell from the primary sidelink carrier to a secondary sidelink carrier of the one or more secondary sidelink carriers based at least in part on the measurement results.

[0174] In some aspects as a transmitting UE, the transmitting component 1404 may use carrier aggregation to transmit reference signals on the primary side link carrier and on one or more secondary side link carriers. The receiving component 1402 may receive a first MAC CE indicating a failure of a beam on a secondary side link carrier in one or more secondary side link carriers. The transmitting component 1404 may transmit one or more non-periodic reference signals on other secondary side link carriers in response to receiving the first MAC CE. The receiving component 1402 may receive a message indicating one or more feasible beams of other secondary side link carriers. The transmitting component 1404 may transmit a beam switching message on the primary side link carrier via a second MAC CE based at least in part on the one or more feasible beams. The transmitting component 1404 may transmit a message on the primary side link carrier to measure one or more non-periodic reference signals.

[0175] In some aspects as a receiving UE, receiving component 1402 can receive a reference signal on a primary sidelink carrier and on one or more secondary sidelink carriers using carrier aggregation. BFD component 1412 can detect beam failure based at least in part on measurements of the reference signal. Transmitting component 1404 can transmit a first non-periodic MAC CE indicating a failure of one or more beams on the primary sidelink carrier or one or more of the one or more secondary sidelink carriers.

[0176] The receiving component 1402 can receive an aperiodic reference signal for a beam failure recovery procedure. The BFR component 1414 can perform a beam failure recovery procedure for a primary sidelink carrier, wherein the beam failure recovery procedure is a RACH procedure, and the transmitting component 1404 can transmit a RACH preamble on the primary sidelink carrier.

[0177] The receiving component 1402 may receive an aperiodic reference signal on the secondary side link carrier. The receiving component 1402 may receive a message to measure the aperiodic reference signal on the primary carrier. The BFR component 1414 may measure the aperiodic reference signal. The sending component 1404 may send the measurement result in a second aperiodic MAC CE on the secondary side link carrier.

[0178] The receiving component 1402 can receive a switching message to switch the serving cell. The carrier component 1410 can switch the serving cell from a beam of a primary sidelink carrier to a beam of a secondary sidelink carrier of one or more secondary sidelink carriers.

[0179] Transmitting component 1404 can transmit a RACH preamble on the primary sidelink carrier based at least in part on one or more of the measurement results, an unsuccessful beam reselection on the primary sidelink carrier, or an unsuccessful handover of the serving cell.

[0180] Receiving component 1402 can receive a message to measure one or more aperiodic reference signals on a primary sidelink carrier.Receiving component 1402 can receive one or more aperiodic reference signals on one or more other secondary sidelink carriers.

[0181] The BFR component 1414 can select one or more viable beams of one or more other secondary link carriers based at least in part on measuring one or more non-periodic reference signals. The transmitting component 1404 can transmit a message indicating the one or more viable beams on a secondary link carrier of the one or more other secondary link carriers.

[0182] The receiving component 1402 can receive a beam switching message on the primary sidelink carrier via a MAC CE.The carrier component 1410 can switch to a viable beam of a secondary sidelink carrier of one or more other secondary sidelink carriers.

[0183] Fig.14 The number and arrangement of components shown are provided as examples. In practice, there may be Fig.14 Additional components, fewer components, different components, or components arranged in a different manner than those shown. Fig.14 Two or more components shown may be implemented in a single component, or Fig.14 The single component shown may be implemented as multiple distributed components. Additionally or alternatively, Fig.14 The assembly of (one or more) components shown may be described as being executable by Fig.14 Another collection of components shown performs one or more functions.

[0184] The following provides an overview of some aspects of the disclosure:

[0185] Aspect 1: A method of wireless communication performed by a user equipment (UE), the method comprising: sending a reference signal on a primary side link carrier and on one or more secondary side link carriers using carrier aggregation; receiving a medium access control control element (MAC CE), the medium access control control element (MAC CE) indicating a beam failure on the primary side link carrier, the one or more secondary side link carriers, or both; and in response to receiving the MAC CE, sending a non-periodic reference signal on the primary side link carrier.

[0186] Aspect 2: The method according to aspect 1, wherein the MAC CE indicates the beam failure on the primary sidelink carrier and the one or more secondary sidelink carriers.

[0187] Aspect 3: A method according to Aspect 2, wherein sending the reference signal comprises: sending a first set of reference signals on the primary sidelink carrier and sending a corresponding set of reference signals on each of the one or more secondary sidelink carriers.

[0188] Aspect 4: The method according to aspect 2 or 3, wherein receiving the MAC CE comprises: receiving the MAC CE on a secondary sidelink carrier among the one or more secondary sidelink carriers.

[0189] Aspect 5: The method according to any one of aspects 2 to 4, wherein the one or more processors are configured to: receive a random access channel (RACH) preamble code on the primary sidelink carrier.

[0190] Aspect 6: According to the method of aspect 5, the method further includes: deactivating the one or more auxiliary sidelink carriers before receiving the RACH preamble code.

[0191] Aspect 7: The method according to any one of aspects 2 to 6, wherein the primary sidelink carrier is associated with a serving cell.

[0192] Aspect 8: The method according to any one of Aspects 2 to 7, wherein the beam failure comprises a failure of all beams on the primary sidelink carrier and the one or more secondary sidelink carriers.

[0193] Aspect 9: The method according to aspect 1, wherein the MAC CE indicates a beam failure on the primary sidelink carrier.

[0194] Aspect 10: The method according to aspect 9 further comprises: sending a message for measuring the non-periodic reference signal on a secondary link carrier among the one or more secondary link carriers.

[0195] Aspect 11: According to the method described in Aspect 10, the method also includes: receiving a non-periodic message indicating the measurement result of the non-periodic reference signal; and sending a switching message for switching the service cell from the primary side link carrier to a secondary side link carrier among the one or more secondary side link carriers based at least in part on the measurement result.

[0196] Aspect 12: A method of wireless communication performed by a user equipment (UE), the method comprising: using carrier aggregation to send reference signals on a primary side link carrier and on one or more secondary side link carriers; receiving a first medium access control control element (MAC CE), the first medium access control control element (MAC CE) indicating a failure of a beam on a secondary side link carrier among the one or more secondary side link carriers; in response to receiving the first MAC CE, sending one or more non-periodic reference signals on other secondary side link carriers among the one or more secondary side link carriers; receiving a message indicating one or more feasible beams of the other secondary side link carriers; and sending a beam switching message on the primary side link carrier via a second MAC CE based at least in part on the one or more feasible beams.

[0197] Aspect 13: A method according to Aspect 12, wherein sending the reference signal comprises: sending a first set of reference signals on the primary sidelink carrier and sending a corresponding set of reference signals on each of the one or more secondary sidelink carriers.

[0198] Aspect 14: The method according to aspect 12 or 13, the method further comprising: sending a message on the primary sidelink carrier for measuring the one or more non-periodic reference signals.

[0199] Aspect 15: A method of wireless communication performed by a user equipment (UE), the method comprising: receiving a reference signal on a primary side link carrier and on one or more secondary side link carriers using carrier aggregation; detecting a beam failure based at least in part on a measurement of the reference signal; and sending a first non-periodic medium access control control element (MAC CE), the first non-periodic medium access control control element (MAC CE) indicating a failure of one or more beams on the primary side link carrier or one or more of the one or more secondary side link carriers.

[0200] Aspect 16: The method according to aspect 15, wherein the beam failure is on the primary sidelink carrier and the one or more secondary sidelink carriers.

[0201] Aspect 17: According to the method described in Aspect 16, the method also includes: receiving a non-periodic reference signal for a beam failure recovery process; and performing the beam failure recovery process for the primary side link carrier, wherein the beam failure recovery process is a random access channel (RACH) process, and wherein the method includes sending a RACH preamble code on the primary side link carrier.

[0202] Aspect 18: The method according to aspect 15 or 16, wherein sending the first non-periodic MAC CE includes: sending the first non-periodic MAC CE on a secondary sidelink carrier among the one or more secondary sidelink carriers.

[0203] Aspect 19: A method according to any one of Aspects 15 to 18, wherein detecting the beam failure includes: detecting the beam failure at least partially based on the expiration of a beam failure count timer, or detecting the beam failure at least partially based on the beam failure counter reaching a beam failure threshold for all beams.

[0204] Aspect 20: A method according to any one of Aspects 15 to 19, wherein receiving the reference signal comprises: receiving a first set of reference signals on the primary side link carrier and receiving a set of reference signals on each of the one or more secondary side link carriers.

[0205] Aspect 21: The method according to aspect 15, wherein the beam failure is on a secondary link carrier among the one or more secondary link carriers.

[0206] Aspect 22: According to the method described in Aspect 21, the method also includes: receiving a non-periodic reference signal on the secondary link carrier; receiving a message for measuring the non-periodic reference signal on the primary carrier; measuring the non-periodic reference signal; and sending the measurement result in a second non-periodic MAC CE on the secondary link carrier.

[0207] Aspect 23: According to the method of Aspect 22, the method also includes: receiving a switching message for switching a service cell; and switching the service cell from the beam of the primary side link carrier to the beam of a secondary side link carrier among the one or more secondary side link carriers.

[0208] Aspect 24: According to the method of Aspect 22 or 23, the method also includes: sending a random access channel preamble code on the primary side link carrier based at least in part on one or more of the measurement results, unsuccessful beam reselection on the primary side link carrier, or unsuccessful switching of the serving cell.

[0209] Aspect 25: According to the method described in Aspect 15, the method also includes: receiving a message for measuring one or more non-periodic reference signals on the primary side link carrier; receiving the one or more non-periodic reference signals on one or more other secondary side link carriers; selecting one or more feasible beams of the one or more other secondary side link carriers based at least in part on measuring the one or more non-periodic reference signals; sending a message indicating the one or more feasible beams on a secondary side link carrier among the one or more other secondary side link carriers; receiving a beam switching message on the primary side link carrier via MAC CE; and switching to a feasible beam of a secondary side link carrier among the one or more other secondary side link carriers.

[0210] Aspect 26: An apparatus for performing wireless communications at a device, the apparatus comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform one or more of the methods described in Aspects 1 to 25.

[0211] Aspect 27: A device for wireless communication, the device comprising a memory and one or more processors coupled to the memory, the one or more processors configured to perform the method according to one or more of aspects 1 to 25.

[0212] Aspect 28: An apparatus for wireless communication, the apparatus comprising at least one component for performing the method according to one or more of aspects 1 to 25.

[0213] Aspect 29: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method according to one or more of aspects 1 to 25.

[0214] Aspect 30: A non-transitory computer-readable medium storing an instruction set for wireless communication, the instruction set comprising one or more instructions that, when executed by one or more processors of a device, cause the device to perform one or more of the methods described in aspects 1 to 25.

[0215] The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the aspects to the precise forms disclosed. Modifications and variations may be made in light of the foregoing disclosure or may be acquired from practice of the various aspects.

[0216] As used herein, the term "component" is intended to be broadly interpreted as a combination of hardware and / or hardware and software. Whether referred to as software, firmware, middleware, microcode, hardware description language or other names, "software" should be broadly interpreted as meaning instructions, instruction sets, codes, code segments, program codes, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, processes and / or functions, etc. As used herein, a "processor" is implemented in a combination of hardware and / or hardware and software. It will be apparent that the systems and / or methods described herein can be implemented by a combination of hardware and / or hardware and software in different forms. The actual dedicated control hardware or software code used to implement these systems and / or methods does not limit various aspects. Therefore, there is no reference to a specific software code herein to describe the operation and behavior of the system and / or method, because those skilled in the art will understand that software and hardware can be designed to implement the system and / or method based at least in part on the description herein.

[0217] As used herein, "satisfying a threshold" may refer to a value being greater than a threshold, greater than or equal to a threshold, less than a threshold, less than or equal to a threshold, equal to a threshold, not equal to a threshold, etc., depending on the context.

[0218] Although the specific combination of features is set forth in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of various aspects. Many of these features can be combined in a manner that is not specifically described in the claims and / or is not disclosed in the specification. The disclosure of various aspects includes each dependent claim combined with each other claim in the claim set. As used herein, the phrase "at least one of" the list of items refers to any combination of these items (which includes a single member). As an example, "at least one of a, b or c" is intended to cover a, b, c, a+b, a+c, b+c and a+b+c, and any combination with multiple identical elements (e.g., a+a, a+a+a, a+a+b, a+a+c, a+b+b, a+c+c, b+b, b+b+b, b+b+c, c+c and c+c+c, or any other ordering of a, b and c).

[0219] Any element, action or instruction used herein should not be interpreted as critical or necessary unless clearly stated. In addition, as used herein, the article "one" is intended to include one or more items, and can be used interchangeably with "one or more". In addition, as used herein, the article "said" is intended to include one or more items connected to the article "said", and can be used interchangeably with "one or more". In addition, as used herein, the terms "set" and "group" are intended to include one or more items, and can be used interchangeably with "one or more". If you only want to refer to an item, the phrase "only one" or similar terms will be used. Moreover, as used herein, the term "having" etc. is intended to be an open term, which does not limit the elements they modify (for example, "having" A elements can also have B). In addition, the phrase "based on" is intended to mean "based at least in part on", unless explicitly stated otherwise. Furthermore, as used herein, the term "or" when used in a series is intended to be open-ended and used interchangeably with "and / or" unless explicitly stated otherwise (e.g., if used in conjunction with "either" or "only one of").

Claims

1. A user equipment (UE) for wireless communication, the user equipment (UE) comprising: Memory; Transceiver; and one or more processors coupled to the transceiver and the memory and configured to: transmitting, via the transceiver, a reference signal on a primary sidelink carrier and on one or more secondary sidelink carriers using carrier aggregation; receiving, via the transceiver, a medium access control control element (MAC CE), the medium access control control element (MAC CE) indicating a beam failure on the primary sidelink carrier, the one or more secondary sidelink carriers, or both; as well as An aperiodic reference signal is transmitted on the primary sidelink carrier via the transceiver and in response to receiving the MAC CE.

2. The UE of claim 1, wherein the MAC CE indicates the beam failure on the primary sidelink carrier and the one or more secondary sidelink carriers.

3. The UE according to claim 2, wherein, in order to send the reference signal, the one or more processors are configured to: send a first set of reference signals on the primary sidelink carrier and send a corresponding set of reference signals on each of the one or more secondary sidelink carriers.

4. The UE of claim 2, wherein to receive the MAC CE, the one or more processors are configured to: receive the MAC CE on a secondary sidelink carrier among the one or more secondary sidelink carriers.

5. The UE of claim 2, wherein the one or more processors are further configured to: receive a random access channel (RACH) preamble on the primary sidelink carrier via the transceiver.

6. The UE of claim 5, wherein the one or more processors are further configured to: deactivate the one or more secondary sidelink carriers before receiving the RACH preamble.

7. The UE of claim 2, wherein the primary sidelink carrier is associated with a serving cell.

8. The UE of claim 2, wherein the beam failure comprises a failure of all beams on the primary sidelink carrier and the one or more secondary sidelink carriers.

9. The UE of claim 1, wherein the MAC CE indicates a beam failure on the primary sidelink carrier.

10. The UE of claim 9, wherein the one or more processors are configured to send a message for measuring the aperiodic reference signal on a secondary link carrier of the one or more secondary link carriers.

11. The UE of claim 10, wherein the one or more processors are configured to: receiving, via the transceiver, an aperiodic message indicating a measurement result of the aperiodic reference signal; and A switching message is sent, via the transceiver and based at least in part on the measurement result, to switch a serving cell from the primary sidelink carrier to a secondary sidelink carrier of the one or more secondary sidelink carriers.

12. A user equipment (UE) for wireless communication, the user equipment (UE) comprising: Memory; Transceiver; and one or more processors coupled to the transceiver and the memory and configured to: transmitting, via the transceiver, a reference signal on a primary sidelink carrier and on one or more secondary sidelink carriers using carrier aggregation; receiving, via the transceiver, a first medium access control control element (MAC CE), the first medium access control control element (MAC CE) indicating a failure of a beam on a secondary sidelink carrier of the one or more secondary sidelink carriers; sending, via the transceiver and in response to receiving the first MAC CE, one or more aperiodic reference signals on other secondary sidelink carriers of the one or more secondary sidelink carriers; receiving, via the transceiver, a message indicating one or more viable beams of the other secondary sidelink carriers; as well as Based at least in part on the one or more viable beams, a beam switch message is sent using a second MAC CE via the transceiver on the primary sidelink carrier.

13. The UE of claim 12, wherein, in order to send the reference signal, the one or more processors are configured to: send a first set of reference signals on the primary sidelink carrier and send a corresponding set of reference signals on each of the one or more secondary sidelink carriers.

14. The UE of claim 12, wherein the one or more processors are further configured to: send, via the transceiver, a message on the primary sidelink carrier to measure the one or more aperiodic reference signals.

15. A user equipment (UE) for wireless communication, the user equipment (UE) comprising: Memory; Transceiver; and one or more processors coupled to the transceiver and the memory and configured to: receiving a reference signal via the transceiver on a primary sidelink carrier and on one or more secondary sidelink carriers using carrier aggregation; detecting a beam failure based at least in part on a measurement of the reference signal; as well as A first non-periodic medium access control control element (MAC CE) is sent via the transceiver, and the first non-periodic medium access control control element (MAC CE) indicates a failure of one or more beams on the primary sidelink carrier or one or more of the one or more secondary sidelink carriers.

16. The UE of claim 15, wherein the beam failure is on the primary sidelink carrier and the one or more secondary sidelink carriers.

17. The UE of claim 16, wherein the one or more processors are further configured to: receiving, via the transceiver, an aperiodic reference signal for a beam failure recovery procedure; and The beam failure recovery procedure is performed for the primary sidelink carrier, wherein the beam failure recovery procedure is a random access channel (RACH) procedure, and wherein the one or more processors are configured to send a RACH preamble code on the primary sidelink carrier.

18. The UE of claim 15, wherein to send the first non-periodic MAC CE, the one or more processors are configured to: send the first non-periodic MAC CE on a secondary sidelink carrier among the one or more secondary sidelink carriers.

19. A UE according to claim 15, wherein in order to detect the beam failure, the one or more processors are configured to: detect the beam failure at least in part based on the expiration of a beam failure count timer, or detect the beam failure at least in part based on the beam failure counter reaching a beam failure threshold for all beams.

20. The UE of claim 15, wherein, in order to receive the reference signal, the one or more processors are configured to: receive a first set of reference signals on the primary sidelink carrier and receive a set of reference signals on each of the one or more secondary sidelink carriers.

21. The UE of claim 15, wherein the beam failure is on a secondary link carrier among the one or more secondary link carriers.

22. The UE of claim 21, wherein the one or more processors are further configured to: receiving, via the transceiver, a non-periodic reference signal on the secondary link carrier; receiving, via the transceiver, a message on the primary carrier for measuring the aperiodic reference signal; measuring the non-periodic reference signal; as well as The measurement result is sent in a second aperiodic MAC CE on the secondary sidelink carrier via the transceiver.

23. The UE of claim 22, wherein the one or more processors are further configured to: receiving, via the transceiver, a switching message for switching a serving cell; and The serving cell is switched from the beam of the primary sidelink carrier to a beam of a secondary sidelink carrier of the one or more secondary sidelink carriers.

24. A UE according to claim 22, wherein the one or more processors are further configured to: send a random access channel preamble code on the primary side link carrier via the transceiver based at least in part on one or more of the measurement results, unsuccessful beam reselection on the primary side link carrier, or unsuccessful switching of the serving cell.

25. The UE of claim 15, wherein the one or more processors are further configured to: receiving, via the transceiver, on the primary sidelink carrier, a message for measuring one or more aperiodic reference signals; receiving, via the transceiver, the one or more aperiodic reference signals on one or more other secondary sidelink carriers; selecting one or more viable beams of the one or more other secondary sidelink carriers based at least in part on measuring the one or more aperiodic reference signals; sending, via the transceiver, a message on a secondary sidelink carrier of the one or more other secondary sidelink carriers indicating the one or more viable beams; receiving, via the transceiver, a beam switching message using a MAC CE on the primary sidelink carrier; and Switch to a feasible beam of a secondary link carrier among the one or more other secondary link carriers.

26. A method of wireless communication performed by a user equipment (UE), the method comprising: transmitting a reference signal on a primary sidelink carrier and on one or more secondary sidelink carriers using carrier aggregation; receiving a medium access control control element (MAC CE) indicating a beam failure on the primary sidelink carrier, the one or more secondary sidelink carriers, or both; as well as In response to receiving the MAC CE, an aperiodic reference signal is sent on the primary sidelink carrier.

27. The method of claim 26, wherein the MAC CE indicates the beam failure on the primary sidelink carrier and the one or more secondary sidelink carriers, and wherein receiving the MAC CE comprises: The MAC CE is received on a secondary sidelink carrier of the one or more secondary sidelink carriers.

28. The method of claim 26, wherein the MAC CE indicates a beam failure on the primary sidelink carrier, and wherein the method comprises: A message for measuring the aperiodic reference signal is sent on a secondary link carrier of the one or more secondary link carriers.

29. The method according to claim 28, further comprising: receiving an aperiodic message indicating a measurement result of the aperiodic reference signal; as well as Based at least in part on the measurement results, a handover message is sent to switch a serving cell from the primary sidelink carrier to a secondary sidelink carrier of the one or more secondary sidelink carriers.

30. A method of wireless communication performed by a user equipment (UE), the method comprising: transmitting a reference signal on a primary sidelink carrier and on one or more secondary sidelink carriers using carrier aggregation; receiving a first medium access control control element (MAC CE) indicating a failure of a beam on a secondary link carrier of the one or more secondary link carriers; In response to receiving the first MAC CE, sending one or more non-periodic reference signals on other secondary link carriers of the one or more secondary link carriers; receiving a message indicating one or more feasible beams of the other auxiliary sidelink carriers; as well as A beam switching message is sent via a second MAC CE on the primary sidelink carrier based at least in part on the one or more viable beams.

31. The method of claim 30, wherein sending the reference signal comprises: A first set of reference signals is transmitted on the primary sidelink carrier and a respective set of reference signals is transmitted on each of the one or more secondary sidelink carriers.

32. The method of claim 30, further comprising: A message is sent on the primary sidelink carrier to measure the one or more aperiodic reference signals.

33. A method of wireless communication performed by a user equipment (UE), the method comprising: receiving a reference signal on a primary sidelink carrier and on one or more secondary sidelink carriers using carrier aggregation; detecting a beam failure based at least in part on a measurement of the reference signal; as well as A first non-periodic medium access control control element (MAC CE) is sent, and the first non-periodic medium access control control element (MAC CE) indicates a failure of one or more beams on the primary sidelink carrier or one or more of the one or more secondary sidelink carriers.

34. The method of claim 33, wherein the beam failure is on the primary sidelink carrier and the one or more secondary sidelink carriers, and wherein the method comprises: receiving an aperiodic reference signal for a beam failure recovery process; as well as The beam failure recovery procedure is performed for the primary sidelink carrier, wherein the beam failure recovery procedure is a random access channel (RACH) procedure, and wherein the method includes sending a RACH preamble on the primary sidelink carrier.

35. The method of claim 33, wherein sending the first aperiodic MAC CE comprises: The first aperiodic MAC CE is sent on a secondary sidelink carrier of the one or more secondary sidelink carriers.

36. The method of claim 33, wherein the beam failure is on a secondary link carrier of the one or more secondary link carriers, and wherein the method comprises: Receiving a non-periodic reference signal on the secondary link carrier; receiving, on the primary carrier, a message for measuring the aperiodic reference signal; measuring the non-periodic reference signal; as well as The measurement result is sent in a second aperiodic MAC CE on the secondary sidelink carrier.

37. The method of claim 33, further comprising: receiving, on the primary sidelink carrier, a message for measuring one or more aperiodic reference signals; receiving the one or more aperiodic reference signals on one or more other secondary sidelink carriers; selecting one or more viable beams of the one or more other secondary sidelink carriers based at least in part on measuring the one or more aperiodic reference signals; sending a message indicating the one or more viable beams on a secondary side link carrier of the one or more other secondary side link carriers; receiving a beam switching message on the primary sidelink carrier via a MAC CE; and Switch to a feasible beam of a secondary link carrier among the one or more other secondary link carriers.

38. An apparatus for wireless communication, the apparatus comprising: means for transmitting a reference signal on a primary sidelink carrier and on one or more secondary sidelink carriers using carrier aggregation; means for receiving a medium access control control element (MAC CE) indicating a beam failure on the primary sidelink carrier, the one or more secondary sidelink carriers, or both; and Means for sending an aperiodic reference signal on the primary sidelink carrier in response to receiving the MAC CE.

39. An apparatus for wireless communication, the apparatus comprising: means for transmitting a reference signal on a primary sidelink carrier and on one or more secondary sidelink carriers using carrier aggregation; means for receiving a first medium access control control element (MAC CE) indicating a failure of a beam on a secondary sidelink carrier of the one or more secondary sidelink carriers; means for transmitting one or more aperiodic reference signals on other secondary sidelink carriers of the one or more secondary sidelink carriers in response to receiving the first MAC CE; means for receiving a message indicating one or more viable beams of said other secondary sidelink carriers; and Means for sending a beam switching message on the primary sidelink carrier via a second MAC CE based at least in part on the one or more viable beams.

40. An apparatus for wireless communication, the apparatus comprising: means for receiving a reference signal on a primary sidelink carrier and on one or more secondary sidelink carriers using carrier aggregation; means for detecting beam failure based at least in part on measurements of said reference signal; and Means for sending a first non-periodic medium access control control element (MAC CE) indicating a failure of one or more beams on the primary sidelink carrier or one or more of the one or more secondary sidelink carriers.

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